• Title/Summary/Keyword: 신호처리(signal processing)

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Robust 1D inversion of large towed geo-electric array datasets used for hydrogeological studies (수리지질학 연구에 이용되는 대규모 끄는 방식 전기비저항 배열 자료의 1 차원 강력한 역산)

  • Allen, David;Merrick, Noel
    • Geophysics and Geophysical Exploration
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    • v.10 no.1
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    • pp.50-59
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    • 2007
  • The advent of towed geo-electrical array surveying on water and land has resulted in datasets of magnitude approaching that of airborne electromagnetic surveying and most suited to 1D inversion. Robustness and complete automation is essential if processing and reliable interpretation of such data is to be viable. Sharp boundaries such as river beds and the top of saline aquifers must be resolved so use of smoothness constraints must be minimised. Suitable inversion algorithms must intelligently handle low signal-to-noise ratio data if conductive basement, that attenuates signal, is not to be misrepresented. A noise-level aware inversion algorithm that operates with one elastic thickness layer per electrode configuration has been coded. The noise-level aware inversion identifies if conductive basement has attenuated signal levels so that they are below noise level, and models conductive basement where appropriate. Layers in the initial models are distributed to span the effective depths of each of the geo-electric array quadrupoles. The algorithm works optimally on data collected using geo-electric arrays with an approximately exponential distribution of quadrupole effective depths. Inversion of data from arrays with linear electrodes, used to reduce contact resistance, and capacitive-line antennae is plausible. This paper demonstrates the effectiveness of the algorithm using theoretical examples and an example from a salt interception scheme on the Murray River, Australia.

A Study on Development of Remote Crane Wire Rope Flaws Detection Systems (원격 크레인 와이어 로프 결함 탐지 시스템 개발에 관한 연구)

  • Min, Jeong-Tak;Lee, Jin-Woo;Lee, Kwon-Soon
    • Journal of Navigation and Port Research
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    • v.27 no.1
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    • pp.97-102
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    • 2003
  • Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, the wire rope of crane is important component to container transfer. If it happens wire rope failures during the operation, it may lead to safety accident, economic loss by productivity decline and so on. To solve this problem, we developed remote wire rope fault detecting system, and this system is consisted of 3 parts that portable fault detecting part, signal processing part and remote monitoring part. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data. It is verified that the detecting system by de-noising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension fo wire ropes exchange period and could competitive power. Also, this system is possible to apply in several field such as elevator, lift and so on.

Enhancing A Neural-Network-based ISP Model through Positional Encoding (위치 정보 인코딩 기반 ISP 신경망 성능 개선)

  • DaeYeon Kim;Woohyeok Kim;Sunghyun Cho
    • Journal of the Korea Computer Graphics Society
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    • v.30 no.3
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    • pp.81-86
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    • 2024
  • The Image Signal Processor (ISP) converts RAW images captured by the camera sensor into user-preferred sRGB images. While RAW images contain more meaningful information for image processing than sRGB images, RAW images are rarely shared due to their large sizes. Moreover, the actual ISP process of a camera is not disclosed, making it difficult to model the inverse process. Consequently, research on learning the conversion between sRGB and RAW has been conducted. Recently, the ParamISP[1] model, which directly incorporates camera parameters (exposure time, sensitivity, aperture size, and focal length) to mimic the operations of a real camera ISP, has been proposed by advancing the simple network structures. However, existing studies, including ParamISP[1], have limitations in modeling the camera ISP as they do not consider the degradation caused by lens shading, optical aberration, and lens distortion, which limits the restoration performance. This study introduces Positional Encoding to enable the camera ISP neural network to better handle degradations caused by lens. The proposed positional encoding method is suitable for camera ISP neural networks that learn by dividing the image into patches. By reflecting the spatial context of the image, it allows for more precise image restoration compared to existing models.

Design of Cic roll-off Compensation Filter in Digital Receiver For W-CDMA NODE-B (W-CDMA 기지국용 디지털 수신기의 CIC 롤 오프 보상필터 설계)

  • 김성도;최승원
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.12
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    • pp.155-160
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    • 2003
  • Owing to the advances in ADC and DSP technologies, signals in If band, which once had to be processed in analog technology, can new be digitally processed. This is referred to as "Digital IF" or "Digital Radio", which is a preliminary stage of SDR. Applying the digital radio technology to a multi-carrier receiver design, a processing gain is generated through an over-sampling of input data. In the digital receiver, decimation is performed for reducing the computational complexity CIC and half band filter is used together with the decimation as an anti-alising filter. The CIC filter, however, should introduce the roll-off phenomenon in the passband, which causes the receiving performance to be considerably degraded due to the distorted Passband flatness of receiving filter. In this paper, we designed a CIC roll-off compensation filter for W-CDMA digital receiver. The performance of the proposed compensation filter is confirmed through computer simulations in such a way that the BER is minimized by compensating the roll-off characteristics.off characteristics.

Design of After-processing Encrypted Record System for Copy Protection of Digital Video Optical Discs (디지털 비디오 광 디스크의 복제방지를 위한 후처리 암호화 기록 장치의 설계)

  • Kim, Hyeong-Woo;Joo, Jae-Hoon;Kim, Jin-Ae;Choi, Jung-Kyeng
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.6
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    • pp.1435-1440
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    • 2010
  • This paper presents encrypted secret code recording system which can insert an unique manufacture ID code after complete disc process. First, we detect a memory block synchronizing signal which is SYNC. by using FPGA, then, design a recording pattern to write Multi Pulse. Finally, a method that any data is recorded in any place in any data area of optical disc by using a FPGA was proposed. Newly proposed method in this paper that any user records user data in protected data areas on digital video optical discs, can be very useful for effective software copy protection, and can be applicable to encrypted record on high density DVD in near future.

