• Title/Summary/Keyword: disaster safety

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Development of a Acoustic Acquisition Prototype device and System Modules for Fire Detection in the Underground Utility Tunnel (지하 공동구 화재재난 감지를 위한 음향수집 프로토타입 장치 및 시스템 모듈 개발)

  • Lee, Byung-Jin;Park, Chul-Woo;Lee, Mi-Suk;Jung, Woo-Sug
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.7-15
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    • 2022
  • Since the direct and indirect damage caused by the fire in the underground utility tunnel will cause great damage to society as a whole, it is necessary to make efforts to prevent and control it in advance. The most of the fires that occur in cables are caused by short circuits, earth leakage, ignition due to over-current, overheating of conductor connections, and ignition due to sparks caused by breakdown of insulators. In order to find the cause of fire at an early stage due to the characteristics of the underground utility tunnel and to prevent disasters and safety accidents, we are constantly managing it with a detection system using image analysis and making efforts. Among them, a case of developing a fire detection system using CCTV-based deep learning image analysis technology has been reported. However, CCTV needs to be supplemented because there are blind spots. Therefore, we would like to develop a high-performance acoustic-based deep learning model that can prevent fire by detecting the spark sound before spark occurs. In this study, we propose a method that can collect sound in underground utility tunnel environments using microphone sensor through development and experiment of prototype module. After arranging an acoustic sensor in the underground utility tunnel with a lot of condensation, it verifies whether data can be collected in real time without malfunction.

Petrological Characteristics and Nondestructive Deterioration Assessments for Foundation Stones of the Sebyeonggwan Hall in Tongyeong, Korea (통영 세병관 초석의 암석학적 특성 및 비파괴 손상평가)

  • Han, Doo Roo;Kim, Sung Han;Park, Seok Tae;Lee, Chan Hee
    • Economic and Environmental Geology
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    • v.54 no.2
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    • pp.199-212
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    • 2021
  • The Sebyeonggwan Hall (National Treasure No. 305) is located on the Naval Headquarter of Three Provinces in Tongyeong, and it has partly undergone with several rebuilding, remodeling, repairing and restorations since it's the first establishment in Joseon Dynasty (AD 1605) of ancient Korea. This study focuses on 50 foundation stones that comprise the Sebyeonggwan. These stones are made of six rock types and currently have various shapes of the surface damages. As the foundation stones, the dominant rock type was dacitic lapilli tuffs, and provenance-based interpretation was performed to supply alternative stones for conservation. Most of the provenance rocks for foundation stones showed highly homogeneity with their corresponding stones of petrography, mineralogy and magnetic susceptibility. According to surface deterioration assessments, the most serious damages of the stones were blistering and scaling. The deterioration mechanism was identified through the analysis of inorganic contaminants, and the primary reason is considered salt weathering caused by sea breeze and other combined circumstances. Based on the mechanical durability of the stones, there was no foundation stone that required the replacement of its members attributed to the degradation of the rock properties, but conservation treatment is considered necessary to delay superficial damage. The foundation stones are characterized by a combined outcome of multiple petrological factors that caused physical damage to surfaces and internal defects. Therefore, it's required to diagnosis and monitoring the Sebyeonggwan regularly for long-term preservation.

A Study on the Particle Size of Sand to Prevent Penetration of Subterranean Termite (Reticulitermes speratus kyushuensis) in Wooden Buildings (국내 지중흰개미의 목조건축물 유입 차단을 위한 모래의 적정 입도 연구)

  • Kim, Si Hyun;Kim, Tae Heon;Chung, Yong Jae
    • Journal of Conservation Science
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    • v.38 no.2
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    • pp.80-86
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    • 2022
  • Termites cause massive damage to wooden architectural heritage structures. Chemical treatments have been commonly used to control them. In foreign countries, physical barriers made of sheet and particles impenetrable to termite are being used as an alternative to the chemical method. To study the efficacy of physical barriers, we investigated the appropriate sand particle size that can prevent the penetration of R. speratus kyushuensis. Upon evaluating the barrier properties of sand with particle sizes ranging from 0.85 to 4.00 mm, the penetration of termites was found to be effectively blocked at a particle size range of 1.00 to 2.80 mm. At smaller particle sizes, termites managed to move the sand particles and build an almost linear mud tube to penetrate the sand layer. At larger particle sizes, the termites could penetrate the sand layer by passing through the sand gaps.

