• 한국터널지하공간학회 논문집
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• 제10권3호
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• pp.207-219
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• 2008

도심지내 굴착공사는 기존 지하구조물의 근접시공의 시계가 증가하는 추세이다. 근접시공에 따른 터널의 안정성은 가이드라인이 제시되어 있으나, 굴착공사에서 유발되는 발파신동이 터널구조물에 미치는 영향에 대한 연구는 미미한 실정이다. 본 연구는 국내외의 터널 안전영역 기준과 발파진동의 허용기준을 검토하고 진동가이드라인을 추정하기 위하여 수치해석적인 방법을 사용하여 수행하였다. 해석에 사용된 발파하중은 이론식인 International Society of Explosive Engineers(2000) 제안식을 이용하여 폭굉압력(detonation pressure)을 산정하였고 해석 모델은 서울지하철을 대상으로 하였다. 실제발파현장에 인접한 지하철 구간의 진동계측치를 수치해석결과와 비교하여 수치해석의 적정성을 검토하였다. 동적수치해석 결과 라이닝의 절점에 작용하는 진동속도의 영향원으로부터 허용값을 만족하는 영역을 제시하였다.

• 한국기계가공학회지
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• 제11권3호
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• pp.55-61
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• 2012

The structure of winch brake disk was successfully designed and developed based on sizing optimization. In this research, static analysis was performed by commercial software ANSYS v12.0. To simulate the working process of disk brake, the real properties of materials and working conditions were considered. Based on the results of the static structural analysis, the existing designs of the brake discs were optimized. Among existing designs, there are three cases that have achieved an efficient light weight around 200g. As a result, the optimized weight of each case was 3.41kg, 3.42kg, and 3.44kg, respectively. Finally, through prototyping and performance testing, the stability of the optimized brake disc was verified. Although, this free-fall winch brake disk had been developed in design and evaluation techniques, more detailed plans for developing the disk brake structure were also proposed as a further study based on this research.

• Structural Monitoring and Maintenance
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• 제10권3호
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• pp.243-260
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• 2023

Indonesia has had seismic codes for earthquake-resistant structures designs since 1970 and has been updated five times to the latest in 2019. In updating the Indonesian seismic codes, seismic hazard maps for design also update, and there are changes to the Peak Ground Acceleration (PGA). Indonesian seismic design uses the concept of building performance levels consisting of Immediate occupancy (IO), Life Safety (LS), and Collapse Prevention (CP). Related to this performance level, cases still found that buildings were damaged more than their performance targets after the earthquake. Based on the above issues, this study aims to analyze the performance of base isolation design on existing target buildings and analyze the seismic fragility for a case study in Indonesia. The target building is a prototype design 8-story medium-rise residential building using the reinforced concrete moment frame structure. Seismic fragility analysis uses Incremental Dynamic Analysis (IDA) with Nonlinear Time History Analysis (NLTHA) and eleven selected ground motions based on soil classification, magnitude, fault distance, and earthquake source mechanism. The comparison result of IDA shows a trend of significant performance improvement, with the same performance level target and risk category, the base isolation structure can be used at 1.46-3.20 times higher PGA than the fixed base structure. Then the fragility analysis results show that the fixed base structure has a safety margin of 30% and a base isolation structure of 62.5% from the PGA design. This result is useful for assessing existing buildings or considering a new building's performance.

