• 한국항공우주학회지
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• 제45권7호
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• pp.550-557
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• 2017

GNSS 측위 정확도에 영향을 주는 전리층 오차는 전리층에 존재하는 전자로 인해 위성의 전파가 굴절됨에 따라 발생하는데 태양활동 정도, 지역, 시간에 따라 그 값이 변한다. 정밀한 전리층 오차 추정이 가능한 이중주파수 수신기와 달리 단일 주파수 수신기의 경우에는 전리층 오차 모델이나 인근 고정기준국을 통해 제공 받는 의사거리 보정정보에 의존해야 한다. 하지만 일반적인 전리층 오차 경향과 달리, 국지적으로 전리층 총 전자수의 급격한 변화가 발생하는 경우 전리층 오차모델을 통한 오차 보정이 어려우며 만약 전리층의 변화가 고정기준국 상공의 전리층과 상이하다면, 의사거리 보정정보를 이용하여도 전리층 오차를 보정하지 못한다. 본 논문에서는, 이런 위험에 대처하기 위한 국지적 전리층 이상 현상에 대한 감시 기법에 대해 제안하고 실제 전리층 이상 현상이 발생한 데이터를 이용해 이를 검증하였다. 제시된 기법을 통해 전리층 이상 현상 발생 여부를 파악하고 단일 주파수 수신기 사용자의 항법해에 대한 신뢰도를 증가시킬 수 있을 것이다.

• 대한기계학회논문집A
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• 제41권2호
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• pp.149-156
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• 2017

핵연료는 고도의 신뢰성과 안전성이 요구되는 구조물로서 손상유발 이물질이 유입되지 않도록 이물질여과 기구를 포함하고 있다. 핵연료의 이물질여과 성능은 건전성에 가장 중요한 영향 인자로 합리적이고 객관적으로 평가되어야 하는 지표이다. 본 연구에서는 표준 여과효율 성능지수를 수립하고자 가중평균을 이용하여 종합 이물질여과 효율 계산 방법을 제시하였다. 제안된 방법의 적합성을 확인하기 위해 대표 이물질 시편을 선정하고 이물질여과 실험을 통해 가중평균 여과 효율을 산술평균 여과 효율과 비교하였다. 가중평균법은 성능의 변별력을 강화하고자 이물질의 통과 가능 정도를 가중인자로 사용하였다. 부가적으로 이물질 시편의 크기와 여과 기구의 주요 치수에 따른 상용 핵연료의 여과 거동 분석을 수행하였다.

• 산업기술연구
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• 제30권B호
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• pp.125-135
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• 2010

The influences on water quality of each river by effluents from environmental facilities $located^{*}$ in 14 unit watersheds of North- and South-Han River, and Gyungan-cheon were analyzed. Also, the water quality modeling for study area was carried out to analyze the improvement effect of water quality by the strengthening of T-P effluent standard of environmental facilities. For the calibration and verification of model, water quality data and effluent loading calculated for 2006 were used. Data of low water period were used for calibration, and normal water period for verification. The results of calibration and verification were well matched with the real water quality dataset of revers. Also, the validity of the results were estimated using RI (Reliability Index) method. When the T-P effluent standards for environmental facilities were strengthened, T-P concentrations were predicted to improve from $0.025mg/{\ell}$ to $0.023mg/{\ell}$ in the outlet location of North-Han River, from $0.056mg/{\ell}$ to $0.040mg/{\ell}$ for South-Han River,and from $0.233mg/{\ell}$ to $0.146mg/{\ell}$ for Gyungan-cheon. Also, the T-P concentrations of tributaries including Jojong-cheon, Dal-cheong, Sumgang, Chungmi-cheon, Bokha-cheon, Heuk-cheon, and Wonju-cheon were predicted to improve from $0.063mg/{\ell}$ to $0.010mg/{\ell}$, from $0.091mg/{\ell}$ to $0.053mg/{\ell}$, from $0.199mg/{\ell}$ to $0.100mg/{\ell}$, from $0.168mg/{\ell}$ to $0.148mg/{\ell}$, from $0.186mg/{\ell}$ to $0.105mg/{\ell}$, from $0.019mg/{\ell}$ to $0.013mg/{\ell}$, and from $0.822mg/{\ell}$ to $0.236mg/{\ell}$, respectively.

