Should We Be so Quick to Judge People Essay Example for Free

Should We Be so Quick to Judge People Essay I ask this question in an attempt to focus on the tendencies of judging and the norm. Everybody has their own perceptions of what is normal and they make judgments based off of these perceptions. Many of these perceptions cause biases to be formed. A bias is â€Å"a particular tendency or inclination, esp. one that prevents unprejudiced consideration of a question; prejudice. † This essentially means that everyone has formed their own prejudice beliefs from life experience. Everyone has their own bias, whether it is towards a certain race, gender, music genre, what a person wears, and so forth. Biases are formed for almost everything you could possibly think of. So can someone truly understand a person by making quick judgments? Must we not first analyze and truly understand a person before we make a judgment about something like their personality or character. Thesis It is my belief that, in society today, everyone has the tendency to judge people. These judgments, whether rational or irrational, are, more often than not, based on biases and prior beliefs. These judgments could be right but, is it right to judge people? In a sense, can judging people based on your own perceptions be acceptable? There is the age old proverb: Don’t judge a book by its cover. This idea seems to be very true, because often we make judgments when we first meet a person. As we begin to understand and associate with this person we tend to find our judgment was not exactly correct, and that we misunderstood the true nature of this person. However, what if we stop making our judgments and not following our first instinct? Suppose we do not judge someone as a bad person, and therefore they take advantage of us. So should we try and avoid judging people? That too could become harmful to us in the future. In the oncoming sections I will show how judging people can be helpful in some cases; however I will also show how judging people so quickly can be wrong as well. In the end, I do believe that judgment is acceptable under certain terms which will be explained throughout. Analytical Section with Close Reading In Do Androids Dream of Electric Sheep, Philip K. Dick constantly addresses the idea of judgment. In this book it seems that there is a lot of disapproval with judgment and yet it is still made. When talking about the androids, Phil Resch states: â€Å"This is necessary. Remember: they killed humans in order to get away. And if I hadn’t gotten you out of the Mission police station, they would have killed you. That’s what Garland wanted me for; that’s why he had me come down to his office. Didn’t Polokov almost kill you? Didn’t Luba Luft almost? We’re acting defensively’ they’re here on our planet- they’re murderous illegal aliens masquerading as-. This quote, to me, does show some judgment. Now looking at this statement it does someone like some rational thought was put into it; however, at certain points there is a sense of bias which makes me second guess the rationality of Phil Reschs’ thinking. When Resch states, â€Å"Didn’t Polokov almost kill you? Didn’t Luba Luft almost† , he is making judgments about these androids. However, these judgments have been based on prior actions made by the androids. That is to say, he does not simply try and say that Polokov and Luba Luft are bad because they are androids. Instead, he has seen how these androids have reacted to Rick and that has allowed him to judge their character. But, later in the quote he does make a much more irrational statement. When Resch states, â€Å"†¦ they’re here on our planet-they’re murderous illegal aliens†¦Ã¢â‚¬  , we see a completely new sense of judgment. When Resch claims that â€Å"they’re murderous illegal aliens† he has made a generalization about all androids. Yes, he has experienced androids who have attempted the murderous acts that he speaks of; however, because of this experience he now perceives all androids as murderous and unhelpful to society. Furthermore, even some of the androids could be seen as contributors to society. Rick points this out when he states â€Å"She was a wonderful singer. The planet could have used her. This is insane. † Rick brings an understanding that many of us may not have seen. Yes, some androids have done unforgivable acts towards humans. But, should the androids that have done nothing wrong be treated the same? Must they all face the same fate? Rick says it perfectly when he says, â€Å"The planet could have used her. † Rick has a much more balanced outlook of everyone. He does not instantly assume that an android cannot contribute to society simply because, it is an android. Instead, Rick has based his judgments off of his analysis of each and every person’s character. I believe that character is the key to making good judgments of people. When Rick analyzes Luba Luft he doesn’t see her as just another mindless killing machine. Rather, Rick looks at Luba Luft’s life and comes to find that â€Å"She was a wonderful singer. The planet could have used her. This is insane. † He appreciates the contributions that Luba has made and identifies Luba’s contributions to society. He does not simply see that she is an android that must be exterminated. Instead, he states â€Å"This is insane. † He understands how androids can contribute to society and believes that this extermination is truly unnecessary. I believe this is his way of saying that there must be outright evidence that termination is necessary. There must be a true threat within each and every android that he gets rid of. Otherwise, these androids can be a key contribution, a necessity to society. Based on these ideas I still ask the question, should we be so quick to judge people?

Assessment And Management Of Diabetic Ketoacidosis

Assessment And Management Of Diabetic Ketoacidosis Diabetic Ketoacidosis: Diabetic ketoacidosis (DKA) results from absolute or relative deficiency of circulating insulin (Kitabchi AE, Umpierrez GE, Murphy MB, Kreisberg RA, 2006). DKA is characterized by severe depletion of water and electrolytes from both the intra and extracellular fluid compartments. Despite their dehydration, patients continue to maintain normal blood pressure and have considerable urine output until extreme volume depletion and shock occurs leading to a critical decrease in renal blood flow and glomerular filtration. Assessment: Perform a clinical evaluation to confirm the diagnosis and determine its cause. Carefully look for evidence of infection. Also weigh the patient. Assess clinical severity of dehydration. Assess level of consciousness using Glasgow coma scale [GCS]. Management: Laboratory blood glucose should be measured at diagnosis. An ECG monitor should be applied until the patient is stable. Consulate the Diabetes Team as soon as possible for a decision on continuing management. Transfer to subcutaneous (SC) insulin one the patient is able to eat and drink properly. Do not stop the IV insulin until SC insulin has been given. Patient with known diabetes should go back to their previous insulin regimen. If possible identify the precipitating cause of DKA. Always inform the Diabetes Team so that education can be given to reduce the risk of future episodes of DKA. Hyperosmolar non ketotic coma (HONK): Type 2 diabetes, usually in patients over 60 years. This condition is characterized by hyperglycemia and high plasma osmolality without significant keton-uria or acidosis (Pinies JA, Cairo G, Gaztambide S, et al.1994). Assessment: Same as Diabetic ketoacidosis (DKA) but look for precipitating medical condition, e.g. sepsis, myocardial infarction etc Management: Management of Hyperosmolar non ketotic coma is same as DKA . Also the insulin infusion rate should be halved as paradoxically these patients can be quite insulin sensitive. Elderly patients are more likely to need a CVP line to optimize fluid replacement. Risk of thromboembolic disease is high anticoagulant fully if no contraindications. Most patient can be managed with oral hypoglycemic agents or diet, but recovery of insulin may take time and insulin may be required for few weeks. Hypoglycemia: Hypoglycemia is the result of a mismatch between insulin dose, food consumed, and recent exercise and is rarely, if ever, a spontaneous event (Kovatchev BP, Cox DJ, Farhy LS, Straume M, Gonder-Frederick L, Clarke WL,2003).Because it can be accompanied by unpleasant, embarrassing, and potentially dangerous symptoms and because it causes significant anxiety and fear in the patient and their caregivers, its occurrence is a major limiting factor in attempts to achieve near normal BG levels (Clarke WL, Gonder-Frederick A, Snyder AL, Cox DJ 1998,Cryer PE 2002). Assessment: Each hypoglycaemic episode should be assessed carefully to determine its cause evaluating the insulin action profile (time of insulin administration, peak insulin action and intensity of insulin action). Check the recent food intake (timing and amount of carbohydrates eaten and peak BG effect on recent food. Also check recent physical activity (timing, duration and intensity). Also check and missed signs and symptoms of early hypoglycaemia. Management: Management of hypoglycemia involves immediately raising the blood sugar to normal, determining the cause, and taking measures to hopefully prevent future episodes. Initially Glucose 10-20 g is given by mouth either in liquid form or as granulated sugar (2 teaspoons) or sugar lumps (Smeeks FC, 2006). If hypoglycemia causes unconsciousness, or patient is unco-operative, 50 mL of glucose intravenous (IV) infusion 20% can be given. Alternatively, 25 mL of glucose intravenous infusion 50% may be given, but this higher concentration is viscous, making administration difficult; it is also more irritant. Once the patient regains consciousness oral glucose should be administered as above. References : Kitabchi AE, Umpierrez GE, Murphy MB, Kreisberg RA. Hyperglycemic crises in adult patients with diabetes: a consensus statement from the American Diabetes Association. Diabetes Care 2006 Dec: 29(12): 2739-48. Hanas R, Lindgren F, Lindblad B. A 2-yr national population study of pediatric ketoacidosis in Sweden: predisposing conditions and insulin pump use. Pediatr Diabetes 2009 Feb: 10(1): 33-7. McDonnell CM, Pedreira CC, Vadamalayan B, Cameron FJ, Werther GA. Diabetic ketoacidosis, hyperosmolarity and hypernatremia: are high-carbohydrate drinks worsening initial presentation? Pediatr Diabetes 2005 Jun: 6(2): 90-4. Rewers A, Klingensmith G, Davis C, Petitti DB, Pihoker C, Rodriguez B, et al. Presence of diabetic ketoacidosis at diagnosis of diabetes mellitus in youth: the Search for Diabetes in Youth Study. Pediatrics 2008 May: 121(5): e1258-66. Pinies JA, Cairo G, Gaztambide S, et al. Course and prognosis of 132 patients with diabetic non ketotic hyperosmolar state. Diabete Metab 1994; 20: 43-48. Kovatchev BP, Cox DJ, Kumar A, Gonder-Frederick L, Clarke WL. Algorithmic evaluation of metabolic control and risk of severe hypoglycemia in type 1 and type 2 diabetes using self-monitoring blood glucose data. Diabetes Technol Ther 2003: 5: 817-828. Kovatchev BP, Cox DJ, Farhy LS, Straume M, Gonder-Frederick L, Clarke WL. Episodes of severe hypoglycemia in type 1 diabetes are preceded and followed within 48 hours by measurable disturbances in blood glucose. J Clin Endocrinol Metab 2000: 85: 4287-4292. Clarke WL, Gonder-Frederick A, Snyder AL, Cox DJ. Maternal fear of hypoglycemia in their children with insulin dependent diabetes mellitus. J Pediatr Endocrinol Metab 1998: 11(Suppl. 1) : 189-194. Cryer PE. Hypoglycaemia: the limiting factor in the glycaemic management of type I and type II diabetes. Diabetologia 2002: 45: 937-948. Strategies for Dealing with the Psychological Issues such as Fear and Anxiety Associated with Diagnosis of Cancer, and How These Can Improve Coping A diagnosis of breast cancer is a great shock. Women report that they fear breast cancer more than heart disease, even though they have a better chance of surviving breast cancer, and dying of stroke or heart failure. Breast cancer has been with us since the early Egyptians, and fear of this disease as well as the treatments for it, seems to be inherent in women all across the world. Normal Emotions and Breast Cancer Here are some normal emotions that you may experience at diagnosis and during treatment. Fear, shock Denial Anger Depression Sadness Anxiety Stress Guilt Loneliness, alienation Hope Physical Responses to Strong Emotions As you begin to deal with diagnosis and treatment, your body will be reacting to emotions as well as surgery and drugs. Your physical responses to the overall stress may be: Fear trouble sleeping, headaches, body aches Anger change in blood pressure Depression fatigue, crying, feeling moody Stress pain, irritability, tension Unresolved or Unexpressed Emotions May Lead to Other Problems You are not alone with your diagnosis or your emotions. Expressing your feelings can give you quite a bit of relief, helping you move forward in your journey. Not all of us are freely expressive, but there are safe and creative outlets for your feelings. Letting out your emotions will help you get support and heal more quickly. Your bottled-up emotions may lead to: Loneliness, withdrawal from others Frustration Hopelessness Feeling out of control Emotional Concerns and Breast Cancer When youve accepted your diagnosis, you may be facing other emotional concerns. The loss of a breast, or part of a breast, has an impact that goes beyond the physical fact. If aggressive treatment is required, it might have long-term impact on your health. It is normal to be concerned about: Fear of recurrence Loss of attractiveness Difficulty with sexual function Loss of fertility Coping With and Surviving Breast Cancer You can improve your emotional health and reduce your physical symptoms with good coping strategies. A study published in the Journal of Psychosocial Oncology reports that women who get help with pain and emotional distress have lower levels of anxiety, fatigue and depression. Here are some ways to cope with