Continuous-time Proportional-Integral Distributed Optimization for Networked Systems

In this paper we explore the relationship between dual decomposition and the consensus-based method for distributed optimization. The relationship is developed by examining the similarities between the two approaches and their relationship to gradient-based constrained optimization. By formulating each algorithm in continuous-time, it is seen that both approaches use a gradient method for optimization with one using a proportional control term and the other using an integral control term to drive the system to the constraint set. Therefore, a significant contribution of this paper is to combine these methods to develop a continuous-time proportional-integral distributed optimization method. Furthermore, we establish convergence using Lyapunov stability techniques and utilizing properties from the network structure of the multi-agent system.Comment: 23 Pages, submission to Journal of Control and Decision, under review. Takes comments from previous review process into account. Reasons for a continuous approach are given and minor technical details are remedied. Largest revision is reformatting for the Journal of Control and Decisio

On the Existence of the Moments of the Asymptotic Trace Statistic

In this note we establish the existence of the first two moments of the asymptotic trace statistic, which appears as weak limit of the likelihood ratio statistic for testing the cointe- gration rank in a vector autoregressive model and whose moments may be used to develop panel cointegration tests. Moreover, we justify the common practice to approximate these moments by simulating a certain statistic, which converges weakly to the asymptotic trace statistic. To accomplish this we show that the moments of the mentioned statistic converge to those of the asymptotic trace statistic as the time dimension tends to infinity.Cointegration, Trace statistic, Asymptotic moments, Uniform integrability

Panel Cointegration Testing in the Presence of a Time Trend

The purpose of this paper is to propose a new likelihood-based panel cointegration test in the presence of a linear time trend in the data generating process. This new test is an extension of the likelihood ratio (LR) test of Saikkonen & Lütkepohl (2000) for trend-adjusted data to the panel data framework, and is called the panel SL test. The idea is first to take the average of the individual LR (trace) statistics over the cross-sections and then to standardize the test statistic with the appropriate asymptotic moments. Under the null hypothesis, this standardized statistic has a limiting normal distribution as the number of time periods (T) and the number of cross-sections (N) tend to infinity sequentially. In addition to the approximation based on asymptotic moments, a second approximation approach involving the moments from a vector autoregressive process of order one is also introduced. By means of a Monte Carlo study the finite sample size and size-adjusted power properties of the test are investigated. The test presents reasonable size with the increase in T and N, and has high power in small samples.Panel Cointegration Test, Likelihood Ratio, Time Trend, Monte Carlo Study

Health Insurance Competition: The Effect of Group Contracts

In countries like the US and the Netherlands health insurance is provided by private firms. These private firms can offer both individual and group contracts. The strategic and welfare implications of such group contracts are not well understood. Using a Dutch data set of about 700 group health insurance contracts over the period 2007-2008, we estimate a model to determine which factors explain the price of group contracts. We find that groups that are located close to an insurers’ home turf pay a higher premium than other groups. This finding is not consistent with the bargaining argument in the literature as it implies that concentrated groups close to an insurer’s home turf should get (if any) a larger discount than other groups. A simple Hotelling model, however, does explain our empirical results.health insurance;health-plan choice;managed competition

The effect of writing to a real audience for a real purpose on the writing skills and self esteem of seventh grade inner city students.

The purpose of this study was to determine the effects of writing to a real audience for a real purpose on the writing skills and self esteem of seventh grade students. Inner city, culturally diverse seventh graders exchanged a series of letters with successful members of an urban community. The study investigated the effects of this exchange on the writing skills and self esteem of the students. The twenty five seventh graders in the study were matched randomly with the adults. They wrote at least four letters each, over a four month period, and received responses. They celebrated their connection by meeting at the middle school for a breakfast. The results of the study were documented by pre and post tests, opinion questionnaires from students, teachers and parents, overall grades and grades in English and reading, anecdotal observations, and an exit interview. The data supports the general hypothesis that when seventh grade students in an inner city, culturally diverse middle school write to a real audience for a real purpose, their writing skills improve and their self esteem is enhanced. After writing at least four letters to caring local adults, many students showed improved overall grades, and better English and reading grades. They used the appropriate friendly letter heading, longer sentences, varied end punctuation, and more interesting topic sentences. Their paragraphs indicated clear thought, and were better organized. Their stories during the exit interview proved to be overwhelmingly in favor of the writing exchange. Their parents and teachers felt the students showed improved self esteem, and a clearer connection to their community. Students indicated a greater comfort level with school, made friends with their Pals, got advice from them, and enjoyed their company. The study validated the idea that students become more conscious of thinking and learning when their tasks are real and that learning is best achieved in a social context

