Engineering ambient visual sensors

Visual sensors are an indispensable prerequisite for those AmI environments that require a surveillance component. One practical issue concerns maximizing the operational longevity of such sensors as the operational lifetime of an AmI environment itself is dependent on that of its constituent components. In this paper, the intelligent agent paradigm is considered as a basis for managing a camera collective such that the conflicting demands of power usage optimization and system performance are reconciled

Morfología polínica de las Proteaceae nativas de Argentina: una nueva clave dicotómica para su identificación

A dichotomous key for the identification of eight proteaceous species, native to Argentina, based on pollen morphology is presented. These species are: Embothrium coccineum, Gevuina avellana, Lomatia dentata, L. ferruginea, L. hirsuta, Orites myrtoidea, Roupala meisneri and R. montana. The pollen morphology was analyzed with both, light and electron scanning microscopes. The morphological characters selected for species/ genera recognition are: ornamentation, pore number, equatorial diameter, the ratio of sexine/nexine thickness, and equatorial diameter/pore diameter ratio.Se presenta una clave dicotómica para la identificación de las ocho especies de Proteacea nativas de la Argentina. Las especies son: Embothrium coccineum, Gevuina avellana, Lomatia dentata, L. ferruginea, L. hirsuta, Orites myrtoidea, Roupala meisneri and R. montana. La morfología polínica fue analizada utilizando microscopio óptico y microscopio electrónico de barrido. Los caracteres morfológicos elegidos para reconocer las especies/géneros son: tipo de ornamentación, número de poros, diámetro ecuatorial, relación de espesor sexina/nexina y relación diámetro ecuatorial/diámetro de poro.Fil: Fernández, Damián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin

Extracting material data for superplastic forming simulations

In subatomic particle physics, unstable particles can be studied with a so-called vertex detector placed inside a particle accelerator. A detecting unit close to the accelerator bunch of charged particles must be separated from the accelerator vacuum. A thin sheet with a complex 3D shape prevents the detector vacuum from polluting the accelerator vacuum. Hence, this sheet should be completely leak tight with respect to gases. To produce such a complex thin sheet, superplastic forming can be very attractive if a small number of products is needed. This is a forming process in which a sheet of superplastic material is pressed into a one-sided die by means of gas pressure.\ud In order to develop a material model which can be used in superplastic forming simulations, uniaxial and biaxial experiments are necessary. The uniaxial, tensile, experiments provide information about the one-dimensional material data, such as the stress as a function of equivalent plastic strain and strain rate. These data are extracted from the experiments by using inverse modeling, i.e. simulation of the tensile experiment. To fit these curves into a general material model, three parts in the uniaxial mechanical behavior are considered: initial flow stress, strain hardening and strain softening caused by void growth. Since failure in superplastic materials is preceded by the nucleation and growth of cavities inside the material, the void volume fractions of the tested specimens were also observed.\ud A very important factor in this research is the study of the permeability of the formed sheet with respect to gas. If internal voids start to coalesce, through-thickness channels will start to form, thereby providing a gas leak path. To study the twodimensional behavior, including the gas leakage, bulge experiments were performed. Within these experiments, circular sheets were pressed into a cylindrically shaped die. From these experiments it followed that the plastic straining is dependent on an applied backpressure during the forming stage. This backpressure can postpone cavity nucleation and growth

Axiomatizations of the Value of Matrix Games

The function that assigns to each matrix game (i.e., the mixed extension of a finite zero-sum two-player game) its value is axiomatized by a number of intuitive properties.game theory;noncooperative games;matrix games;axiomatic methods

A Face Can Launch a Thousand Shares—and an 0.80% Abnormal Return

In this paper we examine the market reaction—price and volume—to the appearance of a firm in the Who’s News column of The Wall Street Journal. We differentiate between those firms whose articles are accompanied by a picture of an executive and a control set of firms whose articles on the same day are not accompanied by a picture. The results show a more pronounced market reaction to the “cum picture” articles, consistent with the incomplete information theory of Merton [1987] and the heuristic-based familiarity hypothesis. There is no evidence of significant long-run abnormal performance for the sample firms

The role of eigenvalues in linear feature selection theory

A particular measure of pattern class distinction called the average interclass divergence, or more simply, divergence, is considered. Here divergence will be the pairwise average of the expected interclass divergence derived from Hajek's two-class divergence

Line tensions, correlation lengths, and critical exponents in lipid membranes near critical points

Membranes containing a wide variety of ternary mixtures of high chain-melting temperature lipids, low chain-melting temperature lipids, and cholesterol undergo lateral phase separartion into coexisting liquid phases at a miscibility transition. When membranes are prepared from a ternary lipid mixture at a critical composition, they pass through a miscibility critical point at the transition temperature. Since the critical temperature is typically on the order of room temperature, membranes provide an unusual opportunity in which to perform a quantitative study of biophysical systems that exhibit critical phenomena in the two-dimensional Ising universality class. As a critical point is approached from either high or low temperature, the scale of fluctuations in lipid composition, set by the correlation length, diverges. In addition, as a critical point is approached from low temperature, the line tension between coexisting phases decreases to zero. Here we quantitatively evaluate the temperature dependence of line tension between liquid domains and of fluctuation correlation lengths in lipid membranes in order to extract a critical exponent, nu. We obtain nu=1.2 plus or minus 0.2, consistent with the Ising model prediction nu=1. We also evaluate the probability distributions of pixel intensities in fluoresence images of membranes. From the temperature dependence of these distributions above the critical temperature, we extract an independent critical exponent beta=0.124 plus or minus 0.03 which is consistent with the Ising prediction of beta=1/8.Comment: 22 pages, 7 figure