dissertation com do not use dez 1999 (14 results)

Taschenbuch. Condition: Neu. Neuware - Scope of Study: This dissertation summarizes the current use of concurrent software engineering (CSE) by information technology (IT) organizations in the United States and its effectiveness in improving software delivery time, quality, and cost. From a total population of 7,173 IT organizations, a one-third sample of 2,391 were surveyed. A net valid response of 142 organizations was received, which represents a valid return rate of 6.2 percent. The responses were then analyzed against software development time, quality, and cost metrics according to the software development methodologies used. Findings and Conclusions: This study shows the extent to which pure CSE and CSE in combination with the traditional system development life cycle (SDLC) are used in the United States. There are strong indications that CSE improves software development time and cost, but this could not be statistically proven from the data. There is no indication that CSE improves software quality.

Taschenbuch. Condition: Neu. Neuware - Scope of Study: This dissertation investigates the effect of cost and dose on the hemodialysis treatment modality. This modality of dialysis is an alternative to renal transplantation for people diagnosed with end-stage renal disease. The mortality rate is used as a quality indicator of the hemodialysis treatment by assessing the quality of service in Colombia and comparing it with the quality of service in the United States.Findings and Conclusions: The hypothesis testing used in this research shows that there is a significant difference between the delivered dose of hemodialysis in Colombia and the United States. The mortality rate for patients in hemodialysis in Colombia for a comparable age group (45-64) is higher than that of the United States. This is attributed in great part to the effect of the hemodialysis dose on the treatment. A simple linear regression shows a strong negative relationship between mortality rate and dose. Cost also has an impact on the quality of service of the hemodialysis therapy. Nevertheless, a direct relationship between cost and mortality rate could not be established. Factors such as patient's vascular access and dialyzer flow rates are not evaluated in this investigation.

Taschenbuch. Condition: Neu. Neuware - As distance education schools grow in popularity, contemporary educators are raising important instructional questions about quality of these programs. A vital question involves concerns about the level of interactivity or interaction between students and between teachers and students. Interactivity is a challenging subject because there are few research studies that address the issue. It is a dynamic entity that involves a number of important elements, but the researcher stressed three vital elements: communication, participation, and feedback. The study highlights research results from a survey of students who were pursuing on-line graduate degrees (masters and doctoral). Important distance education issues are discussed such as feedback from professors and the quality of academic dialog during a computer-mediated class. The text offers a relevant analysis of interactivity that should help distance educators and administrators in their quest to develop programs that meet the needs of todayÍs adult learners.

Taschenbuch. Condition: Neu. Neuware - Quasi-Monte Carlo methods, which are often described as deterministic versions of Monte Carlo methods, were introduced in the 1950s by number theoreticians. They improve several deficiencies of Monte Carlo methods; such as providing estimates with deterministic bounds and avoiding the paradoxical difficulty of generating random numbers in a computer. However, they have their own drawbacks. First, although they provide faster convergence than Monte Carlo methods asymptotically, the advantage may not be practical to obtain in 'high' dimensional problems. Second, there is not a practical way to measure the error of a quasi-Monte Carlo simulation. Finally, unlike Monte Carlo methods, there is a scarcity of error reduction techniques for these methods. In this dissertation, we attempt to provide remedies for the disadvantages of quasi-Monte Carlo methods mentioned above. In the first part of the dissertation, a hybrid-Monte Carlo sequence designed to obtain error reduction in high dimensions is studied. Probabilistic results on the discrepancy of this sequence as well as results obtained by applying the sequence to problems from numerical integration and mathematical finance are presented. In the second part of the dissertation, a new hybrid-Monte Carlo method is introduced, in an attempt to obtain a practical statistical error analysis using low-discrepancy sequences. It is applied to problems from mathematical finance and particle transport theory to compare its effectiveness with the conventional methods. In the last part of the dissertation, a generalized quasi-Monte Carlo integration rule is introduced. A Koksma-Hlawka type inequality for the rule is proved, using a new concept for the variation of a function. As a consequence of the rule, error reduction techniques and in particular an 'importance sampling' type statement are derived. Problems from different disciplines are used as practical tests for our methods. The numerical results obtained in favor of the methods suggest the practical advantages that can be realized by their use in a wide variety of applications.

