期刊文献+
共找到252篇文章
< 1 2 13 >
每页显示 20 50 100
Release Model of Water-soluble Chitosan Nanoparticles for Protein Delivery 被引量:2
1
作者 王春 孙胜玲 +2 位作者 肖惠宁 何北海 杨连生 《Agricultural Science & Technology》 CAS 2009年第3期144-147,共4页
[Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinet... [Objective] The experiment aimed to explore release rule of water-soluble chitosan (WSC) in vitro. [Method]The bovine serum albumin(BSA) was taken as a model protein drug and some existing release models such as Kinetics model, Gompertz model, Weibull model, Higuchi model and Logistic model were used to fit the BSA release profile from WSC carriers. [Result] Except Higuchi model and Logistic model, other models could fit BSA release profile better. [Conclusion] Gompertz two-order kinetics model could fit the release of WSC nano-particles better and model parameters had practical physical meaning. 展开更多
关键词 Water-soluble chitosan Nano-particle carriers Protein delivery Release model
下载PDF
Monitoring and Assessment System of Agricultural Drought Based on GIS Technology 被引量:4
2
作者 李卫宁 匡昭敏 +4 位作者 卢远 李莉 何立 罗永明 曾行吉 《Agricultural Science & Technology》 CAS 2011年第9期1350-1354,共5页
[Objective] The research aimed to simplify the operating process of agricultural drought monitoring and assessment product,and improve fine level of monitoring and assessment map.[Method] By comprehensively using GIS ... [Objective] The research aimed to simplify the operating process of agricultural drought monitoring and assessment product,and improve fine level of monitoring and assessment map.[Method] By comprehensively using GIS and mathematics,meteorology,management science,computer science,the monitoring and assessment of drought were as the core,the monitoring and assessment system of agricultural drought based on GIS technology was studied.[Result] The drought in Guangxi on November 4,2006 was monitored by using the system,and the actual situation was used to test.The result proved that the good monitoring effect was obtained.[Conclusion] The monitoring and assessment system of agricultural drought based on GIS realized the organic combination of GIS and professional monitoring,assessment model.The flexible HCI interface and visualization expression were provided.The monitoring and assessment function of agricultural drought was realized.It had the good practicality and advancement. 展开更多
关键词 Agricultural drought Monitoring and assessment system GIS Professional model
下载PDF
Analysis on the Core Competitiveness of Rice Seed Industry in Guangxi Province Based on Diamond Model
3
作者 张晓丽 薛艳霞 +6 位作者 吕荣华 王强 陈雷 唐茂艳 陶伟 高国庆 梁天锋 《Agricultural Science & Technology》 CAS 2016年第8期1963-1967,1977,共6页
By using diamond model, the current development status and core competitiveness of the rice seed industry in Guangxi Province were analyzed in detail from the 6 aspects of production factors, demand factors, related i... By using diamond model, the current development status and core competitiveness of the rice seed industry in Guangxi Province were analyzed in detail from the 6 aspects of production factors, demand factors, related industries and support industries, firm strategy, chance factor and government factor, which clarified the advantages of the rice seed industry of Guangxi in the nature and technological factors, firm strategy and government policy, and the disadvantages in demand factors, production cost, infrastructure and related industries. And the corresponding countermeasures were proposed to enhance the competitiveness of the rice seed industry of Guangxi. 展开更多
关键词 Diamond model RICE Core competitiveness GUANGXI
下载PDF
Dynamic business process modeling and verification for inter-organizational collaboration 被引量:1
4
作者 胡庆成 邢春晓 +2 位作者 杨吉江 严琪 李益民 《Journal of Southeast University(English Edition)》 EI CAS 2007年第3期455-460,共6页
To achieve an on-demand and dynamic composition model of inter-organizational business processes, a new approach for business process modeling and verification is introduced by using the pi-calculus theory. A new busi... To achieve an on-demand and dynamic composition model of inter-organizational business processes, a new approach for business process modeling and verification is introduced by using the pi-calculus theory. A new business process model which is multi-role, multi-dimensional, integrated and dynamic is proposed relying on inter-organizational collaboration. Compatible with the traditional linear sequence model, the new model is an M x N multi-dimensional mesh, and provides horizontal and vertical formal descriptions for the collaboration business process model. Finally, the pi-calculus theory is utilized to verify the deadlocks, livelocks and synchronization of the example models. The result shows that the proposed approach is efficient and applicable in inter-organizational business process modeling. 展开更多
关键词 inter-organizational collaboration PI-CALCULUS business process modeling model verification
下载PDF
"Labor Shortage" or "Difficult Employment":A Study on the Employment Problem of College Students from the Perspective of Demographic Dividend 被引量:2
