Estimating ordered parameters by linear programming

There are many models that require the estimation of a set of ordered parameters. For example, multivariate analysis of variance often is formulated as testing for the equality of the parameters versus an ordered alternative. This problem, referred to as isotonic inference, constrained inference, or isotonic regression, has led to the development of general solutions, not often easy to apply in special models. In this expository paper, we study the special case of a separable convex quadratic programming problem for which the optimality conditions lead to a readily solved linear complementarity problem in the Lagrange multipliers, and subsequently to an equivalent linear programming problem, whose solution can be used to recover the solution of the original isotonic problem. The method can be applied to estimating ordered correlations, ordered binomial probabilities, ordered Poisson parameters, ordered exponential scale parameters, or ordered risk differences.     

骨干网IPv4/IPv6协议转换网关设计

阐述了骨干网上部署IPv6网络中,解决既要满足IPv4和IPv6网络互联互通的需要,同时减少IPv4地址消耗的问题。比较了几种比较成熟的IPv4/IPv6转换技术,提出了在IPv4/IPv6网络边界的协议转换网关上使用改进的NAPT-PT协议转换方案,指出了在城域网环境下采用NAPT-PT方案的不足和实现过程中的解决办法。     

Bayesian analysis of outlier problems using divergence measures

A Bayesian approach is presented for detecting influential observations using general divergence measures on the posterior distributions. A sampling-based approach using a Gibbs or Metropolis-within-Gibbs method is used to compute the posterior divergence measures. Four specific measures are proposed, which convey the effects of a single observation or covariate on the posterior. The technique is applied to a generalized linear model with binary response data, an overdispersed model and a nonlinear model. An asymptotic approximation using Laplace method to obtain the posterior divergence is also briefly discussed.     

四级阅读测试题型与对策

分析了最近 1 3年 2 2套四级考试阅读理解部分全部问题 ,并以文字、图表数据说明五类题型的比例及测试特点。同时结合《大学英语教学大纲》,分析了师生在平常教与学的过程中可采取的对策。     

视频在IP网络中传输的质量研究

利用MEPEG-4视频TRACE作为输入源,通过分析MPEG-4视频的帧特性,提出了一种针对视频质量的网络传输服务质量保证机制;搭建了视频传输的仿真系统,分析了视频在网络传输中的特性,利用PSNR作为视频质量的衡量标准,在有服务质量保证和无服务质量保证机制的两种网络环境下做了仿真并比较结果,证明了提出的方法能有效提高视频质量．     

Two point priors and Γ-minimax estimating in families of uniform distributions

It is shown that when a parameter lying in a sufficiently small interval is to be estimated in a family of uniform distributions, a two point prior is least favourable under squared error loss. The unique Bayes estimator with respect to this prior is minimax. The Γ-minimax estimator is derived for sets Γ of priors consisting of all priors that give fixed probabilities to two specified subintervals of the parameter space if a two point prior is least favourable in Γ.     

"五四"新文学运动前二十年文学理论批评文体的演进

文学理论批评文体是文学理论批评形式特征的总和。中国古代文论文体有其鲜明的特色 ,但也有明显的局限性。至近代 ,尤其是五四新文学运动前二十年 ,文学理论批评文体发生了巨大的变化。其变革的方向 ,总的来说是向现代文学理论批评文体演进。具体来看 ,体式向多样化、大容量发展 ;篇章结构趋向完整精致 ;语言文字趋向通俗浅显 ;对西方文体从模仿趋向融会贯通 ;文体的外在形式向规范化发展     

The Roles Played by the Staff and Workers’ Representative Congress in the Formation of Work Regulations

Article 4 of the Labor Contract Law lays down the right of the Staff and Workers’ Representative Congress (SWRC) to deliberate on the formulation of (intra-enterprise) work regulations, but this has become a “soft” law in judicial practice. The judicial criteria for judging the validity of work regulations are in essence determined by the judge’s judgment on their reasonableness. As an important embodiment of Chinese politics, economics and culture, the transformation of the SWRC that accompanied the market economy has not negated its value as an indigenous traditional resource. The SWRC does not just enjoy deliberative rights in the formation of regulations, as clearly specified in constitutional law, but also has rights under the law in local legislation and practice. Hence the system of work regulations is neither a unilateral decision on the part of management nor a contract, but rather an autonomous norm developed through the SWRC mechanism. Given the mandatory nature of Article 4 of the Labor Contract Law, regulations will only be valid after they have gone through a democratic process. The further development of the theory of normative system formation should endow the SWRC with greater rights and integrate it smoothly with the collective contract system to standardize collective labor relations.     

Reliability analysis of systems with components having two dependent subcomponents

In this article, a system that consists of n independent components each having two dependent subcomponents (A_i, B_i), i = 1, …, n is considered. The system is assumed to compose of components that have two correlated subcomponents (A_i, B_i), and functions iff both systems of subcomponents A₁, A₂, …, A_n and B₁, B₂, …, B_n work under certain structural rules. The expressions for reliability and mean time to failure of such systems are obtained. A sufficient condition to compare two systems of bivariate components in terms of stochastic ordering is also presented.     

Why Frequency is Not Well Defined for Engineering Systems with Nonexponential Failure Times

Dr. Yellman proposes to define frequency as “a time‐rate of events of a specified type over a particular time interval.” We review why no definition of frequency, including this one, can satisfy both of two conditions: (1) the definition should agree with the ordinary meaning of frequency, such as that less frequent events are less likely to occur than more frequent events, over any particular time interval for which the frequencies of both are defined; and (2) the definition should be applicable not only to exponentially distributed times between (or until) events, but also to some nonexponential (e.g., uniformly distributed) times. We make the simple point that no definition can satisfy (1) and (2) by showing that any definition that determines which of any two uniformly distributed times has the higher “frequency” (or that determines that they have the same “frequency,” if neither is higher) must assign a higher frequency number to the distribution with the lower probability of occurrence over some time intervals. Dr. Yellman's proposed phrase, “time‐rate of events … over a particular time interval” is profoundly ambiguous in such cases, as the instantaneous failure rates vary over an infinitely wide range (e.g., from one to infinity), making it unclear which value is denoted by the phrase “time‐rate of events.”