• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.592-600
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• 2006

The pattern recognition of the complicated grasping operation based on electroencephalography (simply named as EEG) is very helpful on realtime control of the robotic hand. In the paper, a new spectral feature analysis method based on Band Pass Filter (simply named as BPF) and Power Spectral Analysis (simply named as PSA) is presented for discriminating the complicated grasping operations. By analyzing the spectral features of grasping operations with the use of the two-channel EEG measurement system and the pattern recognition of the BP neural network, the degree of recognition by the traditional spectral feature method based on FFT and the new spectral features method based on BPF and PSA could be compared. The results show that the proposed method provides highly improved performance than the traditional one because the new method has two obvious advantages such as high recognition capability and the fast learning speed.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1073-1080
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• 2011

In this study, a target detection algorithm was proposed for using hyperspectral imagery. The proposed algorithm is designed to have minimal processing time, low false alarm rate, and flexible threshold selection. The target detection procedure can be divided into two steps. Initially, candidates of target pixel are extracted using matching ratio of spectral pattern that can be calculated by spectral derivation. Secondly, spectral distance is computed only for those candidates using Euclidean distance. The proposed two-step method showed lower false alarm rate than the Euclidean distance detector applied over the whole image. It also showed much lower processing time as compared to the Mahalanobis distance detector.

• 한국의학물리학회지:의학물리
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• 제6권2호
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• pp.103-109
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• 1995

자율신경계는 서로 상반되게 작용하는 교감신경과 부교감신경으로 구성되어 그 활성의 균형에 의해 신체의 향상성이 유지된다. 자율신경계는 각종 스트레스나 질환에 의해 그 활성이 변화한다. 그러나 자율신경계의 메카니즘은 너무나 복잡하여 해석이 용이하지 않은 관계로 인체에서 유기되는 여러가지 생체신호중에서 자율신경에 의해 지배되는 심전도 신호와 호흡을 매개변수로하여 자율신경의 활성도를 측정하는 시스템의 설계와 제작이 본 연구의 목적이다. 본 논문을 수행하기 위해서 심전도 신호 증폭기, 호흡변위 증폭기, interval time generator 및 처리 소프트웨어 등을 제작하였다. 그리고 심전도 신호와 호흡요소에 대한 power spectrum을 나타낼 뿐만 아니라 이들을 합성하여 하나의 graph로 표현할 수 있도록 하였다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.587-599
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• 1995

This paper proposes a method for pattern recognition using spectral analysis and a hybrid genetic-neural-fuzzy networks. The feature vectors using spectral analysis on contour sequences of 2-D images are extracted, and the vectors are not effected by translation, rotation and scale variance. A combined model using the advantages of conventional method is proposed, those are supervised learning BP, global searching genetic algorithm, and unsupervised learning fuzzy c-method. The proposed method is applied to 10 aircraft recognition to confirm the performance of the method. The experimental results show that the proposed method is better accuracy than conventional method using BP or fuzzy c-method, and learning speed is enhanced.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.81-86
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• 2007

Spectral features of the seismic wave propagation from Odaesan Earthquake were evaluated based on the commonly treated random error between the observed data and the prediction values by the stochastic point-source ground-motion spectral model regarding the source, path and site effects. Radiation pattern of the error according to azimuth angle was found to be similar to the theoretical estimate. It was also observed that the spatial distribution of the errors was correlated with the geological map and the Q0 map which are indicatives of seismic boundaries.

• 한국소음진동공학회논문집
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• 제25권11호
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• pp.739-746
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• 2015

Several damage counting methods can be applied for the fatigue issues of a ground vehicle system using strain data and acceleration data is partially used for a high cyclic loading case. For a vibration test, acceleration data is, however, more useful than strain one owing to the good nature of signal-to-random ratio at acceleration response. The test severity can be judged by the fatigue damage and the pseudo-damage from the acceleration response stated in ISO-16750-3 is one of sound solutions for the vibration test. The comparison of fatigue damages, derived from both acceleration and strain, are analyzed in this study to determine the best choice of fatigue damage over multi-spectral input pattern. Uniaxial excitation test was conducted for a notched simple specimen and response data, both acceleration and strain, are used for the comparison of fatigue damages.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.41-48
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• 1987

In estimating the freguency-dependent attenuation coefficient, we analyzed the range-dependent ultrasonic beam and proposed the method of calculating the experimental equation of beam pattern in order to reduce the error on the influence of beam pattern. These experimental equations are divided into the spectral centroid and the spec ural standard deviation slope according to axial propagation length. These are repnesented by the first-order equation in the near field of the beam and the second- order eqLlatlon In the far field. In order to prove the validity of this method, the attenuation coefficients of the non-corrected ease and the corrected case are compared. Using the reflected signal from acryle plate, the attenuation coefficients were estimated by the spectral shift method ann the spectral difference method. The result shows attenuation coeffi talents after correction are better than attenuation coefficients before correction. And this method can be applied In vivo measurement.

• 한국소음진동공학회논문집
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• 제24권11호
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• pp.840-845
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• 2014

Vibration profiles consist of two kinds of pattern, random and harmonic, at general engineering problems and the detailed vibration test mode of a target system is decided by the spectral condition that is exposed under operation. In moving mobility, random responses come generally from road source; whereas the harmonic responses are triggered from rotating machinery parts, such as combustion engine or drive shaft. Different spectral input may accumulate different damage in frequency domain since the accumulated fatigue damage dependent on the pattern of input spectrum in high cyclic loading condition. To evaluate the sensitivity of spectral damage according to different loading conditions, a linear elastic system is introduced to conduct a uniaxial vibration testing. Measured data, acceleration and strain, is analyzed using energy isocline function and then, the calculated fatigue damage is compared by different loading cases, random and harmonic.

• 말소리와 음성과학
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• 제1권4호
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• pp.111-117
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• 2009

In this paper, a new speech endpoint detector in noisy environment is proposed. According to the previous research, the energy feature in the speech region is easily distinguished from that in the speech absent region. In conventional method, the endpoint can be found by applying the edge detection filter that finds the abrupt changing point in feature domain. However, since the frame energy feature is unstable in noisy environment, the accurate edge detection is not possible. Therefore, in this paper, the novel feature extraction method based on spectrum envelop pattern is proposed. Then, the edge detection filter is applied to the proposed feature for detection of the endpoint. The experiments are performed in the car noise environment and a substantial improvement was obtained over the conventional method.

• 대한산업공학회지
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• 제24권2호
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• pp.223-240
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• 1998

The purpose of this paper is to develop the pattern recognition system with a 'Robust' concept to be applicable to flexible manufacture automation in practice. The 'Robust' concept has four meanings as follows. First, pattern recognition is performed invariantly in case the object to be recognized is translated, scaled, and rotated. Second, it must have strong resistance against noise. Third, the completely learned system is adjusted flexibly regardless of new objects being added. Finally, it has to recognize objects fast. To develop the proposed system, contouring, spectral analysis and Fuzzy ART neural network are used in this study. Contouring and spectral analysis are used in preprocessing stage, and Fuzzy ART is used in object classification stage. Fuzzy ART is an unsupervised neural network for solving the stability-plasticity dilemma.