• 로봇학회논문지
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• 제9권4호
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• pp.264-271
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• 2014

In this study, we have developed the humanoid joint modules which provide a variety of service while living with people in the future home life. The most important requirement is ensuring the safety for humans of the robot system for collaboration with people and providing physical service in dynamic changing environment. Therefore we should construct the mechanism and control system that each joint of the robot should response sensitively and rapidly to fulfill that. In this study, we have analyzed the characteristic of the joint which based on the target constituting the humanoid motion, developed the optimal actuator system which can be controlled based on each joint characteristic, and developed the control system which can control an multi-joint system at a high speed. In particular, in the design of the joint, we have defined back-drivability at the safety perspective and developed an actuator unit to maximize. Therefore we establish a foundation element technology for future commercialization of intelligent service robots.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.9-12
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• 2008

For the large-sized and post-ultra definition TFT-LCD, improved drivability is prerequisite not only for the integration of driving circuit on glass but also for the chargeability of each pixel. In order to meet required drivability, currently adopted process architecture and materials are modified for the RC delay reduction, including the drastic increase of gate bus thickness and its related solution for step coverage. We present new process architecture and material selection for the next generation TFT-LCD devices.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.334-341
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• 2002

Nowadays, owing to the development of analysis techniques for PDA test, we can evaluate the serious damage of pile during driving in site. In this study, we checked the damage of pile by pulling it out after evaluation of the pile damage during driving by PDA testing. After that, almost damaged pile was checked and the outline depth of damage could be verified. To increase the quality of driven pile, we have to increase the number of PDA testing for drivability analysis with checking the damage especially for preliminary pile driving and dynamic load test for checking the bearing capacity and consider the application of driving by energy monitoring.

• 한국철도학회논문집
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• 제14권6호
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• pp.575-583
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• 2011

철도 지선 구간의 유지보수 비용을 최소화하기 위해 ICT 기반 차상제어시스템을 개발 중이다. 이 시스템은 기존의 열차제어방식과 달리 선로 주변 신호기와 고정폐색장치를 없애고 이동폐색방식을 적용하며 차상에서 선로전환기와 건널목을 제어하는 방식이다. 본 논문의 목적은 ICT 기반 차상제어시스템 개발 이전에 고려해야 할 주요 운영 이슈 사항을 분석하며 주요 대상은 열차운행준비, 운전 편의성, 관제역할, 폐색방식, 그리고 운영비용을 고려하였다. 열차 출발 전에 기관사가 DMI를 통해 입력하여야 할 입력데이터를 정의하였고 관련 업무 프로세스를 UML 도구를 활용하여 설계하였다. 기관사의 운전 편의성 측면에서는 역 진입 시의 제동시점 지원 필요성과 기관사의 원활한 운전 훈련을 위한 운전시뮬레이터가 필요하다. 기관사가 선로전환기와 건널목을 직접 제어하는 업무절차를 UML 도구로 설계하였다. 기존 운영 방식과의 차이를 확인하기 위해 고정폐색방식과 이동폐색방식 간에 비교 분석하였으며, 비용 측면에서는 기존방식과 ICT 방식의 신호설비에 따른 유지보수 비용 이점을 제시하였다.

• 한국지반공학회논문집
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• 제39권1호
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• pp.27-38
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• 2023

본 연구에서는 3D 프린팅 기술을 활용하여 타입말뚝 선단의 모양에 따른 관입성 분석을 현장 축소모형시험을 통해 관찰하고, 대변형 수치해석을 통해 타입 중 말뚝 선단에 집중되는 최대응력의 변화를 확인하였다. 3D 프린터를 통하여 다양한 직경, 각도 그리고 모양의 말뚝 선단 모형을 제작하였고, 이를 현장 축소모형시험에 활용하였다. 이를 통해, 말뚝 선단 조건에 따른 말뚝의 침하량의 변화를 관찰하였다. 더 나아가, 대변형 수치해석 기법을 적용하여 다양한 말뚝 선단 조건에 따른 타입 중 말뚝 선단부의 최대응력의 변화와 최대응력 작용 위치 또한 확인하였다. 현장 축소모형시험과 대변형 수치해석의 결과 분석을 토대로 말뚝 선단 조건의 변화를 통해 타입말뚝의 관입성을 향상 시킬 수 있으며 선단부에 집중되는 최대응력 또한 완화 시켜 말뚝 시공 중 말뚝 손상을 방지할 수 있을 것으로 결론지을 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.70-77
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• 2010

In this paper, a case study of drivability and bearing capacity of large diameter steel pipe piles at PTT LNG site in Thailand is introduced. The LNG facilities were designed to be founded on steel pipe pile foundations driven into the weathered rock formation overlaid by sand layers. The drivability analyses of open ended pipe piles were carried out using GRL WEAP program and the bearing capacities of the piles were estimated. Dynamic load tests were performed to evaluate end bearing resistance, and it is shown that the measured end bearing resistance is smaller than the calculated end bearing because the plugging does not develop sufficiently in case of large diameter pipe piles.

