• 한국정밀공학회지
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• 제15권5호
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• pp.72-84
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• 1998

This paper studies the relationship between assemblability and assembly time. After analyzing characteristic factors of bolts and parts, seven different kinds of assemblability parameters were determined according to assembly process, and assemblability was also evaluated. MTM (Method-Time Measurement) and Work factor methods were used for an estimation of assembly time. It shows the relationship can be found on the basis of characteristic factors of parts and bolts by relational graphs and numerical formulas.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.67-70
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• 2002

This paper presents an optimal robust LQ-PID controller design method for a second order system with time-delay to meet design specifications. By LQR formulation of the second order system with time-delay, tuning parameters of PID controller are related by the weighting factors Q and R of cost function. The selection of the weighting factors Q and R are chosen to satisfy such the design specifications as overshoot and settling time.

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.590-596
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• 2016

Objective : Rheumatoid arthritis (RA) is a systemic disease that can affect the cervical spine, especially the atlantoaxial region. The present study evaluated the risk factors for atlantoaxial subluxation (AAS) development and progression in patients who have undergone surgical treatment. Methods : We retrospectively analyzed the data of 62 patients with RA and surgically treated AAS between 2002 and 2015. Additionally, we identified 62 patients as controls using propensity score matching of sex and age among 12667 RA patients from a rheumatology registry between 2007 and 2015. We extracted patient data, including sex, age at diagnosis, age at surgery, disease duration, radiographic hand joint changes, and history of methotrexate use, and laboratory data, including presence of rheumatoid factor and the C-reactive protein (CRP) level. Results : The mean patient age at diagnosis was 38.0 years. The mean time interval between RA diagnosis and AAS surgery was $13.6{\pm}7.0$ years. The risk factors for surgically treated AAS development were the serum CRP level (p=0.005) and radiographic hand joint erosion (p=0.009). The risk factors for AAS progression were a short time interval between RA diagnosis and radiographic hand joint erosion (p<0.001) and young age at RA diagnosis (p=0.04). Conclusion : The CRP level at RA diagnosis and a short time interval between RA diagnosis and radiographic hand joint erosion might be risk factors for surgically treated AAS development in RA patients. Additionally, a short time interval between RA diagnosis and radiographic hand joint erosion and young age at RA diagnosis might be risk factors for AAS progression.

• 성인간호학회지
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• 제27권1호
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• pp.83-93
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• 2015

Purpose: This study was to investigate the relationship among the symptom recognition, health behavior compliance, and the hospital arrival time to identify factors influencing the hospital arrival time in patient with acute myocardial infarction (AMI). Methods: The subjects of this study were 200 patients with AMI in C hospital in D city. Data were analyzed using descriptive statistics, independent t-test, One way ANOVA, Pearson's correlation coefficients, and stepwise multiple liner regression tests. Results: Level of symptom recognition and health behavior compliance was low. The median value of hospital arrival time was 4.48 hours (ST-segment Elevation Ml was 2.43 hours and Non ST-segment Elevation MI was 7.83 hours). Among the studied factors, only symptom recognition had a statistically significant positive correlation with health behavior compliance (r=0.38, p<.001). Factors influencing the hospital arrival time were MI classification, diabetes mellitus (DM) and transport vehicle to the 1st hospital, and they accounted for 13% of the variance for hospital arrival time in AMI patients. Conclusion: To prevent the delay of hospital arrival time in MI patients, a more robust nursing strategic intervention according to MI classification and DM is necessary; further education on the importance of transportation utilization is also mandated.

• 한국산림과학회지
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• 제97권2호
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• pp.135-139
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• 2008

Seed production and germination could be influenced by some factors. The picking time and climate factors are regarded as the elements to obtain sound seeds. We have observed the seed productivity and germination of seeds from trees of Chamaecyparis obtusa selected in a clonal seed orchard. Depending on picking time, various shapes from liquid material, something jellied to the fully matured one were observed. Germination aspects varied throughout the test days. After 20days of seeding in a glass petri-dish, germinal apparatuses appeared from the all seeds which had been picked from after at the end of August. The highest germination rate of about 30% was observed from the seeds picked from $20^{th}$ of September and $10^{th}$ of October. Seed production was about two times higher in 2005 than in 2006 and the average germination rate was also higher in 2005. We have also analyzed the effects of climatic factors about two consecutive years on seed productivity. Among the climatic factors, monthly sum of temperature and of precipitation were the main factors for maturation of Chamaecyparis obtusa seeds.

