Choice between fixed and variable delays with different reward amounts.

Choice between a variable and a fixed food source was studied in pigeons. The variable source yielded different durations of access to food (changed across experimental conditions) uniquely associated with equiprobable delays of either 20 sec or 60 sec, timed from the choice point. A comparison, elapsing alternative (time-left procedure [J. Gibbon and R. M. Church; see PA, Vol 67:2812]), was associated with fixed access to feeder after a 60-sec delay, timed from the beginning of the trial. Preference was best characterized as reflecting an average of the 2 local rates of reinforcement in the variable alternative (the average of the ratio of each standard amount and its associated delay). The averaging rule characterized initial choice link data well, but terminal link responding showed that Ss also remembered the 2 delay–amount combinations separately. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A network approach to the French system of legal codes—part I: analysis of a dense network

We explore one aspect of the structure of a codified legal system at the national level using a new type of representation to understand the strong or weak dependencies between the various fields of law. In Part I of this study, we analyze the graph associated with the network in which each French legal code is a vertex and an edge is produced between two vertices when a code cites another code at least one time. We show that this network distinguishes from many other real networks from a high density, giving it a particular structure that we call concentrated world and that differentiates a national legal system (as considered with a resolution at the code level) from small-world graphs identified in many social networks. Our analysis then shows that a few communities (groups of highly wired vertices) of codes covering large domains of regulation are structuring the whole system. Indeed we mainly find a central group of influent codes, a group of codes related to social issues and a group of codes dealing with territories and natural resources. The study of this codified legal system is also of interest in the field of the analysis of real networks. In particular we examine the impact of the high density on the structural characteristics of the graph and on the ways communities are searched for. Finally we provide an original visualization of this graph on an hemicyle-like plot, this representation being based on a statistical reduction of dissimilarity measures between vertices. In Part II (a following paper) we show how the consideration of the weights attributed to each edge in the network in proportion to the number of citations between two vertices (codes) allows deepening the analysis of the French legal system.     

Comparing and evaluating the effectiveness of mobile Web adequacy evaluation tools

Universal Access in the Information Society - The number of Web sites is growing exponentially and so are the people who are accessing them on mobile devices including people with special...     

Automatic Lighting Design using a Perceptual Quality Metric

Lighting has a crucial impact on the appearance of 3D objects and on the ability of an image to communicate information about a 3D scene to a human observer. This paper presents a new automatic lighting design approach for comprehensible rendering of 3D objects. Given a geometric model of a 3D object or scene, the material properties of the surfaces in the model, and the desired viewing parameters, our approach automatically determines the values of various lighting parameters by optimizing a perception-based image quality objective function. This objective function is designed to quantify the extent to which an image of a 3D scene succeeds in communicating scene information, such as the 3D shapes of the objects, fine geometric details, and the spatial relationships between the objects.
Our results demonstrate that the proposed approach is an effective lighting design tool, suitable for users without expertise or knowledge in visual perception or in lighting design.     

Dufour Gland Contents of Ants of the Cataglyphis bicolor Group

The species of desert-dwelling ants of the Cataglyphis bicolor (Hymenoptera: Formicidae) group are difficult to distinguish by morphological features. Analysis of the secretion from the Dufour glands of workers of a number of colonies was undertaken to see if it provided a clear test of species. Linked 6c-ms showed in all samples straight and branched-chain alkanes, linear alkenes, ketones, aldehydes, acetates, and a group of C₂₂ to C₂₈ esters not previously identified in this genus. Contents of the Dufour glands of C. savignyi from Tunisia and Egypt were similar, and comprised straight and branched-chain alkanes, alkenes and small amounts of esters. C. bicolor from Tunisia contained compounds similar to C. savignyi but was distinguished from the latter by larger amounts of the esters. The major compound in the glands of C. viaticus was tridecane, in contrast to the pentadecane of other species. It also contained a branched alkane, 3-methyltridecane as a major component. Branched-chain esters and a wide variety of acetates were also found in this species. C. diehlii had a limited range of compounds, with branched alkanes almost completely absent and high proportions of pentadecene and dodecyl acetate. C. bombycinus, a sympatric species, but recognized as not belonging to the bicolor group by its different mandibular gland substances, was notable in having butanoate esters in its Dufour glands. Despite these differences among species, both the great variability of individuals from a single colony and the among between conspecific colonies make species diagnosis from a few individuals difficult, in contrast with postpharyngeal glands, which, as recently reported, give a clearer indication of species.     

Numerical and experimental investigations of mixing in T-shaped and cross-shaped micromixers

Mass transfer within the T-shaped and cross-shaped micromixers has been studied using CFD and confocal laser scanning microscopy methods. The concentration profiles, based on flow regimes, were used to compare the T- and cross-geometries. The cross-shaped micromixer tends to intensify the mixing and this is occurring for lower flow rates in comparison to the T shape. The improvement made by the cross geometry is attributed to the stronger vortex stretching and high shear rate, which reduces the liquid transfer length. The presence of a single outlet in the T-shaped micromixer induces a smaller degree of freedom for the fluid. A higher pressure drop is calculated in T-shaped micromixer than in cross-shaped micromixer.     

Content‐Aware Automatic Photo Enhancement

Automatic photo enhancement is one of the long‐standing goals in image processing and computational photography. While a variety of methods have been proposed for manipulating tone and colour, most automatic methods used in practice, operate on the entire image without attempting to take the content of the image into account. In this paper, we present a new framework for automatic photo enhancement that attempts to take local and global image semantics into account. Specifically, our content‐aware scheme attempts to detect and enhance the appearance of human faces, blue skies with or without clouds and underexposed salient regions. A user study was conducted that demonstrates the effectiveness of the proposed approach compared to existing auto‐enhancement tools.     

Integrated material flow and radioactivity distribution methodology within the calculation tool for evaluation of parameters for decommissioning of nuclear installations

Decommissioning of nuclear facilities becomes an important issue in all areas of nuclear technology, mainly in their energetic applications. Decommissioning process has to be planned in the safe, ecological and economic manner. It determines the requirements on appropriate evaluation of needed technologies, media, amount of solid materials released into the environment, radioactivity of effluents, amount of radioactive waste for disposal, number and exposure of personnel and finally the financial demands. A detailed evaluation of these parameters may be done by analytical calculation approach. This approach models a real process of decommissioning with its individual basic activities. The methodology of integrated material flow and radioactivity distribution within this calculation evaluation tool is applied and implemented to describe the real decommissioning activities and their mutual relations to obtain more accurate outputs.