1,986 research outputs found

    Rapid Determination of Receiver Sensitivity via Integral Search

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    Receiver sensitivity is a measure of the lowest signal strength that a receiver can detect. Receiver sensitivity is typically measured by linearly incrementing the received power level until a target packet error rate (PER) is reached. Linear search is slow and can occupy substantial test resources such as test stations and instruments. This disclosure describes techniques to rapidly determine the receiver sensitivity of a device-under-test (DUT) by learning the ensemble characteristics of devices under test, building a packet error rate (PER) model, performing limited-range measurements of the DUT, and using the PER model and the results of the measurements to predict the sensitivity of the DUT. By speeding up the determination of receiver sensitivity, the described techniques reduce test cycle times and enable improvement of the units per hour (UPH) of a factory, resulting in a lower cost of owning and operating test stations and instruments

    An XCS-Based Intelligent Searching Model for Cross-Organization Identity Management in Web Service

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    Internet services in distributive organization are normally built on an open network environment. In the environment internet service provisioning cannot be expected executing in a single close organization [1]. Identity management in cross-organization becomes an issue for handling Internet service and distributive business process. The “identity” in cross-organization web service is defined as global identity rather than private identity from client. Global identity searching table that registers all related service organization is the normal way we used to [2]. Through global identity searching table the target service organization can be looked up directly. For some business program, however, global identity is not necessary registered in specific service organization, e.g. IMSI (International Mobile Subscriber Identification) registration in NP (Number Portability) Service [3], for instance. In NP Service each IMSI can be re-assigned to different mobile service provider if the IMSI apply the re-assignment. In the example about IMSI in NP service mentioned above, if there is an internet service will be executed according to identity management with IMSI, then it will be a challenge to find the organization for available IMSI in very short response time. To dynamically re-assign a IMSI in different mobile service provider, the traditional global identity searching table will not be practical due to frequently changing the registration of IMSI in different service provider. To give an intelligent searching model for cross-organization global identity management is a better way than a static global identity searching table management in Web service. In this article the XCS (eXtended Classifier System) classifier system [4] will be proposed as the kernel system. With the characteristics in machine learning and rules management, the XCS-based intelligent searching model can help to predict where the web service can find the global identity in the open and cross-organization environment

    PALM: A Paralleled and Integrated Framework for Phylogenetic Inference with Automatic Likelihood Model Selectors

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    BACKGROUND: Selecting an appropriate substitution model and deriving a tree topology for a given sequence set are essential in phylogenetic analysis. However, such time consuming, computationally intensive tasks rely on knowledge of substitution model theories and related expertise to run through all possible combinations of several separate programs. To ensure a thorough and efficient analysis and avert tedious manipulations of various programs, this work presents an intuitive framework, the phylogenetic reconstruction with automatic likelihood model selectors (PALM), with convincing, updated algorithms and a best-fit model selection mechanism for seamless phylogenetic analysis. METHODOLOGY: As an integrated framework of ClustalW, PhyML, MODELTEST, ProtTest, and several in-house programs, PALM evaluates the fitness of 56 substitution models for nucleotide sequences and 112 substitution models for protein sequences with scores in various criteria. The input for PALM can be either sequences in FASTA format or a sequence alignment file in PHYLIP format. To accelerate the computing of maximum likelihood and bootstrapping, this work integrates MPICH2/PhyML, PalmMonitor and Palm job controller across several machines with multiple processors and adopts the task parallelism approach. Moreover, an intuitive and interactive web component, PalmTree, is developed for displaying and operating the output tree with options of tree rooting, branches swapping, viewing the branch length values, and viewing bootstrapping score, as well as removing nodes to restart analysis iteratively. SIGNIFICANCE: The workflow of PALM is straightforward and coherent. Via a succinct, user-friendly interface, researchers unfamiliar with phylogenetic analysis can easily use this server to submit sequences, retrieve the output, and re-submit a job based on a previous result if some sequences are to be deleted or added for phylogenetic reconstruction. PALM results in an inference of phylogenetic relationship not only by vanquishing the computation difficulty of ML methods but also providing statistic methods for model selection and bootstrapping. The proposed approach can reduce calculation time, which is particularly relevant when querying a large data set. PALM can be accessed online at http://palm.iis.sinica.edu.tw

    Bactericidal antibody against a representative epidemiological meningococcal serogroup B panel confirms that MATS underestimates 4CMenB vaccine strain coverage

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    AbstractBackground4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology.ObjectiveTo experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting.Methods and resultsWe used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007–2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55–85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72–95%). MATS had 78% accuracy and 96% positive predictive value against hSBA.ConclusionMATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents

    The Influence of Abacavir and Other Antiretroviral Agents on Virological Response to HCV Therapy Among Antiretroviral-Treated HIV-Infected Patients.

