• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.328-330
• /
• 2009

1 kW class Polymer Electrolyte Fuel Cell(PEFC) co-generation systems have been developed from 2001 and evaluated for improvement of efficiency, durability and reliability of the system. This paper introduce new version system including with excellent reliability, durability and user friendly applications. Its electrical and overall efficiency showed 35 % and 80 %, respectively, and noise level of the system was less than 45 dB. In addition, this system have various functions such as load change, $N_2$ less purge, low emission and low temperature operation ($-15^{\circ}C$) through development of operation logic. This system was designed for convenient installation in indoor and outdoor due to the compactness of size and the separation of electrical and heat recovery units, which means a user can select the size of heat recovery unit.

• 한국전기전자재료학회논문지
• /
• 제11권6호
• /
• pp.477-480
• /
• 1998

In this paper, we investigated the liquid crystal(LC) alignment and generation of pretilt angle by using photo-alignment techniques on two kinds of polyimide(PI) surface, It was found that the uniform alignment for nematic(N) LC is obtained in a cell with slanted UV light irradiation on PI surface without side chain. We successfully observed that the pretilt angle of NLC is generated about $3^{\circ}$ with an incident angle of 70 degree on the PI surface without side chain. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecules and the polymer surfaces.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
• /
• pp.458-459
• /
• 2006

System has to be applied as protection at existent supply of electric power system and link is different from when system is operated individually Co-Generation. When equipment is driven Co-Generation that associate in existent equipment in this paper, displayed operating state of function by duty of protective system.

• 한국전산유체공학회지
• /
• 제9권4호
• /
• pp.7-12
• /
• 2004

In the present study a semi-automatic mesh generation program has been developed by using DXF file containing contour line data. The program consists of DXF file reader and mapping algorithm. Pre-generated 2-D planar mesh points are to be mapped one by one onto triangular surface whose three vertices are three nearest contour points surrounding the mapping point. The present program has been successfully tested for mesh generations for the road tunnel ventilation analysis and analysis of lava movement in mountain area.

• 전기전자학회논문지
• /
• 제3권2호
• /
• pp.285-294
• /
• 1999

본 논문에서는 다치논리 함수의 GRM(Generalized Reed-Huller)계수 생성 방법에 관하여 제안하였다 일반적인 GRM계수의 생성 방법은 Reed-Muller(RM) 전개식를 이용하여 극수 P=0의 RM계수를 구하고 이를 확장하여 모든 GRM계수를 구하는 방법을 사용한다. 본 논문에서 제안한 알고리즘은 모든 극수의 GRM계수를 구하지 않고 극수의 0의 개수를 순차적으로 비교해가며 GRM계수를 구하는 방식이다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권2호
• /
• pp.367-375
• /
• 2004

We have developed a highly efficient boiler system using the 2,600cc Diesel engine. In this system, the co-generation concept is utilized in that the electric power is produced by the generator connected to the engine, and waste heat is recovered from both the exhaust gases and the engine itself by the shell-and-tube heat exchangers. The heat exchanger connected to the engine outlet is specially designed such that it not only recovers waste heat effectively from the exhaust gases, but significantly reduces an engine noise. It is found that the total efficiency(thermal efficiency plus electric power generation efficiency) of this system reaches maximum 96.3％ which is about 15％ higher than the typical Diesel engine boiler system currently being used worldwide.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
• /
• pp.687-691
• /
• 2003

In photovoltaic generation, PV module is used to generate the electricity, and this system has been in limelight as nonpolluting alternative energy source. But, as energy density is low and PV module cost is high, there is a disadvantage that initial investment cost go up. In this study, we studied the method of allowing a tracker, adequate to photovoltaic generation, for Increasing the generating. We determined the proper error angle in order to decrease the repeating number of tracking without a reduction of the generating by using our developed simulator. And, we presented the photovoltaic approach tracking control and achieved its experiment. Through the result of experiment, it is expected that the fault rate and the consumption of electric power in a tracker get reduced and its cost become cut down.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
• /
• pp.6.1-10
• /
• 1996

Starting from the Debye theory of rotational Brownian motion equation, we derive an expression for explaining the generation of Maxwell displacement current (MDC) across single monolayers on a material surface. The orientational order parameter and the dielectric relaxation the of monolayers are derived. Based on fille analyses developed here, we examine the MDC across phospholipid monolayers with thermal stimulation due to the change in the spontaneous polarization, and the generation of MDC from 4-cyano-4\`-5-alkayl-biphenyl(5CB) Langmuir-film at the onset of transition by monolayer compression

• Journal of Korean Society for Atmospheric Environment
• /
• 제19권E4호
• /
• pp.169-175
• /
• 2003

The effect of gas composition on the discharge characteristics and the ozone production in silent discharge (SD) process was investigated. The major gas components, $N_2$, $O_2$, and $H_2O$ influence the discharge properties according to their relative magnitude of ionization thresholds and electron affinities. The generated amount of ozone increased with the discharge energy by increasing the electron mean energy. The higher oxygen content injected, the higher ozone produced. A small amount of water vapor significantly lowered the discharge onset voltage by the ionization threshold decreasing effect and high electrical conductivity. However, the further increase of water vapor contributes to decrease the electron density by the electron affinity The addition of water greatly reduced the ozone generation through the formation of OH radical and the catalytic ozone destruction process.

• 대한전기학회논문지:전력기술부문A
• /
• 제55권10호
• /
• pp.440-445
• /
• 2006

As an electricity industry transforms into a competitive system, an electricity market revolves into a combined market consisting of generation and operating reserve. This paper presents a market model combined by an energy market and an operating reserve market. In a competitive structure, Gencos strive to choose strategic bidding parameters that maximize total profit resulting from an energy market and a reserve market. The primary goal of the paper is to analyze power transactions of generation and operation reserve based on marginal profits and capacity limits at NE(Nash Equilibrium). In case studies, the reserve market and the energy market are compared at the n from the viewpoints of marginal profits, prices and transaction quantities. It is shown that the marginal profit in an energy market is equal to that in a reserve market, and Gencos strategic bidding is greatly influenced by capacity limit.