• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.29-30
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• 2022

Tile defects in apartment houses are caused by a combination of various factors. These factors cannot be specified, and it is difficult to determine the exact cause because a number of causes are intertwined. In addition, because the climate of Korea is different by season, the coefficient of thermal expansion between materials is different, which is a major cause of tile defects. Therefore, this study analyzed the difference between the construction location and the period of defect occurrence according to the types of tile defects caused by environmental differences between indoor and outdoor environments. Two-way ANOVA was used, indoor and outdoor spaces were selected, and defect types were selected accordingly to show the difference in the occurrence period of each defect.

• Geomechanics and Engineering
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• 제16권4호
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• pp.415-421
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• 2018

A location determining method is proposed for critical sliding surface in the stability analysis of the filling materials in karst caves. First, a preliminary location of the sliding surface is determined based on simulation results which includes displacement contour and plastic zone. The sliding surface will locate on the bottom contact interface when the friction angle is relative small. However, a weakened contact interface always becomes the critical sliding surface no matter what the friction angle is. Then when the friction angle becomes larger, the critical sliding surface inside fillings can be determined by a parabola, the coefficient of which increases linearly with the friction angle under the same cohesion. Finally, the critical sliding surface approximately remains unchanged with friction angle. The influence of cohesion is similar to that of friction angle. Although affected by shape, size or position of the karst cave, the critical sliding surface mainly depends on both friction angle and cohesion. Thus, this method is always useful in determining the critical sliding surface.

• 대한기계학회논문집
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• 제16권4호
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• pp.795-802
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• 1992

본 연구에서는 일정한 각도의 분사를 갖는 평씨일(plain seal)에 대하여 각 인자들이 누수성능에 미치는 영향을 수치적으로 조사하였다. 인자들로는 축방향 레 이놀즈수, 축회전속도, 분사의 유입속도, 간극비, 분사의 위치 및 유입각 등이 고려되 었다.

• Structural Engineering and Mechanics
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• 제72권5호
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• pp.585-595
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• 2019

Foundations are a vital part of structures. Over time, the foundations can deteriorate due to unforeseen overloads and/or settlements, resulting in the appearance of cracks in the concrete. These cracks produce changes in the static and dynamic behavior of the affected foundation, which alter its load carrying capacity. In this work, non-destructive techniques of relative simplicity of application are presented for the detection, location, and quantification of damage, using numerical models, solved with the finite element method and Power Series. For this, two types of parameters are used: static (displacement and elastic curvature) and dynamics (natural frequencies). In the static analysis, the damage detection is done by means of a finite elements model representing a beam supported on an elastic foundation with a discrete crack that varies in length and location. With regard to dynamic analysis, the governing equations of the model are presented and a method based on Power Series is used to obtain the solution for a data set, which could be the Winkler coefficient, the location of the crack or the frequency. In order to validate the proposed methodologies, these techniques are applied to data obtained from laboratory tests.

• 한국수자원학회논문집
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• 제46권11호
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• pp.1103-1113
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• 2013

본 연구에서는 상수관망의 수압모니터링지점 선정방법을 제시하고 이를 모의하기 위해 단순화된 샘플관망에 적용하여 최적위치를 선정하였다. 또한, 최적의 수압모니터링지점 선정방법을 도출하고 실제 도시의 상수관망에 적용하여 모니터링 지점을 선정해보았다. 모니터링 지점선정방법은 크게 세 가지로 구분하여 계산하였다. 먼저 조도계수 변화로 인한 민감도분석, 유량변화로 인한 압력기여도분석과 민감도분석을 통하여 모니터링 지점을 선정하였다. 그리고 부정류 해석결과를 이용한 압력기여도분석과 민감도분석결과를 정류해석결과와 비교하였다. 결과를 통하여 가장 효과적이고 간편한 방법을 선정하였고 실제 상수관망에 적용하였다. 본 연구에서 제시된 모니터링 지점선정방법은 상수관망의 유지관리는 물론 누수탐지를 위한 수압관리 모니터링 지점선정방법으로 활용이 가능할 것으로 판단된다.