Optical transmission technology of Ultra high-speed and Ultra long distance (초고속 초장거리 광전송 기술)

  • 이봉영
    • Information and Communications Magazine
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    • v.11 no.2
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    • pp.77-89
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    • 1994
  • High speed optical fiber transmission technology has been remarkably improved during the past 20 years. This paper presents recent research status and future technological issues for the future information society, that is, the Tb/s transmission by frequency division multiplexing and the ultra long-distance by optical soliton transmission. Erbium-doped fiber amplifier and recent optical technology have brought optical transmission system of up to 10 Gb/s to the point of commercialization. Taking into account the future super information highway, that is, B-ISDN network, ultra wide-band picture-based information can be provided for many subscribers via existing optical fiber cables. However, to achieve the high speed transmission, the technologies must be developed not only for transmission lines but also for transmission nodes. Since the conventional signal transmission/processing technique using electronics has the limit in its speed, novel photonic technology is being developed for this purpose. On the other hand, optical solitons propagate stably through optical fibers, without pulse broadening effect of the fiber dispersion. Since the pulse broadening effect becomes serious as the transmission speed increases, optical solitons is the important technologies to realize the high speed, long distance transmission.

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Design of an Automatic Titration System for Caustic Soda Treatment System Using the Equivalent Point Estimation Algorithm (당량점 예측 알고리듬에 의한 가성소다 처리 섬유감량 시스템용 자동적정 장치 설계)

  • Cho, Jin-Ho;Jin, Kyoung-Chan;You, Byoung-Heui;Koo, Sung-Mo;Kim, Myoung-Nam;Lee, Jong-Hyun;Lee, Heung-Lark
    • Journal of Sensor Science and Technology
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    • v.3 no.3
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    • pp.28-35
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    • 1994
  • Caustic Soda Treatment Systems need a concentration measurement device in order to monitor the weight reduction amount of polyester fabrics. Since the reduction process requires several concentration measurements, we have to do the unit titration fast and exactly. Therefore, a proposition of estimation algorithm for finding the equivalent point in the titration process is needed. In this paper, we used the cardinal spline algorithm, to estimate the proper curve with the measured pH-values after each injection of titration sdution, to predict the equivalent point. While the processing time is elapsed, several equivalent points are estimated and drawed the line graph of fabrics weight reduction automatically. Finally, we designed the hardware and the software of an automatic titration system that can generate the reduction ending signal of Caustic Soda Treatment System.

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Implementation of Optimized 3D Input & Output Systems for Web-based Real-time 3D Video Communication (웹 기반의 입체 동영상 통신을 위한 3차원 입출력 시스템의 최적화 구현)

  • Ko, Jung-Hwan;Lee, Jung-Suk;An, Young-Hwan
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.105-114
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    • 2006
  • In this paper, 3D input and output systems for a web-based real-time 3D video communication system using IEEE 1394 digital cameras, Intel Xeon Server system and Microsoft Directshow library is proposed. And some conditions for optimizing the operations of the stereo camera, 3D display and signal processing system are analyzed. Input & output systems are carefully selected, which can satisfy the required optimization conditions and the final 3D video communication system is implemented by using three optimized devices. The overall control system is developed with Microsoft Visual C++.Net and Microsoft DirectX 9.1 SDK. Some experimental results show that the observer can feel the natural presence from multi-view(4-view) 3D video of server system in real-time and also can feel the natural presence from 3D video of client system and finally suggest an application possibility of the proposed web-based real-time 3D video communication in real fields.

A Method of Designing Low-power Feedback Active Noise Control Filter for Headphones/Earphones (헤드폰/이어폰을 위한 저전력 피드백 능동 소음 제어 필터 설계 방법)

  • Seo, Ji-ho;Youn, Dae-Hee;Park, Young-Cheol
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.1
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    • pp.57-65
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    • 2017
  • This paper presented a method of designing low-power feedback active noise control filter optimized for headphones/earphones. Using constrained optimization, we obtained a high order FIR noise control filter to ensure reasonable noise attenuation performance at high sampling frequency environment. Then using infinite impulse response (IIR) approximation method called Balanced Model Truncation (BMT), we obtained a low order IIR noise control filter suitable for low-power digital signal processing system like headphones/earphones. For further performance improvement, we utilized frequency warping method so that we could obtain more accurately approximated IIR filter and we ensured system stability by reconstructing the low order IIR filter in form of cascaded second order IIR filters. ANC simulation with white noise and stability test verified that the proposed algorithm had superior attenuation performance and better robustness compared to the conventional algorithm.

Developing the Installation Guideline of Building Monitoring Systems for Hazardous Symptom Measurements with Visual Perception (시지각적 요소를 갖춘 건축물 위험징후 측정 모니터링 시스템 설치 가이드라인 개발연구)

  • Kim, Heejae;Kim, Geunyoung;Shin, Jungjae
    • Journal of the Society of Disaster Information
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    • v.16 no.2
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    • pp.374-382
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    • 2020
  • Purpose: Recently, structural defects in old safety management facilities have led to the collapse of buildings and facilities. The purpose of this study is to develop guidelines for the installation of regular monitoring systems that determine the optimal sensor location for monitoring exhibition space building sensors equipped with visual elements in order to analyze the risk signs of exhibition space buildings and develop measurement technology. Method: The components, installation locations, alarm criteria, and management measures of the instrument are presented. Result: A measure was proposed to determine the location of sensors, secure signal processing technology for analysis by having unified visual perception, and configure optimal 'risk sign detection' based on sensor monitoring through test-bed operation. Conclusion: The results of this study can be prepared against the disasters that may arise from the collapse of exhibition buildings, and contribute to strengthening safety management capabilities.