• Geomechanics and Engineering
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• 제9권6호
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• pp.775-791
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• 2015

Due to the extension of communication ways (metro, highways, railways), hence, to improve traffic flow imposes often the difficult crossing that generally drive to the construction of underground works (tunnel, water conveyance tunnel...) plays a major role in the redevelopment of urban areas. This study is focused on the assessment of the interaction response of parallel tunnels, so this study uses the results from the simulation of two tunnels to illustrate a few observations that may aid in practical designs. In this article, simultaneous drilling of highway's twin tunnels is simulated by means of Finite Element Method (FEM) implemented in Plaxis program. So the treated subject appears in a setting of geotechnical where one can be to construct several tunnels sometimes in a ground of weak mechanical characteristics. The objective of this study is to simulate numerically the interaction effects caused by construction of two parallels tunnels. This is an important factor in the study of the total answer of the problem interaction between parallels underground works. The importance of the effects transmitted is function of several parameters as the type of the works, and the mechanical characteristics (tunnel size, depth, and the relative position between two tunnels, lining thickness...). This article describes numerical analyses of two parallels tunnels interaction. This study will be applied to a real case of a section tunnel T4 of the highway East-West (Algeria); the study presented below comprises a series of numerical simulations of two tunnels using the computer program Plaxis which is used in the analyses is based on Finite Element Method.

• 한국병원경영학회지
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• 제23권4호
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• pp.53-64
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• 2018

Purposes: The hospitals needs to generate a minimum profit, in order to perform its own role such as providing high-quality medical services. The demand for hospital management is increasing, as the social demands are diversified and the financial transparency is emphasized. The purpose of this study is to compare hospitals management based on Dupont Identity, by various hospital classification. Methodology: This study is based on '2016 Statistics for Hospital Management' provided by the Korea Health Industry Development Institute. The hospitals were classified according to the scope of care, the type of establishment, the location, and the number of beds. We analyzed the general and financial characteristics of over 337 hospitals using the method of Dupont Identity. Findings: Net profit margin (PM) has the biggest impact on return of equity (ROE). By the number of beds, general hospital with 160-299 beds have the highest return on equity (ROE). By location, hospitals in local municipalities have higher return on equity than hospitals in urban municipalities. According to the type of establishment, public hospitals have lower business performance, and although they invest more than private hospitals. Practical Implications: This study can inspire interest and provide understanding in hospital management and financial structure, by analyzing through an intuitive indicator named Dupont identity. It is possible to provide basic data for hospital management methods for each financial elements, in order to increase the profitability of hospitals.

• Computers and Concrete
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• 제23권1호
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• pp.61-68
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• 2019

This paper presents a computational rational model to predict the ultimate and optimized load capacity of reinforced concrete (RC) beams strengthened by a combination of longitudinal and transverse fiber reinforced polymer (FRP) composite plates/sheets (flexure and shear strengthening system). Several experimental and analytical studies on the confinement effect and failure mechanisms of fiber reinforced polymer (FRP) wrapped columns have been conducted over recent years. Although typical axial members are large-scale square/rectangular reinforced concrete (RC) columns in practice, the majority of such studies have concentrated on the behavior of small-scale circular concrete specimens. A high performance concrete, known as polymer concrete, made up of natural aggregates and an orthophthalic polyester binder, reinforced with non-metallic bars (glass reinforced polymer) has been studied. The material is described at micro and macro level, presenting the key physical and mechanical properties using different experimental techniques. Furthermore, a full description of non-metallic bars is presented to evaluate its structural expectancies, embedded in the polymer concrete matrix. In this paper, the mechanism of mechanical interaction of smooth and lugged FRP rods with concrete is presented. A general modeling and application of various elements are demonstrated. The contact parameters are defined and the procedures of calculation and evaluation of contact parameters are introduced. The method of calibration of the calculated parameters is presented. Finally, the numerical results are obtained for different bond parameters which show a good agreement with experimental results reported in literature.

