• Journal of Advanced Marine Engineering and Technology
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• 제29권4호
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• pp.443-452
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• 2005

The purpose of this study is experimentally to analyze the effects of intake port swirl, injection system and turbocharger on the engine performance and the emission characteristics in a V8 type turbocharger intercooler D.I. diesel engine of the displacement 16.7L, and to suggest the improvement of engine performance. Generally to enhance engine power, TCI diesel engine is put to practically use turbocharged intercooler in order to increase volume efficiency which is cooled boost air. As results of considering the factors of the intake port of swirl ratio 2.25, compression ratio 17.5. re-entrant $8.5^{\circ}$ combustion bowl, nozzle hole diameter ${\phi}0.33{\ast}3+{\phi}0.35{\ast}2$. nozzle protrusion 3.18mm, injection timing BTDC $12^{\circ}CA$ and turbocharger(compressor 0.6A/R+46Trim. turbine 1.0 A/R+57Trim) is the best in the full load in the engine performance and the exhaust characteristics of NOx concentration. Therefore. their factors are appropriated as intake system, injection and turbocharger system.

• 근관절건강학회지
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• 제29권1호
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• pp.60-68
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• 2022

Purpose: This study aimed to investigate the changes in reality shock among new nurses and their influencing factors to identify turnover reduction methods. Methods: A total of 146 new nurses from 6 general hospitals participated in the survey. The survey data were collected from August 5 to November 10, 2015. Results: The mean scores for factors related to turn over were 2.75 for nurse practice environment, 2.84 (4point scale) for reality shock, and 3.08 (5point scale) for turnover intention. A significant difference in the impact of reality shock was observed depending on whether the nurses selected their work unit (F=6.24, p=.003) and whether they could take the possibility of holiday on the desired day at will (t=-2.57, p=.013). Changes in reality shock correlated with turnover intention, with the 'increased reality shock' group demonstrating an odds ratio of 2.37 (CI: 1.41~3.98) for turnover intention. Conclusion: The current findings indicate the need for lowering reality shock and turnover intention by considering nurses' work-related characteristics and improving their practice environments. To further study the changes in reality shock new nurses experienced, additional research is warranted while homogenizing the participants in terms of preceptorship duration and timing of independence.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.233-234
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• 2021

겨울철 한파로 인한 수도계량기의 동파는 수돗물 공급 중지, 유출된 후 결빙에 따른 각종 안전사고 유발 및 복구에 따른 비용 발생 등 여러 가지 불편과 문제를 야기시킨다. 본 연구에서는 수도계량기가 실제 동파가 발생되는 환경과 유사한 시험장치를 개발하여 동파영향인자인 온도, 습도, 유량, 압력, 밸브개도, 펌프 가동상태 등을 변화시켜 반복시험을 수행하고자 한다. 이를 통해 얻어지는 데이터를 기반으로 동파 영향인자 간 상관관계를 AI 기술을 적용해 동파시기를 예측하고자 한다.

• 비만대사연구학술지
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• 제2권2호
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• pp.54-63
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• 2023

Estrogen is crucial in regulating food intake, energy expenditure, glucose metabolism, and lipid metabolism. During menopause, the decline in estrogen levels predisposes women to weight gain, abdominal obesity, insulin resistance, type 2 diabetes, hypertension, and cardiovascular disease (CVD). Menopausal hormone therapy (MHT) prevents weight gain, improves lipid metabolism by lowering low-density lipoprotein cholesterol while raising high-density lipoprotein cholesterol, and delays the onset of type 2 diabetes in menopausal women. The effect of MHT on CVD in menopausal women remains controversial. The Women's Health Initiative study was terminated prematurely after it revealed that hormone administration increased the risk of myocardial infarction, stroke, and thromboembolism. However, some studies have found that MHT had no effect or decreased the risk of CVD. The inconsistent results were likely due to multiple factors, including the timing of hormone therapy initiation, duration of therapy, type and dosage, and presence or absence of CVD risk factors at the start of treatment. Despite its benefits in terms of managing weight gain and reducing the risk of type 2 diabetes, dyslipidemia, and CVD associated with obesity, it is not recommended as the primary therapy for weight loss or diabetes prevention. MHT is primarily indicated for postmenopausal women, who are likely to benefit from its potential to prevent weight gain and improve lipid metabolism.

