Uniform and optimal schemes for stiff initial-value problems

We formulate a class of difference schemes for stiff initial-value problems, with a small parameter ε multiplying the first derivative. We derive necessary conditions for uniform convergence with respect to the small parameter ε, that is the solution of the difference scheme u_i^h satisfies |u_i^h−u(x_i)| Ch, where C is independent of h and ε. We also derive sufficient conditions for uniform convergence and show that a subclass of schemes is also optimal in the sense that |u_i^h−u(x_i)| C min (h, ε). Finally, we show that this class contains higher-order schemes.     

Alcohol consumption as a self-handicapping strategy in women.

Assessed whether women self-handicap with alcohol consumption prior to engaging in a social evaluation task, which may be more relevant to their self-esteem than the intellectual tasks used in past self-handicapping studies on substance use. 113 women (aged 19–32 yrs), who were evaluated as normal drinkers, performed either a solvable or an insolvable social judgment task and then received either success feedback or no feedback. Ss received access to alcoholic and nonalcoholic beverages while awaiting a retest. The study terminated before the retest. The self-handicapping hypothesis that noncontingent success would produce relatively greater alcohol consumption was not supported. Regardless of feedback, insolvable test Ss consumed more alcohol than did solvable test Ss. Findings suggest that the hypothesis may be limited as a general model of alcohol consumption in both sexes. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An asymptotically efficient ARMA estimator based on sample covariances

An asymptotically efficient autoregressive moving-average (ARMA) spectral estimator is presented, based on the sample covariances of observed time series. The estimate of the autoregressive (AR) part is shown to be identical to the optimal instrumental variable (IV) estimator in [7] although derived here using a different approach. The moving-average (MA) spectral parameter estimate is new.     

IDENTIFICATION OF VOLATILE COMPOUNDS FROM RIPE MAYHAW FRUIT (CRATAEGUS OPACA,C. AESTIVALIS,AND C. RUFULA)1

Steam volatile fractions obtained from three commercial mayhaw cultivars and two native selections were analyzed by GC and GC/MS. Twenty-four compounds were identified. The nine major components, which comprised 70–80% of the volatile fraction, were hexanal, butyl acetate, (E)-2-hexenal, butyl butyrate, linalool, butyl hexanoate, methyl octanoate, pentyl hexanoate, and hexyl hexanoate. Minor constituents included eight esters, four terpenes, two benzenoid compounds and (E)-2-hexenol.     

BerlinTainment: an agent-based context-aware entertainment planning system

Service providers, especially in the mobile entertainment domain, are facing increasing competition. The ability to design, develop, and deploy unique context-aware entertainment services fast and easily as well as the capability to provide intuitive user interfaces becomes essential for market players. Furthermore, today's mobile world is made up of heterogeneous networks accessible via various devices with different characteristics. Progressive users have the desire to utilize the same services and access the same information content on all available devices. At the same time, service providers have to diversify their services in order to remain competitive and attract the various customer segments making up the mass market. We introduce an agent-based serviceware framework to assist service providers in developing innovative services, thus reducing the time to market of the respective applications. The realized serviceware framework offers personalization, location awareness, and the multi-access service platform, a flexible solution for ubiquitous service access. Thus, our solution allows a heterogeneous landscape of end devices to access an application server's mobile services in a multimodal, multilingual, and multimedia-based manner. We describe the utilization of the different modules of the service framework as well as the BerlinTainment application, an entertainment planning system based on the framework.     

Analysis and synthesis of on-chip spiral inductors

This paper presents a physically based compact model for estimating high-frequency performance of spiral inductors. The model accurately accounts for skin and proximity effects in the metal conductors as well as eddy current losses in the substrate. The model shows excellent agreement with measured data mostly within 10% across a variety of inductor geometries and substrate dopings up to 20 GHz. A web-based spiral inductor synthesis and analysis tool COILS, which makes use of the compact models, is presented. An optimization algorithm using binary searches speeds up the synthesis of inductor designs.     

The incompatibility of knowledge regimes: consequences of the material world for cross-domain work

In this paper, we argue that successful integration of knowledge across work domains in the short-term can mask the generation of long-term consequences. We explore a setting, the introduction of environmental considerations into semiconductor manufacturing, where the eventual adoption of common measurement artifacts and associated practices enabled knowledge integration, but failed to address significant underlying consequences. Drawing from observational, interview, and archival data we develop an understanding of the work practices of the Tech and EnviroTech groups as structured by the material world and broader collective conventions. We introduce the concept of knowledge regime to outline the differences in knowledge across these work domains. More specifically, we find that differences in the causal specificity and developmental time horizon of knowledge and the measurement artifacts that result contribute to the relative power of one knowledge regime over another. Understanding these sources of incompatibility provides insight into the design requirements of information systems as boundary objects for knowledge integration, but also specifies the potential limits to any design effort.