• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.1405-1409
• /
• 2006

본 연구는 다목적 유전자알고리즘을 이용해서 상수도관망의 펌프 스케쥴링을 최적화하는 방안을 도출하기 위한 연구이다. 상수도관망의 시스템을 모의하기 위한 방법으로는 EPANET을 이용해서 각각의 결정변수에 관한 펌프운영비용을 산정하였으며, 이렇게 계산된 편익함수의 값을 다목적 유전자알고리즘의 목적함수로 이용해서, 펌프스케쥴링에 관한 여러 가지 대안을 제시하였다. 상수도관망의 운영을 위해서는 안정적인 용수공급이 가능하면서도 최소한의 에너지비용을 필요로 하는 펌프운영방식을 필요로 하게 되는데, 이때 용수수요량의 변화 등 운영여건이 바뀌게 되더라도, 수리적 안정성이 확보되는 범위내에서의 최적 운영방안이 필요하게 된다. 이와 같은 펌프운영방안의 최적화는 상당히 많은 수의 결정변수를 요구하게 되고, 결정변수의 탐색범위 또한 상당히 넓은 경우가 대부분이기 때문에, 국부최적해에 수렴하는 현상이 나타나지 않고, 넓은 범위의 결정변수 영역을 빠르게 탐색할 수 있으며, 여러 가지 대안을 효율적으로 제시할 수 있는 다목적 유전자알고리즘을 사용하였다. 본 연구를 통하여 개발된 상수도 관망 펌프 스케쥴링 기법을 이용하면, 운영여건의 변화에 따른 펌프운영비용의 최소화 여부를 검토할 수 있으며, 이를 바탕으로 각 단계별 수도시설을 종합적으로 고려한 경제적 운영방안의 검토가 가능할 것으로 판단된다.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1153-1154
• /
• 2011

본 논문은 3상 30kW 및 50kW 계통연계형 태양광 인버터의 개발에 관한 것으로, 그에 대한 제어기 및 성능에 대해 소개한다. 본 논문에 소개되는 3상 30/50kW LSPV 태양광 인버터는 태양전지에서 발생하는 가변성 직류에너지를 한전계통에 최적으로 주입시키는 계통연계형 전력변환장치이며 국내의 발전사업자용으로 개발되었다. 3상 380V의 한전계통에 절연형으로 연계되며 낮은 THD 와 높은 역률로 고효율을 달성하였다. DC입력측의 개방전압은 900V로 태양전지모듈 조합의 편의성 및 DC과전압등에 대한 안전성을 향상하였고, EMI 전도노이즈에 대한 Filter를 장착하여 노이즈성분을 크게 개선하였다.

• Annual Conference of KIPS
• /
• 2017.04a
• /
• pp.493-496
• /
• 2017

본 논문은 딸기 재배 시설에서의 이루어지고 있는 온실 환경에서 생장 관리 기술의 생장 상태 및 환경 변화를 인지하는 과정에서 수집되는 환경데이터와 제어장치 간의 상관관계를 비교 및 분석하고, 이를 통해 전력소비량에 대한 에너지효율을 높이면서 최적의 생장 환경을 제공할 수 있는 시스템을 제안한다. 제안하는 시스템은 딸기 재배 시설의 품질 향상 및 생산량 증대를 지원하는 온실 생장 환경 모니터링 시스템 개발에 대한 연구이다. 향후에는 다양한 환경데이터와 제어장치 간의 상관관계의 정밀 분석을 통해 온실환경제어 시스템을 개선할 수 있는 연구가 될 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.3
• /
• pp.1275-1278
• /
• 2012

Compositional design and optimization of processing parameters are key factors for controlling and improving the properties of electroconductive ceramic composites. Temperature rising time of sheath heater is 1.1 times faster than SiC ceramic heater. Heating insulation of SiC ceramic heater is 2.7 times larger than sheath heater. If SiC ceramic heater is one body type of a product application, contact resistance will decrease. I think that temperature initial rising time is faster than now. The more SiC ceramic heater is used for a long time, the more economic benefit is larger in the view point of heat insulation.

