• 대한기계학회논문집A
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• 제37권11호
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• pp.1397-1405
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• 2013

본 연구에서 탑승자 머리 보호를 위한 센터 필라 트림의 리브 패턴 최적설계는 두 가지 방법에 의해 수행된다. 첫째는 실험계획법과 반응표면법을 이용한 근사최적화 기법으로써, 상대적으로 큰 비중을 차지하는 해석비용 저감을 위하여 근사모델 구성에 필요한 최소한의 해석만을 수행하고 실제 최적화 과정에는 구성된 모델을 이용함으로써 근사적으로 최적 점을 찾아가는 방법이다. 하지만 이러한 방법은 시행착오적인 반복과정을 거쳐야 하는 단점이 있다. 따라서 저자들의 선행연구에서 제안한 순차적 실험계획법과 인공신경망을 이용하여 인자의 상한 또는 하한에 걸리지 않는 근사최적 해를 체계적인 반복과정을 통해 도출하고자 하며, 이를 수학적인 예제와 구조물 문제에 적용함으로써 실용성을 확인하고자 한다.

• 한국의류학회지
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• 제28권6호
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• pp.723-733
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• 2004

This study was designed to find out the effects of country-of-origin and price on the perceived quality, perceived value and purchase willingness of t-shirt products. This study will allow marketers to find the target consumers and to choose both the suitable country -of -origin and the reasonable selling price. This study was based on theoretical and empirical methods. For the empirical methodology, 3${\times}$3 between subjects factorial design with country-of-origin (U.S.A. vs. Korea vs. China) and price(high price vs. middle price vs. low price) was used. The nine types surveys by country-of-origin and price were transmitted to 960 undergraduate and graduate school students in Seoul. A total of 912 questionnaires were used in the final statistical analyses using factor analysis, MANOVA, Duncan test, and Tukey test. The results of this study were as follows: First, in the case of the perceived quality, participants evaluated t-shirt products better when the origin is U.S.A. followed by Korea and China in the order. Second, price affected the perceived value and purchase willingness. In the perceived value and purchase willingness, low priced t-shirt products were evaluated higher than the middle and high priced ones. Third, in the perceived quality, high priced Korean t-shirt products were evaluated lower than high and middle priced American t-shin products. In the perceived value, low priced Chinese t-shirt products were evaluated lower than middle priced Korean t-shirt products. In the purchase willingness, low priced American and low priced Korean t-shirt products and middle priced Korean t-shirt products were evaluated higher than all priced Chinese t-shirt products.

• 환경영향평가
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• 제9권3호
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• pp.203-214
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• 2000

Health risk assessment is applied to streamlining LCA(Life Cycle Assessment) using Monte carlo simulation for probabilistic/stochastic exposure and risk distribution analysis caused by data variability and uncertainty. A case study was carried out to find benefits of this application. BTC(Benzene, Trichloroethylene, Carbon tetrachloride mixture alias) personal exposure cases were assumed as production worker(in workplace), manager(in office) and business man(outdoor). These cases were different from occupational retention time and exposure concentration for BTC consumption pattern. The result of cancer risk in these 3 scenario cases were estimated as $1.72E-4{\pm}1.2E+0$(production worker; case A), $9.62E-5{\pm}1.44E-5$(manger; case B), $6.90E-5{\pm}1.16E+0$(business man; case C), respectively. Portions of over acceptable risk 1.00E-4(assumed standard) were 99.85%, 38.89% and 0.61%, respectively. Estimated BTC risk was log-normal pattern, but some of distributions did not have any formal patterns. Except first impact factor(BTC emission quantity), sensitivity analysis showed that main effective factor was retention time in their occupational exposure sites. This case study is a good example to cover that LCA with probabilistic risk analysis tool can supply various significant information such as statistical distribution including personal/environmental exposure level, daily time activity pattern and individual susceptibility. Further research is needed for investigating real data of these input variables and personal exposure concentration and application of this study methodology.

