• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.366-366
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• 2004

• Explosives and Blasting
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• v.23 no.4
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• pp.19-29
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• 2005

Blasting design methods applied in Korea were originally made for foreign rock conditions and blasting environments. Therefore, it has not been fully fitted to the Korean rock renditions. Since 1998, several studies for the automated pattern design of tunnel blasting have been carried out. As the result, a new blasting design method which can settle the problems was developed. Through it is more complex than prior method, it call provide a variety of advantages for us. Through the method, it is possible to vary charge weight according to the changing advance. It ran also be applied to the various design for contour holes. In this study, the newly developed method is introduced.

• Fire Science and Engineering
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• v.22 no.5
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• pp.1-8
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• 2008

The study is to perform numerical analysis of train fire characteristics in an underground subway tunnel, depending the different locations of ventilation facility. To study the characteristics of train fire, two kinds of worst-case scenarios are selected, based on escape distance, escape time, and fire zone, and trends and thermal environments of tunnel are analyzed by changing the locations of ventilation facility for times. Fire characteristics is calculated by using FLUENT v.6.3.26, and turbulent flow is calculated by using the standard k-${\varepsilon}$ model. The numerical results show distribution of carbon monoxide concentration, temperature, and velocity. The results of this study will contribute to building the most suitable ventilation systems when designing subway stations and tunnels.

• ETRI Journal
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• v.43 no.3
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• pp.377-388
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• 2021

Owing to the difficulties associated with conducting millimeter-wave (mmWave) field measurements, especially in high-speed train (HST) environments, most propagation channels for mmWave HST have been studied using methods based on simulation rather than measurement. In this study, considering a linear cell layout in which base stations are installed along a railway, measurements were performed at 28 GHz with a speed up to 170 km/h in two prevalent HST scenarios: viaduct and tunnel scenarios. By observing the channel impulse responses, we could identify single- and double-bounced multipath components (MPCs) caused by railway static structures such as overhead line equipment. These MPCs affect the delay spread and Doppler characteristics significantly. Moreover, we observed distinct path loss behaviors for the two scenarios, although both are considered line-of-sight (LoS) scenarios. In the tunnel scenario, the path loss exponent (PLE) is 1.3 owing to the waveguide effect, which indicates that the path loss is almost constant with respect to distance. However, the LoS PLE in the viaduct scenario is 2.46, which is slightly higher than the free-space loss.

• Journal of Biosystems Engineering
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• v.21 no.4
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• pp.429-435
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• 1996

A wind tunnel consisting of two air flow conditioners with polycarbonate pipes, a plant growth room, a suction fan and fan controller, and fluorescent lamps, was designed to investigate the interactions between the growth of plug seedlings under artificial light and their Physical environments. Light transmissivities in the plant growth room based on the photosynthetic photon flux density and photosynthetically active radiation was appeared to be 96.3% and 96.8%, respectively. Measurement showed a uniformity in the vertical profiles of air current speed at the middle and rear regions of plug trays in wind tunnel. This result indicated that the development of a wind tunnel based on the design criteria of the American Society of Mechanical Engineers was adequate. Air current speed inside the plug stand was significantly decreased due to the resistance by the leaves of plug seedlings and boundary layer developed over and below the plug stand. Driving force to facilitate the diffusion of gas inside the plug stand might be regarded as extremely low. Aerodynamic characteristics above the plug stand under artificial light were investigated. As the air current speed increased, zero plane displacement decreased but roughness length and frictional velocity increased. Zero plane displacement linearly increased with the average height of plug seedlings. The wind tunnel developed in this study would be useful to investigate the effects of air current speed on the microclimate over and inside the plug stand and to collect basic data for a large-scale plug production under artificial light in a semi-closed ecosystem.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.4
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• pp.59-70
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• 2008

In this paper, we proposed image processing technique for automatic real-time fire and smoke detection in tunnel environment. To avoid the large scale of damage of fire occurred in variety environments, it is purposeful to propose many studies to minimize and to discover the incident as fast as possible. But we need new specific algorithm because tunnel environment is quite different and it is difficult to apply previous fire detection algorithm to tunnel environment. Therefore, in this paper, we proposed specific algorithm which can be applied in tunnel environment. To minimize false detection in tunnel we used color and motion information. And it is possible to detect exact position in early stage with detection, test, verification procedures. In addition, by comparing properties of each algorithm throughout experiment, we have proved the validity and efficiency of proposed algorithm.

