一种基于区间数偏离度的方案排序方法

针对特征取值为区间数的方案排序问题,提出两个区间数的偏离度概念用以构造方案间的偏离度矩阵,并给出一种基于总体偏离度优化的特征权重确定方法。利用提出的区间数向量的相对贴近度概念刻画一个方案接近于另一个方案的程度,进而对候选方案的优劣排序。该方法提出的各种度量较直观、易于理解,并通过实例验证方法的有效性和实用性。     

高生产率计算系统

以往的高端计算领域将峰值运算速度作为衡量计算系统的最重要的指标.然而体系结构的失衡和落后的编程支持成为困扰高性能计算技术发展的关键问题.未来高端计算的发展方向应该着眼于提高系统的生产率,强调系统的易用性和好用性.介绍了HPCS的背景、目标、主要技术挑战以及主要的解决方案和关键技术.     

神经网络余数制系统与余数制神经网络模型

余数制和神经网络各有其独特优点，将其有机结合这些优点得以充分发挥。将神经网络结构和方法引人余数制信号处理系统，构造出完成余数约化运算和余／十转换运算以及余数加法运算的新结构，开辟了高速实时信号处理的新途径．将余数制引入神经网络，即神经网络中的数据、权值均按余数制表示和运算，构造出一种新的感知机模型—余数制神经网络，由于余数制运算具有一种独特的非线性特点，使这种模型比常规神经网络具有更强的功能。     

虚拟机自省中一种消除语义鸿沟的方法

虚拟机自省技术已经广泛应用于入侵检测和恶意软件分析等领域。但是由于语义鸿沟的存在,获取虚拟机内部信息时会导致其通用性和执行效率降低。通过分析现有语义鸿沟修复技术的不足,提出了一种称为ModSG的语义鸿沟消除方法。ModSG是一个模块化系统,将语义修复分为2部分：与用户直接交互的在线语义视图构建和与操作系统知识交互的离线高级语义解析。二者以独立的模块实现且后者为前者提供语义重构时必要的内核语义信息。针对不同虚拟机状态和不同内核版本操作系统的实验表明,ModSG在消除语义鸿沟上是准确和高效的。模块化设计和部署也使ModSG容易扩展到其他操作系统和虚拟化平台上。     

The Full Cost of Cryptanalytic Attacks

An open question about the asymptotic cost of connecting many processors to a large memory using three dimensions for wiring is answered, and this result is used to find the full cost of several cryptanalytic attacks. In many cases this full cost is higher than the accepted complexity of a given algorithm based on the number of processor steps. The full costs of several cryptanalytic attacks are determined, including Shanks method for computing discrete logarithms in cyclic groups of prime order n, which requires n^1/2+o(1) processor steps, but, when all factors are taken into account, has full cost n^2/3+o(1). Other attacks analyzed are factoring with the number field sieve, generic attacks on block ciphers, attacks on double and triple encryption, and finding hash collisions. In many cases parallel collision search gives a significant asymptotic advantage over well-known generic attacks.     

一种便携式光纤功率计的设计方法

介绍了一种便携式光纤功率计设计的硬件结构和软件流程,给出了其标定方法和实测性能指标。该光功率计采用InGaAs材料的光电探测器实现光电信号的转换,满足了光纤功率计对波长范围和测量精度的要求;采用高性能运放TLC2652和18位的A/D转换芯片MAX132以保证测量精度;选用高速单片机AT89C52来控制信号的检测、处理以及数据的显示,在确保运算速度的同时使光纤功率计具有多波段响应、量程自动转换、测量精度高的特点。实测的性能指标表明该光功率计达到了设计要求,在光信息、光通信等领域具有广泛的应用前景。     

Household consumption of electricity in Brazil between 1985 and 2013

This article describes the electricity consumption in Brazilian residences between 1985 and 2013 through linear regressions. The explanatory variables considered were the number of households, effective consumption of families as a proxy for family income, and electricity tariff for households. To deal with the power generation crisis of 2001 we have introduced a dummy variable in the form of a step function. With such explanatory variables, we were able to account for the reduction of household electricity consumption caused by the policies conducted in 2001 and their permanent consequences. The regression presented coefficient of determination of 0.9892, and the several statistic tests conducted assured the existence of long-term relation between the electricity consumption in residences and the explanatory variables. The obtained elasticities for the household consumption of electricity with respect to number of residences, family income and residential tariff of electricity were 1.534±0.095, 0.189±0.049, and −0.230±0.060, respectively. These results allowed understanding the evolution over time of the household consumption of electricity in Brazil. They suggest that the electric sector in Brazil should pursue an active policy to manage demand of residential electricity using tariffs as a means to control it.     

非点对点消息网间互联互通技术方案

介绍了我国开放非点对点消息网间互联互通的背景,并分阶段对我国实现非点对点消息网间互联互通的技术方案进行了介绍和分析。     

Who wants to be “friend-rich”? Social compensatory friending on Facebook and the moderating role of public self-consciousness

The present research aims to provide insight into social compensatory friending on social network sites by investigating the effects of self-esteem and self-consciousness on number of friends in the context of Facebook use. It was hypothesized that Facebook users low in self-esteem, when compared with high-self-esteem individuals, would engage in friending more actively and thereby accumulate a large number of friends as a way to compensate for the deficiency in self-esteem. We also hypothesized that the relationship between self-esteem and number of Facebook friends would vary depending on the levels of public self-consciousness. Data were collected from a college student sample in the United States (N = 234) based on an online cross-sectional survey. The results supported the hypothesis on social compensatory friending, demonstrating a negative association between self-esteem and number of Facebook friends. Furthermore, the data yielded support for the hypothesized moderating role of public self-consciousness in social compensatory friending: the negative association between self-esteem and number of Facebook friends was significant only for Facebook users who are high in public self-consciousness but not for those who are low in public self-consciousness. Implications for understanding social network site users’ friending behavior in light of social compensation motives are discussed.