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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Liu, Qiao He, Ke-xue Jiang, Liang-zhong Changsha Univ Sci & Technol Elect & Informat Engn Coll Changsha 410076 Peoples R China S China Univ Technol Dept Mech Engn Guangzhou 510640 Peoples R China

ISBN: (纸本)9781424402588

By modeling the networked robot system (NRS) that drops packets randomly, we considered the problem of optimal linear quadratic Gaussian (LQG) control and analyzed the stability of a NRS. We presented a mathematical model based on a packet-based setting, extended the familiar LQG separation principle that allows us to solve this problem using a standard LQR state-feedback design, proposed an optimal algorithm irrespective of the packet drop pattern by constructing an encoder for the unreliable channel and designing the decoder that uses the information it receives across the link to construct an estimate of the state of the networked robot. For the case of packet drops occurring according to a Markov chain, the stability analysis was carried out. Because the separation theorem for linear systems and quadratic cost does not apply to the general framework of NRSs, we used the uncertainty threshold principle to show that under certain conditions there was a rate for dropped packets for which an undisturbed networked control system with imperfect state observation was mean square stable, used a sub-optimal method to simplify the calculation of the estimator and controller, got the solution to the Riccati-like equation and guaranteed the mean square stability of the NRS with perfect state information. This design does not assume any statistical model of the packet drop events and can be implemented as a small modification of an existing LQG control design.

关键词： LQG control networked robot system (NRS) data dropout stability analysis optimal algorithm

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optimal Self Boundary Recognition with Two-Hop Information for Ad Hoc Networks

Optimal Self Boundary Recognition with Two-Hop Information f...

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IEEE Wireless Communications and Networking Conference (WCNC)

作者： Chen, Yen-Hsu Chung, Wei-Ho Ni, Guo-Kai Zhang, Hongke Kuo, Sy-Yen Natl Taiwan Univ Dept Elect Engn Taipei 10764 Taiwan

ISBN: (纸本)9781467304375;9781467304368

The ad hoc network is composed of multiple sensor nodes to serve various applications, such as data collection or environmental monitoring. In many applications, the sensor nodes near the boundary of the deployment region provide biased or low-quality information because they have limited number of neighboring nodes and only partial information is available. Hence, the boundary recognition is an important issue in the ad hoc networks. By the statistical approach in high node density networks, Fekete's pioneer work identified the boundary node by number of neighboring nodes and using a specific threshold. By exploiting the number of nodes in the two-hop region, our proposed algorithm has significant improvement of boundary recognition contrasted with Fekete's algorithm in the low-density network. Given the information topology and the cost function, the analyses provide a framework to obtain the optimal threshold for boundary recognition. Besides, the simulation results reveal the proposed algorithm has greater than 90% detection rate and lower than 10% false alarm rate.

关键词： ad hoc networks boiundary recognition decision optimal algorithm

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optimal ERROR AND GMDH PREDICTORS - A COMPARISON WITH SOME STATISTICAL TECHNIQUES

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INTERNATIONAL JOURNAL OF FORECASTING 1987年第2期3卷 313-328页

作者： VICINO, A TEMPO, R GENESIO, R MILANESE, M POLITECN TORINO I-10129 TURIN ITALY

This paper presents some results obtained in time series forecasting using two nonstandard approaches and compares them with those obtained by usual statistical techniques. In particular, a new method based on recent results of the General Theory of optimal algorithms is considered. This method may be useful when no reliable statistical hypotheses can be made or when a limited number of observations is available. Moreover, a nonlinear modelling technique based on Group Method of Data Handling (GMDH) is also considered to derive forecasts. The well-known Wolf Sunspot Numbers and Annual Canadian Lynx Trappings series are analyzed; the optimal Error Predictor is also applied to a recently published demographic series on Australian Births. The reported results show that the optimal Error and GMDH predictors provide accurate one step ahead forecasts with respect to those obtained by some linear and nonlinear statistical models. Furthermore, the optimal Error Predictor shows very good performances in multistep forecasting. [ABSTRACT FROM AUTHOR]

关键词： optimal algorithm Time series GMDH Application Comparative methods Lead time

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ON optimal HEURISTIC RANDOMIZED SEMIDECISION PROCEDURES, WITH APPLICATION TO PROOF COMPLEXITY

ON OPTIMAL HEURISTIC RANDOMIZED SEMIDECISION PROCEDURES, WIT...

