• Journal of Electrical Engineering and Technology
• /
• 제5권1호
• /
• pp.28-35
• /
• 2010

This paper presents new Adaptive Linear Combination Structure (ADALINE) for tracking/estimating voltage-current phasor and frequency of power system. To estimate the phasors and frequency from sampled data, the algorithm assumes that orthogonal coefficients and speed of angular frequency of power system are unknown parameters. With adequate sampled data, the estimation problem can be considered as a linear weighted least squares (LMS) problem. In addition to determining the phasors (orthogonal coefficients), the procedure estimates the power system frequency. The main algorithm is verified through a computer simulation and data from field. The proposed algorithm is tested with transient and dynamic behaviors during power swing, a step change of frequency upon islanding of small generators and disconnection of load. The algorithm shows a very high accuracy, robustness, fast response time and adaptive performance over a wide range of frequency, from 10 to 2000 Hz.

• 정보보호학회논문지
• /
• 제9권1호
• /
• pp.115-126
• /
• 1999

통신 및 컴퓨터 시스템의 처리 속도가 높아짐에 따라 에러 정정을 위해서 고속의 데이터 처리가 필요하게 된다 본 논문에서는 무선 통신 시스템에서 적용 가능한 복호 알고리즘을 제안하고, 이를 이용하여 부호기 및 복호기를 설계한다. 부호기와 복호기를 VHDL로 설계한 후, V-system을 이용하여 관련 회로를 시뮬레이션 한다. 설계된 알고리즘은 SYNOPSYS 툴을 사용하여 합성하고, XILINX XC4010EPC84-4를 이용하여 one chip화하여, 입력 클락으로 20MHz를 사용하였을 때 data arrival time은 29.20ns였고, data require time은 48.70ns였다.

• 한국산업경영시스템학회:학술대회논문집
• /
• 한국산업경영시스템학회 2002년도 춘계학술대회
• /
• pp.125-132
• /
• 2002

We study clustering algorithm for sequences of categorical values. Clustering is a data mining problem that has received significant attention by the database community. Traditional clustering algorlthms deal with numerical or categorical data points. However, there exist many important databases that store categorical data sequences. In this paper we introduce new similarity measure and develope a hierarchical clustering algorithm. An experimental section shows performance of the proposed approach.

• 한국항공운항학회지
• /
• 제15권2호
• /
• pp.1-8
• /
• 2007

In this research, algorithm and software for the medium frequency signal analysis of DGPS(Differential Global Positioning System) station were developed. Based on new MF(Medium Frequency) algorithm, the software of NDGPS(National DGPS) signal analysis was developed for coverage analysis. Predicted MF propagation data from this software was compared to the measurement data for the verification of a developed MF algorithm. GIS(Geographic Information System) techniques including digital map with elevation data were used because MF propagation is closely related to ground conductivity, mountains, building intensity.

• 한국산업정보학회논문지
• /
• 제8권1호
• /
• pp.55-61
• /
• 2003

표준 암호화 알고리즘(DES : Data Encryption Standard)은 20년 이상 국제 암호화 표준으로 사용되고 있다. DES는 64비트의 데이터 블록을 56비트의 키를 이용하여 암호화시키는 블록 암호화 기법중의 하나이다. 이 알고리즘은 64비트의 입력을 연속된 과정에 의해 64 비트의 출력으로 전환하는 방법이며, 이렇게 암호화시킨 문장은 키 없이는 해독이 불가능하다. 본 논문에서는 DES 알고리즘을 이용하여 RFID(Radio Frequency Identification) 판독 시스템을 구현하였다. 구현된 시스템은 CBC(Cipher Block Chining) 모드를 사용하여 암호화 알고리즘의 신뢰성을 높였으며, 기존 상용 제품과의 성능 비교 결과 카드 접근 시간과 동작 시간이 상용 제품보다 우수함을 알 수 있었다.

