• Title/Summary/Keyword: Damage spread

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The Analysis on the Traces of Short Pass Behavior on Lawn Fields in Urban Parks (도시공원내 잔디밭 가로지르기 흔적 분석)

  • 노재현;강인애
    • Journal of the Korean Institute of Landscape Architecture
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    • v.32 no.1
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    • pp.33-46
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    • 2004
  • This study is aimed to redesign established parks and to propose a series of devices protecting them from vandalism. To solve the problems, we ascertained the damaged areas of the park greens. The trace analysis was performed to grasp the transverse inside the parks of Jeonju and Iksan in Collabuldo. Then, we presented the basic plan for minimizing park damage and for remodeling the system of movement. The results of the study are summarized as follows: it is identified that the transverse phenomenon is considerably wide-spread in majority of parks, and has no relationship to the park area or the green area. It is considered that the $\ulcorner$Condition rating class$\lrcorner$ of grass damage, which is grade 6, is extraordinarily high and the damage is accumulated considerably. Also, the damage part of other grade is discovered equally, and when unattended, the acceleration of damage is positive. A damage width a 0.5∼1.5m makes up the greater part of 79.6%. It also constitutes most of a rectilinear form. The difference in the height between the original point and destination point is below 0.7m, which is above 70%. It is identified that the interrelationship between the damage continuation length and plan distance is relatively high by the simple regression: analysis and by Pearson' correlation analysis. In spite of the normal damage continuation length is 20m, the frequency degree is downward with extreme point at 10m. Accordingly, it is assumed that park users have physical and psychological pressure when they cross the lawn field. Damage types are classified as the Simple cut cross type, the Behavioral facilitates type, Access advantage type and the Strolling type through type classification. It is considered that this classification is effective when identifying short pass type on lawn field according to the damage length and intensity.

A Study on Treatment of Sleep Disturbance in the Books on Cold Damage (상한문헌에 나타난 수면장애 치료법에 대한 연구)

  • Kim, Sang-Un;Jung, Hyun-Jong
    • The Journal of Korean Medical History
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    • v.27 no.2
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    • pp.99-120
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    • 2014
  • Purpose : There are two types of sleep disturbance: inability to sleep (不眠) and somnolence (多眠). This study is to examine treatments of the two types of sleep disturbance in the Books of Cold Damage and how those theories were established and formed. Methods : 1. Verses including the words related to inability to sleep and somnolence were extracted from "Treatise on Cold Damage Diseases" (傷寒論). 2. Among the Books on Cold Damages that are classified according to the symptoms, 17 books with contents related to inability to sleep and somnolence were selected to collect and classify data in three perspectives: mechanism of disease (病機), method of treatment (治法) and disease pattern (病證). 3. Data collected through the above methods were compared and diagramed. Results & Conclusions : 1. On Cold Damage, inability to sleep is mostly rooted when human body lacks yin energy while having excessive yang energy (陽盛陰虛) due to fire and heat (火熱). The reason could be misuse of perspiration inducing method (汗法) or purgation (下法) on the doctors' part. 2. On Cold Damage, somnolence is rooted when pathogen (邪氣) is spread to yin meridians (陰經) and the human body lacks yang while having excessive yin energy (陰盛陽虛) or when heat (熱邪) is invaded into interior parts (裏部). 3. Many scholars of Cold Damage in later periods had copied the "Treatise on Cold Damage Diseases" for treatments of sleep disturbance but many others have applied the verses from "Treatise on Cold Damage Diseases" or added new treatments. Do jeol-am (陶節庵) and Wang Geung-dang (王肯堂) particularly had deep understanding on "Treatise on Cold Damage Diseases" and utilized the content freely or suggested new remedies because they had thorough knowledge on relating formula as well.

Biological Damage and Risk Assessment of The Wood Cultural Properties in Fire Prevention Area (화재방제구역에 따른 목조문화재 생물손상 및 생물위험도 평가)

  • Kim, Dae Woon;Chung, Yong Jae
    • Journal of the Korean Wood Science and Technology
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    • v.43 no.1
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    • pp.104-111
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    • 2015
  • The three-year inspection of 20 tree stumps in the fire prevention area around the wooden building confirmed that termite colonies had been rapidly spread. In particular, four buildings among thirty one wooden buildings of Songgwang-sa temple were infected by the termite, indicating that the habitate of termite has been spread across the fire prevention area over the temple area. However, a non-destructive microwave diagnosis showed that internal damages have been progressed until now, suggesting a high risk to the building. These results suggest that the fire prevention area should be properly maintained to have harmful element controlled. Therefore, effective methods are required to eliminate tree stumps or wood materials used to establish fire prevention area near wooden buildings.

