In relational semantics, the input-output semantics of a program is a relation on its set of states. We generalize this in considering elements of Kleene algebras as semantical values. In a nondeterministic context, the demonic semantics is calculated by considering the worst behavior of the program. In this paper, we concentrate on while loops. Calculating the semantics of a loop is difficult,...

Whereas the analysis of loops in imperative programs is, justifiably, dominated by the concept of invariant assertion, we submit a related but different concept, of invariant relation, and show how it can be used to compute or approximate the function of a while loop. We also introduce the concept of invariant function, which is used to generate a broad class of invariant relations.

Context Regulation of the availability of alcohol has been found to be a very important factor in alcohol impaired driving, as well as other alcohol related problems. Such factors as minimum purchase age for alcohol, the density and location of alcohol outlets, and alcohol service and sales practices have all been found to be related to impaired driving. Recent research has added to knowledge a...

This article reports the findings of an experiment designed to evaluate the effect of four questionnaire formats on the willingness of drivers convicted of drunken driving to admit to this socially undesirable behaviour. Four samples of convicted drunk drivers each received a different version of a mail questionnaire about driving behaviour and attitudes. Two versions of the questionnaire inclu...

ECAUSE Marcuse did not surface as a semi-popular social critic till the 1960s during the time of mounting and, for awhile, hopeful social protest, he is often assumed to be a spokesman for the protestors. Indeed, some of his writings in the sixties (most notably his Essay on Liberation) directly addressed the protest movement. Moreover, as protest in the U.S. subsided in the seventies, Marcuse ...

Design Principles Meet the Real World The main reason, IAB argued, that it favored CLNP was that it was necessary for the Internet to ® nd a solution very soon (IAB, 1992a, p. 14). CLNP is a protocol that a is already speci® ed, and several implementations existo so it a will avoid design of a new protocol from scratch, a process that would consume valuable time and delay testing and deployment...

BACKGROUND Traffic Injuries are a major public health problem, especially among young people. However, we have not found any useful questionnaire designed in our country for the epidemiological research in this field. The objective of this study was to design and validate an easy and quickly-to-fill questionnaire aimed to collect information on how frequently university car drivers report to be...

OBJECTIVE We examined the associations between the density of alcohol establishments and five types of nonviolent crime across urban neighborhoods. METHOD Data from the city of Minneapolis, MN, in 2009 were aggregated and analyzed at the neighborhood level. We examined the association between alcohol establishment density and five categories of nonviolent crime: vandalism, nuisance crime, pub...

India had earned the dubious distinction of having more number of fatalities due to road accidents in the world. Road safety is emerging as a major social concern around the world especially in India. Drinking and driving is already a serious public health problem, which is likely to emerge as one of the most significant problems in the near future. The role of alcohol in traffic safety has pro...

Diffusion-weighted and diffusion tensor imaging (DWI/DTI) has revolutionized clinical neuroimaging. Pathology may be detected earlier and with greater specificity than with conventional magnetic resonance imaging sequences. In addition, DWI/DTI allows exploring the microarchitecture of the brain. A detailed knowledge of the basics of DWI/DTI is mandatory to better understand pathology encounter...