• 디지털융복합연구
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• 제14권4호
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• pp.277-283
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• 2016

본 논문에서는 가중 퍼지소속함수 기반 신경망(neural network with weighted fuzzy membership functions; NEWFM) 기반의 웨이블릿 변환(wavelet transform)과 힐버트 변환(Hilbert transform)에 의해 추출한 첨점(peak)을 사용하여 뇌파(EEG)로부터 정상 파형과 간질 파형을 분류하는 새로운 방안을 제안하였다. NEWFM의 입력을 추출하는데 다음과 같은 3개의 단계가 수행되었다. 첫 번째 단계에서는 뇌파로부터 잡음을 제거하기 위해서 웨이블릿 변환을 사용하였다. 두 번째 단계에서는 웨이블릿 계수로부터 첨점(peak)을 추출하기 위해서 힐버트 변환을 사용하였다. 또한 크기가 큰 첨점을 추출하기 위해서 첨점의 평균값보다 큰 첨점만을 선택하였다. 세 번째 단계에서는 통계적 방법을 이용하여 첨점으로부터 NEWFM의 입력으로 사용할 16개의 특징을 추출하였다. NEWFM은 이들 16개의 특징을 입력으로 사용하여 99.25%, 99.4%, 99%의 정확도, 특이도, 민감도를 각각 구하였다. 향후 연구에서는 특징선택을 이용하여 16개의 특징으로부터 좋은 특징을 선택하여 정확도를 향상시킬 계획이다.

• Journal of Radiation Protection and Research
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• 제39권4호
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• pp.176-181
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• 2014

The object of this paper is to evaluate the fission product inventories and radiological doses in a non-LOCA event, based on the U.S. NRC's regulatory methodologies recommended by the TID-14844 and the RG 1.195. For choosing a non-LOCA event, one fuel assembly was assumed to be melted by a channel blockage accident. The Hanul nuclear power reactor unit 6 and the CE $16{\times}16$ fuel assembly were selected as the computational models. The burnup cross section library for depletion calculations was produced using the TRITON module in the SCALE6.1 computer code system. Based on the recently licensed values for fuel enrichment and burnup, the source term calculation was performed using the ORIGEN-ARP module. The fission product inventories released into the environment were obtained with the assumptions of the TID-14844 and the RG 1.195. With two kinds of source terms, the radiological doses of public in normal environment reflecting realistic circumstances were evaluated by applying the average condition of meteorology, inhalation rate, and shielding factor. The statistical analysis was first carried out using consecutive three year-meteorological data measured at the Hanul site. The annual-averaged atmospheric dispersion factors were evaluated at the shortest representative distance of 1,000 m, where the residents are actually able to live from the reactor core, according to the methodology recommended by the RG 1.111. The Korean characteristic-inhalation rate and shielding factor of a building were considered for a series of dose calculations.

• 해양환경안전학회지
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• 제13권1호
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• pp.55-60
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• 2007

해월송전선의 해상고에 의하며 선박의 항로가 제한되는 해역에 있어서, 해월송전선에 관하여 현재 알 수 있는 정보는 아주 제한적인데, 주어진 정보를 토대로 송전선철탑들 사이의 임의의 위치에서도 해월송전선의 해상고를 알아낼 수 있는 방법을 제시하였다. 그리고 해월송전선의 하부를 선박이 항해할 경우의 안전성을 평가할 수 있는 방법론적 모델을 제시하였다. 실제 표본선박이 항해한 궤적을 조사하여 통계처리를 한 결과, 선박이 안전통항구간을 벗어날 확률은 약 0.00001 정도로 밝혀졌다. 따라서 네델란드 응용과학연구소의 보고서에 의한 안전기준(항만 내, 방파제 입구 부근에서는 0.0001 이하이면 안전하다고 판단.)보다 10배 정도 더 안전하다고 판단된다.

• 멤브레인
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• 제12권2호
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• pp.90-96
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• 2002

멤브레인 여과 실험에서 얻어진 데이터 처리에 간단한 수치해석을 적용하여 삼투압(osmotic pressure) 과 구배확산계수(gradient diffusion coefficient)를 도출하는 새로운 방법론을 제시하였다. 삼투압과 구배확산계수는 이론 및 실험적으로 쉽게 구할 수 없는 물리적 특성치로서 멤브레인 여과의 특성 규명에 중요하다. 모델 라텍스 콜로이드의 여과시간에 따른 투과플럭스(permeate flux) 값과 이에 대한 수치적분과 수치미분 데이터로부터 분산된 입자농도의 함수인 삼투압 관계식을 구했다. 이로부터 계산된 열역학적 계수(thermodynamic coefficient)는 입자농도가 증가할수록 감소하는 거동을 보였고, 여기에 기존에 제시되어 있는 수력학적 계수(hydrodynamic coefficient)를 도입하여 구배확산계수를 산출하였다. 아울러, 본 연구에서 계산된 입자농도에 따른 구배확산계수의 결과와 동일한 멤브레인과 라텍스 콜로이드의 여과에 대해서 기존에 통계역학적 시뮬레이션으로 예측한 결과를 비교하였다.

