Minimum neighborhood in a generalized cube

Generalized cubes are a subclass of hypercube-like networks, which include some hypercube variants as special cases. Let theta(G)(k) denote the minimum number of nodes adjacent to a set of k vertices of a graph G. In this paper, we prove theta(G)(k) >= -1/2k(2) + (2n - 3/2)k - (n(2) - 2) for each n-dimensional generalized cube and each integer k satisfying n + 2 <= k <= 2n. Our result is an extension of a result presented by Fan and Lin [J. Fan, X. Lin, The t/k-diagnosability of the BC graphs, IEEE Trans. Comput. 54 (2) (2005) 176-184]. (c) 2005 Elsevier B.V. All rights reserved.

A lower bound on the size of k-neighborhood in generalized cubes

The determination of the minimum size of a k-neighborhood (i.e., a neighborhood of a set of k nodes) in a given graph is essential in the analysis of diagnosability and fault tolerance of multicomputer systems. The generalized cubes include the hypercube and most hypercube variants as special cases. In this paper, we present a lower bound on the size of a k-neighborhood in n-dimensional generalized cubes, where 2n + 1 <= k <= 3n - 2. This lower bound is tight in that it is met by the n-dimensional hypercube. Our result is an extension of two previously known results. (c) 2005 Elsevier Inc. All rights reserved.

Pseudolikelihood equations for Potts MRF model parameter estimation on higher order neighborhood systems

This letter presents pseudolikelihood equations for the estimation of the Potts Markov random field model parameter on higher order neighborhood systems. The derived equation for second-order systems is a significantly reduced version of a recent result found in the literature (from 67 to 22 terms). Also, with the proposed method, a completely original equation for Potts model parameter estimation in third-order systems was obtained. These equations allow the modeling of less restrictive contextual systems for a large number of applications in a computationally feasible way. Experiments with both simulated and real remote sensing images provided good results.

Neighborhood feedbacks, endogenous stratification, and income inequality

This paper explores the evolution of the cross-section income distribution in economies where endogenous neighborhood formation interacts with positive within-neighborhood feedback effects. We study an economy in which the economic success of adults is determined by the characteristics of the families in the neighborhood in which a person grows up. These feedbacks take two forms. First, the tax base of a neighborhood affects the leveI of education investment in offspring. Second, the effectiveness of education investment is affected by a neighborhood's in come distribution, reflecting factors such as role model or labor market connection effects. Conditions are developed under which endogenous stratification, defined as the tendency for families wi th similar incomes to choose to form common communities, will occur. When families are allowed to choose their neighborhoods, wealthy families will have an incentive to segregate themselves from the rest of the population. This resulting stratification is supported by house price differences between ricli and poor communities. Endogenous stratification can lead to pronounced intertemporal inequality as different families provide very different interaction environments for offspring. When the transformation of human capital into in come exhibits constant retums to scale, cross-section in come differences may also grow across time. As a result, endogenous stratification and neighborhood feedbacks can interact to produce long run inequality.

Neighborhood information exchange and voter participation : an experimental study

We study the effect of social embeddedness on voter turnout by investigating the role of information about other voters’ decisions. We do so in a participation game, where some voters (‘receivers’) are told about some other voters’ (‘senders’) turnout decision at a first stage of the game. Cases are distinguished where the voters support the same or different candidates or where they are uncertain about each other’s preferences. Our experimental results show that such information matters. Participation is much higher when information is exchanged than when it is not. Senders strategically try to use their first mover position and some receivers respond to this.

Canine rabies epidemiology in Araçatuba and neighborhood, Northwestern São Paulo State - Brazil

São apresentadas algumas características epidemiológicas da raiva canina na região de Araçatuba, no período de 1993 a 1997. Dentre 1.984 cães submetidos ao diagnóstico de raiva, 351 foram positivos sendo que 89% dos casos (312/351) ocorreram na zona urbana e destes, 85% (266/312) eram de animais com proprietário. As informações sobre sexo estavam presentes em 83% das fichas e destas 61% eram de machos. A média de idade dos cães positivos foi de 34 meses. A agressividade foi um dos sintomas mais comumente observado (77%), seguido por incoordenação motora e/ou paralisia (42%) e 48% dos cães positivos haviam agredido pessoas ou outros animais. Das 182 fichas epidemiológicas que possuíam dados de vacinação, 51% (92/182) dos cães não eram vacinados. Aponta-se como possíveis razões para o aparecimento da epidemia no município de Araçatuba a baixa cobertura vacinal demonstrada pelo índice de cães não vacinados que adquiriram a doença aliado à elevada relação cão/homem (1:3,5) revelada em estudo anterior.

Neighborhood Interactions and Larval Dispersal Behavior in Blowflies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of neighborhood impacts caused by companies of the high-tech industrial cluster of São Carlos, SP, Brazil

The purpose of this study was to develop a methodology for evaluating neighborhood impacts using a Geographic Information System (GIS) and to apply the procedures to the companies of the High-Technology Industrial Cluster of São Carlos. To this end, an evaluation was made of the neighborhood impacts on the physical environment, urban components, quality of life, and urban infrastructure using impact matrices, and the impacts were assigned scores according to type, order, magnitude and duration. Fifty one companies were examined based on data provided by the companies themselves and on field surveys. The impacts are represented spatially in proportional symbols maps, based on the spatial distribution of the companies in the urban area of the city of São Carlos and the areas of influence of each company. The application of the proposed methodology served to validate it and indicated that the neighborhood impacts caused by the companies of this study are related to each company's type of activity, its size, and its occupation of the area. © 2008 Journal of Urban and Environmental Engineering (JUEE). All rights reserved.