your emotions: Communicate with family and friends Maintain intimacy (if you have a partner) Visit with a counselor or spiritual director Join a support group Express your needs and ask for help Report your symptoms to your healthcare team Keep a log of medical visits, save test results, keep receipts Educate yourself about your cancer and treatments Exercise Make plans for a crisis Getting Help for Emotions Is Not a Sign of Weakness You may feel under pressure to be strong or act brave when you least feel that way. Perhaps you dont easily share your feelings with others. You may be in a position of responsibility and trust, and feel like you must contain your fears and hide your disease or the effects of treatment. Sharing these feelings and struggles may make you feel vulnerable. A study published in the Journal of Personality shows that women with breast cancer who do express their anger, fear, sadness, and affection in a group setting live longer than women who suppress these emotions. Here are some ways to express your emotions and boost your emotional and physical health: Make time to talk to family members Communicate with friends and coworkers Attend a support group, or join an online support list Find a good therapist and commit to regular visits Take-Home Message Your feelings about breast cancer and its affect on your body, family, relationships, finances, and mortality are valid and normal. Expressing your emotions and needs will help boost your mental and physical health. Letting it out lets you live longer! Sources: Journal of the American Geriatric Society. Effect of depression on diagnosis, treatment, and survival of older women with breast cancer. Published January 2004. Journal of Psychosocial Oncology. Examining the influence of coping with pain on depression, anxiety, and fatigue among women with breast cancer. Published 2005. National Institute of Health. Womens Fear of Heart Disease Has Almost Doubled in Three Years, But Breast Cancer Remains Most Feared Disease. Published 2008. National Cancer Institute. Support for People with Cancer Taking Time. Published 2005. California Breast Cancer Research Program. Does Change in Emotional Expression Mediate Cancer Survival? Final Report Published 1999. Breast cancer is an uninvited and life-altering event frequently associated with a rapid entry into a challenging treatment regimen and a long process of learning to cope with significant physical, practical, and emotional challenges (Boehmke Dickerson, 2006). Boehmke, M., Dickerson, S. (2006). The diagnosis of breast cancer: Transition from health to illness. Oncology Nursing Forum, 33(6), 1121-1127. Breast cancer can engender negative emotional and interpersonal responses throughout the continuum of cancer care (including the phases of diagnosis, treatment, survivorship, and end of life) (Ganz et al., 1996). Support groups have become central to psychosocial interventions for cancer patients because they provide a confidential atmosphere where cancer patients can discuss their challenges and insights with each other. Compared to control groups, patients who participate in support groups have fewer self-reported physical symptoms, lower cortisol levels, better immune system function and quality of life, and longer survival time (Winzelberg, A. J., Classen, C., Alpers, G. W., Roberts, H., Koopman, C., Adams, R. E., et al. (2003). Ganz, P. A., Coscarelli, A., Fred, C., Kahn, B., Polinsky, M. L., Petersen, L. (1996). Breast cancer survivors: Psychosocial concerns and quality of life. Breast Cancer Research and Treatment, 38(2), 183-199. Winzelberg, A. J., Classen, C., Alpers, G. W., Roberts, H., Koopman, C., Adams, R. E., et al. (2003). Evaluation of an internet support group for women with primary breast cancer. Cancer, 97(5), 1164-1173. However, face-to-face groups, as noted above, have improved well-being, but often pose barriers to people with limited mobility or who live a distance from where they are held. A growing number of patients use online support groups, which are available anytime in the privacy of ones home Eysenbach, G. (2003). The impact of the internet on cancer outcomes. Cancer Journal of Clinicians, 53, 356-371. Understanding how cancer patients use online support groups is an important factor in determining the value of Internet-based services to support cancer patients. Research that characterizes communication patterns can enhance our understanding of the mechanisms that facilitate positive coping with cancer diagnosis, treatment, survival, or death. A growing body of research on online support group messages suggests that qualitative analysis is a valuable method for categorizing patient cancer-related experiences and concerns, identifying existing gaps in knowledge, and guiding priorities for future research (Eysenbach Till, 2001) Eysenbach, G., Till, J. E. (2001). Ethical issues in qualitative research on internet communities. British Medical Journal, 323(10), 1103-1105. Belinda has just had her right breast removed, and she is not feeling alright. In fact, she has not been feeling alright since the moment the doctor told her she was symptomatic. Even if it turns out the mastectomy was completely successful and she becomes a survivor, Belinda will probably still continue to feel psychological anxiety about the possible recurrence of her cancer, not to mention embarrassment about the aesthetic change to her body. The key to helping Belinda is a strong social support network, connections to her ordinary life and high quality nursing communication. Depression Mood Disorder occurs within 10 25% of cancer patients, and physical reactions include palpatations, high blood pressure (seen in Belinda), anxiety and depression. Depression and anxiety can lead to social regression, poor medical compliance, and even suicide. If Belinda becomes depressed she is likely to stay in hospital longer, and complain more of adverse drug effects. Depression makes patients highly sensitised, meaning they are more likely to experience vomiting, nausea and anorexia than a patient in a more positive frame of mind, and their discomfort may eventually cause them to stop treatment. Strategies for battling this sensitisation include fully informing patients of adverse drug symptoms ahead of time, explaining that all drugs have adverse symptoms but not all patients experience them, and that having a positive attitude can have a big impact. (Zhou, Duan, Zhou, Cai, Huang, Zeng Zu, 2010). Patient fear begins the moment the patient is informed that they have cancer. While being told she was symptomatic, Belinda would have struggled to take in more complex information (Gunderman Brown, 2010). In most cases it is important to organise a follow-up appointment a few days following so that the cancer can be fully explained. Disbelief can be exacerbated if Belinda was feeling completely healthy at the time. (Gunderman et al., 2010). Additionally, fertility preservation needs to be discussed early in fertile patients, as chemotherapy can lead to infertility a fact that can be extremely upsetting later on (Wilkes, Coulson, Crosland, Rubin Stewart, 2010). For Indigenous patients of Cherbourg, while cancer occurrence in Indigenous Australians is lower than the overall population, cancer mortality is higher because many Indigenous Australians distrust westernised health facilities and will only present when they are very unwell. Many Indigenous Australians link cancer with curses, imminent unstoppable death and contagion, and dont seek treatment or hide symptoms because they believe they have done wrong, deserve illness, the outcome is already decided, they feel ashamed of their wrong-doing or they fear ostracism. These beliefs are prevalent in urban as well as rural populations (Shahid, Finn, Bessarab Thompson, 2010) and bush medicine is widely used. Encouragingly, Indigenous health care workers can find a successful balance between traditional and westernised medicine. Developing this balance in Indigenous Australian patients will allow them to participate in their own care. Nurses can consciously bring up the subject of traditional medicines and discuss these with the patient and family, as well as provide information about cancer in plain language so that patients can make informed decisions. (Shahid et al., 2010). In the case of younger Cherbourg cancer patients, teenaged and young adult cancer patients often feel quite out of place as they are either the oldest in paediatric unit or the youngest in an adult unit at the hospital. Additionally they are developing into independent adults, but are suddenly thrown back into a dependent role as cancer patients. They require high levels of social networking support. These dilemmas have been battled by a hospital in Denmark where teenaged and young adult (15 22 years) cancer patients are placed in a dedicated youth unit and are involved in specialised care appropriate to their age and needs. This includes network meetings involving the patient, family, friends the patient selects, and health care workers involved in the patients care. These meetings allow the nurse to be the voice for the patient, letting friends know the patient needs support and might find it hard to ask, and letting the parents know the patient may need some parent-free hours. Th e nurse can also make the space youth friendly, offering friends chips and soft drink when they visit so that they will return and helping them schedule so that at least one friend visits each week. (Olsen Harder, 2011). Generally, the key with all cancer patients, including Belinda, is to encourage a strong social support network, encourage them to be involved in their normal lives as much as possible, and communicate both information and empathy. Getting patients involved in their own treatment, such as encouraging them to research their disease, and encouraging them to return to work if they can are also positive strategies. (Gunderamn et al., 2010). Interesting Topics for Further Exploration: Honesty, particularly with late or terminally ill patients, is a controversial issue as some families may want to withhold information, while generally health workers support full disclosure. (Locatelli, Piselli, Cicerchia, Raffaele, Abbatecola and Repetto, 2010). The psychological affect of treatment-induced infertility or sexual impotence Anticipatory grieving in parents of children with cancer Religious coping and its advantages and pitfalls The psychology and struggles of cancer survivors Coping With and Surviving Breast Cancer You can improve your emotional health and reduce your physical symptoms with good coping strategies. A study published in the Journal of Psychosocial Oncology reports that women who get help with pain and emotional distress have lower levels of anxiety, fatigue and depression. Here are some ways to cope with your emotions: Communicate with family and friends Maintain intimacy (if you have a partner) Visit with a counselor or spiritual director Join a support group Express your needs and ask for help Report your symptoms to your healthcare team Keep a log of medical visits, save test results, keep receipts Educate yourself about your cancer and treatments Exercise Make plans for a crisis Getting Help for Emotions Is Not a Sign of Weakness You may feel under pressure to be strong or act brave when you least feel that way. Perhaps you dont easily share your feelings with others. You may be in a position of responsibility and trust, and feel like you must contain your fears and hide your disease or the effects of treatment. Sharing these feelings and struggles may make you feel vulnerable. A study published in the Journal of Personality shows that women with breast cancer who do express their anger, fear, sadness, and affection in a group setting live longer than women who suppress these emotions. Here are some ways to express your emotions and boost your emotional and physical health: Make time to talk to family members Communicate with friends and coworkers Attend a support group, or join an online support list Find a good therapist and commit to regular visits Take-Home Message Your feelings about breast cancer and its affect on your body, family, relationships, finances, and mortality are valid and normal. Expressing your emotions and needs will help boost your mental and physical health. Letting it out lets you live longe Eliza, you have given a prefect picture of emotion and stress which Belinda is facing. Now a days diagnosis of breast cancer is a great shock. Today women fear breast cancer more than heart diseases, even though they have a better chance of surviving cancer than dying to stoke or heart failure (National institute of Health 2008). As the women being to deal with diagnosis and treatment of breast cancer, their body automatically start reacting to emotions. Their physical response to overall stress may be fear (trouble sleeping, headaches or body aches), Anger (Change of blood pressure), Depression (fatigue, crying. Feeling moody), stress (pain, irrtability, tension). Also once women accept her diagnosis, they may also face another emotional concern. The loss of breast or part of breast has a deep impact that goes beyond the physical fact. Moreover if aggressive treatment is required, it may also be long term impact on the health. The fear of recurrence. Loss of attractiveness, difficulty in sexual function and loss of fertility also plays important role to increase the stress. Every woman who is facing this situation should understand that getting help for emotion is not the sign of weakness. There are certain ways to cope with this emotion. The best is communicate with family and friend, maintaining intimacy with your partner, visiting the counselor or spiritual person, joining the support team are some of the sign which will make great difference to tackle emotions. In term of health care practice, Report any symptoms or change to the healthcare team. Always maintain a log of health visit, test result etc. educating yourself about the cancer and the treatment and having regular exercise along with plan for crisis make a huge impact.

