• Magazine of korean Tunnelling and Underground Space Association
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• v.1 no.2
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• pp.161-170
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• 1999

본고에서는 $1986.8\~1988.7$월중에 시공된 부산지하철 1호선 3단계 건설구간 중 서대신동 로타리에서 괴정국민학교 앞까지 연${\cdot}$경암지역에서의 TBM(Tunnel Boring Machine)으로 시행된 단선터널(7.0m)과 NATM으로 시행한 복선터널의 근접시공에 따른 간벽부 보강설계 내용과 근접부 시공시 계측결과 분석, 지보 Pattern조정 및 시공 실적 등을 제시하였다. 원설계 내용 분석 결과 지보 Pattern이 현장 지반조건에 비해 과다하였고 TBM 굴진시 Thrust 2500kN(본 기계 기준) 이상인 연암이상의 지반에서는 TBM 굴착으로의 효율성이 있었고, 경암구간에서 병행터널의 간섭영향을 배제하려면 터널간의 중심거리가 터널직경의 2배 이상이 되어야 하며, TBM 단선터널(7.0m)의 일 평균 굴진 길이는 4.6m로 분석되었다. 앞으로 이와 유사한 암층에서의 터널근접 시공 및 TBM 굴착시 본 분석내용이 참고가 되기를 기대하여 본고를 작성하였다.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1995.03a
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• pp.27-40
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• 1995

한강하저의 지질은 수많은 대ㆍ소 단층들로 인해 심하게 교란되어 있어 지질상황의 변화가 매우 심하며, 터널을 굴착함에 있어 지하수의 유입을 차단하는 것이 안전시공을 위한 필수 과제로 직면한다. 본 고에서는 기 시공실적을 바탕으로 암반상태에 따른 차수그라우딩의 패턴을 비교ㆍ검토하였다. 본 구간에서는 암반상태에 따라 5가지 패턴이 적용되었으며, 경암 암반일 경우는 상부반단면만을 주입범위(주입범위 : 3.5m, 28공)로 하고 암반의 전단강도증진을 위해 강관보강을 시행하였다. 연암 암반 내지 파쇄대가 부분적으로 협재된 경우는 상부반단면만을 주입하되 주입범위 및 그라우팅 공수를 늘리는 방식(주입범위 : 5∼7, 42∼56공)으로 보강하였다. 풍화암 암반의 경우는 전단면을 주입범위로 하여 그라우팅 공수를 늘림(주입범위 : 7m, 81공)으로서 차수효과를 증진시켰다. 또한 본 공사구간 중 가장 난제였던 연약지반대(잔류토 내지 풍화토) 85m 구간은 자문회의 등을 거쳐 주입범위, 주입길이 및 주입공수, bulk head 구간을 늘려 시공하고, 굴착하면서 차수효과를 확인하는 방식을 취하였다.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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• pp.679-686
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• 2023

According to the PSPC (Performance Standard for Protective coatings) rule, the edge preparation must keep 2R or 3-pass grinding. The stiffener plate edge grinding of the ship inside is manually progressed by worker and worked with just one pass grinding. In addition, the poor working condition cause grinding workers to avoid working in them, and the quality is determined by the skill-level of a worker. This research developed optimal tool for edge milling. In order to milling various collar plates edge, this research developed vision system that can recognize the edge points and it developed a program that operator can adjust the amount of cutting and speed, and add various features so that milling quality would be improved. So, this research focused on overcoming the difficulties in working condition and development of automated milling machine for ship stiffener plate.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.8
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• pp.39-52
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• 1995

In order to design and improve a new machine tool, there is a need for a better understanding of the dynamic cutting force. In this paper, the computer programs were developed to predict the dynamic cutting force by the mean specific cutting pressure in the face milling process. The simulated cutiing forces in X, Y, Z directions resulted from the developed dynamic cutting force model are compared with the measured cutiing forces in the time and frequency domains. The simulated cutting force model have a good agreement with the measured forces in comparison with those resulted from the existing cutting force model.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_2
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• pp.359-370
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• 2023

For a vehicle to follow a reference path accurately, its position must be estimated accurately and reliably. In this paper, we propose a lateral control algorithm for autonomous navigation of a vehicle via USAT(Ultrasonic Satellite System), which is an absolute position measurement system using an ultrasonic wave and INS(Inertial Navigation System) integration. In order to estimate the vehicle's parameters, a J-turn test is used. And the autonomous navigation performances of proposed lateral control algorithm and validity of proposed lateral control algorithm are verified and evaluated by simulation and experiments.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.70-76
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• 1993

Burnishing, as a micro plastic working, is a finishing process used in conjuction with or in replacement of reaming, honing, lapping, and/or grinding. The tool which is a smooth, round steel ball slightly larger than the bore is pushed through pre-machined hole, leaving a closely controlled finish. The major application of the processes is to improve the geometric and mechanical properties of surface such as (1) dimensional accuracy, (2) surface roughness, (3) bearing ratio, (4) surface hardness, (5) wear resistance, (6) fatigue and corrosion resistance, etc. Therefore, this study carried out some experiments to illustrate the theoretical formula and to investigate surface accuracy (e.g. variation of diameter, surface roughness, bearing ratio) in accordance with the applied burnishing load.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.92-99
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• 1997

A model reference adaptive control(MRAC) theory is very useful for controlling a plant of which the parameters are unknown or vary during operation usint only input-output signal of plant. In this study, 2' nd order discreter time MRAC controller is designed for an electrohydraulic position control system which is represented with nonlinear mathematical model and the least square method is adopted for the para-meter adjustment law. This control algorthm is applied to the position control of electrohydraulic servosystem through computer simulation and the effect of the change of load, sampling time upon the performance following reference model and upon the performance of estimating plant parameters are examined.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.176-176
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• 2020

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.175-175
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• 2020

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2020.10a
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• pp.181-181
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• 2020