Effects of seed orientation on the growth behavior of single grain REBCO bulk superconductors

이희균 한국초전도.저온공학회 2017 한국초전도저온공학회논문지 Vol.19 No.2

This study presents a simple method to control the seed orientation which leads to the various growth characteristics of a singlegrain REBCO (RE: rare-earth elements) bulk superconductors. Seed orientation was varied systematically from c-axis to a-axiswith every 30 degree rotation around b-axis. Orientations of a REBCO single grain was successfully controlled by placing the seedwith various angles on the prismatic indent prepared on the surface of REBCO powder compacts. Growth pattern was changed fromcubic to rectangular when the seed orientation normal to compact surface was varied from c-axis to a-axis. Macroscopic shapechange has been explained by the variation of the wetting angle of un-reacted melt depending on the interface energy betweenYBa2Cu3O7-y (Y123) grain and melt. Higher magnetic levitation force was obtained for the specimen prepared using tilted seed withan angle of 30 degree rotation around b-axis.

韓國人力開發 行政組織의 改編方向

李熙均 서울大學校 行政大學院 1979 發展政策硏究 Vol.1979 No.7

Interior seeding combined with top seeding for the fabrication of single grain REBCO bulk superconductors

이희균 한국초전도.저온공학회 2017 한국초전도저온공학회논문지 Vol.19 No.2

This study presents three dimensional (3-D) seeding technique which is a modification of interior seeding. 3-D seeding isbeneficial for shortening the processing period and enhancing the magnetic properties of REBCO bulk superconductors fabricatedby melt growth. Oxygen channels were provided by using divided powder compacts instead of by using a rubber insert. Microstructure observations revealed that the grains grown from the seeds impinged each other and formed low angle grainboundaries of (001)/(001). It has been shown that the 3-D seeding technique reduces the volume fraction of a-c growth sector andthereby maximizes the area of a-b growth sector which attribute to the high magnetic characteristics of single grain REBCO bulksuperconductors.

자동차부품제조업체의 품질관리와 품질원가 측정에 관한 연구

이희균 한국회계학회 1997 회계저널 Vol.6 No.2

영구전류모드 운전을 위한 coated conductor의 가공 및 자석 제조

이희균,김재근,이선왕,김우석,이승욱,최경달,홍계원,고태국,Lee, Hee-Gyoun,Kim, Jae-Geun,Lee, Sun-Wang,Kim, Woo-Seok,Lee, Seung-Wook,Choi, Kyung-Dal,Hong, Gye-Won,Ko, Tae-Kuk 한국초전도학회 2006 Progress in superconductivity Vol.7 No.2

Coated conductors suitable for the fabrication of persistent mode high $T_c$ magnets are suggested and the fabrication method of persistent mode magnets using coated conductor are demonstrated. Persistent current was observed in a small piece of coated conductor. Closed loop of coated conductor with a diameter of around 1 em was successfully prepared and was cooled with a magnetic field of about 500 Gauss in order to induce supercurrent. Coated conductor with a $I_c$ of 100 A/cm-width was used for the preparation of closed loop of coated conductor. Persistent current was confirmed by measuring the magnetic field generated from closed loop of coated conductor by using Gauss meter. Magnetic field of 4.4 Gauss was detected from the supercurrent of closed loop of coated conductor. It shows that superconducting joint of coated conductor is not a prerequisite for the construction of persistent mode magnets. It is thought that this work opens the possibility to use coated conductor for the construction of persistent mode high $T_c$ magnets for MRI, NMR and magnetic separation applications.

Wind-and-flip technique for the fabrication of a persistent mode superconductive magnet by using a coated conductor

이희균,김재근,김우석,이승욱,최경달,홍계원,고태국 한국초전도.저온공학회 2007 한국초전도저온공학회논문지 Vol.9 No.2

Persistent mode HTS pancake coil has beenfabricated using a coated conductor by a wind-and-flip method. A coated conductor with the length of 1.2 meters was divided at the center along the length. The sliced coated conductor was wound on a pair of bobbins with a diameter of around 4 cm and two pancake coils connected flipping one of the pancake coils, the magnetic field generated by each coil is to be aligned to the same direction and generate meaningful magnetic field while the magnetic fields of two spit coils are canceled without flipping. Permanent current was induced by flowing current to the coil immersed in liquid nitrogen pool using a power supply. A magnetic field of 48.8 Gauss was generated when 20 A of current was flowing in the pancake coils. The Wind and flip method can be applied for the fabrication of a long solenoid magnet by winding a sliced coated conductor on a cylindrical bobbin. It is also introduced that the construction of multiple sets of pancake (or solenoid) coils is possible by a wind-and-flip method using a wide coated conductor.