• Journal of Korean Neurosurgical Society
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• 제46권1호
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• pp.31-37
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• 2009

Objective : This study was performed to elucidate the technical and patient-specific risk factors for postoperative ischemia in patients undergoing temporary arterial occlusion (TAO) during the surgical repair of their aneurysms. Methods : Eighty-nine consecutive patients in whom TAO was performed during surgical repair of an aneurysm were retrospectively analyzed. The demographics of the patients were analyzed with respect to age. Hunt and Hess grade on admission, Fisher grade of hemorrhage, aneurysm characteristics, timing of surgery, duration of temporary occlusion, and number of temporary occlusive episodes. Outcome was analyzed at the 3-month follow-up, along with the occurrence of symptomatic and radiological stroke. Results : In overall, twenty-seven patients (29.3%) had radiologic ischemia attributable to TAO and fifteen patients (16.3%) had symptomatic ischemia attributable to TAO. Older age and poor clinical grade were associated with poor clinical outcome. There was a significantly higher rate of symptomatic ischemia in patients who underwent early surgery (p=0.007). The incidence of ischemia was significantly higher in patients with TAO longer than 10 minutes (p=0.01). In addition, patients who underwent repeated TAO, which allowed reperfusion, had a lower incidence of ischemia than those who underwent single TAO lasting for more than 10 minutes (p=0.011). Conclusion : Duration of occlusion is the only variable that needs to be considered when assessing the risk of postoperative ischemic complication in patients who undergo temporary vascular occlusion. Attention must be paid to the patient's age, grade of hemorrhage, and the timing of surgery. In addition, patients undergoing dissection when brief periods of temporary occlusion are performed may benefit more from intermittent reperfusion than continuous clip application. With careful planning, the use of TAO is a safe technique when used for periods of less than 10 minutes.

• Radiation Oncology Journal
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• 제31권2호
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• pp.72-80
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• 2013

Purpose: We designed this study to identify and suggest the reasonable timing of adjuvant radiotherapy in the treatment of uterine carcinosarcoma according to the surgical intent and patterns of progression. Materials and Methods: We retrospectively analyzed a total of 50 carcinosarcoma patients diagnosed between 1995 and 2010. Among these 50 patients, 32 underwent curative surgery and 13 underwent maximal tumor debulking surgery. The remaining five patients underwent biopsy only. Twenty-six patients received chemotherapy, and 15 patients received adjuvant radiotherapy. Results: The median follow-up period was 17.3 months. Curative resection (p < 0.001) and stage (p < 0.001) were statistically significant factors affecting survival. During follow-up, 30 patients showed progression. Among these, eight patients (16.0%) had loco-regional progression only. The patients who had received adjuvant radiotherapy did not show loco-regional progression, and radiotherapy was a significant negative risk factor for loco-regional progression (p = 0.01). The time to loco-regional progression was much earlier for non-curative than curative resection (range, 0.7 to 7.6 months vs. 7.5 to 39.0 months). Conclusion: Adjuvant radiotherapy in the treatment of carcinosarcoma might be related to a low loco-regional progression rate. Radiotherapy should be considered in non-curatively resected patients as soon as possible.

