检索结果-内蒙古大学图书馆

AFRICON Conference

作者： H. Gheraia E.M. Berkouk G. Manesse Laboratoire d'Electronique de Puissance et Commande DER Genie Electrive et Informatique-ENPAlger Algiers Algeria

In this paper, the authors examine the input DC voltage source stability of a three-phase seven-level NPC voltage source inverter. In spite of the advantages of multilevel inverters compared to two-level topologies, the unbalance voltage of the different input DC voltage sources constitute a major limitation of multilevel inverters. In this paper, the authors study the performances of a three-phase two-level PWM rectifier-three-phase seven-level NPC voltage source inverter-induction machine cascade in the case of open loop and closed loop DC output voltage of the two-level PWM rectifier.

关键词： Feedback control Voltage Pulse width modulation inverters Stability Rectifiers Open loop systems Performance analysis density estimation robust algorithm Induction machines Hysteresis

来源：评论

学校读者我要写书评

暂无评论

DTM extraction from topographic maps

DTM extraction from topographic maps

引用

International Conference on Document Analysis and Recognition

作者： F. Dupont M.P. Deseilligny M. Gondran Institut Géographique National Saint Mande France EDF/DER Clamart France

This paper deals with the automatic quotation of the contour lines extracted from a scanned paper map, in the way to create a DTM (digital terrain model). The great number of contour line interruptions, the connections between two (or more) contour lines and the low density of the elevation information contained on the map, make the quotation task very difficult. Our technique is based on the computation of an intermediate DTM from the global analysis of the main contour lines and the elevation dots. By using this intermediate DTM, we are able to estimate the contour line orientation (i.e. the slopeway), and then to quote the contour lines. By analyzing the trust on the orientation and the coherence of the quotation transitions, we select all the unsuspicious elevations and use them to create a new DTM. We assume that this new DTM is more precise than the intermediate DTM. So we can use, if necessary, this new DTM as a new intermediate DTM to repeat the process (orientation estimation and quotation).

关键词： Read only memory density estimation robust algorithm Topology Geometry Humans Skeleton

来源：评论

学校读者我要写书评

暂无评论

Analysis of an experimental technique for determining Van der Pol parameters of a transistor oscillator

引用

IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1998年第7期46卷 914-922页

作者： Chen, KY Biernacki, PD Lahrichi, A Mickelson, A Univ Colorado Dept Elect & Comp Engn Boulder CO 80309 USA Univ Colorado Guided Wave Opt Lab Boulder CO 80309 USA

The Van der Pol (VDP) model of a transistor oscillator describes the behavior of the oscillator with three parameters. When operating in steady state, only two parameters can be determined by spectrum analysis, these being the oscillation frequency and amplitude of oscillation, In this paper, a technique for measuring the other VDP parameter is examined. In this approach, a periodically modulated voltage is added to the bias of the oscillator to perturb the operational state. A theoretical derivation shows that the power spectrum of the perturbed oscillator contains additional information for determination of the other VDP parameter, A simple analytical perturbation formula predicts the oscillator's response to the ramped bias. Our experimental results agree with the analytical perturbation solution and, therefore, this allows one to read off the other VDP parameter from the experimental data. The VDP model allows one to predict the behavior of coupled transistor oscillators more accurately and simply than does the traditional large-signal model of the transistor. This VDP model mill simplify oscillator array design since the number of parameters needed to describe each oscillator is reduced from that which would be required using a large-signal circuit model.

关键词： density estimation robust algorithm Microwave oscillators Laboratories Predictive models Coupling circuits Nonlinear optics Optical saturation Phased arrays Performance analysis Microwave transistors

来源：评论

学校读者我要写书评

暂无评论

Thierry Van der Pyl and European HPCN trends

引用

IEEE CONCURRENCY 1998年第2期6卷 11-12页

作者： Bergen, S IEEE Concurrency sbergen@***

As Europe competes in today's global marketplace and strives to influence high-tech research and development, leaders of the European Commission must determine strategic areas of research and development and successfully support and finance projects in these areas. To this end, the EC has set up Framework Programs to define central R&D areas and draft a five-year budget for each program. As the end of the current program, FP4, draws near, those involved with the EC are busy planning for FP5, set to start in 1999. One influential EC voice belongs to Thierry Van der Pyl, head of the HPCN unit in the EC Program on Information Technologies (Esprit). He has been with the Commission since 1984 and has helped shape Europe's HPC R&D programs. The author considers how HPC is a central factor in European research. She considers a user-friendly model, the new networking dimension and the five main Esprit HPCN research areas.

