Mixed group ranks: preference and confidence in classifier combination

Classifier combination holds the potential of improving performance by combining the results of multiple classifiers. For domains with very large numbers of classes, such as biometrics, we present an axiomatic framework of desirable mathematical properties for combination functions of rank-based classifiers. This framework represents a continuum of combination rules, including the Borda Count, Logistic Regression, and Highest Rank combination methods as extreme cases. Intuitively, this framework captures how the two complementary concepts of general preference for specific classifiers and the confidence it has in any specific result (as indicated by ranks) can be balanced while maintaining consistent rank interpretation. Mixed Group Ranks (MGR) is a new combination function that balances preference and confidence by generalizing these other functions. We demonstrate that MGR is an effective combination approach by performing multiple experiments on data sets with large numbers of classes and classifiers from the FERET face recognition study.     

Renaming and the weakest family of failure detectors

We address the question of the weakest failure detector to circumvent the impossibility of $(2n-2)$ -renaming in a system of up to $n$ participating processes. We derive that in a restricted class of eventual failure detectors there does not exist a single weakest oracle, but a weakest family of oracles $\zeta _n$ : every two oracles in $\zeta _n$ are incomparable, and every oracle that allows for solving renaming provides at least as much information about failures as one of the oracles in $\zeta _n$ . As a by product, we obtain one more evidence that renaming is strictly easier to solve than set agreement.     

Fast and scalable rendezvousing

In an asymmetric rendezvous system, such as an unfair synchronous queue or an elimination array, threads of two types, consumers and producers, show up and are matched each with a unique thread of the other type. Here we present new highly scalable, high throughput asymmetric rendezvous systems that outperform prior synchronous queue and elimination array implementations under both symmetric and asymmetric workloads (more operations of one type than the other). Based on this rendezvous system, we also construct a highly scalable and competitive stack implementation.     

Bacteriophages as viral pollution indicators

f2 Phage, attenuated Polio I (LSC) strain introduced daily to a 350 l. experimental oxidation pond showed no decrease in bacterial viruses f2 or other coliphages or Polio I strain.Ratios of coliphages to human enteric viruses ranged in flood waters from concentrations as low as 1:1 to as high as 10³:1; in wastewater at various seasons the ratio was 10⁵:1; in trickling filter effluents in winter it was 10⁴:1; in spring 10⁵:1, in summer and fall 10⁴:1, in oxidation pond effluents in winter 10³:1; in spring 10⁴:1; and in summer and fall 10³:1. Out of three epidemics in small communities caused by failure of water supply, coliphages were found to be positive. At the same time only two samples of human enteric viruses were positive (the third was contaminated with yeasts).Chlorination experiments using the experimental oxidation pond showed that f2 was most resistant, MS₂ was very resistant, and coliphages were more resistant than attenuated Polio I virus. Experiments with the oxidation pond effluents showed that coliphages were at least as or even more resistant to chlorine than human enteric viruses.     

Examined lives: Outcomes after holistic rehabilitation.

This article poses the question whether the attainment of optimal outcomes following neuropsychological rehabilitation requires that the individual achieve an "examined self." The author answers the question in the affirmative and provides data from a retrospective pilot study to substantiate his claim. Implications from the findings are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A relational database for non-manipulative representation of solid objects

As the heart of any solid modelling system, much effort has been spent on formulating the data models which represent the shape of a polyhedral solid object within the computer in an accurate, unique and complete manner. Most of this effort has been devoted to make the models manipulateable in terms of computational efficiency, and preserve their semantic integrity. The price paid for achieving these goals is a proliferation of cross-reference data links which, coupled with multiple redundancy, renders the models inefficient for storage or transmission over communication channels. Moreover, the interrogation of these models by non-manipulative applications is usually unsupported functionally, requiring direct accesses to the data, which involves extensive pointer chasing and therefore high familiarity with the manipulative data structure.This paper presents an example relational model as a complementary logical scheme for viewing the shape database that facilitates compact storage and supports non-manipulative query operations through the projection, selection and join operators defined for the relational model, without requiring expert knowledge of the manipulative structure. The flexibility of the relational model, compared with that of the hierarchical, manipulative one, allows easy extensibility and the association of non-geometric attributes with each data item.     

Film thickness in horizontal annular flow

Film thickness in horizontal annular flow in small diameter pipes (8-12 mm) was measured as a function of circumferential position. In addition a simple analytical model for the prediction of the film thickness at the top and bottom of the pipe is proposed.     

Contact hypothesis in ethnic relations.

Reviews research regarding the effects of intergroup contact on ethnic relations. The investigations discussed include both intra- and cross-cultural studies involving contact between various ethnic groups. The principles and generalizations emerging from these studies are categorized under (1) opportunities for contact, (2) the principle of equal status, (3) contact with high-status representatives of a minority group, (4) cooperative and competitive factors, (5) casual vs. intimate contact, (6) institutional support, (7) personality factors, and (8) direction and intensity of initial attitude. The major generalization derived from the present review is that changes in ethnic relations do occur following intergroup contact, but the nature of this change is not necessarily in the anticipated direction; "favorable" conditions do tend to reduce prejudice, but "unfavorable" conditions may increase intergroup tension and prejudice. Ethnic attitudes may also change in their intensity, and they may be limited to specific areas of the ethnic attitude and not be generalized to other aspects of the intergroup relationships. Some practical applications are also considered. (2 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)