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Navigation application and calibration method for gyroscope free strap-down inertial navigation system

Hangkong Taikong ji Minhang Xuekan/Journal of Aeronautics, Astronautics and Aviation 2006年第1期38 A卷 57-68页

作者： Hung, Chao-Yu Fang, Chun-Min Wang, Chen-Yu Lee, Sou-Chen Department of Weapon System Engineering Chung Cheng Institute of Technology National Defense University Taoyuan 33509 Taiwan College of Electrical Engineering and Computer Science Lunghwa University of Science and Technology Taiwan

The accuracy of a gyroscope free INS is deeply affected by the bias, scale factor and misalignment. However, these error parameters can be obtained by calibration. This paper presents two research issues. The first is an improvement to the original six-accelerometer model to achieve more realistic performance. The second is a novel calibration method for the proposed six-accelerometer INS. In navigation applications the improved model will determine the rotational and translational acceleration of a vehicle from the six accelerometer outputs. The proposed calibration method will decrease the system error to enhance the navigation performance.

关键词： Inertial navigation systems

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Cellular Automata for Self-Organizing Data Clustering

Cellular Automata for Self-Organizing Data Clustering

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IEEE International Conference on systems, Man and Cybernetics

作者： Dianxun Shuai D. Li Xu Bin Zhang Yumin Dong Department of Computer Science and Engineering East China University of Science and Technology Shanghai China College of Business and Public Administration Old Dominion University Norfolk VA USA Center of Computer Networks Qingdao Technological University Qingdao China

A data clustering method based on the generalized cellular automata (GCA) is presented. The stochastic process over a GCA array is used to realize the self-organization of data clusters for the given data sets. Due to its particular stochastic characteristics, GCA can deal with dynamical data, noise data, multi-type data, asymmetrically distributed data, multi-shaped-cluster data, high-dimensional data and massive data sets. The GCA-based data clustering also has advantages over other sequential methods in terms of the high parallelism, the learning ability, and the easier hardware implementation with the VLSI systolic technology.

关键词： Clustering algorithms Partitioning algorithms Clustering methods Iterative algorithms Shape Iterative methods Cybernetics Stochastic processes Stochastic resonance Hardware

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Particle Dynamics Approach to Multi-Agent systems

Particle Dynamics Approach to Multi-Agent Systems

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IEEE International Conference on systems, Man and Cybernetics

作者： Dianxun Shuai Qing Shuai Li D. Xu Yumin Dong Department of Computer Science and Engineering East China University of Science and Technology Shanghai China College of Business and Public Administration Old Dominion University Norfolk VA USA Center of Computer Networks Qingdao Technological University Qingdao China

The resources allocation and task assignment in complex distributed network environment is a typical problem of multi-agent systems (MAS). Even without taking into account interactions, coordinations, and a variety of random phenomena in networks, the bandwidth allocation problem in ATM networks is also NP-complete. This paper presents a particle dynamics approach (GPDA) that transforms the MAS problem-solving into the kinematics and dynamics of particles in a force-field. As an important application for problem-solving in MAS, this paper uses GPDA to optimize the bandwidth allocation and QoS in ATM networks. The GPA has features in terms of the high-degree parallelism, multi-objective optimization, multi-type coordination, multi-granularity coalition, and easier hardware implementation. Simulations and comparisons show the effectiveness and suitability of GPDA.

关键词： Multiagent systems Channel allocation Resource management Problem-solving Quality of service Hardware Telecommunication traffic Traffic control Bandwidth Aggregates

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Point Constriction, Interface, and Boundary Conditions for Kinematic-Wave Model

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Transportation Research Record 2006年第1期1965卷 60 - 69页

作者： Paul Nelson Nishant Kumar Department of Computer Science Texas A&M University College Station TX 77843-3112 and Kinetic Traffic Models P.O. Box 13535 College Station TX 77841. Department of Computer Science Texas A&M University College Station TX 77843-3112 and Texas Transportation Institute Texas A&M University System College Station TX 77843-3135.

The entropy solutions of the Riemann problem for the kinematic-wave model are described for (entrant and exiting) boundary conditions, interfaces (e.g., lane drops), and point constrictions (e.g., bottlenecks or signalized intersections) for kinematic-wave models. These results are used to obtain analytic solutions and computational solutions, by the method of Godunov, for the three test scenarios earlier suggested by Ross. Results show that the kinematic-wave model, with a correct computational solution (i.e., converging to the entropy solution), correctly produces the analytic (entropy) solutions of the kinematic-wave model and that analytic and computational solutions both satisfy intuitive expectations at least as well as the novel model suggested by Ross and even avoid some acknowledged deficiencies of the latter. They also emphasize the necessity of using discrete approximations that satisfy the entropy condition and of exercising care in ensuring that the discretization parameters are sufficiently small.