DSP-OFDM Modulator Project

DSP-OFDM Modulator Project Chapter One Introduction to the DSP-OFDM Modulator Project 1.1 Introduction The Orthogonal Frequency Division Multiplexing (OFDM) digital communication technique has been attracting a great concern of researchers all over the world, due to its unique characteristics. The designers and engineers of mobile wireless communication systems and wireless multimedia broadband are looking forward to exploit the OFDM to be the air interface of these devices and systems. This exploitation has already been done with several systems and standards such as Wireless Local Area Networks 802.11a and Digital Video Broadcast-Terrestrial (DVB-T). The DSP-OFDM Modulator project studies the essential parts of the OFDM modulator and demodulator and implements the OFDM modulator and demodulator on two separate DSP boards. For the OFDM modulator, the project studies the hardware DSP implementation of the OFDM modulators different parts such as the QAM mapper and the IFFT. This applies on the OFDM demodulator too. Additionally, for the OFDM demodulator, the project studies the carrier recovery issue to recover the OFDM information signal from the carrier signal and the OFDM symbol timing recovery issue to correctly pinpoint each OFDM symbols boundaries. The Projects involves several aspects of the digital communications and the theoretical and practical DSP and uses the MATLAB and the Code Composer Studio (CCS) to analyze and simulate the designs to be practically implemented. 1.2 The Aim and the Objectives The aim of the DSP OFDM Modulator project is to implement OFDM modulator and demodulator on two separate DSP boards. The implementation is not tied to any existing OFDM standard such that used in the DVB-T or other standards. The DSP hardware implantation comprises many DSP and digital communication operations to be implemented through writing the C codes that perform these operations i.e. the QAM mapping and de-mapping, the IFFT and FFT, the digital IIR filters and the synchronization. Therefore, the implementation will be first simulated by MATLAB and the Code Composer Studio (CCS) part by part before and with the hardware implementation on the DSP boards. The CCS will be used to simulate not only the modulator and demodulator but also the subparts of the hardware implementation such as the FFT and IFFT C codes. For example, the C code that will be used to perform N-Point IFFT to a complex array containing N complex elements to produce N outputs. These N outputs or discrete values will be compared with those N outputs or discrete values obtained from performing N-Point IFFT to the same N element-complex array in MATLAB in order to check that this C code will work properly in the DSP real time implementation of the OFDM modulator. 1.3 The Research Background and Motivations The good presentation of the theoretical and practical DSP during the taught part of the course encouraged me to tackle this project, as I had not done any practical DSP before I enrolled in the MSc Wireless Communication Systems course. The good understanding of the discrete Fourier transform (DFT) allows presenting the Conjugate Symmetric approach. The use of the Conjugate Symmetric distribution of the subcarrier vectors on the IFFT input points makes the IFFT produce a multicarrier signal with a real part (In-phase) (I) only in the time domain, as the imaginary part (Quadrature) (Q) is always set to zero. It is easier to modulate and demodulate the OFDM information signal with a real part only, as the quadrature modulation is no longer required. The Conjugate Symmetric proposal allows applying the FM modulation to transmit and receive the multicarrier OFDM information signal. 1.4 The Thesiss Organization The thesis consists of five chapters. Chapter two is considered as a literature survey. Chapter two explains the OFDM spectrum and the principles of the OFDM modulator and demodulator. It illustrates how the OFDM information signal carries or represents the digital data bits and how the IFFT N outputs (discrete values) are actually the samples of the OFDM multicarrier information signal for the current OFDM symbol being generated. It will be shown how the OFDM symbol has longer duration than those of other digital communication modulation techniques without affecting the data rate to be more resilient with dispersive channels and many other aspects of the OFDM modulation technique. This project is not tied to any existing OFDM standard. However, it resembles these standards in terms of the general block diagrams of the OFDM systems and the use of the pilot carriers, hence the employment of the OFDM in the DVB-T and the WLAN 802.11a are described briefly in chapter two. Chapter three shows and simulates by using MATLAB the approaches and ideas that will be used for the hardware DSP implementation. It discusses the (Conjugate Symmetric) proposal that has come out of this project to facilitate the modulation and demodulation of the OFDM information signal and the use of the squared cosine method to recover the OFDM information signal from the modulated carrier signal. The use of the cyclic prefix (CP) to recover the OFDM symbol timing is also discussed in chapter three. Chapter four presents the hardware implementation of the DSP OFDM modulator and demodulator on two separate DSP boards and shows the different results of the hardware implantation on the oscilloscopes screen as well as it shows the results of the CCS simulation of the OFDM modulator and demodulator and compares the OFDM spectrum of the generated OFDM information signal generated by the Conjugate Symmetric approach with that generated from the traditional method. Chapter five is for the conclusion points that have come out of this project and the further work to be implemented in the future. The attached CD contains the real time DSP implantation CCS projects of the OFDM modulator (OFDM-TX project) and OFDM demodulator (OFDM-RX project) and the CCS simulation of the OFDM modulator and demodulator (Simulation project) as well as the MATLAB codes and an electronic copy of the thesis. Chapter Two OFDM Basics 2.1 Introduction In the digital communications, the transmitted signal over a wireless channel is more preferred, when the symbol duration is significantly greater than the delay spread (s) of this channel to avoid the intersymbol interference (ISI) due to the time dispersion of transmitted symbols. But unfortunately, the symbol duration is reversely proportional to the bit rate which means a great constraint when high data rate transmission is required over a wireless channel with a relatively high delay spread due to the multipath environment of that channel [1]. The OFDM technique produces the solution to this problem, as it divides the high rate bit stream into (N) very low rate bit streams that are transmitted simultaneously using (N) orthogonal subcarriers for every OFDM symbol. Each of these low rate bit streams modulates an individual subcarrier. Therefore, the symbol duration is increased as many as (N) times without reducing the actual bit rate. 2.2 The Spectrum of the OFDM Subcarriers Figure (2-1) y(t) (the dotted curve) is the algebraic summation of the 5 sinusoidal waves Figure (2-2) the spectrum of y(t) in the frequency domain (five stems or tones) Figure (2-3) the rectangular function with (?t) duration in the time domain Figure (2-4) the spectrom of the rectangular function in the frequency domain Figure (2-5) the spectrum of the OFDM symbol with five subcarriers Suppose y(t) is a signal consisting of the algebraic summation of five sinusoidal waves (subcarriers) in the time domain with five different frequencies (f1, f2, f3, f4 and f5) respectively figure (2-1). Suppose these subcarriers have the same frequency spacing (?f) between each adjacent subcarriers in the frequency domain. The spectrum of y (t) in the frequency domain in terms of the magnitude has five stems at f1 to f5 respectively. Each stem (single tone) represents one of these five sinusoidal waves or subcarriers figure (2-2). Now, suppose an OFDM symbol (with symbol duration = (?t)) consists of the same five sinusoidal subcarriers mentioned earlier. The spectrum of this OFDM symbol in the frequency domain does not now consist of five stems; instead the spectrum is like that one in figure (2-5). The spectrum in figure (2-5) consists of five overlapped sinc functions each of which represents an individual subcarrier. Actually, our OFDM symbol is not identical to y(t). More precisely, it is a (truncated y(t)) with truncation duration equal to the OFDM symbol duration (?t). When a signal is truncated in the time domain with equal gain over all the truncated points within the period (?t), that means mathematically multiplying this signal with a rectangular function in the time domain with a time duration equal to (?t) figure (2-3). The shape of the spectrum of rectangular function in terms of the magnitude is single sinc wave in the frequency domain cutting the horizontal axis at points equal to the integer multiples of the reciprocal of the time duration (1/?t) figure (2-4). Basically, when any two signals are multiplied in the time domain, the resultant signal of this multiplication has a spectrum in the frequency domain equal to the convolution of the spectrums of the two original signals. Therefore the spectrum in figure (2-5) represents the resultant of the convolution operation between the fiv e stems of y(t) figure (2-2) and the sinc of the rectangular function figure (2-4) in the frequency domain. Looking at figure (2-5) again, it is easy to notice that the peak of each subcarrier sinc occurs at a point where all other four sincs have magnitudes equal to zero at which. This situation is the condition of the orthogonality between the subcarriers as it ensures the least interference between the subcarriers in the frequency domain. The orthogonality between subcarriers is not achieved, unless the frequency spacing between the subcarriers (?f) is equal to the reciprocal of the OFDM symbol duration (1/(?t)) [2]. 