• Journal of Astronomy and Space Sciences
• /
• 제35권4호
• /
• pp.287-293
• /
• 2018

This paper presents a satellite relative navigation strategy for formation flying, which chooses an appropriate navigation algorithm according to the operating environment. Not only global positioning system (GPS) measurements, but laser measurements can also be utilized to determine the relative positions of satellites. Laser data is used solely or together with GPS measurements. Numerical simulations were conducted to compare the relative navigation algorithm using only laser data and laser data combined with GPS data. If an accurate direction of laser pointing is estimated, the relative position of satellites can be determined using only laser measurements. If not, the combined algorithm has better performance, and is irrelevant to the precision of the relative angle data between two satellites in spherical coordinates. Within 10 km relative distance between satellites, relative navigation using double difference GPS data makes more precise relative position estimation results. If the simulation results are applied to the relative navigation strategy, the proper algorithm can be chosen, and the relative position of satellites can be estimated precisely in changing mission environments.

• 대한전기학회논문지:전력기술부문A
• /
• 제54권9호
• /
• pp.449-456
• /
• 2005

The preventive diagnostic technique prevents transformers from power failure through giving alarm and observing transformers in service. And it helps to establish the plan for optimum maintenance of the transformer as well as to find location or cause of fault using accumulated data. Data detection and experience of the preventive diagnostic system need to establish the preventive diagnostic algorithm regarding interrelationship between detected data and deterioration of equipment. Therefore in-depth analysis about the preventive diagnosis system is required. KEPCO has adopted the preventive diagnostic system at nine 345kV substations since 1997. Techniques for component sensors of the preventive diagnosis system were settled but diagnosis algorithm, diagnostic criteria and practical use of accumulated data are not yet established. This paper, to build up the base of preventive diagnostic algorithm for the Power transformer. investigated the preventive diagnostic criteria for the power transformer.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.838-841
• /
• 2005

DNA Chip is able to show DNA-Data that includes diseases of sample to User by using complementary characters of DNA. So this paper studied Neural Network algorithm for Image data processing of DNA-chip. DNA chip outputs image data of colors and intensities of lights when some sample DNA is putted on DNA-chip, and we can classify pattern of these image data on user pc environment through artificial neural network and some of image processing algorithms. Ultimate aim is developing of pattern classifying algorithm, simulating this algorithm and so getting information of one's diseases through applying this algorithm. Namely, this paper study artificial neural network algorithm for classifying pattern of image data that is obtained from DNA-chip. And, by using histogram, gradient edge, ANN and learning algorithm, we can analyze and classifying pattern of this DNA-chip image data. so we are able to monitor, and simulating this algorithm.

• Journal of Computational Design and Engineering
• /
• 제2권3호
• /
• pp.137-147
• /
• 2015

In this study, a new methodology in predicting a system output has been investigated by applying a data mining technique and a hybrid type II fuzzy system in CNC turning operations. The purpose was to generate a supplemental control function under the dynamic machining environment, where unforeseeable changes may occur frequently. Two different types of membership functions were developed for the fuzzy logic systems and also by combining the two types, a hybrid system was generated. Genetic algorithm was used for fuzzy adaptation in the control system. Fuzzy rules are automatically modified in the process of genetic algorithm training. The computational results showed that the hybrid system with a genetic adaptation generated a far better accuracy. The hybrid fuzzy system with genetic algorithm training demonstrated more effective prediction capability and a strong potential for the implementation into existing control functions.

• 설비공학논문집
• /
• 제14권7호
• /
• pp.560-566
• /
• 2002

The fault detection and diagnosis technology may be applied in order to decrease the energy consumption and the maintenance cost of the air-conditioning system. In this study, two different types of faults in the air-conditioning system, such as the condenser fouling and the evaporator fan slowdown, were considered. The neural network algorithm combined with data preprocessor was developed and applied to detect the faults of the real system. Test results show that this method is very effective to detect the faults in the air-conditioning system. Therefore, this developed method can be used for the development of the air-conditioner fault detection system.