74 research outputs found

    A Dynamic Resource Manager with Effective Resource Isolation Based on Workload Types in Virtualized Cloud Computing Environments

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    To use computing resources for processing parallel algorithms on demand, cloud computing has been widely used since it is able to scale in response to load increases and decreases. Typically, cloud computing providers offer virtual machines to cloud users with static configurations, and these configurations are not changed until virtual machines are shutting down. To accelerate parallel processing computations in cloud computing environments, we design and implement a dynamic resource manager by isolating resources based on workload types. To avoid unnecessary context switching and increase CPUs affinity, our dynamic resource manager determines whether vCPU to physical CPU core pinning is required. If so, the VM’s vCPUs are pinned by our dynamic resource manager, which can guarantee the resource and performance isolation. With our proposed resource manager for virtual machines, we can achieve a performance boost and load balancing at the same time. Performance results show that our proposed method outperforms the default scheduler of Xen about 36.2% by reducing the number of context switching for VMs

    Meteorological characteristics and assessment of the effect of local emissions during high PM10 concentration in the Seoul Metropolitan Area

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    In this study, we investigate the meteorological characteristics and the effect of local emissions during high PM10 concentrations in the Seoul Metropolitan Area (SMA) by utilizing data from a high-resolution urban meteorological observation system network (UMS-Seoul) and The Air Pollution Model (TAPM). For a detailed analysis, days with PM10 concentrations higher than 80 ??g m-3 for daily average PM10 concentration (classified as unhealthy by the Korean Ministry of Environment) in the Seoul Metropolitan Area (SMA) were classified into 3 Cases. Case I was defined as when the prevailing effect was from outside the SMA. Case II was defined as when the prevailing effect was a local effect with outside. Case III was defined as when the prevailing effect was local. Overall, high PM10 concentrations in the SMA mostly occurred under weak migratory anticyclone systems over the Korean Peninsula during warm temperatures. Prior to the PM10 concentration reaching the peak concentration, the pattern in each case was distinctive. After peak concentrations, however, the pattern for the 3 cases became less distinct. This study showed that nearly 50% of the high PM10 concentrations in the SMA occurred in spring and were governed by the conditions for Case II more than these for Cases I and III. In spring, the main sources of the high PM10 concentrations in the SMA were local emissions due to the predominance of weak winds and local circulation. The simulation showed that the non-SMA emissions were about 63 to 73% contribution to the spring high PM10 concentrations in the SMA. Specifically, local point sources including industrial combustion, electric utility, incineration and cement production facilities scattered around the SMA and could account for PM10 concentrations more than 10 ??g m-3 in the SMA

    Impact Comparison of Synoptic Meteorology and Nationwide/local Emissions on the Seoul Metropolitan Area during High PM Multi-event and Non-event Days

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    Meteorology and emissions play very important roles in the concentrations of air pollutants during severe haze/smog periods. This study compares the impacts of synoptic meteorology and nationwide/local emissions during high PM10 multi-event and non-event days in the Seoul Metropolitan Area (SMA). The multi-event and non-event cases were selected based on daily mean PM10 concentrations in Seoul from January 2014 to March 2019. The multi-event cases in spring and winter were closely associated with weak synoptic winds, while that in autumn was due to the strong winds at the rear side of a strong cold front, which induced the Asian dust event in northeastern China and Korea. The multi-event case in spring was found to be mainly due to series of migratory anticyclones, while winter case was due to the stagnant system after northerly winds. The surrounding low pressure systems as well as high pressure systems could be important to determine whether the synoptic systems would be stagnant or not. The fractional contributions of SMA emissions to the mean PM10 and PM2.5 concentrations were 24%-35% and 22%-35% for the multi-event cases, respectively. The contributions to the maximum PM10 and PM2.5 concentrations were larger than those to the mean concentrations by 16%-23% and 19%-26% for the multi-event cases, respectively

    Differences in Clinical Features According to Boryoung and Karp Genotypes of Orientia tsutsugamushi

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    Scrub typhus is an infectious disease caused by Orientia tsutsugamushi. The differences in virulence of O. tsutsugamushi prototypes in humans are still unknown. We investigated whether there are any differences in the clinical features of the Boryoung and Karp genotypes.Patients infected with O. tsutsugamushi, as Boryoung and Karp clusters, who had visited 6 different hospitals in southwestern Korea were prospectively compared for clinical features, complications, laboratory parameters, and treatment responses. Infected patients in the Boryoung cluster had significantly more generalized weakness, eschars, skin rashes, conjunctival injection, high albumin levels, and greater ESR and fibrinogen levels compared to the Karp cluster. The treatment response to current antibiotics was significantly slower in the Karp cluster as compared to the Boryoung cluster.The frequency of occurrence of eschars and rashes may depend on the genotype of O. tsutsugamushi

    Changes in Sea-Level Pressure over South Korea Associated with High-Speed Solar Wind Events

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    We explore a possibility that the daily sea-level pressure (SLP) over South Korea responds to the high-speed solar wind event. This is of interest in two aspects: First, if there is a statistical association this can be another piece of evidence showing that various meteorological observables indeed respond to variations in the interplanetary environment. Second, this can be a very crucial observational constraint since most models proposed so far are expected to preferentially work in higher latitude regions than the low latitude region studied here. We have examined daily solar wind speed V{\rm V}, daily SLP difference ΔSLP{\rm \Delta SLP}, and daily log(BV2){\rm \log(BV^{2})} using the superposed epoch analysis in which the key date is set such that the daily solar wind speed exceeds 800 kms1{\rm kms^{-1}}. We find that the daily ΔSLP{\rm \Delta SLP} averaged out of 12 events reaches its peak at day +1 and gradually decreases back to its normal level. The amount of positive deviation of ΔSLP{\rm \Delta SLP} is +2.5 hPa. The duration of deviation is a few days. We also find that ΔSLP{\rm \Delta SLP} is well correlated with both the speed of solar wind and log(BV2){\rm \log(BV^{2})}. The obtained linear correlation coefficients and chance probabilities with one-day lag for two cases are r0.81r \simeq 0.81 with P>99.9P> 99.9%, and r0.84r \simeq 0.84 with P>99.9P> 99.9%, respectively. We conclude by briefly discussing future direction to pursue.Comment: 23 pages, 4 figure, accepted to Advances in Space Researc

    Mutations in KEOPS-Complex Genes Cause Nephrotic Syndrome with Primary Microcephaly

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    Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms
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