• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.475-477
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• 2002

Mobile ad hoc network은 관리나 표준화된 지원 서비스 없이 무선 이동 노드들만으로 구성되는 임시적인 망이다. Mobile ad hoc network에서는 노드들의 이동성으로 인해 각각의 노드들이 경로를 결정하고, 경로가 무효화되었을 때 빠르고 효과적으로 복구하는 것이 중요하다. 본 논문에서는 On-Demand 방식의 대표적인 프로토콜인 AODV에서 경로 설정 과정과 경로 파손이 발생했을 때 경로 재설정 과정을 알아보고, 액티브 경로의 길이가 망의 직경에 가깝게 확장되어 졌을 경우에 경로 설정 과정에서 흡수를 이용해 mark-up 한 노드들과 RREP 전송과정에서 mark-up한 노드에 의한 부분적인 다중 경로를 설정함으로서 보다 효과적이긴 신뢰성 있는 새로운 경로 재설정 기법을 제안한다.

• Asian review of World Histories
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• v.2 no.2
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• pp.217-248
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• 2014

The Aid-India Consortium was organized in 1958 as an international scheme to support the economic development of India, and led by the World Bank. This article reconsiders the economic diplomacy of the Indian Government in the 1950s and 1960s, by paying attention to the interactions between the Indian authorities and the donor countries and institutions, in the context of the Cold War regime, decolonization and economic aid to the newly independent countries. First, it deals with the development of the Aid-India Consortium by considering debates at its annual meetings and the skillful negotiations of the Indian Government and financial authorities. It focuses especially on the leading role of an Indian diplomat and financial expert, B. K. Nehru. The article then tries to reveal an Indian initiative in solving the 'food crises' of 1965-67 through intimate collaboration with the US government and the World Bank, using the framework of the Aid-India Consortium. These attempts lead to a reconsideration of the economic order of Asia in the 1950s and 1960s.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.3
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• pp.243-250
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• 2004

We describe a practical implementation of DVR (Digital Video Recording) system. And we propose a new image compression algorithm, that input video signal is divided into two parts, a moving target and a non-moving background part to achieve efficient compression of image sequences. This algorithm reorganizes a target area and a back-ground area by use of Macro Block(MB) unit on encoding scheme. The proposed algorithm allows high quality image reconstruction at low bit rates.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1422-1426
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• 1987

In this paper, an adaptive DPCM scheme is presented for encoding monochrome images with easy hardware implementation at a transmission rate of exactly 1 bit/pel. The system is mainly composed of a compensated mean predictor and an adaptive two-level quantizer with backward estimation. In this system, the predictor is a sort of two-dimensional ARMA predictor in which a moving-average part is added to the conventional mean predictor. The quantizer adapts to the local statistics of its input without overhead information. To reduce annoying granular noise in the reconstructed image, Lee filter is used after reconstruction in the receiver.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.223-230
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• 2001

This paper proposes a new contour detection method and adaptive reconstruction scheme for the cylindrical organs, such as blood vessels or arteries. Furthermore, we present java-based navigation controller which has been built to examine the inside of cylindrical objects. Tn the preprocessing procedure, a few preprocessing image filters are applied in order to remove unwanted artifacts from the medical images and to estimate threshold values for the object of interest. We define a context-free grammar, which is proper fur properties of contours of cylindrical objects. In the next procedure, we extract contours using advanced radial gradient method and represent contours as context-free grammar derivation trees. We build polygons between two contours efficiently by traversing the derivations trees of the contours. We fly through the reconstructed virtual models using java-based navigation controller and VRML viewer.

• 한국전산유체공학회:학술대회논문집
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• 1998.11a
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• pp.48-54
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• 1998

Three-dimensional incompressible Navier-Stokes equations have been solved by the node-centered finite volume method with unstructured hybrid grids. The pressure-velocity coupling is handled by the artificial compressibility algorithm and convective fluxes are obtained by Roe's flux difference splitting scheme with linear reconstruction of the solutions. Euler implicit method is used for time-integration. The viscous terms are discretised in a manner to handle any kind of grids such as tetrahedra, prisms, pyramids, hexahedra, or mixed-element grid. The numerical efficiency and accuracy of the present method is critically evaluated for several example problems.

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.452-455
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• 1995

Various physical limitations which intrinsically exist in the manipulator control system, for example kinematic limits and torque limit, cause some undesirable effects. Specifically, when one or more actuators are saturated the expected control performance can not be anticipated and in some cases it induces instability of the system. The effect of torque limit, especially for redundant manipulators, is studied in this article, and an analytic method to reconstruct the control input using the redundancy is proposed based on the kinematically decomposed modeling of redundant manipulators. It results to no degradation of the output motion closed-loop dynamics at the cost of the least degradation of the null motion closed-loop dynamics. Numerical simulations help to verify the advantages of the proposed scheme.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1150-1157
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• 1988

In this paper, the reconstruction of complex permittivity distribution on a rectangular cross section of inhomogeneous dielectric cylinders is performed by employing the spectral inverse scattering scheme presented in the part I of these companion papers. Numerical simulations provide the superresolution to the permitivity profiles nearly regardless of the measurement locations of the scattered field and the permittivity distributions on the cross section.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.958-961
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• 1999

A new image encoding and identification scheme is proposed for security verification by using CGH(computer generated hologram), random phase mask, and correlation technique. The encrypted image, which is attached to the security product, is made by multiplying QPH(quadratic phase hologram) using SA(simulated annealing) algorithm with a random phase function. The random phase function plays a role of key when the encrypted image is decrypted. The encrypted image could be optically recovered by 2-f system and automatically verified for personal identification. Simulation results show the proposed method cand be used for the reconstruction and the recognition of the encrypted. Image.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.106-114
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• 1994

A new merging technique is adopted for combining rectangular parallelepipes produced by 2-D rectangular code into more intuitive 30D volume elements. Rectangular parallelepiped codes (RP codes) can be used in volume-based representation of a three-dimensional object. We proposed more regularity-conserving 2-D rectangular coding scheme to merge rectangular cells represented by RP codes in three-dimensional space. After being constructed from modified 2-D rectangular code, 3-D RP codes are merged in the two orthogonal directions using new merging algorithm. The shape of merged 3-D object reconstructed by proposed algorithm is shown to be much closer to the original object shape than that of conventional RP codes. The storage requirement of merged object can be also reduced.