Taschenbuch. Condition: Neu. Neuware - The problem this project attempts to solve is to develop a workable moral education in light of the clash between religious forms of moral education and U.S. Supreme Court decisions concerning them. The concept of story and storytelling has been suggested as a unifying focus for disparate prescriptions for moral education. Several recent approaches to moral storytelling have been proposed. The approaches of William Bennett, Nel Noddings, and Herbert Kohl are among those which have attempted to combine moral education and storytelling within the last decade. Bennett is identified with other theorists whose primary concern is the moral content of a story. Noddings is identified as a process theorist, whose primary concern is the process of moral storytelling, not the content. Kohl is identified as a reflection theorist, whose approach challenges tradition in the hope of creating a more moral society. Each one of these three approaches attempts to provide a comprehensive program of moral education, but they fall short of that goal. The purpose of this project, then, is to construct a storytelling moral education program that improves upon earlier approaches. Using the three levels of moral thinking posited by R.M. Hare, a three-level approach to moral storytelling is proposed. The intuitive, critical, and meta-ethical levels of moral thinking that Hare refers to are used to frame a new, three-level, approach to moral storytelling. The three-level approach combines content, process, and reflection into a unified prescription for moral education. Thus, a more comprehensive plan for moral education through storytelling is developed, one that respects traditional forms of moral education while remaining within the parameters set by the U.S. Supreme Court.

Taschenbuch. Condition: Neu. Neuware - The effect of video and written modeling on self-efficacy of 70 master's degree students enrolled in their first techniques course was investigated. The ability to understand and use reflection of content, feeling, and meaning was presented to the experimental group through videotaped instruction and examples and the control group through written instruction and examples. Facts about reflecting skills, which included information and three vignettes, demonstrated the use of the skills. Through two pilot studies, the Reflecting Skills Questionnaire (RSQ) developed for this study showed convergent validity with the Counseling Self-Estimate Inventory (COSE). Participants' indication of self-efficacy for the reflection of content, feeling, and meaning was assessed by the RSQ. A t - test was computed to determine whether video or written treatment had an effect on the self efficacy of counselors in training. Using a two-tailed t - test for independent groups, no significant difference (p > .05) was found.

Taschenbuch. Condition: Neu. Neuware - The problem of controlling sensory perception for use in discrete event feedback control systems is addressed in this thesis. The sensory perception controller (SPC) is formulated as a sequential Markov decision problem. The SPC has two main objectives; 1) to collect perceptual information to identify discrete events with high levels of confidence and 2) to keep the sensing costs low. Several event recognition techniques are available where each of the event recognisers produces confidence levels of recognised events. For a discrete event control system running in normal operation, the confidence levels are typically large and only a few event recognisers are needed. Then, as the event recognition becomes harder, the confidence levels will decrease and additional event recognisers are utilised by the SPC. The final product is an intelligent architecture with the ability to actively control the use of sensory input and perception to achieve high performance discrete event recognition. The discrete event control framework is chosen for several reasons. First, the theory of discrete event systems is applicable to a wide range of systems. In particular, manufacturing, robotics, communication networks, transportation systems and logistic systems all fall within the class of discrete event systems. Second, the dynamics of the sensing signals used by the event recognisers are often strong and contain a large amount of information at the occurrence of discrete events. Third, because of the discrete nature of events, feedback information is not required continuously. Hence, valuable processing time is available between events. Fourth, the discrete events are a natural common representational format for the sensors. A common sensor format aids the decision process when dealing with different sensor types. Fifth, the sensing aspect of discrete event systems has often been neglected in the literature. In this thesis we present a unique approach to on-line discrete event identification. The thesis contains both theoretical results and demonstrated real-world applications. The main theoretical contributions of the thesis are 1) the development of a sensory perception controller for the dynamic real-time selection of event recognisers. The proposed solution solves the Markov decision process using stochastic dynamic programming (SDP). SDP guarantees cost-efficiency of the real-time SPC by solving a sequential constrained optimisation problem. 2) A sensitivity analysis method for the sensory perception controller has been developed by exploring the relationship between Markov decision theory and linear programming. The sensitivity analysis aids in the robust tuning of the SPC by finding low sensitivity areas for the controller parameters. Two real-world applications are presented. First, several event recognition techniques have been developed for a robotic assembly task. Robotic assembly fits particularly well in the discrete event framework, where discrete events correspond to changes in contact states between the workpiece and the environment. Force measurements in particular contain a significant amount of information when the contact state changes. Second, the sensory perception control theory and the sensitivity analysis have been demonstrated for a mobile navigation problem. The cost-efficient use of sensory perception reduces the need for mobile robots to carry heavy computational resources.

