期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
Fund budget model for multipurpose transit smart card systems
1
作者 张宁 钱振东 +1 位作者 陈恺 杨利强 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期95-98,共4页
The fund budget of multipurpose transit smart card systems is studied by stochastic programming to assign limited funds to different applications reasonably. Under the constraints of a gross fund, models of chance-con... The fund budget of multipurpose transit smart card systems is studied by stochastic programming to assign limited funds to different applications reasonably. Under the constraints of a gross fund, models of chance-constrained and dependentchance for the fund budget of multipurpose transit smart card systems are established with application scale and social demand as random variables, respectively aiming to maximize earnings and satisfy the service requirements the furthest; and the genetic algorithm based on stochastic simulation is adopted for model solution. The calculation results show that the fund budget differs greatly with different system objectives which can cause the systems to have distinct expansibilities, and the application scales of some applications may not satisfy user demands with limited funds. The analysis results indicate that the forecast of application scales and application future demands should be done first, and then the system objective is determined according to the system mission, which can help reduce the risks of fund budgets. 展开更多
关键词 multipurpose transit smart card systems fund budgeting stochastic programming genetic algorithm
下载PDF
Novel predictive model for metallic structure corrosion status in presence of stray current in DC mass transit systems 被引量:7
2
作者 许少毅 李威 +1 位作者 邢方方 王禹桥 《Journal of Central South University》 SCIE EI CAS 2014年第3期956-962,共7页
The novel method to analyze metallic structure corrosion status was proposed in the presence of stray current in DC mass transit systems. Firstly, the characteristic parameter and the influence parameters for the corr... The novel method to analyze metallic structure corrosion status was proposed in the presence of stray current in DC mass transit systems. Firstly, the characteristic parameter and the influence parameters for the corrosion status were determined. Secondly, an experimental system was established for simulating the corrosion process within the stray current interference. Then, a predictive model for the corrosion status was built, using a support vector machine(SVM) method and experimental data. The data were divided into two sets, including training set and testing set. The training set was used to generate the SVM model and the testing set was used to evaluate the predictive performance of the SVM model. The results show that the relationship between the characteristic parameter and the influence parameters is nonlinear and the SVM model is suitable for predicting the corrosion status. 展开更多
关键词 DC mass transit systems stray current CORROSION support vector machine (SVM)
下载PDF
Approximate trace and singleton failures equivalences for transition systems 被引量:2
3
作者 Chao Wang Jinzhao Wu Hongyan Tan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第4期886-896,共11页
Established system equivalences for transition systems, such as trace equivalence and failures equivalence, require the ob- servations to be exactly identical. However, an accurate measure- ment is impossible when int... Established system equivalences for transition systems, such as trace equivalence and failures equivalence, require the ob- servations to be exactly identical. However, an accurate measure- ment is impossible when interacting with the physical world, hence exact equivalence is restrictive and not robust. Using Baire met- ric, a generalized framework of transition system approximation is proposed by developing the notions of approximate language equivalence and approximate singleton failures (SF) equivalence. The framework takes the traditional exact equivalence as a special case. The approximate language equivalence is coarser than the approximate Slc equivalence, just like the hierarchy of the exact ones. The main conclusion is that the two approximate equiva- lences satisfy the transitive property, consequently, they can be successively used in transition system approximation. 展开更多
关键词 approximate equivalence TRACE singleton failures(SF) transition systems.
下载PDF
ON DISTRIBUTIONAL n-CHAOS
4
作者 谭枫 符和满 《Acta Mathematica Scientia》 SCIE CSCD 2014年第5期1473-1480,共8页
Let (X, f ) be a topological dynamical system, where X is a nonempty compact and metrizable space with the metric d and f :X →X is a continuous map. For any integer n≥2, denote the product space by X(n)=X ... Let (X, f ) be a topological dynamical system, where X is a nonempty compact and metrizable space with the metric d and f :X →X is a continuous map. For any integer n≥2, denote the product space by X(n)=X · · · × X| {z }n times . We say a system (X, f ) is generally distributionally n-chaotic if there exists a residual set D ?X(n) such that for any point x=(x1, · · · , xn)∈D, lim inf k→∞#({i:0≤i≤k-1, min{d(fi(xj), fi(xl)):1≤j 6=l≤n}〈δ0}) k=0 for some real numberδ0〉0 and lim sup k→∞#({i:0≤i≤k-1, max{d(fi(xj), fi(xl)):1≤j 6=l≤n}〈δ}) k=1 for any real number δ 〉 0, where #(·) means the cardinality of a set. In this paper, we show that for each integer n ≥ 2, there exists a system (X,σ) which satisfies the following conditions: (1) (X,σ) is transitive;(2) (X,σ) is generally distributionally n-chaotic, but has no distributionally (n+1)-tuples;(3) the topological entropy of (X,σ) is zero and it has an IT-tuple. 展开更多
关键词 transitive systems distributional chaos
下载PDF
Faraday laser at Rb 1529 nm transition for optical communication systems 被引量:1
5
作者 常鹏媛 史田田 +3 位作者 张盛楠 商浩森 潘多 陈景标 《Chinese Optics Letters》 SCIE EI CAS CSCD 2017年第12期53-56,共4页