2.3 The OFDM Modulator The OFDM Modulator uses the Quadrature Amplitude Modulation (QAM) Mapper and the Inverse Fast Fourier Transformer (IFFT) to simultaneously generate and modulate the subcarriers of each OFDM symbol. Figure (2-6) shows a general block diagram of the OFDM modulator. The OFDM modulator builds and transmits each OFDM symbol consisting of a number of subcarriers equal to N as follows. The QAM mapper maps the data bits to (N) QAM vectors. Each of these vectors has real and imaginary components and represents a single subcarrier. The number of data bits that are mapped to each QAM vector (subcarrier) depends on the QAM order (M) as shown in table (2-1). Using QAM mapper with higher order produces higher data rate. However, this will be at the cost of the reception quality as the constellation of higher order QAM allows higher Bit Error Rate (BER) for a given The QAM Mapper stage maps data bits to QAM vectors in accordance with the QAM constellation. The Serial to Parallel (S/P) buffers the QAM vectors of each OFDM symbol to prepare them for the IFFT operation. The IFFT stage converts the buffered QAM vectors (the subcarriers) from the frequency domain to produce an OFDM symbol sequence equivalent to the algebraic summation of these sinusoidal subcarriers in the time domain to be buffered in the next stage. Guard Interval Insertion and Parallel to Serial stages add the guard interval to each buffered OFDM symbol sequence and produces it serially to the next stage. The DSP Low Pass Filter (LPF) and The Digital to Analogue Convertor (DAC) stages are to smooth the signal and convert the digital sequence into analogue signal. The Up Conversion and The Power Amplification stages. Figure (2-6) general block diagram of the OFDM modulator. The 4-QAM constellation, which is identical to Quadrature Phase Shift Keying (QPSK) constellation, gives the receiver more tolerance to the changes of the amplitude and phase of any received QAM vector and allows the receiver to de-map it to the correct 2-bit-combination, as long as it still lies in the same quadrant from which it was originated at the transmitter, whereas 16 and 64 QAM constellations give less tolerance to the change in the phase and amplitude of the received QAM vector due to the noise and interference. Not all subcarriers of an OFDM symbol are used to carry the data bits, some of which are used as pilot carriers for the synchronization and channel estimation purposes and for providing the receiver with specific information such as the order of QAM being used by the transmitter. The Serial to Parallel (S/P) stage buffers the N vectors from the QAM stage for each OFDM symbol to produce them in parallel way to IFFT stage. The number of IFFT points is always greater than the number of the subcarriers (N), so the (S/P) pads the remaining IFFT points, which have not been assigned QAM vectors, with zeroes. The IFFT stage is the heart of the OFDM modulator. It gives the QAM vectors the mathematical ability to be considered as the OFDM subcarriers in the frequency domain and converts them to the time domain to form the multi-subcarrier information signal. In other words, as all the (N) QAM vectors of each OFDM symbol are the parallel inputs of the IFFT operation, the IFFT stage considers these QAM vectors as tones or stems in the frequency domain and converts them into correspondent subcarriers in the time domain for the given OFDM symbol duration. Each QAM vector has a specific phase and amplitude which corresponds to the bit combination this vector represents in accordance with the QAM constellation. The IFFT coverts each QAM vector into a correspondent sinusoidal subcarrier in the time domain with amplitude and phase directly related to those of that vector and a frequency that is directly proportional with the sequence of IFFT point, to which the vector has been assigned. That means if a QAM vector with sequence (n) (assigned to an IFFT point with sequence n) generates a subcarrier with frequency equal to (f), the vector with sequence (n-1) generates a subcarrier with a frequency equal to (f ?f) and the vector with sequence (n+1) generates a subcarrier with a frequency equal to (f + ?f). The IFFT stage can simultaneously produce all the N-subcarriers for each OFDM symbol as it performs the conversion from the frequency domain to the time domain for N (QAM vectors) in one parallel operation for each OFDM symbol. The OFDM symbol signal in the time domain represents the algebraic summation of all subcarriers of that symbol. Now, it is obvious how the OFDM modulator divides the high rate bit stream into (N) lower rate bit streams which are simultaneously transmitted over (N times higher OFDM symbol duration) without reducing the actual bit rate. The Guard Interval Insertion stage appends a guard period at the beginning of each OFDM. The Guard Interval (GI) (also called the Cyclic Prefix (CP)) makes a separation between the consecutive OFDM symbols to contribute in the ISI reduction and to eliminate the Intercarrier Interference (ICI) between the subcarriers. The guard interval must be greater than the highest path difference duration. As a result, multipath signals with delay smaller than the GI cannot cause ICI [3]. The guard interval is generally equal to or less than the quarter symbol duration [4]. Practically, the guard interval is generated by taking an exact copy of the end part of the OFDM symbol and adding it to the beginning of the symbol. The guard interval (GI) can be used by the receiver to determine the beginning and end of each received OFDM symbol through the cross correlation operation. Now, the sequence of the OFDM symbol is converted into serial sequence. The Guard Interval Insertion and the Parallel to Serial (P/S) stages are shown as one stage in figure (2-6). The DSP LPF smoothes the information signal. The Digital to Analogue Convertor (DAC) converts the incoming digital sequence into analogue signal. Finally, the Up Conversion and Power Amplification stage mixes the information signal with a locally generated carrier and boosts the resulted signal to be transmitted. The input data bits to the OFDM modulator in figure (2-6) may be first scrambled for the security purposes, encoded for the Forward Error Correction (FEC) purposes and interleaved (to randomize the bursts of error [5]). Therefore, scrambler, encoder and interleaver blocks may precede the other stages to provide the OFDM modulator with scrambled, encoded and interleaved coded bits [6]. It is also possible to up convert the signal whilst it is still in the digital signal processing domain before converting it to the analogue form. The Carrier Recovery and the Down Converting stage recovers the information signal from the carrier signal. The Sample and Hold circuit and the Analogue to Digital Convertor (ADC) stage converts the information signal from the analogue form to produce the digital sequence for the DSP processing. The Guard Interval Removal and the Serial to Parallel (S/P) stage removes the cyclic prefix (CP) and produces all the useful samples of the current OFDM symbol being processed to the FFT stage simultaneously. The FFT stage converts the subcarriers of the OFDM symbol from the time domain to the frequency domain and produces them to the QAM De-mapper as vectors through the (P/S) buffer. One tap Equalizer can be used to equalize the vector constellation after the FFT stage. The Parallel to Serial (P/S) stage buffers the vectors of each OFDM symbol to produce them serially to the QAM De-mapper. The QAM De-mapper assigns each vector to the correspondent bit combination to produce the data bits. Figure (2-7) general block diagram of the OFDM demodulator. 2.4 The OFDM Demodulator The OFDM modulation operation is completely reversed in the demodulator. At first, the information signal must be recovered from the carrier. This is done by the carrier recovery and down converting stage. Figure (2-7) shows a general block diagram of the OFDM demodulator. The analogue to digital convertor (ADC) converts the information signal into a digital sequence. The guard interval removal stage removes the inserted guard interval or cyclic prefix from the beginning of each OFDM symbol. The OFDM demodulator could use the cyclic prefix at the beginning of each OFDM symbol to pinpoint the beginning and end of each symbol, as the cyclic prefix at the beginning of each OFDM symbol is identical to the end part of that symbol within a duration equal to the cyclic prefix duration. Now, the digital sequence of each OFDM symbol, which represents the algebraic summation of the subcarriers signals in the time domain, is simultaneously presented to the FFT stage to convert these subcarriers into their correspondent vectors in the frequency domain. The parallel presentation of the symbols digital sequence to the FFT stage involves the idea of serial to parallel conversion of this sequence. The subcarriers may also be equalized before being presented to the QAM de-mapper using a one tap equalizer. The QAM de-mapper assigns each vector in the frequency domain to the correspondent binary bit combination in accordance with the QAM constellation being used in the transmitter and receiver. The serial sequence of the received coded bits must be de-interleaved and then decoded and descrambled, if the scrambling, encoding and the interleaving are applied in the transmission side. The number of data bits per each OFDM symbol can be easily calculated by multiplying the number of subcarriers that are used to carry the data bits (Payload subcarriers) by the number of bits represented by the QAM vector in accordance with the QAM constellation table (2-1). The carrier recovery operation can also be done after the sample and hold stage within the digital signal processing unit. 2.5 Digital Video Broadcasting-Terrestrial (DVB-T) The DVB-T employs the OFDM due to its excellent performance in the multipath environments which are common in the terrestrial broadcasting, as the OFDM distributes a high bit stream over a high number of orthogonal subcarriers, each of which carries a low bit rate stream simultaneously, which makes the symbol duration much higher than the delay of the indirect paths [7]. The DVB-T has two modes 2K and 8K. As 2K and 8K modes have the same data rata, selecting which mode should be used depends on the requirements. The 2K mode has about 250 Â µ S symbol duration and 4 KHz spacing between its subcarriers, whereas the 8K mode has about 1 m S symbol duration and 1 KHz spacing between its subcarriers. These characteristics make the 8K mode with its higher symbol duration more resilient with multipath situations and channels with a high delay spread but the 2K mode resists better the shift in the frequency caused by Doppler effects due to the relative mobility between the transmitter and receiver, as it has higher frequency spacing between its subcarriers. The DVB-T has (FEC) similar to that of the DVB-S (Satellite) [8]. It has the following code rates (1/2, 2/3, 3/4, 5/6 and 7/8). Not all subcarriers are used as payload carriers to carry the coded bits (data bits + redundant bits); some subcarriers are used for channel estimation and correction. These subc arriers are the pilot carriers which have vectors lying on the I (In-phase) axis of the QAM constellation with angles equal to either 0 degrees or 180 degrees, hence they have only real components unlike the payload vectors which have real and imaginary components in order to recognize between them. The mapping of the pilot carriers to be delivered as vectors to the IFFT stage in the OFDM modulator is achieved through the BPSK modulation which uses the I (in-phase) axis of the constellation. Figure (2-8) shows the locations of DVB-T subcarriers on the 4-QAM constellation. The locations of the payload carriers The locations of the continual and scatter pilot carriers The locations of the TPS pilot carriers Figure (2-7) general block diagram of the OFDM demodulator. The DVB-T uses 4, 16 or 64 QAM to modulate the coded bits to be represented as payload subcarrier vectors, therefore each payload subcarrier can carry 2, 4 or 6 coded bits every OFDM symbol respectively. The DVB-T uses a guard interval length equal to (1/4, 1/8, 1/16 or 1/32) of the OFDM symbol duration [8]. 