296 research outputs found

    Applicaton of USB Serial Communication to Radon Measuring System

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    The USB serial communication such as USB-Serial-for PC and USB-Serial-for-Android is studied in order to monitor the measure radon data using a PC screen or a smart phone screen. Through some experimental studies, we believe that the USB serial communication module is useful for checking the data transmitted to a PC from a microcontroller

    A New Hardware Correlator in Korea: Performance Evaluation using KVN observations

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    We report results of the performance evaluation of a new hardware correlator in Korea, the Daejeon correlator, developed by the Korea Astronomy and Space Science Institute (KASI) and the National Astronomical Observatory of Japan (NAOJ). We conducted Very Long Baseline Interferometry (VLBI) observations at 22~GHz with the Korean VLBI Network (KVN) in Korea and the VLBI Exploration of Radio Astrometry (VERA) in Japan, and correlated the aquired data with the Daejeon correlator. For evaluating the performance of the new hardware correlator, we compared the correlation outputs from the Daejeon correlator for KVN observations with those from a software correlator, the Distributed FX (DiFX). We investigated the correlated flux densities and brightness distributions of extragalactic compact radio sources. The comparison of the two correlator outputs show that they are consistent with each other within <8%<8\%, which is comparable with the amplitude calibration uncertainties of KVN observations at 22~GHz. We also found that the 8\% difference in flux density is caused mainly by (a) the difference in the way of fringe phase tracking between the DiFX software correlator and the Daejeon hardware correlator, and (b) an unusual pattern (a double-layer pattern) of the amplitude correlation output from the Daejeon correlator. The visibility amplitude loss by the double-layer pattern is as small as 3\%. We conclude that the new hardware correlator produces reasonable correlation outputs for continuum observations, which are consistent with the outputs from the DiFX software correlator.Comment: 13 pagee, 9 figures, 3 tables, to appear in JKAS (received February 9, 2015; accepted March 16, 2015


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    Improving the wheelchair design can be an important determinant of high performance in the wheelchair basketball. Researchers have focused on increasing the efficiency of the wheelchair, looking at the factors such as the seat position, handrim size, and wheel camber. Most handrim and wheel chamber studies, however, have focused only on the propulsive phase. Quick turn as well as fast propulsion is essential to the success in a wheelchair basketball game and the energy efficiency becomes particularly important in a prolonged wheelchair use. The purpose of this study was to investigate the effects of wheelchair camber and handrim size on the linear propulsion, turn velocity, and efficiency


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    It has been reported that approximately 80% of individuals with Down syndrome (DS) exhibit abnormal gait characteristics. They are exhibited by flat-footed contact with no heel-strike, excessive abduction of the leg in the swing phase, and abnormal knee and hip flexion throughout the gait cycle (Matteo, 2002). The purpose of this study was to examine the influence of a 12-week strength training program on the gait characteristics during walking by an adolescent with DS

    Giant Cell Tumor of Soft Tissue: a Case with Atypical US and MRI Findings

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    We report the case of a giant cell tumor with diffuse interstitial hemorrhaging and unusually prominent cystic components in the soft tissue of the thigh which has not been reported previously. Magnetic resonance image (MRI), showed signal intensity typical of a giant cell tumor. However, because of its conspicuous large well-circumscribed cystic components, the differential diagnoses, based on the image findings from an ultrasonography (US) and MRI, were complicated epidermoid cyst, cystic change of a neurogenic tumor, and a parasitic cyst

    Electric polarization enhancement in multiferroic CoCr2O4 crystals with Cr-site mixing

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    Single crystals of multiferroic cobalt chromite Co (Cr2-x Cox) O4 have been grown via several methods to have different Co3+ doping levels (x=0.0, 0.14, and 0.18). Under magnetic fields, all the crystals display electric polarization reversal below their spiral spin ordering temperatures. We find that both saturated electric polarization and magnetization under magnetic fields increase significantly with the increase in x. This result can be qualitatively explained by a broken balance between at least two electric polarization contributions existing in CoCr2 O4 and is expected to be useful in tailoring electric polarization in similar kinds of multiferroics. &amp;#169; 2009 American Institute of Physics.open222

    Unusual Presentation of Cystic Lymphangioma of the Gallbladder

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    Cystic lymphangioma of the gallbladder is quite a rare tumor with only a few cases having been reported in the literature. We describe here a rare case of cystic lymphangioma of the gallbladder, which was unusual in that the patient presented with biliary pain and an abnormal liver test. Ultrasonography and computed tomography of the abdomen showed a multi-septated cystic mass in the gallbladder fossa and an adjacent compressed gallbladder. Endoscopic retrograde cholangiography showed there was no communication between the bile tract and the lesion, and there were no other abnormal findings with the exception of a laterally compressed gallbladder. After performing endoscopic sphincterotomy, a small amount of sludge was released from the bile duct. The histological findings were consistent with a cystic lymphangioma originating from the subserosal layer of the gallbladder. This unusual clinical presentation of a gallbladder cystic lymphangioma was attributed to biliary sludge, and this was induced by gallbladder dysfunction that was possibly from compression of the gallbladder due to the mass