Relational structures model of concurrency

The paper deals with the foundations of concurrency theory. We show how structurally complex concurrent behaviours can be modelled by relational structures (X, ¨, \sqsubset){(X, \diamondsuit, \sqsubset)} , where X is a set (of event occurrences), and ¨{\diamondsuit} (interpreted as commutativity) and \sqsubset{\sqsubset} (interpreted as weak causality) are binary relations on X. The paper is a continuation of the approach initiated in Gaifman and Pratt (Proceedings of LICS’87, pp 72–85, 1987), Lamport (J ACM 33:313–326, 1986), Abraham et al. (Semantics for concurrency, workshops in computing. Springer, Heidelberg, pp 311–323, 1990) and Janicki and Koutny (Lect Notes Comput Sci 506:59–74, 1991), substantially developed in Janicki and Koutny (Theoretical Computer Science 112:5–52, 1993) and Janicki and Koutny (Acta Informatica 34:367–388, 1997), and recently generalized in Guo and Janicki (Lect Notes Comput Sci 2422:178–191, 2002) and Janicki (Lect Notes Comput Sci 3407:84–98, 2005). For the first time the full model for the most general case is given.     

Variations for the <Emphasis Type="Italic">Q</Emphasis>- and <Emphasis Type="Italic">H</Emphasis>-factors in the polar decomposition

In this paper, the variations of both subunitary polar factors and Hermitian positive semidefinite polar factors in the polar decomposition are studied. New perturbation bounds of both polar factors are given without the restriction that A and its perturbed matrix à have the same rank. These improve recent results.     

Approximation processes for resolvent operators

We introduce general sequences of linear operators obtained from classical approximation processes which are useful in the approximation of the resolvent operators of the generators of suitable C ₀-semigroups. The main aim is the representation of the resolvent operators in terms of classical approximation operators. Work performed under the auspices of PRIN 2006–07 “Kolmogorov equations” (coordinator G. Da Prato)     

The anti-reflective algebra: structural and computational analysis with application to image deblurring and denoising

Anti-reflective (AR) boundary conditions (BC) have been introduced recently in connection with fast deblurring algorithms, both in the case of signals and images. Here we extend such BCs to d dimensions (d ≥ 1) and we study in detail the algebra induced by the AR-BCs, with strongly symmetric point spread functions (PSF), both from a structural and computational point of view. The use of the re-blurring idea and the computational features of the AR-algebra allow us to apply Tikhonov-like techniques within O(n ^d log(n)) arithmetic operations, where n ^d is the number of pixels of the reconstructed object. Extensive numerical experimentation concerning 2D images and strongly symmetric PSFs confirms the effectiveness of our proposal.      

达到标准,收益很容易吗?

我非常钟爱办公用品商店的商业模式,就如同按下按钮那般简单。如果收益同按按钮一样简单,你能想象将会发生什么吗?现在就有这样一个例子:我们写(按钮),您接受(动),每个人都获取收益(这很简单)。标准其实就处于可盈利的按钮之间。我坚信ISA88第5部分标准的价值,如果可以得到广泛的应用,将意味着许多设施的盈     

Family psychosocial screening: should we focus on high-risk settings?

The objective of this study was to address the question of whether or not psychosocial screening should be focused on "high-risk" populations. A cross-sectional survey of mothers of young children was conducted in various clinics: 758 in teaching clinics, 444 in private practices, and 202 at a military clinic. The self-administered questionnaire covered demographic factors, problems in mothers family of origin, maternal depression, and substance abuse. Mothers in the teaching clinics were younger and had less education and lower incomes than mothers in private practices, with intermediate levels in the military clinic. However, a substantial proportion of mothers seen in all sites reported psychosocial problems. Approximately 20% of mothers in all sites reported a family history of alcoholism. Positive screens for maternal depression ranged from about 15% to 35%. Binge drinking was reported by 10% to 20% at different sites. Psychosocial problems were common even among families seen in "low-risk" settings. Focusing screening only on high-risk clinics would miss many families with psychosocial problems.     

"Evaluation of child witnesses for confrontation by criminal defendants": Erratum.

