• 한국간담췌외과학회지
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• 제27권2호
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• pp.195-200
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• 2023

Backgrounds/Aims: We aimed to build a machine learning tool to help predict low-grade intraductal papillary mucinous neoplasms (IPMNs) in order to avoid unnecessary surgical resection. IPMNs are precursors to pancreatic cancer. Surgical resection remains the only recognized treatment for IPMNs yet carries some risks of morbidity and potential mortality. Existing clinical guidelines are imperfect in distinguishing low-risk cysts from high-risk cysts that warrant resection. Methods: We built a linear support vector machine (SVM) learning model using a prospectively maintained surgical database of patients with resected IPMNs. Input variables included 18 demographic, clinical, and imaging characteristics. The outcome variable was the presence of low-grade or high-grade IPMN based on post-operative pathology results. Data were divided into a training/validation set and a testing set at a ratio of 4:1. Receiver operating characteristics analysis was used to assess classification performance. Results: A total of 575 patients with resected IPMNs were identified. Of them, 53.4% had low-grade disease on final pathology. After classifier training and testing, a linear SVM-based model (IPMN-LEARN) was applied on the validation set. It achieved an accuracy of 77.4%, with a positive predictive value of 83%, a specificity of 72%, and a sensitivity of 83% in predicting low-grade disease in patients with IPMN. The model predicted low-grade lesions with an area under the curve of 0.82. Conclusions: A linear SVM learning model can identify low-grade IPMNs with good sensitivity and specificity. It may be used as a complement to existing guidelines to identify patients who could avoid unnecessary surgical resection.

• 인터넷정보학회논문지
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• 제15권5호
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• pp.25-32
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• 2014

현대 지식정보사회에서 한 나라의 경제력은 IT 산업과 기술에 크게 의존하고 있다. 이러한 관점에서 대부분의 국가들은 새롭고 혁신적인 IT 기술을 개발함으로써 IT 산업을 부흥시키려고 노력하고 있다. 전통적으로 IT 산업에 있어서는 단지 소수의 뛰어난 인재가 전체 산업을 주도하고 있다. 따라서, 조기에 정보영재를 판별하고 양성하는 것은 IT산업의 육성에 있어서 매우 중요하며 필요하다. 본 논문의 목적은 정보영재아동의 학년별 학업능력을 조사하는 것이다. 이러한 목적을 위해 본 연구는 초등학교 4학년, 5학년 및 6학년 정보영재아동에 초점을 두고 있다. 본 연구에서는 정보영재의 다양한 능력 가운데서 프로그래밍 능력과 논리적 사고력에 중점을 두었다. 현재까지 정보영재아동의 학년별 차이를 비교하고 분석한 연구는 없었다. 이러한 연구목적을 위해 서울시의 한 대학부설 과학영재교육원에 재학한 정보영재아동들을 대상으로 연구하였으며, 8년 동안의 성적이 분석되었다. 통계처리결과로부터 정보영재아동의 프로그래밍 능력과 논리적 사고력에 있어서 4학년, 5학년 및 6학년 간에 유의미한 차이는 없다고 결론을 내릴 수 있다. 이 연구결과는 향후 정보영재교육에 있어서 교육내용, 교육과정 및 법과 제도를 제안하는 데 있어서 도움이 될 것으로 기대한다.

• 가정과삶의질연구
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• 제29권5호
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• pp.85-105
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• 2011

The purpose of this study was to investigate the variables on adolescents' perception of parents and children's relationship. Independent variables were the expectation of the parents' role, role performance by adolescents' perception and socio-demographic variables. In order to achieve this purpose, the survey was taken by 758 adolescents (middle & high school students) from Daegu. The data were analyzed by frequency, percentage, mean, Factor Analysis, Cronbach's ${\alpha}$, Pearson's correlation coefficient, Multivariate Analysis of Variance, Scheffe test for post hoc, and Multiple Regression. The major findings were: 1) Role expectation had significant differences in the grade, gender, birth order, father's level of education, father's job, mother's age, and household economy of socio-demographic variables. Role performance showed significant differences in the grade, gender, father's age, parents' level of education, father's job, and household economy of socio-demographic variables. 2) Adolescents' perception of parents and children's relationship was affected by role expectation and role performance.

