• Title/Summary/Keyword: Damage Patterns

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Simulation of the behaviour of RC columns strengthen with CFRP under rapid loading

  • Esfandiari, Soheil;Esfandiari, Javad
    • Advances in concrete construction
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    • v.4 no.4
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    • pp.319-332
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    • 2016
  • In most cases strengthening reinforced concrete columns exposed to high strain rate is to be expected especially within weak designed structures. A special type of loading is instantaneous loading. Rapid loading can be observed in structural columns exposed to axial loads (e.g., caused by the weight of the upper floors during a vertical earthquake and loads caused by damage and collapse of upper floors and pillars of bridges).Subsequently, this study examines the behavior of reinforced concrete columns under rapid loading so as to understand patterns of failure mechanism, failure capacity and strain rate using finite element code. And examines the behavior of reinforced concrete columns at different support conditions and various loading rate, where the concrete columns were reinforced using various counts of FRP (Fiber Reinforcement Polymer) layers with different lengths. The results were compared against other experimental outcomes and the CEB-FIP formula code for considering the dynamic strength increasing factor for concrete materials. This study reveals that the finite element behavior and failure mode, where the results show that the bearing capacity increased with increasing the loading rate. CFRP layers increased the bearing capacity by 20% and also increased the strain capacity by 50% through confining the concrete.

Development of Vertical Wet Equipment for BGA Develop Process and Evaluation of Its Process Characteristics (BGA 현상 공정 용 수직 습식 장비 개발 및 공정 특성 평가)

  • Ryu, Sun-Joong
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.3
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    • pp.45-51
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    • 2009
  • Vertical wet equipment was newly developed in stead of horizontal wet equipment which has been widely used for BGA develop process. We intended to eliminate the collision problem between equipment's transferring rollers and fine circuit patterns, which could be achieved by fixing the BGA panel vertically using jig unit. The process characteristics of vertical wet equipment were evaluated by conducting uniformity evaluation, pattern damage evaluation and defect analysis. The process uniformity of the vertical equipment was measured to be the same level as the uniformity of horizontal equipment. And it was measured that $3{\sim}4{\mu}m$ finer circuit pattern could be processed adopting vertical equipment rather than horizontal equipment.

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A Study of Multiple Compression for Malicious Code Execution and Concealment (악성코드 실행과 은닉을 위한 다중 압축 연구)

  • Yi, Jeong-Hoon;Park, Dea-Woo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.299-302
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    • 2010
  • Recently, the malicious code is not easily detectable in the vaccine for the virus, malicious code as a compressed file by modulation pattern is the tendency to delay. Among the many antivirus engines on the market a compressed file that can be modulated by malicious code, and test whether the pattern will need to know. We cover a multi-compressed files, malicious code modulated secreted by examining patterns of test engine is being detected is through a computer simulation. Analysis of secreted activities of malicious code and infect the host file tampering with the system driver files and registry, it gets registered is analyzed. this study will contribute hidden malicious code inspection and enhance vaccine efficacy in reducing the damage caused by malicious code.

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Decay Process of Charge Distribution in E-Beam Irradiated Polymers (E-빔 조사된 폴리머의 전하 분포의 축퇴 과정)

  • Yun, Ju-Ho;Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.329-330
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    • 2007
  • Decay processes of accumulated charge in e-beam irradiated polymers during elevating temperature are observed using pulsed electro-acoustic measurement system. Since the polymeric materials have many superior properties such as light-weight, good mechanical strength, high flexibility and low cost, they are inevitable materials for spacecrafts. In space environment, however, the polymers sometimes have serious damage by irradiation of high energy charged particles. When the polymers of the spacecraft are irradiated by high energy charged particles, some of injected charges accumulate and remain for long time in the bulk of the polymers. Since the bulk charges sometimes cause the degradation or breakdown of the materials, the investigation of the charging and the decay processes in polymeric materials under change of temperature is important to decide an adequate material for the spacecrafts. By measuring the charge behavior in e-beam irradiated polymer, such as polyimide or polystyrene, it is found that the various accumulation and decay patterns are observed in each material. The results seem to be useful and be helpful to progress in the reliability of the polymers for the spacecraft.

