• Title/Summary/Keyword: damage type

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Hazardous Analysis for Train Collision and Derailment through the Analysis of Railroad Accident Type at Domestic and Foreign (국내외 철도 사고 사례분석을 통한 열차 충돌/탈선 사고 위험도 분석)

  • Lee, Chan-Woo;Kang, Jong-Bae
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.151-154
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    • 2007
  • THE DOMESTIC AND FOREIGN OF THE COUNTRY RAILROAD ACCIDENT ANALYSIS IT LED FROM THE PAPER WHICH IT SEES AND IT ANALYZED A TRAIN COLLISION/DERAILED ACCIDENT RISK FIXED QUANTITY. THE TRAIN ACCIDENT OCCURS DIRECT AND LATENT DAMAGE. IT CLASSIFIES THE ACCIDENT WHICH 5 YEAR FOR OCCURS RECENTLY DOMESTIC AND FOREIGN OF THE COUNTRY WITH A TYPE FROM THE RESEARCH WHICH IT SEES. IT TRIED TO ANALYZE THE DAMAGE SIZE AGAINST A TRAIN COLLISION/DERAILED ACCIDENT WITH DANGEROUS QUOTIENT.

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Finite element analysis of the structural material by the theory of continuum damage mechanics (연속체 손상역학에 따른 구조재료의 유한요소해석)

  • 김승조;김위대
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.3
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    • pp.58-67
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    • 1991
  • A theory of continuum damage mechanics based on the theory of materials of type N was developed and its nonlinear finite element approximation and numerical simulation was carried out. To solve the finite elastoplasticity problems, reasonable kinematics of large deformed solids was introduced and constitutive relations based on the theory of materials of type-N were derived. These highly nonlinear equations were reduced to the incremental weak formulation and approximated by the theory of nonlinear finite element method. Two types of problems, compression moulding problem and pure bending problem, were solved for aluminum 2024.

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A comparison of detergency and dimensional stability between wet cleaning and dry cleaning (물세탁과 드라이클리닝의 세탁성능과 형태안정성 비교)

  • Kwak, Soo-Kyung;Kim, Ah-Ri;Oh, Hwawon;Park, Myung-Ja
    • Journal of the Korea Fashion and Costume Design Association
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    • v.21 no.1
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    • pp.181-189
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    • 2019
  • The washability, redeposition, fill power, and fabric damage of wet cleaning and dry cleaning solvents were measured to identify the optimal type of washing that would increase washability while maintaining dimensional stability. The soiled fabric is a polyester cotton blend and the types of soil were wine, blood, make-up and sebum with carbon black. Petroleum and silicone solvents were used in dry cleaning. Results from this study are as follows. First, detergency is significantly influenced by the type of washing and type of soil. Wet cleaning is superior to dry cleaning. Wet cleaning shows a strong washing performance against hydrophilic soils, whereas, dry cleaning is stronger against hydrophobic soils. Second, redeposition is significantly affected by the type of washing, fabrics, and soils. Redeposition occurred little on cotton during wet cleaning, but showed a high rate for nylon. However, when the two types of fabric were dry cleaned, redeposition occurred on both types. Third, the fill power of duck-down is very affected by the type of washing. Resilience is the best in wet cleaning; and in dry cleaning, petroleum solvents showed a higher resilience when as compared to silicone solvents. Last, the level of fabric damage to cotton fabrics is highly influenced by the type of washing. Wet cleaning damages cotton fabrics significantly more than dry cleaning. For dry cleaning, petroleum solvents damage these fabrics slightly more than silicone solvents. In conclusion, the type of soil must initially be identified to determine the optimal type of washing. Special caution is required when textiles with particulate soil and nylon are washed. When considering the resilience of duck-down clothing, wet cleaning is more appropriate than dry cleaning. Dry cleaning, especially when using silicone-based solvents, is more suitable than wet cleaning for maintaining the shape of clothing.

The Survey on Actual Condition Depending on Type of Degraded area and Suggestion for Restoration Species Based on Vegetation Information in the Mt. Jirisan Section of Baekdudaegan (식생정보에 기초한 백두대간 지리산권역 내 훼손지 유형별 실태조사)

