Symbolic correlation integral

This paper aims to introduce the concept of symbolic correlation integral SC that is extensively used in many scientific fields. The new correlation integral SC avoids the noisy parameter 𝜀 of the classical correlation integral, defined by Grassberger and Procaccia (1983 Grassberger, P., Procaccia, I. (1983). Measuring the strangeness of strange attractors. Physica D: Nonlinear Phenomena 9(1–2):189–208.[Crossref], [Web of Science ®] , [Google Scholar]) and extensively used for constructing correlation-integral-based statistics, as in the BDS test. Once the free parameter 𝜀 disappears, it is possible to construct a nonparametric powerful test for independence that can also be used as a diagnostic tool for model selection. The symbolic correlation integral is also extended to deal with multivariate models, and a test for causality is proposed as an example of the theoretical power of the new concept. With extensive Monte Carlo simulations, the paper shows the good size and power performance of symbolic correlation-integral-based tests.     

考虑进口配额的跨国供应商选择与订单分配模糊多目标优化决策

针对跨国供应商选择与订单分配问题,在考虑进口配额限制和需求不确定的情境下,构建了一个实现核心制造商利润最大化和供应商交货质量最大化的模糊多目标混合整数规划模型。该模型考虑汇率、关税等多个全球因素,采用一种交互式模糊多目标规划方法对模型进行求解,并应用一个算例进行验证。研究表明:1.存在进口配额限制时,制造商会优先考虑低成本高质量的海外供应商,达到配额限制后再选择本土供应商补充剩余订单;2.人民币汇率正向影响制造商海外采购。当人民币汇率上升时,制造商进口成本降低,其会将更多订单分配给海外供应商;3.关税负向影响制造商海外采购。当关税上升时,制造商会减少关税高的供应商的进口数量,选择替代供应商来满足其需求。由此获得如下管理启示:1,制造商企业在选择跨国供应商时,应重点关注本国的进口配额政策,使供应商多样化以减少针对单一供应商配额政策剧烈波动对制造商采购成本和企业利润的不利影响。2.汇率时刻都在变动,制造商企业应关注本国和供应商所在国的长期汇率政策以及短期突发事件对汇率的影响,及时调整订单分配决策。3.制造商企业在选择供应商时,需要对供应商所在国的短期和中长期关税政策进行综合评估。     

考虑属性关联的两阶段获胜者确定模型

研究了多属性逆向拍卖的获胜者确定问题。考虑属性之间的两两关联，以定义在2-可加模糊测度上的Choquet积分表达拍卖人的偏好，其中模糊测度的值由拍卖人提供的偏好信息推测得出。由于一般情况下与偏好信息一致的模糊测度取值并不唯一，考虑所有一致的评分函数提出了两阶段获胜者确定方法。首先采用线性规划挑选出在任意评分函数下可能获胜的报价，再通过混合整数规划确定一个与所有一致的评分函数的评价结果最为接近的报价排序，以得分最高者为稳健获胜报价。仿真实验表明，大量的报价为不可能获胜报价，说明了在第一阶段进行筛选的必要性。与现有方法的比较表明了该方法的有效性，且在拍卖轮数较大、报价数目较多时，该方法在计算效率上更有优势。     

Bi-objective multi-resource scheduling problem for emergency relief operations

Abstract

Resource scheduling for emergency relief operations is complex as it has many constraints. However, an effective allocation and sequencing of resources are crucial for the minimization of the completion times in emergency relief operations. Despite the importance of such decisions, only a few mathematical models of emergency relief operations have been studied. This article presents a bi-objective mixed integer programming (MIP) that helps to minimize both the total weighted time of completion of the demand points and the makespan of the total emergency relief operation. A two-phase method is developed to solve the bi-objective MIP problem. Additionally, a case study of hospital network in the Melbourne metropolitan area is used to evaluate the model. The results indicate that the model can successfully support the decisions required in the optimal resource scheduling of emergency relief operations.     

