SEQUENTIAL,BOTTOM‐UP VARIABLE SELECTION FOR HIGH‐DIMENSIONAL CLASSIFICATION

Most methods for variable selection work from the top down and steadily remove features until only a small number remain. They often rely on a predictive model, and there are usually significant disconnections in the sequence of methodologies that leads from the training samples to the choice of the predictor, then to variable selection, then to choice of a classifier, and finally to classification of a new data vector. In this paper we suggest a bottom‐up approach that brings the choices of variable selector and classifier closer together, by basing the variable selector directly on the classifier, removing the need to involve predictive methods in the classification decision, and enabling the direct and transparent comparison of different classifiers in a given problem. Specifically, we suggest ‘wrapper methods’, determined by classifier type, for choosing variables that minimize the classification error rate. This approach is particularly useful for exploring relationships among the variables that are chosen for the classifier. It reveals which variables have a high degree of leverage for correct classification using different classifiers; it shows which variables operate in relative isolation, and which are important mainly in conjunction with others; it permits quantification of the authority with which variables are selected; and it generally leads to a reduced number of variables for classification, in comparison with alternative approaches based on prediction.     

男女两性对现代启蒙认识的差异——由文本对照引起的思考

本文以共时和历时为轴,以现代启蒙为核心,通过对六部作品的具体分析,发现不同性别的文本中,男女两性对自我和对异性的认识是呈悖反方向发展的两条线.结合文本小语境和社会文化心理的大语境进行深入分析,看到现代人真正实现启蒙目标的艰难.而对于女性来说,除了外在因素的阻挠,更有长期的社会整体文化心理所造成的自我心理暗示.由此,女性在拆解男性乌托邦神话的行为,是伴随着浓重的感伤意绪的.启蒙目标始终未完成,根本原因就在于男性不肯放弃其在社会和两性模式中的绝对优势,这就导致了相当多的男性的启蒙者的深层心理和实质行为的反启蒙性质,或者说伪启蒙性.     

论行动研究方法在反腐败领域的运用

行动研究作为一种扎根于真实情境的研究方法,其在反腐败领域的运用,具有独特的价值。既可以解决反腐败一线工作中的问题,提高反腐败工作的质量及一线工作者的业务素质,促进其职业发展;又可以在强化反腐败一线工作者的职业意识、增强其职业成就感的同时,推进反腐败研究范式的变革,推动反腐败理论的发展。在反腐败领域引入行动研究方法的关键节点主要包括研究的出发点、研究的实施者、研究的全过程以及研究成果的运用等。而将反腐败领域引入行动研究方法应注意的事项主要有三,即尽可能通过多种途径发现反腐败实践中存在的问题,尽可能采取多种方式开展合作研究,尽可能推进多维度的行为反思等。     

Fast Covariance Estimation for Innovations Computed from a Spatial Gibbs Point Process

In this paper, we derive an exact formula for the covariance of two innovations computed from a spatial Gibbs point process and suggest a fast method for estimating this covariance. We show how this methodology can be used to estimate the asymptotic covariance matrix of the maximum pseudo‐likelihood estimator of the parameters of a spatial Gibbs point process model. This allows us to construct asymptotic confidence intervals for the parameters. We illustrate the efficiency of our procedure in a simulation study for several classical parametric models. The procedure is implemented in the statistical software R , and it is included in spatstat , which is an R package for analyzing spatial point patterns.     

Computer-Generated Neighbor Designs

Neighbor designs are useful to remove the neighbor effects. In this article, an algorithm is developed and is coded in Visual C + +to generate the initial block for possible first, second,…, and all order neighbor designs. To get the required design, a block (0, 1, 2,…, k ? 1) is then augmented with (v ? 1) blocks obtained by developing the initial block cyclically mod (v ? 1).     

Convolution of Binomial and Negative Binomial Variables

This paper considers a distribution formed by convolution of binomial and negative binomial variables. The distribution has the flexibility to adapt to the model under, equi, and over dispersion. Some properties of the proposed distribution are discussed, including characterization. Three stochastic processes leading to the distribution are also considered: (1) a three-dimensional random walk; (2) a birth, death, and immigration process; and (3) a thinned stochastic process.     

从地缘政治角度看冷战后中蒙关系

中国的北部邻国蒙古,从地缘政治角度看,其地处亚洲大陆中部,仅有两个邻国,中国、俄罗斯,地缘战略位置极为重要。冷战结束后中蒙两国关系平稳健康发展,双方高层互访频繁,经贸往来规模不断扩大。随着蒙古国政治、经济领域改革的深入和“多支点”外交政策的出台,尤其是“第三邻国”的进人使各国在蒙古境内包括能源等领域的竞争日益激烈,中国北部面临的地缘政治环境发生了复杂微妙的变化。     

The design of experiments for correlated error structures: Layout and robustness

Observations with correlated error structures are sometimes unavoidable. Appropriate designs and analyses are reviewed for such situations. Serious problems can occur if conventional designs and analyses are used when correlated errors and layout are ignored or when the error structure is not known. Robust designs are discussed which guard against these problems.     

面向双层自动分拣系统的包裹分拣优化模型与算法研究

近年来随着电子商务的快速发展,分拣订单呈现批量小、品种多、配送周期短、精度要求高等特征,这对分拣作业提出了更高的要求。为了缩短分拣时间、降低分拣成本、提高分拣效率,物流企业开始逐步使用双层分拣设备。本文采用了"成组分拣"方法以提升托盘利用率,"成组分拣"是指一种将分散的单件包裹按一定的规则组合在一起,成为一个规格化、标准化的大分拣单元进行分拣的方法。根据"成组分拣"的定义,本文研究了一个考虑成组分拣的双层分拣设备目的地指派问题,并设计了一种高效的变邻域禁忌搜索算法,该算法能在较短时间内对该问题进行求解,得到一个满意解。实验结果表明,采用"成组分拣"方法与考虑目的地指派问题可有效提高分拣设备的分拣效率。     

论海事强制救助报酬请求权

海事强制救助属于海难救助的特殊形式,可定义为“海事主管机关,在其管辖水域,为维护公共利益,使用强制力,对遇险船舶或其他财产实施救助的行为”,其法律本质是海事行政强制。根据邻居原则理论,遇险船舶和相邻船舶存在邻居关系,对其负有普遍注意义务。遇险船舶的海难事故不仅对己船具有危险性,对相邻船舶也存在危险,故违反该义务,对相邻船舶产生潜在侵权责任。海事主管机关为维护公共利益实施海事强制救助,是对潜在侵权责任进行救助,存在救助效果,故享有报酬请求权。海事强制救助是对遇险船舶潜在侵权责任的救助,可参考国际油污损害赔偿体系,通过设立区域性海事救助基金,实现海事强制救助报酬请求权。