• Title/Summary/Keyword: real scale

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A study on the properties of ETBF using subwindow filters (부여파기를 이용한 ETBF의 성질 분석에 관한 연구)

  • 송종관
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.3
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    • pp.547-552
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    • 1999
  • In [1], it is shown that a subclass of ETBFs, which are self-dual ETBFs can be expressed as a weighted average of median subfiltered outputs. In this paper, the ETBF is extended for real-valued input. Using this result, the scale-preservation and translation-invariance properties of the ETBFs are investigated. In particular, it is shown that the ETBFs are scale-preserving if and only if it is extended self-dual.

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Constructing a Social Contact Network based on Cellphone Call Records and Analysis of its Scale-free Property (휴대폰 통화기록 기반의 소셜 컨택 네트워크 구성 및 Scale-free 특성에 관한 분석)

  • Lee, Jinho
    • Journal of Korean Institute of Industrial Engineers
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    • v.40 no.1
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    • pp.1-7
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    • 2014
  • We consider a human contact social network that has connections through cellphone addresses. To construct such a social network, we use real call records provided by a large carrier, and connect to each other if there exists a call record between any two cellphone users. Due to its huge amount of data, we down-sample it in a way that the smallest-degree nodes are removed, in turn, from the network. For a moderate size of the networks we show that the degree distribution of the network follows a power-law distribution via linear regression analysis, implying the so-called scale-free property. We finally suggest some alternative measures to analyze a social network.

Linear regression under log-concave and Gaussian scale mixture errors: comparative study

  • Kim, Sunyul;Seo, Byungtae
    • Communications for Statistical Applications and Methods
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    • v.25 no.6
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    • pp.633-645
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    • 2018
  • Gaussian error distributions are a common choice in traditional regression models for the maximum likelihood (ML) method. However, this distributional assumption is often suspicious especially when the error distribution is skewed or has heavy tails. In both cases, the ML method under normality could break down or lose efficiency. In this paper, we consider the log-concave and Gaussian scale mixture distributions for error distributions. For the log-concave errors, we propose to use a smoothed maximum likelihood estimator for stable and faster computation. Based on this, we perform comparative simulation studies to see the performance of coefficient estimates under normal, Gaussian scale mixture, and log-concave errors. In addition, we also consider real data analysis using Stack loss plant data and Korean labor and income panel data.

Design of an Image Processor for UXGA Class LCD

  • Cho, Hwa-Hyun;Choi, Myung-Ryul
    • Journal of Information Display
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    • v.2 no.2
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    • pp.13-21
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    • 2001
  • We propose a universal image processor for a-Si TFT LCD of UXGA class that can display the full screen on the LCD panel with low resolution of video sources such as NTSC, VGA, SVGA, XGA, and SXGA by using the proposed interpolation filter. In addition, we propose a real-time contrast controller for image improvement of multi-gray scale image. The operation of the proposed methods has been verified using Synopsys VHDL and computer simulation. Results show that the proposed methods might be suitable for a UXGA LCD controller for real-time image improvement.

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Analysis of delay compensation in real-time dynamic hybrid testing with large integration time-step

  • Zhu, Fei;Wang, Jin-Ting;Jin, Feng;Gui, Yao;Zhou, Meng-Xia
    • Smart Structures and Systems
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    • v.14 no.6
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    • pp.1269-1289
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    • 2014
  • With the sub-stepping technique, the numerical analysis in real-time dynamic hybrid testing is split into the response analysis and signal generation tasks. Two target computers that operate in real-time may be assigned to implement these two tasks, respectively, for fully extending the simulation scale of the numerical substructure. In this case, the integration time-step of solving the dynamic response of the numerical substructure can be dozens of times bigger than the sampling time-step of the controller. The time delay between the real and desired feedback forces becomes more striking, which challenges the well-developed delay compensation methods in real-time dynamic hybrid testing. This paper focuses on displacement prediction and force correction for delay compensation in the real-time dynamic hybrid testing with a large integration time-step. A new displacement prediction scheme is proposed based on recently-developed explicit integration algorithms and compared with several commonly-used prediction procedures. The evaluation of its prediction accuracy is carried out theoretically, numerically and experimentally. Results indicate that the accuracy and effectiveness of the proposed prediction method are of significance.

