• Journal of Electrical Engineering and Technology
• /
• 제7권5호
• /
• pp.681-688
• /
• 2012

This paper presents the application of Differential Evolution (DE) algorithm to obtain a solution for Bid Based Dynamic Economic Dispatch (BBDED) problem including the transmission losses and to maximize the social profit in a deregulated power system. The IEEE-30 bus test system with six generators, two customers and two trading periods are considered under various bidding strategies in a day-ahead electricity market. By matching the bids received from supplying and distributing entities, the Independent System Operator (ISO) maximize the social profit, (with the choices available). The simulation results of DE are compared with the results of Particle swarm optimization (PSO). The results demonstrate the potential of DE algorithm and show its effectiveness to solve BBDED.

• Journal of Electrical Engineering and Technology
• /
• 제8권5호
• /
• pp.959-968
• /
• 2013

This paper presents a new approach with artificial immune system algorithm to solve the profit based unit commitment problem. The objective of this work is to find the optimal generation scheduling and to maximize the profit of generation companies (Gencos) when subjected to various constraints such as power balance, spinning reserve, minimum up/down time and ramp rate limits. The proposed hybrid method is developed through adaptive search which is inspired from artificial immune system and genetic algorithm to carry out profit maximization of generation companies. The effectiveness of the proposed approach has been tested for different Gencos consists of 3, 10 and 36 generating units and the results are compared with the existing methods.

• 센서학회지
• /
• 제23권5호
• /
• pp.320-325
• /
• 2014

Volatile flavor compounds from milk were analyzed and identified by using the analysis methods of headspace solid phase microextraction gas chromatography/mass spectrometry (HSPME-GC/MS) and electronic nose (E-Nose) system. About 30 volatile compounds were identified by HSPME-GC/MS for the fresh and off-flavor milk samples. Also, the correlation between rancidity and ageing days of milk was obtained by the aid of principal component analysis algorithm. It shows that the E-Nose system can identify the various types of milk flavor. These results imply that the analysis method based on the E-nose system can apply to the quality control of milk flavor and the rancidity.

• 한국염색가공학회지
• /
• 제20권5호
• /
• pp.41-46
• /
• 2008

Recently, computational calculation of molecular energy potentials and electrochemical reduction/oxidation behaviors are of very importance in view point of prediction of dye's properties such as energy levels and bandgaps of absorption. This can be influenced by their different constituents or substituents in chromogen molecules. Structural conformations and properties with computational modeling calculation are numerically simulated, which are fully or partly based on fundamental laws of physics. In addition, cyclic voltammetric measurement was used to obtain the experimental redox potential values, which were compared to the computed simulation values.

• Journal of Biosystems Engineering
• /
• 제28권5호
• /
• pp.457-464
• /
• 2003

The purpose of this study was to develop a pilot scale bio-filter system removing ammonia gas with microorganisms. The system consisted of chaff(filter medium), a blower, a temperature sensor, a moisture sensor, a solenoid valve, and a heating system. Temperature and moisture contents were controlled via a PC to provide the microorganisms with proper environment. The microorganisms used in this study were Bacillius. coagulans NLRI T-6 and Pseudononas. putida NLRI S-21 of bacilli. Performance tests were performed to evaluate gas removal rate during 20 days. The result was shown that the removal rate was high in early days and gradually dropped below 90% without injecting the microbes. However, it was shown that when injecting the microbes, the removal rate was almost 100% and pH value was maintained at between 7 and 9 during the whole twenty-day period.

• Journal of Microbiology and Biotechnology
• /
• 제4권4호
• /
• pp.333-337
• /
• 1994

In order to develop the whey beverage, we examined the optimum conditions for alcohol fermentation by Kluyveromyces tragilis ATCC 46537. The optimum conditions for alcohol production by K. fragilis ATCC 46537 were as follows; pH 4.5, $30^{\cir}C$, with a supplement of 50 g/l of lactose. To develop a continuous production of alcohol from whey, we compared batch fermentation with continuous iermentation in conjunction with UF system. Batch fermentation produced 11.0 g/l of alcohol, whereas pseudocontinuous and continuous fermentation with UF system produced 8.5 g/l of alcohol. To increase the alcohol production, we added 50 g/l of lactose to both fermentations. Batch fermentation with lactose supplement produced 15.7 g/l of alcohol and continuous fermentation with lactose supplement in conjunction with UF system produced 15.0 g/l of alcohol. These results clearly demonstrate that the UF system can be used to increase the alcohol production from whey, supplemented with exogenous lactose.

• International Journal of Railway
• /
• 제5권3호
• /
• pp.124-128
• /
• 2012

The ESS(energy storage system, here after) for a DC 1500V was developed in 2009. A ESS was installed on the track of Daejeon HRT in 2010. The advantage of the ESS is that it can save the energy and plus stable the catenary voltage. This paper presents the energy saved by the ESS in Daedong substation. When the ESS is on/off, the field tests are performed.

• 대한임베디드공학회논문지
• /
• 제11권5호
• /
• pp.299-304
• /
• 2016

As public interest in air quality and environment problem is increasing, many researches are being carried out the gas measurement system. Especially, Non-dispersive infrared (NDIR) measurements using Beer-Lambert gas sensing principle with very high selectivity and long life time are noted for reliable method. It is possible to detect various gases such as carbon dioxide (CO2), carbon monoxide (CO), and nitrogen dioxide (NO2), but many researches are mostly concentrated on CO2 sensor. The multi-gas measuring instrument is high price and unwieldy, therefore it is not suitable for wide area required numerous instrument. So we study the NDIR multi-gas measurement system for air quality based on wireless sensor network, and experiment the realized measurement system.

• Journal of Electrical Engineering and Technology
• /
• 제5권4호
• /
• pp.522-529
• /
• 2010

Distance relay plays an important role in the protection of transmission lines. The application of flexible AC transmission systems (FACTS) devices, such as the static synchronous compensator (STATCOM), could affect the performance of the distance relay because of compensation effect. This paper analyzes the application of distance relay on the protection of a transmission line containing STATCOM. New setting principles for different protection zones are proposed based on this analysis. A typical 500 kV transmission system employing STATCOM is modeled using Matlab/Simulink. The impact of STATCOM on distance protection scheme is studied for different fault types, fault locations, and system configurations. Based on simulation results, the performance of distance relay is evaluated. The setting principle can be verified for the transmission line with STATCOM.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1988년도 춘계학술대회 논문집
• /
• pp.43-45
• /
• 1988

Four W/Cu system(60wt%W-40wt%Cu, -0.lwt%Ni, -0.5wt%Ni, -0.lwt%C) and four WC/Cu system(60wt%WC-40wt%Cu, -0.lwt%Ni, -0.5wt%Ni, 0.lwt%C) electrical contacts were prepared by a press-sinter-infiltration process to compare with their properties. Hardness and electrical conductivity are proportional to the refractory metal(W or WC) properties and showed the effect of additives. Arc erosion trend of switch test is changed by current level. High currant test at 1kA showed a different crack formation pattern and erosion mode between W/Cu system and WC/Cu system contacts.