Location of courts of justice: The making of the new judiciary map of Portugal

Location modeling techniques have been applied to an extremely wide variety of public facilities. However, their application to one of the most ubiquitous public facilities – courts of justice – has been very rare. In this paper, we describe a study promoted by the Ministry of Justice of Portugal to define a proposal for the country's new judiciary map – that is, the spatial organization of the judicial system. The new map aims to promote the efficiency and specialization of the justice system (leading to better and faster court decisions) and to provide a good level of accessibility to courts. We developed two optimization models addressing those goals – a districting model, to determine the borders of new, large judicial districts; and a court location model, to determine the location, type, size, and coverage area of the courts included in each new district. Both models are discrete facility location models and consider hierarchical facilities – generic courts and specialized courts of multiple types. Our study was publicly acknowledged by the Portuguese government as having contributed to the new judiciary map that has since been approved and implemented.     

Convergence of densities of some functionals of Gaussian processes

The aim of this paper is to establish the uniform convergence of the densities of a sequence of random variables, which are functionals of an underlying Gaussian process, to a normal density. Precise estimates for the uniform distance are derived by using the techniques of Malliavin calculus, combined with Stein?s method for normal approximation. We need to assume some non-degeneracy conditions. First, the study is focused on random variables in a fixed Wiener chaos, and later, the results are extended to the uniform convergence of the derivatives of the densities and to the case of random vectors in some fixed chaos, which are uniformly non-degenerate in the sense of Malliavin calculus. Explicit upper bounds for the uniform norm are obtained for random variables in the second Wiener chaos, and an application to the convergence of densities of the least square estimator for the drift parameter in Ornstein–Uhlenbeck processes is discussed.     

Student achievement effects of technology-supported remediation of understanding of fractions

Students have difficulty learning fractions, and problems in understanding fractions persist into adulthood, with moderate to severe consequences for everyday and occupational decision-making. Remediation of student misconceptions is hampered by deficiencies in teachers’ knowledge of the discipline and pedagogical content knowledge. We theorized that a technology resource could provide the sequencing and scaffolding that teachers might have difficulty providing. Five sets of learning objects, called CLIPS (Critical Learning Instructional Paths Supports), were developed to provide remediation on fraction concepts. In this article, we describe one stage in a research program to develop, implement and evaluate CLIPS. Two studies were conducted. In Study 1, 14 grade 7–10 classrooms were randomly assigned, within schools, to early and late treatment conditions. A pre-post, delayed treatment design found that CLIPS had no effect on achievement for the Early Treatment group due to unforeseen implementation problems. These hardware and software issues were mitigated in the late treatment in which CLIPS contributed to student achievement (Cohen's d = 0.30). Study 2 was a pre-post, single group replication involving 18 grade 7 classrooms. The independent variable was the number of CLIPS completed. Completion of all five CLIPS contributed to higher student achievement: Cohen's d = 0.53, compared to students who completed none (d = 0.00) or 1–4 CLIPS (d = 0.02). The two studies indicate that a research-based set of learning objects is effective when the full program is implemented. Incomplete sequences deprive students of instruction in one or more constructs linked to other key ideas in the conceptual map and reduce the amount of practice required to remediate student misconceptions.     

大学生职业生涯发展的决定因素的相关研究

本文利用探索性因素分析方法提出了一个可以用作为甄别大学生涯发展的决定因素的诊断工具,以期帮助职业生涯咨询、指导人员对个体的有关职业生涯态度、职业生涯倾向性有一个基本的了解;同时利用这个工具可以提高个体对职业生涯的认知水平,帮助个体更好地进行职业生涯规划。     

On students' understanding of volumes of solids of revolution: An APOS analysis

We apply Action-Process-Object-Schema theory (APOS) to (1) examine the textbook used by students in the study to infer mental constructions the book proposes that students could do to understand solids of revolution, (2) use semi-structured interviews with nine students to find out which of the textbook’s proposed constructions students actually do, and what unconjectured or unexpected constructions students do, and (3) use the results of the interviews and the research literature to inform and set forth an alternative proposal for constructing volumes of revolution. Results suggest that many students have not constructed processes to visualize solids of revolution and to relate Riemann sums to the corresponding definite integrals. Implications for curriculum and instruction are discussed.     

Asymptotic behaviour of bounded solutions of a class of higher-order neutral dynamic equations

In this paper, necessary and sufficient conditions for the asymptotic behaviour of all bounded solutions of a class of nonlinear higher-order neutral dynamic equations are stated related to various ranges of the coefficient associated with the neutral part, in one of which the coefficient is allowed to oscillate and not tend to zero asymptotically. The new results improve and generalize the known results stated for difference equations and differential equations, and answer some problems left open for the case for arbitrary time scales. Some certain examples, which the results in the literature fail to deliver an answer to, are given to illustrate the applicability and significance of the new results.     