• Journal of Korea Trade
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• 제27권1호
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• pp.176-191
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• 2023

Purpose - When recovered through arbitration a contractual penalty that is disproportionately high can become grounds for challenging an arbitral award or an obstacle to its enforcement within Russian jurisdiction. This article investigates how violation of the principle of proportionality can affect the enforcement and challenging of arbitral awards in Russia. Based on the examination of the current legislation, along with the analysis of recent court cases on the subject, the ultimate object of this article is to discern practical recommendations for Korean practitioners who are looking to challenge and/or enforce arbitral awards in Russian courts. Design/methodology - The research process included the reviewing of current Russian legislation conducted in concurrence with academic literature review, searching and analyzing recent court cases where the relevant legal provisions and concepts were applied, and formulating practical implications of the research at its final stage. Findings - Through its relation to the principle of fairness/justice the authors establish the connection between the principle of proportionality and the public policy of Russia. Analysis of recent court cases showed two conflicting trends of whether a disproportionate penalty can be considered a public policy violation. The authors offer practical recommendations on how to substantiate a relevant claim regarding contractual penalty reduction by the court, depending on the desired outcome. Originality/value - The article contains an up-to-date summary of the legal provisions on the principle of proportionality of civil liability in Russia and identifies the most recent trends in court practice on the issue that is not covered by existing studies.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.597-598
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• 2015

In order to improve the reliability of cost estimation results using CBR, there has been a continuous issue on similarity measurement to accurately compute the distance among attributes and cases to retrieve the most similar singular or plural cases. However, these existing similarity measures have limitations in taking the covariance among attributes into consideration and reflecting the effects of covariance in computation of distances among attributes. To deal with this challenging issue, this research examines the weighted Mahalanobis distance based similarity measure applied to CBR cost estimation and carries out the comparative study on the existing distance measurement methods of CBR. To validate the suggest CBR cost model, leave-one-out cross validation (LOOCV) using two different sets of simulation data are carried out. Consequently, this research is expected to provide an analysis of covariance effects in similarity measurement and a basis for further research on the fundamentals of case retrieval.

• 산경연구논집
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• 제9권10호
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• pp.63-72
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• 2018

Purpose - This thesis is to develop a management plan and checklist by analyzing the prevention of accidents in advance by presenting the management plan for the major causes of railway accidents. Research design, data and methodology - In recent 5 years, we have analyzed the cases of railway accident, presented the management plan for the accident, and made a practical safety checklist focusing on the main measures according to the management plan. Results - The analysis of the cases of near-railway accidents suggests more concrete and practical safety management measures because the similar accidents are continuously occurring due to formal safety management. Conclusions - It is more valuable to apply to the adjacent construction of the railway line by creating a detailed checklist based on cases rather than the existing checklist. This study is written only as a human factor. For future real - time safety management, it is necessary to study more precisely cause analysis and safety equipment as a big data - based safety control system for more systematic safety management.

• 대한기계학회논문집A
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• 제29권12권
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• pp.1605-1614
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• 2005

For the last four decades, tension test of notched bars has been performed to investigate the effect of stress triaxiality on ductile fracture. To quantify the effect of the notch radius on stress triaxiality, the Bridgman equation is typically used. However, recent works based on detailed finite element analysis have shown that the Bridgman equation is not correct, possibly due to his assumption that strain is constant in the necked ligament. Up to present, no systematic work has been performed on fully plastic stress fields for notched bars in tension. This paper presents fully plastic results for tension of notched bars and plates in plane strain, via finite element limit analysis. The notch radius is systematically varied, covering both un-cracked and cracked cases. Comparison of plastic limit loads with existing solutions shows that existing solutions are accurate for notched plates, but not for notched bars. Accordingly new limit load solutions are given for notched bars. Variations of stress triaxiality with the notch radius and depth are also given, which again indicates that the Bridgman solution for notched bars is not correct and inaccuracy depends on the notch radius and depth.

