• Title/Summary/Keyword: Damage factors

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Development of Heterogeneous Damage Cause Estimation Technology for Bridge Decks using Random Forest (랜덤포레스트를 활용한 교량 바닥판의 이종손상 원인 추정 기술 개발)

  • Jung, Hyun-Jin;Park, Ki Tae;Kim, Jae Hwan;Kwon, Tae Ho;Lee, Jong-Han
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.1
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    • pp.19-32
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    • 2024
  • An investigation into the detailed safety diagnosis report indicates that domestic highway bridges mainly suffer from defects, deterioration, and damage due to physical forces. In particular, deterioration is an inevitable damage that occurs due to various environmental and external factors over time. In particular, bridge deck is very vulnerable to cracks, which occur along with various types of damages such as rebar corrosion and surface delamination. Thus, this study evaluates a correlation between heterogeneous damage and deterioration environment and then identifies the main causes of such heterogeneous damage. After all, a bridge heterogeneous damage prediction model was developed using random forests to determine the top five factors contributing to the occurrence of the heterogeneous damage. The results of the study would serve as a basic data for estimating bridge maintenance and budget.

Damage-Based Seismic Performance Evaluation of Reinforced Concrete Frames

  • Heo, YeongAe;Kunnath, Sashi K.
    • International Journal of Concrete Structures and Materials
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    • v.7 no.3
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    • pp.175-182
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    • 2013
  • A damage-based approach for the performance-based seismic assessment of reinforced concrete frame structures is proposed. A new methodology for structural damage assessment is developed that utilizes response information at the material level in each section fiber. The concept of the damage evolution is analyzed at the section level and the computed damage is calibrated with observed experimental data. The material level damage parameter is combined at the element, story and structural level through the use of weighting factors. The damage model is used to compare the performance of two typical 12-story frames that have been designed for different seismic requirements. A series of nonlinear time history analyses is carried out to extract demand measures which are then expressed as damage indices using the proposed model. A probabilistic approach is finally used to quantify the expected seismic performance of the building.

Identification of Damages within a Plate Structure (평판 구조물의 손상규명)

  • Kim, Nam-In;Lee, U-Sik
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.671-675
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    • 2000
  • In this study, an FRF-based structural damage identification method (SDIM) is proposed for plate structures. The present SDIM is derived from the partial differential equation of motion of the damaged plate, in which damage is characterized by damage distribution function. Various factors that might affect the accuracy of the damage identification are investigated. They include the number of modal data used in the analysis and the damage-induced modal coupling. In the present SDIM, an efficient iterative damage self-search method is introduced. The iterative damage search method efficiently reduces the size of problem by searching out and then by removing all damage-free zones at each iteration of damage identification analysis. The feasibility of the present SDIM is studied by some numerically simulated tests.

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A Study on the Improvement of Health Damage Relief Regulation due to Environmental Hazardous Factors (환경유해인자로 인한 건강피해 구제제도의 개선방안에 관한 고찰)

  • Baek, Woonsuk;Shim, Younggyoo
    • Journal of Environmental Policy
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    • v.12 no.1
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    • pp.75-100
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    • 2013
  • Health damages such as pneumoconiosis and kidney damage, caused by environmental hazardous factors are being reported in health impact assessment conducted on environmentally vulnerable areas, including cement factories and refineries. Current legal system for relieving the environmental victims is not effective enough because the environmental health act does not specify the environmental hazardous factors to be considered for the relief. The aim of this study is to examine the problems of the existing system by making empirical analysis on health damages and afflicted people as well as on cases when afflicted people were able to be covered by remedy system. The results show that, insufficiencies of the relief system are due to the following reasons: First, current Environmental Health Act does not act well as a remedy system. Second, due to its unique nature of environmental health damage, it is hard to identify and prove the cause of health damage and unlawful actions of violators in the process of environmental dispute conciliation and lawsuits against polluters. This paper suggests following solutions on above mentioned problems. First, in defining the range and definition of environmental diseases, negative system should be used alongside with the current positive system. Second, we suggest adding the nature of public law to relief system, in order to ease the legal burden of proof. Third, in case when it is hard to identify the polluters and one cannot expect reliefs for their damage, it is possible to elevate the effectiveness of the relief measure by expanding scope of the search for possible environmental hazardous factors that caused the health damage. It is urgent to improve the relief system so as to secure the environmental rights of Koreans.

