• Korean Journal of Optics and Photonics
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• v.10 no.2
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• pp.89-94
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• 1999

The 1.54 ${\mu}{\textrm}{m}$ forward and backward stimulated Raman scattering (SRS) have been studied in CH$_4$pumped by 1.06 ${\mu}{\textrm}{m}$ Nd:YAG laser. The forward and backward SRS output energy in a single pass were measured at dufferent CH$_4$pressures. Under steady state conditions, the pump input threshold energies and Raman gains in forward and backward directions were for Raman conversion at various CH$_4$pressures for a tight focusing geometry. The forward and backward slope efficiency for Raman conversion were 18% and 34% respectively. The pump input threshold energy of the backward SRS was lower than that of the forward. In backward SRS, the experimental input laser threshold and Raman gain values were in good agreement with the calculated values at different pressures of CH$_4$. The retio of the backward to the forward SRS gain was appoximately 1.4 times above 1200 psi. We obtained that the backward Raman gain coefficient was 0.32 cm/GW, and the forward Raman gain coefficient 0.23cm/GW at 1400 psi. Asymmetry of the forward and backward Raman gain is caused by the interaction between different pump intensities of each direction duting the amplification of the Stokers. The backward Raman gain is proportional to the average pump intensity. However, the forward SRS output grows by depleting the local pump intensity.

• Proceedings of the Korean Society of Computer Information Conference
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• 2024.01a
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• pp.195-198
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• 2024

이 연구의 목적은 EMG 바이오피드백을 이용한 가로막 호흡 재교육 운동이 전방머리자세 성인의 들숨 기능의 효과를 알아보고자 하였다. 이연구 결과 EBDBEG에서 최대들숨압(PIP) 유의하게 증가하였다(P<.0.5). 따라서 바이오피트백을 적용한 시각적 되먹임을 통해 가로막호흡운동 시 보다 정확하게 가로막의 수축과 이완의 움직임을 인지하고 호흡 보조근을 억제를 유도할 수 있을 거라 생각되며 좀 더 장시간의 적용은 호흡기능 및 전방머리자세에도 긍정적인 역할을 할 것이다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.55-72
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• 2018

A method that can predict the mixed-ground condition ahead of a TBM tunnel face during tunnel construction utilizing electrical resistivity and induced polarization (IP) was proposed in this study. Effect of TBM advancement approaching the mixed-ground condition (composed of soil layer overlying rock layer) when currently running through soil zone on the electrical resistivity and IP measuring was assessed with laboratory-scale experiments. The resistivity and IP values were measured using four electrodes, by installing two electrodes on the tunnel face (at the cutterhead), and the other two electrodes on the segment lining. The test results showed that both of the measured resistivity and IP values were kept increasing as the TBM is approaching the soil-rock mixed-ground. Also, to get the more reliable results for predicting the mixed-ground condition, it was recommended that the measurement is made at the tunnel face utilizing 4-electrodes installed at the cutterhead as well as it is made utilizing the 2-electrodes installed at the segment lining along with the 2-electrodes installed on the tunnel face (at the cutterhead) so that two measured results are compared each other.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.11
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• pp.979-987
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• 2012

This paper implements and integrates algorithms for terrain following of UCAVs (Unmanned Combat Aerial Vehicles): trajectory generation, guidance, and navigation. Terrain following is very important for UCAVs because they perform very dangerous missions such as Suppression of Enemy Air Defences while the terrain following can improve the survivability of UCAVs against from the air defence systems of the enemy. To deal with the GPS jamming, terrain referenced navigation based on nonlinear filter is chosen. For the trajectory generation, Voronoi diagram is adopted to generate horizontal plane path to avoid the air defense system. Cubic spline method is used to generate vertical plane path to prevent collisions with ground while flying sufficiently close to surface. Follow-the-Carrot and pure pursuit tracking methods, which are look-ahead point based guidance algorithms, are applied for the guidance. Numerical simulation is performed to verify the performance of the integrated terrain following algorithm.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.3
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• pp.323-345
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• 2019

