• International Journal of Computer Science & Network Security
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• v.22 no.11
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• pp.163-171
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• 2022

A conceptual model represents an understanding of a system that is going to be developed, which in this research, a driving simulation software to study driver behavior at signalised intersections. Therefore, video observation was conducted to examine driver compliance behaviour within the dilemma zone at signalised intersection, pertaining to driver's distance from the stop line during yellow light interval. The video was analysed using Thematic Analysis and the data extracted from it was analysed using Chi-Square Independent Test. The Thematic Analysis revealed two major themes which were traffic situation and driver compliance behaviour. Traffic situation is defined as traffic surrounding the driver, such as no car in front and behind, car in front, and car behind. Meanwhile, the Chi-Square Test result indicates that within the dilemma zone, there was a significant relationship between driver compliance behaviour and driver's distance from the stop line during yellow light interval. The closer the drivers were to the stop line, the more likely they were going to comply. In contrast, drivers showed higher noncompliant behavior when further away from stop line. This finding could help us in the development of conceptual model of driving simulation with purpose of studying driver behavior.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.2
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• pp.154-160
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• 2012

Recently, development of technologies for autonomous vehicles has been actively carried out. This paper proposes a computer vision system to recognize lanes, crosswalks, and stop lines for autonomous vehicles. This vision system first recognizes lanes required for autonomous driving using the RANSAC algorithm and the Kalman filter, and changes the viewpoint from the perspective-angle view of the street to the top-view using the fact that the lanes are parallel. Then in the reconstructed top-view image this system recognizes a crosswalk based on its geometrical characteristics and searches for a stop line within a region of interest in front of the recognized crosswalk. Experimental results show excellent performance of the proposed vision system in recognizing lanes, crosswalks, and stop lines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.97-103
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• 2000

In this paper band-stop filters that reject the undesired 3th and/or 5th harmonics generated from high frequency generator are analyzed using equivalent circuit concept, and optimized using iterative optimization algorithm. The length of the band-stop filter is setup initially a quarter of a wavelength of the harmonic, but initial filter structure is exactly unable to cutoff the harmonics because of the fringing effect at the discontinuous boundary. To reduce the mismatch between the cutoff frequency and the harmonics, iterative LMA(Levenberg-Marquardt Algorithm) is introduced and band-stop filters in coaxial line are optimized.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6022-6026
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• 2012

This article presents a band-stop filter (BSF) by using a periodic structure property of frequency selective surfaces (FSSs) embedded in a microstrip transmission line. The proposed BSF is designed with FSS unit cells modifying the cross-loop slots. The BSF is interpreted with an equivalent circuit model and a dispersion diagram. The center frequency (fo) of the BSF is 6.6GHz. Proposed filter increases the number of unit cell. As a result, 3dB bandwidth is wider and insertion loss is reduced. Also, Facbricated BSF exhibits uniplanar geometry, simple fabrication.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1678-1684
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• 2007

Platform Screen Door(PSD) has been installed in train manual operation section(ATS/ATC) by SeoulMetro since 2005. PSDs are now operating at 17 stations in SeoulMetro lines. As a result, it increases the safety of passenger, makes a comfortable platform and saves the energy of air conditioning. For PSD operation, train shall stop within 600mm of the train stop reference point. In train manual operation section, the detection system of train position is required to notify the train driver of train position and to ensure the condition that train stops the correct position for PSD operation. To detect the train stop position, the optical sensor shall be installed at platform. However, in case of SeoulMetro lines, the detection criterions of the train correct position stop are different because of using various types of trains which have different size and shape of front cars. In this paper, to solve this problem, the precise detection algorithm of the train stop at the correct position is used, and Laser distance measure sensor is introduced to notify the distance form the reference point of the train correct stop to train driver. This system has been applying to Seoul Metro line total.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.133-134
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• 2015

