• Journal of applied mathematics & informatics
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• v.7 no.2
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• pp.629-640
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• 2000

this paper present an efficient line-drawing algorithm that reduces the amount of space required, Because of its efficiency , this line-drawing algorithm is faster than the Bresenham algorithm or the recursive bisection method. this efficiency was achieved through a new data structure; namely , the modified segment tree (MST). Using the modified segment tree and the distribution rule suggested in this paper, we dra lines without generating the recursive calls used in [3] and without creating the binary operation used in [4]. we also show that line accuracy improves in proportion to the display resolution . In practice, we can significantly improve the algorithm's performance with respect to time and space, This improvement offer an increase in speed, specially with lines at or near horizontal, diagonal. or vertical ; that is, this algorithm requires the time complexity of (n) and the space complexity O(2k+1), where n is the number of pixels and k is a level of the modified segment tree.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.1-8
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• 2009

There are several ways to solve parking problem in the downtown. One of them is to manage parking efficiently, that is, to raise use-efficiency of parking place and to help in the block efficiently, it can prevent disproportion that some parking space is over capacity and the other parking one is under. It causes not only the disproportion of economic efficiency but also the congestion of local road. The precondition to manage parking efficiently is to analyse the parking characteristics. In this paper we build up total D/B by collecting every information about parking space. We developed the Parking Management System by using RFID and Sensor. The efficient Parking Management System is for convenience of drivers and efficient usage of parking space. And this system is also the basic study to be developed as the total Parking Management System by upgrading every information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1362-1365
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized buckling strength of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result optimization achievement repeatedly using statistical orthogonal array of experimental design.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.13-21
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• 2016

Since the direct-gradient (DG) method uses the Shack-Hartmann wave front sensor (SH-WFS), based on the phase-conjugation principle, for atmospheric compensation in free-space optical (FSO) communication, it cannot effectively correct high-order aberrations. While the stochastic parallel gradient descent (SPGD) can compensate the distorted wave front, it requires more calculations, which is sometimes undesirable for an FSO system. A hybrid compensation (HC) method is proposed by properly using the DG method and SPGD algorithm to improve the performance of FSO communication. Simulations show that this method can well compensate wave-front aberrations and upgrade the coupling efficiency with few computations, preferable correction results, and rapid convergence rate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.830-833
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• 2009

Deblocking Filter (DF) is newly introduced into H.264/AVC to remove blocky artifacts. It improves the picture quality and the improved picture is set to the frame buffer for motion compensation. As a result, higher coding efficiency is achieved by DF. However, if the original image has heavily-slanted patterns, DF removes the edges to be kept because it is applied only perpendicularly to the block boundaries. In this paper, we propose Edge Adaptive Deblocking Filter (EADF) which is applied not only for the perpendicular but also for several slanted directions to deal with the problem. Simulation results showed us that EADF was especially effective for the sequence "Foreman" with PSNR gain of 0.04 dB.

• International Journal of High-Rise Buildings
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• v.4 no.2
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• pp.153-160
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• 2015

As the predominant mode of vertical urban development in China, mixed-use complexes provide the optimal case for the research of sustainable and vertical urbanism. This paper reviews three typical mixed-use complexes with various vertical space systems in Shanghai via the combination of field observation, questionnaires and software analysis. It then proceeds to determine which vertical space system is most effective for encouraging sustainable vertical urban development from the perspective of spatial efficiency. Finally, it concludes with an evaluation of the relative capabilities of the design features of a mixed-use complex: to create external dimensional-connections, to create multiple internal connections, and to organize overall composite functions.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.6
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• pp.423-429
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• 2003

On this study. we improved the efficiency applying algorithm that is repeatedly using table of orthogonal array in discrete design space and filling a defect of gradient method in continuous design space. we showed optimal ply angle that maximized 1st natural frequency of CFRP laminated composite plate without a hole and with a hole by each aspect ratio. In the case of CFRP laminated composite plate without a hole, we confirmed the reliance and efficiency of algorithm in comparison with the result of optimization achievement repeatedly using statistical table of orthogonal array of experimental design and the BFGS optimal design method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.255-264
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• 1996

This Paper presents a heuristic algorithm for machine-part group formation considering part production information (Production volume, roution sequence, unit operation time, facility size) in cellular manufacturing logistics system. In general, factory space is restricted within limited size when cells are located. A twofold heuristic algorithm is developed for considering factory space restrictions of located cells. The first phase is a aggregation procedure to minimize inter cell movement for satisfactoring space restriction. The second phase is a rearrangement procedure to maximize line balancing efficiency between machines within the cell and non assigned machine during first phase. Numerical example is presented to verify the efficiency of proposed algorithm.

• Particle and aerosol research
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• v.12 no.4
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• pp.161-168
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• 2016

The purpose of this study is to determine the performance characteristics of the paint particulate and volatile organic compounds(VOCs) simultaneous removal from the spraying paint booth in the laboratory and real site by sticky paint particulate and VOCs simultaneous removal demonstration unit. The sticky paint particulate and VOCs simultaneous removal unit is composed of the horizontal type pleated filter modules and the zig-zag type granular activated carbon packing modules. The test conditions at the laboratory are $50.15g/m^3$ of average paint aerosol concentration and 300 ppm of VOCs concentration which were same as the working conditions of spraying paint booth in the real site. But, the demonstration conditions at the real site are varied according to the working condition of spraying paint booth for the kind of passenger car bodies. The test results at the laboratory obtained that 99% of total particulate collection efficiency at 0.62 m/min of filtration velocity and 84% at 1.77 m/min of filtration velocity. The VOCs removal efficiencies are 97% at $3500hr^{-1}$ of gas hour space velocity and 59% at $10,000hr^{-1}$ of gas hour space velocity. In the real site test, the average removal efficiency of PM10 was measured to be 99.65%, the average removal efficiency of PM2.5 was 99.38%, the average removal efficiency of PM1 was 98.52%, and the average removal efficiency of VOCs was 89%.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2874-2879
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• 2008

The Selective catalytic reduction(SCR) system is a highly-effective device of $NO_x$ reduction for diesel engines. Generally, the ammonia($NH_3$) generated from a liquid urea-water solution is used for the reductant. The ideal ratio of $NH_3$ molecules to $NO_x$ molecules is 1:1 based on $NH_3$ consumption and having $NH_3$ available for reaction of all of the exhaust $NO_x$. However, under the too low and too high temperature condition, the $NO_x$ reduction efficiency becomes lower, due to temperature window. And space velocity also affects to $NO_x$ conversion efficiency. This paper reviews a laboratory study to evaluate the effects of $NO_x$ and $NH_3$ concentrations, gas temperature and space velocity on the $NO_x$ conversion efficiency of the SCR system. The maximum conversion efficiency of $NO_x$ was indicated when the $NH_3$ to $NO_x$ ratio was 1.2 and the space velocity was $60,000\;h^{-1}$. The results of this paper contribute to improve overall $NO_x$ reduction efficiency and $NH_3$ slip.