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Interactive natural language interface

WSEAS Transactions on computers 2009年第4期8卷 661-680页

作者： El-Mouadib, Faraj A. Zubi, Zakaria Suliman Almagrous, Ahmed A. El-Feghi, I. Computer Science Department Faculty of Information Technology Garyounis University Benghazi Libya Computer Science Department Faculty of Science Al-Tahadi University Sirt Libya High Computer Technology Institute Academy of Science Benghazi Libya Electrical Engineering Department Faculty of Engineering Al-Fateh University Tripoli Libya

To override the complexity of SQL, and to facilitate the manipulation of data in databases for common people (not SQL professionals), many researches have turned out to use natural language instead of SQL. The idea of using natural language instead of SQL has prompted the development of new type of processing method called Natural Language Interface to Database systems (NLIDB). The NLIDB system is actually a branch of more comprehensive method called Natural Language Processing (NLP). In general, the main objective of NLP research is to create an easy and friendly environment to interact with computers in the sense that computer usage does not require any programming language skills to access the data;only natural language (i.e. English) is required. Many systems have been developed to use the concept of NLP in different varieties of domains, for example the system LUNAR and the system LADDER. One drawback of previous systems is that the grammar must be tailor-made for each given database. Another drawback is that many NLP systems cover only a small domain of the English language questions. In this paper we present the design and implementation of a natural language interface to a database system. The system is called Generic Interactive Natural Language Interface to Databases (GINLIDB). It is designed by the use of UML and developed using Visual ***-2005. Our system is generic in nature given the appropriate database and knowledge base. This feature makes our system distinguishable.

关键词： Database systems

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Cognitive Wireless Sensor Networks: Emerging topics and recent challenges

Cognitive Wireless Sensor Networks: Emerging topics and rece...

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IEEE Toronto International Conference on Science and technology for Humanity (TIC-STH)

作者： Amir Sepasi Zahmati Sattar Hussain Xavier Fernando Ali Grami Department of Electrical and Computer Engineering Ryerson University Canada Faculty of Engineering and Applied Science University of Ontario Institute of Technology (UOIT) Canada

ISBN: (纸本)9781424438778

Adding cognition to the existing Wireless Sensor Networks (WSNs), or using numerous tiny sensors, similar to the idea presented in WSNs, in a Cognitive Radio Network (CRN) bring about many benefits. In this paper, we present an overview of Cognitive Wireless Sensor Networks (CWSNs), and discuss the emerging topics and recent challenges in the area. We discuss the main advantages, and suggest possible remedies to overcome the challenges. CWSNs enable current WSNs to overcome the scarcity problem of spectrum which is shared with many other successful systems such as Wi-Fi and Bluetooth. It has been shown that the coexistence of such networks can significantly degrade a WSN's performance. In addition, cognitive technology could provide access not only to new spectrum, but also to spectrum with better propagation characteristics. Moreover, by the adaptive change of system parameters such as modulation type and constellation size, different data rates can be achieved which in turn can directly influence the power consumption and the network lifetime. Furthermore, sensor measurements obtained within the network can provide the needed diversity to cope with spectrum fading at the physical layer.

关键词： Wireless sensor networks Cognition Cognitive radio Bluetooth Degradation Adaptive systems Energy consumption Sensor phenomena and characterization Fading Physical layer

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Location-Release Signature for Vehicular Communications

Location-Release Signature for Vehicular Communications

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International Conference on computer Communications and Networks (ICCCN)

作者： Xiaodong Lin Rongxing Lu Xuemin Shen Faculty of Business and Information Technology Institute of Technology University of Ontario Canada Department of Electrical and Computer Engineering University of Waterloo Waterloo ONT Canada

In this paper, we propose a location-release signature scheme based on bilinear pairings for vehicular ad hoc networks (VANETs). Location-release signature is a capsule signature signed by a source location server that becomes valid after the signature arrives at a specific destination location, where a location server publishes some trapdoor information associated with such a destination location. The scheme can efficiently and effectively resolve the fairness problem in Store-Carry-Forward (S-C-F) communication, which is a very important issue in VANETs. With the provable security techniques, we also demonstrate the proposed scheme is provably secure in the random oracle model.

关键词： Position measurement Network servers Ad hoc networks Information security Road safety Telecommunication traffic Job shop scheduling Road vehicles Digital signatures Cryptography

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A Tri-directional power electronic transformer for photo voltaic based distributed generation application

A Tri-directional power electronic transformer for photo vol...

