• Title/Summary/Keyword: limitation

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A Study on the Barrier of Intrinsic Safety Type (본질안전방폭용 BARRIER에 관한 연구)

  • 오진석
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.938-945
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    • 2004
  • Intrinsic safety is generally considered the safest method of operating electrical instrumention in potentially explosive atmospheres. The method of intrinsic safety limits the energy passing into the hazardus area. The energy limitation is provided by the use of safety barriers which are mounted in the safe area. Because of the energy limitation, regardless of the fault in the hazardous area, sufficient energy cannot be released to ignite the explosive atmosphere. The following industries are known to have hazardous locations: chemical. munitions, petrochemical, auto(paint spray booths), grain, waste water, printing, distillers, pharmaceutical. breweries, cosmetics, and utilities. In this paper, a isolator type barrier for ship(LNG, LPG, etc,) and test equipment confidence are proposed. The test equipments are designed for mechanical electrical life time test and vibration. All of test results satisfy the goal and the studied barrier shows the improved confidence.

Isolation and Characterization of a Methylotroph Producing 3-hydroxybutyrate-3-hydroxyvalerate Copolymer

  • JUNG HOE KIM;KIM, PIL;SEON WON KIM;GYUN MIN LEE;HYUN SOO LEE
    • Journal of Microbiology and Biotechnology
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    • v.5 no.3
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    • pp.167-171
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    • 1995
  • A bacterial strain C-02 using methanol as a carbon source was isolated from Gumi Industrial Estate and selected based on its rapid growth and capability of poly-$\beta$-hydroxybutyrate accumulation. Characteristics of strain C-02 showed that it belongs to the Methylococcaceae family, Type II subgroup. Strain C-02 could incorporate valerate into the PHB chain to form 3-hydroxybutyrate and 3-hydroxyvalerate (P(3HB-co-3HV)). Among various nutrient limitation tests, the nitrogen limitation test resulted in the highest content of P(3HB-co-3HV) per dry cell weight, 50$%$. Under the nitrogen limited condition, the average molecular weight of P(3HB-co-3HV) obtained was determined to be approximately $2.8\times 10^5$ daltons.

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Development of radiotracer for polo-box domain of polo-like kinase 1

  • Ryu, Eun Kyoung
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.5 no.2
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    • pp.152-157
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    • 2019
  • Polo-like kinase 1 (Plk1) is crucial regulator of cell cycle progression during mitosis. It is known to highly overexpress in many different tumor types, and has been implicated as a potential antimitotic cancer target. The phosphopeptide, Pro-Leu-His-Ser-p-Thr (PLHSpT), was shown a high level of affinity and specificity for the polo-box domain (PBD) of Plk1. However, the peptide has the limitation of cell permeability. We designed the derivatives to enhance the limitation of PLHSpT using drug delivery system. In addition, we synthesized and evaluated its radiotracer for tumor diagnosis. This review discusses the derivative and radiotracer that are suitable for tumor treatment and diagnosis for PBD of Plk1.

Angle resolved photoemission spectroscopy with surface-electron-doping (표면전자도핑 기법을 활용한 각분해능 광전자분광 연구)

  • Kim, Yeong Kwan
    • Vacuum Magazine
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    • v.3 no.4
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    • pp.19-23
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    • 2016
  • Angle resolved photoemission spectroscopy (ARPES) is a powerful technique which can directly visualize the electronic structure of solid in detail including many-body interaction information. However, ARPES has a certain limitation in applying control parameters such as doping or pressure, which helps to dig out the clue to understand the desired phenomena or the target system. During ARPES experiment, the control parameter is the temperature only. Other parameters especially electric- and magnetic- field cannot be applied. Recently introduced surface-electron doping technique highlights new avenue to overcome such limitation. In this article, starting from introducing basic concepts of ARPES and its current status, the power of new technique will be demonstrated when it is combined to ARPES by introducing recent results on iron based superconductors.

Reference Current Limit Control for Stable Generative Breaking of SRG (SRG의 안정발전제동을 위한 기준전류 제한방식에 관한 연구)

  • Kim, Tae-Hyung;Park, Sung-Jun;Ahn, Jin-Woo
    • Proceedings of the KIEE Conference
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    • 2003.04a
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    • pp.69-71
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    • 2003
  • Switched reluctance machine has much attention because of high efficiency, high power and DC series torque characteristics with a traction drive. But the motor has to have a regenerative mode when it is adopted in an electric vehicle. A current divergence during the regeneration makes difficulties in the control of SRM. This paper proposes a reference current limitation strategy for a stable regeneration based on simulations and experimental tests. The motor is operated with conventional current limit and switching angle control method in motoring mode. Simulations and experiments are executed to verify proposed method.

