Electrochemical cell lab Aim Essay Example for Free

Electrochemical cell lab Aim EssayAim - To encounter out the feasibility of a oxidation-reduction reaction by looking at the cell potential of the reaction .Quantitative observationThe table below shows the values of cell potential that were save when the experiment was performedReaction cellular telephone potential (0.01V)CuSO4 and ZnSO40.99VCuSO4 and AgNO30.64VAg1.39VQualitative ObservationReactionObsevrationsCuSO4 and ZnSO4Copper sulphate turns from clear to blue , whereas zinc sulphate the Great Compromiser colorlessCuSO4 and AgNO3Copper sulphate is blue in color , silver nitrate is colorlessAgData processingExperiment 1Zn(s) - Zn2+ (aq) + 2e- (aq)Cu2+ (aq) + 2e- (aq) - Cu (s)Cu2+ (aq) + Zn(s) - Cu(s) + Zn2+ (aq)Experiment 2Cu(s) - Cu2+ (aq)+ 2e- (aq)Ag+(aq) + e- (aq) - Ag(s)Cu(s) + 2Ag+ (aq) - Cu2+ (Aq) + 2Ag (s)Experiment 3Zn(s) - Zn2+ (aq) + 2e- (aq)Ag+ (aq) + e- (aq)- Ag(s)Zn(s) + 2Ag+ (aq) - Zn2+ (aq) + 2Ag (s)The table below shows the literature values for the respectiv e cell potentialReactionCell potential (0.01V)CuSO4 and ZnSO40.34VCuSO4 and AgNO30.46 V.Ag1.10 VError percentage= (difference between the literature and experimental value)/(the literature value )x100= (0.34V 0.99V)/(0.34V) x100= 191.17%We can similarly find the error percentages for other cell potentials alsoThe table below shows the respective error percentages of each of the cell potentialReactionError percentageCuSO4 and ZnSO4191.17%CuSO4 and AgNO339.13%Ag16.36%TheoryElectrochemical cellsIn an electrochemical cell, electricity is produced through chemical reactions. There consist two electrodes the negative electrode and the positive electrode. At the negative electrode

Weight Loss Maintenance Essay Example for Free

Weight Loss Maintenance EssayThe book that I choose for my provender presentation was Weight Loss nutrition from the Oklahoma State University Library , I chose this book because I feel that most people go on these crash diets and unloosen all the freight except over meter gain all the charge back because they dont do weight passing game keep. This book tallyered a plentifulness of ideas for ways to self monitor your weight and your behaviors to keep the weight off for the long term, not only does this book discuss the physical aspects for weights dismission but the physiological aspects. This book discussed very seriously how much weight loss is defined by the successfulness of keeping the weight off that you loose, it is stated that if you loose 10% of your body weight keeping that amount off for a year or more is considered success. Considering that 10 % seems relatively low only 20% are actually successful with keeping the weight off. But it also says that succes sful weight loss can still be considered successful with a minimal amount of weight gain, this is still considered an over all improved health.Weight loss can either be intentional or unknowing in studies our population looses weight often UN intentional, this can be a factor in how people are either successful with thither weight loss or UN successful. In weight loss maintenance success you have to have a strict criterion that can last up to five years, according to there data if this lifestyle is accomplished 21% of overweight/ obese persons will be able to keep the weight off and become healthy.Research done in this book comes from the national weight control registry which was founded in 1994 to study weight loss and weight maintenance strategies of successful weight loss maintenance. In the studies that they did any individual who qualifies to be a candidate must maintain at least a 30lb weight loss for at least a year, this process would not only monitor there weight loss but there weight loss maintenance behaviors, weight loss history, and their quality of life.About half of the subjects report having been overweight as a child and have struggled with weight loss there entire life, also subjects usually had a family history of obesity. In most cases 90% of the subjects experienced unsuccessful weight loss, for many reasons that participants did not have a strong commitment, strict dieting, and keeping up with an exercise plan.In weight loss and weight loss maintenance to be successful studies show that you guide to modify both your diet and exercise to achieve your goal, you have to have strict ambition of certain types of foods, exercise, and calorie counting. In the strategies for maintenance of weight loss approaches to weight loss can differ widely among different people but the most common success is the three strategies eating a diet low in fertile and high in carbohydrate, frequent self monitoring, and regular physical activity.Furthermore, t his book talks about how you need to determine what your dietetical intake recommendations is and find a diet that is satisfied in the daily reference intake for calcium, vitamin c, vitamin a, and vitamin e. Recently popular diets have recommended restricting carbohydrates to lose weight, in analyzing the participants 7. 6% only reported eating fewer to 90 g of carbohydrates but most of these individuals energy intake was unreasonable low.The participants that had a higher intake of carbohydrates maintained there weight loss for less time and were less physically active. Individuals that watched there over all intake of food could enjoy meals at restraunts. Other studies have shown that successful weight loss maintenance is associated with changes in both the quantity and quality of foods consumed. Again, these findings state how much eating low fat is an importance in maintenance of weight loss this includes reduction portion sizes, reduced frequency of snacks.In conclusion, this book discussed some of the major factors that effect either diet plan, and issues that we all face when it comes to dieting, there is a lot of difficulty in long term weight maintenance but sticking to a diet low in fat, self- monitoring body weight and food intake, and engaging in high levels of physical activity can make a diet successful for you long term. Self monitoring requires substantial effort but is worth it in the end, it can be a life time struggle but once you have maintained a weight loss for 2-5 years the chances of longer term success greatly increases.

Recommendations For Teenage Drug Addiction Social Essay

Recommendations For Teenage Drug Addiction Social EssayAddiction is a chronic, often relapsing brain disease that ca use of goods and servicess compulsive medicate seeking and use despite harmful consequences to the individual who is given and to those around them. Many bulk do non understand why individuals become addicted to doses or how do mediciness change the brain to foster compulsive dose demoralize. They mistakenly view medicine abuse and addiction as strictly a social problem and may characterize those who take medicines as morally weak. One very common belief is that drug abusers should be able to just plosive consonant taking drugs if they ar only willing to change their behavior. What people often underestimate is the complexity of drug addiction-that it is a disease that impacts the brain and because of that, stopping drug abuse is not simply a matter of willpower. done scientific advances we now deal much to a greater extent about how exactly drugs wor k in the brain, and we similarly know that drug addiction can be successfully treated to help people stop abusing drugs and resume their productive lives.People who be suffering emotionally use drugs, not so much for the rush, but to escape from their problems. They ar provideing to self-medicate themselves out of loneliness, low self-esteem, unhappy relationships, or stress. This is a pattern that too often leads to drug abuse and addiction.Drug abuse and addiction be a major burden to society. Drug aw arness and drug testing are two of the about powerful deterrents in identifying and preventing teen drug abuse. These are the three criteria to consider when there is a problem of drug abuse in teens.Awareness/IdentificationPreventionEradicationAwareness/ IdentificationClear communication by parents about the negative physical, emotional, and functional somebodyal set up of drugs, as well as about their expectations regarding drug use accept been put in to significantly de crease burden abuse in teens. Adequate maternal supervision has also been found to be a deterrent to drug use in youth. Specifically, parents knowing how, where, and with whom adolescents socialize, as well as limiting their chelarens main course to substances that can be abused have been associated with little teenage drug use. Limiting the substance of alcoholic drink, cleaning solutions (inhalants), prescription, and over-the-counter medications that are kept in the al-Qaeda to amounts that can be closely monitored and identifyed for has also been found to decrease substance abuse by teens.How can you tell if your child is using drugs or alcohol? It is difficult because changes in mood or attitudes, unusual temper outbursts, changes in sleeping habits and changes in hobbies or other interests are common in teens. What should you pure tone for? You can also look for signs of depression, withdrawal, careless(prenominal)ness with grooming or hostility. Also ask yourself, is your child doing well in school, feelting along with friends, taking straggle in sports or other activities?These changes often signal that something harmful is going on-and often that involves alcohol or drugs. You may want to take your child to the compensate and ask him or her about screening your child for drugs and alcohol. This may involve the health professional asking your child a simple question, or it may involve a urine or blood drug screen. However, some of these signs also indicate there may be a deeper problem with depression, group involvement, or suicide. Be on the watch for these signs so that you can spot trouble before it goes too far.In order for a parent to loll their teen to be aware of the drug usage and identifying if their teen is entangled in this matter, they have to do the following Have The Talk Let Them last You KnowYou should sit down and talk with your child. Be sure to have the conversation when you are all calm and have plenty of time. This isnt an easy task-your feelings may range from anger to guilt that you have failed