Resource Allocation using Virtual Clusters

In this report we demonstrate the utility of resource allocations that use virtual machine technology for sharing parallel computing resources among competing users. We formalize the resource allocation problem with a number of underlying assumptions, determine its complexity, propose several heuristic algorithms to find near-optimal solutions, and evaluate these algorithms in simulation. We find that among our algorithms one is very efficient and also leads to the best resource allocations. We then describe how our approach can be made more general by removing several of the underlying assumptions

A spatial multi-criteria model for the evaluation of land redistribution plans

A planning support system for land consolidation has been developed that has, at its heart, an expert system called LandSpaCES (Land Spatial Consolidation Expert System) which contains a "design module" that generates alternative land redistributions under different scenarios and an "evaluation module" which integrates GIS with multi-criteria decision making for assessing these alternatives. This paper introduces the structural framework of the latter module which has been applied using a case study in Cyprus. Two new indices are introduced: the "parcel concentration coefficient" for measuring the dispersion of parcels; and the "landowner satisfaction rate" for predicting the acceptance of the land redistribution plan by the landowners in terms of the location of their new parcels. These two indices are used as criteria for the evaluation of the land redistribution alternatives and are transferable to any land consolidation project. Moreover, a modified version of the ratio estimation procedure, referred to as the "qualitative rating method" for assigning weights to the evaluation criteria, is presented, along with a set of non-linear value functions for standardizing the performance scores of the alternatives and incorporating expert knowledge for five evaluation criteria. The application of the module showed that it is a powerful new tool for the evaluation of alternative land redistribution plans that could be implemented in other countries after appropriate adjustments. A broader contribution has also been made to spatial planning processes, which might follow the methodology and innovations presented in this paper

LandParcelS: A module for automated land partitioning

Land fragmentation is a widespread problem and schemes for consolidating land are required to improve agricultural efficiency. This paper explains the development of a module called LandParcelS (Land Parcelling System) that is part of an integrated planning and decision support system called LAONISS which is being developed to assist land consolidation planning in Cyprus. LandParcelS is the component of the system that automates the land partitioning process by optimising land parcels in terms of shape, size and value. The methodology employs a genetic algorithm and results are presented when treating the partitioning task as either a single or multi-objective problem

A decade into Facebook: where is psychiatry in the digital age?

Social networking sites are a part of everyday life for over a billion people worldwide. They show no sign of declining popularity, with social media use increasing at 3 times the rate of other Internet use. Despite this proliferation, mental healthcare has yet to embrace this unprecedented resource. We argue that social networking site data should become a high priority for psychiatry research and mental healthcare delivery. We illustrate our views using the world’s largest social networking site, Facebook, which currently has over 1 billion daily users (1 in 7 people worldwide). Facebook users can create personal profiles, socialize, express feelings, and share content, which Facebook stores as time-stamped digital records dating back to when the user first joined. Evidence suggests that 92% of adolescents go online daily and disclose considerably more about themselves online than offline. Thus, working with Facebook data could further our understanding of the onset and early years of mental illness, a crucial period of interpersonal development. Furthermore, a diminishing ‘digital divide’ has allowed for a broader sociodemographic to access Facebook, including homeless youth, young veterans, immigrants, patients with mental health problems, and seniors, enabling greater contact with traditionally harder-to-reach populations

Using item response theory to develop measures of acquisitive and protective self-monitoring from the original self-monitoring scale

For the past 40 years, the conventional univariate model of self-monitoring has reigned as the dominant interpretative paradigm in the literature. However, recent findings associated with an alternative bivariate model challenge the conventional paradigm. In this study, item response theory is used to develop measures of the bivariate model of acquisitive and protective self-monitoring using original Self-Monitoring Scale (SMS) items, and data from two large, nonstudent samples (Ns = 13,563 and 709). Results indicate that the new acquisitive (six-item) and protective (seven-item) self-monitoring scales are reliable, unbiased in terms of gender and age, and demonstrate theoretically consistent relations to measures of personality traits and cognitive ability. Additionally, by virtue of using original SMS items, previously collected responses can be reanalyzed in accordance with the alternative bivariate model. Recommendations for the reanalysis of archival SMS data, as well as directions for future research, are provided

Pseudo-Riemannian geodesic foliations by circles

We investigate under which assumptions an orientable pseudo-Riemannian geodesic foliations by circles is generated by an $S^1$-action. We construct examples showing that, contrary to the Riemannian case, it is not always true. However, we prove that such an action always exists when the foliation does not contain lightlike leaves, i.e. a pseudo-Riemannian Wadsley's Theorem. As an application, we show that every Lorentzian surface all of whose spacelike/timelike geodesics are closed, is finitely covered by $S^1\times \R$. It follows that every Lorentzian surface contains a non-closed geodesic.Comment: 14 page

SPIN TRAPPING THE OXIDIZED PRODUCTS OF PUFA IN MODEL MEMBRANES: THE PROTECTION CONFERRED BY VITAMIN E

poster abstractElectron paramagnetic resonance (EPR) spectroscopy is recognized as the most sensitive and noninvasive means to quantify free radicals of biological relevance such as reactive oxygen species (ROS). In spin trapping a molecule (the spin trap) reacts with the free radical producing a spin adduct that is sufficiently stable to be detected by EPR. Here we apply a novel spin trapping technique to investigate the protection that α-tocopherol (vitamin E), the major lipid soluble antioxidant in membranes, confers on polyunsaturated lipids in model membranes. Polyunsaturated fatty acids (PUFA) readily oxidize because they have a cis,cis-1,4-pentadiene motif that renders the central methylene group vulnerable to attack by ROS. Our method quantifies the oxidized products of PUFA in lipid vesicles that have been exposed to a peroxyl radical generator 2,2'-azobis-(amidinopropane) dihydrochloride (AAPH) that initiates the free radical chain reaction. By measuring the reduction in lipid peroxidation due to the presence of αtocopherol, we test the hypothesis that the vitamin co-localizes with polyunsaturated lipids in membrane domains to ensure close proximity to the most vulnerable lipid species

Personality and intrinsic motivational factors in end-user programming

We explore the factors that determine whether individuals are likely to experience intrinsic motivation in end-user programming (EUP). We report two experiments: one that tests whether there are reliable psychometric constructs that describe different aspects of intrinsic motivation, and one that tests whether these constructs are successful in predicting individuals' own self-reported intrinsic motivation after using a popular EUP product. We conclude that there are identifiable and distinct motivational factors in EUP, and that these are associated with particular psychometric personality traits. We offer several suggestions for future research that could apply these findings to improve uptake and quality of user experience for educational and general-purpose EUP applications

Dryland salinity: a multi-disciplinary conceptual model designed for on-farm salinity control

Non-Peer Reviewe