• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 하계종합학술발표회논문초록집
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• pp.366-366
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• 2004

• 화약ㆍ발파
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• 제23권4호
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• pp.19-29
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• 2005

국내에서 발파설계에 적용하고 있는 수식은 외국의 암반조건과 발파환경에 맞게 만들어진 것으로써 암질과 현장조건이 상이한 국내에서는 잘 맞지 않거나 발파패턴의 자동설계에도 적절하지 않은 문제가 있었다. 1998년부터 터널발파설계 자동화를 구현하기 위한 여러 연구가 시행되었고, 이를 통해 개발된 발파 설계식은 이러한 문제들을 해결할 수 있었다. 개발된 발파 설계식은 기존의 수식에 비해 복잡하기는 하지만, 암반상태에 따른 굴진장의 변화를 고려하여 장약량을 변화시킬 수 있고 최외곽공과 전열공의 설계도 다양하게 적용할 수 있는 등 여러 가지 장점이 있다. 이 연구에서는 터널발파설계 자동화를 위해 개발된 설계식에 대해 검토하였다.

• 한국화재소방학회논문지
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• 제22권5호
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• pp.1-8
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• 2008

본 연구의 목적은 지하철 터널에서 화재가 발생한 경우 역사와 환기실의 위치에 따른 화재특성을 수치적으로 분석하는데 있다. 이를 위해 피난거리, 피난시간 및 최악조건 화재가 발생한 2가지 시나리오를 선정하고, 환기실 위치 변경에 따른 시간별 화재상황에 대한 터널내의 시류 및 열환경을 분석하였다. 화재해석을 위해 FLUENT v.6.3.26을 이용하였으며, 난류모델은 표준 k-${\varepsilon}$ 모델을 사용하였다. 경우에 따른 터널 내 일산화탄소의 농도 분포, 온도분포 및 속도분포의 결과를 분석하였고 본 연구의 결과는 지하철 역사 및 터널 설계시 최적의 방재 및 환기시스템을 구축하는데 기여할 것으로 생각된다.

• ETRI Journal
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• 제43권3호
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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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• 제21권4호
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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.

• 대한전자공학회논문지SP
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• 제45권4호
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• pp.59-70
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• 2008

본 논문에서는 터널 환경 내에서 발생할 수 있는 화재를 조기에 실시간으로 탐지하기 위한 시각 처리 기법을 제시한다. 다양한 환경 하에서 화재 발생 시 이를 조기에 발견하여 인명 및 재산 피해를 최대한 줄이기 위한 목적을 가지고 많은 연구들이 제안되었다. 그러나 터널 화재 탐지의 경우 터널 환경이라는 특이성 때문에 기존의 화재 탐지 기법을 적용하기 어려우며, 터널 공간에 특성화된 새로운 알고리즘이 필요하다. 이에 본 논문에서는 컬러정보를 기반으로 한 화염 후보 영역 검출기법, 움직임 정보를 기반으로 한 연기 후보 영역 검출 기법을 사용하고 모폴로지 기법, 재검증 및 제거 기법을 이용하여 화재 검출 시 발생할 수 있는 오검출 영역을 제거하는 방법을 통해서 정확한 위치 탐지와 조기 탐지가 가능한 알고리즘을 개발하였다. 또한 실험 결과를 통해 각각의 성능을 비교함으로써 제시한 알고리즘의 타당성을 보여주었다.

• 한국안전학회지
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• 제30권6호
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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.

• 한국전산유체공학회지
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• 제20권4호
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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.

• 지질공학
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• 제18권2호
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• pp.153-158
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• 2008

진동현식 변형률 게이지는 습기가 많은 터널에서의 장기적 안정성이 우수하여 국내외 터널 현장에서 널리 사용되고 있다. 국내 터널 현장의 진동현식 게이지는 외국 제품도 일부 사용 되고 있으나 국내 게이지에 비하여 고가이어서 주로 국내에서 제작된 게이지가 이용되고 있다. 국산 진동현식 변형률 게이지는 상당히 많은 업체에서 제작되고 있으나 게이지의 신뢰상에 대해서는 검증이 제대로 이루어지지 못하고 있는 실정이다. 본 연구에서는 실내시험을 통하여, 국내 터널계측에 널리 사용되고 있는 2.5인치 진동현식 변형률 게이지에 대한 신뢰성을 검증하였다.

• 한방재활의학과학회지
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• 제32권1호
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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.