• 대한안전경영과학회지
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• 제16권1호
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• pp.119-127
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• 2014

This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< $18.5^{\circ}$), medium risk($18.5^{\circ}{\sim}36.0^{\circ}$), high risk(> $36.0^{\circ}$), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.

• 대한조선학회논문집
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• 제38권1호
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• pp.116-122
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• 2001

본 논문에서는 화재안전공학에서 사용되는 모델링 기법과 통계자료들을 검토하고 구조 신뢰성 분야의 확률론적 안전도 평가방법을 도입하여 선박에 대한 방화설계나 선급 규정을 정량적으로 평가하는 방법을 마련하였다. 본 논문에서 개발된 FSEM(Fire Safety Evaluation Module)은 화재안전도의 척도로서 마지막으로 대피하는 사람의 사망확률을 산정하는 프로그램이며, 이를 이용해서 규정에 의한 방화설비를 갖춘 소규모의 화재실에서 대피자에 대한 사망확률을 추정해 보았고, 민감도 해석을 통해 선박에 대한 정량적인 화재안전 평가에의 적용가능성을 검토해 보았다. 계산결과와 검토로부터 선박화재에 대한 새로운 설계지표와 대피상황에서의 인간행동에 대한 폭넓은 연구의 필요성 및 선박의 특수 상황을 고려할 수 있는 새로운 화재진척 모델에 대한 개발이 수행되어야 함을 제시하였다.

• 융합정보논문지
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• 제10권6호
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• pp.35-40
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• 2020

미래 사회로 접어들면서, 건강한 삶의 증대를 위한 노력은 현대인들의 주요 관심 분야이다. 특히, ICT 기술과 경쟁력 있는 의료산업 환경을 융합하여 건강한 삶을 위한 기술 개발은 차세대 성장 동력으로 자리잡고 있다. 따라서, 본 논문에서는 건강 검진 프로세스에서 검진 결과에 대한 인공지능 기반의 데이터 분석을 적용하여 종합 판정의 신뢰성을 향상시킬 수 있는 지식 베이스 모델링을 구축하는 연구를 수행하였다. 이를 위해, 딥러닝 분석을 통한 알고리즘을 설계하여 검사 결과지수를 산출, 검증하고, 판정 지식을 통한 종합 검진 정보를 제공하는 모델링을 연구하였다. 제안한 모델링의 적용을 통해, 국민 건강에 대한 빅데이터 분석, 활용이 가능하여 의료비 절감 및 건강 증대의 효과를 기대할 수 있다.

• 산업경영시스템학회지
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• 제39권1호
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• pp.37-46
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• 2016

Quality has been a key issue to manufacturers. Many distinguished scholars have defined quality with profound insight. Korean firms struggle to make better products to fulfil requirements and satisfy customers. Korean industries have implemented quality management from Japan in early 70s. Statistical quality control, QCC (Quality Control Circle), and total quality management have also been introduced in succession. Chief executive officers, managers, and field employees have been aware of the importance of quality since then. This quality movement force workers to improve quality. They have to maintain the quality of products and compete with foreign products. Korean industries were able to compete with foreign industries in price. However, Korean firms now have to compete in quality as well as price. ISO (International Organization for Standardization) was established and industries around world have started to implement standardized systems depending on their need. ISO 9000 has continuously been revised and firms around world started to register a ISO 9000 certificate. Today's quality competitiveness gets more deeply involved. KSA (Korean Standard Association) have launched QCAS (Quality Competitiveness Assessment System) since 1997. Up until now recent status of QCAS have been reported but the characteristics of QCAS results have not been analyzed. In this article we examine the QCAS results of 41 firms in 2014. QCAS consisted of 13 subsections : strategy and management system, organization culture and development of human resource, information management, quality system, customer satisfaction, management achievement, TPM, logistics, product development and technology, PL, QCC, SQC/SPC, and reliability. We performed one way ANOVA to discover the difference among the levels of firm size, business type, and quality hall of fame using the total scores of 13 subsections resulted from QCAS. We also analyzed the scores of 13 individual subsections of QCAS to see if there is any differences based on firm size and business type. We interpret the results and implication of analysis and finally draw a conclusion.

