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Study on the Characteristics, Problems, and Models of China's Aid to Africa under the New Situation
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作者 Kanghui SONG 《International Journal of Technology Management》 2013年第6期84-86,共3页
In this paper, the characteristics of China's aid to Africa under the new situation are summarized, and also the existing problems are smmnarized from the level of strategy, the level of public opinion, the level of ... In this paper, the characteristics of China's aid to Africa under the new situation are summarized, and also the existing problems are smmnarized from the level of strategy, the level of public opinion, the level of methods and contents, and the level of effect. Combined with the change of the current international political and economic trend, the model of China's aid to Afiica is innovatively concluded by tile author as Ihe model of"Bidirectional Balance Improved Aid" and also its definition, main contents, and practice keys are expounded. This model provides a reference model for China's aid to Africa and is good for solving the problems in the aid, so that a better actual effect can be achieved. 展开更多
关键词 Bidirectional Balance hnprovcd aid China's aid to Africa aid Model
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A Collocation Technique via Pell-Lucas Polynomials to Solve Fractional Differential EquationModel for HIV/AIDS with Treatment Compartment
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作者 Gamze Yıldırım Suayip Yüzbası 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期281-310,共30页
In this study,a numerical method based on the Pell-Lucas polynomials(PLPs)is developed to solve the fractional order HIV/AIDS epidemic model with a treatment compartment.The HIV/AIDS mathematical model with a treatmen... In this study,a numerical method based on the Pell-Lucas polynomials(PLPs)is developed to solve the fractional order HIV/AIDS epidemic model with a treatment compartment.The HIV/AIDS mathematical model with a treatment compartment is divided into five classes,namely,susceptible patients(S),HIV-positive individuals(I),individuals with full-blown AIDS but not receiving ARV treatment(A),individuals being treated(T),and individuals who have changed their sexual habits sufficiently(R).According to the method,by utilizing the PLPs and the collocation points,we convert the fractional order HIV/AIDS epidemic model with a treatment compartment into a nonlinear system of the algebraic equations.Also,the error analysis is presented for the Pell-Lucas approximation method.The aim of this study is to observe the behavior of five populations after 200 days when drug treatment is applied to HIV-infectious and full-blown AIDS people.To demonstrate the usefulness of this method,the applications are made on the numerical example with the help of MATLAB.In addition,four cases of the fractional order derivative(p=1,p=0.95,p=0.9,p=0.85)are examined in the range[0,200].Owing to applications,we figured out that the outcomes have quite decent errors.Also,we understand that the errors decrease when the value of N increases.The figures in this study are created in MATLAB.The outcomes indicate that the presented method is reasonably sufficient and correct. 展开更多
关键词 Collocation method fractional differential equations HIV/aidS epidemic model Pell-Lucas polynomials
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Applications of Computer Aided Modeling Techniques to Complex ICE Components 被引量:1
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作者 左正兴 冯慧华 +1 位作者 廖日东 邹文胜 《Journal of Beijing Institute of Technology》 EI CAS 2000年第4期451-458,共8页
Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide req... Design of internal combustion engine (ICE) components is one of the earliest and also the most active areas in which computer aided modeling techniques are applied. Computer aided modeling techniques could provide requisite information for follow up designing segments such as structural analysis, design of technological process and manufacturing etc, and thereby lead to the reduction of product design period and the quality and reliability improvement of ICE components. So the developing situations of ICE components' 2 D drafting, 3 D modeling of ICE, overall CAD of ICE as well as component design expert system etc. are surveyed, which are the typical applications of computer aided modeling techniques in ICE component design process, and some existent problems and tasks are pointed out so as to make some references for the further research work. 展开更多
关键词 internal combustion engine(ICE) components computer aided modeling CAD 3 D model
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DYNAMIC FOR A STOCHASTIC MULTI-GROUP AIDS MODEL WITH SATURATED INCIDENCE RATE 被引量:2
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作者 Qixing HAN Daqing JIANG 《Acta Mathematica Scientia》 SCIE CSCD 2020年第6期1883-1896,共14页
In this paper,a stochastic multi-group AIDS model with saturated incidence rate is studied.We prove that the system is persistent in the mean under some parametric restrictions.We also obtain the sufficient condition ... In this paper,a stochastic multi-group AIDS model with saturated incidence rate is studied.We prove that the system is persistent in the mean under some parametric restrictions.We also obtain the sufficient condition for the existence of the ergodic stationary distribution of the system by constructing a suitable Lyapunov function.Our results indicate that the existence of ergodic stationary distribution does not rely on the interior equilibrium of the corresponding deterministic system,which greatly improves upon previous results. 展开更多
关键词 multi-group aidS model Lyapunov function stationary distribution persistence in the mean
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Projecting the Dynamic Trends of Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome:Modeling the Epidemic in Sichuan Province, China
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作者 Yuan Li Qinxi Liu +3 位作者 Rongsheng Luan Yi Yang Tao Wu Bihui Yang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第9期1003-1014,共12页
Objective Our study aimed to provide a comprehensive overview of the current status and dynamic trends of the human immunodeficiency virus(HIV)prevalence in Sichuan,the second most heavily affected province in China,a... Objective Our study aimed to provide a comprehensive overview of the current status and dynamic trends of the human immunodeficiency virus(HIV)prevalence in Sichuan,the second most heavily affected province in China,and to explore future interventions.Methods The epidemiological,behavioral,and population census data from multiple sources were analyzed to extract inputs for an acquired immunodeficiency syndrome(AIDS)epidemic model(AEM).Baseline curves,derived from historical trends in HIV prevalence,were used,and the AEM was employed to examine future intervention scenarios.Results In 2015,the modeled data suggested an adult HIV prevalence of 0.191%in Sichuan,with an estimated 128,766 people living with HIV/AIDS and 16,983 individuals with newly diagnosed infections.Considering current high-risk behaviors,the model predicts an increase in the adult prevalence to 0.306%by 2025,projecting an estimated 212,168 people living with HIV/AIDS and 16,555 individuals with newly diagnosed infections.Conclusion Heterosexual transmission will likely emerge as the primary mode of AIDS transmission in Sichuan.Furthermore,we anticipate a stabilization in the incidence of AIDS with a concurrent increase in prevalence.Implementing comprehensive intervention measures aimed at high-risk groups could effectively alleviate the spread of AIDS in Sichuan. 展开更多
