• 베이커리
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• no.10 s.315
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• pp.114-115
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• 1994

• Journal of Korean Society of Transportation
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• v.19 no.2
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• pp.73-73
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• 2001

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.192-193
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• 2001

높은 파장 선택도를 가지고 광신호를 제어하는 광섬유격자는 단주기 격자, 장주기 격자, 첩 격자 등이 있는데 이러한 격자의 제작 기술은 여러 응용분야에서 활용도 높은 소자를 제작하는 데 이용되어져 왔다. 본 논문에서는, 주어진 반사 파장 내에 매우 좁은 선폭의 여러 투과 스펙트럼 밴드를 가지며 그 응용성이 다양한 격자 제작을 목표로 이미 수행되어진 위상천이 격자의 시뮬레이션[1]을 토대로 $\pi$위상천이 격자를 제작하였다. (중략)

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.9
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• pp.7-14
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• 2000

This paper examines the constraints imposed in the usage of the conventional two-mode coupling model in the context of a cascaded long-period fiber grating and presents a set of approximate conditions that must be satisfied for the model to be applicable in the analysis of such a structure. Numerical examples based on the guidelines are provided for a set of realistic grating parameters and their practical implications on the allowed grating period variations for a given bandwidth are discussed.

• Journal of ILASS-Korea
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• v.24 no.3
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• pp.105-113
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• 2019

In this paper, a study of Urea-SCR System for Dosing Injector for responding to enhanced environmental regulations has been conducted. There is a limit to the experimental approach due to the structural characteristics of the injector. In order to overcome this problem, The analysis was performed assuming unsteady turbulent flow through computational fluid analysis and the internal flow characteristics of the injector were analyzed. By changing the nozzle shape of the injector, the performance factors of the swirl injector by shape were selected and compared. The design parameters were modified by changing the diameter of the nozzle at a constant ratio compared to the base model. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. The Conv. model to which the taper was applied showed the dominance in mass flow rate, discharge coefficient and swirl because of the smooth fluid flow by shape. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. As a result of the comparison coefficient derivation with those performance parameters for comparing the performance of the model-specific injector, the Conv-140 model with the nozzle diameter expanded by 140% showed the best value of the comparison coefficient.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.103-108
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• 2004

The motivation of this study comes from the problem recognition that the headway of passing vehicle in signalized intersections can not be merely determined by departing sequence. Traffic speed and headway data of passing vehicles in signalized intersection have been obtained by using magnetic detectors(NC 97) and detecting program, and the data was analyzed. Without special treatment, the model established on passing behavior of vehicles was meaningless from statistical view point. Hence, special treatments such as filtering (upper 85% offensive driver driven vehicle's) and log scaling of data were carried on. With this new data, meaningful model (where coefficient of determination is 0.91) was established. This model explained the fact that vehicle headway in signalized intersection is affected by speed and headway of previous vehicle and speed of itself.