• Title/Summary/Keyword: IGC

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TWO DIMENSIONAL STUDY OF HYDRAULIC FRACTURING CRITERIA IN COHESIVE SOILS

  • 유택영사
    • Proceedings of the Korean Geotechical Society Conference
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    • 1994.03b
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    • pp.3-12
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    • 1994
  • Based on the shear failure mechanism, hydraulic fracturing criteria are extended to three dimensional stress state. According to the situation of the directions of borehole and major principal stress axes, three equations can be derived for three dimensional hydraulic fracturing problems. By comparing these equations, a single criterion is selected for hydraulic fracturing pressure in cohesive soils. The criterion is a function of maximum principal stress, minimum principal stress and soil parameters in UU conditions. The equation indicates that with any increase in maximim principal stress, hydraulic fracturing pressure decreases. In order to prove the integrity of the criteria, laboratory tests are performed on compacted cubical specimens using true a triaxial apparatus. The shape and direction of fractures are determined by injecting colored water after fracture initiation. It is found that the direction of fractures are perpendicular to the o1 plane.

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A study on the interararanular corrosion behavir of stainless steel in molten carbonate salt EPR test (EPR 방법에 의한 용융탄산염 내에서의 스텐인레스강의 입계부식에 관한 연구)

  • 황응림;서병환;강성군
    • Journal of the Korean institute of surface engineering
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    • v.31 no.4
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    • pp.223-230
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    • 1998
  • The separator for a molten carbonate fuel cell(MCFC) is mode of stainless steel and known to the suscepibility to corrosion due to environments of high temperature molten carbonte electrolyte. Considering the sensitization of stainless steel in the temperature range of 425~$815^{\circ}C$, the separator is expected to be sensitized so that the interganular corrosion (IGC) occurs during the cell operation at about $650^{\circ}C$. In this study, EPR(electrochemical potentiokinetic reactivation) technique was examined by relating some elements(mainly C and Cr) to the degree of sensitization of austenitic stainless steels in the molten carbonate salt at $650^{\circ}C$and the possible mechanism of intergranular corrosion was analyzed.

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Recent Contributions by Geographers to Natural Hazards Mapping and Mitigation (자연재해의 지도화와 피해경감 방안에 관한 지리학자들의 최근 성과)

  • Rosenfeld, Charles L.
    • Journal of the Korean Geographical Society
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    • v.33 no.spc
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    • pp.721-728
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    • 1998
  • UN은 1990년대를 전세계적인 자연재해 감소를 위한 10년(IDNDR)으로 지정하고 이러한 취지로 제네바에 사무국을 개설했다. 그에 대한 반응으로 국제 과학 연합회는 IGU를 통해 여러 지역에서의 지리적 연구를 지원하고 있다. IGU는 1992년에 개최된 제 27차 IGC에서 자연재해연구 분과를 개설하여 지리학에 있어서 새로운 기술을 개발하는데 강조를 두는 다양한 자연재해 프로젝트에 지리학자들을 포함시키려는 노력을 시작했다. 지리학자들은 IDNDR에 중요한 공헌을 하고 있는데, 특히 재해 관리를 위한 GIS의 영역과 지도화와 재해 평가를 위한 원격탐사, 재해 반응에 대한 GPS의 이용 등이 이에 포함된다. 지리학자들은 지도화와 재해를 경감시키려는 노력에 중요한 역할을 하고 있으며, 이미 재해를 입은 지역에 대해 복구 계획을 세우고 있다. CONAHA는 2000년에 서울에서 개최되는 제 29차 IGU에서 UN에 의해 시작된 안건을 지지하게 됨으로 그 역할을 마무리하게 될 것이다. 영구적인 공헌 중에는 1998년에 산악 재해에 관한 발간을 시작으로 자연재해에 관한 책 시리즈와 UNESCO에 의해 발간된 Life Systems 백과사전 내용 중 자연재해에 대한 부분이 포함된다는 것이다

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Processing of Tin Oxide Nanoparticles by Inert Gas Condensation Method and Characterization

  • Simchi, Abdolreza;Kohi, Payam
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.122-123
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    • 2006
  • Tin oxide nanoparticles (n-SnO and $n-SnO_2$) were synthesized by the inert gas condensation (IGC) method under dynamic gas flow of oxygen and argon at various conditions. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) method were used to analysis the size, shape and crystal structure of the produced powders. The synthesized particles were mostly amorphous and their size increased with increasing the partial pressure of oxygen in the processing chamber. The particles also became broader in size when higher oxygen pressures were applied. Low temperature annealing at $320^{\circ}C$ in air resulted to crystallization of the amorphous n-SnO particles to $SnO_2$.

