• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.161-167
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• 1999

This paper describes the calibration method and the calculation equations of expanded uncertainty for a precision electric force measuring device. The calibration of the electric force measuring device is performed three times (0 ${\circ}$(first time), $120{\circ}$(second time), $240{\circ}$(third time)) at each calibration point. It is usually selected ten points from zero load to rated load of the electric force measuring device. The expanded uncertainty is calculated by combining A type standard uncertainty and B type standard uncertainty. The calibration method and the calculation equations of expanded uncertainty can be widely used in the calibration of the precision electric force measuring device.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.5
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• pp.598-606
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• 2013

After the missile is launched, the umbilical connector should be separated from it without any physical interference. The umbilical separation device, for this purpose, was developed by means of new concept. Using the investigation of various methods to separate the umbilical connector, a suitable method was selected and a corresponding device was designed and manufactured. To ensure the performance of the developed device, numerical analysis and performance test were conducted and correction was followed. The umbilical separation device was applied to real system operation test and its operation performance was tested. In consequence, several problems were founded, however, good results were generally obtained.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.740-745
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• 2014

ZnO nanowires were grown by hydrothermal synthesis process and piezoelectric poly vinylidene fluoride (PVDF) was then coated on top of the ZnO-nanowires by spray-coating technique. The composite layer of ZnO-nanowires/PVDF was applied to an energy harvesting device based on piezoelectric-conversion mechanism. A defined mechanical force was given to the nanogenerator device to evaluate their electric power generation characteristics, where output current density and voltage were examined. Electric power generation property of the ZnO-nanowires/PVDF based nanogenerator device was compared to that of the nanogenerator device with ZnO-nanowires as single active layer. Effect of the ZnO-nanowires on improvement of power generation was discussed to examine its feasibility for the nanogenerator device.

• Archives of design research
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• v.19 no.3 s.65
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• pp.5-18
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• 2006

Digital information society shows a variety of contents of cross-categorial digital media in their inner or outer forms and concepts of the artistic aspects. In order to cope with such a complicated, unexpected trend in digital media and its industry, a new approach in the design process needs to be developed and adjusted with the new equipment of the creativity-thinking process of 'the Multi-Sensory Device (MSD),' 'the Multi-Dimensional Device (MDD),' and 'the Storytelling Device (SD)' in the Prism Effect-based Creativity-Thinking Process (PECTP). The PECTP is in principle designed to practically work with the four distinct techniques: 1) Physical Activity, 2) Linguistic Activity, 3) Visual Activity, and 4) Complex Activity. Consequently, this thesis notes that the nature of the cross-categorial design contents is necessarily non-directional since the creativity power inside the Prism Effect results in openness and diversity.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.8
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• pp.78-88
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• 1992

To improve the characteristics of sub$\mu$m short channel MOSFET device, a new device having the convex structure is proposed. This device has 3-dimensionally expandable channel length according to the vertical etched silicon height. For the purpose of comparing the DC and AC characteristics, planar device is also fabricated. Comparing the channel length, the convex device with 0.4$\mu$m silicon height is larger about 0.56$\mu$m in NMOS and 0.78$\mu$m in PMOS than planar devices. DC characteristics, such as threshold voltage, operational current, substrate current and breakdown voltage are compared together with AC characteristics using the ring oscillator inverter delay. Also process and device simulation are performed and the differences between convex and pranaldevice are also compared.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.627-632
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• 2009

This paper proposes a new haptic cue vehicle accelerator pedal device using magnetorheological (MR) brake. As a first step, an MR fluid-based haptic cue device is devised to be capable of rotary motion of accelerator pedal. Under consideration of spatial limitation, design parameters are optimally determined to maximize control torque using finite element method. The proposed haptic cue device is then manufactured and integrated with accelerator pedal. Its field-dependant torque is experimentally evaluated. Vehicle system emulating gear shifting and engine speed is constructed in virtual environment and communicated with the haptic cue device. Haptic cue algorithm using the feed-forward control algorithm is formulated to achieve optimal gear shifting in driving. Control performances are experimentally evaluated via feed-forward control strategy and presented in time domain.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.953-958
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• 2001

The antifuse is a semi-permanent memory device like a ROM which shows the open or short state, and a switch device connecting logic blocks selectively in FPGA. In addition, the antifuse has been used as a logic device to troubleshoot defective memory cells arising from SDRAM processing. In this study, we have fabricated ONO antifuses consisted of PIP structure. The antifuse shows a high resistance more than several G Ω in the normal state, and shows a low resistance less than 500 Ω after program. The program resistance variation according to temperature shows the very stable value of $\pm$20 Ω. At this time, its program voltage shows 6.7∼7.2 V and the program is performed within 1 second. Therefore this result shows that the PIP antifuse is a very stable and programmable logic device.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.5
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• pp.462-468
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• 2009

In this study, a workpiece-chucking device that generates a chucking force from a shape memory alloy is introduced. This paper first presents train procedure to transform a commercial one-way shape memory alloy into a two-way shape memory alloy, which makes unclamping mechanism of the chucking device simpler than that using the one-way shape memory alloy Second, it describes a conceptual design of the workpiece-chucking device using the two-way type shape memory alloy. Third, it presents a prototype and its chucking characteristics, such as time-response of clamping/unclamping operations and a relationship between temperatures and chucking forces. Finally, it describes a mill-machining test conducted with the prototype. The results confirm that the proposed workpiece-chucking device is feasible for micro machine-tools.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.197-203
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• 2005

This paper presents kinematic calibration of parallel manipulators with partial pose measurements using a device that measures a rotation of the end-effector along with its position. The device contains an LVDT, a biaxial inclinometer, and a rotary sensor and facilitates automation of the measurement procedure. The device is designed in a modular fashion and links of different lengths can be used. The additional kinematic parameters required for the measurement device are discussed, kinematic relations are derived, and cost function is established to perform calibration with the proposed device. The study is performed for a six degree-of-freedom(DOF) fully parallel HexaSlide Mechanism(HSM). Experimental results show significant improvement in the accuracy of the HSM.

• Journal of radiological science and technology
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• v.30 no.2
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• pp.153-159
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• 2007

Digital medical image commenced with an introduction of PACS has become more popular today in the radiation diagnosis and radiation treatment and made great progress, in particular, for medical testing field, whereas it has made slow progress for radiation treatment field. In order to accommodate the current trend of digital from analog, a spherical mechanical check device(SMCD) that is the form of spherical differing from the existing form of flat or cube has been designed and tested its practicability to replace the part in mechanical check with digital image from QA operation. If the distance maintains constance between source(target) and image detector with constant distance to the center of spherical mechanical check device(SMCD), the size will be shown as a constant image at all times regardless of its direction exposed. For the test, two accurate hemispheres are made and put together which results in a sphere of the equilateral circle. It enables a variety of implementation of the existing mechanical check using digital image as follows: congruity level of radiation field and light field, size accuracy of radiation field and collimation field, gantry rotation isocenter check, collimation rotation isocenter check, room laser accuracy check, collimation rotation angle check, couch rotation angle check, and more. In addition, it has proved its practicability in checking isocenter congruity level as real time at the time of simultaneous rotation between gantry and couch that is applied to the non-coplanar field, which had been hard to apply as a device formed of existing flat or cube.