• The Journal of Korea Robotics Society
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• v.9 no.4
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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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• 2008.10a
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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.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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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.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.575-583
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• 2011

In order to minimize the maintenance cost at local lines, Information & Communication Technology based onboard train control system is being developed. Unlike the central traffic control based fixed block system, this system use a moving block method and railway driver direct control switch and railway crossing. The purpose of this paper is to analyze the concerned main operational issues are as follows: the preparation of train operation, drivability, the role of driver and controller, block system and cost. We defined the role of driver and driver's input data for train service, and we designed the business process of driver using UML tool. We considered the aspect of drivability, DMI is needed to support the braking moment for the driver and driver training simulator. We designed the driver business process for control of switch and railway crossing. We analyzed the fixed block system and moving block system to confirm the difference with the existing operational method. The cost analysis structure is also needed for the operation cost comparison.

• Journal of the Korean Geotechnical Society
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• v.39 no.1
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• pp.27-38
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• 2023

In this study, the impact of pile tip geometry, including shape, size, and angle, on the drivability and stress concentration during pile driving was investigated using 3D printing technology and finite element numerical analysis. A series of field loading tests were conducted on a test pile with various pile tip conditions, including width, angle, and shape. The changes in settlement were quantified as a ratio to the settlement of a conventional pile tip case and large deformation finite element analysis was used to investigate the maximum stress on a pile tip and the location of possible damage during pile driving. The results showed that by modifying the shape, size, and angle of the pile tip, the drivability of the pile could be improved and the maximum stress concentration around the pile tip could be significantly reduced, thereby ensuring the structural integrity of the pile during pile driving.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.223-234
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• 1993

The main characteristics of PHC piles is that silica material and autoclave curing technique are used when manufacturing to have higher strength than PC piles. In this paper, pile drivability and bearing capacity characteristics of the PHC piles are studied through numerical analysis based on wave propagation theory, driving records and pile load tests in situ. It is found that we can have higher bearing capacity by using the PHC piles rather than the PC on condition that the most effective driving equipment is chosen when driving the pile. In other words, since the PHC piles have higher resistance to driving energy, the heavier ram can be used in the driving process, which results in the higher bearing capacity.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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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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• v.18 no.6
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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.

• Journal of the Ergonomics Society of Korea
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• v.32 no.5
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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.