货物列车的编组调度问题

研究的是货物列车的编组和调度问题.通过对问题的深入研究,设计了一种车辆编组调度方案的算法.按照这种算法,在数据处理的基础上利用VC编写每个问题的处理程序,实现了对列车的快速安全高效的调度.对每个问题进行处理,都得到符合要求的结果.问题一首先对整个车辆编组调度的问题进行分析,在尽量保证新组装列车满载的基础上,使每班的中时尽可能少.为此,本文解决了两个关键问题:一是选车问题,二是拆解重组的问题.采用梯形方案对列车车辆进行编队重组,对选车问题主要采用按照时间先后顺序的选车方案,然后通过启发式算法配合遗传算法的选车方案对按时间先后顺序的方案进行检验.从编写的VC程序的运行结果来看,两种方案都可得到满意的结果,遗传算法得到的结果更为合理.另外,为了达到中时最短,采用双推双滑的方式利用驼峰线,提高了调度效率,并在驼峰线和编组道之间加入了碰撞检验模块,保证了列车调度时的安全性.问题二的求解是在问题一的基础上对待拆列车按优先级进行分类.对优先级高的列车先进行拆解.救灾车辆最高,其次是军列和发往S1的车辆,最后是一般车辆.问题三的处理主要是在问题二的基础上,通过提前获得列车的相关信息来决定编组场的列车离开编组场的时刻,从而缩短车辆的中时.问题四在原有模型基础上对编组方案进行了修改,利用编写的VC程序重新计算了每班的中时和列车的调度方案.问题五主要分析了整个系统瓶颈所在,分析了提高资源利用率的可行性.最后,通过对站名的调整,达到了对地质灾害等对铁路系统的破坏突发情况的有效处理,并且进一步分析了如何提高车站的效率的调度方案和建议.     

Invertibility of the Difference of Idempotents

We study conditions equivalent to the invertibility of f -g when f and g are idempotents in a unital ring, and give applications to bounded linear operators in Banach and Hilbert spaces. In the setting of rings we are able to show that many conditions previously linked to finite dimensionality, rank equalities, norm topology of bounded linear operators or to properties of C *-algebras can be in fact proved by simple algebraic arguments.     

高管个人特征对股权激励模式选择的影响研究

上市公司股权激励模式的选择问题一直受社会各界关注。本文利用2006年到2017年期间实施股权激励的上市公司数据,研究了高管个人特征如何对股权激励模式的选择产生影响。结果表明,被激励高管的个人特征如高管年龄、任期、学历与社会资本显著影响公司股权激励模式的选择,年龄越大、任期越久、学历越高、社会资本越丰富的高管,公司更倾向选择限制性股票激励模式;男性高管越多的公司,越倾向选择股票期权激励模式,然而性别对其影响并不显著。本文在经过一系列的稳健性和内生性检验后,研究结论依然成立。本文研究结果丰富了股权激励相关理论,并为上市公司科学合理地选择股权激励模式提供参考。     

天然气需求影响因素分析及未来需求预测

不同的影响因素对天然气需求的影响程度存在差异,为充分认识上述差异,利用相对关联度定量刻画天然气需求量与影响因素之间的关联程度。依据重要性优先原则,采用逐步回归法逐次地对影响因素的统计显著性进行检验,深度挖掘有效驱动因素,构建“最佳”逐步回归C-D生产函数模型预测未来天然气需求走势。结果表明:(1)GDP是影响中国天然气需求的最主要因素,能源消费结构也是重要的有效驱动因素之一;(2)基于重要有效驱动因素构建的“最佳”逐步回归C-D生产函数模型实现了历史数据拐点拟合预测,具有良好的预测性能,预测结果可作为确定未来天然气需求的重要参考依据;(3)预测2020~2030年中国天然气需求量呈稳步增长趋势,但增速有所减缓,到2030年天然气需求量达约5660亿立方米,天然气需求量增长率降至4%。     

船载特种设备基点轨迹测量的误差分析

对船载特种设备基准点的空间位置进行测量,得到该基准点的运动轨迹并进行测量误差分析,是某项工程数据处理的重要内容.提出了利用三台船载GPS接收机测量船载特种设备基准点的原理和误差分析方法,介绍了该方法的误差源构成,依据测量原理模型,推导出定位精度的估算公式,并叙述了仿真计算与测量实施.     

Undecidability of the elementary theory of groups of measure-preserving transformations

The undecidability of the elementary theory of the automorphism group for a Lebesgue space is proved. It is shown that arithmetic can be interpreted in this theory. The technique of proof can be carried over to certain other groups. Translated fromMatematicheskie Zametki, Vol. 63, No. 3, pp. 414–420, March, 1998. The author wishes to thank the participants of the seminar on dynamical systems headed by D. V. Anosov, R. I. Grigorchuk, and A. M. Stepin as well as the participants of the Kolmogorov seminar of the Mechanics and Mathematics Department of Moscow State University for discussion of this work. The author is also indebted to N. K. Vereshchagin and A. M. Stepin for support and valuable remarks as well as to V. V. Ryzhikov for setting the problem and for his assistance.     

