部分信道交叠多跳无线网络容量渐近估计

无线多跳网络的基本问题是信道交叠情形下系统容量上限的估计以及最大容量的获取.建立有实效参数的容量渐近估计模型,不仅可以准确、深入描述部分交叠信道的竞争性与互助性对系统容量的影响,而且可以为系统容量优化提供重要理论参考依据.该模型揭示,无论是单播还是广播业务,网络容量峰值的达到是可用中继节点数与发送概率的匹配,更具体地说是归一化节点密度与节点数的乘积同节点发送概率的匹配.     

基于二进制关联规则提取算法的大学生就业竞争力分析

目前大学生就业竞争力分析是一个很重要的课题,但现有的分析方法多局限于对竞争力影响因素所占权重的分析,从而制约了大学生对各影响因素间的关联性的认识.根据关联规则分析理论,通过转化决策型数据,利用二进制关联规则挖掘算法对大学生就业竞争力进行科学分析,提取得出有效规则.通过对2007年度毕业生的就业竞争力评价,验证该方法的实用性、可行性.     

大豆分离蛋白酶解液抗氧化性的近红外光谱定量测定

利用近红外光谱技术对四种蛋白酶(菠萝、碱性、木瓜和中性蛋白酶)的大豆分离蛋白水解样品进行测定,探索同一模型应用于不同酶的水解液抗氧化性测定的可行性。基于留一交叉验证方法,分析了采样密度和酶物质差异对全波长模型精度的影响,统计检验表明,采样密度与模型精度之间正相关,酶物质差异对单酶样本模型精度无显著影响,但对综合酶样本模型性能有显著影响。为了建立能够同时准确测定不同酶水解样品抗氧化性能力的综合酶样本预测模型,竞争性自适应重加权抽样(CARS)法用来对模型进行了优化,建模后,校正集R_(cv)和RMSECV分别为0.960 1和0.002 8,验证集的R_p和RMSEP为0.923 7和0.005 3,相对分析误差(RPD)为2.45,预测精度较好,说明建立针对不同酶的水解样品的同一模型是可行的。     

Can a daily electricity bill unlock energy efficiency? Evidence from Texas

This study examines the energy efficiency implications of a daily billed energy service, commonly known as ‘prepaid’ electricity, which is used by a growing percentage of residential customers in the competitive Texas electricity market. Our empirical analysis results suggest that this service could save 9.6% of average daily energy consumption, net of the effect of any disconnections. This quantitative study demonstrates that energy efficiency from prepaid energy products can extend to competitive marketplaces.     

The maximum capture problem with heterogeneous customers

A product is sold in a geographical market and it is provided by different companies. Small unmeasurable differences exist between the products sold by different companies and customers have heterogeneous tastes. A newcomer wishes to enter the market locating p new facilities, in order to gain the maximum number of customers. It is assumed that he is not able to specify the exact behavior of every customer, so he models the consumers’ decision making by a random utility function. Under some more technical assumptions, a closed formula for the probability of patronizing a given facility is obtained. By this way, a formulation of the maximum capture problem can be obtained. The computational features of the problem are considered and two branch-and-bound methods are developed. The first method exploits the Lagrangian relaxation of the problem, the second uses the submodularity of the objective function. Data sets are generated according to different competitive scenarios and problems of up to 100 nodes are solved within a few seconds.     

Designing renewable energy auctions for India: Managing risks to maximize deployment and cost-effectiveness

We examined 20 renewable energy auctions in India and elsewhere to answer two questions: first, have auctions been effective; and second, how can they be designed to achieve India’s renewable energy targets? The significant contributions lie in the larger sample size, use of secondary and primary research, and application of quantitative and qualitative analysis. We found that auctions are almost always cost-effective, with savings up to 58% from baseline feed-in tariffs. However, auctions may not always be deployment-effective, with only 17% of the auctions with greater than 75% deployment. We then examined how to best design auctions by assessing seven major risks, and found the following: first, for every 1% increase in total risk, deployment effectiveness decreased by 2% points; second, project specific risks have 60% greater impact than auction specific risks; and third, deployment effectiveness is most affected by auction design, completion, and financial risks. We also found that effectiveness of auctions in India can be improved by ensuring competition, improving transmission infrastructure, providing payment guarantees, using pay-as-bid auctions, including stringent penalties for delays, and introducing auctions in a controlled manner.     

Complexation of poly(pyrrole-EDTA like) film modified electrodes: Application to metal cations electroanalysis

Complexing polymer-coated electrodes have been synthesized by oxidative electropolymerization of N,N′-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine] (L). There were used for the electrochemical detection of Cu(II), Pb(II) and Cd(II) ions by means of the chemical preconcentration-anodic stripping technique. For thick polymeric binding materials and long accumulation times, competitive experiments showed that the polyL film modified electrodes are selective towards Cu(II) ions and particularly insensitive to the presence of Cd(II). In contrast, imprinted polymer-coated electrodes prepared by electropolymerization of the Cd(II) complex of L allowed an efficient complexation and sensing of Cd(II) cations. The selectivity of the molecular electrode materials can thus be subtly modulated upon playing on the accumulation time and on the pre-structuration of the complexing polymers.     

Electricity prices in a competitive market: a preliminary analysis of the deregulated Thai electricity industry

The electricity industry throughout the world is currently undergoing a significant transition towards restructuring and deregulation. Following this new legislation, Thailand has initiated an institutional and structural reform with a belief that this could be the best way forward for the Thai electricity supply industry (ESI) to improve efficiency, lower electricity prices, and tackle financial debts. This paper presents an analysis of the extent to which prices for generation services in a competitive market may differ from regulated electricity prices, if competitive prices are based on marginal costs and regulated prices are based on average costs, by using Thailand as a case study.     

企业技术创新与市场竞争力

本文通过分析当前国际、国内的经济形势和我国企业所面临的机遇、挑战,系统地论述了如何应对形势的几条具体措施,以及如何实施的几点建议。