• 대한토목학회논문집
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• 제13권5호
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• pp.223-234
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• 1993

일반 PC 말뚝과는 달리 제작시 실리카(silica) 재료를 사용하고 증기양생후 고온, 고압의 추가양생(autoclave curing) 실시함으로써 말뚝자체의 강성을 높인 PHC 말뚝의 항타시공성과 지지력 특성을 파동이론에 근거한 수치해석과 실재현장에서의 항타기록 및 재하시험을 통하여 파악하였다. 임의의 지반조건에 대하여 항타장비에 따른 수치해석과 현장시험의 결과는 PHC 말뚝이 PC 말뚝에 비해 말뚝의 재질강도가 60% 정도 크므로 항타장비에 의해서 발휘되는 타격에너지에 대해 보다 큰 저항력을 가지기 때문에 설계지지력을 보다 크게 얻을 수 있으며 항타장비의 선정에 있어서도 보다 큰 효율을 지닌 장비의 선정이 가능하여 경제적인 항타작업을 수행하는데 유리함을 보였다.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.649-659
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• 2016

This paper describes control algorithm and control structure of vehicle control unit for range-extended electric vehicle equipped with engine-generator system, and specially presents methods which determine optimal operating points and decreases a vibration or a shock for operating the engine-generating system. The vehicle control algorithm is consisted of several parts which are sequence control, calculation of wheel demand torque, determination of operating points, and management of operating points and so vehicle controller has be made possible to efficiently manage calibration parameters. The control algorithm is evaluated by driving test modes, launching performance and operating engine-generator system and so on. In conclusion, this paper present methods for extending a mileage, improving a launching performance and reducing vibration or shock when the engine-generating system is starting or is stopping.

• Geomechanics and Engineering
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• 제18권6호
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• pp.615-626
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• 2019

Lightweight concrete (LWC) provides an attractive alternative to conventional piles by improving the durability of deep foundations. In this paper, the drivability of cylindrical and tapered piles made of lightweight and common concrete (CC) under hammer impacts was investigated by performing field tests and numerical analysis. The different concrete mixtures were considered to compare the mechanical properties of light aggregate which replaced instead of the natural aggregate. Driving tests were also conducted on different piles to determine how the pile material and geometric configurations affect driving performance. The results indicated that the tapering shape has an appropriate effect on the drivability of piles and although lower driving stresses are induced in the LWC tapered pile, their final penetration rate was more than that of CC cylindrical pile under hammer impact. Also by analyzing wave propagation in the different rods, it was concluded that the LWC piles with greater velocity than others had better performance in pile driving phenomena. Furthermore, LWC piles can be driven more easily into the ground than cylindrical concrete piles sometimes up to 50% lower hammer impacts and results in important energy saving.

• 대한인간공학회지
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• 제32권5호
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• pp.437-442
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• 2013

Objective: The objective of this study was to investigate the effects of drive-assisting system in a shower carrier on the upper body muscle activities of caregivers through drivability tests. Background: In care facilities, one of the major ADL (Activities of Daily Living) factors is bathing/showering. Recently, bath/shower-assisting equipment is actively being introduced in care facilities to reduce caregivers' muscle burden. In particular, it is desirable to utilize a shower carrier equipped with drive-assisting system to effectively care for the elderly. However, there were few systematic studies on the relationship between muscle activities and drive-assisting speeds. Method: For the drivability tests to study the effects on the muscle activities according to the drive-assisting speeds(corresponding drive-voltages: 0.0V, 2.0V, 2.1V, 2.3V), 6 females in their 40s($43{\pm}4yrs$, $157{\pm}5cm$, and $54.5{\pm}1.5kg$) were selected. To measure muscle activities of caregivers through drivability tests, 7 muscles in the upper body(TM/Trapezius Muscle, DM/Deltoid Muscle, BBM/Biceps Brachii Muscle, TBM/Triceps Brachii Muscle, ECRLM/Extensor Carpi Radialis Longus Muscle, FCUM/Flexor Carpi Ulnaris Muscle, and ESM/Erector Spinae Muscle) were selected. Results: In the TM, muscle activities were decreased as 21% compared to 0.0V, when drive-voltage 2.0V was applied, as 57% by 2.1V, and 62% by 2.3V(p<0.05), whereas 40%, 56%, and 69% of muscles activities were decreased respectively from the DM(p<0.05). Also, from the UL(BBM+TBM+ECRLM+FCUM), muscle activities were decreased by 17% with 2.0V as against 0.0V, by 47% with 2.1V, and 52% with 2.3V, whereas decreases in muscle activities from the ESM were found by 20%, 34%, and 42% respectively by 2.0V, 2.1V, and 2.3V(p<0.05). Conclusion: The muscle activities were decreased in the order of the DM, TM, ESM, and UL. As muscle activities were remarkably reduced as drive voltage were increased, it was expected to reduce the upper body muscle burden on the caregivers when using shower carriers equipped with driving-assist system. Applications: The results from this study can be applied for the development of a shower carrier including other equipment to possibly reduce the muscle burden of the caregivers.