关键词 HIV/aidS aidS Epidemic Model Heterosexual transmission Sichuan province
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Photogrammetry, CAD Modeling and FE Analysis for Improving the Performance of a Spinnaker
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作者 Massimo Martorelli Domenico Speranza 《Journal of Mechanics Engineering and Automation》 2012年第2期85-90,共6页
Objectives: The sails fabrication knew a significant development under the impulse of sailing races like the America's Cup and the Volvo around the World Race. These competitions require advanced technologies to inc... Objectives: The sails fabrication knew a significant development under the impulse of sailing races like the America's Cup and the Volvo around the World Race. These competitions require advanced technologies to increase performance of the sails. In the paper, Reverse Engineering (RE) acquisition, CAD (Computer Aided Design) reconstruction and FE (Finite Element) analysis are used in the design phase for a spinnaker in order to maximize the performance of the sail boat. Materials and Methods: The comparison, between the design data and the characteristics in the real conditions of use of the sail (constant wind pressure acting on the sail), was carried out by the reconstruction of the three-dimensional CAD model of the spinnaker shape in full-scale, using a non contact Reverse Engineering technique, the photogrammetry and by a FE non linear static analysis. Results: The results of this study show a good correspondence between the design data and the characteristics in the real conditions of use of the sail. Significance: The described methodology is useful for sail makers. It can be successfully adopted to generate three-dimensional CAD-FE models of a sail starting from a very cheap and fast Reverse Engineering non-contact procedure. 展开更多
关键词 SAIL non-contact system PHOTOGRAMMETRY CAD (computer aided design) modelling FEM analysis.
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Decision Aid Model for Private-owned Electric Vehicles Participating in Frequency Regulation Ancillary Service Market
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作者 Liwei Wang Yingyun Sun +2 位作者 Haotian Wang Pengfei Zhao Muhammad Safwan Jaffar 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2024年第2期621-629,共9页
To reduce the difficulty and enhance the enthusiasm of private-owned electric vehicles(EVs) in participating in frequency regulation ancillary service market(FRASM), a decision aid model(DAM) is proposed. This paper p... To reduce the difficulty and enhance the enthusiasm of private-owned electric vehicles(EVs) in participating in frequency regulation ancillary service market(FRASM), a decision aid model(DAM) is proposed. This paper presents three options for EV participating in FRASM, i. e., the base mode(BM), unidirectional charging mode(UCM), and bidirectional charging/discharging mode(BCDM), based on a reasonable simplification of users' participating willingness. In BM, individual EVs will not be involved in FRASM, and DAM will assist users to set the optimal charging schemes based on travel plans under the time-of-use(TOU) price. UCM and BCDM are two modes in which EVs can take part in FRASM. DAM can assist EV users to create their quotation plan, which includes hourly upper and lower reserve capabilities and regulation market mileage prices. In UCM and BCDM, the difference is that only the charging rate can be adjusted in the UCM, and the EVs in BCDM can not only charge but also discharge if necessary. DAM can estimate the expected revenue of all three modes, and EV users can make the final decision based on their preferences. Simulation results indicate that all the three modes of DAM can reduce the cost, while BCDM can get the maximum expected revenue. 展开更多
关键词 Electric vehicle(EV) frequency regulation decision aid model(DAM) utility maximization battery wear cost
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Estimating the Fresh Vegetables Demand System in Jordan: A Linear Approximate Almost Ideal Demand System
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作者 A. S. Jabarin E. K. Al-Karablieh 《Journal of Agricultural Science and Technology》 2011年第3期322-331,共10页
The main objective of this research is to estimate the different types of demand elasticities for the main fresh vegetables consumed in Jordan. The estimated elasticities can be used to measure the impacts of agricult... The main objective of this research is to estimate the different types of demand elasticities for the main fresh vegetables consumed in Jordan. The estimated elasticities can be used to measure the impacts of agricultural policies and can be used to predict future consumption in the context of food security in terms of access, availability, stability, and food quality. The reported demand estimates were obtained through the estimation of a Linear Approximate Almost Ideal Demand Systems (LA/AIDS) for Jordan fresh vegetable crops demand system using the most recent cross-sectional data of household expenditure survey in 2005. A censored regression method for the system of equations was used to analyze fresh vegetables consumption patterns. This method allows for inclusion of a large number of zero consumption for some foods through two-step demand system estimation. All of the own-price demand elasticities have the correct negative signs and statistically significant. According to the expenditure elasticity, tomato, cucumber, and potato are the necessity goods. The mean budget shares indicate that consumers spend 30 percent of their allocated budget to vegetables on tomatoes and potatoes. The green bean elasticity is the highest indicating that demand for beans is highly responsive to any changes in the price. The expenditure elasticities reveal that the demand on all vegetables is expected to grow over the coming few years. High own-price elasticities of all vegetables studied suggests that any changes in the prices of these crops could bring about a significant shift in fruits and vegetable constanption patterns. 展开更多
关键词 Vegetable demand system demand elasticities LA/aidS model Marshallian and Hicksian elasticities censored regression probit model.
