Thursday, October 31, 2019
Aris Dilemma Essay Example | Topics and Well Written Essays - 1250 words
Aris Dilemma - Essay Example She had been sitting in silence for more than an hour now. She had never imagined that it would be like this. She remembered, for the 100th time, how her mother had gasped in shock when she brought Bilal to their home in Western Texas. Her father tried desperately to pretend that he was pleased at his daughter’s choice of friend. However, the rest of her family only gaped at his elaborate headdress. Bilal was kind enough. Her mother had purposefully tried to make him feel uncomfortable. She constantly wore, on her face, expressions full of hatred at Bilal. She permitted him to talk or comment on anything without openly opposing his comments. Beside, she constantly criticized Bilal’s Muslim culture and culture pointing out the unjust and monopolistic way they treated their women. In addition, she kept telling Bilal that he is not any different from all his Muslim folks as long as they live in Saudi Arabia. Bilal tried to persevere the rampage, from his to be mother-in-la w, in silence, perhaps accepting the truth in silence. â€Å"Ghayda!†Ari took some moments to realize that it was she who was being addressed by the old woman at the door to her right. â€Å"Ghayda!†Her husband’s aunt had given her the name to make her a complete Saudi Arabian. The old woman motioned towards the kitchen.
Tuesday, October 29, 2019
The Impact of Substance Abuse on the Adolescent Population Essay Example for Free
The Impact of Substance Abuse on the Adolescent Population Essay Introduction Understanding the scope of drug use and addiction in the world includes knowing the prevalence among various populations and researching the many health and social consequences. The United States is both the largest producer of drug research in the world and the world’s only â€Å"drug-control superpower.†The simultaneous leadership in social science and world agenda setting is not the result of a symbiotic relationship between American research and policy making.During adolescence, friends and peers become far more influential than before, and intimate dating relationships become primary interests (Laursen Williams, 1997). Along with these important developmental changes, however, come increased risks of pregnancy, sexually transmitted disease, and abuse by and toward dating partners (Leaper Anderson, 1997). As well, alcohol and drug use and abuse enters the picture, which may contribute to the occurrence of the other risk behaviors (Milgram, 1993; National Center on Addiction and Substance Abuse, 1999). Although some of these developments are harmless, there is a growing awareness of the importance of education and prevention to increase teens personal safety and responsibility. Not surprisingly, prominent adolescent risk behaviors are alcohol and drug abuse, unsafe sexual behavior, and dating violence-share many of the same contributing risk factors, although to important and differing degrees. These include problems related to the family, such as family conflict and violence, poor relationship attachment, early and persistent behavior problems, as well as peer and academic problems, such as school failure, peer rejection, and exposure to community violence. In addition to the above, teen pregnancy, early sexual intercourse, and risky sexual behaviors are associated with early onset of puberty, truancy, and delinquency (Kilpatrick, Acierno, Saunders, Resnick, Best, 2000). In the absence of compensatory factors, such as education and social competence, these varied risk factors can contribute to or become risk behaviors (e.g., alcohol use is associated with teen pregnancy and violence). Common Elements A common family element found among teens who engage in these high risk behaviors is the amount of time spent without proper adult involvement or supervision (Dishion, Capaldi, Spracklen, Li, 2005). Not surprisingly, children who grow up in caring and supportive homes are more likely to resist risky behaviors, while children who have grown up witnessing or experiencing alcohol abuse or violence in their homes, having poor family structure and insecure attachment-related experiences are more likely to be less resistant to these same risky, unhealthy behaviors. A description of the age, gender, and ethnic identities of youth who engage in high risk behavior is provided by the Youth Risk Behavior Surveillance, which tracks data regarding many health risk behaviors for adolescents in the United States. According to this data, black youth, for example, report significantly higher rates of sexual intercourse before age 13 than do Whites and Hispanics, while White youth report the highest levels of forced sexual intercourse. Black youth also report less alcohol consumption at last sexual intercourse and higher condom use than do White and Hispanic youth. Not surprisingly, males report more alcohol use before the age of 13 than females, across all ethnic groups (YRBSS). However, these data on prevalence of self-reported adolescent risk behaviors is descriptive only, and tells little about the contextual factors contributing to such risk. While looking closer at some of the factors that may contribute to the mentioned risk behaviors, the one can see that alcohol use among teenagers remains prevalent in todays society. A national probability sample of 4,023 adolescents between the ages of 12 and 17 found that 15% of the sample used alcohol, 10% used marijuana, and 2% reported hard drug use in the past year (Kilpatrick et al. 2000). Although some alcohol consumption among adolescents is considered normative, there is great concern for the number of teens who are exhibiting signs of alcohol abuse or dependence with 7% of the above sample meeting diagnostic criteria for alcohol, marijuana, or hard drug abuse or dependence. Trends in alcohol use reported in the Youth Risk Behavior Survey indicate that binge drinking (five or more drinks on one occasion during the 30 days prior to the survey) has shown little variation over the past several years, ranging from 31.3% in 1991 to 33.4% in 1997 to 31.5% in 1999 (Centers for Disease Control, 2000). Binge drinking continues to be a problem among youth and needs to be targeted specifically. Importantly, studies have found that alcohol use influenced the practice or involvement in a number of other high-risk behaviors. Sexual activity, smoking, and drinking and driving were significantly related to heavy drinking. Another study examining trauma experiences among adolescents found that those who reported alcohol abuse or dependence were 6-12 times more likely to have a history of childhood physical abuse, and 18-21 times more likely to have a sexual abuse history (Clark, Lesnick, Hegedus, 2001). The continued increase in alcohol consumption among teenagers is cause for concern, particularly as it relates to and influences other risk factors and behaviors. Teen Addiction, Recovery and Relapse            These three (3) aspects are critical elements of this discussion because they are more closely related to reach other than originally recognized. Teen addiction has often been linked to the risk factors that will be discussed in the later segments of this paper (Kilpatrick et al. 2000). Teen addiction is often correlated to exposure to risk factors. The causal link that has been found is that the risk activities that teens are exposed to often lead to drug addiction and dependency. Alternatively, those that find themselves in drug related problems are often also found to take part in risk activities. The second element, teen recovery is also connected to all of these factors in that the success of recovery treatment depends highly not solely on the teen’s non-exposure to drugs but also with the withdrawal from all of those risk factors such as drinking, smoking and healthier dating relationships. Finally, this section will also shed light on the relapse rate which has also been found to be closely related to alcohol and smoking problems. As found in most studies, continued use of non-drug addictive substances also increases the relapse rate especially among teens.            As previously mentioned, teen addiction is often attributed to many different factors. The foremost among these factors remain peer pressure, troubled childhood and lack of parental and substitute parental guidance (e.g. teachers). These are well documented causes of teen drug addiction which will only be briefly discussed.            While there are theories that suggest it may not be just one single element that promotes teen drug addiction, it cannot be denied that the aforementioned factors when taken together do increase the chances of teen drug addiction. Given this fact, once these factors are added with the risk factors such as social acceptance which leads to increased sexual activity, drug addiction not only becomes guaranteed but continued substance abuse well into the late teens is also certified. In the book entitled, â€Å"Care of Drug Users in General Practice: a harm reduction approach†, it has been found that addiction to drugs is not always the primary addictive element and that in certain cases the addiction is to the other benefits derived from drug addiction that individuals find more appealing such as social acceptance and increased sexual activity (Phillips 2004).            The issue of recovery, as discussed in â€Å"Care of Drug Users in General Practice: a harm reduction approach†often cites that recovery is based on the same factors that caused the addiction but to a varying extent (Phillips 2004). This basically means that in order for one to enter voluntarily, which has been found to have to lowest relapse rate, into drug rehabilitation programs, there is a need for the external aid. The cause which began the substance abuse must also be willing to aid the individual in the rehabilitation stage. An example of this would be sexually active teenagers who attempt rehabilitation but fail due to one of the partner’s refusal to enter the same program.            Teens are at a very impressionable stage and in order to be able to reach out to them one must be able to reach out to their peers. This is easier said than done, however, since the clannish nature of most teenagers makes it almost impossible to be able to get on a more comfortable personal level with any of them (Phillips 2004). Most drug rehabilitation programs have begun implementing peer outreach programs where the former successful teen patients volunteer to help the centers in reaching out to the troubled youth.            Finally, the problem of relapse must also be discussed. Relapse is often a greater problem than getting the addict to rehabilitation. The reason for this is that maintaining the dissociation with drugs and the related elements requires constant vigilance without outside intervention (Phillips 2004). Most of the problems that teen addicts face after rehabilitation lies in breaking away from comfortable and familiar ties who are often still exposed to the drug elements to which the teen seeks to break ties from.            