• Title/Summary/Keyword: Convergence Enhancement

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Comparison of Common Methods from Intertwined Application in Image Processing

  • Shin, Seong-Yoon;Lee, Hyun-Chang;Rhee, Yang-Won
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.405-410
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    • 2010
  • Image processing operations like smoothing and edge detection, and many more are very widely used in areas like Computer Vision. We classify the image processing domain as seven branches-image acquirement and output, image coding and compression, image enhancement and restoration, image transformation, image segmentation, image description, and image recognition and description. We implemented algorithms of gaussian smoothing, laplace sharpening, image contrast effect, image black and white effect, image fog effect, image bright and dark effect, image median filter, and canny edge detection. Such experimental results show the figures respectively.

SPICE Implementation of GaAs D-Mode and E-Mode MESFET Model (GaAs D-Mode와 E-Mode MESFET 모델의 SPICE 삽입)

  • 손상희;곽계달
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.5
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    • pp.794-803
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    • 1987
  • In this paper, the SPICE 2.G6 JFET subroutine and other related subroutines are modified for circuit simulation of GaAs MESFET IC's. The hyperbolic tangent model is used for the drain current-voltage characteristics of GaAs MESFET's and derived channel-conductance and drain-conductance model from the above current model are implemented into small-signal model of GaAs MESFET's. And, device capacitance model which consider after-pinch-off state are modified, and device charge model for SPICE 2G.6 are proposed. The result of modification is shown to be suitable for GaAs circuit simulator, showing good agreement with experimetal results. Forthermore the DC convergence of this paper is better than that of SPICE 2.G JFET subroutine. GaAs MESFET model in this paper is applied for both depletion mode GaAs MESFET and enhancement-mode GaAs MESFET without difficulty.

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Design and Fabrication of a Vacuum Chamber for a Commercial Atomic Force Microscope

  • Park, Sang-Joon;Jeong, Yeon-Uk;Park, Soyeun;Lee, Yong Joong
    • Applied Science and Convergence Technology
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    • v.23 no.2
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    • pp.97-102
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    • 2014
  • A vacuum chamber for a commercial atomic force microscope (AFM) is designed and fabricated. Only minimal modifications were made to an existing microscope in an effort to work in a vacuum environment, while most of the available AFM functionalities were kept intact. The optical alignment needed for proper AFM operations including a SLD (superluminescent diode) and a photodiode can be made externally without breaking the vacuum. A vacuum level of $5{\times}10^{-3}$ torr was achieved with a mechanical pump. An enhancement of the quality factor was observed along with a shift in the resonance frequency of a non-contact-mode cantilever in a vacuum. Topographical data of a calibration sample were also obtained in air and in a low vacuum using the non-contact mode and the results were compared.

Measurement and Analysis of the Korean NDGPS Radiation Spectrum

  • Kim, Young-Wan;Jee, Suk-Kun
    • Journal of information and communication convergence engineering
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    • v.10 no.3
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    • pp.225-230
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    • 2012
  • The Korean nationwide differential global positioning system (NDGPS) reference station transmits a global positioning system (GPS) enhancement signal using minimum shift keying modulation with a 200 bps data rate. The ocean-based DGPS covers the service area of 100 NM with 300 W output power; on the other hand, the land-based DGPS transmits the output power of 500 W, which covers the service area of 100 km. The DGPS reference stations with high output power can radiate spurious signals, which may act as interference sources affecting the other DGPS reference stations or the wireless ground stations that utilize the medium frequency band. In this paper, the radiation spectrums of the DGPS reference stations are measured and analyzed in the spurious domain. The DGPS radiation spectrums are evaluated from the perspective of the interference effect.

Location Estimation Enhancement Using Space-time Signal Processing in Wireless Sensor Networks: Non-coherent Detection

  • Oh, Chang-Heon
    • Journal of information and communication convergence engineering
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    • v.10 no.3
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    • pp.269-275
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    • 2012
  • In this paper, we proposed a novel location estimation algorithm based on the concept of space-time signature matching in a moving target environment. In contrast to previous fingerprint-based approaches that rely on received signal strength (RSS) information only, the proposed algorithm uses angle, delay, and RSS information from the received signal to form a signature, which in turn is utilized for location estimation. We evaluated the performance of the proposed algorithm in terms of the average probability of error and the average error distance as a function of target movement. Simulation results confirmed the effectiveness of the proposed algorithm for location estimation even in moving target environment.

