Parallel processing approaches to edge relaxation

This paper describes several parallel algorithms for image edge relaxation on array processors with different numbers of processing elements (PEs) connected by a mesh or hypercube network. The time complexity of Prager's original edge relaxation scheme is O(N²) per iteration using floating-point operations on a sequential machine, where N² is the number of pixels in the image. Modifications to the scheme are made so that no multiplications are employed and only integer operations are required. Moreover, with parallel processing, the time complexity per iteration is reduced to some constant value. A time complexity analysis on two parallel algorithms is performed. Although the algorithm on an array processor with 4N² PEs achieved higher degree of parallelism, the algorithm with N² PEs is preferred. Further modifications on the latter algorithm are made to accommodate to fewer PEs.     

Three-mode partitioning

The three-mode partitioning model is a clustering model for three-way three-mode data sets that implies a simultaneous partitioning of all three modes involved in the data. In the associated data analysis, a data array is approximated by a model array that can be represented by a three-mode partitioning model of a prespecified rank, minimizing a least squares loss function in terms of differences between data and model. Algorithms have been proposed for this minimization, but their performance is not yet clear. A framework for alternating least-squares methods is described in order to offset the performance problem. Furthermore, a number of both existing and novel algorithms are discussed within this framework. An extensive simulation study is reported in which these algorithms are evaluated and compared according to sensitivity to local optima. The recovery of the truth underlying the data is investigated in order to assess the optimal estimates. The ordering of the algorithms with respect to performance in finding the optimal solution appears to change as compared to the results obtained from the simulation study when a collection of four empirical data sets have been used. This finding is attributed to violations of the implicit stochastic model underlying both the least-squares loss function and the simulation study. Support for the latter attribution is found in a second simulation study.     

Microstructure of cobalt oxide doped sintered ceria solid solutions

The sintering of ceria solid solutions, such as Ce_0.9Gd_0.1O_1.95 (CGO10), is strongly promoted by the addition of 1 cat% of cobalt oxide, lowering the maximum sintering temperature by 200^∘C and triplicating the maximum densification rate. This change in sintering behavior results from cobalt ion segregated at the grain boundaries. An average cobalt ion boundary coverage is at maximum 3.0 ± 1.9 at/nm² and is shown to depend on the cooling rate. Coverage by segregated gadolinium is also found and amounts to 13.2 ± 11.4 at/nm² for a slowly cooled sample. From cobalt excess measured at the boundary, an estimated concentration of only 0.06 cat% of cobalt oxide is necessary to promote the sintering effect. The remaining amount of cobalt oxide is found in triple points and as particles in clusters. It is expected that the amount of cobalt oxide necessary for fast densification can be reduced with a doping process that distributes the additives more homogeneously.     

A survey on participating media rendering techniques

Rendering participating media is important for a number of domains, ranging from commercial applications (entertainment, virtual reality) to simulation systems (driving, flying, and space simulators) and safety analyses (driving conditions, sign visibility). This article surveys global illumination algorithms for environments including participating media. It reviews both appearance-based and physically-based media methods, including the single-scattering and the more general multiple-scattering techniques. The objective of the survey is the characterization of all these methods: identification of their base techniques, assumptions, limitations, and range of utilization. It concludes with some reflections about the suitability of the methods depending on the specific application involved, and possible future research lines.     

Focus theory of normative conduct and terror-management theory: The interactive impact of mortality salience and norm salience on social judgment.

Research on terror-management theory has shown that after mortality salience (MS) people attempt to live up to cultural values. But cultures often value very different and sometimes even contradictory standards, leading to difficulties in predicting behavior as a consequence of terror-management needs. The authors report 4 studies to demonstrate that the effect of MS on people's social judgments depends on the salience of norms. In Study 1, making salient opposite norms (prosocial vs. proself) led to reactions consistent with the activated norms following MS compared with the control condition. Study 2 showed that, in combination with a pacifism prime, MS increased pacifistic attitudes. In Study 3, making salient a conservatism/security prime led people to recommend harsher bonds for an illegal prostitute when they were reminded of death, whereas a benevolence prime counteracted this effect. In Study 4 a help prime, combined with MS, increased people's helpfulness. Discussion focuses briefly on how these findings inform both terror-management theory and the focus theory of normative conduct. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling influenza incidence for the purpose of on-line monitoring

We describe and discuss statistical models of Swedish influenza data, with special focus on aspects which are important in on-line monitoring. Earlier suggested statistical models are reviewed and the possibility of using them to describe the variation in influenza-like illness (ILI) and laboratory diagnoses (LDI) is discussed. Exponential functions were found to work better than earlier suggested models for describing the influenza incidence. However, the parameters of the estimated functions varied considerably between years. For monitoring purposes we need models which focus on stable indicators of the change at the outbreak and at the peak.For outbreak detection we focus on ILI data. Instead of a parametric estimate of the baseline (which could be very uncertain), we suggest a model utilizing the monotonicity property of a rise in the incidence. For ILI data at the outbreak, Poisson distributions can be used as a first approximation.To confirm that the peak has occurred and the decline has started, we focus on LDI data. A Gaussian distribution is a reasonable approximation near the peak. In view of the variability of the shape of the peak, we suggest that a detection system use the monotonicity properties of a peak.     

Physicochemical characterisation of eight Spanish mulberry clones: processing and fresh market aptitudes

The objective of this study was to evaluate and compare, for the first time, white and black mulberry species in terms of their main physicochemical characteristics in eight Spanish clones. The results showed significantly different characteristics between the black and white mulberry species. Fruit weight of mulberry species ranged from 2.10 to 4.15 g, and fruit juice yield, from 41% to 62%. Fructose (~61%) and glucose (~39%) were the predominant sugars in all mulberries. The MN1 clone displayed the highest total acidity (>2.6 g L^?1), and malic acid was the most abundant organic acid (6.65 g kg^?1). Cluster analysis has allowed grouping of the clones into three groups (i) MN1 and MN2; (ii) MN3 and MN4; and (iii) MA1, MA2, MA3 and MA4. Experimental results proved that Spanish mulberries have high potential for fresh consumption (attractive dark colour in Morus nigra clones, high sugars content and intense sweetness) and industrialisation (~50% juice yield, attractive juice colour, high content of crude fibre and intense sweetness). This study is also a step towards identification of this fruit as a potential healthy food, which may also be used in food industry and also have pharmaceutical interest.