There is a lot of literature on this matter which suggests that drug rehabilitation programs should equally pay attention to the â€Å"check out†stage of most recovered addicts. While there is success in getting the addict to quit, for the time being, success can only be measured in its entirety. In this dangerous and socially important aspect, partial success does not count as a victory (Phillips 2004). What truly matters is getting the teen to totally isolate himself or herself from any factor which may bring about a relapse.            In order to tackle this problem, it is important to maintain peer programs such as the AA and the like that have constant monitors on their members. There are programs that have already instituted these types of programs but most have failed due to the lack of commitment by most of its members (Phillips 2004). Teen drug addiction is not an easy problem to admit as most teens often find themselves in denial of their addiction and take it instead as a growing pain that everyone goes through (Phillips 2004). Yet, as revealed earlier, the teen drug abuse rates reveal a different story. Therefore, in order to address the problem of drug relapse, most teenagers must be able to realize that the addiction was not just a part of growing up but rather an experience that is avoidable and must not be repeated. Teen Treatment Systems            This section will briefly tackle the issue on treatment systems such as counseling or outpatient services and its effects on the adolescent population whether it is helpful or only helpful when combined. At the onset, it must be stated that as a part of the rehabilitation system, the issue on counseling and/or outpatient services is critical.            As previously mentioned in the prior section, many of the treatment systems that have been implemented do not focus solely on counseling alone but also include other treatments such as outpatient services and extracurricular activities (Philips 2004). Counseling, as discussed in a number of studies, is only effective up to a certain extent. While generally considered as a more passive approach to treatment, newer and more dynamic systems have also been added to the treatment (Botvin 2005). It has been found that counseling is only the initial step in teen substance abuse rehabilitation. It must be complemented by more dynamic systems as teen outreach programs.            The value of an addict for his or her life is greatly increased when seen in the context of aiding the community. These new treatment systems have been developed specifically to target teens. The reason for this is that it allows for the effective isolation from the harmful and detrimental substance abuse elements and allows the addict or individual to be â€Å"reintroduced†as a productive member of society and the community (Botvin 2005).            The second step in this process is the outpatient service that is offered. The problem of relapse is common among teenagers and as such effective outpatient services to monitor the teens is necessary. The greatest danger comes from not being able to maintain the positive and productive environment for the adolescent. This is perhaps the single most important step in keeping the teens from relapsing into substance abuse (Botvin 2005). Teen Addiction and Risk Factors As such, it is also relevant to discuss how addiction manifests itself in relation to certain aspects such as risky behavior because certain studies have shown that drug addiction is intensified by these elements as well. Dating Relationships Teens generally begin dating, either singly or in small groups, between 13 and 18 years of age, with a range of variability regarding frequency, level of intimacy, seriousness, and importance of these relationships. An illustration of dating, intimacy, and sexual experiences and expectations is provided by an in-depth survey conducted by the Kaiser Family Foundation and YM Magazine, involving 650 boys and girls ages 13-18 years (Henry J. Kaiser Family Foundation and YM Magazine, 1999). They discovered levels or stages of intimacy that developed by age of the youth; that is, intimacy progressed as the youth developed in age chronologically, not as the relationship progressed in length. Most 13-14-year-old teens (72%) reported that it is typical for dating couples their age to kiss, with 45% reporting that French kissing, petting (15%), and intercourse (4%) are expected. Adolescents 15-16 years of age expected an increased level of sexual activity, with 93% reporting kissing, and slightly higher rates of French kissing (71%), petting (48%), and intercourse (28%) as normative. Couples at this age typically spend more time alone together. Older teens (ages 17-18 years) have significantly more sexual experience, with 57% reporting petting to be typical and slightly more than half (52%) reporting intercourse to be typical of their dating relationships. Just as intimacy becomes more involved and prevalent in older teens relationships, so does the significance of the relationship. Although teens continue to value relationships with parents, siblings, other family members, and nonrelated adults, relationships with dating partners begin to gain in importance. Gender differences emerge in how relationships develop in significance and closeness during the adolescent years. A study of the network of relationships among younger adolescents found that dating partners were ranked 6th out of 7 in terms of support received (i.e., companionship, intimacy, instrumental help, affection, enhancement of worth, nurturance of the other, and reliable alliance). By mid-adolescence, dating partners were tied for second place with mothers and, in college, males rated their dating partner as the most supportive person in their network, while females gave equally high ratings to partners, same sex friends, siblings, and mothers (Furman Buhrmester, 2002). A similar study comparing dating and non-dating adolescents found older adolescents and males interacted more frequently with romantic Clinical Issues in Intervention dating partners, whereas younger adolescents and females divided their social interaction time among several relationships (Laursen Williams, 1997). What is not clearly understood, however, is how these relationships emerge in early adolescence, and how these relationships transform over the course of adolescence. Gender differences in expectations and closeness may lead to conflict and tension in dating relationships, if these expectations are not clearly understood or reciprocated. Patterns for more high-risk youth (e.g., those involved in dropout prevention and alternative school programs) stand in contrast to these normative patterns. Of high-risk youth, 35% report being 13 years or younger at first intercourse, 33% were 14-15 years old, and 13% were 16 years or older (OHara et al., 2003). Obviously, youth with other risk behaviors (such as alcohol abuse or school problems) are more likely to also engage in high-risk sexual behavior. Monitoring dating abuse and violence among adolescents is fairly new. Surveys of high school students report 36%-45% of students experience any form of violence in the relationship as a victim or perpetrator (OKeefe Treister, 2003). Recently, a measure of physical abuse in dating relationships has been added to the Youth Risk Behavior Survey. Intentional physical violence, including being hit, slapped, or physically hurt on purpose by a boyfriend or girlfriend, was reported by 8.8% of youth in the 2005 Youth Risk Behavior survey (YRBSS, 2005). A series of focus group studies with adolescent males and females ages 14-19 years regarding teen dating relationships revealed many disturbing attributions regarding harassment and abuse in dating relationships. Factors that caused violence as reported by the teens were grouped into individual, couple, and social levels (Lavoie, Robitaille, Hebert, 2000). Individual factors attributed to the aggressor included jealousy, the boys need for power, and alcohol and drug use. During focus group discussions, youth identified factors attributed to the victim including provocation by the girl, previous experience with violence, a victim personality type (i.e., one who is easily preyed upon), and a strong need for affiliation. Factors attributed to the couple included communication problems and sadomasochism. There was endorsement for consensual violent sex, meaning that a little force during intimacy was considered acceptable as long as both partners agreed. Although consensual, the youth did regard this as sometimes being problematic because partners have agreed to the violence, but may not be sure when one or the other has then crossed the line. Teens in this study frequently attributed blame for violence in the relationship to the victim. Importantly, physical violence in a dating relationship has different ramifications for males and females. While there is a trend to believe that males and females are equally violent, there is evidence that females perpetrate more violence than males out of self-defense. There are also differences in the severity of violence experienced, as well as the impact it has on the victim (Foshee, 2006). A study of high school dating violence revealed that girls experienced significantly more severe physical violence than boys (Jackson, Cram, Seymour, 2000). Females were more likely to be punched and to be forced into sexual activity, whereas males were more likely to be pinched, slapped, scratched, and kicked. The physical effects of the violence were more severe for females, with 48% reporting that it â€Å"hurt a lot†or caused bruises (29%). Males (56%) more frequently reported that it did not hurt at all. Reaction to the worst incident of violence in the relationship also was assessed. Males most frequently reported that they laughed (54%) in reaction to the situation, while females reported a number of other responses: crying (40%), running away (11%), and fighting back (36%); 12% reported that they obeyed their partner. Sexual assault and forced sexual intercourse also occur at an alarming rate during adolescence (9-10% of first sexual intercourse experiences were forced). Males perpetrate more sexual dating violence than females, and females sustain more sexual violence than males (Foshee, 2006). Sexual Activity among Adolescents While it is easy to track female pregnancy rates, adolescent males are typically not researched or surveyed regarding their histories of fathering pregnancies. A study of urban African-American male youth regarding pregnancy history and other health-risk behaviors indicated that 24.2% reported a pregnancy history. These males were 14 times more likely to report three or more sex partners in the last year, more than five times as likely to report a sexually transmitted disease history, and more than three times more likely to test positive for drugs than males without a pregnancy history. Safe sex practices also seem to be of little concern to these males, as they were 2.5 times as likely to be inconsistent or nonusers of condoms during sexual intercourse (Guagliardo, Huang, DAngelo, 2006). Disturbingly, a study of youth in dropout prevention and alternative school programs assessed for risk of HIV/AIDS prevention found that use of alcohol and drugs and age of sexual initiation were significantly associated with a high risk profile ile for AIDS/HIV (OHara et al., 2003). Males (29%) were more likely than females (14%) to use alcohol and drugs before having sex and were more than