• Title/Summary/Keyword: Damage Function

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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.

A Psoriasis Case Report on Liver Damage Related to Scutellaria Radix (황금(黃芩)으로 인한 간손상으로 판단되는 건선 환자 1례 보고)

  • Lee, Ki-Hoon;Yang, Ji-Eun;Chang, Gyu-Tae
    • The Journal of Korean Medicine
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    • v.32 no.4
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    • pp.149-158
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    • 2011
  • Object: Any medication can have the risk of liver damage. To prevent this risk, liver function tests should be monitored carefully during every course of medication. This paper is a psoriasis case report on liver damage related to Scutellaria Radix medication. Shown by this case, herbal medicine has the possibility of liver damage, too. Therefore it should be carefully used under the direction of Oriental Medical Doctors who specialize in it. The purpose of this case report is to suggest this, and that more cases of liver damage related to herbal medicine should be reported. Methods: To monitor the medication's effect on the liver, liver function was evaluated during medications. Reflotron plus was used to evaluate AST and ALT by analyzing peripheral blood. Results: By this test, a case was identified as liver damage caused by a medication including Scutellaria Radix. Conclusion: This case suggests that Scutellaria Radix medication caused liver damage in a certain patient. Therefore, to prevent liver damage related to Scutellaria Radix, doctors should monitor patient's liver function regularly.

Scenario-Based Earthquake Damage Estimation of Bridge Structures in Daegu City Using Hazus-MH Methodology (Hazus-MH 방법을 이용한 대구시 교량의 시나리오 지진에 의한 피해 예측)

  • Kim, Siyun;Kim, Sung Jig;Chang, Chunho
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.4
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    • pp.89-96
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    • 2018
  • The paper presents the damage estimation of bridge structures in Daegu city based on the scenario-based earthquakes. Since the fragility curves for domestic bridge strucures are limited, the Hazus methodology is employed to derive the fragility curves and estimate the damage. A total of four earthuquake scenarios near Daegu city are assumed and structure damage is investigated for 81 bridge structures. The seismic fragility function and damage level of each bridge had adopted from the analytical method in HAZUS and then, the damage probability using seismic fragility function for each bridge was evaluated. It was concluded that the seismic damage to bridges was higher when the magnitude of the earthquake was large or nearer to the epicenter.

Damage Classification by Time Density Function of Ultrasonic Pulse Signal occurred at Tire (타이어에서 발생하는 초음파펄스신호의 시간밀도함수에 의한 손상 분별)

  • Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.6
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    • pp.291-296
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    • 2015
  • The tire damage classification method is researched on the periodicity detection of ramdomness ultrasonic signals to occur at the driving vehicle tire. Setting method of adaptive threshold is proposed in order to valid pulse detection by tire damage in ultrasonic noise on the road and used low pass filter for decrease signal ramdomness as preprocessing. Time interval of detected pulse is setted the density function depend on the vehicle's speed and the method of tire damage detection is proposed that measuring the first peak's time of time density function.The result of time density function in case of one damage material, the first peak's time is measured within the error limit of tire's rotation period, 169.8ms and 97.9ms and 81.8ms, about the speed of 50km/h and 80km/h and 100km/h. In case of more than one damage material, the sum of each peak's time is measured within the error limit of tire's rotation period about the speed.

Development of Estimation Functions for Strong Winds Damage Based on Regional Characteristics : Focused on Jeolla area (지역특성 기반의 강풍피해 예측함수 개발 : 전라지역을 중심으로)

  • Song, Chang Young;Yang, Byong Soo
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.4
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    • pp.13-24
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    • 2020
  • Abnormal weather conditions have lately been occurring frequently due to the rapid economic development and global warming. Natural disasters classified as storm and flood damages such as heavy rain, typhoon, strong wind, high seas and heavy snow arouse large-scale human and material damages. To minimize damages, it is important to estimate the scale of damage before disasters occur. This study is intended to develop a strong wind damage estimation function to prepare for strong wind damage among various storm and flood disasters. The developed function reflects weather factors and regional characteristics based on the strong wind damage history found in the Natural Disaster Yearbook. When the function is applied to a system that collects real-time weather information, it can estimate the scale of damage in a short time. In addition, this function can be used as the grounds for disaster control policies of the national and local governments to minimize damages from strong wind.

Three dimensional finite element simulations of fracture tests using the Craft concrete model

  • Jefferson, A.D.;Barr, B.I.G.;Bennett, T.;Hee, S.C.
    • Computers and Concrete
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    • v.1 no.3
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    • pp.261-284
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    • 2004
  • Two enhancements to a recently developed plastic-damage-contact model for concrete are presented. The model itself, which uses planes of degradation that can undergo damage and separation but that can regain contact according to a contact law, is described. The first enhancement is a new damage evolution function which provides a completely smooth transition from the undamaged to the damaged state and from pre-peak to post-peak regions. The second is an improved contact function that governs the potential degree of contact with increasing opening on a crack plane. The use of a damage evolution function with a pre-peak has implications for the consistent tangent matrix/stress recovery algorithm developed for the model implementation, and amendments to this algorithm to accommodate the new function are described. A series of unpublished experimental tests on notched specimens undertaken in Cardiff in the mid 1990s are then described. These include notched beam tests as well as prismatic and cylindrical torsion tests. The tests are then considered in three dimensional finite element analyses using the modified Craft model implemented in the finite element program LUSAS. Comparisons between experimental and numerical data show reasonable agreement except that the numerical simulations do not fully describe the latter stages of the softening responses for the torsion examples. Finally, it is concluded that the torsion tests described provide useful benchmark examples for the validation of three-dimensional numerical models for concrete.