because your kid is using drugs. This isnt true-by staying involved you can help his/her stop using and make pickings that will make a positive difference in his/her life. Be Specific about Your ConcernsTell your child what you see and how you feel about it. Be specific about the things you have observed that cause concern. Explain exactly how his/her behavior or appearance (bloodshot eyes, different clothing) has changed and why that worries you. Tell his/her that drug and alcohol use is dangerous and its your blood to keep his/her a air from things that put his/her in danger. Dont Make ExcusesAlthough its natural for parents to make excuses for their child, youre not helping him/her if you make excuses when he/she misses school or family functions when you suspect something else is at play. Take the next step Talk to your child and get more information. afflict to Remain Calm and Connect With Hi m/HerHave this discussion without getting sensitive or accusing your child of being stupid or bad or an embarrassment to the family. Be firm but loving with your tone and try not to get hooked into an argument. Knowing that kids are naturally private about their lives, try to find out whats going on in your childs life. Try not to make the discussion an inquisition simply try to connect with your teen and find out why he/she may be making bad choices. Find out if friends or others offered your child drugs at a party or school. Did he/she try it just out of curiosity, or did he/she use marijuana or alcohol for some other reason? That alone will be a signal to your child that you care and that you are going to be the parent exercising your rights.PreventionDrug addiction is a preventable disease. Results from a research have shown that prevention programs that involve families, schools, communities, and the media are effective in reducing drug abuse. Although many events and cultural factors affect drug abuse trends, when youths perceive drug abuse as harmful, they reduce their drug taking. It is necessary, therefore, to help youth and the general public to understand the happens of drug abuse, and for teachers, parents, and healthcare professionals to keep sending the message that drug addiction can be prevented if a person never abuses drugs.Drug prevention generally begins in the following places and programs Schools where drug education programs are initiated to children. Family focused abuse-prevention programs Multidimensional family therapy (MDFT) Multifamily educational intervention (MFE) replacement centersMany programs lead to the scare tactic approach which usually does not work it only leads to youth to wanting to try them anyway. New programs should be created which are more focused on speaking with the kids on their terms, not ours. Many of the speakers involved in the programs are former addicts themselves. They give a detailed account of their past experience with drugs leaving the child to form their own opinion of what drugs are like instead of telling them to just say no. Through these programs they will found out reasons why kids decide to quit using drugs (for those who are already using them), why they change their minds to not try or use drugs and why they believe so strongly to not use or try drugs. The programs also use a more appropriate amount of humor in their presentations. They found that children respond better to the light-heartedness of the issue, although they still know what a serious issue it is.Prevention of drug use is a bad issue to face. There are several programs out there geared towards children and young adults to help them make the right decision on using or trying drugs.Family focused abuse-prevention programs have produced reductions in adolescent drug abuse. Those who strongly identify with their communities and cultures have been found to be less likely to experience risk factors for usin g drugs compared to their peers who are less connected to their communities and cultures. Therefore, incorporation of a cultural component to drug abuse prevention programs may enhance the effectiveness of those programs. Moreover, teens 15 to 16 years old who use religion to cope with stress tend to use drugs significantly less often than their peers who do not use religion to cope.The Institutes of Drug Abuse recommends that treatment of substance abuse be readily available when the addicted person is ready to enroll be tailor to the complex, multiple and changing needs (for example medical, mental health, social, legal, and family) of each individual and consider the use of medication treatment when appropriate and include random drug testing. There are numerous individual treatments for drug addiction in teens. Relapse prevention uses methods for recognizing and amending problem behaviors. Individualized drug counseling specifically emphasizes short-term behavioral goals in an attempt to help the individual reduce or stop the use of drugs altogether. Some such programs include drug testing. Twelve-step programs like Narcotics unidentified are individualized drug-counseling methods. Motivational enhancement therapy encourages the teen to increase their desire to participate in therapy. Stimulus control refers to a treatment method that teaches the person to stay away from situations that are associated with substance abuse and to replace those situations with activities that are contrary to using drugs. Urge control is an approach to changing patterns that lead to drug use. Social control involves family members and other significant others of the addict in treatment.Family interventions for drug addiction that tend to be effective for teens include multidimensional family therapy (MDFT), group therapy, and multifamily educational intervention (MFE). MDFT has been found to be quite effective. Longer-term residential treatment of three to five months that addresses peer relationships, educational problems, and family issues is often used in treating substance abuse in teens.When one enters a drug rehab center many factors go into determining which program is right for you. A trained health professional, generally a doctor specializing in addiction medicine, makes a diagnosis to prescribe which treatment program is best for you.Programs usually include inpatient, residential, outpatient, and/or short-stay options. There is a exquisite difference between inpatient and residential programs. The inpatient services are provided by a licensed hospital, while the residential services are less meticulous in their medical care standards. The length of stay in the center depends and varies on the severity of the disease and the stage the person is in at the time.Recovery of drug abuse is a hard situation to deal with because every person is different in their degree of dependency, their attitude towards their abuse, their health at the time o f entry to a center and their willingness to change their old ways and accept help for ways to live their life differently and better. Recovery is an on-going process. Once a person leaves a center or treatment area, they must apply the skills they have learned into their everyday lifestyle. This can be exceedingly hard for some. However, some treatment centers do offer follow-up programs to ensure and monitor the process of ones recovery. The hardest part is realizing you have a problem and making the choice to enter a treatment facility.EradicationYou can begin to more closely monitor your childs activities. Have a few conversations. Ask Who? What? Where? When? Reflect with your child on why he/she is using drugs and try to understand the reasons why so that you can help solve the problem. When you get a better thought process of the situation, then you can decide next steps. These could include setting new rules and consequences that are reasonable and enforceable such as a n ew curfew, no cell phone or computer privileges for a period of time, or less time hanging out with friends. You may want to get them involved in pro-social activities that will keep them busy and help them meet new peopleLimiting their childrens access to substances that can be abused have been associated with less teenage drug use. Limiting the amount of alcohol, cleaning solutions (inhalants), prescription, and over-the-counter medications that are kept in the home to amounts that can be closely monitored and accounted for has also been found to decrease substance abuse by teensA community based program for the prevention of the drug usage should be developed. In order to release communities of drug abuse and crimes related to drugs, we must put drug dealers out of business. Since drug trafficking and the sale of drugs are so profitable, it has become sizable business. The only way to put any business out of business is to decrease the demand for the product or service.To accom plish this, each community must provide stay interventions in their small part of the world. Collectively, we can have a long-term impact on ridding the world of illicit drug use and drug abuse.Creating a substance abuse prevention program will change the lives of residents in your community. Drugs and crimes related to drugs are in every community. It does not matter if it is a sozzled community or the poorest of the poor. This is why it is so important that every community creates a program for substance abuse prevention. Accordingly, a powerful program for substance abuse prevention incorporates drug education with community mobilization, youth development, and community action. Yes, the community must get involved.