Land parceling and neighborhood impacts in Brazil

The proposal and implementation of parceling real estate into smaller lots in Brazil is done according to legal and technical formalities. However, these instruments have proved inefficient in reducing the resulting environmental impacts. The ambiguities of the federal, state and municipal laws and regulations have limited the effectiveness of the actions of urban administrators. Law 10257/2001 emerged as an alternative to overcome these difficulties, proposing the adoption of neighborhood impact studies as an instrument to evaluate new proposals of urban occupation for purposes of environmental licensing. Thus, the purpose of this law is to provide the foundations for municipal public authorities to establish criteria for the assessment, mitigation and compensation of impacts resulting from new occupations. However, the very vagueness of the generic nature of this federal law and its incorrect application in the municipal sphere has posed the greatest obstacles to the good use of this instrument of urban environmental management. These deficiencies are classified herein in the categories of philosophical, technical and operational problems. The problems of a philosophical nature lead to technical difficulties, which in turn trigger operational deficiencies. This article discusses these deficiencies and points out ways to reduce them. © 2009 Journal of Urban and Environmental Engineering (JUEE). All rights reserved.

Partially Observed Markov Random Fields Are Variable Neighborhood Random Fields

The present paper has two goals. First to present a natural example of a new class of random fields which are the variable neighborhood random fields. The example we consider is a partially observed nearest neighbor binary Markov random field. The second goal is to establish sufficient conditions ensuring that the variable neighborhoods are almost surely finite. We discuss the relationship between the almost sure finiteness of the interaction neighborhoods and the presence/absence of phase transition of the underlying Markov random field. In the case where the underlying random field has no phase transition we show that the finiteness of neighborhoods depends on a specific relation between the noise level and the minimum values of the one-point specification of the Markov random field. The case in which there is phase transition is addressed in the frame of the ferromagnetic Ising model. We prove that the existence of infinite interaction neighborhoods depends on the phase.

Perceived neighborhood problems: multilevel analysis to evaluate psychometric properties in a Southern adult Brazilian population

Abstract Background Physical attributes of the places in which people live, as well as their perceptions of them, may be important health determinants. The perception of place in which people dwell may impact on individual health and may be a more telling indicator for individual health than objective neighborhood characteristics. This paper aims to evaluate psychometric and ecometric properties of a scale on the perceptions of neighborhood problems in adults from Florianopolis, Southern Brazil. Methods Individual, census tract level (per capita monthly familiar income) and neighborhood problems perception (physical and social disorders) variables were investigated. Multilevel models (items nested within persons, persons nested within neighborhoods) were run to assess ecometric properties of variables assessing neighborhood problems. Results The response rate was 85.3%, (1,720 adults). Participants were distributed in 63 census tracts. Two scales were identified using 16 items: Physical Problems and Social Disorder. The ecometric properties of the scales satisfactory: 0.24 to 0.28 for the intra-class correlation and 0.94 to 0.96 for reliability. Higher values on the scales of problems in the physical and social domains were associated with younger age, more length of time residing in the same neighborhood and lower census tract income level. Conclusions The findings support the usefulness of these scales to measure physical and social disorder problems in neighborhoods.

Mass extinctions, galactic orbits in the solar neighborhood and the Sun: a connection?

The orbits of the stars in the disk of the Galaxy, and their passages through the Galactic spiral arms, are a rarely mentioned factor of biosphere stability which might be important for long-term planetary climate evolution, with a possible bearing on mass extinctions. The Sun lies very near the co-rotation radius, where stars revolve around the Galaxy in the same period as the density wave perturbations of the spiral arms. conventional wisdom generally considers that this status makes for few passages through the spiral arms. Controversy still surrounds whether time spent inside or around spiral arms is dangerous to biospheres and conductive to mass extinctions. Possible threats include giant molecular clouds disturbing the Oort comet cloud and provoking heavy bombardment: a higher exposure to cosmic rays near star forming regions triggering increased cloudiness in Earth atmosphere and ice ages; and the desctruction of Earth's ozone layer posed by supernova explosiosn. We present detailed calculations of the history of spiral arm passages for all 212 solar-type stars nearer than 20 parsecs, including the total time spent inside armsin the last 500 Myr, when the spiral arm position can be traced with good accuracy. We found that there is a large diversity of stellar orbits in the solar neighborhood, and the time fraction spent inside spiral arms can vary from a few percent to nearly half the time. The Sun, despite its proximity to the galactic co-rotation radius, has exceptionally low eccentricity and a low vertical velocity component, and therefore spends 30% of its lifetime crossing the spiral arms, more than most nearby stars. We discuss the possible implications of this fact to the long-term habitability of the Earth, and possible correlations of the Sun's passage through the spiral arms with the five great mass extinctions of the Earth's biosphere from the Late Ordovician to the Cretaceous-Tertiary.