• Title/Summary/Keyword: failure protection system

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GEOTECHNICAL DESIGNS OF THE SHIP IMPACT PROTECTION SYSTEM FOR INCHEON BRIDGE

  • Choi, Sung-Min;Oh, Seung-Tak;Park, Sang-Il;Kim, Sung-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.72-77
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    • 2010
  • The Incheon Bridge, which was opened to the traffic in October 2009, is an 18.4 km long sea-crossing bridge connecting the Incheon International Airport with the expressway networks around the Seoul metropolitan area by way of Songdo District of Incheon City. This bridge is an integration of several special featured bridges and the major part of the bridge consists of cable-stayed spans. This marine cable-stayed bridge has a main span of 800 m wide to cross the vessel navigation channel in and out of the Incheon Port. In waterways where ship collision is anticipated, bridges shall be designed to resist ship impact forces, and/or, adequately protected by ship impact protection (SIP) systems. For the Incheon Bridge, large diameter circular dolphins as SIP were made at 44 locations of the both side of the main span around the piers of the cable-stayed bridge span. This world's largest dolphin-type SIP system protects the bridge against the collision with 100,000 DWT tanker navigating the channel with speed of 10 knots. Diameter of the dolphin is up to 25 m. Vessel collision risk was assessed by probability based analysis with AASHTO Method-II. The annual frequency of bridge collapse through the risk analysis for 71,370 cases of the impact scenario was less than $0.5{\times}10^{-4}$ and satisfies design requirements. The dolphin is the circular sheet pile structure filled with crushed rock and closed at the top with a robust concrete cap. The structural design was performed with numerical analyses of which constitutional model was verified by the physical model experiment using the geo-centrifugal testing equipment. 3D non-linear finite element models were used to analyze the structural response and energy-dissipating capability of dolphins which were deeply embedded in the seabed. The dolphin structure secures external stability and internal stability for ordinary loads such as wave and current pressure. Considering failure mechanism, stability assessment was performed for the strength limit state and service limit state of the dolphins. The friction angle of the crushed stone as a filling material was reduced to $38^{\circ}$ considering the possibility of contracting behavior as the impact.

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Evaluation of the Actual Conditions for the Construction of a Firefighting Safety Management System in Domestic Power Plants (국내발전소 소방안전경영시스템구축을 위한 실태평가에 관한 연구)

  • Kang, Gil-Soo;Choi, Jae-wook
    • Fire Science and Engineering
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    • v.32 no.1
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    • pp.89-98
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    • 2018
  • Fire accidents in foreign countries, like the accident in a thermal power plant in Beijing, the accidents in domestic power plants, including Boryeong Power Plant in 2012 and Taean Power Plant in 2016, a disaster in a nuclear power plant in Fukushima in 2011 or the large-scale power failure in California in 2001 are safety accidents related to electric power, which caused losses in the people's stable lives and the countries. Electricity has an absolute impact on the people's life and the economy, so we can easily expect the serious situation affecting economic growth as well as direct damage to the protection of the people's lives and the losses of properties, if there are fire or explosion accidents or radioactive leak because of negligence in safety management, or problems because of natural disasters like an earthquake in power plants that generate electricity. In this study, it was drawn the improvement of the organizations exclusively in charge of firefighting, the operation of a program for the improvement of professional competency, the development of a customized firefighting management system for plants for systematic firefighting safety management and the improvement of the earthquake-proof correspondence system, which has recently become an issue, as measures for improvements through a survey of the actual conditions concerning the necessity of the construction of a firefighting safety management system for power plants with five power generation companies, including Korea Southern Power Co., Ltd., and the persons in charge of firefighting safety Korea Hydro & Nuclear Power Co., Ltd.

A Study on the Mediation and Arbitration of Traffic Accident Disputes (자동차교통사고 분쟁의 조정과 중재에 관한 연구)

  • Nam, Seon-Mo
    • Journal of Arbitration Studies
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    • v.24 no.2
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    • pp.81-107
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    • 2014
  • ADR has recently been expanded, making it possible to solve traffic accident disputes, which is a matter of urgency for parties to avoid. This point serves as an important procedural element. Such disputes are an area that requires a quick resolution. To try to solve any dispute that occurs in the complex environment of modern times one-by-one through litigation does not make sense. It gives an undue burden on the judicial body and the investigation agency. Like litigation, today's arbitration system, should have effective conflict resolution. The arbitration of automobile traffic accident disputes can be seen as roughly adjusted through the insurance company, the Dispute Coordinating Committee, and the Crime Victims Protection Act. It consists of experts mainly, and the resolution of automobile traffic accident disputes can be resolved through the Sajonsa and workers insurance company. However, adjustments to failure incident mostly need attention. Most of a company's compensation insurance indemnity needs to be processed in practice. In addition, a vicious cycle of litigation and delay period is repeated if a lawyer is appointed. There are unreasonable adjustment systems in the midst of these. Avoiding traffic accidents allows parties to resolve disputes better. Arbitration of disputes in automobile traffic accidents handled by arbitration institutions is desirable. It is determined that the handling of a case by a village attorney is efficient.

