523 research outputs found

    1999 Flight Mechanics Symposium

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    This conference publication includes papers and abstracts presented at the Flight Mechanics Symposium held on May 18-20, 1999. Sponsored by the Guidance, Navigation and Control Center of Goddard Space Flight Center, this symposium featured technical papers on a wide range of issues related to orbit-attitude prediction, determination, and control; attitude sensor calibration; attitude determination error analysis; attitude dynamics; and orbit decay and maneuver strategy. Government, industry, and the academic community participated in the preparation and presentation of these papers

    Workshop on Particle Capture, Recovery and Velocity/Trajectory Measurement Technologies

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    A workshop on particle capture, recovery, and velocity/trajectory measurement technologies was held. The primary areas covered were: (1) parent-daughter orbit divergence; (2) trajectory sensing; (3) capture medium development: laboratory experiments, and (4) future flight opportunities

    Compressive Faraday Imaging for Next-Generation Radio Telescopes

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    Modeling and Optimization Algorithm for SiC-based Three-phase Motor Drive System

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    More electric aircraft (MEA) and electrified aircraft propulsion (EAP) becomes the important topics in the area of transportation electrifications, expecting remarkable environmental and economic benefits. However, they bring the urgent challenges for the power electronics design since the new power architecture in the electrified aircraft requires many benchmark designs and comparisons. Also, a large number of power electronics converter designs with different specifications and system-level configurations need to be conducted in MEA and EAP, which demands huge design efforts and costs. Moreover, the long debugging and testing process increases the time to market because of gaps between the paper design and implementation. To address these issues, this dissertation covers the modeling and optimization algorithms for SiC-based three-phase motor drive systems in aviation applications. The improved models can help reduce the gaps between the paper design and implementation, and the implemented optimization algorithms can reduce the required execution time of the design program. The models related to magnetic core based inductors, geometry layouts, switching behaviors, device loss, and cooling design have been explored and improved, and several modeling techniques like analytical, numerical, and curve-fitting methods are applied. With the developed models, more physics characteristics of power electronics components are incorporated, and the design accuracy can be improved. To improve the design efficiency and to reduce the design time, optimization schemes for the filter design, device selection combined with cooling design, and system-level optimization are studied and implemented. For filter design, two optimization schemes including Ap based weight prediction and particle swarm optimization are adopted to reduce searching efforts. For device selection and related cooling design, a design iteration considering practical layouts and switching speed is proposed. For system-level optimization, the design algorithm enables the evaluation of different topologies, modulation schemes, switching frequencies, filter configurations, cooling methods, and paralleled converter structure. To reduce the execution time of system-level optimization, a switching function based simulation and waveform synthesis method are adopted. Furthermore, combined with the concept of design automation, software integrated with the developed models, optimization algorithms, and simulations is developed to enable visualization of the design configurations, database management, and design results

    High-Performance Modelling and Simulation for Big Data Applications

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    This open access book was prepared as a Final Publication of the COST Action IC1406 “High-Performance Modelling and Simulation for Big Data Applications (cHiPSet)“ project. Long considered important pillars of the scientific method, Modelling and Simulation have evolved from traditional discrete numerical methods to complex data-intensive continuous analytical optimisations. Resolution, scale, and accuracy have become essential to predict and analyse natural and complex systems in science and engineering. When their level of abstraction raises to have a better discernment of the domain at hand, their representation gets increasingly demanding for computational and data resources. On the other hand, High Performance Computing typically entails the effective use of parallel and distributed processing units coupled with efficient storage, communication and visualisation systems to underpin complex data-intensive applications in distinct scientific and technical domains. It is then arguably required to have a seamless interaction of High Performance Computing with Modelling and Simulation in order to store, compute, analyse, and visualise large data sets in science and engineering. Funded by the European Commission, cHiPSet has provided a dynamic trans-European forum for their members and distinguished guests to openly discuss novel perspectives and topics of interests for these two communities. This cHiPSet compendium presents a set of selected case studies related to healthcare, biological data, computational advertising, multimedia, finance, bioinformatics, and telecommunications

    Systems in management 7th annual ANZSYS conference 2001: The relevance of systems thinking in the contemporary world

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    Welcome to Perth, Western Australia, and to the Systems in Management 7th Annual ANZSYS Conference 2001 the relevance of systems thinking in the contemporary world hosted by the We-B Centre, School of Management Information Systems at Edith Cowan University. The conference provides an opportunity for sharing and networking among academics and industry specialists in systems and related fields. The conference has drawn participants from national and international organizations. All submitted papers were subjected to an anonymous peer review process managed by the Conference Committee. Stringent review criteria resulted in an unprecedented number of papers declined this year. Based on these reviews, the final programme was determined. A total of 54 papers were submitted for consideration and 39 were accepted for presentation. The Conference Committee would like to recognise the efforts of many people who have contributed to the success and support in the organising of this conference and without their efforts the conference could not have occurred. The authors are thanked for their continued support to the Systems in Management 7th Annual ANZSYS Conference 2001 and we hope that the conference will receive similar support into the future. The reviewers deserve a special vote of thanks for their commitment and dedication in having their reviews conducted professionally. This year saw the launch of our Best Paper and Paper of Distinction award program. Papers nominated for this honour received particularly rigorous reviews. The winners will be announced at the conference. Thank you and enjoy the conference
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