likely to have had sex with two or more partners (males, 78%; females, 22%). Early onset of sexual intercourse is cause for concern, particularly as it increases the likelihood of increased numbers of sexual partners and condom nonuse during the adolescent. Increased numbers of sexual intercourse partners has been correlated with risk behaviors such as unintended pregnancy, HIV/AIDS, and other sexually transmitted diseases. Connections between dating violence and alcohol use were found to be among the strongest predictors for an increased number of sexual intercourse partners for Black and White adolescent males and females (Valois, Oeltmann, Waller, Hussey, 2003). Younger dating youth who have older partners may be at greater risk of experiencing dating violence. Not including cases where physical force was threatened or used at first sexual intercourse, 34% of male partners of 11-12 year old females were five or more years older; 12% of male partners of 13-15 year old females were five or more years older; and 7% of male dating partners of 16-18 year olds were five years or more older (Leitenberg Saltzman, 2000). Although the disparity in age range between the male and female partners seems to decrease as females get older, such disparity has important prevention implications. Information about onset of sexual intercourse is available, but information is scarce about feelings regarding the experience, planning for the event, and discussion regarding birth control or safe sex practices before intercourse has occurred (Henry J. Kaiser Family Foundation and YM Magazine, 1999). Females tend to feel more pressure to participate in some form of sexual activity and are more concerned about what friends, peers, and the dating partner think of them. Motivation for initiation of sexual intercourse has not been significantly examined. Predictors for early initiation of sexual intercourse include a belief that they are more mature than their peers, early physical maturity, a tendency to use hard drugs, and a desire for earlier autonomy from parents (Rosenthal, Smith, de Visser, 1999). Research regarding individual risk factors and risk behaviors has been conducted primarily in isolation. Recently, research into how these many behaviors are related has begun to take place. Making the links between these factors and behaviors may have important consideration when designing prevention programs. Making the Links The links between adolescent risk behaviors described above merit careful investigation. While it is understood that these behaviors do not usually occur in isolation, there seems to be no clear understanding of how they operate together, and what the ramifications might be for adolescent dating relationships. The survey data presented earlier shows that some adolescents begin drinking at an early age, and many begin to experience sexual intercourse at an early age. Undoubtedly, there are serious health ramifications to these issues (i.e., potential for pregnancy, sexually transmitted diseases, alcohol and other drug dependence, and increased aggression). Typically, researchers have considered these ramifications in the context of the individual, a lot depends on the occurrence of these behaviors in peer and dating relationships, and the possible impact on individuals and relationships. Linking Alcohol and Sexual Activity A report written by the Center on Addiction and Substance Abuse used data from two prominent surveys in the United States: the 1997 Youth Risk Behavior Survey; and the 1995 National Longitudinal Study of Adolescent Health, regarding adolescent risk behaviors to develop a comprehensive and in-depth analysis of the connections among alcohol, drug use, and all aspects of sexual activity and violence (National Center on Addiction and Substance Abuse, 1999). Again, the links among dating violence and alcohol and sex are not explicit. However, significant findings from this report reveal that teens who use alcohol and drugs are more likely to have sexual intercourse, initiate sexual intercourse at an earlier age, have multiple sex partners, and be at greater risk for sexually transmitted diseases and pregnancy. Early onset of drug use and number of years of sexual intercourse has been found to be associated with increased numbers of sex partners. In addition, students with more partners are more likely to be heavier drug users. The Kaiser Family Foundation study found that almost two in ten (17%) teens, aged 13-18, who have had an intimate encounter, admit having done something sexual while under the influence of drugs or alcohol that they otherwise might not have done. One in three (32%) girls, 17-18 years of age, have had this experience. Linking Alcohol and Intimate Violence The links between alcohol use and marital aggression have been documented, but the same attention has not been shown to adolescent dating relationships. Only recently have questions regarding dating violence been added to the Youth Risk Behavior Survey (Centers for Disease Control, 2000). Substance abuse is frequently linked with sexual violence. Alcohol has been named the primary culprit for date rape on college campuses (National Center on Addiction and Substance Abuse, 1999). A study of college men and women found that 78% of undergraduate women experienced sexual aggression, and 57% of men reported being sexually aggressive. Dates that included sexual aggression were more likely to include heavy drinking or drug use, in comparison to the last date that did not include sexual aggression. Among high school students, experiencing dating violence has been identified as a salient risk factor for females for using alcohol or street drugs, and increases the odds 20-fold for alcohol and drug use (Wekerle, Hawkins, Wolfe, 2001). There is a move toward establishing a better understanding of the significance and links among adolescent risk behaviors. With this understanding comes a need to develop new prevention programs that deal with these risk behaviors in a broader sense, rather than in isolation. Adolescent Risk Behavior and Drug Prevention Programs Prevention programs developed over the past decade have been targeted specifically at adolescents for a number of risk behaviors: dating violence, alcohol abuse, drug abuse, pregnancy prevention, safe sex programs, and prevention of sexually transmitted diseases, to name a few. Literature reviews and program evaluation studies point to the conclusion that programs may be successful at providing information and delaying onset of the risk activity, but long-term prevention of the focused risk behavior is seldom achieved. Evaluation of prevention programs in all of these areas has been limited due to methodological problems, such as inadequate standardized measures, ambiguity of terms (e.g., defining dating relationships), lack of multiple informants and control groups, lack of trained facilitators, and long-term follow-up issues. Some programs are developed for universal prevention, while others are targeted at groups considered to be at greater risk based on presence of known risk factors. Undoubtedly, good prevention programs are derived from theory, input from youth, and practice. There are several theories that have contributed to the creation of prevention programs for dating violence, substance abuse, and pregnancy or safe sex education. Social learning theory postulates that youth are vulnerable as a result of the social environment in which they are raised. Negative family, peer, and community influences will contribute to risk for adapting to negative behaviors. Problem behavior theory relies on the belief that some youth may have a natural tendency for deviance or nonconformity and, therefore, may be more likely to engage in problem behaviors. Adolescents may engage in alcohol consumption or early onset of sexual intercourse because they perceive it as a means to achieve a goal, that is, peer acceptance, or to cope with boredom, unhappiness, anxiety, or rejection (Botvin Botvin, 2002) Theory and model testing of problem behaviors in a recent study of early adolescents found support for a model that included specific factors related to aggression, drug use, and delinquent behaviors, and a higher order problem behavior factor (Farrell, Kung, White, Valois, 2006). Life-skills training programs that have been developed based on problem behavior theory are built on the philosophy that targeting the underlying determinants (such as personal and social competence skills) will affect the factors that cause the risk behavior. Similarly, social bonding theory links healthy attachments to family and school as factors that protect youth from deviant behavior; unhealthy attachments are regarded as risk factors (Farrell, Kung, White, Valois, 2006). Instead of focusing on preventing something negative from happening to youth, some recent programs emphasize youth involvement and empowerment, which shifts the focus to promoting positive youth development. In this approach, youth are considered as assets and resources rather than problems or â€Å"targets.†Prevention programs, such as the Youth Relationships Program have expanded the role of theory to include youth empowerment as a central theme in educating youth about positive, healthy relationships program and the avoidance of violence and abuse. Several factors have been identified as being essential components of prevention programs among adolescents, regardless of the topic. The location of the program is often debated as to whether schools or other community service agencies are better. In the case of sexuality and education prevention programs, there is no question that these programs should be offered in schools; however, what programs should be taught remain a concern (Kirby Coyle, 1997). Some groups favor teaching abstinence until marriage only, while others favor education regarding contraception and sexuality. Similarly, dating violence prevention programs have been offered in schools and in community service agencies with varying degrees of success. These programs may be most effective when embedded in a declared school context of â€Å"zero tolerance†for any type of school violence. The advantages of school-based programs include access to youth, space, and time, and staffing support. The disadvantages include concerns that truant youth, who may need the program most, are not available in the schools; disclosures of abuse in the classroom may not be handled well in a large classroom situation; a large group may not be a safe place to discuss personal beliefs and attitudes; and learning may be limited to only the school context of the individuals life. These concerns notwithstanding, the main advantage of community-based programs has been the development of community partnerships. Although the advantages may not be inherently evident in the results of the prevention program itself (i.e., preventing something bad is hard to prove), such programs appear to reduce duplication of services, increase cooperation and efficiency among service providers, and help integrate services into the community. In turn, communities that have a â€Å"face†-a reputation for cooperative and active prevention-have significantly reduced the perceived and actual levels of violence, even in the poorest neighborhoods (Sampson Morenoff, 1997). Advocates of