35,987 research outputs found

    Measuring the Efficiency of an FCC Spectrum Auction

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    FCC spectrum auctions sell licenses to provide mobile phone service in designated geographic territories. We propose a method to structurally estimate the deterministic component of bidder valuations and apply it to the 1995–1996 C-block auction. We base our estimation of bidder values on a pairwise stability condition, which implies that two bidders cannot exchange licenses in a way that increases total surplus. Pairwise stability holds in many theoretical models of simultaneous ascending auctions, including some models of intimidatory collusion and demand reduction. Pairwise stability is also approximately satisfied in data that we examine from economic experiments. The lack of post-auction resale also suggests pairwise stability. Using our estimates of deterministic valuations, we measure the allocative efficiency of the C-block outcome.

    Home-Based Therapy for Young Children in Low-Income Families: A Student Training Program

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    The purpose of this project was to develop an internship training program that offered in-home therapy for young children with significant emotional and behavior problems. The children lived in single-parent, low-income homes in unsafe neighborhoods of a large, urban area. A year-long, training and supervision program was implemented with 10 second-year, graduate students enrolled in 5 different university programs that prepared mental health professionals. Students received specialized instruction in working with diverse families living in poverty and in an evidence-based treatment program. They initially observed veteran counselors implementing the treatment program in homes and gradually assumed responsibility for conducting sessions on their own. Students’ scores on a measure of counseling self-efficacy improved significantly from pre-to post-internship. Students reported high levels of satisfaction with the training program and significantly improved confidence levels in their counseling skills at the conclusion of their internship experience. The limitations of these preliminary outcomes for this pilot program are discussed along with the need for more research in this understudied area

    Efficiency enhancement of dual-mode traveling wave tubes at saturation and in the linear range by use of spent-beam refocusing and multistage depressed collectors

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    An axisymmetric, multistage depressed collector of fixed geometric design was evaluated in conjunction with an octave-bandwidth, dual-mode TWT. The TWT was operated over a wide range of conditions to simulate different applications. The collector was operated in three-, four-, and five-stage configurations, and its performance was optimized (within the constraint of fixed geometric design) over the range of TWT operating conditions covered. For operation of the dual-mode TWT at and near saturation, the collectors increased the TWT overall efficiency by a factor of 2 1/2 to 3 1/2. Collector performance was relatively constant for both the high and low TWT modes and for operation of the TWT across an octave bandwidth. For operation of the TWT in the linear, low-distortion range, collector efficiencies of 90 percent and greater were obtained, leading to a five- to twelvefold increase in the TWT overall efficiency for the range of operating conditions covered and reasonably high (greater than 25 percent) overall efficiencies well below saturation

    Efficiency enhancement of octave-bandwidth TWT's by the use of multistage depressed collectors

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    A small size two and four stage depressed collector was evaluated in conjunction with a 4.8 to 9.6 GHz traveling wave tube of 325 to 675 W power output. In spite of large fixed traveling wave tube losses, very significant efficiency enhancement was demonstrated with both the two and four stage multistage depressed collectors (MDC). The improvement in the overall efficiency ranged from a factor of 2.5 to 3.0 for the two stage MDC and a factor of 3.0 to 3.5 for the four stage MDC. An overall efficiency of 37.0 to 44.3 percent across the frequency band was demonstrated with the use of harmonic injection

    The Sheffield Wargames Corpus.

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    Recognition of speech in natural environments is a challenging task, even more so if this involves conversations between sev-eral speakers. Work on meeting recognition has addressed some of the significant challenges, mostly targeting formal, business style meetings where people are mostly in a static position in a room. Only limited data is available that contains high qual-ity near and far field data from real interactions between par-ticipants. In this paper we present a new corpus for research on speech recognition, speaker tracking and diarisation, based on recordings of native speakers of English playing a table-top wargame. The Sheffield Wargames Corpus comprises 7 hours of data from 10 recording sessions, obtained from 96 micro-phones, 3 video cameras and, most importantly, 3D location data provided by a sensor tracking system. The corpus repre-sents a unique resource, that provides for the first time location tracks (1.3Hz) of speakers that are constantly moving and talk-ing. The corpus is available for research purposes, and includes annotated development and evaluation test sets. Baseline results for close-talking and far field sets are included in this paper. 1

    Evaluating Wireless Carrier Consolidation Using Semiparametric Demand Estimation

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    The US mobile phone service industry has dramatically consolidated over the last two decades. One justification for consolidation is that merged firms can provide consumers with larger coverage areas at lower costs. We estimate the willingness to pay for national coverage to evaluate this motivation for past consolidation. As market level quantity data is not publicly available, we devise an econometric procedure that allows us to estimate the willingness to pay using market share ranks collected from a popular online retailer, Amazon. Our semiparametric maximum score estimator controls for consumers%u2019 heterogeneous preferences for carriers, handsets and minutes of calling time. We find that national coverage is strongly valued by consumers, providing an efficiency justification for across-market mergers. The methods we propose can estimate demand for other products using data from Amazon or other online retailers where quantities are not observed, but product ranks are observed. Since Amazon data can easily be gathered by researchers, these methods may be useful for the analysis of other product markets where high quality data are not publicly available.
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