Development of Plant Phenology and Snow Cover Detection Technique in Mountains using Internet Protocol Camera System (무인카메라 기반 산악지역 식물계절 및 적설 탐지 기술 개발)

  • Keunchang, Jang;Jea-Chul, Kim;Junghwa, Chun;Seokil, Jang;Chi Hyeon, Ahn;Bong Cheol, Kim
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.24 no.4
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    • pp.318-329
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    • 2022
  • Plant phenology including flowering, leaf unfolding, and leaf coloring in a forest is important to understand the forest ecosystem. Temperature rise due to recent climate change, however, can lead to plant phenology change as well as snowfall in winter season. Therefore, accurate monitoring of forest environment changes such as plant phenology and snow cover is essential to understand the climate change effect on forest management. These changes can monitor using a digital camera system. This paper introduces the detection methods for plant phenology and snow cover at the mountain region using an unmanned camera system that is a way to monitor the change of forest environment. In this study, the Automatic Mountain Meteorology Stations (AMOS) operated by Korea Forest Service (KFS) were selected as the testbed sites in order to systematize the plant phenology and snow cover detection in complex mountain areas. Multi-directional Internet Protocol (IP) camera system that is a kind of unmanned camera was installed at AMOS located in Seoul, Pyeongchang, Geochang, and Uljin. To detect the forest plant phenology and snow cover, the Red-Green-Blue (RGB) analysis based on the IP camera imagery was developed. The results produced by using image analysis captured from IP camera showed good performance in comparison with in-situ data. This result indicates that the utilization technique of IP camera system can capture the forest environment effectively and can be applied to various forest fields such as secure safety, forest ecosystem and disaster management, forestry, etc.

A Study on Flood Susceptibility of Heritage Sites by Heritage Type Depending on Locational Characteristics (입지특성에 따른 문화재 유형별 홍수 민감성 기초연구)

  • Kim, Ji-Soo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.3
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    • pp.46-56
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    • 2022
  • This study aimed to analyze the locational characteristics of heritage sites in Seoul in order to identify flood susceptibility by type. As for the location factors related to flood susceptibility, elevation, slope, distance to streams, and topographic location were analyzed. Literature review was supplemented for the historical and humanistic environments of heritage sites. The results of the study are as follows. First, heritage sites in Seoul are distributed throughout the city, and are especially highly dense in the Hanyangdoseong fortress. It was also confirmed that heritage sites were concentrated around Jung-gu, Jongno-gu, Jingwan-dong, and Ui-dong in the quantitative spatial analyses. Second, types of heritage sites at the circumstance susceptible to flood damage were related to commerce and distribution, traffic, modern traffic and communication, geological monument, residence, government office, and palace. Third, heritage types with locational characteristics that showed low flood susceptibility were found to be natural scenic spots, telecommunication, ceramics, Buddhism, tombs, and tomb sculptural heritage assets. In a time when risk factors that can damage the value of heritage are gradually increasing due to anthropogenic influences along with changes in the natural environment, this study provides basic data for vulnerability analysis that reflects the unique characteristics of heritage assets. The results can contribute to more comprehensive and comprehensive insights for the management and protection of heritage by including the humanities and social science data together with natural factors in the analysis.

Prediction of cyanobacteria harmful algal blooms in reservoir using machine learning and deep learning (머신러닝과 딥러닝을 이용한 저수지 유해 남조류 발생 예측)

  • Kim, Sang-Hoon;Park, Jun Hyung;Kim, Byunghyun
    • Journal of Korea Water Resources Association
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    • v.54 no.spc1
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    • pp.1167-1181
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    • 2021
  • In relation to the algae bloom, four types of blue-green algae that emit toxic substances are designated and managed as harmful Cyanobacteria, and prediction information using a physical model is being also published. However, as algae are living organisms, it is difficult to predict according to physical dynamics, and not easy to consider the effects of numerous factors such as weather, hydraulic, hydrology, and water quality. Therefore, a lot of researches on algal bloom prediction using machine learning have been recently conducted. In this study, the characteristic importance of water quality factors affecting the occurrence of Cyanobacteria harmful algal blooms (CyanoHABs) were analyzed using the random forest (RF) model for Bohyeonsan Dam and Yeongcheon Dam located in Yeongcheon-si, Gyeongsangbuk-do and also predicted the occurrence of harmful blue-green algae using the machine learning and deep learning models and evaluated their accuracy. The water temperature and total nitrogen (T-N) were found to be high in common, and the occurrence prediction of CyanoHABs using artificial neural network (ANN) also predicted the actual values closely, confirming that it can be used for the reservoirs that require the prediction of harmful cyanobacteria for algal management in the future.

