• Title/Summary/Keyword: Time-shifting

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Wireless Technologies for Ultra Low Latency Communications (초저지연 서비스를 위한 무선 접속 기술)

  • Kim, Eunkyung;Park, Hyunseo;Lee, Anseok;Lee, Heesoo;Lee, Yuro;Kim, Taejoong
    • Electronics and Telecommunications Trends
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    • v.32 no.5
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    • pp.74-84
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    • 2017
  • In wireless access networks, it is extremely important to provide high quality of real time and interactive services, including voice and video traffic. Furthermore, low latency communication is shifting toward new paradigm which enhances user's high quality of experience, meeting the requirements for specific applications such as tactile internet, remote-control robot and machines, and mission critical application. In this paper, we introduce the approaches to achieve the extremely low latency service. The approaches include the core requirements and the key technologies providing low latency communication maintaining high reliability in wireless access networks.

The Appropriatness of Government Support of Shipping Industry ; A General Equilibrium Approach (해운산업에 대한 정부지원의 타당성 검토)

  • 정봉민
    • Journal of Korean Society of Transportation
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    • v.8 no.2
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    • pp.27-41
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    • 1990
  • In this study the economic impacts of government support of shipping industry in the labor rich country are appraised in a general equilibrium model. Shipping industry subsidies (which are supposed to be supplied by lump-sum tax) will decrease disposable income by shifting productive resources from traded goods to the comparatively disadvantageous transport sector, and at the same time reduce the implicit tariff effect by lowering transport costs. The net effect of shipping industry subsidies is to increase social welfare because the latter positive effect of shipping industry subsidies is to increase social welfare because the latter positive effect dominates the former negative effect. Such an increase in social welfare can never be expected from competitive traded goods industry subsidies in the case of which social welfare will actually decrease because of inefficient resource allocation resulting from the subsidies. In addition it is worth noting that the subsidies on the most capital intensive shipping industry will rectify unevenness in income distribution by raising relative price of labor contrary to subsidies on capital intensive traded goods.

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Optimized Channel Coding of Control Channels for Mobile Packet Communication

  • Song, Young-Joon
    • Journal of electromagnetic engineering and science
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    • v.3 no.1
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    • pp.50-56
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    • 2003
  • This paper proposes a coding scheme of control channel for mobile packet communication to maximize the minimum Hamming distance, which is based on shifting of basis vectors of Reed Muller code with optimized dynamic puncturing and/or(partial) sequence repetition. Since the maximum likelihood decoding can be performed using the extremely simple FHT(Fast Hadamard Transformation), it is suitable for real time optimum decoding of control channel information with very little complexity. We show applications of the proposed coding method to TFCI(Transport Format Combination Indicator) code in split and normal modes of 3GPP W-CDMA system. We also discuss how this method can reduce rate indication error over AWGN(Additive White Gaussian Noise) as well as fading channels when the proposed coding scheme is applied to 1xEV-DV system of $3^{rd}$TEX> generation partnership project 2(3GPP2) to indicate the data rate transmitted on the reverse traffic channel by a Mobile Station(MS).

The shape measurement of 3D object by using the method of interference pattern projection. (간섭무늬 투영 방식의 3차원 형상 측정)

  • 이연태;강영준;박낙규;황용선;백성훈
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.271-274
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    • 2002
  • The 3-D measurement using interference pattern projection is very attractive because of its high measuring speed and high sensitivity. When a sinusoidal amplitude grating was projected on an object, the surface-height distribution of the object is translated into a phase distribution of the deformed grating image. The patters was generated by a interferometer, and a PZT was used to shift the fringes on the target surface. The phase-acquisition algorithms are so sufficiently simple that high-resolution phase maps using a CCD camera can be generated in a short time. A working system requires a interferometer, a PZT, and a detector array interfaced to a microcomputer. Results of measurements on the diffused test objects are described.

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Motion of a System with Varying Damping Subject to Harmonic Force - Analytical Analysis (변화하는 감쇠를 갖는 계가 조화력을 받을 때의 운동 - 이론적 해석)

  • Park, O-Cheol;Lee, Gun-Myung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.898-902
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    • 2006
  • The motion of a system composed of a plate, constant springs and varying dampers is considered when the system is subject to harmonic force. Letting the frequencies of harmonic force and damper variation ${\Large f}_1\;and\;{\Large f}_2$ respectively, the displacement at the center of the plate has the strongest component at frequency ${\Large f}_1$. The angular displacement of the plate has strong components at ${\Large f}_1-{\Large f}_2$ and the natural frequency of the rotational mode of the system. If these two frequencies coincide, the plate oscillates with almost single frequency and a large amplitude. Part of these simulation results are proved analytically.

