• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.891-895
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• 1996

Performance and efficiency of hybrid (hydraulic-mechanical) pick-up device of deep sea manganese nodules collector are very sensitive to altitude and altitude of pick-up head relative to undulating seafloor. For this reason, motion control of pick-up head relative to the changing deep sea topography and other disturbances is of particular importance in design of pick-up device. The concept of design axiom is applied to a pick-up device of hybrid type. Kinematic analysis conducted in absolute Cartesian coordinates gives position, velocity, and acceleration of the hydraulic cylinders which enable the pick-up head to keep the preset optimal distance from seafloor. Inverse dynamic analysis provides the driving forces of hydraulic cylinders and the reaction forces at each joint. Design sensitivity analysis is performed in order to investigate the effects of possible design variables on the change of the maximum strokes of hydraulic cylinders. The direct differentiation method is used to obtain the design sensitivity coefficients.

• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.415-422
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• 2001

A seedling pick-up device for vegetable transplanters was developed and its work performance was evaluated at the laboratory. The pick-up device extracts seedlings from a 200-cell tray of seedlings and transfers them to the place where they are to be transplanted into the soil. The device consists of a path generator, pick-up pins and a pin driver. The path generator is a five-bar mechanism comprised of a fixed link, a driving link, a driven link, a connecting link and a slider. The slider is constrained to move along the driven link and a fixed slot of combined straight-line and circular paths. The connecting link joins the driving link and the slider. When the slider moves along the straight-line path of the slot it takes seedlings out from the cell and transfers them to the transplanting hopper when moving along the circular path. A proto-type of the pick-up device was built and tested under the various operational conditions such as age of seedling, approach direction and penetration depth of pins to the cell, holding method of seedling and extracting velocity. The device extracted 30 seedlings per minute with the maximum success ratio of 97% using the seedlings of 23 days old. Some design details were also discussed and suggested to enhance the performance of the device.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.38-49
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• 1998

The 3rd generation optical pick-up used popularly in resent years is composed of many optical and electronic components such as laser diode, photo diode, beam splitter, objective lens, grating lens, concave lens, collimator lens etc. Therefore, the design of its optical system and its main base which the said optical and electronic components are set on, is complicated and needs high precision. Its assembly and adjustment in the production line is also difficult. This complication and the demand of high precision get its production cost to be high and its reliability to be low. In this paper, the 4th generation optical pick-up is designed and developed, with the hologram device which laser diode. photo diode, beam splitter. and grating lens are integrated in. This optical pick-up reduces the number of points of adjustment by 3, compared with the 3rd generation optical pick-up of which the number of points of adjustment is 6. This optical pickup also decreases by 4 the number of points of W bonding to have bad influence on environmental reliability, decreases by about 10 the number of parts, and establishes about 20% cost-down of material cost, compared with the 3rd generation optical pick-up.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1339-1343
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• 2004

This paper presents a development of the control algorithm and Pick & Placer. The Pick & Placer provides a powerful multi-task system that includes both graphical and remote interface. Users can easily set up sorting parameters and record important data including wafer number, data, and operator information. This System sets up a dustproof device and massively machined components to provide an extremely stable sorting environment. Precise resolution and accuracy result from using machine vision, a pneumatic slide drive and close -looped positioning.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.373-374
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• 2012

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.3
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• pp.162-170
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• 2020

In this paper, we report our study of the current measuring technique by implementing a pick-up coil in the PCB pattern instead of the current measuring sensor in a power converter using a WBG device. The proposed PCB pattern coil structure has a higher mutual inductance value than the conventional pattern by constructing the coil using the multi layer board. It has high sensitivity and is configured without additional process outside the PCB. In the current measurement, the integrator is measured by integrating the coil at the back end and the current waveform measured using proposed pick-up coil is confirmed by comparing it with the original current waveform through DPT simulation.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.3
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• pp.9-14
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• 2008

The application of an excavator can be expanded to various works through change of end-effector. In this paper, a gripper, which can pick up and rotate a fixed formal stone, was developed. The device was designed and produced to pick up and rotate a stone for an excavator. The maximum weight of stone was computed to prevent from reversal in according to each displacement of attachments. The necessary force of a hydraulic cylinder to grip a stone was obtained by simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3301-3306
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• 2012

In LED chip packaging, die bonding is a very important process which fixes the LED chip on the lead frame to provide enough strength for the next process. Conventional pick-up device of the die bonder is simply operated by up and down motion of a collet and an ejector pin. However, this method may cause undesired problems such as position misalignment and/or severe die damage when the pick-up device reaches the die. In this study, to minimize the position alignment error and die damage, a die bonder is developed by adopting a new pick-up head for precise alignment and high speed feeding. To evaluate structural stability of the designed system, required finite element model of the die bonder is generated, and structural analysis is performed. Vibration analysis of the pick-up head is also performed using developed finite element model at operation frequency range. As a result of the analysis, deformation, stress, and natural frequency of the die bonder are investigated.

• Journal of Embryo Transfer
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• v.12 no.2
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• pp.211-218
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• 1997

This experiment was carried out to develop the anesthetic methods for ultrasonography and a new simplified disposable needle guidance device for ovum pick-up(OPU) in cows. Three different anesthetic methods were applied as. 1) epidural analgesia only with 2% lidocaine(20~30 ml), 2) epidural analgesia with 2% under general sedation with xylazine, 3) epidural analgesia with 2% lidocaine under general sedation with detomidine. We evaluated the anesthetic effects with items such as relaxation of anal sphincter, tail movement and rectal wall, retractability of both ovaries, additional anesthesia and possibility of OPU. Through this experiment, the above three anesthetic methods were applicable to OPU, but the epidural anlagesia under general sedation with detomldine was most effective for OPU. We developed a new disposable needle guidance device with stainless steel tube. With this, disposable needles can be easily attatchable to any other intravaginal probes. And also, it was found to he practical, economic and effective for OPU with the recovery rate of 51.2%.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.95-99
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• 2006

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and to inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens, LED illumination systems, and a frame grabber inside the PC. This system loads up to six feeders at a time and inspects them automatically and sequentially. The inspection software was implemented using Visual C++ on Windows with easily usable GUI. Using this system, we can automatically measure and inspect the quality of ail feeders in production process by analyzing the measurement results statistically.