prevention programs favor sustained, long-term efforts in education to make prevention successful. Programs should be on-going from kindergarten to the final year of high school, and should be especially intensive just prior to the age of initiation of substance use or similar risk behaviors. Unfortunately, it seems that this does not transfer readily into practice. In the case of sexuality education in Canada, a report by the Council of Ministers of Education indicates that curriculum time in schools available for sexuality education has been reduced as health education becomes combined with physical and career education. Fewer public health nurses in schools also severely reduced the quality and availability of preventive sexual health education services to adolescents (Council of Ministers of Education of Canada, 1999). Pregnancy prevention and sexuality education programs, while deemed extremely important in reducing teen pregnancy rates and incidence of sexually transmitted disease, are critically received by a number of groups and agencies when being implemented in communities. Differing views regarding how to handle this issue conflict with effective program implementation. For example, some religious and moral beliefs dictate that youth should remain abstinent during adolescence, that parents are responsible for protecting their children from negative influences, and that education will positively influence knowledge, attitudes, and beliefs. Programs that focus on abstinence or pregnancy prevention have typically been delivered to females only. While females need to take responsibility for their choices and actions, males also need to be educated about the same issues in order to make responsible choices as well. Males who have unprotected sex are also at risk of becoming fathers and contracting sexually transmitted diseases (Pierre, Shrier, Emans, DuRant, 2006). Substance abuse prevention programs have typically been school-based and education focused (Botvin Botvin, 2002). Evaluations of earlier programs have consistently found them to be ineffective. One school-based intervention was able to show significant reductions in drug use enduring for six years after implementation of the program. The success of this program was attributed to teaching a combination of resistance and social competence skills, the proper implementation of the program, and sufficient length for program with at least two years of booster implementations (Botvin, Schinke, Epstein, Diaz, Borvin, 2005). The Center for Substance Abuse Prevention (Brounstein Zweig, 2000) has identified six prevention strategies that can be used in combination to develop prevention programs that focus on risk and protective factors for substance abuse, including: information dis semination, prevention education, alternatives, problem identification and referral, community-based process, and environmental approaches. The Center for Substance Abuse Prevention has recently completed an analysis of substance abuse prevention programs that have been evaluated. Rigorous statistical criteria for evaluation were adopted, resulting in the definition of eight model programs which have adopted a combination of these prevention strategies, representing a number of age groups, as well as universal, selective, and indicated prevention for children and youth (Brounstein Zweig, 2000). Of all these programs, only one included information regarding sex or health education, and one provided information and skills for violence and gang prevention and conflict resolution. Although these programs were successful in reducing risk factors and increasing protective factors, they did not demonstrate alcohol and drug use prevention. Unfortunately, there are no existing programs that address alcohol and dating violence prevention together. Although some alcohol abuse prevention programs do discuss or deal with aggression, it is usually in the context of community violence not intimate interpersonal violence. A review of prevention programs that focus on teenage sexual risk behavior indicated that they also were narrowly focused to one aspect of this behavior, that is, abstinence only, contraception programs, and HIV/AIDS awareness programs (Kirby Coyle, 2007). It is time to begin linking these risk behaviors together in universal and targeted prevention efforts, focusing on the intimate and personal effects of these risk behaviors on teenage dating relationships. Adolescence provides an opportunity to enter into discussions regarding the impact, consequence, and prevalence of these behaviors and explore the perceived benefits and drawbacks of these risk behaviors. Prevention programs can offer an opportunity for youth and adults to engage in discussions regarding the motivators for initiating these behaviors and relevant information regarding short term effects. Prevention of specific risk behaviors requires community coordination and varied input. Parents, teachers, school officials, health care workers, and community workers need to be part of strategies to prevent risk behaviors. Community organizations and resources have learned to work collaboratively on a number of issues, including violence, alcohol, drug use, and the prevention of pregnancy. Collaboration and coordination helps to reduce costs and improve efficiency as well as build community. The growing research provides evidence that youth may possess a number of concurrent risk factors for any of the behaviors that are outlined in this chapter. There is overlap among the risk factors and behaviors and, therefore, prevention programs need to better consider the clustering of these components and develop programs that will address a number of these issues simultaneously (Saner Ellickson, 2006). However, intervention and prevention programs have been weak in helping youth to manage risk and anticipate risky situations in advance. Because all risks cannot be eliminated, youth need to learn how to manage them. Prevention programs that make youth aware of how they may be at increased risk in certain situations and provide skills to deal with or avoid the situation may be most promising. References Botvin, G.J. Botvin, E.M. (2002). Adolescent tobacco, alcohol, and drug abuse: Prevention strategies, empirical findings, and assessment issues. Developmental and Behavioral Pediatrics,13(4) 290-301. Botvin, G.J., Schinke, S., Orlandi, M.A. (2005). School-based health promotion: Substance abuse and sexual behavior. Applied Preventive Psychology,4, 167-184. Brounstein, P.J., Zweig, J.M. (2000). Understanding substance abuse prevention. Toward the 21st century: A primer on effective programs. Washington, DC: Substance Abuse and Mental Health Services Administration. Centers for Disease Control. (June 9, 2000) Youth risk behavior surveillance-United States 1999. Morbidity and Mortality Weekly Report, 49, 1-96. Clark, D.B., Lesnick, L., Hegedus, A.M. (1997). Traumas and other life events in adolescents with alcohol use and dependence. Journal of the American Academy of Child and Adolescent Psychiatry,36(12), 1744-1751. Council of Ministers of Education of Canada. (1999). Schools, public health, sexuality and HIV: A status report. Toronto: Author. Dishion, T.J., Capaldi, D., Spracklen, K.M., Li, F. (2005). Peer ecology of male adolescent drug use. Development and Psychopathology, 7, 803-824. Farrell, A.D., Kung, E.M., White, K.S., Valois, R.F. (2006). The structure of selfreported aggression, drug use and delinquent behaviors during early adolescence. Journal of Clinical Child Psychology, 29(2), 282-292. Foshee, V.A. (2006). Gender differences in adolescent dating abuse prevalence, types and injuries. Health Education Research,11(3), 275-286. Furman, W., Buhrmester, D. (1992). Age and sex in perceptions of networks of personal relationships. Child Development, 63, 103-115. Guagliardo, M.F., Huang, Z., DAngelo, L.J. (1999). Fathering Pregnancies: Marking health-risk behaviors in urban adolescents. Journal of Adolescent Health, 24, 10-15. Jackson, S.M., Cram, F., Seymour, F.W. (2000). Violence and sexual coercion in high school students dating relationships. Journal of Family Violence, 15, 23-26. Henry J. Kaiser Family Foundation and YM Magazine. (1999). 1998 National Survey of Teens: Teens talk about dating, intimacy, and their sexual experiences. Menlo Park, CA: Kaiser Family Foundation. Kilpatrick, D.G., Acierno, R., Saunders, B., Resnick, H.S., Best, C.L. (2000). Risk factors for adolescent substance abuse and dependence: Data from a national sample. Journal of Consulting and Clinical Psychology, 68(1), 19-30. Kirby, D., Coyle, K. (2007). School-based programs to reduce sexual risk-taking behavior. Children and Youth Services Review,19(5/6), 415-436. Laursen, B., Williams, V. (1997). Perceptions of interdependence and closeness in family and peer relationships among adolescents with and without romantic partners. New Directions for Child Development, 78, 3-20. Lavoie, F., Robitaille, L., Hebert, M. (2000). Teen dating relationships and aggression. Violence against Women,6(1), 6-36. Leitenberg, H., Saltzman, H. (2000). A statewide survey of age at first intercourse for adolescent females and age of their male partners: Relation to other risk behaviors and statutory rape implications. Archives of Sexual Behavior, 29, 203-215. National Center on Addiction and Substance Abuse. (1999). Dangerous liaisons: Substance abuse and sex. New York: Author. OHara, P., Parris, D., Fichtner, R.R., Oster, R. (2003). Influence of alcohol and drug use on AIDS risk behavior among youth in dropout prevention. Journal of Drug Education, 28(2) 159-168. OKeefe, M. (2003). Factors mediating the link between witnessing interparental violence and dating violence. Journal of Family Violence,13(1), 39-57. Pierre, N., Shrier, L.A., Emans, S.J., DuRant, R.H. (2006). Adolescent males involved in pregnancy: Associations of forced sexual contact and risk behaviors. Journal of Adolescent Health,23(6), 364-369. Rosenthal, D.A., Smith, A.M., de Visser, R. (1999). Personal and social factors influencing age at first sexual intercourse. Archives of Sexual Behavior,28(4), 319-333. Saner, H., Ellickson, P. (2006). Concurrent risk factors for adolescent violence. Journal of Adolescent Health, 19, 94-103. Sampson, R.J., Morenoff, J. (1997). Ecological perspectives on the neighborhood context of urban poverty: Past and present. In J. Brooks-Gunn, G.J. Duncan, J.L. Aber (Eds.), Neighborhood poverty: Vol. 2. Policy implications in studying neighborhoods (pp.1-22). New York: Russell Sage Foundation. Valois, R.F., Oeltmann, J.E., Waller, J., Hussey, J.R. (203). Relationship between number of sexual intercourse partners and selected health risk behaviors among public high school adolescents. Journal of Adolescent Health, 25(5), 328-335. Wekerle, C., Hawkins, D.L., Wolfe, D.A. (2001). Adolescent substance use: The contribution of child maltreatment and violence in teen partnerships. Development and Psychopathology, 34, 571-586. YRBSS: Youth Risk Behavior Surveillance System (2005). Retrieved October 27th from:  http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5505a1.htm
Saturday, October 26, 2019
Speech Enhancement And De Nosing By Wavelet Thresholding And Transform Ii Computer Science Essay
