• Title/Summary/Keyword: Frequence domain

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Linear and Nonlinear Wave Pressure Distributions Acting on Vertical Caisson of Large Size in 3-Dimensional Wave Fields (3차원파동장에 있어서 대형연직케이슨에 작용하는 선형 및 비선형의 파압분포특성에 관한 연구)

  • 김도삼;신동훈;이봉재
    • Journal of Ocean Engineering and Technology
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    • v.15 no.3
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    • pp.114-119
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    • 2001
  • Goda formula (Goda, 1973) has been used in the determination of wave pressures acting on a large size caisson such as the pier of the cable stayed bridge at sea. Goda formula, however, is to evaluate the wave pressures acting the infinite vertical caisson of composite breakwater so that it can`t be applied to a large caisson with finite width and length because of diffraction effects. In the present study, three dimensional nonlinear frequence domain method based on perturbation method and boundary integral method is applied to the computation of the linear and nonlinear wave pressures acting on the front of a large size caisson under the variation of its width and length, and angle of incident wave. The numerical results are compared to Goda\`s ones, and then the characteristics of wave pressure distributions acting on a large size caisson are discussed.

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A Study on the Digital Audio Watermarking for a High Quality Audio (고음질을 위한 디지털 오디오 워터마킹에 관한 연구)

  • Jo, Byeong-Rok;Jeong, Il-Yong;Park, Chang-Gyun;Lee, Gang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.3
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    • pp.53-61
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    • 2002
  • In this paper, the authors proposed the digital audio watermarking algorithm for a high quality audio. Today, the digital watermark is used to confirm to the digital copyright protection, not only the digital image but the digital audio study is an activeness in the digital watermarking area. Especially, the watermark insertion in the digital audio area affects deeply not only a robustness but the audio quality of the watermarked audio data. Generally, the audio watermark is inserted in the frequence domain after FFT, the quality of audio data is affected by the watermark insertion. Thus, a high quality audio to be maintained at the same time, the study related a inserting of the robustness watermark happened to a hot issue. In this paper, the authors proposed the digital audio watermarking algorithm using psychoacoustic model and MDCT/IMDCT (Modified Discrete Cosine Transform/Inverse Modified Discrete Cosine Transform). In the proposed scheme, the authors experimented the stereo audio file with 44.1KHz, and 128kbps for the audio watermarking algorithm proposed. When the audio data is processed by MDCT, the watermark is able to insert into the frequence domain with 256, 1024 and 2048 interval. In case of 50㎳ RMS window, it was confirmed that the difference between the original audio data and the watermarked audio data of RMS power is 0.8㏈.

Watermark Algorithm Using Difference Matrix between Successive Blocks (연속 블록간의 화소차이 행렬을 이용한 워터마크 알고리즘)

  • Park, Ki-Hong;Kim, Yoon-Ho
    • Journal of Advanced Navigation Technology
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    • v.12 no.3
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    • pp.273-279
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    • 2008
  • In this paper, we proposed a watermarking algorithm by using difference matrix between successive blocks in the transform domain. In the preprocessing, original image is decomposed with 1-level sub-bands by DWT. Then, all sub-bands which are excepted the low-frequency bands are set to normalize and make a reference image after transforming inverse DWT. The statistic variance of successive blocks between the original image and the reference image are calculated and finally, watermark is embedded considering the local characteristic with respect to the high-frequence components. Experimental results showed that the proposed approach is robust and better invisible in such attacks as filtering, JPEG and noise addition.

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A Fine Granular Scalable Video Coding Algorithm using Frequency Weighting (주파수 특성을 이용한 미세 계위적 동영상 부호화 방법)

  • 김승환;호요성
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.6
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    • pp.124-131
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    • 2003
  • In this paper, we propose a Progressive scalable video coding algorithm using frequency weighting in the DCT domain. Since the human visual system (HVS) can be modeled as a nonlinear point transformation, called the modulation transfer function (MTF), we tan use the frequency weighting matrix to enhance the video image quality. We change this frequency weighting matrix into the frequency shift matrix to apply to the bit-plane coding method for the fine granular scalable (FGS) video coding We also define a new error metric JNDE (just noticeable difference) to measure the perceptual image quality in terms of human vision.

