광 교환 기술을 이용한 ATM 백본 네트워크

최영복,고성택,김경연,김경식 濟州大學校 工科大學 産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.2

The B-ISDN(Broadband-Integrated Service Digital Network) transports various multimedia information effectively. So optical switching networks which consist of optical transmission links and photonic switching systems are noticeable as a way of a large capacity communication. In this paper, we propose optical packet switching networks which will be used as the backbone network of national high speed communication networks which are operated a way of ATM(Asynchronous Transfer Mode). The B-ISDN transport networks are composed of two-layered networks such as regional networks and a backbone network. The regional network is an average ATM transport network. The optical backbone network gathers fixed length of several ATM cells which come from regional networks, attaches an optical header, and completes an optical packet. And then the network switches and transports with high speed. That is, the backbone network is a transparent optical packet network. The passing speed of signal in the photonic switch is rapid, but the switching speed is limited and the processing speed of the switching controller which consists of electronic circuit is limited. So the optical packet which consists of multi-ATM cells is able to overcome it in the optical backbone network. The performance evaluation by the computer simulation shows us the efficiency of the proposed way of optical packet switching.

막분리기술을 이용한 과실쥬스의 농축에 관한 연구 : 1. Improved Clarification of Citron Juice by Ultrafiltration 1. 한외여과막을 이용한 유자액즙의 청징

하진환,송대진,김효선 濟州大學校 工科大學 産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.1

막분리기술을 식품가공에 응용하기 위하여 한외여과막의 MWCO에 따른 유자과즙의 청징효과를 실험하였다. MWCO가 각각 1K, 20K, 50K, 100K Daltons인 나권형막으로 한외여과 하였을 때 MWCO 가 클수록 유출액즙의 투과플럭스와 전 고형분 함량은 커졌으며, MWCO가 작을수록 탁도는 낮았고 명도는 높은 값을 나타내었다. 한외여과한 유자액즙의 pH는 저장중 서서히 낮아졌으나 큰 변화는 없었고, 가용성고형분의 함량과 산도도 서서히 감소하였다. 저장중 탁도와 갈변도는 증가하였는데 MWCO가 클수록 증가폭이 컸다. 저장중 명도는 MWCO가 작을수록 더 높은 값을 나타내었으며 그 변화폭도 적어 안정성을 보였다. For the application of membrane separation technique on food processing, the effects of molecular weight cut-off(MWCO) of ultrafiltration membrane during clarification of citron juice was investigated. When citron juice was clarified using 1K, 20K, 50K and 100K Daltons MWCO sprial wounded membranes, the larger the membrane pore size, the higher the permeate flux and total solid content and the smaller the membrane pore size, the lower the turbidity while showing higher L-value. During storage pH of ultrafiltered citron juice was slowly down without sudden change while soluble solid content and acidity were decreased gradually. Turbidity and browning during storage were also increased with especially great range in large MWCO. L-value was higher in smaller membrane pore size but shown stability without great change.

Image encryption and identification for security verification

Kim, Jong-Yun,Doh, Yang-Hoi,Kim, Soo-Joong 濟州大學校工科大學産業技術硏究所 1999 尖端技術硏究所論文集 Vol.10 No.1

컴퓨터형성 홀로그램과 무작위 위상 마스크, 광상관 기술을 이용하여 신원보증을 위한 새로운 영상 암호화와 신분증명 체계를 제안하였다. 보안제품에 부착되는 암호화된 영상은 4진 위상 컴퓨터형성 홀로그램에 무작위 위상 함수를 곱하여 제작하였다. 무작위 위상 함수는 암호화된 영상을 복원할 때 핵심적인 역할을 한다. 암호화된 영상은 2-f 영상복원 시스템을 이용하여 복원하고, 4-f 상관 시스템을 이용하여 개인의 신원증명을 위한 확인작업을 자동적으로 수행한다. 제안된 방법을 원래의 영상을 복원하고 암호화된 영상을 인식하는데 사용할 수 있음을 시뮬레이션 결과를 통하여 보였다. A new image encoding and identification scheme is proposed for security verification by using a CGH(computer generated hologram), random phase mask, and correlation technique. The encrypted image, which is attached to the security product, is made by multiplying QP-CGH(quadratic phase CGH) with a random phase function. The random phase function plays a key role when the encrypted image is decrypted. The encrypted image can be optically recovered by a 2-f imaging system and automatically verified for personal identification by a 4-f correlation system. Simulation results show the proposed method can be used for both the reconstruction of an original image and the recognition of an encrypted image.

실리콘 미세가공 기술을 이용한 마이크로 진공 센서

이광만,고성택,김영민,고희선 濟州大學校 工科大學 産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.1

A micro-vacuum sensor has been fabricated by using silicon micromachining techniques and platinum thin film. NON insulator was deposited by LPCVD and APCVD methods. The insulator diaphragm was fabricated by silicon anisotropic etching in TMAH solution. Thin film platinum heater and temperature detector were deposited by rf sputtering method and patterning was performed by means of lift-off method. Deposited platinum heater and temperature detector have been shown a linear Ⅰ-Ⅴ characteristics. TCR(temperature coefficient of resistance) of thin film platinum heater and temperature detector was about 0.0042/℃. Fabricated vacuum sensor was measured in the range of 1x10­³Torr to 1×10² Torr, and shows a good linear operating characteristics in the range of 1x10­² Torr에서 1x10˚Torr.

