Trauma epidemiology in Puerto Rico: in-hospital morbidity and mortality from 2002 to 2011

This study aimed to describe the distribution of injury mechanisms and to assess the impact of those mechanisms on the morbidity and mortality of trauma. All patients admitted to Puerto Rico Trauma Hospital (2002–2011) for road-traffic collisions (RTCs, 5,371), gunshot wounds (GSWs, 2,946), falls (2,319), pedestrian accidents (1,652), and stab wounds (SWs, 1,073) were selected. Gunshot victims were 1.19 (95%CI: 1.07–1.33) times as likely as road-traffic victims to have an ISS ≥25. Pedestrians were 1.76 (95%CI: 1.49–2.09) times more likely to have a GCS ≤8 than road-traffic victims were. The risk of dying was 2.64 (95%CI: 2.20–3.16) times higher for gunshot victims and 1.51 (95%CI: 1.23–1.86) times higher for pedestrians compared to patients who had had RTCs. Gunshot victims and pedestrians had the worst clinical outcomes. Accordingly, these patients should receive the most aggressive clinical management. Furthermore, it is imperative to develop public health campaigns on trauma prevention.     

基于图论的认知无线网络频谱动态分配

在认知无线电网络中，图论与量子遗传算法相结合的频谱分配策略能够提高频谱利用率，但存在早熟和收敛精度不够等缺点。为了解决该问题而实现算法的优化，对图着色理论的频谱分配模型进行数学建模，并针对该模型提出了改进的量子遗传算法。首先，通过使用小生境技术初始化种群，使种群分布更加广泛、算法的收敛度更高；其次，根据进化代数对量子旋转角进行实时动态调整，对染色体进行阈值变异，防止个体陷入早熟，跳出局部解；然后，对干扰约束条件进行重新设计，有效地避免盲目性，提高了网络的公平性和网络效益。仿真结果表明，所提算法有效地提高了频谱利用率，极大地增强了网络系统的性能。     

企业逆向物流系统优化研究

随着市场竞争的加剧、产品生命周期的日益缩短、自然资源的日渐枯竭、人们环保意识的加强,逆向物流越来越受到企业的重视。因而,构建并优化自己的逆向物流系统成为企业具有战略意义的工作。文章首先分析了企业构建逆向物流系统的指标体系和优化时所应采取的措施．并据此建立数学模型,运用遗传算法来进行求解,并对结果进行了分析。,最后用一个算例来验证模型的可行性,并总结了模型的不足之处和将来的研究方向。     

一种求解装箱问题的混合算法

针对一维装箱问题,在考虑遗传算法早熟收敛问题和禁忌搜索算法自适应优点的基础上,将遗传算法和禁忌搜索法结合起来,提出了基于遗传和禁忌搜索的装箱优化算法,与简单遗传算法相比,该算法具有更好的收敛性能。最后通过实例验证了算法的有效性。     

配送中心车辆调度模型及遗传算法设计

针对物流配送中心车辆调度问题,采用混合整数规划方法进行建模。对实际问题进行研兖分析后,基于所研究问题的特点,提出基于遗传算法的求解方法。通过数值实验对算法不同参数组合进行分析、比较,获得最佳参数组合．建立了有效的求解该问题的遗传算法。并通过对实际问题的数值仿真试验．验证了算法的有效性。     

产销不平衡运输问题的遗传算法研究

根据运输问题的特点和要求,在运输成本最低的基础上,构建了产销不平衡运输问题的数学模型,并将该模型转换为产销平衡的运输问题,然后把遗传算法引入到模型的求解中,通过选择恰当的编码方法和遗传算子,求得模型的最优解。     

铁路煤炭调运问题的遗传算法

根据铁路运输中现有煤炭的运输状况，构造出煤炭调运时，煤种间不能相互代用和可以相互代用的数学模型，并基于遗传算法的C语言程序，对该模型进行了遗传算法设计，最后通过算例，验证了模型和算法的可行性。     

Rethinking Urban Epidemiology: Natures,Networks and Materialities

How should we understand the relationship between urban environments and infectious diseases? This article addresses this question from three particular perspectives: that of the materialities of health, that of nature and that of networks. The first perspective analytically blends biological dynamics, environmental influence and social practice. The second perspective, mainly influenced by multispecies ethnographies, foregrounds the liveliness and unboundedness of cities. Finally, the third perspective analyses how health is drawn into the domain of security. The article argues that while globalization and urbanization are often discussed as having triggered the emergence and spread of pathogens, urban epidemics are not self‐evident and ‘natural' consequences of these pro‐cesses. They do not fall neatly into universal categories of space, modernity or risk; rather, they are produced and shaped by a range of social, political, biological and economic sites and scales. Accordingly, the emergence of pathogens depends on its articulation through specific analytical frameworks. This article suggests that a critical focus on how infectious diseases manifest themselves differently in different local contexts may not only provide insights into the manifold forms of urban life, but also into the multiple, complex and highly political constitution of health.     

遗传算法在宽窄波束切换天线阵设计中的应用

采用对天线单元开关通断的方法,使天线阵形成不同的远场辐射方向图,实现阵列天 线方向图宽波束和窄波束的切换。对一个24元线阵天线阵进行了设计。提出了一种改进 的遗传算法及其目标函数模型。采用该算法对天线阵各个天线单元的电流幅度进行了优化 计算,计算结果显示能够产生满足设计要求的宽波束和窄波束方向图。最后采用HFSS软 件进行了仿真,计算结果与仿真结果吻合,证明了所提方法的有效性。