Analysis of Microstrip Circuit using FDTD and Signal Processing (시간영역 유한차분법과 신호처리 기법을 사용한 마이크로스트림 회로 해석)

  • 장홍주;장상건;방성일
    • Journal of Korea Society of Industrial Information Systems
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    • v.4 no.1
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    • pp.110-116
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    • 1999
  • In this paper, signal processing is utilized to reduce the computational time which is one of weak point of FDTD(finite difference time domain) method. Compared with the direct FDTD. combination of FDTD and signal processing achieves the same type of accuracy in much shorter time The combination method spends 140 minutes to analyze the frequence characteristics of the microstrip lowpass filter while the direct FDTD consumes about 900 minutes. To verify the obtained results, microstrip lowpass filter is fabricated on dielectric substrate and the measured results are compared with the analyzed results. It is shown that measured results are in good agreement with the theoretical results.

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A method for Character Segmentation using Frequence Characteristics and Back Propagation Neural Network (주파수 특성과 역전파 신경망 알고리즘을 이용한 문자 영역 분할 방법)

  • Chun Byung-Tae;Song Chee-Yang
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.55-60
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    • 2006
  • The proposed method uses FFT(Fast Fourier Transform) and neural networks in order to extract texts in real time. In general, text areas are found in the higher frequency domain, thus, can be characterized using FFT. The neural network are learned by character region(high frequency) and non character region(low frequency). The candidate text areas can be thus found by applying the higher frequency characteristics to neural network. Therefore, the final text area is extracted by verifying the candidate areas. Experimental results show a perfect candidate extraction rate and about 95% text extraction rate. The strength of the proposed algorithm is its simplicity, real-time processing by not processing the entire image.

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Recognition of the emotional state through the EEG (뇌파를 통한 감정 상태 인식에 관한 연구)

  • Ji, Hoon;Lee, Chung-heon;Park, Mun-Kyu;An, Young-jun;Lee, Dong-hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.958-961
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    • 2015
  • Emotional expression is universal and emotional state impacts important areas in our life. Until now, analyzing the acquired EEG signals under circumstances caused by invoked feelings and efforts to define their emotional state have been made mainly by psychologists based on the results. But, recently emotion-related information was released by research results that it is possible to identify mental activity through measuring and analyzing the brain EEG signals. So, this study has compared and analyzed emotional expressions of human by using brain waves. To get EEG difference for a particular emotion, we showed specific subject images to the people for changing emotions that peace, joy, sadness and stress, etc. After measured EEG signals were converged into frequence domain by FFT signal process, we have showed EEG changes in emotion as a result of the performance analyzing each respective power spectrum of delta, theta, alpha, beta and gamma waves.

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Retrospective study on 100 cases of inpatients with facial paralysis (구안와사(말초성 안면신경마비) 입원환자 100례에 대한 임상적 고찰)

  • Kim, Min-Jeong;Kim, Jong-Han;Park, Soo-Yeon;Choi, Jeong-Hwa;Jung, Min-Young;Song, Jin-Su;Lee, Eu-Jin;Lee, Ji-Eun;Yang, Mi-Sung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.2
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    • pp.128-138
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    • 2009
  • Objectives : The purpose of this study is to make a survey on the oriental medical care and to enlarge the domain of oriental medical treatment concerning facial paralysis. Methods : From May 2008 to April 2009, a clinical study was done on 100 inpatients who were diagnosed and treated as facial nerve paralysis at Mok-dong Oriental Medicine Hospital, Dong-shin University Results : The result were as the following 1. The distribution of sex: male 35%, female 65%. The distribution of age was disclosed that fifty was the most in 22 cases(22%). 2. The distribution of the region of facial palsy: Lt 58%(male 23%, female 35%) Rt 41%(male 11%, female 30%) 3. In distribution of contributing frequence in month, June was the most in number(12%) and in season, spring, summer, winter were the same percentage(26%). 4. In distribution of cause, stress(34%), excessive labor(25%), unknown(22%) were investigated higher than other conditions. 5. The distribution of past history: hypertension 14%, diabetes mellitus 4%, both(hypertension, diabetes mellitus) 6% 6. The distribution of period before admission: within a week 80%, 1$\sim$2 week 8%, 3$\sim$4 week 6% in order. 7. The distribution of attended symptoms: mastoid pain 43 cases, dryness of eye 26 cases, tearing 22 cases, headache 12 cases, dizziness 9 cases in order. 8. Other offices patients visited before coming to this clinic: oriental clinic or hospital 35%, local clinic or hospital 29%, none 26%, both(oriental clinic & local clinic) 10%. 9. The distribution of House-Brackmann grade on admission: Gr III 38%, Gr IV 26%, Gr II 22%, Gr V 14% in order. 10. The distribution of House-Brackmann grade on discharge: Gr II 34%, Gr I 32%, Gr III 22%, Gr V 7%, Gr IV 5% in order.

