• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.49-57
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• 2021

In the case of military supplies, any potential failure and causes of failures must be considered. This study is aimed at examining the failure modes of a rotorcraft landing system to identify the priority items. Failure mode and effects analysis (FMEA) is applied to the rotorcraft landing system. In general, the FMEA is used to evaluate the reliability in engineering fields. Three elements, specifically, the severity, occurrence, and detectability are used to evaluate the failure modes. The risk priority number (RPN) can be obtained by multiplying the scores or the risk levels pertaining to severity, occurrence, and detectability. In this study, different weights of the three elements are considered for the RPN assessment to implement the FMEA. Furthermore, the FMEA is implemented using a fuzzy rule base, similarity aggregation model (SAM), and grey theory model (GTM) to perform a comparative analysis. The same input data are used for all models to enable a fair comparison. The FMEA is applied to military supplies by considering methodological issues. In general, the fuzzy theory is based on a hypothesis regarding the likelihood of the conversion of the crisp value to the fuzzy input. Fuzzy FMEA is the basic method to obtain the fuzzy RPN. The three elements of the FMEA are used as five linguistic terms. The membership functions as triangular fuzzy sets are the simplest models defined by the three elements. In addition, a fuzzy set is described using a membership function mapping the elements to the intervals 0 and 1. The fuzzy rule base is designed to identify the failure modes according to the expert knowledge. The IF-THEN criterion of the fuzzy rule base is formulated to convert a fuzzy input into a fuzzy output. The total number of rules is 125 in the fuzzy rule base. The SAM expresses the judgment corresponding to the individual experiences of the experts performing FMEA as weights. Implementing the SAM is of significance when operating fuzzy sets regarding the expert opinion and can confirm the concurrence of expert opinion. The GTM can perform defuzzification to obtain a crisp value from a fuzzy membership function and determine the priorities by considering the degree of relation and the form of a matrix and weights for the severity, occurrence, and detectability. The proposed models prioritize the failure modes of the rotorcraft landing system. The conventional FMEA and fuzzy rule base can set the same priorities. SAM and GTM can set different priorities with objectivity through weight setting.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.6
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• pp.181-190
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• 2021

Sports activities conducted by multiple people are difficult to proceed in a situation where a widespread epidemic such as COVID-19 is spreading, and this causes a lack of physical activity in modern people. This problem can be overcome by using online exercise contents, but it is difficult to check detailed postures such as during face-to-face exercise. In this study, we present a model that detects posture and tracks movement using IT system for better non-face-to-face exercise content management. The proposed motion tracking model defines a body model with reference to motion analysis methods widely used in physical education and defines posture and movement accordingly. Using the proposed model, it is possible to recognize and analyze movements used in exercise, know the number of specific movements in the exercise program, and detect whether or not the exercise program is performed. In order to verify the validity of the proposed model, we implemented motion tracking and exercise program tracking programs using Azure Kinect DK, a markerless motion capture device. If the proposed motion tracking model is improved and the performance of the motion capture system is improved, more detailed motion analysis is possible and the number of types of motions can be increased.

• Journal of Digital Convergence
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• v.19 no.8
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• pp.319-325
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• 2021

With the advancement of wireless technology and the rapid growth of the infrastructure of mobile communication technology, systems applying AI-based platforms are drawing attention from users. In particular, the system that understands users' tastes and interests and recommends preferred items is applied to advanced e-commerce customized services and smart homes. However, there is a problem that these recommendation systems are difficult to reflect in real time the preferences of various users for tastes and interests. In this research, we propose a Fuzzy-AHP-based movies recommendation system using the Gated Recurrent Unit (GRU) language model to address a problem. In this system, we apply Fuzzy-AHP to reflect users' tastes or interests in real time. We also apply GRU language model-based models to analyze the public interest and the content of the film to recommend movies similar to the user's preferred factors. To validate the performance of this recommendation system, we measured the suitability of the learning model using scraping data used in the learning module, and measured the rate of learning performance by comparing the Long Short-Term Memory (LSTM) language model with the learning time per epoch. The results show that the average cross-validation index of the learning model in this work is suitable at 94.8% and that the learning performance rate outperforms the LSTM language model.

