• Earthquakes and Structures
• /
• 제14권6호
• /
• pp.589-598
• /
• 2018

An attempt is conducted to explore the relationship between the macroscopic global damage and the local damage of shear-type RC frames. A story damage index, which can be expressed as multi-variate functions of modal parameters, is deduced based on the tridiagonal matrix of the shear-type frame. The global damage model is also originated from structural modal parameters. Due to the connection of modal damage indexes, the relationship between the macroscopic global damage and the local story damage is reasonably established. In order to validate the derivation, a case study is carried out via an 8-story shear-type frame. The sensitivities of modal damage indexes to the location and severity of local story damages are studied. The evolution of the global damage is investigated as well. Results show that the global damage is sensitive to the degree of story damage, but it's not sensitive to its location. As the number of the damaged stories increases, more and more modes will be involved. Meanwhile, the global damage evolution curve changes from the concave shape to the S-type and then finally transforms into the convex shape. Through the proposed story damage, modal damage and global damage model, a multi-level damage assessment method is established.

• 한국응용곤충학회지
• /
• 제47권2호
• /
• pp.127-131
• /
• 2008

참나무시들음병의 매개충인 광릉긴나무좀, Platypus koryoensis(Murayama)은 한국에서 참나무시들음병원균인 Raffaelea sp.를 매개하는 것으로 알려져 있다. 참나무시들음 발병정도는 광릉긴나무좀의 밀도에 의존적인 것으로 추정되고 있다. 이에 (樹幹)내 천공수와 집중도가 참나무 피해정도에 미치는 영향을 구명하기 위하여 본 연구를 수행하였다. 수락산 피해지에서 고사목 6그루와 피해목 28그루의 신갈나무의 피해정도, 단위면적당 천공수, 천공간 최근거리를 수간의 상부(지표로부터 50cm)와 하부(지표면)에서 조사하였다. 상부와 하부에서의 천공수는 양의 상관을 보였으며 천공간 최근거리 또한 같은 경향을 보였다. 천공수가 증가할수록 수목의 피해도가 심하였으나 수목의 피해도가 심할수록 천공간 최근거리는 감소하였다. 천공의 분포도 수목의 피해도가 증가할수록 집중분포에서 군일분포로 바뀌었다. 광릉긴나무좀이 초기에는 집중적으로 공격을 하나 수간내 밀도가 증가함에 따라 종내경쟁이 일어나고 경쟁의 결과 개체간 간섭현상이 유도되고 천공의 공간적 분포가 균일하게 변환하게 된다는 것을 암시하는 것이다.

• Molecules and Cells
• /
• 제19권2호
• /
• pp.167-179
• /
• 2005

The cells of metazoans respond to DNA damage by either arresting their cell cycle in order to repair the DNA, or by undergoing apoptosis. This response is highly conserved across species, and many of the genes involved in this DNA damage response have been shown to be inactivated in human cancers. This suggests the importance of DNA damage response with regard to the prevention of cancer. The DNA damage checkpoint responses vary greatly depending on the developmental context, cell type, gene expression profile, and the degree and nature of the DNA lesions. More valuable information can be obtained from studies utilizing whole organisms in which the molecular basis of development has been well established, such as Drosophila. Since the discovery of the Drosophila p53 orthologue, various aspects of DNA damage responses have been studied in Drosophila. In this review, I will summarize the current knowledge on the DNA damage checkpoint response in Drosophila. With the ease of genetic, cellular, and cytological approaches, Drosophila will become an increasingly valuable model organism for the study of mechanisms inherent to cancer formation associated with defects in the DNA damage pathway.

• Geomechanics and Engineering
• /
• 제12권2호
• /
• pp.269-294
• /
• 2017

This study aimed to realize the creation of fuzzy stochastic damage to describe reliability more essentially with the analysis of harmony of damage conception, probability and fuzzy degree of membership in interval [0,1]. Two kinds of fuzzy behaviors of damage development were deduced. Fuzzy stochastic damage models were established based on the fuzzy memberships functional and equivalent normalization theory. Fuzzy stochastic damage finite element method was developed as the approach to reliability simulation. The three-dimensional fuzzy stochastic damage mechanical behaviors of Jianshan mine slope were analyzed and examined based on this approach. The comprehensive results, including the displacement, stress, damage and their stochastic characteristics, indicate consistently that the failure foci of Jianshan mine slope are the slope-cutting areas where, with the maximal failure probability 40%, the hazardous Domino effects will motivate the neighboring rock bodies' sliding activities.