• 한국산학기술학회논문지
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• 제7권5호
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• pp.948-953
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• 2006

본 논문은 일반적으로 사업의 성공적인 요인을 측정함에 있어, 각 요인이 사업 기간 내에 주요하게 인식되는 시점을 예측하기 위한 통계적 방법론을 연구하였다. 일반적으로 사업 성공을 위한 요인의 중요성은 사업을 수행하는 환경의 변화에 따라 변화된다. 환경의 변화는 시간의 흐름에 따라 변화되기 때문에 시간에 따라 요인의 중요성도 각각 상이할 수밖에 없다. 따라서 본 연구에서는 Rogers의 혁신확산(Diffusion of Innovations) 이론을 기반으로 기술적 기반의 산업 구조에서 추진되는 사업의 성공 요인의 연구에 있어 각 요인의 중점적으로 인식되는 시점을 정확히 예측할 수 있는 방법론을 제시하고자 한다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제23권1호
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• pp.29-37
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• 2023

Background: A high incidence (40-73%) of postoperative nausea and vomiting (PONV) has been reported following orthognathic surgery, and various risk factors have been associated with it. Identifying PONV risk factors based on initial onset time will help establish preventive measures. This study aimed to identify factors that are significantly related to PONV based on the initial onset time after orthognathic surgery. Methods: This study included 590 patients who underwent orthognathic surgery. Multivariate logistic regression analysis was performed to identify the risk factors that are significantly related to PONV. The objective variables were classified into three categories: no PONV, early PONV (initial onset time: 0-2 h after anesthesia), and late PONV (initial onset time: 2-24 h after anesthesia). The explanatory variables included relevant risk factors for PONV, as considered in previous studies. Results: Total intravenous anesthesia with propofol was a significant depressant factor for early PONV (adjusted odds ratio [aOR] = 0.340, 95% confidence interval [CI] = 0.209-0.555) and late PONV (aOR = 0.535, 95% CI = 0.352-0.814). The administration of a combination of intraoperative antiemetics (vs. no administration) significantly reduced the risk of early PONV (aOR = 0.464, 95% CI = 0.230-0.961). Female sex and young age were significant risk factors for late PONV (aOR = 1.492, 95% CI = 1.170-1.925 and unit aOR = 1.033, 95% CI = 1.010-1.057, respectively). Conclusion: We identified factors that are significantly related to PONV based on the initial onset time after orthognathic surgery. Total intravenous anesthesia with propofol significantly reduced the risk of PONV not only in the early period (0-2 h after anesthesia) but also in the late period (2-24 h after anesthesia).

• 정보처리학회논문지D
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• 제13D권7호
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• pp.923-930
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• 2006

본 논문에서는 무기체계 임베디드 소프트웨어의 시간 요소를 고려한 TFM(Time Factor Method) 기반의 시스템 테스트 모델을 설계하고, 적용사례를 통하여 결과를 제시한다. 이를 위해 무기체계 임베디드 소프트웨어의 특징과 시스템 테스트 그리고 객체지향 모델의 표현방법인 UML 표기법에 대하여 알아보고, 시스템 테스트 모델 설계를 위한 TFM 접근 방법으로 시간 요소를 고려한 테스트 방법과 시간 요소 측정 방법 그리고 테스트 케이스 선정 알고리즘을 제시한다. 무기체계 임베디드 소프트웨어의 TFM 기반 시스템 테스트 모델은 세 가지 요소 (X,Y,Z) 로 구성되며, 'X' 에서는 최대시간경로를 선정하는 알고리즘을 통해 테스트 케이스가 도출되고, 'Y' 에서는 Sequence Diagram과 관련된 객체를 식별하고, 'Z'에서는 Timing Diagram을 통하여 식별된 각 객체들의 실행시간을 측정한다. 또한 제안한 W:M 기반 시스템 테스트 모델을 '다기능 미사일 방어시스템'에 적용하여 테스트 케이스를 추출하는 방법을 제시한다.

• 한국노년학
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• 제40권4호
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• pp.781-800
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• 2020

본 연구의 목적은 한국 노인의 생활시간 사용을 유형화하여 유형별 영향요인과 차이를 확인하고 각 유형이 생활만족도에 미치는 영향을 파악하는 것이다. 이를 위해 국민노후보장패널 6차 자료를 활용하여 65세 이상 노인 3,963명을 대상으로 잠재프로파일 분석을 실시하였다. 생활시간 유형 분류 결과 한국 노인의 생활시간 활용은 기초생활유지형(16%), 여가자유중심형(26%), 사회활동형(58%)의 3가지로 유형화 되었다. 각 유형별 영향요인 파악을 위한 다항 로지스틱 회귀분석 결과 기초생활유지형 대비 여가자유중심형의 주요 영향요인은 배우자의 유무(p<.01), 심리적 건강상태(p<.001)로 나타났고, 사회활동형의 주요 영향요인은 연령(p<.05), 경제적 활동(p<.001), 만성질환(p<.001)으로 나타났다. 생활만족도에 영향을 미치는 요인을 종합적으로 분석한 결과, 기초생활유지형에 비해 여가자유중심형과 사회활동형의 생활만족도가 더 높게 나타났다. 연구결과를 바탕으로 기초생활유지형으로 시간을 활용하고 있는 노인의 시간사용 유형 변화를 추구하여 노년기 생활만족도를 제고하기 위한 실천적 정책적 제언을 제시하였다.

• 산업경영시스템학회지
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• 제23권55호
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• pp.33-42
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• 2000

It is difficult to estimate the effective factors upon Cumulative Trauma Disorders in real workplace because those are developed by combination of various risk factors for time. The purpose of this paper was to evaluate relative level of CTDs risk factors such as task-related factors, anthropometric factors, joint deviation factors and personal factors using fuzzy linear regression models. And the models are built corresponding to each category with the survey data from telephone operators. The coefficient of fuzzy models are described as the relative level of variable to present risk factors upon CTDs.