基于遗传算法的企业配送路径问题研究

为提高企业竞争力,加快企业发展,企业已将优化重点转向物流配送环节,文中通过遗传算法设计并求解企业配送路径问题,设计合理的配送路线,提高配送效率,降低物流成本。     

基于S7-200系列PLC系统的滑动轴承对接平面拉床技改设计

内燃机等设备中的对开滑动轴承加工工艺关键工序之一是对接平面拉削加工,提高该专用拉床加工质量和效率的技术要点是使启动上料、工件定位、清扫拉屑、执行夹紧、定位复位、拉削、夹具松开及退料等拉削过程中所有动作正确无误。本文在简述对接平面拉削工艺流程的基础上对采用S7-200系列PLC进行全自动对接平面拉床控制系统技术改造设计的过程予以分析阐述,并对相关技术问题给出说明。     

“窗口指导”淡化前后新股折价行为比较研究

2009年6月的新股询价机制改革以后,新股发行正式取消了询价的"窗口指导"。文章以2009年政府对新股发行的"窗口指导"改革为背景,选取改革前后在我国A股中小企业板上首次公开发行上市的股票数据为样本,采用随机边界模型,对"窗口指导"淡化前后新股发行定价中的折价行为进行比较研究。实证研究结果表明,2009年改革以前新股折价行为显著存在,且折价程度不容小视,新股故意折价是IPO高抑价的来源之一;而2009年改革后新股折价行为消失,IPO抑价几乎完全来源于二级市场对其估值过高。     

考虑多模糊时间窗医药物流配送路径优化

以医药物流客户满意度最大和总成本最低为目标,建立了考虑多模糊时间窗的车辆路径问题优化模型。为满足低碳物流的要求,在路径规划中引入碳排放成本,为防止类似大型医疗器械运输超载问题引入超载惩罚项,引入多模糊时间窗来评价客户在可以忍受送达时间段和期待送达时间段的满意度。以单个配送中心3辆配送车辆25个客户为算例,运用遗传算法对模型求解,求解得到的最优车辆配送路径提高了满意度并降低了总成本。该模型亦适用于满足相应约束条件的类似行业的供应链优化。     

Beyond window signs: Understanding the affect‐based effects of window signs on store patronage intentions

Store managers commonly use window signs to decorate their stores and, more importantly, to communicate store‐related information to their customers. This research investigates the role window signs play in influencing consumers’ attitudes and store patronage intentions. Empirical evidence from two studies (data from a real‐life store environment and from an experimental setting) indicates that window signs generate positive inferences to consumers about the store image and the store promotion value, which ultimately influence consumers’ patronage intentions. Furthermore, this study proposes and tests a model suggesting that window signs represent a diagnostic cue from which consumers infer a sense of place identity. The results show that place identity partially mediates the relationship between consumers’ attitude toward window signs and consumers’ store patronage intentions. Moreover, this study includes the store manager's perspective and finds evidence that retail managers have positive attitudes toward window signs, which encourage them to rely on this promotional tool to announce store promotions. Implications of the findings for the role of window signs are discussed.     

The determinants of banking efficiency in Hong Kong 2004-2014

The cost efficiency of the Hong Kong Banking sector over the period 2004–2014 is estimated by data envelopment window analysis. A second stage regression analysis finds that bank size and GDP growth are positively associated with efficiency, whereas revenue diversification and inflation are associated with lower efficiency. Stock exchange listing status is associated with lower efficiency but no clear relationship between measures of market structure and efficiency is found.     

“三鹿奶粉事件”引发国家食品免检制度终结的多源流分析

引用美国学者约翰.金顿的政策窗理论,就国家食品免检制度的终结,按问题源流、政策源流和政治源流的多源流框架进行梳理和分析。认为,是三鹿奶粉等公共食品安全事件引发了"触发机制",使得问题流、方案流和政治流得以汇合,并成功开启了政策终结的机会之窗,直接导致了国家食品免检制度的终结。     

Is the tourism–economic growth nexus time-varying? Bootstrap rolling-window causality analysis for the top 10 tourist destinations

This article explores the time-varying causal nexus between tourism development and economic growth for the top 10 tourist destinations in the world, namely China, France, Germany, Italy, Mexico, the Russian Federation, Spain, Turkey, the UK and the United States of America, over the period 1990–2015. To that end, a bootstrap rolling window Granger causality approach based on the modified Granger causality test is used. A new index for tourism activity which combines via principal component analysis the commonly used tourism indicators is also employed. The results of the bootstrap rolling window causality tests reveal that the causal relations between tourism and economic growth vary substantially over time and across countries in terms of both magnitude and direction. It is shown that the causal linkages tend to be more pronounced for a large group of countries following the global financial crisis of 2008. Additionally, Germany, France and China clearly stand out as the countries with the weakest causal nexus, while the UK, Italy and Mexico emerge as the countries that have the strongest causal links. These results have particularly important implications for policymakers.     

Reserve Accumulation and Money Supply in China: A Time-Varying Analysis

This study investigates the causal relationship between reserve accumulation and money supply in China over the period of 1999 M1–2015 M6. First, we use a Granger causality test and find that there is a unidirectional relationship from money supply growth to reserve accumulation growth; however, taking structural changes into account, we assess stability of parameters of the estimated vector autoregressive models. We find both the short-run and long-run relationships between money supply growth and reserve accumulation growth estimated using full-sample data are unstable over the sample period. This suggests that full-sample causality tests cannot be relied upon. We turn to propose a time-varying (bootstrap) rolling-window approach to revisit the dynamic causal relationship between the two variables. We find that two variables have causal relationships in some sub-periods. We argue that reserve accumulation growth has put pressure on money supply growth. However, in general, sterilization is effective, but not in few months 2006–2007. And money supply has a positive reserve accumulation from the second half of 2001–2003 because RMB was undervalued under the fixed exchange rate regime. We argue that the improvements of monetary policy and the exchange rate regime are crucial to break the relationship between reserve accumulation growth and the money supply growth.