• Fire Protection Technology
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• s.58
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• pp.18-26
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• 2015

• TTA Journal
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• s.169
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• pp.84-90
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• 2017

• Air Cleaning Technology
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• v.32 no.2
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• pp.10-20
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• 2019

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.237-248
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• 2014

Linear cutting test is known to be very effective to determine machine parameters (i.e. thrust force and torque) and to estimate penetration rate of TBM and other operation conditions. Although the linear cutting test has significant advantages, the test is expensive and time-consuming because it requires large size specimen and high load capacity of the testing machine. Therefore, a few empirical prediction models (e.g. CSM, NTNU and QTBM) alternatively adopt laboratory index tests to estimate design parameters of TBM. This study discusses the estimation method of TBM machine parameters and disc cutter consumption using punch penetration test and Cerchar abrasion test of which the researches are rare. The cutter forces and cutter consumption can be estimated by the empirical models derived from the relationship between laboratory test result with field data and linear cutting test data. In addition, the estimation process was programmed through which the design parameters of TBM (e.g. thrust, torque, penetration rate, and cutter consumption) are automatically estimated using laboratory test results.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.803-811
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• 2021

In this study, the exposure amount of IASCC test worker was evaluated by applying the process simulation technology. Using DELMIA Version 5, a commercial process simulation code, IASCC test facility, hot cells, and workers were prepared, and IASCC test activities were implemented, and the cumulative exposure of workers passing through the dose-distributed space could be evaluated through user coding. In order to simulate behavior of workers, human manikins with a degree of freedom of 200 or more imitating the human musculoskeletal system were applied. In order to calculate the worker's exposure, the coordinates, start time, and retention period for each posture were extracted by accessing the sub-information of the human manikin task, and the cumulative exposure was calculated by multiplying the spatial dose value by the posture retention time. The spatial dose for the exposure evaluation was calculated using MCNP6 Version 1.0, and the calculated spatial dose was embedded into the process simulation domain. As a result of comparing and analyzing the results of exposure evaluation by process simulation and typical exposure evaluation, the annual exposure to daily test work in the regular entrance was predicted at similar levels, 0.388 mSv/year and 1.334 mSv/year, respectively. Exposure assessment was also performed on special tasks performed in areas with high spatial doses, and tasks with high exposure could be easily identified, and work improvement plans could be derived intuitively through human manikin posture and spatial dose visualization of the tasks.

• Tunnel and Underground Space
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• v.7 no.2
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• pp.143-149
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• 1997

암석의 파괴인성계수(fracture toughness)는 균열의 성장에 대한 암석의 저항을 나타낸다. 실험실에서 측정한 파괴인성계수는 일반적인 암석의 불균질성이나 이방성 외에도 시험편의 형상이나 하중조건에 의하여 크게 영향을 받는다. 따라서, 제한된 수의 시험편을 사용하여 측정된 파괴인성계수는 자료의 분산이 심하므로 실제 적용에 있어서 문제가 된다. 균열감응도란 파괴인성계수의 측정에 사용되는 시험편의 형상에 따라 결정되는 지수로서, 시험편의 파괴가 균열의 성장에 의한 것인지, 혹은 인장강도에 의한 것인지를 판별하는 기준이 된다. 이러한 균열감응도를 파악하여 암석의 파괴인성계수 측정에 유효한 시험편의 크기나 초기균열 길이의 범위를 설정할 수 있다. 이는 또한 실험실에서 측정된 차괴인성계수의 유효성 여부를 판별하는 기준으로 사용될 수 있다. 본 논문에서는 암석의 파괴인성계수의 측정에 흔히 사용되는 몇 가지 형태의 시험편들에 대하여 균열감응도를 계산하고 이에 따른 초기균열 길이의 범위를 제시하고자 한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2009.04a
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• pp.293-294
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• 2009

정밀한 관측을 요하는 측량장비의 기능을 보정하거나 검증하는 것은 측량시 매우 중요한 일이다. ISO17123-8 규격은 GNSS RTK 정확도를 결정 할 때 사용되는 야외실험 절차와 규정을 명시하고 있으며 정확도 평가방법으로는 약식시험절차와 엄밀시험절차를 제시하고 있다. 본 연구에서는 GNSS RTK 정확도 평가방법 중 엄밀시험절차에 대해 시험할 목적으로 GNSS RTK 규격에 따라 Test-bed를 구축하였고 성능실험을 실시 위하여 GNSS RTK 규격에 제시된 정확도 평가방법을 적용하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.737-740
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• 2003

초고속 정보통신망의 발전과 더불어 컴퓨터의 급속한 보급 및 웹 기술의 발전으로 교육 분야에서도 큰 변화가 일어나고 있다. 인터넷의 대중화로 정보화 마인드가 확산됨에 따라 다양한 학습이 이루어졌고, 이에 따라 자격증 역시 정보화 지수로 중요한 위치를 차지하고 있다. 7차 교육과정에서는 저학년에도 컴퓨터 교육이 이루어지고 정보소양인증제도가 실시됨에 따라 자격증 취득에 대한 요구가 높아지고 있다. 본 논문에서는 많은 컴퓨터 관련 자격증 중에서 정보처리 기능사 필기시험을 가상공간인 웹 상에서 설계 및 구현해 봄으로써 실업계 고등학교 학생들이 보다 손쉽게 자격증을 취득하는데 도움을 주도록 하는데 있다. 이러한 웹에 기반한 교육적 활용의 한 모델로서 자기 주도적 학습이론과 수준별 학습이론을 정보처리 기능사 필기시험에 적용하였다. '자격증 시험을 위한 웹 기반 문제은행 시스템'은 정보처리 기능사 필기시험뿐만 아니라, 문제은행 방식의 많은 컴퓨터 관련 자격증 필기시험에도 적용 및 응용이 가능하다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.283-293
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• 2015

In order to evaluate corrosion resistance of steel fiber-reinforced concrete, accelerated chloride migration and surface resistivity tests were conducted. In addition air content of fresh concrete, compressive strength and water absorption were measured for investigating fundamental characteristics of concrete. Two different water-cement ratios(0.44, 0.5) and three steel fiber contents(0.25%, 0.5%, 1%) were considered as variables. Note that all specimens cast with same compaction work. As a results, corrosion resistance decreased as steel fiber contents increased regardless of water-cement ratio when the concrete was compacted with same amount of work done. However, for concrete with same steel fiber content, the lower water-cement ratio showed the better corrosion resistance. It is found that enhancement of fluidity and enough compaction should be done for corrosion resistance of SFRC.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.6
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• pp.695-702
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• 2015

Recently, the improvement of mechanical and theoretical issues in geo-centrifuge test enhances the applicability and accuracy of the test. Geo-centrifuge test is appropriate to simulate the behaviors of underground structures like tunnel, since tunnel interacts with the soil and/or rock around it and the test can embody the in-situ stress conditions effectively. In this study, the seismic behaviors of twin tunnel were analyzed based on geo-centrifuge test. Flexible segment to mitigate seismic acceleration were implemented in the model with thin and thick thickness. Based on the test results, it was found that flexible segment can decrease the peak acceleration generally, however, thin flexible segment was not able to reduce peak acceleration in short-period seismic wave. Thick flexible segment was more effective in case of high bedrock acceleration condition. Additionally, 3-dimensional numerical analysis was performed to verify the characteristics of seismic behavior and the effect of flexible segment. Consequently, the numerical analysis result showed good agreement with the test result.