We experimentally demonstrate a Faraday laser at Rb 1529 nm transition by using a performance-improved Rb electrodeless-discharge-lamp-based excited-state Faraday anomalous dispersion optical filter as the frequency- ... We experimentally demonstrate a Faraday laser at Rb 1529 nm transition by using a performance-improved Rb electrodeless-discharge-lamp-based excited-state Faraday anomalous dispersion optical filter as the frequency- selective element. Neither the electrical locking scheme nor the additional frequency-stabilized pump laser are used. The frequency of the external-cavity diode laser is stabilized to the Rb 1529 nm transition, and the Allan deviation of the Faraday laser is measured by converting the optical intensity into frequency. The Faraday laser can be used as a frequency standard in the telecom C band for further research on metrology, microwave photonics, and optical communication systems. 展开更多
关键词 Faraday laser at Rb 1529 nm transition for optical communication systems FADOF RB
原文传递
Credit Systems for the Rural Poorin the Economic Transition of China:Institutions, Outreach, and Policy Options
6
作者 Zhu Ling, Jiang Zhongyi, and Joachim von Braun Zhu Ling Ph. D., Senior Fellow, (Deputy director of the institute of Economics under the Chinese Academy of fortal Sciences Jiang Zhongyi, Senior Fellow of the Ministry of Agriculture in China Joachim von Bra 《World Economy & China》 2000年第Z1期12-24,共13页
Siniceundertakingmarket-orientedreformsinthelate1970s,Chinahasenjoyedrapideconomicgrowthandasubstantialreductioninpoverty.Asaresultthecountry’sfinancialsystemisunderincreasingpressuretoadjusttotheneweconomicoutlook.R... Siniceundertakingmarket-orientedreformsinthelate1970s,Chinahasenjoyedrapideconomicgrowthandasubstantialreductioninpoverty.Asaresultthecountry’sfinancialsystemisunderincreasingpressuretoadjusttotheneweconomicoutlook.RuralChina,forinstance,lacksacompre... 展开更多
关键词 and Policy Options Credit systems for the Rural Poorin the Economic Transition of China OUTREACH
原文传递
Exploring the differential impacts of urban transit system on the spatial distribution of local and floating population in Beijing 被引量:4
7
作者 ZHAO Meifeng LIU Shenghe QI Wei 《Journal of Geographical Sciences》 SCIE CSCD 2017年第6期731-751,共21页
The floating population has become the main driver of urban population excessive growth in China's mega cities. Urban transit system (UTS) is a significant factor in population spatial distributions within urban ar... The floating population has become the main driver of urban population excessive growth in China's mega cities. Urban transit system (UTS) is a significant factor in population spatial distributions within urban areas, especially rapid and high-capacity transit systems. This paper analyzes the causal effects of the extension of expressways and subways between 2000 and 2010 in the Beijing Metropolitan Area (BMA), focusing on the group differences between the local residents and the floating population. Due to the endogeneity of transportation improvements and population growth, Instrumental Variable (IV) regression model is applied to avoid this problem. The results show the local residents increased in the inner suburbs but decreased in the city center, while the floating population increased in the majority areas. IV regression results show that the extension of urban transit systems had statistically significant impacts on population growth across the BMA, The results also show that the extension of urban subway system had more effects on the floating population than the local residents across the BMA. It is mainly caused by the rather low fare of urban subway system. This implies that the excessive subsidy on urban subway system could result in ex- cessive floating population growth and residential differentiation, even residential segregation Hence, it is necessary to plan and design reasonable and scientific urban transit systems in order to advance reasonable population size and promote residential integration. Moreover, the regional analysis shows that the effects of urban transportation improvements on the local residents are not statistically significant in the inner suburbs. It implies that urban transportation improvements had limited effects on inducing people to move to suburban areas and controlling center city's population in Beijing. Therefore, it should be stressed the differenti- ated effects of urban transportation improvements on population distribution in the process of urban planning and population control. 展开更多
关键词 urban transit systems (UTS) population spatial distribution causal effects group differences BEIJING
原文传递
Behavioral Consistency Checking between Requirements and Implementations 被引量:1
8
作者 XU Yong LING Xiang +1 位作者 WU Guoqing HUANG Bo 《Wuhan University Journal of Natural Sciences》 CAS 2014年第6期477-488,共12页
Checking if the implementations conform to the requirement models is challenging. Most existing techniques for consistency checking either focus on requirement models(e.g., requirements consistency checking), or on ... Checking if the implementations conform to the requirement models is challenging. Most existing techniques for consistency checking either focus on requirement models(e.g., requirements consistency checking), or on the implementations(e.g., code-based testing) only. In this paper we propose an approach to checking behavioral consistency of implementations against requirement models directly to overcome these limitations. Our approach extracts two behavioral models represented by Labelled Transition Systems(LTS) from requirement models and implementations respectively, and checks the behavioral consistency between these two models based on behavioral simulation relation of LTS. The checking results of our approach provide evidence for behavioral inconsistency as well as inconsistent localization. A research prototype called BCCH and a case study are presented to give initial validation of this approach. 展开更多
关键词 behavioral consistency Labelled Transition systems(LTS) requirement models
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部