• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.482-482
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• 2005

• Journal of Biosystems Engineering
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• v.37 no.2
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• pp.106-112
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• 2012

Purpose: A lab-scale timber carriage using a servo motor system was built. When two motors move a carriage, wire tension is changed according to the different line speeds caused by a wire drum's changing diameter, leading to inappropriate traveling characteristics of the carriage. In order to overcome this problem, PID Control was used to control the motor speed. Methods: Ziegler-Nichols method was used to determine PID gains. Results: The initial PID gains were 1.8, 0.025, and 0.006, respectively, and optimal gains of 1.4 and 0.010 for P and I gain were obtained experimentally. Conclusions: The results showed that constant wire tension could be maintained by controlling the speed of the motor using PI control. Overshoot occurred at initial motor operation due to vibration and elasticity of the wire itself.

• Design & Manufacturing
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• v.11 no.3
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• pp.8-12
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• 2017

In general, metallic bio-materials is more widely used in solid tissue like bone or tooth than flexible tissue such as skin or muscle. Especially, Cobalt Chrome Molybdenum(Co-Cr-Mo), which is used in tooth surgery, has a great corrosion resistance. Because this bio-material is non-toxic in human body, and has a bio-compatibility that the vital reaction is not occurred with tissue in body. However the chemical reaction is occurred by fatal matter that deteriorate the property of material surface in conventional polishing, and it can affect to fatal disease in human body or decrease the material properties such as hardness, yield strength or bio-compatibility. This surface in poor condition can cause development of corrosion or bacteria. In this study, MR fluid polishing is used to minimize the scratch, pit or surface flaws generated in conventional polishing. Surface roughness is measured according to the polishing condition to obtain fine surface condition.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.487-488
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.730-734
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• 2005

Flow injection analysis (FIA) system was developed to monitor glucose concentrations in biotechnological processes. A fiber optic oxygen sensor was used to determine consumption of oxygen concentration by reaction of immobilized glucose oxidase (GOD). The GOD was immobilized on VA-Epoxy carrier and integrated into FIA system. A calibration curve for glucose was obtained in the range of 0.5 $g/L{\sim}3.0$ g/L.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.132-139
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• 2005

Wireless bio-signal sensing system, which is based on the principle of Doppler radar, can measure a respiration and heart rates with a periodic movement of skin and muscle near the heart. Though the sensing monostatic system using a circulator has been studied, this bistatic system can be improved by using a circular polarized antenna which has a high isolation between transmitter and receiver. In this paper, we measured the bio-signal without the direct contact with the person. The design of each system and experimental results are discussed.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.2
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• pp.124-128
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• 2017

A light guide improves the spatial resolution of a gamma ray imaging system by diffusing the scintillation light. Similarly, light diffusion film, which has been applied to flat-panel-display engineering, spreads the light from the light guide panel. In this study, we adopted light diffusion film for the light guide of a gamma ray imaging system, and evaluated its diffusion characteristics. We compared the light diffusion performance of the film to an ordinary acrylic plate. As a result, the diffusion film widely spreads scintillation light. As for the thickness of the light guide, we acquired more distinct images with three films overlapped than with an acrylic plate. We expect light diffusion film to be a promising candidate for light guides in gamma ray imaging systems.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.7
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• pp.783-788
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• 2011

The recent development of bio-ceramic material is being studied in various bio-material engineering field. There are lots of technical difficulties because manufacturing or bonding technique are required bio-friendliness, cleanliness and persistence. Zirconia ceramic powder is cladded on Ti-6AI-4V metallurgically by laser cladding processing. Laser cladding system with powder feeding delivery is designed and manufactured for optimum processing condition. Increasing of manufacturing speed and good quality of clad layer are achieved by application of preheating of substrate before laser cladding. The thin dilution and good clad layer on the substrate are obtained for applications of bio-materials such as the dental materials and the articulated joints of human body.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.176-179
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• 2001

A portable bio-signal measurement system for 24-hours continuous health monitoring of the elderly and the disabled is presented. The measurement system has the functions of acquisition of various bio-signals such as ECG, EMG and EEG, wireless data transmission/receive and adjustment of parameters such as gain and cut-off frequency. The data is sent to a host computer or other device via a Bluetooth. The design targets of the developing system for volume and power consumption are $20{\times}30{\times}5(mm^3)$ and 8mW.

• Carbon letters
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• v.7 no.4
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• pp.266-270
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• 2006

Multi-walled carbon nanotube-poly methyl methacrylate (MWNT/PMMA) nanocomposite has been prepared by in situ polymerization of MMA dispersed with MWNTs. The MWNTs were functionalized by nitric acid and sulfuric acid treatment, and this was confirmed by FTIR spectrometer. The solution mixture of MWNTs and MMA was partially polymerized at $80^{\circ}C$, followed by the addition of AIBN and polymerization at $50^{\circ}C$. The MWNT-PMMA composite was prepared by casting the pre-polymer on the glass plate, and the optical properties have been studied using UV-vis spectrometer. The acid treated MWNTs were well dispersed in MMA with fairly good dispersion stability, while flocculation and sedimentation was observed from raw MWNTs in MMA.