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IEEE General Meeting Power& Energy Society

作者： S. H. Hosseini M. B. B. Sharifian M. Sabahi Z. Hooshi G. B. Gharehpetian Electrical Engineering Department Seraj Higher Education Institute Tabriz Iran Faculty of Electrical & Computer Engineering University of Tabriz Tabriz Iran Electrical Engineering Department Amirkabir University of Technology슠 Tehran Iran

Expanding the size and demand of the electrical network, make the use of distributed generation inevitable especially, when the produced power can be expected as a green power. Furthermore, this growth in size brings up the importance of volume and weight of instruments, used in. Power electronic transformer is an attempt to reduce the weight and occupied space of the electrical devices. In this paper, the combination of these concepts leads to make a new, very controllable structure. The good performance of the proposed circuit is shown through several simulations and experiments. Simulations are carried out in PSCAD/EMTDC software.

关键词： Power electronics Distributed control PSCAD Positron emission tomography Batteries Energy storage Power supplies EMTDC Power generation Circuit simulation

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Online multiple error detection in crossbar nano-architectures

Online multiple error detection in crossbar nano-architectur...

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IEEE International Conference on computer Design: VLSI in computers and Processors, (ICCD)

作者： Navid Farazmand Mehdi B. Tahoori Department of Electrical and Computer Engineering Northeastern University Boston MA USA Faculty of Informatik ITEC Karlsruhe Institute of Technology Germany

Crossbar nano-architectures based on self-assembled nano-structures are promising alternatives for current CMOS technology, which is facing serious challenges for further down-scaling. One of the major challenges in this nanotechnology is elevated failure rate due to atomic device sizes and inherent lack of control in self-assembly fabrication. Therefore, high permanent and transient failure rates lead to multiple faults during lifetime operation of crossbar nano architectures. In this paper, we present a concurrent multiple error detection scheme for multistage crossbar nano-architectures based on dual-rail implementations of logic functions. We prove the detectability of all single faults as well as most classes of multiple faults in this scheme. Based on statistical multiple fault injection, we compare the proposed technique with other online error detection and masking techniques such as Triple Module Redundancy (TMR), duplication, and parity checking, in terms of fault coverage as well as area and delay overhead.

关键词： Circuit faults Fault detection Circuit testing Self-assembly Programmable logic arrays CMOS technology Fabrication Integrated circuit interconnections Semiconductor materials Switches

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Integrated model of IGF-I mediated biosynthesis in a deformed articular cartilage

Integrated model of IGF-I mediated biosynthesis in a deforme...

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作者： Zhang, Lihai Gardiner, Bruce Stuart Smith, David Wamsley Pivonka, Peter Grodzinsky, Alan Jay Department of Civil and Environmental Engineering University of Melbourne Melbourne VIC 3010 Australia Engineering Computational Biology Group School of Computer Science and Software Engineering The University of Western Australia Crawley WA 6009 Australia Faculty of Engineering Computing and Mathematics The University of Western Australia 35 Stirling Highway Crawley WA 6009 Australia Center for Biomedical Engineering Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 United States

Maintenance of articular cartilage's functional mechanical properties ultimately depends on the balance between the extracellular matrix component biosynthesis, degradation, and loss. A variety of factors are known to modulate the rate of cartilage matrix synthesis (e.g., growth factors and stress/strain environment). In the present study, we develop an integrated mathematical model that quantifies biological processes within cartilage tissue modulated by insulin-like growth factors (IGFs). Specifically, the model includes IGF transport through a deforming porous media, competitive binding to binding proteins and cell receptors, and matrix macromolecule biosynthesis - particularly glycosaminoglycans (GAGs). These newly synthesized matrix molecules are then able to modify the material properties of cartilage. The model is used to investigate the effect of synovial fluid IGF-I concentration on cartilage homeostasis. The results presented here suggest that GAG production can be rapidly "switched on" when the concentration of IGF-I reaches a certain threshold, while it is predicted that high receptor concentration leads to heterogeneous matrix production. As for the combined effect of IGF-I and mechanical loading on biosynthesis, the current model predicts that a loading regime with high strain magnitude (e.g., 10%) can achieve a synergistic effect on matrix protein production. Furthermore, dynamic loading is seen to promote spatial homogeneous GAG production. © 2009 ASCE.

关键词： Biosynthesis

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Optimality of Affine Policies in Multi-stage Robust Optimization

Optimality of Affine Policies in Multi-stage Robust Optimiza...