  • Lee, Hye-Jeong;Kim, Ju-Young;Nam, Kyeong-Bae;An, Ji-Hong
    • Korean Journal of Environment and Ecology
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    • v.34 no.6
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    • pp.558-572
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    • 2020
  • The purpose of this study was to classify the types of degraded areas of Mt. Jirisan section in Baekdudaegan and survey the actual condition of each damage type to use it as basic data for the direction of the restoration of damaged areas according to damage type based on the vegetation information of reference ecosystem. The analysis of the Mt. Jirisan section's actual degraded conditions showed that the total number of patches of degraded areas was 57, and the number of patches and size of degraded areas was higher at the low average altitude and gentle slope. Grasslands (deserted lands) and cultivated areas accounted for a high portion of the damage types, indicating that agricultural land use was a major damage factor. The survey on the conditions of 14 degraded areas showed that the types of damage were classified into the grassland, cultivated area, restoration area, logged-off land, and bare ground. The analysis of the degree of disturbance (the ratio of annual and biennial herb, urbanized index, and disturbance index) by each type showed that the simple single-layer vegetation structure mostly composed of the herbaceous and the degree of disturbance were high in the grassland and cultivated land. The double-layer vegetation structure appeared in the restoration area where the pine seedlings were planted, and the inflow of naturalized plants was especially high compared to other degraded areas due to disturbances caused by the restoration project and the nearby hiking trails. Although the inflow of naturalized plants was low because of high altitude in bare ground, the proportion of annual and biennial herb was high, indicating that all surveyed degraded areas were in early succession stages. The stand ordination by type of damage showed the restoration area on the I-axis, cultivated area, grassland, logged-off land, and bare ground in that order, indicating the arrangement by the damage type. Moreover, the stand ordination of the degraded areas and reference ecosystem based on floristic variation showed a clear difference in species composition. This study diagnosed the status of each damage type based on the reference ecosystem information according to the ecological restoration procedure and confirmed the difference in species composition between the diagnosis result and the reference ecosystem. These findings can be useful basic data for establishing the restoration goal and direction in the future.

Damage localization in plate-like structure using built-in PZT sensor network

  • Liu, Xinglong;Zhou, Chengxu;Jiang, Zhongwei
    • Smart Structures and Systems
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    • v.9 no.1
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    • pp.21-33
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    • 2012
  • In this study, a Lamb-wave based damage detection approach is proposed for damage localization in plate. A sensor network consisting of three PZT wafer type actuators/sensors is used to generate and detect Lamb waves. To minimize the complication resulted from the multimode and dispersive characteristics of Lamb waves, the fundamental symmetric Lamb mode, $S_0$ is selectively generated through designing the excitation frequency of the narrowband input signal. A damage localization algorithm based upon the configuration of the PZT sensor network is developed. Time-frequency analysis method is applied to purify the raw signal and extract damage features. Experimental result obtained from aluminum plate verified the proposed damage localization approach.

Damage Simulation of Natural Draught Cooling Towers

  • Noh, S.Y.;Huh, Y.
    • Computational Structural Engineering : An International Journal
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    • v.2 no.1
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    • pp.25-32
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    • 2002
  • Natural draught cooling towers often develop visible crack structures as consequences of progressive damage processes over their life-time. The aim of this paper is a numerical demonstration of the progressive damage process of cooling towers, representatively for the reinforced concrete structures, in order to improve the durability and extend the life-time of structures subjected to such damage processes. For the analyses, the applied material model for reinforced concrete will be briefly introduced. An existing natural draught cooling tower with a pronounced crack structure, in which this crack structure indicates the typical damage pattern of large cooling towers will be numerically simulated. The change of dynamical behavior of the structure with regard to natural frequencies, reflecting the global damage process due to the degrading stiffness of the structure in dependence of the load type and intensity, will be presented and discussed.

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ANN-based Real-Time Damage Detection Algorithm using Output-only Acceleration Signals (가속도를 이용한 인공신경망 기반 실시간 손상검색기법)

  • Kim, Jung-Tae;Park, Jae-Hyung;Do, Han-Sung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.43-48
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    • 2007
  • In this study, an ANN-based damage detection algorithm using acceleration signals is developed for alarming locations of damage in beam-type structures. A new ANN-algorithm using output-only acceleration responses is designed for damage detection in real time. The cross-covariance of two acceleration signals measured at two different locations is selected as the feature representing the structural condition. Neural networks are trained for potential loading patterns and damage scenarios of the target structure for which its actual loadings are unknown. The feasibility and practicality of the proposed method are evaluated from laboratory-model tests on free-free beams for which accelerations were measured before and after several damage cases.