Reports an error in the original article by M. A. Small and G. B. Melton (Professional Psychology: Research and Practice, 1994[August], Vol 25[3], 228–233). Footnote 1 incorrectly indicates that the Craig brief was written without the aid of private legal counsel. Though the brief in question was written with more APA member involvement than has been the case for other briefs, private legal counsel participated and was listed as a coauthor. (The following abstract of this article originally appeared in record 1994-43476-001.) States have passed legislation governing the procedures by which children may testify in cases of child abuse. In Maryland v. Craig (1990), the US Supreme Court reviewed the constitutionality of these procedures. As a result, psychologists may be asked to perform evaluations regarding the potential trauma a child faces in confronting a defendant in a criminal case. Specifically, opinions of psychologists may be sought as to the potential trauma a child may endure as a result of a face-to-face confrontation with a defendant. Research relevant to this assessment is reviewed, and it is suggested that psychologists may be of most help in preparing children to testify.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Photophysical models of aromatic polyesters: excited state interactions in bis(phenalkyl)terephthalate

Summary The nature of the excited state interactions in poly(ethylene terephthalate) is still subject to debate. We study a new series of model compounds composed of a central terephthaloyl group condensed with -hydroxy--phenyl-n-alkanes. Although the molecular architecture prevents these molecules from achieving symmetric ring-ring overlap, the steady-state fluorescence spectra are remarkably similar to those of other models studied earlier, where such overlap was expected. The solvent polarity dependence suggests that the excited state complex is an exciplex and not an excimer.     

Laboratory investigation of the properties of epoxy asphalt rubber (EAR)

Crumb rubber is preliminarily mixed with asphalt in wet process to produce ductile and elastic asphalt rubber (AR), which has been extensively used in high performance bituminous mixtures for road pavement. Epoxy asphalt is a thermosetting polymer modified asphalt with excellent performance and has been widely applied on the pavement of steel bridge decks. Epoxy asphalt rubber (EAR) was prepared by mixing AR with the epoxy (EP). The effect of AR concentration on the phase-separated morphology, viscosity, thermal stability and mechanical properties of the neat EP were compared with that of asphalt. Laser scanning confocal microscopy observations revealed that AR particles disperse in the continuous epoxy phase with co-continuous phase-separated structures in EARs with 40 and 50 wt% AR. However, the phase inverts to continuous asphalt structures with dispersed spherical and co-continuous epoxy phase as AR concentration reaches 60 wt%. The addition of AR increases the viscosity of the neat EP. The thermal stability of the neat EP is improved with the incorporation of AR. The presence of AR decreases the tensile strength of the neat EP, while the elongation at break of the neat EP increases with the increase of AR concentration. The viscosity and mechanical properties of EAR with 50 wt% AR completely satisfy the technical requirement of hot-mix epoxy asphalt binder for steel bridge deck pavements.     

Bond of steel reinforcement with microwave cured concrete repair mortars

This paper investigates the effect of microwave curing on the bond strength of steel reinforcement in concrete repair. Pull-out tests on plain mild steel reinforcement bars embedded in four repair materials in 100 mm cube specimens were performed to determine the interfacial bond strength. The porosity and pore structure of the matrix at the steel interface, which influence the bond strength, were also determined. Test results show that microwave curing significantly reduces the bond strength of plain steel reinforcement. The reduction relative to normally cured (20 °C, 60% RH) specimens is between 21 and 40% with low density repair materials and about 10% for normal density cementitious mortars. The corresponding compressive strength of the matrix also recorded similar reduction and microwave curing resulted in increased porosity at the interface transition zone of the steel reinforcement. A unique relationship exists between bond strength and both compressive strength and porosity of all matrix materials. Microwave curing reduced shrinkage but despite the wide variation in the shrinkage of the repair mortars, its effect on the bond strength was small. The paper provides clear correlations between the three parameters (compressive strength, bond strength and porosity), which are common to both the microwave and conventionally cured mortars. Therefore, bond-compressive strength relationships used in the design of reinforced concrete structures will be also valid for microwave cured elements.