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Science china(Technological Sciences) 2010年第2期53卷 480-485页

作者： HOU XueLiang1 , LU Mei2 & WANG Kai3 1 School of Business Administration, North china Electric Power university, beijing 102206, china 2 Department of Construction management, Tsinghua university, beijing 100084, china 3.college of management, beijing jiaotong university, beijing 100084, china 1. School of Business Administration North China Electric Power University Beijing 102206 China2. Department of Construction Management Tsinghua University Beijing 100084 China3. College of Management Beijing Jiaotong University Beijing 100084 China

The co-adaptability theoretical solution to conflicting events in construction engineering projects has three problems. First, the transformation of constraint conditions of theoretical solution is very difficult in practical engineering applications; second, some coefficients are difficult to be determined; third, there are overfull circular arithmetic operations involved in it. To resolve these problems, a new method to reduce the theoretical solution complications is proposed. By analyzing the operating mechanism of theoretical solution model, redundancies in the theoretical solution can be eliminated, and the ISM mapping with the co-adaptability solution can be set up. Based on this approach, a procedure to solve practical conflicting events in construction projects is established by replacing characteristic variables with mathematic variables. The research results show that the procedure can replace the co-adaptability theoretical solution effectively and solve practical conflicting events in construction projects.

关键词： construction project conflict theoretical solution reduced analysis ISM confirmatory research

A new class of impulse stochastic control models with non-negative control quantity

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Science china(Information Sciences) 2011年第3期54卷 638-652页

作者： LIU XiaoPeng & LIU KunHui college of Science, beijing jiaotong university, beijing 100044, china 1. college of Science Beijing Jiaotong University Beijing 100044 China

This paper advances and studies a new class of impulse stochastic control models. Its state structure is defined by a linear stochastic differential equation of the semi-martingale, its control cost function is a twovariable function of pre-control state quantity and control quantity, and its control quantity is kept non-negative. First this paper constructs a new type of variational equations and proves its solution exists. Using a series of stochastic analysis methods to research the solution function of this type of variational equations, this paper proves the existence of optimal control and analyzes its structure in depth. Because of the big difference between the model in this paper and stochastic control models in previous papers, the analysis method here is quite different from previous ones. It is expected that this paper will have important theoretical significance for stochastic control research, along with wide applicative value in finance control and security management.

关键词： impulse stochastic control control quantity variational equation optimal control semi-martingale

NEW ROBUST UNSUPERVISED SUPPORT VECTOR MACHINES

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Journal of Systems Science & Complexity 2011年第3期24卷 466-476页

作者： Kun ZHAO Mingyu ZHANG ~ Naiyang DENG Logistics School Beijing Wuzi University Beijing 101149 China. School of Economic and management Beijing Jiaotong University Beijing 100044 China. college of Science China Agricultural University Bcijing 100083 China.

This paper proposes robust version to unsupervised classification algorithm based on modified robust version of primal problem of standard SVMs, which directly relaxes it with label variables to a semi-definite progra... 详细信息

关键词： Robust semi-definite programming support vector machines unsupervised learning

Reliability analysis of M/G/1 queues with general retrial times and server breakdowns

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Progress in Natural Science:Materials International 2006年第5期16卷 464-473页

作者： WANG Jinting (Department of Mathematics, beijing jiaotong university, beijing 100044, china) Department of Mathematics Beijing Jiaotong University Beijing 100044 China

This paper concerns the reliability issues as well as queueing analysis of M/G/1 retrial queues with general retrial times and server subject to breakdowns and repairs. We assume that the server is unreliable and customers who find the server busy or down are queued in the retrial orbit in accordance with a first-come-first-served discipline. Only the customer at the head of the orbit queue is allowed for access to the server. The necessary and sufficient condition for the system to be stable is given. Using a supplementary variable method, we obtain the Laplace-Stieltjes transform of the reliability function of the server and a steady state solution for both queueing and reliability measures of interest. Some main reliability indexes, such as the availability, failure frequency, and the reliability function of the server, are obtained.

关键词： retrial queues general retrial times reliability server breakdowns and repairs.

2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of Chinese Geriatrics Society,beijing Hypertension Association,National Clinical Research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina Chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

A BATCH ARRIVAL RETRIAL QUEUE WITH STARTING FAILURES,FEEDBACK AND ADMISSION CONTROL

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Journal of Systems Science and Systems Engineering 2010年第3期19卷 306-320页

作者： Jinting WANG Peng-Feng ZHOU Department of Mathematics,School of Science,beijing jiaotong university,beijing,china Department of Mathematics School of Science Beijing Jiaotong University Beijing China

This paper is concerned with the analysis of a feedback M^[X]/G/1 retrial queue with starting failures and general retrial times. In a batch, each individual customer is subject to a control admission policy upon arrival. If the server is idle, one of the customers admitted to the system may start its service and the rest joins the retrial group, whereas all the admitted customers go to the retrial group when the server is unavailable upon arrival. An arriving customer （primary or retrial） must turn-on the server, which takes negligible time. If the server is started successfully （with a certain probability）, the customer gets service immediately. Otherwise, the repair for the server commences immediately and the customer must leave for the orbit and make a retrial at a later time. It is assumed that the customers who find the server unavailable are queued in the orbit in accordance with an FCFS discipline and only the customer at the head of the queue is allowed for access to the server. The Markov chain underlying the considered queueing system is studied and the necessary and sufficient condition for the system to be stable is presented. Explicit formulae for the stationary distribution and some performance measures of the system in steady-state are obtained. Finally, some numerical examples are presented to illustrate the influence of the parameters on several performance characteristics.

