• Title/Summary/Keyword: frequency problem

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DWT based Digital Image Watermarking using Labview Machine Vision (DWT기반 Labview Machine Vision을 이용한 디지털 이미지 워터마킹)

  • Kim, Hyoung-Gwon;Song, Yun-Jae;Ahn, Tae-Chon
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.198-200
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    • 2005
  • Recently, intellectual property problem caused by illegal copy or circulation of digital contents with computer and advance of network. it will lose producer's desire and cause economic losses. so we need to demand ownership protection technology for prevent illegal copy without an owner consent and protect ownership with effect. in this paper, we change digital image at frequency domain and choose a factor choosing frequency area with human perceptibility. we inserted repetitive and adaptive watermark on the whole image by Labview Machine Vision. watermark inserted into the high frequency concentrated textual area with Wavelet Transform and then reduced damage of image by human visual feature after inserted watermark

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Hardware design and control method for controlling an input clock frequency in the application

  • Lee, Kwanho;Lee, Jooyoung
    • International Journal of Advanced Culture Technology
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    • v.4 no.4
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    • pp.30-37
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    • 2016
  • In this paper, the method of controlling the clock that is inputted on the hardware from the application, and the hardware design method are to be proposed. When the hardware is synthesized to the Field Programmable Gate Array(FPGA), the input clock is fixed, and when the input clock is changed, the synthesis process must be passed again to require more time. To solve this problem, the Mixed-Mode Clock Manager(MMCM) module is mounted to control the MMCM module from the application. The controlled MMCM module controls the input clock of the module. The experiment was process the Neural Network algorithm in the x86 CPU and SIMT based processor mounted the FPGA. The results of the experiment, SIMT-based processors, the time that is processed at a frequency of 50MHz was 77ms, 100MHz was 34ms. There was no additional synthesis time due to a change of the clock frequency.

Initialization of the Radial Basis Function Network Using Localization Method

  • Kim, Seong-Joo;Kim, Yong-Taek;Jeon, Hong-Tae;Seo, Jae-Yong;Cho, Hyun-Chan
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.163.1-163
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    • 2001
  • In this paper, we use time-frequency localization analysis method to analize the target function and the area of the target space. When we analize the function with the time and frequency axis simultaneously, the characteristic of the function is shown more precisely and the area is covered by a certain block. After we analize the target function in the time-frequency space, we can decide the activation functions and compose the hidden layer of the RBFN by choosing the radial basis function which can represent the characteristic of the target function, RBFN made by this method, designs the good structure proper to the target problem because we can decide the number of hidden node first.

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A Study on the Relationship between Flexural Beam Shape and Transport Characteristics for the Ultrasonic Transport Systems (초음파 이송 시스템에서 Flexural Beam의 형태 변화와 물체 이송과의 관계에 대한 연구)

  • 정상화;신병수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.25-29
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    • 2003
  • In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the object transport system using the excitation of ultrasonic wave is proposed. The experiments for finding the optimal excitation frequency, finding phase-difference between two ultrasonic wave generators are performed. The relationship of transporting speed according to the change of flexural beam shape is verified and the system performance for practical use is evaluated.

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A Study on Object Transport System Using 2-Mode Ultrasonic Wave (2-Mode 초음파를 이용한 물체 이송에 관한 연구)

  • 정상화;김택현;신병수;차경래
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1170-1173
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    • 2003
  • In the semiconductor and the optical industry a new transport system which can replace the common system is required. The common systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches, the optical lens. The ultrasonic wave driven system solve these problem. In this paper the object transport system using the excitation of ultrasonic wave is proposed. the experiments for finding the optimal excitation frequency, finding phase-difference between two ultrasonic wave generators are performed. The effect of transporting speed according to the change of amplification voltage is verified. In addition, the system performance for actual use is evaluated

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Analysis of Interior Noise for KTX in Tunnel with Concrete Track (콘크리트 궤도 터널 내 KTX 차량의 실내소음 특성 분석)

