39,820 research outputs found

    Oscillation-based Test Method for Continuous-time OTA-C Filters

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    “This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”Design for testability technique using oscillation-based test topology for KHN OTA-C filters is proposed. The oscillation-based test structure is a vectorless output test strategy easily extendable to built-in self-test. During test mode, the filter under test is converted into an oscillator by establishing the oscillation condition in its transfer function. The oscillator frequency can be measured using digital circuitry and deviations from the cut-off frequency indicate the faulty behaviour of the filter. The proposed method is suitable for both catastrophic and parametric fault diagnosis as well as effective in detecting single and multiple faults. The validity of the proposed method has been verified using comparison between faulty and fault-free simulation results of KHN OTA-C filter. Simulation results in 0.25mum CMOS technology show that the proposed oscillation-based test strategy has 84% fault coverage and with a minimum number of extra components, requires a negligible area overhead.Final Published versio

    Three-Dimensional Topological Insulators

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    Topological insulators in three dimensions are nonmagnetic insulators that possess metallic surface states as a consequence of the nontrivial topology of electronic wavefunctions in the bulk of the material. They are the first known examples of topological order in bulk solids. We review the basic phenomena and experimental history, starting with the observation of topological insulator behavior in Bix_xSb1x_{1-x} by spin- and angle-resolved photoemission spectroscopy and continuing through measurements on other materials and by other probes. A self-contained introduction to the single-particle theory is then given, followed by the many-particle definition of a topological insulator as a material with quantized magnetoelectric polarizability. The last section reviews recent work on strongly correlated topological insulators and new effects that arise from the proximity effect between a topological insulator and a superconductor. While this article is not intended to be a comprehensive review of what is already a rather large field, we hope that it will serve as a useful introduction, summary of recent progress, and guideline to future directions.Comment: 53 pages, 9 figures, 1 table. Preprint version from June 2010 of invited article for Annual Review of Condensed Matter Physics. Final edited version will be published online c. January 201

    Quantifying human mobility resilience to extreme events using geo-located social media data

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    Relative City Price Convergence in Pakistan: Empirical Evidence from Spatial GLS

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    The study estimates relative city price convergence using CPI data from July 2001 to June 2008 on 35 Pakistani cities. Two cities Lahore and Karachi are chosen to be the numeraire cities. The half life of relative city price shock has also been estimated. The study finds average half life of price shock to be less than 5 months but it varies from 1.3 to 68 months in the case of individual cities. The estimates of Spatial GLS are found to be lower than OLS which may imply that Spatial Correlations are important factor for the estimation of half life. Furthermore, the average half life of a price shock in Lahore is less than that of Karachi.Prices; convergence; Spatial GLS

    Management Control Systems and Contextual Variables in the Hospitality Industry

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    Purpose – The paper examined management control systems (MCS) in Indonesian hospitality sector. This study examines the impact of six contextual factors at one time to determine the importance of each factor on the design of MCS. Design/methodology/approach – The paper is based upon data collected through a survey sent to “star” hotels in Central Java, Indonesia. Using Chenhall (2003) design, a regression equation is run to examine the relationship between MCS and the contextual variables of environment, technology, structure, size, strategy and culture. Findings – The paper finds that higher levels of the contextual variables of technology, structure, and culture are related to more sophisticated MCS while size is related to more traditional MCS. Research limitations/implications –These findings are related to the hospitality industry in Indonesia. Future research could examine different settings (i.e. country, industry, etc) and investigate the effect of each contextual variable on the relationships between MCS and firm performance. Originality/value – The present study extends the scope of MCS system in accounting literature by testing Chenhall (2003) works on the relationship between contextual variables and MCS. It attempts to fill the gap in contingency-based studies that have previously focused on one aspect of contingency by considering six contextual factors. Furthermore, this paper also contributes to a fuller understanding of MCS practices in Indonesia and the hospitality industry and helps management in determining its most effective design. Keywords Hospitality management, Management Control Systems, Indonesia, Contextual Variable
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