• 한국측량학회지
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• 제22권4호
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• pp.339-347
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• 2004

본 연구에서는 택지조성공사가 실시되고 있는 대규모 현장을 대상으로 절$.$성토부 풍화암의 정확한 토량환산 계수를 산정하고자 한다. 이를 위해, 먼저 대상지 내의 절 성토부 각각 20개소를 굴착하고 굴착 후의 체적을 계산하였다. 그 결과, 교차에 대한 체적의 상대정확도는 평균 0.5%로 산출되었다. 또한, 계산된 체적에 의한 습윤 단위중량과 실내토질시험에 의한 함수비를 이용하여 정확한 토량환산계수를 산정하였다. 산정된 토량환산계수를 모래치환법에 의한 건조단위중량시험에 의해 결정된 토량환산계수와 비교 $.$분석한 결과, 미소한 차이를 나타내었다. 이는 불규칙한 굴착부분의 체적측정을 정밀수치사진측량기법을 적용하였으므로 현장시험의 신뢰성이 높고 토량환산계수 산정을 위한 합리적인 설계방법이라 판단된다.

• KIEAE Journal
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• 제16권4호
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• pp.41-46
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• 2016

Purpose: This is a study on the planning of temporary housing for post application of Mega Sports facilities. The subject of the study is 2018 Pyeongchang Winter Olympics, which is to suggest building an alternative temporary housing using shipping containers(high cube), which solve the lack of accommodations and recycle temporary housing after Olympics, save money and be eco-friendly in Olympics. Method: This study includes this ; research on the a fact-finding survey about Mega sports facilities post application and demand survey on 2018 Pyeongchang Winter Olympics accomodations and an analysis about temporary housing plan. Furthermore we decided temporary housing building plan by analyzing residents' needs and traits of the housing etc. Through this, we made a schematic design for household units. Result: As a result, this study is a plan of making space, forms, and structure. The planned size is $38.4m^2$(L:12m, W:3.2m) except balcony, and indoor height is 2.5m. The space consists of entrance, bathroom, bedroom and living room with folding furniture system. Also there's a detailed floor plan of the ceiling, wall, and floor we drew up. The ceiling and wall consist of dampproof film, noncombustible board, fire proof urethane form, and color-designed sheet. The floor is composed of floor tile, cement mortar, light concrete(with heat coil), insulation, and dampproof film. Additionally, this study is a plan of interior dry wall with detail using modular construction method for work efficiency and quality improvement.

• 대한건축학회논문집:계획계
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• 제35권8호
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• pp.89-100
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• 2019

The purpose of this study is to critically review the repair works of Seokguram architecture and to search for its original form and space. Seokguram's architectural form has been transformed throughout three repair works. The first transformation occurred during the repair work of the Colonial Government in 1913-1915, and the second occurred during the repair work of the Colonial Government in 1920-1923. The repair work done by the Korean Government in 1961-1964 also caused a severe change in the architectural form and space of Seokguram architecture. The more the repair work was added to Seokguram, the more its original form flew away like a mirage. Through the three repair works, the spatial composition of Seokguram changed in the following directions: from ((front chamber + passageway) + main chamber) to (front chamber + (passageway + main chamber)) through the second repair work, from (front chamber + (passageway + main chamber)) to (front chamber + passageway + main chamber) through the last repair work. Although the compositional space hierarchy of Seokguram was maintained during the first repair work, the architectural form based on the dry method was changed to the form based on the wet method. The Korean government's repair work was a tragedy for the 'Seokguram conservation project' that the people who led the conservation process misunderstood the architectural nature of Seokguram.

