We propose a new method, based on semidefinite optimization, to find tight upper bounds on the expected project completion time and expected project tardiness in a stochastic project scheduling environment, when only limited information in the form of first and second (joint) moments of the durations of individual activities in the project is available. Our computational experiments suggest that the bounds provided by the new method are stronger and often significant compared to the bounds found by alternative methods. / Singapore-MIT Alliance (SMA)

<p><font face="CMR12"> <p align="left">This thesis deals with analysis and implementation of a positivity preserving numerical method for a vaccination model for the transmission dynamics of two HIVsubtypesnin a given community. The continuous model is analyzed for stability and equilibria. The qualitative information thus obtained is used while designing numerical method(s). Three numerical methods, namely, Implicit Finite Difference Method (IFDM), Non-standard Finite Difference Method (NSFDM) and the Runge-Kutta method of order four (RK4), are designed and implemented. Extensive numerical simulation are carried out to justify theoretical outcomes.</p> </font></p>

How do we discover a person’s true personality? How does personality appear from the inside (i.e., to the self)? How does that differ from how personality appears from the outside (i.e., to the observer)? Given that people often see themselves differently than they are seen by others, what are the conditions under which each perspective is accurate? These questions are central to understanding who a person really is and, in turn, how much people are aware of their own and others’ personalities. The goal of this dissertation is to examine these questions. I begin by providing a descriptive account of the differences between self- and other-perceptions in terms of positivity and accuracy. Specifically, in the first two studies, I compare how people see themselves to how they are seen by their friends, romantic partners, parents, and siblings (Chapter 2). Then, in the next two studies, I test the accuracy of self- and other-predictions of behavior by comparing them to actual naturalistic behavior recorded from people’s everyday lives (Chapter 3). Finally, in the fourth study, I examine the accuracy of self, friend, and stranger ratings of personality by comparing personality judgments to laboratory-based behavioral tests of personality (Chapter 4). The results show that self-perceptions are more negative than others’ perceptions of them, people are more aware of their own negative traits than their positive traits, and they fail to notice a substantial number of their own characteristics. Observers agree substantially about what a person is like, and their knowledge of a target’s observable personality is quite good. By comparing perceptions of the person from the inside and outside with objective behavioral criteria, we can come to understand the strengths and limitations of each perspective. In fact, the two perspectives often complement each other – one filling in the gaps left by the other. Furthermore, even when both perspectives are accurate, they are often accurate in different ways. Thus, although neither perspective alone can explain the whole puzzle of who a person really is, they both provide different pieces of the puzzle and together deepen our understanding of the person. / text

Guided by the positive youth development (PYD) framework and the broaden-and-build theory of positive emotions, this dissertation project involved the performance of two studies that were designed to explore the multifaceted aspects of personal and environmental sources of support, positive emotions, stress, depressive symptoms, and resilience. Examined in Study I was the question of whether one's positivity would differentiate levels of personal and environmental resources. Examined in Study II were the association, if any, between stress and resilience on depressive symptoms and whether resilience would exhibit a moderating effect of stress on depressive symptoms. Multivariate analysis of covariance and hierarchical multiple regression were used to test the different models in these studies. A sample of 510 students at an all-girl public middle and high school completed the survey (75% response rate). Results showed that (a) the different categories of positivity distinguished levels of personal and environmental resources, (b) stress had a significant positive direct effect on depressive symptoms, (c) resilience had a significant negative direct effect on depressive symptoms, and (d) the interaction between stress and resilience had a significant buffering effect on depressive symptoms. While adolescence is a challenging time in particular for girls, findings from the present study support PYD and the broaden-and-build theory of positive emotions as advantageous frameworks for developing empirically based interventions. Strategies that increase students' positive emotions in schools, which in turn broaden their thinking, coping, and social interactions, would be efficacious. Further, the results from Study II suggest that students with higher levels of resiliency were protected from the impact of stress, thus potentially explaining their lower scores for depressive symptoms compared to those students with lower levels of reported resilience. This supports the significant role of individual resiliency as a personal resource against depressive symptoms when experiencing higher levels of stress. Given the seriousness of declining psychological well-being in young girls as a major public health concern, coupled with the compounding effects later into life, programs that provide opportunities for young girls to cultivated resiliency will be, theoretically, highly effective. / text

