Considering the complex constraint between operations in nonstandard job shop scheduling problem (NJSSP), critical path of job manufacturing tree is determined according to priority scheduling function constructed. ...Considering the complex constraint between operations in nonstandard job shop scheduling problem (NJSSP), critical path of job manufacturing tree is determined according to priority scheduling function constructed. Operations are divided into dependent operations and independent operations with the idea of subsection, and corresponding scheduling strategy is put forward according to operation characteristic in the segment and the complementarities of identical function machines. Forward greedy rule is adopted mainly for dependent operations to make operations arranged in the right position of machine selected, then each operation can be processed as early as possible, and the total processing time of job can be shortened as much as possible. For independent operations optimum scheduling rule is adopted mainly, the inserting position of operations will be determined according to the gap that the processing time of operations is subtracted from idle time of machine, and the operation will be inserted in the position with minimal gap. Experiments show, under the same conditions, the result that operations are scheduled according to the object function constructed, and the scheduling strategy adopted is better than the result that operations are scheduled according to efficiency scheduling algorithm.展开更多
The grid computing main concern is to use the resources efficiently. For achieving this many grid resource scheduling algorithms are used for the efficient use of unused resources, especially CPU. The scheduling algor...The grid computing main concern is to use the resources efficiently. For achieving this many grid resource scheduling algorithms are used for the efficient use of unused resources, especially CPU. The scheduling algorithms assign single complete job to a single resource. Instead, if these algorithms consider the degree of dependency among the modules of a job, they can be allocated parallel to the different resources. This reduces the completion time of the job and the resources can be utilized to its maximum extent. Towards this, the job scheduling using coupling algorithm is proposed. This algorithm puts forward the idea of considering the coupling degree while allocating the modules of a job parallel to different resources. In this algorithm, resource selection is done by using both its functional and non-functional properties. The algorithm works in 3 phases. It groups the interdependent modules of a job into different sets using coupling in the first phase. It checks the non-functional property i.e. availability of a resource using echo procedure in the second phase and in the third phase, the sets created in first phase, are allocated parallel to different available and matching resources. From the simulation results it is observed that job scheduling using coupling algorithm gives better performance in terms of reduced turnaround time as compared to First Come First Served, Largest Task First and Minimum Execution Time scheduling algorithms.展开更多
Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic ...Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic libraries in China and in the United States from 1998 to 2007.It describes how some of the library professional positions and functional units have gone through a time period of intensified and proactive position allocation realignment in terms of their rise,decline,fission and/or fusion within the administrative context of their library's evolving changes in missions,objectives and service delivery structure under the impact of the rapid development of information technologies.Such changes are graphically demonstrated in several charts in this paper to highlight the evolutionary development of academic librarianship in general and the waves of changes for library position reallocations in specific in the ten-year period under study.It is believed that such a study can be useful for discerning the overall developing trend of academic librarianship,especially in the area of the rising professional and social status of academic librarianship during this period.The movement of library position allocation realignment was a corresponding response at the time to the influx of applicable information technologies to the library scene.It not only made the library operation to become'leaner and meaner,' but also gave added impetus to the rise of the professional and social status of their practitioners in the society due to the latter's enhanced service delivery innovations and capabilities for meeting their constituencies' timely information needs more satisfactorily.展开更多
基金National Natural Science Foundation of China(No. 50575062)Natural Science Foundation of Heilongjiang Province,China (No. F200608)+2 种基金Key Project of Scientific Research Subsidy of Abroad Scholars of Heilongjiang Provincial Education Department, China (No.1152hq08)Scientific Research Fund of Heilongjiang Provincial Education Department, China (No.10551z0008)Harbin Municipal Key Project of Science and Technology, China (No.2005AA1CG061-11).
文摘Considering the complex constraint between operations in nonstandard job shop scheduling problem (NJSSP), critical path of job manufacturing tree is determined according to priority scheduling function constructed. Operations are divided into dependent operations and independent operations with the idea of subsection, and corresponding scheduling strategy is put forward according to operation characteristic in the segment and the complementarities of identical function machines. Forward greedy rule is adopted mainly for dependent operations to make operations arranged in the right position of machine selected, then each operation can be processed as early as possible, and the total processing time of job can be shortened as much as possible. For independent operations optimum scheduling rule is adopted mainly, the inserting position of operations will be determined according to the gap that the processing time of operations is subtracted from idle time of machine, and the operation will be inserted in the position with minimal gap. Experiments show, under the same conditions, the result that operations are scheduled according to the object function constructed, and the scheduling strategy adopted is better than the result that operations are scheduled according to efficiency scheduling algorithm.
文摘The grid computing main concern is to use the resources efficiently. For achieving this many grid resource scheduling algorithms are used for the efficient use of unused resources, especially CPU. The scheduling algorithms assign single complete job to a single resource. Instead, if these algorithms consider the degree of dependency among the modules of a job, they can be allocated parallel to the different resources. This reduces the completion time of the job and the resources can be utilized to its maximum extent. Towards this, the job scheduling using coupling algorithm is proposed. This algorithm puts forward the idea of considering the coupling degree while allocating the modules of a job parallel to different resources. In this algorithm, resource selection is done by using both its functional and non-functional properties. The algorithm works in 3 phases. It groups the interdependent modules of a job into different sets using coupling in the first phase. It checks the non-functional property i.e. availability of a resource using echo procedure in the second phase and in the third phase, the sets created in first phase, are allocated parallel to different available and matching resources. From the simulation results it is observed that job scheduling using coupling algorithm gives better performance in terms of reduced turnaround time as compared to First Come First Served, Largest Task First and Minimum Execution Time scheduling algorithms.
文摘Based on a questionnaire survey,the paper made a comparative study on the changes of traditional library positions within the context of the emerging professional positions and functional units at some large academic libraries in China and in the United States from 1998 to 2007.It describes how some of the library professional positions and functional units have gone through a time period of intensified and proactive position allocation realignment in terms of their rise,decline,fission and/or fusion within the administrative context of their library's evolving changes in missions,objectives and service delivery structure under the impact of the rapid development of information technologies.Such changes are graphically demonstrated in several charts in this paper to highlight the evolutionary development of academic librarianship in general and the waves of changes for library position reallocations in specific in the ten-year period under study.It is believed that such a study can be useful for discerning the overall developing trend of academic librarianship,especially in the area of the rising professional and social status of academic librarianship during this period.The movement of library position allocation realignment was a corresponding response at the time to the influx of applicable information technologies to the library scene.It not only made the library operation to become'leaner and meaner,' but also gave added impetus to the rise of the professional and social status of their practitioners in the society due to the latter's enhanced service delivery innovations and capabilities for meeting their constituencies' timely information needs more satisfactorily.