基于CPLD的0.01s计时器设计

本设计提出了一种基于CPLD的0.01S计时器的设计方案。应用高速集成电路以硬件描述语言VHDL语言描述,采用Altera公司的可编程逻辑器件(CPLD)EPM7064SL84实现的现代智能计时仪表,为广大用户提供了方便。系统具有可靠性高,便于功能扩展,成本低,易普及等优点。     

Modeling children’s school travel mode and parental escort decisions

Understanding of the activity-travel patterns of children is becoming increasingly important to various policy makers. Further, there is also a growing recognition that intra-household interactions need to be explicitly accommodated in travel models for realistic forecasts and policy evaluation. In the light of these issues, this paper contributes towards an overall understanding of the school-travel behavior of children and the related interdependencies among the travel patterns of parents and children. An econometric model is formulated to simultaneously determine the choice of mode and the escorting person for children’s travel to and from school. The 2000 San Francisco Bay Area Travel Survey (BATS) data are used in the model estimation process. Empirical results indicate that the characteristics of child like age, gender, and ethnicity, and employment and work flexibility characteristics of the parents have strong impacts on the mode choice decisions. In addition, the impacts of some of these attributes on the choice of mode to school are different from the corresponding impacts on the choice of mode from school. The distance between home and school is found to strongly and negatively impact the choice of walking to and from school, with the impact being stronger for walking to school. Several land-use and built-environment variables were explored, but were found not to be statistically significant predictors.

试论武术中的艺术美

武术是中国运动项目的国粹,而以动作繁杂、姿态优美的套路,无论在技击还是表演等方面,无不含有艺术性,其中所包含的美更是给人以赏心悦目的理智情感,愉悦身心。本文利用文献资料法、逻辑分析法等方法从艺术美的基本特征出发,结合武术套路运动,通过对人体的动作性、动作的节奏性、体姿的意境性三个方面进行分析,以显示武术套路中艺术美的基本特征,让人以美的角度去欣赏武术套路,从而陶冶情操。     

基于 M/G/1模型的停车场出口排队延误

通过对大型停车场高峰时段出口车辆行驶特性的调查研究,选取了车辆排队的出口车头时距以及出口服务时间两个指标。基于两个指标实测特性和 M/G/1排队模型的分析,计算了停车场出口理论平均排队时间。通过实测车辆平均排队时间,对理论模型计算的平均排队时间进行了修正。实例分析表明：排队时间修正模型能够准确地估计排队时间。提出了基于驾驶员容忍度的排队延误分级标准。     

《2006航运业薪酬福利水平报告》解读

对某舰的单臂尾轴架,采用军标规范中的经验公式对其横向一阶的频率进行了计算;采用有限元数值计算方法,用三维的体单元建立了单臂尾轴架的有限元模型,计算了其前十阶频率和振型;进行了现场的振动特性实验,测得了某舰单臂尾轴架的横向一阶和纵向一阶频率和振型。对所得到的三种结果进行比较研究表明:经验公式计算所得的结果同实验结果相差较大,有限元计算所得的结果同实验结果相差较小;对用于尾轴架振动计算的经验公式应进行进一步的研究;在尾轴架设计时可以采用有限元方法进行振动计算预报。     

论“中华人民共和国引航法”立法的必要性

作为一个拥有诸多港口的海运大国,如何从法律的角度规范引航活动,约束引航员的工作、服务和行为,保障引航员的权益,是我国的一项空白。本文从引航员的角度阐述了“中华人民共和国引航法”立法的必要性。     

如何把握和处理安检中碰到的几个问题

船舶安检是一项专业性很强的工作,如何准确把握和处理船舶缺陷,是安检员的一大难点。例举实际工作中出现的老旧船舶,应急发电机及处所,通风筒、空气管、门槛高度,船舶吨位丈量等问题,如何把握和处理进行了分析和探时,以便促进安检水平的提高。     

舰船惯导航行数据的重构及混沌特性分析

针对现有舰船航行数据处理研究中,对数据内在属性及不同数据间相关性研究不够深入的问题,应用不同方法对舰船惯导航行数据进行了相空间重构及比较分析。分析结果表明,C-C方法对船舶惯导航行数据的重构效果较好。在此基础上,进行了惯导数据的混沌特性定性分析,并计算了惯导数据的最大Lyapunov指数,对舰船惯导数据进行了混沌动力学特性研究。分析结果证实了舰船航行数据具有较为典型的混沌特性,为进一步研究采用混沌控制等方法对舰船航行中的混沌状态进行控制提供必要的数据基础和比较依据。     

基于主成分分析的舰船装备维修费组合预测

针对基于回归的组合预测模型,由于舰船装备维修费预测时可利用的样本小、可用的单项预测方法多,容易导致预测模型的数量比用于组合预测的样本数量多,出现回归系数无法估计的问题。在建立基于回归的舰船装备维修费组合预测模型前,首先对各单项预测方法预测结果进行主成分分析,建立舰船装备维修费实际值在选取主成分上的回归模型,给出基于主成分分析的组合预测模型;然后针对主成分分析中根据主成分的累积贡献率确定主成分数量具有一定的主观性,建议采用AIC确定主成分的数量;最后,采用实例对给出的方法进行分析和验证。结果表明:在舰船装备维修费组合预测中,该方法不仅解决了预测模型多于用来组合预测的样本数量问题,而且还可以解决单项预测方法之间的共线性问题,且其预测性能明显优于常用的组合预测模型。     

Human resources in the mixed ownership reform of Chinese ports: the mediating effects of organizational commitment

In the process of the change to mixed ownership of Chinese ports, the allocation of human resources has become increasingly important because of the workforce’s growing concerns regarding losses of benefits. The mediating effect of organizational commitment in the relationship between person-organization fit and organizational citizenship behavior (OCB) can provide a significant reference for port managers and regulators, i.e., the government, regarding the framework of human resource systems. The data examined in this study were collected from three Chinese ports (Qingdao Port, Yantai Port and Rizhao Port) that are in the process of changing to mixed ownership. Structural equation modeling was applied to test the hypotheses. The results show that it is extremely difficult for groups with vested interests in Chinese ports to achieve consistency fit in the short term and to accept potential losses. Moreover, it is imperative to adopt a scientific and efficient person-organization fit mechanism and personnel system to achieve a higher level of fit.