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.     

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。     

Improvement of a method of the evaluation of allocations of resources to activities

Resources are allocated to activities in order to maximize the ratio od a concave return to an affine cost. A previously given method transforms any feasible solution to an upper bound of the optimal objective value. In this paper a modification is introduced that reduces the upper bound.     

Invariant properties of systems of equations of the mechanics of inhomogeneous fluids

The invariant properties of the fundamental system of equations of the mechanics of inhomogeneous fluids and its widely used approximations are analysed by the methods of continuous group theory. Simplifying assumptions significantly alter the invariant properties of the systems of equations. Both extending and contracting the admissible symmetry group can occur and provide evidence of the violation of the conditions of equivalence between the original and derived systems. For example, the use of the incompressibility and Boussinesq approximations leads to extension of the concept of an inertial reference frame to all frames moving relative to one another with arbitrary linear acceleration.     

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.     

Generalizations of the concept of marginal synchronization of chaos

Generalizations of the concept of marginal synchronization between chaotic systems, i.e. synchronization with zero largest conditional Lyapunov exponent, are considered. Generalized marginal synchronization in drive–response systems is defined, for which the function between points of attractors of different systems is given up to a constant. Auxiliary system approach is shown to be able to detect this synchronization. Marginal synchronization in mutually coupled systems which can be viewed as drive–response systems with the response system influencing the drive system dynamics is also considered, and an example from solid-state physics is analyzed. Stability of these kinds of synchronization against changes of system parameters and noise is investigated. In drive–response systems generalized marginal synchronization is shown to be rather sensitive to the changes of parameters and may disappear either due to the loss of stability of the response system, or as a result of the blowout bifurcation. Nonlinear coupling of the drive system to the response system can stabilize marginal synchronization.     

Time-asymptotic behavior of solutions of systems of conservative differential equations and of measure-preserving transformations

Asymptotic properties of conservative systems and of measurepreserving transformations of a set into itself are already well known. These properties are here extended to the comparison of the evolution when the time goes to plus infinity and when it goes to minus infinity. It leads to an extension of the ergodic theorem and emphasizes the qualitative and quantitative stability of solutions of bounded (or limited) type and of oscillating type.     

Characterization of the speed of convergence of the trapezoidal rule

Summary Our aim is to determine the precise space of functions for which the trapezoidal rule converges with a prescribed rate as the number of nodes tends to infinity. Excluding or controlling odd functions in some way it is possible to establish a correspondence between the speed of convergence and regularity properties of the function to be integrated. In this way we characterize Sobolev spaces, certain spaces of infinitely differentiable functions, of functions holomorphic in a strip, of entire functions of order greater than 1 and of entire functions of exponential type by the speed of convergence.Dedicated to Professor G. Hämmerlin on the occasion of his 60th birthday     

A suggestion of a new measure of importance of system components

In this paper we suggest a new measure of the importance of a component in a coherent system and derive some of its properties. The measure is for the case of components not undergoing repair proportional to the expected reduction in the remaining system life-time due to the failure of the component. This measure seems to be a useful guide during the system development phase as to which components should receive the most urgent attention in order to increase the system's expected life-time. The properties of the measure are compared with the ones of a measure suggested by Barlow and Proschan [1].     

Continuity of Solutions of a Class of Fractional Equations

In practice many problems related to space/time fractional equations depend on fractional parameters. But these fractional parameters are not known a priori in modelling problems. Hence continuity of the solutions with respect to these parameters is important for modelling purposes. In this paper we will study the continuity of the solutions of a class of equations including the Abel equations of the first and second kind, and time fractional diffusion type equations. We consider continuity with respect to the fractional parameters as well as the initial value.     

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.     

Two-step generation of the equations of motion of closed-chains

This paper presents a two-step generation of the equations of motion of planar mechanisms using point and joint coordinates. First, the formulation replaces a rigid body by a dynamically equivalent constrained system of particles and uses Newton’s second law to study the motion of the particles without introducing any rotational coordinates. Then, the equations of motion are transformed to a reduced set in terms of selected relative joint variables using a velocity transformation matrix. For an open-chain, this process automatically eliminates all of the non-working constraint forces and leads to an efficient integration of the equations of motion. For a closed-chain, suitable joints should be cut and few cut-joints constraint equations are included. An example of a closed-chain is used to demonstrate the generality and efficiency of the proposed method.     

Strong convergence of weighted sums of random elements through the equivalence of sequences of distributions

The equivalence of sequences of probability measures jointly with the extension of Skorohod's representation theorem due to Blackwell and Dubins is used to obtain strong convergence of weighted sums of random elements in a separable Banach space. Our results include most of the known work on this topic without geometric restrictions on the space. The simple technique developed gives a unified method to extend results on this topic for real random variables to Banach-valued random elements. This technique is also applied to the proof of strong convergence of some statistical functionals.     

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.     

一类函数第一积分中值定理中值点的渐近性

给出了当积分区间的两个端点都为被积函数的若干次零点时,第一积分中值定理中值点的渐近性质.     

Calculation of optimal controls of specified accuracy

A useful approach to the calculation of optimal controls is to take a piecewise constant approximation to the control and to solve the resulting nonlinear program using available techniques. There is no way of specifying the required number of control intervals a priori, but this paper shows that the adjoint system used to calculate gradients for the optimization provides at each iteration sufficient information to assess the gain from increasing the number of intervals and to indicate the best locations for the appropriate switching times. An example is presented which shows the potential computational savings that can be realized when the number of control intervals is progressively increased until the desired accuracy of the approximation is achieved.     

Cohomology of categories and extensions of twisted diagrams of groups

A twisted diagram of groups assigns a group to every object of an indexing category and a homomorphism of groups to every morphism. However, it does not have to be completely functorial — it preserves composition only up to a compatible family of inner automorphisms. A. Haefliger defined a special case: the complex of groups. We prove that there exists a natural bijective correspondence between equivalence classes of epimorphisms of twisted diagrams of groups and elements of the second cohomology group of a certain small category. If this category is defined by a discrete group, then we obtain the well known classification of extensions of groups.     

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.     

Nonnegative elements of subgroups of

We give a method to compute all nonnegative integer solutions of a homogeneous system of linear equations. We use this method to provide an algorithm to compute all nonnegative integer solutions of homogeneous systems of equations having some of the equations in congruences.     

结构方程模型应用陷阱分析

结构方程模型近几年在我国心理学、管理学应用研究领域得到越来越多的应用,但部分应用者因其对其基本原理理解不够透彻导致误用或错用这种重要统计手段。本文通过结合实证研究实例对一些常见应用错误(问题)的分析揭示结构方程模型的原理,以期帮助应用者避免应用陷阱、提高实证研究水平。