A multiple stream generator based on de Bruijn digraph homomorphisms

We propose a method to obtain several streams of pseudorandom numbers based on a backbone generator of the generalized shift register type. The method is based on inverting one cycle in a de Bruijn digraph into many sequences in a higher-order de Bruijn graph via an appropriate graph homomorphism. We apply this technique to twisted generalized feedback shift register generators and to the Mersenne Twister MT19937. Positive results of statistical testing are reported.     

Valores humanos en trabajadores de bajo nivel educativo en Natal (Brasil)

Resumen

Las investigaciones sobre valores humanos se han incrementado bajo la influencia de la teoría de los tipos motivacionales que abarca una tipología de valores y una estructura dinámica. En dicha perspectiva, se han desarrollado cuestionarios para la medición de los distintos tipos de valores, siendo uno de ellos el Portrait Values Questionnaire (PVQ). En Brasil existe la necesidad de contar con instrumentos de investigación útiles para segmentos de la población de bajo nivel educativo. En la presente investigación se aplicó el referido cuestionario a 474 trabajadores de sectores económicos en los que predomina un nivel educativo bajo. Para analizar las respuestas se aplicaron el análisis factorial (AF) y el smallest space analysis (SSA). A partir de los resultados del AF se identificó una estructura con cuatro factores—Pacifismo-hedónico, Poder, Religiosidad y Conformidad—mientras que gracias al SSA se identificaron siete tipos de valores: Poder-logro, Poder-estimulación, Autodirección, Hedonismo Religioso, Universalismo, Benevolencia y Conformidad. Los resultados revelaron que, entre las personas de bajo nivel formativo, las diferencias entre tipos de valores pierden en exactitud pero presentan nuevos sentidos.     

What we talk about when we talk about ‘walking in the city’1

Originally published. in France in 1980 (and translated. into English in 1984), Michel de Certeau's The Practice of Everyday Life has assumed. the status of an ur-text for many cultural studies academics and students. In particular, his chapter on ‘Walking in the City’ is often cited. as a blueprint for understanding key terms in the cultural studies repertoire such as ‘power’ and ‘resistance’. This article revisits ‘Walking in the City’ in order to supplement some of the established. understandings of his work circulating in the field of cultural studies, as well as the intersecting fields of cultural geography and urban studies. The paper begins by suggesting ways in which established. understandings of Certeau's work might be usefully rethought and extended. through a consideration of differentiated. instances of walking. Critiquing the account of body-subject relations posited. by Certeau through reference to the writings of Marcel Mauss on techniques of the body and self, the author calls, in particular, for a greater consideration of the role of assemblages and affect in understanding everyday urban practices. By the conclusion of the article, the author arrives at a more nuanced. understanding of the feedback loop between the body-subject and the city, and suggests ways in which Certeau's writing on walking remains productive for those strains of cultural studies interested. in the practices of an increasingly virtualized. urban space.     

重视语言教与学中的“情感过滤”

本文在简要论述什么是第二语言习得及二语习得理论对语言教师实践的重要意义的基础上,着重探讨了二语习得中情感因素的研究成果,特别是"情感过滤"现象的存在对外语教与学的启示.     

A Bayesian positive dependence of survival times based on the multivariate arrangement increasing property

We introduce a new notion of positive dependence of survival times of system components using the multivariate arrangement increasing property. Following the spirit of Barlow and Mendel (J. Amer. Statist. Assoc. 87, 1116–1122), who introduced a new univariate aging notion relative to exchangeable populations of components, we characterize a multivariate positive dependence with respect to exchangeable multicomponent systems. Closure properties of such a class of distributions under some reliability operations are discussed. For an infinite population of systems our definition of multivariate positive dependence can be considered in the frequentist’s paradigm as multivariate totally positive of order 2 with an independence condition. de Finetti(-type) representations for a particular class of survival functions are also given.     

n元数及其性质(Ⅰ)

