• Investigative Magnetic Resonance Imaging
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• 제22권1호
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• pp.18-25
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• 2018

Purpose: To investigate the various imaging factors associated with aggravation of lumbar disc herniation (LDH) and develop a scoring system for prediction of LDH aggravation. Materials and Methods: From 2015 to 2017, we retrospectively reviewed the magnetic resonance imaging (MRI) findings of 60 patients (30 patients with aggravated LDH and 30 patients without any altered LDH). Imaging factors for MRI evaluation included the level of LDH, disc degeneration, back muscle atrophy, facet joint degeneration, ligamentum flavum thickness and interspinous ligament degeneration. Flexion-extension difference was measured with simple radiography. The scoring system was analyzed using receiver operating characteristic (ROC) analysis. Results: The aggravated group manifested a higher grade of disc degeneration, back muscle atrophy and facet degeneration than the control group. The ligamentum flavum thickness in the aggravated group was thicker than in the group with unaltered LDH. The summation score was defined as the sum of the grade of disc degeneration, back muscle atrophy and facet joint degeneration. The area under the ROC curve showing the threshold value of the summation score for prediction of aggravation of LDH was 0.832 and the threshold value corresponded to 6.5. Conclusion: Disc degeneration, facet degeneration, back muscle atrophy and ligamentum flavum thickness are important factors in predicting aggravation of LDH and may facilitate the determination of treatment strategy in patients with LDH. The summation score is available as supplemental data.

• 컴퓨터교육학회논문지
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• 제19권5호
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• pp.55-71
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• 2016

최근 청소년의 과도한 인터넷 사용에 관한 부정적인 영향들이 증가함에 따라 인터넷 중독 문제가 지적되고 있다. 이에 본 연구에서는 제11차 청소년건강행태온라인조사 데이터를 활용하여 다양한 분석을 통해 도출된 결과를 기반으로 청소년의 과도한 인터넷 사용 대응방안에 대해 논의하고자 하며, 청소년 시기의 인터넷 이용에 영향을 미치는 요인으로는 인구사회학적 특성 요인, 심리 요인, 행동 요인을 중심으로 탐색하였다. 이 결과, 기존의 연구에서 접근하지 못했던 다양한 변인들이 청소년기의 인터넷 이용에 영향이 있음을 확인하였다. 본 연구의 결과를 통해 청소년기의 인터넷 이용에 영향을 미치는 변수들을 살펴볼 수 있으며, 나아가 청소년기의 과도한 인터넷 사용에 대한 대응방안을 마련할 수 있다.

• Journal of the Korean Data and Information Science Society
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• 제20권5호
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• pp.829-835
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• 2009

다구찌 파라미터 설계는 품질특성의 변동을 최대한 줄이면서 동시에 품질특성의 평균을 목표치 가까이 가져가기 위한 설계인자의 최적조건을 찾는 방법이다. 제품의 설계단계에서 품질특성과 여러 개의 설계인자와의 관계는 복잡한 비선형 형태를 가지는 경우가 대부분이다. 신경망에서 유연한 모형선택과 학습능력은 알 수 없는 복잡한 비선형 형태를 파악하는데 아주 유용한 도구이다. 본 연구는 파라미터 설계에서 설계인자의 최적조건을 찾기 위하여 신경망을 이용한 최적화 방안을 제안하였다.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.198-205
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• 2004

The remodeling of apartment that improves the improves the life level is going to be in the market because of lots of old apartment buildings. Until now, the research of remodeling is mainly restricted to the laws and financial funding, however, the needs in the trend of remodeling. This research, first, through the examples of remodeling in the country, this study draws remodeling factors that can be applied. Secondly, this study targets the study of remodeling to apartments and analyzes the type of housings made by the Korea National Housing Corporation. Thirdly the study analyzes the features that appear in housing units and draws out factors of remodeling This research's result is arranged as follows. \circled1Need Remodeling thorough study of space expanded, grant between artificer and active performance improvement direction such as building equipment expansion along with Remodeling concept of unit repair. \circled2When apartments are newly built, systematic construction is necessary that considers future efficiency improvement from the design stage. \circled3This study, which applied the characteristic factors appearing after the 1990s to remodeling factors, show that they can be applied when remodeling the worn out wall-slab type apartments.

• 한국실내디자인학회논문집
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• 제13권5호
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• pp.48-55
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• 2004

The remodeling of apartment that improves the improves the life level is going to be in the market because of lots of old apartment buildings. Until now, the research of remodeling is mainly restricted to the laws and financial funding, however, the needs in the trend of remodeling. This research, first, through the examples of remodeling in the country, this study draws remodeling factors that can be applied. Secondly, this study targets the study of remodeling to apartments and analyzes the type of housings made by the Korea National Housing Corporation. Thirdly the study analyzes the features that appear in housing units and draws out factors of remodeling This research's result Is arranged as follows. \circled1Need Remodeling thorough study of space expanded, grant between artificer and active performance improvement direction such as building equipment expansion along with Remodeling concept of unit repair. \circled2When apartments are newly built, systematic construction is necessary that considers future efficiency improvement from the design stage. \circled3This study, which applied the characteristic factors appearing after the 1990s to remodeling factors, show that they can be applied when remodeling the worn out wall-slab type apartments.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제29권1호
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• pp.51-72
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• 2015