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27th International Symposium on Theoretical Aspects of Computer Science (STACS)

作者： Hirsch, Edward A. Itsykson, Dmitry Steklov Inst Math St Petersburg 27 Fontanka St Petersburg 191023 Russia

ISBN: (纸本)9783939897163

The existence of a (p-) optimal propositional proof system is a major open question in (proof) complexity;many people conjecture that such systems do not exist. Krajicek and Pudlak [KP89] show that this question is equivalent to the existence of an algorithm that is optimal(1) on all propositional tautologies. Monroe [Mon09] recently gave a conjecture implying that such algorithm does not exist. We show that in the presence of errors such optimal algorithms do exist. The concept is motivated by the notion of heuristic algorithms. Namely, we allow the algorithm to claim a small number of false "theorems" (according to any polynomial-time samplable distribution on non-tautologies) and err with bounded probability on other inputs. Our result can also be viewed as the existence of an optimal proof system in a class of proof systems obtained by generalizing automatizable proof systems.

关键词： propositional proof complexity optimal algorithm

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optimal Implementation of Elliptic Curve Cryptography

Optimal Implementation of Elliptic Curve Cryptography

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IEEE International Conference on Service Operations and Logistics, and Informatics (SOLI)

作者： Lv, Hongqiang Li, Hui Yi, Junkai Lu, Hao Beijing Univ Chem Technol Coll Informat Sci & Technol Beijing 100029 Peoples R China Chinese Acad Sci Inst Automat State Key Lab Management & Control Complex Syst Beijing Peoples R China

ISBN: (纸本)9781479905300;9781479905294

The most time-consuming operation in the Elliptic Curve Cryptography (ECC) calculation is scalar multiplication. Scalar multiplication plays a major role in ECC. Currently, there are several optimization algorithms for point scalar multiplication which have either high computational complexity or additional storage requirement. They are all unsuitable for further applying. In this paper, we present a new compatible optimal algorithm which improves the efficiency by generating a special random number k as the scalar. The experimental results show that the processes of encryption and decryption have been speed up significantly in the same condition.

关键词： Elliptic Curve Cryptography scalar multiplication optimal algorithm random number

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optimal packet scheduling in tree-structured LEO satellite clusters

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MOBILE NETWORKS & APPLICATIONS 2004年第4期9卷 289-295页

作者： Bonuccelli, MA Martelli, F Pelagatti, S Univ Pisa Dipartimento Informat I-56127 Pisa Italy CNR ISTI I-56124 Pisa Italy

Clusters of mobile (LEO) satellites, flying at a non-geostationary orbit, have been recently proposed, designed and made operational for achieving a global coverage of roaming users. An example of these is Teledesic. The satellites of these clusters are equipped with a radio frequency switch and connected via intersatellite links to form a specific topology. Uncoordinated packet transmission in these systems may result in collisions. Collided packets must be retransmitted, with an obvious degradation in performance, in terms of both bandwidth usage and delay. This performance degradation can be overcome by a proper scheduling of the packets. In this paper, we consider optimal (namely minimum length) packet scheduling in LEO satellite clusters. We present a preprocessing algorithm which, together with the optimal, polynomial time, packet scheduling algorithm for isolated satellites, produces an optimal schedule in tree-connected clusters. The overall algorithm inherit the time complexity of the optimal one for isolated systems, and is O(N-4) for a cluster serving N roaming users.

关键词： LEO satellite clusters TDMA packet scheduling optimal algorithm

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optimal flood control operation for the Three Gorges and Qingjiang cascade reservoirs

Optimal flood control operation for the Three Gorges and Qin...

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5th International Symposium on Integrated Water Resources Management/3rd International Symposium on Methodology in Hydrology

作者： Guo, Shenglian Li, Yu Chen, Jionghong Wuhan Univ State Key Lab Water Resources & Hydropower Engn S Wuhan 430072 Peoples R China

ISBN: (纸本)9781907161254

Both separate and joint flood control operation models or the Three Gorges and Qingjiang cascade reservoirs are proposed. The models were solved by the modified progressive optimality algorithm according to the procedure of optimization-veritication-adjustment and its constraint conditions were treated by dynamic penalty function. Four typical years of 1954, 1981, 1982 and 1998 were selected to derive the design flood hydrographs for the corresponding return periods by the peak and volume amplitude method. The conventional, separate and joint cascade operation Hood control models were performed for these reservoirs. The results show that the separate cascade operation gives full play to the role of flood control storage compensation between cascade reservoirs, while joint cascades operation can also perform storage compensation between two cascades. The Jingjiang River flood control standards can be raised to 118-year and 136-year design floods based on 1982 typical year, and 150-year and 168-year design floods based on the average of four typical years, respectively.