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SINS/GPS integrated system state estimation based on covariance assignment

SINS/GPS integrated system state estimation based on covaria...

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systems and Control in Aerospace and Astronautics, 2006. ISSCAA 2006. 1st International Symposium on

作者： Hang Shi Jihong Zhu Haiyan Tian State Key Laboratory of Intelligent Technology and System Department of Computer Science and Technology Tsinghua University Beijing China College of Mathematics and Information Science Hebei Normal University Shijiazhuang China

ISBN: (纸本)0780393953

SINS and GPS are widely used. Combining SINS and GPS organically, we can get an reliable integrated navigating system which can overcome the respective defects of the two systems, including signal blockage for GPS and growth of position errors with time for SINS, and develop their advantages to form a complementary structure at the same time. On the basis of using the SINS/GPS integrated navigation system, we introduce the covariance assignment state estimation algorithm not only to enhance the navigational capability and accuracy, but also enhance the robustness of the navigation system.

关键词： Global Positioning system covariance analysis inertial navigation state estimation Global Positioning system covariance assignment integrated system state estimation strap-down inertial navigation system

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CTH13-6: Distributive High-Rate Space-Frequency Codes Achieving Full Cooperative and Multipath Diversities for Asynchronous Cooperative Communications

CTH13-6: Distributive High-Rate Space-Frequency Codes Achiev...

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IEEE Globecom 2006

作者： Yabo Li Wei Zhang Xiang-Gen Xia Department of Electrical and Computer Engineering CDMA system design group Nortel Networks University of Delaware Richardson TX USA Department of Electric & Electronic Engineering Clear Water Bay Kowloon Hong Kong University of Science and Technology Hong Kong China Department of Electrical and Computer Engineering University of Delaware Newark DE USA

Using OFDM and space-time coding to achieve asynchronous cooperative diversity has been proposed by Mei et. al. and Shin et al, where orthogonal space-time block codes, Alamouti code in particular, were used at relay nodes. This proposed space-time coding can not achieve the multipath diversity when the channels from nodes to nodes are frequency selective fading. In this paper, we also consider asynchronous cooperative communications where the channels are assumed to be frequency-selective fading. We design high rate distributed space-frequency codes to achieve both full asynchronous cooperative diversity and multipath diversities.

关键词： Relays OFDM Frequency synchronization Fading Delay Transceivers Block codes Frequency diversity Receiving antennas Costs

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Digital Ecosystems: Evolving Service-Orientated Architectures 06

Digital Ecosystems: Evolving Service-Orientated Architecture...

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Bio-Inspired Models of Network, Information and Computing systems, BIONETICS

作者： Gerard Briscoe Philippe de Wilde Intelligent Systems and Networks Group Department of Electrical and Electronic Engineering Imperial College London London UK Intelligent Systems Lab School of Mathematical and Computer Science Heriot-Watt University Edinburgh UK

ISBN: (纸本)9781424404636

A novel optimisation technique inspired by natural ecosystems is presented, where the optimisation works at two levels: a first optimisation, migration of services which are distributed in a decentralised peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. Through this two-fold process, the local search is accelerated and will yield better local optima, because the distributed optimisation already provides a good sampling of the search space by making use of computations already performed in other peers with similar constraints. We call this new distributed optimisation architecture a digital ecosystem, an ecosystem-orientated architecture (EOA) created by extending a service-oriented architecture (SOA) with distributed evolutionary computing (DEC). The digital ecosystem will allow services to recombine and evolve over time, constantly seeking to improve their effectiveness for the user base. individuals within our digital ecosystem will be applications (groups of services), created in response to user requests by using evolutionary optimisation to aggregate the services. These individuals will migrate through the digital ecosystem and adapt to find niches where they are useful in fulfilling other user requests

关键词： Ecosystems Constraint optimization computer architecture Peer to peer computing Distributed computing Service oriented architecture Feeds computer networks Acceleration Sampling methods

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An Enhanced IEEE 802.11 MAC Algorithm for Tradeoff between Delay and Energy-Consumption

An Enhanced IEEE 802.11 MAC Algorithm for Tradeoff between D...