• 한국항만경제학회지
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• 제36권2호
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• pp.87-108
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• 2020

우리나라 물류산업은 산업의 발전과 함께 성장하였으며, 물류산업의 발전은 기업비용을 절감하고, 물가 상승을 억제하여 지역민 삶의 질을 향상시켰다. 이러한 물류산업은 국가와 지역 경제성장에 중요한 역할을 하며, 정부에서는 물류산업 육성을 위한 정책적인 노력을 이어오고 있다. 본 연구에서는 지역물류산업의 경쟁력을 분석하고, 물류산업의 지역경제 부가가치 기여도를 분석하여 지역 물류산업 육성을 위한 시사점을 제공하고자 한다. 입지계수를 분석하여 지역별 육상운송, 수상운송, 항공운송, 창고 및 운송관련 서비스업의 특화도를 분석하고, 지역산업연관표에서 부가가치율, 지역내총생산(GRDP) 기여도, 부가가치유발계수, 부가가치 순이입을 분석하여 지역 물류산업이 지역경제 부가가치에 미치는 영향을 알아보고자 한다. 분석결과 우리나라 물류산업은 산업별로 일부 지역에서 부가가치 순이입이 있고, 경쟁력을 가지고 있는 것으로 분석되었다. 지역 물류산업의 입지계수와 부가가치 기여도 사이에는 일정한 관계가 존재하지는 않았다. 우리나라 물류산업은 산업별로 서울, 인천, 경기, 부산, 제주 등을 중심으로 지역에 따라 다른 산업이 경쟁력을 가지고 있는 것으로 분석되었으며, 물류 인프라가 잘 발전된 지역과 육성이 필요한 지역을 구분하여 확인할 수 있었다. 물류산업이 발전한 지역은 고부가가치화를 위한 정책이 필요하며, 육성이 미비한 지역은 지역 수요에 맞는 인력과 자본을 투입하여 물류산업 육성을 위한 지원이 필요하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.259-262
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• 2002

This paper provides the experimental verification of a non-destructive time domain approach to examine structural damage. Time histories of the vibration response of structure were used to identify the presence of damage. Damage in a structure cause changes in the physical coefficients of mass density, elastic modulus and damping coefficient. This paper examines the use of beam like structures with PVDF sensor and PZT actuator to perform identification of those physical parameters, and hence to detect the damage. Experimental results are presented from tests on cantilevered composite beams damaged at different location and with damage of different dimensions. It is demonstrated that the method can sense the presence of damage, and characterize the damage to a satisfactory precision.

• 한국주거학회논문집
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• 제12권2호
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• pp.45-54
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• 2001

The purpose of this research was to analyze the correlation between the Apartment Purchase Price Decision Factor and Amenity decision Factor with cognition of the Consumer. The result are as follows; 1. The correlation coefficient between the Apartment Price Decision Factor and Amenity decision Factor with cognition of the Consumer was 0.587. 2. The ranking of the purchase price factor which it prefers were analyzed orientation > sunlight > view > the rising price expectation > natural environment etc. And the ranking of the amenity were analyzed orientation > natural environment > view > sunlight > noise etc. 3. Consumer group was classified the location, sex, year of ages and unit scale. The rank correlation coefficient of (the significant was below 0.05) sex was 0.617~0.644, year of ages was 0.62~0.771 and unit scale was 0.762~0.852. This research proved the fact that the amenity correlated with the apartment purchase price decision factor, so amenity contained an economic value. And this result will be used in decision-making-process of apartment construction.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2004년도 추계 학술대회논문집
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• pp.25-28
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• 2004

The purpose of this paper is to present essential numerical data of FCV(Flow rate Control Valve) which is used in a projectile ejection system for a underwater vehicle. A commercial CFD code is applied to analyze the 3 dimensional viscous compressible flow field within the FCV as four cases of opening rate, 25, 50, 75, and $100\%$. The flow coefficient of each cases are mainly calculated. And other characteristics such as the location of shock wave and total temperature distribution are also determined.

• Geomechanics and Engineering
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• 제19권6호
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• pp.523-532
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• 2019

Based on the formation characteristics, wellbore parameters and insulated tubing (IT) parameters of the Shengli oilfield, Shandong, China, a geomechanical model is built to predict the temperature distributions of the wellbore and formation. The effects of the IT heat conductivity coefficient (HCC), well depth and IT joint on the temperature distribution of the IT, completion casing, cement sheath, and formation are investigated. Results show the temperature of the formation around the wellbore has an exponentially decreasing relation with the distance to the wellbore. The temperature of the formation around the wellbore has an inverse relation with the IT HCC when the temperatures of the steam and the formation are given. The temperature of the casing outer wall is mainly determined by the steam temperature and IT HCC rather than by the initial formation temperature. The temperature of the casing at the IT joint is much larger than that of the other location. Due to the IT joint having a small size, the effects of the IT joint on the casing temperature distribution are limited to a small area only.