关键词： Batch arrival feedback repair retrial queue starting failure

Co-adaptability solution to conflict events in construction projects by segmented hierarchical algorithm

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Science china(Technological Sciences) 2008年第7期51卷 932-939页

作者： HOU XueLiang1 & LU Mei2 1 Department of Construction management, Tsinghua university, beijing 100084, china 2 college of management, Xi’an university of Architecture and Technology, Xi’an 710055, china 1. Department of Construction management Tsinghua University Beijing 100084 China 2. college of management Xi’an University of Architecture and Technology Xi’an 710055 China

In order to seek the co-adaptability solution to conflict events in construction engineering projects, a new method referred to as segmented hierarchical algorithm is proposed in this paper by means of comparing co-adaptability evolution process of conflict events to the stackelberg model. By this new algorithm, local solutions to the first-order transformation of co-adaptability for conflict events can be obtained, based upon which, a global solution to the second-order transformation of co-adaptability for conflict events can also be decided by judging satisfaction degree of local solutions. The research results show that this algorithm can be used not only for obtaining co-adaptability solution to conflict events efficiently, but also for other general decision-making problems with multi-layers and multi-subsidi-aries in project management field.

关键词： conflict co-adaptability segmented hierarchical algorithm

Urban expressway traffic state forecasting based on multimode maximum entropy model

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Science china(Technological Sciences) 2010年第10期53卷 2808-2816页

作者： SUN XiaoLiang1,2, JIA LiMin1, DONG HongHui1, QIN Yong1 & GUO Min3 1State Key Laboratory of Rail Traffic Control and Safety, beijing jiaotong university, beijing 100044, china 2School of Traffic and Transportation, beijing jiaotong university, beijing 100044, china 3beijing Traffic management Bureau, beijing 100044, china 1. State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing 100044 China2. School of Traffic and Transportation Beijing Jiaotong University Beijing 100044 China3. Beijing Traffic Management Bureau Beijing 100044 China

The accurate and timely traffic state prediction has become increasingly important for the traffic participants,especially for the traffic managements. In this paper,the traffic state is described by Micro-LOS,and a direct prediction method is introduced. The development of the proposed method is based on Maximum Entropy (ME) models trained for multiple modes. In the Multimode Maximum Entropy (MME) framework,the different features like temporal and spatial features of traffic systems,regional traffic state are integrated simultaneously,and the different state behaviors based on 14 traffic modes defined by average speed according to the date-time division are also dealt with. The experiments based on the real data in beijing expressway prove that the MME models outperforms the already existing model in both effectiveness and robustness.

关键词： traffic state forecast maximum entropy model multimode

An attempt to differential Galois theory of second order polynomial system and solvable subgroup of Mbius transformations

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Science china Mathematics 2007年第5期50卷 748-760页

作者： Ke-ying GUAN & Jin-zhi LEI School of Science, beijing jiaotong university, beijing 100044, china Zhou Pei-Yuan Center for Applied Mathematics, Tsinghua university, beijing 100084, china School of Science Beijing Jiaotong University Beijing 100044 China Zhou Pei-Yuan Center for Applied Mathematics Tsinghua University Beijing 100084 China

By introducing the conception "relativistic differential Galois group" for the second order polynomial systems, we establish the relation between the conformal relativistic differential Galois group and the subgroup of Mobius transformations, and prove that the system is integrable in the sense of Liouville if its conformal relativistic differential Galois group is solvable with a derived length at most 2. Some omissions on the structures of solvable subgroups of Mobius transformations at the first author’s article published in this journal in 1996 are refreshed in this paper.

关键词： conformed differential Galois group Mobius transformations integrability in the sense of Liouville

On time-step in structural seismic response analysis under ground displacement/acceleration

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Earthquake Engineering and Engineering Vibration 2009年第3期8卷 341-347页

作者： TianYuji~+ and Yang Qingshan~(++) School of Civil Engineering,beijing jiaotong university,beijing 100044,china +Associate Professor ++Professor School of Civil Engineering Beijing Jiaotong University Beijing 100044 China

There are two models in use today to analyze structural responses when subjected to earthquake ground motions, the Displacement Input Model （DIM） and the Acceleration Input Model （AIM）. The time steps used in direct integration methods for these models are analyzed to examine the suitability of DIM. Numerical results are presented and show that the time-step for DIM is about the same as for AIM, and achieves the same accuracy. This is contrary to previous research that reported that there are several sources of numerical errors associated with the direct application of earthquake displacement loading, and a very small time step is required to define the displacement record and to integrate the dynamic equilibrium equation. It is shown in this paper that DIM is as accurate and suitable as, if not more than, AIM for analyzing the response of a structure to uniformly distributed and spatially varying ground motions.

关键词： integration time step multi-supported structure displacement input model acceleration input model spatially varying ground motions