基于Proteus的80X86外部中断电路的设计与仿真     

王超  符晓玲  李斌 《实验室研究与探索》2020,(3):132-137

针对80x86外部中断发生的随机性而带来的中断过程突发事件比较多等问题,设计了由8086CPU、可屏蔽中断电路、非屏蔽中断电路和显示电路组成的基于Proteus的80X86中断控制电路,在Proteus仿真平台下完成了软、硬件电路的调试,使用激励信号源实现了图表的交互式动态仿真,采用硬件断点和调试弹出窗口方式加快了程序调试的效率。仿真结果表明,使用Proteus分析80X86的外部中断过程,可将复杂、抽象的中断直观地展现出来,有助于学生更好的理解80X86的外部中断过程,提高分析问题和解决问题的能力。  相似文献   

带时间窗车辆路径问题的混合遗传算法     

刘志先 《钦州学院学报》2007,22(3):32-34

针对标准遗传算法在解决带时间窗的车辆路径问题（VRPTW）时存在早熟收敛和易陷入局部极值点的特点,引入遗传算法与禁忌搜索结合的混合算法,同时对杂交算子进行了改进.算法既具有遗传算法的全局性和并行性,又具有禁忌搜索算法的爬山能力.实验表明,改进的混合算法具有计算效率高、收敛速度快等特点,是一种有效的方法.  相似文献   

利用Power Builder数据窗口实现用户对数据库的修改权限     

潘洪军  亓常松 《通化师范学院学报》2001,22(2):51-53

给出了在Power Builder数据窗口中利用Taborder属性和Portect属性以及列对象的属性页实现用户对数据库的操作权限。  相似文献   

Drivers and barriers affecting usage of e-Customs — A global survey with customs administrations using multivariate analysis techniques     

Luca Urciuoli  Juha Hintsa  Juha Ahokas 《Government Information Quarterly》2013

The adoption of e-Customs platforms to simultaneously ensure regulatory compliance and to facilitate trade is a major strategic issue for governments and customs administrations worldwide. It ensures a more cost-efficient usage of resources while preserving a smooth flow of goods across international borders. Hence, customs administrations are challenged to favor the introduction of IT systems that may enhance the ability to improve information sharing with the business sector, as well as with other governmental agencies. This is often not a straightforward process. As many experts point out, e-Government development projects fail commonly due to the lack of thorough understanding of administration requirements as well as barriers for implementation. Hence, the purpose of this study is to understand what factors enable or hinder the exploitation of e-Customs platforms. By means of a Systematic Literature Review (SLR), a theoretical framework is developed to identify drivers and barriers for usage of e-Government/e-Customs platforms. Thereby, a survey instrument was developed and data was collected in occasion of a World Customs Organization (WCO) Annual Council meeting, which was joined by around 400 customs delegates and officers from 178 WCO member administrations. A total of 94 questionnaires have been collected and analyzed, which gives an approximate response rate of 23% (46% considering only the 178 member administrations). The analysis of data has been performed by a combination of multivariate techniques and ANOVA. Results show that factors like cost-savings and ease of use significantly influence the usage of e-Customs platforms. On the contrary, cost-efficiency and usefulness of e-Customs platforms have no significant impacts. From the perspective of barriers preventing adoption, this paper identifies two main factors: 1) technical constraints and costs and 2) quality and trust. Both these factors significantly influence adoption of information sharing, in the context of business-customs communication.  相似文献   

Impact maturity times and citation time windows: The 2-year maximum journal impact factor     

P. Dorta-González  M.I. Dorta-González 《Journal of Informetrics》2013,7(3):593-602

Journal metrics are employed for the assessment of scientific scholar journals from a general bibliometric perspective. In this context, the Thomson Reuters journal impact factors (JIFs) are the citation-based indicators most used. The 2-year journal impact factor (2-JIF) counts citations to one and two year old articles, while the 5-year journal impact factor (5-JIF) counts citations from one to five year old articles. Nevertheless, these indicators are not comparable among fields of science for two reasons: (i) each field has a different impact maturity time, and (ii) because of systematic differences in publication and citation behavior across disciplines. In fact, the 5-JIF firstly appeared in the Journal Citation Reports (JCR) in 2007 with the purpose of making more comparable impacts in fields in which impact matures slowly. However, there is not an optimal fixed impact maturity time valid for all the fields. In some of them two years provides a good performance whereas in others three or more years are necessary. Therefore, there is a problem when comparing a journal from a field in which impact matures slowly with a journal from a field in which impact matures rapidly. In this work, we propose the 2-year maximum journal impact factor (2M-JIF), a new impact indicator that considers the 2-year rolling citation time window of maximum impact instead of the previous 2-year time window. Finally, an empirical application comparing 2-JIF, 5-JIF, and 2M-JIF shows that the maximum rolling target window reduces the between-group variance with respect to the within-group variance in a random sample of about six hundred journals from eight different fields.  相似文献   