  • Kim, Jae-Chul;Lee, Chan-Woo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11b
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    • pp.25-28
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    • 2005
  • The interior noise of KTX in tunnel is becoming the problem since the commercial operating in April 2004. The major sources of interior noise for High speed train ate known as the aerodynamic noise and rolling noise generally. We measure the noise and vibration inside KTX in tunnel in order to find the cause of the interior noise of KTX. The analysis results show that the interior noise of KTX in tunnel with concrete track is increased sharply by a low frequency below 80Hz that is the natural frequency of the KTX carbody. We know that the booming noise inside KTX in tunnel with concrete track is generated by aerodynamic noise outside ganqway and rolling noise at the carbody natural frequency.

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Structural Dynamic Modification of Fixture using Antiresonance Frequency Analysis (반공진 진동수 해석에 의한 치구 설계 변경)

  • 김준엽;윤을재
    • Journal of the Korean Society of Propulsion Engineers
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    • v.1 no.2
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    • pp.48-57
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    • 1997
  • The method of antiresonance frequency analysis of multi-input system is proposed. The structural dynamic modification using antiresonance frequency analysis is also applied to reduce the undertest at specimen attachment points on the fixture in environmental vibration test, which is resulted from the inconsistency of antiresonance frequencies. Several computer simulations show that the proposed method can remove the undertest problem which is not removed in conventional vibration test control. And the effectiveness of the method is verified with the impact hammer excitation of aluminium fixture model.

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Vertical Vibration Analysis of Single Pile-Soil Interaction System Considering the Interface Spring (접합면 스프링요소를 고려한 단말뚝-지반 상호작용계의 수직진동해석)

  • 김민규;김문겸;이종세
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.09a
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    • pp.106-113
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    • 2002
  • In this study, a numerical analysis method for soil-pile interaction in frequency domain problem is presented. The total soil-pile interaction system is divided into two parts so called near field and far field. In the near field, beam elements are used for a pile and plain strain finite elements for soil. In the far field, dynamic fundamental solution for multi-layered half planes based on boundary element formulation is adopted for soil. These two fields are coupled using FE-BE coupling technique In order to verify the proposed soil-pile interaction analysis, the dynamic responses of pile on multi-layered half planes are simulated and the results are compared with the experimental results. Also, the dynamic response analyses of interface spring elements are performed. As a result, less spring stiffness makes the natural frequency decrease and the resonant amplitude increase.

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Phase Referencing Capability in KVN

  • Jeong, Tae-Hyeon;Son, Bong-Won
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.43.2-43.2
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    • 2010
  • Following the success of detecting fringes on KVN (Korean VLBI Network), a phase referencing observation is currently planned in order to achieve a better sensitivity in mm-VLBI. The high frequency observation ($\geq$ 22 GHz), wide bandwidths (~512 MHz) and high speed data recording (~1 Gbps, Mark5B) will result in resolution and sensitivity improvement on KVN. In particular, two powerful techniques of VLBI phase correction by fast-antenna switching and multi-frequency phase referencing are also introduced in KVN, hoping to resolve the problem of atmospheric delay errors which degrade the coherence significantly. In this study, we have compared the expected performance of phase referencing between fast antenna switching and multi-frequency phase referencing and discussed the essential condition and postulates of phase referencing for KVN.

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A Study on the Time-Dependent Bonus-Malus System in Automobile Insurance

  • Kang, Jung-Chul
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.4
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    • pp.1147-1157
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    • 2005
  • Bonus-Malus system is generally constructed based on claim frequency and Bayesian credibility model is used to represent claim frequency distribution. However, there is a problem with traditionally used credibility model for the purpose of constructing bonus-malus system. In traditional Bonus-Malus system adopted credibility model, individual estimates of premium rates for insureds are determined based solely on the total number of claim frequency without considering when those claims occurred. In this paper, a new model which is a modification of structural time series model applicable to counting time series data are suggested. Based on the suggested model relatively higher premium rates are charged to insured with more claim records.

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