• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.628-635
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• 2004

The characteristic of thin film resistor with low TCR( temperature coefficient of resistance ) and high precision are studied. The thin film resistor for 1/4W was fabricated and characteristic of these resistors was investigated. The fabricated device had the thickness of $2.48{\leqq}$ and the resistivity of $0.27{\omega}mm$. The electrical characteristic was evaluated by HP 4339B and 4284A instruments with HP l6339A. The profile of trimmed structure was also measured by non contact interferometer. The change of resistance and TCR increased with increasing roughness and resistance. To reduce the effect of stress annealing treatment was performed in the range of 563 to 623 K after trimming. The characteristic was improved after annealing. It is expected the fabricated device can be useful for high precision and low TCR. Fabricated thin film resistor has average deviation of resistance less than $0.35{\%}$ and TCR within 60.60ppm/K.

• Journal of Oral Medicine and Pain
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• v.41 no.3
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• pp.126-132
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• 2016

Purpose: The aims of this study were to analyze the association between inflammatory cytokine and obstructive sleep apnea (OSA), and to evaluate treatment outcome and changes of plasma inflammatory cytokine levels after oral appliance therapy. Methods: Twenty-seven subjects who visited Department of Oral Medicine in Seoul National University Dental Hospital were performed nocturnal polysomnography and analyzed plasma C-reactive protein (CRP), interleukin (IL)-$1{\beta}$, IL-6, IL-10, and tumor necrosis factor (TNF)-${\alpha}$ levels. Each subject was evaluated with Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). The subjects were classified into 12 OSA patients (apnea-hypopnea index [AHI] >5) and 15 control (AHI ${\leq}5$) groups. The OSA group was treated with mandibular advancement device (MAD) for 3 months and re-evaluated nocturnal polysomnography and plasma inflammatory cytokine levels. Results: Plasma TNF-${\alpha}$, IL-10, and IL-6 levels were significantly higher in OSA patients compared to controls. Total AHI showed significant positive correlations with plasma IL-6 and TNF-${\alpha}$ levels. Percentage time of $SpO_2$ <90 and lowest $SpO_2$ were significantly correlated with plasma TNF-${\alpha}$ level. ESS showed significant positive correlation with plasma IL-10 level. Total AHI, percentage time of $SpO_2$ <90, lowest $SpO_2$, and mean $SpO_2$ were significantly improved after the MAD therapy. Plasma TNF-${\alpha}$ level was significantly decreased after MAD therapy. Conclusions: We suggest that MAD therapy is an effective treatment modality for patients with OSA and can decrease plasma cytokine level.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2648-2654
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• 2012

This study aims to examine the effects of massages using various tools being frequently applied in skin care centers. It suggests the most effective method based on the comparative analysis on the body heat changes before and after the massages and also provides foundational data to develop back treatment programs. This research conducted manual, ultrasonic device, and also suction massages from July 3rd till 10th, 2011 to women at the age of 35 to 45 living in Gwangju, Jeonnam. And five of them were arranged for each tool. The body heat changes before the massages and after the 20-minute massages were measured with the body heat diagnostic device of thermograph DITI IRIS-XP. The collected data went through the t-test using SPSS 18.0. According to the result, the body temperature increased significantly before and after the manual massage from $30.82{\pm}0.52$ to $35.06{\pm}0.36$ (p<.001). The body temperature also increased significantly before and after the ultrasonic massage from $30.66{\pm}0.53$ to $35.14{\pm}0.39$ (p<.001). And the body temperature increased significantly before and after the suction massage from $30.93{\pm}0.47$ to $39.25{\pm}0.19$ (p<.001). The hand, ultrasonic device, and also suction were all effective as massage tools in terms of increasing body temperature, and the suction massage was shown to have the greatest effect in body temperature increase. Thus, the suction was analyzed as the most effective tool to be used to develop back treatment programs.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.526-526
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• 2013

Plasma technology isbeing developed for a range of medical applications including wound healing. However, the effect of plasma on many cells and tissues is unclear. Cell migration and cell proliferation are very important biological processes which are affected by plasma exposure and might be a potential target for plasma therapy during wound healing treatment. In this study, we confirmed the plasma exposure time and incubation time after plasma treatment in skin fibroblast (L-929 cells) to evaluate the optimal conditions forplasma exposure to the cell in-vitro. In addition, we used a scratch method to generate artificial wound for evaluating the cell migration by plasma treatment. Where, the cells were treated with plasma and migration rate was observed by live-cell imaging device. To find the cell proliferation, cell viability assay was executed. The results of this study indicate the increased cell proliferation and migration on mild plasma treatment. The mechanisms for cell migration and cell proliferation after plasma treatment for future studies will be discussed.

• Journal of Welding and Joining
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• v.17 no.2
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• pp.61-65
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• 1999

Because of the need for packages which accommodate high pin count, high density and high speed device, PBGA(plastic ball grid array) package gets more spotlight. But the substrate material which is used for PBGA package is in nature susceptible to moisture penetration. The objective of the study is to find out the path of delamination in the stacked structure of substrate. To increase the adhesion between the cooper laminate and PSR(photo solder resist) which is the weakest part, experiments were performed by changing parameters of printing pre-treatment and post-treatment process. As a result of experiments, the factor effects on the adhesion between the cooper laminate and PSR is caused by all of the pre-treatment and post-treatment condition. A considerable change was observed depending on the amount of UV irradiation after thermal cure which is typical of printing post-treatment condition rather than pre-treatment condition.

