21,223 research outputs found

    Study of Warm Electron Injection in Double Gate SONOS by Full Band Monte Carlo Simulation

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    In this paper we investigate warm electron injection in a double gate SONOS memory by means of 2D full-band Monte Carlo simulations of the Boltzmann Transport Equation (BTE). Electrons are accelerated in the channel by a drain-to-source voltage VDS smaller than 3 V, so that programming occurs via electrons tunneling through a potential barrier whose height has been effectively reduced by the accumulated kinetic energy. Particle energy distribution at the semiconductor/oxide interface is studied for different bias conditions and different positions along the channel. The gate current is calculated with a continuum-based post-processing method as a function of the particle distribution obtained from Monte Carlo. Simulation results show that the gate current increases by several orders of magnitude with increasing drain bias and warm electron injection can be an interesting option for programming when short channel effects prohibit the application of larger drain bias

    Sparse Spectrum Sensing in Infrastructure-less Cognitive Radio Networks via Binary Consensus Algorithms

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    Compressive Sensing has been utilized in Cognitive Radio Networks (CRNs) to exploit the sparse nature of the occupation of the primary users. Also, distributed spectrum sensing has been proposed to tackle the wireless channel problems, like node or link failures, rather than the common (centralized approach) for spectrum sensing. In this paper, we propose a distributed spectrum sensing framework based on consensus algorithms where SU nodes exchange their binary decisions to take global decisions without a fusion center to coordinate the sensing process. Each SU will share its decision with its neighbors, and at every new iteration each SU will take a new decision based on its current decision and the decisions it receives from its neighbors; in the next iteration, each SU will share its new decision with its neighbors. We show via simulations that the detection performance can tend to the performance of majority rule Fusion Center based CRNs

    bdbms -- A Database Management System for Biological Data

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    Biologists are increasingly using databases for storing and managing their data. Biological databases typically consist of a mixture of raw data, metadata, sequences, annotations, and related data obtained from various sources. Current database technology lacks several functionalities that are needed by biological databases. In this paper, we introduce bdbms, an extensible prototype database management system for supporting biological data. bdbms extends the functionalities of current DBMSs to include: (1) Annotation and provenance management including storage, indexing, manipulation, and querying of annotation and provenance as first class objects in bdbms, (2) Local dependency tracking to track the dependencies and derivations among data items, (3) Update authorization to support data curation via content-based authorization, in contrast to identity-based authorization, and (4) New access methods and their supporting operators that support pattern matching on various types of compressed biological data types. This paper presents the design of bdbms along with the techniques proposed to support these functionalities including an extension to SQL. We also outline some open issues in building bdbms.Comment: This article is published under a Creative Commons License Agreement (http://creativecommons.org/licenses/by/2.5/.) You may copy, distribute, display, and perform the work, make derivative works and make commercial use of the work, but, you must attribute the work to the author and CIDR 2007. 3rd Biennial Conference on Innovative Data Systems Research (CIDR) January 710, 2007, Asilomar, California, US

    Interactive boundary element analysis for engineering design.

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    Structural design of mechanical components is an iterative process that involves multiple stress analysis runs; this can be time consuming and expensive. Significant improvements in the eciency of this process can be made by increasing the level of interactivity. One approach is through real-time re-analysis of models with continuously updating geometry. Three primary areas need to be considered to accelerate the re-solution of boundary element problems. These are re-meshing the model, updating the boundary element system of equations and re-solution of the system. Once the initial model has been constructed and solved, the user may apply geometric perturbations to parts of the model. The re-meshing algorithm must accommodate these changes in geometry whilst retaining as much of the existing mesh as possible. This allows the majority of the previous boundary element system of equations to be re-used for the new analysis. For this problem, a GMRES solver has been shown to provide the fastest convergence rate. Further time savings can be made by preconditioning the updated system with the LU decomposition of the original system. Using these techniques, near real-time analysis can be achieved for 3D simulations; for 2D models such real-time performance has already been demonstrated

    Implementation of accurate broadband steering vectors for broadband angle of arrival estimation

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    Motivated by accurate broadband steering vector requirements for applications such as broadband angle of arrival estimation, we review fractional delay filter designs. A common feature across these are their rapidly decreasing performance as the Nyquist rate is approached. We propose a filter bank based approach, which operates standard fractional delay filters on a series of frequency-shifted subband signals, such that they appear in the filters’ lowpass region. We demonstrate the appeal of this approach in simulations

    ANOTHER LOOK AT THE DETERMINANTS OF FOREIGN DIRECT INVESTMENT IN MENA COUNTRIES: AN EMPIRICAL INVESTIGATION

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    The paper is concerned with the analysis of the main determinants of foreign direct investment in MENA countries. The estimation is run on the determinants of FDI in our sample which consist of 36 countries. 12 of these countries were in MENA countries and another 24 were the major recipients of FDI in their respective regions in developing countries. By employing a panel data methodology the study investigates whether the determinants of FDI are similar to the other FDI receiving developing countries. The study reveals that the key determinants of FDI inflows in MENA countries are the size of the host economy, the government size, natural resources and the institutional variables. The paper concludes that, countries that are receiving fewer foreign investments could make themselves more attractive to potential foreign investors. So, the policy makers in the MENA region should remove all barriers to trade, develop their financial system and build appropriate institutions.Foreign Direct Investment, Panel Data, Fixed Effects, MENA

    Antecedents of Voluntary Corporate Governance Disclosure: A Post-2007/08 Financial Crisis Evidence from the Influential UK Combined Code

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    Purpose: This study investigates the level of compliance with, and disclosure of, good corporate governance (CG) practices among UK publicly listed firms, and consequently ascertains whether board characteristics and ownership structure variables can explain observable differences in the extent of voluntary CG compliance and disclosure practices. Design/Methodology/Approach: The study uses one of the largest datasets to-date on compliance and disclosure of CG practices from 2008 to 2013 containing 120 CG provisions drawn from the 2010 UK Combined Code relating to 100 UK listed firms to conduct multiple regression analyses of the determinants of voluntary CG disclosures. A number of additional estimations, including two stage least squares, fixed-effects and lagged structures, are conducted in order to test the robustness of the findings. Findings: The results suggest that there is a substantial variation in the levels of compliance with, and disclosure of, good CG practices among the sampled UK firms. We also find that firms with larger board size, more independent outside directors and greater director diversity tend to disclose more CG information voluntarily, whereas the level of voluntary CG compliance and disclosure is insignificantly related to the existence of a separate CG committee and institutional ownership. Additionally, the results indicate that block ownership and managerial ownership impact negatively on voluntary CG compliance and disclosure practices. The findings are fairly robust across a number of econometric models that sufficiently address various endogeneity problems and alternative CG indices. Overall, the findings are generally consistent with the predictions of neo-institutional theory. Originality/Value: This paper extends, as well as contributes to the extant CG literature by offering new evidence on compliance with, and disclosure of, good CG recommendations contained in the 2010 UK Combined Code following the 2007/08 global financial crisis. This paper also advances the existing literature by offering new insights from a neo-institutional theoretical perspective of the impact of board and ownership mechanisms on voluntary CG compliance and disclosure practices. Keywords: Corporate governance; Board and ownership mechanisms; Comply or explain; Neo-institutional theory; UK Combined Cod
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