• 한국산학기술학회논문지
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• 제10권10호
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• pp.2551-2556
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• 2009

링 레이저 자이로스콥의 주 동작은 폐경로 내의 상대 전파에 대한 위상 차에 의존한다. 공명 블록위에 설치 된 반사경들이 순항 파를 형성한다. 따라서, 공명 블록의 차원 정확도가 빔의 순항 경로에 영향을 미친다. 링의 공진 내에서 안정된 광학 빔 경로를 유지하기 위해서 피에조로 구동되는 이동거울이 공명 블록의 열팽창이나 기계적 변형하에서 경로치 제어를 하고자 선택되었다. 이 논문에서는 피에조 구동 거울의 탄성거동에 대한 수학적 설명을 제시하였다. 이 설명은 피에조 구동 거울의 개념 설계에도 적용될 수 있다.

• Tribology and Lubricants
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• 제20권5호
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• pp.278-283
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• 2004

O-ring seal is widely used for sealing pressure vessels and oil containers in various applications of mechanical equipments. The doughnut shape of the O-ring is very important components in most of the system assembly of mechanical apparatus. This paper presents the sealing force of a pressurized perfluoroelastomer O-ring, which is very important contact seal in sealing the semiconductor equipment. The sealing pressure is measured by experimental method and analyzed numerically by using the non-linear MARC finite element program. The seal tester is made to measure the contact force and displacement of the O-ring with an automatic control system of the working temperature. The results show the reasonable agreements between the computed FEM results and measured ones when the operating temperature is moderate temperature. But the compared values between the computed and tested results show a difference because of the increased temperature, which is related to the non-linear parameter of the O-ring material.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.228-229
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• 2008

In this study, we propose an effective method to improve the clarity and period of the beat in a ring structure. Ring is an simplified model of a Korean bell, in which beating vibration and sound are very important features. An equivalent ring theory is applied and finite element analysis on the equivalent ring is performed to determine the condition of the asymmetric element for the clear and proper period beat. The clarity and the period of the beat are improved by attacking asymmetric mass and decreasing local thickness. Using the equivalent ring, the amount and position of the local variation for the required beat condition are determined and the results are verified by experiment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.17-20
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• 1999

In these days, wavelength division multiplexing(WDM) all-optical network are being deployed to support various multimedia communication services. In this paper, various WDM all-optical network are discussed, and a design of an all-optical backbone network has been proposed by using multiple self-healing ring technology. The proposed multiple self-healing ring network improves network expandability and efficiency of bandwidth, while it retains simplicity and ease of network control, which are from the nature self-healing ring. Using PDI traffic modeling technique, a well-balanced all-optical backbone network using multiple self-healing ring is designed for the 2010s in Korea.

• 오토저널
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• 제6권1호
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• pp.56-62
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• 1984

Various automotive and machine parts are having the shape of circular ring and the study and the verification of its dynamic characteristics can be the important basis of quality control and improvement of performance of inner and outer race of ball and roller radial bearing, ring gear, seal, etc. In this study, three separate sets of governing equations on the flexural vibration of circular ring were formulated each considering the effects of viscous damping, rotatory inertia and shear deformation, and three frequency formulas were derived. Numerical values of frequencies of circular and rectangular cross section ring were tabulated and compared with experimental value. Some important parameters were found in the ring vibration characteristics.

• ETRI Journal
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• 제32권1호
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• pp.53-61
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• 2010

We propose a simple technique to stabilize the optical output intensity of a fiber ring resonator. The electronic feedback circuit system, which consists of two voltage control oscillators, a phase comparator, and a low pass filter, is applied to the fiber ring resonator in order to compensate the optical phase shift in the ring loop. The reference electrical signal determines the operating condition of the fiber ring resonator for the desired optical output signal. The experimental results within the operating range agree well with the analytical results. The simulated performance of the proposed model is also compared with that of other existing models and shows significant improvement over them.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2042-2044
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• 2001

The jumping ring apparatus of the type described in this study is used to demonstrate and educate the effects of electromagnetic induction. Placing an aluminum ring over the core and switching on AC source causes the ring to jump in the air due to induced currents in the ring producing a magnetic field opposed to that produced in the core. If the AC current is slowly increased from zero or ring is placed over the core when AC is already flowing the ring floats due to the balance between its weight and the upward electromagnetic force. Pentimum computer is used to display this value to screen and generate control signal.

