• Title/Summary/Keyword: ect

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Unusual Presentation of a Penetrating Aortic Arch Injury

  • Vural, Fikret Sami;Patel, Atul Kumar;Mustafa, Kashif
    • Journal of Chest Surgery
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    • v.50 no.4
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    • pp.295-297
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    • 2017
  • A 27-year-old man was admitted with a penetrating injury at the mid-manubrium. Computed tomographic (CT) angiography showed a f illing def ect in the aortic arch. This was evaluated as a sign of injury and the patient underwent an emergency operation. No active bleeding or clot was f ound in the mediastinum during the operation. The laceration point was between the innominate and the left carotid artery posteriorly. The injury was approached using hypothermic circulatory arrest. Aortotomy and exploration showed a 2-cm-long full-thickness aortic injury with an overlying clot. A filling defect on angiography as a sign of a penetrating arch injury has never been reported previously, but was the main pathological finding on CT angiography in our case. The aorta is a high-pressure system and injuries to it should be treated aggressively.

EffEct of vacuum annealing on an oxidation of milled WC-Co powder (분쇄된 초경합금 분말의 산화에 미치는 진공열처리 효과)

  • 김소나
    • Journal of Powder Materials
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    • v.3 no.2
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    • pp.91-96
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    • 1996
  • The effect of vacuum annealing on the oxidation behavior of milled WC-15%Co powder mixture has been studied. A cobalt component in the milled powder mixture was oxidized preferentially above 175$^{\circ}C$ in air. The specimens showed a steady increase in weight at 175$^{\circ}C$ but did constant weight followed by rapid increase in specimen weight at the beginning above 20$0^{\circ}C$. Oxidation of the milled powder mixture was significantly suppressed by vacuum annealing at 30$0^{\circ}C$ for 10 h. Suppression of oxidation by vacuum annealing and different oxidation behaviors of the milled powder mixture between 175$^{\circ}C$ and 20$0^{\circ}C$, were attributed to removal of strain energy stored in the cobalt powder during vacuum annealing or oxidation treatment above 20$0^{\circ}C$. The role of stored strain energy on oxidation of milled WC-15%Co powder mixture was proved by X-ray diffraction method and differential thermal analysis.

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Field Welding Technology for Safe Manufacture of Welding Structure & Recent trend of Welding Technology (용접구조물의 안전시공을 위한 현장기술과 용접기술 동향)

  • 유택인
    • Journal of the Korean Professional Engineers Association
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    • v.34 no.2
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    • pp.37-41
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    • 2001
  • In recent days, welding technology developed in various field of industry, a ship, a building, a structure, a high pressure vessel ect. A welding structure should be base on a safety Welding engineers and welding technicians have a problem in acquiring welding technology, because young people avoid state of the art, beginning their careers In this field. The optimum welding state depends upon the most welding condition, mechanical properties of the base metal, welding processes and arc stability. Base on these fact, the suitable parameters of welding condition can be found through various welding experiments. Therefore, it Is very Important for welding professional engineers to take an active role In advancing new welding technology

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Analysis and Understanding of Eddy Current Problem using electromagnetic field Packeg (전자장 해석 프로그램을 이용한 와전류 문제의 해석 및 이해)

  • Lim, Keon-Gyu;Lee, Hyang-Beom
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2203-2204
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    • 2006
  • When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results. using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

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Analysis and Understanding of Eddy Current Problem using electromagnetic field Packeg (전자장 해석 프로그램을 이용한 와전류 문제의 해석 및 이해)

  • Lim, Keon-Gyu;Lee, Hyang-Beom
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.571-572
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    • 2006
  • When the coil with alternating current approaches to the conductor the eddy current flows in conductor. Eddy current is concentrated on the conductor surface and decrescent because of skin effet.. In this paper investigated eddy current characteristic that is happened in conductor. Analyzed characteristic using electromagnetic field finite element analysis program that is commercialized to analyze value of eddy current and penetration depth. Analyzed creation value of eddy current and penetration depth in conductor that change operation frequency and the material of conductor, coil outside diameter, inside diameter, position, type of conductor from analyzed eddy current characteristic. The results, using distribution of eddy current and penetration depth data is that will help to forecast ECT(Eddy Current Testing), Eddy current application and use field, eddy current loss.