• 한국의사학회지
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• 제31권2호
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• pp.27-40
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• 2018

Sauna, or hanjeung (汗蒸) is a physical sweating method that uses external heat to forcibly raise body temperature to treat cold damage disorders (傷寒) in traditional Korean medicine. This study focuses on the fact that the sauna was recorded as a healing and bathing method on the Vinaya Pitaka (律藏), and investigates the records of folk sauna therapy of Joseon Dynasty from the perspective of Buddhist medicine which played a significant role in ancient medicine history in Korea. Although the word 'hanjeung (汗蒸)' first appeared in "The Veritable Records of King Sejong (世宗實錄)" in the Korean literature, this study aims to confirm the possibility that the tradition of Buddhist sauna bathing has already existed since the Three Kingdoms period in Korea, based on the fact that sauna bathing was recorded in the Vinaya Pitaka and that the ancient Buddhist bathing culture was introduced in ancient Japan. In addition, the succession of the Buddhist sauna tradition by Goryeo will be traced back through the records of 1920s urban saunas in Gaesung (개성) which was the old capital of Goryeo and had a strong tendency to adhere to traditional Goryeo customs. Finally, the study tries to identify the elements of the Buddhist sauna bathing on the records of folk sauna therapy in the Joseon Dynasty. As a result, this study examines how the Buddhist sauna bathing culture in ancient Korea, which was led by medical monks, spread in the general public and influenced the folk sauna therapy in the Joseon Dynasty.

• 한국환경복원기술학회지
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• 제24권2호
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• pp.85-102
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• 2021

Phytosociological characteristics on Quercus acutissima forests distribution in Daechong-dam basin survey has been carried out using Z.-M. School's methodology and numerical-classification analyses. A total of 43 phytosociological relevés were sampled. Syntaxa were described as Oplismenus undulatifolius-Quercus acutissima community(typicum subcommunity, Phryma leptostachya var. asiatica subcommunity, Ulmus davidiana var. japonica subcommunity), Quercus acutissima community and Quercus variabilis-Quercus acutissima community (typicum subcommunity, Castanea crenata subcommunity). The above three plant communities were classified with species composition reflecting local environmental characteristics of mountain topographies, inclination degrees, and rock exposure rates. Conclusively, those communities were recognized as secondary vegetation affected by high intensity and frequency of human impacts as they inhabited in southward hill lands and low lying grounds in mountains adjacent to human settlements and arable lands. Quercus acutissima community was classified as rural type syntax based on their inlandward distribution and species composition differences from urban forests. Afforest process and natural succession were discussed in relation with habitat environmental elements of Quercus acutissima forest in the survey area.

• 한국융합학회논문지
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• 제12권1호
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• pp.77-87
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• 2021

도시생활에서 환경은 매우 중요한 요소이다. 환경요소는 스마트 도시 계획에서 꼭 다루어야 하는 주제이나, 도시 환경의 정보화 및 데이터 공유 부분은 현재 미흡한 상태여서 이를 개선할 필요가 있다. 본 연구는 난징시의 스마트화의 일환으로 친환경 정보화 건설 및 서비스 수요에 대한 심층조사를 진행하였고, 난징시의 스마트 도시 계획에 부합하면서, 환경의 품질을 개선하고 환경정보 서비스를 제공하는 지능형 친환경 정보 플랫폼의 디자인 연구와 그 구축에 대한 연구를 수행하였다. 또한 정보를 시각화 하는 부분에 대한 연구도 진행을 하였다. 이 결과는 난징 시 스마트 도시 구축에 중요한 모듈이다.

• 터널과지하공간
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• 제31권4호
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• pp.211-220
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• 2021

한국의 대심도 (>40m 깊이) 터널 공사 시에 터널 붕괴 사고가 종종 일어나고 있으며, 도심지 지하공간의 얕은 심도에 인공적으로 조성된 지반에는 자연 공동뿐만 아니라 상수도관, 하수도관, 전력구 및 지하철 건설로 인한 인위적인 공동들이 복잡하게 분포되어 있다. 대심도 터널 굴착을 위해서는 이러한 다공질의 특성을 보이는 다양한 지반의 특성 및 지질구조가 지반의 안전에 미치는 영향을 이해하여야 한다. 본 연구는 국내외 사례를 바탕으로 한국의 대심도 굴착에서 암반의 위험 산정을 위한 위험 인자를 분석하였다. 연구결과, 대심도 터널 굴착시 지반의 안정성에 영향을 주는 총 7개의 카테고리들과 총 38개의 인자들이 도출되었다. 가중치가 상대적으로 높은 인자들은 단층 및 단층점토, 차응력, 암종, 지하수 및 머드 유입, 암석의 일축압축강도, 터널 단면의 크기, 터널 상부 암반의 두께, 카르스트 및 계곡지형, 습곡, 석회암의 협재, 지하수위 변동, 터널 심도, 암맥, RQD, 절리 특성, 이방성, 암반파열(rockburst) 등으로 나타났다.

