Reasoning about concurrent programs involves representing the information that concurrent processes manipulate disjoint portions of memory. In sophisticated applications, the division of memory between processes is not static. Through operations, processes can exchange the implied ownership of memory cells. In addition, processes can also share ownership of cells in a controlled fashion as long as they perform operations that do not interfere, e.g., they can concurrently read shared cells. Thus the traditional paradigm of distributed computing based on locations is replaced (...) by a paradigm of concurrent computing which is more tightly based on program structure. Concurrent Separation Logic with Permissions, developed by O’Hearn, Bornat et al., is able to represent sophisticated transfer of ownership and permissions between processes. We demonstrate how these ideas can be used to reason about fine-grained concurrent programs which do not employ explicit synchronization operations to control interference but cooperatively manipulate memory cells so that interference is avoided. Reasoning about such programs is challenging and appropriate logical tools are necessary to carry out the reasoning in a reliable fashion. We argue that Concurrent Separation Logic with Permissions provides such tools. We illustrate the logical techniques by presenting the proof of a concurrent garbage collector originally studied by Dijkstra et al., and extended by Lamport to handle multiple user processes. (shrink)
This article focuses on three recent controversies in which Žižek has been embroiled and for which he has taken positions that rest on the notion of antagonism. His views on Eurocentrism, the European refugee crisis and trans politics have been the subject of notable disapproval, if not denunciation. Critics reproach him for being Eurocentric, racist and transphobic, charges which he has repeatedly countered. The article will examine the differing theoretical and political positions in these debates, underlining what Žižek’s critics miss (...) or misunderstand about his notion of antagonism. While I side firmly with Žižek on the substance of these issues, I nonetheless consider the extent to which at least part of the disagreement here centres on the performative rather than the strictly “theoretical”: Might his critics be reacting to his overexposure? Could such overexposure be interpreted as an attempt at having the last word? And to what extent does the antagonistic form of Žižek’s interventions militate against their theoretical content? (shrink)
Students display resistance in the classroom in numerous ways, often in the form of academic misconduct. Some argue that resistance can reflect cleverness and creativity, rather than apathy. This investigation aimed to develop a psychometric tool to examine classroom resistance as well as identify individual and situational determinants of the same. Data from 853 participants was collected on measures of resistance behaviors in educational contexts and their environmental contributors, creativity, personality, and deception. Further, participants indicated their frequency of resistance across (...) two time periods: kindergarten through middle school, and high school through college. Exploratory and confirmatory factor analyses identified a robust three-factor structure for the Classroom Resistance Scale, comprising Test-Oriented Cheating, Blatant Academic Dishonesty, and Unethical Shortcuts. The person-situation analysis indicated that students who engaged in resistance shared some consistent characteristics: they were more likely to be closed to new experiences, unimaginative, more extraverted, and highly influenced by their peers. Moreover, the frequency of classroom resistance increased in higher grades as compared to lower ones. Implications of spillover effects of academic dishonesty into the workplace are discussed, in addition to suggestions for future research. (shrink)
Preface. Quest for reality -- The history that vanished -- From zero to infinity -- Nanocosm. Quantum revolution -- Subatomic world -- Quantum mysticism -- Secrets -- Macrocosm. Fabric of space-time -- Elegant universe -- Conscious universe -- Secrets -- Microcosm. Biocosm -- Circle of life -- Blueprint of life -- Secrets -- Reality. Self-aware universe -- Perception -- Karmic footprints -- Secrets.
The possible differential effects of ABO blood group materno-paternal (fetal) incompatibility on completed reproductive performance were investigated on a sample of 100 couples (100 fathers and 100 mothers) from three villages in the Jind district of Haryana state, India. The average number of live births per mating couple was slightly higher for the incompatible matings (5·32) than the compatible ones (5·05). This advantage was offset by higher postnatal mortality in the former. Consequently, the average number of living children in the (...) compatible matings (4·64) was higher than in the incompatible ones (4·18). With reference to individual ABO matings, the index of relative fertility (Irf) was the highest in A×AB followed by B×A type of incompatible matings. No decrease in live births in O×A and O×B incompatible matings was observed compared with their reciprocal compatible ones, i.e. A×O and B×O matings, as has been hypothesized in previous studies. The total pregnancy wastage was substantially higher in ABO-incompatible matings (24·59%) than compatible matings (8·45%). About 71% of the postnatal deaths took place within one year of the birth in the case of incompatible matings compared with 50% in the case of compatible matings. The study supports the hypothesis that selection is operative at the ABO locus as revealed by the measures of selection intensity. The loss of fitness in the present sample was associated with differential mortality. There were no differences in the proportions of average number of male live births in the compatible (0·55) and incompatible matings (0·58). However, in the individual mating types, there was some evidence of higher or lower proportions of male live births. (shrink)
Le concept d’authenticité sert de base à la valorisation de la thématique de « l’identité » qui domine aujourd’hui. Anish Kapoor présente toutes les garanties de cette « hybridité » actuellement très à la mode. Toutefois, il résiste explicitement à toute tentative de « mise en boîte » qui le cantonnerait à l’expression d’une quelconque « indianité ». Kapoor est connu pour l’aspect sensoriel et aléatoire de son travail. Shooting into the Corner est un excellent exemple d’une œuvre (...) qui évacue l’identification culturelle ; elle trouble par ailleurs les catégories goodmaniennes habituelles d’autographique et d’allographique. Son slogan – « Je n’ai rien à dire » – semble confirmer ce rejet de l’authenticité. Je compte démontrer que même l’aléatoire et l’auto-engendré sont reliés au critère d’authenticité, si cette notion repose sur l’intentionnalité et « l’intensionnalité » de l’œuvre d’art. Redéfini ainsi, le concept d’authenticité deviendrait une « règle constitutive » de notre institution. (shrink)
We developed an integrated method that can better constrain subsalt tomography using geology, thermal history modeling, and rock-physics principles. This method, called rock-physics-guided velocity modeling for migration uses predicted pore pressure as a guide to improve the quality of the earth model. We first generated a rock-physics model that provided a range of plausible pore pressure that lies between hydrostatic and fracture pressure. The range of plausible pore pressures was then converted into a range of plausible depth varying velocities as (...) a function of pore pressure that is consistent with geology and rock physics. Such a range of plausible velocities is called the rock-physics template. Such a template was then used to flatten the seismic gathers. We call this the pore-pressure scan technique. The outcome of the pore-pressure scan process was an “upper” and “lower” bound of pore pressure for a given earth model. Such velocity bounds were then used as constraints on the subsequent tomography, and further iterations were carried out. The integrated method not only flattened the common image point gathers but also limited the velocity field to its physically and geologically plausible range without well control; for example, in the study area it produced a better image and pore-pressure prognosis below salt. We determined that geologic control is essential, and we used it for stratigraphy, structure, and unconformity, etc. The method had several subsalt applications in the Gulf of Mexico and proved that subsalt pore pressure can be reliably predicted. (shrink)