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Specification of dynamic structure discrete event systems using single point encapsulated control functions

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International Journal of Modeling, Simulation, and Scientific Computing 2014年第3期5卷 171-190页

作者： Alexandre Muzy Bernard P.Zeigler I3S UMR CNRS 7271 Bio-info team CS 40121—06903 Sophia-Antipolis CedexFrance RTSync Corp 530 Bartow Drive Suite A Sierra Vista AZ 85635United States of America

In Discrete Event System Specification(DEVS),the dynamics of a network is constituted only by the dynamics of its basic *** state of each component is fully *** in the network is fully decentralized to each *** dynamic structure level,DEVS should permit the same level of ***,it is hard to ensure structure consistency while letting all components achieve structure ***,this solution can be complex to *** avoid these difficulties,usual dynamic structure approaches ensure structure consistency allowing structure changes to be done only by the network having newly added dynamics change *** is a safe and simple way to achieve dynamic ***,it should be possible to simply allow components of a network to modify the structure of their network,other components and/or their own structure—without having to modify the usual definition a DEVS *** this manuscript,it is shown that a simple fully decentralized approach is possible while ensuring full modularity and structure consistency.

关键词： dynamic structure discrete event system specification

dynamic structures and their sedimentation effects of the Yamen Inlet,Huangmaohai Estuary

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Science China Earth Sciences 2011年第6期54卷 936-946页

作者： WEI Xing WU XiaoXing Key Laboratory of Tropical Marine Environmental dynamics South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Center for Coastal Ocean Science and Technology Research Sun Yetsen UniversityGuangzhou 510275China South China Sea Marine Prediction Center State Oceanic AdministrationGuangzhou 510300China

One of eight gates of the Pearl River Estuary,the Yamen Inlet is a bedrock channel mouth connecting the Huangmao Sea and Yamen *** wider water surfaces of the upper and lower reaches of the entrance produce a unique bidirectional asymmetrical jet *** observed hydrology and historical charts,the ECOMSED model was applied in morphodynamic analysis of the dynamic structures and dynamic equilibrium of the Yamen jet system and its effect on *** was found that (1) the nonlinear interaction of Yamen dynamic structures could not be ignored,as while the Coriolis force and friction force were generally of the same order of magnitude,the effect of friction force was greater;(2) the bidirectional asymmetrical jet system was flood preferential flow to the north of the channel mouth and ebb preferential flow to the south;and (3) the bidirectional asymmetrical jet system was the dominant factor in the long term stability of the Yamen deep trough.

关键词： Yamen Inlet bidirectional jet dynamic structure dynamic equilibrium sedimentation

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Large dynamic Covariance Matrix Estimation with an Application to Portfolio Allocation:A Semiparametric Reproducing Kernel Hilbert Space Approach

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Journal of Systems Science & Complexity 2022年第4期35卷 1429-1457页

作者： PENG Siyang GUO Shaojun LONG Yonghong School of Mathematics Renmin University of ChinaBeijing100086China Institute of Statistics and Big Data Renmin University of ChinaBeijing100086China

The estimation of high dimensional covariance matrices is an interesting and important research topic for many empirical time series problems such as asset allocation. To solve this dimension dilemma, a factor structure has often been taken into account. This paper proposes a dynamic factor structure whose factor loadings are generated in reproducing kernel Hilbert space(RKHS), to capture the dynamic feature of the covariance matrix. A simulation study is carried out to demonstrate its performance. Four different conditional variance models are considered for checking the robustness of our method and solving the conditional heteroscedasticity in the empirical study. By exploring the performance among eight introduced model candidates and the market baseline, the empirical study from 2001 to 2017 shows that portfolio allocation based on this dynamic factor structure can significantly reduce the variance, i.e., the risk, of portfolio and thus outperform the market baseline and the ones based on the traditional factor model.

关键词： dynamic structure factor models high dimensional covariance matrices portfolio allocation reproducing kernel Hilbert space

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Elastic period of vibration calculated experimentally in buildings hosting permanent GPS stations

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Earthquake Engineering and Engineering Vibration 2018年第3期17卷 607-625页

作者： Marco Gatti Department of Engineering University of Ferrara

During the earthquake in Emilia（Italy） of 2012,ca.30 permanent GPS stations were in operation within a radius of about 100 km from the epicenter,each equipped with an antenna rigidly fixed to the host building and sampling the GPS signal at a high rate（〉 1 Hz）.From the recording of the GPS measurements,the instantaneous displacements s（t） in the NorthSouth and East-West directions of the phase centers of the single GPS antennas at each permanent station during the most important seismic sequences were calculated in kinematic ***,for each of the two displacements considered as two distinct external forces,the elastic response spectra of the building were determined and from them the two periods of vibration T along two orthogonal directions coinciding with the walls of the building were *** experimentally obtained periods of vibration were compared with those inferable from the technical *** this way,a sufficiently large sample was obtained per building type,geometry（square,rectangular,regular or irregular planimetry）,height（from a minimum of 4 to a maximum of 20 m） and materials（masonry,reinforced concrete,etc.）.From the computational point of view,the study confirmed that GPS is an emerging tool for monitoring dynamic displacements and the experimentally estimated value of T is always lower than the one estimated with the formulae reported in the *** limitations of the study lie in the impossibility to choose a priori the geometry and/or structural type of the building hosting the GPS station.

关键词： permanent GPS stations Emilia-Romagna Italy earthquake period vibrations dynamic structure

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珠江三角洲乡村城市化的形成机制与调控措施

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