CReMeS: A CORBA COmpliant Reflective Memory based Real-time Communication Service

  • Chung, Sun-Tae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.10B
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    • pp.1675-1689
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    • 2000
  • We present CReMeS a CORBA-compliant design and implementation of a new real-time communication service. It provides for efficient predictable and scalable communication between information producers and consumers. The CReMeS architecture is based on MidART's Real-Time Channel-based Reflective Memory (RT-CRM) abstraction. This architecture supports the separation of QoS specification between producer and consumer of data and employs a user-level scheduling scheme for communicating real-time tasks. These help us achieve end-to-end predictability and allows our service to scale. The CReMeS architecture provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer. Thus it can run on non real-time Off-The-Shelf ORBs enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition an application designer can select whether to use an out-of-band channel or the ORB GIOP/IIOP for data communication. This permits a trade-off between performance predictability and reliability. Experimental results demonstrate that our architecture can achieve better performance and predictability than a real-time implementation of the CORBA Even Service when the out-of-band channel is employed for data communication it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.

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Real-Time Estimation and Compensation of the Laser Interferometer in Nano-Scale

  • Lee, Yong-Woo;Choi, Hyun-Seok;Park, Tong-Jin;Han, Chang-Soo;Choi, Tae-Hoon;Lee, Nak-Kyu;Lee, Hyoung-Wook;Na, Kyung-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1225-1230
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    • 2003
  • In this study, Real-time estimation and compensation procedure are developed for the laser interferometer. This system is designed with homodyne quadrature-phase detection method using the Laser interferometer. The errors in this system are due to noise, disturbance and undefined model dynamics. DSP(Digital Signal Processor) is applied for real time compensation of these errors. This estimator and compensation is verified with measurement test.

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Development of a Capacitance-type wave Recorder for Measuring Real-Time Wave Height Based on Microprocessor Technique (마이크로프로세서 기술에 기초한 실시간 파고 계측용 용량식 파고계의 개발)

  • 김제윤;김환성;김상봉
    • Journal of Ocean Engineering and Technology
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    • v.10 no.3
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    • pp.162-167
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    • 1996
  • This paper deals with an implementation method for the one chip microprocessor(8097)-based capacitance type wave recorder for a measuring real-time wave height. The system was developed to make it possible to real-time remote sensing the wave height by deploying the RS-232/422/485 communication methods. The system test results for the developed system such as linearity, system stability and robustness of the disturbance was also verified through the performance tests of the system. Furthermore, the system was developed after due consideration with connecting the public network such as satellite mobile communication system and LAN, through the deploying VLSI(Very Large Scale Integration) design techniques.

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Design and Implementation of an Intelligent System for Real-Time Route Guidance (실시간 경로 조언을 위한 지능형 시스템의 설계 및 구축)

  • Kim, Seong-In;Kim, Hyun-Kee
    • IE interfaces
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    • v.15 no.4
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    • pp.374-381
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    • 2002
  • In this paper, we design and implement a real-time route guidance system(RGS) in large-scale networks. Coupled with the well-known mathematical routing algorithms, we devise an RGS for knowledge aquisition and self-learning ability within the framework of the expert system. Through off-line construction of database, on-line treatment of unexpected traffic accidents, etc., the developed RGS can provide drivers with good quality real-time routing information. The practical effectiveness of the proposed system is demonstrated in terms of response time and route appropriateness.

Enhancement of Common-path Fourier-domain Optical Coherence Tomography using Active Surface Tracking Algorithm (표면 추적 알고리즘을 적용한 공통경로 FD-OCT의 성능개선)

  • Kim, Min-Ho;Kim, Keo-Sik;Song, Chul-Gyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.4
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    • pp.639-642
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    • 2012
  • Optical coherence tomography(OCT) can provide real-time and non-invasive subsurface imaging with ultra-high resolution of micrometer scale. However, conventional OCT systems generally have a limited imaging depth range within a depth of only 1-2 mm. To overcome the limitation, we have proposed an active surface tracking algorithm used in common-path Fourier-domain OCT system in order to extend the imaging depth range. The surface tracking algorithm based on the threshold and Savitzky-Golay filter of A-scan data was applied to real-time tracking. The algorithm has controlled a moving stage according to the sample's surface variance in real time. An OCT image obtained by the algorithm clearly show an extended imaging depth range. Consequently, the proposed algorithm demonstrated the potential for improving the conventional OCT systems with limitary depth range.