An appointment scheduling problem is studied with the consideration of customer impatience.On the assumption that both the time of leaving queue and the time of service are exponentially distributed,in order to minimi...An appointment scheduling problem is studied with the consideration of customer impatience.On the assumption that both the time of leaving queue and the time of service are exponentially distributed,in order to minimize the joint cost,the optimal appointment schedule of the fixed number of customers is studied.The joint cost function is composed of customers expected delay time and service availability time.The expected delay time of each customer in the queue is recursively computed in terms of customer interarrival time.Furthermore,the effect of impatience on the optimal schedule as well as the total operating cost is studied.The results show that as the impatience rate increases,the optimal interarrival time becomes shorter and the interarrival time of the last few customers gradually approaches that of the customers in the middle.In addition,impatient behaviors can increase the joint cost.展开更多
The black soil area in Northeast China serves as a“ballast”to ensure China’s food security.Unreasonable development and utilization lead to serious black soil degradation in some areas and affect regional food prod...The black soil area in Northeast China serves as a“ballast”to ensure China’s food security.Unreasonable development and utilization lead to serious black soil degradation in some areas and affect regional food production and economic and social development.In the context of the intensification of the contradiction between food supply and demand worldwide,we should pay more attention to the overall situation of regional sustainable development and seek for systematic,scientific,and economic solutions.This study establishes a regional all-for-one customization model of black soil granary on the basis of the regional system of human–land relationship,customized and accurate management,agricultural system theory,and agricultural informatization with the guidance of integrated geography concept.The aim of this regional all-for-one customization model is to systematically diagnose the key problems and leading factors of black soil degradation and determine a solution that combines the commonness and individuality of black soil protection from the perspective of multiscale linkage,multifactor coupling,and multitechnology cooperation.The regional all-for-one customization model of black soil granary integrates the two perspectives of“regional”and“customization”into the protection and comprehensive utilization of black soil for the first time.It adopts zoning,grading,and classification as the main strategy and big data and artificial intelligence as the main technical approaches.This model constructs three strategies of different scales by combining the“satellite–air–ground–network”3D monitoring system and the all-for-one customization platform driven by big data and artificial intelligence.First,the“implementing strategies by regions”are implemented at the regional scale to formulate the regional agricultural resource allocation scheme and agricultural zoning,which can provide strategies to protect and utilize black soil effectively.Second,the“determining strategies in accordance with villages”are implemented at the village scale to formulate a black soil protection and utilization model for different categories of villages,which can promote the organic integration of black soil protection and rural revitalization.Third,a“one strategy for one field”concept is applied at the field scale to provide accurate strategies for soil restoration and yield improvement in a fixed,quantitative,and regular manner.Multiscale integrated demonstration and scheme verification of the regional all-for-one customization model of black soil granary are conducted in Qiqihar City at three scales,namely,region,village,and field,to solve the key issues in black soil protection and utilization and form a replicable and popularized system solution,thereby providing a model for the sustainable development of Chinese and global black soil agriculture.The proposed regional all-for-one customization model of black soil granary has important theoretical and practical value in promoting the high-quality development of regional agriculture and rural revitalization,and provides a demonstration model of land protection and utilization for the black soil area in China and the whole world.展开更多
This article examines the effects of reneging, server breakdown and server vacation on the various states of the batch arrivals queueing system with single server providing service to customers in three fluctuating mo...This article examines the effects of reneging, server breakdown and server vacation on the various states of the batch arrivals queueing system with single server providing service to customers in three fluctuating modes. In this queueing system, any batch arrival joins the queue if the server is busy or on vacation or under repair. However, if the server is free, one customer from the arriving batch joins the service immediately while others join the queue. In case of server breakdown, the customer whose service is interrupted returns back to the head of the queue. As soon as the server has is repaired, the server attends to the customer in mode 1. For this queueing system, customers that are impatient due to breakdown and server vacation may renege (leave the queue without getting service). Due to fluctuating modes of service delivery, the system may provide service with complete or reduced efficiency. Consequently, we construct the mathematical model and derive the probability generating functions of the steady state probabilities of several states of the system including the steady state queue size distribution. Further, we discuss some particular cases of the proposed queueing model. We present numerical examples in order to demonstrate the effects of server vacation and reneging on the various states of the system. The study revealed that an increase in reneging and a decrease in server vacation results in a decrease in server utilization and an increase in server’s idle time provided rates of server breakdown and repair completion are constant. In addition, the probability of server vacation, the probability of system is under repair and the probabilities that the server provides service in three fluctuating modes decreases due to an increase in reneging and a decrease in vacation completion rates.展开更多
In this paper, the conflict between individual needs of market and the efficient mass production requirement of manufacture under the background of market globalization is discussed, a trend that the main production m...In this paper, the conflict between individual needs of market and the efficient mass production requirement of manufacture under the background of market globalization is discussed, a trend that the main production mode for domestic steel industry should be the mass customization is pointed out, and the problems to be solved for domestic enterprise are analyzed. Summarizing the practice of Baosteel Co. LTD on the new production mode, the achievements and experiences are presented.展开更多
针对煤炭企业客户关系管理系统的信息化、智能化需求,提出了一种基于SQL Server 2008的煤炭企业智能客户关系管理系统的设计方案;给出了智能客户关系管理系统的数据挖掘流程,详细介绍了SQL Server 2008中的商业智能工具在煤炭企业智能...针对煤炭企业客户关系管理系统的信息化、智能化需求,提出了一种基于SQL Server 2008的煤炭企业智能客户关系管理系统的设计方案;给出了智能客户关系管理系统的数据挖掘流程,详细介绍了SQL Server 2008中的商业智能工具在煤炭企业智能客户关系管理系统中的应用,包括煤炭企业智能客户关系管理系统的集群部署结构及其软件架构。实例分析结果验证了该系统的可行性。展开更多
基金The National Natural Science Foundation of China(No.71671036)the Scientific Innovation Research of Graduate Students in Jiangsu Province(No.KYLX_0211)
文摘An appointment scheduling problem is studied with the consideration of customer impatience.On the assumption that both the time of leaving queue and the time of service are exponentially distributed,in order to minimize the joint cost,the optimal appointment schedule of the fixed number of customers is studied.The joint cost function is composed of customers expected delay time and service availability time.The expected delay time of each customer in the queue is recursively computed in terms of customer interarrival time.Furthermore,the effect of impatience on the optimal schedule as well as the total operating cost is studied.The results show that as the impatience rate increases,the optimal interarrival time becomes shorter and the interarrival time of the last few customers gradually approaches that of the customers in the middle.In addition,impatient behaviors can increase the joint cost.