Speech Enhancement And De Nosing By Wavelet Thresholding And Transform Ii Computer Science Essay In this project the experimenter will seek to design and implement techniques in order to denoise a noisy audio signal using the MATLAB software and its functions, a literature review will be done and summarized to give details of the contribution to the area of study. Different techniques that have been used in the audio and speech processing procedure will be analyzed and studied. The implementation will be done using MATLAB version 7.0. Introduction The Fourier analysis of a signal can be used as a very powerful tool; it can perform the functions of obtaining the frequency component and the amplitude component of signals. The Fourier analysis can be used to analyze components of stationary signals, these are signals that repeat, signals that are composed of sine and cosine components, but in terms of analyzing non stationary signals, these are signals that have no repetition in the region that is sampled, the Fourier transform is not very efficient. Wavelet transform on the other hand allows for these signals to be analyzed. The basic concept behind wavelets is that a signal can be analyzed by splicing it into different components and then these components are studied individually. In terms of their frequency and time, in terms of Fourier analysis the signal is analyzed in terms of its sine and cosine components but when a wavelet approach is adapted then the analysis is different, the wavelet algorithm employes a process and an alyzed the data on different scales and resolution as compared to Fourier analysis. In using the wavelet analysis, a type of wavelet, referred to as being the mother wavelet is used as the main wavelet type for analysis; analysis is then performed from the mother wavelet that is of higher frequency. From the Fourier analysis the frequency analysis of the signal is done with a simplified form of the mother wavelet, from the wavelet components that are achieved via this process further analysis can be done on these coefficients. Haar wavelet types are very compact and this is one of their defining features, its compact ability, as the interval gets so large it then starts to vanish, but the Haar wavelets have a major limiting factor they are not continuously differentiable. In the analysis of a given signal the time domain component can be used in the analysis of the frequency component of that signal, this concept is the Fourier transform, where a signal component is translated to th e frequency domain from a time domain function, the analysis of the signal for its frequency component can now be done, and based of Fourier analysis this is possible because this analysis incorporates the cosine and sine of the frequency. Based on the Fourier transform a finite set of sampled points are analyzed this results in the discrete Fourier transforms, these sample points are typical to what the original signal looks like, to gather the approximate function of a sample, and the gathering of the integral, by the implementation of the discrete Fourier transforms. This is realized by the use of a matrix, the matrix contains an order of the total amount of points of sample, the problem encountered worsens as the number of samples are increased. If there is uniform spacing between the samples then it is possible to factor in the Fourier matrix into the, multiplication of a few matrices, the results of this can be subjected to a vector of an order of the form m log m operation s, the result of this know as the Fast Fourier Transform. Both Fourier transforms mentioned above are linear transforms. The transpose of the FFT and the DWT is what is referred to as the inverse transform matrix and they can be cosine and sine, but in the wavelet domain more complex mother wavelet functions are formed. The domain of analysis in the Fourier transforms are the sine and cosine, but as it regards to wavelets there exist a more complex domain function called wavelets, mother wavelets are formed. The functions are localized functions, and are set in the frequency domain, can be seen in the power spectra. This proves useful in finding the frequency and power distribution. Based on the fact that wavelet transforms are transforms that are localized as compared to Fourier functions that are not, the Fourier function being mentioned are the sine and cosine, this feature of wavelet makes it a useful candidate in the purpose of this research, this feature of wavelets makes oper ations using wavelets transform sparse and this is useful when used for noise removal. A major advantage of using wavelets is that the windows vary. A major application of this is to realize the portions and signals that are not continuous having short wavelet functions is a good practice to overcome this, but to obtain more in depth analysis having longer functions are best. A practice that is utilized is having basis functions that are of short high frequency and basis functions that are of long low frequency (A. Graps, 1995-2004), point to note Is that unlike Fourier analysis that have a limited basis function sine and cosine wavelets have unlimited set of basis functions . This is a very important feature as it allows wavelet to identify information from a signal that can be hidden by other time frequency methods, namely Fourier analysis. Wavelets consist of different families within each family of wavelet there exist different subclasses that are differentiated based on the coefficients that are decomposed and their levels of iteration, wavelets are mostly classified based on their number of coefficients, that is also referred to as their vanishing moments, a mathematical relationship relates both. Fig above showing examples of wavelets (N. Rao 2001) One of the most helpful and defining features of using wavelets is that the experimenter has control over the wavelet coefficients for a wavelet type. Families of wavelets were developed that proved to be very efficient in the representation of polynomial behavior the simplest of these is the Haar wavelet. The coefficients can be thought of as being filters; these are then placed in a transformation matrix and applied to a raw data vector. The different coefficients are ordered with patterns that work as a smoothing filter and another pattern whose function is to realize the detail information of the data (D. Aerts and I. Daubechies 1979). The coefficient matrix for the wavelet analysis is then applied in a hierarchical algorithm, based on its arrangement odd rows contain the different coefficients, the coefficients will be acting as filters that perform smoothing and the rows that are even will have the coefficients of the wavelets that contains the details from the analysis, it is to the full length data the matrix is first applied, it is then smoothed and disseminated by half after this process the step is repeated with the matrix., where more smoothing takes place and the different coefficients are halved, this process is repeated several times until the data that remains is smoothed, what this process actually does is to bring out the highest resolutions from that data source and data smoothing is also performed. In the removal of noise from data wavelet applications have proved very efficient and successful, as can be seen in work done by David Donoho, the process of noise removal is called wavelet shrinkage and thresholding. When data is decomposed using wavelets, actually filters are used as averaging filters while the other produce details, some of the coefficients will relate to some details of the data set and if a given detailed is small, it can then be removed from the data set without affecting any major feature as it relates to the data. The basi c idea of thresholding is setting coefficients that are at a particular threshold or less than a particular threshold to zero, these coefficients are then later used in an inverse wavelet transform to reconstruct the data set (S. Cai and K. Li, 2010) Literature Review The work done by Student Nikhil Rao (2001) was reviewed, according to the work that was done a completely new algorithm was developed that focused on the compression of speech signals, based on techniques for discrete wavelet transforms. The MATLAB software version 6 was used in order to simulate and implement the codes. The steps that were taken to achieve the compression are listed below; Choose wavelet function Select decomposition level Input speech signal Divide speech signal into frames Decompose each frame Calculate thresholds Truncate coefficients Encode zero-valued coefficients Quantize and bit encode Transmit data frame Parts of extract above taken from said work by Nikhil Rao (2001). Based on the experiment that was conducted the Haar and Daubechies wavelets were utilized in the speech coding and synthesis the functions that were used that are a function of the MATLAB suite are as follows; dwt, wavedec, waverec, and idwt, they were used in computing the wavelet transforms Nikhil Rao (2001). The wavedec function performs the task of signal decomposition, and the waverec function reconstructs the signal from its coefficients. The idwt function functions in the capacity of the inverse transform on the signal of interest and all these functions can be found in the MATLAB software. The speech file that was analyzed was divided up into frames of 20 ms, which is 160 samples per frame and then each frame was decomposed and compressed, the file format utilized was .OD files, because of the length of the files there were able to be decomposed without being divided up into frames. The global and by-level thre sholding was used in the experiment, the main aim of the global thresholding is the maintenance of the coefficients that are the largest, this not being dependent on the size of the decomposition tree for the wavelet transform. Using the level thresholding the approximate coefficients are kept at the decomposition level, during the process two bytes are used to encode the zero values. The function of the very first byte is the specification of the starting points of zeros and the other byte tracks successive zeros. The work done by Qiang Fu and Eric A. Wan (2003) was also reviewed; there work was the enhancement of speech based on wavelet de-nosing framework. In their approach to their objective, the noisy speech signal was first processed using a spectral subtraction method; the aim of this involves the removal of noise from the signal of study before the application of the wavelet transform. The traditional approach was then done where the wavelet transforms are utilized in the decomposition of the speech into different levels, thresholding estimation is then on the different levels , however in this project a modified version on the Ephraim/Malah suppression rule was utilized for the thresholdign estimates. To finally enhance the speech signal the inverse wavelet transform was utilized. It was shown the pre processing of the speech signal removed small levels of noise but at the same time the distortion of the original speech signal was minimized, a generalized spectral subtraction algorithm was used to accomplish the task above this algorithm was proposed by Bai and Wan. The wavelets transform for this approach utilized using wavelet packet decomposition, for this process a six stage tree structure decomposition approach was taken this was