1,256 research outputs found

    Effects of Moral Self, Self Esteem and Parental Bonding on Delinquency among Young People in Hong Kong

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    This study was designed to investigate the effects of global self-esteem, moral self, and parental bonding on youth's delinquency. A sample of young Chinese adults (N=200) were drawn from public areas such as playgrounds and campus. Respondents were to complete a questionnaire consisted of the General Self, Moral Self, Parental Bonding, and Behavior Checklist on an individual basis. As a result, males reported higher delinquency as well as general self-esteem than females. Among the demographic variables, gender was found to significantly predict delinquency. For the self variables, moral self but not global self-esteem was found to predict delinquency significantly, even when the effect of gender was being controlled. Among the parenting aspects (authoritarianism, protectiveness, care), protectionism significantly predicted delinquency, while parental care and authoritarianism did not. These findings confirmed the need of considering multidimensional aspects of self-esteem and the cultural perspective in explaining the parental impacts on delinquency

    From Fake Supergravity to Superstars

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    The fake supergravity method is applied to 5-dimensional asymptotically AdS spacetimes containing gravity coupled to a real scalar and an abelian gauge field. The motivation is to obtain bulk solutions with R x S^3 symmetry in order to explore the AdS/CFT correspondence when the boundary gauge theory is on R x S^3. A fake supergravity action, invariant under local supersymmetry through linear order in fermion fields, is obtained. The gauge field makes things more restrictive than in previous applications of fake supergravity which allowed quite general scalar potentials. Here the superpotential must take the form W(\phi) ~ exp(-k\phi) + c exp(2\phi/(3k)), and the only freedom is the choice of the constant k. The fermion transformation rules of fake supergravity lead to fake Killing spinor equations. From their integrability conditions, we obtain first order differential equations which we solve analytically to find singular electrically charged solutions of the Lagrangian field equations. A Schwarzschild mass term can be added to produce a horizon which shields the singularity. The solutions, which include "superstars", turn out to be known in the literature. We compute their holographic parameters.Comment: 42 pages, 3 figure

    Black strings in AdS_5

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    We present non-extremal magnetic black string solutions in five-dimensional gauged supergravity. The conformal infinity is the product of time and S^1xS_h, where S_h denotes a compact Riemann surface of genus h. The construction is based on both analytical and numerical techniques. We compute the holographic stress tensor, the Euclidean action and the conserved charges of the solutions and show that the latter satisfy a Smarr-type formula. The phase structure is determined in the canonical ensemble, and it is shown that there is a first order phase transition from small to large black strings, which disappears above a certain critical magnetic charge that is obtained numerically. For another particular value of the magnetic charge, that corresponds to a twisting of the dual super Yang-Mills theory, the conformal anomalies coming from the background curvature and those arising from the coupling to external gauge fields exactly cancel. We also obtain supersymmetric solutions describing waves propagating on extremal BPS magnetic black strings, and show that they possess a Siklos-Virasoro reparametrization invariance.Comment: 40 pages, 7 figures, JHEP3. v2: minor corrections, 2 references added. v3: typos in holographic stress tensor corrected, 3 references adde

    Competition in Access to Content

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    Part 5: Cooperation and CollaborationInternational audienceWe study competition between users over access to content in a telecom market that includes several access providers and several content providers. We focus situations where exclusive agreements exist between content and access providers, which allows access providers to offer content services for free for their subscribers. We call access providers having such agreements ”super” providers or ”enhanced” service providers. We show that the competition between the users results in a paradoxical phenomenon in which subscribers of enhanced providers prefer to defer part of their demand to other content providers whose content is costly. We show how this phenomena can be exploited by the content providers so as to maximize their benefits

    Reaction Diffusion Models in One Dimension with Disorder

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    We study a large class of 1D reaction diffusion models with quenched disorder using a real space renormalization group method (RSRG) which yields exact results at large time. Particles (e.g. of several species) undergo diffusion with random local bias (Sinai model) and react upon meeting. We obtain the large time decay of the density of each specie, their associated universal amplitudes, and the spatial distribution of particles. We also derive the spectrum of exponents which characterize the convergence towards the asymptotic states. For reactions with several asymptotic states, we analyze the dynamical phase diagram and obtain the critical exponents at the transitions. We also study persistence properties for single particles and for patterns. We compute the decay exponents for the probability of no crossing of a given point by, respectively, the single particle trajectories (Ξ\theta) or the thermally averaged packets (ξˉ\bar{\theta}). The generalized persistence exponents associated to n crossings are also obtained. Specifying to the process A+A→∅A+A \to \emptyset or A with probabilities (r,1−r)(r,1-r), we compute exactly the exponents ÎŽ(r)\delta(r) and ψ(r)\psi(r) characterizing the survival up to time t of a domain without any merging or with mergings respectively, and ÎŽA(r)\delta_A(r) and ψA(r)\psi_A(r) characterizing the survival up to time t of a particle A without any coalescence or with coalescences respectively. ξˉ,ψ,ÎŽ\bar{\theta}, \psi, \delta obey hypergeometric equations and are numerically surprisingly close to pure system exponents (though associated to a completely different diffusion length). Additional disorder in the reaction rates, as well as some open questions, are also discussed.Comment: 54 pages, Late

    Characterization of a Mixed Methanotrophic Culture Capable of Chloroethylene Degradation

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    A consortium of methanotrophs cultured from the St. Joseph's aquifer in Schoolcraft, MI, was found to exhibit similar methane consumption rates as pure cultures of methanotrophs. The methanotrophic consortium resides within a portion of the aquifer contaminated with a mixed waste plume of perchloroethylene (PCE) and its reductive dechlorination products from natural attenuation, trichloroethylene (TCE), cis-dichloroethylene (c-DCE), and vinyl chloride (VC). Oxidation kinetics for TCE, c-DCE, and VC were measured for the mixed methanotroph consortium and compared to reported rate parameters for degradation of these chloroethylene compounds by pure methanotrophic cultures. The results demonstrate that the kinetics of chloroethylene oxidation by the Schoolcraft methanotroph population mimic the degradation rates of pure methanotrophic cultures that primarily express particulate methane monooxygenase (pMMO). Molecular and biochemical analyses confirmed that sMMO was not being expressed by these cells. Rather, using competitive reverse transcriptionpolymerase chain reaction, pmoA, a gene encoding one of the polypeptides of the pMMO was found at a level of (1.57 ± 0.10) × 10–17 mol pmoA mRNA/g wet soil in soil slurries and (2.65 ± 0.43) × 10–17 mol pmoA mRNA/ÎŒl in groundwater. No expression of mmoX, a gene encoding one of the polypeptides of the sMMO, was detected.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63398/1/ees.2005.22.177.pd

    A Calibration Method for the Integrated Design of Finishing Robotic Workcells in the Aerospace Industry

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    Industrial robotics provides high flexibility and reconfigurability, cost effectiveness and user friendly programming for many applications but still lacks in accuracy. An effective workcell calibration reduces the errors in robotic manufacturing and contributes to extend the use of industrial robots to perform high quality finishing of complex parts in the aerospace industry. A novel workcell calibration method is embedded in an integrated design framework for an in-depth exploitation of CAD-based simulation and offline programming. The method is composed of two steps: a first offline calibration of the workpiece-independent elements in the workcell layout and a final automated online calibration of workpiece-dependent elements. The method is finally applied to a robotic workcell for finishing aluminum housings of helicopter gear transmissions, characterized by complex and non-repetitive shapes, and by severe dimensional and geometrical accuracy demands. Experimental results demonstrate enhanced performances of the robotic workcell and improved final quality of the housings
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