基金Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA28130500。
文摘The black soil area in Northeast China serves as a“ballast”to ensure China’s food security.Unreasonable development and utilization lead to serious black soil degradation in some areas and affect regional food production and economic and social development.In the context of the intensification of the contradiction between food supply and demand worldwide,we should pay more attention to the overall situation of regional sustainable development and seek for systematic,scientific,and economic solutions.This study establishes a regional all-for-one customization model of black soil granary on the basis of the regional system of human–land relationship,customized and accurate management,agricultural system theory,and agricultural informatization with the guidance of integrated geography concept.The aim of this regional all-for-one customization model is to systematically diagnose the key problems and leading factors of black soil degradation and determine a solution that combines the commonness and individuality of black soil protection from the perspective of multiscale linkage,multifactor coupling,and multitechnology cooperation.The regional all-for-one customization model of black soil granary integrates the two perspectives of“regional”and“customization”into the protection and comprehensive utilization of black soil for the first time.It adopts zoning,grading,and classification as the main strategy and big data and artificial intelligence as the main technical approaches.This model constructs three strategies of different scales by combining the“satellite–air–ground–network”3D monitoring system and the all-for-one customization platform driven by big data and artificial intelligence.First,the“implementing strategies by regions”are implemented at the regional scale to formulate the regional agricultural resource allocation scheme and agricultural zoning,which can provide strategies to protect and utilize black soil effectively.Second,the“determining strategies in accordance with villages”are implemented at the village scale to formulate a black soil protection and utilization model for different categories of villages,which can promote the organic integration of black soil protection and rural revitalization.Third,a“one strategy for one field”concept is applied at the field scale to provide accurate strategies for soil restoration and yield improvement in a fixed,quantitative,and regular manner.Multiscale integrated demonstration and scheme verification of the regional all-for-one customization model of black soil granary are conducted in Qiqihar City at three scales,namely,region,village,and field,to solve the key issues in black soil protection and utilization and form a replicable and popularized system solution,thereby providing a model for the sustainable development of Chinese and global black soil agriculture.The proposed regional all-for-one customization model of black soil granary has important theoretical and practical value in promoting the high-quality development of regional agriculture and rural revitalization,and provides a demonstration model of land protection and utilization for the black soil area in China and the whole world.
文摘This article examines the effects of reneging, server breakdown and server vacation on the various states of the batch arrivals queueing system with single server providing service to customers in three fluctuating modes. In this queueing system, any batch arrival joins the queue if the server is busy or on vacation or under repair. However, if the server is free, one customer from the arriving batch joins the service immediately while others join the queue. In case of server breakdown, the customer whose service is interrupted returns back to the head of the queue. As soon as the server has is repaired, the server attends to the customer in mode 1. For this queueing system, customers that are impatient due to breakdown and server vacation may renege (leave the queue without getting service). Due to fluctuating modes of service delivery, the system may provide service with complete or reduced efficiency. Consequently, we construct the mathematical model and derive the probability generating functions of the steady state probabilities of several states of the system including the steady state queue size distribution. Further, we discuss some particular cases of the proposed queueing model. We present numerical examples in order to demonstrate the effects of server vacation and reneging on the various states of the system. The study revealed that an increase in reneging and a decrease in server vacation results in a decrease in server utilization and an increase in server’s idle time provided rates of server breakdown and repair completion are constant. In addition, the probability of server vacation, the probability of system is under repair and the probabilities that the server provides service in three fluctuating modes decreases due to an increase in reneging and a decrease in vacation completion rates.
文摘In this paper, the conflict between individual needs of market and the efficient mass production requirement of manufacture under the background of market globalization is discussed, a trend that the main production mode for domestic steel industry should be the mass customization is pointed out, and the problems to be solved for domestic enterprise are analyzed. Summarizing the practice of Baosteel Co. LTD on the new production mode, the achievements and experiences are presented.
文摘针对煤炭企业客户关系管理系统的信息化、智能化需求,提出了一种基于SQL Server 2008的煤炭企业智能客户关系管理系统的设计方案;给出了智能客户关系管理系统的数据挖掘流程,详细介绍了SQL Server 2008中的商业智能工具在煤炭企业智能客户关系管理系统中的应用,包括煤炭企业智能客户关系管理系统的集群部署结构及其软件架构。实例分析结果验证了该系统的可行性。