5
作者 王东红 《Agricultural Science & Technology》 CAS 2017年第3期548-552,共5页
[Objective] The aim was to analyze the phenomenon of employment diffi- culty and labor shortage, and to reveal the influencing factors of employment difli- culty and labor shortage. [Method] On the basis of the econom... [Objective] The aim was to analyze the phenomenon of employment diffi- culty and labor shortage, and to reveal the influencing factors of employment difli- culty and labor shortage. [Method] On the basis of the economic principle of popu- lation dividend, the use of human resources and natural resource constraints The IS-LM model describes these two states. [Results] The resource constraints have a "squeeze" effect on the demographic dividend, and employment pressure is shown in terms of the population opportunity window; the labor market segmentation, the ir- rational industrial structure, the backward curriculum and employment concept are the main factors affecting employment and labor shortage. [Conclusion] The way to solve this dilemma must be removed from the division of labor market, the adjust- ment of industrial structure, the setting of university specialty, the change of em- ployment concept of university graduates as well as the improvement of the quality of labor. 展开更多
关键词 Demographic dividend Employment of college students Employmentpressure IS-LM Model
下载PDF
NEW MODEL OF THEODOLITE INDUSTRIAL MEASURING SYSTEM
6
作者 熊春宝 叶声华 +1 位作者 王仲 匡绍君 《Transactions of Tianjin University》 EI CAS 1999年第2期78-82,共5页
Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision... Comparing with the coordinates measuring machine (CMM),the theodolite industrial measuring system (TIMS) can be easily moved and it can measure large sized industrial targets contactlessly.But up to now the precision of the TIMS has been considered so low that the TIMS isnt applied to some precise measurements.The error in self locating TIMS is a main factor which affects the precision of the TIMS.A new model of the TIMS is given out in this paper,and it can eliminate the error in self locating the TIMS.The new model is not only investigated and analyzed theoretically but also verified by the real measured data. 展开更多
关键词 model theodolite industrial measuring system (TIMS) self location of system
下载PDF
Agricultural Policy Simulation Based on Computable General Equilibrium Model
7
作者 李志刚 《Agricultural Science & Technology》 CAS 2012年第5期1119-1122,共4页
[Objective] This study aimed to examine the simulated effect of Computable General Equilibrium (CGE)-based agricultural policy simulation system. [Method] The policy simulation platform based on CGE model was constr... [Objective] This study aimed to examine the simulated effect of Computable General Equilibrium (CGE)-based agricultural policy simulation system. [Method] The policy simulation platform based on CGE model was constructed by integrating policy simulation, CGE model and Decision Supporting System (DSS). The scenario analysis method was used to analyze the agricultural subsides policy simulation through empirical analysis. [Result] Farmers were the main beneficiaries of increasing agricultural production subsidies, which increased farmers' income and improved the export of agriculture products. The prototype system could solve the problems in actual policy simulation. [Conclusion] The results lay the foundation for the quantitative study on agricultural subsidy policy in China. 展开更多
关键词 Policy simulation Computable General Equilibrium Model Agricultural subsidizes policy
下载PDF
Research on workflow meta model supporting activity based costing
8
作者 周晓俊 曹建 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期324-330,共7页
Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and ... Activity based costing (ABC) is a method which can solve many limitations of the traditional cost systems in manufacturing management. In this paper, we investigate how to integrate ABC with workflow technology, and build a workflow meta model supporting ABC. Firstly, the concept and concept model of activity based costing (ABC) are introduced. Next, the meta model of P -PROCE (Process, Product, Resource, Organization, and Cost & Evaluation) is presented. Then the cost meta model is defined by adding ABC to P -PROCE model. Object constraint language (OCL) is used to express meta model and constraints. Finally, we show an enterprise modeling and simulation tool based on the workflow meta model. We can systematically construct an enterprise model and easily and efficiently conduct simulation. Moreover it enables us to analyze and evaluate business processes and its costs. 展开更多
关键词 activity based costing WORKFLOW meta model object constraint language enterprise model
下载PDF
MULTI-CLASS TRAFFIC QOS ROUTING FOR LEO SATELLITE NETWORKS 被引量:3
9
作者 蒋文娟 宗鹏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第3期254-262,共9页
Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS sat... Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS satellite routing algorithm for multi-class traffic is proposed. The goal of the routing algorithm is to provide the distinct QoS for different traffic classes and improve the utilization of network resources. Traffic is classified into three classes and allocated priorities based on their QoS requirements, respectively. A priority queuing mechanism guarantees the algorithm to work better for high-priority classes. In order to control the congestion, a blocking probability analysis model is built up based on the Markov process theory. Finally, according to the classification link-cost metrics, routings for different classes are calculated with the distinct QoS requirments and the status of network resource. Simulations verify the performance of the routing algorithm at different time and in different regions, and results demonstrate that the algorithm has great advantages in terms of the average delay and the blocking probability. Meanwhile, the robustness issue is also discussed. 展开更多
关键词 low earth orbit satellite networks traffic classification routing algorithm quality of service traffic and topology model
下载PDF
Business domain oriented AI planning for web service composition
10
作者 代钰 杨雷 张斌 《Journal of Southeast University(English Edition)》 EI CAS 2007年第3期421-424,共4页
In order to improve the effectiveness of the artificial intelligence (AI) planning based web service composition problem, a business domain oriented AI planning algorithm for web service composition is introduced. T... In order to improve the effectiveness of the artificial intelligence (AI) planning based web service composition problem, a business domain oriented AI planning algorithm for web service composition is introduced. The algorithm uses the proposed business relation model to minimize the searching space and uses the proposed goal distance as a heuristic rule. Compared with other algorithms tackling web service composition such as AI planning, the proposed algorithm focuses not only on how to convert the web service composition problem to the AI planning problem, but also exerts its effort on how to apply the business feature of web service composition into planning in order to improve the effectiveness. The experiment shows the better performance of the proposed algorithm. 展开更多
关键词 AI planning web service web service composition business relation model
下载PDF
MULTI-AGENT BASED DISTRIBUTED MANUFACTURING EXECUTION SYSTEM MODEL 被引量:1
11
作者 杨浩 朱剑英 周娜 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第1期16-22,共7页
A multi-agent based manufacturing execution system (MES) model is presented. It is open, modula-rized, distributed, configurable, integratable and maintainable. By analyzing the MES domain in manufacturing systems, th... A multi-agent based manufacturing execution system (MES) model is presented. It is open, modula-rized, distributed, configurable, integratable and maintainable. By analyzing the MES domain in manufacturing systems, this paper proposes a multi-agent based MES model and analyzes the partitioned functions of MES in the model using unified modeling language (UML) diagrams, and establishes the ongoing implemented MES architecture. This MES can be facilely integrated with the enterprise resource planning (ERP), the floor control system (FCS), and the other manufacturing applications. 展开更多
关键词 MES MAS UML ERP modeling INTEGRATION
下载PDF
Population parameters and dynamic pool models of commercial fishes in the Beibu Gulf, northern South China Sea 被引量:13
12
作者 WANG Xuehui QIU Yongsong +3 位作者 DU Feiyan LIN Zhaojin SUN Dianrong HUANG Shuolin 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第1期105-117,共13页
Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters w... Length-frequency data of eight commercial fish species in the Beibu Gulf (Golf of Tonkin), northern South China Sea, were collected during 2006-2007. Length-weight relationships and growth and mortality parameters were analyzed using FiSAT II software. Five species had isometric growth, two species had negative allometric growth, and one species had positive allometric growth. Overall, the exploitation rates of the eight species were lower in 2006 2007 than in 1997-1999: for four species (Saurida tumbil, Saurida undosquamis, Argyrosomus macrocephalus, and Nemipterus virgatus) it was lower in 2006-2007 than in 1997 1999, for two species (Parargyrops edita and Trichiurus haumela) it remained the same, and for the other two species (Trachurus japonicus and Decapterus maruadsi) it was higher in 2006~007 than in 1997-1999. The exploitation rates might have declined because of the decline in fishing intensity caused by high crude oil prices. The optimum exploitation rate, estimated using Beverton-Holt dynamic pool models, indicated that although fishes in the Beibu Gulf could sustain high exploitation rates, the under-size fishes at first capture resulted in low yields. To increase the yield per recruitment, it is more effective to increase the size at first capture than to control fishing effort. 展开更多
