一类无界的不相容工件族分批排序加权总完工时间问题

考虑极小化加权总完工时间的一类无界的不相容工件族分批排序问题,给出了最优排序的性质和算法,并加以证明．对工件有k个到达时间的情形,给出了一个复杂性为D（2^k-1nlogn）的启发式算法．     

加工时间相同的分族分批排序加权总完工时间问题

考虑极小化加权总完工时间的单机分族分批排序问题,给出了最优排序的性质和算法,并加以证明,对工件有k个到达时间的情形,给出了一个复杂性为O(2k-1nlogn)的启发式算法.     

同型平行机上的在线分批排序问题

本文首次考虑了同型平行机上的在线分批排序问题,用三元素法表示为pm｜rj∈{0,r},B｜Cmax,并对这一问题给出了一个竞争比为8/3-2/3m的在线算法MBLPT算法．     

带有霸王工件的单机在线分批排序

研究了一个带有霸王工件且允许重启的单机在线分批排序,其目标函数值为求时间表长．对于批容量无限的情况,给出了一个最坏竞争比为2的在线算法．     

同型平行机上的在线分批排序问题

对同型平行机上的在线分批排序问题,进行分析的基础上,用三元素法表示为Pm｜rj∈{0,r）,B｜Cmax,并对这一问题给出了一个竞争比为8/3-2/2m的在线算法MBLPT算法。     

一类带批安装时间的平行机在线分批排序问题

研究一类带批安装时间的平行机排序问题。工件按时间到达,在任何时刻,只知道当前已经就绪工件的信息。工件成批加工,同一批中工件的完工时间为批中最后一个工件的完工时间,每批开工前有一个固定的批安装时间。目标函数为极小化所有工件的总完工时间。主要考虑两个到达时间且工件加工时间都相等的特殊情形,给出竞争比为3/2的在线算法,并且有实例说明此界为紧致的。     

工件有优先约束和尺寸的单机分批排序问题

研究了工件有优先约束和尺寸大小关系的分批排序问题,这里目标函数为工件的极大完工时间,这类问题是NP—完备的.对工件加工时间相同和有特殊到达时间的情况给出了它的近似算法,并证明其最差性能比不超过2.     

带学习效应的供应链排序算法研究

考虑了机器在加工工件时会具有学习效应这一实际条件,将具有单制造商的供应链排序推广到具有多制造商的供应链排序问题.以总的加权配送时间和配送费用达到最小作为目标,在分析解的最优性条件的基础上,分别给出问题在工件具有一致性权重和不分批配送假设下的最优算法,并分析算法的时间复杂性.最后给出该问题的近似值.     

两个带机器准备时间的半在线排序

研究两个带机器准备时间的半在线排序算法,一个是当总加工时间已知时,工件在有准备时间的同类机上加工的半在线排序,证明了其竞争比的上下界分别为2ν和ν+1/2ν+1,都与机器加工速度有关;另一个是当最大加工时间已知时,工件在有准备时间的同型机上加工的半在线排序,证明了其竞争比为2/3.     

工件具有学习效应的分批排序问题

讨论了分批排序中工件具有学习效应、目标函数为极小化加权总完工时间的几个问题,分别就所有工件的基本加工时间都相等的情况给出了几种算法,并证明了算法的最优性.     

高校互联网人才市场供求信息开发利用与管理对策研究

大学毕业生与用人单位越来越注重互联网人才市场的供求信息。通过对大学毕业生网上就业出现的问题的分析．有针对性地提出了一些对策．以推进大学毕业生网上就业的开展。     

M台同型机极大化最小机器负载的半在线问题

In this paper, a semi on-line version on m identical machines M1, M2, …,Mm(m≥3) was considered, where the processing time of the largest job is known in advance. Our goal is to maximize the minimum machine load, an NPLS algorithm was presented and its worst-case ratio was proved to be equal to m-1 which is the best possible value. It is concluded that if the total processing time of jobs is also known to be greater than (2m-1)pmax where pmax is the largest job's processing time, then the worst-case ratio is 2-1/m.     

“主导—主体”网络课程建设与教学改革一体化推进研究

＂主导—主体＂网络课程以课堂教学为主,以网络教学为辅,能够使传统课程和网络课程优势互补。在当前高校＂主导—主体＂网络课程建设的初期,存在着课程网站建设水平低、网络课程负责人态度不端正、缺乏积极性,教学利用率不高,组织管理不完善等问题。＂主导—主体＂网络课程建设必须与教学改革一体化推进。就这一过程的完善而言,提高认识是观念基础,教学改革是实践关键,行动研究是基本路径。     

网络教育的质量因素探析

针对网络教育系统中存在的质量问题，本文分析了影响网络教育质量的重要因素，从网络教育的满意度入手，提出了网络教育的质量保障因素。在此基础上，本文引进了整合的公共服务体系思想。     

核心自我评价与员工工作态度的关系研究

采用核心自我评价、工作满意度、工作倦怠问卷为研究工具,对1 010名企业员工进行问卷调查,探讨核心自我评价与工作满意度、工作倦怠的关系.结果表明：核心自我评价与员工工作满意度存在显著正相关,与工作倦怠存在显著负相关,且能够有效预测员工的工作满意度和工作倦怠.     