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Comparative Analysis of Segmentation Methods in Psoriasis Area (건선 영역 분할기법 비교분석)

  • Yoo, Hyun-Jong;Lee, Ji-Won;Moon, Cho-I;Kim, Eun-Bin;Baek, Yoo-Sang;Jang, Sang-Hoon;Lee, OnSeok
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.657-659
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    • 2019
  • 본 논문에서는 피부 이미지에서 건선 병변만을 가장 효과적으로 분할 할 수 있는 분할기법 선별을 목표로 한다. Interactive graph cuts (IGC)와 Level set method (LSM)를 사용하여 건선 영역을 분할한 후 Jaccard Index (JI)와 Dice Similarity Coefficient (DSC)을 사용하여 건선 영역에 효과적인 분할 방법을 제안한다.

Stress Corrosion Cracking Behavior of Cold Worked 316L Stainless Steel in Chloride Environment

  • Pak, Sung Joon;Ju, Heongkyu
    • Journal of Korea Foundry Society
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    • v.40 no.5
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    • pp.129-133
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    • 2020
  • The outcomes of solution annealing and stress corrosion cracking in cold-worked 316L austenitic stainless steel have been studied using x-ray diffraction (XRD) and the slow strain rate test (SSRT) technique. The good compatibility with a high-temperature water environment allows 316L austenitic stainless steel to be widely adopted as an internal structural material in light water reactors. However, stress corrosion cracking (SCC) has recently been highlighted in the stainless steels used in commercial pressurized water reactor (PWR) plants. In this paper, SCC and inter granular cracking (IGC) are discussed on the basis of solution annealing in a chloride environment. It was found that the martensitic contents of cold-worked 316L stainless steel decreased as the solution annealing time was increased at a high temperature. Moreover, mode of SCC was closely related to use of a chloride environment. The results here provide evidence of the vital role of a chloride environment during the SCC of cold-worked 316L.

A Study for Database of Uibang Yuchui (醫方類聚) and Its Value as the Intellectual Property of Traditional Korean Medical Knowledge (지식재산으로서의 의방유취의 가치와 DB구축의 필요성에 관한 소고)

  • Ahn, Sang-Woo;Han, Jiwon;Park, Joo-Young;Cha, Wung-Seok
    • The Journal of Korean Medical History
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    • v.31 no.1
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    • pp.123-134
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    • 2018
  • Today, knowledge itself has become a resource which must be protected by the pertinent community of its contributors and users, from being manipulated or distorted by third-party players. The preservation of knowledge in relationship to the cultural context of its origins, has been recognized by international organizations intent on maintaining authentic voice and perspective. Globally, the WIPO (World Intellectual Property Organization) organizes the annual IGC (Intergovernmental Committee) meeting to address various issues associated with each country's utilization of intellectual and bio source property. Korean Medicine is the official name for the traditional medicine that has been inherited from the cultures of the Korean Peninsula. It is one of the four practices of East Asian Medicine including Traditional Chinese Medicine (TCM) from China, Kampo Medicine of Japan, and Sino-Vietnamese Medicine in Vietnam. As a cultural treasure representing centuries of evolving knowledge, Korean Medicine is protected under intellectual property rights afforded by WIPO, and must be understood in relationship to, and distinct from, TCM. It is understood that China has a strong political purpose to claim all the traditional medicines of the East Asian region under the name of TCM, including Korean Medicine. In fact TCM was authorized as the representative name for all East Asian medicine by decisions made by the ISO (International Standard Organization) in 2015. This paper proposes a pilot study on how to protect the intellectual property of Korean Medicine from efforts by China to claim it under the umbrella of TCM. Using the Uibang Yuchui (醫方類聚, Classified Collection of Medical Formulas) this paper suggests establishing a Database of UBYC, which was published in 1477 by the Joseon Korea government. UBYC was the reorganized version of contemporary East Asian medical sources, and has already hundreds of year's rich indigenous and culturally specific medical history of Korea, from which Korean Medicine has been built.

