• 제목/요약/키워드: 신호변환

검색결과 2,729건 처리시간 0.029초

EEG 16 channel variations between the non-stimulation and the moxibustion stimulated subjects for CV4, CV8, and CV12 acupuncture points (중완, 신궐 및 관원 경혈의 뜸 자극과 무 자극 대상군의 16채널 뇌파 변화에 관한 연구)

  • Yoon, Dong-Eop;Song, Hong-Bok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • 제14권12호
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    • pp.2755-2760
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    • 2010
  • The moxibustion therapy of orient medical is well known. Moxibustion method is used to burning moxibustion. The variation factors of the moxibustion stimulation for body can be applied to the electronic moxibustion method. This study is to analyze and examine the electroencephalogram(EEG) variations for moxibustion stimulation. In experiment, we divided six healthy male subjects into two same sized groups : with and without stimuli. The given stimuli are the moxibustion for CV4(Kwan-Won), CV8(Shin-Guel), and CV12(Jung-wan) acupuncture points. We have analyzed the power spectrum for ${\alpha}$, ${\beta}$, ${\delta}$, ${\Theta}$ waves and the average EEG variation level and each channels variation level of EEG. The result was that the moxibustion stimulation decreased the EEG levels of parietal lobe(ch 2, 3, 6, 7) according to the somatosensory system. And the apparent different points are that mild-heat($42{\sim}44^{\circ}C$) stimulation generating ${\alpha}$-wave is increased and ${\beta}$-wave is decreased, also slight-hot($45{\sim}48^{\circ}C$) stimulation made ${\alpha}$-wave decrease and ${\beta}$-wave increase for occipital lobe(ch 4,8) on the simulation group.

A new spect of offset and step size on BER perfermance in soft quantization Viterbi receiver (연성판정 비터비 복호기의 최적 BER 성능을 위한 오프셋 크기와 양자화 간격에 관한 성능 분석)

  • Choi, Eun-Young;Jeong, In-Tak;Song, Sang-Seb
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제27권1A호
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    • pp.26-34
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    • 2002
  • Mobile telecommunication systems such as IS-95 and IMT-2000 employ frame based communication using frames up to 20 msec in length and the receiving end has to store the whole frome before it is being processed. The size of the frame buffer ofter dominates those of the processing unit such as soft decision Viterbi decoder. The frame buffer for IMT-2000, for example, has to be increased 80 times as large as that of IS-95. One of the parameters deciding the number of bits in a frame will be obviously the number of bits in soft quantization. Start after striking space key 2 times. This paper has studied a new aspect of offset and quantization step size on BER performance and proposes a new 3-bit soft quantization algorithm which shows similar performance as that of 4-bit soft decision Viterbi receiver. The optimal offset values and step sizes for the other practical quantization levels ---16, 8, 4, 2--- have also been found. In addition, a new optimal symbol metric table has been devised which takes the accumulation value of various repeated signals and produces a rescaled 3-bit valu.tart after striking space key 2 times.

Copyright Protection for Fire Video Images using an Effective Watermarking Method (효과적인 워터마킹 기법을 사용한 화재 비디오 영상의 저작권 보호)

  • Nguyen, Truc;Kim, Jong-Myon
    • KIPS Transactions on Software and Data Engineering
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    • 제2권8호
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    • pp.579-588
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    • 2013
  • This paper proposes an effective watermarking approach for copyright protection of fire video images. The proposed watermarking approach efficiently utilizes the inherent characteristics of fire data with respect to color and texture by using a gray level co-occurrence matrix (GLCM) and fuzzy c-means (FCM) clustering. GLCM is used to generate a texture feature dataset by computing energy and homogeneity properties for each candidate fire image block. FCM is used to segment color of the fire image and to select fire texture blocks for embedding watermarks. Each selected block is then decomposed into a one-level wavelet structure with four subbands [LL, LH, HL, HH] using a discrete wavelet transform (DWT), and LH subband coefficients with a gain factor are selected for embedding watermark, where the visibility of the image does not affect. Experimental results show that the proposed watermarking approach achieves about 48 dB of high peak-signal-to-noise ratio (PSNR) and 1.6 to 2.0 of low M-singular value decomposition (M-SVD) values. In addition, the proposed approach outperforms conventional image watermarking approach in terms of normalized correlation (NC) values against several image processing attacks including noise addition, filtering, cropping, and JPEG compression.