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A Research Trend on Space Charge Analysis in Polymer Irradiated by Electron Beam (온도 상승시에 전자빔 조사된 폴리머내의 전하 분포의 축퇴 현상 연구 동향)

  • Ko, Sung-Min;Kim, Nam-Yong;Kim, Dae-Yeol;Choi, Yong-Sung;Moon, Jong-Dae;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1992-1993
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    • 2007
  • Decay processes of accumulated charge in e-beam irradiated polymers during elevating temperature are observed using pulsed electro-acoustic measurement system. Since the polymeric materials have many superior properties such as light-weight, good mechanical strength, high flexibility and low cost, they are inevitable materials for spacecrafts. In space environment, however, the polymers sometimes have serious damage by irradiation of high energy charged particles. When the polymers of the spacecraft are irradiated by high energy charged particles, some of injected charges accumulate and remain for long time in the bulk of the polymers. Since the bulk charges sometimes cause the degradation or breakdown of the materials, the investigation of the charging and the decay processes in polymeric materials under change of temperature is important to decide an adequate material for the spacecrafts. By measuring the charge behavior in e-beam irradiated polymer, such as polyimide or polystyrene, it is found that the various accumulation and decay patterns are observed in each material. The results seem to be useful and be helpful to progress in the reliability of the polymers for the spacecraft.

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Implementation of Quality Manageemtn Policy and ISO 9000 Series under Product Liability Law (제조물 책임법 시행에 따른 품질경영 정책 및 ISO 9000 시리즈의 수행)

  • 변승남;이동훈
    • Journal of Korean Society for Quality Management
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    • v.26 no.1
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    • pp.27-47
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    • 1998
  • The primary objective of this research is to provide the basis of total quality management policies by reviewing previous studies which investigated effective ways to reduce product liability exposure. Specifically, the present study intends (1) to examine recent patterns and trends of product liability law in OECD countries, (2) to propose quality management policies for preventing product liability litigations, and (3) to guide the proper implementation process of ISO 9000 certification programs. The survey results show that the shift from a negligence law theory to strict liability is evident in most countries. The trend has led to make it easier for consumers to bring product liability lawsuits. Furthermore, the damage awards won by consumers have been drastically increasing. To minimize product liability exposure, manufactures should reflect comprehensive product safety concepts in establishing total quality management policies. Cooperative activities are also required between departments in companies to reach safe and satisfactory quality level. These quality management activities should be performed consistently during the total product life cycle. Failure to comply with the ISO 9000 certifications might be used as an evidence of negligence or as evidence of a design defect in court. Previous lawsuit cases, however, reveal that ISO 9001-9003 registration process alone is not sufficient in terms of product liability pervention perspectives. Therefore, manufactures should take into account ISO 9004 before implementing any other section of ISO 9000 standards.

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Toxicogenomics Study on ${\alpha}-Naphthylisothiocyanate\;(ANIT)$ Induced Hepatotoxictiy in Mice

  • Hwang, Ji-Yoon;Lim, Jung-Sun;Jeong, Sun-Young;Park, Han-Jin;Cho, Jae-Woo;Yoon, Seok-Joo
    • Molecular & Cellular Toxicology
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    • v.2 no.1
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    • pp.48-53
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    • 2006
  • [ ${\alpha}-Naphthylisothiocyanate$ ] (ANIT) induces intrahepatic cholestasis, involving damage to biliary epitheial cells. This study investigates hepatic gene expression and histopathological alterations in response to ANIT treatment in order to elucidate early time response of ANIT-induced hepatotoxicity. ANIT was treated with single dose (3, 6, and 60 mg/kg) in corn oil by oral gavage. Serum biochemical and histopathological observation were performed for evaluation of hepatotoxicity level. Affymetrix oligo DNA chips were used for gene expression profile by ANIT-induced hetpatoxicity. Hepatic enzyme levels (ALT, AST, and ALP) were increased in 24 hr high dose group. In microscopic observations, moderate hepatocellular necrosis, were confirmed 24 hr high dose groups. We found that gene expression patterns were dependent on time and dose. Our selected genes were related inflammation and immunomodulation. In this study, ANIT-induced hepatotoxicity was involved in acute phase responses and provides evidence for role of neutrophil could be mechanism associated with ANIT-mediated hepatotoxicity.

