系统极化码的置信传播译码性能分析

置信传播（BP）算法可以为系统极化码提供软信息作为判决依据,也可以为系统极化码在级联迭代译码中提供交换软信息。在详细描述基于信道极化结构的置信传播算法基础上,比较了系统极化码在软信息判决方法和极化编码判决方法下错误率性能的差异。仿真结果表明,软信息判决方法可以提高系统极化码的误比特率,在高信噪比下误帧率方面也略有提高。     

Is exchange rate stability beneficial for stabilizing consumer prices in China?

This study examines the relationship between real effective exchange rates (REERs) and the consumer price index (CPI) in China, utilizing a bootstrap Granger full-sample causality test and a sub-sample rolling-window estimation. Considering structural changes, we assess the stability of the parameters and find that both the short-run and long-run relationships between the two estimated variables are unstable. This result suggests that full-sample causality tests cannot be relied upon. We instead employ a time-varying (bootstrap) rolling-window approach to revisit the dynamic causal relationship, and we find that the CPI is affected by the REER for several sub-samples due to the role of exchange rate pass-through (ERPT) under the managed floating exchange rate regime in China. These findings provide further proof of the impact of stable exchange rates on the maintenance of relatively steady price levels especially during the economic crisis and economic reform in China. The policy implication of these findings is that maintaining exchange rate stability is beneficial for controlling inflation during the economic crisis and economic reform.     

塑钢窗制作安装质量控制浅析

塑钢门窗发展迅速,应用日益广泛,但由于塑钢门窗制作、安装以中小型企业偏多,在塑钢门窗的制作安装中尚存在一定的问题。因此,本文对塑钢门窗制作、安装中亦出现的质量的几个问题进行探讨。     

带时间窗的应急救助物资配送车辆路径优化模型研究

在自然灾害突发后,必须将救助物资在规定的时间内运送到受灾点。针对带有时间窗的应急救助物资配送车辆路径优化问题进行研究,建立车辆路径优化模型并运用了蚁群算法进行求解,取得了较好的效果。     

公司内部人具有交易时机的选择能力吗?——来自中国上市公司内部人卖出股票的证据

本文以内部人卖出股票的交易为对象,研究发现从短窗口来看,上市公司内部人卖出本公司股票时表现出很强的时机把握能力。回归分析发现,在卖出股票时,除董事长和总经理外的内部董事和经理的超常回报显著高于监事和独立董事,董事长和总经理的超常回报可能低于监事和独立董事;内部人本人交易的超常回报显著高于内部人直系亲属;小规模公司内部人的超常回报显著高于大规模公司内部人;国有控股公司内部人的超常回报可能高于其他公司内部人。本文经验证据表明,内部人的时机选择能力可能来自于其掌握的非公开信息,且受公司信息透明度影响。     

Demand-following or supply-leading? Trade openness and financial development in China

This study explores the causal relationship between financial development and trade openness in China, using the research methodology namely bootstrap Granger full-sample causality test and sub-sample rolling-window estimation. The results reveal that there is a significant bidirectional relationship between financial development and trade openness in China, pointing out the existence of both ‘demand-following’ and ‘supply-leading’ hypotheses. Furthermore, their relationship fits well the fact that China has experienced economic restructuring and structural changes in the past few decades. As financial development improves trade openness robustly, the Chinese policymakers should further increase financial reform to promote trade development.     

More than window dressing: visual merchandising and austerity in London’s West End, 1945–50

Abstract

In the aftermath of the Second World War, the fashion departments of London’s West End department stores were not only challenged by austerity and bomb damage but also by the growth of multiple retailers selling branded ready-to-wear goods. This article investigates how department stores responded by investing in display and visual merchandising to attract custom and rebuild their fashionable reputations. It argues that the difficulties caused by austerity conditions forced department stores to embrace new retail methodologies that helped them adapt to the changed circumstances of post-war fashion retail and compete with multiple retailers.     

低复杂度的连续相位调制与LDPC联合迭代译码算法

连续相位调制与低密度奇偶校验(LDPC)码编译码技术在提高频谱利用率的同时能够有效降低发射功率,然而这会增加通信系统的复杂度。为此,提出了一种低复杂度的联合迭代译码算法解决此问题。该算法以符号/比特的可靠度作为内外译码器之间的迭代信息。仿真结果表明,新的联合迭代译码算法的性能与概率域下的算法几乎没有差异,在总迭代次数相同的情况下,采用低复杂度联合迭代的性能相比于未采用联合迭代的性能有约0.75 dB的增益。     

Corruption and Economic Efficiency: Panel Data Evidence

Abstract

This paper investigates empirically the effect of corruption on countries' economic efficiency. By using a sample of 79 countries for the time period 2000–2006 the paper applies DEA window analysis and econometric panel data techniques. The results reveal that there is a U-shaped relationship between countries' corruption perception levels and economic efficiency. Furthermore, it appears that corruption has a negative effect on countries' economic efficiency. For the first time the turning points of such a relationship are being produced indicating that on average terms and regardless of countries' economic structure, Corruption Perception Index (CPI) above five initiate a positive effect on a countries' economic efficiency.     

随机需求下带时间窗IRP问题的遗传算法研究

研究随机需求条件下带时间窗的IRP问题的数学模型,并借助遗传算法来求解这一模型。以某物流公司配送系统为例,获得了路径安排和库存策略的优化目标解。实验结果表明这不仅能明显减少迭代次数,而且可以改善优化计算结果。