The field of psychology has traditionally focused on the deleterious effects of adversity to the exclusion of positive effects. However, a literature on positive sequelae of traumatic events has burgeoned over the past decade. The issue of whether individual's reports of positive changes are merely illusory self-enhancing biases or are reflective of objective, quantifiable change is perhaps the most contentious in the posttraumatic growth research at this time. This dissertation begins with a broad overview of the extant research on posttraumatic growth, then presents the evidence supporting each side of the validity debate. As the population studied in this dissertation is adults with traumatic-onset spinal cord injuries, a presentation of research that ties disability to the posttraumatic growth literature follows. Finally, the introductory chapter concludes with an argument for the importance of including a disability perspective in psychological science. Three papers follow, each taking up aspects of this relatively new focus on positive aspects of disability. / Psychology

<p><font face="CMR12"> <p align="left">This thesis deals with analysis and implementation of a positivity preserving numerical method for a vaccination model for the transmission dynamics of two HIVsubtypesnin a given community. The continuous model is analyzed for stability and equilibria. The qualitative information thus obtained is used while designing numerical method(s). Three numerical methods, namely, Implicit Finite Difference Method (IFDM), Non-standard Finite Difference Method (NSFDM) and the Runge-Kutta method of order four (RK4), are designed and implemented. Extensive numerical simulation are carried out to justify theoretical outcomes.</p> </font></p>

Background: Hepatitis E (HEV) is a small, non-enveloped virus that belongs to the viral genus Hepevirus. HEV is a positive sense single-stranded RNA virus and there is insufficient information regarding its replication. This is mainly because the virus has low capacity to grow in normally used cell cultures. Many specific strand assay detection studies have been done in order to understand more about HEV replication. Unfortunately, these assays have the disadvantage of giving false positive results. Aim: The aim of this project was to improve the positive strand assay to increase specificity and eliminate false positivity which is due to high sensitivity of the polymerase chain reaction (PCR). False positivity occurs as remains of transfected material in the cell are amplified. Method: The samples used in this project were swine samples from Sweden and a human sample (plasmid clone of genotype 1) from India. Negative samples, extracted positive samples and transcribed RNA positive sense samples were used. The methods applied were cDNA synthesis, exonuclease I and RNase treatments, DNA purification kits followed by first and nested PCR. Result: The results of this study indicated great improvement of the detection assay especially for the transcribed RNA samples. Best results were obtained at a final concentration of 1.5mM MgCl2 in the mastermix.  Conclusion: Changing the concentration of MgCl2 appeared to have a great effect on PCR specificity. Improving detection assays is very essential as they can be applied in the research field and in public health centers either for diagnosis or tracking disease outbreaks.

A quantum system which evolves in time while interacting with an external environ- ment is said to be an open quantum system (OQS), and the influence of the environment on the unperturbed unitary evolution of the system generally leads to non-unitary dynamics. This kind of open system dynamical evolution has been typically modeled by a Standard Prescription (SP) which assumes that the state of the OQS is initially uncorrelated with the environment state. It is here shown that when a minimal set of physically motivated assumptions are adopted, not only does there exist constraints on the reduced dynamics of an OQS such that this SP does not always accurately describe the possible initial cor- relations existing between the OQS and environment, but such initial correlations, and even entanglement, can be witnessed when observing a particular class of reduced state transformations termed purity extractions are observed. Furthermore, as part of a more fundamental investigation to better understand the minimal set of assumptions required to formulate well defined reduced dynamical quantum maps, it is demonstrated that there exists a one-to-one correspondence between the set of initial reduced states and the set of admissible initial system-environment composite states when G-consistency is enforced. Given the discussions surrounding the requirement of complete positivity and the reliance on the SP, the results presented here may well be found valuable for determining the ba- sic properties of reduced dynamical maps, and when restrictions on the OQS dynamics naturally emerge.

M. Comm. / The assessment and measurement of positive psychology have been largely survey driven, given the way in which this domain’s focus areas have been operationalised. The disadvantage of using surveys in the measurement of positive psychology is that measurement is to an extent ‘disembodied’ in this approach, meaning that positive psychology is reduced to a mental activity – something which implies the negation of the physical. The purpose of the study was therefore to explore to what extent an alternative instrument, the Positivity Projective Technique (PPT), based on embodiment theory, serves as a valid projective technique for eliciting positivity. Data were collected by means of a sentence completion technique (SCT) whereafter it was quantitatively (to a limited extent) and qualitatively analysed by means of a content analysis. The results were similar to, but greater in number than, the variables proposed by formal theories/models of positivity. Given the results, the PPT seems to be a valid projective technique of positivity and may be applied for positive developmental purposes within individual, organisational and consumer contexts.

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