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Spatial Pattern and Heterogeneity of Port & Shipping Service Enterprises in the Yangtze River Delta,2002–2016
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作者 CAO Youhui JIANG Ziran +2 位作者 YE Shilin WU Wei LIANG Shuangbo 《Chinese Geographical Science》 SCIE CSCD 2019年第3期474-487,共14页
Using the ‘theoretical hypothesis—empirical study—case verification' method, this paper studies the spatial distribution and differentiation of port & shipping service enterprises(PSSE), as well as the vari... Using the ‘theoretical hypothesis—empirical study—case verification' method, this paper studies the spatial distribution and differentiation of port & shipping service enterprises(PSSE), as well as the variation process and underlying mechanism in the Yangtze River Delta(YRD). First, through inductive and deductive reasoning, we propose the following hypothesis: the regional distribution of different types of PSSE would show different spatial agglomeration-decentralization tendency; and there would be distinct regional differentiation in the industrial structure of the enterprises. Second, based on data obtained from enterprises, empirical research is conducted using Gini coefficient and spatial interpolation simulation methods. Results show that: 1) The overall enterprise distribution is decentralized within a city. 2) Different types of enterprises show different spatial agglomeration-decentralization tendencies. At 3000 m×3000 m grid scale, there is an agglomeration tendency along seas and rivers in the spatial distribution of enterprises. Shanghai has been identified consistently as a hot spot. 3) There is significant regional differentiation in 12 port cities with respect to the industrial structures of enterprises. Finally, the transportization and the increase of shipping service demand, the globalization and the expansion of multinational corporate activities, the hierarchization and the cooperation among port cities as well as the decentralization and the behavioral difference between the central and local states can be seen as main driving mechanism of the spatial phenomenon. 展开更多
关键词 PORT & SHIPPING service ENTERPRISES spatial distribution regional differentiation HUB PORT city YANGTZE River Delta
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Formation Mechanism of the Accumulative Magnification Effect in a Financial Time Series 被引量:1
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作者 段文奇 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第3期271-274,共4页
Structural information contained in financial time series can be magnified effectively by constructing the accumulative return.In order to make the magnification effects of different financial time series comparative,... Structural information contained in financial time series can be magnified effectively by constructing the accumulative return.In order to make the magnification effects of different financial time series comparative,we first propose a standard method to characterize the strength of the accumulative magnification effect.Then,we employ decomposed-randomized technology to uncover the formation mechanism of the accumulative magnification effect.Our results show that(1)the standard deviation pattern is determined by volatility dependence,(2)the Hurst exponent pattern is induced by sign dependence,(3)an approximate entropy pattern is caused by the combined effect of sign dependence and volatility dependence. 展开更多
关键词 EFFECT STRENGTH PATTERN
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Research and application of the virtual simulation system teaching method in NC machining course
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作者 Yongxiang Li Xiaoping Lu +2 位作者 Cong Yu Haixia Guo Dan Zhang 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2018年第1期168-184,共17页
Virtual simulation technology has become one of the most popular technologies in the field of engineering education after the multimedia information technology in recent years.This paper,based on the comprehensive int... Virtual simulation technology has become one of the most popular technologies in the field of engineering education after the multimedia information technology in recent years.This paper,based on the comprehensive integrated simulation and verification module of UG NX software,describes and discusses a novel virtual simulation system teaching(VSST)for numerically controlled machining to support the student engineering training to achieve the theoretical knowledge and practical techniques in numerically controlled machining.The findings of a study designed to evaluate the impact of VSST for the development of numerically controlled machining course are presented here.In addition,analysis of the follow-up surveys indicates that the VSST method enables to provide the concrete experience of interaction between the students and the simulation environment and to further stimulate students’interest in learning,so that the students who used VSST achieve significantly higher results than their co-workers. 展开更多
关键词 Architectures for educational technology systems virtual reality computerbased models and simulations computer-supported learning environment
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Intelligence attention model based on object behavior
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作者 ZOU Yimin ZHANG Zhixiong LIU Jianhua 《Journal of Library Science in China》 2013年第1期184-197,共14页
Intelligence attention model is a premise of implementing the structured monitoring of science and technology(S&T) information,and plays an important role in identifying intelligence value of S&T information a... Intelligence attention model is a premise of implementing the structured monitoring of science and technology(S&T) information,and plays an important role in identifying intelligence value of S&T information and intelligence monitoring system.Analyzing the characteristics of scientific information based on monitoring the express in the energy technology domain,this paper has found that the object and its behavior have an important role in intelligence value judgment and have institutional particularity,and the number of important institutions in the domain has convergence.Using these characteristics,an intelligence attention model based on object behavior has been proposed,which not only focuses on the objects themselves,but also is more concerned about object behavior as well as the event behind the behavior.After evaluating and analyzing the application effect of this model,we find that this model can improve the degree of accuracy and refinement of intelligence value iudement. 展开更多
关键词 INTELLIGENCE VALUE INTELLIGENCE ATTENTION model KNOWLEDGE OBJECT OBJECT BEHAVIOR INTELLIGENCE monitoring system
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