2.5.1 The DVB-T OFDM Subcarriers The DVB-T 2K mode has 2048 subcarriers, but it only uses 1705 subcarriers and sets the rest to zero. The 1705 carriers are numbered from 0 to 1704. It uses 1512 subcarriers as payload carriers and the remaining 193 subcarriers as pilot carriers. There are three types of the pilot carriers the continual pilots, scatter pilots and the (Transmission Parameter Signaling) (TPS) pilots. The continual pilots have fixed positions in the OFDM symbol spectrum. For example the sequences 0, 48, 969, 1683 and 1704 in the range (0 1704) are reserved as positions for the continual pilots. The continual pilots are used by the receiver to estimate the amount of phase rotation of the received QAM vectors. Every group of 12 subcarrier vectors has only one scatter pilot. The scatter pilots do not have fixed positions. Among each 12 carriers positions there is one variable position for one scatter pilot. The position of each scatter pilot regularly varies from symbol to symbol by jumping 3 positions for ward with respect to its position in the previous symbol. The scatter pilots are used to estimate the channel too. The TPS pilot carriers have fixed positions and are used by the transmitter to inform the receiver about the transmission parameters such as. The DVB-T mode (2K or 8K) Modulation type of the payload subcarrier vectors (4, 16, or 64) QAM FEC code rate (1/2, 2/3, 3/4, 5/6 or 7/8) Length of the guard interval (1/4, 1/8, 1/16 or 1/32) Like the continual and scatter pilots, the TPS pilot carriers lie on the I (in-phase) axis. Each OFDM symbol in the 2K mode has 17 TPS pilot carriers with fixed positions. Within the same symbol all the 17 TPS pilots are either at 0 degrees or 180 degrees. The receiver determines the state of TPS pilots whether the TPS pilots of the received symbol are at 0 degrees or 180 degree based on the majority voting rule. Through the TPS pilots, the transmitter sends the receiver 67 information bits every OFDM frame. The OFDM frame consists of 68 OFDM symbols. The TPS pilots are Differential Bi-Phase Shift Keying (DBPSK) modulated. That means the receiver considers receiving an information bit = (0), if the state of the TPS pilots change from the previous symbol to the current symbol and considers receiving an information bit = (1), if the phase or state of the TPS pilots does not change from the previous symbol to the current symbol. 68 OFDM symbols are required to transmit the 67 informatio n bits, as the first symbol is used to determine the initializing state of the TPS pilots. The 67 bits inform the receiver about the transmission parameters, for example: Bits 26 and 27 represent the QAM order (00=4, 01=16, 10=64) Bits 31, 32 and 33 represent the code rate (000=1/2, 001=2/3, 010=3/4, 011=5/6, 100=7/8) The DVB-T 8K mode has 6817 subcarrier per each OFDM symbol. The subcarriers of the 8K have the same principles and use of those of 2K with difference in their numbers only. Table (2 2) shows the different subcarriers of both 2K and 8K modes. The scatter pilot carriers have two different numbers of the subcarriers, as the scatter pilot carriers coincide with fixed locations of the continual pilot carriers due to their jumping [8]. 2.6 WLAN 802.11a Wireless Local Area Networks (WLANs) 802.11a employ OFDM as a digital communication technique for reliable and high data rate transmission. Each OFDM symbol is expressed by 64 subcarriers, but the actual used subcarriers are (52) (64 52 =12 subcarriers are set to zero). There are 48 payload carriers to carry the coded bits (data and redundancy bits) and 4 pilot carriers. The frequency spacing between the subcarriers is (?f = 312.5 KHz). The required channel bandwidth can be calculated by multiplying the total number of subcarriers by the frequency spacing = 312.5 K * 64 = 20 MHz. To achieve the orthogonality between the subcarriers the OFDM symbol duration (?t) must be equal to the reciprocal of (?f) (?t = 1/ ?f), hence ?t = 1/312.5 KHz = 3.2 Â µs. 802.11a appends a guard interval (GI) equal of (1/4) the OFDM symbol duration at the beginning of each OFDM symbol (GI = 0.25 * 3.2 Â µs = 0.8 Â µs), therefore each OFDM symbol occupies (3.2 Â µs + 0.8 Â µs = 4 Â µs) time interval. That means a wireless device transmits 250,000 OFDM symbol per second. 802.11a allows wireless devices to have (8) transmission data rates or modes (6, 9, 12, 18, 24, 36, 48 and 54) M bits/sec. 802.11a uses (BPSK, QPSK, 16-QAM or 64-QAM) to modulate the payload carriers and uses (1/2, 2/3 or 3/4) code rate for the FEC in accordance with transmission data rate being used. The different (8) modes use different modulation types and different code rates as shown in table (2-3) [6]. 802.11a uses BPSK modulation to modulate the payload carries in modes 1 and 2 unlike the DVB-T which only uses QAM modulation to modulate the payload carriers. For each mode, the OFDM symbol has the same total duration (4 Â µs) (250,000 OFDM symbol/Sec) and the same channel bandwidth (20 MHz), as it has the same number of subcarriers (48 payload carriers and 4 pilot carriers). Looking back at table (2-3) (Mode (8) 54 Mbps), as the 64-QAM modulation is used to modulate the payload carriers, each payload carrier in the OFDM symbol carries (log2 (64) = 6 coded bits). Each OFDM symbol carries (48 payload carriers/OFDM symbol * 6 coded bits/payload carrier = 288 coded bits / OFDM symbol). The number of data bits per each OFDM symbol = 288 * (code rate = 3/4) = 216 data bits / OFDM symbol. There are 250,000 OFDM symbols / Sec, hence the data bit rate = 216 * 250,000 = 54 Mbps. Chapter Three The MATLAB Analyses for the Hardware Implementation Approaches 3.1 Introduction Throughout this chapter the ideas and approaches that will be used for the DSP hardware implementation of the OFDM modulator and demodulator on two separate DSP boards will be discussed and simulated by using the MATLAB. There are mainly three approaches. The use of the (Conjugate Symmetric) with the carrier vectors which are the inputs of the IFFT stage in the OFDM modulator to produce an OFDM information signal in the time domain with a real part only for easier modulation and demodulation, which is the proposal that has come out from this project. The use of the squared cosine to recover the OFDM information signal from the carrier signal in the receiver (the synchronization of the carrier frequency signal). The make use of the guard interval (GI) or the cyclic prefix (CP) for the synchronization of the OFDM symbol (i.e. The Symbol Clock Recovery) to allow the receiver to know the correct boundaries of each received OFDM symbol to set the FFT window at the correct positions of the received OFDM signal. 3.2 The Mathematical Analysis of a Multicarrier Signal To understand the idea of the (Conjugate Symmetric) and the role of the IFFT and FFT in the OFDM system, lets consider y(t) as a continuous multicarrier signal with a real part only in the time domain consisting of the algebraic summation of five sinusoidal waves or subcarriers which have the following frequencies (1, 2, 3, 4 and 5) KHz and phase shifts (p4,,3p4, 5p4, 7p2, 9p4) respectively with equal amplitude = (28) for each. For our y(t), each two adjacent subcarriers (in the frequency domain) have 90 degrees phase shift. y(t) can be expressed in the time domain as in Eq. (3-1) It is not necessary for the five subcarriers forming y(t) to have the same magnitude. It is just to simplify this discussion. Now, if y(t) is sampled with sampling frequency (Fs). Fs must be greater than (2 * 5 KHz = 10 KHz), where 5 KHz is the highest frequency of y(t) according to the Nyquist-Shannon theorem. Nyquist-Shannon theorem stipulates that the sampling rate or frequency must be at least two times greater than the highest frequency of the sampled signal to avoid the aliasing which prevents providing the DSP system with a right copy of the sampled signal [9]. When a continuous signal in the time domain is sampled, a sample is taken at every (t = n * Ts). Ts is the sampling interval (Ts = 1 / Fs) and n is zero or positive integer number representing the sequence of the sample. y(t) is no longer continuous. Now, y(t) represents a sequence of discrete values. In Eq. (3-1), y(t) is replaced by y(n) in the left hand side and (t) is replaced by (n * Ts) or (n / Fs) in the right hand side as in Eq. (3-2). If Fs is set to 16 KHz (16 KHz > 10 KHz) and 16-point FFT operation is performed to y(n) to produce y(n)s spectrum in the frequency domain in order to study it. The 16 point FFT operation needs 16 discrete values or samples of y(n) for n = 0, 1, 2,13, 14, 15. The results of 16 point FFT operation are 16 complex vectors in the frequency domain. The 16 discrete values (samples) of y(n) are the inputs of the FFT in the time domain and the outputs are 16 complex vectors of Y(m) which represents y(n)s spectrum in the frequency domain. Table (3-1) lists the 16 discrete values of y(n) in the time domain and table (3-2) lists the 16 vectors

Rediscovery of the Voice in Charlotte Brontes Jane Eyre Essay

Jane Eyre:   Rediscovery of the Voice Jane has endured hell. Indeed, most of this novel becomes a test of what she can endure. Helen Burns and Miss Temple teach Jane the British stiff upper lip and saintly patience. Then Jane, star pupil that she is, exemplifies the stoicism, while surviving indignity upon indignity. Jane’s soul hunkers down deep inside her body and waits for the shelling to stop. Only at Moor’s End, where she teaches and grows, does her soul come out. She stops enduring and begins living. Jane begins to become an â€Å"I† in her 19th year. In the sentence, â€Å"Reader, I married him.† Jane makes clear who is in charge of her life and her marriage; she is. That â€Å"I† stands resolutely as the subject of the sentence commanding the verb and attaching itself to the object, â€Å"him.† She is no longer passive, waiting and sitting for Rochester’s attention. Rather, she goes out and gets him. She has gone a long way from the beginning of the novel. At Gateshead, Jane tries to direct her life. Her little â€Å"I† scolds Mrs. Reed and chastises John. Like the later Jane, she knows... Rediscovery of the Voice in Charlotte Bronte's Jane Eyre Essay Jane Eyre:   Rediscovery of the Voice Jane has endured hell. Indeed, most of this novel becomes a test of what she can endure. Helen Burns and Miss Temple teach Jane the British stiff upper lip and saintly patience. Then Jane, star pupil that she is, exemplifies the stoicism, while surviving indignity upon indignity. Jane’s soul hunkers down deep inside her body and waits for the shelling to stop. Only at Moor’s End, where she teaches and grows, does her soul come out. She stops enduring and begins living. Jane begins to become an â€Å"I† in her 19th year. In the sentence, â€Å"Reader, I married him.† Jane makes clear who is in charge of her life and her marriage; she is. That â€Å"I† stands resolutely as the subject of the sentence commanding the verb and attaching itself to the object, â€Å"him.† She is no longer passive, waiting and sitting for Rochester’s attention. Rather, she goes out and gets him. She has gone a long way from the beginning of the novel. At Gateshead, Jane tries to direct her life. Her little â€Å"I† scolds Mrs. Reed and chastises John. Like the later Jane, she knows...

