• Title/Summary/Keyword: ect

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Thermo-Oxidative Stability of Epoxy/Carbon Fiber Composites under Thermal Cycling Conditions (반복되는 열주기환경에 노출된 에폭시/탄소섬유 복합재료의 열산화 안정성 연구)

  • 남재도
    • The Korean Journal of Rheology
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    • v.10 no.2
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    • pp.106-112
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    • 1998
  • 항공기용 소재로 개발된 에폭시/탄소섬유 복합재료가 매트릭스의 유리전이온도에 육 박하는 온도주기를 경험할 때 발생하는 복합재료의 구조 및 물성변화를 실험과 모델링을 통 하여 연구하였다. 복합재료의 표준 경화온도인 177$^{\circ}C$에서 2시간 체류시킨후 냉각시키는 바 복 열주기는 복합재료를 취약하게 하여 결국 표면에서부터 미세크랙이발생한다는 것을 알수 있었다. 이러한 열주기에 따른 미세크랙 현상은 매트릭스의 분해반응이 발생할수 있는 유효 표면적을 증가시키고 크랙을 통하여 산소의투과를 용이하게 함으로서 산화반응을 가속화하 여 복합재료시편의 무게감소를 가속화시키는 것으로 판단된다. 특히 본 연구에서는 등온과 등속도 승온조건을 주기적으로 반복하는 열주기 조건을 해석하기 위하여 열주기 조건을 특 정온도에서의 등오시간으로 전환할 수 있는 e-quivalent cycle time(ECT)를 제안하였고 이 를 이용하여 열주기에 의한 복합재료 손상의 가속/감속 현상을 규명할수있었다.

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An Application of a Magnetic Camera for an NDT System for Aging Aircraft

  • Kim, Jung-Min;Jun, Jong-Woo;Lee, Jae-Sun;Lee, Jin-Yi
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.3
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    • pp.212-224
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    • 2010
  • The usefulness of the magnetic camera for non-destructive testing of aging aircraft is discussed in this paper. The magnetic camera can be used f magnetic particle testing(MT), magnetic flux leakage testing(MFLT), eddy current testing(ECT) and penetration testing(PT). It measures the distribution of a magnetic field and visualizes the magnetic pattern. Near and far side cracks, fatigue, thickness degradation, and cracks under rivets have been detected. The possibility of quantitative evaluation was also examined. Using indirect experiments, we verified the detection ability of the sensor for cracks in titanium and advanced composite materials.

The Education Direction of the Library and Information Science. (문헌정보학의 교육방향에 관한 고찰)

  • Kim Myung-Ok
    • Journal of the Korean Society for Library and Information Science
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    • v.31 no.2
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    • pp.121-138
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    • 1997
  • From 1996, Some universities tried to reform the educational systems in Korea. Almost all departments of university except some departments are integrated In large subjects. humanities, social sciences ect. This study is on the relationship between the university education and a science, the Library and Information science position, the merits and demerits of the reformated educational system and it tries to suggest the educational direction of the library and information science.

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Influence of Maekmoondong-Tang on the respiratory aspect of the allergic asthma

  • Park, Dong-Il;Seo, Chang-Hoon
    • Journal of Life Science
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    • v.10 no.2
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    • pp.33-38
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    • 2000
  • Maekmoondong-Tang is prescription recorded on Zang‘s ${ulcorner}$Synopsis of the Golden Chamber${\lrcorner}$ for the first time. It can be used in abnormal rising of qi, asthma, swelling throat ect. So it is observed influence of Maekmoondong-Tang on respiratory aspect of allergic asthma patient, we have significant result and report it. We used egg-white and ovalbmuin (OVA) to induce asthma in experimental animals for observe what maekmoondong-Tang have an effect on asthma. And it is observed respiratory aspect and obtained next conclusions. 1. Number of total respiration in group that is prescribed Maekmoondong-Tang slightly increased than in control group. 2. Number of abnormal respiration in group that is prescribed Maekmoondong-Tang decreased than in control group significantly.

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Analytical Study on the Cooking in 'On Zu Bub' ("온주법(溫酒法)"의 조리(調理)에 관한 분석적(分析的) 고찰(考察))

  • Kim, Gwi-Young;Lee, Sung-Woo
    • Journal of the Korean Society of Food Culture
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    • v.3 no.2
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    • pp.143-151
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    • 1988
  • 'On Zu Bub,' written in Korean, is the anonymous old cook book. The kinds of cooking food recorded-Wine 44, Nu Ruk 2, Sauce 2, dessert 6, side dish 2 etc.-are fifty-six items in all. Especially it was written mirutely about brewage. The wines such as Sub Wang Mo You Bok Gyung Hyang Zu, Gu Ga Zu, Sin Bang Zu, Bang Se Hyang Zu, Zuhk Sun So Zu, Gye Dang Zu, Sa Mi Zu, Gwa Ha Jul Mi Zu were not found in other old cook books, 'Eum Sik Di Mi Bang' and 'Zu Bang Moon' and the contents about Gu Gi Za Zu was guoted from Zi Bung You Suhl. The seasonings used were black pepper, ginger, Chun Cho, Cinnamon, Sugar, ect, but red pepper was not used. But, we can find 'Bingsagua' from this book. First 'Bingsagua' has been found in 1789. 'On zu Bub' is guessed developed in late 1700's.

