• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 1991년도 추계학술발표회논문집
• /
• pp.33-37
• /
• 1991

A now signal precessing system for real time displacement measurement in sinusoidal phase modulating interferometry is described. Although sinusoidal phase modulating interferometry is effective in measuring with high accuracy the displacement of an object, conventional signal processing takes along time. In this method, detection of the object's displacement is easily achieved by sampling the interference signal at those times that satisfy certain conditions and by processing the sampled signals with electric circuits in real time. the delay time of this signal processing system is < 45 $\mu$s. Specially in this paper we describe all electronic circuit and optical system design

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1992년도 학술논문발표회 논문집 제11권 1호
• /
• pp.87-90
• /
• 1992

Detecting acoustic emission (AE) provides an appropriate method to diagonize on-line transformers, since acoustic signal is not influenced by strong electric field. Then AE versus AE signal processing method is investigated. But this processing is difficult that decision of starting point of AE wave with acoustic noise. This problem is sloved by correlation which calculate time interval between two signals eactly. This paper presents a technique locating the eact position of the partial discharge (PD) in a power transformer by the correlation of the AE signals from two ultrasonic sensors. And PD position is displayed on monitor. Laboratory tests confirmed that the proposed method can be used for locating the PD in power transformer.

• Journal of Information Processing Systems
• /
• 제13권2호
• /
• pp.360-369
• /
• 2017

In this paper, a new iterative algorithm for reconstructing block sparse signals, called block backtracking-based adaptive orthogonal matching pursuit (BBAOMP) method, is proposed. Compared with existing methods, the BBAOMP method can bring some flexibility between computational complexity and reconstruction property by using the backtracking step. Another outstanding advantage of BBAOMP algorithm is that it can be done without another information of signal sparsity. Several experiments illustrate that the BBAOMP algorithm occupies certain superiority in terms of probability of exact reconstruction and running time.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1254-1258
• /
• 2003

One of the major factors that effect sensor performance is analog noise that added in a sensor signal such as voltage. In multi-axis force sensors, error sources may be classified mainly in two groups. One is structural error due to inaccuracy of sensor body. The other error source is noise signals existing in the sensed information. This paper presents a brief review about the principle of multi-axis force sensors, and then proposes a method that can reduce the effect of noise signal to sensor performance. The method is to convert analog voltage signal to digital numbers near sensor body and then to read these digital signals and conduct signal processing in the computer. By this way, we can eliminate a bad effect of electromagnetic wave emitted from computer and of 60 Hz noise emitted from AC source. The proposed method is investigated through experimental demonstration. The experimental results show that it improves S/N ratio of the sensor about 40 times in our experimental setup.

• 한국통신학회논문지
• /
• 제17권5호
• /
• pp.529-538
• /
• 1992

최근들어 HDTV를 위한 영상 신호처리 기술이 급속히 발전하고있다. 이러한 신호처리 기술의 향상에 따라 영상신호용 특수 기억소자의 개발이 요구되고 있다. 본 논문에서는 입력 스트로브로 부터 정보를 반아 기억하는 CMOS 플립플롭을 채용한 데이타 래치 방식과 HDTV 신호에 적합한 엑세스 시간을 얻기 위하여 새로운 읽기 방식이 고안 되었다. 기존의 쓰기 방식과 비교하여 데이터 래치 방식은 완전한 쓰기 동작을 위하여 비트라인 쓰기와 메모리셀 쓰기의 2개의 과정이 필요하고 같은 번지의 동시 입출력이 가능하다. 또한 스태틱 칼럼 모드를 응용한 읽기 방식과 분리된 읽기 워드라인을 채용하여 읽기 동작시 빠른 정보 감지가 가능하다.

