114,937 research outputs found

    Spin facilitated Ising model with long range interaction

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    We study the dynamics of a spin facilitated Ising model with long range kinetic constraints. To formulate those restrictions within an analytical approach we introduce the size of a kinetic active environment of a given spin. Based on a Master equation in second quantized form, the spin-autocorrelation function is calculated. It exhibits a pronounced slow dynamics, manifested by a logarithmic decay law of the spin-autocorrelation function. In case of an infinite kinetic interaction the mean field solution yields an asymptotic exact expression for the autocorrelation function which is in excellent agreement with Monte Carlo Simulations for finite interaction lengths. With increasing size of the active zone the cooperative processes, characterizing the facilitated model with short range kinetic interaction, become irrelevant. We demonstrate that the long range kinetic interaction dominates the actual spin configurations of the whole system and the mean field solution is the exact one.Comment: 18 pages, 5 figure

    Collective Diffusion and a Random Energy Landscape

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    Starting from a master equation in a quantum Hamiltonian form and a coupling to a heat bath we derive an evolution equation for a collective hopping process under the influence of a stochastic energy landscape. There results different equations in case of an arbitrary occupation number per lattice site or in a system under exclusion. Based on scaling arguments it will be demonstrated that both systems belong below the critical dimension dcd_c to the same universality class leading to anomalous diffusion in the long time limit. The dynamical exponent zz can be calculated by an ϵ=dcd\epsilon = d_c-d expansion. Above the critical dimension we discuss the differences in the diffusion constant for sufficient high temperatures. For a random potential we find a higher mobility for systems with exclusion.Comment: 15 pages, no figure

    Ants and Fairies: The Debate with Darwinism in A. S. Byatt’s Morpho Eugenia

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    Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej nauk

    The SPIRE Photometer Interactive Analysis Package SPIA

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    The Herschel Common Science System (HCSS) (Ott et al. 2006) (Ott & Science Ground Segment Consortium 2010) is a substantial Java software package, accompanying the development of the Herschel Mission (Pilbratt et al. 2010), supporting all of its phases. In particular the reduction of data from the scientific instruments for instrument checkout, calibration, and astronomical analysis is one of its major applications. The data reduction software is split up in modules, called "tasks". Agreed-upon sequences of tasks form pipelines that deliver well defined standard products for storage in a web-accessible Herschel Science Archive (HSA) (Leon et al. 2009). However, as astronomers and instrument scientists continue to characterize instrumental effects, astronomers already need to publish scientific results and may not have the time to acquire a sufficiently deep understanding of the system to apply necessary fixes. There is a need for intermediate level analysis tools that offer more flexibility than rigid pipelines. The task framework within the HCSS and the highly versatile Herschel Interactive Processing Environment (HIPE), together with the rich set of libraries provide the necessary tools to develop GUI-based interactive analysis packages for the Herschel instruments. The SPIRE Photometer Interactive Analysis (SPIA) package, that was demonstrated in this session, proves the validity of the concept for the SPIRE instrument (Griffin et al. 2010), breaking up the pipeline reduction into logical components, making all relevant processing parameters available in GUIs, and providing a more controlled and user-friendly access to the complexities of the system.Comment: Proceedings accompanying a focus demo given at the ADASS 2010 in Bosto

    Review of Nelson's analysis of Bell's theorem

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    This article contains a review of Nelson's analysis of Bell's theorem. It shows that Bell's inequalities can be violated with a theory of local random variables if one accepts that the outcomes of these variables are not predetermined prior to measurement. The article describes the relation between Bell's theorem and the Strong Free Will theorem of Conway and Kochen. Then, the original articles of Bell are analyzed in detail. Following an article of Faris, it is explained that Bell's work on the hidden variable question in fact describes two separate theorems. Bell's first theorem says that there can be no model for the singlet state where an outcome does not depend locally on the settings of the detector where the outcome was measured. Bell's second theorem shows that Bell's inequalities can be violated by a theory that is either not deterministic, or violates causality in the sense of relativity or the free will assumption of the experimenters. It is shown in detail where Bell implicitly makes the various locality assumptions that Nelson has shown to be necessary for deriving Bell's inequality. The article closes by relating the various assumptions needed to derive Bell's theorem with the reality criterion of EPRComment: 19 pages, section added where Bell's original articles are analyzed and compared in detail with Nelson's wor

    The Psychological Impact of Long-Term Solitary Confinement on Inmates in the United States

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    Psychological distress among inmates is prevalent in correctional facilities throughout the United States. Although, according to Haney (2003), severe isolation of incarcerates has been commonplace in prisons since their inception, the use of secure housing units (SHU) and the development of ‘supermax’ prisons are becoming increasingly utilized within the last several decades. Legislators have expressed the need to increase punitive measures against delinquents in response to the rising prison population (Arrigo and Bullock 2008). Thus harsher crime control policies, such as administrative and disciplinary segregation, have been established in order to limit the personal freedoms of prisoners (Arrigo and Bullock 2008). Within these institutions, inmates are increasingly subjected to solitary confinement, a method of incarceration characterized by “the confinement of a prisoner in isolation with limited chance for social interaction or environmental stimulus” (The Psychology of Cruelty 2015). Theories surrounding the use of solitary confinement emphasize its potential to deter future misconduct among inmates (Morris 2015); however, little attention has been given to the potential psychological effects of long-term segregation. In response, this paper seeks to examine the exacerbating and detrimental psychological effects experienced by inmates subjected to solitary confinement in the United States

    Micro-Sociological Implications of Domestic Violence on Adolescents in a School Setting

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    Adolescent victimization and exposure to domestic violence has the ability to yield negative psychological, social, behavioral, developmental, and cognitive outcomes. Unfortunately, violence within the home is becoming increasingly prevalent. In 2007 alone, the U.S. Department of Health and Human Services reported that roughly 794,000 adolescents were either abused or neglected within their household (Sousa et al. 2011:112). Another form of violence that is becoming recognized as a widespread public-health concern is intimate partner violence. According to the U.S. Department of Justice, intimate partner violence is present when the juvenile is not directly involved and acts more as a witness to domestic violence between his/her caregivers. Within many households where this occurs, adolescents may witness the physical and emotional pain inflicted on adult victims, or they may not actually observe the altercations but are well aware of their existence. It is conservatively estimated that over 200,000 cases of intimate partner violence occur in the United States annually (Sousa et al. 2011:112). Within this Literature Review, the overall purpose is to examine how the side effects of domestic violence impact an adolescent’s school performance. This paper will analyze several characteristics that come with the results of domestic violence separately, such as developmental, psychological, cognitive, social, and behavioral outcomes in order to sufficiently explain how this public-health problem impacts adolescents within a school setting. This paper will mainly focus on the negative outcomes associated with this phenomenon in heterosexual relationships, as they are the most commonly reported
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