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A literature study on the treatments of the Decubitus ulcer (褥瘡의 治療에 關한 文獻的 考察)

  • Kim, Hong-jin;Choi, Jung-hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.2
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    • pp.104-121
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    • 1999
  • The results were as follows ; 1. The treatment method is most used reinforcing the spleen and strengthening of Ki(氣) detoxication and draining of pus on each stage. In first stage, the method of actirating blood and aeration of Lag(絡) nourishing blood and moisturizing skin is used. In ulcer stage, the method of expelling blood stasis and detoxication, promoting pus and drainage is used. In chronic stage, strengthening of Ki(氣) and blood, invigiration and dispersion is used. 2. In the frequency of prescription, the most numerous prescription is Paljintang(八珍湯) and the next are Insamyangyoungtang(人蔘養榮湯). Taglisodongum(托裏消耗飮) ect. In the frequency of medicine the most numerous medicine is Angelicae Gigantis Radix(當歸) and the next are Glycyrrhizae Radix (甘草), Astragali Radix(황기) etc. 3. In the frequency of prescription of exteral therapy. the most numerous prescription is Saengioghongo(生肌玉紅膏), Saengisan(生肌散) and the next are hongsungdan(紅升丹), guildan(九一丹) etc. In the frequency of medicine of exteral therapy, the most numerous medicine is Glycyrrhizae Radix (甘草) and the next are Calomelas(輕粉), Draconis Resina(血竭) etc.

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Detectability evaluation of the loose parts in steam generator by eddy current testing techniques

  • Kim, Kyungcho;Min, Kyongmahn;Kim, Changkuen;Kim, Jin-Gyum;Jhung, Myungjo
    • Nuclear Engineering and Technology
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    • v.50 no.7
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    • pp.1160-1167
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    • 2018
  • Detectability of the loose parts (LPs) in steam generator (SG) was studied with eddy current testing technique such as X-probe, bobbin and rotating coils ($MRPC^{(R)}$) as a function of LP size and spacing between LP and tube or between LP and support structures. SG mockup simulating SG tube and support structures with LP was fabricated. The X-probe showed slightly better detectability than $MRPC^{(R)}$ for LP of ferrous (F-LP) material and vice versa for LP of nonferrous (NF-LP) material. In terms of feasibility, inspection rate and other predictable features of the SG tubing inspections, X-probe can be used reliably for monitoring the LPs and the flaws formed by LPs on SG tubes.

Impact of Topic Distribution on Review Sentiment: A Comparative Study between South Korea and the U.S.

  • Mina Cho;Dugmee Hwang;SeongMin Jeon
    • Asia pacific journal of information systems
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    • v.32 no.3
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    • pp.514-536
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    • 2022
  • Online reviews offer valuable information to businesses by reflecting consumer experiences about their products and services. Two crucial aspects of online reviews are the topics consumers choose to address, and the sentiments expressed in their reviews. Building upon previous literature that shows online reviews are context-dependent, we employ the Expectation-Confirmation Theory (ECT) to examine the impact of topic distribution on review sentiment in South Korea and the U.S. during pre- and post-pandemic periods. After applying a topic modeling to Airbnb app review data, we measure the contribution of each topic on review sentiment using SHAP values. Our results indicate variations in topic distribution trends between 2018 and 2021. In addition, the order and magnitude of topics' impact on review sentiment change between pre- and post-pandemic periods for both countries. This study can help businesses understand how topics and sentiments associated with their products and services changed after the pandemic and thus identify areas of improvement.

Signal Analysis of Eddy Current Array Probe According to Size Variation of FBH Defects (배열 와전류 프로브의 FBH 결함 크기 변화에 따른 신호 해석)

  • Kim, Ji-Ho;Lim, Geon-Gyu;Lee, Hyang-Beom
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.2
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    • pp.137-144
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    • 2009
  • In this paper, the signal analysis of eddy current array probe was performed to analyze the electromagnetic characteristics with the variation of FBH(flat bottomed hole) defects size on steam generator tube in NPP(nuclear power plants) using the electromagnetic finite element method. To obtain the electromagnetic characteristic of probes, the governing equation was derived from Maxwell's equations, and the individual problem was analyzed by using the 3-dimensional finite element method. For the simulation FBH defects were used. The depth of FBH defects were 20%, 40%, 60%, 80% and 100% of steam generator(SG) tube thickness, and it was assumed that the defects were located on the tube outside. And the operation frequencies of 100 kHz, 300 kHz and 400 kHz were used. Material of specimen was Inconel 600 which is usually used for SG tubes in NPP. The signal difference could be observed according to the size variation of depth of FBH defects and operation frequencies. The results in this paper can be helpful when the ECT(eddy current testing) signals from EC array probe are evaluated and analyzed.

A study on development strategy of Automated Container Terminal (자동화 컨테이너터미널 개발 전략에 관한 연구)

  • 최형림;박남규;박병주;유동호;권해경
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.479-485
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    • 2004
  • The interest of ACT (Automated Container Terminal) is increasing because of expansion of container's transportation quantity, appearance of large-sized and. high-speed vessel, high labor cost of container terminal and the change of technical level. Therefore, the ACT had been developed in several ports in the world, such as ECT (Europe Combined Terminals) and CTA (Container Terminal Altenwerder). They have studied detailed technique for the operation of ACT. In Korea, it also has increased not only expansion and improvement of container terminal, but also necessity of ACT. Now, many projects related to the development of ACT are working in Korea. And the technical improvement of operating system, automated equipments and information system has accomplished by the projects. The ACT consists of the basic equipment and the integrated information system for operating and controlling automated equipments. The productivity of ACT is maximized through efficient connection between them. Thus, the automated degree of container terminal is dependent on the developing time of operating system, reliability, transportation quantity of container, investment amount and technical level. In this paper, we propose important strategy in developing ACT through analyzing the property of each ACT.

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