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Moving Image Compression with Splitting Sub-blocks for Frame Difference Based on 3D-DCT (3D-DCT 기반 프레임 차분의 부블록 분할 동영상 압축)

  • Choi, Jae-Yoon;Park, Dong-Chun;Kim, Tae-Hyo
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.37 no.1
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    • pp.55-63
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    • 2000
  • This paper investigated the sub-region compression effect of the three dimensional DCT(3D-DCT) using the difference component(DC) of inter-frame in images. The proposed algorithm are the method that obtain compression effect to divide the information into subband after 3D-DCT, the data appear the type of cubic block(8${\times}$8${\times}$8) in eight difference components per unit. In the frequence domain that transform the eight differential component frames into eight DCT frames with components of both spatial and temporal frequencies of inter-frame, the image data are divided into frame component(8${\times}$8 block) of time-axis direction into 4${\times}$4 sub block in order to effectively obtain compression data because image components are concentrate in corner region with low-frequency of cubic block. Here, using the weight of sub block, we progressed compression ratio as consider to adaptive sub-region of low frequency part. In simulation, we estimated compression ratio, reconstructed image resolution(PSNR) with the simpler image and the complex image contained the higher frequency component. In the result, we could obtain the high compression effect of 30.36dB(average value in the complex-image) and 34.75dB(average value in the simple-image) in compression range of 0.04~0.05bpp.

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Research of Change of Heart Rate Variability by Psychological Types before and after Meditation Program (α Version) (명상프로그램(α version) 시행 전 후의 심리유형별 HRV 변화 연구)

  • Kim, Geun-Woo;Bae, Hyo-Sang;Kim, Ji-Hwan;Kim, Byoung-Soo;Lee, Pil-Won;Park, Seong-Sik
    • Journal of Oriental Neuropsychiatry
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    • v.26 no.2
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    • pp.89-102
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    • 2015
  • Objectives: To examine the medical effectiveness of meditation programs ($\alpha$ version) by psychological types. Methods: MBTI, which was created by Katharine Cook Briggs and Isabel Briggs Myers, was used as the Psychological Type test and to investigate psychological temperament and functions and psychological preferences. Heart rate variability was used to test the effectiveness of meditation by investigating time domains (mean HR, SDNN, PSI) and frequence domain parameters (TP, LF, HF, LF or HF norm, Ln (TP or VLF or LF or HF). Results: 1. The autonomic nervous system became active, and both time domains and frequency domains showed positive responses to meditation in heart rate variability tests, without distinction of Psychological Types. 2. In Psychological Types using sensing over intuition for perception, there were positive responses as well as an increase of the parasympathetic nervous system's activeness to meditation for heart rate variability tests, depending on psychological temperaments and psychological functions. 3. In heart rate variability tests by preferences, there was no difference. Extroversion and Introversion types, Sensing over Intuition Types, Thinking over Feeling Types, Judging over Perception Types had an increase of activeness of the parasympathetic nervous system. Therefore, meditation has a positive physical and psychological relaxing effect. Conclusions: A complex meditation program has a positive effect on overall meditation. Especially in the MBTI test, sensing was superior to intuition when people recognized objects. The Sensing, Thinking and Judging type was more advantageous than Intuition, Feeling and Perception, respectively. In the future, a well-designed control study is needed, to develop a suitable meditation for each personality type.