A Discontinuous Galerkin Method for Linear Symmetric Hyperbolic Systems in Inhomogeneous Media

The Discontinuous Galerkin (DG) method provides a powerful tool for approximating hyperbolic problems. Here we derive a new space-time DG method for linear time dependent hyperbolic problems written as a symmetric system (including the wave equation and Maxwell’s equations). The main features of the scheme are that it can handle inhomogeneous media, and can be time-stepped by solving a sequence of small linear systems resulting from applying the method on small collections of space-time elements. We show that the method is stable provided the space-time grid is appropriately constructed (this corresponds to the usual time-step restriction for explicit methods, but applied locally) and give an error analysis of the scheme. We also provide some simple numerical tests of the algorithm applied to the wave equation in two space dimensions (plus time).This revised version was published online in July 2005 with corrected volume and issue numbers.     

Integrated-optic versus microoptic devices for fiber-optictelecommunication systems: a comparison

We assess the relative merits and prospects of integrated-optics in comparison with microoptic and fiber-based techniques. Firstly, the market for fiber-optic components for telecommunications is analyzed. Secondly, the technological issues which make integrated optics quite different from integrated electronics will be discussed. Thirdly, a specific comparison between the potential of the competing optical technologies will be made for the polarization-diversity hybrid and the optical wavelength (de)multiplexer, two optical devices used in networks that are based on optical frequency division multiplexing (OFDM)     

Prolonged pulseless perfusion in unanesthetized calves

Nonpulsatile left ventricular (LV) bypass was achieved in nine alert, active calves for periods of up to two weeks using a centrifugal blood pump. Data were compared to prebypass control values and to results obtained from seven calves that underwent nonthoracotomy, retrograde LV cannulation, and pulsatile bypass for up to 35 days. Nonpulsatile flow produced an increase in heart rate of 20% (P less than .05) and an increase in aortic pressure of 10% (P less than .05). Cardiac output and systemic vascular resistance were similar in both groups for three days; thereafter, vascular resistance decreased as cardiac output progressively increased. Serum renin, lactate, and pyruvate values remained normal; creatinine clearances were not significantly different than control values, and there were no significant changes in body weight. These data indicate no untoward effects as a result of prolonged pulseless perfusion.     

Fear and social comparison.

Schachter (1959) had found a positive relationship between fear and the desire to be with others (affiliation). Schachter concluded, following Festinger (1954), that a person will attempt to reduce cognitive dissonance with regard to his self-picture in terms of information obtainable from others. This investigation attempts to determine the validity of this hypothesis by focusing on the dimension of the intensity of the emotion. "If a person is uncertain as to the intensity of his emotional reaction, he should seek information from others that will help him measure it. To the extent that he has information from others regarding the intensity of their reactions, his desire to be with them prior to the impending experience should be reduced." The hypothesis was supported; however, factors such as sex and order of birth were seen to affect S's reaction to threat. From Psyc Abstracts 36:04:4GE86G. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A simple learning decision algorithm for character recognition and pattern classification

A learning decision algorithm, using a set of distinctive features, is described and applied to character recognition. It is based on assumptions which have a wide application area. Emphasis is given on the help it can provide to an industrial user who has to design a character recognizer. In relation to a statistical model, convergence properties are proved at a theoretical level. At a practical level, satisfactory results are shown for three different applications. Tools for performance analysis are sketched.     

Amplified spontaneous emission in a Ti:sapphire regenerative amplifier

Amplified spontaneous emission power and contrast ratio in a linear miltipass Ti:sapphire regenerative amplifier with a wavelength centered at 1054 nm are calculated and measured. It is shown that the passive losses of a seed pulse and the losses in coupling to the regenerative amplifier cavity mode degrade the intensity contrast ratio to 10(-6)-10(-7). The advantage of an optical parametric chirped pulse amplifier with respect to the contrast ratio is discussed.     

Hot extraction and characterization of a ligninlike fraction involved in larvicidal effects of decomposed leaf litter against mosquito

Hot water-extraction was performed on decomposed leaf litter in order to solubilize the toxic fraction involved in the dietary interaction against mosquito larvae in subalpine breeding sites. The toxic fraction was partially extracted by water with an optimum temperature of 60°C and recovered in an insoluble form. Phytochemical characterization was achieved through differential enzymatic hydrolyses, using the laccase mediator delignifying system, and aluminum chloride chelation monitored by standard bioassays; comparative spectrophotometric analyses in ultraviolet light after solubilization in acetyl bromide; and comparative reversed-phase high-performance liquid chromatography of the phenolic aldehydes after alkaline nitrobenzene oxidation. The results suggested the involvement of ligninlike compounds in the toxicity of the isolated fraction. Toxicity of this fraction appeared far stronger than that of the crude leaf litter. The involvement of this ligninlike fraction in the dietary toxicity of leaf litter against larval mosquito was then investigated.     

PD knowledge rules for insulation condition assessment of distribution power cables

This paper discusses practical experiences in the Netherlands with insulation condition assessment of distribution power cable networks by partial discharge diagnosis and database support. In particular, practical steps are discussed in collecting, analysing and processing the diagnostic data for decision support of utility asset management.