Characterization of Tree Composition using Images from SENTINEL-2: A Case Study with Semiyang Oreum (SENTINEL-2 위성영상을 이용한 조림 특성 조사: 세미양오름를 통한 사례 연구)

  • Chung, Yong Suk;Yoon, Seong Uk;Heo, Seong;Kim, Yoon Seok;Ahn, Jinhyun;Han, Gyung Deok
    • Journal of Environmental Science International
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    • v.31 no.9
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    • pp.735-741
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    • 2022
  • Global warming affects forests and their ecology. Diversity in the forest is a buffer that reduces the damage due to global warming. Mixed forests are ecologically more valuable as versatile habitats and are effective in preventing landslides. In Korea, most forests were created by simple afforestation with trees of evergreen species. Typically, evergreen trees are shallow-rooted, and deciduous trees are deep-rooted. Mixed forest tree roots grip the soil effectively, which reduces the occurrence of landslides. Therefore, improving the distribution of tree types is essential to reduce damage due to global warming. For this improvement, the investigation of tree types of the forest is needed. However, determining the tree type distribution of forests that are spread over wide areas is labor-intensive and time-consuming. This study suggests effective methods for determining the distribution of tree types in a forest that is spread across a relatively wide area. Using normalized difference vegetation index and RGB images from unmanned aerial vehicles, each evergreen and deciduous tree, and grassland area can be distinguished. The distinguished image determines the distribution of tree type. This method is effective compared to directly determining the tree type distribution in the forest by the use of manpower. The data from these methods could be applied to plan a mixed forest or to prepare for future damage due to global warming.

The Real Scale Fire Tests for Vertical Fire Spread Study of External Finishing Material (외벽 마감재료의 수직화재 확산 연구를 위한 실물화재 실험)

  • Kweon, Oh-Sang;Yoo, Yong-Ho;Kim, Heung-Youl;Kim, Jung-Hyun;Min, Se-Hong
    • Fire Science and Engineering
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    • v.26 no.6
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    • pp.85-91
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    • 2012
  • To reduce human life and property damage at the fire in a building, it is most critical to control flame spread in the early stage. Fire spread prevention measure generally includes fire resistance performance securing of structure member in the arson zone and use limitation based on combustion performance of finishing material. The latter is most fundamental fire safety design to determine flame spread, but domestic combustion test determines combustion performance by specimen sized fire test method. Thus, there are many restrictions in the determination of combustion performance by composite material such as sandwich panel. Especially, outer finishing material uses a variety of composite material such as dry bit, aluminum composite panel, and metal panel compared to inner finishing material. Therefore, this study would determine vertical fire spread features by a full scaled fire experiment through the test method of ISO 13785-2, an international test standard.

Natural Spread Pattern of Damaged Area by Pine Wilt Disease Using Geostatistical Analysis (공간통계학적 방법에 의한 소나무 재선충 피해의 자연적 확산유형분석)

  • Son, Min-Ho;Lee, Woo-Kyun;Lee, Seung-Ho;Cho, Hyun-Kook;Lee, Jun-Hak
    • Journal of Korean Society of Forest Science
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    • v.95 no.3
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    • pp.240-249
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    • 2006
  • Recently, dispersion of damaged forest by pine wilt disease has been regarded as a serious social issue. Damages by pine wilt disease have been spreaded by natural area expansion of the vectors in the damaged area, while the national wide damage spread has induced by human-involved carrying infected trees out of damaged area. In this study, damaged trees were detected and located on the digital map by aerial photograph and terrestrial surveys. The spatial distribution pattern of damaged trees, and the relationship of spatial distribution of damaged trees and some geomorphological factors were geostatistically analysed. Finally, we maked natural spread pattern map of pine wilt disease using geostatistical CART(Classification and Regression Trees) model. This study verified that geostatistical analysis and CART model are useful tools for understanding spatial distribution and natural spread pattern of pine wilt diseases.

A vibration based acoustic wave propagation technique for assessment of crack and corrosion induced damage in concrete structures