*The law enforcement should be able to locate where the drugs are being brought in, they should find out the roots its coming from and destroy it there only. They should keep a watch on the people who bring it in and who are the people who get the stuff to come in th e cities. The law enforcement is expected to keep the places clean and out of drugs so the young generation will not come in contact with these different substances that are being sold in the market. There should be brutal punishments for the sellers when they are caught selling these drugs to the teens or anyone. short-circuit and Long Term Effects of Drug AbuseSource National Institute on Drug AbuseShort-Term Effects Rush dispirited respiration Clouded mental functioning Nausea and vomiting Suppression of pain Spontaneous abortion Long-Term Effects Infectious diseases (HIV/AIDS and Hepatitis) Collapsed veins bacterial infections Abscesses Infection of heart lining and valves Arthritis and other rheumatologic problemsSummaryIn order to solve the drug addiction in teens, the above listed criteria play a big role because it is a must to identify is someone that you care about is on drugs. They should be well aware of the consequences and the effects of the drug they are using. When they know the right information and someone is to take them seriously and help them from getting out of this addiction will solve this crucial matter. Even if you have to get to the depth of it by finding out where is the supply coming from and getting those drug dealers in the right place where they belong which is prison will also eradicate the drug usage of your closed one.Drug addiction is a brain disease because the abuse of drugs leads to changes in the structure and function of the brain. Although it is true that for virtually people the initial decision to take drugs is voluntary, over time the changes in the brain caused by repeated drug abuse can affect a persons self control and ability to make sound decisions, and at the same time send intense impulses to take drugs.Fortunately, there are treatments that help people to counteract addictions powerful disruptive effects and regain control. Research shows that combining addiction treatment medications, if available, with b ehavioral therapy is the best way to ensure success for most patients. Treatment approaches that are tailored to each patients drug abuse patterns and any co-occurring medical, psychiatric, and social problems can lead to sustained recovery and a life without drug abuse.RecommendationsBased on the results and solutions to solve this problem of increasing the number of teens in drug addiction, I recommendAll the parents should make their kids well aware of the facts and effects of the drug usage and what could be the consequences of the usage of these drugs. Only the parents friendly behavior and necessarily restrictions can keep their kid away from using these substances. It is only the love ones whom you care for can help the drug addicts get rid of this problem and put themselves in some rehabilitation centers if necessary. Also there should be more care given in rehab centers and more programs can be established to finish of this matter for good.Material Cited1. http//www.csun.ed u/vcpsy00h/students/drugs.html2. http//www.medicinenet.com/teen_drug_abuse/article.html3. Drug Addiction by John Hicks, Millbrook rack (August 1, 1997)

Time and Cost Performance in Construction

while and approach Performance in ConstructionOne of the most requisite problems confronting the pissing and sanitation sector in the northern land of Ghana is humans presentation of cost and epoch. In most cases while oerruns occur in the donor-funded sicks and in the extreme cases cost overruns. Time and cost overruns occur in almost exclusively related water and sanitation spin tasks in the northern region of Ghana. It is in that locationfore essential to define the factual instruction execution difficulties in target to make light of and avoid the delays and increasing cost in any donor-funded water and sanitation communicate. In the ESAs funded water and sanitation nourishs, the aim of brook rule is to ensure the checks finish on time, within budget and achieving opposite project objectives. It is a complex task undertaken by project managers in practice, which involves aeonianly measuring progress evaluating plans and taking corrective actions when req uired (Kerzner, 2003). During the last few decades, numerous project control methods, much(prenominal) as Gantt Bar Chart, Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM), have been developed (Nicholas, 2001) (Lester, 2000). A variant of package packages have become visible(prenominal) to support the application of these project control methods, for example Microsoft Project, Asta Power Project, Primavera, etc. Despite the wide use of these methods and softw be packages in practice, more of these donor-funded projects in the north still suffer time and cost overruns. This chapter reviews literature concerning the major issues of and cost and time process in order to recognize the related discipline regarding those issues.Definition of Time and Cost PerformanceTime PerformanceTime mathematical process is define as meeting the length baseline in the initial planning process of the project. Time overruns occurs when there is an extension of time beyond planned completion views traceable to the major stakeholders (Kaming et al., 1997). Delays are incidents that impact a projects progress and postpone project activities delay causing incidents may include unavailability of resources, communication problems, slowness in decision making, role delays, etc. In general, project delays occur as a result of project activities that have both external and internal cause and effect blood (Vidalis and Najafi, 2002). (Choudhury and Phatak, 2004) and (Chan-Albert, 2001) defined the time overruns as the differentiation surrounded by the actual completion time and the estimated completion time. Project delays are those that cause the project completion date to be delayed (Al-Gahtani and Mohan, 2007).Cost PerformanceCost executeance is defined as the zero difference between the budgeted/original cost estimate of the project and in some cases spending infra the estimated cost of the project. Cost variance occurs when there is an excess of actual cost over budget or below budget. Cost variance in expression projects often result in an overrun which is also occasionally called cost escalation, cost increase, or budget overrun. (Zhu and Lin, 2004). Cost overrun is defined as the change in contract amount divided by the original contract award amount .This calculation fucking be converted to a percentage for ease of comparison (Jackson, 1999).(Choudhury and Phatak, 2004), defined the cost overruns as the differentiation amid the original cost estimate of project and actual cost on completion of reverses of a commercial sector facial expression project.Cost is among the major consideration throughout the project charge manner cycle and can be regarded as one of the most master(prenominal) parameters of a project and the driving force of project winner (Azhar et al., 2008, p. 7). (Gido and Clement, 2003), mentioned that cost procedure is an effective technique in project caution effort expended and it is widely accepted in the literature and persistence. Earned Value Analysis (EVA) is used to respect cost surgery of different types of projects. Cost control, cost estimating, and cost budgeting are tercet cost related processes that interact among each other and with other place settings of complex body part projects.Time variance for water and sanitation projectsTime variance (Tv) is the time between the scheduled contract time and the completion time in labor the projects.Bromilows Time-Cost ModelBromilow was the first to develop an empirical model for the prediction of reflexion time using the project cost. The model known as Bromilows time-cost (BTC) model, developed and make in Australia in 1969, was developed for giving a fast and wind schedule estimate using project cost. The model provides a forecast of construction schedule using the estimated final cost of the project. Bromilows model disclosed that the construction duration was highly correlated with the project cost ( Bromilow, 1969). The model was developed by the use of a linear lapse model. (Hoffman et al, 2007), confirmed that, Bromilow was triumphant in providing a point estimate as well as upper and trim quartile limits of construction duration using past project data. (Ameyaw et al, 2012).The correlation was re-tested by (Bromilow, 1988) collaborated with the Australian Institute of Quantity Surveyors (AIQS) in deuce transcribe contract time transaction studies, in 1976 and 1988. (Bromilow, 1988), investigated 408 projects built between 1970 and 1976 and establish that despite indication of superior disparity between the time effect of projects of comparable value, the correlation between construction duration and project cost revealed in the 1960s is pertinent. Even though project time is processd by many other factors including cost, some success has been chalked in an attempt to model project time. The model as first developed by (Bromilow, 1969) is expressed as T = KCB. T represen ts project duration, C actual cost of the project including fluctuations and variations, K is a constant showing the level of time death penalty for a unit of C, and B is a constant describing how the time exercise was affected by project size as measured by the cost. (Long et al, 2009), argued that the application of Bromilows time-cost model in estimating and benchmarking the project duration has been agile while some studies have suggested that the application of this model is unsuitable. More centrally, (Mensah, 2010), adopted the Bromilows time cost model to estimate project duration on donor funded feeder roads in Ghana and found it applicable.Auxiliary analysis showed the original Bromilow time-cost model is not the best fit regression form, and alternative models were proposed. on the whole the researchers place cost was a poor forecaster of time performance, and further proposed an alternative model to that proposed by Bromilow (1969). (Kaka and Price, 1991), used the time-cost model for both civil and build projects and indicated that the original model, as introduced by (Bromilow, 1969), re of imported unchanged but the coefficient of the equation changed with the project type.