Investigating Genetic Algorithm Optimization Techniques in Video Games

Immersion is essential for player experience in video games. Artificial Intelligence serves as an agent that can generate human-like responses and intelligence to reinforce a player’s immersion into their environment. The most common strategy involved in video game AI is using decision trees to guide chosen actions. However, decision trees result in repetitive and robotic actions that reflect an unrealistic interaction. This experiment applies a genetic algorithm that explores selection, crossover, and mutation functions for genetic algorithm implementation in an isolated Super Mario Bros. pathfinding environment. An optimized pathfinding AI can be created by combining an elitist selection strategy with a uniform distribution crossover and minimal mutation rate

Optimal Lower Bounds for Projective List Update Algorithms

The list update problem is a classical online problem, with an optimal competitive ratio that is still open, known to be somewhere between 1.5 and 1.6. An algorithm with competitive ratio 1.6, the smallest known to date, is COMB, a randomized combination of BIT and the TIMESTAMP algorithm TS. This and almost all other list update algorithms, like MTF, are projective in the sense that they can be defined by looking only at any pair of list items at a time. Projectivity (also known as "list factoring") simplifies both the description of the algorithm and its analysis, and so far seems to be the only way to define a good online algorithm for lists of arbitrary length. In this paper we characterize all projective list update algorithms and show that their competitive ratio is never smaller than 1.6 in the partial cost model. Therefore, COMB is a best possible projective algorithm in this model.Comment: Version 3 same as version 2, but date in LaTeX \today macro replaced by March 8, 201

Contextualized Measurement Scale Adaptation: A 4-Step Tutorial for Health Psychology Research.

Health psychology research is inherently context specific: Different health behaviors are executed by different target groups (e.g., gender, age) in different social structures, cultures, and environments. This asks for the adaptation of research instruments to enhance specificity. For example, when using measurement scales in new contexts, translation and psychometric validation of the instruments are necessary but not sufficient if the validity of the psychological concept behind a measurement scale has not been researched. In this study, we build on existing guidelines of translation as well as psychometric validation and present four steps on how to adapt measurement scales to a new context: Step 1 asks whether the psychological concept is found in the new context. Step 2 asks whether the measurement scale and its items are understood in the new context. Step 3 asks whether a measurement scale is valid and reliable. Step 4 asks how the items of the measurement scale perform individually. Following these four steps, measurement scales are carefully translated, adapted, and validated and can therefore be transferred to very different contexts

Interpreting the will of the people: a positive analysis of ordinal preference aggregation

We investigate how individuals think groups should aggregate members’ ordinal preferences – that is, how they interpret “the will of the people.” In an experiment, we elicit revealed attitudes toward ordinal preference aggregation and classify subjects according to the rules they apparently deploy. Majoritarianism is rare. Instead, people employ rules that place greater weight on compromise options. The classification’s fit is excellent, and clustering analysis reveals that it does not omit important rules. We ask whether rules are stable across domains, whether people impute cardinal utility from ordinal ranks, and whether attitudes toward aggregation differ across countries with divergent traditions

Evaluating deliberative competence: a simple method with an application to financial choice

We examine methods for evaluating interventions designed to improve decision-making quality when people misunderstand the consequences of their choices. In an experiment involving financial education, conventional outcome metrics (financial literacy and directional behavioral responses) imply that two interventions are equally beneficial even though only one reduces the average severity of errors. We trace these failures to violations of the assumptions embedded in the conventional metrics. We propose a simple, intuitive, and broadly applicable outcome metric that properly differentiates between the interventions, and is robustly interpretable as a measure of welfare loss from misunderstanding consequences even when additional biases distort choices