• Journal of Periodontal and Implant Science
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• v.28 no.4
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• pp.823-828
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• 1998

A primary goal of periodontal therapy is the creation of root surfaces that are free of plaque and calculus. It is not yet to be determined whether it is desirable to have a smooth root surface after treatment. It is also not clear what degree of roughness result from different instruments. In the present study various instruments for root surface debridement were evaluated. 20 extracted teeth were utilized, and the teeth were treated with one of the following instrument: Gracey curette, Perio Clean, and piezo ultrasonic device(Setlec, P Max) with general scaler tip, curette-like tip, and diamond tip. 3 dimensional planimetric device(Accura) was used to evaluate the average surface roughness. It was demonstrated hand and power-driven instruments did not have a significant difference in roughness of the root surface following instrumentation. And ultrasonic scaler tip tended to make a most smooth surface than other instruments. The possible reasons of the result were discussed.

• Electronics and Telecommunications Trends
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• v.32 no.6
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• pp.27-39
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• 2017

A variety of medical devices are utilized to repair or help injured body functions after accidental injury(such as a traffic accident), population aging, or disease. Such medical devices are being actively researched and developed in portable form, skin patchable type, and further, implantable form. In the future, active implantable medical devices for neuro and brain sciences are expected to be developed. Active implantable medical devices that detect brain signals and control neurology for a wider understanding of human cognition and nerve functions, and for an understanding and treatment of various diseases, are being actively pursued for future use. In this paper, the core elements of implantable devices that can be applied to neuro and brain sciences are classified into electrode technologies for bio-signal acquisition and stimulation, analog/digital circuit technologies for signal processing, human body communication technologies, wireless power transmission technologies for continuous device use, and device integration technologies to integrate them. In each chapter, the latest technology development trends for each detailed technology field are reviewed.

• Medical Lasers
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• v.10 no.2
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• pp.96-105
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• 2021

Background and Objectives Skin aging is reportedly associated with regulation in collagen and elastin synthesis. This study investigated the potential of combining light-emitting diode (LED) treatments using a 630-nm and 850-nm LED with simultaneous microcurrent application. Materials and Methods The dorsal skin of female pigs was treated with a home-use device. We examined the treatment effects using photography, thermocamera, microscopic pathology, and histological examination to determine the mechanism of action, efficacy, and safety of the procedure. A histological observation was performed using hematoxylin and eosin, Masson's trichrome, Victoria blue, and immunohistochemical staining. We also used the Sircol soluble collagen and elastin assay kit to measure the amounts of collagen and elastin in the porcine back skin tissue after 2 and 6 weeks. Results Evaluation by visual inspection and devices showed no skin damage or heat-induced injury at the treatment site. Histological staining revealed that accurate treatment of the targeted dermis layer effectively enhanced collagen and elastin deposition. Collagen type I, a protein defined by immunohistochemical staining, was overexpressed in the early stages of weeks 2 and 6. Combined therapy findings showed the superior capability of the 630-nm and 850-nm LED procedures to induce collagen; in contrast, elastin induction was more pronounced after microcurrent treatments. Conclusion The home-use LED device, comprising a combination of 630-nm and 850-nm LEDs and microcurrent, is safe and can be used as an adjunctive treatment for self-administered facial rejuvenation.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.145-156
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• 2011

Objectives: This study was resigned to observe change of body temperature for patients with low back muscular pain after NUGA MRT-II(pulsed electromagnetic therapy) treatment. Methods: This study was a randomized, patient-assessor blind, placebo-controlled, pilot trial study. After the approval of institutional review board(IRB), we have recruited 38 patients suffering from low back muscular pain and divided them into two groups randomly: the treatment group and control group. To the treatment group, NUGA MRT-II was practiced and to the control group sham device was practiced and their low back muscles and acupuncture points three times a week for 2 weeks from February 2011 to May 2011. After 1 week of last treatment, We compared body temperature of two groups. Results: 1. There was significant decrease of body temperature on both Shinsu(BL23), Chishil(BL52), Kwanwonsu(BL26) acupunture points for the treatment group. 2. There was no difference in the decrease of body temperature between treatment group and control group except. Left Kwanwonsu(BL26). Conclusions: We found out that treatment of NUGA MRT-II on low back muscular pain can reduce the temperature of low back.

• Korean Circulation Journal
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• v.53 no.3
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• pp.134-150
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• 2023

Ventricular septal defects (VSDs) are the most common kind of congenital heart disease and, if indicated, surgical closure has been accepted as a gold-standard treatment. However, as less-invasive methods are preferred, percutaneous device closure has been developed. After the first VSD closure was performed percutaneously by Lock in 1988, both techniques and devices have developed consistently. A perventricular approach for closure of muscular VSD in small patients and the closure of perimembranous VSD using off-label devices are key remarkable developments. Even though the Amplatzer membranous VSD occluder (Abbott) could not be approved for use due to the high complete atrioventricular conduction block rate, other new devices have shown good results for closure of perimembranous VSDs. However, the transcatheter technique is slightly complicated to perform, and concerns about conduction problems after VSD closure with devices remain. There have been a few reports demonstrating successful closure of subarterial-type VSDs with Amplatzer devices, but long-term issues involving aortic valve damage have not been explored yet. In conclusion, transcatheter VSD closure should be accepted as being as effective and safe as surgery but should only be performed by experienced persons and in specialized institutes because the procedure is complex and requires different techniques. To avoid serious complications, identifying appropriate patient candidates for device closure before the procedure is very important.