It is essential to predict ground conditions ahead of a tunnel face in order to successfully excavate tunnels using a shield TBM. This study proposes a forward prediction method for a mixed soil ground and/or a ground containing core stones by using electrical resistivity and induced polarization exploration. Soil conditioning in EPB shield TBM is dependent upon the composition of mixed soils; a special care need to be taken when excavating the core-stoned soil ground using TBM. The resistivity and chargeability are assumed to be measured with four electrodes at the tunnel face, whenever the excavation is stopped to assemble one ring of a segment lining. Firstly, the mixed ground consisting of weathered granite soil, sand, and clay was modeled in laboratory-scale experiments. Experimental results show that the measured electrical resistivity considerably coincides with the analytical solution. On the other hand, the induced polarization has either same or opposite trend with the measured resistivity depending on the mixed ground conditions. Based on these experimental results, a method to predict the mixed soil ground that can be used during TBM tunnel driving is suggested. Secondly, tunnel excavation from a homogeneous ground to a ground containing core stones was modeled in laboratory scale; the irregularity of the core stones contained in the soil layer was modeled through random number generation scheme. Experimental results show that as the TBM approaches the ground that contains core stones, the electrical resistivity increases and the induced polarization fluctuates.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.175-178
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• 2009

도로조명에서 선형유도는 교통과 관련하여 매우 중요한 질적인 요소이며 도로 주행 시 운전자에게 전방의 도로 형태를 미리 인지할 수 있도록 도와준다. 본 논문에서는 개발 중에 있는 낮은 조명 방식과 가로등 조명 방식에서 선형유도 성능을 평가할 수 있는 시험법을 고안하였다. 이 후 20대와 60대의 피험자를 선발하여 평가 시험을 실시할 예정이다.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2002.03a
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• pp.16-16
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• 2002

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.82-85
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• 2009

Purpose: In anterior cruciate ligament (ACL) reconstruction, preservation of the remnant original tissue might promote graft healing and be helpful in proprioception. But this procedure is difficult and causes the notch impingement. So we introduce a surgical technique that makes a transtibial femoral tunnel at 10 or 2 o'clock position with preservation of remnant tissue. Surgical approach: We tried to preserve the remnant tissue and synovium as much as possible, especially those of tibial attachment and extending to the posterior cruciate ligament (PCL), so as to have some tension and to prevent notch impingement. We set the tibial drill guide at 40~45 degrees and the intra-articular guide tip was 1 mm anterior and medial to the conventional site. The starting point of tibial guide pin was proximal to the pes anserinus and anterior to the medial collateral ligament. When the reamer approached the cortical bone of the tibial articular surface, the reamer must be advanced very carefully to minimize injury to the remnant tissue. The tibial and femoral tunnel at 10 or 2 o'clock position were made with the reamer, the diameter of which was same with that of the graft. Conclusion: We report a remnant preserving technique in ACL reconstruction that makes a transtibial femoral tunnel at 10 or 2 o'clock position

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.360-367
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• 2018

Extensive dental erosion and wear will cause serious loss of function and aesthetics in the mouth. In order to recover this condition, careful analysis of the patient's bite relationship is required. In particular, a treatment plan should be established considering the possibility of reproduction of the vertical dimension and centric relation, and appropriateness of the occlusal plane and anterior guidance. Also, the choice of prosthetic materials is an important consideration in patients with severe wear. In this case, patients with overall wear and erosion on tooth was established anterior guidance by orthodontic treatment and fully restored with monolithic zirconia, without increasing vertical dimension.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.4
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• pp.345-350
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• 2016

Transferring condylar and anterior guidance on an articulator is essential to the diagnosis of a patient for full mouth reconstruction. In this clinical report, ARCUS digma I system was used to measure inherent condylar guidance of a patient requiring full mouth reconstruction in preoperate treatment, and the patients was given provisional restoration based on a functional anterior guidance. Then, ARCUS digma II system was used to mount the final casting model on an articulator, and the definitive prosthesis was placed in the patient. An esthetic and functionally proper clinical result regarding inherent condylar path of the patient was observed, and results from comparison of the two systems are given in this case.