(Al-Momani, 2000), stated that the owner satisfaction for performance can be defined as the gap between what the owner expects and the level of performance they believe is being delivered by the contractors. (Lehtonen, 2001), stated that performance measuring stick is a basis for progressive overture and monitoring of company productivity. (Chan and Kumaraswamy, 2002) remarked that project performance measurement include time, budget, safety, quality and overall client satisfaction. (Thomas et al., 2002), defined performance measurement as monitoring and compulsory of projects according to regular basis. (Kuprenas, 2003), stated that project performance measurement means an remediatement of cost, schedule, and quality for send off and construction stages. (Long et al, 2004), stated that a project performance measurement is related to many indicators such as time, budget, quality, specifications and stakeholders satisfaction. (Navon, 2005), defined performance measurement as a comparison between the desired and the actual performances. business of Performance in Construction IndustryThe failure of any construction project is mainly related to the problems and failure in performance. Moreover, there are many reasons and factors which attribute to such problem. (Ogunlana et al., 1996), stated that the construction industry performance problems in developing economies can be classified in cardinal layers inadequacies in industry infrastructure (resources supply), clients and consultants caused problems and contractor incompetence/inadequacies. (Okuwoga, 1998), identify that the performance problem is related to poor budgetary and time control. (Long et al, 2004), remarked that performance problems swot in large construction projects due to many reasons such as incompetent designers/contractors, poor estimation and change management, social and technological issues, site related issues and improper techniques and tools. (Navon, 2005), stated that the main performance problem can be divided into two groups (a) unrealistic target setting (i.e., planning) or (b) causes originating from the actual construction (in many cases the causes for deviation bulge from both sources).(Samson and Lema, 2002), found that the traditional performance measurement remainss have problems because of large and complex amount of information with absence of approaches to assist decision maker understand, gussy up and use such information to manage organizational performance. (Navon, 2005), remarked that traditional project performance control is usually generic (e.g., cost control techniques). It relies on manual of arms data collection, which means that it is done at low frequency (normally once a month) and quite some time after the controlle d event occurred (i.e., not in real-time). Moreover, manual data collection normally gives low quality data.(Ling et al., 2007), remarked that architectural, engineering and construction (AEC) firms may encounter challenges managing construction projects performance in China because of curiousness with this new operating environment. (Kim et al., 2008), stated that international construction projects performance is affected by more complex and changing factors than domestic projects frequently being receptive to serious external uncertainties such as political, economical, social, and cultural risks, as well as internal risks from within the project.Project Management and PerformanceThere is a toughened relation between project management and project performance. Management in construction industry is considered as one of the most important factors affect performance of reports. (Brown and Adams, 2000) studied a new approach to the measurement of the effect of Building Projec t Management (BPM) on time, cost and quality outputs using 15 cases derived from UK data. The catch up withgrade undertaken demonstrates that BPM as it is presently implemented in the UK fails to perform as expected in relation to the three predominant performance evaluation criteria time, cost and quality. (Lehtonen, 2001), obtained a model for performance measurement which assist both firms top management and operational managers for continuous feedback on operational activities. (Thomas et al., 2002), stated that documenting and archiving performance data could be useful for approaching reference, such as for settling disputes on claims, and in maintenance and repair works. (Kuprenas, 2003), remarked that quantification of the impacts of the project management processes are identified through three steps of analysis comparison of summary statistics of design performance, proof of statistical significance of any differences and calculation of a least squares regression line of a plot of design performance measurement versus amount/application of project management as a means to quantify management influence to design signifier cost performance.(Cheung et al., 2004), studied the project performance related to project managers and remarked that development of a Web- ground construction Project Performance supervise System (PPMS) can assist project managers in exercising construction project performance indicators and can help senior project management practitioners, etc., in monitoring and assessing project performance. (Pheng and Chaun, 2006), stated that while project management is only one of the many criteria upon which project performance is contingent, it is also arguably the most probative as people formulating the processes and systems who deliver the projects. (Ugwu and Haupt, 2007), stated that an adequate understanding and knowledge of performance are desirable for archiving managerial goals such as improvement of institutional transformations , and efficient decision making in design, specification and construction, at various project-level interfaces, using appropriate decision-support tools. (Ling et al., 2007), investigated Project Management (PM) practices adopted by Singaporean construction firms and dogged the level of performance of their projects in China they identified PM practices that led to better performance and recommended key PM practices that could be adopted by overseas construction firms in China to improve project performance.Water and Sanitation Projects and PerformanceSuccess of projects depends mainly on success of performance. Many preceding(prenominal) researches had studied performance of construction projects. (Dissanayaka and Kumaraswamy, 1999), remarked that one of the principal reasons for the construction industrys poor performance has been attributed to the inappropriateness of the chosen procurement system. (Reichelt and Lyneis, 1999), remarked three important structures underlying the propulsive of a project performance which are the work accomplishment structure, feedback effects on productivity and work quality and effects from upstream phases to downstream phases. (Thomas et al., 2002), identified the main performance criteria of construction projects as financial stability, progress of work, standard of quality, health and safety, resources, relationship with clients, relationship with consultants, management capabilities, claim and contractual disputes, relationship with subcontractors, story and amount of subcontracting. (Chan and Kumaraswamy, 2002), stated that construction time is increasingly important because it often serves as a crucial benchmarking for assessing the performance of a project and the efficiency of the project organization.(Cheung et al., 2004), identified project performance categories such as people, cost, time, quality, safety and health, environment, client satisfaction, and communication. It was obtained by (Navon, 2005), that a co ntrol system is an important element to identify factors affecting construction project effort. For each of the project goals, one or more Project Performance Indicators (PPI) is needed. (Pheng and Chaun, 2006), obtained that human factors played an important role in determine the performance of a project. (Ugwu and Haupt, 2007) remarked that both early contractor involvement (ECI) and early supplier involvement (ESI) would minimize constructability-related performance problems including costs associated with delays, claims, wastages and rework, etc. (Ling et al., 2007), obtained that the most important of practices relating to scope management are controlling the quality of the contract document, excellence of reaction to perceived variations and extent of changes to the contract. It was recommended for foreign firms to adopt some of the project management practices highlighted to help them to achieve better project performance in China.Information Technology and Water and Sanitati on Projects PerformanceInformation technology technique is precise important in the entire world. Information technology (IT) opens new visions in the businesses and industries performance of the world. The construction industry is considered as one of the industries using IT technique such as software management systems, database and communications. For many years, many processes, courses, operations were done difficulty because of absence of IT field. In addition, most of the work was done manually which confidential information to more cost, time and poor performance. Furthermore, IT usage in the construction industry leads to many changes, innovations and developing in many aspects which lead finally to good and strong performance. There are many benefits and relations of using IT in the construction projects such as greater use of IT correlates with better project performance, owners and contractors realize meaning(prenominal) benefits, IT affects schedule compression bene ficially, and overall project cost savings which lead to a success performance of project (Schwegler et al., 2001).(Nitithamyong et al., 2004), remarked that information Technology (IT) is now routinely used in the construction industry as a tool to reduce some of the problems generated by fragmentation. The use of IT improves coordination and collaboration between firms participating in a construction project, leading to better communication practices and so good performance. Its benefits include an increase in the quality of documents and the speed of the work, better financial control and communications, and simpler and faster access to common data as well as a decrease in documentation errors.