• Steel and Composite Structures
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• 제46권3호
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• pp.385-401
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• 2023

Steel is becoming increasingly popular due to its high strength, excellent ductility, great assembly performance, and recyclability. In reality, steel structures serving for a long time in atmospheric, industrial, and marine environments inevitably suffer from corrosion, which significantly decreases the durability and the service life with the exposure time. For the mechanical properties of corroded steel, experimental studies are mainly conducted. The existing numerical analyses only evaluate the mechanical properties based on corroded morphology at the isolated time-in-point, ignoring that this morphology varies continuously with corrosion time. To solve this problem, the relationships between pit depth expectation, standard deviation, and corrosion time are initially constructed based on a large amount of wet-dry cyclic accelerated test data. Successively, based on that, an in-situ pitting evolution method for evaluating the residual tensile strength of corroded steel is proposed. To verify the method, 20 repeated simulations of mass loss rates and mechanical properties are adopted against the test results. Then, numerical analyses are conducted on 135 models of corrosion pits with different aspect ratios and uneven corrosion degree on two corroded surfaces. Results show that the power function with exponents of 1.483 and 1.091 can well describe the increase in pit depth expectation and standard deviation with corrosion time, respectively. The effect of the commonly used pit aspect ratios of 0.10-0.25 on yield strength and ultimate strength is negligible. Besides, pit number ratio α equating to 0.6 is the critical value for the strength degradation. When α is less than 0.6, the pit number increases with α, accelerating the degradation of strength. Otherwise, the strength degradation is weakened. In addition, a power function model is adopted to characterize the degradation of yield strength and ultimate strength with corrosion time, which is revised by initial steel plate thickness.

• 한국건설관리학회논문집
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• 제8권1호
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• pp.132-140
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• 2007

건설 산업의 새로운 부가가치 영역으로 초고층 주거건축에 대한 관심과 투자가 증가하고 있다. 이러한 초고층 건축물을 시공하는 과정에서 많은 작업들이 층별로 반복적이며 동시에 진행되는 마감공사는 업체별 공사 관리 능력에 따라 공기 차이가 발생하고 있고, 이는 전체 사업 공기에 큰 영향을 주고 있는 것으로 나타났다. 마감공사의 효율적 수행을 위해서는 초고층 주거 건축물 마감공사의 현장 특성을 고려한 작업의 생산성 영향요인을 도출하고 중요 요인에 대한 중점 관리의 필요성이 제기되고 있다. 생산성 영향요인에는 기술적 요소 외에도 마감공사의 프로세스를 계획하고 관리하는 많은 복합적인 요소들이 존재한다. 본 연구에서는 계층 분석적 의사결정 기법인 AHP 분석을 통해 마감공사 프로세스의 계획 및 관리 요인측면에서 생산성 영향요인의 중요도를 분석하였다. 이와 같이 중요도가 높게 나온 요인 중 잠재 개선 효과가 큰 요인들에 대한 중점 관리 및 연구를 수행한다면 마감공사의 생산성 영향요인에 대한 이해를 높여주는 한편 실무적 관리방향을 제시함으로써 건설기업의 체계적 인 생산성 관리에 기여할 수 있을 것이다.

• 콘크리트학회논문집
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• 제26권4호
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• pp.507-515
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• 2014

콘크리트 구조물의 시공이음부는 적절한 처리에도 불구하고 누수되는 사례가 빈번히 발생되고 있다. 이 연구에서는 이러한 누수 현상이 신 구 콘크리트 간의 부착특성과도 관련이 있을 것으로 보고 이에 대한 실험을 실시하였다. 여러가지 조건하에서 부착특성을 평가하기 위해 신 구 콘크리트의 접합부를 모사하는 시편들을 제작하여 접합부의 접착강도, 휨강도 및 쪼갬인장강도를 측정하였다. 주요 실험 변수는 혼화재의 종류 및 혼입률, 접합면의 처리 방법, 지수판의 종류였다. 그 외 신 구 콘크리트 타설 간격의 영향, 강도시험 재령에 따른 영향도 고찰하였다. 실험 결과 혼화재 사용에 따라 부착강도가 어느정도 증가하는 것으로 나타났는데, 이는 포졸란 반응에 의해 생성되는 칼슘실리케이트 수화물이 접합부의 공극을 메우기 때문으로 생각된다. 한편, 접합면이 거칠고 건조할수록 부착성능이 향상되었으며, 지수판의 표면 거칠기는 지수판의 부착성능에 영향을 미치는 것으로 나타났다. 또한 시험 방법에 따른 부착강도의 차이가 발생하므로 이를 고려한 평가가 요망된다.

