基于通勤行为的小城镇土地利用与格局优化对策研究——以扬中市为例

研究目的:从居民的通勤行为特征中寻求小城镇土地利用格局优化路径,为产城融合的实现提供理论支持。研究方法:构建通勤流矩阵,运用Arc GIS路径分析测算通勤距离,并通过缓冲区分析通勤距离在空间上的特征,并与土地利用类型进行对比分析,同时建立通勤距离与社会经济因素的回归方程,分析通勤距离的影响因素。研究结果:小城镇通勤方式以便捷型工具为主,通勤高峰集中于上下班,通勤距离随着城镇化和工业化水平的提高,短距离占比增大。主要结论:在城镇化和工业化发展较快的区域,短距离通勤集聚更具有"同心圆"特征,核心力更强。工业化带动的聚集结构呈现出"条带形"态势,与区域工业布局结构有较密切的关系,也与城镇化和工业化扩增融合有关。短距离通勤集聚区会随着城镇化水平的提高而由"双核"向"单核"结构发展,并针对以上问题提出了相应的对策。     

华为负值PBGT切换技术应用

负值PBGT切换技术的实现和分层分级算法相似,但比分层分级算法更加灵活,它是移动通信系统中非常重要的技术。现通过工程实践多次使用网络优化工具设置负值PBGT切换参数,实现在双频网优化上的应用,可以避免乒乓切换引起掉话,该技术的应用有重要的现实意义。     

浅谈价值工程在地下管线探测项目设计方案评价中的应用

价值工程作为一种将功能与成本、技术与经济相结合而进行技术经济评价的方法,又称为价值分析。本文通过结合地下管线探测项目的具体实例,探讨了在具体的施工过程中,为了在降低工程成本的同时能够有效的保证施工工程的质量和进度,如何采用价值工程的方法选择以及优化施工组织设计的方案。实践证明,在施工项目中应用价值工程的方法不仅能够完善施工方案,还能有效确保施工进度并且能够有效提高利润,最重要的是还能够很好的保证施工质量。     

Pareto efficient allocation of an in-motion wireless charging infrastructure for electric vehicles in a multipath network

Electric vehicles (EV) use an eco-friendly technology that limits the greenhouse gas emissions of the transport sector, but the limited battery capacity and the density of the battery are the major barriers to the widespread adoption of EV. To mitigate this, a good method seems to be the innovative wireless charging technology called ‘On-Line EV (OLEV)’, which is a contactless electric power transfer technology. This EV technology has the potential to charge the vehicle’s battery dynamically while the vehicle is in motion. This system helps to reduce not only the size of the battery but also its cost, and it also contributes to extending the driving range before the EV has to stop. The high cost of this technology requires an optimal location of the infrastructure along the route. For this reason, the objective of this paper is to study the problem of the location of the wireless charging infrastructure in a transport network composed of multiple routes between the origin and the destination. To find a strategic solution to this problem, we first and foremost propose a nonlinear integer programming solution to reach a compromise between the cost of the battery, which is related to its capacity, and the cost of installing the power transmitters, while maintaining the quality of the vehicle’s routing. Second, we adapt the multi-objective particle swarm optimization (MPSO) approach to our problem, as the particles were robust in solving nonlinear optimization problems. Since we have a multi-objective problem with two binary variables, we combine the binary and discrete versions of the particle swarm optimization approach with the multi-objective one. The port of Le Havre is presented as a case study to illustrate the proposed methodology. The results are analyzed and discussed in order to point out the efficiency of our resolution method.     

Diversified behavioral portfolio as an alternative to Modern Portfolio Theory

The traditional mean–variance approach has been complemented by alternative theories that use risk measures different from standard deviation of returns or involve additional distributional features of returns like skewness and kurtosis. We propose a portfolio choice model that combines different distributional characteristics of the returns in the decision-making making process, considering preferences of investors which are modeled as non-statistical uncertainties of investors using fuzzy theory. We use 20 stocks of the S&P500 from January 2013 to December 2017. We assess the obtained portfolios’ performance, and the diversified behavioral portfolios outperform than the mean–variance portfolio. This methodological proposal can be seen as a strong managerial tool to make investment portfolio decisions.     

An integrated replenishment-recruitment policy in a sustainable retailing system for deteriorating products

Currently, retail facilities play a significant role both economically and socially for their contributions to job creation and to reducing unemployment. In this paper, economic, environmental, and social issues, including unemployment, job creation for the local workforce within their hometown, the immigration of an unemployed workforce, and the naturalization of non-natives are addressed for a retailer. We explore the class of deteriorating products from the viewpoint of its economic and environmental features. Then, a linear multi-objective mathematical model is developed to determine an integrated replenishment and recruitment policy for the retailer in the direction of sustainability. Using data from the flower industry, a numerical analysis is presented. The results indicate that if necessary facilities and infrastructures are provided to permanently settle qualified immigrants, both social and economic indicators will be improved. We also determine that by concentrating on strategies such as job creation for natives through retail facilities with no increase in production capacity and by applying careful policies for immigration and naturalization, social welfare can be improved.     

集装箱船初稳性高度优化模型的建立

为解决目前集装箱配积载中尚需结合人工经验来进行箱位选配的问题,通过研究集装箱船配积载前重心距基线高,运用集装箱船初稳性高度计算原理,结合集装箱船的结构特点,建立集装箱船初稳性高度优化模型。运用交互式的线性和通用优化求解器编写程序,其研究成果将为实现集装箱船自动化配积载目标提供理论基础。     

Stochastic regularization for the mean-variance allocation scheme

Despite being based on sound principles, the original Markovitz portfolio allocation theory cannot produce sound allocations, and restrictions or modifications need to be imposed from outside the theory in order to obtain meaningful portfolios. This is unsatisfactory, and the reasons for this failure are discussed, in particular, the unavoidable small eigenvalues of the covariance. Within the original principles of risk minimization and return maximization, several modifications of the original theory are introduced. First, the strategic and tactical time horizons are separated. A base long-term allocation is chosen at the strategic time horizon, while the portfolio is optimized at the tactical time horizon using information from the price histories. Second, the tactical portfolio is financed by the strategic one, and a funding operator is introduced. The corresponding optimal allocation (without constraints) has one free parameter fixing the leverage. Third, the transaction costs are taken into account. This includes the current re-allocation cost, but crucially the expected costs of the next reallocation. This last term depends on the sensitivity of the allocation with respect to the covariance, and the expectation introduces another dependency on the (inverse) covariance. The new term regularizes the original minimization problem by modifying the lower part of the spectrum of the covariance, leading to meaningful portfolios. Without constraints, the final Lagrangian can be minimized analytically, with a solution that has a structure similar to the original Markovitz solution, but with the inverse covariance regularized by the expected transaction costs.     

湘桂铁路下穿全兴高速公路设计方案优化

新建湘桂铁路于DK233+503处下穿全兴高速公路,原设计采用顶进框架桥方案。通过对安全质量的可控性、经济、工期等方面进行综合比选,取消顶进框架桥,变更为公路箱梁桥上跨铁路方案,采用分幅封道、分幅施工,既安全快速地穿过全兴高速公路,又创造了良好的经济效益和社会效益,为类似的工程提供了一定的参考价值。     

山区高速公路施工成本控制——优化大临工程及设计方案节约施工成本

本文以承秦高速三标为背景,通过优化施工便道、临时电力、弃土场、拌和站、梁场等大临工程施工方案,优化隧道、桥梁设计方案,有效降低了施工成本,取得了较好的经济效益,对山区高速公路施工成本管理有一定的借鉴意义。