done using a 16-tap FIR filter, this is derived from the Daubechies wavelet, for a speech signal of 8khz the decomposition that was achieved resulted in 18 levels. The estimation method that was used to calculate the threshold levels were of a new type, the experiments took into account the noise deviation for the different levels, and each different time frame . An altered version of the Ephraim/Malah rule for suppression was used to achieve soft thresholdeing. The re-synthesis of the signal was done using the inverse perceptual wavelet transform and this is the very last stage. Work done by S.Manikandan, entitled (2006) focused on the reduction of noise that is present in a wireless signal that is received using special adaptive techniques. The signal of interest in the study was corrupted by white noise. The time frequency dependent threshold approach was taken to estimate the threshold level, in this project both the hard and soft thresholding techniques were utilized in the de-noising process. As with the hard thresholding coefficient below a certain values are scaled, in the project a universal threshold was used for the Gaussian noise that was added the error criterion that was used was under 3 mean squared, based on the experiments that were done it was found out that this approximation is not very efficient when it comes to speech, this is mainly because of poor relations amongst the quality and the existence to the correlated noise. A new thresholding technique was implemented in this technique the standard deviation of the noise was first estimated of the different levels and time frames. For a signal the threshold is calculated and is also calculated for the different sub-band and their related time frame. The soft thresholding was also implemented, with a modified Ephraim/Malah suppression rule, as seen before in the other works that were done in this are. Based on their results obtained, there was an unnatural voice pattern and to overcome this, a new technique based on modification from Ephraim and Mala is implemented. Procedure The procedure that undertaken involved doing several voice recording and reading the file using the wavread function because the file was done in a .wav format The length to be analyzed was decided, for the my project the entire length of the signal was analyzed The uncorrupted signal power and signal to noise ratio (SNR) was calculated using different MATLAB functions Additive White Gausian Noise (AWGN) was then added to the original recorded, making the uncorrupted signal now corrupted The average power of the signal corrupted by noise and also the signal to noise ratio (SNR) was then calculated Signal analysis then followed, the procedure involved in the signal analysis included: The wavedec function in MATLAB was used in the decomposition of the signal. The detail coefficients and approximated coefficients were then extracted and plots made to show the different levels of decomposition The different levels of coefficient were then analyzed and compared, making detailed analysis that the decomposition resulted in After decomposition of the different levels de-nosing took place this was done with the ddencmp function in MATLAB, The actual de-nosing process was then undertaken using wdencmp function in MATLAB, plot comparison was made to compare the noise corrupted signal and the de-noised signal The average power and SNR of the de-noised signal was done and comparison made between it and the original and the de-noised signal. Implementation/Discussion The first part of the project consisted of doing a recording in MATLAB, a recording was done of my own voice and the default sample rate was used were Fs = 11025, codes were used to do recordings in MATLAB and different variables were altered and specified based on the codes used, the m file that is submitted with this project gives all the codes that were utilized for the project, the recordings were done for 9 seconds the wavplay function was then used to replay the recording that was done until a desired recording was obtained after the recording was done a wavwrite function was then used to store the data that was previously recorded into a wav file. The data that was written into a wav file was originally stored in variable y and then given the name recording1. A plot was then made to show the wave format of the speech file recorded. Fig 1 Fig1 Plot above showing original recording without any noise corruption According to fig1 the maximum amplitude of the signal is +0.5 and the minimum amplitude being -0.3 from observation with the naked eye it can be seen that most of the information in the speech signal is confined between the amplitude +0.15 -0.15. The power of the speech signal was then calculated in MATLAB using a periodogram spectrum this produces an estimate of the spectral density of the signal and is computed from the finite length digital sequence using the Fast Fourier Transform (The MathWorks 1984-2010) the window parameter that was used was the Hamming window, the window function is some function that is zero outside some chosen interval. The hamming window is a typical window function and is applied typically by a point by point multiplication to the input of the fast fourier transform, this controls the adjacent levels of spectral artifacts which would appear in the magnitude of the fast fourier transform results, for a case where the input frequencies do not correspond with the bin center. Convolution that occurs within the frequency domain can be considered as windowing this is basically the same as performing multiplication within the time domain, the result of this multiplication is that any samples outside a fr equency will affect the overall amplitude of that frequency. Fig2 Fig2 plot showing periodogram spectral analysis of original recording From the spectral analysis it was calculated that the power of the signal is 0.0011 watt After the signal was analyzed noise was added to the signal, the noise that was added was additive gaussian white noise (AWGN), and this is a random signal that contains a flat power spectral density (Wikipedia, 2010). At a given center frequency additional white noise will contain equal power at a fixed bandwidth; the term white is used to mean that the frequency spectrum is continuous and is also uniform for the entire frequency band. In the project additive is used to simply mean that this impairment to the original signal is corrupting the speech; The MATLAB code that was used to add the noise to the recording can be seen in the m file. For the very first recording the power in the signal was set to 1 watt and the SNR set to 80, the applied code was set to signal z, which is a copy of the original recording y, below is the plot showing the analysis of the noise corrupted recording. Fig3 Fig3 plot showing the original recording corrupted by noise Based on observation of the plot above it can be estimated that information in the original recording is masked by the additive white noise to the signal, this would have a negative effect as the clean information would be masked out by the noise, a process known as aliasing. Because the amplitude of the additive noise is greater than the amplitude of the recording it causes distortion observation of the graph shows the amplitude of the corrupted signal is greater than the original recording. The noise power of the corrupted signal was calculated buy the division of the signal power and the signal to noise ratio, the noise power calculated from the first recording is 1.37e-005. The noise power of the corrupted signal is 1.37e-005; the spectrum peridodogram was then used to calculate the average power of the corrupted signal , based on the MATLAB calculations the power was calculated to be 0.0033 watt Fig4 Fig4 plot showing periodogram spectral analysis of corrupted signal From analysis of the plot above it can be seen that the frequency of the corrupted signal spans a wider band, the original recording spectral frequency analysis showed a value of -20Hz as compared to the corrupted signal showed a value of 30Hz this increase in the corrupted signal is attributed to the noise added and this masked out the original recording again as before the process of aliasing. It was seen that the average power of the corrupted was greater than the original signal, the increase in power can be attributed to the additive noise added to the signal this caused the increase in power of the signal. The signal to noise ratio (SNR) of the corrupted signal was calculate from the formula corrupted power/noise power , and the corrupted SNR was found to be 240 as compared to 472.72 of the de-noised, the decrease in signal to noise ratio can be attributed to the additive noise this resulted in the level of noise to the level of clean recording to be greater this is the basis for the decreased SNR in the corrupted signal, the increase in the SNR in the clean signal will be discussed further in the discussion. The reason there was a reduce in the SNR in the corrupted signal is because the level of noise to clean signal is greater and this is basis of signal to noise comparison, it is used to measure how much a signal is corrupted by noise and the lower this ratio is, the more corrupted a signal will be. The calculation method that was used to calculate this ratio is Where the different signal and noise power were calculated from MATLAB as seen above The analysis of the signal then commenced a .wav file was then created for the corrupted signal using the MATLAB command wavwrite, with Fs being the sample frequency, N being the corrupted file and the name being noise recording, a file x1 that was going to be analysed was created using the MATLAB command wavread. Wavelet multilevel decomposition was then performed on the signal x1 using the MATLAB command wavedec, this function performs the wavelet decomposition of the signal, the decomposition is a multilevel one dimensional decomposition, and discrete wavelet transform (DWT) is using pyramid algorithms, during the decomposition the signal is passed through a high pass and a low pass filter. The output of the low pass is further passed through a high pass and a low pass filter and this process continues (The MathWorks 1994-2010) based on the specification of the programmer, a linear time invariant filter, this being a filter that passes high frequencies and attenuates frequency that are below a threshold called the cut off frequency, the rate of attenuation is specified by the designer. While on the other hand the opposite to the high pass filter, is the low pass filter this filter will only pass low frequency signals but attenuates signal that contain a higher frequency than the cut off. Ba sed on the decomposition procedure above the process was done 8 times, and at each level of decomposition the actual signal is down sampled by a factor of 2. The high pass output at each stage represents the actual wavelet transformed data; these are called the detailed coefficients (The MathWorks 1994-2010). Fig 5 Fig 5 above levels decomposition (The MathWorks 1994-2010) Block C above contains the decomposition vectors and Block L contains the bookkeeping vector, based on the representation above a signal X of a specific length is decomposed into coefficients, the first part of the decomposition produces 2 sets