65,753 research outputs found

    Fairs for e-commerce: the benefits of aggregating buyers and sellers

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    In recent years, many new and interesting models of successful online business have been developed. Many of these are based on the competition between users, such as online auctions, where the product price is not fixed and tends to rise. Other models, including group-buying, are based on cooperation between users, characterized by a dynamic price of the product that tends to go down. There is not yet a business model in which both sellers and buyers are grouped in order to negotiate on a specific product or service. The present study investigates a new extension of the group-buying model, called fair, which allows aggregation of demand and supply for price optimization, in a cooperative manner. Additionally, our system also aggregates products and destinations for shipping optimization. We introduced the following new relevant input parameters in order to implement a double-side aggregation: (a) price-quantity curves provided by the seller; (b) waiting time, that is, the longer buyers wait, the greater discount they get; (c) payment time, which determines if the buyer pays before, during or after receiving the product; (d) the distance between the place where products are available and the place of shipment, provided in advance by the buyer or dynamically suggested by the system. To analyze the proposed model we implemented a system prototype and a simulator that allow to study effects of changing some input parameters. We analyzed the dynamic price model in fairs having one single seller and a combination of selected sellers. The results are very encouraging and motivate further investigation on this topic

    ZEUS Results

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    Several results from the ZEUS Collaboration were presented at this Workshop. The highlights are presented in this summary, and include results from NLO QCD fits and determination of alphas, from forward jets and diffractive final states, from pentaquarks and searches and from heavy flavour production. Also the first results from the analysis of the HERA II e+p/e-p data are shown.Comment: 12 pages, Proceedings of the DIS05 Workshop, Madison, 200

    Single particle slow dynamics of confined water

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    Molecular dynamics simulations of SPC/E water confined in a Silica pore are presented. The simulations have been performed at different hydration levels and temperatures to study the single-particle dynamics. Due to the confinement and to the presence of a hydrophilic surface, the dynamic behaviour of the liquid appears to be strongly dependent on the hydration level. On lowering temperature and/or hydration level the intermediate scattering function displays a double-step relaxation behaviour whose long time tail is strongly non-exponential. At higher hydrations two quite distinct subsets of water molecules are detectable. Those belonging to the first two layers close to the substrate suffer a severe slowing down already at ambient temperature. While the behaviour of the remaining ones is more resemblant to that of supercooled bulk SPC/E water. At lower hydrations and/or temperatures the onset of a slow dynamics due to the cage effect and a scenario typical of supercooled liquids approaching the kinetic glass transition is observed. Moreover, for low hydrations and/or temperatures, the intermediate scattering function clearly displays an overshoot, which can be assigned to the so called ``Boson Peak''.Comment: 7 pages with one table and 8 figures; revTeX style. Based on an invited talk presented at the International Bunsed Discussion Meeting on "Metastable Water", Sept. 1999. In press on PCCP (2000

    Basics of RF electronics

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    RF electronics deals with the generation, acquisition and manipulation of high-frequency signals. In particle accelerators signals of this kind are abundant, especially in the RF and beam diagnostics systems. In modern machines the complexity of the electronics assemblies dedicated to RF manipulation, beam diagnostics, and feedbacks is continuously increasing, following the demands for improvement of accelerator performance. However, these systems, and in particular their front-ends and back-ends, still rely on well-established basic hardware components and techniques, while down-converted and acquired signals are digitally processed exploiting the rapidly growing computational capability offered by the available technology. This lecture reviews the operational principles of the basic building blocks used for the treatment of high-frequency signals. Devices such as mixers, phase and amplitude detectors, modulators, filters, switches, directional couplers, oscillators, amplifiers, attenuators, and others are described in terms of equivalent circuits, scattering matrices, transfer functions; typical performance of commercially available models is presented. Owing to the breadth of the subject, this review is necessarily synthetic and non-exhaustive. Readers interested in the architecture of complete systems making use of the described components and devoted to generation and manipulation of the signals driving RF power plants and cavities may refer to the CAS lectures on Low-Level RF.Comment: 36 pages, contribution to the CAS - CERN Accelerator School: Specialised Course on RF for Accelerators; 8 - 17 Jun 2010, Ebeltoft, Denmar

    One Time to Sue: The Case for a Uniform Statute of Limitations for Consumers to Sue Under the Fair Debt Collection Practices Act

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    In 1977, Congress enacted the Fair Debt Collection Practices Act (FDCPA) in an effort to provide injured consumers with uniform protection against the systematically abusive practices of the debt collection industry. The FDCPA created a private right of action for victims to sue; however, an individual who wishes to bring a private suit under the FDCPA must do so “within one year from the date on which the violation occurs.” The effectiveness of this private right of action has been unsettled due to the circuit split over the meaning of this provision. For many FDCPA violations, the debt collector might engage in the violative conduct several days, weeks, months, or even years before that conduct actually harms the consumer. Thus, the principal disagreement focuses on when the “violation occurs”: Does it occur when the debt collector engages in the proscribed conduct, or does it occur when that conduct actually harms the consumer? Moreover, if the violation occurs when the debt collector engages in the proscribed act, can a “discovery rule” apply to delay the running of the statute of limitations until the consumer finds out about the violation? This Note explores the various analyses circuit courts apply to determine the date on which an FDCPA violation occurs. Unless federal courts adopt a uniform analysis to determine when an FDCPA violation occurs for the purpose of triggering the running of the statute of limitations, injured consumers will continue to receive inconsistent protection under the statute. This Note argues that in order to promote the FDCPA’s remedial nature, federal courts should adopt the following guidelines to determine the date on which an FDCPA violation occurs: (1) a violation occurs, and a cause of action accrues, when a consumer suffers the kind of harm for which Congress intended to provide a private damages remedy; and (2) where a debt collector fraudulently conceals his or her violative conduct from an injured consumer, the equitable tolling doctrine should apply to toll the running of the FDCPA’s statute of limitations for the duration of the concealment

    Smarter Outsourcing for Grantmakers

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    With the subsequent downturn in the economy, outsourcing became an even more attractive opption for some funders. Today, more than ever, grantmakers facing fluctations in the economy need to work more resourcefully, efficiently, and effectively. This paper will explore why grantmakers choose to outsource, what functions are typically contracted out, and how an outsourcing arrangement is best managed, based on the lessons TCC Group--and our clients--have learned over the past 30 years
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