Socrates Essay examples -- essays research papers fc

In Crito, Plato recounts the last days of Socrates, immediately before his execution was to take place in Athens. In the dialogue, Socrates’ pupil, Crito, proposes that Socrates escape from prison. Socrates considers this proposal, trying to decide whether escaping would be â€Å"just† and â€Å"morally justified.† Eventually, Socrates concludes that the act is considered â€Å"unjust† and â€Å"morally unjustified.† Socrates then decides to accept his fate and proceeded with his execution. Socrates was a man who was in pursuit of the truth (Durant). In his refusal to accept exile from Athens or a commitment of silence as a penalty, he chooses death and is thrown into prison. While Socrates is awaiting his execution, many of his friends, including Crito, arrive with a foolproof plan for his escape from Athens to live in exile voluntarily. Socrates calmly debates with each friend over the moral value and justification of such an act. â€Å"...people who do not know you and me will believe that I might have saved you if I had been willing to give money, but that I did not care.† -Crito (Wolff 37). Crito believed that by helping Socrates to escape, he could go on to fulfill his personal obligations. Also, if Socrates does not follow the plan, many people would assume that his friends did not care about him enough to help him escape or that his friends are not willing to give their time or money in order to help him. Therefore, Crito goes on to argue that Socrates ou ght to escape from the prison. After listening to Crito’s arguments, Socrates dismisses them as irrelevant to a decision about what action is truly right. â€Å"Now you, Crito, are not going to die to-morrow-...-and therefore you are disinterested and not liable to be deceived by the circumstances in which you are placed.† -Socrates (Wolff 40). In the arguments that Socrates makes, he emphasizes that what other people think does not matter. The only opinions that should matter are the ones of the individuals that truly know. â€Å"The truth alone deserves to be the basis for decisions about human action, so the only proper approach is to engage in the sort of careful moral reasoning by means of which one may hope to reveal it† (Wolff 43). According to Socrates, the only opinion that he is willing to consider would be that of the state. â€Å"...if you go forth, returning evil for evil, and injury for injury,...we shall be angry with you ... ... state of Athens, constitutes disobedience against the state. He argues that obeying the state is a requirement right up until death. He says that by not obeying the state that he was raised in, it's like not obeying his parents that raised him. Socrates was a man who stuck to his commitment to truth, morality and philosophy over life. He had a great commitment to his state, therefore by disobeying it, he would be committing suicide in a sense. If Socrates had disobeyed his state, he would never be allowed to enter it again, nor would any other allow him to live peacefully. His arguments throughout the whole dialogue were very strong. Socrates looked out for his state, while Crito’s arguments were based on himself and how others would view him. Socrates’ conclusion to stay in the prison may have cost him his life, but his act saved the morality and truth of Athens. Works Cited Wolff, Robert Paul. â€Å"Ten Great Works of Philosophy†. New York: Penguin Group, 1969. Durant, William. â€Å"The Story of Philosophy†. New York: Washington Square Press Publications, 1961. Volume I, Ninth Edition. â€Å"Civilization: Past & Present†. New York: Addison-Wesley Longman, Inc., 2000. Socrates Essay examples -- essays research papers fc In Crito, Plato recounts the last days of Socrates, immediately before his execution was to take place in Athens. In the dialogue, Socrates’ pupil, Crito, proposes that Socrates escape from prison. Socrates considers this proposal, trying to decide whether escaping would be â€Å"just† and â€Å"morally justified.† Eventually, Socrates concludes that the act is considered â€Å"unjust† and â€Å"morally unjustified.† Socrates then decides to accept his fate and proceeded with his execution. Socrates was a man who was in pursuit of the truth (Durant). In his refusal to accept exile from Athens or a commitment of silence as a penalty, he chooses death and is thrown into prison. While Socrates is awaiting his execution, many of his friends, including Crito, arrive with a foolproof plan for his escape from Athens to live in exile voluntarily. Socrates calmly debates with each friend over the moral value and justification of such an act. â€Å"...people who do not know you and me will believe that I might have saved you if I had been willing to give money, but that I did not care.† -Crito (Wolff 37). Crito believed that by helping Socrates to escape, he could go on to fulfill his personal obligations. Also, if Socrates does not follow the plan, many people would assume that his friends did not care about him enough to help him escape or that his friends are not willing to give their time or money in order to help him. Therefore, Crito goes on to argue that Socrates ou ght to escape from the prison. After listening to Crito’s arguments, Socrates dismisses them as irrelevant to a decision about what action is truly right. â€Å"Now you, Crito, are not going to die to-morrow-...-and therefore you are disinterested and not liable to be deceived by the circumstances in which you are placed.† -Socrates (Wolff 40). In the arguments that Socrates makes, he emphasizes that what other people think does not matter. The only opinions that should matter are the ones of the individuals that truly know. â€Å"The truth alone deserves to be the basis for decisions about human action, so the only proper approach is to engage in the sort of careful moral reasoning by means of which one may hope to reveal it† (Wolff 43). According to Socrates, the only opinion that he is willing to consider would be that of the state. â€Å"...if you go forth, returning evil for evil, and injury for injury,...we shall be angry with you ... ... state of Athens, constitutes disobedience against the state. He argues that obeying the state is a requirement right up until death. He says that by not obeying the state that he was raised in, it's like not obeying his parents that raised him. Socrates was a man who stuck to his commitment to truth, morality and philosophy over life. He had a great commitment to his state, therefore by disobeying it, he would be committing suicide in a sense. If Socrates had disobeyed his state, he would never be allowed to enter it again, nor would any other allow him to live peacefully. His arguments throughout the whole dialogue were very strong. Socrates looked out for his state, while Crito’s arguments were based on himself and how others would view him. Socrates’ conclusion to stay in the prison may have cost him his life, but his act saved the morality and truth of Athens. Works Cited Wolff, Robert Paul. â€Å"Ten Great Works of Philosophy†. New York: Penguin Group, 1969. Durant, William. â€Å"The Story of Philosophy†. New York: Washington Square Press Publications, 1961. Volume I, Ninth Edition. â€Å"Civilization: Past & Present†. New York: Addison-Wesley Longman, Inc., 2000.

Comment on the Positive Function and Dysfunction of Social Policy in Hong Kong.

2. Definition of Social Policy Social policy primarily refers to guidelines and interventions for the changing, maintenance or creation of living conditions that are conducive to human welfare. Thus, social policy is a part of public policy that has to do with social issues. More specifically, it also considers detailed issues in policy and administration of social services, including policies for health, housing, education and social work, and needs and issues affecting the users of services, including poverty, old age, disability, and family policy. To have more clearly speaking, terms of social needs, social integration and alienation will be elaborated. Social needs are people’s needs which are socially defined according to social conditions. Yet we can still have a look at Hierarchy of ‘Need† as a reference since social needs are part of the basic needs. According to A. H. Maslow (1943), there are a hierarchy of five sets of goals including physiological, safety, love, esteem and respect, and self-actualization. These goals are related to one another, being arranged in hierarchy of prepotency. Social integration is referred to the process of building up a sense of community and social network amongst different community groups and individuals, hence people all live together in a peaceful and harmonious manner. It is the key element to social stability and can be achieved by promoting social mobility. Alienation is opposite to social integration, which means the feeling of being neglected or isolated and excluded from the rest. Such feeling of seclusion may destroy any sense of community or belonging and hence lead to social instability. Various types of social policy are being implemented in a society, such as family policy, education policy, and healthcare policy and so forth. We will particularly focus on social policies which aim to improve human welfare and to meet human needs for health, education and housing. 3. Overview and Comment On Social Policy in Heath Aspect The health system of Hong Kong is considered as one of the best world-wide. It is divided into two parts, which are public health services and private health services. Our government heavily subsided for the former services but citizens need to pay for the fee for the latter services. The Department of Health executes health care policies and statutory functions so as to safeguard the health of the community through preventive and rehabilitative services. In order to achieve the goal, subvention for the Hospital Authority has been increased in recent years. Besides, it is expected that ageing population will increase, expectations of health care will rise, and medical costs will soar. Therefore, it is not difficult to foresee that health expenditure will become a heavy burden for our government. Based on this problem, our government proposed to have a reform and some policies were implemented. I will look at two schemes in the following part. 3. 1 Early Health Care Voucher Pilot Scheme Early Health Care Voucher Pilot Scheme (HCVS) was addressed in the Policy Address 2007 -2008. The Scheme is to give elders who aged 70 or above five health care voucher of $50 annually. It aims to allow elderly to gain access to health care services in the private sector with subsidy and hence minimize the number of patients on the waiting list in the public sector. Through the Scheme, the elderly can have additional choices on top of the existing public healthcare services which would continue to be provided, hence equity is encouraged as a universal access to medical services regardless of wealth or status is promoted. It will contribute as a positive function since social integration is encouraged. Besides, complaints are always arouse due to the long waiting list of the public sector, patients can now save their time by visiting private doctors with partially subsidization. However, in order to further fulfill the social needs, eligibility for joining the Scheme should be relaxed from 70 to, for example, 65 years old and the subsidized amount of $250 should be increased. It is because only small amount of people can benefit from the scheme and financial support given to them is not enough due to the high consultation fee of private doctors. 3. 2Health Care Reform A lot of people support there is an urgent need for the reform especially after consultation documents in health services and financing reforms during the past ten years. One part of the proposed reform is tax deduction should be provided for private medical insurance premium or expenses. Our government is working out a supplementary healthcare financing option operating on a voluntary participation basis, containing insurance and savings components. For using this kind of method, it is believed that indemnification can be provided for citizens, which meets the second level of basic need in Maslow’s Hierarchy Needs. Moreover, it can release the pressure on the public sector and hence ensure a high quality of services in public sector. On the other hand, the reform should be taken into deep consideration, if health insurance plan is mandatory to all citizens, it may lead to dissatisfaction of some citizens and which will at last violate the aim of social policy. In short, providing both public health services and private health services can maintain competition in the private sectors which can ensure its quality. Giving welfare to our citizens can foster a sense of belonging and unity in the community. Subsidization in health care services given to the poor by various scheme can encourage redistribution of wealth and hence promote social mobility. Though Hong Kong’s health care standards are comparable to many major European cities and always being praised at, it will be a shame if our citizens cannot receive appropriate treatment due to the long waiting list problem. Therefore, it has been urged to think of new schemes and more partnerships between the city's public and private hospitals in a bid to ease the burden on the public sector. 