• Title/Summary/Keyword: impact failure

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Structural Factors of the Middle East Respiratory Syndrome Coronavirus Outbreak as a Public Health Crisis in Korea and Future Response Strategies

  • Kim, Dong-Hyun
    • Journal of Preventive Medicine and Public Health
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    • v.48 no.6
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    • pp.265-270
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    • 2015
  • The recent Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak has originated from a failure in the national quarantine system in the Republic of Korea as most basic role of protecting the safety and lives of its citizens. Furthermore, a number of the Korean healthcare system's weaknesses seem to have been completely exposed. The MERS-CoV outbreak can be considered a typical public health crisis in that the public was not only greatly terrorized by the actual fear of the disease, but also experienced a great impact to their daily lives, all in a short period of time. Preparedness for and an appropriate response to a public health crisis require comprehensive systematic public healthcare measures to address risks comprehensively with an all-hazards approach. Consequently, discussion regarding establishment of post-MERS-CoV improvement measures must focus on the total reform of the national quarantine system and strengthening of the public health infrastructure. In addition, the Korea Centers for Disease Control and Prevention must implement specific strategies of action including taking on the role of "control tower" in a public health emergency, training of Field Epidemic Intelligence Service officers, establishment of collaborative governance between central and local governments for infection prevention and control, strengthening the roles and capabilities of community-based public hospitals, and development of nationwide crisis communication methods.

Significance of Proliferation Markers and Prognostic Factors in Egyptian Patients with Multiple Myeloma

  • Abdelgawad, Iman A;Radwan, Noha H;Shafik, Roxan E;Shokralla, Hala A
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1351-1355
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    • 2016
  • Background: Multiple myeloma (MM) is influenced by genetic and micro-environmental changes. Malignant plasma cells produce an abnormal monoclonal immunoglobulin, as well as cytokines, such as IL-10 and IL-6 which stimulate cells of the bone marrow microenvironment (BMM) and cause dysfunction and failure of many organs. B cell activating factor (BAFF), IL6 and IL10 are known to influence the growth and survival of malignant clones. Aim: The objectives of the present study were to investigate the circulating levels of BAFF, IL-10 and IL-6, correlate them with well-known parameters of disease activity in patients with MM, and to detect their impact on patients' survival. Materials and Methods: This study was conducted on 89 newly diagnosed MM patients and seventy apparently healthy volunteers as a normal control group. BAFF, IL6, IL10 were measured by ELISA for both groups and survival analysis was performed for all patients. Results: Studied markers were higher in the MM patients compared to the normal control subjects. Patients survival was improved by high serum BAFF levels. Conclusions: High levels of BAFF were found to improve patients' survival. BAFF and IL-6 can be considered probable diagnostic markers for MM.

Estimation of Fatigue Characteristics Using Weibull Statistical Analysis with Aramid Fiber on LNGC Secondary Barrier (LNGC 2차 방벽에 적용된 Aramid 섬유의 Weibull 통계 분석을 이용한 피로특성 평가)

  • Park, Jin Hyeong;Oh, Dong Jin;Kim, Min Gyu;Kim, Myung Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.5
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    • pp.415-420
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    • 2017
  • Insulation systems in Liquefied Natural Gas Carriers (LNGC) are vulnerable to sloshing impact and fatigue loads because of waves. If gas leaks into the primary barrier, the Flexible Secondary Barrier (FSB) prevents the leakage of gas in this system. Fatigue strength of the FSB largely depends on the behavior of composite materials. In this study, a new system is applied to the FSB using aramid fiber to improve the fatigue strength of the secondary barrier, with the intention of replacing conventional E-glass fibers. The manufacturing method involved varying the ratio of the aramid fiber to the E-glass fiber for optimum design of the FSB. The fatigue tests results of the secondary barrier using aramid fiber were superior to that using E-glass fiber. The statistical analysis is performed to obtain the fatigue test results and estimate the probability of failure as well as the design guideline of LNGC secondary barriers.

