基于自组网技术的燃气无线抄表系统研究

为解决现阶段燃气无线抄表系统数据采集中无线网络不稳定、路由协议复杂、自修复能力薄弱等问题，提出并设计了一种基于cc1101无线传送模块的树形拓扑结构无线自组网系统。系统中主要对数据采集层路由协议和硬件实现进行了研究和设计，分析了该燃气无线抄表系统与传统燃气无线抄表系统的不同之处，设计了该系统数据采集层网络传输协议和总体结构。无线节点建在穿透力强的433 MHz的频率下进行通信，保证了系统自组网的稳定快速。     

Flexible work planning of service agents with load balancing

This work emerged from the need to better plan the daily work of 29 travelling service agents, who provide 1090 services to 412 customers in 283 sites, on daily average. A handy and flexible tool was developed and is presented herein. A major contribution of this study is an explicit consideration of the multi-dimensional nature of the problem by the inclusion of workload balancing, which may stand in conflict to cost minimisation. Further, the geographical distribution of the demand is highly irregular. Therefore, two load measures are required and balanced. This required to fitting a proper planning scheme. The planning tool has been applied successfully by the commercial service provider. Improvements in the order of 20% and more were obtained in key performance measures. Moreover, cost reductions, service improvement and load balance were obtained simultaneously: the standard deviations of the service times and working day’s duration were reduced by 18 and 58%, respectively. This enables to reduce the number of agents with no significant harm in performance. Additional practical advantages of the proposed tool are also discussed and demonstrated, for example, the ability to cope with geographical distributions and the flexibility to respond to daily variations in demand.     

An evaluation of the tandem configuration automated guided vehicle system

The performance of a tandem automated guided vehicle (AGV) system is compared with that of conventional AGV track systems. In the tandem system the track is divided into non-overlapping, single-vehicle closed loops. Using simulation it is shown that, because of trips requiring delivery across loops, the tandem system has a higher expected travel time per load and thus a greater average time in system. When the loads are delivered within the original loop only, the tandem system has a lower average time in system than in conventional systems, although the difference is modest. Track layout appears to influence the average time in system much more than docs the dispatching rule invoked. The success of the tandem system is highly dependent on approximately even AGV utilization, which may be difficult to obtain in practice.     

城市交通中车辆择路行为实证研究

随机、时变的交通流分布,偶发的交通事故等因素导致了路径随机的车辆旅行时间,也决定了现实城市交通网络中只存在随机最短路.已有的路径选择研究大都假设人们力求选择最短路,而通过实际调查发现:人们的择路行为依赖出行情景,随出行目的、约束时间、对路径的熟悉程度以及路径的不确定程度而变化.验证了城市交通中人们在不确定环境下的择路行为也符合展望理论.     

Another economy: towards a cultural dialectics between energy and society

The looming oil crisis, pollution, and climate change have pushed governments, corporations, and individuals to think of new policies, new objects/products and new manners to market them – usually under the label of “green economy” (or the shifting towards a sustainable economy).

The changes that are on the way as a result of the envisaged “green revolution” need a broad vision that couples the economy of energetic techniques with the related socio-cultural economy that is induced by, and at the same time reciprocally influences, the mere technical transformations.

Based on previous analysis of theories of socio-technological change and putting at its center the concept of subjectivation in social sciences, this article proposes a theoretical understanding of cultural shifts and their relationship with changes in the practices of production, transfer and use of energy.

First part presents a schema of subjectivation in triangulation, that links the biological level with the material culture and with the representational realm of normativities in our society. It will be developed through the example of electric vehicle as metaphor of the energetic transition. Through this understanding, second part deals with the modeling of the three items as a processual energetic system by using the concepts of surplus and expenditure. Within this frame, we show how disruptions in one of the poles of this model influences the others and bring about changes in the entire Anthropo-Social level. Third part proposes possible types of emerging subjectivities and advances the idea of extending the realm of consciousness to the energetic transfers and their potentiality.     

基于功率约束及节点频谱选择的认知协同路由

为了提升认知无线网络的数据传输效率,优化节点能量负载,提出一种协同路由算法。基于覆盖与底层技术的协作设计一种协同网络架构,该架构针对网络频带表现多样化提供了一种新的频谱选择策略,提升频谱资源效用。结合协同网络频谱选择时的干扰特性,根据频谱、干扰和功率约束关系,提出最大化链路容量的频谱及节点功率分配方法。在协同路由设计上引入了频谱效用参数,参数的度量标准涉及节点剩余能量和链路容量,以优化路由节点能量负载和传输效率为目的。仿真对比结果表明,算法有效地利用信道接入机会进行数据转发,提高了传输效率,相比基于竞争进化算法的多播路由方法,数据包传递成功率提升了1．4％,平均网络吞吐量高出8．4％,平均节点剩余能量高出3．2％,在均衡节点负载上性能良好。     

具有模糊旅行时间的VRP的一种混合遗传算法

传统确定性车辆路径问题是近几十年来运筹学领域研究的一个热点问题.但在许多实际的应用中,由于受客观世界中存在的不确定性因素以及人类观察、认识事物的模糊性的影响,车辆路径问题的某些参数可能是模糊的、不确定的.文中传统确定性车辆路径问题被扩展为具有模糊特征的模糊车辆路径问题.在对具有模糊旅行时间的车辆路径问题进行简单描述的基础上,构建了该问题的数学模型,并通过将模糊逻辑、模糊控制方法与传统车辆路径问题的遗传算法进行有效结合,提出了解决该问题的一种混合遗传算法.最后给出了该问题的一个计算实例,并通过随机模拟试验验证了该算法的有效性和优越性.     

震后伤员救援车辆两阶段规划模型及算法研究

不确定情景下的应急物资配送和车辆路径优化问题是目前国内研究的一大热点,其中 震后伤员运送车辆调度及路径优化问题随着近几年地震等自然灾害的频繁发生也逐渐引起人 们的重视． 本文采用聚合优化算法对灾区进行应急救援区域划分,建立了以总救援时间最短和 相对综合救援权重值最大为目标的救援车辆两阶段数学规划模型,设计了带三角函数变异的 离散型萤火虫优化算法进行求解,并与常规算法求解结果做了对比分析． 通过算例进行模拟实 验表明,所提出的模型和算法可以有效解决地震情景下的伤员救援车辆调度问题,且改进算法 的全局搜索性能更优．     

河北省金融资源充分利用的路径选择

在开放的市场条件下,金融作为现代经济的核心,其资源的优化配置对区域经济发展有着及其重要的作用,本文根据河北省金融资源配置现状,分析了河北省金融资源利用中存在的问题,指出要充分利用河北省金融资源,必须从调整经济产业结构、改善金融生态环境、抑制金融资源外流和提高金融业自身水平做起。只有这样才能提高河北金融的竞争能力,促进河北经济的整体发展。     

工程车辆液力变矩器与发动机匹配的研究

对工程车辆中液力变矩器与发动机匹配的原则、评价指标和评价方法进行了分析研究，并结合工程车辆中使用工况比较复杂的装载机，进行了液力变矩器与发动机匹配评价的实例分析．