Development of Quality Evaluation and Management System for Assembled Temporary Equipment - Focused on Steel Pipe Scaffolding, System Scaffolding and Support - (조립 가설기자재 품질평가 및 관리 시스템 개발 - 강관 비계, 시스템 비계, 시스템 동바리를 중심으로 -)

  • Jang, Ji young;Lee, Ji yeon;Kim, Ha yoon;Lee, Jun ho;Kim, Jun-Sang;Kim, Jung-Yeol;Kim, Young Suk
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.5
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    • pp.43-55
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    • 2022
  • Since assembled temporary equipment is widely used for construction work that should be carried out before this construction begins, it is essential to secure quality during assembly and prevent safety accidents caused by assembled temporary equipment after installation. However, it was investigated that most construction site managers are not aware of its importance, such as recognizing the quality management of assembled temporary equipment as a task of managing temporary structures that are dismantled after installation for this construction. The quality management work of assembled temporary equipment at the construction site is carried out in different ways for each construction site because there is no formalized procedure and the subject of performing. In addition, it is analyzed that the manager of the general construction company inspects and reflects the parts that need to be inspected without evidence, so transparency is not guaranteed and the result leads to a serious disaster. Therefore, the purpose of this study is to establish a document preparation-oriented system that provides systematic quality evaluation and management procedures for securing the quality of assembled temporary equipment, develops a checklist for quality evaluation and management, and supports history management on the web.

A Study on Area-Wide Integrated Termite Management for the Preservation of Wooden Built Heritage (목조건축문화재의 예방 보존을 위한 공간적 통합 흰개미 관리(AW-ITM)의 적용)

  • KIM, Sihyun;CHUNG, Yongjae
    • Korean Journal of Heritage: History & Science
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    • v.55 no.3
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    • pp.60-72
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    • 2022
  • A number of wooden built heritage remain in Korea, and most have been damaged by various biological factors including termite. Owing to the irreversible damage caused by termites, wooden built heritage are losing their authenticity and structural stability. In this study, Area-Wide Integrated Termite Management(AW-ITM) was proposed to prevent termite damage. First, to understand the locational characteristics of these sites, the distance from adjacent forests and surrounding forest areas was analyzed for 182 national designated wooden built heritage(national treasures, treasures) using the Geographic Information System(GIS). By analyzing existing pest control projects(2003-2020) and the components of the ITM, the characteristics of termite control for cultural heritages were determined. Based on these results, the cultural heritage sites and their surrounding spaces were divided into three areas, and the types of cultural properties were divided into six types according to the location and number of buildings. Along with this, termite control measures were proposed for each area and type. The concept of AW-ITM has been partially applied to the "Comprehensive Control of Termites in wooden built heritages Sites" by the Cultural Heritage Administration. Caution must be taken with regard to the establishment of a cultural heritage management policy; AW-ITM should be applied on a trial basis with the results then being carefully analyzed and reflected in the establishment of policies pertaining to the conservation management of cultural heritage.

Major Factors Influencing Landslide Occurrence along a Forest Road Determined Using Structural Equation Model Analysis and Logistic Regression Analysis (구조방정식과 로지스틱 회귀분석을 이용한 임도비탈면 산사태의 주요 영향인자 선정)

  • Kim, Hyeong-Sin;Moon, Seong-Woo;Seo, Yong-Seok
    • The Journal of Engineering Geology
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    • v.32 no.4
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    • pp.585-596
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    • 2022
  • This study determined major factors influencing landslide occurrence along a forest road near Sangsan village, Sancheok-myeon, Chungju-si, Chungcheongbuk-do, South Korea. Within a 2 km radius of the study area, landslides occur intensively during periods of heavy rainfall (August 2020). This makes study of the area advantageous, as it allows examination of the influence of only geological and tomographic factors while excluding the effects of rainfall and vegetation. Data for 82 locations (37 experiencing landslides and 45 not) were obtained from geological surveys, laboratory tests, and geo-spatial analysis. After some data preprocessing (e.g., error filtering, minimum-maximum normalization, and multicollinearity), structural equation model (SEM) and logistic regression (LR) analyses were conducted. These showed the regolith thickness, porosity, and saturated unit weight to be the factors most influential of landslide risk in the study area. The sums of the influence magnitudes of these factors are 71% in SEM and 83% in LR.

Risk Assessment of Smoke Generated During Combustion for Some Wood (일부 목재의 연소 시 발생되는 연기의 위험성 평가)

  • Chung, Yeong-Jin;Jin, Eui
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.373-380
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    • 2022
  • In this study, Chung's equations 1, 2, and 3 were extended to standardize smoke safety rating evaluation in case of fire, and Chung's equations-V, smoke performance index-V, and smoke growth index-V were calculated. Five types of wood were selected and their smoke indices were measured using the cone calorimeter method according to ISO 5660-1. The smoke risk was graded by the smoke risk index-VI according to Chung's equation-VI. Smoke risk index-VI increased in the order of PMMA (1) ≈ maple (1.01) < ash (1.57) < needle fir (4.98) < paulownia (46.15) < western red cedar (106.26). It was predicted that maple and ash had the lowest smoke risk, and paulownia and western red cedar had the highest. The five samples' CO mean production rate (COPmean) was 0.0009~0.0024 g/s, indicating that these woods were incompletely burned than the polymethyl methacrylate (PMMA) reference material. Regarding the smoke properties of the chosen woods, the smoke performance index-V (SPI-V) increased as the bulk density increased, and the smoke risk index-VI (SRI-VI) decreased.