65 research outputs found

    Distributed microprocessors in a tactical universal modem

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    The distributed microprocessor system associated with a wideband signal conversion unit (WBSCU) is described. Multiple embedded 8086 and 2901 microprocessors, supported by dedicated hardware modules, perform the required real time operations for both transmit and receive functions. Commands from a host computer determine the configuration of the WBSCU via the IEEE 488 bus. Each of the four WBSCU channels is assigned to process a specified IF waveform; each channel configures its own resources and, in some cases, borrows resources from other channels. The processed waveform data is communicated from individual channels to redundant global memories. Data flow between the user community and global memories occurs via redundant 1553 buses through intelligent Bus Interface Units. Each WBSCU channel contains one 2901 bit slice machine and one 8086 microprocessor. The 2901 provides high speed processing capability for the most time critical operations. The 8086 is used for lower speed processing tasks where its high level language capability can be better exploited. Each 8086 has a global bus for wideband interprocessor communication, and a local bus for 8086/2901, master/slave communication. Software architecture consists of a control and communications structure governing mode dependent signal processing tasks

    Implementation of ETX Metric within the AODV Protocol in the NS-3 Simulator

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    Modern life cannot be imagined without wireless ad hoc networks (WANETs). People use, in a daily manner, smart phones, laptops or tablet computers. With an increasing number of users of WANETs, the need for a fast throughput and small delay is increasing as well. One efficient way to provide users with such demands is to find an optimal route between source and destination node. Therefore, many routing protocols and metrics for WANETs are proposed in last decades. It is very important to test performances of the proposed protocols in various network scenarios. The computer simulation is a very efficient way to test routing protocols and to evaluate their significance and practical value. One of the most recent but very frequently used discrete-event network simulators is Network Simulator 3 (NS-3). In order to contribute to the NS-3 simulator development, an implementation of one of the most commonly used metric in WANET protocols the expected transmission count (ETX) is proposed in this paper. ETX metric is implemented within an ad-hoc on demand distance vector (AODV) protocol. The source code of this implementation is publicly available

    Application of Consensus Scoring and Principal Component Analysis for Virtual Screening against β-Secretase (BACE-1)

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    BACKGROUND: In order to identify novel chemical classes of β-secretase (BACE-1) inhibitors, an alternative scoring protocol, Principal Component Analysis (PCA), was proposed to summarize most of the information from the original scoring functions and re-rank the results from the virtual screening against BACE-1. METHOD: Given a training set (50 BACE-1 inhibitors and 9950 inactive diverse compounds), three rank-based virtual screening methods, individual scoring, conventional consensus scoring and PCA, were judged by the hit number in the top 1% of the ranked list. The docking poses were generated by Surflex, five scoring functions (Surflex_Score, D_Score, G_Score, ChemScore, and PMF_Score) were used for pose extraction. For each pose group, twelve scoring functions (Surflex_Score, D_Score, G_Score, ChemScore, PMF_Score, LigScore1, LigScore2, PLP1, PLP2, jain, Ludi_1, and Ludi_2) were used for the pose rank. For a test set, 113,228 chemical compounds (Sigma-Aldrich® corporate chemical directory) were docked by Surflex, then ranked by the same three ranking methods motioned above to select the potential active compounds for experimental test. RESULTS: For the training set, the PCA approach yielded consistently superior rankings compared to conventional consensus scoring and single scoring. For the test set, the top 20 compounds according to conventional consensus scoring were experimentally tested, no inhibitor was found. Then, we relied on PCA scoring protocol to test another different top 20 compounds and two low micromolar inhibitors (S450588 and 276065) were emerged through the BACE-1 fluorescence resonance energy transfer (FRET) assay. CONCLUSION: The PCA method extends the conventional consensus scoring in a quantitative statistical manner and would appear to have considerable potential for chemical screening applications

    Predictors of three dose on-time compliance with HPV4 vaccination in a disadvantaged, underserved, safety net population in the US Midwest.

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    HPV4 is approved as a series of three timed doses expected to result in efficacy against specific HPV infections. Completion rates in the US are quite low at the same time the structure of health care delivery is changing. The aim of this study was to determine how the patient-, clinic- and systems-level characteristics facilitate or hinder the timely completion of three HPV4 doses in both adolescent and adult female populations in a high-risk safety net population.This is a retrospective study in which patient-, clinic- and systems-level data are abstracted from the electronic medical record (EMR) for all females 10-26 years of age receiving at least one dose of HPV4 between July 1, 2006 and October 1, 2009.Adults were more likely to complete the three dose series if they had at least one health care visit in addition to their HPV4 visit, (aOR = 1.54 (95% CI:1.10, 2.15). Adults were less likely to complete the three dose series if they received their second HPV4 dose at an acute health care, preventive care or postpartum visits compared to an HPV4-only visit (aOR = 0.31 (95% CI: 0.13, 0.72), 0.12 (0.04, 0.35), 0.30 (0.14, 0.62), respectively). Hispanic adults were less likely than whites to complete the series (aOR = 0.24 (95% CI:0.10, 0.59). 39% of adolescents who completed two doses completed the series.HPV4 is more likely to be effectively administered to adults in a safety net population if multiple health care needs can be met within the health care system

    Descriptors by number of appropriately timed doses.

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    <p>Singleton means only one dose was administered; doublet means that two doses were appropriately timed; triplet means that three doses were appropriately timed.</p><p>Bold font signifies significant differences among singleton, doublet and/or triplet doses at p<0.001.</p>*<p>Doses administered at visits at which counseling for smoking cessation, depression, or contraceptive use; and procedures including IUD placement occurred.</p>†<p>Doses administered to Other races than White, Black and Hispanic make up 4% of singleton and doublet doses and were not included in this table.</p
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