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Agent-oriented Aid-modeling for the Distributed Activity Network 被引量:4
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作者 DENG Gui\|shi\+1,\ LI Wen\|lei\+1,\ O. Moeschlin\+2 1.Institute of Systems Engineering, Dalian University of Technology Dalian 116024, China 2.Department of Mathematics, Fern University in Hagen, D 58084 Germany 《Systems Science and Systems Engineering》 CSCD 2000年第1期65-71,共7页
An agent in the decision support system (DSS) has to cope with quantitative analysis processing normally. However, from the view of agent working style, the agent oriented aid modeling operations need new procedure ... An agent in the decision support system (DSS) has to cope with quantitative analysis processing normally. However, from the view of agent working style, the agent oriented aid modeling operations need new procedure accepted by the agent. For example, in the distributed activity planning processes, the transforming problem description has to use a unified pattern first, then to compute the activity′s 6 time parameters, activity′s duration, entity plan scheme, optimal calculation and so on. In this paper, we propose a process manner of agent oriented modeling for the distributed activity network. The goal is to introduce an agent working procedure included model usage, multi agent cooperating, communicating among agents and interaction between system and human. Also, it included the problem representation, the initial process, agent design, transform and the computing with interaction in detail. 展开更多
关键词 AGENT agent oriented aid modeling multi agent cooperation
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QUALITATIVE ANALYSIS FOR A MATHEMATICAL MODEL OF AIDS
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作者 井竹君 刘正荣 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1993年第4期302-316,共15页
In this paper a mathematical model of AIDS is investigated.The conditions of the existence of equilibria and local stability of equilibria are given.The existences of transcritical bifurcation and Hopf bifurcation are... In this paper a mathematical model of AIDS is investigated.The conditions of the existence of equilibria and local stability of equilibria are given.The existences of transcritical bifurcation and Hopf bifurcation are also considered.in particular,the conditions for the existence of Hopf bifurcation can be given in terms of the coefficients of the characteristic equation.The method extends the application of the Hopf bifurcation theorem to higher differential equations which occur in biological models,chemical models,and epidemiological models etc. 展开更多
关键词 QUALITATIVE ANALYSIS FOR A MATHEMATICAL MODEL OF aidS REAL HOPF
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STEP-based Feature Recognition System for B-spline Surface Features 被引量:3
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作者 Bitla Venu Venkateswara Rao Komma Deepanshu Srivastava 《International Journal of Automation and computing》 EI CSCD 2018年第4期500-512,共13页
The geometrical and topological information of 3D computer aided design (CAD) models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data... The geometrical and topological information of 3D computer aided design (CAD) models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data implies that the companies must exchange complete information about their products, all the way from design, manufacturing to inspection and shipping. This informa- tion should be available to each relevant partner over the entire life cycle of the product. This led to the development of an international standard organization (ISO) neutral format file named as standard for the exchange of product model data (STEP). It has been ob- served from the literature, the feature recognition systems developed were identified as planar, cylindrical, conical and to some extent spherical and toroidal surfaces. The advanced surface features such as B-spline and its subtypes are not identified. Therefore, in this work, a STEP-based feature recognition system is developed to recognize t--spline surface features and its sub-types from the 3D CAD model represented in AP203 neutral file format. The developed feature recognition system is implemented in Java programming language and the product model data represented in STEP AP203 format is interpreted through Java standard data access interface (JSDAI). The developed system could recognize B-spline surface features such as B-Spline surface with knots, quasi uniform surface, uniform surface, rational surface and Bezier surface. The application of extracted B-spline surface features information is discussed with reference to the toolpath generation for STEP-NC (STEP AP238). 展开更多
关键词 Feature recognition 3D computer aided design(CAD)model geometrical information standard for the exchange ofproduct model data(STEP)AP203 Java standard data access interface(JSDAI).
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