최근 전자기술이 발달함에 따라, 전자기기의 집적도가 높아지고 있으며, 그에 따라 전자기적 간섭(Electromagnetic Interference)이 큰 문제로 대두되고 있다. 특히, 집적도가 높은 스마트 기기(Smart Device)의 AP(Applicaton Processor)의 경우, 여러 기능을 수행하는 부품이 집적된 SOC(System On Chip)이기 때문에, 전자기적 간섭에 더 민감할 수 있다. 더불어 LTE(Long Term Evolution)을 무선통신으로 이용하는 다양한 주파수대에서 전자기적 간섭은 어플리케이션 및 전자기기의 오작동을 초래할 수 있다. 이를 해결하기 위하여 본 논문에서는 칩패캐지 레벨의 Meander 구조의 기존 필터(Filter)가 가진 문제점을 해결한 구조를 설계하여 3차원 상의 전자장 시뮬레이션을 수행하였다. 또한, 칩의 내성(Immunity)이 취약한 여러 주파수 범위를 차단할 수 있는 이 중 대역차단 필터(Dual Band Stop Filter)를 Meader Line구조를 단순하게 만들어 설계하고 그에 따른 결과를 분석하였다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.810-813
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• 2003

The present headway on KNR(Korea National Railway) lines varies from 6 to 10 minutes depending on the each line and by the operation of High Speed line in 2004, the bottleneck would be expected within a few sections such as Daejeon-Daejeon shunting yard which will be the common mute between KTX(Korea Train Express) and conventional trains. Therefore, KNR would like to reduce the headway of the all lines by 4 minutes with the implementation of ERTMS/ETCS on-board system. Where ETCS(European Train Control system), the subsystem of ERTMS, is Automatic Train Protection system for safety train running. This study will be analyze expected braking distance and running time depending on characteristics of conventional passenger and freight trains and high speed train will be operated within electrified conventional line for comparing the headways of ATS(Automatic Train Stop) system and ETRMS/ETCS system within the Daejeon-Daejeon shunting yard section.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.78-81
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• 2000

A new type low-pass filter design method based on a coupled line and transmission line theory is proposed to suppress harmonics by attenuation poles in the stop band The design formula are derived using the equivalent circuit of a coupled transmission line. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range and low insertion loss. The seventh-order low-pass filter designed by present method Ins a cutoff frequency of 0.9 GHz with a 0.01 dB ripple level. The coupled line type low-pass filter with stripline configuration was fabricated by using a high-temperature superconducting (HTS ; $YBa_2Cu_3O_{7-x}$) thin film on MgO(100) substrate. Since the HTS coupled line type low-pass filter was proposed with five attenuation poles in stop band such as 1.8, 2.5, 4, 5.5, 62 GHz. The fabricated low-pass filter has improved the attenuation characteristics up to seven times of the cutoff frequency Bemuse of good rejection of the spurious signals and harmonics, our low-pass filter is applicable to mobile base station systems such as cellular, personal communication systems and international mobile telecommunication(IMT)-2000 systems.

• The KSFM Journal of Fluid Machinery
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• v.15 no.6
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• pp.70-76
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• 2012

Recently, because people are taking a great interest in the water supply system and the related facilities are getting larger, the surge suppression is very important problem. The waterhammer occurs when the pumps are started or stoped for operation or tripped due to the power failure. As the waterhammer problems as a result of the pump power failure were very serious, these situations were carefully investigated. Accordingly, we carried out both numerical simulations and field tests to confirm the safety of Juam intake pumping station in which had the in-line pumps. In this paper, it was reviewed that the water supply system has the reliability on the pressure surge, in case the air chambers were installed at both the inlet and the oulet of the in-line pumping station. From the numerical simulations, we found that negative pressure occurred at the inlet disappeared and high pressure occurred at the outlet reduced due to the air chambers. And these results of numerical simulations verified by the field tests. The field tests carried out in case of normal start, normal stop, one and two of pumps emergency stop. By results of simulations and field tests, we are sure that Juam intake pumping station in which have the air chambers is safe for the waterhammer. In addition, we suggested the operation methods of facilities for safe maintenance of the pumping station.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.217-225
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• 2009

The study on the left turning trajectory has not done many times in Korea. Because of this, there are a lot of intersections built without considering on turning trajectory of vehicles, in Korea, and we can see many conflicts, reduced capacity of turn, especially at small intersections. Even if left turn trajectory is designed well, it is not easy to mark exactly on the pavement according to the turn trajectory. This study suggests "drop Islands" which can be seen in Europe, and is introduced in Korea recently, to solve the problems of conflicts and reduced capacity of turning. It suggests a table of location of the stop line so that the engineers who design the intersection design appropriate left turn trajectory and marking of the stop line and turn trajectory is done more exactly. To evaluate the effect of "drop island", two intersections with and without drop island were compared on the turnning radii and location of stop line. Construction of "drop island" can increase the capacity of intersection and safety without additional land and construction expenses.