Ray and van cittert-zernike characterization of spatial coherence

We discuss a ray and a van Cittert-Zernike characterization of spatial coherence in condensers for projection systems. We present a rule of thumb with which to estimate the modulus of the coherence function at a given point of the illuminated object and a ray-tracing methodology with which to determine this modulus. For uniform illumination of the pupil we relate the modulus of the coherence function and the pupil-filling factor. We suggest that the rms of the angular ray spread at a given object point is an appropriate metric with which to characterize local coherence properties.     

Wettability changes in trichloroethylene-contaminated sandstone

It is usually assumed that chlorinated solvent nonaqueous-phase liquids (NAPLs) are nonwetting with respect to water-saturated porous media. The focus of this work was to examine whether this supposition is appropriate for used trichloroethylene (TCE) samples. In this work, the term "used" indicates that the sample has been employed industrially and therefore contains solutes and breakdown products related to its previous use. The data obtained in this study indicate that exposure of initially water wet quartz slides to industrially used solvents can cause a contact angle change, measured through the aqueous phase, of 100 degrees with a maximum stable contact angle of 170 degrees (indicative of strong NAPL wetting characteristics) being recorded. The work on quartz slides was complemented by the use of sandstone cores. Wettability was measured using the Amott test. Used TCE again proved able to alter the wetting properties of sandstone to neutral wetting. The complexity of the industrially used samples precluded any realistic attempt to examine the agents causing these wetting changes. The data captured in these experiments were compared with laboratory grade TCE, and some attempts were made to synthesize known mixtures in order to replicate wetting changes. These experiments resulted in contact angle changes but did not alter the overall wettability of the quartz slides or sandstone cores. Finally the work reported here also demonstrates that increasing the duration of exposure to solvent has an important impact upon measured contact angle.     

Crowds by Example

We present an example-based crowd simulation technique. Most crowd simulation techniques assume that the behavior exhibited by each person in the crowd can be defined by a restricted set of rules. This assumption limits the behavioral complexity of the simulated agents. By learning from real-world examples, our autonomous agents display complex natural behaviors that are often missing in crowd simulations. Examples are created from tracked video segments of real pedestrian crowds. During a simulation, autonomous agents search for examples that closely match the situation that they are facing. Trajectories taken by real people in similar situations, are copied to the simulated agents, resulting in seemingly natural behaviors.     

INFORMATION MACRODYNAMIC MODEL AND INFORMATION STRUCTURE OF A MARKET ECONOMIC SYSTEM

Information represents a common and universal substance, active participating in a diversity of physical or virtual interactions, including various forms of economic interactions.

The math-information controlled model based on an information path functional evaluates the information regularities of macrodynamic economic processes.

The built information systemic models focus on an elementary production-organization, the production's interaction and management, and different market dynamics. An organization is modeled by the hierarchical structure of an information cooperative dynamic space distributed network.

The found formalized information mechanisms govern market's cooperative dynamics, and impose the information restrictions on these processes.

The considered systemic mechanisms of self-control, adaptation, and evolution, represent a general attribute of an economical system.     

On the Initialisation of Sammon’s Nonlinear Mapping

The initialisation of a neural network implementation of Sammon’s mapping, either randomly or based on the principal components (PCs) of the sample covariance matrix, is experimentally investigated. When PCs are employed, fewer experiments are needed and the network configuration can be set precisely without trial-and-error experimentation. Tested on five real-world databases, it is shown that very few PCs are required to achieve a shorter training period, lower mapping error and higher classification accuracy, compared with those based on random initialisation. Received: 20 April 1999, Received in revised form: 08 July 1999, Accepted: 05 August 1999     

Further specification of the five robust factors of personality.

Factor analysis of teacher ratings of 499 6th graders on 43 adjectives (e.g., curious, fearful) supported a 5-factor model of personality trait information. The factors are interpreted as reflecting introversion–extraversion, conscience-governed concern for others, will, anxiety, and intellect. A weak 6th factor related to creativity was also observed. Findings are discussed in relation to the existence of additional factors, the possibility that the correlations reflect the language used by raters rather than behavioral traits, and the potential utility of the ratings. The relation of the 5 robust factors to theories of interpersonal relations, H. J. Eysenck's (1953) 3-factor model, R. B. Catell's (1947) multiple-factor system, and studies of the semantic meaning of personality terms is also considered. (65 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cold-cathode emitter based on a metal-diamond tunneling junction

Recently Geis fabricated a composite cold cathode emitter made of diamond doped by substitutional nitrogen on a roughened metallic substrate, which is characterized by high field emission currents at very low power. Using an internal field emission mechanism through the Schottky barrier at the metal diamond interfaces to populate the conduction band of diamond, we have developed a quantitative theory to describe the operation of such a device. The calculated I-V characteristics are in good agreement with the experimental results of Geis, et al     

Transient processes in an oscillatory circuit caused by stepwise phase changes

Transient processes at the output of an isolated oscillatory circuit caused by stepwise phase changes at the circuit input are studied in the time and frequency domains. A mathematical model of this type of transient processes in the form of a narrowband process is presented. Analytical expressions describing the behavior of the transient process in the time and frequency domains are obtained. New features of this type of transient processes are revealed.