THE IMPLICATIONS OF TRADER COGNITIVE ABILITIES ON STOCK MARKET PROPERTIES

Market structure and individual rationality remain at the centre of a debate as to which is the main driving force in market performance. We examine the role of individual rationality, comparing zero‐intelligence traders with traders with different levels of intelligence using a special adaptive form of strongly typed genetic programming‐based learning algorithm. We use this approach with real data: historical quotes of the S&P 500 and Coca‐Cola stock prices. We find a mixture of positive and negative impacts from intelligence on market performance. Because the concept of market structure as a driving force has been significantly challenged in the literature, we suggest that the inclusion of both intelligence and market structures is important when examining the driving forces of market performance. This inclusion is consistent with the research of Todd and Gigerenzer (Journal of Economic Psychology, 24 (2003) 143–165), which asserts that both environment (market structure) and agents’ cognition play important roles. Copyright © 2013 John Wiley & Sons, Ltd.     

基于改进GA的滑行道路径冲突解脱研究

为解决多航空器在飞行区场面活动时存在的冲突问题,以优化后的滑行路径距离作为目标代价函数,提出一种滑动时间窗与GA相融合的冲突解脱模型。首先在滑行规则、安全间隔与滑行道实际条件等约束条件下构建场面滑行路径模型;其次提出基于滑动时间窗与GA融合的求解算法;最后选取成都双流机场为例进行仿真,并与传统GA算法进行对比分析,证明基于改进GA的算法模型在飞行区冲突解脱上更具有鲁棒性与自适应性。     

考虑多类型产品新鲜度的生鲜配送路径优化

生鲜产品由于其特殊性,在配送过程中存在损耗。针对不同种类的生鲜产品,差异化新鲜度敏感系数,引入生鲜努力保鲜系数,构建生鲜产品新鲜度函数,同时考虑固定成本、运输成本、制冷成本、货损成本及时间惩罚成本,构建了生鲜配送路径优化模型。设计混合遗传粒子群算法进行求解,验证了模型的合理性及算法的有效性。对比不同的生鲜努力保鲜系数对各项成本的影响,得出综合成本最优的保鲜策略,为生鲜企业末端配送优化提供参考。     

Classical Swine Fever Changes the Way Farmers Value Pigs in South Africa

Although there is growing demand for animal products in Africa, production is stagnating. Appropriate management of livestock diversity could help reinvigorate production, contribute to food security and improve farmers’ livelihoods, particularly in subsistence‐oriented systems. We assess differences in farmers’ preferences and economic values for pig traits across different production systems and across areas that have been affected and unaffected by classical swine fever (CSF). Not surprisingly, market‐oriented farmers derived higher values from the productive traits such as heavy slaughter weight and large litter size found in exotic pig genotypes. Subsistence‐oriented farmers, particularly in swine fever affected areas, placed high value on tolerance to disease. We found that CSF changed farmers’ preferences for adaptive traits, and less so for productive traits. Therefore, indigenous breeds become more valuable for subsistence farmers and crossbreeds for market‐oriented farmers if CSF is a risk. Our results can have implications for breeding and conservation strategies and for compensation strategies after culling, and will become increasingly relevant if, as predicted, heat waves and disease outbreaks become more frequent in pig production systems in South Africa with climate change.     

The Geographic Extent of the Market for Soybeans and Soybean Products

This study looks at the question of whether soybeans, soybean meal, and soybean oil produced in the United States and exported were part of a single, world geographic market during the decade of the 1980s. An answer to this question is sought using an approach to defining a geographic market based on the notion of instantaneous causality. The empirical results suggest that there was but a single identifiable world market for these commodities over the period of study.     

现代生物技术在食品领域中的应用研究

现代生物学和分子生物学的发展,对基因工程、细胞工程、酶工程、发酵工程等现代生物技术工程产生重要影响,其在食品发酵生产中的应用越来越广。本文阐述了基因工程、细胞工程、酶工程等现代生物技术在食品发酵业的应用。     

Exceeding the speed limit: prevalence and determinants in Iran

Speeding is one of the most common risk behaviours associated with crashes causing signficant injury. The objective of this study is to explore the prevalence and determinants of speeding on a road between Tehran and Hamadan, Iran. In a cross-sectional study in 2009, stretches of the road were studied including three groups of posted speed limits: < 50 km/h, 50–100 km/h and > 100 km/h. Each stretch was evaluated both in daylight and dark. Randomly identified driver's speed was checked by a handheld speed camera and then the driver was invited to participate in a survey. Statistical analysis was performed using Chi-Square, crude and adjusted odds ratio, 95% confidence interval and multiple logistic regression models. Overall, 52.8% of the drivers were travelling more than 10 km/h above the posted limit. Where limits were < 50 km/h, 74.6% of drivers were speeding. This declined to 46.9% for sections with limits between 50 and 100 km/h and to 36.9% for sections posted more than 100 km/h. Finally, more than half the drivers were observed to be speeding. Driving more than the posted limit was far more likely on the areas with the lowest posted speed limits, personal passenger vehicles, modern vehicles not using seat belts, and male drivers.     

遗传算法在装配线平衡中的应用

装配线平衡是混合装配生产线调度的重要基础,是面向订单装配(ATO)得以实施的技术瓶颈,对提高生产率和设备利用率也具有重要意义。在工位数量给定的条件下,文章针对装配线平衡的数学模型,提出了一种面向装配线平衡的非标准遗传算法。该算法基于各操作之间的逻辑优先关系产生可行操作序列而生成初始种群,保证解的可行性;在此基础上实现寻找最小节拍、选定较优序列进行遗传,并采用最优保存策略确保算法收敛到最优或近优解。最后通过实例验证了该算法的有效性和可行性。     

中铁快运北京分公司配送网络优化研究

随着社会经济的发展,货物运输呈现几大趋势,其中包括货物运输的物流化。而物流作业(装卸搬运、储存、运输、包装、流通、加工、信息处理等)的很大部分都是在物流节点上完成的,所以,配送中心的选址是否合理直接影响配送中心各项经济活动的成本,同时也关系到企业的长久发展。针对中铁快运公司的具体实例,提出可行的网络优化设计方案,为中铁快运的决策提供支持。     

大口径三通管翻边成形工艺参数优化

本文主要研究以冲压变形规律设计的预制孔管件一次成形特定高度的三通管是可行的,但需对工艺参数优化。