• 한국군사과학기술학회지
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• 제2권1호
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• pp.139-149
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• 1999

본 논문에서는 몸체진동에 의하여 Lock-in을 보상해주는 링레이저 자이로의 환산계수 오차와 불규칙잡음 특성을 시뮬레이션에 의해서 예측하였다. 그리고 그 결과를 약 0.5deg/sec의 static Lock-in을 갖는 28cm인 4각형 링레이저 자이로에 대한 정적시험 결과와 비교하였다. 진폭이 일정한 정현파 몸체진동을 인가하는 경우에 자이로의 출력 펄스가 몸체진동 진동수의 정수배가 되는 지점에서 주기적으로 dynamic Lock-in이 발생한다. Dynamic Lock-in의 폭은 몸체진동의 진폭에 따라서 변화하는데, 입력가속도가 몸체진동 진동수의 짝수배 지점과 홀수배 지점에서 나타나는 dynamic Lock-in의 폭은 180도 위상차이를 가짐을 알 수 있었다. 그리고 dynamic Lock-in을 보상해주기 위하여 불규칙진동을 추가로 인가하는데 이 불규칙성이 작으면 dynamic Lock-in에 의한 환산계수 오차가 제거되지 않으며, 불규칙성이 커지면 환산계수 오차는 줄어들지만 불규칙 잡음이 상대적으로 커짐을 알 수 있었다. 그리고 불규칙 잡음은 몸체진동의 진폭이 클수록 작아짐을 확인하였다.

• 생명과학회지
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• 제27권12호
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• pp.1515-1522
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• 2017

대부분의 사람은 오래 살기를 원한다. 고대 중국과 한국의 신화에 동방삭이라는 인물이 일만 팔천 년을 살았다고 전해진다. 현실 세계에서는 WHO의 보고에 따르면 사람의 평균수명이 1960년대에 50세에서 2016년에는 75-85세로 25~35세가 늘었다. 두 마리의 실험 동물을 외과적 수술을 통해 병렬로 결합하여 두 동물의 순환계(혈액)이 서로 연결되게 하는 개체병렬결합(parabiosis) 실험모델이 1860년도에 개발된 이래 이 방법은 in vivo에서 한 개체가 다른 개체에게 어떤 영향을 미칠 수 있는가에 대한 연구를 위한 강력한 실험 모델이 되어 왔다. 여러 가지 실험조건의 연구 중에서도 개체병렬결합모델은 노화의 진행을 역행하는 현상을 조사하는 연구에서 필수적인 모델이 되고 있다. 본 총설에서는 개체병렬결합모델의 탄생과 이로 인한 중요한 발견을 시간대에 따라 소개하며, 아직은 확정적이지는 않지만 젊은 쥐와 늙은 쥐의 순환계를 연결시킨 이 모델을 사용하여 노화의 진행을 역행시킬 수 있는 "젊음의 인자"인 growth differentiation factor 11 (GDF11)을 발견한 연구 결과에 대해 서술하고자 한다. 지금까지 밝혀지고 있는 여러 조건에서의 연구결과가 증명하였듯이 개체병렬결합모델은 향후 다양한 생리적 현상을 규명하는데 더욱 중요한 실험모델이 될 것으로 예상된다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권10호
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• pp.4713-4718
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• 2016

Objective: The aim of this study was to assess the effects of tobacco smoking on the dorsum of the tongue and buccal epithelium. Methodology: This case control cross-sectional study was conducted with 174 smoking and non-smoking volunteers living in the city of Hail, Northern KSA. Cytological Materials were obtained from buccal mucosa and dorsum of the tongue, and assessed using cytopathological methods. Results: In buccal smears, cytological atypia was observed in 17 out of 101 (16.8%) smoker cases but only 3/73(4.1%) of the controls. For cytological atypia in buccal and tongue smears, the adjusted odd ratio (OR) and the 95% confidence interval (CI) were found to be 4.7 (1.3-16.8), P < 0.016)) and 4.3 (0.93- 20.2), P <0.06)), respectively, in the two sites. Conclusion: Tobacco smoking is a major risk factor for occurrence of cytological atypia, which might subsequently develop into oral precancerous and cancerous lesions. Oral exfoliative cytology is an easy and cheap non-invasive procedure which appears highly suitable for screening populations at risk of developing oral cancer.

• 한국소음진동공학회논문집
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• 제15권1호
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• pp.29-38
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• 2005

The track pull-in behavior analysis in an optical disk drive (ODD) using plane phase and the evaluations for effecting parameters of it are discussed. Track pull-in, track capture procedure to do track following control, is a key factor to increase data transfer rate. First, the relative velocity between the beam spot of an optical pick-up and the target track of an optical disk is analyzed during the track pull-in procedure. In this process, it is showed that the track error signal has nonlinear characteristics which are depending on the time. Second, Runge-Kutta method to solve the nonlinear equation is applied to find the track pull-in behavior, and some optimal parameters to get stable and fast pull-in condition are obtained. Then, the phase plane analysis for track pull-in procedure is presented. Finally, some comments for the simulated results are discussed briefly.

• 한국소음진동공학회논문집
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• 제14권5호
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• pp.385-393
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• 2004

This paper proposes a swing-arm type dual-stage actuator, which consists of a PZT actuator for fine motion and a VCM(voice coil motor) for coarse motion, for an SFF ODD(small form factor optical disk drive), in order to achieve fast access speed and precise track-following control. Over the past few decades there have been a lot of researches related to the VCM and dual-stage actuator. In this paper, we focus our attention on the design and control of the PZT actuator. Due to the dual cantilever structure. the PZT actuator can generate precise translational tracking motion at its tip to which an optical pickup is attached. and the effect of hysteric behavior of the PZT element is reduced. The dynamic model of the PZT actuator is derived by using the Hamilton's principle, and verified by comparing it with the experimental frequency response. The sliding mode control is designed in order to be robust against modeling uncertainties. Simulations and experimental results confirm the effectiveness of the suggested control scheme.