(Thomas et al., 2002), proposed contractor Performance Appraisal and insurance coverage (PAR) system for reviewing contractor performance at an organizational level. Advancements in World Wide Web techniques provide enhanced capacities to collect compile and disseminate performance-related information to various construction stakeholders in a timely and cost-effective manner. (Becerik, 2004), stated that the rapid advances of web-based project management and collaboration technology offer new opportunities to improve existing construction project performance. (Cheung et al., 2004) obtained fabric software to measure project performance based on project performance measurement system (PPMS). The system contains four stages which are data entry, database, report and action. This system has eight categories to measure performance which are people, cost, time, quality, safety and health, environment, client satisfaction, and communication. (Goh, 2005), remarked that information technology management leads to performance improvement in the construction industries. For instance, in Singapore 2003, general administration, design, project management and site management were enhanced by using of IT. In addition, there were more advantages as quick working, good quality of w ork and fast access of information.Factors Affecting Performance of Managers(Ogunlana et al., 1996), recommended the need for focused effort by deliverance managers and construction industry associations to provide the infrastructure needed for efficient project management and performance. (Dissanayaka and Kumaraswamy, 1999), stated that the knowledge that would influence potential performance enables project managers to pay special attention to control performance more effectively. (Chan and Kumaraswamy, 2002), remarked that effective communication and fast information transfer between managers and participants help to accelerate the building construction process and performance. (Kuprenas, 2003), studied the impact of the use of a project management based organizational structure, project manager cookery, frequency of design meetings, and frequency of design reports on design phase cost performance. The process of a design team meeting frequency and the process of written report ing of design phase progress were found to be statistically significant in reducing design phase costs.(Navon, 2005), stated that data are collected and used for construction managers as a basis to evaluate the Project Performance Indicators (PPI) actual value to compare it with the planned value and forecast its future value based on past performance. (Pheng and Chaun, 2006), identified the importance of the working environment variables for the performance of a project manager in the private and public sectors according to three main groups which are job condition, project characteristic and organizational related categories. The result revealed that working hours, physical condition of project site, complexity of project, material and supplies, project size, duration of project and time availability were viewed differently in terms of importance by the contractors and consultants groups. Team relationship was ranked as the most important variable affecting the performance of a pr oject manager. It is obtained that project managers experiences do not have much effect on how they perceive their working environment.Time Impact AnalysisTime is an essential part of every plan organisations develop for performing contract work. There is a relationship between the schedule, the scope of work, and the project conditions. According to (Anabari, 2003), Time Impact Analysis is typically associated with the modeling of the effects of a single delay. It requires a CPM schedule that is able to show the unadulterated CPM calculation differences between a schedule that does not include a delay and one that does include an activity modeling a delay. The difference for project completion between the non-impacted schedule and that of the schedule with the impact is considered to be the impact of the delay for time duration considerations.Project Cost Time Relationship bring project costs include both channel costs and indirect costs of performing the activities of the proje ct. Direct costs for the project include the costs of doing work related to some specific activities of the project. Indirect costs, on the other hand, are the necessary costs of doing work which cannot be related to a particular activity, and in some cases cannot be related to a specific project (Davison, 2003),.If each activity was scheduled for the duration that resulted in the minimum direct cost in this way, the time to complete the entire project might be too long and substantial penalties associated with the late project completion might be incurred (Dlakwa and Culpin, 1990). Thus, planners perform what is called time-cost trade-off analysis to shorten the project duration. This can be done by selecting some activities on the critical path to shorten their duration. As the direct cost for the project equals the sum of the direct costs of its activities, then the project direct cost will increase by decreasing its duration. On the other hand, the indirect cost will decrease by decreasing the project duration, as the indirect cost are almost a linear function with the project duration (Al-Khalil and AL-Ghafly, 1999).Factors Affecting Cost and Time Performance(Chan and Kumaraswamy, 2002), remarked that studies in various countries appear to have contributed significantly to the body of knowledge relating to time performance in construction projects over the past three decades, while (Iyer and Jha, 2005), remarked that project performance in term of cost is studied since 1960s. These studies range from theoretical work based on experience of researcher on one end to structured research work on the other end. Moreover, (Pheng and Chaun, 2006), stated that there have been many past studies on project performance according to cost and time factors.(Chan and Kumaraswamy, 1996) stated that a number of unexpected problems and changes from original design arise during the construction phase, leading to problems in cost and time performance. It is found that poor s ite management, unforeseen ground conditions and low speed of decision making involving all project teams are the three most significant factors causing delays and problems of time performance in local building works. (Okuwoga, 1998), stated that cost and time performance has been identified as general problems in the construction industry worldwide. (Dissanayaka and Kumaraswamy, 1999), remarked that project complexity, client type, experience of team and communication are highly correlated with the time performance whilst project complexity, client characteristics and contractor characteristics are highly correlated with the cost performance. (Reichelt and Lyneis, 1999), obtained that project schedule and budget performance are controlled by the dynamic feedback process. Those processes include the rework cycle, feedback loops creating changes in productivity and quality, and effects between work phases.(Chan-Albert, 2001), identified that the best predictor of come construction t ime performance of public sector projects in Malaysia is T = 269 C 0.32. This relationship can serve as a convenient tool for both project managers and clients to predict the average time required for delivery of a construction project. (Kuprenas, 2003), stated that process of a design team meeting frequency and the process of written reporting of design phase progress were found to be statistically significant in reducing design phase costs. Otherwise, the use of project manager training and a project management based organizational structure were found to be processes that do not create a statistically significant in reducing design phase costs.(Iyer and Jha, 2005), remarked that the factors affecting cost performance are the competence of project managers support of top management coordinating and leadership skills of project managers monitoring and feedback by the participants decision making coordination among project participants owners competence social condition, economical condition and climatic condition. Coordination among the various participants of the project was as the most large of all the factors having utmost influence on cost performance of projects. (Love et al., 2005), studied project time-cost performance relationships by using project scope factors for 161 construction projects that were ideal in various Australian States. It was noticed that gross floor area and the number of floors in a building are key determinants of time performance in projects. Besides, the findings indicate that cost is a pitiable forecaster of time performance.(Chan and Kumaraswamy, 2002), proposed specific technological and managerial strategies to increase speed of construction and so to raise the construction time performance. It is remarked that effective communication, fast information transfer between project participants, the better selection and training of managers, and detailed construction programs with advanced available software can help to acceler ate the performance. (Jouini et al., 2004) stated that managing speed in engineering, procurement and construction projects is a key factor in the competition between innovative firms. It is found that customers can consider time as a resource and, in that case, they will encourage the contractor to improve the time performance.Identifying factors that influence cost performancePrevious research has attempted to establish reasons for the difference between the tender sum and the final account. This segment identifies the factors that influence cost performance. 4 factors were identified from the obtainable research findings, (Morris, 1990), (Kaming et al., 1997) and (Chimwaso, 2001). These are design changes, inadequate planning, irregular weather conditions and fluctuations in the cost of building materials.To expand the research it was decided to sync the above list of factors with other factors gleaned from the final account reports. These were compared with the factors from th e existing research findings, and a final list of 18 factors was prepared. These were then separated into two groups of sevensome significant factors and nine other factors, which are usually ignored, but perceived to be of equal significance (Chimwaso, 2001).Measurement of Project Performance(Karim and Marosszeky, 1999), stated that performance measurement systems have been one of the primary tools used by the manufacturing sector for business process re-engineering in order to monitor the outcomes and effectiveness of instruction execution. (Brown and Adams, 2000), obtained an evaluation framework to measure the efficiency of building project management (BPM) by using conventional economic analysis tools such as time, cost and quality. (Lehtonen, 2001), stated that performance measurement systems are imminent in the construction firms. (Samson and Lema, 2002), stated that effective and efficient management of contractors organizational performance requires commitment to effectiv e performance measurement in order to evaluate, control, and improve performance today and in the future.