• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.321-327
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• 2017

China is experiencing the urbanization at an unprecedented speed and scale in human history. The continuing growth of China's big cities, both in city land and population, has already led to great challenges in China's urban planning and construction activities, such as the continuous increase of construction and demolition (C&D) waste. Therefore, how to characterize cities' construction activities, particularly dynamically quantify the flows of building materials and construction debris, has become a pressing problem to alleviate the current shortage of resources and realize urban sustainable development. Accordingly, this study is designed to employ 4D-GIS (four dimensions-Geographic Information System) and Internet Plus to offer new approach for accurate but dynamic C&D waste management. The present study established a spatio-temporal pattern and material metabolism evolution model to characterize the geo-distribution of C&D waste by combing material flow analysis (MFA) and 4D-GIS. In addition, this study developed a mobile application (APP) for C&D waste trading and information management, which could be more effective for stakeholders to obtain useful information. Moreover, a cloud database was built in the APP to disclose the flows of C&D waste by the monitoring information from vehicles at regional level. To summarize, these findings could provide basic data and management methods for the supply and reverse supply of building materials. Meanwhile, the methodologies are practical to C&D waste management and beyond.

• 생명과학회지
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• 제22권6호
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• pp.736-743
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• 2012

본 연구에서는 부산 신항 공사 지역 주변 해역의 총 16개 지역에서 2005년부터 2011년까지 분기별로 매년 4회씩 수달의 배설물을 수집하여 배설물 내 생물 잔해 즉 먹이의 종류를 알아보고, 신항 개발이 수달의 섭식 변화에 미치는 영향에 대해서 조사하였다. 그 결과, 수달은 주로 어류를 섭취하지만 갑각류와 복족류 등도 소수 섭취하는 것이 밝혀졌고, 숭어목이 수달의 주 먹이임이 밝혀졌다. 한편 어류는 모든 계절에 출현했지만 대부분의 어목의 출현 빈도와 어획량이 계절별로 매우 유사한 점으로부터, 수달이 섭취하는 어류의 양은 이 지역에 서식하는 어류의 양과 매우 밀접한 관련이 있음이 시사되었다. 한편 배설물에 출현한 대부분의 어류, 갑각류 및 복족류의 출현 빈도가 2010년 이후에 감소했는데, 이는 공사에 의해서 수달의 먹이가 감소했고, 가까운 장래에 수달의 개체 수가 감소할 수 있음을 시사한다. 이러한 추론은 2010년 이후 수달의 배설물 수가 감소했고, 최근에 이 지역의 어획량이 급감했고, 수질 오염도 증가했다는 연구들로부터 뒷받침된다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.500-503
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• 2004

급속한 경제성장과 더불어 복지 및 생활여건의 개선에 따라 재개발 $\cdot$ 재건축이 크게 증가하고 있으며, 또한 변화하는 사회 환경에 맞추어 건설공사의 규모 또한 점차 대형화 되어가고 있는 추세이다. 따라서 이러한 재개발 재건축 등의 활성화로 인하여 도심지 해체공사가 증가함에 따라 건설폐기물의 발생량이 대폭 증가하고 있다. 따라서 건설폐기물의 적정관리는 매우 중요한 사항이 되어 가고 있으나, 발생 폐기물을 정확히 예측하기 위한 연구가 부족하였다. 따라서 본 연구에서는 공통주택의 해체물량을 정확히 예측학 수 있는 건설폐기물 원단위 산정 기준을 제시한다. 이것은 해체공사 시 발생 가능한 건설폐기물을 손쉽고 정확히 예측할 수 있으며, 이것은 국가 폐기물 정책에 매우 중요한 자료로 활용될 수 있을 것이다.

• 환경영향평가
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• 제20권1호
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• pp.89-96
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• 2011

This study was carried out to assess the variations of water quality caused by the dam construction on the river. Six dams-Yongdam, Miryang, Hoengseong, Boryeong, Jangheung and Buan- constructed recently in Korea were selected for the study. Chemical oxygen demand(COD) was increased in the initial stage of water storage at dams compared to the lotic(river) environment, but after 3 years it was maintained lower and stabilized concentrations. Five dams except for Jangheung Dam were maintained Ia~Ib grade conditions under the water quality criteria of Korea. The concentrations of total nitrogen(T-N) were decreased under the lentic(reservoir) environment compared to the river status. Total phosphorus(T-P) was decreased 13~63% at the reservoir condition. We concluded that increase of COD concentration was due to the debris organic materials of the land, but temporary phenomenon. T-N and T-P concentrations were decreased at the lentic condition compared to the lotic.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.242-243
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• 2021

The concrete inside the steel tube of CFT columns enables them to have great strength and ductility. CFT columns are also excellent in fire-resistance because explosive heat upon a fire can be contained in the tube by the concrete debris. However, the studies to evaluate the residual strength of CFT columns after a fire have not been conducted enough. The studies to evaluate the residual strength of CFT columns after a fire are indispensable because it is the barometer of the damage of composite columns caused by a fire and the degree of repair and reinforcement work for the columns after a fire. Accordingly, the purpose of this study is to evaluate the deterioration of load capacity and structural behavior of square CFT columns with the same shapes and boundary conditions before and after a fire. The study also evaluates the influential factors of the CFT columns reinforced to secure the residual strength after a fire.

