4,341 research outputs found

    Overlapping time of a virtual customer in time-varying many-server queues

    Full text link
    Motivated by the ongoing COVID-19 pandemic, this paper investigates customers' infection risk by evaluating the overlapping time of a virtual customer with others in queueing systems. Most of the current methodologies focus on characterizing the risk in stationary systems, which may not apply to the more practical time-varying systems. As such, we propose an approximation framework that relies on the fluid limit to compute the expected overlapping time in time-varying queueing systems. Simulation experiments verify the accuracy of our approach

    Design and Implementation of Storage System Using Byte-index Chunking Scheme

    Get PDF
    In this paper, we present an enhanced storage system that supports Byte-index chunking algorithm. The storage system aims to provide efficient data deduplication with high performance and to be performed in rapid time. We describe the overall procedure of Byteindex chunking based storage system including read/write procedure and how the system works. The key idea of Byte-index chunking is to adapt fixed-size block chunk scheme which are distributed to “Index-table ” by chunk’s both side boundary values. We have found that Byte-index chunking in storage system provides high performance compared with other chunking schemes. Experiments result shows that the storage system with Byte-index chunking compresses overall data with high deduplication capability and reduce the speed of file processing

    DEVELOPMENT AND EVALUATION OF A NOVEL TAEKWONDO CHEST PROTECTOR TO IMPROVE MOBILITY WHEN PERFORMING AXE KICKS

    Get PDF
    The axe kick, in Olympic style taekwondo, has been identified as the most popular scoring technique aimed to the head during full contact competition. The first purpose of this study was to identify and investigate design issues with the current World Taekwondo Federation approved chest protector. A secondary purpose was to develop a novel chest protector addressing the identified design issues and to conduct a biomechanical analysis. Fifteen male elite Taekwondo players were selected to perform three different styles of the axe kick, i.e., front, in-out, and out-in axe kick five times each for a total of 45 kicks. Two-way repeated measures ANOVA showed significant differences between the novel and existing chest protector conditions for vertical height of the toe, downward kicking foot speed, hip flexion angle and ipsilateral shoulder flexion extension range of motion (ROM) (p0.05). These results indicate that the novel chest protector interferes less with both the lower and upper limbs during the performance of the axe kick and provides a more natural, free-moving alternative to the current equipment used

    Basaloid Squamous Cell Carcinoma in Nasal Cavity

    Get PDF
    Basaloid squamous cell carcinoma (BSCC) is often founded in the head and neck region. However, BSCC in the sinonasal tract is rare. We report here on the case of a 58-yr-old woman who presented with nasal obstruction and epistaxis. Computed tomography and examination of the nasal cavity revealed a tumor mass that originated from the right inferior turbinate with erosion of the nasal floor. The tumor that was attached to the inferior turbinate, the lateral nasal wall and the eroded right side hard palate, and so all this was resected. Histopathologic examination of the excised tumor confirmed BSCC in the nasal cavity. We report here on a nasal cavity BSCC that was treated with partial maxillectomy only

    Helicobacter pylori Infection and Halitosis – Evidence, Hypothesis, and Korean Red Ginseng to Mitigate Its Effect

    Get PDF
    Halitosis is a common and ignored condition, but in some, it is a disease-associated health problem, suggestive of overt disease conditions and hasaffected about 25–30% of world’s population, bothering nonmedical social disturbance in many people. Although two kinds, pseudohalitosis and halitophobia, are also concerned, genuine halitosis originated from the oral cavity, such as gingivitis, caries, and poor oral hygiene, in 80% and the remaining 20% are extraoral sources of halitosis, which should not be ignored because of stigmata suggestive of overt tissue dysfunctions, for instance, poor nutrition and hygiene, alcohol abuse, smoking, and systemic illness such as chronic obstructive pulmonary disease, liver cirrhosis, diabetes mellitus, and chronic renal diseases. In this chapter, Helicobacter pylori (H. pylori)–associated halitosis as one of the extragastric manifestations is introduced. Since diagnostics of halitosis includes subjective methods (examiner’s sense of smell) and objective methods (instrumental analysis), under the hypothesis of a possible relationship between H. pylori infection and objective halitosis, the real levels of volatile sulfur compounds (VSCs) in the breath showed significant correlation between VSC levels and the degree of H. pylori–associated erosive gastritis as well as gastric cancer. These findings are further validated through either measuring H2S level in gastric juices of H. pylori–infected gastritis or checking the expressions of cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) responsible for H2S generation in biopsied stomach. The eradication of H. pylori significantly ameliorated halitosis, accompanied with significant reductions in gastric H2S levels (p<0.01). Korean red ginseng was very effective in either reducing H. pylori–associated H2S or alleviating halitosis in patients with H. pylori–associated chronic atrophic gastritis. Conclusively, H. pylori infection demonstrates to have an important relationship with the development of halitosis, and its eradication could possibly promote the improvement of this condition

    Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment

    Get PDF
    An evaluation of the performance of a physically-based distributed model of a small Mediterennean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreactic surface level and actual evapotranspiration. A-priori model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judge in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated againts a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water was preventing adequate representation of drainage from soils during hydrogeraph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid.This work was carried out as part of project VAHMPIRE (Validating Hydrological Models using Process Studies and Internal Data from Research Basins: tools for assessing the hydrological impacts of environmental change), which was funded by the European Commission Framework IV Environment and Climate Program (Contract No. ENV4- CT95-0134). Simulations were carried out on a UNIX workstation funded jointly by UK Nirex Ltd. and NERC grant GR3/ E0009.Peer Reviewe

    THE POSSIBILITY OF CLASSIFYING V1 AND V2 SUB-TECHNIQUES OF A SINGLE IMU SENSOR THROUGH COMPARISON OF MOTION-SPECIFIC DATA(PITCH, YAW AND ROLL ANGLE VALUES-ORIENTATION ANGLE VALUE) IN XC SKI

    Get PDF
    The purpose of this study is to confirm whether the single IMU sensor module(LGE developing and providing for the experiments) that attached to the pelvis can distinguish the motion of the sub-techniques (V1, V2, V2A) with the accuracy of commercial XSENS(equipment consisting of 17 sensors) in freestyle(skate) xc skiing. Therefore, one elite male xc skier with eleven years experience was investigated by measuring the three-directional rotation angle for each of the three sub-techniques used in XC ski freestyle. Through this method, we could found not only the difference of motion patterns of each sub-techniques but also the possibility for replacement of multiple sensor system by a single IMU sensor module from LGE. Thus, it is expected that a single LGE IMU sensor module could be applied to repetitive and periodic sports such as XC ski
    • …
    corecore