An Object-Based Image Retrieval Techniques using the Interplay between Cortex and Hippocampus (해마와 피질의 상호 관계를 이용한 객체 기반 영상 검색 기법)

  • Hong Jong-Sun;Kang Dae-Seong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • 제42권4호
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    • pp.95-102
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    • 2005
  • In this paper, we propose a user friendly object-based image retrieval system using the interaction between cortex and hippocampus. Most existing ways of queries in content-based image retrieval rely on query by example or query by sketch. But these methods of queries are not adequate to needs of people's various queries because they are not easy for people to use and restrict. We propose a method of automatic color object extraction using CSB tree map(Color and Spatial based Binary をn map). Extracted objects were transformed to bit stream representing information such as color, size and location by region labelling algorithm and they are learned by the hippocampal neural network using the interplay between cortex and hippocampus. The cells of exciting at peculiar features in brain generate the special sign when people recognize some patterns. The existing neural networks treat each attribute of features evenly. Proposed hippocampal neural network makes an adaptive fast content-based image retrieval system using excitatory learning method that forwards important features to long-term memories and inhibitory teaming method that forwards unimportant features to short-term memories controlled by impression.

A Re-configurable 0.8V 10b 60MS/s 19.2mW 0.13um CMOS ADC Operating down to 0.5V (0.5V까지 재구성 가능한 0.8V 10비트 60MS/s 19.2mW 0.13um CMOS A/D 변환기)

  • Lee, Se-Won;Yoo, Si-Wook;Lee, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • 제45권3호
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    • pp.60-68
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    • 2008
  • This work describes a re-configurable 10MS/s to 100MS/s, low-power 10b two-step pipeline ADC operating at a power supply from 0.5V to 1.2V. MOS transistors with a low-threshold voltage are employed partially in the input sampling switches and differential pair of the SHA and MDAC for a proper signal swing margin at a 0.5V supply. The integrated adjustable current reference optimizes the static and dynamic performance of amplifiers at 10b accuracy with a wide range of supply voltages. A signal-isolated layout improves the capacitor mismatch of the MDAC while a switched-bias power-reduction technique reduces the power dissipation of comparators in the flash ADCs. The prototype ADC in a 0.13um CMOS process demonstrates the measured DNL and INL within 0.35LSB and 0.49LSB. The ADC with an active die area of $0.98mm^2$ shows a maximum SNDR and SFDR of 56.0dB and 69.6dB, respectively, and a power consumption of 19.2mW at a nominal condition of 0.8V and 60MS/s.

Design of a CMOS Tx RF/IF Single Chip for PCS Band Applications (PCS 대역 송신용 CMOS RF/IF 단일 칩 설계)

  • Moon, Yo-Sup;Kwon, Duck-Ki;Kim, Keo-Sung;Park, Jong-Tae;Yu, Chong-Gun
    • Journal of IKEEE
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    • 제7권2호
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    • pp.236-244
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    • 2003
  • In this paper, RF and IF circuits for mobile terminals which have usually been implemented using expensive BiCMOS processes are designed using CMOS circuits, and a Tx CMOS RF/IF single chip for PCS applications is designed. The designed circuit consists of an IF block including an IF PLL frequency synthesizer, an IF mixer, and a VGA and an RF block including a SSB RF mixer and a driver amplifier, and performs all transmit signal processing functions required between digital baseband and the power amplifier. The phase noise level of the designed IF PLL frequency synthesizer is -114dBc/Hz@100kHz and the lock time is less than $300{\mu}s$. It consumes 5.3mA from a 3V power supply. The conversion gain and OIP3 of the IF mixer block are 3.6dB and -11.3dBm. It consumes 5.3mA. The 3dB frequencies of the VGA are greater than 250MHz for all gain settings. The designed VGA consumes 10mA. The designed RF block exhibits a gain of 14.93dB and an OIP3 of 6.97dBm. The image and carrier suppressions are 35dBc and 31dBc, respectively. It consumes 63.4mA. The designed circuits are under fabrication using a $0.35{\mu}m$ CMOS process. The designed entire chip consumes 84mA from a 3V supply, and its area is $1.6㎜{\times}3.5㎜$.

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An Electromagnetic Shock Wave Generator Employing a Solenoid Coil for Extracorporeal Shock Wave Therapy: Construction and Acoustical Properties (체외 충격파 치료술을 위한 솔레노이드 코일을 이용한 전자기식 충격파 발생기: 구성 및 음향학적 특성)

  • Choi Min Joo;Lee Jong Soo;Kang Gwan Suk;Paeng Dong Guk;Lee Yoon Joon;Cho Chu Hyun;Rim Geun Hie
    • The Journal of the Acoustical Society of Korea
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    • 제24권5호
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    • pp.271-281
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    • 2005
  • An electromagnetic type shock wave generator suitable for extracorporeal shock wave therapy has been constructed by employing a solenoid coil. The Property of the shock waves produced by the shock wave generator was evaluated using a needle hydrophone. It was shown that, as the capacitor discharging voltage increased from 8 to 18 kV, the Positive Peak Pressure (P+) of the shock wave increased non-linearly from 10 to 77 Wa. In contrast. the negative peak Pressure (f) varied between -3.2 and -6.8 MPa. had its absolute maximum of -6.9 ma at 14 kV The peak amplitudes P+ measured repeatedly under the same voltage setting varied within $5\;\%$ from mean values and this is very small compared to about $50\;\%$ for electrohydraulic type shock wave generators. It could be observed, from the hydrophone signal recorded over 1 ms. several sequential acoustic impulses representing bubble collapses. namely. acoustic cavitation. induced by the shock wave. A technique based on wavelet transformation was used to accurately measure the time delay between the 1st and 2nd collapse known to be closely related to the shock strength. It was observed that the measured time delay increased almost linearly from 120 to $700\;{\mu}s$ with the shock wave Pressure P+ increasing from 10 to 77 MPa.