• 상하수도학회지
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• 제31권6호
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• pp.567-575
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• 2017

It is not cost effective to raise the density of catch basins in preparation for heavy rainfall in terms of construction and maintenance. Our researchers have developed the new catch basin for increasing interception capacity of runoff with internal filtration structure. To compare interception capacity of an existing catch basin with the invented catch basin, a hydraulic experiment device with 4% of road gradients and 0.2% of road gradients was constructed. For runoff conditions of 4.4 l/s, 6.7 l/s and 10.4 l/s, capability of runoff and separation capability of debris (sand and leaves) were evaluated. As the main experimental results, the effectiveness of the developed catch basin has been verified with an increase in interception rate of approximately 22% for the runoff of 6.7 l/s as heavy rainfall. However, the results of invented catch basin showed only 4.5% of settlement rate of debris regarding sand. Therefore, the authors proposed an improved tilted screen structure additionally. After reviewing the performance of improved catch basin, application of the invented catch basin is expected to drain runoff effectively when it is applied to the faulty road drainage section.

• Smart Structures and Systems
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• 제17권1호
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• pp.149-165
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• 2016

Floods have been known to be one of the main causes of bridge collapse. Contrary to earthquakes, flood events tend to occur repeatedly and more frequently in rainfall areas; flood-induced damage and collapse account for a significant portion of disasters in many countries. Nevertheless, in contrast to extensive research on the seismic fragility analysis for civil infrastructure, relatively little attention has been devoted to the flood-related fragility. The present study proposes a novel methodology for deriving flood fragility curves for bridges. Fragility curves are generally derived by means of structural reliability analysis, and structural failure modes are defined as excessive demands of the displacement ductility of a bridge under increased water pressure resulting from debris accumulation and structural deterioration, which are known to be the primary causes of bridge failures during flood events. Since these bridge failure modes need to be analyzed through sophisticated structural analysis, flood fragility curve derivation that would require repeated finite element analyses may take a long time. To calculate the probability of flood-induced failure of bridges efficiently, in the proposed framework, the first order reliability method (FORM) is employed for reducing the required number of finite element analyses. In addition, two software packages specialized for reliability analysis and finite element analysis, FERUM (Finite Element Reliability Using MATLAB) and ABAQUS, are coupled so that they can exchange their inputs and outputs during structural reliability analysis, and a Python-based interface for FERUM and ABAQUS is newly developed to effectively coordinate the fragility analysis. The proposed framework of flood fragility analysis is applied to an actual reinforced concrete bridge in South Korea to demonstrate the detailed procedure of the approach.

• 드라이브 ㆍ 컨트롤
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• 제21권2호
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• pp.23-29
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• 2024

Potatoes are one of the world's four major crops, and domestic consumption is currently increasing in Korea. However, the mechanization rate of potatoes is very low, and especially, harvesting is the most labor-intensive task in potato production. In Korea, potato-collecting work depends on manpower, so it is necessary to develop a gathering-type harvester that can be used for processes from digging to harvesting. Therefore, in this study, a self-propelled-type potato harvester was developed, and its performance was analyzed to mechanize harvesting. The potato harvester was developed to have a crawler-type driving part with a 60 hp diesel engine and consisted of a digging part that digs potatoes from the ground, a vertical transporting part that transfers the dug potatoes to the height of the collection bag, a separating part that separates debris, such as stones and soil, and a collecting part that loads the collection box. A field test of the potato harvester was conducted, and performance was evaluated by the damage, loss, and debris mixing proportions, which were 2.5%, 2.8%, and 2.6%, respectively. The working capacity was 1.2 h/10 a. The economic analysis results showed that the cost of harvesting work could be reduced by 12.7% compared to manual harvesting.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.107-116
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• 2005

Korea has been suffering from various natural disasters. Slope-stability related disasters such as landslides usually occur during typhoon and torrential rain season. Types of slope-stability related disasters can be classified as failures in cut slopes along constructed roads, landslides in natural terrain, and retaining structure failures in urban area. This paper summarizes human casualties for the last 29 years in Korea, reviews field studies for the disaster sites that caused human casualties due to torrential rains in the Summer of 2005, analyzes causes of slope-stability related disasters and includes recommendations for an effective management system.

• 대한원격탐사학회지
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• 제38권6_2호
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• pp.1643-1652
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• 2022

해양생태계 및 수산자원, 해상안전에 부정적인 영향을 미치는 해양침적쓰레기는 주로 음파탐지기, 인양틀 및 잠수부를 통해 탐지되고 있다. 시간과 비용을 고려하여 최근에는 수중영상과 인공지능을 결합한 방법이 시도되고 시작했다. 본 연구에서는 효율적이고 정확한 해양침적쓰레기 탐지를 위하여, 수중영상과 딥러닝 객체탐지 모델인 You Only Look Once Version 5 (YOLOv5)와 You Only Look Once Version 7 (YOLOv7)을 학습 및 비교평가를 수행하였다. 유리, 금속, 어망, 타이어, 나무, 플라스틱 등의 객체탐지에 있어, 두 모델 모두 0.85 이상의 Mean Average Precision (mAP@0.5)를 기록하였다. 향후 영상자료 용량이 충분해지면, 보다 객관적인 성능평가 및 모델 개선이 가능할 것으로 사료된다.