Development and Safety Evaluation of Earth Leakage Alarm Breaker Equipped with Fire Current (IGR) Alarming Function (화재전류(IGR) 경보 기능이 내장된 누전경보차단기의 개발 및 안전성 평가에 관한 연구)

  • Ko, Wan-Su;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.34 no.3
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    • pp.43-48
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    • 2020
  • The purpose of this study is to develop an earth leakage alarm circuit breaker, equipped with a leakage alarming function (JER-E2S, ETECKOREA Co., Korea), and to analyze its characteristics. The developed mechanism is exclusively used for single-phase and 220 V circuits, with a rated current of 32 A, 20 A, 20 A (for restrooms), 16 A, etc. It satisfies all characteristics of existing earth leakage circuit breakers (ELB). If a fire current, which is a resistive leakage current (Igr), flows through an electric line, the device detects the leakage current in real time and warns against the leakage through a blinking LED lamp. Since the developed device displays a tolerance to a capacitative leakage current (Igc) that inevitably occurs in LED lamps, communication devices, etc., it ensures a stable power supply. In addition, the earth leakage alarm circuit breaker protects against power failure due to a momentary ground fault. Therefore, it can supply power without the risk of the circuit breaker malfunctioning due to a momentary ground fault caused by water droplets, leaves, etc. Moreover, with a standby power of less than 0.1 W, the developed earth leakage alarm circuit breaker exhibits a power saving performance that is 3~8 times greater than that of other ELBs. Installation of approximately 10 earth leakage alarm circuit breakers in one apartment household, with an area of 120 ㎡, can save 2~5 kWh per month. Therefore, the developed earth leakage alarm breaker not only satisfies the characteristics of existing earth leakage breakers, but also exhibits outstanding power supply quality since it has the functions of electric fire prevention and malfunction prevention. Therefore, this device can innovatively contribute to electric fire prevention.

A Study on Perceptions for Establishment of Comprehensive Operation Plan for Incheon Global Campus Library (인천글로벌캠퍼스도서관 종합운영계획 수립을 위한 인식조사 연구)

  • Kwak, Seung-Jin;Noh, Younghee;Ko, Jae Min;Kang, Bong-suk;Kim, Jeong-Taek
    • Journal of the Korean Society for information Management
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    • v.39 no.2
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    • pp.255-273
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    • 2022
  • This study is a basic study for establishing a comprehensive operation plan for the Incheon Global Campus Library in preparation for the 4th Industrial Revolution and the post-corona era. Based on this, it was intended to propose a direction for establishing a comprehensive operation plan in the future. As a result of the study, in the case of the first collection, a mid- to long-term plan for continuous expansion of the collection is required, and in particular, it seems that the expansion of major-related collections is necessary. In the case of the second service, it is necessary to support users' research by providing information services customized for each stage of research by users, information services customized for researchers, and research support services for departments, and it is necessary to provide information utilization education programs. Third, in the case of space, IGC users have very high demands for learning and research space, so it is necessary to improve education and related spaces that users want through space reorganization in the future. It is also necessary to expand the creative collaboration space as a place closely related to the lives of students, such as rest, etc. Lastly, in order to activate the homepage in relation to the homepage and information system, it is necessary to first expand the various contents and up-to-date data that users want on the homepage. In addition, it seems that the domestic electronic journal and DB provision plan should be implemented.

Scale Effect Analysis of LNG Cargo Containment System Using a Thermal Resistance Network Model (열저항 네트워크 모델을 이용한 LNG 화물창 Scale Effect 분석)

  • Hwalong You;Taehoon Kim;Changhyun Kim;Minchang Kim;Myungbae Kim;Yong-Shik Han;Le-Duy Nguyen;Kyungyul Chung;Byung-Il Choi;Kyu Hyung Do
    • Journal of the Society of Naval Architects of Korea
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    • v.60 no.4
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    • pp.222-230
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    • 2023
  • In the present work, the scale effect on the Boil-Off Rate (BOR) was investigated based on an analytical method to systematically evaluate the thermal performance of a Liquefied Natural Gas (LNG) Cargo Containment System (CCS). A two-dimensional thermal resistance network model was developed to accurately estimate the heat ingress into the CCS from the outside. The analysis was performed for the KC-1 LNG membrane tank under the IGC and USCG design conditions. The ballast compartment of both the LNG tank and cofferdam was divided into six sections and a thermal resistance network model was made for each section. To check the validity of the developed model, the analysis results were compared with those from existing literature. It was shown that the BOR values under the IGC and USCG design conditions were agreed well with previous numerical results with a maximum error of 1.03% and 0.60%, respectively. A SDR, the scale factor of the LNG CCS was introduced and the BOR, air temperature of the ballast compartment, and the surface temperature of the inner hull were obtained to examine the influence of the SDR on the thermal performance. Finally, a correlation for the BOR was proposed, which could be expressed as a simple formula inversely proportional to the SDR. The proposed correlation could be utilized for predicting the BOR of a full-scale LNG tank based on the BOR measurement data of lab-scale model tanks.