• 대한한방내과학회지
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• 제33권2호
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• pp.160-171
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• 2012

Background and Objective : Warfarin is the standard anticoagulation treatment for atrial fibrillation, venous thromboembolism (VTE), and mechanical heart valves. Close monitoring of the International Normalized Ratio (INR) is required due to the drug's very narrow therapeutic window. Many factors can affect INR levels. Drug and food interactions are frequently cited as causes of adverse events with warfarin. We discussed interactions between herbs and warfarin studied in this research. Methods : In this review, PubMed was used to search medical journals. Keywords "warfarin AND interaction" were applied. Results : 55 articles were included. The possibility of correlation between warfarin and single herbal medicines such as Salviae Miltiorrhizae Radix, Angelicae Gigantis Radix, Ginseng Radix Alba, Lycii Fructus, Ginkgo Folium, Menthae Herba, Trigonellae semen was suggested. Furthermore, some herbal compounds interacting with warfarin were reported. The conclusion of studies reporting the effect of herbal medicine on warfarin were controversial due to small size or quality of research. Conculsions : We suggest that we should prescribe therapeutic herbal medicines to patients using warfarin more carefully and do INR follow-up regularly.

• 대한전자공학회논문지TC
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• 제49권3호
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• pp.37-46
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• 2012

레이더 및 소나와 같은 탐지 시스템에서 잡음 환경은 균질 (homogeneous) 환경과 비균질 (heterogeneous) 환경으로 구분되며 비균질 환경은 간섭 신호 환경 (target masking)과 클러터 경계 환경 (clutter edge)으로 모델링 할 수 있다. VI (variability index) CFAR (constant false alarm rate)는 이러한 다양한 잡음 환경에 강건한 표적신호 탐지 성능의 확보를 위한 방법으로서, mean-level CFAR 알고리즘들 중에서 주어진 잡음 환경에 최적화된 기법을 선택하는 방법이다. 하지만, VI CFAR의 경우 클러터 잡음 경계 환경과 간섭 신호 환경에서 검출 확률이 저하되는 단점을 보인다. 이를 극복하기 위해, 본 논문에서는 TM (trimmed mean) CFAR와 sub-window를 이용하여 비균질 환경에 의한 검출 확률의 저하를 최소화시키는 방법을 제안한다. 모의 전산 실험 결과에 따르면, 제안된 알고리즘은 기존의 VI CFAR 및 단일 CFAR 알고리즘에 비해 간섭 신호 환경과 클러터 경계 환경에서 검출 확률 및 오경보 확률 측면에서 우수한 성능을 보인다.

• Nuclear Engineering and Technology
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• 제44권1호
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• pp.53-60
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• 2012

The aim of this study was to explore the spatial and energy resolutions of a PET scanner that we have recently developed. The scanner, which consists of six detector modules with 1-layer LGSO crystals, has a hexagonal configuration with a faceto- face distance of 86.4 mm between two opposite PET modules; such properties facilitate the imaging of small animals. A $^{22}Na$ point source was employed to estimate horizontal and vertical spatial resolutions. To assess the energy resolution, a uniform $^{18}F$ cylindrical phantom was scanned. A software-based spectrum analysis of list-mode data was used to assign a local energy window centered on the photopeak position for every single crystal. For the image reconstruction, an ML-EM algorithm was used. The spatial resolutions at the center of the scanner were 0.99 mm in the horizontal direction and 1.13 mm in the vertical direction. The energy resolution averaged over each PMT ranged from 13.3%-14.3%, which gave an average value of 13.8%. These results show that this simple system is promising for small animal imaging with excellent spatial and energy resolutions.

• 한국소음진동공학회논문집
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• 제24권3호
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• pp.213-218
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• 2014

썬루프 버페팅 소음의 고유특성을 의미하는 속도에 따른 소음강도의 증-감쇠 현상을 살펴보고자, HSM(Hyundai simplified model) 형상에 대해서 유동소음 해석 프로그램인 STAR-CCM+을 통하여 전체 차속 범위에 걸쳐 시험과 비교 검토하였다. 차량 내부의 재질에 따른 압축성 효과 및 감쇠효과는 인공 압축성과 감쇠 보정 기법인 FRET(frequency response test)를 이용하였다. 시뮬레이션 결과는 특정 속도에서 나타나는 소음 강도의 증-감쇠 시험결과를 매우 잘 예측하였으며 최대 SPL 수치도 정확히 예측하였다. 이는 썬루프 개방에 의해 발생하는 전단면에서의 유동 박리 주파수를 유동 소음 해석인 STAR-CCM+가 전 차속에 걸쳐서 매우 잘 예측하고 있음을 나타낸다.

