19 research outputs found

    Heuristic Satisficing Inferential Decision Making in Human and Robot Active Perception

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    Inferential decision-making algorithms typically assume that an underlying probabilistic model of decision alternatives and outcomes may be learned a priori or online. Furthermore, when applied to robots in real-world settings they often perform unsatisfactorily or fail to accomplish the necessary tasks because this assumption is violated and/or they experience unanticipated external pressures and constraints. Cognitive studies presented in this and other papers show that humans cope with complex and unknown settings by modulating between near-optimal and satisficing solutions, including heuristics, by leveraging information value of available environmental cues that are possibly redundant. Using the benchmark inferential decision problem known as ``treasure hunt", this paper develops a general approach for investigating and modeling active perception solutions under pressure. By simulating treasure hunt problems in virtual worlds, our approach learns generalizable strategies from high performers that, when applied to robots, allow them to modulate between optimal and heuristic solutions on the basis of external pressures and probabilistic models, if and when available. The result is a suite of active perception algorithms for camera-equipped robots that outperform treasure-hunt solutions obtained via cell decomposition, information roadmap, and information potential algorithms, in both high-fidelity numerical simulations and physical experiments. The effectiveness of the new active perception strategies is demonstrated under a broad range of unanticipated conditions that cause existing algorithms to fail to complete the search for treasures, such as unmodelled time constraints, resource constraints, and adverse weather (fog)

    A comparative study of different evaluation techniques for appraising alternative transportation plans

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    Includes bibliography at end of each chapter.This thesis studies the evaluation element of the general transportation planning process from a broad systems perspective. Evaluation linkages are identified with the other activities of the planning process which, if not recognised and accounted for, can unnecessarily restrict the efficiency of plan evaluation thereby reducing the effectiveness of the evaluation element as an aid to decision making. The nature and scope of the evaluation element is examined in some detail. Certain key aspects are discussed; the value framework that is used to assess plan performance, the principles of measurement used therein, and some procedural steps are put forward to guide the selection of appropriate criteria to indicate plan performance. The latter part of the thesis is devoted to comparing the capabilities and limitations of six different evaluation techniques, namely; cost benefit analysis, cost-effectiveness technique, ranking and rating matrices, utility analysis and goals-achievement matrix. As a conclusion to the thesis, it is felt that due to the divergent nature of transportation planning each of the foregoing methods without exception, has its relative strengths and weaknesses. The aspects of robustness and weakness of each methodology are shown to be a reflection of certain fundamental paradoxical requirements that runs through the whole planning process. It is these conflicting requirements that consequently neutralise any one method from being totally effective. Consequently, for an evaluation to be comprehensive, complex transportation problems should be evaluated in two stages. The primary evaluation should be undertaken with the "most appropriate" methodology followed with a supplementary evaluation augmenting any deficiency in the initial evaluation

    A Total Systems analysis Method for the Conceptual design of Spacecraft: An application to Remote Sensing Imager Systems

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    Increased emphasis is being placed on improving the performance of space projects, within tighter budgets and shorter development times. This has led to a need for more efficient space system design methods. The research described here represents an effort to develop and evaluate such a method. Systems engineering and concurrent engineering together provide the theoretical foundation for the method. The method, derived from both this theoretical foundation and ideas from experts in the space industry, emphasizes a total systems analysis approach, taking into account given mission requirements, and the mathematical modeling of interactions between system variables and between subsystems. The emphasis makes it possible to apply the method for effectively sizing and configuring the full space project, its subsystems, and its variables. Size and configuration issues are especially important in the early conceptual design stages. The focus of this research and the developed method was, therefore, put on facilitating the design decisions taking place during those design stages. Mass, as a proxy for cost, was selected as the evaluation and optimization criterion. To make the method practical, LabVIEW was selected for developing the total systems analysis model. LabVIEW is a graphical programming language that is easy to learn, program, modify, and run; and, it has a good user interface. These characteristics make it well suited for rapid model development and for performing the large number of analysis runs required in the early conceptual design stages. The method was demonstrated for a V/IR (Visual/Infrared) space based Earth observation system. The mathematical model describing the interactions in this system was developed in close cooperation with subsystem specialists, primarily at NASA Langley Research Center, making it as realistic as possible. The model includes some 300 variables and 130 equations, and uses 1.7 MB of code. The demonstration, focusing on size and configuration issues, showed how the method and model could be used for better understanding of model dynamics, for evaluating alternative technologies, for detecting technology limits, for performing inter-subsystem analyses, and for suggesting new technology developments. It is hoped that this research will encourage engineers and project managers in the space sector to apply the developed design method to other types of space projects