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Joint 48th IEEE Conference on Decision and Control and 28th Chinese Control Conference

作者： Dimitris Bertsimas Dan A.Iancu Pablo A.Parrilo Faculty of the Sloan School of Management and the Operations Research Center Massachusetts Institute of Technology the Operations Research Center Massachusetts Institute of Technology the Laboratory for Information and Decision Systems and the Faculty of Electrical Engineering and Computer Science Massachusetts Institute of Technology

In this paper,we prove the optimality of disturbance-affine control policies in the context of onedimensional,box-constrained,multi-stage robust *** results cover the finite horizon case,with minimax(worstcase) objective,and convex state costs plus linear control *** proof methodology,based on techniques from polyhedral geometry,is elegant and conceptually simple,and entails efficient algorithms for the case of piecewise affine state costs,when computing the optimal affine policies can be done by solving a single linear program.

关键词： Optimality of Affine Policies in Multi-stage Robust Optimization

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An Improved Model for Prediction of the Dynamics of Lightning Channel Corona Sheath

An Improved Model for Prediction of the Dynamics of Lightnin...

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International Zurich Symposium on Electromagnetic Compatibility (EMC Zurich)

作者： Grzegorz Maslowski Vladimir A. Rakov Jovan Cvetic Megumu Miki Department of Electrical and Computer Engineering Rzeszow University of Technology Poland Department of Electrical and Computer Engineering University of Florida Gainesville FL USA Faculty of Electrical Engineering University of Belgrade Serbia Central Research Institute of Electric Power Industry Tokyo Japan

We consider dynamics of the lightning-channel corona sheath that is implicitly specified by lumped-current-source lightning return-stroke models. Two slightly different corona models for prediction of charge motion in the corona sheath are proposed. Both models can be viewed as generalizations of the model proposed by Maslowski and Rakov (2006) and are in agreement with measurements of the horizontal (radial) electric field component made in the immediate vicinity of triggered lightning channel.

关键词： Predictive models Lightning Corona computer industry Current measurement Charge measurement Electric variables measurement Motion measurement Engine cylinders Coaxial components

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Greedy routing in wireless mesh network: Performance and analysis

Greedy routing in wireless mesh network: Performance and ana...

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IEEE International Conference on Networking, Sensing and Control

作者： Hao Liu Feodor Vainstein Department of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA USA Faculty of Computer and Information Sciences Texas A and M University Texarkana TX USA

Uniform random network (URN) is perhaps the most basic and generic model of complex networks. In a URN, each node links to exactly k other nodes which are randomly chosen from the entire network with equal probability. With such a simple topology assumption, URN is suitable for modeling homogeneous wireless mesh networks. However, compared to inhomogeneous networks like small world or power-law network, the routing performance of URNs has been less investigated. For small world, it is widely known that a message can be expected to reach its destination through averagely 6 hops. But how many hops for URNs? In this paper, we try to evaluate the performance of URN routing through discrete-event simulation, which reveals two interesting and surprising findings: (1) most routings in URNs end up with incorrect destinations after one or two hops; (2) given a key, the diversity of all possible routing results closely approximates to N/k, where N is the network size and k is the outgoing degree. Tuning of these two parameters does not change above observations.

关键词： Routing Wireless mesh networks Performance analysis

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Phase based SNR estimation in OFDM over the medium voltage network

Phase based SNR estimation in OFDM over the medium voltage n...

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IEEE International Symposium on Power Line Communications and Its Applications (ISPLC)

作者： Ilias Trachanas Klaus Dostert Norbert J. Fliege HYTEC Gerätebau GmbH Mannheim Germany Institute of Industrial Information Technology Faculty of Electrical Engineering and Information Technology University of Karlsruhe Karlsruhe Germany Chair of Electrical Engineering Faculty of Mathematics & Computer Science University of Mannheim Mannheim Germany

Modern digital communications over the aggressive medium voltage network (MVN) channel are based on reliable signal to noise ratio (SNR) estimation. In this work, a novel phase based SNR estimation method for Orthogonal Frequency Division Multiplexing (OFDM) systems transmitting over the MVN is proposed. By exploiting the fact that under additive white Gaussian noise (AWGN) conditions the phase errors at the receiver are normally distributed when the real SNR is over 10dB, the method estimates the SNR by only making use of the signal's phase samples. The knowledge of the current channel's transfer function as well as the current transmission power is not necessary for the SNR estimation, which simplifies the calculations and increases the method's applicability in practical systems communicating within the MVN environment. Immunity against constant phase errors and phase jitter caused by noise, the MVN channel or/and realistic OFDM synchronization count to further beneficial properties of the proposed estimator.

关键词： Phase estimation OFDM Medium voltage Signal to noise ratio Additive white noise AWGN Digital communication Telecommunication network reliability Frequency estimation Transfer functions

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