• 융합신호처리학회논문지
• /
• 제3권2호
• /
• pp.58-63
• /
• 2002

OFDM 시스템에 있어서 송신 신호의 큰 PAPR는 비선형 증폭기를 통과할 때 심각한 신호 왜곡을 일으킨다. 이러한 PAPR을 감소하는 방법으로, 본 논문에서는 가장 간단한 클리핑 방법을 사용하여 시스템에 미치는 영향을 BER 특성의 기준으로 나타내고 제안된 시스템과 다른 여러 가지 시스템들을 비교하였다. 본 논문에서 제안한 방법은 QPSK 매핑후에 매핑된 신호사이에 0을 삽입하는 방법을 사용하여 동일한 PAPR 조건하에서 시스템에 미치는 영향을 비교하였다. 또한 다른 시스템들과의 BER 성능에 대한 데이터 전송률과 대역폭 관계의 trade-off가 있음을 보였다.

• 한국정보전자통신기술학회논문지
• /
• 제2권2호
• /
• pp.29-36
• /
• 2009

비선형적인 위상 변화를 지닌 비정상(non-stationary)신호는 레이더(Radar), 통신(telecommunication), 생체공학, 지질탐사, 음향 등 여러 분야에서 쉽게 접하는 신호이다. 비정상신호는 일반적으로 시간에 따라 신호의 물리적 특성이 변화하는 신호를 의미하며, 순간 주파수는 신호의 특정시간에 해당하는 신호의 주파수를 의미한다. 이 논문에서는 순간 주파수를 결정하기 위한 연속 웨이브렛 변환의 적용에 대하여 논하였다.

• 한국통신학회논문지
• /
• 제39C권7호
• /
• pp.608-614
• /
• 2014

이 논문에서는 비간섭 전력 부하 감시에 알맞은 패턴 인식 시스템을 다룬다. 전력 신호의 고차 적률 정보를 써서 전기기구를 효과적으로 분별하여 인식할 수 있는 새로운 특징 추출 방법을 제안한다. 동작 특성이 비슷한 두 전기기구를 제안한 고차 적률 특징과 커널 판별 분석을 쓰는 패턴 인식 시스템이 효과적으로 분별하여 인식할 수 있다는 것을 모의실험으로 보인다.

• Journal of Welding and Joining
• /
• 제16권3호
• /
• pp.102-110
• /
• 1998

The horizontal fillet welding is prevalently used in heavy and ship building industries to fabricate the large scale structures. A deep understanding of the horizontal fillet welding process is restricted, because the phenomena occurring in welding are very complex and highly non-linear characteristics. To achieve the satisfactory weld bead geometry in robot welding system, the seam tracking algorithm should be reliable. The number of seam tracker was developed for arc welding automation by now. Among these seam tracker, the arc sensor is prevalently used in industrial robot welding system because of its low cost and flexibility. However, the accuracy of arc sensor would be decreased due to the electrical noise and metal transfer. In this study, the signal processing algorithm based on the neural network was implemented to enhance the reliability of measured welding current signals. Moreover, the seam tracking algorithm in conjunction with the signal processing algorithm was implemented to trace the center of weld line. It was revealed that the neural network could be effectively used to predict the welding current signal at the end of weaving.

• Journal of Information Processing Systems
• /
• 제18권1호
• /
• pp.97-114
• /
• 2022

Interest is increasing in electrocardiogram (ECG) signal analysis for embedded devices, creating the need to develop an algorithm suitable for a low-power, low-memory embedded device. Linear approximation of the ECG signal facilitates the detection of fiducial points by expressing the signal as a small number of vertices. However, dynamic programming, a global optimization method used for linear approximation, has the disadvantage of high complexity using memoization. In this paper, the calculation area and memory usage are improved using a linear approximated template. The proposed algorithm reduces the calculation area required for dynamic programming through local optimization around the vertices of the template. In addition, it minimizes the storage space required by expressing the time information using the error from the vertices of the template, which is more compact than the time difference between vertices. When the length of the signal is L, the number of vertices is N, and the margin tolerance is M, the spatial complexity improves from O(NL) to O(NM). In our experiment, the linear approximation processing time was 12.45 times faster, from 18.18 ms to 1.46 ms on average, for each beat. The quality distribution of the percentage root mean square difference confirms that the proposed algorithm is a stable approximation.