Supercomputing and grid computing on the verification of covering arrays

The Covering Arrays (CAs) are mathematical objects with minimal coverage and maximum cardinality that are a good tool for the design of experiments. A?covering array is an N×k matrix over an alphabet v s.t. each N×k subset contains at least one time each combination from {0,1,??,v?1} ^t , given a positive integer value?t. The process of ensuring that a CA contains each of the v ^t combinations is called verification of CA. In this paper, we present an algorithm for CA verification and its implementation details in three different computation paradigms: (a)?sequential approach (SA); (b)?parallel approach (PA); and (c)?Grid approach (GA). Four different PAs were compared in their performance of verifying a matrix as a CA; the PA with the best performance was included in a different experimentation where the three paradigms, SA, PA, and GA were compared in a benchmark composed by 45 possible CA instances. The results showed the limitations of the different paradigms when solving the verification of CA problem, and points out the necessity of a Grid approach to solve the problem when the size of a CA grows.     

Hyperwelcome

Web page annotation and adaptive navigation support are two active, but independent research directions focused on the same goal: expanding the functionality of the Web as a hypertext system. The goal of the AnnotatEd system presented in this paper has been to integrate annotation and adaptive navigation support into a single value-added service where the components can reinforce each other and create new unique attributes. This paper describes the implementation of AnnotatEd from early prototypes to the current version, which has been explored in several contexts. We summarize some lessons we learned during the development process and which defined the current functionality of the system. We also present the results of several classroom studies of the system. These results demonstrate the importance of the browsing-based information access supported by AnnotatEd and the value of both the annotation and navigation support functionalities offered by the system.     

Comparative study of 3C-SiC layers sublimation-grown on a 6H-SiC substrate

n-3C-SiC/n-6H-SiC heterostructures grown by vacuum sublimation on CREE commercial 6H-SiC substrates are studied. Transmission electron microscopy (TEM) demonstrated that a transitional layer of varying thickness, composed of a mixture of 3C- and 6H-SiC polytypes, is formed on the substrate. A 3C polytype layer was obtained on the interlayer. Cathodoluminescence study of the surface of the film demonstrated that defects in the form of inclusions of another phase (6H-polytype), stacking faults, and twin boundaries (separating domains of cubic modification, grown in various orientations) are found on the surface and in the surface layer with a thickness on the order of 100 μm. Varying the growth conditions changes the concentration of various types of defects.     

THE DEVELOPMENT OF COMMERCIAL CRYPTOSYSTEM STANDARDS

There are many requirements for commercial cryptosystems for transmission of intelligence between terminals, between terminals and computers, and between computers. Much commercial information has great value and can warrant the cost of cryptographic protection. This paper claims that the slow rate of implementation of commercial cryptosystems is due to the lack of standardization. This standardization is necessary to achieve general acceptance of cryptosystem products by users. General acceptance is required to permit production volumes which lead to reasonable crypto product prices. This paper discusses the standards efforts that are now ongoing, and projects the types of commercial cryptosystems which will be available in the near future.     

Rental Discrimination in the Multi-ethnic Metropolis: Evidence from Sydney

Investigating differential treatment in rental housing markets is important to ensure that renters are not discriminated against based on their personal characteristics. However, little Australian research has focused systematically on this question. This paper reports the results of a study that used paired tests to estimate the extent of differential treatment of Anglo, Indian, and Muslim Middle Eastern renters in the Sydney metropolitan housing market. We find statistically significant differences in treatment on several measures, including the likelihood an agent will offer an individual appointment, will provide additional information about other housing, will provide additional information about completing the application form, and will contact a prospective renter after an inspection.     

Comparison of Peleg and Azuara et al. models in the modeling mass transfer during pile salting of goat sheets

Application of the Peleg and Azuara et al. models for describing mass transfer during pile salting of goat sheets using different mixtures of NaCl, KCl, CaCl₂ and MgCl₂ was investigated The high coefficient of determination (R² > 0.97 and R² > 0.95 for Peleg and Azuara et al. models, respectively) and the modulus of mean relative errors (MRE < 10% for both models) indicated the acceptability of both Peleg and Azuara et al. models for predicting both moisture loss and salt uptake. The equilibrium moisture and salt contents were estimated using Peleg rate constants and Azuara et al. model parameters. Equilibrium moisture (x_w) and salt contents (x_s) varied from 0.522 to 0.860 g water/g db and from 0.311 to 0.352 g NaCl/g db respectively. Multiple comparison of means showed that x_w and x_s predicted by the Peleg model were lower than those estimated by the Azuara et al. model. The values differed by 1.86–13.6% for x_w and by 1.13–10.57% for x_s.     

Differential effects of air conditioning type on residential endotoxin levels in a semi‐arid climate

Residential endotoxin exposure is associated with protective and pathogenic health outcomes. Evaporative coolers, an energy‐efficient type of air conditioner used in dry climates, are a potential source of indoor endotoxins; however, this association is largely unstudied. We collected settled dust biannually from four locations in homes with evaporative coolers (n=18) and central air conditioners (n=22) in Utah County, Utah (USA), during winter (Jan‐Apr) and summer (Aug‐Sept), 2014. Dust samples (n=281) were analyzed by the Limulus amebocyte lysate test. Housing factors were measured by survey, and indoor temperature and relative humidity measures were collected during both seasons. Endotoxin concentrations (EU/mg) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons. Endotoxin surface loads (EU/m²) were significantly higher in homes with evaporative coolers from mattress and bedroom floor samples during both seasons and in upholstered furniture during winter. For the nine significant season‐by‐location comparisons, EU/mg and EU/m² were approximately three to six times greater in homes using evaporative coolers. A plausible explanation for these findings is that evaporative coolers serve as a reservoir and distribution system for Gram‐negative bacteria or their cell wall components in homes.