ABC가 국내 도입 기업에 미친 영향에 관한 연구

이희균 한국회계학회 1999 회계저널 Vol.8 No.1

企業合倂에 關한 硏究

李喜均 울산대학교 1984 연구논문집 Vol.15 No.1

本 論文의 목적은 企業合倂에서 발생하는 會計上의 문제점을 살펴 보고 동시에 우리나라 合倂會計의 문제점에 대한 改善策이 무엇인가를 考察하는데 있다. 硏究結果는 다음과 같다. 會計情報의 有用性을 높이기 위해서, 대부분의 合倂會計는 買收法으로 처리하여야 한다. 왜냐하면 이 方法으로 처리함으로써 財務除標가 企業의 財務狀態와 營業結果를 公正하게 나타내 주기 때문이다. 그러나 우리나라에서는 持分「푸울링」法의 立場에 가깝다고 볼 수 있다. 이 現實을 감안할 때, 持分 「푸울링」法에 의한 企業의 濫用 혹은 惡用을 방지하기 위한 여러 가지 方案이 提示되어야 할 것이다. The purpose of this study is to find out problem of accounting arising from business combination and to establish a guide to solve them in Korea. The promote the usefulness of accounting information, most business combinations should be accounted for as purchase method, for this way financial statements present fairly the enterprises financial position and results of operations. On the contrary, it tend to use a near pooling of interest method in Korea. Being considered the of fact, it is nessary to present the device so that we prevent the abuse or misuse of the method.

企業年金會計에 관한 硏究

李喜均 울산대학교 1988 연구논문집 Vol.19 No.2

선진국에서는 勤勞者의 退職金支給保?制度로서 企業年金制度가 보편적으로 실시되고 있으며 또한 退職金制度가 年金制度로 전환되는 추세도 증가하고 있다. 年金制度를 채용한 기업에서는 退職勤勞者에게 未來에 지급할 給付金이 기업의 財務狀態와 經營成科에 중대한 영향을 미치기 때문에 給付金支給에 충당할 基金積立額을 조달하기 위한 年金原價의 測定과 年金關聯情報의 公示가 중효한 會計問題로 제기된다. 그리고 企業年金會計는 年金制度의 관련법규와 기업의 年金財政 그리고 年金原價를 산출하는데 필요한 保險數假定등의 영향으로 복잡한 문제를 가지고 있다. 따라서 본 연구는 미국의 企業年金制度를 중심으로 발전한 年金會計基準의 변천과정, 年金原價의 認識과 測定, 年金資産과 負債의 測定 그리고 公示에 관한 主要會計方法을 理論的, 體系的으로 分析하여 한국에서도 1988년부터 시행되고 있는 現幸年金制度에 적합한 年金會計基準을 제정하기 위한 방향을 제시하는데 그 목적이 있다. The guarantee system for employee's retirement benefits has pervasively been changed fro mretirement benefit system to employee pension plans in developed countries. As the benefit has a significant influence on the firm's financial position and business performance, the measurement of pension cost and the disclosure of pension-related information become important issues. These are more complicated by the following problems, the legislation of the plan, firm's pension fienace, and actuarial assumptions on pension cost. In this paper, we review theoretically and systematically the history of accounting standard for pensions, the recognition and measurement of pension cost, the measurement of pension assets and liabilities, and the important accounting methods of disclosure in America. On the basis of the review, we suggest the direction of the establishment of accounting standard for pension in Korea.

金融先物 및 옵션去來의 會計處理에 관한 硏究

李喜均 울산대학교 1994 경영학연구논문집 Vol.1 No.2

본 연구는 金融先物 및 옵션 去來에 관해 회계상 제기될 문제와 회계처리방법을 대상으로 한 것이다. 본 연구에서는 文獻調査를 통해 금융선물 및 옵션거래의 특성을 파악하고, 금융선물 및 옵션거래에 대한 미국, 일본 및 한국의 關聯會計處理基準을 비교·검토한다. 그리고 국내기업들의 금융선물 및 옵션거래의 現狀과 展望에 비추어 기업회계기준의 한계와 관련회계처리방법의 規程化의 필요성을 제시하며 또한 기업회계기준은 금융선물 및 옵션거래의 理論的·制度的 특성에 관한 先行硏究와 去來類型別 충분한 事例硏究를 통해 회계처리방법을 보완하여 발전시켜 나가야 할 것을 제안한다. This paper focuses on problems to be raised on the accounting procedures and methods for the financial futures and option transactions. This study captures the characteristics of the financial futures and option transactions through the literature reviews, and examines and compares the related accounting standards of U.S., Japan and korea in these transactions. And in the light of the conditions and prospects of the financial futures and option transactions in Korea, it provides the limits of accounting standards, the necessities of the related accounting methods, and the future legislation of accounting standards out the financial futures and option transactions.