• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.6
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• pp.408-413
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• 2015

Road lighting has emerged in importance as an essential system to secure safety and visibility for drivers and pedestrians. According to the Road Lighting Standards (KS A 3701), the luminance uniformity (U0) should be 0.4, the luminance uniformity for lanes (UI) should be 0.5, and a threshold increment (TI) of 10% should be satisfied. In this study, we conducted simulations using the Relux program in which the secondary optical lens was applied to a 21 W engine. Ten LED engines were installed on a two-way four-lane road, and the simulation result satisfied the requirements with U0 0.47, UI 0.63 and TI 8%. The U0, UI, and TI were compared with the angle of the LED streetlight varied in the range of $9^{\circ}{\sim}15^{\circ}$ with $0.5^{\circ}$ intervals. The range was selected as ${\pm}25%$ of the standard inclination angle of $12^{\circ}$ according to the Road Lighting Standard. The U0 was high and the UI and TI were low when the tilting angle was in the range of $9.5^{\circ}{\sim}10.5^{\circ}$. Consequently, an optimum-design of lighting distribution was obtained for the concrete two-way four-lane road when the inclination angle was $9^{\circ}$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.7-13
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• 2013

There has been a need for the systematic evaluation of the economic efficiency between conventional fluorescent lamp lighting systems that have been used in tunnels and LED lighting systems. This study has evaluated basic tunnel lighting between the conventional fluorescent lighting systems and the LED lighting system using the evaluation tool of tunnel lighting by Life Cycle Cost (LCC) and using the economic efficiency evaluation method. In addition, the unit discount rate of the LED lighting system and the estimated increase in the price of electricity have made the estimated cost of LCC the same if two luminaires were used in the basic part of the tunnel.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.47-51
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• 2000

This report compares illuminance of formula with the one of the Lightscape which is lighting simulation system, and applied IES file to the Lightscape by angles and coordinate. As a result of correct solution in comparison, we got a satisfactory result from this study. We effectively hope to make the road lighting calculations through the collection and preparation for the lighting data in detail.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.429-436
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• 2013

In this study, we researched a pendant-type aspherical optical system, which could be applied to street lighting and security lighting in Europe. The goal of this research was eco-friendly artificial lighting that could be used for the one-to-one replacement of ordinary lighting. LED lighting was miniaturized by using one COB LED Module and one aspherical optical system, which could control the luminosity of the LED. Through the aspherical optical system, the light distribution angle could be controlled in a range of $140^{\circ}$ for the X-axis and $40^{\circ}$ for the Y-axis. This means that this optical system is appropriate for catenary-type lighting, which is widely used in Europe on both narrow and broad roads. The performance was determined using a lighting simulation program. This lighting system simulation showed that road rates M4 and M5 could be satisfied, with the condition of a 13-m height and 50-m distance (U0 and TI). The simulation program estimated that light pollution, which disturbs sleep, could beeliminated in the European streetlight case. Determining methods for the light distribution control, performance, and optimal lighting setup conditions is very important to prevent light pollution. Moreover, the initial step of developing the lighting system design and post management will require an effort with much analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.5
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• pp.385-393
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• 2011

As the economic growth achieved and the straight road was increased. so, the tunnel built more than before. In these days, lighting of tunnel entrance is important for safety and comfortable driving. Most of the tunnel lighting depend on artificial lighting and they use a lot of energy. In this paper, as a research for illumination improvement and saving energy at tunnel, reflecting mirror system is suggested. The performance of the system was evaluated with respect to various aspects. By applying a reflective mirror system, tunnel lighting and environment can be improved. This study is a preliminary study for developing a system to save energy of tunnel artificial lighting.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.395-399
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• 2006

A method to recognize unpaved road region using a 3D depth measurement system is proposed for mobile robots. For autonomous maneuvering of mobile robots, recognition of obstacles or recognition of road region is the essential task. In this paper, the 3D depth measurement system which is composed of a rotating mirror, a line laser and mono-camera is employed to detect depth, where the laser light is reflected by the mirror and projected to the scene objects whose locations are to be determined. The obtained depth information is converted into an image. Such depth images of the road region represent even and plane while that of off-road region is irregular or textured. Therefore, the problem falls into a texture identification problem. Road region is detected employing a simple spatial differentiation technique to detect the plain textured area. Identification results of the diverse situation of unpaved trail are included in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.1
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• pp.1-6
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• 2008

It is important to grasp the accurate lighting level for appropriate maintenance of the road lighting equipment. It is developed 2 division illuminance measurement systems. This system has a small size and no need to block the way and achieves the speedy measurement and high accuracy data in automatically measurement. As a result, this system can save expense and time to measure roadway lighting.

• International Journal of Highway Engineering
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• v.15 no.3
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• pp.127-135
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• 2013

PURPOSES : The purpose of this study is development of automatic equipment to measure the road water-reservoir which can be one of factors for road traffic safety inspection and its application to safety analysis. METHODS : The scopes of this study are the examination of the riskiness and location of road water-reservoir through literature review, development of appropriate sensor and automatic equipment to survey the road water-reservoir and evaluation of field application. RESULTS: The laser lighting and IR camera were selected to develop the equipment. It was found from the field calibration that there is a high correlation between rutting and road water-reservoir and road water-reservoir caused by rutting can be correctly calculated. About 20.2km of national highway were inspected for case study and field application. It was found from correlation of traffic incident that 2.08km of the latent length for water-reservoir which is related to 12 traffic incidents were analyzed. CONCLUSIONS : This technique can be utilized evaluation method for road condition such as road water-reservoir for conventional evaluation system such as road traffic safety assessment and safety analysis and it can be use to new evaluation system to apply various road condition and traffic condition.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.497-504
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• 2013

This research uses numerical analysis to examine the tunnel portal landscape affecting the brightness level of interior lighting when designing lights for road tunnels through the L20 method. In order to extract the brightness recognition per form of a tunnel entrance and to evaluate the effects of the characteristics of the materials of facilities near a tunnel portal, brightness analysis was conducted by filming brightness on a video photometer called Hi-land Elf System, and a surface brightness photometer called LMK Mobile Advanced. Tunnels in Korea are mostly distributed in mountain areas; thus, the ratio occupied by the sky, which has the highest brightness within the angle of L20, is close to zero, while most of the ratio was occupied by brightness by the area near the tunnel entrance or road surface. However, for a tunnel portal retaing wall, which allows the width of a tunnel entrance to seem wider within the L20 angle, appeared to be have higher brightness compared to nearby areas or the surface, which is an element increasing the tunnel portal brightness within the tunnel, and the road facilities near the tunnel portal appeared to have an effect on the brightness as well. Thus, when designing tunnel lights based on brightness, the form of the tunnel entrance and the area width, material, and color of areas near the tunnel portal appeared to affect outside brightness and become an element affecting the establishment of the brightness level of the interior lights of tunnels. Consequently, reviewing such matters is a prerequisite when designing tunnel portal landscape.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.04c
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• pp.6-9
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• 2008

A 3D depth measurement system is proposed for mobile vehicles. Depth measurement system which is composed of a rotating mirror, a line laser and mono-camera is employed to detect depth, where the laser light is reflected by the mirror and projected to- the scene objects whose locations are to be determined. The obtained depth information is converted into an image. Such depth images of the road region represent even and plane while that of off-road region is irregular or textured. Road region is detected employing a simple spatial differentiation technique to detect the plain textured area. Identification results of the diverse situation of Non-linear trail are included in this paper.