• Journal of the Daesoon Academy of Sciences
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• v.43
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• pp.179-209
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• 2022

In order to show the achievements of eminent monks who made great contributions to the spread and establishment of Buddhism in China, Huijiao (慧皎) compiled the Gaosengzhuan (高僧傳, Biographies of Eminent Monks) and set up ten subjects, the Shike (十科); meaning the ten rules for translating. The ten subjects served as an important framework for the Gaosengzhuan and its significance as a general history of Buddhism. This significance was further confirmed by the Xu-Gaosengzhuan (續高僧傳 The Continued Biographies of Eminent Monks), the Song-Gaosengzhuan (宋高僧傳 The Song Dynasty Biographies of Eminent Monks), and the Daming-Gaosengzhuan (大明高僧傳 The Great Ming Dynasty Biographies of Eminent Monks) which were compiled successively after the Gaosengzhuan. The ten subjects of the Gaosengzhuan underwent change in terms of the subject titles and their meanings in the subsequent versions of the Gaosengzhuan. In the Xu-Gaosengzhuan, Daoxuan (道宣) changed the titles of some subjects and added a new subject, and in the Song-Gaosengzhuan, Zanning (贊寧) gave new meanings to each subject without changing the ten subjects as they appeared in the earlier Xu-Gaosengzhuan. In the Daming-Gaosengzhuan, Ruxing (如惺) retained three of the subjects but removed seven. This evolution of formation and meaning in the ten subjects was the result of the author's deep recognition and also reflections on major changes and transitions in Buddhist history. Edification was emphasized in the Gaosengzhuan, self-discipline in the Xu-Gaosengzhuan, and wisdom and enlightenment were stressed in the Song-Gaosengzhuan. Ruxing showed that the collapse of the ten subjects reflected the decline of Buddhism. The fact that the ten subjects from each Gaosengzhuan were given different meanings demonstrates that these authors recognized Buddhist history differently. Therefore, it can be argued that the processing of Chinese Buddhist history has been reflected through each of their lens. But it is necessary to analyze and compare various aspects of each version of the Gaosengzhuan.

• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.57-70
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• 2008

The advantage of piezocone penetration test is a guarantee of continuous data, which is a source of reliable interpretation of target soil layer. Many researches have been carried out f3r several decades and several classification charts have been developed to classify in-situ soil from the cone penetration test result. Since most present classification charts or methods were developed based on the data which were compiled over the world except Korea, they should be verified to be feasible for Korean soil. Furthermore, sometimes their charts provide different soil classification results according to the different input parameters. However, unfortunately, revision of those charts is quite difficult or almost impossible. In this research a new soil classification model is proposed by using fuzzy C-mean clustering and neuro-fuzzy theory based on the 5371 CPT results and soil logging results compiled from 17 local sites around Korea. Proposed neuro-fuzzy soil classification model was verified by comparing the classification results f3r new data, which were not used during learning process of neuro-fuzzy model, with real soil log. Efficiency of proposed neuro-fuzzy model was compared with other soft computing classification models and Robertson method for new data.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.454-454
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• 2021

하천 환경에 대한 최근의 사회적 관심은 하천횡단구조물에 대한 평가를 기존의 이□치수적 관점에서 환경□생태학적 관점으로 변화시키고 있다. 이는 자연하천(특히 충적하천)이 수공구조물에 가로막히면 일반적으로 유사, 식생 등의 하천 제반 환경에 부정적인 영향을 준다는 전제에서 댐에 대한 평가가 시작되는 것으로, 국내에서는 이러한 인식의 변화가 2010년대 이후 널리 퍼지면서 현재는 더 이상 신규 댐을 건설할 수 없게 되었다. 댐에 의한 수리 특성과 기후 변화 등으로 댐 하류하천의 유사, 식생, 생태변화는 최근 급격하게 진행되었지만, 정량적인 변화량 및 지표 도출에 대한 연구는 대부분 최근의 data를 반영하지 못하고 있어 관련 원인과 대책 제시에 다소 한계가 있다고 생각된다. 이에 본 연구에서는 낙동강 주요 지류 중 하나이며, 충적하천인 황강을 대상으로 가용한 data를 활용하여, 합천댐 건설 전□후의 유사, 식생변화로 대표되는 하천 환경변화를 정량적으로 분석하고, 변화 원인을 파악하고자 하였다. 유사환경의 변화 분석은 댐 건설 전부터 최근까지의 문헌들에서 조사□제시된 data를 이용하였다. 연도별 최심 및 평균하상고는 댐 건설 전과 비교해 1.0 m가량 감소하였는데, 댐에 의한 세류사 공급차단보다는 골재 채취 및 하도 정비 등이 지배적인 원인인 것으로 파악되었다. 유사 입경의 변화는 댐 건설 전 대비 조립화가 진행되어 모래비율이 감소하고 유사 입경(댐 직하류 약 2배)이 증가하였다. 이는 골재 채취 및 댐에 의한 세류사 차단에 기인한 것으로, 준설된 지역의 하상이 모래 대신 자갈로 대체되고 있기 때문인 것으로 판단된다. 유사량의 경우 몇 번의 조사 과정이 있었으나, 기준이 명확하지 않아 정량적인 변화는 파악하기 어려웠다. 제외지의 식생 분포는 본 연구에서 개발한 이미지 처리 기법을 동원하여 분석하였으며, 대상은 합천댐 하류 중 모래 사주의 비율이 큰 곳을 선택(3지점)하였다. 분석 결과 2008~2011년 이전까지 큰 폭으로 사주가 식생 서식처로 변화(약 20%)되었으며, 이후 큰 변화 없이 안정화 된 경향을 보였다. 이는 2009~2011년 동안 식생이 활착되는 봄~초여름의 강우량 감소, 댐의 홍수조절 및 하상 조립화로 인한 다년생 식생의 활착되고 성장할 시간이 확보되면서 홍수 등 외부 변화에 대한 식생의 대응 능력이 증가했기 때문인 것으로 생각된다. 합천댐이 황강 환경변화에 주는 영향은 분명하지만, 현재 상황은 기후 변화와 인위적인 골재채취도 주요 원인으로 판단되는 바, 향후 하천 환경 개선 계획 수립 시 이러한 변화 원인이 고려된 대책이 수립되어야 할 것이다.

