The K-Server Dual and Loose Competitiveness for Paging

This paper has two results. The first is based on the surprising observation that the well-known ``least-recently-used'' paging algorithm and the ``balance'' algorithm for weighted caching are linear-programming primal-dual algorithms. This observation leads to a strategy (called ``Greedy-Dual'') that generalizes them both and has an optimal performance guarantee for weighted caching. For the second result, the paper presents empirical studies of paging algorithms, documenting that in practice, on ``typical'' cache sizes and sequences, the performance of paging strategies are much better than their worst-case analyses in the standard model suggest. The paper then presents theoretical results that support and explain this. For example: on any input sequence, with almost all cache sizes, either the performance guarantee of least-recently-used is O(log k) or the fault rate (in an absolute sense) is insignificant. Both of these results are strengthened and generalized in``On-line File Caching'' (1998).Comment: conference version: "On-Line Caching as Cache Size Varies", SODA (1991

A non-singular black hole model as a possible end-product of gravitational collapse

In this paper we present a non-singular black hole model as a possible end-product of gravitational collapse. The depicted spacetime which is type [II,(II)], by Petrov classification, is an exact solution of the Einstein equations and contains two horizons. The equation of state in the radial direction, is a well-behaved function of the density and smoothly reproduces vacuum-like behavior near r=0 while tending to a polytrope at larger r, low density, values. The final equilibrium configuration comprises of a de Sitter-like inner core surrounded by a family of 2-surfaces of matter fields with variable equation of state. The fields are all concentrated in the vicinity of the radial center r=0. The solution depicts a spacetime that is asymptotically Schwarzschild at large r, while it becomes de Sitter-like for vanishing r. Possible physical interpretations of the macro-state of the black hole interior in the model are offered. We find that the possible state admits two equally viable interpretations, namely either a quintessential intermediary region or a phase transition in which a two-fluid system is in both dynamic and thermodynamic equilibrium. We estimate the ratio of pure matter present to the total energy and in both (interpretations) cases find it to be virtually the same, being 0.83. Finally, the well-behaved dependence of the density and pressure on the radial coordinate provides some insight on dealing with the information loss paradox.Comment: 12 Pages, 1 figure. Accepted for publication in Phys. Rev.

Novel assessment of affective distress intolerance: Behavioral paradigm development and ecological momentary assessment in individuals with binge eating

Distress intolerance is defined as the inability and/or unwillingness to endure negative emotional or physical experiences, specifically by engaging in maladaptive behaviors to alleviate the experience. Affective distress intolerance (pertaining specifically to negative emotional experiences) is theorized to be a key dimension underlying a wide range of maladaptive behaviors, such as loss-of-control (LOC) eating. Those with poor affective distress tolerance engage in behaviors that achieve temporary relief from negative affect, despite the potential long-term negative consequences of such behaviors. As such, affective distress intolerance is a key theoretical target for change in the development and evaluation of promising new psychological treatments. However, nearly all examinations in the current literature have relied on retrospective self-report measurement of affective distress intolerance, which is laden with problematic biases that may halt treatment development and evaluation. As such, the current project aimed to (1) iteratively develop a novel behavioral paradigm that tapped specifically into affective distress intolerance and (2) use ecological momentary assessment (EMA) to examine the interaction between momentary distress tolerance and negative affect in predicting subsequent episodes of LOC eating. We recruited 69 individuals with (n=39) and without (n=30) LOC eating to test seven iterations of the behavioral paradigm developed in the current study. A subset of individuals with LOC eating (n=12; data collection ongoing) completed an EMA protocol over the course of two weeks. While the iterations of the behavioral paradigm developed were largely successful in inducing dysphoric emotional experiences, qualitative and quantitative data suggested we were unable to successfully tap into behavioral affective distress intolerance with any iteration of the paradigm. EMA results provided preliminary support for the model that the relation between momentary changes negative affect and subsequent episodes of LOC is strongest for those with lower levels of affective distress tolerance. Ideas for future iterations of the behavioral paradigm, including methods for increasing distress induced by the task, alternative mood induction paradigms, and ways of assessing behavioral escape, are discussed.Ph.D., Psychology -- Drexel University, 201

An approximate binary-black-hole metric

An approximate solution to Einstein's equations representing two widely-separated non-rotating black holes in a circular orbit is constructed by matching a post-Newtonian metric to two perturbed Schwarzschild metrics. The spacetime metric is presented in a single coordinate system valid up to the apparent horizons of the black holes. This metric could be useful in numerical simulations of binary black holes. Initial data extracted from this metric have the advantages of being linked to the early inspiral phase of the binary system, and of not containing spurious gravitational waves.Comment: 20 pages, 1 figure; some changes in Sec. IV B,C and Sec.

