免费WiFi随身带

正对于经常出差的朋友来说,配有无线WiFi的酒店还是甚少,而身边的手机、平板电脑等移动设备却都需要WiFi网络的支持,那么用一台随身携带的笔记本电脑组建小型WiFi无线网络就显得很是重要了。现代生活最离不开的是什么?有人说是"手机",有人说是"电脑"……没错,都对,但是我们始终离不开的却是"网络"——互联网。网络已经成为了我们生活中,甚至是生命中的一部分,现代社会突然没有了网络,估计没有人知道,将会发生什么,世界末日?     

具有区间参数的VRP及其改进的C-W节约算法

在传统的车辆路径问题的基础上,针对配送中心到客户以及客户到客户之间的费用为区间参数时的车辆路径问题,建立了相应的数学模型.用可能度的区间数排序方法对费用区间参数进行排序并应用到C-W(clark-wright)节约算法中,提出了改进的C-W节约算法.通过算例验证了该算法的有效性和可行性.     

吴哥的朝阳与微笑

吴哥是我向往已久的旅行目的地,因此,我为这次春节柬埔寨之行做了大量功课。各种游记、攻略下载了一堆,旅行指南也买了很多本。在春节放假前抓紧时间一通恶补,除各种难以分辨的寺庙名称之外,日出和微笑成为我对吴哥的最深印象。     

我的随身电脑——华硕Eee PC 1000HE上网本使用体会

上网本 我办公室有办公用笔记本电脑,家里有台式PC,而华硕Eee PC 1000HE算是我的随身电脑。     

一种基于智能体的游戏消息公平处理方法

首先分析了现有网络游戏相关的消息处理方法,然后给出了分布式游戏服务器中一种基于智能体的消息处理结构,在此结构中,智能体处理游戏消息的算法可以实现一种公平的消息处理效果.通过选择离用户较近的服务器创建与用户直接通信的智能体,使得用户与该智能体间的网络时延抖动较小,不需要同步用户和服务器之间的时间就能够从游戏中获得一个相对公平的游戏效果.最后在模拟环境中给出了该算法的实验结果.     

Prosthetic valve endocarditis: superiority of surgical valve replacement versus medical therapy only

The objective of our study was to assess the long-term outcome of patients with prosthetic valve endocarditis. We used a multicenter, prospective, observational study design. Six university teaching hospitals with high volume cardiothoracic surgery participated. Seventy-four patients with prosthetic valve endocarditis as defined by explicit, objective criteria were selected for participation. All patients were followed up prospectively for 1 year. Thirty-one percent and 69% had development of endocarditis within 60 days of valve insertion ("early") and after 60 days ("late"), respectively. The most common causes were Staphylococcus epidermidis (40%), Staphylococcus aureus (20%), streptococcal species (18%), and aerobic gram-negative bacilli (11%). Physical signs of endocarditis (new or changing murmur, stigmata, emboli) were seen in 58%. At 6 months and 12 months, mortality was 46% and 47%, respectively. Surgical replacement of the infected valve led to significantly lower mortality (23%) as compared with medical therapy alone (56%), as assessed by both univariate and multivariate analyses (p < 0.05). Improved outcome was seen for the surgical group even when controlling for severity of illness at time of diagnosis. From these findings we conclude that accurate assessment of outcome in prosthetic valve endocarditis requires long-term follow-up of at least 6 months following diagnosis. Surgical therapy warrants greater scrutiny; evaluation in controlled clinical trials is appropriate.     

Three-year outcome after balloon aortic valvuloplasty. Insights into prognosis of valvular aortic stenosis

BACKGROUND: To identify predictors of long-term outcome after balloon aortic valvuloplasty, we analyzed data on 674 adults (mean age, 78 +/- 9 years; 56% were women) undergoing this procedure at 24 clinical centers who had a mean initial increase in aortic valve area of 0.3 cm2. METHODS AND RESULTS: Baseline data included clinical, echocardiographic, and catheterization variables. Follow-up data included mortality, cause of death, rehospitalization, 6-month echocardiography, and functional status. Kaplan-Meier curves and log-rank tests were used to evaluate survival in subgroups. Multivariate Cox regression models were used to identify independent predictors of survival. Overall survival was 55% at 1 year, 35% at 2 years, and 23% at 3 years, with the majority of deaths (70%) classified as cardiac by an independent review committee. Rehospitalization was common (64%), although 61% of survivors at 2 years reported improved symptoms. Echocardiography at 6 months (n = 115) showed restenosis from the postprocedural valve area of 0.78 +/- 0.31 cm2 to 0.65 +/- 0.25 cm2 (P < .0001). With stepwise multivariate analysis, sequentially adding clinical, echocardiographic, and catheterization variables, the overall model identified independent predictors of survival as baseline functional status, baseline cardiac output, renal function, cachexia, female gender, left ventricular systolic function, and mitral regurgitation. Baseline and postprocedural variables were examined to identify which subgroup of patients has the best outcome after aortic valvuloplasty. A "lower-risk" subgroup (28% of the study population), defined by normal left ventricular systolic function and mild clinical functional limitation, had a 3-year survival of 36% compared with 17% in the remainder of the study group. CONCLUSIONS: Long-term survival after balloon aortic valvuloplasty is poor with 1- and 3-year survival rates of 55% and 23%, respectively. Although survivors report fewer symptoms, early restenosis and recurrent hospitalization are common.     

一类积分不等式的机器判定

将一类积分不等式转化为Tarski模型外的齐次对称多项式不等式,该类齐次对称多项式的次数是给定的,变元个数可以是任意多个,并且多项式的系数是与变元个数相关的变系数.这些特点与杨路等人最近提出的几个公开问题密切相关,是比较有代表性的一类齐次对称多项式.然后利用Timofte关于对称多项式不等式判定的降维方法,结合不等式证明软件BOTTEMA及差分代换方法,给出对应的一类Tarski模型外的齐次对称多项式不等式的机器判定算法,从而实现原积分不等式的机器判定.当给定的积分不等式及齐次对称多项式不等式不成立时,可给出具体不成立的数值反例.应用例子表明问题的广泛性及算法的有效性.     

VMStore: Distributed storage system for multiple virtual machines

Desktop virtualization is a very hot concept in both industry and academic communities. Since virtualized desktop system is based on multiple virtual machines (VM), it is necessary to design a distributed storage system to manage the VM images. In this paper, we design a distributed storage system, VMStore, by taking into account three important characteristics: high performance VM snapshot, booting optimization from multiple images and redundancy removal of images data. We adopt a direct index structure of...