• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.188-196
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• 2007

In this paper we propose an efficient offset curve generation algorithm for open and closed 2D point sequence curve(PS curve) with line segments in the plane. One of the most difficult problems of offset generation is the loop intersection problem caused by the interference of offset curve segments. We propose an algorithm which removes global as well as local intersection loop without making an intermediate offset curve by forward tracing of tangential circle. Experiment in computer sewing machine shows that proposed method is very useful and simple.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.2
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• pp.269-282
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• 1998

The visual preference of interiors focusing on lobbies was investigated as a function of six predictor variable on the base of the Informational Approach: complexity, coherence, mystery, spaciousness, brightness, plant. The Common Fcator Analysis of preference ratings yielded six common factors which helped to account for 22.3 percent of the variance in preference response to the scene. Among these factors, the factor defined as 'bright with many plants' was the most preferred and the factor defined as 'simple and closed' was the least preferred. The environmental attributes reflected in six groups of scenes were colour, resting place, window and the six predictors. In the commercial building scenes, complexity, spaciousness, coherence, brightness and mystery out of six predictors accounted for 74 percent of preference variance as the significant contributors. In the business building scenes, three predictors which are brightness, complexity, spaciousness accounted for 84 percent of preference variance. 'The amount of plant' not only influenced the preference indirectly through the intervening variable, complexity, but also was moderately correlated with brightness. The overall pattern of the resulted confirmed the usefulness of the Informational Approach to predict the preference in interiors focusing on lobbies.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1602-1605
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• 1987

This paper describes the isolated word recognition using binary patterns denoting the presence or absence of a local peak at a particular channel. In closed test, 81.3% and 76.8% of correct recognition rate were achieved in case of 10 males and 10 females with each 1588 test samples.

• Transactions of Materials Processing
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• v.3 no.2
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• pp.202-214
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• 1994

An upper bound elemental technique(UBET) is applied to predict the forging load and die-cavity filling for non-axisymmetric ring forging. In order to analyze the process easily, it is suggested that the finial product is divided into three different deformation regions. That is axisymmetric part in corner, lateral plane-strain part and shear deformation on boundaries between them. the place-strain and axisymmetric part are combinded by building block method. Also the total energy is computered through combination of three deformation part. Experiments have been carried out with pure plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agreement with the experimental results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.94-102
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• 2011

In this paper, a novel drowsiness detection algorithm using eye-blink pattern is proposed. The proposed drowsiness detection model using finite automata makes it easy to detect eye-blink, drowsiness and sleep by checking the number of input symbols standing for closed eye state only. Also it increases the accuracy by taking vertical projection histogram after locating the eye region using the feature of horizontal projection histogram, and minimizes the external effects such as eyebrows or black-framed glasses. Experimental results in eye-blinks detection using the JZU eye-blink database show that our approach achieves more than 93% precision and high performance.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.489-492
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• 2010

This paper proposes the planar-type modified monopole antennas of loop structure. This antenna has an opened center of a conventional closed loop structure with an inside-folded terminal of the loop microstrip line. The size of the proposed antenna was minimized by folding the end of the loop. Also, the reactance value has been minimized by increasing capacitances between the coupled microstrip line. Therefore the proposed antenna has been compacted to about 20% from a conventional loop antenna and has increased its efficiency. The proposed antennas have an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6~3.56 GHz) with VSWR$\leq$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9%. These properties could satisfy the S-DMB band.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.2
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• pp.50-57
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• 2004

Mercurous Bromide ($Hg_2Br_2$) crystals hold promise for many acousto-optic and opto-electronic applications. This material is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects of solutal convection on the crystal growth rate in a horizontal configuration for diffusive-convection conditions and purely diffusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factor of one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 $g_O$ the growth rate pattern exhibits relatively flat which is intimately related to diffusion-dominated processes. The growth rate nonuniformity is regardless of aspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in the gravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 by a factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.10
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• pp.120-131
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• 1997

This paper prsents a new method that automatically recognizes the dimension lines (consisting of shape lines, tail lines and extension lines) from the mechanical drawings. In the proposed method, the object and closed-loop symbols are separated from the character-free drawings. Then the object lines and interpretation lines are vectorized by using several techniques such as thinning, line-vectorization, and vector-clustering. Finally, after recognizing arrowheads by using pattern matching, we recognize dimension lines from interpretation lines by using arrohead's directional vector and centroid. By using the methods of geometric modeling and mathematical operation, the proposed method readility recognizes the dimension lines from complex drawings. Experimental resuls are presented, which are obtained by applying the proposed method to drawings drawn in compliance with the KS drafting standard.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1211-1219
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• 1995

An upper bound elemental technique (UBET) program has been developed to analyze forging load, die-cavity filling and effective strain distribution for flash and flashless forgings. The simulation for flash and flashless forgings are applied axisy mmetric and plane-strain closed-die forging with rib-web type cavity. Inverse triangular and inverse trapezoidal elements are used to analyze flashless forging. The analysis is described for merit of flashless precision forging. Experiments have been carried out with pure plasticine billets at room temperature. Theoretical predictions of the forging load and the flow pattern are in good agreement with experimental results.

• Journal of ILASS-Korea
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• v.15 no.3
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• pp.109-114
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• 2010

The implementation of gelled propellants systems offers high performance, energy management of liquid propulsion, storability, and high density impulse of solid propulsion. The present study focused on the macroscopic spray characteristics of liquid sheets formed by triplet impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are compared to experiments conducted on spray images which formed by triplet impinging jets concerning with airassist effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure and high pressure, closed rim pattern shape appeared by polymeric effect from molecular force and showed inactive atomization characteristics, because of extensional viscosity related by restriction of atomization process and breakup time delay of turbulence transition. As increasing mass flow rate of the air(increasing GAR), spray breakup level is also increased.