In order to reduce the possibility that quality problems occur resulting from “ bad ” weather, a new dispatching rule is designed for the job sequencing problem in the machine shop of a wood furniture factory. First...In order to reduce the possibility that quality problems occur resulting from “ bad ” weather, a new dispatching rule is designed for the job sequencing problem in the machine shop of a wood furniture factory. First, two indices including risky duration and risk magnitude are established to characterize the weather conditions. Based on these two indices, the job suitability under the future air state is derived by the fuzzy decision method, and integrated with atraditional heuristic to compute the dispatching priority of each job. Then, a new measure matching degree is constructed to evaluate the effectiveness of the dispatching rule. The greater the matching degree, the smaller the possibility that the quality problems of wood products occur. Finally, simulation experiments show that the dispatching rule can greatly increase the matching degree while maintaining low weighted tardiness.展开更多
In the early years of reform and opening up, with the household contract management as the core, the land reform has been adapted to the prevailing agricultural productivity development and management level, achieved ...In the early years of reform and opening up, with the household contract management as the core, the land reform has been adapted to the prevailing agricultural productivity development and management level, achieved to mobilize the peasants＇ production enthusiasm and creativity, to improve production efficiency, basically solved the food and clothing problem; but it has formed small-scale decentralized business model. With the rapid development of the rural economy, along with urbanization and industrialization, it has been further increased the degree of market-oriented agriculture. The contradiction between big market and small-scale production is more prominent; such small -scale decentralized form of management has begun not to meet agricultural development request and the market economy development. It needs changes to moderate scale. Eleventh Five-Year Plan and construction of new socialist village require clearly various forms of appropriate scale.展开更多
Due to the complex,uncertainty and dynamics in the modern manufacturing environment,a flexible and robust shop floor scheduler is essential to achieve the production goals.A design framework of a shop floor dynamical ...Due to the complex,uncertainty and dynamics in the modern manufacturing environment,a flexible and robust shop floor scheduler is essential to achieve the production goals.A design framework of a shop floor dynamical scheduler is presented in this paper.The workflow and function modules of the scheduler are discussed in detail.A multi-step adaptive scheduling strategy and a process specification language,which is an ontology-based representation of process plan,are utilized in the proposed scheduler.The scheduler acquires the dispatching rule from the knowledge base and uses the build-in on-line simulator to evaluate the obtained rule.These technologies enable the scheduler to improve its fine-tune ability and effectively transfer process information into other heterogeneous information systems in a shop floor.The effectiveness of the suggested structure will be demonstrated via its application in the scheduling system of a manufacturing enterprise.展开更多
Small-scale household agricultural production has been in conflict with China＇s agricultural modernization.In the context of vigorously promoting rural land circulation and moderate scale management nationwide,resear...Small-scale household agricultural production has been in conflict with China＇s agricultural modernization.In the context of vigorously promoting rural land circulation and moderate scale management nationwide,research on the relationship between farm size and scale efficiency has become increasingly important.In this paper,we use the ＂DEA-OLS＂ two stage method to analyze data from 368 surveys of rice farming households in the Jianghan Plain.The scale efficiency of rice farming was calculated,and the relationship between farm size and scale efficiency investigated.The results indicate that（1） the rice farm size is generally small in Jianghan Plain,with an average of 0.77 ha.The average scale efficiency is 0.88,and it is the main factor limiting an increase in comprehensive technical efficiency.Moreover,88.32% of households are in the stage of increasing returns to scale.（2） There is a stable inverted ＂U＂ type relationship between rice farm size and scale efficiency.Considering characteristics of the householder,the household and land quality,the maximum scale efficiency corresponds to a household with 5 ha of rice farm.（3） Among householder characteristics,age has a significant negative influence on scale efficiency,and scale efficiency is lower for a household whose householder is engaged in non-farm work than for one whose householder is devoted to farming.As for land quality,there was a significant positive effect of irrigation on scale efficiency.Among family characteristics,the application of a machine during the seeding process increased scale efficiency by 3.07%.Therefore,we suggest that local government should actively promote rural land circulation,implement a staged-scale management subsidy,and other forms of support for the purchase of agricultural machinery and technical popularization.Increased investment in irrigation improvements and mechanical facilities and encouragement of farmers to enlarge their farm size could improve scale efficiency and farming profit and lead to the development of moderate scale management.展开更多
基金The National Natural Science Foundation of China(No.61273119)
文摘In order to reduce the possibility that quality problems occur resulting from “ bad ” weather, a new dispatching rule is designed for the job sequencing problem in the machine shop of a wood furniture factory. First, two indices including risky duration and risk magnitude are established to characterize the weather conditions. Based on these two indices, the job suitability under the future air state is derived by the fuzzy decision method, and integrated with atraditional heuristic to compute the dispatching priority of each job. Then, a new measure matching degree is constructed to evaluate the effectiveness of the dispatching rule. The greater the matching degree, the smaller the possibility that the quality problems of wood products occur. Finally, simulation experiments show that the dispatching rule can greatly increase the matching degree while maintaining low weighted tardiness.