• 한국건축시공학회지
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• 제11권6호
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• pp.530-537
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• 2011

연구는 SHCC의 건축시공 현장적용을 목적으로 현장 제조설비인 배치플랜트 2-Shaft 믹서를 이용하여 SHCC 제조 및 타설을 통해 실부재 실험을 실시하고, 이를 실내실험 결과와 비교 검토함으로서 향후 SHCC의 현장적용을 위한 기초자료로 제시하고자 하였다. 그 결과, 실내 Omni 믹서와 2-Shaft 믹서에서 SHCC 제조시 인장강도는 유사하였지만, 변형률에서 Omni 믹서가 2.5 % 이상 우수하였다. 배치플랜트 3500 L 2-Shaft 믹서에서 제조된 SHCC의 경우, 실내 100 L 2-Shaft 믹서에서 제조한 SHCC에서 인장 성능이 보다 높게 나타났다. SHCC의 현장적용 확대를 위해서는 배치플랜트 현장 제조시 건비빔, 모르타르 비빔시간을 충분히하여 매트릭스를 균질성을 확보하고, 비빔단계에서 적절한 점성 및 유동성을 확보할 수 있는 다양한 방법을 고려해야 한다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.233-233
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• 2015

Vu Gia - Thu Bon basin is located in central Vietnam between Truong Son mountain range on the border with Lao in the west and the East Sea in the east. The basin occupies about 10,350 km2 or roughly 90% of the Quang Nam Province and includes Da Nang, a very large city with about 876,000 inhabitants. Total annual rainfall ranges from about 2,000 mm in central and downstream areas to more than 4,000 mm in southern mountainous areas. Rainfall during the monsoon season accounts for 65 to 80% of total annual rainfall. The highest amount of rainfall occurs in October and November which accounts for 40 to 50% of the annual rainfall. Rainfall in the dry season represents about 20 to 35% of the total annual rainfall. The low rainfall season usually occurs from February to April, accounting for only 3 to 5% of the total annual rainfall. The mean annual flow volume in the basin is $19.1{\times}109m 3$. Similar to the distribution of rainfall, annual flows are distinguished by two distinct seasons (the flood season and the low-flow season). The flood season commonly starts in the mid-September and ends in early January. Flows during the flood season account for 62 to 69% of the total annual water volume, while flows in the dry season comprise 22 to 38% of total annual run-off. The water volume gauged in November, the highest flow month, accounts for 26 to 31% of the total annual run-off while the driest period is April with flows of 2 to 3% of the total annual run-off. There are some hydropower projects in the Vu Gia - Thu Bon basin as the cascade of Song Bung 2, Song Bung 4, and Song Bung 5, the A Vuong project currently under construction, the Dak Mi 1 and Dak Mi 4 projects on the Khai tributary, and the Song Con project on the Con River. Both the Khai tributary and the Song Con join the Bung River downstream of SB5, although the Dak Mi 4 project involves an inter-basin diversion to Thu Bon. Much attention has recently been focused on the effects that climate variability and human activities have had on runoff. In this study, data from the Vu Gia - Thu Bon River Basin in the central of Viet Nam were analyzed to investigate changes in annual runoff during the period of 1977-2010. The nonparametric Mann-Kendall test and the Mann-Kendall-Sneyers test were used to identify trend and step change point in the annual runoff. It was found that the basin had a significant increasing trend in annual runoff. The hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. This study quantitatively distinguishes the effects between climate variability and human activities on runoff, which can do duty for a reference for regional water resources assessment and management.

