• Tribology and Lubricants
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• 제1권1호
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• pp.46-58
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• 1985

피스톤링과 실린더벽 사이의 윤활이 왕복운동을 하며 동하중을 받는 포물선형의 슬라이드 베어링의 유체 윤활로 보고 전개하였다. 싸이클 상의 유막 두께의 변화, 윤활유 운반과 마찰력을 계산하는 과정이 개략적으로 설명되었고, 이들 성능 특성들에 대한 링 높이, 링 앞면 곡률반경과 링의 비대칭의 영향을 고찰하였다. 단독링에 대한 해석결과를 조금 더 복잡한 링 팩에 대해 확대 적용하였다. 링의 부하가 되는 링 주위의 압력들은 실험적으로 또는 가스 흐름 해석으로부터 얻을 수 있는데 본 연구에서는 후자를 택하였다. 링팩에서의 유체 연속 및 윤활유 부족에 따른 수치 해석에 주안점을 두었다.

• 센서학회지
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• 제11권6호
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• pp.365-370
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• 2002

교류 220V에 의해 동작하는 점핑링 장치를 제작하고 광센서를 사용하여 링의 높이정보를 받아 부상한 링의 높이를 실시간으로 검출하고 교육적 효과를 높이기 위해 디지털 높이정보를 아날로그 변환하여 쉽게 높이를 알 수 있도록 하였다. 교육용 시스템을 직접 제작하여 시스템을 모형화하여 제어신호를 구하고 제어 프로그램에 의해 원하는 높이로 링을 부상할 수 있도록 하였다. 본 논문은 광센서를 사용하여 링의 위치를 실시간으로 검출하였고 광센서의 배열과 높이 정보를 발광다이오드 5개로 디지털 값을 보여주었고, D/A변환하여 교육용 시스템을 제작하여 A/D 변환기를 통해 데이터 신호처리 하였다. 교육용 시스템을 모형 화하여 원하는 링의 높이를 실시간으로 제어 할 수 있게 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2652-2654
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• 2005

A vacuum chamber temperature control system of Pohang Accelerator Laboratory (PAL) storage ring is a subsystem upgraded PAL control system, which is based upon Experimental Physics and Industrial Control System (EPICS) [1]. There are two control components, data acquisition system (SA120 data logger), development control system IOC (Input/Output Controller) at the storage ring of PAL. There are 240 vacuum chamber at the storage ring. It was a very important problem to solve how to monitor such a large number of vacuum chamber temperature distributed around the ring. The IOC connect MODBUS/JBUS field network to asynchronous serial ports for communication with serial device. It can simultaneously control up to 4 data acquisition systems. Upon receiving a command from a IOC running under Windows2k through the network, the IOC communicate through the slave serial interface ports to SA120. We added some software components on the top of EPICS toolkit. The design of the vacuum control system is discussed. This paper describes the development vacuum chamber temperature control system and how the design of this system.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.562-570
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• 2002

The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.

• International journal of advanced smart convergence
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• 제8권1호
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• pp.35-43
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• 2019

A metro ring network using WDM technology requires many issues to be considered even though its transmission distance is shorter and its transmission capacity is lower than a long-haul WDM system. Unlike a long-haul WDM system, which is basically point-to-point configuration, a metro ring network usually equips with capabilty of wavelength reconfiguration. Therefore network performance considering crosstalk within OADM and the network behavior when the ring network is closed should be analyzed before implemented. We discussed some of results analyzed for the issues. Furthermore we proposed a novel method to design a dispersion map for a ring network, and demonstrated the methodology with an exemplary 8-node ring network of 399km circumference.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.613-617
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• 2001

The test items like as endurance, air leakage and oil endurance test is requested for reliability evaluation about O-ring which is a kind of core machinery accessories of semi-conduct manufacturing equipment. For verification of these, we design and manufactured a test system for endurance, air leakage and oil endurance of O-ring for semi-conduct manufacturing equipment, and also performed the test for two kinds of O-ring, as it were Viton and Kalretz. The characteristics of this test equipment consist in realization of the test conditions of semi-conduct manufacturing equipment and satisfying the test method. The test conditions are cut gas, vacuum grade, temperature and revolution numbers in the endurance test system, vacuum grade and temperature in the air leakage test system, temperature and time in the oil endurance test system. The separating test results for wearing which is an oil endurance test item, the wearing index of domestic produced Viton O-ring is higher than foreign product by 2%, wearing rate of Kalretz O-ring better than Viton O-ring by 17%, and particles existed in various place. The test result of air leakage which is measured through the RGA sensor used Helium, the vacuum grade was $10^-3$Torr. And the test result of oil endurance, the volume change rate was 7~15%. Hereafter, we intend to analysis the reliability test evaluation and to utilize for domestic manufacturing companies by establishing data base and developing reliability softwares.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.366-369
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• 2003