(Tangen, 2004), obtained that performance measurement is a complex issue that normally incorporates at least three different disciplines economics, management and accounting. Measurement of performance has garnered significant interest recently among both academics and practitioners. (Tangen, 2004), remarked the choice of a suitable measurement technique depends on a number of factors, including the purpose of the measurement the level of detail required the time available for the measurement the existence of available predetermined data and the cost of measurement.(Navon, 2005), defined performance measurement as a comparison between the desired and the actual performances. For example, when a deviation is detected, the construction management analyzes the reasons for it. The reasons for deviation can be schematically divided into two groups (a) unrealistic target setting (i.e., planning) or (b) causes originating from the actual construction (in many cases the causes for deviation originate from both sources). (Navon, 2005), stated that performance measurement is needed not only to control current projects but also to update the historic database. Such updates enable better planning of future projects in terms of costs, schedules, labor allocation, etc. (Pheng and Chaun, 2006), stated that the measurement of project performance can no longer be restricted to the traditional criteria, which lie down of time, cost and quality. There are other measurement criteria such as project management and products.(Cheung et al., 2004), stated that New South Wales Public Works segment in Australia launched a Project Performance Evaluation (PPE) framework, which covers an extensive array of performance parameters. PPE parameters are communication, time, cost, quality, safety, claims and issues resolution, environment, contract relations. PPEs purpose is to broaden pro ject performance procedures to inclose soft parameters also, such as communication and resolution of dispute. In the UK, a performance measurement tool for project referred to as the Key Performance Indicators (KPIs) was developed by the KPI working group under the UK Construction Industry Best Practice Programme to include time, cost, quality, client satisfaction, change orders, business performance, health and safety. The implementation steps of KPIs are as follows Decide what to measure, Collect data and calculate the KPIs. That notwithstanding, both the PPE and KPIs are valuable tools for measuring performance of a project over a period of time. Anyway, it is obtained from previous study that both methods PPE and KPIs can be used for measuring of performance as the indicators are similar in two methods. In this study KPIs method will be used to measure performance.(Iyer and Jha, 2005), stated that measuring the performance of any construction project is a very complex process b ecause modern construction projects are generally multidisciplinary in nature and they involve participation of designers, contractors, subcontractors, specialists, construction managers, and consultants. With the increasing size of the project, number of participants in the project also increases. The objectives or goals of all participants need not be same even in a given project. Hence to measure performance of a project witho

Statistical techniques for cryptanalysis

statistical techniques for crypt analysisIntroduction Cryptography is the art of writing essences in code or goose egg, to disguise, and thereby secure the con xt of a peculiar(a) stream of text. When engraveed, a plain text message undersurface be revealed only through the in bow out of the primaeval utilise to encode the think. Cryptography does non mask the existence of the message, but does disguise its content 1. In contrary, cryptanalysis is the art of recovering the plaintext of a message with verboten access to the break. Successful cryptanalysis whitethorn recover the plaintext or the paint for a specific ciphertext 2. There ar five general types of cryptanalytic antiaircraft guns- 1. Ciphertext-only attack In this type of attack, the cryptologist has a series of cipher texts entered apply the same write in codeion algorithm. Then, the cryptanalyst withholds the plain text of each of the cipher texts or identifies the recognise used to inscribe the cip her text2. Known-plaintext attack In this type of attack, the cryptanalyst has a series of ciphertext and their corresponding plaintext values encrypted using a specific key. The cryptanalyst then tries to deduce the key by forming a relationship between the ciphertext and plaintext entries. 3. Chosen-plaintext attack In this type of attack, the cryptanalyst not only has access to the ciphertext and associated plaintext for several messages, but he also chooses the plaintext that gets encrypted. His job is to deduce the key used to encrypt the messages or an algorithm to trace all new messages encrypted with the same key.4. Frequency analysis It is the study of the oftenness of every(prenominal)owtersor groups of earns in aciphertext. The manner is used as an aid to breakingclassical ciphers. Frequency analysis is found on the event that, in any given exsert of written language, certain garner and combinations of letters occur with varying frequencies.5. Rubber-hose crypt analysis The cryptanalyst threatens, tortures or blackmails the person who has the key until they give it up.Among the many cryptanalytic techniques, frequency analysis or frequency counting is the or so basic technique applied to break substitution cipher based algorithms, among the varied list of attack techniques. The basic use of frequency analysis is to first count the frequency of ciphertext letters and then associate pass judgmented plaintext letters with them. More complex use of statistics domiciliate be conceived, such as considering counts of pairs of letters digrams, trigrams, and so on. This is done to provide more than information to the cryptanalyst.It exploits the flunk in the substitution cipher algorithm to encrypt similar plaintext letters to similar ciphertext letters. Frequency analysis based cryptanalysis techniques were used to break ciphers based on the traditional cryptologic algorithms, but they do not work well with the modern block cipher based cryp tographic algorithms. Statistical properties of EnglishFrequency analysis based cryptanalysis uses the item that natural language is not random in nature and case-by-case alphabetical based substitution does not hide the statistical properties of the natural language. In the case of encryption using monoalphabetic substitution, to start deciphering the encryption it is useful to get a frequency count of all the letters. The just about frequent letter may represent the most common letter in English, E followed by T, A, O and I whereas the least frequent are Q, Z and X 7. Statistical patterns in a language can be detected by tracing the redundancy of the text in the language. It has been realized that various universal regularities remember text from dissimilar domains and languages. The best-known is Zipfs law on the distribution of word frequencies 5, according to which the frequency of terms in a collection decreases inversely to the wander of the terms. Zipfs law has been f ound to apply to collections of written documents in virtually all languages 5. English language characters have a actually high redundancy set up when used for cryptographic substitutions. If we have a message encrypted using the substitution cipher that charters to be break danceed, we can use frequency analysis. In otherwise words, if the sender has used an encryption scheme, that replaces one letter in the English to be another letter in English, we can still recognize the skipper plain text as, the frequency characteristics of the original plain text allow be passed on the new cipher text characters 4. To apply frequency analysis, we forget need to know the frequency of every letter in the English alphabet, or the frequency characteristics of the language used by the sender to encrypt the text. beneath is a list of average frequencies for letters in the English language. So, for example, the letter E accounts for 12.7% of all letters in English, whereas Z accounts for 0.1 %. All the frequencies are tabulated and plot below-For example, let us consider the following sentence We study Cryptography as part of our course. Using a simple substitution cipher, let us consider the following a-c , b- d, c-e..w-y, x-z, y-a, z-bSo, the cipher text becomes yg uvwfa etarvqitcrja cu rctv qh qwt eqwtug. A simple frequency analysis of the cipher text can be carried out and the results are as given belowThe above data can be used by a cryptanalyst to identify the key or the plaintext by using simple substitution to the cipher text till a suitable plaintext value is not identified.Apart from the use of mono alphabetic frequency analysis, cryptanalysts also identify frequency of paired letters better known as digram frequency and that of three letter words, called as Trigram frequencies. These help the cryptanalyst to exploit the redundant features of English language to break the cipher.The most common Digrams (in order) th, he, in, en, nt, re, er, an, ti, es, on , at, se, nd, or, ar, al, te, co, de, to, ra, et, ed, it, sa, em, ro.The most common Trigrams (in order) the, and, tha, ent, ing, ion, tio, for, nde, has, nce, edt, tis, oft, sth, men Table 1 Digram and Trigram Frequencies 6These help in identifying the most commonly used terms in English to break a cipher. The digram frequencies are used to break dickens letter words such as an, to, of etc and the trigram frequencies are used to break three letter words such as the, are, for etc. After breaking a significant twain letter and three letter words, it is practically east to identify the key from the cracked values of plaintext by matching the corresponding values in the ciphertext. This huge weakness in English language is used to break cipher texts encrypted using simple algorithms that make use of English alphabets. In practice the use of frequency analysis consists of first counting the frequency of ciphertext letters and then assigning guessed plaintext letters to them. Many lett ers will occur with roughly the same frequency, so a cipher with Xs may indeed social occasion X onto R, but could also map X onto G or M. But some letters in every language using letters will occur more frequently if there are more Xs in the ciphertext than anything else, its a upright guess for English plaintext that X is a substitution for E. But T and A are also very common in English text, so X might be either of them also 4. Thus the cryptanalyst may need to try several combinations of mappings between ciphertext and plaintext letters. Once the common iodin letter frequencies have been resolved, then paired patterns and other patterns are solved. Finally, when sufficient characters have been cracked, then the rest of the text can be cracked using simple substitution. Frequency analysis is highly effective against the simpler substitution ciphers and will break astonishingly short cipher texts with ease.Attacks on Traditional algorithms Encrypting using traditional algorithm s have been defenseless against cryptanalytic attacks as they use bit by bit encryption, which can be easily broken using frequency analysis based attacks. 