• 한국콘텐츠학회논문지
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• 제10권12호
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• pp.415-424
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• 2010

최근 지방과 국가차원에서 관광산업의 일환으로 전통음식의 개발을 시도하고 있다. 전통음식은 지역의 전통, 역사와 특성, 문화를 구성하는 중요요소로 새롭게 강조되고 있다. 본 연구는 전통음식을 관광자원개발로 연결하고자 하는 목적으로 수행되었다. 전통음식과 관련하여 1985년부터 2009년까지 출판된 연구 129개를 대상으로하여 연구시기와 저자, 연구비지원과 연구내용의 동향, 조사대상과 지역, 연구형식과 분석기법의 동향을 중심으로 분석하였다. 연구결과는 다음과 같다. 첫째, 저자관련분석으로 단독연구가 40.3%, 공동연구가 59.7%로 나타났고 지속적으로 단독연구가 많아지고 있으며, 둘째, 선호도와 인식과 관련한 분야에 대한 연구가 39%로 높게 나타나 향후, 메뉴개발이나 실태조사 등과 관련한 연구를 통한 상품화와 자원화에 대한 연구의 필요성을 알 수 있었다. 셋째, 연구대상을 학생으로 한 연구가 24%로 나타나 관광객과 외국인에 대한 연구의 필요성이 제기되었고, 넷째, 현재 57.4%에 이르는 설문지연구가 지속적으로 증가하고 있어 다양한 연구방법을 이용한 연구가 수행되어야 할 필요성이 제기되며, 중앙정부 및 지방자치단체와 관련 산업체를 중심으로 하는 연구 지원 등이 수행된다면 학계의 연구결과가가 산업현장에 기여할 수 있게 될 것이며, 이는 지속적인 학문적 노력과 연구를 통하여 가능하게 될 것이다.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.960-967
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• 2011

Tannin acyl hydrolase, also known as tannase, is an enzyme with important applications in the food, feed, pharmaceutical, and chemical industries. However, despite a growing interest in the catalytic properties of tannase, its practical use is very limited owing to high production costs. Several studies have already demonstrated the advantages of solid-state fermentation (SSF) for the production of fungal tannase, yet the optimal conditions for enzyme production strongly depend on the microbial strain utilized. Therefore, the aim of this study was to improve the tannase production by a locally isolated A. niger strain in an SSF system. The SSF was carried out in packed-bed bioreactors using polyurethane foam as an inert support impregnated with defined culture media. The process parameters influencing the enzyme production were identified using a Plackett-Burman design, where the substrate concentration, initial pH, and incubation temperature were determined as the most significant. These parameters were then further optimized using a Box-Behnken design. The maximum tannase production was obtained with a high tannic acid concentration (50 g/l), relatively low incubation temperature ($30^{\circ}C$), and unique low initial pH (4.0). The statistical strategy aided in increasing the enzyme activity nearly 1.97-fold, from 4,030 to 7,955 U/l. Consequently, these findings can lead to the development of a fermentation system that is able to produce large amounts of tannase in economical, compact, and scalable reactors.

• Journal of Acupuncture Research
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• 제18권6호
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• pp.35-43
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• 2001

Objective : The purpose of this study is to examine the reason of choosing acupuncture and moxibustion at first and the change of preference along with the improvement of the causes of avoiding acupuncture and moxibustion. Methods : As for the methodology of the research, we had a questionnaire survey of the freshmen at Dongguk University in 2000. Out of 3095 freshmen, 2158 students (1170 males and 988 females) replied to the questionnaire and statistical analysis was carried out mainly on the items answered by the respondents. Comparison between groups concerning acupuncture and moxibustion treatment utilized x 2 test. Results : The results of the research are as follows: 1. The most frequent reason of choosing acupuncture and moxibustion initially was that it seemed to be effective, and the second reason was that they were encouraged by acquaintances. 2. The most frequent reason of revisiting acupuncture and moxibustion was that it was proved effective, and the second reason was that it did not induce pains. 3. The most frequent reason of not revisiting acupuncture and moxibustion was it was proved ineffective, and the second reason was that it induced pains. A large part of the respondents who did not revisit said they would do if the reasons of not revisiting were improved. Conclusion : The reasons of choosing acupuncture and moxibustion initially and revisiting appear to be closely related to the efficacy of acupuncture. It was shown that whether it was painful was also a crucial factor in the decisions. Based on the results, we consider that it is required to develop acupuncture manipulations that enhance the efficacy and reduce pains, as well as to invent various innovative acupuncture and moxibustion techniques and instruments.