Taschenbuch. Condition: Neu. Neuware - That neuropsychological performance is impaired in patients with affective disorders is now widely accepted, and there is growing evidence that attentional dysfunction (effortful attention in particular) is one of the major impairments normally observed. The present study aimed at defining the nature of attentional dysfunction in depression by means of tests designed to measure specific aspects of attention, such as sustained, selective, focused, divided attention, etc. We also tested the effect of increasing effortful attentional demands on subjects' performance. To that end, effort level was increased on the task variable that was considered to be the defining characteristic of each task. For example, the Stroop Color-Word is a test of perceptual interference, so that on the high effort condition we presented two types of interference - visual as well as auditory (recorded messages). Fourteen unipolar and thirteen bipolar patients were recruited from the inpatient psychiatry unit at the University of Massachusetts Medical Center, based on DSM-III criteria and score on the Inventory to Diagnose Depression (IDD). An age and education matched control group (N=20) was recruited from hospital workers. Subjects were administered a battery of twenty neuropsychological tests, including: Computerized Stroop Test, Continuous Performance Test, Trail Making, Symbol-Digit Modalities Test, Finger Tapping & Controlled Word Generation, Visual Letter Search, Digit Span, and a Levels of Processing Memory task. For each of these tasks, a low and high effort levels were employed. Subjects filled out two self-report scales, Fatigue Assessment Inventory and Profile of Mood States, before and after testing. Both unipolar and bipolar patients exhibited severe depression as measured by the IDD. ANOVA procedures indicated that on most measures patients performed significantly poorly when compared to normal controls (p.

Taschenbuch. Condition: Neu. Neuware - In this dissertation, a new spare capacity planning methodology is proposed utilizing path restoration. The approach is based on forcing working flows/traffic which are on paths that are disjoint to share spare backup capacity. The algorithm for determining the spare capacity assignment is based on genetic algorithms and is capable of incorporating non-linear variables such as non-linear cost function and QoS variables into the objective and constraints. The proposed methodology applies to a wider range of fault scenarios than most of the current literature. It can tolerate link-failures, node-failures, and link-and-node failures. It consists of two stages: the first stage generates a set of network topologies that maximize the sharing between backup paths by forcing them to use a subset of the original network. The second stage utilizes a genetic algorithm to optimize the set of solutions generated by the first stage to achieve an even better final solution. It can optimize the solution based on either minimizing spare capacity or minimizing the total network cost. In addition, it can incorporate QoS variables in both the objective and constraints to design a survivable network that satisfies QoS constraints.Numerical results comparing the proposed methodology to Integer Programming techniques and heuristics from the literature are presented showing the advantages of the technique. The proposed methodology was applied on 4 different size networks based on spare capacity optimization criteria and it was found that it achieved solutions that were on average 9.3% better than the optimal solution of the IP design that is based on link-restoration. It also achieved solutions that were on average 22.2 % better than the previous heuristic SLPA. The proposed methodology is very scalable. It was applied on networks with different sizes ranging from a 13-node network to a 70-node network. It was able to solve the 70-node network in less than one hour on a Pentium II PC. The curve-fitting of the empirical execution time of the methodology was found to be O(n3).

