• Journal of the Korean Society of Mechanical Technology
• /
• v.13 no.4
• /
• pp.15-21
• /
• 2011

The safety at this study is investigated by flow or stress analyses due to configuration or installation direction of fuel tank in the existing CNG bus. In case of the lower ceiling with sharp type, the equivalent stress due to the explosion of fuel tank is less than the type of flat or arc. it becomes safer on passenger. In case of the installation direction of fuel tank in the existing CNG bus, the stress applied on the lower ceiling at transverse direction becomes less than at longitudinal direction. It is more stable on the safety of passenger. The harm on the explosion accident can be prevented by use of the analysis result at this study.

• New & Renewable Energy
• /
• v.16 no.4
• /
• pp.76-82
• /
• 2020

Soiling on the surface of a PV module reduces the amount of light reaching the solar cells, decreasing power performance. The performance of the PV module is generally restored after contaminants on the module surface are washed away by rain, but it accumulates at the bottom of the module owing to the thickness of the module frame, causing an output mismatch on the PV module. Since PV modules are usually installed horizontally or vertically outdoors, soiling can occur at the bottom of the PV module, depending on the installation direction due to external environmental factors. This paper is analyzed the output characteristics of a PV module considering its installation direction and the soiling area. The soiling was simulated to use transparent films with 5% transmittance, and the transmission film was attached to the bottom part of the PV module horizontally and vertically. When the soiling area was 33% of the string at the bottom of the PV module, the power output decreased similarly regardless of installation direction. However, when the soiling area was 66% of the string at the bottom of the PV module, it was confirmed that the output performance decreased sharply when installed vertically rather than horizontally.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.21 no.5
• /
• pp.689-698
• /
• 2019

In tunnel excavation by TBMs, a cutterhead, which practically excavates the ground, is an important part directly affecting net penetration rate. Most of the researches on the cutterhead design that have been carried out until now are on the cutter arrangement. It is difficult to find a study for the effect of the scraper installation direction on TBM excavation although same cutterheads except for direction of the scraper are used in Korea. Therefore, this paper shows how the direction of scraper installation affects shield-TBM excavation. Discrete element method was used to identify the effect of scraper installation direction on shield-TBM excavation. When the scraper installation direction was outward, the amount of particles per unit time flowed into the cutter head opening was smaller than when the scraper installation direction was inward, and more loads were applied to the cutterhead.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.1
• /
• pp.145-151
• /
• 2010

This paper presents the design and implementation of direction controllers by microstep control and dc servo control for material transport system. The perfomances of direction control systems are compared in position responses and motor power consumptions between microstep control of a step motor and dc servo control.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.8 no.4
• /
• pp.345-354
• /
• 2006

During installation of face bolts, they are often deviated from the designed horizontal direction. In this study, a laboratory test and numerical analysis were conducted to examine the change of support effect by them. Also, the number of bolts to be added for achieving the designed support effect was considered. It was verified in this study that the horizontal installation is more effective. Under the test condition of this study, 1.5 bolts/section should be added in the face of which the installation density was 3 bolts/section when the bolts were installed with $R15^{\circ}$ angle from the horizontal position.

• International Journal of Highway Engineering
• /
• v.20 no.1
• /
• pp.127-135
• /
• 2018

PURPOSES : Traffic cameras have been installed to reduce traffic accidents. The effectiveness of traffic cameras has been proved by dozens of studies, but recently questions over its effectiveness have been raised by a series of studies. In this study, the effectiveness of traffic cameras was analyzed with a focus on different road environments. METHODS : The effectiveness of the traffic cameras was analyzed by extracting the occurence frequency before and after camera installation. The effect of reduction was analyzed comprehensively considering the installation position, monitoring direction, and surrounding environment of traffic cameras. RESULTS : The result of this study is as follows. First, the installation of cameras in an area with relatively low accidental traffic was more effective. Secondly, the effect of camera installation on car-to-pedestrian collisions was better than that of car-to-car collisions. Thirdly, accidents tended to occur more frequently when cameras were installed in front of the accident-prone owing to the negative spill-over effect. CONCLUSIONS : The result can be used to guide placement of traffic cameras. Moreover, the installation of cameras with consideration of the road environment is expected to contribute to a reduction in traffic fatalities.

• Journal of the Korean Institute of Rural Architecture
• /
• v.18 no.3
• /
• pp.25-34
• /
• 2016

The purpose of this study is to investigate installation status of information facilities and condition of walking road influencing to psychological safety of walking tourists. For this purpose, four roads for walking tour are selected; the course no. 16 of Jeju Olle Trail, Sarabong Byeoldobong walkway in Jeju and the course no. 8 of Bougil, Gyeongpo Lake walkway in Gangneung. Facilities installed on roads for walking tour are classified into four facilities; safety facility, information facility, amenity facility, local cultural facility. In order to consider installation status of information facilities and condition of walking road influencing to psychological safety of walking tourist, a field experiment was conduced focusing on the course no. 16 of Jeju Olle Trail. Thirteen cases were happened as confusing situation while walking tour. Of the 13 cases, the situation of being lost and wandering on the trail accounted for six cases. In contrast to the expectation that the situation of being lost and wandering would occur only at a crossroads, it is not that such situation took place at specific places like a crossroads or where direction signs were inaccurate. Walking tourists of this field experiment also confronted situations of having lost confidence about continuing the ongoing direction, of having anxiety over walking a walking trail, of feeling discomfort caused by walking and of being offended by uncomfortable or messy areas of walking trial. These confusing situations are happened inappropriate installation of direction sign, so direction sign is needed to install more carefully and detailed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.5
• /
• pp.92-97
• /
• 2011

This paper deals with the improvement of electrode installation for measurement of ground resistance through investigation on the spot in buildings. The investigation was carried out for an earthing terminal board for measurement of ground resistance, installation of auxiliary electrode, etc. The criteria value is set up by measuring method of ground resistance in international standard. In case of inadequate installation of auxiliary electrode, a relative error is analyzed and adequate installation method of auxiliary electrode is proposed. As a consequence, it is necessary to write direction of ground and equipment, and separate auxiliary electrode for measurement of ground resistance in order to minimize measuring error.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.10
• /
• pp.63-68
• /
• 2014

This paper deals with a methodology that applies the time-varying magnetic fields produced by the cloud discharges to find the direction of thunderstorm movement. We investigated the basic performance of the magnetic field measurement system composed of multi-turn loop-type sensors, the differential amplifier and active integrator. As a result, the response characteristics of the magnetic field sensor system to sinusoidal signals was excellent. The frequency bandwidth ranges from about 1 kHz to 500 kHz, the response sensitivity was 0.16mV/nT. In addition, we proposed the algorithm that determines the direction of lightning discharges using the comparison of the output signals of right-angled loop-type magnetic field sensors. The accuracy of the direction finding of lightning discharges is fairly well within the measurement error of less than $5^{\circ}$. The magnetic field measurement system proposed in this work can be used to track the direction of thunderstorm movement.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2002.11a
• /
• pp.243-246
• /
• 2002

We proposed a new spatio-angularly multiplexed holographic memory system using moving windows and double-focusing lens, which can eleminate crosstalk due to two neighboring moving windows(MW) in the vertical direction of the conventional MW holographic memory system and demonstated its feasibility through optical experiments.