• Corrosion Science and Technology
• /
• 제21권2호
• /
• pp.158-169
• /
• 2022

The objective of this study was to investigate the electrochemical behavior and damage degree of metal surface under different conditions by performing a potentiodynamic polarization experiment using an electropolishing solution for UNS S31603 based on initial delay time and surface roughness (parameters). A second anodic peak occurred at initial delay time of 0s and 100s. However, it was not discovered at 1000s and 3600s. This research referred to an increase in current density due to hydrogen oxidation reaction among various hypotheses for the second anodic peak. After the experiment, both critical current density and corrosion current density decreased when the initial delay time (immersion time) was longer. As a result of surface analysis, characteristics of the potentiodynamic polarization behavior were similar with roughness, although the degree of damage was clearly different. With an increase in surface roughness value, the degree of surface damage was precisely observed. As such, electrochemical properties were different according to the immersion time in the electropolishing solution. To select electropolishing conditions such as applied current density, voltage, and immersion time, 1000s for initial delay time on the potentiodynamic polarization behavior was the most appropriate in this experiment.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2020년도 봄 학술논문 발표대회
• /
• pp.113-114
• /
• 2020

In the design and maintenance of buildings, identifying the degree of damage in the event of a fire is an important factor in fire prevention and fire safety design. In order to predict fire damage, safety measures should be established by predicting the nature of evacuation according to fire, smoke and in-house characteristics, and the effects of the operation of fire safety facilities should also be considered, but in Korea, the risk analysis due to the operation of fire safety facilities is insufficient. Accordingly, this study uses fire statistics and sprinkler inspection data to analyze the degree of fire damage caused by the operation of sprinkler facilities in a probabilistic manner.

• 한국전산구조공학회논문집
• /
• 제34권4호
• /
• pp.231-241
• /
• 2021

교량의 노후화는 다양한 원인에 기인하겠지만 겨울철에 제설용으로 살포하는 염화칼슘이 교량부재에 침투하여 부식을 유발하는 것이 대표적인 교량 노후화 원인중 하나라고 할 수 있다. 본 연구의 목적은 교량의 부식에 의한 노후화 정도를 정량화하고 이를 교량의 해석모델에 적용하여 노후화 정도에 따른 지진취약도 해석을 수행하고 노후화 정도와 지진취약도 곡선의 관계를 평가하는 것이다. 노후화 정도를 고려한 지진취약도 해석에 각 손상상태별로 한계값을 적절히 정의하는 것이 중요하다. 본 연구에서는 손상정도에 따른 변위 연성도 능력의 저하 특성에 관한 기존 연구결과를 활용하여 손상상태를 정의하였다. 세 가지 교량받침과 두 가지 교각 높이에 따른 예제 교량들의 지진취약도 해석으로부터 노후화 정도가 증가할수록 지진취약도가 증가하는 경향이 나타냄을 알 수 있다. 이러한 노후화 정도에 따른 지진취약도의 차이는 손상상태가 경미, 보통, 심각, 붕괴의 상태로 갈수록 증가하는 경향을 나타낸다.

• 한국대기환경학회지
• /
• 제6권1호
• /
• pp.103-110
• /
• 1990

To investigate the damage on the black pine(Pinus thunbergii) by the air pollution around Ulsan Industrial Complex, forty-six plots were set up and the effects of air pollution were evaluated with the injured index of black pine. The injured index of black pine showing the degree of air pollution from 1987 to 1988 indicated that the central area of Yeochun-dong and Youngjam-dong were heavily damaged. The effective indicaters of black pine damage from air pollution in the order of importance were the color change of one-year-old branch, the ratio of fallen needle of two-year-old branch, the degree of reducing needle, and the degree of growing shoot growth. There was a reliable relationship between the content of $SO_3$ and F in the air and the injured index of black pine. There was no significant correlation between the injured index of the black pine and the content of chemical properties in soil.

• 한국공간구조학회논문집
• /
• 제18권2호
• /
• pp.87-97
• /
• 2018

Stone pagoda structures have continued to be aged due to the combination of various damage factors. However, some studies on nonstructural damage have been carried out, but assessment studies on structural damage have not been done in various ways. Therefore, in this study, structural and nonstructural influencing factors according to the damage types are classified and the damage assessment according to the structural influencing factors affecting the behavior of the stone pagoda structure is performed. In addition, the damage rating classification criteria for each type of structural damages or damage locations are presented, and the damage index is calculated by providing the criteria for the classification of damage according to the degree of damage to which the damage is caused. Therefore, this study can evaluate quantitatively the damage status of stone pagoda structures.

• 한국방재학회 논문집
• /
• 제7권5호
• /
• pp.119-127
• /
• 2007

본 연구에서는 지역별 재해 발생 위험과 피해규모를 재해연보상의 다양한 유형으로 재구성하고 시설물별 재해 저감능력 및 예방정도를 평가할 수 있는 지표를 개발하였다. 각 지표는 기상학적, 수문학적 취약성과 재해 발생 확률과 같은 내용을 포함하고 있다. 이러한 내용을 GIS 기반의 DB 시스템으로 구축하여 시설물별 저감능력 대비 피해규모를 매칭하여 지역안전도를 진단하였다. 개발된 안전도 지표는 지역의 인명을 보호하고, 피해를 감소하며, 방재 시설물을 보호하는 내용을 담고 있다. 또한 재해 유형별 피해유형분석을 GIS 기반의 자료를 이용하여 시행하였다.