• Journal of Satellite, Information and Communications
• /
• v.11 no.4
• /
• pp.52-57
• /
• 2016

The backscatter signals are very weak so they can be easily interfered by signal interferences and channels. In this paper, we propose a two-level classification algorithm for backscatter communications which chooses the idle frequency channel based on cognitive radio systems. The two-level classification algorithm provides an optimal idle frequency channel by obtaining informations about idle frequencies, fading of the channels, and the channels' usage state by primary users. Our simulation results show the improvement of BER and received power performance in backscatter communications by using the proposed algorithm, and the improvement of the algorithm's performance in backscatter communications.

• Food Science and Preservation
• /
• v.8 no.3
• /
• pp.313-319
• /
• 2001

In order to produce the high quality rehydrated acorn Mook(Korean tradition gel flood) that enhance acceptability, the optimum condition was investigated for the rehydration process of dried Monk as salt concentration(0, 1, 2%), temperature(20, 70, 80, 90$^{\circ}C$) and time. The estimation of moisture gain, rehydration efficiency was analyzed statistically. The surface color md seniory evaluation were undertaken to evaluate the rehydrated Mook quality The optimum rehydration time was decided to 15 minutes and it takes 3 minutes for the cooling tilde. The moisture gain increased as the rehydration temperature increase. And the moisture gain and moisture gain rate were higher at 1% salt solution than other concentration. As the rehydration efficiency, surface color and sensory properties of rehydrated Mook, 1% salt treatment was superior.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.2
• /
• pp.148-153
• /
• 2012

In this paper, we propose a fault-tolerant QoS routing scheme based on interference awareness for providing both high throughput and minimum end-to-end delay for wireless sensor networks. With the proposed algorithm, it is feasible to find out the optimal transmission path between sensor nodes to the sink node by using cumulative path metric where real-time delivery, high energy efficiency and less interference are considered as in path selection. Finally, simulation results show that network throughput and delay can be improved by using the proposed routing scheme.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.10a
• /
• pp.7-11
• /
• 2008

The fluorescent lamp is one of a discharge lane that is used by electric discharge to transfer from electrical energy to light The fluorescent lamp needs a ballast stabilizer when turn it on because it has negative resistance. Characters of electric discharge and transformed characters of ballast stabilizer are connected closely. Therefore, bring out best design directive that consider economical efficiency and term of a application is very important for both characters matching. In this case, we will team to develop tester and functions for expression for recognizing the end of fluorescent lamp life to solve fire problem and losing efficiency of light when a fluorescent lamp goes the end of the expected its life span.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.657-658
• /
• 2015

In an wireless sensor network, energy efficient routing protocol is important for multi-hop transmission because senor nodes are powered by battery. In multi-hop transmission, specifice nodes are used and the battery power becomes low, it induce the asymetric remaining power among the nodes and makes the network lifetime reduced. In this paper, we propose a power-aware routing protocol which determines the routing path considering the remaining power of the nodes. Simulation results shows that the proposed routing scheme minimize the transmission delay and increase the network lifetime.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.8B
• /
• pp.712-721
• /
• 2012

In this paper, we propose an Enhanced cross-layer Geographic Forwarding (EGF) protocol for wireless sensor networks (WSNs). EGF uses an optimal back-off time to make the packet forwarding decisions using only source and destination's location information and energy cost without information about neighbor nodes' location or the number of one hop neighbor nodes. EGF is also a cross-layer protocol by combining efficient asynchronous MAC and geographic routing protocol. The proposed protocol can find optimal next hop location quickly without broadcasting node's location update and with minimizing overhead. In our performance evaluation, EGF has better performance in terms of packet success ratio, energy efficiency and end-to-end delay in wireless sensor networks.