• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.397-408
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• 2021

The construction industry has the highest occupational accidents/injuries and has experienced the most fatalities among entire industries. Korean government installed surveillance camera systems at construction sites to reduce occupational accident rates. Construction safety managers are monitoring potential hazards at the sites through surveillance system; however, the human capability of monitoring surveillance system with their own eyes has critical issues. A long-time monitoring surveillance system causes high physical fatigue and has limitations in grasping all accidents in real-time. Therefore, this study aims to build a deep learning-based safety monitoring system that can obtain information on the recognition, location, identification of workers and heavy equipment in the construction sites by applying multiple object tracking with instance segmentation. To evaluate the system's performance, we utilized the Microsoft common objects in context and the multiple object tracking challenge metrics. These results prove that it is optimal for efficiently automating monitoring surveillance system task at construction sites.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.2
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• pp.25-32
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• 2000

Fire-resistant boom is one of the most important facilities in in situ homing of spilled oil. Thermal response of a fire-resistant boom to turning is experimentally investigated in this paper by using an electric furnace and a burning test facility. This test facility is composed of a test tank, a fire boom, a hood for inhaling smoke, an incinerator for burning up gases and thermocouples, etc. Thereby a systematic method of approach in small laboratory scale is developed to study the performance of a fire-resistant boom. Burning test is carried out for the fire boom model which has been developed through the present study. It is shown that the present fire boom model has capability to withstand the high temperature around 800℃ and high rate of heat flux on it due to homing. For more realistic experimental environments, larger dimensions in devices and longer time in experiments are recommended in near future.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.33-36
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• 2011

Recently, It has increased to use ultra high strength concrete. It is effective to mix organic fibers for preventing spalling. But if fiber mixed, flowability of concrete is decreases. The aim of this study is to evaluation of fire resistance performance for fiber-mixed ultra high strength concrete on field application. As a result, flowability of nylon fiber mixed concrete is better than polyethylene fiber mixed. In non-fiber and polyethylene fiber mixed concrete, spalling occurred. And strain converged at 0.004. Also, residual strength could not evaluate. Nylon fiber mixed concrete is effective to prevent spalling. And it remians 50% residual strength compare with compressive strength at room temperature.

• Journal of the Korea Institute of Building Construction
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• v.14 no.3
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• pp.259-265
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• 2014

This study is to analyze durability of water-repellent paints mixed with water-repellents as outer surface finishing materials, and evaluate its feasibility. General functions and water-repelling effects were tested, and the feasibility was evaluated based on the test results. The experimental results of heat conduction durability, air permeability, absorption, and bond strength suggested that water-repellent paints mixed with water-repellents were suitable for finishing materials. Considering overall general durability performances, stable mixing ratios were 2, 5, and 8%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.6
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• pp.70-76
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• 2019

This paper presents a methodology for priority decision of performance evaluation of small-and-medium-sized highway bridges. This methodology could be used for establishing a maintenance strategy of those bridges which are not liable to the law of the Special Act on the Safety Control and Maintenance of Establishments and are thought laid under blind spot. The risk index are calculated considering vulnerability and social influence, then the bridges are classified as three types, one requiring immediate evaluation, the other one requiring evaluation within next year, and the third one observing, according to the index. The suggested method was applied to a small bridge under service and its field applicability verified. From this study, it was judged that this methodology could be used appropriately for establishing maintenance strategy and saving the maintenance budget.

• Transactions of the KSME C: Technology and Education
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• v.4 no.1
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• pp.3-10
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• 2016

Heat pump unit performance is represented by the COP(Coefficient of Performance) and expressed by the one point design condition according to KS C 9306. However, when heat pump operated to the real buildings, the simulations are changed continuously according to the actual weather conditions, the building load and heat pump source conditions. The purpose of this paper is to evaluate the APF(Annual performance factor) for a climate dependent building integrated air-to-air heat pump system in major cities in Korea. TRNSYS simulation tool with an international MV standard based IPMVP 4.4.2 was utilized to perform the annual performance analysis. The APF with the multi-performance data based method was calculated as 2.29 for Daejeon residential building case while Busan residential building case appeared as the highest with 2.36.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.715-721
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• 2008

공동주택에서의 음환경 성능은 실내환경의 질과 연관시켜 설계단계부터 충분한 검토가 필요한 성능항목이다. '국토해양부'는 '공통주택 성능등급 표시제도'에서 Air Duct를 통해 상하층간 전파되는 소음을 제어하기 위한 대책을 요구하고 있다. 이에 화장실에 적합한 구조 및 재질로 소음 저감기를 개발하고, 소음기 성능평가 장치를 구성하여 이론과 비교평가하고, 실제 현장에 설치 시 적용효과를 분석하였다.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.110-116
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• 2016

The rapid expansion of buildings and paved roads increases the risk of flood disaster in an urban area. One of the solutions can be the use of permeable pavements. This study evaluated the permeability of permeable blocks used for the roadway pavement. Joint fillers and mat sands of the investigated blocks met the corresponding standards. The flexural strength of the blocks was 5.29 MPa to meet these standards. Based on interior permeability test results after pollution, the four products evaluated were categorized into the following three levels: One for the $1^{st}$ level, one for the $2^{nd}$ level and two for the $3^{rd}$ level. From the field permeability test and pervious concrete infiltration test results nine months after their construction, all the products except one passed the quality standards of 0.1 mm/s.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.539-546
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• 2022

The current ｢Detailed guidelines for the safety and maintenance of facilities (performance Evaluation)｣ prescribes that the durability of surface concrete is evaluated by comparing the measuring the surface rebound value between sound parts and non-sound parts that have surface damage due to winter rain or leakage on concrete. However, this evaluation method was proposed by analyzing the correlation with an experimental DB obtained under freeze-thaw simulation promoting the environment without reviewing on-site applicability. Therefore, this study reviewed on-site application appropriateness of the concrete freeze-thaw damage evaluation method for the 21 concrete bridges in Korea. From the results, it was clearly confirmed that there was a difference in the surface rebound value between the sound part and the non-sound on the concrete surface; the current evaluation method is considered appropriate for application at the site. In addition, the necessity of adding a specific method and a measurement position of surface rebound value were also analyzed, and the effectiveness of the current evaluation method was also analyzed when targeting the entire concrete bridge, not the evaluation of some sections.

• Magazine of the Korea Concrete Institute
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• v.8 no.2
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• pp.109-117
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• 1996

Recently, High-Workable Concrete has been developed and began to be used to a great extent in foreign countries, but it is not familiar with and fully Introduced in Korea yet. Therefore the aim of this paper is to suggest a reference data. for the development of High-Workable Concrete according to the comparative analysis which were done on the effects of mix proportion(water-binder ratio, sand-aggregate ratio, unit water, a kind of superplasticizer) on the flowing characteristics. And also this paper aims to examine the compactability and segregation resistance of High-Workable Concrete in a mock-up test and in a field test. From the result, we concluded that it is possible to produce and to use the High-Workable Concrete at the construction site.