关键词 commercial fish population parameters dynamic pool model stock status Beibu Gulf northern South China Sea
下载PDF
The Training Model and Development Route of Market-oriented Professional Farmers
13
作者 李彬 《Agricultural Science & Technology》 CAS 2016年第3期747-750,共4页
To cultivate new professional farmers is a key way for rural labor development, resolving existing problems such as how to farming. It is notable that government and market take advantages in training of new professio... To cultivate new professional farmers is a key way for rural labor development, resolving existing problems such as how to farming. It is notable that government and market take advantages in training of new professional farmers. Therefore, it is necessary to guarantee government and market playing the roles. The research explored market-oriented farmer training model and the characteristics and investigated training routes for new professional farmers. 展开更多
关键词 New professional farmers Market-oriented training model Development route
下载PDF
Support vector machine based nonlinear model multi-step-ahead optimizing predictive control 被引量:9
14
作者 钟伟民 皮道映 孙优贤 《Journal of Central South University of Technology》 EI 2005年第5期591-595,共5页
A support vector machine with guadratic polynomial kernel function based nonlinear model multi-step-ahead optimizing predictive controller was presented. A support vector machine based predictive model was established... A support vector machine with guadratic polynomial kernel function based nonlinear model multi-step-ahead optimizing predictive controller was presented. A support vector machine based predictive model was established by black-box identification. And a quadratic objective function with receding horizon was selected to obtain the controller output. By solving a nonlinear optimization problem with equality constraint of model output and boundary constraint of controller output using Nelder-Mead simplex direct search method, a sub-optimal control law was achieved in feature space. The effect of the controller was demonstrated on a recognized benchmark problem and a continuous-stirred tank reactor. The simulation results show that the multi-step-ahead predictive controller can be well applied to nonlinear system, with better performance in following reference trajectory and disturbance-rejection. 展开更多
关键词 nonlinear model predictive control support vector machine nonlinear system identification kernel function nonlinear optimization
下载PDF
Integrated reliability of travel time and capacity of urban road network under ice and snowfall conditions 被引量:4
15
作者 冷军强 张亚平 +1 位作者 张倩 赵莹萍 《Journal of Central South University》 SCIE EI CAS 2010年第2期419-424,共6页
In order to evaluate and integrate travel time reliability and capacity reliability of a road network subjected to ice and snowfall conditions,the conceptions of travel time reliability and capacity reliability were d... In order to evaluate and integrate travel time reliability and capacity reliability of a road network subjected to ice and snowfall conditions,the conceptions of travel time reliability and capacity reliability were defined under special conditions.The link travel time model(ice and snowfall based-bureau public road,ISB-BPR) and the path choice decision model(elastic demand user equilibrium,EDUE) were proposed.The integrated reliability was defined and the model was set up.Monte Carlo simulation was used to calculate the model and a numerical example was provided to demonstrate the application of the model and efficiency of the solution algorithm.The results show that the intensity of ice and snowfall,the traffic demand and supply,and the requirements for level of service(LOS) have great influence on the reliability of a road network.For example,the reliability drops from 65% to 5% when the traffic demand increases by 30%.The comprehensive performance index may be used for network planning,design and maintenance. 展开更多
关键词 integrated reliability urban road network travel time capacity Monte Carlo simulation bi-level program ice and snowfall
下载PDF
IFC-based integration tool for supporting information exchange from architectural model to structural model 被引量:5
16
作者 刘照球 李云贵 张汉义 《Journal of Central South University》 SCIE EI CAS 2010年第6期1344-1350,共7页
With the purpose of enhancing effective collaboration between architects and structural engineers in the building design field, an integration tool was developed for supporting information exchange from architectural ... With the purpose of enhancing effective collaboration between architects and structural engineers in the building design field, an integration tool was developed for supporting information exchange from architectural model to structural model. The PKPM (Bopomofo acronym, a Chinese building design software) structural model and an industry foundation classes (IFC) data model were adopted and analyzed to design the framework of the integration tool. The technique of mixed program languages (C++ and FORTRAN) was applied to developing the tool software, and the connectivity relationships and intersection nodes between the structural elements were optimized and simplified. A case study was implemented to illustrate the method to use the integration tool for information exchange from IFC-format architectural model to PKPM structural model. The results show that the tool can extract the information of architectural model and form a corresponding structural model. The presented method can help to enhance the modeline efficiency at the structural design phase. 展开更多