Categories of models of R-mingle

We give a new Esakia-style duality for the category of Sugihara monoids based on the Davey-Werner natural duality for lattices with involution, and use this duality to greatly simplify a construction due to Galatos-Raftery of Sugihara monoids from certain enrichments of their negative cones. Our method of obtaining this simplification is to transport the functors of the Galatos-Raftery construction across our duality, obtaining a vastly more transparent presentation on duals. Because our duality extends Dunn's relational semantics for the logic R-mingle to a categorical equivalence, this also explains the Dunn semantics and its relationship with the more usual Routley-Meyer semantics for relevant logics.     

Degenerations of Representations of Associative Algebras

The purpose of this note is to give a fast introduction to some problems of homological and geometrical nature related to finite-dimensional representations of finitely generated, and especially, finite-dimensional algebras over a field. Some of these results can also be extended to the situation where the field is not algebraically closed, and some of the results can even be extended to the situation where one is considering algebras over a commutative artin ring. For the results which hold true in the most general situation the proofs become most elegant since they depend on using length arguments only and thereby forgetting about the nature of a field altogether. Received: July 2007     

Computational Modeling of Organizations Comes of Age

As they are maturing—i.e., as they are becoming validated, calibrated and refined—computational emulation models of organizations are evolving into: powerful new kinds of organizational design tools for predicting and mitigating organizational risks; and flexible new kinds of organizational theorem-provers for validating extant organization theory and developing new theory. Over the past 50 years, computational modeling and simulation have had enormous impacts on the rate of advancement of knowledge in fields like physics, chemistry and, more recently, biology; and their subsequent application has enabled whole new areas of engineering practice. In the same way, as our young discipline comes of age, computational organizational models are beginning to impact behavioral, organizational and economic science, and management consulting practice. This paper attempts to draw parallels between computational modeling in natural sciences and computational modeling of organizations as a contributor to both social science and management practice.To illustrate the lifecycle of a computational organizational model that is now relatively mature, this paper traces the evolution of the Virtual Design Team (VDT) computational modeling and simulation research project at Stanford University from its origins in 1988 to the present. It lays out the steps in the process of validating VDT as a computational emulation model of organizations to the point that VDT began to influence management practice and, subsequently, to advance organizational science. We discuss alternate research trajectories that can be taken by computational and mathematical modelers who prefer the typical natural science validation trajectory—i.e., who attempt to impact organizational science first and, perhaps subsequently, to impact management practice.The paper concludes with a discussion of the current state-of-the-art of computational modeling of organizations and some thoughts about where, and how rapidly, the field is headed.     

Stochastic Perturbations of Line Solitons of KP

We consider the properties of localized solutions of the KP equation coupled to a stochastic noise. Corresponding to white noise, we find that the traveling waves are destroyed asymptotically, and we determine the distribution of the wave position and the arrival time. For generalized Ornstein–Uhlenbeck processes, we show that the only effect of noise is to render the asymptotic position random; in particular, when the noise has a sufficiently strong attenuation mechanism, the random wave coincides asymptotically with the unperturbed one. We also consider linearization of the corresponding Cauchy problem in the plane corresponding to this kind of initial data.     

基于现金流量的虚拟企业协同增值评估模型研究

虚拟企业是个开放性的复杂系统,其本质是协调成员企业的管理,提高和协调其有序性以达到协调增值的目的.基于现金流,通过黑箱理论与投入产出模型分别建立了成员企业、虚拟企业以及信息共享下的虚拟企业价值评估模型,通过比较三者的差值评估虚拟企业的协同增值效应.     

复数在鱼雷或舰船平面运动规律研究中的应用

为了更方便地研究鱼雷、水面舰船等武器或装备的平面运动规律,运用复数的指数表示,在相应坐标系下对它们的运动规律进行描述,得到任意时刻的轨迹方程,从而利用复数的运算性质和数学分析的方法进行分析,不仅能简单明确的描述问题,又能很大程度地省去了直角坐标系下繁琐的运算过程,还可以直接在MATLAB环境实现相关的结果,从而为平面运动规律问题的研究提供了的更为方便的工具和方法,尤其是对解决有关转角运动的问题意义更大.     

关于需求价格弹性的探讨

需求价格弹性是管理经济学中的一个重要概念,是指导市场行为的重要指标,如何理解需求价格弹性概念,掌握弹性的计算方法就显得格外重要.本文探讨需求价格弹性的概念及计算方法.     

Stabilization of invariants of discretized differential systems

Many problems of practical interest can be modeled by differential systems where the solution lies on an invariant manifold defined explicitly by algebraic equations. In computer simulations, it is often important to take into account the invariant's information, either in order to improve upon the stability of the discretization (which is especially important in cases of long time integration) or because a more precise conservation of the invariant is needed for the given application. In this paper we review and discuss methods for stabilizing such an invariant. Particular attention is paid to post-stabilization techniques, where the stabilization steps are applied to the discretized differential system. We summarize theoretical convergence results for these methods and describe the application of this technique to multibody systems with holonomic constraints. We then briefly consider collocation methods which automatically satisfy certain, relatively simple invariants. Finally, we consider an example of a very long time integration and the effect of the loss of symplecticity and time-reversibility by the stabilization techniques. This revised version was published online in June 2006 with corrections to the Cover Date.