Optimal congestion control algorithm for ad hoc networks： Penalty function-based approach

INTRODUCTION Congestion control is a critical issue for ensuring the efficient and fair allocation of network resource among communication flows. In wireline networks, TCP has resolved this issue of concern. However, it was reported that TCP performance in a multihop ad hoc environment degrades severely (Xu and Wu, 2006). Thus, some optimization-based congestion control schemes have been proposed to improve TCP performance in ad hoc networks (Chiang, 2005; Chen et al., 2005; Lee et a…     

济慈、雪莱诗的"宇宙精神"浅析--析《夜莺颂》、《灿烂的星》和《阿多尼》

面对生与死,古往今来,许多文学作品、许多才子名人都对其进行了探索.本文通过对济慈、雪莱这两位英年早逝的英国浪漫主义诗人的优美诗篇<夜莺颂>、<灿烂的星>、<阿多尼>的分析,探讨了他们认为精神永恒的"宇宙精神"生死观.     

Dynamics of visual feedback in a laboratory simulation of a penalty kick

Sport scientists have devoted relatively little attention to soccer penalty kicks, despite their decisive role in important competitions such as the World Cup. Two possible kicker strategies have been described: ignoring the goalkeeper action (open loop) or trying to react to the goalkeeper action (closed loop). We used a paradigm simulating a penalty kick in the laboratory to investigate the dynamics of the closed-loop strategy in these controlled conditions. The probability of correctly responding to the simulated goalkeeper motion as a function of time available followed a logistic curve. Kickers on average reached perfect performance only if the goalkeeper committed him or herself to one side about 400 ms before ball contact and showed chance performance if the goalkeeper motion occurred less than 150 ms before ball contact. Interestingly, coincidence judgement?-?another aspect of the laboratory responses?-?appeared to be affected for a much longer time (>500 ms) than was needed to correctly determine laterality. The present study is meant as groundwork for experiments in more ecological conditions applicable to kickers and goalkeepers.     

A field simulation study of the effectiveness of penalty kick strategies in soccer: Late alterations of kick direction increase errors and reduce accuracy

Abstract

This field experiment investigated the relative merits of approaching the penalty kick with either a keeper-independent or keeper-dependent strategy. In the keeper-independent strategy, the shooter selects a target location in advance and disregards the goalkeeper's actions during the run-up. In the keeper-dependent strategy, the shooter makes a decision resting on the anticipation of the goalkeeper's movements during the run-up. Ten intermediate-level soccer players shot at one of two visually specified targets to the right and left side of the goal. In the keeper-independent strategy condition, participants were told that the visually specified target would not change. In the keeper-dependent strategy condition, participants were told that in half of the trials the visually specified target would change side at different times before ball contact, indicating that the direction of the kick needed to be altered. The results showed that penalty-taking performance was apt to be less than perfect in the keeper-dependent strategy condition. A decrease in the time available to alter kick direction resulted in a higher risk of not only an incorrect but also inaccurate shot placement. It is concluded that anticipating the goalkeeper's movements may degrade penalty kick performance, mainly due to insufficient time to modify the kicking action.     

拘役刑废除之商讨

拘役刑是在较短时间内剥夺或限制罪犯人身自由的刑罚。根据刑罚报应理论和刑罚功利理论，适用拘役刑难以使受刑人罪与刑相适应，刑罚的教育改造功能、预防犯罪功能和威慑功能未能有效地发挥，在现实中运用也不够广泛，因此，笔者建议废除拘役刑。替代拘役刑的手段包括广泛适用罚金刑，拘役刑易科罚金、缓刑、管制刑，以及改用半自由刑性质的刑罚等。     

普通高校足球运动员竞赛中损伤原因的探讨

通过对福州高校足球队员在参加各种规模的正规足球比赛中损伤情况进行调查、统计、分析和探讨,归纳出损伤的原因及常出现的区域和部位,以便今后教学训练、比赛中引起各队教练的重视和借鉴。     

《生死场》：女性生命世界里悖论的悲哀

在萧红的成名作《生死场》中,充斥着作者对女人的理解和怜悯。在这个悲剧的＂生死场＂上,作者为我们描述了一些女人在这个男权世界里卑微而无助的生活和死亡。从女性学角度理解和阐释小说中众多的女性形象,我们感受到了女性作为他者的悲剧。     

投资收益总额为poisson过程的风险模型

通过讨论投资收益总额为复合poisson过程的风险模型,得到了其Gerber-Shiu折现罚金函数满足的积分-微分方程,并且在索赔额和收益额的分布为指数分布的情况下得到了Gerber-Shiu折现罚金函数及其相关精算量满足的微分方程。     

彝族创世史诗《冷斋调》的死亡文化解析

流传于云南直苴彝族地区的创世史诗《冷斋调》,是在丧葬祭祀场合使用的祭词,也是“梅葛”中最古老的部分。其中表现的原始宗教思想,尤其是对神灵的崇拜及相应的禁忌规定,构成了直苴彝族死亡文化的一个有机组成部分。尽管在现实生活中史诗的影响力不断下降。但它的传承场丧葬仪式却一直得到较完整的保留,史诗中的神灵禁忌思想也继续影响着祭祀仪式,保证了仪式的神圣和完整。     

The Man in the War--a character analysis of Jeremiah Donovan in ＂Guests of the Nation＂

Jeremiah Donovan is one of the five main characters in Frank O'Connor's "Guests of the Nation". The story narrates how war distorts human mind and the struggles of people living in the war. This article analyses Donovan's behaviours in different settings and discusses his feelings and motivations may beneath along with author's intention of writing this story.