• 동아시아식생활학회지
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• 제22권2호
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• pp.219-223
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• 2012

The purpose of this study was to investigate the body composition, biochemical parameters, and consumption of convenience foods according to leptin receptor polymorphism in university students. A survey was conducted on a total of 418 students - 271 males and 147 females. Based on a self-reporting method, questionnaires were administered for over 20 minutes, and leptin receptor and blood samples were analyzed. The genotype frequencies of leptin receptor polymorphism were Gln/Arg heterozygote (64.8%) and Gln/Gln homozygote (35.2%). Leptin polymormphism showed no significant association with biochemical parameters(ALT, cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol, and hemoglobin) and body composition. GG homozygote was associated with a higher risk of visceral fat obesity compared to those with GA heterozygote (odd ratio 1.758, 95% confidence intervals 0.812~3.803). Leptin polymorphism appeared to be a genetic risk factor for visceral fat obesity. This study suggests that leptin polymorphism has a causative role to body fat distribution in Korean.

• 중환자간호학회지
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• 제12권1호
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• pp.36-45
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• 2019

Purpose : The purpose of this study was to identify status and characteristics of patients who have been readmitted to ICU, and to analyze risk factors associated with the readmission to ICU within 48hours. Method: Data were collected from patient's electronic medical reports from one hospital in B city. Participants were 2,937 patients aged 18 years old or older admitted to the ICU. Data were analyzed using odd ratios (ORs) from multivariate logistic regressions. Results: 2.2% of the 2,937 patients were early readmitted to ICU. Risk factors for early readmission to ICU were existence of respiratory disease, use of mechanical ventilator, and duration of hospitalization (longer). Conclusion: The assessment on the respiratory system of the patient who will be discharged from the ICU was identified as an important nursing activity. Therefore, the respiratory system management and education should be actively conducted. In addition, early ICU readmission may be prevented and decreased if a link was built to share the information on patient condition between the ICU and general wards.

• 한국정보전자통신기술학회논문지
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• 제17권1호
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• pp.10-16
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• 2024

마이크로스트립 선로를 사용한 방향성 결합기는 기판의 유전율과 공기의 유전율이 서로 달라서 지향성 특성이 좋지 않다. 이를 해결하기 위해서 결합 선로 사이에 보상용 커패시터를 부착하여 지향성을 높이기도 한다. 본 논문에서는 추가적으로 개별 소자인 커패시터 대신에 전송선을 이용한 인터디지털 커패시터를 적용하여 높은 지향성을 갖는 방향성 결합기를 제안하였다. 제안한 방법으로 설계하여 제작한 방향성 결합기는 2.14GHz에서 결합도 20dB에서 지향성은 30dB 이상의 특성을 나타내었다. 이 방향성 결합기는 2개의 결합 포트와 2개의 고립 포트를 갖고 있어 2개의 방향성 결합기로 사용이 가능하다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.437-441
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• 2012

Objective: Health risk appraisal is often utilized to modify individual's health behavior, especially concerning disease prevention, and web-based health risk appraisal services are being provided to the general public in Korea. However, little is known about the psychological effect of the health risk appraisal even though poorly communicated information by the web-based service may result in unintended adverse health outcomes. This study was conducted to explore the psychological effect of health risk appraisal using epidemiological risk factor profile. Methods: We conducted a randomized trial comparing risk factor list type health risk appraisal and risk score type health risk appraisal. We studied 60 women aged 30 years and older who had no cancer. Anxiety level was assessed using the Spielberger State-Trait Anxiety Inventory YZ. Results: The results of multivariate analysis showed that risk status was the independent predictors of increase of state anxiety after health risk appraisal intervention when age, education, health risk appraisal type, numeracy, state anxiety, trait anxiety, and health risk appraisal type by risk status interaction was adjusted. Women who had higher risk status had an odd of having increased anxiety that was about 5 times greater than women who had lower risk status. Conclusions: Our findings indicate that communicating the risk status by individual health risk appraisal service can induce psychological sequelae, especially in women having higher risk status. Hospitals, institutes, or medical schools that are operating or planning to operate the online health risk appraisal service should take side effects such as psychological sequelae into consideration.

• Parasites, Hosts and Diseases
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• 제61권4호
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• pp.463-470
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• 2023

This study aimed to identify the recent risk factors for Opisthorchis viverrini infection and cholangiocarcinoma (CCA) to improve disease prevention. The participants were divided into the following 3 groups based on their health status: healthy control (nonOV and nonCCA), those with O. viverrini infection (OV), and those with CCA. A questionnaire was used to explore their lifestyle and behaviors. Multivariate logistic regression and backward elimination were used to identify the significant risk factors. The results showed that the significant risk factors for both O. viverrini infection and CCA were age>50 years (odd ratio (OR)=8.44, P<0.001, 95% confidence intervals (CI) 2.98-23.90 and OR=43.47, P=0.001, 95% CI 14.71-128.45, respectively) and raw fish consumption (OR=8.48, P<0.001, 95% CI 3.18-22.63 and OR=3.15, P=0.048, 95% CI 1.01-9.86, respectively). A history of O. viverrini infection was identified as an additional risk factor for CCA (OR=20.93, P=0.011, 95% CI 2.04-215.10). This study provided an update on the risk factors for O. viverrini infection and CCA. Asymptomatic patients with O. viverrini infection, particularly those>50 years old, should be carefully monitored to prevent CCA.