1. Caesar CipherConsidering the case of one of the oldest ciphers, the Caesar Cipher, this cipher replaces one letter of the plaintext with another to produce the ciphertext, and any particular letter in the plaintext will ever, acidulate into the same letter in the cipher for all instance of the plaintext character. For instance, all Bs will turn into Fs. Frequency analysis is based on the fact that certain letters, and combinations of letters, appear with characteristic frequency in essentially all texts in a particular language 9. For instance, in the English language, E is very common, while X is not. Likewise, ST, NG, TH, and QU are common combinations, while XT, NZ, and QJ are very uncommon, or even im manageable to occur in English. This clearly shows how the Caesar cipher can be broken with ease by just identifying the frequency of each letter in the cipher text. A message encrypted using Caesar cipher is extremely insecure as an exhaustive cryptanalysis on the keys easily breaks the code.2. Substitution Ciphers The Caesar cipher forms a subset of the entire set of substitution ciphers. Here, the key of the encryption procedure is the permutation of all the twenty six characters of the English alphabets. Rather than choosing a particular key for all encryption process, we use a different key for successive encryption processes. This technique increases the number of possible key to 26, which is about 4 X 1026, which eliminates the exhaustive cryptanalysis attack on the keyspace 7. To decrypt the cipher the, statistical frequency distribution of single letter occurrence in English language is analyzed. Then, the digram and trigram frequencies of standard English words are compared with the frequencies of the trigrams in the cipher to finally reconstruct the key and in turn decipher the text. This is an efficient method to break the substitution cipher as, each plaintext letter is stand for by the same ciphertext letter in the message. So, all properties of plaintext are carried on to the cipher text.3. Vigenere Cipher In a Vigenere cipher, there is greater security as, a given plaintext letter is not always represented by the same ciphertext letter. This is achieved by using a sequence of n different substitution ciphers to encrypt a message. This technique increases the possible number of keys from 26 to (26)n. Although this was considered to be unbreakable, the Kasiskis method of attacking a Vigenere cipher yielded successful results of decrypting the message. According to this method, the first step is to discern the key continuance (n). Find identical segments of plain text that get encrypted to the same ciphertext, when they are b positions apart, where b=0 mod n. According to Kasiski, the near step is to find all the identical segments of length greater than 3, and record the distance between them 7. This can then be used to predict the length of the key (n). Once this is found the key is found by an exhaustive search of the keyspace for all possible combinations to identify the key. This is done by substituting all possible values for n to generate substrings. Once the substring is formed, the plaintext message can be automatically identified by using the back substitution of the key into the cipher 7. This can be done for all possible values for n until finally arriving at the actual key, which reveals the plaintext that was encrypted. This method can purport a long time to break the key to identify the plaintext incase the key length is very long, as the keyspace value would be large for larger keys.Defeating frequency based attacks Frequency based attacks have been used for a long time to break traditional encryption algorithms. It uses the fact that, traditional encryption algorithms do not eliminate the statistical properties of the l anguage upon encryption. The first way to defeat frequency based attacks is to encrypt blocks of characters at a time rather than single letters 7. This would ensure that, the same text in the plaintext is not encrypted to the same text in the ciphertext upon encryption. For e.g., if we use the Caesar cipher encryption scheme, the word ADDITIONAL will be encrypted to CFFKVKQPCN, we can see that the alphabets A, D and I are repeated more than once and at each instance, the encryption scheme used always encrypts A to C, D to F and I to K. This can clearly be used during frequency analysis to analyze the redundancy of the characters and in turn map them back to get the original plaintext character. Using a block encryption scheme, one can be satisfied that, this phenomenon does not occur as, in a block encryption scheme, the whole plaintext is broken into chunks or blocks of data, that is fed in as input to the encryption algorithm. The algorithm then, reads the input block along with the key and encrypts the complete block of plaintext, rather than individual characters, so there is a smaller chance that two blocks will produce the same chunk of ciphertext.The routine way of defeating frequency analysis is to make use of synonyms of words 7, rather than repeating the same word over and over again in a sentence. There are a lot of words in English, which have more than one synonym, thus providing with a set of words to be used as convenient in the particular context. To help in the selection of a synonym, grammar checking would have to be used to ensure that, the meaning expressed in the sentence is not altered by changing the words. Attacks against this technique could include creating a list of the best synonyms, but this would not help the attacker as different word could be used at each instance the same meaning needs to be expressed, defeating the benefit of this technique. This technique of using change words to represent common words to defeat cryptanal ysis attacks is called Homophones 7 in cryptography.A third technique that can effectively defeat cryptanalysis is Polyalphabetic substitution, that is, the use of several alphabets to encrypt the message 3, rather than using the same substitution technique again and again. The Vigenere Cipher is a form of Polyalphabetic cipher. This ensures that, no two characters are encrypted to the same ciphertext alphabet in the same message. This ensures that, direct frequency analysis of the cipher is not possible to successfully retrieve the original message. However, other techniques need to be used to identify the key length, if this is possible, then frequency analysis attack could be used to identify the original plaintext message successfully.Finally, a possible technique that could be used to defeat frequency analysis is to encrypt a single character of plaintext with two ciphertext characters 3. Upon encountering the same character twice, then different characters should be used to en crypt the message. This can be achieved by using a key size double that of the plaintext message and then encrypting the same plaintext with two values in the key and save them together for the same plaintext character. This would ensure that no two plaintext characters will have the same ciphertext character, defeating the frequency analysis method of breaking the cipher. Modern encryption algorithms and cryptanalysis Modern cryptographic algorithms take a better approach in defeating frequency analysis based attacks. The cryptographic algorithms nowadays use block encryption, rather than encrypting characters bit by bit, thus eliminating the redundancy of ciphertext alphabets for similar plaintext alphabets. Block ciphers are the central tool in the heading of protocols for shared-key cryptography. A block cipher is a function E 0, 1k - 0, 1n 0, 1n. This notation means that E takes two inputs, one being a k-bit string and the other an n-bit string, and returns an n-bit string 2. The first input is the key, which is used to encrypt the secret message. The second string is called the plaintext, and the output is called a ciphertext. The key-length k and the block-length n are parameters associated to a specific block cipher. They vary from block cipher to block cipher, and depend on the design of the algorithm itself. both(prenominal) of the most trusted symmetric ciphers include AES, Triple-DES, Blowfish, CAST and IDEA. In public-key cryptography, the most commonly used cryptosystems are RSA and the Diffie-Hellman systems, which have not been found to have any vulnerabilities till date. Preferably, the block cipher E is a public specified algorithm. In typical usage, a random key K is chosen and kept secret between a pair of users. The function EK is used by the sender to encrypt the message, for a given key, before sending it to the intended receiver, who decrypts the message using the same key 2. Security relies on the secrecy of the key. So, at first, one might think of the cryptanalysts goal as recovering the key K given some ciphertext, intercepted during transmission. The block cipher should be designed to make this task computationally difficult. In order to achieve this, the algorithms that are used to