关键词： density estimation robust algorithm Research and development Communications technology Europe Information technology IP networks Finance Shape Turning System testing

来源：评论

学校读者我要写书评

暂无评论

Reality in certification of IFE and telephone equipment

Reality in certification of IFE and telephone equipment

引用

Conference on Digital Avionics Systems (DASC)

作者： A.M. Christofferson R.L. Triplett Boeing Cabin Syst. Seattle WA USA Boeing Cabin Systems-Rockwell IFE DER Seattle WA USA

This paper provides an overview of the process followed by Boeing to certify In-Flight Entertainment (IFE) and Telecommunication Systems. It is not intended to provide an in-depth description of the certification proc... 详细信息

关键词： Certification Telephone equipment Airplanes FAA density estimation robust algorithm Manufacturing processes Maintenance engineering Aircraft manufacture Meeting planning Testing

来源：评论

学校读者我要写书评

暂无评论

Effect of the T-stress in the adhesively bonded joints on the locus of failure in rubber toughened epoxy system

Effect of the T-stress in the adhesively bonded joints on th...

引用

International Conference on Adhesive Joining and Coating Technology in Electronics Manufacturing

作者： B. Chen D.A. Dillard J.G. Dillard Engineering Science and Mechanics Department Virginia Polytechnic Institute and State University Blacksburg VA USA Chemistry Department Virginia Polytechnic Institute and State University Blacksburg VA USA

Summary form only given. This study addresses T-stress effects on the locus of failure in adhesively bonded joints. Double cantilever beam (DCB) specimens were made using Al 6061-T6 adherends and DER 331 epoxy resin with rubber concentrations from 0% to 8%. In order to obtain different stress levels, specimens were loaded uniaxially to plastically deform the adherends. T-stress increased with the plastic deformation left in the specimen upon unloading. Under mode I loading, unstable or alternating crack propagation was seen when the T-stress in the specimen increased. After this stability transition occurred, failure occurred at or very close to the interfaces. However, the T-stress level where the stability transition occurred increased with adhesive rubber concentration. Post-failure XPS and SEM analysis showed that as rubber concentrations in the adhesive increased, failure tended to be more cohesive. FEA modeling using Franc2DI was conducted to predict crack propagation behavior. Results showed that when the crack is perturbed by an air bubble or flaw ahead of the crack tip, the crack continued to deviate from its original path if the T-stress was tensile. However, if the T-stress was compressive, a deviated crack would converge back to its original path. The convergence rate depended on the T-stress value. The FEA also predicted that under mode I loading, T-stress in specimens with thinner adherends was higher than that in specimens with thicker adherends, and failure tended to occur closer to the interfaces. This prediction was verified using DER 331 epoxy resin with 8.1% rubber and Al 6061-T6 adherends of varying thickness.

关键词： Bonding Rubber density estimation robust algorithm Epoxy resins Stability Structural beams Stress Plastics Failure analysis Predictive models

来源：评论

学校读者我要写书评

暂无评论

How bad is reliable multicast without local recovery?

How bad is reliable multicast without local recovery?