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    BACKGROUND: It remains unclear if certain antiretroviral medications, particularly abacavir, compromise response to HCV therapy. Such data could inform the selection of appropriate antiretrovirals in HIV/HCV-coinfected patients. The aim of this study was to determine if use of abacavir, as well as other antiretrovirals, was associated with reduced response to pegylated interferon (PEG-IFN) plus ribavirin. METHODS: A cohort study was performed among antiretroviral-treated HIV/HCV-coinfected patients initiating PEG-IFN plus ribavirin between January 2001 and June 2007 at six sites in the United States. Abacavir and other antiretrovirals represented exposures of interest. Study outcomes included an early virological response (\u3e or =2 log IU/ml decrease in HCV viral load at 12 weeks) and sustained virological response (undetectable HCV viral load 24 weeks after treatment discontinuation). RESULTS: Among 212 patients, 74 (35%) received abacavir. For patients infected with HCV genotype 1 or 4, no differences were observed between abacavir users and non-users in early virological response (26 [40%] versus 53 [44%]; adjusted odds ratio [OR] 1.00; 95% confidence interval [CI] 0.50-2.00) or sustained virological response (8 [13%] versus 13 [12%]; adjusted OR 1.34; 95% CI 0.50-3.62). Among genotype 2 and 3 patients, rates of early virological response (7 [78%] versus 16 [89%]; OR 0.44; 95% CI 0.05-3.76) and sustained virological response (3 [33%] versus 8 [44%]; OR 0.63; 95% CI 0.12-3.32) were also similar between abacavir users and non-users. No association was found between other antiretrovirals and a lack of early or sustained response. CONCLUSIONS: Use of abacavir or other antiretroviral medications was not associated with reduced early or sustained virological response rates

    Microyielding of Core-Shell Crystal Dendrites in a Bulk-metallic-glass Matrix Composite

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    In-situ synchrotron x-ray experiments have been used to follow the evolution of the diffraction peaks for crystalline dendrites embedded in a bulk metallic glass matrix subjected to a compressive loading-unloading cycle. We observe irreversible diffraction-peak splitting even though the load does not go beyond half of the bulk yield strength. The chemical analysis coupled with the transmission electron microscopy mapping suggests that the observed peak splitting originates from the chemical heterogeneity between the core (major peak) and the stiffer shell (minor peak) of the dendrites. A molecular dynamics model has been developed to compare the hkl-dependent microyielding of the bulk metallic-glass matrix composite. The complementary diffraction measurements and the simulation results suggest that the interface, as Maxwell damper, between the amorphous matrix and the (211) crystalline planes relax under prolonged load that causes a delay in the reload curve which ultimately catches up with the original path

    A new cable clip module with moveable cable clip

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    For a server system, we would have many kinds of configurations for customer’s different application. Some configurations like 2.5” / 3.5” HDD or different length PSU might have different PCBA, cable, mechanical part and cable clip in the chassis. It will have the part’s maintenance and inventory cost on these parts for different configuration. So if we could use the same part at different configuration, it will reduce our cost. So we propose a new cable clip module with moveable cable clip to let the cable routing more flexible by moving the location of the cable clip. By using this cable clip module, we could use the same cable for different configuration like different length PSU and different size HDD. And we also could use the cable clip module at the same location in the chassis for these configurations

    VAST: An ASKAP Survey for Variables and Slow Transients

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    The Australian Square Kilometre Array Pathfinder (ASKAP) will give us an unprecedented opportunity to investigate the transient sky at radio wavelengths. In this paper we present VAST, an ASKAP survey for Variables and Slow Transients. VAST will exploit the wide-field survey capabilities of ASKAP to enable the discovery and investigation of variable and transient phenomena from the local to the cosmological, including flare stars, intermittent pulsars, X-ray binaries, magnetars, extreme scattering events, interstellar scintillation, radio supernovae and orphan afterglows of gamma ray bursts. In addition, it will allow us to probe unexplored regions of parameter space where new classes of transient sources may be detected. In this paper we review the known radio transient and variable populations and the current results from blind radio surveys. We outline a comprehensive program based on a multi-tiered survey strategy to characterise the radio transient sky through detection and monitoring of transient and variable sources on the ASKAP imaging timescales of five seconds and greater. We also present an analysis of the expected source populations that we will be able to detect with VAST.Comment: 29 pages, 8 figures. Submitted for publication in Pub. Astron. Soc. Australi
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