Taschenbuch. Condition: Neu. Neuware - During the adolescent years, young people seek to leave behind childhood and the age of 'informed consent'--i.e, the years when adults informed and expected children to consent! Teenagers strive for adult roles and passionately seek ways to prove their maturity to themselves, peers, and adults. This quest for adult roles leads teens through a variety of rites of passage both formal and informal. Some rites of passage which involve youth/adult partnerships delineate the movement from childhood to adulthood in positive ways while young people (psychological orphans) who do not have adult support for rites of passage often create their own rites which involve dangerous risk-taking and destructive behavior.Aching to Age explores rites of passage both ancient and modern, formal and informal; examines the place of these rites in meeting the adolescent psychological quest for adulthood (adult roles); and also explores popular cultural practices by adolescents who lack or eschew established rites of passage. Further, Aching to Age looks at the purpose of these rites in the lives of adolescents and finally explores the importance of rites of passage and how adults who interact with adolescents become partners with young people in the transition to adult roles and responsibilities.

Taschenbuch. Condition: Neu. Neuware - This study is designed to show how personality dispositions and cognitive variables may combine with social norms to influence wife abuse. Prior research examining the role of individual differences in wife abuse has been sparse, unsystematic, and appear questionable for two reasons. First, these studies have not considered that contextual norms and cognitive variables are likely to interact with dispositional variables to either facilitate or discourage abuse. Second, the theoretical relationship between dispositional variables and macrolevel approaches (i.e. feminist and sociological) has not been investigated. How demographic variables, contextual norms, and individual differences interact may have important implications for the study of wife abuse. The present project addresses these issues by focusing on a description of the relationship between personality (authoritarianism & sex-role attitudes), cognitive variables (self-consciousness & the hostile attribution bias), contextual norms (military experience & regional background) and wife abuse. 149 males completed a questionnaire containing the Conflict Tactics Scale, RWA scale, Self-Consciousness Scale, Adversarial Sexual Beliefs Scale, and the Attitudes Toward Women Scale. Furthermore, subjects responded to a variety of demographic items designed to assess income level, age, regional background, alcohol consumption, educational level, and military experience. Results suggest three principal conclusions. First, they show that the hostile attributional bias is the most powerful predictor of verbal and physical abuse. Analyses consistently indicated that subjects possessing hostile attributions toward women are the most likely to verbally and physically abuse their present partner. Second, the contextual norms and demographics emphasized in past models of abuse were found to interact with personality and cognitive variables. The effect of military experience, Southerness, and alcohol use were mediated by personality and cognitive variables. Finally, the present results are consistent with past studies showing that abusers consume more alcohol, are younger, and earn less than non-abusers. Insofar as the results show significant relationships between relevant of cognitive, personality, and contextual factors, they provide a new, more accurate description of the problem, and may allow more effective forms of prediction, intervention and treatment.

Taschenbuch. Condition: Neu. Neuware - America is a mobile nation and frequent relocation is a way of life for many corporate families. This qualitative review of literature relating to the sociological impact of relocation on the corporate family appears to show that relocation has short-term and long-term implications for the family system. Relocation is not an isolated event but a process of adjustment over time involving emotional stages similar to the stages of grief and loss. Each family member may experience the relocation differently and progress through the stages at a different rate. This creates a period of disorganization and disorientation for the family similar to a prolonged jet-lag, which I call Relo-Lag(TM). This period of adjustment for the family system is the most frequently cited short-term effect and can last up to two years. Frequent relocations may also precipitate a long-term effect by causing the family system to become too tightly closed. The family may not seek outside help when needed or accept it when offered. Individual family members may experience difficulty with long-term close friendships and relationships outside the family. In addition, children appear to be particularly vulnerable when relocating during the individuation stages, years 3-5 and adolescence, years 13-16. Not all families experience relocation negatively and some families cope well with relocation. Relocation can improve career and financial opportunities for some corporate families, but there may be emotional costs that need to be considered before making a decision to relocate.