• Journal of the Korean Society of Safety
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• v.30 no.6
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• pp.122-131
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• 2015

Recently, starting with the deep underground road construction plan in Seobu Expressway, Korea, there area many studies on deep underground roads to be newly built. However, there is an extreme lack of safety standards, which does not consider traffic conditions and road driving characteristics. Therefore, this study reviewed safety elements to reflect in the deep underground road planning by analyzing driving stability of longitudinal tunnels with road environments, which resemble deep underground roads. For comprehensive analysis, the characteristics and causes of the accidents that have occurred in seven longitudinal tunnels with a length of 2km or over in Gangwon area, were collected. Specifically, geometric structures and facilities of each tunnel were investigated. Also, the present state of facility installation and the changes in driving speed of vehicles passing through each tunnel were observed to analyze the causes for the traffic accidents in each tunnel and accident reduction alternatives. It was revealed that the most frequent accidents in the tunnels resulted from the changes of traffic flow due to the abrupt speed reduction of forward vehicles, or the failure in speed control of following vehicles during the traffic congestion situation. Moreover, installing facilities such as plane and longitudinal curves, median strips and marginal strips seem to induce consistent driving speed. These results mean that for accident prevention, speed management must be preceded and there is a need to develop and introduce safety facilities actively to control the driving flow of forward and following vehicles.

• Journal of computational fluids engineering
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• v.20 no.4
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• pp.28-35
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• 2015

BARAM system that means 'wind' in Korean has been established as a virtual wind tunnel system for aircraft design. Its aim is to provide researchers with easy-to-use, production-level environment for all stages of CFD simulation. To cope with this goal an integrated environment with a set of CFD solvers is developed and coupled with an highly-efficient visualization software. BARAM has three improvements comparing with previous CFD simulation environments. First, it provides a new automatic mesh generation method for structured and unstructured grid. Second, it also provides real-time visualization for massive CFD data set. Third, it includes more high-fidelity CFD solvers than commercial solvers.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.153-158
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• 2008

Vibrating-wire strain gauges are widely used for the tunnel instrumentation because of the long-term stability at humid environments. Domestic strain gauges are mainly used in Korea due to the high cost of the foreign strain gauges. The credibility of the domestic strain gauges is not properly proven even though strain gauges produced by many different companies are available in the markets. The purpose of this paper is to investigate the credibility of the 2.5" strain gauges by using a laboratory compression test.

• Journal of Korean Medicine Rehabilitation
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• v.32 no.1
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• pp.21-36
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• 2022

Objectives The purpose of this study is to investigate the research trend of Korean traditional medicine for musculoskeletal disorders related to wrist and hand under Korean healthcare facilities. Methods We collected data from search engines for research including foreign and domestic online database using the keywords ligament tendon, wrist sprain, tendinitis, trigger finger, carpal tunnel, ganglion cyst, de Quervain's and Raynaud. Results A total of 45 articles were about ligament tendon, wrist sprain, tendinitis, tenosynovitis, trigger finger, carpal tunnel syndrome, ganglion cyst, de Quervain's tenosynovitis and Raynaud disease. Out of 45 articles, 20 articles were about carpal tunnel syndrome and the most commonly used measurement was visual analog scale. Conclusions This study shows the research trend of musculoskeletal disorders related with the wrist and hand. Through the collected data, the treatment methods and specific information of treatments were organized. This study can be used in clinical environments and will contribute for further study in musculoskeletal disorders related with the wrist and hand.