• Korean Journal of Materials Research
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• v.27 no.5
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• pp.248-254
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• 2017

In the present work, graphene powder was synthesized by laser scribing method. The resultant flexible light-scribed graphene is very appropriate for use in micro-supercapacitors. The effect of the laser scribing process in reducing graphene oxide (GO) was investigated. GO was synthesized using a chemical mixture of GO solution; then, it was coated onto a LightScribe DVD disk and laser scribed to reduce GO and create laser-scribed graphene (LSG). The CV curves of pristine rGO at various scan rates showed that the ultimate product possesses the ability to store energy at the supercapacitor level. Charge-discharge curves of pristine rGO at two different current densities indicated that the specific capacitance ($C_m$) increases due to the reduction of the discharge current density. Finally, the long-term charge-discharge stability of the LSG was plotted and indicates that the specific capacitance decreases very slightly from its primary capacitance of ${\sim}10F\;cm^{-3}$ and that the cyclic stability is favorable over 1000 cycles.

• The Journal of Korean Physical Therapy
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• v.23 no.3
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• pp.1-5
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• 2011

Purpose: This study examined the relationship between the center of pressure (COP) displacement time during the stance phase and dynamic balance ability when older adults cross a 10 cm obstacle. Methods: Fifteen older adults were enrolled in this study (all ${\geq}65$ years of age). The F-scan was used to measure the COP displacement time when subjects cross a 10 cm obstacle, and the Dynamic gait index. Berg's balance scale and the Four square step test were used to measure dynamic balance ability. Results: The Dynamic gait index, Berg's balance scale and the Four square step test were correlated with each other. Dynamic balance ability was correlated with COP displacement time during the stance phase at an obstacle crossing in older adults. Conclusion: People with higher dynamic balance ability show a smaller COP displacement time during the stance phase at an obstacle crossing. Therefore, dynamic balance ability can be predicted by measuring the center of pressure displacement time.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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• pp.662-666
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• 2008

Electrochemical properties of carbon cryogel electrode for the application of composite electrode materials mixed with metal oxide in supercapacitor have been studied. Carbon cryogels were synthesized by sol-gel polycondensation of resorcinol with form aldehyde, followed by a freeze drying, and then pyrolysis in an inert atmosphere. Physical properties of carbon cryogel were characterized by BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is found that carbon cryogel is amorphous material. The electrochemical properties of carbon cryogel were measured by cyclic voltammetry as a function of concentration of liquid electrolyte, galvanostatic charge-discharge with different scan rates and electrochemical impedance measurements. The result of cyclic voltammetry indicated that the specific capacitance value of a carbon cryogel electrode was approximately 150.2 F/g (at 5 mV/s in 6M KOH electrolyte).

• Korean Journal of Computational Design and Engineering
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• v.18 no.3
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• pp.155-166
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• 2013

We present recent human-vehicle interaction (HVI) research conducted in the area of defense and military application. Research topics discussed in this paper include: training simulation for overland navigation tasks; expertise effects in overland navigation performance and scan patterns; pilot's perception and confidence on an overland navigation task; effects of UAV (Unmanned Aerial Vehicle) supervisory control on F-18 formation flight performance in a simulator environment; autonomy balancing in a manned-unmanned teaming (MUT) swarm attack, enabling visual detection of IED (Improvised Explosive Device) indicators through Perceptual Learning Assessment and Training; usability test on DaViTo (Data Visualization Tool); and modeling peripheral vision for moving target search and detection. Diverse and leading HVI study in the defense domain suggests future research direction in other HVI emerging areas such as automotive industry and aviation domain.

• Journal of Breast Cancer
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• v.21 no.4
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• pp.463-467
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• 2018

Metastasis from primary cancer to the thyroid is uncommon in breast cancer. Here we present a case of lobular breast carcinoma that metastasized to the thyroid. A 54-year-old woman without symptoms was admitted to our institution for staging of the lymph node above the left clavicle. An $^{18}F$-fluoro-deoxy-D-glucose positron emission tomography scan was performed for staging, and low uptakes were observed in the left supraclavicular and cervical lymph nodes. High uptake was seen in the posterior and lower left lobe of the thyroid. Histologic findings indicated lobular breast carcinoma (positive GATA3, loss of E-cadherin expression) metastatic to the thyroid with a luminal profile. Immunohistochemical analysis was negative for primary thyroid or parathyroid carcinoma. To our knowledge, this is the first report of a patient presenting a metastatic invasive lobular carcinoma in the thyroid and lymph nodes without a prior diagnosis of breast cancer.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.99-103
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• 2019

A derivative of 1,4-Naphthoquinone coded HBU671 was synthesized and used in addition to activated carbon as composite electrode for supercapacitor application. From the electrochemical properties analysis, a specific capacitance of about $300F\;g^{-1}$ exhibited almost two times of that of activated carbon at a scan rate of $100mV\;s^{-1}$ and a potential window of - 0.2 - 1V. This improvement is due to the inherent redox reaction in HBU671. Cycle test also proved that this composite is still stable even after 1000 cycle within the applied potential window and it is highly recommended for practical application.