본 논문은 대학생 124명을 대상으로 수학 교과와 수학 학습에 대한 긍정적 또는 부정적 인식과 그러한 인식을 갖게된 시기와 이유를 조사하여 범주화하고 각 범주별 특성을 분석하는 것을 목적으로 하였다. 이를 위해 수학에 대한 느낌을 은유로 표현하고 그 이유를 자세히 설명하도록 하였으며 학생들의 은유 표현을 긍정형, 부정형, 혼재형, 판정불가로 분류하여 남녀 성별 및 계열별로 각 유형별 비율과 유형별 표현의 특성을 살펴보았다. 또한, 학생들의 수학에 대한 선호 시기와 비선호 시기를 초등학교, 중학교, 고등학교, 대학교, 항상, 없음의 여섯 시기로 나누어 각 영역별 비율을 살펴보았고, 선호 및 비선호 이유를 성적요인, 정의적 요인, 내용적 요인, 교사 요인, 기타 요인과 같이 다섯가지로 나누어 분석하였다. 본 연구의 결과는 다음과 같다. 첫째, 학생들의 제시한 수학 은유 표현은 긍정형이 27%, 부정형이 42%, 혼재형이 27%로 부정형 표현을 가장 많이 제시하였다. 특히, 계열별 분석에서는 인문사회계열과 공학계열의 학생들은 부정형 표현이 긍정형에 비하여 2배 정도 높았지만, 자연계열 학생들의 경우에는 반대로 긍정형 표현이 부정형에 비하여 2배 정도 높은 비율을 보였다. 둘째, 수학에 대한 선호시기와 이유를 묻는 질문을 한 결과, 초, 중, 고등학교로 진급할수록 수학에 대한 선호 비율이 높아졌다. 당시 수학을 선호했던 이유로는 성적 요인과 정의적 요인이 높은 비율을 보였다. 셋째, 수학 비선호 시기와 이유에 대한 질문 결과를 보면, 마찬가지로 초, 중, 고등학교로 진급할수록 수학에 대한 비선호 비율이 높아졌다. 그 이유로는 수학 학습 내용의 난이도가 갑자기 높아졌다는 내용적 요인과 성적 요인을 제시한 경우가 많았다.

• 상하수도학회지
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• 제20권1호
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• pp.147-155
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• 2006

For the further study of the solids flux theory, several researchers have proposed models to predict sludge settling velocity for each different concentration by using sludge indexes, SVI, SSVI and $SSVI_{3.5}$. It is difficult to apply the above models to predict sludge-water interface height in a batch column because sludge settling velocity changes while sludge settle down. While sludge settle down in a batch column, sludge concentration becomes high. The sludge concentration change is one of the most critical causes of the change of sludge settling velocity. Also, sludge concentration change causes of sludge index to change. SVI is more sensitive than SSVI or $SSVI_{3.5}$ to the change of sludge concentration. Each sludge has physical characteristics of its own which makes the settling velocity for each sludge different. The purpose of this study is to establish the correction factors that are able to compensate the errors derived from each different sludge settling characteristic by using sludge indexes, therefore the correction factors are applicable to the model for the change of sludge-water interface height.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2567-2570
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• 2013

Background: This study analyzed Surveillance, Epidemiology and End Results (SEER) data to assess if socio-economic factors (SEFs) impact on endometrial cancer survival. Materials and Methods: Endometrial cancer patients treated from 2004-2007 were included in this study. SEER cause specific survival (CSS) data were used as end points. The areas under the receiver operating characteristic (ROC) curve were computed for predictors. Time to event data were analyzed with Kaplan-Meier method. Univariate and multivariate analyses were used to identify independent risk factors. Results: This study included 64,710 patients. The mean follow up time (S.D.) was 28.2 (20.8) months. SEER staging (ROC area of 0.81) was the best pretreatment predictor of CSS. Histology, grade, race/ethnicity and county level family income were also significant pretreatment predictors. African American race and low income neighborhoods decreased the CSS by 20% and 3% respectively at 5 years. Conclusions: This study has found significant endometrial survival disparities due to SEFs. Future studies should focus on eliminating socio-economic barriers to good outcomes.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.121-129
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• 1999

Recently, the regulations from the govemment and the concems of the people give rise to the interest in exhaust noise of passenger car as much as other vehicles. The exact analysis of various mufflers is needed to reduce the level of exhaust noise. In this paper, we propose a design to improve the mufflers capacity by reducing noise of exhaust system combining Taguchi method and fractional factorial design. In order to measure the performance of a muffler, the performance prediction software which is developed by the Dept. of Automotive Engineering at Hanyang University is used. From the current muffler system we select control factors such as lenght and radius of each component that are thought to be effective on capacity of muffler. Factors are arranged using L18, L27 table of orthogonal array and the fractional factorial design for analysis. We find some significant interaction effects using 1/3 fractional factorial design and accomplish the reduction of noise from the muffler.

• 한국건설관리학회논문집
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• 제5권4호
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• pp.147-154
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• 2004

Project value can be increased by implementing the most suitable one or more Value Management Processes (VMP). For the past decades, a variety of innovative management processes have been increasingly introduced into the construction industry. Each VMP is considered to be significantly beneficial for capital facility projects to proactively achieve one or more project value objectives. This paper covers the compilation of the 44 VMPs and provides their leveraging project characteristics that require the implementation of one or more VMPs. The results of data collection establish relative importance between the VMPs and the project characteristic factors in collaboration with 51 experts from both industry and academia. In the lack of industry awareness of both VMPs and their causal factors, the results of this study can facilitate the implementation of the VMPs and ultimately enhance the value of a particular capital project.