• Analytical Science and Technology
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• v.22 no.1
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• pp.44-50
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• 2009

In this study, the use of purge & trap GC-MS technique for determination of methylmercury in sediment samples was described. The method detection limit of the method was determined as 0.06 ng/g and the recovery of the method was $102{\pm}11.4%$, with precisions better than 11.2%. The method was validated by analysis of CRMs such as ERM CC580 (estuarine sediment) and IAEA 405 (sediment). Additionally, the performance of the method was tested on river sediment samples and the analytical results were compared with those of the GC-CVAFS, which has been widely used for methylmercury analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.35-45
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• 2009

In this study, a laboratory experiment has been performed on a S-curved channel with two curved sections. In the experiments, effects of 3-D velocity structures on mixing characteristics of tracer material were investigated. As a result, it was clearly noticed that the primary flow travels taking the shortest course of the meandering channel and has a very ununiform distribution at the bends. The secondary cell which was developing at the first bend disappears at the crossover, and then, at the next bend, secondary cell is re-developing in the opposite direction. The experimental results show that mixing of tracer is significantly affected by the combined action of ununiform primary flow and secondary cell. The ununiform primary flow separates the tracer cloud in the longitudinal direction, and the secondary cell further separates the retarding tracer cloud mainly in the transverse direction. As a result, these complex flow structures cause separation and spreading of tracer cloud both in the longitudinal and in the transverse directions. The measured dimensionless transverse dispersion coefficients calculated using 2-D routing procedure ranges 0.012-0.875, and is generally proportional to width to depth ratio (W/h). The predicted values calculated by the theoretical equation overestimate slightly the measured transverse dispersion coefficients.

• Korean Journal of Social Welfare Studies
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• v.41 no.2
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• pp.279-308
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• 2010

This study examines the association between family policies and family gap using data for 14 OECD countries. As family policies have different assumptions about women's roles and include variant sub-policies, this study identify two distinct family policies: 'employment support policy' to support women as employed workers and 'caregiving support policy' to support women as caregivers. Meanwhile, women's wage cannot be determined by the effect of 'only' family policy. Therefore, analysis model includes variant macro structure supposed to affect women's labor status and wage, like labor market structure, wage structure(compression), women's social status and economic status, and examines interaction effects between family policies and these labor market and social structures using Fuzzy-Set Qualitative Comparative Analysis (FSQCA). The FSQCA result shows that relatively low family gap is associated with the conjunctual causation of developed 'employment support policy' and compressed wage structure.

• Journal of the Daesoon Academy of Sciences
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• v.21
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• pp.29-97
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• 2013