• 한국항해항만학회지
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• 제40권6호
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• pp.441-450
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• 2016

연안오염퇴적물에 함유된 유기물질과 PAHs의 현장정화를 위한 생물활성촉진제의 효능을 파일럿 규모의 현장실험을 통하여 1년간 평가하였다. 실험 해역의 수온은 계절적인 요인으로 인해 $16.5^{\circ}C$에서 $21^{\circ}C$까지 변화가 있었으나, 파일럿 반응조의 오염퇴적물의 pH는 8.4-8.5로서 비교적 일정하였다. 파일럿 실험종료 후 바탕시험구와 초산, 황산이온, 질산이온을 함유한 생물활성촉진제를 주입한 오염퇴적물의 화학적 산소요구량은 각각 39% 및 79%까지 감소하였으며, 휘발성고형물은 초기 약 15 g/kg에서 7 g/kg 및 2.5 g/kg까지 각각 감소하였다. PAHs는 2- ,3- ,4- ,5-ring 과 6-ring 16PAHs를 평가하였으며, 생물활성촉진제를 주입한 오염퇴적물에서 2-ring 화합물인 나프탈렌은 실험시작 2개월 후 100%(바탕시험구의 감소율 55.6%)까지 감소되어 가장 빨랐고, 12개월 후 3-ring 및 4-ring PAHs의 감소율은 모두 100%(바탕시험구의 감소율 46%-100%)에 달하였다. 5-ring과 6-ring PAHs의 12개월 후의 감소율은 바탕시험구와 생물활성촉진제를 투여한 오염퇴적물에서 각각 26%-87% 및 77%-100%로 평가되었다. 연안오염퇴적물에 투입한 생물활성촉진제는 유기물질 및 난분해물질인 PAHs의 제거속도를 향상시킬 수 있는 것으로 평가되었다.

• Journal of Ceramic Processing Research
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• 제19권5호
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• pp.439-443
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• 2018

The outstanding characteristics of high quality GaN single crystal substrates make it possible to apply the manufacture of high brightness light emitting diodes and power devices. However, it is very difficult to obtain high quality GaN substrate because the process conditions are hard to control. In order to effectively control the formation of GaN polycrystals during the bulk GaN single crystal growth by the HVPE (hydride vapor phase epitaxy) method, a quartz ring was introduced in the edge of substrate. A variety of evaluating method such as high resolution X-ray diffraction, Raman spectroscopy and photoluminescence was used in order to measure the effectiveness of the quartz ring. A secondary ion mass spectroscopy was also used for evaluating the variations of impurity concentration in the resulting GaN single crystal. Through the detailed investigations, we could confirm that the introduction of a quartz ring during the GaN single crystal growth process using HVPE is a very effective strategy to obtain a high quality GaN single crystal.

• Journal of Pharmaceutical Investigation
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• 제22권3호spc1호
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• pp.35-47
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• 1992

Hydrogel coated ring shaped ocular inserts (containing the antibiotic, tylosin tartrate) were used in an evaluation of the effectiveness of polymeric ocular drug release devices for treating infectious bovine keratoconjunctivitis. The in vivo experiments represent the first experiments using hydrogel ocular inserts containing an antibiotic for treating infectious bovine keratoconjunctivitis. In the infection tests, ten calves. were challenged with $2.4{\times}10^8{\sim}1.6{\times}10^9$ Moraxella bovis (a bacterium) colonies per eye following two ten minute ultraviolet radiation eye preconditioning exposures. Ninety five percent of the eyes (19 of 20 eyes) were successfully infected by this method. All infected eyes were monitored for the presence of the bacteria quantitiatively, and clinical observations were made for 14 days. The test was performed by three consecutive steps: 1) inoculation with 2 ultraviolet (UV) radiations, 2) growth of bacterial colonies and 3) treatment with medicated ring-shaped devices. The first. bacteriological measurements after 2 UV exposures were performed at day 3 of the tests. At day 7 after inoculation of both eyes of a calf with M. bovis, a medicated or a non-medicated ring-shaped device was inserted into each eye of a calf. The eye receiving the non-medicated ring was taken as a control for comparison with the eye that received a medicated ring. During the next 7 day period following a medicated ring insertion, the number of bacteria in the treated eyes dropped dramatically to negligible levels (0 to 30 colony forming units/swab), while the control eyes which received a non-medicated ring still exhibited a relatively high number of bacteria ($10^3\;to\;10^6$ colony forming units/swab). The number of bacteria was significantly reduced by the antibiotic released from the medicated ocular insert.