44 research outputs found

    Agent architecture for simulating pedestrians in the built environment

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    The paper discusses an agent architecture for investigating visualized simulated pedestrian activity and behavior affecting pedestrian flows within the built environment. The approach will lead to a system that may serve as a decision support tool in the design process for predicting the likely impact of design parameters on pedestrian flows. UML diagrams are used to communicate about the interpretation of the agent architecture

    Proceedings, MSVSCC 2017

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    Proceedings of the 11th Annual Modeling, Simulation & Visualization Student Capstone Conference held on April 20, 2017 at VMASC in Suffolk, Virginia. 211 pp

    THREE ESSAYS ON OFFSHORING DECISION-MAKING

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    This thesis studies biases in offshoring decisions and proposes a tool to improve understanding of the value of lead-time. Recent research results show local responsive production reduces mismatch between supply and demand, but this aspect of the cost is often overlooked in offshoring decisions, leading to suboptimal decisions. The tradeoff between lower unit costs and mismatch cost under demand uncertainty as lead-time increases, and the benefits of a local portfolio of products with different demand volatility, make the offshoring decision complex and the optimal solution sometimes counterintuitive. Building on behavioral research, I designed software-based laboratory trials to explore patterns of decisions in an offshoring problem, and a simulation-game to help teach and communicate research insights. In the first paper, I find that participants facing an offshoring problem fail to apply the economically optimal strategy. In the second paper, I find that non-economic factors like peer influence play a role in offshoring decisions. These trials are exploratory in nature and do not provide generalizable results, rather, they are a step towards a better understanding of the fundamental research questions and the conception of experiments. In the third paper, I describe the development and use of a simulation-game to help students, managers and policy makers understand the value of lead-time and volatility portfolio through an active learning approach. My work contributes to the understanding of the impact of bounded rationality in offshoring decisions and proposes a teaching method adapted to the challenges posed by the concepts involved

    Pervasive computing reference architecture from a software engineering perspective (PervCompRA-SE)

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    Pervasive computing (PervComp) is one of the most challenging research topics nowadays. Its complexity exceeds the outdated main frame and client-server computation models. Its systems are highly volatile, mobile, and resource-limited ones that stream a lot of data from different sensors. In spite of these challenges, it entails, by default, a lengthy list of desired quality features like context sensitivity, adaptable behavior, concurrency, service omnipresence, and invisibility. Fortunately, the device manufacturers improved the enabling technology, such as sensors, network bandwidth, and batteries to pave the road for pervasive systems with high capabilities. On the other hand, this domain area has gained an enormous amount of attention from researchers ever since it was first introduced in the early 90s of the last century. Yet, they are still classified as visionary systems that are expected to be woven into people’s daily lives. At present, PervComp systems still have no unified architecture, have limited scope of context-sensitivity and adaptability, and many essential quality features are insufficiently addressed in PervComp architectures. The reference architecture (RA) that we called (PervCompRA-SE) in this research, provides solutions for these problems by providing a comprehensive and innovative pair of business and technical architectural reference models. Both models were based on deep analytical activities and were evaluated using different qualitative and quantitative methods. In this thesis we surveyed a wide range of research projects in PervComp in various subdomain areas to specify our methodological approach and identify the quality features in the PervComp domain that are most commonly found in these areas. It presented a novice approach that utilizes theories from sociology, psychology, and process engineering. The thesis analyzed the business and architectural problems in two separate chapters covering the business reference architecture (BRA) and the technical reference architecture (TRA). The solutions for these problems were introduced also in the BRA and TRA chapters. We devised an associated comprehensive ontology with semantic meanings and measurement scales. Both the BRA and TRA were validated throughout the course of research work and evaluated as whole using traceability, benchmark, survey, and simulation methods. The thesis introduces a new reference architecture in the PervComp domain which was developed using a novel requirements engineering method. It also introduces a novel statistical method for tradeoff analysis and conflict resolution between the requirements. The adaptation of the activity theory, human perception theory and process re-engineering methods to develop the BRA and the TRA proved to be very successful. Our approach to reuse the ontological dictionary to monitor the system performance was also innovative. Finally, the thesis evaluation methods represent a role model for researchers on how to use both qualitative and quantitative methods to evaluate a reference architecture. Our results show that the requirements engineering process along with the trade-off analysis were very important to deliver the PervCompRA-SE. We discovered that the invisibility feature, which was one of the envisioned quality features for the PervComp, is demolished and that the qualitative evaluation methods were just as important as the quantitative evaluation methods in order to recognize the overall quality of the RA by machines as well as by human beings

    Pertanika Journal of Science & Technology

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    Speciation analysis of <sup>129</sup>I in the Environment

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    AMS and ICP-MS for determination of long-lived environmental radionuclides

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