4. Overview and Comment on Social Policy in Education Aspect Education has long been regarded as a long term method to stabilize the society and promote economic development in the city. In Hong Kong, Education Bureau’s Vision is to provide quality school education for our students to develop their potential to the full and to prepare them for the challenges in life. Hence, it promises to deliver professional services and ensure effective use of resources, and forge partnerships to promote excellence in school education. The Bureau is responsible for formulating, developing and reviewing policies, programmes and legislation in respect of education from pre-primary to tertiary level. Those policies formulated by the Bureau will be divided into the four categories in the following part. . 1Kindergarten Our Government plays as a supporting role in pre-primary education, which provides in-service teacher training facilities, lower rent to non-profit-making kindergartens, permission of allocating kindergartens in public housing estates, and supplies financial assistance in the form of reimbursement rates to parents and kindergartens. 4. 1. 1Kindergarten Scheme In 1996 Policy Add ress, our government brought up the idea of allocating more financial assistance and providing additional training for existing kindergarten teachers through implementing Kindergarten Scheme. One of its commitments is to ensure more than 40% of kindergarten teachers would complete the Qualified Kindergarten Teacher Education Course by September, 1997. Although such policies legislated by the government were reacted because of pressure from the public, it still can ensure the quality of preschool education to all. Besides, equity is advocated as good quality preschool education made available universally. Yet, the policies can only partially fulfill social needs because our government is always taking a supporting role only, a higher degree of support for preschool education is needed. . 1. 2 Pre-primary Education Voucher Scheme The Pre-primary Education Voucher Scheme (PEVS) provides fee subsidy for parents or legal guardians or registered custodians to meet towards school fees for pre-primary education of their children in the form of pre-primary education vouchers. Eligible children who attend nursery, lower or upper classes in eligible local non-profit-making kindergar tens or Kindergarten-cum-Child Care Centres may benefit from PEVS. The Scheme was launched in 2007 to promote the â€Å"3A's† of early childhood education (ECE): affordability, accessibility, and accountability. The PEVS has three unique features. The first one is discriminating against profit kindergartens and hence to discourage social alienation. The second feature is promoting teacher professional development to ensure quality of preschool education so that the gap of quality between profit kindergartens and non-profit kindergartens can be minimized. Children from poor families can still have a qualified and good education. The last feature is limiting parents’ choice to only non-profit schools. On one hand, it can promote freedom of choices; on the other hand, it can encourage social integration as children may get into the school they want regardless of wealth of the families. To conclude, the majority of the parents perceive positive impacts towards schemes launched by the government. Nevertheless, principals and teachers of kindergartens reported some implementation difficulties and more sufficient support are needed for parents. 4. 2Primary and Secondary Education The Government's policy objectives are to provide a balanced and diverse school education that meet the different need of our students and help them build up knowledge, values and skills for further studies and personal growth. 4. 2. 1Universal Basic Education Compulsory primary education was introduced in 1971; afterwards, 9-year free education was implemented in 1978 to fully subsidize both primary and junior secondary education. Starting from the 2008/09 school year, senior secondary education is provided free through public sector schools. In addition, with effect from the 2008/09 school year, the Government provides full subvention for full-time courses run by the Vocational Training Council for Secondary 3 leavers to offer an alternative free avenue for senior secondary students outside mainstream education. Advocating universal basic education can promote social integration as the poor can be able to receive education. Besides, it can equip students with ample knowledge and prepare them for entrance into the knowledge-based economy. Hence, it will be easier for the poor to climb up the social ladder, without basic knowledge they may need to work as low-skilled workers for the whole life. 4. 2. 2 School Entrance System In 1978, two systems were used to determine whether the students can get into the secondary school. Secondary School Entrance Examination is a selected mechanism by which students who scored higher would be selected for places given higher priority in their school choices. Feeder and Nominated System is a mechanism allowed feeder and nominated secondary schools to directly admit a certain proportion of their students from designated primary schools. Through the Secondary School Entrance Examination, social mobility can be promoted as children from poor families can still have a chance to get into the best school. Oppositely, the other scheme would minimize the effect of promoting social mobility. It is because wealthy families can send their children to prestigious primary schools and hence let them to go into the linked prestigious secondary school. Hence, it may bias towards wealthy people. 4. 2. 3 Secondary School Places Allocation System Secondary School Entrance Examination was later changed to Secondary School Places Allocation System. It is a mechanism to allocate secondary school places to primary school-leavers. The allocation mechanism is designed in such a way so that it would help reduce public examination pressure on Primary six students and restore a more balanced education in primary schools. In addition, due regard is given to parental choices and, through regionalization, the need for students to travel long distances to schools is minimized. Moreover, it helps to achieve a degree of mixed ability intake at Secondary one level. Therefore, social integration can be promoted in this way, nevertheless, it can never be promoted into full extent since well-off families can afford to move within the proximity of prestigious schools, for instance mid levels of Hong Kong Island, to get into those famous traditional schools. 4. 2. 4School Management Initiative Programme School Management Initiative Programme (SMI), introduced in 1991, provides participating schools with school planning/staff development days, approved collection of charges for specific purposes, and computer system for school administration. It aims to attain an effective school system. In the spirit of the SMI, it was proposed that the school funding system should be able to meet the basic needs of students to ensure fairness across the school sector, provide schools with greater flexibility in the effective use of resources in order to achieve individuality. However, the teachers complained about the heavy increase of work load and reported that the accountability framework failed to make any impact on the quality of teaching. The focus of our government should be the attitudinal and behavioral change in those directly involved in delivery of services instead of structural and administrative change. 4. 3Tertiary Education The government increased the number of degree places in late 1970s and 1980s. Today, 14,500 first-year first-degree places are provided to cater for about 18% of the 17 to 20 age group through the eight institutions funded by the University Grants Committee to further develop Hong Kong as a regional education hub. Moreover, our government has financial support to students who are in financial needs. By increasing the number of degree places, equity is promoted as students can have a higher chance to admit into tertiary education. Providing subsidization to students can ensure that no qualified students are denied access to higher and post-secondary education due to a lack of financial means. Besides, it can improve the standard of living as the rate of illiteracy is lowered and hence stimulate economy of the city due to the increase in competitiveness. However, demand of post-secondary education is progressively increasing, policies, which are being implemented, still cannot meet the social needs. 5. Conclusion Based on the review above on the social policies in Hong Kong, we can see that each social policy has its positive functions and dysfunctions. With regard to the three aspects in social policy, there is much room for improvement. But at least, our government is working hard to improve the conditions of our society and paying effort to meet social needs, promote social integration and discourage alienation.

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Science Form 2 note CHAPTER 1: THE WORLD THROUGH OUR SENSES 1. 1 Sensory Organs and Their Functions Sensory Organs and Their Stimuli 1. Humans being have five main sensory organ, which are skin, nose, tongue, ears and eyes. 2. Sense detects stimuli, that is changes in surroundings (around us). 3. Five senses: i. sight ii. hearing iii. touch iv. taste v . smell 4. Senses are part of the body called sensory organs. 5. Changes or object that can detect by our senses are called stimuli. 6. The ability of the sensory organs to detect stimuli is called senses. 7.All the sensory organs are complete with sensory receptors, that is the nerve endings that can detect stimuli. Stimuli Sense Sensory organ Light(Brightness, colour) Sight Eye Sound Hearing Ear Touch, heat, cold, pain, pressure Touch Skin Sweet, sour, bitter, salty Taste Tongue Smell or odors Smell Nose The World through our senses senses Light and sight Sound and hearing Stimuli and responses in plants Touch (skin) Smell (nose) Tas te (tongue) Hearing (ear) Sight (eye) Properties of light Vision defects Optical illusions Stereoscopic and monocular Properties of sound Reflection and absorption limitations stereophonicPhototropism (light) Geotropism (gravity) Hydrotropism (water) Thigmotropism (move toward) Nastic movement (move run away) Science Form 2 note 2012 Laman web. http://freda. auyeung. net/5senses/see. htm http://freda. auyeung. net/5senses/touch. htm http://freda. auyeung. net/5senses/hear. htm http://freda. auyeung. net/5senses/taste. htm http://freda. auyeung. net/5senses/smell. htm 1. 2 The Pathway from Stimulus to Response PMR 05 Figure 1. 2 The summary of the pathway from stimulus to response 1. Our sensory organs are used to detect stimuli (Singular: stimulus).A stimulus is anything that causes a reaction in a living organism, e. g. Pain, heat, sound, chemicals. 2. When a stimulus is detected, receptor cells in the sensory organ will be triggered and generate impulses. 3. These impulses will be transmitted through the nerve and than to the brain. 4. The brain will further process and interpret the impulse signals as specific information than the organism has to respond to. 5. This information is than sent back to the sensory organ through the nerve to provide responses. Stimulus > Sensory organ > Nerves > Brain > Nerves >Response Stimulus Sensory organs NervesBrain Nerve Response Science Form 2 note 2012 EXERCISE Sense of Touch PMR 07 http://freda. auyeung. net/5senses/touch. htm Go to www. brainpop. com/health/integumentary/skin/index. weml Watch a movie on the skin. For easy access, go to www. icd. com. my 1. The sense of touch is the sense that is sensitive towards the touch stimulus provided by specific objects. 2. Organ involve in the detection of touch stimulus is the skin. 3. Structure of human skin: a) The skin divided into three layer epidermis, dermis, fat layer (subcutaneous layer @ adipose layer @ fat layer) ) Receptors are cell in our body that detected stimu li. c) Our body have different types of receptors. These are: i. pain receptor ii. touch receptor iii. heat receptor iv. cold receptor v. pressure receptor Sensory organ 1 Eye 2 Tongue 3 Ear 4 Nose 5 Skin Stimulus (a) Light (a) Chemical substance (a) Sound (a) Chemical substance (a) Cold Pressure Pain Heat Detected by sense of (b) Sight (b) Taste (b) hearing (b) smell (b) touch Science Form 2 note 2012 d) The pain receptor is in the epidermis. e) The touch, heat and cold receptors are in the dermis.The pressure receptors are in the fat layer. f) Each type of receptor can detect only one particular stimulus. g) The part or our body contain receptor are called sensory organs h) These receptor have nerves attached to them Draw figure 1. 3, page 6 4. The degree of sensitivity of the skin depends on the: a) Thickness of the epidermis †¢ The thinner the epidermis, the more sensitive the skin is to the stimulus b) Number of receptors present PMR 05 †¢ The more receptors found on the skin the more sensitive is that part of the skin. 5. The part of the body that have thin epidermis and many receptors sensitive to touch are ) lips b) fingertips c) behind the ears d) armpit e) the back of the neck 6. The part of the body that are not so sensitive to touch are the: a) elbow b) knee c) palm of the hand and sole of the foot d) buttocks/hip 7. The parts of the body usually chosen by the doctor for injection are along the upper arm and the buttocks. This is because these parts have thick epidermis and fewer receptors. 8. Braille is a code made up of small raised dots on paper. Blind people use their sense of touch to read Braille. 