  • Kundu, Rahul Dev;Sasmal, Saptarshi
    • Structural Engineering and Mechanics
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    • v.78 no.5
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    • pp.599-610
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    • 2021
  • Early detection of small concrete crack or reinforcement corrosion is necessary for Structural Health Monitoring (SHM). Global vibration based methods are advantageous over local methods because of simple equipment installation and cost efficiency. Among vibration based techniques, FRF based methods are preferred over modal based methods. In this study, a new coupled method using frequency response function (FRF) and proper orthogonal modes (POM) is proposed by using the dynamic characteristic of a damaged beam. For the numerical simulation, wave finite element (WFE), coupled with traditional finite element (FE) method is used for effectively incorporating the damage related information and faster computation. As reported in literature, hybrid combination of wave function based wave finite element method and shape function based finite element method can addresses the mid frequency modelling difficulty as it utilises the advantages of both the methods. It also reduces the dynamic matrix dimension. The algorithms are implemented on a three-dimensional reinforced concrete beam. Damage is modelled and studied for two scenarios, i.e., crack in concrete and rebar corrosion. Single and multiple damage locations with different damage length are also considered. The proposed methodology is found to be very sensitive to both single- and multiple- damage while being computationally efficient at the same time. It is observed that the detection of damage due to corrosion is more challenging than that of concrete crack. The similarity index obtained from the damage parameters shows that it can be a very effective indicator for appropriately indicating initiation of damage in concrete structure in the form of spread corrosion or invisible crack.

Study on the Analysis of Damage Patterns of Cellular Phone Batteries According to Energy Sources (에너지원에 따른 이동전화기 배터리의 소손패턴 해석에 관한 연구)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.21-26
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    • 2011
  • The purpose of this paper is to present the damage patterns of cellular phone (SCH_W830) batteries according to energy sources and have them utilized as data for the settlement of disputes between manufactures and consumers. The reliability was secured by maintaining the ambient temperature and humidity at $22{\pm}2^{\circ}C$ and 40~60 %, respectively. The voltage of the battery used for the tests was measured to be 4.18V between positive pole (+) and negative pole (-)(1), and 4.19 V between positive pole (+) and negative pole (-)(2). This study applied the Korean Industrial Standard (KS) to the flammability test of cellular phones due to a general flame applied to them and found that no damage occurred to the built-in battery even though the flame was applied to the cases of cellular phones for 30 seconds. From the results of immersing the cellular phones in the saline solution (NaCl, 0.9 %) for 180 seconds, it was found that there was a trace of carbonization and melting due to the heat caused by leaking current. It can be seen that when the cellular phones were heated for 70 seconds using a microwave oven (MWO), the areas containing the metal holder, recharging connector, antenna, etc., were melted and discolored and that other areas showed no particular problems. That is, while the external carbonization of cellular phones, built-in metals and dielectric materials, and damage and deformation of the battery terminal block, etc., occurred differently depending on the types of energy sources, the voltage showed comparatively constant characteristics. Therefore, it is thought to be possible to attribute the cause of damage to the battery by performing analysis taking into consideration comprehensively the characteristics of the flame spread pattern as well as the melting and deformation of metals.

A Study on Block from Spread of Fire of the Exteriors Installation Space (외장재 설치 공간의 화재확산 차단에 관한 연구)

  • Min, Se-Hong;Yun, Jung-Eun;Kim, Mi-Suk
    • Journal of the Korea Safety Management & Science
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    • v.14 no.2
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    • pp.83-89
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    • 2012
  • In this study, FDS fire simulation experiments and measured wind speed by applying the exterior installation portion for blocking the spread of the fire was investigated. As a result, aluminum composite panels installed in the lower and the upper part of the panel to remove all the lower side, and then the maximum wind speed 0.24 m/s and the upper side 0.58 m/s were measured. In the FDS, the measured wind speed difference air currents are approximately 3.7 times in 12 seconds, the occurrence of 17 seconds early moment wind 2.2 m/s was measured from. Before and after the fire occurred in early of the air velocity about 39 seconds was 3.5 times difference. Such air currents caused by the temperature of the building but also by the building height was found. Turbulent flame of fire by expanding the vertical extent of damage become greatly important factor. Therefore, through the exterior installation portion of the block that can delay the spread of fire is expected that this should be taken.

Trends in Disaster Prediction Technology Development and Service Delivery (재난예측 기술 개발 및 서비스 제공 동향)

  • Park, Soyoung;Hong, Sanggi;Lee, Kangbok
    • Electronics and Telecommunications Trends
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    • v.35 no.1
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    • pp.80-88
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    • 2020
  • This paper describes the development trends and service provision examples of disaster occurrence and spread prediction technology for various disasters such as tsunamis, floods, and fires. In terms of fires, we introduce the WIFIRE system, which predicts the spread of large forest fires in the United States, and the Metro21: Smart Cities Institute project, which predicts the risk of building fires. This paper describes the development trends in tsunami prediction technology in the United States and Japan using artificial intelligence (AI) to predict the occurrence and size of tsunamis that cause great damage to coastal cities in Japan, Indonesia, and the United States. In addition, it introduces the NOAA big data platform built for natural disaster prediction, considering that the use of big data is very important for AI-based disaster prediction. In addition, Google's flood forecasting system, domestic and overseas earthquake early warning system development, and service delivery cases will be introduced.