关键词： cascade reservoirs storage compensation flood control operation optimal algorithm

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Determination of optimal Measurement Configurations for Robot Calibration Based on a Hybrid optimal Method

Determination of Optimal Measurement Configurations for Robo...

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IEEE International Conference on Information and Automation

作者： Huang, Chenhua Xie, Cunxi Zhang, Tie S China Univ Technol Sch Mech Engn Guangzhou Guangdong Peoples R China

ISBN: (纸本)9781424421831

Robot calibration is an important method to improve robot accuracy. optimal measurement configurations for robot calibration are helpful to reducing measure points, and save time consume. In this paper, a hybrid optimal method was proposed, and the measuring configurations for a six degree-of-freedom industrial robot calibration were selected based on the proposed algorithm. First, the robot error model was constructed according to a modified complete and parametrically continuous (MCPC) kinematic model, and then the optimal objective function was obtained, which was the condition number of error identification Jacobi. Second, the validity and the procedure of the proposed algorithm were discussed in detail. The hybrid optimal algorithm realized the combination of global search and local search, and the distinct characteristics are good global ability;good convergence and time consumed less, also easy to programme. Simulation studies were conducted to examine the efficiency of the hybrid optimal algorithm, and the results show that the hybrid optimal algorithm is good at determination of optimal measurement configurations. The results also suggest that the proposed algorithm is better than the single chaos optimal algorithm.

关键词： industrial robot robot calibration optimal algorithm

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optimal Radiometric Detection of Band-limited Noise Signal 37

Optimal Radiometric Detection of Band-limited Noise Signal

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37th IEEE International Conference on Electronics and Nanotechnology (ELNANO)

作者： Volosyuk, V. K. Pavlikov, V. V. Zhyla, S. S. Odokienko, O. V. Zhukovsky Natl Aerosp Univ KhAI Aircraft Radioelect Syst Design Kharkov Ukraine

ISBN: (纸本)9781538617014

optimal algorithms of band-limited noise signal detection are synthesized. The decision on the presence or absence of a signal is taken from the result of likelihood functions comparison. The block diagrams of optimal and quasi-optimal detectors are developed. The analytical expressions of probabilistic and power characteristics for different ratios of useful and noise signals are obtained. Curves of probability detection are constructed.

关键词： likelihood ratio optimal algorithm signal-to-noise ratio probabilistic and power characteristics

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First Efficient Convergence for Streaming k-PCA: a Global, Gap-Free, and Near-optimal Rate 58

First Efficient Convergence for Streaming k-PCA: a Global, G...

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58th IEEE Annual Symposium on Foundations of Computer Science (FOCS)

作者： Allen-Zhu, Zeyuan Li, Yuanzhi Microsoft Res Cambridge MA 02142 USA Princeton Univ Princeton NJ 08544 USA

ISBN: (纸本)9781538634646

We study streaming principal component analysis (PCA), that is to find, in Omicron(dk) space, the top k eigenvectors of a d x d hidden matrix Sigma with online vectors drawn from covariance matrix Sigma. We provide global convergence for Oja's algorithm which is popularly used in practice but lacks theoretical understanding for k > 1. We also provide a modified variant Oja(++) that runs even faster than Oja's. Our results match the information theoretic lower bound in terms of dependency on error, on eigengap, on rank k, and on dimension d, up to poly-log factors. In addition, our convergence rate can be made gap-free, that is proportional to the approximation error and independent of the eigengap. In contrast, for general rank k, before our work (1) it was open to design any algorithm with efficient global convergence rate;and (2) it was open to design any algorithm with (even local) gap-free convergence rate in Omicron(dk) space.

关键词： principal component analysis streaming algorithm online algorithm global convergence stochastic optimization convergence optimal algorithm nonconvex optimization

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