7,940 research outputs found
Deterministic Transformations of Multipartite Entangled States with Tensor Rank 2
Transformations involving only local operations assisted with classical
communication are investigated for multipartite entangled pure states having
tensor rank 2. All necessary and sufficient conditions for the possibility of
deterministically converting truly multipartite, rank-2 states into each other
are given. Furthermore, a chain of local operations that successfully achieves
the transformation has been identified for all allowed transformations. The
identified chains have two nice features: (1) each party needs to carry out at
most one local operation and (2) all of these local operations are also
deterministic transformations by themselves. Finally, it is found that there
are disjoint classes of states, all of which can be identified by a single real
parameter, which remain invariant under deterministic transformations.Comment: 27 pages, 1 figure; added new references and improved the
presentatio
Sequential item pricing for unlimited supply
We investigate the extent to which price updates can increase the revenue of
a seller with little prior information on demand. We study prior-free revenue
maximization for a seller with unlimited supply of n item types facing m myopic
buyers present for k < log n days. For the static (k = 1) case, Balcan et al.
[2] show that one random item price (the same on each item) yields revenue
within a \Theta(log m + log n) factor of optimum and this factor is tight. We
define the hereditary maximizers property of buyer valuations (satisfied by any
multi-unit or gross substitutes valuation) that is sufficient for a significant
improvement of the approximation factor in the dynamic (k > 1) setting. Our
main result is a non-increasing, randomized, schedule of k equal item prices
with expected revenue within a O((log m + log n) / k) factor of optimum for
private valuations with hereditary maximizers. This factor is almost tight: we
show that any pricing scheme over k days has a revenue approximation factor of
at least (log m + log n) / (3k). We obtain analogous matching lower and upper
bounds of \Theta((log n) / k) if all valuations have the same maximum. We
expect our upper bound technique to be of broader interest; for example, it can
significantly improve the result of Akhlaghpour et al. [1]. We also initiate
the study of revenue maximization given allocative externalities (i.e.
influences) between buyers with combinatorial valuations. We provide a rather
general model of positive influence of others' ownership of items on a buyer's
valuation. For affine, submodular externalities and valuations with hereditary
maximizers we present an influence-and-exploit (Hartline et al. [13]) marketing
strategy based on our algorithm for private valuations. This strategy preserves
our approximation factor, despite an affine increase (due to externalities) in
the optimum revenue.Comment: 18 pages, 1 figur
Screening of maize germplasm for Turcicum leaf blight resistance
: A study was conducted during Kharif 2012 and 2013 at Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Shalimar Campus Srinagar with the objective of screening sixty maize genotypes against Turcicum leaf blight caused by Exserohilum turcicum (Pass.) Leonard and Suggs. Field experiment was laid out in a randomized block design with three replications. In order to ensure establishment of infection, artificial inoculation of E. turcicum on test genotypes was made twice at 30 and 40 days after sowing with two different methods of inoculation (spraying on foliage of maize with spore suspension of pathogen @ 5x104 spores/ml at 30 DAS and by whorl drop inoculation of pathogen multiplies on sorghum grains at 40 DAS). Disease severity on test entries was scored at silk drying stage and studies revealed that two inbred lines, viz., NAI-112 and NAI-147, and one hybrid, viz., HQPM-1 were found resistant with pooled disease intensity of 4.12 per cent, 4.04 per cent and 4.38 per cent, respectively. Four inbred lines, viz., KDM 381 A, KDM 918 A, NAI-152 and NAI-167 were found susceptible with pooled disease intensity of 52.82 per cent, 51.02 per cent, 58.58 per cent and 61.33 per cent, respectively. The remaining genotypes were moderately resistant to moderately susceptible
Designing cost-sharing methods for Bayesian games
We study the design of cost-sharing protocols for two fundamental resource allocation problems, the Set Cover and the Steiner Tree Problem, under environments of incomplete information (Bayesian model). Our objective is to design protocols where the worst-case Bayesian Nash equilibria, have low cost, i.e. the Bayesian Price of Anarchy (PoA) is minimized. Although budget balance is a very natural requirement, it puts considerable restrictions on the design space, resulting in high PoA. We propose an alternative, relaxed requirement called budget balance in the equilibrium (BBiE).We show an interesting connection between algorithms for Oblivious Stochastic optimization problems and cost-sharing design with low PoA. We exploit this connection for both problems and we enforce approximate solutions of the stochastic problem, as Bayesian Nash equilibria, with the same guarantees on the PoA. More interestingly, we show how to obtain the same bounds on the PoA, by using anonymous posted prices which are desirable because they are easy to implement and, as we show, induce dominant strategies for the players
Correlates to the variable effects of cannabis in young adults: a preliminary study
Background: Cannabis use can frequently have adverse affects in those that use it and these can be amplified by various characteristics of an individual, from demographic and environmental variations to familial predisposition for mental illnesses. Methods: The current study of 100 individuals, who were cannabis users during their adolescence and may still be users, was a survey of the self perceived effects of cannabis and their correlates. A reliable family member was also interviewed for determination of family history of various major mental illnesses and substance use. Results: As many as 40% of cannabis users had paranoid feelings (suspiciousness) when using cannabis, although the most frequent effect was feeling relaxed (46%). Having a familial background for mental illnesses such as depression or schizophrenia did not determine the effects of cannabis nor its pattern of use, although the number of subjects with such a history was small. An age at which an individual began using cannabis did have an effect on how heavily it was used and the heavier the cannabis use, the more likely the individual was also to have had psychotic symptoms after use. There were no sex differences in effects of cannabis. These results are tempered by the reliance on self-report for many of the variables ascertained. Conclusion: Cannabis can frequently have negative effects in its users, which can be amplified by certain demographic and/or psychosocial factors. Thus, users with a specific profile may be at a higher risk of unpleasant effects from cannabis use and caution should be noted when cannabis is administered to young people for medicinal purposes
Photocurrent response of B12As2 crystals to blue light, and its temperature-dependent electrical characterizations
Citation: Gul, R., Cui, Y., Bolotnikov, A. E., Camarda, G. S., Egarievwe, S. U., Hossain, A., . . . James, R. B. (2016). Photocurrent response of B12As2 crystals to blue light, and its temperature-dependent electrical characterizations. Aip Advances, 6(2), 6. doi:10.1063/1.4941937With the global shortage of He-3 gas, researchers worldwide are looking for alternative materials for detecting neutrons. Among the candidate materials, semiconductors are attractive because of their light weight and ease in handling. Currently, we are looking into the suitability of boron arsenide (B12As2) for this specific application. As the first step in evaluating the material qualitatively, the photo-response of B12As2 bulk crystals to light with different wavelengths was examined. The crystals showed photocurrent response to a band of 407- and 470- nm blue light. The maximum measured photoresponsivity and the photocurrent density at 0.7 V for 470 nm blue light at room temperature were 0.25 A.W-1 and 2.47 mA.cm(-2), respectively. In addition to photo current measurements, the electrical properties as a function of temperature (range: 50-320 K) were measured. Reliable data were obtained for the low-temperature I-V characteristics, the temperature dependence of dark current and its density, and the resistivity variations with temperature in B12As2 bulk crystals. The experiments showed an exponential dependence on temperature for the dark current, current density, and resistivity; these three electrical parameters, respectively, had a variation of a few nA to mu A, 1-100 mu A.cm(-2) and 7.6x10(5)-7.7x10(3) Omega.cm, for temperature increasing from 50 K to 320 K. The results from this study reported the first photoresponse and demonstrated that B12As2 is a potential candidate for thermal-neutron detectors. (C) 2016 Author(s)
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