1,222 research outputs found

    Constraint specification by example in a Meta-CASE tool

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    CASE tools are very helpful to software engineers in different ways and in different phases of software development. However, they are not easy to specialise to meet the needs of particular application domains or particular software modelling requirements. Meta-CASE tools offer a way of providing such specialisation by enabling a designer to specify a tool which is then generated automatically. Constraints are often used in such meta-CASE tools as a technique for governing the syntax and semantics of model elements and the values of their attributes. However, although constraint definition is a difficult process it has attracted relatively little research attention. The PhD research described here presents an approach for improving the process of CASE tool constraint specification based on the notion of programming by example (or demonstration). The feasibility of the approach will be demonstrated via experiments with a prototype using the meta-CASE tool Diagram Editor Constraints System (DECS) as context

    Locality Enhancement and Dynamic Optimizations on Multi-Core and GPU

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    Enhancing the match between software executions and hardware features is key to computing efficiency. The match is a continuously evolving and challenging problem. This dissertation focuses on the development of programming system support for exploiting two key features of modern hardware development: the massive parallelism of emerging computational accelerators such as Graphic Processing Units (GPU), and the non-uniformity of cache sharing in modern multicore processors. They are respectively driven by the important role of accelerators in today\u27s general-purpose computing and the ultimate importance of memory performance. This dissertation particularly concentrates on optimizing control flows and memory references, at both compilation and execution time, to tap into the full potential of pure software solutions in taking advantage of the two key hardware features.;Conditional branches cause divergences in program control flows, which may result in serious performance degradation on massively data-parallel GPU architectures with Single Instruction Multiple Data (SIMD) parallelism. On such an architecture, control divergence may force computing units to stay idle for a substantial time, throttling system throughput by orders of magnitude. This dissertation provides an extensive exploration of the solution to this problem and presents program level transformations based upon two fundamental techniques --- thread relocation and data relocation. These two optimizations provide fundamental support for swapping jobs among threads so that the control flow paths of threads converge within every SIMD thread group.;In memory performance, this dissertation concentrates on two aspects: the influence of nonuniform sharing on multithreading applications, and the optimization of irregular memory references on GPUs. In shared cache multicore chips, interactions among threads are complicated due to the interplay of cache contention and synergistic prefetching. This dissertation presents the first systematic study on the influence of non-uniform shared cache on contemporary parallel programs, reveals the mismatch between the software development and underlying cache sharing hierarchies, and further demonstrates it by proposing and applying cache-sharing-aware data transformations that bring significant performance improvement. For the second aspect, the efficiency of GPU accelerators is sensitive to irregular memory references, which refer to the memory references whose access patterns remain unknown until execution time (e.g., A[P[i]]). The root causes of the irregular memory reference problem are similar to that of the control flow problem, while in a more general and complex form. I developed a framework, named G-Streamline, as a unified software solution to dynamic irregularities in GPU computing. It treats both types of irregularities at the same time in a holistic fashion, maximizing the whole-program performance by resolving conflicts among optimizations

    Articulation estimation and real-time tracking of human hand motions

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    Schröder M. Articulation estimation and real-time tracking of human hand motions. Bielefeld: Universität Bielefeld; 2015.This thesis deals with the problem of estimating and tracking the full articulation of human hands. Algorithmically recovering hand articulations is a challenging problem due to the hand’s high number of degrees of freedom and the complexity of its motions. Besides the accuracy and efficiency of the hand posture estimation, hand tracking methods are faced with issues such as invasiveness, ease of deployment and sensor artifacts. In this thesis several different hand tracking approaches are examined, including marker-based optical motion capture, data-driven discriminative visual tracking and generative tracking based on articulated registration, and various contributions to these areas are presented. The problem of optimally placing reduced marker sets on a performer’s hand for optical hand motion capture is explored. A method is proposed that automatically generates functional reduced marker layouts by optimizing for their numerical stability and geometric feasibility. A data-driven discriminative tracking approach based on matching the hand’s appearance in the sensor data with an image database is investigated. In addition to an efficient nearest neighbor search for images, a combination of discriminative initialization and generative refinement is employed. The method’s applicability is demonstrated in interactive robot teleoperation. Various real human hand motions are captured and statistically analyzed to derive low-dimensional representations of hand articulations. An adaptive hand posture subspace concept is developed and integrated into a generative real-time hand tracking approach that aligns a virtual hand model with sensor point clouds based on constrained inverse kinematics. Generative hand tracking is formulated as a regularized articulated registration process, in which geometrical model fitting is combined with statistical, kinematic and temporal regularization priors. A registration concept that combines 2D and 3D alignment and explicitly accounts for occlusions and visibility constraints is devised. High-quality, non-invasive, real-time hand tracking is achieved based on this regularized articulated registration formulation