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Developing Standards for Measuring Consumers' Ability of College Student: Focus on the Consumer Education Effects (대학생 소비자능력 측정을 위한 척도개발: 소비자교육효과 측정을 중심으로)

  • Seo, In-Joo
    • Journal of Family Resource Management and Policy Review
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    • v.13 no.4
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    • pp.115-139
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    • 2009
  • This study focused on the development of a scale measuring the effect of consumer education. The purposes of this study were to develop a tool which could measure consumer knowledge, consumer attitudes and consumer behavior. Data were collected from 266 college students. Analysis was done using frequency, cross tabulation analysis, reliability test, principle components factor analysis, confirmatory factor analysis (Amos 5.0), and multiple regression analysis. The results from this study were as follows: 1) Nine consumer knowledge factors (23-items) were identified: consciousness of consumer education and evaluation, consumer rights and allowance management, methods of consumer education and consumer institutions, green energy and environmental consumption, essence and content of consumer education, consumer rights and consumer duty, critical consideration and consumer's damage salvation, buying minds and decision-making, independent consumers. Total variance was 58.4%. Cronbach's alpha for the nine factors ranged from .68-.79. 2) Five consumer attitude factors (26-items) were identified: green environmental consumption, consumer's role and rights, resources saving and consumer's damage salvation, consciousness of consumers, and right consumption. Total variance was 59.2%. Cronbach's alpha for the five factors ranged from .89-.94. 3) Seven consumer behavior factors (27-items) were identified: social role and rights of consumer and consumer movement, right buying and segregated garbage collection, green environmental consumption and resources saving, altruism and decision-making, allowance management and impulse buying, consumer's damage salvation, and consciousness of consumer. The total variance was 59.1%. Cronbach's alpha for the seven factors ranged from .77-.88. Finally, a scale measuring the effect of consumer education consisting of 76 items (consumer knowledge: 23 items (9 factors), consumer attitude: 26 items (5 factors), consumer behavior: 27 items (7 factors)) was constructed.

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A Study on the Characteristics of Flood Damage Caused by landslide and Its Minimization Using GIS-The Case Study in the Samwhadong, Donghae city, Kangwondo, Korea

  • Kang, Sang-Hyuk
    • Spatial Information Research
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    • v.10 no.4
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    • pp.493-499
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    • 2002
  • This paper presents the disaster control due to flooding through the case study of Samwhadong, Donghae city, Kangwondo, broken out at 31, August 2002. In order to assess the characteristics of flood damage one must consider social and geological conditions, the factors of flood risk were derived based on GIS. For reduction of flood damage, flood hazard map was prepared for local residents. These information will support refuge activities, it would aid the reduction of flood damage.

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Development of Estimation Functions for Strong Winds Damage Reflecting Regional Characteristics Based on Disaster Annual Reports : Focused on Gyeongsang Area (재해연보 기반 지역특성을 반영한 강풍피해예측함수 개발 : 경상지역을 중심으로)

  • Rho, Jung-Lae;Song, Chang-young
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.223-236
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    • 2020
  • Purpose: In this study, a strong wind damage prediction function was developed in order to be used as a contingency during disaster management (preventive-preventive-response-recovery). Method: The predicted strong wind damage function proposed in this study took into account the re-enactment boy power, weather data and local characteristics at the time of damage. The meteorological data utilized the wind speed, temperature, and damage history observed by the Korea Meteorological Administration, the disaster year, and the recovery costs, population, vinyl house area, and farm water contained in the disaster report as factors to reflect the regional characteristics. Result: The function developed in this study reflected the predicted weather factors and local characteristics based on the history of strong wind damage in the past, and the extent of damage can be predicted in a short time. Conclusion: Strong wind damage prediction functions developed in this study are believed to be available for effective disaster management, such as decision making by policy-makers, deployment of emergency personnel and disaster prevention resources.

