A permutation test approach to the choice of size k for the nearest neighbors classifier

The k nearest neighbors (k-NN) classifier is one of the most popular methods for statistical pattern recognition and machine learning. In practice, the size k, the number of neighbors used for classification, is usually arbitrarily set to one or some other small numbers, or based on the cross-validation procedure. In this study, we propose a novel alternative approach to decide the size k. Based on a k-NN-based multivariate multi-sample test, we assign each k a permutation test based Z-score. The number of NN is set to the k with the highest Z-score. This approach is computationally efficient since we have derived the formulas for the mean and variance of the test statistic under permutation distribution for multiple sample groups. Several simulation and real-world data sets are analyzed to investigate the performance of our approach. The usefulness of our approach is demonstrated through the evaluation of prediction accuracies using Z-score as a criterion to select the size k. We also compare our approach to the widely used cross-validation approaches. The results show that the size k selected by our approach yields high prediction accuracies when informative features are used for classification, whereas the cross-validation approach may fail in some cases.     

中国钢铁产业关联效应及国际比较分析

 本文应用投入产出表计算了中国钢铁产业关联效应及其国际比较,并分析了各项最终需求对钢铁产业生产的诱发作用。研究结果显示,我国钢铁产业对黑色金属矿采选业后向直接关联效应明显高于其它七国;包括中国、巴西等在内的发展中国家和韩国等新兴工业化国家的钢铁产业对建筑业的前向关联效应远远高于发达国家;我国钢铁产业对国民经济的拉动效应低于其它七个产钢大国,且其对我国国民经济的推动作用呈降低趋势;投资需求仍然是诱发我国钢铁产业生产的最重要因素,明显高于日本、美国等钢铁强国,也高于印度和巴西等钢产量很大的发展中国家;出口需求对钢铁产业生产的拉动效应明显低于钢产量远小于中国的日本等OECD国家。     

Gambling and problem/pathological gambling among ex-offenders in Hong Kong

This paper considers the issue of ex-offenders who can be identified as having an addiction to gambling; one that has been long-neglected in Hong Kong. It reports on a study in which 378 ex-offenders were asked to assess their gambling involvement. The paper identifies the importance of social workers developing a better understanding of this issue in their work with ex-offenders and the findings suggest there is further scope for research and analysis about the extent of this problem and its management.     

Sharing inventory risk in supply chain: The implication of financial constraint

A supply chain may operate under either preorder mode, consignment mode or the combination of these two modes. Under preorder, the retailer procures before the sale and takes full inventory risk during the sale, while under consignment, the retailer sells the product for the supplier with the supplier taking the inventory risk. The combination mode shares the risk in the supply chain. The existing research has examined the supply chain modes from various operational aspects. However, the impact of financial constraint is neglected. This paper examines the impact of financial constraint and investigates the supply chain efficiency under each mode. Based on a Stackelberg game with the supplier being the leader, we show that without financial constraint the supplier always prefers the consignment mode, taking full inventory risk. Whereas, in the presence of financial constraint, the supplier will sell part of the inventory to the retailer through preorder, which shares the inventory risk in the supply chain. We show that with financial constraint, the combination mode is the most efficient mode even if the retailer earns zero internal capital.     

论余靖哲学及其思想特质

余靖从世界的物质性出发,分析了“道”与“权”的辩证关系,强调把握“度”的意义;从现象与本质关系中,揭示出透过现象把握事物本质的认识过程,批判和驳斥了仁宗时期的“舍利”、“祥瑞”等迷信现象,强调了“在人不在神”的观点,从而肯定了人的实践主体性,并从实际出发阐述社会变革思想。余靖的思想基本上是唯物主义的,并且有一些辩证因素。余靖是一个朴素唯物主义者。     

铲除恐怖主义根源,建设民族和谐社会

少数分裂分子是靠歪曲历史和现实,宣扬极端宗教狂热来制造事端的。政教合一的政权必然导致宗教压迫和精神奴役,宗教对抗是人民之间相互摧残的悲剧。恐怖主义是极端宗教的产物;违背良善谋划宗教对抗是对时代的反动。民族地区稳定和谐的基础是信仰自由和宗教和谐,必须划清群体事件和犯罪案件的界限。     

李提摩太对大乘佛教的回应:从后殖民对东方学的批判着眼

虽然李提摩太对大乘佛教的诠释受到他自己的基督教信仰影响,甚至是受到传教使命驱使,但他的进路迥然不同于具殖民色彩的东方学,并且在动机和态度上颇为符合大乘佛教的精神。他在翻译佛典的过程中,没有强调东西方宗教观念之间的差异,反而突出它们的相通之处,希望以此作为基督教与佛教建立合作或友谊的共同基础,而不是使佛教徒皈依基督教。基于他的著述,可以发现他实际上实践了一种后殖民的批评,与殖民势力是对抗的。他的终极目的是全人类的解放,但进路与心态截然不同于那种解救东方人的殖民主义式思维,因为他从来不曾假设西方文明更为高等。就萨义德对东方学或东方主义的批判来说,李提摩太对大乘佛教的响应可以说是一个例外,甚至是反例。     

品质和引擎——北京十二五时期商业发展的主题词

十二五时期是北京建设中国特色世界城市,全面实施＂人文北京、科技北京、绿色北京＂发展战略,深入推进经济发展方式加快转变的关键时期。世界经济格局的变化,我国经济发展阶段的转变,北京社会经济发展水平的全面提升,对科学规划首都的发展提出了更高的要求。针对北京商业发展现状,十二五时期是北京商业发展应当围绕＂品质＂与＂引擎＂这两个主题词规划与思考。     

The effect of alliance experience and intellectual capital on the value creation of international strategic alliances

This paper investigates the effects of intellectual capital (IC), alliance experience and their interaction on the value creation of international strategic alliances (ISAs). Based on a sample of ISAs formed by US firms, we find that firms with a higher level of IC receive greater announcement-period wealth gains. In addition, the empirical results suggest experience positively enhances the wealth effect of ISAs. Finally, we find a significant positive interaction effect between experience and IC on the wealth creation of ISAs. The results demonstrate the importance of considering the joint effects of IC and experience in assessing the value creation of ISAs.     

Firm-level correlates of emergent green supply chain management practices in the Chinese context

Greening the supply chain is increasingly a concern for many business enterprises and a challenge for logistics management in the 21st century. Of particular concern is how to arouse organizational environmental awareness and put environmental activities into practice in the logistics activities of their supply chains. This paper investigates the correlation of two major factors, organizational learning and management support, with the extent of adoption of green supply chain management (GSCM) practices in Chinese manufacturing firms, where their inbound and outbound logistics activities are potential polluters to the environment. Organizational and operational learning was derived from the firm's experience with programs such as total quality management and environmental management systems. Management support included support for GSCM ideas and practices from top and middle-level management and cooperation across organizational functions. We find significant positive relationships between organizational learning mechanisms, organizational support and the adoption of GSCM practices, after controlling for a number of other influences including regulations, marketing, supplier, cost pressures, industry levels of the relevant practice and organizational size. Implications of our findings on logistics management are discussed.