Fracture Mechanics Characteristics of Wheel and Axle For High Speed Train (고속철도용 차륜과 차축의 파괴역학적 특성)

  • Kwon, Seok-Jin;Seo, Jung-Won;Lee, Dong-Hyung;Ham, Young-Sam
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.8
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    • pp.28-34
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    • 2010
  • Railway wheel and axle is the most critical components in railway system. A wheel and axle failure can cause a derailment with its attendant loss of life and property. The service conditions of railway vehicles have become severe in recent years due to a general increase in operating speeds. Therefore, more precise evaluate of wheelset strength and safety has been desired. Fracture mechanics characteristics such as dynamic fracture toughness, fatigue threshold and charpy impact energy with respect to the tread, plate, disc hole of wheel and the surface of press fitted axle are evaluated. This paper describes the difference of fracture toughness, fatigue crack growth and fatigue threshold at the locations of wheel and axle. The results show that the dynamic fracture toughness, $K_{ID}$, is obviously lower than static fracture toughness, $K_{IC}$ and the fracture mechanics characteristics are difference to the location of wheel tread and hole.

Evaluation of Blades Vibration Reliabilities of KGT-74 Small Gas Turbine (KGT-74소형 가스터빈 블레이드의 진동 신뢰성 평가)

  • 김영철;이동환;이안성
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.5
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    • pp.410-415
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    • 2004
  • To ensure a safe operation of the prototype KGT-74 kW small gas turbine, vibrational reliabilities of the compressor 1st, 2nd, and 3rd stages and turbine blades have been estimated and reviewed. FE analyses have been carried out to obtain the natural vibration characteristics of the blades, and impact modal testings have been performed on every each one of the blades to measure their 1st natural frequencies. Then, the Campbell diagram analyses have been carried out to judge the safety of the blades from resonant failures up to 6k harmonics. Results show that the compressor 1st stage blade is exposed to a potential resonant failure with 3k harmonic around a rated speed of 30,000 rpm but that the other compressor 2nd and 3rd stages and turbine blades are safe from resonant failures. Finally, 27,900 rpm is selected as the safe operation limit for the KGT-74 ㎾ gas turbine relative to the blade vibrations.

Adaptive Scheduling Technique Based on Reliability in Cloud Compuing Environment (클라우드 컴퓨팅 환경에서 신뢰성 기반 적응적 스케줄링 기법)

  • Cho, In-Seock;Yu, Heon-Chang
    • The Journal of Korean Association of Computer Education
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    • v.14 no.2
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    • pp.75-82
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    • 2011
  • Cloud computing is a computing paradigm that provides user's services anywhere, anytime in a virtualized form composed of large computing resources based on internet or intranet. In Cloud computing environments, reliability of system is impact factor because many applications handle large data. In this paper, we propose an adaptive scheduling technique based on reliability with fault tolerance that manages resource variable and resolves problems(change of user's requirement, failure occurrence) in Cloud computing environment. Futhermore, we verified the performance of the proposed scheduling through experiments in CloudSim Simulation.

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Feeding the Larvae of the Sea Urchin Strongylocentrotus intermedius on a Red-Tide Dinoflagellate Cochlodinium polykrikoides

  • Lee, Chang-Hoon
    • Journal of Aquaculture
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    • v.15 no.2
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    • pp.79-86
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    • 2002
  • This study is the first attempt to understand the feeding physiology of a sea-urchin larva on a red-tide dinoflagellate. Fifteen day old larvae of S. intermedius capture C. polykrikoides cells by localized reversal of ciliary beats. No failure to transporte the algal cells from theciliated band to mouth and no rejection at the mouth suggest that C. polykrikoides has no feeding deterrence to S. intermedius larvae. The trend obtained for the clearance rate of S. intermedius larvae is similar to that of other sea urchin larvae. Thus, the clearance rate decreased as the algal concentration increased. Maximum clearance rate of S. intermedius on C. polykrikoides was 17.7 $\mu l$/larva/hr. Ingestion rate rapidly increased at lower algal concentrations and saturated at higher concentrations. There was no inhibition in ingestion rate at the highest prey concentration of ca. 3000 cells/ml. Maximum ingestion rate of S. intermedius on C. polykrikoides was 131 ngC/larva/d, which is higher than that reported for the larvae of the mussel Mytilus gal-lotrovincialis, but lower than that of the ciliate Strombidinopsis sp. The grazing rate, calculated by combining the field data on algal abundances with experimental data on ingestion rate, suggests that due to its low abundance, sea urchin Iarva has no significant grazing impact on C. polykrikoides population.