Principal Recruitment: An Empirical Evaluation of a School District’s Internal Pool of Principal Certified Personnel

Applicant pools for principal vacancies are shrinking nationwide. This shortage of job applicants requires school districts to evaluate their internal pools of principal certified personnel. In this study, 194 certified individuals from a large school district responded to a survey measuring attraction to the job of principal, current job satisfaction versus expected satisfaction in the job of principal, barriers to pursuing the job, and recommended changes in the job. Few participants intended to apply for principal vacancies due to age (median=51), lack of self-reported capability to do the job, and satisfaction with the current job. Participants perceived their job satisfaction would decrease on assuming the job of principal relative to factors such as time with family and job security, and increase relative to factors such as salary and opportunity to experience varied activities. Implications for principal recruitment and recommendations for restructuring the job are discussed.     

On-line Literature: The Challenge of Integrating Web-based Materials

This classroom research discusses the challenges of integrating face-to-face interactions with the use of on-line resources in secondary English classrooms. Examining the lesson plans of pre-service and early career teachers in the US, I found that the uses of on-line resources were frequently neither coherent nor consistent with the goals and objectives teachers had planned for their lessons. As well, on-line resources rarely furthered teachers’ attempts to support students’ analytical or close reading of literary texts, but instead were used primarily to foster student engagement with the literature. Although on-line literature resources provide almost unimaginable possibilities for enriching classrooms, teachers must learn to identify and clarify their objectives for reading, and they must distinguish their objectives from those of website developers and sponsors. If we want on-line resources to transform our classrooms, then we must be willing and able to transform those materials, to translate them for our students through developing robust questions that will guide their viewings and readings. Additionally, we must acknowledge that on-line contexts may themselves change reading behaviours, and that when using the World-Wide Web, our local contexts matter greatly.     

开放教育学生上网学习问题的调查分析与建议

对电大在线用户访问情况的调查分析表明,近年来学生上网访问量显著增加,学生上网时间也有规律可循;如何维持与提高上网访问量,提高网上学习活动的质量是目前面临的主要问题。电大要积极推进课程资源的建设与整合,充分发挥教师在网上教学活动中的主导作用,适时制定网上学习的监控评价与激励措施,着力强化网上学习的支持服务,以促进网上学习的有效开展。     

大学生上网时间与其心理健康的关系

采用症状自评量表(SCL-90)对455名大学生进行调查,了解大学生心理健康与其上网时间的关系。研究发现心理障碍者出现于各个上网时间,大学生每天上网时间与其心理健康得分之间有统计学意义的正相关(r=0.116,P=0.014)。上网时间越长,心理健康水平越低,2.5小时是每天健康上网时间和不健康上网时间的分界点。因此,上网时间对大学生心理健康有显著影响。     

Development of the child care worker job stress inventory

After a series of instrument development studies, a mail survey was conducted with 196 randomly selected family day care providers (FDCPs) and child care center workers (CCCWs) residing in the state of Maryland (response rates were 76.6% and 70.5%, respectively). Embedded in the instrument were three job stress scales, specific to child care workers, measuring job demands, job control, and job resources. Extensive psychometric testing of the three 17-item instruments demonstrated several areas of strength. The job demands scale, because of its breadth of stressors covered, fared slightly worse on indicators of reliability (alpha = 0.77; mean interitem correlation [MIC] = 0.17; item-to-total correlations [ITCs] = 0.14 to 0.49) than did job control (alpha = 0.88; MIC = 0.31; ITCs = 0.26 to 0.69) and job resources (alpha = 0.89; MIC = 0.35; ITCs = 0.32 to 0.70). Known groups validity was demonstrated through a conceptually meaningful pattern of differences between FDCPs and CCCWs. Construct validity for all three scales was demonstrated by a pattern of stronger correlations with conceptually similar versus dissimilar instruments. Average correlations with similar versus dissimilar instruments were: job demands, 0.54 versus 0.24; job control, 0.74 versus 0.30; and job resources, −0.53 versus 0.30. Similar to the reliability analysis, results of factor analysis were stronger for job control and job resources than for job demands.