关系数据库性能的优化研究

数据库管理是数据管理的重要部分,是计算机学科的重要分支。数据库性能的好坏直接决定着数据库应用系统的运行效率。在阐述影响数据库性能的主要因素的基础上,结合实际探讨了优化数据库性能的一些策略,分析和比较了不同策略可能对数据库性能的具体影响。     

Conditions for mental health in education: Towards relational practice

There are concerns globally about the emotional wellbeing and mental health of young people and in this paper a critical orientation comprises both theoretical and empirical data sources. The case is made that (1) the medical model of mental health – that of problem identification, diagnosis and medical treatment at the level of the individual – is not appropriate for the vast majority of children and young people in schools and (2) relational approaches would be more sensitive in responding to the complexity of the ‘conditions’ in the schools, homes and communities in which young people live. Articulations of these conditions in the literature are explored while we also draw on empirical data from part of an evaluation of a school-based teacher-training programme in which interviewees and respondents mapped out their own conditions for emotional wellbeing and mental health. We conclude with proposals for relational approaches which (1) acknowledge the links between affect, cognition and school climate and culture, (2) foreground mental health and poverty as impacting on young people’s emotional wellbeing in their communities, families and schools and (3) attend to voice – providing spaces in which young people can develop their own ‘preferred narratives’ concerning emotional wellbeing and mental health.     

Academic scientists’ affiliation with university research centers: Selection dynamics

University research centers have been institutionalized as a part of the science policy repertoire committed to strategic use of science and technology. Based on a representative sample of academic scientists and engineers in American research universities, this study investigates the selection dynamics, attempting to unfold the determinants of department-affiliated faculty members to be center affiliates. The findings suggest that university research centers select their affiliates on the basis of individual scientific and technical human capital. Scientists from prestigious departments are more likely to be center affiliates, so are prolific scientists, former postdoctoral scholars and the elder cohorts. In the meantime, university research centers are able to overcome the incentive incongruity with academic departments, as is evidenced by a higher likelihood among junior scientists to secure center connections. Dedicated to diversity and equity, university research centers provide a level playing field for women, minority and foreign-born scientists. The study concludes with a discussion of the scientific and technical human capital theory and policy implications in the science enterprise.     

顾客参与新产品开发中顾客角色探究

引入顾客在新产品开发中作为资源、共同创造者、用户的三种角色,探明不同的项目复杂性和产品创新性下,顾客的三种角色对新产品绩效的影响会有怎样的不同;同时,探索企业如何通过企业关系治理机制促使顾客角色得到有效发挥。发现,(1)双边专项投资、关系规范都能促进顾客角色的发挥;(2)产品创新性能加强顾客作为资源、用户对新产品绩效的作用,而削弱顾客作为共同创造者对新产品绩效的作用;(3)项目复杂性能加强顾客作为资源、共同创造者对新产品绩效的作用。     

团购导航网站用户满意度研究

为了对团购导航网站进行较为客观的用户满意度评价,本文在文献回顾、专家咨询、问卷调查的基础上,运用因子分析法归纳出影响团购导航网站用户满意度的五大公因子：网站界面、网站性能、网站信息质量、网站服务、网站形象,并由此建立了相应的评价指标体系。然后以此为基础,提出了运用灰色关联分析法对团购导航网站用户满意度进行测评,并建议结合第三方监测机构的监测数据对导航网站的实际运营情况进行分析,最后利用本文提出的指标体系和研究方法,对3个团购导航网站进行了实证分析。有利于网站运营者从用户角度出发,发现网站存在的缺陷,并为网站改进指明了方向。     

基于信息关联的负面网络舆情风险分级与预测研究

【目的/意义】网络社会充斥大量负面网络舆情,负面网络舆情风险分级和研判对提高网络治理能力和网络 社会治理成效意义重大。【方法/过程】构建负面网络舆情风险指标体系,并采用熵权法计算风险指标权重;基于加 权GRA模型计算灰色加权信息关联度,在此基础上,运用k-means聚类算法构建负面网络舆情风险分级方案,据此 对负面网络舆情进行风险预测。【结果/结论】实证分析结果表明,所建负面网络舆情风险分级模型客观性强、可靠 度高,可为负面网络舆情风险精准响应提供有效决策依据。【创新/局限】以信息关联为视角,为负面网络舆情风险 分级与预测提供了新的研究框架,但典型案例数据库有待继续完善。     

基于模糊关系数据库的聚类算法研究

聚类是人类一项最基本的认识活动 ,通过适当的聚类 ,事物才便于研究 ,事物的内部规律才可能为人类所掌握。但是 ,由于人们不总是能对客观世界进行精确的描述 ,很多信息和数据都是不确定的、模糊的。为了处理模糊数据 ,把模糊性引入数据库系统中 ,从而形成了模糊关系数据库。本文对模糊关系数据库下的基于距离函数的聚类算法进行了研究 ,并通过例子来说明如何建立和应用这种数据挖掘模型     

产学合作网络中企业关系势能与自主创新绩效——基于地理边界拓展的调节作用

本文采用中国有机化学行业的产学合作专利数据,进行专利地图分析,并以参与产学合作的企业的自主创新绩效为因变量,构建非平衡面板数据下的负二项回归模型,研究产学合作网络中,企业的关系势能对企业自主创新绩效的影响,并考察合作网络的地理边界拓展对二者关系的调节作用。分析结果发现我国有机化学行业的产学合作近几年增速放缓,且已呈现出地理边界拓展的形态,回归结果支持了部分假设:企业的直接关系规模和间接关系强度与企业自主创新绩效正相关,合作网络的地理边界拓展正向调节间接关系规模、间接关系强度与企业自主创新绩效的关系。     

风险影响下的改进灰色关键链进度管理研究

关键链进度管理将资源限制与工序路径放在同等重要的地位,并能有效解决人员惰性问题,确保项目按时完成。在综合考虑风险因素对项目的影响下,优化指标系统,并提出用改进灰色关联分析法来进行关键链管理。此方法既可以在最大程度上消除项目不确定性,又能有效缩减项目工期,能为项目管理者提供对策意见,具有一定的现实意义。     

伙伴选择、伙伴控制与供应商网络治理

针对企业的供应商网络治理行为,探讨了供应商伙伴选择策略、伙伴控制机制及其交互作用对供应商投机的影响。在中国制造行业189家公司调查问卷的基础上进行了实证研究,结果表明社会选择/关系控制相对于公共选择/契约控制更容易降低供应商投机;社会选择和关系控制以及公共选择和契约控制的共同使用促进了供应商投机,公共选择和关系控制的共同使用降低了供应商投机。