Damage and Fracture Analysis of Concrete using Homogenized Crack Model (혼합균열모델을 적용한 콘크리트의 손상 및 파괴해석)

  • Kim Kwang-Soo;Song Ha-Won;Nam Jin-Won
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.155-158
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    • 2005
  • Damage and fracture of concrete is characterized as the degradation of strength and stiffness. There can be modeled as the so-called homogenized crack model which can overcome the mesh sensitivity. But the plasticity and damage modeling for damage behavior before the fracture of concrete should be combined with the crack model. In this study, a damage function and an unified hardening-softening function are applied to the homogenized crack model to develope a 3-dimensional FEM program for nonlinear damage and fracture analysis of concrete. The comparison of numerical results and experimental data show that the combined modeling in this study can simulate the damage and fracture of concrete without the mesh-sensitivity. It is also shown that the behavior of the so-called Engineering Cementitious Composite(ECC) characterized by strain-hardening and multiple cracks can be well simulated using the modeling.

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Effects of Catechin on Mixed Function Oxidase System and Oxidative Damage in Rat Liver Exposed to Microwave (전자파 조사 흰쥐 간조직의 Mixed Function Oxidase System과 산화적 손상에 미치는 Catechin의 영향)

  • 김미지;이준하;이순재
    • Journal of Nutrition and Health
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    • v.34 no.3
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    • pp.299-305
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    • 2001
  • The purpose of this study was to investigate the effects of catechin on the changes of microsomal mixed function oxidase(MFO) system and oxidative damage in rat liver exposed to microwave. Sprague-Dawley male rats weighing 200$\pm$10g body weight were randomly assigned to one normal and microwave exposed groups: microwave exposed groups were divided three groups: catechin free diet(MW) group, 0.25% catechin(MW+0.25C) group and 0.5% catechin(MW+0.5C) group to the levels of dietary catechin supplementation. The rats were irradiated with microwave at frequency 2.45GHz for 15 min and then the changes pattern of mixed function oxidase system and oxidative damage were investigated for 16 days. The activity of XOD in MW group was increased from 4 day to 8 days after irradiation, compared to normal group and decreased to the level of normal group 16 days. But catechin supplementation group were maintained to the normal level. The contents of cytochrome P(sub)450 and NADPH cytochrome P(sub)450 reductase activities in liver of MW group was increased from 4 day to 8 day after irradiation, compared to normal group and decreased to the level of normal group at 16 day. But catechin supplementation group were recovered to the normal level. The contents of superoxide radical in liver of MW group was increased 1.28, 1.25, 1.17 fold of normal group at 4,6 and 8 days days after irradiation. respectively, but catechin supplementation group were maintained the normal level. The contents of lipifuscin in liver have a same tendency in superoxide radical contents. These result suggested that the supplementation of catechin have control the mixed function oxidase system and oxidative damage and that may help to recover tissues from microwave damage. (Korean J Nutrition 34(3) : 299~305, 2001)

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A Feasibility Study on the Application of the Topology Optimization Method for Structural Damage Identification (구조물의 결함 규명을 위한 위상최적설계 기법의 적용가능성 연구)

  • Lee, Joong-Seok;Kim, Jae-Eun;Kim, Yoon-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.2 s.107
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    • pp.115-123
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    • 2006
  • A feasibility of using the topology optimization method for structural damage identification is investigated for the first time. The frequency response functions (FRFs) are assumed to be constructed by the finite element models of damaged and undamaged structures. In addition to commonly used resonances, antiresonances are employed as the damage identifying modal parameters. For the topology optimization formulation, the modal parameters of the undamaged structure are made to approach those of the damaged structure by means of the constraint equations, while the objective function is an explicit penalty function requiring clear black-and-white images. The developed formulation is especially suitable for damage identification problems dealing with many modal parameters. Although relatively simple numerical problems were considered in this investigation, the possibility of using the topology optimization method for structural damage identification is suggested through this research.

Evaluation of Seismic Fragility of Concrete Faced Rockfill Dam (콘크리트 표면차수벽형 석괴댐의 지진 취약도 평가)

  • Baeg, Jongmin;Park, Duhee;Yoon, Jinam;Choi, Byoung-Han
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.103-108
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    • 2018
  • The fragility curves for CFRD dams are derived in this study for probabilistic damage estimation as a function of a ground motion intensity. The dam crest settlement, which is a widely used damage index, is used for minor, moderate, and extensive damage states. The settlement is calculated from nonlinear dynamic numerical simulations. The accuracy of the numerical model is validated through comparison with a centrifuge test. The fragility curve is represented as a log normal distribution function and presented as a function of the peak ground acceleration. The fragility curves developed in this study can be utilized for real time assessment of the damage of dams.