    Supporting the management of electronic engineering design teams through a dynamic contingency approach

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    The contribution to knowledge presented in this thesis is the dynamic contingency approach, supported through software, which supports the management of the early, conceptual stages of electronic engineering team design. 1he term contingency pertains to the design environment being in a contingent state, that is "dependent on uncertain issues" (Hayward & Sparkes, 1991). These issues are typically dynamic, that is ''pertaining to forces not in equilibrium, forces that produce motion" (Hayward & Sparkes, 1991). The concept for the dynamic contingency approach was developed through a soft systems analysis. This analysis drew upon an ethnographic study conducted in parallel with the present work by another researcher. Both the present work and the ethnographic study were carried out within a multidisciplinary research team in collaboration with an industrial partner (company A). This thesis discusses the evolution of this multidisciplinary research method, including the development of a software prototype (EDAPT), which enabled the requirements for the dynamic contingency approach to be established. Through this research method key issues were identified which affect the ability of design managers, and to a lesser extent design engineers, to adequately perceive the current situation of a design project; and to determine appropriate corrective responses to potential problem situations. The work indicates that this is particularly true when under pressure in such a complex, interdependent and dynamic environment. This thesis illustrates how the environment of design can be dependent upon these key issues which are often uncertain, that is, the environment is in a contingent state. Furthermore, the thesis depicts the dynamic nature of these issues. The dynamic contingency approach was developed in response to these issues in partnership with the industrial collaborator. The approach synthesises a variety of such issues to support the coordination of interdependencies, provide a view of the current project situation, alert stakeholders to potential problem situations, and present possible responses to potential problem situations. In short, what has been achieved is a design management worldview with sufficient detail to help people expect and anticipate what might happen, and how others may behave in a team design environment, together with the foundations for a system which enables and supports this perspective. In essence the approach provides a way of conceptualising the design environment which should enable improvements in the management of design teams at the early, conceptual stages of electronic engineering design projects

    Short Term Unit Commitment as a Planning Problem

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    ‘Unit Commitment’, setting online schedules for generating units in a power system to ensure supply meets demand, is integral to the secure, efficient, and economic daily operation of a power system. Conflicting desires for security of supply at minimum cost complicate this. Sustained research has produced methodologies within a guaranteed bound of optimality, given sufficient computing time. Regulatory requirements to reduce emissions in modern power systems have necessitated increased renewable generation, whose output cannot be directly controlled, increasing complex uncertainties. Traditional methods are thus less efficient, generating more costly schedules or requiring impractical increases in solution time. Meta-Heuristic approaches are studied to identify why this large body of work has had little industrial impact despite continued academic interest over many years. A discussion of lessons learned is given, and should be of interest to researchers presenting new Unit Commitment approaches, such as a Planning implementation. Automated Planning is a sub-field of Artificial Intelligence, where a timestamped sequence of predefined actions manipulating a system towards a goal configuration is sought. This differs from previous Unit Commitment formulations found in the literature. There are fewer times when a unit’s online status switches, representing a Planning action, than free variables in a traditional formulation. Efficient reasoning about these actions could reduce solution time, enabling Planning to tackle Unit Commitment problems with high levels of renewable generation. Existing Planning formulations for Unit Commitment have not been found. A successful formulation enumerating open challenges would constitute a good benchmark problem for the field. Thus, two models are presented. The first demonstrates the approach’s strength in temporal reasoning over numeric optimisation. The second balances this but current algorithms cannot handle it. Extensions to an existing algorithm are proposed alongside a discussion of immediate challenges and possible solutions. This is intended to form a base from which a successful methodology can be developed

    A Case Study of Stakeholders’ Motivation to Invest in Classical Christian Education

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    The purpose of this qualitative case study is to describe the motivation of parents, teachers, and school board members to invest their efforts in classical Christian education in a modern American K-12 school. The theory guiding this study is expectancy-value theory as it relates to the evaluative aspects of stakeholders’ beliefs about classical Christian education and their motives to become involved in it. Classical Christian education includes the concepts of the trivium, explicit instruction, the Socratic method, and basic skills mastery, as well as carrying on the traditions of the West; all steeped in a Christian worldview. Data came in the form of interviews, documents, and focus groups from parents, teachers, and school board members who are involved with a classical Christian education. An analysis of the data revealed that stakeholders are motivated to invest their efforts in a classical Christian school by a variety of factors including, a disapproval of the mainstream educational philosophy and a strong desire to experience the core elements of the classical Christian philosophy. This study found that no matter what participants believed about classical Christian education, they placed a great deal of value on their expectations about the philosophy, and those expectations were being met, with few exceptions

    Scaffolding Students’ Information Literacy Skills with an Online Credibility Evaluation Learning Tool.