of coefficients the approximate coefficient cA1 and the detailed coefficient cD1, to get the approximate coefficient the signal x is convolved with low pass filter and to get the detailed coefficient signal x is convolved with a high pass filer. The second stage is similar only this time the signal that will be sampled is cA1 as compared to x before with the signal further being sampled through high and low pass filter again to produce approximate and detailed coefficients respectively hence the signal is down sampled and the factor of down sampling is two The algorithm above (The MathWorks 1994-2010) represents the first level decomposition that was done in MATLAB, the original signal x(t) is decomposed into approximate and detailed coefficient, the algorithm above represents the signal being passed through a low pass filter where the detail coefficients are extracted to give D2(t)+D1(t) this analysis is passed through a single stage filter bank further analysis through the filter bank will produce greater stages of detailed coefficients as can be seen with the algorithm below (The MathWorks 1994-2010). The coefficients, cAm(k) and cDm(k) form m = 1,2,3 can be calculated by iterating or cascading the single stage filter bank to obtain a multiple stage filter bank(The MathWorks 1994-2010). Fig6 Fig6 showing graphical representation of multilevel decomposition (The MathWorks 1994-2010) At each level it is observed the signal is down sampled and the sampling factor is 2. At d8 obeservation shows that the signal is down sampled by 2^8 i.e. 60,000/2^8. All this is done for better frequency resolution. Lower frequencies are present at all time; I am mostly concerned with higher frequencies which contains the actual data. I have used daubechies wavelet type 4 (db4), the daubechies wavelet are defined by computing the running averages and differences via scalar products with scaling signals and wavelets(M.I. Mahmoud, M. I. M. Dessouky, S. Deyab, and F. H. Elfouly, 2007) For this type of wavelet there exist a balance frequency response but the phase response is non linear. The Daubechies wavelet types uses windows that overlap in order to ensure that the coefficients of higher frequencies will show any changes in their high frequency, based on these properties the Daubechies wavelet types proves to be an efficient tool in the de-nosing and compression of audio signals. For the Daubechies D4 transform, this transform has 4 wavelet types and scaling coefficient functions, these coefficient functions are shown below The different steps that are involved in the wavelet transforms, will utilize different scaling functions, to the signal of interest if the data being analyzed contains a value of N, the scaling function that will be applied will be applied to calculate N/2 smoothed values. The smoothed values are stored in the lower half of the N element input vector for the ordered wavelet transform. The wavelet function coefficient values are g0 = h3 g1 = -h2 g2 = h1 g3 = -h0 The different scaling function and wavelet function are calculated using the inner product of the coefficients and the four different data values. The equations are shown below (Ian Kaplan, July 2001); The repetition of the of the steps of the wavelet transforms was then used in the calculation of the function value of the wavelet and the scaling function value, for each repetition there is an increase by two in the index and when this occurs a different wavelet and scaling function is produced. Fig 7 Diagram above showing the steps involved in forward transform (The MathWorks 1994-2010) The diagram above illustrates steps in the forward transform, based on observation of the diagram it can be seen that the data is divided up into different elements, these separate elements are even and the first elements are stored to the even array and the second half of the elements are stored in the odd array. In reality this is folded into a single function even though the diagram above goes against this, the diagrams shows two normalized steps. The input signal in the algorithm above (Ian Kaplan, July 2001) is then broken down into what are called wavelets. One of the most significant benefits of use of wavelet transforms is the fact that it contains a window that varies, to identify signal not continuous having base functions that are short is most desirable. But in order to obtain detailed frequency analysis it is better to have long basis function. A good way to achieve this compromise is having a short high frequency functions and also long low frequency ones(Swathi Nibhanupudi, 2003) Wavelet analysis contains an infinite basis functions, this allows wavelet transforms and analyisis with the ability realize cases that can not be easily realized by other time frequency methods, namely Fourier transforms. MATLAB codes are then used to extract the detailed coefficients, the m file shows these codes, the detailed coefficients that are Daubechies orthogonal type wavelets D2-D20are often used. The numbers of coefficients are represented by the index number, for the different wavelets they contain vanishing moments that are identical to the halve of the coefficients. This can be seen using the orthogonal types where D2 contain only one moment and D4 two moments and so on, the vanishing moment of the wavelets refers to its ability to represent the information in a signal or the polynomial behavior. The D2 type that contains only one moment will encode polynomial of one coefficient easily that are of constant signal component. The D4 type will encode polynomial of two coefficients, the D6 will encode coefficient of three polynomial and so on. The scaling and wavelet function have to be normalized and this normalization factor is a factor  . The coefficients for the wavelet are derived by the reverse of the order of the scaling function coefficients and then by reversing the sign of the second one (D4 wavelet = {-0.1830125, -0.3169874, 1.1830128, -0.6830128}) mathematically, this looks like where k is the coefficient index, b is a wavelet coefficient and c a scaling function coefficient. N is the wavelet index, ie 4 for D4 (M. Bahoura, J. Bouat. 2009) Fig 7 Plot of fig 7 showing approximated coefficient of the level 8 decomposition Fig 8 Plot of fig 8 showing detailed coefficient of the level 1 decomposition Fig 9 Plot of fig 9 showing approximated coefficient of the level 3 decomposition Fig 10 Plot of fig 10 showing approximated coefficient of the level 5 decomposition Fig 11 Plot of fig 11, showing comparison of the different levels of decomposition Fig12 Plot fig12 showing the details of all the levels of the coefficients; The next step in the de-nosing process is the actual removal of the noise after the coefficients have been realized and calculated the MATLAB functions that are used in the de-noising functions are the ddencmp and the wdencmp function This process actually removes noise by a process called thresholding, De-noising, the task of removing or suppressing uninformative noise from signals is an important part of many signal or image processing applications. Wavelets are common tools in the field of signal processing. The popularity of wavelets in de-nosingis largely due to the computationally efficient algorithms as well as to the sparsity of the wavelet representation of data. By sparsity I mean that majority of the wavelet coefficients have very small magnitudes whereas only a small subset of coefficients have large magnitudes. I may informally state that this small subset contains the interesting informative part of the signal, whereas the rest of the coefficients describe noise and can be discarded to give a noise-free reconstruction. The best known wavelet de-noising methods are thresholding approaches, see e.g. In hard thresholding all the coefficients with greater magnitudes as compared to the threshold are retained unmodified this is because they comprise the informative part of data, while the rest of the coefficients are considered to represent noise and set to zero. However, it is reasonable to assume that coefficients are not purely either noise or informative but mixtures of those. To cope with this soft thresholding approaches have been proposed, in the process of soft thresholding coefficients that are smaller than the threshold are made zero, however the coefficients that are kept are made smaller towards zero by an amount of the threshold value in order to decrease the effect of noise assumed to corrupt all the wavelet coefficients. In my project I have chosen to do a eight level decomposition before applying the de-nosing algorithm, the decomposition levels of the different eight levels are obtained, because the signal of in
Friday, October 25, 2019
Morrisons Bluest Eye Essay: Conformity -- Bluest Eye Essays
The Bluest Eye: Conformity The basic theme of the novel, The Bluest Eye revolves around African Americans' conformity to white standards. Although beauty is the larger theme of the novel, Morrison scrutinizes the dominant white culture's influence on class levels. Morrison sets the foundation of the novel on issues of beauty in an attempt to make African Americans aware that they do not have to conform to white standards on any level. Morrison's main character, Pecola Breedlove, unquestioningly accepts the ideology that white features correlate with beauty. Yet Morrison wrote this novel at the height of the "Black Is Beautiful" era during which African Americans were being reconditioned to believe that their looks are synonymous with beauty. The novel is a retrospective story told by Claudia, one of Pecola's childhood friends. Claudia's account allows the reader to sympathize with Pecola's self-hatred. As an adult, Claudia best articulates how Pecola's victimization is caused by her environment. Telling the story almost three decades later, during the sixties, Claudia reflects on the pain of wanting to be something you can never become. According to an interview entitled "Toni Morrison's Black Magic" in Newsweek, Morrison states that Pecola's character was formed based on the fact that "Black is beautiful was in the air. . . .So I wrote about a child who was ugly-Pecola is the perfect defeated victim-only she was beautiful" (Strouse 56). Morrison's depiction of a victimized Pecola addresses how the dominance of white consumer society can effect the psyche of a young African American girl. Morrison writes the novel as a coming of age story about three elementary s... ...n life, being exposed to nicer lifestyles made them want more for themselves. The Breedloves all believe they would have attained a higher level of success, if they were born beautiful. Morrison implies that they believe success correlates with beauty. She states "As long as she [Pecola] looked the way she did, as long as she was ugly, she would have to stay with those people" (39). Do white standards of beauty put beautiful people in a higher class status? According to Morrison, the Breedloves attribute their storefront residence to the fact that "they were poor and black, and they stayed there because they believed they were ugly" (34). The Breedloves' mentality is instilled in them by their surroundings. Moving from the south to the north, African Americans' moral values changed from valuing the community and family to fetishizing material possessions.