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A Study on the Connection Method for the Collapse Damage of Electric Power Facilities due to Earthquake Effects (지진 영향으로 인한 전기시설물의 붕괴피해 연계 방안 연구)

  • Lee, Byung-Hoon;Lee, Byung-Jin;Oh, Seung-Hee;Jung, Woo-Sug;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.5
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    • pp.203-208
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    • 2018
  • In this paper, we selected power and power distribution facilities corresponding to urban infrastructure from the types of damage that could be caused by earthquakes and studied how they were calculated to damage. To calculate the damage, a graph of the magnitude of the damage was produced by applying the vulnerability curve calculation formula, which can be calculated for each type and type of facility. The scale of the earthquake and the probability of the occurrence of damage by the maximum earthquake acceleration were shown in the form of a vulnerability rate when the earthquake occurred in the urban infrastructure facility for utilizing the calculation result. It also applied a method of quantifying the fragility, which is a method of converting the calculated fragility into an integrated form, to represent a constant value for the magnitude of the damage. Continuing research, such as the method applied in this paper, could help identify in advance the types of structures affected by an earthquake and respond to reducing damage.

Compensation for Injury to Publicly Owned Marine Resources : Legal and Economic Aspects (해양 공공자연자원 피해보상의 법.경제적 평가)

  • 표희동;이흥동
    • The Journal of Fisheries Business Administration
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    • v.22 no.2
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    • pp.53-74
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    • 1991
  • Interest on ocean environment has increased with the development of industrialized activities. Public marine resorces are defined broadly to include fish stocks, beaches, marine waters, recreational fishing, biota, waterfowls, shorebirds, seabirds and marine mammals But, it is not easy to analyze compensation for injury to publicly owned marine resources because the claimants do not exist clearly and the economic methodology of damage on public goods is not developed fully. This paper introduces basic idea of welfare economic theory and environmental legislation to the research question : How the economics and law can be applied to the case of damage on publicly owned marine resource. The paper discusses the concepts of willingness to pay (WTP) and willingness to accept (WTA). It is accepted generally that WTA is correct concept of welfare change in the case of damaged public goods. Four methods (compensating variation, equivalent variation, compensating surplus, equivalent surplus of measuring welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes are compared. Compensating variation(CV) is the best measure of welfare changes caused by environmental damage. Vartia (1983) showed CV could be measured from the ordinary demand function using the differential equations. This paper also provides an overview of the emerging U.S. and Korea legal system for compensation for natural resource damages, with particular emphasis on U.S. legal system under Comprehensive Environmen-tal Response Compensation and Liability Act (CERCLA). These regulations are to include two different types of standardized procedures for assessing natural resources injury : Type A or simplified assessment techniques for small releases ; and Type B protocols that would include detailed and extensive assessment methodologies for major releases. Type A procedures are specified by Natural Resources Damage Assessment Model for Coastal and Marine Environment (NRDAM/CME) of the U.S. CERCLA provides a legal 'legitimization for the use of economic-based nonmarket valuation in the courts and have introduced appropriate and accurate nonmarket valuation methods based on willingness to-pay for damage assessment. By briefly reviewing economic theory and environmental legislation, we hope to help provide a better understanding of the compensation process and the economics of publicly owned marine resources in the U.S. and to integrate the economics and law of natural resources valuation into a single comprehensive package in Korea.

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Factorial Experiment for Drum-type Secondary Separating Part of Self-propelled Pepper Harvester

  • Nam, Ju-Seok;Kang, Young-Sun;Kim, Su-Bin;Kim, Dae-Cheol
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.242-250
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    • 2017
  • Purpose: This study was conducted to determine the appropriate operating conditions through a factorial experiment for the secondary separating part of the self-propelled pepper harvester. Methods: An experimental setup that simulates the secondary separating part of the self-propelled pepper harvester was organized. Test samples were classified into three types according to the number of peppers on a stem, and 12 sets were prepared for each type. Among the operating conditions of the secondary separating part, the rotational speed of drum B (four levels), radial clearance between drums and cylindrical teeth (three levels), and speed ratio between the three drums (two levels) were set as the test factors, and tests were repeated three times for different levels of each factor. The appropriate operating conditions were determined by analyzing the separation ratio and damage ratio of the peppers collected through the secondary separating part. Results: The test factors changed the overall separation ratio and overall damage ratio in similar trends. In other words, the conditions that caused high overall separation ratios also exhibited high overall damage ratios. Owing to the high overall damage ratio in the condition with the highest overall separation ratio, the operating conditions should be selected considering both ratios. Conclusions: When the condition with more than 60% of overall separation ratio and less than 15% of overall damage ratio was considered as the appropriate operating condition, 70 rpm of the rotational speed of drum B, 5 mm of the radial clearance between drums and cylindrical teeth, and 7:3:5 for the speed ratio of the three drums A, B, and C should be applied for the secondary separating part used in this study. Supplementary studies will be required in the future to find optimal operating conditions through the actual field test under further divided test factors.