关键词 architectural model structural model industry foundation classes informatiOn exchange
下载PDF
IFC implementation in lifecycle costing 被引量:7
17
作者 Charlie Fu Ghassan Aouad +2 位作者 Amanda Marshall Ponting Angela Lee Song Wu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第4期437-441,共5页
Life Cycle Costing (LCC) is always a major concern in the Architecture, Engineering and Construction (AEC) industry. This paper presents the implementation of Building Information Modeling (BIM) technology in the deve... Life Cycle Costing (LCC) is always a major concern in the Architecture, Engineering and Construction (AEC) industry. This paper presents the implementation of Building Information Modeling (BIM) technology in the development of a lifecycle cost-estimating tool. The IFC (Industry Foundation Classes) model as an interoperable building information model has been adopted as the central data repository to deliver the integrated information of building designs from CAD design systems into the lifecycle-costing database. In this paper, the conceptions and relevant factors, which could affect the LCC estimation, have been introduced. The problems of current LCC applications have been identified as the lack of LCC data and the complexity of LCC exercises. The software application of IFC models and relevant auxiliary are depicted as a solution of the problem identified. The lifecycle costing tool is a part of the nD Modeling tool and as such is based on its integrated interface prototype toolkit and is able to holistically present an IFC model into a 3D virtual reality view, a tree-view and a list of element properties. The functions and some technical points are also detailed in the paper. Through the research, it demonstrates the potential and possibility of implementing BIM methods and techniques, particularly IFCs to enhance the computer applications in the processes of building construction and facility management. 展开更多
关键词 AEC industry life cycle costing building information modeling industry foundation classes
下载PDF
Coupled simulation of recirculation zonal firebox model and detailed kinetic reactor model in an industrial ethylene cracking furnace 被引量:8
18
作者 Zhou Fang Tong Qiu Weiguo Zhou 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第8期1091-1100,共10页
A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convecti... A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convection to simulate heat transfer in the furnace.A two-dimensional recirculation model is proposed to estimate the flow field in furnace.The reactor model integrates the feedstock reconstruction model,an auto-generator of detail kinetic schemes,and the reactor simulation model to simulate the reaction process in the tubular coil.The coupled simulation result is compared with industrial process and shows agreement within short computation time. 展开更多
关键词 Ethylene cracking Coupled simulation Tubular furnace Recirculation zone modeling Detailed reaction kinetic
下载PDF
Parametric Study of Two-Body Floating-Point Wave Absorber 被引量:6
19
作者 Atena Amiri Roozbeh Panahi Soheil Radfar 《Journal of Marine Science and Application》 CSCD 2016年第1期41-49,共9页
In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber... In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber (FPA) with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter's efficiency when considering specific conditions. 展开更多
关键词 floating-point absorber wave energy energy absorption Wave Energy Converter (WEC) Power Take Off (PTO) numerical simulation
下载PDF
An Extended Enterprise Modeling Approach to Enterprise-based Integration 被引量:6
20
作者 杨建华 XUE Hengxin 《High Technology Letters》 EI CAS 2002年第1期63-66,共4页
The paradigm of extended enterprise is the core competency focused. An extended enterprise expands its scope from bounding a single enterprise to including additional processes performed by other enterprises. The inte... The paradigm of extended enterprise is the core competency focused. An extended enterprise expands its scope from bounding a single enterprise to including additional processes performed by other enterprises. The integration of processes is enterprise based. This paper proposes a recursive enterprises interconnected chain model for the extended enterprise, and presents an enterprise-based integration framework for the extended enterprise. The case study is based on a motorcycle group corporation. 展开更多
关键词 Extended enterprise MODELING Enterprise integration Core competency
下载PDF
上一页 1 2 13 下一页 到第
使用帮助 返回顶部