• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.97-101
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• 1999

Purpose : The purpose of this study is to prevent thc graft-tunnel mismatch by measuring the patellar tendon length, intertunnel distance, tibial tunnel length and by obtaining appropriate bone block length. Materials and Methods : Authors analyzed 15 patients who had taken the anterior cruciate ligament reconstruction from March 1997 to June 1999. Tibial guide was always set on the "endo" $40^{\circ}$ position(Acufex, MA, USA). We measured the following indices, intertunnel distance(X), tibial tunnel length(T), patellar tendon length(N), tibia bone plug length(Y). Both of the femoral tunnel length(F) and the patellar bone plug length(P) were made in 25mm. The appropriate tibial bone plug length was simply calculated by subtracting the patellar tendon length from the sum of the intertunnel distance and thc tibial tunnel length(Y=X+T-N). Results : The average indices were as follows ; the intertunnel distance(X) was $23.4{\pm}1.4mm$, the tibial tunnel length(T) was $43.6{\pm}1.7mm$, the patellar tendon length was $40{\pm}2.4mm$, and the tibia bone plug length was $27{\pm}2.4mm$. Conclusion : In authors' endoscopic technique, establishment of individually determined optimal tibial bone plug length, based on total tunnel length and patellar tendon length could prevent the problem of graft-tunnel mismatch.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.41-52
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• 2016

When the queue length of congestion vehicles in tunnel fire is extended beyond tunnel length, the capacity of smoke control system needs to be increased in line with ventilation resistance. However, the vehicle queue length is not defined, so a rational equation is necessary in current fire prevention guideline. This study is intended to propose an equation to calculate the queue length considering the number of vehicles in queue in tunnel fire and evaluate the applicability by tunnel length as well. When it comes to normal tunnel, it is necessary to compare the vehicle queue length with tunnel length up to the length of 1,200 m in a bid to avoid applying the vehicle queue length excessively in case of fire. As a result of evaluation of applicability to model a tunnel, saving the number of jet fan for smoke control appeared to be effective. Besides, quantitative approach to explain the vehicle queue length through the relationship between the percentage of large vehicles and tunnel length was presented. Consequently, when the queue length of the congestion vehicles exceeds the tunnel length in determining the capacity of smoke control system in case of fire, the number of vehicles beyond the tunnel length needs to be excluded from estimating the ventilation resistance by vehicles.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.162-167
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• 2002

열차가 고속으로 터널에 진입하게 되면 터널 내부에서 극심한 압력 교란이 발생하게 되며 이로 인한 이명현상은 승객들에게 불쾌감을 크게 유발시키고, 열차 구조물에 작용하는 반복적인 하중변화 또한 구조상 큰 문제를 일으킬 수 있게 된다. 따라서 이를 해결하기 위해서는 터널 내부의 유동장에 대한 정확한 예측이 필요하다. 본 논문은 긴 터널을 효율적으로 해석하기 위해서 최소 차원의 공간 가정을 통하여 계산 시간을 절약할 수 있는 혼합차원 기법을 이용하여 현재 G7 시제차의 시험 운행 구간내의 터널들에 대해서 수치해석을 수행하였다. 해석 결과 터널 내부에서는 압축파, 팽창파의 상호 작용에 의한 복잡한 압력 교란이 발생하였고, 이러한 압력 변화는 열차 속도, 터널 길이, 측정위치에 따라 각각 다르게 나타났다. 따라서 터널 내부의 유동장을 정확히 예측하려면 열차 속도, 터널 길이, 열차 길이, 열차/터널 단면적 비, 측정 위치 등을 고려하여 해석을 수행하여야 한다. 이러한 수치 해석 결과는 시제차 시험 계획의 수립 및 시험기기의 선택과 설치 위치 등을 결정하는 중요한 자료로 활용될 수 있을 것이며, 고속 열차의 여압 시스템과 외부 부착 구조물에 대해서도 중요한 정보를 제공할 수 있을 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.7
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• pp.1311-1316
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• 2016

This paper analyzes the influence of tunneling current on threshold voltage shift by channel length of short channel asymmetric double gate(DG) MOSFET. Tunneling current significantly increases by decrease of channel length in the region of 10 nm below, and the secondary effects such as threshold voltage shift occurs. Threshold voltage shift due to tunneling current is not negligible even in case of asymmetric DGMOSFET to develop for reduction of short channel effects. Off current consists of thermionic and tunneling current, and the ratio of tunneling current is increasing with reduction of channel length. The WKB(Wentzel-Kramers-Brillouin) approximation is used to obtain tunneling current, and potential distribution in channel is hermeneutically derived. As a result, threshold voltage shift due to tunneling current is greatly occurred for decreasing of channel length in short channel asymmetric DGMOSFET. Threshold voltage is changing according to bottom gate voltages, but threshold voltage shifts is nearly constant.