区域科技投入产出效率的DEA视窗分析   总被引：10，自引：0，他引：10  

谢友才  张红辉 《研究与发展管理》2007,19(3):85-92

利用浙江省11个地区的1999--2003年科技投入产出数据,应用基于数据包络分析（DEA）的视窗分析方法,测量了浙江省各地区的科技投入产出效率,研究了其效率的趋势和稳定性．研究发现,较发达地区的效率显著高于其他地区,而经济发展迅速的地区其效率也是迅速提高;效率与科技投入相对性指标没有显著的关系,而与科技产出的相对性指标有显著的正相关关系．其蕴含的启示是：经济活跃程度、市场机制完善显著地影响到科技应用效率进而影响到科技投入产出效率;对于不发达地区是促进提高科技成果的生产力转化,而不是加大科技投入．  相似文献   

基于NSGAⅡ的带时间窗生鲜品配送路径优化     

李善俊  陈淮莉 《上海海事大学学报》2020,41(2):58-64

考虑到生鲜品的易腐性、高时效性和对运输环境要求高的特点,为减少生鲜品配送企业的配送成本,提高客户满意度,在车辆载重、时间窗、生鲜品保质期等约束条件下,提出将配送总成本最小化和生鲜品新鲜度最大化的多目标车辆路径优化模型。利用改进的非支配排序遗传算法(non-dominated sorting genetic algorithmⅡ,NSGAⅡ)对模型进行求解。求出满足配送总成本最小和生鲜品新鲜度最大的相对较优解,证明模型的有效性。该模型在大规模配送和客户地理位置分布较为分散的情况下,对生鲜品新鲜度的优化较为明显。  相似文献   

重大体育赛事对城市经济发展的影响--基于中国70个大中城市面板数据分析     

毛丰付  郑芳  朱书琦 《上海体育学院学报》2020,(5):24-36

重大体育赛事的举办在一定程度上能推动承办城市转型发展,但也可能对当地经济产生某种不良影响,这主要源于对重大体育赛事与城市经济发展的内在规律和作用机制认识不够清晰。以2000-2017年22项具有全国影响力的重大体育赛事为基础,利用中国70个大中城市面板数据,采用双重差分法,分析重大体育赛事对城市经济发展的影响。发现:全样本数据下重大体育赛事的举办会促进城市第一产业向第二、第三产业发展;对比国内和国际赛事,重大体育赛事对第三产业的促进作用均显著高于第二产业;以1 085家上市公司数据为样本,采用事件研究法进行分析,发现不同行业利用重大体育赛事的窗口期存在显著差异。  相似文献   

虚拟科技创新团队科研合作效率的实证研究          下载免费PDF全文

张宝生  王晓红  陈浩 《科学学研究》2011,29(7):1056-1063

 虚拟科技创新团队的科研合作效率是团队管理者普遍关注的问题。运用DEA模型的视窗分析和相关分析,将经费设施、人力资本、制度保障作为投入指标,合作深度、合作广度、合作提高为产出指标,以16个虚拟科技创新团队2004-2009年的调研数据为样本,对团队科研合作效率变化趋势、稳定性和影响因素进行研究。结果表明,随着合作时间的延长,团队科研合作的总体效率（TE）、纯技术效率（PE）具有波动上升的趋势,规模效率（SE）不存在明显的规律性,各团队效率稳定性存在较大差异;要提高SE应该从提高经费设施的相对产出入手,要提高PE应该从提高人力资本的相对产出入手,制度保障对TE、PE和SE都有影响,团队应在完善制度的基础上进行“有序扩张”。  相似文献   

对电大教育30年发展政策的反思——基于多源流分析理论的视角     

张珠龙 《江苏广播电视大学学报》2009,20(1)

多源流分析理论是用来解释政策如何制定的一种方法.审视30年的发展历程,正是问题、政策与政治三大源流的耦合促成了电大教育的诞生、发展与变革.建设社会主义新农村的重大历史任务和国家发展远程教育的战略规划,为电大的发展打开了"政策之窗",新时期电大教育应以服务农村建设为重点,实现发展定位的战略调整,以推进实体办学实现发展模式的理念转变,以完善公共教育平台推进学习型社会建设,推动远程教育的创新发展.  相似文献