• 창의정보문화연구
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• 제6권3호
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• pp.209-217
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• 2020

최근 데이터 분석에 대한 관심이 높아지며 공학, 자연과학, 사회과학 영역 등 다양한 분야에서 데이터 분석을 통한 융·복합 연구가 활발하게 이루어지고 있다. 건축분야 역시 데이터 분석을 활용한 다양한 연구가 진행되고 있으며 특히, 이를 통해 도시화 과정을 통해 양적 확대를 진행해왔던 건축분야의 문제점을 해결하고자 하는 노력이 이루어지고 있다. 본 연구에서는 도시재생사업을 통한 주거환경 개선지역과 유사 인근지역 주거자의 주거만족도에 대한 데이터 분석을 수행한다. 건물 건축과 입주 후 진행되는 거주 후 평가 요소에 대해 R을 활용한 분석을 통해 각 평가 요소 간의 연관규칙 분석과 거주자의 주요 요구 사항의 빈도 수 파악을 통해 주거환경 만족도에 영향을 미치는 중요 평가 항목을 파악한다. 이를 통해, 향후 건축 분야에서 주거지 구성 시 양질의 주거 공간 확보를 위한 데이터 제공과 함께 양질의 주거지역을 추천할 수 있는 시스템의 개발 등 IT와 건축분야 간의 융·복합 연구를 진행하고자 한다.

• 한국항공우주학회지
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• 제50권2호
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• pp.111-118
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• 2022

전기-기계식 구동기(EMA)는 전기 모터와 기계적 동력전달 요소를 결합한 것으로 설계 자유도와 유지보수 측면에서 도심 항공 모빌리티(UAM)에 적합하다. 본 논문에서는 UAM의 로터 블레이드 피치각을 조종하는 EMA에 대한 연구 결과를 제시한다. 구동기는 역구동형 롤러 스크류를 기반하며, 2절 링크를 통하여 블레이드 피치각을 조종한다. 구동기만의 동역학과 이것을 포함한 블레이드 피치운동의 동역학 방정식을 유도하였다. 블레이드 피치 동역학 방정식의 경우 링크의 영향으로 등가 관성모멘트는 링크 각도에 따라 변한다. 넛트 운동의 관점과 블레이드 피치 운동의 관점에서 등가 관성모멘트의 변동을 분석·비교하는 과정을 제시하였다. 사례로 선정한 모델의 경우에 전자의 등가 관성모멘트 변동이 후자에 비하여 작았으며, 그래서 넛트 운동의 관점에서 유도한 모델이 제어기 설계에 적합하다고 판단한다.

• International Journal of Computer Science & Network Security
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• 제21권12호
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• pp.309-315
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• 2021

The purpose of the article is to analyze the functioning of economic systems in the context of the development of their potential in a circular economy. It is determined that the functioning of economic systems to ensure their sustainability should meet modern challenges and provide for the formation of competitive institutional architecture, the introduction of structural and regulatory innovations, the transition to an innovative model of development. The specific principles of functioning of economic systems include openness, nonlinearity, multivectority, dynamism, emergence, uncertainty about the development of economic processes. It is substantiated that the linear nature of development and equilibrium are not dominant in the functioning of economic systems, and increasing the level of economic efficiency should go hand in hand with minimizing the activities of enterprises, which necessitates the use of circular economy. The main prerequisites for the transition to a circular economy are analyzed. It is determined that the basic concept of the circular economy involves the development of a system of production and consumption, which is based on processing, reuse, repair, product sharing, change of consumption patterns and new business models and systems. The main elements of the circular economy include: a closed cycle, the use of renewable energy sources, systems thinking. The correlation of the principles of sustainable development and the peculiarities of the application of the circular economy is analyzed. It is determined that the circular economy contrasts with the traditional linear economic model, which is based on the model of "take-do-consume-throw away". The advantages and disadvantages due to the use of the principles of circular economy are given. Based on the study, steps are identified to accelerate the transition from a linear economy to a circular economy.