• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.1075-1079
• /
• 2002

This paper presents a result of sound transmitting system with power line communication technique, Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detesting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirm the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

• Proceedings of the KIEE Conference
• /
• 2006.07a
• /
• pp.3-4
• /
• 2006

본 논문에서는 계통의 불확실성을 고려한 확률론적인 방법으로 전력계통의 신뢰도를 평가한다. 발전기 3 state modeling 및 부하의 정규분포 곡선으로 확률론 신뢰도 평가 모델을 가정하였다. 그리하여 Adequacy 및 계통의 전압 및 송전선제약 조건 외에도, 소신호 안정도 항목을 추가하여 보다 동적인 측면에서의 신뢰도 평가가 이루어지도록 하였다. 이러한 평가 방법의 결과에 의하여 각 평가 항목간의 비율을 비교하였으며, 이를 통한 PSS의 설치 위치 선정의 근거를 마련하였다. 모의 방법은 Monte Carlo Simulation방법을 사용하였으며, WSCC 3기 9모선과 New England 10기 39모선을 모의계통으로 하였다.

• Proceedings of the Safety Management and Science Conference
• /
• 2000.05a
• /
• pp.481-490
• /
• 2000

First, in order to improve selecting method of quality characteristic level desired by customers, S/H(Signal-to-Noise) ratio of Taguchi in larger-the-better characteristics was applied. Second, the Matrix classification standard of ACE(Attribute Categorization Evaluation) is presented using KANO model on difference analysis of importance and satisfaction through questionnaire from customers. This is for reflecting the diverse EC which customers want in EC quality sufficiently. Also, establishing sales point will be helpful in business strategy through presenting types that are able to decide planning quality. Third, the important measure of EC about correlation among quality characteristics and a new weight o( EC are calculated depending on importance of EC and the weight of customer attribute and materials of relationship matrix through correlation matrix analysis.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.1
• /
• pp.199-205
• /
• 2010

The research proposes the three-factor random measurement models for estimating the precision about operator, part, tool, and various measurement environments. The combined model with crossed and nested factors is developed to analyze the approximate F test by degrees of freedom given by Satterthwaite and point estimation of precisions from expected mean square. The model developed in this paper can be extended to the three useful models according to the type of nested designs. The study also provides the three-step procedures to evaluate the measurement precisions using three indexes such as SNR(Signal-To-Noise Ratio), R&R TR(Reproducibility&Repeatability-To-Total Precision Ratio), and PTR(Precision-To-Tolerance Ratio), The procedures include the identification of resolution, the improvement of R&R reduction, and the evaluation of precision effect.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.33A no.7
• /
• pp.55-63
• /
• 1996

In this paper, a multiple-access algorithm for PCN is proposed. The proposed algorithm provides th integrated service of information soruces and can be operated stably in high load state. Given bandwidth is efficiently used for it in the microcell environment. And system performance can be improved through the statistical-multiplexing technque. In order to process the speech signal usually requiring real-tiem processing, we adopt a random access of AlOHA type for th ebasic protocol sturcture and assume the form of ALOHA-reservation. We have analyzed the performance of the proposed algorithm through system throughput and packet delay in the microcell environment.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.10a
• /
• pp.429-436
• /
• 2004

For the in-situ health monitoring of critical members in civil infra-structures, ultrasonic guided Lamb waves-based non-destructive evaluation (NDE) is very suitable. However, a chief drawback of the Lamb wave techniques is that multiple modes exist at all frequencies and the modes are generally dispersive, which means that the received signals may be very complicated. To overcome these complications, selective transmitting and receiving of a single A/sub 0/ mode within a frequency range can be adopted. Furthermore, a wavelet technique can be utilized to decompose the Lamb wave response into wavelet coefficients as a tool for signal processing. The changes in the Lamb waves interacting with damages in the steel plates are successfully characterized by this wavelet technique, through the amplitude change of the wavelet coefficients. In this paper, the feasibility of detecting a line crack on the surface of a steel plate and loosened bolts in a joint steel specimen using the Lamb waves and the wavelet technique is investigated.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.726-730
• /
• 1997

One approach to testing the suitability of an adhesive joint for a particular application is to build and test to destruction a representativc, sample of the joini. The noncdestructive test will not measure strength directly but will measure a parameter which can be correlated to strength. It is thercforc, essential that a suitable nondestructive rest is chosen and that its results are correctly intcrpreted. In this paper, typical Ultrasonic Signal Analysis in adhesive joints are cvaluatcci together with Interface Stress from the result of Finite Elenlent Method.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2004.04a
• /
• pp.470-473
• /
• 2004

In this paper, the comparison of speech feature parameters for emotion recognition is studied for emotion recognition using speech signal. For this purpose, a corpus of emotional speech data recorded and classified according to the emotion using the subjective evaluation were used to make statical feature vectors such as average, standard deviation and maximum value of pitch and energy. MFCC parameters and their derivatives with or without cepstral mean subfraction are also used to evaluate the performance of the conventional pattern matching algorithms. Pitch and energy Parameters were used as a Prosodic information and MFCC Parameters were used as phonetic information. In this paper, In the Experiments, the vector quantization based emotion recognition system is used for speaker and context independent emotion recognition. Experimental results showed that vector quantization based emotion recognizer using MFCC parameters showed better performance than that using the Pitch and energy parameters. The vector quantization based emotion recognizer achieved recognition rates of 73.3％ for the speaker and context independent classification.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.2
• /
• pp.252-257
• /
• 2010

SAR has pulse compression gain through the process including range and azimuth. Efficient jammers against the SAR with simulated elements are evaluated in the view of power and SAR image. In this paper, J/S is analysed for SAR with RF propagation equation firstly. Several jamming signals on SAR signal are made into SAR image through pulse compression process. Objective jamming performance is evaluated using euclidean distance.

• Journal of information and communication convergence engineering
• /
• v.2 no.4
• /
• pp.224-227
• /
• 2004

The purpose of this paper is to theoretically analysis of performance of MRC diversity for detection of M-ary signals on the Rician fading channels. To do it, the difference between the approximation to bit error probability and the exact bit error rate (BER) in evaluating the performance of MPSK signals is investigated by numerical analyses. In addition, the performance evaluation of MDPSK signals in the independent branch diversity is performed by an integral-form expression in case of when MDPSK signal in MRC system is experiencing the Rician fading.