9. Other functions of the human skin. i. Water proof – prevent water loss from skin. ii.Prevents entry of microorganisms that cause illnesses. iii. Remove waste products – excess water, urea and mineral salts. iv. Produces Vitamin D in the presence of the sunlight. v. Stabilise body temperature Science Form 2 note 2012 â€⠀œ sweat glands produce more sweat to cool the body if body temperature rises. Quick check Fill in the blank with the suitable terms given in the box. Receptors thickness thinner sense of touch touch more number 1. The skin is an organ of __________________ 2. There are five types of __ ___ in the skin sensitive to various stimuli. . The sensitivity of the skin depends on the ___________ of the epidermis and the ____________ receptors on the skin. 4. The ____________ the epidermis, the more sensitive it is to stimulus. 5. The ________ receptors there are on the skin, the more sensitive it is to stimulus. 6. Blind people use their ____ to help them read Braille THE SENSE OF SMELL http://freda. auyeung. net/5senses/smell. htm Go to www. innerbody. com/htm/body/html. choose `nervous system’ and click on the `nose’ for detailed information. For easy access, go to www. icd. com. my mucus Sensory Cells (smell receptors) Nerve to brainNose Nasal cavity Air in > tongue Roof o f the mouth nostril Science Form 2 note 2012 1. The nose is sensory organ for smell. 2. Cells sensitive to smell (smell receptors) are found on the top of the nasal cavity. Draw figure 1. 8, page 9 3. Structure of the human nose. a. The human nose has a cavity lined with epithelium tissue. b. On the surface of the epithelium tissue are the sensory cells known as olfactory cells. c.The surface of the nasal cavity is moist because of the mucus secreted by the cells of a gland. d. The nasal cavity has a pair of external opening (nostrils) which have hair to filter dust from the air inhaled through the nose. 4. The nose detects smell in the following way. The inside of the nasal cavity produce mucus v The chemical vapor entering nose during breathing dissolves in mucus. The dissolve chemicals stimulates the smell receptor at the top of the nasal cavity. The smell receptor then produce impulse which are sent through the nerves to the brain v The brain interprets / evaluates the smell . W hen we have a cold or flu, a lot of mucus is produce. The smell receptors are surrounded by this thick layer of mucus and vary little of chemical vapor gets to the smell receptors. Therefore, the smell receptors do not get stimulated enough to effectively function as a sensory organ of smell. 6. The sensitivity of the nose towards stimuli is influenced by the following factors: PMR 05 i. The strength of the smell. A stronger smell will be detected by the nose easily compared with a weaker smell. ii. The presence of mucus in the nose. A lot of mucus will reduce the sensitivity of the nose.Science Form 2 note 2012 Quick check 1. 3 1. Where are the smells receptors found? he top of t he nasal cavity 2. Explain why when we have cold or flu , the nose cannot function effectively as a sensory organ of smell The sensitive receptor cells covered with mucus block the chemical substances from stimulating the smell receptors. THE SENSE OF TASTE http://freda. auyeung. net/5senses/taste. htm dra w figure 1. 10, page 11 1. The tongue is the sensory organ for taste. 2. The surface of the tongue has groups of cells known as taste buds which are sensitive to taste. . There are four types of taste buds on the tongue sensitive to sweet , bitter, sour and salty. PMR 03 4. The tongue detects taste in the following way: Dissolved substance > taste receptors > message >brain > type of taste 5. The sense of smell helps the sense of taste . This explains why food dose not taste appetizing when we have a cold or flu because we cannot smell effectively Figure 1. 8 Structure of the human tongue and the areas of taste on the tongue Science Form 2 note 2012 The Sense of Taste and the Sense of Smell Go to www. brainpop. om/health/senses/taste/ Watch a short movie on taste and try a quiz about taste.. For easy access, go to www. icd. com. my 1. All our sense work together:- sense of smell and taste are special partner 2. When we eat, our tongue gives us the taste and our nose smell of the foo d. THE SENSES OF HEARING http://freda. auyeung. net/5senses/hear. htm 1. The ear is the sense organ that is sensitive to sound stimuli produced by vibrating object. 2. A human ear has three main part. i. the outer ear, filled with air. ii. The middle ear, filled with air. iii. The inner ear, filled with liquid Draw figure 1. 15, page 14 3.Function of the different parts of the human ear. Salin table 1. 4, page 15 Science Form 2 note 2012 The Hearing Mechanism Lukis/Photostat figure 1. 16 m/s 15 FUNCTIONS OF DIFFERENT PARTS OF THE HUMAN EAR Part function OUTER EAR Pinna collects and directs sound waves into the ear canal. ear canal / auditory canal transmits sound waves to the eardrum. Eardrum vibrates and transmits sound waves to the ossicles. MIDDLE EAR Ossicles intensify the vibrations of the sound waves by 22 times before transmitting to the oval window. Eustachian tube balances the air pressure at both side of the eardrum. val window transmits sound vibrations from the middle ea r to the inner ear. INNER EAR Cochlea transforms sound vibrations into impulses. semicircular canals balance the body position. auditory nerves send messages to the brain which interprets the messages as sound. Limitations of hearing. 1. We cannot hear all the sounds around us. 2. The range of frequencies of hearing in man is 20 Hz until 20 000 Hz. The following table shows the range of frequencies of hearing of several animals: ANIMAL RANGE of FREQUENCIES snake 100-800Hz frog 50-10 000Hz dog 10-50 000Hz cat 60-60 000Hz bat 1000-120 000Hz grasshopper 100-15 000Hz hale 10-50Hz Science Form 2 note 2012 3. Different people have different limitations of hearing. 4. For example, old people generally cannot hear as well as young people. 5. Our ear drum become less sensitive to sound as we grow older. 6. To overcome the limitations of hearing, we use i. the stethoscope – enables doctor to detect the soft heartbeats of patients. ii. hearing aids – collects sound signals before being sent to the middle ear. iii. amplifier – boosts weak sound signals. Stereophonic hearing Go to : http://www. wardless. co. uk/hearing aids/twoEarsBetter. html Find out more about stereophonic hearing from this website or other websites. . For easy access, go to www. icd. com. my 1. Stereophonic hearing is hearing using both ears. 2. The advantages of stereophonic hearing: i. enables the direction of the source of hearing to be detected more accurately. ii. This is because the ear nearer the source of sound receives sound louder and earlier than the other ear. iii. Animals that have stereophonic sound can detect the presence of preys and predators more quickly. Properties of sound (see page 16 science volume 1) 1. The transfer of sound requires a medium. 2. ound can transferred through; b. solids c. liquids d. gases e. cannot be transferred through in vacuum. 3. Sound can be transferred fastest in solids and slowest in gases. 4. This is because the particles in solids a nd liquids are closer each other compared to the molecules in gases. 5. Vacuum is space that does not have any particles. Science Form 2 note 2012 6. Speed of sound transferred in various media. MEDIUM SPEED of SOUND (m/s) Air 340 Water 1500 Wood 3600 Iron 5000 Steel 6000 Reflection and absorption of sound 1. Sound can be reflected or absorbed by the surface of an object. . The sound reflected repeatedly from one surface is known as echo. 3. Surfaces that are smooth, even and hard are good sound reflectors and produce loud echo. For examples, concrete, plank, metal and mirror 4. Surfaces that are rough, hollow and soft are good sound absorbers and produce weak echo. For examples cloth, sponge, cork, rubber, carpet and cushion. SENSE OF SIGHT http://freda. auyeung. net/5senses/see. htm 1. The sense of sight is the sense that can detect light stimulus. 2. Structure of the human eye: PMR 04 i. the sclera (outermost) ii. the choroids (middle) and iii. the retina (innermost) ukis rajah m /s 22 3. The function of each part of the eye. Pelajar diminta mencari maklumat ini (isi maklumat seperti jadual dibawah) Science Form 2 note 2012 part Structure / characteristic function sclera cornea choroids conjunctiva iris pupil Lens PMR 04 Transparent and elastic convex lens Refracts and focuses light onto the retina. ciliary muscle supportive ligament vitreous humour aqueous humour retina optic nerve Mechanism of Sight PMR 03, 07 1. The lens in the human eye is a transparent convex lens. 2. An inverted image is focused on the retina. 3.Light rays are refracted by the eye lens. The eye lens focuses the image onto the retina by changing the thickness of the eye lens. The thickness of the lens is changed by the ciliary muscles. i. Focusing near objects To focus near objects onto the retina, the ciliary muscles contract. The eye lens become thicker. ii. focusing distant object. To focus distant objects onto the retina, the ciliary muscles relax. The eye lens becomes thinner. draw figure `How do we see’ m/s 23 Light and sight 1. Light is a form of energy. 2.. light travels at a speed of ; i. 300,000,000 meter/second (m/s) in the air. ii. 25,000,000 m/s in water iii. 200,000,000 m/s in glass 3. Light travels in a straight lines. Science Form 2 note 2012 Reflection of light. http://www. phys. ufl. edu/- delamater/optics_pictures. pdf#search=`what%20is%20incident%20and%20ref lected%20ray’ 1. Light can be reflected. (that’s mean change direction) 2. When the reflected light rays enter our eyes, we can see the object. 3. The image in a plane mirror is, i. virtual (cannot be formed on a screen) ii. upright iii. laterally inverted iv. the same size as the object v. the same distance behind the mirror as the object is in mirror.Refraction of light. PMR 03, 05 1. Refraction of light is the bending of light. This happens when light travels from one transparent medium to another which is of a different density. 2. The speed of light decrease when l ight enters a denser medium. 3. Light travels through media like air, water and glass. draw figure 1. 27 page 24 Experiment page 25. LAPORAN PEKA 1 Various defect of vision. PMR 03, 06, 07 http://www. chemsoc. org/exemplarchem/entries/2002/upton/defects_of_the _eye. htm 1. Two common vision defects are long-sightedness (hypermetropia) and short-sightedness (myopia).Science Form 2 note 2012 2. Comparison between long-sightedness and short-sightedness. `Comparison between long-sightedness and short-sightedness’ Short-sightedness Differences Long-sightedness 1. Symptoms of defect. 1. 2. Causes of defect 1. Position of image of object Lihat power point Diagram Science Form 2 note 2012 Correction method 3. Astigmatism is another vision defect. i. Its caused by the cornea and the eye lens that are not evenly curved. ii. As a result, the image formed on the retina is distorted and not clear (hazy/blurred). ii. This defect can be overcome by wearing glasses with cylindrical lenses or contact lens or by surgery. 4. Optical illusion. http://www. michaelbach. de/ot/ http://www. indianchild. com/3d%20mainpage. htm i. Optical illusion occurs when the brain cannot interpret impulses received properly. ii. Examples of optical illusion. draw figure 1. 41 page 30 5. Blind spot i. The blind spot is a spot on the retina of the eye that cannot detect light stimulus. ii. The image of the object formed at the blind spot cannot be seen by the eye because there are no light-sensitive cells (photoreceptors) at the blind spot.Experiment seperti ms 29 Monocular and stereoscopic vision. http://nzphoto. tripod. com/sterea/3dvision. htm Science Form 2 note 2012 1. The stereoscopic vision is vision using both eyes. 2. The overlapping area of the vision of both the left and right eyes is called stereoscopic field 3. Advantages of stereoscopic vision. a. See three-dimensional pictures of objects. b. Enables more accurate estimation of distance and position. c. Animal predators normally have stereoscopis vision so better estimate the distance when getting to pounce on their prey. draw figure 1. 3 page 31 4. Monocular vision is a vision using only one eye. 5. The advantage of monocular vision is having a wide vision field. 6. Its disadvantage is that it cannot estimate distance accurately. 7. Animal preys use monocular vision to detect predators coming from all direction. draw figure 1. 42 page 30 Appropriate devices to overcome the limitations of sight Go to www. google. com. Type LASIK or PRK . you can get more information about the latest technologies to correct the different types of defects of vision. 1. Optical devices are invented to increase the ability to see minute or very distant objects.INSTRUMENT FUNCTION Microscope To see minute objects such as microorganisms and bacteria. Telescope to see far-off objects such as stars and planets. Binocular to see tiny distant objects such as birds in the sky. Magnifying to magnify tiny objects to become glass larger than original. Science Form 2 note 2012 STIMULI AND RESPONSE IN PLANTS. Go to www. emc. maricopa. edu/faculty/farabee/BIOBK/Biobook TOC. html Click on `24 plant hormones and nutrition’ then `plants respond to external stimuli’.. For easy access, go to www. icd. com. my . Movements of any plant parts towards stimuli are known as tropic movement or tropism. 2. Type of tropism: a. Growth of plant part towards an external stimulus is known as positive tropism. b. Growth away from an external stimulus is known as negative tropism. 3. Tropism responses in plants include: a. Phototropism PMR 03, 08 b. Geotropism PMR 06 c. Hydrotropism PMR 03, 08 d. Thigmotropism – move towards – to obtain support e. Nastic movement – move run away – Salin nota sendiri dari buku teks m/s 33, 34, 35 masukkan gambar rajah sekali †¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. tammat†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