• 대한건축학회논문집:구조계
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• 제33권12호
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• pp.81-90
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• 2017

This study was conducted to investigate the thermal environment status of nursery rooms in workplace daycare centers in Jeju and propose measures to improve their indoor physical thermal environment. For this purpose, measurements were performed in the winter indoor physical environment of 51 nursery rooms in 11 workplace daycare centers and a psychological evaluation survey on the thermal environment of nursery rooms was conducted for 70 nursery teachers. The investigation was carried out over 11 days in January 2017. The results are as follow. The average indoor temperature of the nursery rooms was $21.3^{\circ}C$($18.7-23.8^{\circ}C$) and the indoor temperatures of 47 nursery rooms (92.9%) were higher than the environmental hygiene management standard for domestic school facilities ($18-20^{\circ}C$). The average relative humidity was 33.9% (16.4-56.0%), and 37 nursery rooms (86.3%) showed a lower average relative humidity than the standard (40-70%). The average absolute humidity was $9.1g/m^3$ ($4.7-13.6g/m^3$), which was lower than the standard for preventing influenza ($10g/m^3$). When the indoor temperature and humidity of the nursery rooms were compared with international standards, it was found that 85% or more of the 51 nursery rooms maintained appropriate indoor temperatures, but 40-50% of the nursery rooms maintained a low humidity condition. Therefore, they need to pay attention to maintaining the appropriate humidity of the nursery room to keep the children healthy. The average indoor temperature of the nursery rooms showed a weak negative correlation with the average relative humidity. The indoor temperature had a significant effect on the relative humidity: a higher indoor temperature resulted in lower relative humidity. Regarding the fluctuations in the average indoor temperature of the nursery rooms during the day, in daycare centers that used floor heating, the indoor temperature gradually increased form the morning to the afternoon and tended to decrease during lunch time and the morning and afternoon snack times, due to ventilation. The daycare centers that used both floor heating and ceiling-type air conditioners showed a higher indoor temperature and greater fluctuations in temperature compared to the daycare centers that used floor heating only. In the survey results, the average value of the whole body thermal sensation was 3.0 (neutral): 32 respondents (62.7%) answered, "Neutral", Which was the largest number, followed by 21 respondents (30%) who answered, "Slightly hot" and 17 respondents (24.2%) who answered, "Slightly cold." Twenty-nine respondents answered, "Slightly dry," which was the largest number, followed by 28 respondents (54.9%) who answered, "Neutral" and 10 respondents (19.6%) who answered, "Dry." The total number of respondents who answered, "Slightly dry" or "Dry" was large at 39 (56.4%), which suggests the need for indoor environment management to prevent a low-humidity environment. To summarize the above results about the thermal environment of nursery rooms, as the indoor temperature increased, the relative humidity decreased. This suggests the effect of room temperature on the indoor relative humidity; however, frequent ventilations also greatly decrease the relative humidity. Therefore, the ventilation method and the usage of air conditioning systems need to be re-examined.

• 한국수자원학회논문집
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• 제42권4호
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• pp.271-279
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• 2009

본 연구는 단순한 직사각형 하도에서 발생한 댐 붕괴 및 홍수전파 등에서 만족스러운 결과를 보였던 Riemann 근사해법을 이용한 1차원 유한체적기법을 불규칙한 하도형상의 자연하도에 적용하기 위하여 새로운 기법을 개발하는 것이 목적이다. 이를 위하여 자연하천 단면을 등가의 직사각형 단면으로 변환하는 개념을 도입하였으며, 그 결과, 운동량방정식이 수정되었다. 새롭게 개발된 기법을 정확해가 존재하는 삼각형 단면하도의 댐 붕괴 흐름에 적용하고 그 결과를 비교함으로써, 기법의 정확성 및 적용성이 검증되었다. 단면의 형상 및 단면간 거리가 균일하지 않는 자연하도에 적용한 결과는 실측수위와 비교하여 홍수파의 전파 양상, 도수의 발생 위치 및 크기, 그리고 전 구간에서의 최대 수위가 잘 일치함을 나타낸다. 본 연구결과로부터 기존의 균일한 단면을 사용하여 개발된 기법들을 복잡한 수치처리과정 없이 자연하천 단면에 직접 적용할 수 있을 것으로 판단된다.