Mechanisms of 5-azacytidine-induced damage and repair process in the fetal brain

  • Ueno, Masaki
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2006.11a
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    • pp.55-64
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    • 2006
  • The fetal central nervous system (CNS) is sensitive to diverse environmental factors, such as alcohol, heavy metals, irradiation, mycotoxins, neurotransmitters, and DNA damage, because a large number of processes occur during an extended period of development. Fetal neural damage is an important issue affecting the completion of normal CNS development. As many concepts about the brain development have been recently revealed, it is necessary to compare the mechanism of developmental abnormalities induced by extrinsic factors with the normal brain development. To clarify the mechanism of fetal CNS damage, we used one experimental model in which 5-azacytidine (5AZC), a DNA damaging and demethylating agent, was injected to the dams of rodents to damage the fetal brain. 5AzC induced cell death (apoptosis)and cell cycle arrest in the fetal brain, and it lead to microencephaly in the neonatal brain. We investigated the mechanism of apoptosis and cell cycle arrest in the neural progenitor cells in detail, and demonstrated that various cell cycle regulators were changed in response to DNA damage. p53, the guardian of genome, played a main role in these processes. Further, using DNA microarray analysis, tile signal cascades of cell cycle regulation were clearly shown. Our results indicate that neural progenitor cells have the potential to repair the DNA damages via cell cyclearrest and to exclude highly affected cells through the apoptotic process. If the stimulus and subsequent DNA damage are high, brain development proceeds abnormally and results in malformation in the neonatal brain. Although the mechanisms of fetal brain injury and features of brain malformation afterbirth have been well studied, the process between those stages is largely unknown. We hypothesized that the fetal CNS has the ability to repair itself post-injuring, and investigated the repair process after 5AZC-induced damage. Wefound that the damages were repaired by 60 h after the treatment and developmental processes continued. During the repair process, amoeboid microglial cells infiltrated in the brain tissue, some of which ingested apoptotic cells. The expressions of genes categorized to glial cells, inflammation, extracellular matrix, glycolysis, and neurogenesis were upregulated in the DNA microarray analysis. We show here that the developing brain has a capacity to repair the damage induced by the extrinsic stresses, including changing the expression of numerous genes and the induction of microglia to aid the repair process.

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DNA Damage in Lymphocytes after Hair Dyeing and Related Factors among Women Volunteers (일부 자원 여성에서 모발염색 후 림프구의 DNA손상과 관련 요인)

  • Cho, Jin-A;Oh, Eun-Ha;Sull, Dong-Geun;Lee, Eun-Il
    • Journal of Preventive Medicine and Public Health
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    • v.35 no.4
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    • pp.275-281
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    • 2002
  • Objectives : To evaluate the DNA damage by hair dyeing in human lymphocytes Methods : Comet assays were carried out to evaluate the DNA damage in lymphocytes by hair dyeing. Twenty subjects were selected from women volunteers whose age ranged from 55 to 67 year old. All subjects had no smoking history. Blood samples were collected before and 6 hours after hair dyeing. DNA damage was evaluated by means of the tail moments, which were quantified by a KOMET 4.0 image analysis system. Results : The tail moments before hair dyeing showed no significant differences among subjects except for the high frequency group. The mean values of the tail moments in subjects with low and high frequencies of hair dyeing were 1.39 and 1.77, respectively (p<0.05). The tail moments after hair dyeing increased significantly, The mean values of tail moments in subjects before and after hair dyeing were 1.45 and 1.79, respectively (p<0.01). However, the difference levels of DNA damage in lymphocytes before and after hair dyeing were found to be slightly lower in both the dietary supplement taking group and high frequency group. Conclusions : The high frequency group appears to have a higher level of DNA damage than the low frequency group before hair dyeing. DNA damage in lymphocytes was found to be significantly higher in the volunteers after hair dyeing. In this study, the related factors such as high frequency and taking dietary supplements appeard to reduce DNA damage in lymphocytes after hair dyeing.

Influence Factors Suggestion and Prediction Model Development of Regional Building Damage Costs according to Typhoon (태풍에 따른 지역별 건물피해액에 영향을 미치는 요인 도출 및 피해 예측모델 개발)

  • Kim, Ji-myung;Kim, Boo-Young;Yang, Seongpil;Oh, Jeongill;Son, Kiyoung
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.5
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    • pp.515-525
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    • 2015
  • Currently, according to the climate change, serious damage by typhoon has been occurred in the world. In this respect, the research on the prediction model to minimize the damage from various natural disaster has been conducted in several developed countries. In the case of U.S, various models to predict building damage costs have been used widely in many organizations such as insurance companies and governments. In South Korea, although studies regarding damage prediction model according to typhoon have been conducted, the scope has been only limited to consider the property of typhoon. However, it is necessary to consider various factors such as typhoon information, geography, construction environment, and socio-economy factors to predict the damages. Therefore, to address this issue, first, correlation analysis is conducted between various variables based on the data of typhoon from 2003 to 2012. Second, the damage prediction model by using regression analysis is developed based on suggested influence factors. The findings of this study can be utilized to develop the model for predicting the damage costs of buildings by typhoon like HAZUS-MH of US.