Adaptive Digital Predistorter Using the NLMS Algorithm for the Nonlinear Compensation of the OFDM Communication System (OFDM통신시스템의 비선형 왜곡 보상을 위한 NLMS 알고리즘 방식의 디지털 적응 전치 왜곡기)

  • Kim Sang-Woo;Hieu Nguyen Thanh;Kang Byoung-Moo;Ryu Heung-Gyoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • 제16권4호
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    • pp.389-396
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    • 2005
  • In this paper, we propose a pre-distortion method using the NLMS(Normalized Least Mean Square) algorithm to cope with hish PAPR(Peak to Average Power Ratio) problem in OFDM communication system. This proposed scheme estimates the distortion characteristics of HPA, and changes the characteristic against the distortion. Therefore, it can be shown that the adaptive characteristic of the NLMS pre-distorter is good to track the various nonlinear characteristic of HPA, even though HPA characteristic is changed by temperature variation or aging. From the performance analysis, SNR efficiency of NLMS pre-distorter is about $0.5\;\cal{dB}$ less than that of common numerical non-adaptive pre-distorter, when IBO(Input Back Off) is $0\;\cal{dB}$. However, the NLMS pre-distorter is better than the common numerical pre-distorter, because these two pre-distorters have similar performance in higher than $3\;\cal{dB}$ IBO, and the NLMS pre-distorter maintains the constant performance even though characteristic of HPA is changed.

Underwater Channel Environment Analysis Using 10Khz Carrier Frequency at the Shore of West Sea (10kHz 반송파를 사용한 서해안 수중 채널환경 분석)

  • Kim, Min-sang;Ko, Hak-lim;Kim, Kye-won;Lee, Tae-seok;Im, Tae-ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제41권1호
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    • pp.132-139
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    • 2016
  • This study was carried out near the waters of Jango port, Dangjin-gun, Chungcheongnam-do by utilizing 10kHz carrier frequency, for the purpose of measurement and analysis of underwater channel environment of the Western sea. For the measurement of horizontal channel environment, the separation distance between transmitter and receiver is made differently in the range between 10m and 4000m. Meanwhile, for the measurement of vertical channel environment, transmission and receiving side ships are fixed as contacted each other and measured differently depending on their depth of submergence. In this study, the Coherence Bandwidth and the Coherence Time were estimated by analyzing the Power delay profile of the real sea based on the measured data, and analyzing the doppler frequency through frequency conversion of received tone-signal, respectively. This study is expected to become a base study in carrying out the frame design for underwater communication to improve the communication and secure the reliability of communication in future underwater channel environment.

Toward 6 Degree-of-Freedom Video Coding Technique and Performance Analysis (6 자유도 전방위 몰입형 비디오의 압축 코덱 개발 및 성능 분석)

  • Park, Hyeonsu;Park, Sang-hyo;Kang, Je-Won
    • Journal of Broadcast Engineering
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    • 제24권6호
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    • pp.1035-1052
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    • 2019
  • Recently, as the demand for immersive videos increases, efficient video processing techniques for omnidirectional immersive video is actively developed by MPEG-I. While the omnidirectional video provides a larger degree of freedom for a free viewpoint, the size of the video increases significantly. Furthermore, in order to compress 6 degree-of-freedom (6 DoF) videos that support motion parallax, it is required to develop a codec to yield better coding efficiency. In this paper, we develop a 6 DoF codec using Versatile Video Coding (VVC) as the next generation video coding standard. To the authors' best knowledge, this is the first VVC-based 6 DoF video codec toward the future ISO/IEC 23090 Part 7 (Metadata for Immersive Media (Video)) MPEG-I standardization. The experiments were conducted on the seven test video sequences specified in Common Test Condition (CTC) in two operation modes of TMIV (Test Model for Immersive Media) software. It is demonstrated that the proposed codec improves coding performance around 33.8% BD-rate reduction in the MIV (Metadata for Immersive Video) mode and 30.2% BD-rate reduction in the MIV view mode as compared to the state-of-the-art TMIV reference software. We also show the performance comparisons using Immersive Video PSNR (IV-PSNR) and Mean Structural Similarity (MSSIM).