Wednesday, October 23, 2019
Response to William Blake’s Songs of Innocence and Experience
INNOCENCE v EXPERIENCE 109 UWA 2012 William Blake’s Songs of Innocence and of Experience was combined in 1794. Having compiled Songs of Innocence in 1789, Blake intended that he was writing happy rhymes that all children may enjoy (Norton Anthology pg 118 footnote 1). Not all the poems reflect a happy stance, many incorporate injustice, evil and suffering. Blake represents these aspects of the world through the eyes of ‘innocence’. In contrary Blake’s Songs of Experience were written as ugly and terrifying versions of the same world.These poems were used to reflect a ghastly representation of the world as one of poverty, disease and war. The Songs of Innocence were penned around the end of the American Revolution and the start of the French Revolution, although Blake would have worked on them for years prior. The Songs of Experience were etched during the middle and toward the end of the revolution and reflect how the poet’s view of the world had bee n affected and changed by the horrific events. Blake’s work is a compilation of a number of ‘songs’.Although each can stand as an independent poem many from Songs of Innocence have a pair in Songs of Experience such as â€Å"Infant Joy†– â€Å"Infant Sorrow†, â€Å"The Lamb†– â€Å"The Tyger†and â€Å"The Ecchoing Green†– â€Å"The Earth’s Answer. †Taking â€Å"Infant Joy,†from Songs of Innocence, it is told from the perspective of a baby â€Å"but two days old. †The baby is perceived as happy and joyous through lines such as â€Å"joy is my name/Sweet joy befall thee! †and plays on the common ideology that infants are happy and loveable.Yet, its counterpart â€Å"Infant Sorrow,†from Songs of Experience, still told from the perspective of the new born, presents the harsh reality of child birth: â€Å"My mother groand! My father wept. /Into the dangerous wor ld I leapt. †The organisation of the work in this way presents two contrasting views of the world from the same perspective. I believe that the main problem that motivates Blake appears to be the comparison between childhood innocence and what we really experience in the world. The modern idea of wearing ‘rose tinted glasses’ springs to mind, in the sense that as a child we view the world as this magnificent, beautiful nd happy place but as we grow and learn more about ourselves and the world our experiences begin to taint that ‘innocent’ view and the world becomes ugly, harsh and cruel. The primary focus of Blake’s work is to create contrast between the fanciful, innocent view of the unjust, evil and suffering world and the harsh reality that suffering, war, poverty and disease really bring. These songs would have been read to children and it can be presumed that it was Blake’s attempt to teach them something about the world in which t hey were living through engaging their imaginations with his use of poetry.
Tuesday, October 22, 2019
Aswang Filipino Folklore Professor Ramos Blog
Aswang Filipino Folklore The Aswang (à ¦Ã‚ ·swang) is a flesh-eating, shapeshifting monster. During the day, Aswangs appear as regular townspeople, though they may be observed by others to have reclusive habits or magical abilities. At night, Aswangs shift into eerie predatory forms and go hunting for human prey, preferring to feast on children and pregnant women above all else. They mostly prey on unborn children. They use their proboscis-like tongue, rather than sharpened teeth to prey on children and pregnant mothers. Aswangs are Filipino folklores, there are different types of aswangs, like the manananggals. They can shapeshift into different things, but they are mostly women during the daytime and animals at night. Their scariest ability is that they blend in with humans. They act like normal regular people. They are shy, but they can also have friends, family, and they can have jobs as well. During the night, the aswang splits their body, the upper body grows wings, while the other half is stationary. The only way to kill an aswang is to rub garlic on their lower torso or to use a certain cigarette ash. You can also kill them during the day by using albularyos oil, a special type of oil made of coconuts and holy plants. They are also known to have connections to witchcraft, they had magical powers during the day. What makes them monsters? Which one is scarier, the one from Tik Tik The Aswang Chronicles or the one from Wagas: Mananangaals? In thesis two: The Monster Always Escapes, an aswang can easily escape because their lower body is hard to find when hunting the monster. Even if you kill an aswang, there is always another one that is roaming around you or other places. â€Å"Each time the grave opens and the unquiet slumberer strides forth (â€Å"com from the dead. / Come back to tell you all†), the message proclaimed is transformed by the air that gives its speaker new life†(Cohen 5). This quote is telling us that even we try to kill it, there will always be another one waiting to prey on us. It will always come back even if someone goes hunting for them. You can lessen them by doing a witch hunt, during the day and the night. The way to kill them during the day is harder because they do not transform, and you can only detect them by looking into their eyes. They say if you see your reflection in their eyes and it is upside down, that means you are looking and perhaps talking to an aswang. In thesis three: The Monster Is the Harbinger of Category Crisis, it talks about how â€Å"the monster escapes because it refuses easy categorization†(Cohen 6). The aswang can turn into different kinds of animals and there are different types of aswangs as well. They mostly shape shift into a dog, pig, a large bird and while zegben, their companion, can sometimes take the form of a Tasmanian devil. Aswangs shapeshift during the night to something that is better suited for hunting its prey. They can also transform their appearance of o ther objects and also turn plants into a doppelganger of one its victims, in order to hide their feeding habits. The plants can also replace the corpses that the aswangs feed on. The doppelganger can also replace a living person by returning to the victim’s home and acting as them, they will end up getting sick and eventually dying. They always appear at funeral wakes and when they hunt their prey, they are waiting at the bedside of a pregnant woman. In thesis four: The Monster Dwells at the Gates of Difference, there is a quote â€Å"Any kind of alterity can be inscribed across (constructed through) the monstrous body, but for the most monstrous difference tends to be cultural, political, racial, economic, sexual†(Cohen 7). Aswangs are mostly female and they use their charms to attract their victims. They befriend pregnant women so they can prey on them. The aswangs can also be economic because many people in the Philippines are poor and will most likely befriend people who are somewhat rich or are financially stable. It seems shallow but, the way the aswangs can lure the pregnant women is by showering them with gifts for their unborn child. In Monster Thesis Five: The Monster Polices the Borders of the Possible there is a quote, â€Å"The monster prevents mobility (intellectual, geographic, or sexual), delimiting the social spaces through which private bodies may move. To step outside this official geography is to risk attack by some monstrous border patrol or(worse) to become monstrous oneself. It fits the Aswang because as a pregnant woman in the Philippines, it is hard to be alone by yourself at night. The houses in the Philippines are also poorly made and have many openings for the Aswang to enter, especially small cracks that will fit their tongue that will suck the blood or the fetus out of the mother. Pregnant women in the Philippines were never allowed to go out late at night by themselves and are accompanied by their signifi cant other during the whole night. It also applies to the children who want to play outside at night. They have to be guarded at night, or at least stay in sight of their parents. The Aswang keeps us from doing night activities, because during the night that is when it is active and hunting for their prey. The Aswang from the movie â€Å"Tik Tik The Aswang Chronicles†, the monster is seen as a male whose body does not split in half and did not have the tongue that can suck out the blood or fetus from inside the pregnant woman. That Aswang was not very scary because it was not the traditional Aswang that first appeared on the shows. It looked more of like a monster that crawled on all four and the skin was completely greyish white. In the television show version of the Aswang, it was the real deal. It looked like the ones that Filipino parents and elders told us about the terrifying monster that preyed on children and pregnant women. There is a scene in the episode wher e we see the Aswang transforming into the monster after rubbing a certain oil all over her body. She grew wings and severed her torso from her bottom which made it vulnerable for hunters to find and kill. That version of the Aswang is the one that will terrify everyone Filipino who was told about this folklore. Annotated Bibliography: Aswang Mythical Creature From Philippine | Mythology.Net. Mythology.Net, 2019, https://mythology.net/monsters/aswang/. Accessed 24 July 2019. This article helps me with my monster because it broke down the basics of what an Aswang is and had more information. Cohen, Jeffrey Jerome. Monster Culture: Seven Theses. From Monster Theory: Reading Culture. Minneapolis: University of Minnesota Press, 1996. 3-25. This article talks about all seven monster theories and gives examples, as well as quotations. This source is credible, because we as a class have been discussing. This will help me with my essay by helping me understand what my â€Å"monster†belongs to what thesis or theses. Wagas: Married Couple Elopes To A Place Where Manananggal Exists. GMA Network, 2019. This film is about how a young eloped couple into a unknown place that had something sinister waiting for them and they unborn baby. This will help me by comparing this Aswang to another one. Wikipedia contributors. Tiktik: The Aswang Chronicles. Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 19 Mar. 2019. Web. 25 Jul. 2019. In this movie, an ill-mannered playboy wanted to make amends with his pregnant girlfriend, and how he now has to protect her from the monsters who are after his unborn child. This will help my monster by comparing this movie to another show about the same monster.
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