• 교육시설
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• 제13권4호
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• pp.15-23
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• 2006

The purpose of this study is to establish the objective deterioration grades and evaluation criteria of building equipment system of educational facilities available for reasonable maintenance and remodeling of them. For the purpose of it, the actual conditions of building equipment systems of the 148 buildings of 84 middle and high schools in Seoul 20 years after construction are investigated and surveyed through one-on-one interviews and questionnaires. And, deterioration grades of them are estimated by the evaluation criteria which is proposed in this study. As a result of this study, the 10 deterioration grades and the 4 evaluation criteria of the 6 performances of building equipment system, which are heating and cooling, water supply and drainage, hot water supply and electrical power performance, are suggested. And, as a result of the survey, it showed that 24% of the investigated school buildings were estimated C grade which needs partial remodelling, and 51% of the school buildings were estimated D grade which needs extensive remodelling. And, 25% of the school buildings were estimated E grade which needs overall remodelling or alteration of building equipment system.

• BMB Reports
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• 제46권5호
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• pp.244-251
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• 2013

Lignocellulosic materials are commonly used in bio-$H_2$ production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-$H_2$ production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to $H_2$ by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-$H_2$ production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized.

• 대한기계학회논문집A
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• 제24권3호
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• pp.718-727
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• 2000

Nowadays, most passenger cars equipped with automatic transmissions use torque converter clutches to reduce fuel consumption, and recently the slip control scheme of torque converter clutches is widely studied for the expansion of the operating region of torque converter clutches and thus for the further improvement of the fuel economy of vehicles. In this study, the analysis of the torque converter clutch system including the line pressure control unit of the automatic transmission and the actuating hydraulic control unit of the torque converter clutch is performed, and a feedforward controller and a fuzzy logic controller for its slip control are proposed. Also, for the slip controller to use the grade resistance information during control, an observer-based grade resistance estimator is designed. The performance of the designed grade resistance estimator and the slip controller is verified by dynamic simulations, and the effect of the torque converter clutch slip control on the fuel economy is examined using a driving cycle simulation.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.891-894
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• 2014

This study is aimed to investigate the role of paired boxed gene 1 (PAX1) methylation analysis by methylation-sensitive high-resolution melting (MS-HRM) in the detection of high grade lesions in atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and compared its performance with the Hybrid Capture 2 (HC2) human papillomavirus (HPV) test. In our study, 130 cases with a diagnosis of ASC-H from the cervical cytological screening by Thinprep cytologic test (TCT) technique were selected for triage. Their cervical scrapings were collected and evaluated by using PAX1 methylation analysis (MS-HRM) and high-risk HPV DNA test (HC2), followed by colposcopy and cervical biopsy. Chi-square test were used to test the differences of PAX1 methylation or HPV infection between groups. In the detection of CIN2+, the sensitivity, specificity, the PPV, NPV and the accuracy of PAX1 MS-HRM assay and high-risk HPV (HR-HPV) tests were respectively 80.6% vs 67.7%, 94.9% vs 54.5%, 83.3%, vs 31.8%, 94.0% vs 84.4%, and 91.5% vs 57.7%. The PAX1 MS-HRM assay proved superior to HR-HPV testing in the detection of high grade lesions (CIN2+) in ASC-H. This approach could screen out the majority of high grade lesion cases of ASC-H, and thus could reduce the referral rate to colposcopy.