• 대한원격탐사학회지
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• 제33권6_1호
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• pp.993-1001
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• 2017

가뭄은 전 지구차원의 다방면에 걸쳐 피해를 주는 자연 재해이다. 21세기 들어 최근까지 다양한 위성관측 기기를 활용하여 다양한 가뭄의 유형을 모니터링 할 수 있게 되었는데, SMAP위성의 토양수분, GRACE 위성의 생태계 물 저장량, Terra & Aqua의 생태계 생산량과 증발산량 그리고 위성 강우 관측 등이 그 예이다. 이들 위성 자료의 분석을 통해 지역적 수자원 현황 및 가뭄과 이로 인한 (수)생태계 영향, 농업 등의 산업, 그리고 인간사회의 영향을 시공간적으로 파악할 수 있다. 가시광선부터 마이크로파까지 채널 (밴드)마다 관측할 수 있는 기상 및 환경 변수가 다르기 때문에 다양한 센서로부터 획득할 수 있는 원격탐사자료는 한반도 전역을 대상으로 가뭄에 대한 수자원 변화와 연관된 피해를 시공간적으로 파악하는 데에 상호 보완적이며 효과적인 수단이다. 따라서 이러한 위성자료들을 통해 국가 재난 대응 차원의 활용방안을 제안하고자 한다.

• 한국컴퓨터정보학회논문지
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• 제18권7호
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• pp.47-55
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• 2013

임베디드 시스템에 구현되는 대부분의 어플리케이션들은 MCU가 제공하는 타이머를 사용한다. 타이머 사용의 목적은 실시간 운영체제의 소프트웨어 타이머 구현에서부터 센서의 워밍업이나 처리의 경과 시간 측정 등에 이르기까지 다양하다. 이들어플리케이션들이의시간측정은그길이뿐만아니라정밀도측면에서수us~수백ms 정도로 그 범위가 다양하다. 이 논문에서는 타이머를 활용하는 과정에서 클록 펄스 비동기화로 인해 발생할 수 있는 오차 요인을 분석하고, 이러한 오차를 감소시키기 위한 타이머 클록 펄스 동기화 방안을 제시한다. 실험 결과, 32768Hz의 타이머를 8 분주한 4096Hz 타이머의 경우 약 230us까지의 편차가 발생하지만, 제안된 방법을 적용하면 타이머로 인한 편차를 10us 이내로 유지할 수 있다.

• 대한전자공학회논문지SD
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• 제46권10호
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• pp.79-85
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• 2009

본 논문은 $0.18{\mu}m$ CMOS 공정을 이용하여 3.2 Gb/s serial link receiver를 설계하였다. High-speed links의 performance를 제한하는 가장 큰 요소는 transmission channel bandwidth, timing uncertainty가 있다. 이러한 문제점을 해결하기 위한 방법으로 multi-level signaling(4-PAM)을 이용하였다. 추가적으로 전송속도를 높이고 BER를 낮추기 위한 방법으로 current-mode amplifier, CML sampling latch를 사용하였다. 4-PAM receiver의 최대 데이터 전송속도는 3.2 Gb/s이다. BER은 $1.0{\times}10^{-12}$ 이하이며 chip size는 $0.5\;{\times}\;0.6\;mm^2$이고 1.8 V supply voltage에서 49mA current를 소모한다.

• 전자공학회논문지SC
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• 제46권2호
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• pp.22-27
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• 2009

본 논문에서는 LCD 구동 모듈 PCB의 기능 검사를 위한 자동 검사 시스템인 EVT (Emulated Vision Tester)를 제안하고 구현하였다. 기존의 대표적인 자동검사 방법으로는 전기적 검사나 영상기반 검사방식이 있으나 전기적 검사만으로는 Timing이 주요한 변수가 되는 LCD 장비에서는 검출할 수 없는 구동불량이 존재하며 영상기반 검사는 영상획득에 일관성이 결여되거나 Gray Scale의 구분이 불명확하여 검출결과의 재현성이 떨어진다. EVT 시스템은 Pattern Generator에서 인가된 입력 패턴 신호와 구동 모듈을 통한 후 출력되는 디지털 신호를 직접 비교하여 패턴을 검사하고 아날로그 신호 (전압, 저항, 파형)의 이상 여부도 신속 정확하게 검사할 수 있는 하드웨어적인 자동 검사 방법이다. 제안된 EVT 검사기는 높은 검출 신뢰도와 빠른 처리 속도 그리고 간결한 시스템 구성으로 원가 절감 및 전공정 검사 자동화의 실현을 가능케 하는 등 많은 장점을 가진다.