中国农村公共服务评价体系研究

农村公共服务水平低下和不平衡是导致城乡差距日益扩大的重要影响因素之一。本文试图构建农村公共服务发展状况评价指标体系,并基于2006年的数据进行实证研究,给出了研究结果的进一步分析评价。     

ML and Bayes estimation in a two-phase tandem queue with a second optional service and random feedback

ABSTRACT

In this article, we consider a two-phase tandem queueing model with a second optional service and random feedback. The first phase of service is essential for all customers and after the completion of the first phase of service, any customer receives the second phase of service with probability α, feedback to the tail of the first queue with probability β if the service is not successful and leaves the system with probability 1 ? α ? β. In this model, our main purpose is to estimate the parameters of the model, traffic intensity, and mean system size, in the steady state, via maximum likelihood and Bayesian methods. Furthermore, we find asymptotic confidence intervals for mean system size. Finally, by a simulation study, we compute the confidence levels and mean length for asymptotic confidence intervals of mean system size with a nominal level 0.95.     

Kernel estimation of a distribution function

A distribution function is estimated by a kernel method with

a poinrwise mean squared error criterion at a point x. Relation- ships between the mean squared error, the point x, the sample size and the required kernel smoothing parazeter are investigated for several distributions treated by Azzaiini (1981). In particular it is noted that at a centre of symmetry or near a mode of the distribution the kernei method breaks down. Point- wise estimation of a distribution function is motivated as a more useful technique than a reference range for preliminary medical diagnosis.     

SOJOURN TIMES IN NON-HOMOGENEOUS QBD PROCESSES WITH PROCESSOR SHARING

We study sojourn times of customers in a processor sharing queue with a service rate that varies over time, depending on the number of customers and on the state of a random environment. An explicit expression is derived for the Laplace–Stieltjes transform of the sojourn time conditional on the state upon arrival and the amount of work brought into the system. Particular attention is paid to the conditional mean sojourn time of a customer as a function of his required amount of work, and we establish the existence of an asymptote as the amount of work tends to infinity. The method of random time change is then extended to include the possibility of a varying service rate. By means of this method, we explain the well-established proportionality between the conditional mean sojourn time and required amount of work in processor sharing queues without random environment. Based on numerical experiments, we propose an approximation for the conditional mean sojourn time. Although first presented for exponentially distributed service requirements, the analysis is shown to extend to phase-type services. The service discipline of discriminatory processor sharing is also shown to fall within the framework.     

一种适用于NGSO MSS网络的混合信道分配方案

针对ＮＧＳＯＭＳＳ网络的动态特性,提出了一种适用于该网络的混合信道分配方案。在该方案中,固定信道采用非均匀压缩图案分配算法分配给各小区作为标称信道专用,并定期根据变化了的业务条件进行重新分配,动态信道的指派采用最先可行ＦＡ（ＦｉｒｓｔＡｖａｉｌａｂｌｅ）算法。仿真结果表明,在较宽的负载范围内,运用该方案比固定信道分配方案均有更好的性能,并能有效地降低切换呼叫和信道更新期间的呼损率,从而显著提高网络的业务承载量。     

论充分发挥教学秘书的服务与管理职能

积极努力、主动热情、严谨求实、理解与宽容、牺牲与奉献,是高校教学秘书的基本素质与要求;变被动服务为主动服务,是提高服务质量的重要标志;实施科学管理,是教学秘书的历史使命;学习教育管理理论,是教学秘书提高服务质量的重要保证。     

医学科研项目的风险管理对策研究

医学科研项目存在着投入资金高、研发周期长、失败率高以及实验环节多等特点,其研究结果往往具有不确定性和不可预期性,因此,有必要从项目的风险角度来进行管理,以规避项目过程的风险.文章旨在对医学科研项目风险成因分析的基础上,较为系统地提出项目风险管理对策.根据项目实施流程,设计医学科研项目风险管理流程,具体分析了立项、实施、结题的不同阶段其风险管理的特点,以期为我国逐步形成医学科研项目风险管理的科学方法提供有益的理论参考.     

智能网联汽车体系结构与关键技术

智能网联汽车（Intelligent connected vehicles,ICV）是无人驾驶技术的核心载体,产业链长,市场巨大,吸引了国内外众多汽车厂商和信息企业都纷纷投向ICV的研发与测试,部分ICV车型已进入量产阶段,新的概念车型也陆续提出。针对新型ICV的发展现状与关键技术,从ICV智能化和网联化两个维度对ICV中涉及到的相关技术进行分析,进一步从信息处理的感知层、决策层、控制层3个层次构建了ICV发展过程中的关键技术体系结构。研究表明,车辆环境感知和通信技术技术涵盖自车状态和外部环境,短程通信技术（DSRC）、机器视觉和激光雷达技术是实现车辆环境信息采集功能完善的关键;车路协同系统涉及车—车通信、车—路通信、车—云通信,协同智能交通系统、云平台和大数据技术是车路协同技术的关键;驾驶辅助技术包括自适应巡航控制系统、车道偏离/避免系统、碰撞预警/避免系统等8个构成,这是辅助驾驶、部分自动驾驶和有条件的自动驾驶3个智能化阶段中的关键;具有自主学习、自我决策的人工智能技术和信息安全技术也是智能网联汽车的关键技术,在此基础上,还应该实现多种技术间的相互支撑与融合,克服关键技术协同障碍,才能实现ICV的市场推广与普及应用。     

略论本科医学教育创新型人才培养模式的构建

随着《本科医学教育标准》的发布和医学创新型人才建设目标的提出,高等医学教育必须转变人才培养模式,培养创新人才。参照本科医学教育标准对医学人才培养的新要求,讨论构建医学创新人才培养模式这一重要问题,为高等医学院校开展医学创新人才培养提供参考依据。     

健全我国政府经济职能体系的若干思考

完善我国政府经济职能体系不仅与经济体制改革密切相关,也为和谐社会的构建提供重要保障。我国政府经济职能有个演变的过程,目前的体系在经济调节、市场监管、社会管理、公共服务等方面存在问题,从这四个方面初步探讨健全我国政府经济职能体系的基本思路。