encrypt the message must be designed with a high degree of mathematical complexity, which cannot be reversed to obtain the plaintext from a known ciphertext. The length of the key used during encryption of a message plays an important role in deciding the effectiveness of an algorithm. Key length is conventionally measured in bits, and most of the well known strong ciphers have key lengths between 128 and 256 bits. A cipher is considered strong if, after years of attempts to find a weakness in the algorithm, there is no known effective cryptanalytic attack against it. This indicates that, the most efficient way of breaking an encrypted message without knowing the key used to encrypt it is to brute force it, i.e. trying all po ssible keys. The effort required to break an encrypted message is determined by the number of possible keys, known as thekeyspace. Knowing the speed of the computer to break the key, it is easy to calculate how long it would take to search the keyspace to break a particular cipher 2.For example, considering a cipher that uses 128-bit keys, each bit can either be 0 or 1, so, there are 2128 or 3-1038 keys approximately. Suppose we imagine that about ten billion computers are assigned the task of breaking the code, each capable of testing ten billion keys per second, then, the task of running through the entire keyspace would take around 3-1018seconds, which is about 100 billion years. But, in fact, it would be necessary to run through only half the keyspace to hit upon the correct key, which would take around 50 billion years. This is longer than the estimated age of the universe according to modern cosmology, which is about 15 billion years 2. This shows that, it is practically infea sible to crack modern cryptographic algorithms using Brute Force attacks. So, one can imagine the effectiveness of the modern cryptographic algorithms and their resistance towards cryptanalytic attacks.Conclusions Cryptography has progressed in recent years and modern cryptographic algorithms have proved to be successful in defending against most forms of cryptanalytic attacks. Frequency analysis based attacks have proved to exploit the weaknesses in traditional encryption algorithms into revealing the plaintext message that was encrypted using them. The natural language used to encrypt messages is not considered to be random in nature, which is exploited by frequency counting based attacks. Based upon the frequency of letters that occur in the ciphertext, one can guess the plaintext characters due to their redundancy rate and the specific combination of letters in a word. This weakness can be repelled by using stream ciphers, which do not carry the redundancy in the plaintext to th e ciphertext. Modern block cipher, encrypt a chunk of plaintext into ciphertext and vice versa, eliminating the redundancy of language used in encryption. Although the algorithm plays an important part, it is the key length used in block ciphers that helps in repelling cryptanalysis. Modern ciphers use a key length starting from 128 bits, eliminating the speculation of a brute force attack to decrypt the message. The higher the key length, the more time it takes to break these ciphers. These advantages have made modern cryptographic algorithms more popular among the security community. No known weaknesses have been found in these algorithms yet, that may allow one to identify the plaintext message. Bibliography1 Stallings, W., Cryptography and Network Security, Chapter 1, Third Edition, apprentice Hall, 20032 Schneier, B., Applied Cryptography, Chapter 1, Second Edition, John Wiley Sons, newfangled York City, New York, USA, 19963 Hart, G.W., To Decode Short Cryptograms, Communic ations of the ACM 37(9), 1994, pp. 102-1084 Lee, K.W., Teh, C.E., Tan, Y.L., Decrypting English Text Using Enhanced Frequency Analysis, National Seminar on Science, Technology and Social Sciences (STSS 2006), Kuantan, Pahang, Malaysia5 Zipf, GK., Human Behaviour and the Principle of Least Effort, 1949, Cambridge Addison Wesley Publications.6 Lewand, R.E., Cryptological Mathematics, The Mathematical Association of America, 2000, Pages 345-3467 Stamp, M and Low, R.M., Applied Cryptanalysis, 2007, Chapter 1 and 2, John Wiley Sons, New York City, New York, USA 8 http//www.simonsingh.net, Online internet frequency analysis tools9 http//www.textalyser.net, online text analysis and frequency analysis information

Bipolar Disorder Essay example -- Research Disorders Bipolar Essays

Bipolar Disorder Bipolar derangement is often considered a hereditary illness. According to the National kind Health Association (2001) a specific genetic link to bipolar disorder has not been found. Studies show that 80 to 90 percent of those who suffer from bipolar disorder have relatives with some form of depression (NIMH, 2001). Bipolar disorder is a mental illness involving one or to a greater extent episodes of serious monomania and depression which causes individuals to feel an euphoric type high or feeling really low. Over 2.5 million people in America have bipolar disorder. This disorder usually occurs during adolescence or early adulthood and continues throughout life. Although, young children can be diagnosed with manic depression as well. Bipolar disorder also shows symptoms by being very irritable and having destructive tantrums throughout the day. Sommers (2000), wrote that teenage guys and girls are equally likely to experience manic depression, but it is often m ore apparent in girls ( p.15 ). This is because guys do not like admitting to being depressed because it makes them look weak and have no control, so they tend to hold endure their feelings which will only make their life more difficult. In contrast girls are more prone to talk about their feelings than guys are. Diagnosing individuals with bipolar disorder is very difficult due to the fact that many people deny that anything is wrong because he or she likes the feeling of being in high mood. other reason diagnosing is difficult is because the problem may be related to some other type of illness or accompanied with a coexisting problem like substance abuse, poor performance in schoolwork and jobs.Bipolar disorder ( a.k.a. Manic Depressive illness) is a disorder that causes unusual shifts in a persons mood, energy, and ability to function ( National Institute of Mental Health NIMH, 2001 ). This disorder consist of severe episodes of highs and lows that individuals go through. Thes e highs and lows have a untold greater impact on an individuals life than the normal highs and lows people go through everyday. These episodes can lead to unwanted behaviors, depression, anxiety and can lead to self-destruction if not treated. There are four categories in which bipolar disorder is classified according to symp... ...s through musics. There are several different types of medications on the market today used for treating bipolar patients but the oldest one that has shown a significant decrease of episodes is known as lithium. Lithium is a natural and modular mood stabilizer that has been extremely beneficial in treating bipolar patients. Also, many BD patients will also be prescribed to some type of antidepressants like, Zoloft, Prozac, and Paxil. Sleeping back up are sometimes prescribed for short term therapy for patients dealing with insomnia. Most common prescribed sleeping aids are xanax, topamx. A combination of these medication has shown to be effective, bu t reported patients having hard-take side effects. Taking a combination of anti-psychotics, sleeping aids, thyroid supplements, and benzodiazepine is sometimes called med cocktails. Patients taking medications are also advised to render professional help from psychiatrist, psychologist, psychotherapist, or some type of mental health professional. This is an essential part of treating people with bipolar disorder who want to keep this disease in control and not it controlling ones life.

The History of the Holocaust Essay -- World History

Adolf Hitler said I believe that I am acting in the accordance with the will of the all properly Creator, by defending myself against the Jew, I am fighting for the work of the lord. This is how he rationalized his malicious acts against the Jewish people in Germany. A horrendous act that would ulterior become known as the Holocaust.The first act toward the holocaust was on January 30th, 1933, when Adolf Hitler became chancellor of Germany. Paul Von Hindenberg, the current president of Germany, did his best to keep Hitler out of office, only if in the end it wasnt enough. At that time the Jewish population in Germany was approximately 566,000 people. From that point on things only went down hill for the Jews in Germany. Just a few months after Hitler became chancellor and a mere week after he became the dictator he passed a law parliamentary law a boycott on all Jewish banks, shops, offices, and department stores that would take effect on April 1st, 1933. Then on September 15th, 1935 Hitler passed a series of laws that came to be known as the Nuremberg Laws. The first of these laws was put in place to protect the honor and blood line of the German people. It stated that no Jew would be allowed to tie or participate in marital intercourse with anyone that was not of the same race. The second law robbed the Jewish people of their citizenship. Kristallnacht, also known as the shadow of Broken Glass, was a series of attacks on the Jewish people by the Nazi soldiers on the nights of November 9th and 10th, 1938. Nazi soldiers attacked Jewish homes and destroyed their businesses, not to mention the more(prenominal) that 200 synagogues that were burned to the ground. Nearly 100 Jewish people were murdered and approximately 200,000 were sent to concentrat... ...nihilate all the Jews in Germany. Instead Hitler ultimately left us with a lesson to be learned from his narrow minded vision. That lesson is simply this We are all different because of that, individual ly of us has something different and special to offer and each and every one of us can make a difference by not being indifferent Henry Friedman Chairman. Works CitedN.p., n.d. Web. 22 demoralize 2015. .N.p., n.d. Web. march 15 2015. .N.p., n.d. Web. 22 Mar 2015. .Hill, Jeff. the holocaust. PrintN.p., n.d. Web. 22 Mar 2015. .N.p., n.d. Web. 22 Mar 2015. .N.p., n.d. Web. 22 Mar 2015. .