• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.655-660
• /
• 2000

Animation technique from the PIV database is particularly emphasized to give macroscopic and quantitative description of complex flow fields. This paper shows animation construction and application example for the post-processing of PIV data. As examples, first case is a pitching airfoil immersed in tree surface water circulating tunnel. Second case is a wake of a model-ship. Third case of PIV data is a large scale surface flow field. Obtained images are processed in time sequence by PIV exclusive routines where an efficient and reliable cross correlation algorithm is included for vector identification. All. animation Jobs are implemented completely on single personal computer environment. Compressed digital images are obtained initially by Motion-JPEG board and various An files are finally obtained through graphic processes.

• 한국음향학회지
• /
• 제18권5호
• /
• pp.35-43
• /
• 1999

본 논문에서는 크게 계산량이 증가하지 않으면서 음향 반향 제거기의 성능을 향상시킬 수 있는 잡음에 강건한 적응 알고리즘과 후처리기를 제안한다. 제안하는 적응 알고리즘은 기준 입력신호와 마이크 입력신호의 전력 합으로 적응 상수를 정규화 한다. 근단화자의 음성신호나 주변 잡음이 마이크로 입력되면 그 전력만큼 적응 상수가 작아지기 때문에 이들 주변 잡음에 의한 계수 오조정을 줄일 수 있다. 잔여 반향을 제거하기 위해서 잡음에 강건한 알고리즘과 연동하는 새로운 후처리 방법을 제안한다. 제안하는 후처리 방법은 마이크 입력신호와 추정 오차신호의 상관도를 활용한다. 잔여 반향은 마이크 입력신호의 전력으로 정규화된 상관도에 의해서 감쇠되어 제거한다. 정규화 상관도는 잔여 반향에 대해서 Wiener 필터 역할을 한다. 동시 통화시에는 추정 오차신호에는 근단화자의 음성신호가 대부분을 차지함으로 정규화 상관도는 거의 1이 되어 근단화자의 음성신호는 감쇠없이 전송된다. 반향 신호만 있을 때에는 잔여 반향은 후처리기에 의해서 대부분 감쇠되어 제거된다. 제안하는 후처리기를 이용한 음향 반향 제거기의 계산량은 NLMS 알고리즘에 비해서 크게 증가하지 않는다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2000년도 하계종합학술대회 논문집(3)
• /
• pp.19-22
• /
• 2000

This paper presents new on-line handwritten algorithm for continuous alphabet uppercase characters. The algorithm is based on the idea that alphabet uppercase character consists of at most 4 strokes. It tries to determine the maximum output for a recognition result among outputs of four recognizers which have the capacity to discriminate the character using from 1 through 4 stroke information. The recognition module has 4 neural network based recognizers, which can recognize from 1 through 4 stroke character. We also use specialized post-processing techniques for improving the recognition performance. Trained on 440 input data and choosing 390 uppercase words for a recognition test we reached a 92% recognition rate.

• 한국CDE학회논문집
• /
• 제13권2호
• /
• pp.153-161
• /
• 2008

This paper proposes an efficient algorithm for deriving inverse kinematics equation of 5-axis machine. Because the joint order and direction of 5-axis machine are different for each type of machine, each type of machine needs its own inverse kinematics equation for post-processing of NC data. Also derived inverse kinematics equation may cause problems of indeterminate and inconsistent solution. In order to resolve these problems, we have developed a generic method to derive direct kinematics equation by considering orthogonal joints of 5-axis machines. Using this method, we also have proposed a general algorithm for deriving inverse kinematics equation for various types of 5-axis machines.

• 한국정보처리학회논문지
• /
• 제7권6호
• /
• pp.1795-1802
• /
• 2000

본 논문에서는 네트워크 지원뿐만 아니라 서버의 부하를 크게 경감시켜 MOD의 시비스 품질을 향상시키는 멀티캐스팅을 사용한 새로운 노래방 서비스 알고리듬을 제안한다. 제안된 효율적인 노래방 서비스 알고리듬은 유니캐스트로 전송되는 노래를 서비스 받음과 동시에 후-순위 예약 곡이 현재 서비스되고 있는 다른 클라이언트들의 예약 곡고 동일할 경우 멀티캐스트 채널을 통해 자신의 버퍼에 저장하는 방법을 채택하였다. 따라서 유니캐스트 채널을 통한 서비스 종료에 이어 다음 순서의 예약 곡을 네트워크 자원을 통하지 않고 직접 버퍼로부터 서비스되는 방법을 사용한다. 제안된 효율적인 노래방 서비스를 위한 전송 알고리듬은 예약 곡이 많을 수록 소요되는 채널의 수가 크게 감소될 수 있으며, 실시간으로 서비스될 수 있다. 본 알고리듬을 이용한 시뮬레이션을 통해 노래방 서비스 시스템의 성능이 크게 향상되었음을 확인하였다.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제51권4호
• /
• pp.167-174
• /
• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
• /
• pp.2232-2235
• /
• 2003

In speech communication systems where two different speech codecs are interoperated, transcoding algorithm is a good approach because of its low complexity and improved synthesized speech quality. This paper proposes an efficient method to further improve the performance of transcoding algorithms as well as to reduce the complexity. In the conventional transcoding algorithms. a post-filter and a perceptual weighting filter should be operated sequentially because both decoding and encoding processes are needed. This results in the redundancy of the processing in terms of complexity and perceptual quality. Using the fact that their filter structures are similar, we replaced the two filters with one. The proposed algorithm requires 72.8% lower complexity than the conventional transcoding algorithm when we compare only the complexity of the filtering processes. The results of both objective and subjective tests verify that the proposed algorithm has slightly better quality than the conventional one.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 ITC-CSCC -1
• /
• pp.500-503
• /
• 2002

Biomedical signals are ubiquitously contaminated and degraded by background noise which span nearly all frequency bandwidths. This paper proposes the MADF (multiplication free adaptive digital filter) algorithm to cancel the noise. And the convergence characteristics of the algorithm is analyzed. In the experimental results, the MADF algorithm has the advantage in which has superior to a condition of low-frequency and slow data speed. This application gives an important significance in ensuring the objectivity of clinical information and in promoting the representation and the disease diagnosis.

• 한국멀티미디어학회논문지
• /
• 제17권4호
• /
• pp.413-419
• /
• 2014

In this paper, we develop an automatic coin calculation system by using digital image processing. Existing schemes have the problem that is not able to exclude non-circular shape from the calculation. We propose a method to detect only coins which have circular form by applying the circular Hough transform(CHT). However, the CHT has the drawback that detects multiple circles even for just one coin because of shadow noise, the patterns on coins, and non-circular edge detection. We propose a post processing algorithm to overcome these limitations. The proposed system was implemented and successfully calculated the coin amount in the case that non-circular objects are mixed with coins.

• 한국군사과학기술학회지
• /
• 제6권1호
• /
• pp.49-58
• /
• 2003

Compared with generic GPS receiver, post-processing software GPS receiver has many advantages for high dynamic vehicle tracking. It has the advantage of the application of various tracking algorithms and aiding schemes. The post-processing system observes the carrier phase measurement data from the recorded GPS signals, detects and isolates the cycle slip. The observed carrier phase data and the raw data of the reference station are processed by carrier phase DGPS scheme. And the integer ambiguity resolution algorithm is used for resolving single frequency carrier phase ambiguity. The results of static and real flight test are presented and show that the proposed GPS translator processing system satisfies submeter accuracy.