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    This research explored how to effectively teach today’s students Information Literacy (IL) and credibility evaluation skills in the online information environment. In light of students’ reliance on the Internet, their general lack of IL skills, limited critical evaluation practices, and the lack of consistent institutional IL training, new pedagogical methods are needed to teach effective online IL skills. Specifically, there is a need for IL training that is customized to the online information environment and relevant to the research habits of today’s students. To address this problem, an online learning tool incorporating scaffolding and metacognitive support was prototyped and built. The tool decomposes credibility evaluation into a structured set of stages, giving students repeated practice in each stage while providing scaffolded support for learning and metacognitive reflection, and integrating the instruction into the online information environment. An experimental study was conducted to test the tool's effectiveness, with a total of 84 students randomly assigned to three experimental conditions to allow for statistically valid analysis of the results. The findings show that use of the online credibility evaluation tool significantly increased subjects' understanding of credibility criteria. The results did not show a significant difference between groups in the application of evidence-based source characteristics as the basis for their credibility evaluations, or in metacognitive awareness of the evaluation process, although descriptive trends suggest some improvement in the treatment group. Along with these three research questions, the study also examined the types of sources that students used in their research, showing that they relied on blogs and other hybrid online genres that do not conform to the traditional genres often covered by IL instruction. The study also solicited self-reports of student learning, with students reporting that they learned that online credibility evaluation is more complex than they thought, involving asking systematic questions and using critical thinking. Overall, this research demonstrates that IL instruction needs to address the specific challenges of online credibility evaluation, and that scaffolding and metacognitive support in the form of an online learning tool can effectively integrate IL instruction into the online information environment where students actually do their research.PhDInformationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/110460/1/cleeder_1.pd

    Challenging the Assumption of Rationality in Performance-Based Accountability Systems: A Comparative Case Study of School and District Decision-Making Approaches

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    CHALLENGING THE ASSUMPTION OF RATIONALITY IN PERFORMANCE-BASED ACCOUNTABILITY SYSTEMS: A COMPARATIVE CASE STUDY OF SCHOOL AND DISTRICT DECISION-MAKING APPROACHES Jessica K. Beaver Richard M. Ingersoll Performance-based accountability systems provide schools and districts with detailed student performance data on the front end and demand that schools meet rigorous minimum proficiency thresholds on the back end or face a set of sanctions that ratchet up year after year. The process by which schools and districts make decisions for improvement in order to meet these requirements, however, is opaque at best. Each district is like an island unto itself, with its own political context, financial constraints, demographic and economic makeup, human capital, and social dynamics. Especially given the immense amount of money spent every year in improvement grants to districts, as well as the plethora of vendors touting new products, there is a clear imperative to understand how schools and districts select particular programs or strategies for improvement above other options. In this dissertation study, I apply the literature on search and decision-making in other disciplines to the field of public elementary and secondary education, paying particular attention to schools and districts under pressure to improve from performance-based accountability systems. I employ a comparative case study approach, using three consecutive years of data from a stratified random sample of eight schools (nested within their districts) in Pennsylvania. I find that schools and districts are under immense pressure to demonstrate student achievement gains, and that this pressure extends to all phases of the decision-making process, including problem identification, search, and the decision point. Despite this pressure, I find that schools do not descend into chaos when making decisions for improvement - they generally approach the decision-making process in a linear manner and let building-level administrators employ a middle-out approach to decision-making. But on the other hand, schools are far from purely rational organizations, as there are forces internal and external to the school or district that constrain decision-making processes. Although these constraints affect all stages of the decision-making process, they have the most severe influence on the search phase. Finally, I create a framework that advances the literature on decision-making in education by establishing four distinct typologies of decision-making approaches