• Journal of Electrochemical Science and Technology
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• v.8 no.2
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• pp.107-114
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• 2017

Pseudo capacitors belong to one group of super capacitors which are consisted with non carbon based electrodes. As such, conducting polymers and metal oxide materials have been employed for pseudo capacitors. Conducting polymer based pseudo capacitors have received a great attention due to their interesting features such as flexibility, low cost and ease of synthesis. Much work has been done using liquid electrolytes for those pseudo capacitors but has undergone various drawbacks. It has now been realized the use of solid polymer electrolytes as an alternative. Among them gel polymer electrolytes (GPEs) are in a key place due to their high ambient temperature conductivities as well as suitable mechanical properties. In this study, composition of a polyacrylonitrile (PAN) based GPE was optimized and it was employed as the electrolyte in a pseudo capacitor having polypyrrole (PPy) electrodes. GPE was prepared using ethylene carbonate (EC), propylene carbonate (PC), sodium thiocyanate (NaSCN) and PAN as starting materials. The maximum room temperature conductivity of the GPE was $1.92{\times}10^{-3}Scm^{-1}$ for the composition 202.5 PAN : 500 EC : 500 PC : 35 NaSCN (by weight). Performance of the pseudo capacitor was investigated using Cyclic Voltammetry technique, Electrochemical Impedance Spectroscopy (EIS) technique and Continuous Charge Discharge (GCD) test. The single electrode specific capacity (Cs) was found out to be 174.31 F/g using Cyclic Voltammetry technique at the scan rate of 10 mV/s and within the potential window -1.2 V to 1.2 V. The same value obtained using EIS was about 84 F/g. The discharge capacity ($C_d$) was 69.8 F/g. The capacity fade over 1000 cycles was rather a low value of 4%. The results proved the suitability of the pseudo capacitor for improving the performance further.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.732-737
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• 2005

Distal 3D Real Object Duplication System(RODS) consists of 3D Scanner and Solid Freeform Fabrication System(SFFS). It is a device to make three-dimensional objects directly from the drawing or the scanning data. In this research, we developed an office type SFFS based on Three Dimensional Printing Process and a industrial SFFS using Dual Laser. An office type SFFS applied sliding mode control with sliding perturbation observer(SMCSPO) algorithm for control of this system. And we measured process variables about droplet diameter measurement and powder bed formation etc. through experiments. Also, in order to develop more elaborate and speedy system for large objects than existing SLS process, this study applies a new Selective Multi-Laser Sintering(SMLS) process and 3-axis dynamic Focusing Scanner for scanning large area instead of the existing $f\theta$ lens. In this process, the temperature has a great influence on sintering of the polymer. Also the laser parameters are considered like that laser beam power, scan speed, scan spacing. Now, this study is in progress to eveluate the effect of experimental parameters on the sintering process.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.932-937
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• 2002

A partial genome scan using porcine microsatellites was carried out to detect quantitative trait loci (QTL) for backfat thickness (BFT) in a pig reference population. This population carried QTL on chromosomes 1, 13 and 18. The QTL on chromosome 1 was located between marker loci S0113 and SW1301. The QTL corresponded to very low density lipoprotein receptor gene (VLDLR) in location and in biological effects, suggesting that VLDLR might be a candidate gene. The QTL found on chromosome 13 was found between marker loci SWR1941 and SW864, but significance for the marker-trait association was inconsistent by using data with different generations. The QTL on chromosome 18 was discovered between markers S0062 and S0117, and it was in proximity of the regions where IGFBP3 and GHRHR were located. The porcine obese gene might be also a candidate gene for the QTL on chromosome 18. In order to understand genetic architecture of BFT better, fine mapping and positional comparative candidate gene analyses are necessary.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.27-32
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• 2008

Purpose: The evaluation of SUV (Standardized Uptake Values) for quantitative analysis in PET exam is the most significant. In PET exam, we make attenuation correction images by using $^{68}Ge$, $^{137}Cs$ or CT data. At this time, a distorted attenuation map affects quantitative analysis. After the exam using barium-sulfate and high density of barium contrast make attenuation map distorted. And then it brings bed influences on SUV. The aim of this study is to verify the relationship between high density barium-sulfate and SUV in PET exam. Materials and Methods By using $^{18}F$-FDG, we made barium-sulfate powder, density of 0, 1.5, 3, 5, 10 and 15% respectively and acquired PET and PET/CT images per each density. And we examined SUV variations from PET and PET/CT images according to differences of barium's density. Moreover, we finally calculated SUV causing variations in HU (Hounsfield Units) values to justify whether the differences of barium density bring any changes in PET/CT exam. Results: From PET images acquired from transmission scan with $^{68}Ge$, we got SUV figures from 6.46 to 6.8 in barium density between 0 to 15 percent. On the other hand, In PET images acquired from Tx scan that using CT, SUV was 6.77 to 23.73, derived from the same barium density. And CT HU values range from 29 to 2004. Conclusion: PET images from Tx data using $^{68}Ge$ weren't affected by barium density and had no differences in SUV. But in the PET/CT images using CT Tx data, there's considerable variations in HU and SUV values according to a difference of barium density in HU values. To perform a precise examination, barium sulfate should be removed from a human body before performing a PET exam.