A Study on the Application of Under Voltage Load Shedding Scheme in Line Contingency considering Motor Load (모터부하를 고려한 상정사고 발생 시 저전압 부하차단 적용 방안에 대한 연구)

  • Lee, Yun-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.1
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    • pp.21-26
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    • 2017
  • Failure of high-voltage transmission line, which is responsible for large-scale power transmission, can be reason for system voltage instability. There are many methods to prevent voltage instability like adjustment of equipment, the generator voltage setting, and load shedding. Among them, the load shedding, have a problem of economic loss and cascading effect to power system. Therefore, the execution of load shedding, amount and timing is very important. Conventionally, the load shedding setting is decided by the preformed simulation. Now, it is possible to monitor the power system in real time by the appearance of PMU(Phasor Measurement Unit). By this reason, some of research is performed about decentralized load shedding. The characteristics of the load can impact to amount and timing of decentralized load shedding. Especially, it is necessary to consider the influence of the induction motor loads. This paper review recent topic about under voltage load shedding and compare with decentralized load shedding scheme with conventional load shedding scheme. And simulations show the effectiveness of proposed method in resolving the delayed voltage recovery in the Korean Power System.

Evaluation of Degraded Materials by Automated Ball Indentation(ABI) Technique (압입법을 이용한 재료의 열화도 평가)

  • 김석민;석창성;이승석;권재도
    • Journal of the Korean Society of Safety
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    • v.15 no.1
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    • pp.28-35
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    • 2000
  • As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. So determination of the integrity of the metallic structure is required either to en4sure that failure will not occur during the service life of the components or to evaluate the lifetime extension of the structure. An automated ball indentation(ABI) method was developed as a non-destructive technique for evaluating the integrity of such metallic components. In this paper, we would like to present the aging evaluation technique by the ABI method. The five classes of the thermally aged CF8M specimens were prepared using an artificially accelerated aging method. After holding 100, 300, 900, 1800 and 3600 hours at 43$0^{\circ}C$, the specimens were cooled down using water to room temperature respectively. The tensile test, hardness test, charpy impact test, ABI test were performed. The results of the fracture test were compared with those of ABI test and the new evaluation technique of the integrity of metallic structures was developed.

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Numerical simulation of dynamic Interactions of an arctic spar with drifting level ice

  • Jang, H.K.;Kang, H.Y.;Kim, M.H.
    • Ocean Systems Engineering
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    • v.6 no.4
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    • pp.345-362
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    • 2016
  • This study aims to develop the numerical method to estimate level ice impact load and investigate the dynamic interaction between an arctic Spar with sloped surface and drifting level ice. When the level ice approaches the downward sloped structure, the interaction can be decomposed into three sequential phases: the breaking phase, when ice contacts the structure and is bent by bending moment; the rotating phase, when the broken ice is submerged and rotated underneath the structure; and the sliding phase, when the submerged broken ice becomes parallel to the sloping surface causing buoyancy-induced fictional forces. In each phase, the analytical formulas are constructed to account for the relevant physics and the results are compared to other existing methods or standards. The time-dependent ice load is coupled with hull-riser-mooring coupled dynamic analysis program. Then, the fully coupled program is applied to a moored arctic Spar with sloped surface with drifting level ice. The occurrence of dynamic resonance between ice load and spar motion causing large mooring tension is demonstrated.