The vertical fountain plating system with the point contact has been used in semiconductor industry. But the plating shape in the opening of photoresist becomes gradated shape, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. So, we designed the tilted electrode ring contact to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and $\alpha$-step. A photoresist was coated to a thickness of $60{\mu}m$ and vias were patterned by a contact aligner After via opening, solder layer was electroplated using the fountain plating system and the tilted electrode ring contact system. In $\alpha$-step measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were ${\pm}16%,\;{\pm}3.7%$ respectively. In this study, we could get high uniformity bumps by the tilted electrode ring contact system. So, tilted electrode ring contact system is expected to improve workability and yield in module process.

• 한국생산제조학회지
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• 제19권5호
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• pp.622-630
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• 2010

The increase of the spindle speed to enhance the productivity in ring spinning processes has been limited by yarn tension and heat generation of the traveller/ring. The main causes of yarn tension are 1) the force added directly to the yarn by the rotation of the spindle and 2) the centrifugal force exerted by the yarn balloon generated by traveller rotation. The dominant causes of heat generation are 1) the friction between the ring and traveller and 2) the friction between the traveller and yarn. These factors cause yarn end-breaks and heat damage. In the case of the staple yarn manufacturing process for PET (polyester) and nylon (a heat plasticity material), the rotational speed of the ring spinning system has deteriorated to 10,000rpm. The objective of this study was to develop a rotating ring which has dynamic stability, high productivity and a simple structure to overcome the limitations of the conventional fixed ring/traveller system. The results of this study revealed that the spinning tension could be reduced by 67.8% using the newly developed rotating ring.

• 한국정보과학회논문지:시스템및이론
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• 제31권9호
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• pp.487-494
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• 2004

다중 프로세서 시스템을 구성하기 위하여 점유가 발생하는 버스를 채용한 이래로, 상호연결망의 병목현상을 개선하기 위한 노력은 점대점 연결을 이용한 링 구조까지 발전되어 왔다. 상호연결망의 병목 현상은 다중 프로세서 시스템이 프로세서 수에 따른 선형적 성능 개선을 나타내지 못하게 하는 주요 제한 요소로 작용하였으며, 이러한 병목 현상을 개선하기 위한 상호연결망 구성 방법이 다수 연구되어 왔다. 본 논문은 현재 활발히 채용되고 있는 두 개의 점대점 연결을 이용한 링 구조에서 일정 규칙에 기반한 건너뜀 연결을 갖도록 개선하고 트랜잭션의 전송 경로를 정적 알고리즘으로 구현하여, 이중 링크를 가지는 CC-NUMA 시스템의 부하를 균일하게 분배시킴으로써 시스템의 성능과 확장성을 개선시켰다. 실험 결과에 의하면 단일 링크를 이용한 링 구조의 경우, 프로그램의 부하가 커질수록 프로세서의 추가에 따른 특정 링크의 병목 현상이 발생하였고, 시스템의 성능이 저하되었다. 본 논문에서 제시된 건너뜀 연결 구조의 경우, 동일한 대역폭을 가진 반대 방향 이중 링 구조에 비하여 높은 성능과 균등한 부하 분배에 의한 개선된 확장성을 얻을 수 있었고, 반대 방향 이중 링의 경우에 발견되는 부하 편차를 크게 줄일 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.212-214
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• 2004

Hardware implemented ring buffer systems and methods are presented for the effective management of the ring buffer in TCP/IP communication. The layer interface of the ring buffer systems transfer free buffer and used buffer size information to the TCP/IP stack upper or low layer. The pointer updation interface calculates a temporary pointer from the data size which is needed by the present pointer of the ring buffer and upper or lowyer layer. The pointer manager of the ring buffer systems is responsible for saving the present pointer of the ring buffer, updating the ring buffer pointer to the new pointer, calculating the free buffer size and used buffer size of the ring buffer, and transferring the information to the upper layer. The ring buffer systems help the TCP/IP layer and TCP/IP upper or lower layer to decide the sending or receiving data size effectively. The delay of transferring data can be lowered by the ring buffer system.