Taschenbuch. Condition: Neu. Neuware - Intensive Case Management (ICM) did not evolve from a single, well-defined model format but from different case management models. As a result, it has been vaguely defined as meaning more 'intense' than usual case management, thus highlighting the lack of consensus about ICM's definition and parameters. Despite these differences, ICM programs aspire to a set of common principles and core operational functions derived from the concept of continuity of care. Recent literature reviews have found mixed results regarding studies examining ICM effectiveness ( e.g., psychiatric hospitalizations, etc.). It has been difficult to make comparisons between studies because operational definitions have not been standardized.This study attempted to construct a program theory that unifies the various ICM practice orientations and specifies its operationalization so that more effective implementation and evaluation can occur. An integrative approach was used that synthesized information from the existing literature and by surveying three distinct stakeholder groups (researchers/ administrators, program managers, case managers) for their perspectives.Twenty-two researchers/ administrators who were considered experts, 21 ICM program managers and 46 ICMs working in 4 separate programs in New York City rated the importance of 68 program elements. Respondents identified 32 out of 68 program components as critical. A preliminary fidelity index was developed from these results. In addition, empirically derived norms for 12 model specifications were operationalized (e.g. ideal caseload size, etc.). Agreement among all respondents on ratings of importance was high (intraclass r = .92), although there was less agreement for some areas and respondent groups. Consensus was highest among ICMs, followed by program managers and experts.Significant findings included the perceived importance of a bachelors degree in human services, access to psychiatric consultation, optimum caseload size of 1:11, access to funds for client purchases and 85% of contacts occur in the community. Under treatment foci, a number of practice elements from the Personal Strengths and Rehabilitation perspectives were identified as critical.Additional suggestions from respondents focused on ICMs participating in the hospitalization/discharge process, how revenues are derived, and the lower success rates ICM has with clients suffering from character disorders and severe substance abuse. Results reinforced the idea that ICM is a 'client driven' intervention in contrast to typical case management programs that are 'system driven'.

Taschenbuch. Condition: Neu. Neuware - The study of Multivariate Time Series has always been more difficult at the modeling stage than the univariate case. Identification of a suitable model, questions of stability, and the difficulties of prediction are well recognised. A variety of methods appear to be worth examining. This thesis is concerned with the proposal of an useful tool which is to apply canonical analysis to a realisation of a Multivariate Time Series and concentrates it's attention on k-variate ARMA(p,q) models. The multivariate series is partitioned into two overlapping or non-overlapping sets of different sizes. The left set is kept at lag 0 (without loss of generality) and the right set at a sequence of lags s=0,1, . The model includes the possibility that the same subset of variables belong to the left set at lag 0 and to the right set at lag s. A technique for dimension reduction is suggested. We tried to elucidate identification and the internal structure of time-dependence at several pairs of lags as a tool for identification. As the technique suggested provide a method of investigation of patterns of interrelations between two multivariate sets or subsets of variables with a joint distribution, it is an efficient tool for use in multivariate series of economic data. A review of the basic models of Multivariate Time Series is given and their canonical auto and cross correlation analysis is presented. In order to study the asymptotic distribution, several Monte Carlo experiments were necessary. We attempted to provide information through simulation about the distributional and other statistical properties for the canonical statistics obtained by our procedures. New software is provided and data experience is given. The first computer program provides us with information, graphs for the canonical auto and cross correlations, test statistics for the 'useful' canonical auto and cross correlations as well as the left and right eigenvectors, left and right intraset and interset matrices of correlations, proportions of variances extracted by the canonical variates of the left and of the right sets and left and right redundancies for lags s=0,1, .The second program gives similar calculations for the k-variate ARMA(p,q) models when the matrices of parameters and variance-covariance matrix of the error are known. The third program provides us with the mean value, minimum and maximum values, excess kurtosis, histogram and cumulative distribution for each one of the canonical auto and cross correlations at every lag s calculated from several simulations of Monte Carlo generated k-variate ARMA(p,q) models when the matrices of parameters and variance-covariance matrix of the error are given or when they are generated. The second part of the thesis is devoted to the generalisation of the robust and practically useful univariate Holt-Winters model. We developed formula for the Multivariate Additive Holt-Winters (Seasonal and Non-Seasonal) to the point of application and its reduction to Moving Average form. New software is produced. The link between the two main themes consists on the canonical analysis of a Multivariate Holt-Winters from its reduced MA form and reducing its dimension as well as detecting the basic linear relationships between variables, between and within several lags. We also attempted to investigate the effect of outliers, the removal of non-stationary trends via cubic spline fitting , differencing as well as transformations such as loge (data).