뇌법은 도교의 중요한 법술로서 당송(唐宋)이래 매우 흥했는데, 북송의 임영소 등이 신소파(神霄派)를 개창한 이후에 도교 법문을 대표하는 영역이 되었다. 그로부터 각종의 뇌법이 천하에 성행하였고, 도교에는 새로운 뇌신들이 거듭 나타나게 되었다. 그 대표적인 것이 뇌법신앙의 구진천존(九宸天尊)인데, 이 아홉 천존들은 도교의 최고신인 삼청성조(三清聖祖)의 통치 하에 있는 것으로 간주되었다. 『옥추보경』은 북송 때 탄생하였는데 이 경전이 세상에 널리 발간되어 구천응원뇌성보화천존에 대한 신앙이 형성된 것은 남송 시기 백옥섬(白玉蟾) 이후이다. 『옥추보경』은 구천응원뇌성보화천존의 법문(法門)을 선양하기 위한 방책으로 천존의 성호를 부를 것을 권장한다. 법문을 염송하는 것은 매우 쉽고도 간단하여 누구나 할 수 있었으므로 사회적으로 크게 확대되었다. 특히 『봉신연의』와 『서유기』와 같은 문예소설에 뇌성보화천존이 등장함으로 해서, 민중들은 뇌성보화천존을 더욱 널리 숭배하게 되었다. 현재도 중국의 민간에서 이 신격에 대한 신앙은 매우 보편적이다. 구천응원뇌성보화천존은 옥청진왕(玉清真王)의 화신(化身)이다. 뇌성보화천존은 시방에 그 형체를 나타내고, 중생들을 고뇌로부터 구제하고 이끈다. 36천을 주재할 권능이 있으며, 자비로운 모습으로 모든 겁에 응한다. 또 뇌성보화천존의 주변에는 뇌공(雷公), 우사(雨師), 풍백(風伯)을 비롯한 십대원사(十大元帥)와 등백온원사(鄧伯溫元帥), 신한신원사(辛漢臣元帥) 등의 신장들이 보인다. 이러한 신장들은 양송(兩宋) 시대에 출현하였으며 대다수가 뇌부의 제신들이다. 뇌성보화천존 신앙을 구현하기 위한 재초 의식에는 천지 제신(諸神)이 강림하기를 청하는 뇌정사과(雷霆謝過)와 죄를 뉘우치고 복을 비는 참의(懺儀) 또는 참회문식(懺悔文式) 등이 있다. 이런 법식들은 매우 전문적인 것이고, 일반인들에게는 법문을 염송하는 간편한 방법인 십자천경법(十字天經法)이 널리 퍼졌다. 즉 늘 경건한 마음으로 천존의 성호를 오랫동안 염송하게 되면 공덕원만(功德圓滿)의 경지에 도달할 수 있다는 것이다. 『옥추보경』은 민중의 세계에 깊은 영향을 끼치고 광범위하게 알려져 그 주해나 주석본만도 이십여 종에 이르렀고 송원 이래의 핵심적인 도교 문헌의 하나로 자리매김하였다. 『옥추보경』은 일본과 한국 등지에도 급속히 전파되었다. 한국에는 고려시대에 신소뇌법(神霄雷法)이 전해졌는데, 특히 고려 예종 13년(1118년) 7월에 중국 도교 의학이 고려에 전승되었을 때의 도교 의학이 『옥추보경』을 위주로 한 치료법이었다. 그리고 그 흔적은 조선의 허준이 주편한 『동의보감』에서도 찾아볼 수 있다. 조선의 민간에서는 많은 사람들이 『옥추보경』을 송독하였고 거기에 수록된 부록(符籙)을 운용하였으며 이로써 병을 몰아내고 잡귀를 물리쳐 생명을 지키기를 바랐다. 현대 한국에서는 구천응원뇌성보화천존강성상제에 대한 신앙이 크게 성행하고 있으니, 그 종단이 바로 대순진리회이다. 대순진리회는 증산 성사께서 인세에 강림하시기 전에 구천대원조화주신이며, 화천 후 구천응원뇌성보화천존상제의 위에 임하였다고 신앙한다. 즉 증산이 천존상제의 화신이라 믿는 것이다. 이것과는 좀 다르지만, 인간이 신의 화신이 되는 신성한 변화를 뇌법에서는 '변신(變神)'이라고 부른다. 변신은 내련(內煉)을 행할 때나 시법(施法)시에 도인들이 필히 진입해야 할 특이한 정신 상태로서, 자아의 존재를 망각하고 신진(神真)으로 변화하여 인신합일(人神合一)을 이루는 것을 의미한다. 이러한 변신은 대순진리회의 수도 목적인 도통과도 한편으로는 유사한 면이 있다고 생각된다. 대순진리회가 목적하는 지상신선실현이 의미하는 것은, 사람이 도를 깨닫는 노력을 통해 신의 경지에 도달하는 것이 아니라 인간의 본질과 천성을 회복하여 이에 상응하는 신과 합일하는 것이라는 점에서 뇌법의 변신과 유사한 점이 있다고 할 것이며 이에 대해서는 추후 연구과제로 남겨둔다.