• 방재와보험
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• s.111
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• pp.20-27
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• 2006

피난길이가 긴 장대터널에서 화재가 발생되면 생성된 연기가 상승하고 천장을 만나 터널의 길이방향으로 전파된다. 연기의 독성가스에 의해 질식하게 되는 인명피해를 줄이기 위해서는 발생한 화재의 크기에 따라 제연유속이 필요하며, 제연 팬의 용량과 신뢰성을 확보해야 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.7
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• pp.1617-1622
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• 2015

This paper analyzes the ratio of tunneling current for channel doping concentration of sub-10 nm asymmetric double gate(DG) MOSFET. The ratio of tunneling current for off current in subthreshold region increases in the region of channel length of 10 nm below. Even though asymmetric DGMOSFET is developed to reduce short channel effects, the increase of tunneling current in sub-10 nm is inevitable. As the ratio of tunneling current in off current according to channel doping concentration is calculated in this study, the influence of tunneling current to occur in short channel is investigated. To obtain off current to consist of thermionic emission and tunneling current, the analytical potential distribution is obtained using Poisson equation and tunneling current using WKB(Wentzel-Kramers-Brillouin). As a result, tunneling current is greatly changed for channel doping concentration in sub-10 nm asymmetric DGMOSFET, specially with parameters of channel length, channel thickness, and top/bottom gate oxide thickness and voltage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.611-613
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• 2016

The characteristics of tunnel field-effect transistor(TFET) structure with source-overlapped gate was investigated using a TCAD simulations. Tunneling is mostly divided into line-tunneling and point-tunneling, and line-tunneling is higher performance than point-tunneling in terms of subthreshold swing(SS) and on-current. In this paper, from the simulation results of source-overlapped gate length effects at silicon(Si), germanium(Ge), Si-Ge hetero TFET structure, the guideline of optimal structure with highest performance are proposed.

• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.51-59
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• 2000

네일(또는 락볼트)은 토사터널의 NATM 시공 시 보강재로 사용되어진다. 그러나, 네일의 적절한 설치방법이 아직까지 정립되지 않았다. 본 연구에서는 네일의 길이와 위치를 변화하여, 그 효용성을 연구하였다. 그 결과, 네일이 지반보강을 위하여 토사지반에 사용될 시 경제적인 길이는 터널직경의 0.5배이다. 보강의 효용성은 네일의 위치에 따라 터널라이닝 측벽의 하부, 중부, 상부의 순서이다.

• Tunnel and Underground Space
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• v.11 no.1
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• pp.30-35
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• 2001

Focusing on the bench length, this paper presents the results of 3-dimensional elafto-plastic FE Analysis un tunnels of full face, mini-bench and short bench excavated in weathered rock. Influences of unsupported span, horizontal to vertical stress ratio, thickness of shotcrete on the behavior of rock and support were a1so studied. Results showed that displacements of mini-bench tunnels responded more sensitively to bench lengths than those of short bench. The effects of bench excavation on upper half displacement increased with longer unsupported span. Horizontal to vertical stress ratio showed a greater influence on displacement and preceding displacement ratio or sidewall rather than those of crown and invert.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.163-168
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• 2015

This paper analyzed the deviation of tunneling current for bottom gate voltage of sub-10 nm asymmetric double gate MOSFET. The asymmetric double gate MOSFET among multi gate MOSFET developed to reduce the short channel effects has the advantage to increase the facts to be able to control the channel current, compared with symmetric double gate MOSFET. The increase of off current is, however, inescapable if aymmetric double gate MOSFET has the channel length of sub-10 nm. The influence of tunneling current was investigated in this study as the portion of tunneling current for off current was calculated. The tunneling current was obtained by the WKB(Wentzel-Kramers-Brillouin) approximation and analytical potential distribution derived from Poisson equation. As a results, the tunneling current was greatly influenced by bottom gate voltage in sub-10 nm asymmetric double gate MOSFET. Especially it showed the great deviation for channel length, top and bottom gate oxide thickness, and channel thickness.