• 한국지반환경공학회 논문집
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• 제21권6호
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• pp.19-25
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• 2020

최근 도심지 공사에 있어서는 공간부족 및 주변환경의 영향으로 기성파일의 시공이 불가능한 경우가 많다. 이러한 경우에 소형 장비로 시공이 가능하고 기존 파일의 지지능력을 발휘할 수 있는 소구경 파일 공법이 많이 사용되고 있다. 소구경 파일공법은 현장타설말뚝의 한 종류로서 파일의 직경이 75mm~300mm인 정도로 주변 구조물이나 지반 그리고 공간적인 장애물이 있는 경우에도 시공의 어려움이 거의 없으며 모든 종류의 토질조건에서 시공이 가능하다. 또한 시공과정에서 진동과 소음이 적고 건물 천장이 낮은 곳에서도 시공이 가능하므로 기존 건물의 기초보강에도 많이 이용된다. 이러한 마이크로파일이 압축력이나 인장력을 받았을 때 혹은 시공된 지반특성에 따라 변화되는 거동 특성에 대해서는 연구가 많지 않은 실정이다. 따라서 이 연구에서는 현장에 시공된 마이크로파일에 대한 현장재하시험 자료 분석을 통하여 마이크로 파일에 압축력 및 인장력을 가했을 경우 지반을 구성하는 성분과 파일의 근입조건에 따른 침하 및 지지력 특성을 규명하고 통계분석프로그램인 SAS를 활용하여 마이크로파일의 침하와 지지력에 영향을 미치는 주요한 인자에 대한 분석을 수행하였다.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제12권9호
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• pp.381-386
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• 2023

기존의 다양한 테스트 케이스 생성에 대한 연구는 모델로부터 테스트 케이스를 추출한다. 하지만 실무의 경우 자연어 요구사항 문장으로부터 테스트 케이스를 생성할 수 있어야 한다. 이를 위해 자연어 문장의 분석하고, 분석 과정 및 결과를 요구공학 영역에 접목하는 연구는 매우 필요하다. 하지만 한국어 문장의 다양성 때문에, 한국어 자연어 요구사항 분석은 어려운 이슈이다. 우리는 한국어 자연어 요구사항으로부터 테스트 케이스 생성 연구 중 하나로써, 자연어 요구사항의 정의 분석, C3Tree 모델의 생성, 원인-결과 그래프의 생성, 결정 테이블의 생성 단계를 통한 테스트 케이스 생성 방법을 연구한다. 본 논문은 중단 단계로써, 메타모델링 변환 기법을 이용하여 C3Tree 모델 기반의 결정 테이블로부터 테스트 케이스 생성 방법을 제안한다. 이 방법은 모델 변환 규칙의 수정을 통해 모델 to 모델, 모델 to 텍스트로의 변환 과정을 제어한다. 모델이 변형되거나, 새로운 모델이 추가되더라도 프로그램 알고리즘의 직접적인 수정 없이 모델 변환 규칙을 유지보수 할 수 있다. 평가 결과, 결정 테이블에 대한 모든 조합이 테스트 케이스로 자동 생성되었다.

• 척추신경추나의학회지
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• 제17권2호
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• pp.109-118
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• 2022

Objectives The purpose of this study was to investigate Korean medicine treatment on hemifacial spasm and to suggest future research direction. Methods We used seven electronic databases to find articles on Korean medicine treatment of hemifacial spasm and by analyzing the title, abstract, and main text, articles elucidating on Korean medicine treatment on hemifacial spasms were included. Results A total of 68 articles were searched from seven electronic databases. Excluding duplicate articles and articles that satisfied the exclusion criteria, nine articles were included in this study. Acupuncture was used in nine cases, herbal medicine in five cases, physical therapy in three cases, and cupping therapy in one case. In acupuncture, general acupuncture was used in five cases, pharmacopuncture in three cases, and Meridian tendino-musculature acupuncture and thread-embedding therapy in two cases each. Gamigwibi-tang used in two cases was the most frequently used herbal medicine. In physical therapy, carbone, hot pack, interferential current therapy, and silver spike point were used in two cases each. Conclusions It was confirmed that Korean medicine treatment for hemifacial spasm was attempted in varying methods and nearly all cases included in this study showed improvement. However, because of the low level of evidence due to the nature of these case reports, further studies should be conducted for an objective comparison and analysis on the effect of Korean medicine treatment compared to existing treatments.