文摘In the early years of reform and opening up, with the household contract management as the core, the land reform has been adapted to the prevailing agricultural productivity development and management level, achieved to mobilize the peasants＇ production enthusiasm and creativity, to improve production efficiency, basically solved the food and clothing problem; but it has formed small-scale decentralized business model. With the rapid development of the rural economy, along with urbanization and industrialization, it has been further increased the degree of market-oriented agriculture. The contradiction between big market and small-scale production is more prominent; such small -scale decentralized form of management has begun not to meet agricultural development request and the market economy development. It needs changes to moderate scale. Eleventh Five-Year Plan and construction of new socialist village require clearly various forms of appropriate scale.
基金National Defense Fund(No.20030119)NSFC(No.60775060)the Foundation Research Fund of Harbin Engineering University(No.HEUFT07027)
文摘Due to the complex,uncertainty and dynamics in the modern manufacturing environment,a flexible and robust shop floor scheduler is essential to achieve the production goals.A design framework of a shop floor dynamical scheduler is presented in this paper.The workflow and function modules of the scheduler are discussed in detail.A multi-step adaptive scheduling strategy and a process specification language,which is an ontology-based representation of process plan,are utilized in the proposed scheduler.The scheduler acquires the dispatching rule from the knowledge base and uses the build-in on-line simulator to evaluate the obtained rule.These technologies enable the scheduler to improve its fine-tune ability and effectively transfer process information into other heterogeneous information systems in a shop floor.The effectiveness of the suggested structure will be demonstrated via its application in the scheduling system of a manufacturing enterprise.
基金National Natural Science Foundation of China(41571095)
文摘Small-scale household agricultural production has been in conflict with China＇s agricultural modernization.In the context of vigorously promoting rural land circulation and moderate scale management nationwide,research on the relationship between farm size and scale efficiency has become increasingly important.In this paper,we use the ＂DEA-OLS＂ two stage method to analyze data from 368 surveys of rice farming households in the Jianghan Plain.The scale efficiency of rice farming was calculated,and the relationship between farm size and scale efficiency investigated.The results indicate that（1） the rice farm size is generally small in Jianghan Plain,with an average of 0.77 ha.The average scale efficiency is 0.88,and it is the main factor limiting an increase in comprehensive technical efficiency.Moreover,88.32% of households are in the stage of increasing returns to scale.（2） There is a stable inverted ＂U＂ type relationship between rice farm size and scale efficiency.Considering characteristics of the householder,the household and land quality,the maximum scale efficiency corresponds to a household with 5 ha of rice farm.（3） Among householder characteristics,age has a significant negative influence on scale efficiency,and scale efficiency is lower for a household whose householder is engaged in non-farm work than for one whose householder is devoted to farming.As for land quality,there was a significant positive effect of irrigation on scale efficiency.Among family characteristics,the application of a machine during the seeding process increased scale efficiency by 3.07%.Therefore,we suggest that local government should actively promote rural land circulation,implement a staged-scale management subsidy,and other forms of support for the purchase of agricultural machinery and technical popularization.Increased investment in irrigation improvements and mechanical facilities and encouragement of farmers to enlarge their farm size could improve scale efficiency and farming profit and lead to the development of moderate scale management.
