• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4A
• /
• pp.219-226
• /
• 2012

We investigated the performance of a visible light communication (VLC) transceiver applicable to both of illumination and wireless communication. we considered the visibility of VLC, the easy connection for wireless communication and high-speed transmission and implemented VLC transceiver based on edge-emitting laser diode and silicon photodiode. The proposed VLC transceiver is designated to operate in a full duplex mode at high speed of 120 Mbit/s. The shielding method that is employed as a means to reduce the light cross coupling effect inside the VLC transceiver is proposed and its performance is experimentally measured. We also applied optical antenna to have the larger angle of field of view (FOV) to novel structure of VLC transceiver and examined and analyzed their bit error rate performance, photometric result with respect to the transmission distance, the coverage range and the tilt degree as transmission link characteristic between two transceivers without optical antenna and with optical antenna.

• Journal of Life Science
• /
• v.20 no.7
• /
• pp.1047-1053
• /
• 2010

This study was conducted to evaluate the effects of dietary Korean red pine bark extract as an antibiotic replacement on cecum microflora, immune functions, blood lipids, carcass characteristics, and growth performance in broiler chickens. There were four treatment groups: a control group, an antibiotic group, and two treatment groups receiving 65 and 80 ppm Korean red pine bark extract. Growth performance, carcass weight, dressing percentage, and breast and thigh muscle weight of the broiler chickens fed 80 ppm of red pine bark extract was higher than the broilers of the control group and the antibiotic group. Abdominal fat was lower in both groups of broiler chickens fed red pine bark extract, but the growth of immune organs such as the thymus, spleen, and bursa of Fabricius was significantly higher in the group that received a diet supplemented with 80 ppm red pine bark extract than in the control group and antibiotic group. Concentrations of triacylglyceride and total cholesterol were significantly lower in both groups that received red pine bark extract when compared to the control group and the antibiotic group. The concentration of serum IgG was significantly higher in the 80 ppm red pine bark extract group than in the control group and the antibiotic group. The numbers of Bifidobacterium and Lactobacillus in the cecum digesta were significantly increased, while the numbers of Escherichia coli and Salmonella were significantly reduced in the group that received 80 ppm red pine bark extract when compared to the control group and the antibiotic group. These results suggest that the a diet with 80 ppm Korean red pine bark extract as a replacement for antibiotics improve the cecum microflora, immune functions, blood lipids, carcass characteristics and growth performance of broiler chickens.

• Journal of Korea Water Resources Association
• /
• v.51 no.12
• /
• pp.1171-1180
• /
• 2018

Korea's water transmission system is operated by the nonpressure flow method that flows from highlands to lowlands due to the nature of Korea with many mountainous areas. In order to store water in the highlands, the water pumps are installed and operated. However, In this process, a lot of electrical energy is consumed. therefore, it is necessary to minimize the energy consumption by optimizing the size and operation schedule of the water pumps. The optimal capacity and operation method of the water pump are affected by the size of the tank (distributing reservoir). Therefore, in order to economically design and operate the water transmission system, it is reasonable to consider both the construction cost of the water pump and the tank and the long-term operation cost of the water pump at the step of determining the scale of the initial facilities. In this study, the optimum design model was developed that can optimize both the optimal size of the water pump and the tank and the operation scheduling of the water pump by using the genetic algorithm (GA). The developed model was verified by applying it to the water transmission systems operated in Korea. It is expected that this study will help to estimate the optimal size of the water pump and the tank in the initial design of the water transmission system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11A
• /
• pp.933-940
• /
• 2011

In this paper, Ka-band transceiver for road watch radar system is designed and fabricated. The transceiver for road watch radar system is composed of waveform generator, frequency generator. IF transceiver and RF up/down converter. The transceiver especially has 3 different waveform mode for target detection range. The transceiver had over 150 MHz bandwidth in Ka-band and 22 dBm output power. The receiver gain and noise figure was 30 dB and 4 dB respectively. The receive dynamic range was 65.28dB and amplitude imbalance and phase imbalance of I/Q channel was 0.3 dB and 1.8 degree respectively. The transceiver meets the required electrical performances through the individual tests.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.5
• /
• pp.2285-2290
• /
• 2011

This paper is the research on SMSR yield improvement of the optical transceiver using modulated DFB laser. In general, the wavelength of DFB laser optical transceiver are 1310, 1490 and 1550 nm. Usually SMSR in modulated DFB is difficult to improve as low as 30 dB because of high slop efficiency trade off. In modulation condition, we studied SMSR improvement according to adjust bias current, extinction ratio and optical line terminal receiver sensitivity. As our test results, we can found a method how to improve SMSR for optical transceiver for long distance.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2017.05a
• /
• pp.158-158
• /
• 2017