基于双层规划的反恐应急设施选址模型及算法

恐怖袭击常以人流密集地区的平民作为袭击目标，并存在突发性和随机性等特点，极易造成严重的袭击后果。通过反恐应急设施的合理布局可以缩短救援人员和物资的到达时间，从而减轻袭击后果。首先，对反恐应急设施选址问题进行描述，并将其构造为一类离散双层规划模型。其中，上层规划是关于政府选址的0-1规划问题，下层规划则是关于恐怖分子袭击目标选择的0-1规划问题。其次，结合模型和问题的特征设计算法，利用分支定界算法实现上层选址变量的隐枚举，同时通过下层问题的求解来确定上下界并判断是否满足分枝或剪枝的条件。最后，结合南疆地区的交通拓扑网络进行算例分析，结果证明有效的选址方案可以大大降低袭击损失。     

改进区间可接受度的证券投资组合区间二次规划模型

本文首先基于Markowitz的经典均值方差模型，针对不确定环境下的投资组合问题，把证券的收益率、风险损失率和流动性用区间数描述，建立了一种新的含交易成本的证券投资组合区间二次规划模型。其次，为求解该模型，提出了改进的区间可接受度确定性转换方法，通过引入优化水平α与可接受水平η将不确定二次规划转化为确定型规划。最后，通过数值实验将提出的方法与传统方法进行比较，结果表明本文所提出的方法与模型具有相对较好的可行性与实用性。     

Building Virtual Age-Friendly Communities in Minecraft

A key theme of Age-Friendly Honolulu’s initiative is intergenerational exchange. The initiative believes that youth need to be aware of aging issues, demographic change, and think critically about the potential impact on their lives. The goal of the Age-Friendly Honolulu Youth Engagement Initiative is to teach youth about the role of the built environment and community features in promoting active aging and engagement among older adults. This article describes a new program in the field that teaches youth and older adults to assess the built environment and then use design thinking and Minecraft (a popular video game in which players use 3-D blocks to create virtual lands) to develop and envision ideas to improve the livability of their neighborhood.     

碳金融市场下基于模糊测度和Choquet积分的碳期权估值

基于投资者对投资财富和风险的偏好研究碳期权定价模型。运用λ-可加模糊测度表示投资者对碳期权价值模糊度量的差异性，借助Choquet期望积分构建投资者的期望收益效用函数；根据投资财富效用最大化推导无约束条件下碳期权的最优价；结合现实约束条件，构建投资财富效用最大化下的碳期权定价模型；通过数值计算分析效用函数、模糊参数和现实约束对碳期权定价的影响。研究结果表明:效用函数的选择会体现投资者对碳期权投资风险态度的变化，模糊测度参数的取值能够反映碳期权投资者个体的主观情绪和市场信息获取程度，现实约束会迫使碳期权投资者放弃部分投资隐含价值。     

Integrated retail decisions with multiple selling periods and customer segments: Optimization and insights

Integrating retail decisions on such aspects as assortment, pricing, and inventory greatly improves profitability. We examine a multi-period selling horizon where a retailer jointly optimizes assortment planning, pricing, and inventory decisions for a product line of substitutable products, in a market with multiple customer segments. Focusing on fast-moving retail products, the problem is modeled as a mixed-integer nonlinear program where demand is driven by exogenous consumer reservation prices and endogenous assortment and pricing decisions. A mixed-integer linear reformulation is developed, which enables an exact solution to large problem instances (with up to a hundred products) in manageable times. Empirical evidence is provided in support of a classical deterministic maximum-surplus consumer choice model. Computational results and managerial insights are discussed. We find that the optimal assortment and pricing decisions do not exhibit a simple, intuitive structure that could be analytically characterized, which reflects the usefulness of optimization approaches to numerically identify attractive trade-offs for the decision-maker. We also observe that suboptimal inventory policies significantly decrease profitability, which highlights the importance of integrated decision-making. Finally, we find that the seasonality of consumer preferences and supply costs present an opportunity for boosting the profit via higher inventory levels and wider assortments.     

儿童编程工具发展历程、特征及对未来教育路向的影响

摘 要：从1960年代LOGO的诞生开始,儿童编程经历了准备期、发展期、实施期、停滞期、复兴期五个时期的发展。总体特征是从复杂语法到简单语法、从抽象系统到可视化系统、从文本编程到非文本编程、从软件编程到物理编程。编程工具的不断发展和完善,让儿童学习编程成为可能。随着数字化社会的到来,编程教育将逐渐成为儿童教育中不可或缺的一部分,并将向下延伸到小学和幼儿园,其教育路向很可能朝学校化、普及化、低龄化发展。