A comparison between matter wave and light wave interferometers for the detection of gravitational waves

We calculate and compare the response of light wave interferometers and matter wave interferometers to gravitational waves. We find that metric matter wave interferometers will not challenge kilometric light wave interferometers such as Virgo or LIGO, but could be a good candidate for the detection of very low frequency gravitational waves

An investigation of the neurocognitive profile of binge eating disorder

Although current interventions for BED are moderately effective, long-term binge abstinence and weight control are a challenge. Adding neurocognitive targets to intervention has the potential to improve treatment for BED, but the neurocognition of binge eating and binge eating disorder (BED) is currently poorly understood. Very preliminary evidence suggests that executive functions (EF), which are comprised of diverse, overlapping frontal lobe processes that enable an individual to engage in self-initiated, healthy, and adaptive behavior may be weak in individuals with BED. Weaknesses in specific processes that may be associated with binge eating are inhibitory control (inhibiting a prepotent response towards a stimuli), cognitive flexibility (the ability to flexibly generate strategies), decision-making (prioritizing immediate versus delayed reward), and working memory (the ability to keep goal-relevant information online). However, at this time, evidence is mixed as to whether individuals with BED show deficits in these areas, potentially due to significant methodological weaknesses in the studies that comprise the current literature. The current study compared several dimensions of EF in a sample of overweight women with (n=31) and without (n=43) full and sub-threshold BED, with the aim of conducting a thorough investigation of the neurocognitive profile of binge eating. A neuropsychological battery (including tests of inhibitory control, cognitive flexibility, delayed discounting, and working memory), a palatable-foods implicit attitudes task, and a self-report measure of food reactivity were administered to all participants before entry into either a behavioral weight loss program or cognitive-behavioral treatment for BED. Results indicate that after controlling for IQ and age, individuals with BED displayed poorer performance on tasks of executive planning and inhibitory control, and also displayed higher prioritization of immediate versus delayed rewards compared to the control group. The pattern of results remained unchanged when depression was added as a covariate. Full and sub-threshold BED groups did not differ in performance on any executive functioning tasks. Additionally, the combination of less positive implicit attitudes towards highly palatable food and poor inhibitory control was associated with higher frequency of binge episodes in the BED sample. Results suggest a distinct neurocognitive profile associated with binge eating, independent of weight status and frequency and size of binge episodes. Implications include testing of treatment components that target such executive functioning deficits, and future research should examine what deficits predict or moderate outcome in psychological treatments.M.S., Psychology -- Drexel University, 201

Archaeological survey in the territory of Diaguita Indigenous community from El Mollar, Tucumán, Argentina

Hoy, que en distintas partes del mundo los “restos arqueológicos” son concebidos como patrimonio cultural de los pueblos indígenas, la Comunidad Indígena Diaguita de El Mollar plantea la necesidad de exponer públicamente saberes construidos en una articulación de conocimientos arqueológicos (científicos) e indígenas (no-científicos). Dar cuenta de la existencia de evidencias materiales del pasado / presente indígena responde a la intención de avanzar en la territorialización explícita del espacio de la comunidad. Como objetivo central de este trabajo presentaremos información arqueológica que conformará parte de una cartografía de recursos culturales en proceso de elaboración. Comentaremos, en primera instancia, las condiciones de producción de esta investigación, para, luego, presentar brevemente a la Comunidad Indígena en su contexto social, cultural e histórico, procurando brindar información que permita avizorar la problemática desde la cual se diseña la propuesta del registro de materialidades culturales prehispánicas. Explicitaremos esta última, profundizando en sus objetivos y la metodología abordada, atendiendo al marco teórico y conceptual que le va dando respaldo. Como tercer punto, realizamos una evaluación de la información científica preexistente para así articular/contrastar con la información elaborada en el marco de este trabajo de relevamiento. Finalmente, realizaremos algunos comentarios sobre los resultados obtenidos, reflexionando sobre este particular contexto de producción transitado.Nowadays, when “archaeological remains” are conceived in different parts of the world, as the cultural heritage of indigenous peoples, the indigenous community of El Mollar Diaguita raises the need to present the knowledge built together between archaeological (scientific) and indigenous (non-scientific) knowledge. To account for the existence of material evidence of the indigenous past/present is related to the intention of advancing on the explicit territorialization of community space. As a central objective of this paper we present archaeological information that form part of a cultural resource mapping process. First we discuss the conditions of the production of this research, in order to briefly introduce the indigenous community in its social, cultural and historical scenery, trying to provide information to foresee the difficulties of this proposal for the registration of Hispanic cultural materiality. We will explicit the latter, delving on its objectives and the methodology addressed, considering its theoretical and conceptual framework. As a third point, we evaluate existing scientific information in order to articulate/contrast it with the information developed as part of this survey work. Finally, we will make a few remarks on the obtained results, thinking about this particular context of the production

Factoring by electronic mail

Describes a distributed implementation of two factoring algorithms, the elliptic curve method (ECM) and the multiple polynomial quadratic sieve algorithm (MPQS). The authors' ECM-implementation on a network of DEC MicroVAX processors has factored several numbers from the Cunningham project. The authors have also implemented the multiple polynomial quadratic sieve algorithm on the same network. On this network alone, they are now able to factor any 100 digit integer, or to find 35 digit factors of numbers up to 150 digits long within one month. To allow an even wider distribution of their programs they made use of electronic mail networks for the distribution of the programs and for inter-processor communication. Even during the initial stage of this experiment, machines all over the United States and at various places in Europe and Australia contributed 15 percent of the total factorization effort. At all the sites where the program is running, the authors only use cycles that would otherwise have been idle. This shows that the enormous computational task of factoring 100 digit integers with the current algorithms can be completed almost for free. Since they use a negligible fraction of the idle cycles of all the machines on the worldwide electronic mail networks, the authors could factor 100 digit integers within a few days with a little more hel