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A study on the development of an efficient subspace iteration method (부공간축차법의 효율향상을 위한 연구)

  • Lee, Byeong-Chae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.11
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    • pp.1852-1861
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    • 1997
  • An enhanced subspace iteration algorithm has been developed to solve eigenvalue problems reliably and efficiently. Basic subspace iteration algorithm has been improved by eliminating recalculation of converged eigenvectors, using Krylov sequence as initial vectors and incorporating with shifting techniques. The number of iterations and computational time have been considerably reduced when compared with the original one, and reliability for catching copies of the multiple roots has been retained successfully. Further research would be required for mathematical justification of the present method.

The Artistic Thinking and Expressive Characteristics of Installation Art (설치미술의 조형적 사고와 표현특성)

  • 김주미
    • Korean Institute of Interior Design Journal
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    • no.26
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    • pp.104-111
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    • 2001
  • This study deals with the expressive characteristics of Installation Art and their applicability to environmental design, and as such, aims to specify a artistic methods from the contemporary art. What Installation Art is search of in their works is "the state of relationships" which is "to replace the concept of form with that of structure, and the concept of space with that of the environment" that is, the terms of relations in the overall environment of time and space. Installation Art essentially relies on a multiplicity of forms and attitudes leading to projects which positively make use of "spatial-temporal process" to reaffirm and "problematise" their open-endedness manifest in complex contextuality and shifting temporality. This study presents a new interpretation of spatial-temporal dimension, site-specificity, and intermedia art that we find in Installation Art and tries to combine that new artistic insight a with environmental design to provide a basis for integrated art. This study places a great emphasis on the interdisciplinary approaches to the environment we inhabit, which I hope will contribute to generating a greater number of creative possibilities for environmental design.

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A Study on the method to collect Vehicle-Data using Wireless LAN (전동차운행정보수집을 위한 무선랜 활용방안 연구)

  • Ahn Tae-Ki;Lee Ho-Yong;Park Ki-Jun;Kim Gil-Dong
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1459-1461
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    • 2004
  • EMU, Electrical Multiple Unit, stores various information in the computer system installed on the vehicle when train is running. The stored information has to be moved into a computer installed on the ground. The information is used to all kinds of planning concerned EMU, and taken advantage of maintenance with information importantly. IC memory card is used to move the information from vehicle to the ground at present. But this method has many weaknesses from hours and manpower aspect because it spends much time shifting data. So this paper proposes a method to move data as quickly and correctly as possible. We propose the method to collect the information using wireless LAN automatically in this paper. And we carried out data-transfer-test on the real field using wireless LAN to confirm possibility of this method. This paper shows the result of the data-transfer-test.

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Time Dependent Maintenance Models of Bridges (시간의존적 교량유지관리 모델)

  • Yang, Seung Ie
    • Journal of Korean Society of Steel Construction
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    • v.14 no.3
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    • pp.443-452
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    • 2002
  • Construction of highway bridges is almost complete in many countries. Thus, the government and highway agencies are shifting their remaining life span from the viewpoint of system reliability. As such, it is necessary to develop maintenance models based on system reliability concept. In this paper, preventive and essential maintenance models were developed using system reliability and lifetime distribution.

Extension of Range Migration Algorithm for Airborne Single Track Bistatic Spotlight SAR Imaging (하나의 경로를 가진 항공기 탑재형 Bistatic Spotlight SAR 영상형성을 위한 Range Migration Algorithm의 확장)

  • Shin, Hee-Sub;Jeon, Jae-Han;Lim, Jong-Tae
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.165-166
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    • 2008
  • Bistatic spotlight synthetic aperture radar(BSSAR) with single track configuration uses the transmitter and the receiver which travel along the single track such as the leader-follower. For the BSSAR imaging, we modify the range migration algorithm. In time domain, we make the monostatic SAR using shifting of path, Then, in frequency domain, we compensate the separated distance between the scene center and the flight path using the principle of the stationary phase (PSP).

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