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A Study on Mechanical Characteristics of Interface of Ceramic/Metal Composites (세라믹/금속 이종재료 계면의 기계적 특성에 관한 연구)

  • Seo, Do-Won;Kim, Hak-Kun;Song, Jun-Hee;Lim, Jae-Kyoo;Park, Chan-Gyung
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.121-126
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    • 2000
  • Metal/Ceramic structures have many attractive properties, with great potential for applications that demand high stiffness, as well as chemical and biological stability, thermal and electrical insulation. They are currently in use for mechanical and thermal protection in cutting tool and engine parts. With all their great advantage, ceramics suffer from one major problem they are brittle, and are especially susceptible to cracking from surface contacts. Delamination at the interfaces with adjacent layers is a particularly disturbing problem, and can cause premature failure of a composite system. so determination of adhesive properties of coating is one of the most important problems for the extension of the use of coated materials. In this work, mechanical characteristics of Interface of ceramic/Metal composites are evaluated by means of hardness test, indentation test apparent interfacial toughness and bonding strength test. The interface indentation test provides a relation between the applied load(P) and the length of the crack(a) created at the interface between the coating and the substrate.

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Protection of Mercury induced Acute Respiratory Injury by Inhaled Oxidizing Agent (수은에 의한 급성호흡손상시 산화물질의 억제효과)

  • 황태호
    • Journal of Life Science
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    • v.11 no.3
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    • pp.259-265
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    • 2001
  • Mercury vapor inhalation-induced acute respiratory failure(ARF) has been reported to be fatal. This study was designed to observe the possible mechanism of inhaled mercury vapor poisoning in the respiratory system. Sixty percent of rats(12/20) exposed to mercury vapor were dead within 72 hours of exposure whereas all the rats(20/20) exposed to mercury vapor combined with dithiothreitol(DTT) vapor survived. The histological observation showed that ARF was a direct cause of the death induced by mercury vapor inhalation, which was significantly circumvented by DTT vapor. Cyclic AMP mediated chloride secretion was inhibited by luminal side but not serosal side sulfhydryl blocking agents (Hf$^{2+}$ $\rho$-chloromercuribenzoic acid or $\rho$-chloromercuriphenyl sulfonic acid) in a dose-dependent manner in a primary cultured rat airway monolayer. The inhibitory component of cAMP induced chloride secretion was completely restored by luminal side DTT(0.5mM). these results suggest that the oxidized form(Hg$^{2+}$) of mercury vapor(Hg0) contribute to ARF and subsequent death. The finding is important as it can provide important information regarding emergency manipulation of ARF patients suffering from by mercury vapor poisoning.ing.

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Research on the Oxidation-Protective Coatings for Carbon/Carbon Composites

  • Li, He-Jun;Fu, Qian-Gang;Huang, Jian-Feng;Zeng, Xie-Rong;Li, Ke-Zhi
    • Carbon letters
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    • v.6 no.2
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    • pp.71-78
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    • 2005
  • Anti-oxidation coatings are the key technique for carbon/carbon (C/C) composites used as the thermal structural materials. The microstructure and oxidation behavior of several kinds of high-performance ceramic coatings for C/C composites prepared in Northwestern Polytechnical University were introduced in this paper. It showed that the ceramic coatings such as SiC, Si-$MoSi_2$, SiC-$MoSi_2$, $Al_2O_3$-mullite-SiC and SiC/yttrium silicate/glass coatings possessed excellent oxidation resistance at high temperatures, and some of these coatings were characterized with excellent thermal shock resistance. The SiC-$MoSi_2$ coating system has the best oxidation protective property, which can effectively protect C/C composites from oxidation up to 1973 K. In addition, the protection and failure reasons of some coatings at high temperature were also provided.