IDENTIFYING THE INFLUENCE OF SELECTIVE EPISODES AND MECHANISMS ON REPRODUCTIVE SUCCESS IN TRIBOLIUM CASTANEUM AND DROSOPHILA MELANOGASTER

Parsing out what makes some individuals more reproductively successful than others is a key pursuit in evolutionary biology. While reproductive success can ultimately be defined as the number of offspring produced over an individual’s lifetime, there are many selective episodes that shape this outcome. Because the majority of animals have multiple mates, achieving matings is but one influence on reproductive success. After copulation occurs, sperm from multiple males compete within the female reproductive tract to fertilize eggs, while females morphologically or behaviorally bias fertilization to preferred males, further shaping reproductive success. Additionally, the act of mating itself may influence parental lifespan or rate of offspring production. Here, I investigate the influence of multiple selective episodes on different aspects of reproductive success in two insects: the fruit fly, Drosophila melanogaster and the red flour beetle, Tribolium castaneum. Established genomes in both systems enabled the generation of transgenic, fluorescently labeled lines: green fluorescent protein (GFP) driven by a ubiquitin promoter in D. melanogaster to look at paternity in eggs, and GFP or red fluorescent protein (RFP) tagged protamines to identify different male’s sperm by head color in T. castaneum. I investigated relationships between different episodes of reproductive success in D. melanogaster and found positive correlations between sperm competitive success and offspring viability; offspring viability itself was influenced by a male × female interaction on hatching success. In T. castaneum, I explored potential drivers of their extremely promiscuous mating system and how that system influences mechanisms of postcopulatory reproductive success. I found that repeated receipt of a complete ejaculate directly benefits female reproductive success, but comes at a longevity cost to males. This direct benefit of remating to females may explain why I found that the proportion of different male’s sperm in the main chamber of the female reproductive tract, and not the specialized sperm storage organ as in D. melanogaster and many other arthropods, determine the proportion of offspring sired by each male. The great differences in postcopulatory mechanics between D. melanogaster, found previously, and T. castaneum, found here, illustrate the importance of mating system in shaping aspects of reproductive success

Batch Informed Trees (BIT*)

Path planning through complex obstacle spaces is a fundamental requirement of many mobile robot applications. Recently a rapid convergence path planning algorithm, Batch Informed Trees (BIT*), was introduced. This work serves as a concise write-up and explanation of BIT*. This work includes a description of BIT* and how BIT* operates, a graphical demonstration of BIT*, and simulation results where BIT* is compared to Optimal Rapidly-exploring Random Trees (RRT*).Comment: 10 pages, 7 figure

Encoding Prose: The Complete Letters of Willa Cather a Literary Project in Digital Humanities

The purpose of this study is to further the progress of annotating and sharing renowned Nebraskan author Willa Cather’s correspondence through digital means. I will do this by assisting the current team at the Willa Cather Archive with their project titled The Complete Letters of Willa Cather. The team behind this project has made about 1,600 letters available to the public, and they estimate that by 2022 over 3,000 letters will be accessible through their website. Many libraries, foundations, and collections throughout the United States have cooperated with the project to allow Cather’s work and life to be understood more thoroughly. Although Cather’s will from 1943 initially stated that her correspondence was not to be published, the Willa Cather Trust changed this policy in 2011. With this decision, the project I have been working on since the fall of 2018 was born so that readers and scholars of Cather’s writing could have the opportunity to learn more about her not only as an accomplished author, but also as a family member, friend, and an independent thinker. The project has finished the first stage and is in the first half of stage two. This means hundreds of new letters will need to be encoded, researched, and annotated before they can be published as part of the edition