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Prevalence and Its Influencing Factors on Depression among Elderly Vulnerable People in Urban Community (일 도시지역 취약노인의 우울 유병률과 영향 요인)

  • Kim, Hye-Ryoung
    • The Korean Journal of Health Service Management
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    • v.7 no.3
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    • pp.275-286
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    • 2013
  • To identify the prevalence and its influencing factors on depression among elderly vulnerable people in one urban community. This study used data from 381 of elderly vulnerable people in the community. The prevalence of depression was found to be 51.97%. Multivariate logistic regression analysis shows that depression was more prevalent as people in female gender; people with lower self-esteem compared to those with higher self-esteem; in elderly who perceived lower social support compared to those who perceived higher social support; and in the older adults with limitation in instrumental activity of daily living. The finding of a significant association between gender difference; self-esteem; perceived social support, and limitation in instrumental activity of daily living and occurrence of depression expected to promote the screening strategy for elderly at risk of depression in Korean community.

Analysis of Optimistic Cache Protocols based on broadcasting for Mobile Computing Environments (이동 컴퓨팅 환경에서 방송기반의 낙관적 캐쉬 프로토콜들에 대한 분석)

  • Cho, Sung-Ho
    • Journal of Internet Computing and Services
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    • v.6 no.5
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    • pp.177-185
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    • 2005
  • Caching in mobile computing environments Is an important technique that will reduce the effects such as limitation of bandwidth, restriction of resources and frequent disconnection. To reduce limitation and disconnection problems in mobile computing, a new form of caching system have been proposed based on a broadcast approach. This paper proposes a broadcast based cache protocol and examines the behaviors of the proposed scheme and well known schemes such as multiversion based scheme and Certification Reports. By a detailed simulation, we show some characteristics of different approaches to detect and resolve conflicts. We also show proposed scheme out performs other schemes with a low space and operation overhead.

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A Study on Force Majeure and Hardship in the International Sales Laws (국제상거래법상 Force Majeure와 Hardship에 관한 고찰)

  • OH, Hyon-Sok
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.69
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    • pp.179-199
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    • 2016
  • There is legal relation between both parties after contract formation. The parties are liable for performing each duties but a party is not liable for a failure to perform the duties if party proves that the failure was due to the force majeure. The forec majeure has different concepts and legal principles such as change circumstance, hardship, frustration, impediment and so on. Therefore, it need to analyze a historical background and their presence in various domestic legal systems. Although the CISG describes Art. 79 impediment instead of using the force majeure, the impediment has several interpretative limitation. The CISG pursue to harmonize divergent legal concepts and principles from various national laws and legal systems but the harmonization of legal systems make the impediment more confused. The article goes on to analyzes about limitation of the impediment and reviews to examine the force majeure and hardship in PICC. Thus both parties of international contract insert hardship clause in order to prevent the problem of judgment in a court or a court of arbitration under impediment of CISG.

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Possibility & Limitation of 1D Nano Scale Electron Shielder (나노 구조물을 이용한 전자선 차폐 가능성과 한계 조사)

  • Ahn, Sung-Jun;Lee, Bum-Su;Kim, Chong-Yeal
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.5 no.2
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    • pp.109-112
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    • 2007
  • The possibility and limitation of one dimensional nano scale electron shielder is briefly discussed. A Nano scale electron shielder will reduce the weight and size of shielding materials. However, practical application still requires further research. In this work, we discuss general problems related to nano scale electron shielder, by taking an arbitrary one dimensional potential barrier as an example.

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A Study on Decommission Cost Estimation Framework with Engineering Approach (공학적 접근을 통한 해체비용 산정 프레임워크에 대한 고찰)

  • Lee, Sun Kee
    • Journal of the Korean Society of Systems Engineering
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    • v.8 no.2
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    • pp.57-67
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    • 2012
  • It is the sensitivity and confidentiality of nuclear power plant decommissioning cost that prevent detailed cost information to be released to the public, which causes some limitation to analyze and reuse the costs. This limitation to access cost information means that the lessons learned from preceding cost estimating may not systematically feed back into following cost estimates. As an alternative, decommissioning cost estimation framework is indispensable to reflecting available experience and knowledge for decommission costs. This study provides the cost estimation framework including data flow and structuralization based on engineering and bottom up approach to enhance decommissioning cost estimation.