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Signal transfduction pathways for infection structure formation in the rice blast fungus, Magnaporthe grisea

  • Lee, Yong-Hwan;Khang, Chang-Hyun
    • Proceedings of the Botanical Society of Korea Conference
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    • 1999.07a
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    • pp.41-44
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    • 1999
  • Magnaporthe grisea (Hebert) Barr (anamorph: Pyricularia grisea) is a typical heterothallic Ascomycete and the causal agent of rice blast, one of the most destructive diseases on rice (Oryza sativa L.) worldwide. The interactions between cells of the pathogen and those of the host involve a complex of biological influences which can lead to blast disease. The early stages of infection process in particular may be viewed as a sequence of discrete and critical events. These include conidial attachment, gemination, and the formation of an appressorium, a dome-shaped and melanized infection structure. Disruption of this process at any point will result in failure of the pathogen to colonize host tissues. This may offer a new avenue for developing innovative crop protection strategies. To recognize and capture such opportunities, understanding the very bases of the pathogenesis at the cellular and molecular level is prerequisite. Much has been learned about environmental cues and endogenous signaling systems for the early infection-related morphogenesis in M. grisea during last several years. The study of signal transduction system in phytopathogenic filamentous fungi offers distinct advantages over traditional mammalian systems. Mammalian systems often contain multiple copies of important genes active in the same tissue under the same physiological processes. Functional redundancy, alternate gene splicing, and specilized isoforms make defining the role of any single gene difficult. Fungi and animals are closely related kingdoms [3], so inferences between these organisms are often justified. For many genes, fungi frequently possess only a single copy, thus phenotype can be attributed directly to the mutation or deletion of any particular gene of interest.

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북한산 국립공원의 식물상

  • 이영노
    • Proceedings of the Botanical Society of Korea Conference
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    • 1985.08b
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    • pp.19-22
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    • 1985
  • Magnaporthe grisea (Hebert) Barr (anamorph: Pyricularia grisea) is a typical heterothallic Ascomycete and the causal agent of rice blast, one of the most destructive diseases on rice (Oryza sativa L.) worldwide. The interactions between cells of the pathogen and those of the host involve a complex of biological influences which can lead to blast disease. The early stages of infection process in particular may be viewed as a sequence of discrete and critical events. These include conidial attachment, gemination, and the formation of an appressorium, a dome-shaped and melanized infection structure. Disruption of this process at any point will result in failure of the pathogen to colonize host tissues. This may offer a new avenue for developing innovative crop protection strategies. To recognize and capture such opportunities, understanding the very bases of the pathogenesis at the cellular and molecular level is prerequisite. Much has been learned about environmental cues and endogenous signaling systems for the early infection-related morphogenesis in M. grisea during last several years. The study of signal transduction system in phytopathogenic filamentous fungi offers distinct advantages over traditional mammalian systems. Mammalian systems often contain multiple copies of important genes active in the same tissue under the same physiological processes. Functional redundancy, alternate gene splicing, and specilized isoforms make defining the role of any single gene difficult. Fungi and animals are closely related kingdoms [3], so inferences between these organisms are often justified. For many genes, fungi frequently possess only a single copy, thus phenotype can be attributed directly to the mutation or deletion of any particular gene of interest.

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A Study on an Overload Control Scheme for Intelligent Networks Based on Mobile Agent Technology (지능망에서의 이동 에이전트를 이용한 과부하제어 메커니즘에 관한 연구)

  • 이광현;박승균;박주희;오영환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.7C
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    • pp.696-703
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    • 2002
  • In traditional approaches to IN load control, there has been a focus on the protection of individual SCPs. On the other hand, the load control of network level can be achieved by using a mobile agent technology, which is a software element responsible for moving from one system to another and performing their task. In this thesis, we propose an mobile agent mechanism and two mobile agent migration procedures and analyze the performance of the Call Gapping mechanism and the mobile agent mechanism. The mobile agent mechanism showed that the SCP load control rate and attempt the number of attempted call failure were better than those of Call Gapping mechanism. Also, the amount of SS NO.7 traffics was reduced in the case of an overload condition.

Site Suitability Assessment for Joint Forest Management(JFM) - a Geospatial Approach

  • Jayakumar, S.;Ramachandran, A.;Bhaskaran, G.;Heo, Joon;Kim, Woo-Sun
    • Korean Journal of Remote Sensing
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    • v.23 no.5
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    • pp.473-481
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    • 2007
  • Joint Forest Management(JFM) is a concept of developing partnerships between fringe forest user groups and the Forest Department(FD) on the basis of mutual trust and jointly defined roles and responsibilities with regard to forest protection and development. In India, JFM was started during 1992 and it was implemented in many states. However success rate of JFM activity was not promising. Though there are many factors attributed to the failures, one of the main factors is the JFM site. This paper deals with the significant ground works to be done before planning for JFM using recent technologies such as remote sensing(RS) and Geographic Information System(GIS). Also it deals with the advantages of weighted overlay analysis in selecting suitable sites for JFM taking into consideration the various criteria. As a result of weighted overlay analysis, there were four types of suitability classes viz., less, moderate, highly and un-suitable. The moderately suitable class occupied maximum area(13209.64 ha) than less and highly suitable classes. If JFM is implemented on the suitability area, then the failure could be avoided in the future.