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IEEE International Conference on Communications (ICC)

作者： Hang Su Xi Zhang Peiliang Qiu Mohsen Guizani Networking and Information System Laboratories ECE Department Texas A and M University College Station TX USA Department of Information Science & Electrical Engin. University of Zhejiang Hangzhou China Department of Computer Science Western Michigan University Kalamazoo MI USA

One of the most crucial requirements of a wireless ad-hoc network is to work efficiently and reliably over a long period of time. It is important to design a control technique that minimizes the transmission power of each mobile node without losing much of the performance while retaining the fairness of the network. The contribution of this paper is twofold. First, we show that the transmission energy consumption and the media access delay can be expressed as a function of the conditional collision probability in the IEEE 802.11 MAC protocol. Based on the analyses, a fundamental tradeoff between the system energy consumption and its performance can be found by tuning up the system control parameter CWmin. Second, we propose an enhanced energy-aware scheme based on the IEEE 802.11 protocol. The simulation results show that this technique is more energy efficient than the original IEEE 802.11 protocol while keeping a similar media access delay and a better fairness.

关键词： Delay Media Access Protocol Energy consumption Batteries Ad hoc networks Access protocols Power control Throughput USA Councils Performance analysis

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Inter-Satellite Microwave Radiometer Calibration Between AMSR and TMI

Inter-Satellite Microwave Radiometer Calibration Between AMS...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： L. Hong W. Jones T. Wilheit Central Florida Remote Sensing Laboratory Electrical and Computer Engineering Department University of Central Florida Orlando FL USA Brazos Earth System Science Inc. College Station TX USA

There are many satellites in orbit using total power microwave radiometers with external calibration targets. Pre- launch and on-orbit calibrations have been developed and applied to ensure accurate measurements over decades. But because of different designs as well as instrument aging effects, subsequent calibration is necessary to improve or maintain measurement accuracy. In-orbit inter-satellite radiometric calibration techniques could provide a long-term, group-wise solution. This paper presents our current research, which analyzes two methods to perform this calibration based upon coincident brightness measurements. In the first approach we build a transfer relationship based on three adjacent frequency measurements and major environmental parameters using radiative transfer model normalization. In the second approach, a linear regression is used among all frequency and both polarization measurements and their transforms. We utilize Radiative transfer models (RTM's) in both methods, and refine them under different environmental conditions and later, we test the RTM models in order to better simulate brightness temperature retrieval before use in building transfer relationships. We validate the two different approaches by comparing external measurements between AMSR on ADEOS-II and TMI on TRMM. Results of calibration comparisons are provided along with accuracy prediction and error source analysis. By pursuing this research, the feasibility of building calibrations between polar-orbit satellites can be established for improved operational and scientific utilization of microwave radiometer measurements.

关键词： Microwave radiometry Calibration Extraterrestrial measurements Satellite broadcasting Frequency measurement Instruments Aging Performance analysis Performance evaluation Brightness

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Detection and Avoiding Ventricular Suction of Ventricular Assist Devices

Detection and Avoiding Ventricular Suction of Ventricular As...

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Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

作者： A. Tanaka M. Yoshizawa P. Olegario D. Ogawa K. Abe T. Motomura S. Igo Y. Nose Faculty of Symbiotic System Science Fukushima University Fukushima Japan Information Synergy Center University of Tohoku Sendai Japan Graduate School of Engineering University of Tohoku Sendai Japan Department of Computer Science College of Engineering Nihon University Koriyama Japan Michael E. DeBakey Department of Surgery Baylor University College of Medicine Houston TX USA

Continuous flow blood pumps, such as axial flow and centrifugal pumps, have been gaining interest as circulatory devices for total artificial hearts (TAHs) and a biventricular assist device (BVAD) because of their smaller size and simpler structure compared to pulsatile pumps. However, continuous flow pumps are more prone to suction of the left ventricle than pulsatile pumps are. Sudden increases in flow rate to meet changes in physiological demand, especially in the left pump, often cause ventricle suction. In this study, a control algorithm to prevent suction from occurring in the left ventricle by controlling the rotational speed of the right pump, instead of reducing the cardiac output of the left pump, was developed and investigated. The method was tested in acute animal experiments with calves. The results indicate that this proposed method is capable of preventing suction and could simultaneously maintain circulatory control. A key advantage of this control system is that flow rates can be maximized while avoiding ventricle suction conditions particularly when the circulatory system is unstable such as in a the first few days after operation

关键词： Artificial heart Biomedical engineering Electronic mail Testing Animals Control systems Circulatory system Blood flow Pressure control Medical control systems

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