基于Cyclic-2伪最大似然算法的Turbo乘积码在高速移动通信系统中的译码方法

采用扩展汉明码作为Turbo乘积码 (TPC)的子码时,与传统的Chase算法相比,Cyclic-2PML(循环 2伪最大似然)算法复杂度低。本文研究了基于该算法的TPC在高速移动通信系统中的译码方法,仿真比较了采用不同子码组合的TPC结合不同的调制方式在高斯信道和多径衰落信道中的性能。结果表明,以(32, 26, 4)扩展汉明码为子码的TPC,不仅具有较高的码率,同时可以获得更好的误比特率性能。     

Local authority and academic attitudes to urban road pricing: a UK perspective

Urban road pricing as an instrument of traffic management has generated a great deal of interest in the UK in recent years. Whilst this is the case there is still no urban road pricing scheme in operation in the UK. The reason for this is primarily one of ‘acceptability.’ This paper, through the use of a national survey, examines the attitudes of key stakeholder groups with respect to urban road pricing. How serious is traffic congestion and traffic related pollution perceived to be by Local Authority Councillors, Officials and the Academic community in the UK? How is urban road pricing viewed by this sub-group of the population in terms of its effectiveness and public acceptance when compared to other policy options? and how could the saleability of urban road pricing be improved? This raises issues in terms of how the revenue raised from urban road pricing should be utilised, the use of urban road pricing as part of a package of measures, the concerns expressed by the stakeholders with respect to urban road pricing, such as the invasion of road users’ privacy, and the type of technology which should be considered. Overall, the paper aims to further the debate among policy makers.     

The performance of business incubators and their potential development in the north east region of england

The creation of incubators is viewed by many local and regional strategic bodies in the UK and abroad as an effective way of nurturing and facilitating the success of new technology-based companies. Drawing on a survey of 17 incubators operating in the North East of England, based on original findings, this paper empirically examines the crucial role of existing incubators in the local economy in enterprise creation and attempts to identify areas of good practice that can be used as benchmarks for the creation of future Incubators.     

A typical Italian phenomenon: The “albergo diffuso”

In Italy, the “albergo diffuso” represents a new alternative to traditional tourist accommodations, such as hotels, B&Bs or farmhouses. It is part of a formula for accommodation capacity that is particularly suitable for small rural centres.     

入世后，山西煤炭营销战略之我见

针对入世后煤炭行业的机遇与挑战，不仅从企业方面而且从政府方面分析了我们的现状与问题，提出了几点关于煤炭营销战略的思考，论述了坚持一个中心；以用户为中心，和两个关键点；经济效益与创新营销管理的思想。     

Forecasting volatility: A reality check based on option pricing, utility function, value-at-risk, and predictive likelihood

We analyze the predictive performance of various volatility models for stock returns. To compare their performance, we choose loss functions for which volatility estimation is of paramount importance. We deal with two economic loss functions (an option pricing function and an utility function) and two statistical loss functions (a goodness-of-fit measure for a value-at-risk (VaR) calculation and a predictive likelihood function). We implement the tests for superior predictive ability of White [Econometrica 68 (5) (2000) 1097] and Hansen [Hansen, P. R. (2001). An unbiased and powerful test for superior predictive ability. Brown University]. We find that, for option pricing, simple models like the Riskmetrics exponentially weighted moving average (EWMA) or a simple moving average, which do not require estimation, perform as well as other more sophisticated specifications. For a utility-based loss function, an asymmetric quadratic GARCH seems to dominate, and this result is robust to different degrees of risk aversion. For a VaR-based loss function, a stochastic volatility model is preferred. Interestingly, the Riskmetrics EWMA model, proposed to calculate VaR, seems to be the worst performer. For the predictive likelihood-based loss function, modeling the conditional standard deviation instead of the variance seems to be a dominant modeling strategy.     

Turbo乘积码的两种迭代译码器的比较

提出了Turbo乘积码的并行迭代译码原理，对比分析了一种新的并行迭代译码器和传统的串行译码器，给出了以扩展汉明码(32，26，4)、(64，57，4)为子码的二维Turbo乘积码(32，26，4)。、(64，57，4)。在通过两种不同的译码器时的仿真结果。仿真结果表明，采取并行迭代译码器，在保持同样的译码性能的同时降低了译码延时。     

略论中小民营企业对促进河北省外贸发展的作用

在我国国民经济发展中,民营企业占据着不可或缺的重要地位,也是一支对外贸易的主要队伍。河北中小民营企业发展相对落后,然而河北却并非不具备发展中小民营企业的优势。河北劳动力资源丰富,劳动力素质较高,且潜藏在民间的资本较为雄厚。河北各级地方政府应高度重视民营中小企业的发展,并制定相应的政策、法规,尤其要解决好它们融资难的问题。河北中小企业发展了,就一定会促进河北对外贸易的发展。     

Trade Unions in Local and Regional Development and Governance: The Northern Trades Union Congress in North East England

From a position of relative isolation, trade unions have become increasingly important agents in local and regional development and governance in the UK since the election of the New Labour government in 1997. Analysis of the experience of the Northern Trades Union Congress (NTUC) suggests that devolution and regionalisation are exerting increasing pressures upon trade union federations to adopt a multi-level approach to organisation across a range of scales—local, sub-regional, regional, sub-national, national and international—to connect with the evolving multi-layered governance structures of the UK political economy. Strategic multi-level organisation suggests the decentralisation of power, authority and resources within the labour movement—challenging the national and centralised legacy of its collective bargaining history—and a division of labour and set of priorities at the different scales to build the links between local and regional engagement and trade union renewal.     

扶植中小企业国际电子商务促进出口贸易持续发展

本文从中小企业在国际贸易中的战略地位和电子商务在中小企业国际化经营战略中的作用入手,对我国中小企业电子商务发展的现状进行评价,并分析了发展障碍因素,强调地方政府扶植中小企业电子商务发展的重要性和可行性,提出了具体政策建议。