WIND ENERGY POTENTIAL ASSESMENT and SITING a WIND FARM in CHEJU ISLAND

김건훈,조경호,고장권,허종철,고경남 濟州大學校 工科大學 産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.2

본 연구는 제주도내 풍력발전기 보급 및 적지선정을 검토하는데 그 목적을 두었다. 이를 위하여 제주도내 다풍지역으로 예상되는 3개지역을 선정하여 1년간 풍력자원조사를 행하였고, 계측된 자료는 통계분석으로 풍력자원을 정량화하였으며 또한 세계적으로 경제성이 인증된 600kW 풍력발전기를 모델로하여 가상 출력을 산출함으로서 최적 풍력단지를 제시하였다. The possibility in the practical use and supply of the wind turbine in Cheju island was investigated. The wind data measured in three regions which have a plenty wind energy potential were utilized to quantify the wind power resources by statistical analysis. Power output was calculated for 600 kW wind turbine. The coastal area of Guja was superior to Daejung and Hoichun in wind power energy densities. The calculated capacity factor of 600 kW wind turbine in this site was high as much as 30%. Hoichun site, the intermediate region between the Halla mountain and the sea, was rich in wind power energy resources in winter. Hourly ideal energy density at three regions increased at sunrise, reached the maximum at 13-16 O'clock, decreased steadily, and finally remained constant at sunset.

X-ray 照射에 의한 濟州産 감자 貯藏

金在河,康勳 濟州大學校工科大學附屬産業技術硏究所 1993 尖端技術硏究所論文集 Vol.4 No.-

濟州産 감자의 장기 저장을 위하여 방사선을 5 Krad 10 Krad 및15 Krad로 照射한 것과 照射하지 않은 것 및 各 線量과의 품질상의 차이를 비교하였다. 放射線 照射는 부패방지에는 별 효과가 없다는 것을 알 수 있었고 5 Krad는 10 Krad나 15 Krad와 비교 할 때 너무 線量이 낮았으며 10 Krad가 15 Krad보다 더 효율적이었다. 같은 선량에서는 실외에 통풍이 잘되게 저장한 것이 실내에 밀폐된 공간에 저장한 것 보다 저장효과가 높게 나타났다. For extension of storage with Cheju grown potatoes, irradiations with doses of 5 Krad, 10 Krad and 15 Krad were applied and the differences of quality were compared between the irradiated and the unirradiated and also between doses. Irradiation is not effective on the prevention of decaying. Irradiation of 5 Krad is too low compare with 10 Krad and 15 Krad and 10 Krad is more effective and energy saving than 15 Krad. Among same irradiation doses, outdoor storage showed better quality than those stored in enclosed space in the room.

광대역 통신망에서의 트래픽 제어기술에 관한 연구

안기중,유인태 濟州大學校工科大學産業技術硏究所 1995 尖端技術硏究所論文集 Vol.6 No.-

In this paper, an ATM cell monitor/control algorithm is proposed to enhance the efficiency of bandwidth management and statistical multiplexing for various types of cell traffics. This algorithm is based on the usage parameter control and bandwidth allocations. The traffic is monitored and controlled by counters, lookup table and cell control unit to reduce the burden of the traffic overload. And for the bandwidth management the entire bandwidth is separated into two classes : the basic bandwidth is allocated to each type of traffic and the shared bandwidth may be used when more bandwidth is required due to the burst. The network resources can be allocated to more virtual connections accordingly.

흡습성 에어로졸의 거동에 미치는 수증기 응축의 영향

박재우 濟州大學校 工科大學 産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.1

The growth by steam condensation of an hygroscopic aerosol is investigated using the condensation rate model which has been derived from the mass and heat transfer equations and considers both the solute and Kelvin effects. Considering the hygroscopicity shows that condensation can occur on hygroscopic seed particles even under subsaturated steam conditions. Investigations are made regarding the effect of hygroscopicity on the evolution of the particle size distribution and decay of the total aerosol concentration. It is found that hygroscopicity causes the particle size distribution to rapidly move upward even in a very short time, resulting in substantially higher decay of the total aerosol concentration than the case without considering hygrscopicity.

평방근 정보필터를 이용한 상관된 측정잡음을 갖는 기동표적의 추적을 위한 상호간섭다중모델 기법

권성숙,김경연 濟州大學校 工科大學 産業技術硏究所 1998 尖端技術硏究所論文集 Vol.9 No.1

In tracking a maneuvering target by a rader system, the measurement noise is significantly correlated when the measurement frequency is high. In this paper, we describe an efficient interacting multiple model(IMM) approach for tracking a maneuvering target with correlated measurement noise based on the square root information filter(SRIF). The SRIF is employed instead of conventional Kalman filter since it exhibits more efficient features in handling the decorrelation process and improved numerical characteristics. The Monte Carlo simulations for the maneuvering target are provided to demonstrate the enhanced tracking performance of the proposed algorithm.

위성방송 중계기용 H면 다이플렉서 설계

서수덕,양두영 濟州大學校工科大學産業技術硏究所 1997 尖端技術硏究所論文集 Vol.8 No.1

In this paper, we analyze H-plane T-junction using TE mode theory and design a diplexer for the broadcasting transponder of satellite. A diplexer is constructed by H-plane T-junction combined transmitting filter with receiving filter. These filters are designed by the insertion loss method. Matching elements are designed to reduce mismatching conditions on the discontinuity of T-junction, so that a diplexer is optimized and has the best property. An optimum diplexer has characteristics that reflected power is about -20dB in the receiving passband and the transmitting passband.