2,134 research outputs found

    The Role of Application Domain Knowledge in Using OWL DL Diagrams: A Study of Inference and Problem-Solving Tasks

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    Diagrammatic conceptual schemas are an important part of information systems analysis and design. For effectively communicating domain semantics, modeling grammars have been proposed to create highly expressive conceptual schemas. One such grammar is the Web Ontology Language (OWL), which relies upon description logics (DL) as a knowledge representation mechanism. While an OWL DL diagram can be useful for representing domain semantics in great detail, the formal semantics of OWL DL places a burden on diagram users. This research investigates how user’s prior knowledge of the application domain impacts solving inference tasks as well as schema-based problem-solving tasks using OWL DL diagrams. Our empirical validation shows that application domain knowledge has no effect on inference performance but enhances schema-based problem-solving performance. We contribute to the conceptual modeling literature by studying task performance for a highly expressive modeling grammar and introducing inference tasks as a new task type

    The Potential of the Intel Xeon Phi for Supervised Deep Learning

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    Supervised learning of Convolutional Neural Networks (CNNs), also known as supervised Deep Learning, is a computationally demanding process. To find the most suitable parameters of a network for a given application, numerous training sessions are required. Therefore, reducing the training time per session is essential to fully utilize CNNs in practice. While numerous research groups have addressed the training of CNNs using GPUs, so far not much attention has been paid to the Intel Xeon Phi coprocessor. In this paper we investigate empirically and theoretically the potential of the Intel Xeon Phi for supervised learning of CNNs. We design and implement a parallelization scheme named CHAOS that exploits both the thread- and SIMD-parallelism of the coprocessor. Our approach is evaluated on the Intel Xeon Phi 7120P using the MNIST dataset of handwritten digits for various thread counts and CNN architectures. Results show a 103.5x speed up when training our large network for 15 epochs using 244 threads, compared to one thread on the coprocessor. Moreover, we develop a performance model and use it to assess our implementation and answer what-if questions.Comment: The 17th IEEE International Conference on High Performance Computing and Communications (HPCC 2015), Aug. 24 - 26, 2015, New York, US

    Understanding cognitive differences in processing competing visualizations of complex systems

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    Node-link diagrams are used represent systems having different elements and relationships among the elements. Representing the systems using visualizations like node-link diagrams provides cognitive aid to individuals in understanding the system and effectively managing these systems. Using appropriate visual tools aids in task completion by reducing the cognitive load of individuals in understanding the problems and solving them. However, the visualizations that are currently developed lack any cognitive processing based evaluation. Most of the evaluations (if any) are based on the result of tasks performed using these visualizations. Therefore, the evaluations do not provide any perspective from the point of the cognitive processing required in working with the visualization. This research focuses on understanding the effect of different visualization types and complexities on problem understanding and performance using a visual problem solving task. Two informationally equivalent but visually different visualizations - geon diagrams based on structural object perception theory and UML diagrams based on object modeling - are investigated to understand the cognitive processes that underlie reasoning with different types of visualizations. Specifically, the two visualizations are used to represent interdependent critical infrastructures. Participants are asked to solve a problem using the different visualizations. The effectiveness of the task completion is measured in terms of the time taken to complete the task and the accuracy of the result of the task. The differences in the cognitive processing while using the different visualizations are measured in terms of the search path and the search-steps of the individual. The results from this research underscore the difference in the effectiveness of the different diagrams in solving the same problem. The time taken to complete the task is significantly lower in geon diagrams. The error rate is also significantly lower when using geon diagrams. The search path for UML diagrams is more node-dominant but for geon diagrams is a distribution of nodes, links and components (combinations of nodes and links). Evaluation dominates the search-steps in geon diagrams whereas locating steps dominate UML diagrams. The results also show that the differences in search path and search steps for different visualizations increase when the complexity of the diagrams increase. This study helps to establish the importance of cognitive level understanding of the use of diagrammatic representation of information for visual problem solving. The results also highlight that measures of effectiveness of any visualization should include measuring the cognitive process of individuals while they are doing the visual task apart from the measures of time and accuracy of the result of a visual task

    Going Mobile: Teaching First-Year Business Students Mobile Application Design

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    Information systems (IS) enrollment has been declining in recent years. In an attempt to introduce key IS concepts to freshmen business students in a more engaging way, we introduced a semester-long mobile application-design project and a separate tutorial assignment involving real smartphones. Through this process, students learned basic tenets of IS while simultaneously recognizing the relevance and applicability of the field to their future lives as 21st century business professionals. In this paper, we outline the core course progression for a typical IS department, detail the process through which we engaged the students, and confirm our assertions through textual analysis of self-reported comments about their experience with this mobile application project

    Dagstuhl News January - December 2007

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    "Dagstuhl News" is a publication edited especially for the members of the Foundation "Informatikzentrum Schloss Dagstuhl" to thank them for their support. The News give a summary of the scientific work being done in Dagstuhl. Each Dagstuhl Seminar is presented by a small abstract describing the contents and scientific highlights of the seminar as well as the perspectives or challenges of the research topic

    Software languages engineering: experimental evaluation

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    Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia InformáticaDomain-Specific Languages (DSLs) are programming languages that offer, through appropriate notation and abstraction, still enough an expressive control over a particular problem domain for more restricted use. They are expected to contribute with an enhancement of productivity, reliability, maintainability and portability, when compared with General Purpose Programming Languages (GPLs). However, like in any Software Product without passing by all development stages namely Domain Analysis, Design, Implementation and Evaluation, some of the DSLs’ alleged advantages may be impossible to be achieved with a significant level of satisfaction. This may lead to the production of inadequate or inefficient languages. This dissertation is focused on the Evaluation phase. To characterize DSL community commitment concerning Evaluation, we conducted a systematic review. The review covered publications in the main fora dedicated to DSLs from 2001 to 2008, and allowed to analyse and classify papers with respect to the validation efforts conducted by DSLs’ producers, where have been observed a reduced concern to this matter. Another important outcome that has been identified is the absence of a concrete approach to the evaluation of DSLs, which would allow a sound assessment of the actual improvements brought by the usage of DSLs. Therefore, the main goal of this dissertation concerns the production of a Systematic Evaluation Methodology for DSLs. To achieve this objective, has been carried out the major techniques used in Experimental Software Engineering and Usability Engineering context. The proposed methodology was validated with its use in several case studies, whereupon DSLs evaluation has been made in accordance with this methodology

    Applications of Virtual Reality

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    Information Technology is growing rapidly. With the birth of high-resolution graphics, high-speed computing and user interaction devices Virtual Reality has emerged as a major new technology in the mid 90es, last century. Virtual Reality technology is currently used in a broad range of applications. The best known are games, movies, simulations, therapy. From a manufacturing standpoint, there are some attractive applications including training, education, collaborative work and learning. This book provides an up-to-date discussion of the current research in Virtual Reality and its applications. It describes the current Virtual Reality state-of-the-art and points out many areas where there is still work to be done. We have chosen certain areas to cover in this book, which we believe will have potential significant impact on Virtual Reality and its applications. This book provides a definitive resource for wide variety of people including academicians, designers, developers, educators, engineers, practitioners, researchers, and graduate students
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