상수관망을 통한 용수 공급에서는 송수펌프, 배수지 등의 수리 시설물이 중요한 역할을 수행한다. 우리나라의 송 배수 방식은 송수펌프를 통해 고지대의 배수지에 물을 확보하고, 이를 자연유하 방식으로 공급하는 것이 일반적이며, 따라서 송 배수시스템의 운영이란 송수펌프의 가동과 그에 따른 배수지의 수위 현황을 관리하는 것을 의미한다. 이 때, 펌프의 가동을 위한 전력소모에 많은 비용이 발생되므로 효율적인 펌프 운영을 위한 최적화 연구의 필요성이 제기되었다. 기존 연구를 통해 송 배수시스템의 운영을 모의하고, 펌프 가동비용을 최소화 하는 실시간 최적 펌프운영 모형이 개발되었으나, 미리 결정된 펌프와 배수지를 바탕으로 송 배수시스템을 모의하기 때문에 계획 및 설계 단계에서 이를 활용할 수 없는 한계점이 존재하였다. 본 연구에서는 최적화 알고리즘 중 하나인 유전자 알고리즘(Genetic Algorithm, GA)을 사용하여, 실시간 펌프운영뿐만 아니라 송수펌프와 배수지의 효율적인 용량을 제시할 수 있는 최적화 모형을 개발하였다. 특히, 개발 모형은 펌프와 배수지의 설계/운영 시, 국내 설계기준, 시설물 비용, 시간별 전력단가 등을 제약조건으로 고려하여 현실적인 결과를 도출할 수 있도록 개발되었다. 본 연구는 실제 운영 중인 S시의 광역상수도 시스템을 바탕으로 개발 모형을 적용하였으며, 또한 송 배수시스템의 계획 및 관리에 활용할 수 있을 것으로 기대된다.

• Proceedings of the KIEE Conference
• /
• 2005.07d
• /
• pp.2992-2994
• /
• 2005

수십 센티미터 이내의 오차를 만족시키는 거리/위치판별 기능 및 저속 데이터 송수신 기능 구현을 주목적으로 발족된 저속 무선 개인영역 네트워크(LR-WPAN: Low Rate Wireless Personal Area Network)의 표준인 IEEE802.15.4a는 간단하고 경제적이며 전력 소모가 적은 송수신기 구조를 요구한다. 이에 본 논문에서는 PEWB(Parallel Energy Window Banks)를 이용한 독창적인 비동기(noncoherent) OOK(On-Off Keying) UWB(Ultra-Wide Band) 송수신기 구조를 제안한다. 또한 무선 다중경로 채널상황을 다소 극복할 수 있는 펄스와 비트 반복 기법을 사용한다. 제안된 송수신기의 잡음 특성 분석을 위해 chi-square 분포가 사용되며, 반복적 계산을 통해 얻어진 임계값을 적용하여 BER(Bit Error Rate) 성능을 분석한다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 2009.10a
• /
• pp.67-70
• /
• 2009

송수신기 일체형인 소형 루프 시스템을 해저 전자탐사 기술의 적용 가능을 확인하는 과정의 시작 단계로 자기 쌍극자 송신원을 이용한 층서구조에서의 전자가 반응을 계산 하였다. 전도성인 해양 환경에서 측정되는 신호의 크기가 작은 한계가 있지만 전자기장 반응 해석을 통행 지하 하부의 정보를 얻을 수 있었다. 기반암 위의 층이 바닷물보다 저항성인 해저 지각인 경우와 전도성인 열수광상인 경우에 따라 반응이 달라짐을 확인하였고, 그 층의 두께에 따라서 변화하는 전자기 반응을 계산하여 탐지 가능한 층의 두께를 예상할 수 있었다. 송수신기가 모두 바다 속에 위치하기 때문에 송수신기의 배치 방법과 송수신기가 해저면에서 떨어지게 될 때 신호의 반응 변화를 파악하였다. 해양 소형 루프 전자탐사의 실제 적용을 위해서 이상의 연구들이 기초가 될 것으로 기대된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.974-977
• /
• 2003

In this paper, the system that can be controlled in remote site by wireless data and video transceiver is represented. This system has functions and equipments such as video capturing and processing by CCTV camera, auto tracking for object, wireless video and data transceiver, Internet network.

• Proceedings of the KAIS Fall Conference
• /
• 2009.05a
• /
• pp.511-513
• /
• 2009

본 논문은 절전형 센서에 사용되는 24GHz대역의 CW 레이더 송수신기의 설계에 관한 것이다. K 밴드 대역의 송수신기 회로의 기본 구조와 분배기가 디자인 되었고 발진기, 주파수혼합기, 고주파 증폭기는 기존 제품을 사용하였다. 제안된 송수신기의 크기는 $35{\times}35{\times}10(mm)$이며 여러 가지 제품에 사용될 수 있도록 설계되었다.