The effect of CO₂ infused ice on the formation and dissociation of CO₂ hydrate

CO₂ gas hydrates are crystalline water ice cages around a CO₂ molecule. CO₂ affects global climate change on Earth and a major atmospheric component of the Martian atmosphere. CO₂ hydrates likely have minor effects on terrestrial atmospheric CO₂ , but may be an present in large deposits on Mars. On Earth ice deposits are found in permafrost and glaciers and contain gas bubbles. These gas bubbles may have an effect on hydrate formation and dissociation rates. Such bubbles are also likely present on Mars and may significantly influence gas hydrate fluxes. In this study, CO₂ hydrate formation and dissociation rates were measured experimentally on ultrapure and CO₂ infused water ice (ice containing previously trapped CO₂ gas bubbles). Overall, increasing pressure and temperature increased hydrate formation rates. Formation and dissociation rates both increased significantly in infused ice experiments as did the overall amount of hydrate formed. The bubbles formed during freezing of the infused ice likely provided more surface area for hydrate nucleation, increasing the rate of formation. Dissociation rates were higher in infused ice compared to ultrapure ice likely due to the larger amount of hydrate formed. Investigation of CO₂ hydrate formation from infused ice in hand sample revealed distinctive hydrate and ice layers. Most of the hydrate was observed to form in the first four hours, which agrees with other experimental data. During the dissociation of the hand sample experiments, a new opaque layer was observed forming after 5-10 minutes that is possibly hydrate. This could represent hydrate formation at room temperature and pressure through remobilization and clathration of CO₂ in the ice

Effect of special education funding models in Illinois on district placement practice

The provision of special education services to students with disabilities has grown dramatically since the passage of Public Law 94-142, the first federal legislation guaranteeing this right to publicly educated children. This legislation ensured that students with disabilities adversely affecting their ability to access the general education curriculum must be provided services within the least restrictive environment of a school setting. For some students with more significant disabilities, the least restrictive environment can mean placement in a self-contained setting or even a separate school. The costs associated with self-contained settings can be high, and school districts rely on federal and state reimbursements to offset expenses. The structure of these special education reimbursements varies dramatically across the United States. In Illinois, school districts rely on a combination of revenue from federal, state, and local governments to address costs associated with educating students with disabilities. For students with severe disabilities, Illinois currently provides a greater reimbursement to school districts for students placed at private school placements rather than public settings, creating a potential incentive to access a more restrictive placement for these individuals. This study sought to examine whether this incentive occurs in practice and how it may influence decision making by special education administrators. A sequential mixed methods design was selected to collect data in two phases. Five research questions were developed to address this topic: (a) How does each Illinois school district’s placement rate of students into separate special education settings compare to the state average placement rate? (b) Are any of five demographic variables (operational expenditure per pupil, district size, percent of students in special education, percentage of students receiving free or reduced-price lunch, percentage of non-White students) characteristic of school districts that place students above the statewide average rate into separate settings? (c) What factors guide special education administrators in their decision-making practices regarding the placement of students with disabilities in the least restrictive environment? (d) To what degree does a special education director's understanding of Illinois special education funding models influence placement of students into separate settings? and (e) To what extent do the placement decision-making practices of special education directors reflect children’s best interests? The study used a conceptual framework based on the Best Interests of the Student model (Shapiro & Stefkovich, 2011). In the first quantitative phase, placement and demographic data from 859 school districts were used to analyze both the number of students placed into separate facilities and the characteristics of districts with significantly more students placed than the state average. Results showed that 11% of districts in Illinois placed into separate settings at a rate higher than the state average. Findings also revealed that districts with higher operating per pupil expenditures and districts with lower enrollments were more likely to place students into these private therapeutic settings. In the qualitative phase, special education directors working in 12 of 95 districts found significant in the first phase were interviewed regarding least restrictive environment, district placement practices, and awareness and involvement in district special education budgeting. These interviews revealed factors special education administrators considered when making placement decisions, including the severity of a student’s disability, the availability of a continuum of services, enrollment of the district, professional development for faculty and staff, and awareness of funding issues. District directors reported that independent decision making was a critical factor in making ethical decisions for students, and their placement decisions were not influenced by state incentives. Several recommendations for policy development, practice, and further study are presented

Quality of life of survivors of paediatric intensive care

Objective: The mortality rate in paediatric intensive care units (PICU) has fallen over the last two decades. More advanced treatment is offered to children with life-threatening disease and there is substantial interest in knowing whether long term outcome and quality of life after intensive care are acceptable