• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권7호
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• pp.1293-1310
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• 2011

A simple modification of well known Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is proposed to exploit cooperative diversity. Instead of selecting a single cluster-head, we propose M cluster-heads in each cluster to obtain a diversity of order M. The cluster-heads gather data from all the sensor nodes within the cluster using same technique as LEACH. Cluster-heads transmit gathered data cooperatively towards the destination or higher order cluster-head. We propose a code combining based cooperative diversity protocol which is similar to coded cooperation that maximizes the performance of the proposed cooperative LEACH protocol. The implementation of the proposed cooperative strategy is analyzed. We develop the upper bounds on bit error rate (BER) and frame error rate (FER) for our proposal. Space time block codes (STBC) are also a suitable candidate for our proposal. In this paper, we argue that the STBC performs worse than the code combining cooperation.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.1080-1084
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• 2007

Many different methods for sound source localization have been developed. Most of them mainly depend on time delay of arrival (TDOA) or on empirical or analytic head related transfer functions (HRTFs). In real implementation, since the direct path between a source and a sensor is interrupted by obstacles as like a head or body of robot, it has to be considered the number of sensors as well as their positions. Therefore, in this paper, we present the methods, which are included sensor position problem, to localize the sound source with 4 microphones to cover the 3D space. Those are modified two-step TDOA methods. Our conclusion is that the different method has to be applied in case to be different microphone position on real robot platform.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.354-358
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• 1997

Some sulfur coompounds dissimilation characteristcs of Thermococcus sp. DT1331 were studied. DT1331 had ether-like lipid compounds in addition to esters in the cell membrane. The specific growth rates of DT1331 decreased with increasing head spaces of the cultures. However, when the ratio of head space volume to medium volume was 5.60, the strain showed no growth. DT1331 showed vigo- rous growth with 1% or more elemental sulfur addition. Cystine could substitute elemental sulfur and DT1331 showed moderate growth with 0.1% or more cystine concentration. The specific growth rate and maximum cell concentration of Thermococcus sp. DT1331 in the presence of elemental sulfur were 0.80 hr$^{-1}$ and 2.0 x 10$^{8}$ cells/ml, respectively, while they were 0.67 hr$^{-1}$ and 1.1 x 10$^{8}$ cells/ml, respectively in the presence of cystine.

• 대한기관식도과학회지
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• 제12권2호
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• pp.42-46
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• 2006

Descending necrotizing mediastinitis (DNM) is defined as mediastinal infection that begins at the cervical region and spread through deep fascial planes into the mediastinum. This is a rare and life-threatening complication of deep neck space infection. As infection reaches the mediastinum, widespread cellulitis, necrosis, abscess formation and sepsis may occur. So, early diagnosis and immediate antibiotics and surgical treatment are required to improve the poor prognosis of DNM. We present four cases of deep neck infection causing a virulent mediastinitis with a literature review.

• 한국통신학회논문지
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• 제29권1C호
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• pp.45-49
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• 2004

본 논문은 수정된 이방성 확산 펄터를 이용한 영상 개선 방법을 제안하였다. 이를 위하여 최소 신뢰 스케일을 기반으로 하는 센서 잡음 추정과 스케일 스페이스 방법을 도입하였다. 이때 이방성 필터는 구해진 임계값 함수와 국부 기울기에 의해 수정되었다. 모의 실험을 통해 제안한 방법이 평탄 영역에서의 잡음을 거의 증폭시키지 않으면서도 뛰어난 에지 향상을 보임을 증명할 수 있었다.

• 소음진동
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• 제6권6호
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• pp.709-715
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• 1996

In recent years, the piping vibration in many Power Plants is being increased by the aged generating facilities due to a long time use. Generally, the pressure fluctuations associated with the flow-induced excitations in this case are broadband in nature. Mainly, the dominant sources of vibration are a vortex-shedding, plane waves and boundary layer turbulence. The peak level of the spectrum is proportional to the dynamic head. A severe disturbance in pipeline results in the generation of intense broadband internal sound waves which can propagate through the piping system. The characteristic frequencies of operating loads of 20%, 57%, 70%, 100% are 4 - 6 Hz and coincide with the results from impact hammering test and FEM analysis. We chose the wire energy absorbing rope restraint as a vibration reduction method after reviewing the various conditions such as site, installing space and economic cost etc. After installation, the vibration level was reduced about 54% in velocity.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.259-261
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• 2005

The needs of improving the performance of wet shotcrete has become one of the most important issues in the tunnel field. The aim of this paper is to research the construction method of reinforced shotcrete using structural polymer fiber which exhibits a high quality in toughness and durability for the support of tunnel.

• Childhood Kidney Diseases
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• 제1권1호
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• pp.86-90
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• 1997

The author experienced a case of $Henoch-Sch\"{o}nlein$ purpura with epididymitis in a 6-year-old boy who was admitted to our hospital due to left scrotal pain and the relapse of purpura on lower extremities for 3 days. Scrotal ultrasonography on admission revealed homogenously enlarged left epididymal head and small amount of fluid collection in left tunical space. The size of left epididymal head decreased gradually with no more evidence of fluid collection on day 7 and recovered completely on day 21. The author reports a case of $Henoch-Sch\"{o}nlein$ purpura with epididymitis with brief review of related literatures.

• Journal of Korean Neurosurgical Society
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• 제47권6호
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• pp.470-472
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• 2010

Subdural empyema of the brain is an uncommon disorder that occurs more frequently in children than in adult. Authors report a very rare of subdural empyema following the subdural hygroma after mild head injury. The exact mechanism of infection is not known. However, we have to consider subdural infection as one of differential diagnosis in elderly patient with subdural hygroma when new abnormal density lesion is developed in the subdural space.

• Journal of Chest Surgery
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• 제26권7호
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• pp.538-542
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• 1993

An approach to the treatment of post-operative pain by the injection of bupivacaine into the pleural space through an intrapleural cathter has been studied. Among 24 thoracotomy patients, bupivacaine was injected only to experimental group[ 12 patients ] when the patient was able to head up for oneself during recovery from anesthesia. The pain and ROM[ range of motion ] scores, respiration rate, PaCO2 level of both experimental and control group were measured at the time of head-up and 30 and 120 minutes thereafter.The scores of pain and ROM of experimental group were significantly[ P value < 0.05 ] decreased in 30 minutes and 120 minutes after bupivacaine injection compared with those of control group but respiration rate and PaCO2 level were not changed significantly. With this result, we can suggest that intrapleural injection of bupivacaine is useful for pain relief following thoracotomy.