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A Study on Development of Trade Relations and Logistics System between North Korea and China (북한과 중국의 무역과 물류체계 활성화 방안)

  • Lee, Choong-Bae
    • International Commerce and Information Review
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    • v.12 no.3
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    • pp.243-265
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    • 2010
  • North Korea sharing a border with China has developed economic relations with China for a long time. During the cold war(from 1950s to late 1980s), political, military and economic ties between the two countries have become stronger because they had maintained the same political and economic system. However their economic relations have significantly changed after China has adopted market economies since the late 1970s. In particular, trade volume has been shrinked significantly since the late 1990s when China began to ask hard currency payments in their commercial transactions. This paper aims to investigate the conditions and prospects of trade and logistics relations between North Korea and China including the problems existed and then make some suggestions to foster their trade relations. In conclusion in order to develop its trade relations with China, it is suggested that North Korea should make significant changes in its economic and logistics system including infrastructure, institutional schemes, social and trade practices ect. because most problems in bilateral trade have been incurred from North Korea.

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Corrosion Detection of ACSR Power Lines Using Non-Destructive Test Method (비파괴 탐상에 의한 ACSR 전선의 결함 검출)

  • Kang, J.W.;Jang, T.I.;Min, B.W.;Kim, B.K.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1712-1714
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    • 2001
  • This paper deals with the development and application of an inner corrosion detector for the ACSR(Aluminum Conductor Steel Reinforced) power lines. The detector runs on an ACSR power line and inspects the inner corrosion of the conductor using the technology of the nondestructive eddy current test. It is consists of an ECT sensor, signal processing units, a RF transmitter/receiver, and etc.. The experimental result through field tests shows the detector can efficiently find both the zinc and aluminum loss of ACSR power lines.

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A Study on Extraction of the Center Point of Steam Generator Tubes of YoungKwang Nuclear Power Plant

  • Cho, Jai-Wan;Kim, Chang-Hoi;Seo, Yong-Chil;Park, Young-Soo;Kim, Seung-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.96.5-96
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    • 2002
  • This paper describes extraction procedures for the center coordinates of steam generator tubes of Youngkwang nuclear power plant No. 6 unit. The centering coordinates of tubes are needed for monitoring whether ECT probe is exactly inserted into tube or not. However, The tube image tends to have poor contrast because steam generator bowl is sealed. The centering coordinates extraction procedure consists of two steps. The first step is to process the region with high contrast in entire image of steam generator tubes. Using the center points extracted in the first step and the geometry of tubes lined up in regular triangle patterns the centering coordinates of the rest region with low contrast...

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Customers' View of Agility: The Expectation-confirmation Theory Perspective

  • Atapattu, Maura;Sedera, Darshana;Ravichandran, T.;Grover, Varun
    • Asia pacific journal of information systems
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    • v.26 no.1
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    • pp.80-108
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    • 2016
  • Contemporary organizations strive for customer agility through the deployment of digital technologies on customer-focused operations to build enduring customer relationships, with mobile apps being one of its prominent examples. Drawing on prior agility and ECT literature, this study proposes a model to examine customers' view of a firm's customer agility. Our empirical test of conceptual model from data collected in a field study from 128 customers demonstrated that the conceptual model offers good explanation for customers' view of a firm's customer agility through relationships among customer expectations-customer perceived firm's responsiveness-satisfaction. Data were analyzed using PLS, polynomial modeling, and response surface methodology to examine the relationships between customers' digital interactions with the firm, influence of digitized interactions on customer expectations, customers' evaluation of firm's responsiveness, and subsequent customer satisfaction.

Statistical Methods for Tomographic Image Reconstruction in Nuclear Medicine (핵의학 단층영상 재구성을 위한 통계학적 방법)

  • Lee, Soo-Jin
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.118-126
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    • 2008
  • Statistical image reconstruction methods have played an important role in emission computed tomography (ECT) since they accurately model the statistical noise associated with gamma-ray projection data. Although the use of statistical methods in clinical practice in early days was of a difficult problem due to high per-iteration costs and large numbers of iterations, with the development of fast algorithms and dramatically improved speed of computers, it is now inevitably becoming more practical. Some statistical methods are indeed commonly available from nuclear medicine equipment suppliers. In this paper, we first describe a mathematical background for statistical reconstruction methods, which includes assumptions underlying the Poisson statistical model, maximum likelihood and maximum a posteriori approaches, and prior models in the context of a Bayesian framework. We then review a recent progress in developing fast iterative algorithms.