引用

IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： J. Nonnenmacher M. Lacher M. Jung E.W. Biersack G. Carle Institut Eurecom Provence-Alpes-Cote d'Azur France

We examine the impact of the loss recovery mechanisms on the performance of a reliable multicast protocol. Approaches to reliable multicast can be divided into two major classes: source-based recovery, and distributed recovery. For both classes we consider the state of the art: for source-based recovery, a type 2 hybrid ARQ scheme with parity retransmission; for distributed recovery, a scheme with local multicast retransmission and local feedback processing. We further show the benefits of combining the two approaches and consider a type 2 hybrid ARQ scheme with local retransmission. The schemes are compared for up to 10/sup 6/ receivers under different loss scenarios with respect to network bandwidth usage and completion time of a reliable transfer. We show that the protocol based on local retransmissions via type 2 hybrid ARQ performs best for bandwidth and latency. For networks, where local retransmission is not possible, we show that a protocol based on type 2 hybrid ARQ comes close to the performance of a protocol with local retransmissions.

关键词： density estimation robust algorithm Multicast protocols Automatic repeat request Telecommunication network reliability Bandwidth Forward error correction Feedback Delay Error correction Application software

来源：评论

学校读者我要写书评

暂无评论

Effects of the deviation of element values in a ring of three and four coupled van der Pol oscillators

Effects of the deviation of element values in a ring of thre...

引用

IEEE International Symposium on Circuits and Systems (ISCAS)

作者： T. Ookawara T. Endo Department of Electronics and Communication Faculty of Science and Technology Meiji University Kawasaki Japan

This paper investigates the effect of element value deviation on the degenerate mode in rings of three and four coupled van der Pol oscillators. By using the averaging method, we elucidate that the element value deviation has different effects on the rings of three and four coupled oscillators. Namely, for the ring of three coupled oscillators, two single modes, which bifurcate from the two-fold degenerate mode in the symmetric system can be synchronized when they are close, but they lose synchronization and a quasi-periodic oscillation appears when they are separated to some extent. In contrast, for the ring of four coupled oscillators, the two single modes cannot be synchronized even if they are close, but in some rare cases they can be synchronized when they are separated to some extent. We confirm these results of the averaging method by both computer simulation and experiments.

关键词： density estimation robust algorithm Ring oscillators Frequency synchronization Bifurcation Computer simulation Mutual coupling Brain modeling Digestive system Animals Coupled mode analysis

来源：评论

学校读者我要写书评

暂无评论

Generation of quadrilateral meshes from triangular data with resulting smooth surface reconstruction

Generation of quadrilateral meshes from triangular data with...

引用

International Conference on Information Visualisation (IV)

作者： O. Volpin M. Bercovier Institute of Computer Science Hebrew University Jerusalem Israel DER Genie Informatique Pole Universitaire Leonard de Vinci Paris France

A new method for surface reconstruction from an initial triangular mesh is introduced. The method transforms the mesh to a quadrilateral one and then builds a smooth surface on top of it. This approach is efficient for large collections of triangular patches, including difficult situations such as sharp junctions and n-patch vertices. During the reconstruction process, the number of mesh elements is considerably reduced. The possibility of parallel computation makes the method efficient in practice. The method is illustrated by building several free-form surfaces from a triangular mesh.

关键词： Surface reconstruction Mesh generation Clouds Assembly Tensile stress Computer science density estimation robust algorithm Concurrent computing Surface emitting lasers Linear programming

来源：评论

学校读者我要写书评

暂无评论

Model order selection for multidimensional innovations based detection in airborne radar

Model order selection for multidimensional innovations based...

引用

IEEE National Conference on Radar

作者： J. Castro J.P. LeBlanc Klipsch Sch. of Electr. & Comput. Eng. New Mexico State Univ. Las Cruces NM USA Klipsch School of ECE New Mexico State University Las Cruces NM USA

This paper investigates the model order selection problem for use with the multidimensional autoregressive (MAR) process in airborne radar detection processing which uses an innovations based detection algorithm (IBDA). Results indicate that a low order model should be used to accurately portray the return signal spectrum. Specifically, this paper investigates the use of the Akaike (1971) information criterion for model order selection. Examples are included for physically modeled data sets as well as actual radar data sets.

关键词： Multidimensional systems Technological innovation Radar detection Airborne radar Object detection Surveillance Radar applications Reflection density estimation robust algorithm Autoregressive processes

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：