• 동의생리병리학회지
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• 제26권6호
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• pp.823-833
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• 2012

Now a days, number of non alcoholic fatty liver patients are increasing more rapidly compare to past rate, and the average age of patients is getting younger, but there are no appropriate therapeutics in non alcoholic fatty liver disease. This study was aimed to analyze relationship between non alcoholic fatty liver disease and Injinho-tang. The papers were collected and analysed from domestic and international journals. The effects of Injinho-tang and constituent-herb were researched. Non-alcoholic fatty liver disease was induced complex causes of the metabolic syndrome. Medications that can be used in non-alcoholic fatty liver disease, it should be have many effects such as anti-hepatic fibrosis, hepatocyte protection, liver cancer inhibitory effect, inflammatory cytokine regulation, improving hyperlipidemia, weight control, decrease the toxicity of the drug, antioxidant. Injinho-tang (Artemisia capillaris Thunb, Gardenia fructus, Rhei rhizome) has been widely used in disease that causes jaundice and liver biliary disease. Drugs for standardization of Injinho-tang index components(6,7-Dimethylesculetin, geniposide, rhein) have been presented. And Injinho-tang has been proven reliability in the administration of single dose toxicity. Also clinical stability in the administration of four years was reported. Injinho-tang has been reported some effects which anti-hepatic fibrosis, hepatocyte protection, liver cancer inhibitor, inflammatory cytokine regulation, improving hyperlipidemia, weight control, decrease the toxicity of the drug, and antioxidant. Therefore, Injinho-tang can be used in Non alcoholic fatty liver disease without Syndrome Differentiation.

• 한국과학교육학회지
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• 제14권2호
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• pp.225-235
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• 1994

Concidering environmental education as an ultimate resolution for environmental problems, we conducted a study focusing on affective matters. An instrument was developed to evaluate attitudes of elementary and middle school students toward environmental problems. To develop a reliable Likert-type evaluation instrument scale with which emotional intensity could be judged, mean, standard deviation, response frequency distribution, discrimination index, reliability were calculated. As a result, 21 statements for recognition level and 14 statements for behavioral level were made(The Cronbach alpha coefficient of the instrument was .786). This instrument was used to evaluate 5th and 6th grade elementary school students and 1st and 2nd grade middle school students(total number of subjects was 980). The result of this survey can be summarized as follows. 1. Students recognized the seriousness of environmental problems but they did not behave in such a manner as to prevent it. 2. As a result of t-test, behavioral level score of elemenatary school students was significantly higher than that of middle school students(p<.001). 3. This study showed that there was a significant correlation between the recognition level score and the behavioral level score(r=.386, p<.001). 4. Two-Way ANOVA was used to analyze that there was any significant difference according to grade and sex. The results were as follows. (1) No significant difference was found in total score. (2) On recognition level, female students' score was signigicantly higher than that of male students(p<.01). (3) On behavioral level, higher-grade students' score was lower than that of lower-grade-students (p<.001).

• 한국터널지하공간학회 논문집
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• 제5권3호
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• pp.241-250
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• 2003

암반은 그 특성상 매우 불균질하며, 조사 및 시험을 통하여 얻을 수 있는 자료는 아주 한정적이다. 이러한 이유 때문에 암반 중에 구조물을 구축하는 작업은 많은 불확실성 (uncertainties)을 내포하게 된다. 터널 설계에 있어서 주요 설계 파라미터인 지보패턴, 굴진장 및 굴착방법 등은 최적의 값으로 결정되어야 하나 그 결정이 쉽지 않으며, 결정을 잘못할 경우 원하지 않는 risk, 즉 터널 안정성의 저하 혹은 지보재의 지나친 보강으로 인한 경제적 손실을 발생시킨다. 본 연구에서는 터널설계 시 주요한 설계 파라미터인 지보패턴 및 굴진장을 위험도 분석 기법에 근거하여 결정하는 방법을 소개하였다. 지보량이 증가할수록 신뢰지수가 증가하여 터널의 안정성이 증가함을 정량적으로 확인할 수 있었으며, 터널의 붕괴 등으로 말미암아 발생할 수 있는 손실비용 및 공사비를 고려하여 위험도 분석을 실시함으로서 최적의 지보패턴 및 굴진장을 정량적으로 결정할 수 있었다.