• 한국초지조사료학회지
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• 제34권3호
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• pp.202-208
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• 2014

This study was carried out investigate the effects of dietary addition of mineral and sugar on the dry matter intake, daily gain, yield grade and quality grade of Hanwoo (Bos taurus coreanae) steers. Three diets fed to steers included a control diet (concentrate mix and rice straw : C) and two treatments diet (control diet + black sugar 100 g + mineral 100 g : T1, and control diet + black sugar 150 g + mineral 50 g : T2). The results are summarized as follows; total feeding intake, body weight gain and daily gain did not show significant differences among the three treatments. Cold carcass weight was significantly (p<0.05) higher in T2 than in the other two treatments (C and T1). There was no significant difference in yield traits of back fat thickness, longissimus muscle area and yield grade among the three treatments (C, T1 and T2). Marbling score showed significantly (p<0.05) higher in order of T2 (5.67) > T1 (4.67) > C (3.67). Meat color, fat color, texture and maturity were no significant difference. Quality grade was higher in T2 than in the other two treatments (C and T1), but there was no significant difference. The results show that marbling score and quality grade of Hanwoo can be increased by high dry matter intake with feeding addition of mineral and sugar.

• 치위생과학회지
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• 제14권3호
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• pp.332-341
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• 2014

이 연구는 본 학과 졸업생의 학교 성적과 국시 성적을 비교하여 분석하고자 하였다. 즉 본 학과의 6개 연도 졸업생 185명의 학교 성적과 국시 성적의 상관관계를 파악하고, 성별과 졸업 연령 등에 따라 학교 성적과 국시 성적에 차이가 있는지 평가하며, 학교 성적의 여러 세부항목 가운데 국시성적을 가장 적절히 예측할 수 있는 주요 요인이 무엇인지 밝히고자 하였다. 본 학과 졸업생의 학년 평점 및 종합시험 점수는 국시 필기 점수와, 1~3학년의 학년 평점 및 종합시험 점수는 국시총점수와 유의한 양의 상관관계가 있었다. 특히 2학년의 학년 평점이 국시 필기 점수와, 2차 종합시험 점수가 국시 총 점수와 상관성이 가장 높았다. 졸업 총평점이 높거나, 여학생이거나, 졸업 연령이 낮은 졸업생이 국시 필기 점수가 의미 있게 높았으나 국시 실기 점수에는 유의한 차이가 없었다. 2차 종합시험 점수가 국시 총점수와 상관성이 가장 높게 나타난 바, 4학년 2학기에 최종적으로 시행하는 종합시험 점수가 국시 성적을 예측할 수 있는 가장 주된 요인으로 판단된다. 그러나 4년 전체의 졸업 평점이 우수하더라도 국시실기 점수에는 그 영향이 없었으며, 국시 실기와 직접 관련이 있는 4학년의 학년 평점은 오히려 국시 실기 점수와 반대의 양상을 보였다. 또한 국시 실기 점수와 이에 해당하는 학교 교과목 평점도 유의한 상관관계가 없었다. 결론적으로, 학교 성적으로 국시 필기 점수는 신뢰성있게 예측할 수 있으나 국시 필기 점수는 그렇지 못하였다. 이 연구는 일개 학교의 사례라는 한계가 있다. 그러나 학교 교육과 국시가 상치되지 않아야 한다면 치위생학 교육과 치과위생사 국시의 연계성에 관련하여 심층적인 연구가 더욱 활발히 수행되어야 할 것으로 생각된다.

• 한국항공우주학회지
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• 제39권8호
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• pp.788-795
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• 2011

본 논문에서는 각종 탑재체에 가장 광범위하게 사용되는 중급성능의 레이저 관성항법 장치에 적용 가능한 소형 링레이저 자이로를 설계하기 위한 요구규격을 제시한다. 이를 위하여 우선 중급성능 관성항법장치 구성을 위하여 요구되는 링레이저 자이로의 요구 성능규격을 분석하였다. 그리고 이를 만족시키기 위하여 해외기술 조사 및 이론적으로 분석을 통하여 링레이저 자이로 시스템을 설계한 결과를 제시하였으며 요구 기술을 정리하였다.