一种高效的OFDM载波频偏盲估计方法

针对正交频分复用（OFDM）系统,提出了一种低复杂度、高性能的载波频偏盲估计 方法。该方法充分利用载波频偏估计代价函数在一定区间内的单谷特性,采用黄金分割法搜 索载波频偏估计代价函数极值,从而大大降低其计算复杂度。最后对该方法和Tureli′s MU SIC-like(TML)载波频偏估计方法在加性高斯白噪声信道和多径信道环境下进行了仿真,结 果表明, 在同等条件下该方法的计算复杂度大大低于TML载波频偏估计方法。     

浅埋大断面小净距隧道支护受力特性实测与模拟研究

浅埋大断面小净距隧道围岩稳定性差,加上相邻隧道间相互扰动频繁,支护结构受力复杂,极易引发隧道塌方与地表变形等问题,严重威胁隧道施工安全。以重庆海天堡隧道为背景,采用现场监测与数值模拟相结合的方法,对浅埋大断面小净距隧道围岩压力与复合式衬砌内力的施工响应规律进行研究。结果表明：相邻隧道施工相互扰动明显,后行隧道核心土开挖对先行隧道围岩压力释放影响最为显著;先行隧道支护可通过加固围岩实现小净距隧道压力拱水平减跨,进而提高后行隧道围岩承载力;针对浅埋大断面小净距隧道开挖,双侧壁导坑法可有效控制围岩变形及压力释放。基于该隧道开挖方法的围岩压力及支护受力施工响应规律可为施工方案的优化提供借鉴与参考。     

Analysing consumers' ‘activism’ in response to rising prices

The purpose of this paper was to compose the profile of active consumers in Greece during a period of rising prices taking into account shifts in their consumption. A survey was conducted from 1 September 2008 to 21 November 2008 to collect the primary data source for the study. Questionnaires were administered to 200 consumers. To our knowledge this was the first attempt to offer insight into the characteristics of the Greek consumer in a period of economic crisis. For this purpose, econometric analysis was employed. Empirical results suggested that high‐income groups spend more for food commodities and are less likely to be active consumers. It was concluded that consumers have reduced spending for some basic and semi‐luxury products like fruits, meat, alcohol, sweets and coffee, and entertainment activities. The main factor which affected the reaction to price increases, as expected, was the monthly private income. Twenty per cent of the consumers are members of a national consumer movement organization, and support their actions against rising prices. Women, who research the market before purchasing a product, are more likely than men to participate in economic boycotts. By examining the profile of non‐active consumers and the reasons for their behaviour, we are able to propose a policy for the activation of the Greek consumer movement, which is necessary for the consumers' resistance to rising prices. Taking into consideration that Greek consumers face increased prices for food commodities and services, a policy framework to activate consumers is among the main prerequisites for maintaining consumers' well being. We suggest that the Greek Consumer Protection Institutes should regain consumers' confidence and focus on the dissemination of information about organized economic boycotts.     

一种商用车型A柱结构设计及验证

文章对商用车型A柱结构设计过程进行了分析,分析的内容包括功能设计、截面设计、具体的结构设计,以及制造工艺性设计、CAE分析验证等,经过系统的分析总结,提高了设计效率,缩短了汽车的开发时间。     

50米钢箱梁加工制造施工技术研究

成都天府机场高速公路50m钢箱梁施工,为克服长大件钢箱梁的制架梁难点,由中铁山桥在成都基地工厂先制造板单元,其次拼装梁段,经大件运输28km至施工现场,然后现场吊装架设,本项目钢梁为工字型结构,每个梁段由底板、腹板、顶板、横联及挑臂组成.梁段制造,每桥钢板梁实际拼装为各个节段全部在同一胎模架上进行预拼装,按照由中间向两...     

现代法的发展与法理学的变革

现代法的综合化、社会化、自足化发展趋势对法的部门划分、法的调整模式、法的本位及法的精神等方面都提出了挑战,法理学必须适应这种变化,及时进行调整,构建新的法理学体系。     

Ritual legitimation, de-coupling and the budgetary process: managing organizational hypocrisies in a multinational company

The study of participation in the budgetary cycle has formed a prominent part of the research literature concerned with the budgetary process. More recently there has emerged a body of literature concerned with exploring the political and symbolic nature of the budgetary process. The paper reports upon the outcomes of an empirical study of the introduction of `budgetary participation' in a division of a European subsidiary of a large North American car manufacturer. We detail the long process of consultation and negotiation within the subsidiary, and between it and the European Headquarters. The study provides a revealing instance of the roles of formal budget participation as a ritual of control and legitimation without the substantive involvement of middle managers and suggested to us the introduction of de-coupling and organizational hypocrisy alongside the introduction of budget participation. The study pays close attention to the contingent effects of the wider political context of the division and the relationships between the division, its organizational context and organizational environment, and how this context played upon the budgetary process in the division. The outcomes that we analyse at `Delta' reflect the de-coupling strategies and organizational hypocrisies commonly found in public sector organizations. In this wider setting the corporation persists with the ritual of `tight' budget negotiation and target setting and apparent underachievement in performance. Yet we conclude that the complex technological and political context to the formation and siting of Delta continued and may continue to support its existence.$g0     

小型农田水利工程灌溉渠道造价对比分析

以引水农渠为研究对象,采用经验公式和对比分析法,探讨渠道在不同断面结构形式和不同材料情况下单位工程造价的变化情况,进一步分析不同渠道的工程特点和存在差异的原因。结果表明:渠道所采用的材料、断面结构和施工工艺是造成造价差异大的主要因素。     

浅谈大截面深井开挖施工

本文介绍了深井泵房开挖前的分析策划及施工过程调整。质量、环境、安全在施工中要高度重视,从而确保工程的顺利推进。     

圣维南原理和轴向拉(压)正应力公式的研究

本文通过在静力等效的轴向载荷作用下薄壁杆的正应力和变形的分析,论述了只要静力等效的轴向力产生双力矩,圣维南原理和实心杆的轴向拉(压)正应力公式对薄壁开口截面杆和部分薄壁闭合截面杆都是不适用的。给出了薄壁矩形截面杆的适用条件和适用曲线。