    Aircrew Adaptive Decision Making: A Cross-Case Analysis

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    Although the accident rate for military aviation has declined significantly from earlier decades, during the 1990\u27s it reached a plateau. Human error in the cockpit still accounts for over 80% of the aircraft mishaps resulting in loss of life or over one million dollars in damage. Decision error has been a contributing factor for approximately 60% of these mishaps. The purpose of this research was to investigate aircrew process performance variables as predictors of decision-making outcomes. This study was modeled on elements of previous research in naturalistic decision making. Data were collected for cross-case analysis of the role experience plays in efficient decision strategy selection and use in an uncertain, dynamic high stakes environment. Multiple raters evaluated eight novice and eight experienced military aircrews at seven decision points in a 20-minute flight scenario conducted in a full motion flight simulator. Other raters independently rank ordered the quality of the final outcome. A comprehensive approach to collecting and analyzing data included: (1) development and use of a behaviorally-anchored assessment instrument, (2) use of a digitally integrated presentation of audio/video and flight data, and (3) development of context-specific analytical frameworks and models of observed behaviors and metacognitive processes. Results included inferential and descriptive statistics of process/outcome scores, instructor comments, excerpts of cockpit recordings, participant interviews, and field notes. The study findings were: (1) high individual and collective crew experience had a significant positive effect on process and outcome scores, (2) there was no statistically reliable difference in process scores between experience levels in the three procedurally-based events, (3) experienced crews performed better than novice crews in the four less structured events, (4) novice crews\u27 process/outcome correlation did not approach significance, (5) a strong positive correlation of process/outcome scores was found for experienced crews in the two most challenging (i.e., unstructured) scenario events, (6) qualitative analysis revealed strong relationships between performance and crew interactions/attributes, and (7) in dynamic, time critical situations, the use of adaptive decision-making strategies led to better performance outcomes

    Intuitive and rational approaches to decision making in education

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    The key question that this research focuses on is: How do head teachers make decisions? In addition, there are a range of sub questions that are worthy of consideration within the remit of this study. What strategies do head teachers use in making decisions? How do factors such as accountability, metrics, complexity and uncertainty affect decision making? What is the impact of experience on decision making? Does increased accountability lead to a greater choice of rational or intuitive decision making strategies? To what extent do head teachers rely on their "gut feelings" in making decisions? What mix of rational and intuitive strategies do head teachers use in making decisions and do head teachers make use of their staff to explore different perceptions and frames?In considering what is the best research approach to answer these questions, reference can be made to a new branch of research known as Naturalistic Decision Making (NDM) which has arisen over the past fifteen years. The proponents of NDM have questioned both the application and validity of the rational methods. One of the major proponents of this approach is Gary Klein who has undertaken research into decision making within a wide range of professional domains such as fire fighting, health and the armed forces. His research (1999) suggests that, in real life situations, experts employ a range of strategies very different from the oft espoused rational models of decision making. Instead they habitually use strategies that rely very heavily on domain specific knowledge developed through extensive experience. They do not involve the generation of alternative options but rather use perception and mental simulations, for example, as tools for decision making. The decision making strategies that experts employ mark them out from novices and can perhaps give us an insight into the acquisition of expertise. In this thesis the application of NDM to the work of primary head teachers will be considered.In chapter one the relationship between education leadership, accountability and decision making will be explored making reference to the many changes that have influenced and created the current educational context. The extent to which decision making strategies may be influenced by the context in which they are made will also be considered.In chapter two an overview of theoretical approaches to decision making will be provided, drawing out the many distinctions between rationalistic methods and what can be termed "intuitive" methods such as those "discovered" by NDM. The relationship and tension between rationalistic and intuitive approaches to decision making will be considered. This will involve exploring the well worn battleground between these two age old competing ideologies within Western civilisation: "Traditionally, two forms of cognition analysis and intuition have been distinguished. This sharp dichotomy was made early; indeed, it is as old as the history of thought. Plato, Aristotle, Hume, and Kant all recognized that the difference between the two forms of cognition is fundamental. Even today, almost every study of human judgment employs these concepts, implicitly or explicitly" (Hammond, 1996, p.60).A definition of "intuitive" and "rational" will be provided in this chapter and will be used throughout the thesis to highlight the differences between these two approaches.Chapter three will give a detailed account and critique of the work of Gary Klein discussing the model of decision making he has developed and his ideas on recognition, mental simulations, stories, decisions within teams and decision making mistakes.Chapters four and five will consider research methodology and the practical application of research to this thesis. Details of how the research was conducted, head teachers recruited and interviewed and basic data analysis will be described. Chapter six will provide a quantitative analysis of the interview data to provide the reader with a context for understanding and judging the research findings.Chapter seven is at the heart of this research project. Here the qualitative analysis of the research data will be outlined using substantial quotations from the interview transcripts to enhance credibility and ensure that the findings are truly grounded in the research evidence. Issues such as accountability, working with staff and, most importantly, head teachers' preferred decision making styles will be discussed and illuminated.Chapter eight will then summarise the main findings of the research and discuss possible implications arising from the findings including a description of decision making to aid our understanding of this subject.A postscript will retrospectively consider the work of Klein in the light of this research as well as provide a reflection on the research process
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