本文研究了所谓“几元阵”的运算特性,考察了二元阵与复数的一致对应规律,概括出关于n维实向量的统一的算术运算(加法、减法、乘法、除法)体系,从而导致n元数的发现,把数的概念——实数和复数,推广到一般的n维实向量。     

The rhetorical construction of efficiency: Restructuring and industrial democracy in Mondragón,Spain

This paper examines the tension between the struggle to survive in a competitive economy and efforts to create more democratic workplaces in the Basque worker cooperative complex in Mondragón, Spain. Data from archival research, participant observation, and interviews are used to outline the historical context of structural change and policy-making in the complex. Language used in internal policy discussions is analyzed to explore the way in which arguments about efficiency have shaped interpretations of structural change and these organizations' policy responses. It is argued that in these cooperatives, the concept of efficiency does not operate as a neutral, objective benchmark of organizational performance, but is socially and rhetorically constructed. The predominant approach to efficiency that is emerging in Mondragón aims to make the cooperatives more competitive, but also facilitates a gradual displacement of collectively established organizational objectives such as relative equality, job security, and favorable work conditions for ones that privilege institutional interests of profitability and stability. More importantly, it has helped usher in important changes in the policy-making process itself, limiting the range of legitimate participation and weakening broad-based control over the identification of appropriate objectives and means. The paper suggests that reframing an existing rhetorical strategy to highlight more clearly the link between efficiency and any given set of objectives would stimulate a broader discussion of policy issues and help balance more effectively the diverse interests at stake in Mondragón's restructuring.An earlier version of this paper was presented at the 1992 annual meetings of the American Sociological Association in Pittsburgh, Pennsylvania.     

Environmental assessment and evaluation research: examples from mental health and substance abuse programs.

Evaluation researchers have been broadening the traditional client input--"black box" treatment--client outcome paradigm that has guided many evaluations of mental health, substance abuse treatment, and other intervention programs. The points of expansion are in the areas of treatment implementation and treatment processes, as well as "extratreatment" influences on treatment selection, duration, and, especially, outcome. This review illustrates the application of environmental assessment procedures--particularly social climate measures--in four aspects of evaluation research suggested by the more comprehensive model: (a) evaluating treatment implementation; (b) exploring treatment processes; (c) identifying extratreatment influences on client posttreatment functioning; and (d) operationalizing outcome variables. Conceptual and methodological issues raised by these applications are discussed, and the benefits to be derived from an expanded model of evaluation research--especially the greater potential for program improvement--are considered.     

Wide diameters of de Bruijn graphs

The wide diameter of a graph is an important parameter to measure fault-tolerance of interconnection network. This paper proves that for any two vertices in de Bruijn undirected graph UB(d,n), there are 2d−2 internally disjoint paths of length at most 2n+1. Therefore, the (2d−2)-wide diameter of UB(d,n) is not greater than 2n+1. Dedicated to Professor Frank K. Hwang on the occasion of his sixty fifth birthday.     

Mesurer les coǔts de licenciement: de l'intérět des méthodes directes

Les coǔts de licenciement, ainsi que l'appareil législatif et réglementaire régissant les relations professionnelles, sont souvent blǎmés pour les mauvaises performances du marché du travail. Toutefois, les études théoriques et économétriques sur l'impact économique de ces coǔts ne sont pas concluantes. Par le passé, on s'est surtout intéressé aux hypothèses fonctionnelles et à l'incidence des divers paramètres, mais on a très peu analysé la qualité et la précision des méthodes de mesure de ces coǔts, dont dépendent pourtant la plupart des résultats en cette matière. L'auteur examine les méthodes de mesure directes et indirectes couramment utilisées en ce domaine, et soutient qu'il est essentiel d'employer les méthodes quantitatives directes, rarement utilisées par les chercheurs, pour compléter les méthodes de mesure indirectes auxquelles on a généralement recours. Ce point est illustré par les résultats d'un sondage expérimental récemment mené en Australie.