A robustness enhancement of adaptive control system by improvement of parameter estimation method. (매개변수 추정 방법 개선에 의한 적응 제어 시스템의 견실성 향상)

  • Choi, Chong-Ho;Lhe, Ha-Jeong
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.144-147
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    • 1987
  • An adaptive control algorithm for a plant with unmodelled dynamics is proposed. The upper bounds of the output due to the unmodelled dynamics and measurement noise is assumed to be known. Linear programming is used in estimating the bounds of plant parameters. Projection type algorithm is used in estimating the plant parameter with these bounds. This algorithm is nearly the same as those proposed by Kreisselmeier or Middleton except that the bounds are computed by linear programming. The stability of the proposed algorithm Can be proved in nearly the same way as that of Middleton. Simulation results show that the proposed algorithm gives better parameter convergence and smaller overshoot in the plant output than the algorithm without computing the bounds of plant parameters by linear programming.

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Propagation Analysis of DGPS Antenna for Radial Ground and Obstacle

  • Kim, Young-Wan
    • Journal of information and communication convergence engineering
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    • v.9 no.4
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    • pp.363-368
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    • 2011
  • The DGPS transmits the enhancement signal to GPS using the medium frequency band. The NDGPS service that covers the Korean peninsula has been started since 2009. The service area of ocean-based DGPS(maritime-DGPS) reference stations covers the 100NM, but land-based DGPS(land-DGPS) covers 80km service area less than that of maritime DGPS. The DGPS's antenna has the top-loaded monopole antenna type. Top-loaded monopoles are the logical antennas to be used in order to get a low profile antenna and a performance according to the broadcaster and communication needs. The antenna needs to get the ground plane with good conductivity characteristics and flat ground plane without obstacle near to the transmitting antenna. In this paper, the radiation characteristics of an equivalent MF antenna are analyzed in view points of the ground conductivity and the ground plane with obstacle near to the antenna.

Enhanced RBF Network by Using Auto- Turning Method of Learning Rate, Momentum and ART2

  • Kim, Kwang-baek;Moon, Jung-wook
    • Proceedings of the KAIS Fall Conference
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    • 2003.11a
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    • pp.84-87
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    • 2003
  • This paper proposes the enhanced REF network, which arbitrates learning rate and momentum dynamically by using the fuzzy system, to arbitrate the connected weight effectively between the middle layer of REF network and the output layer of REF network. ART2 is applied to as the learning structure between the input layer and the middle layer and the proposed auto-turning method of arbitrating the learning rate as the method of arbitrating the connected weight between the middle layer and the output layer. The enhancement of proposed method in terms of learning speed and convergence is verified as a result of comparing it with the conventional delta-bar-delta algorithm and the REF network on the basis of the ART2 to evaluate the efficiency of learning of the proposed method.

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A Method of Grouping Features from Big Data based on Semantic Hierarchy for Accuracy Enhancement (빅데이터 환경에서 학습 정확도 향상을 위한 의미 계층 기반 속성 집단화 기법)

  • Lee, Keonsun;Lee, Keonsoo;Kang, Byeong-G
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.892-894
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    • 2019
  • 빅데이터 기반의 기계학습은 대규모 데이터를 이용하여, 숨겨진 패턴을 찾아내는 학습과정과, 그렇게 찾아낸 패턴을 이용하여 새로운 데이터를 해석하는 추론과정으로 이루어진다. 이 과정을 통해 학습된 패턴은 데이터를 구성하는 속성들과 긴밀한 연관성을 갖고 있다. 학습에 사용된 데이터의 원 데이터를 구성하는 각각의 속성과 추론 결과가 동일한 계층 관계를 갖고 있다면, 모든 속성을 동일하게 처리할 수 있지만, 그렇지 않은 경우, 속성들 사이의 계층 정보를 고려하는 것이, 추론 결과의 정확도를 높일 수 있다. 이에 본 연구에서는 속성들 사이의 계층 관계를 고려한 추론 기법을 제안하고, 사례연구를 통해 제안 방법을 실제 상황에 적용하는 방법을 제시한다.

Fitness Management System for the Enhancement of Exercise Capability in Youth (유소년 운동능력 발달을 위한 피트니스 관리 시스템)

  • Heo, Myeong-Hyeon;Kim, Dongho
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.10a
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    • pp.630-632
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    • 2019
  • 정부는 IT기술을 활용하여 국민의 건강증진을 목적으로 체력 상태 측정 및 평가를 제공하는 체육복지 서비스가 수행하고 있다. 특히, 모든 성장발육발달이 이루어지는 유소년기는 성인의 생활체육과는 그 중요성이나 효과의 측면에서 다르게 다루어야 한다. 따라서, 본 연구는 골연령에 따른 발육단계별 체력을 분석하여 유소년들에게 적합한 신체활동 서비스를 효율적으로 제공하기 위한 피지컬 피트니스 관리 시스템을 제안한다. 이를 통해, 골연령 평가를 위한 영상처리기술은 한국형 골연령 측정의 정확도를 높여주고, 유소년들에게 적합한 피트니스 프로그램을 효율적으로 제공할 수 있다.