• Journal of Trauma and Injury
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• 제30권4호
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• pp.166-172
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• 2017

Purpose: Thoracic traumas represent 10-15% of all traumas and are responsible for 25% of all trauma mortalities. Traumatic cardiac injury (TCI) is one of the major causes of death in trauma patients, rarely present in living patients who are transferred to the hospital. TCI is a challenge for trauma surgeons as it provides a short therapeutic window and the management is often dictated by the underlying mechanism and hemodynamic status. This study is to describe our experiences about emergency cardiac surgery in TCI. Methods: This is a retrospective clinical analysis of patients who had undergone emergency cardiac surgery in our trauma center from January 2014 to December 2016. Demographics, physiologic data, mechanism of injuries, the timing of surgical interventions, surgical approaches and outcomes were reviewed. Results: The number of trauma patients who arrived at our hospital during the study period was 9,501. Among them, 884 had chest injuries, 434 patients were evaluated to have over 3 abbreviated injury scale (AIS) about the chest. Cardiac surgeries were performed in 18 patients, and 13 (72.2%) of them were male. The median age was 47.0 years (quartiles 35.0, 55.3). Eleven patients (61.1%) had penetrating traumas. Prehospital cardiopulmonary resuscitations (CPR) were performed in 4 patients (22.2%). All of them had undergone emergency department thoracotomy (EDT), and they were transferred to the operating room for definitive repair of the cardiac injury, but all of them expired in the intensive care unit. Most commonly performed surgical incision was median sternotomy (n=13, 72.2%). The majority site of injury was right ventricle (n=11, 61.1%). The mortality rate was 22.2% (n=4). Conclusions: This study suggests that penetrating cardiac injuries are more often than blunt cardiac injury in TCI, and the majority site of injury is right ventricle. Also, it suggests prehospital CPR and EDT are significantly responsible for high mortality in TCI.

• 지능정보연구
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• 제14권4호
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• pp.89-101
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• 2008

제조 분야에서 품질관리를 위해 가장 많이 사용되는 도구는 관리도이다. 하지만 휴대용 카메라 모듈과 같은 소형 전자부품의 제조 라인은 자동화되어 여러 개의 공정이 유기적으로 연결되어 있는 경우 관리도의 적용이 쉽지 않다. 이러한 문제점을 해결하기 위해 공정의 흐름을 파악할 수 있는 모니터링체계와 수율 예측 및 주요공정 변수 파악 등의 주요 공정 파라메터 추출 체계로 구성된 데이터마이닝 기반 품질관리시스템을 구축하고자 한다. 데이터마이닝을 위해 품질관리시스템은 의사결정나무, 신경망, 패턴분석 등의 모듈을 사용한다. 제안된 시스템을 통해 제조 공정은 안정적인 품질의 유지 및 공정 이상 유무의 신속한 파악, 수율 예측 등 품질관리를 위한 유용한 정보를 제공하고 공정의 신뢰성을 높이는데 기여할 수 있을 것이다.

• 한국멀티미디어학회논문지
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• 제21권9호
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• pp.1076-1089
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• 2018

Respiration is the process of moving air into and out of the lung. Respiration changes the temperature in the chamber while exchanging energy. Especially the temperature of the face. Respiration monitoring using an infrared camera measures the temperature change caused by breathing. The conventional method assumes that motion is not considered and measures respiration. These assumptions can not accurately measure the respiration rate when breathing moves. In addition, the respiration rate measurement is performed by counting the number of peaks of the breathing waveform by displaying the position of the peak in a specific window, and there is a disadvantage that the breathing rate can not be measured accurately. In this paper, we use KLT tracking and block matching to calibrate limited weak movements during breathing and extract respiration waveform. In order to increase the accuracy of the respiration rate, the position of the peak used in the breath calculation is calculated by converting from a single point to a high resolution. Through this process, the respiration signal could be extracted even in weak motion, and the respiration rate could be measured robustly even in various time windows.

• 한국군사과학기술학회지
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• 제17권5호
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• pp.672-679
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• 2014

To improve sensing capability of infrared, heat-resistance and mechanical properties, the $SiO_2$ and $TiO_2$ anti-reflective layers were coated on sapphire substrate by MOCVD. The standard wavelength was 4,600nm, and the thickness of anti-reflective layers were 379 and 758nm in case of ${\lambda}/4$ and ${\lambda}/2$ of incident angle($65^{\circ}$), respectively. The $SiO_2$ and $TiO_2$ anti-reflective layers were coated 12.6 and 9.7nm/min of deposition rates by increasing oxygen pressure to set the ideal refractive index of 1.283. In case of $SiO_2({\lambda}/2)$ coating, the transmittance increased from 55.0 to 62.7%. The transmittance of $TiO_2({\lambda}/2)$ anti-reflective layer also increased from 55.0 to 64.8%. The flexural strength of $SiO_2({\lambda}/2)$ and $TiO_2({\lambda}/2)$ layer coated sapphire increased from 337.8 to 362.9 and 371.8MPa, respectively. The flexural strength at $500^{\circ}C$ of these materials also increased respectively to 304.5, 358.2MPa from 265.9MPa. From these results, we confirmed these materials can be used as transmission window of infrared light.

• KIEAE Journal
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• 제16권5호
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• pp.39-45
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• 2016

Purpose: The purpose of this study is to analyze the energy saving and cost benefit analysis of the Low-income Energy Efficiency Treatment Program supported by KOREF(Korea Energy Foundation). This program was launched in 2007 and performs building energy retrofit for the low-income and energy poverty houses. Method: Energy simulation and cost benefit analysis were accomplished for the low-income detached houses. The structure of detached house was a lot og block structure, wood frame (single glass) and concrete roof. Baseline model of the low-income detached houses was proposed. Result: Annual heating energy consumptions were decreased by about 3.2% with the window system replacement(Case 1), 9.3% with reinforcement of insulation(Case2), and 12.5% with both(Case 3) compared to those of baseline model. The construction cost will be recouped within 5 years for the Case 1, 3 years for the Case 2, and 3 years for the Case 3. Case 3 was the most cost beneficient construction method in the analyzed cases in this study.

• Journal of Astronomy and Space Sciences
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• 제33권3호
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• pp.221-227
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• 2016

As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.