Compensation of Inclined Rotating Axis Using Unsymmetric Groove Patterns (비대칭 Groove를 이용한 FDB 회전축의 기울기 보상)

  • Lee, Nam-Hun;Han, Jae-Hyuk;Oh, Dong-Ho;Kim, Chul-Soon;Byun, Yong-Kyu;Koo, J.C.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.582-585
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    • 2004
  • Most of hard disk drives currently employ fluid dynamic bearing (FDB) for their rotor support. Stiffness of the FDB is affected by many design factors such as bearing clearance, fluid viscosity, and rotational speed. For the high rotating speed HDDs stiffness of the rotor is normally high enough to accomodate load disturbances. However small form factor HDDs that are to be operated in low power consumption are often designed with low stiffness rotors. Although the low stiffness rotor clearly benefits low power operation, it could damage the entire motor structure or head disk interface even by a light mechanical load disturbance such as shock or vibration. In addition, since a single channel HDD does not provide gram load equilibrium in axial direction the rotor could be tilted and make a hard contact to stator. A non-symmetric groove pattern could successfully compensate the tilted rotor angle during operation.

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DNA Double-Strand Breaks Serve as a Major Factor for the Expression of Arabidopsis Argonaute 2

  • Lee, Sungbeom;Chung, Moon-Soo;Lee, Gun Woong;Chung, Byung Yeoup
    • Journal of Radiation Industry
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    • v.10 no.4
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    • pp.243-248
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    • 2016
  • Argonaute 2 (AtAGO2) is a well characterized effector protein in Arabidopsis for its functionalities associated with DNA double-strand break (DSB)-induced small RNAs (diRNAs) and for its inducible expression upon ${\gamma}$-irradiation. However, its transcriptional regulation depending on the recovery time after the irradiation and on the specific response to DSBs has been poorly understood. We analyzed the 1,313 bp promoter sequence of the AtAGO2 gene ($1.3kb_{pro}$) to characterize the transcriptional regulation of AtAGO2 at various recovery times after ${\gamma}$-irradiation. A stable transformant harboring $1.3kb_{pro}$ fused with GUS gene showed that the AtAGO2 is highly expressed in response to ${\gamma}$-irradiation, after which the expression of the gene is gradually decreased until 5 days of DNA damage recovery. We also confirm that the AtAGO2 expression patterns are similar to that of ${\gamma}$-irradiation after the treatments of radiomimetic genotoxins (bleomycin and zeocin). However, methyl methanesulfonate and mitomycin C, which are associated with the inhibition of DNA replication, do not induce the expression of the AtAGO2, suggesting that the expression of the AtAGO2 is closely related with DNA DSBs rather than DNA replication.

Application of Hidden Markov Chain Model to identify temporal distribution of sub-daily rainfall in South Korea

  • Chandrasekara, S.S.K;Kim, Yong-Tak;Kwon, Hyun-Han
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.499-499
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    • 2018
  • Hydro-meteorological extremes are trivial in these days. Therefore, it is important to identify extreme hydrological events in advance to mitigate the damage due to the extreme events. In this context, exploring temporal distribution of sub-daily extreme rainfall at multiple rain gauges would informative to identify different states to describe severity of the disaster. This study proposehidden Markov chain model (HMM) based rainfall analysis tool to understand the temporal sub-daily rainfall patterns over South Korea. Hourly and daily rainfall data between 1961 and 2017 for 92 stations were used for the study. HMM was applied to daily rainfall series to identify an observed hidden state associated with rainfall frequency and intensity, and further utilized the estimated hidden states to derive a temporal distribution of daily extreme rainfall. Transition between states over time was clearly identified, because HMM obviously identifies the temporal dependence in the daily rainfall states. The proposed HMM was very useful tool to derive the temporal attributes of the daily rainfall in South Korea. Further, daily rainfall series were disaggregated into sub-daily rainfall sequences based on the temporal distribution of hourly rainfall data.

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