    PPP - personalized plan-based presenter

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    Ergonomic Models of Anthropometry, Human Biomechanics and Operator-Equipment Interfaces

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    The Committee on Human Factors was established in October 1980 by the Commission on Behavioral and Social Sciences and Education of the National Research Council. The committee is sponsored by the Office of Naval Research, the Air Force Office of Scientific Research, the Army Research Institute for the Behavioral and Social Sciences, the National Aeronautics and Space Administration, and the National Science Foundation. The workshop discussed the following: anthropometric models; biomechanical models; human-machine interface models; and research recommendations. A 17-page bibliography is included

    Knowledge Representation in Synthetic Biology

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    PhD ThesisSynthetic biology, or SynBio, is a relatively new and exciting field concerning the formalisation of genetic engineering into a design, build, test, learn lifecycle common to other engineering disciplines. This lifecycle can be used to systematically develop biological systems, such as synthetic genetic circuits — where transcriptional machinery is repurposed to construct familiar electronic circuit concepts such as logic gates — and other engineered devices such as biosensors or drug production factories. Synthetic biological systems are typically designed by repurposing existing natural and synthetic biological parts. This design process is made possible by knowledge about part structure and function, which can be experimentally derived or predicted using bioinformatics methodologies. However, the process of gathering such knowledge is arduous, as it is often computationally intractable, distributed across multiple disparate databases with semantic and syntactic heterogeneity, or even not recorded at all. The research question motivating this work is how the machine-tractability of knowledge can be improved in order to make the synthetic biology design process more efficient. There are both short-term and long-term approaches. The short-term approach is to improve the ease of access and machine-tractability of existing knowledge relevant to SynBio design. The long-term approach is to establish the software and data infrastructure necessary to enable knowledge about future designs to be documented in a standardized manner. This work investigates both approaches with research into data standards, significantly furthering the development of the Synthetic Biology Open Language (SBOL) to improve the machine-tractability of design knowledge; the research and development of novel technology for data integration to make existing information easier to access; conversion of an existing dataset, the iGEM Registry, into an enriched SBOL representation; the development of SynBioHub, a repository for the sharing and dissemination of future SynBio designs; and SynBioCAD, a visual tool enabling synthetic biologists to capture their designs using data standards

    Expert System Applications in Sheet Metal Forming

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    The synergistic effect of operational research and big data analytics in greening container terminal operations: a review and future directions

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    Container Terminals (CTs) are continuously presented with highly interrelated, complex, and uncertain planning tasks. The ever-increasing intensity of operations at CTs in recent years has also resulted in increasing environmental concerns, and they are experiencing an unprecedented pressure to lower their emissions. Operational Research (OR), as a key player in the optimisation of the complex decision problems that arise from the quay and land side operations at CTs, has been therefore presented with new challenges and opportunities to incorporate environmental considerations into decision making and better utilise the ‘big data’ that is continuously generated from the never-stopping operations at CTs. The state-of-the-art literature on OR's incorporation of environmental considerations and its interplay with Big Data Analytics (BDA) is, however, still very much underdeveloped, fragmented, and divergent, and a guiding framework is completely missing. This paper presents a review of the most relevant developments in the field and sheds light on promising research opportunities for the better exploitation of the synergistic effect of the two disciplines in addressing CT operational problems, while incorporating uncertainty and environmental concerns efficiently. The paper finds that while OR has thus far contributed to improving the environmental performance of CTs (rather implicitly), this can be much further stepped up with more explicit incorporation of environmental considerations and better exploitation of BDA predictive modelling capabilities. New interdisciplinary research at the intersection of conventional CT optimisation problems, energy management and sizing, and net-zero technology and energy vectors adoption is also presented as a prominent line of future research

    Custom Integrated Circuits

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    Contains reports on ten research projects.Analog Devices, Inc.IBM CorporationNational Science Foundation/Defense Advanced Research Projects Agency Grant MIP 88-14612Analog Devices Career Development Assistant ProfessorshipU.S. Navy - Office of Naval Research Contract N0014-87-K-0825AT&TDigital Equipment CorporationNational Science Foundation Grant MIP 88-5876
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