• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.7-8
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• 1989

The graft copolymer of chitosan with amino acid, L-lysine was synthesized by heterogeneous copolymerization and was evaluated as an artificial skin. The mechanical properties under dry and wet state, water content, water vapor transmittance rate and biodegradability were measured. The tensile strength and elongation under wet state ranged $0.3-0.5\;kg/mm^2$, 10-13%, respectively. Water vapor transmittance rate ranged $450-500\;g/m^2{\cdot}day$ like that of the normal skin. The weight loss of prepared membrane by protease IV was measured for the degree of biodegradation. The degree of biodegradation was around 15% and after 4 days it was slow. Biocompatibility was evaluated by studying the attachment of human fibroblast on the prepared membrane surface.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.21-30
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• 2006

Alginate, a polymer of guluronic and mannuronic acid, is used as a scaffolding material in biomedical applications. The research was to produce highly-purified alginate from seaweeds and to evaluate the efficacy of alginate as dermal substrate. Our alginate purification method showed a production rate as high as 25%. The purified alginate contained little polyphenol contents and endotoxin, proteins. For study of wound healing, full thickness skin defects were made on the dorsal area of the animal models. And then alginate, fibroblast-growth-factor mixed alginate, alginate-collagen complex, vaseline gauze as control were applied on the wound, respectively, and were evaluated grossly and histopathologically. For biocompatibility test, alginate and alginate-collagen complex discs were implanted on the back of Sprague-Dawly rats. Four weeks after implantation, the animals were examined immunologically against alginate and collagen. Alginate and FGF-mixed alginate, alginate-collagen complex group showed statistically higher percentage of wound contraction and wound healing than control group(p<0.05). Alginate-collagen complex group and FGF-mixed alginate group showed statistically higher percentage of wound healing than alginate group. The experiment of biocompatibility and immunologic reaction against impanted alginate or collagen needs more investigation. Highly-purified alginate from seaweeds by our purification method, showed the effect of wound healing, and addition of FGF or collagen increases the alginate's wound healing effect. It shows the possibility of alginate as a dermal substrate.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.447-456
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• 1995

As a part of electro-mechanical totally implantable artificial heart (TIAH) program, a transcut- aneous energy transmission system has been developed. By mutual magnetic induction between the first coil on the skin and the subcutaneously implanted second coil, the system transfers elctrical power through the skin. This research aimed at minimizing the size of the implanted part as well as maximizing the transfer efficiency. Using class I amplifier, we achieved above 75% power transfer efficiency at average 40W power transfer level which is required for normal TIAH operation. In vivo performance of the developed system and bio-compatibility of the material used in Implanted parts were evaluated through animal experiments.

• KSBB Journal
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• v.29 no.1
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• pp.42-49
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• 2014

The aim of this study was to develop a composite human skin equivalent for wound healing. Collagen type1 and acellular dermal matrix powder were utilized as the scaffold with dermal fibroblasts and keratinocytes for the development of a composite human skin equivalent. Fibroblast maintained the volume of composite skin equivalent and also induced keratinocytes to attach and proliferate on the surface of composite skin equivalent. The composite human skin equivalent had a structure and curvature similar to those of real skin. Balb-C nu/nu mice were used for the evaluation of full-thickness wound healing effect of the composite human skin equivalent. Graft of composite skin equivalent on full-thickness wound promoted re-epithelialization and granulation tissue formation at 9 days. Given the average wound-healing time (14 days), the wound in the developed composite skin equivalent healed quickly. The overall results indicated that this three-dimensional composite human skin equivalent can be used to effectively enhance wound healing.

• The KIPS Transactions:PartB
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• v.16B no.6
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• pp.443-450
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• 2009

This paper develops a novel technique of face detection using brightness distribution in the surrounding area of eye. The proposed face detection consists of facial component candidate extraction, facial component candidate filtering through eye-lip combination, left/right eye classification using brightness distribution, face verification confirming edges in nose region. Because the proposed technique don't use any skin color, it can detect multiple faces in color images with complicated backgrounds and different illumination levels. The experimental results reveal that the proposed technique is better than the traditional techniques in terms of detection ratio.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.461-463
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• 2023

MZ세대를 중심으로 자기관리를 열심히 하는 사람들이 증가함에 따라 화장의 기본이 되는 개인 피부톤(퍼스널 컬러)을 찾는 것이 중요시되고 있다. 현재 대다수 사람은 자신에게 어울리는 퍼스널 컬러를 찾기 위해 높은 비용을 지불하여 전문가를 이용하거나 객관적이고 정량화된 기준 없이 오랜 시간을 투자하여 스스로 퍼스널 컬러를 찾는 등 시간과 비용 측면에서의 한계점을 가지고 있다. 본 논문에서는 이를 보완하기 위해 이미지 기반 인공지능 기술(객체 탐지, 객체 분할, BeautyGAN)을 적용하여 데이터 기반의 정량적인 기준을 생성하고, 퍼스널 컬러에 알맞은 화장품 추천 웹 서비스를 제안한다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.21-25
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• 2009

Generally, fully implantable middle ear hearing device (F-IMEHD) is implanted under the skin nearby human temporal bone with all components including implantable microphone and vibration transducer. The microphone and transducer have different characteristic before and after implant. Fitting process is performed for this characteristic change of them and proper performance of hearing aids for each patient. Conventional hearing aids and partially implantable hearing aids, they have wired connector for fitting process. However in case of F-IMEHD, it is difficult this wired connection, because all components of F-IMEHD is implanted. In this paper, fitting software that can be apply wireless fitting hardware for F-IMEHD has been designed and implemented. It can find out proper fitting parameter reflecting characteristics of the microphone and transducer for patients who has difficulty in hearing.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.11
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• pp.1111-1117
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• 2012

Implants for rhinoplasty should ideally be biocompatible and possess long-term stability after implantation. Silicone implants are most widely used for rhinoplasty. However, these implants suffer from problems related to high extrusion and infection rates. To minimize these complications, we propose a novel augmentation rhinoplasty technique using tissue engineering. To demonstrate its feasibility, a nasal-implant-shaped scaffold was designed using commercialized CAD software and fabricated using a Multi-head Deposition System, which is a solid freeform fabrication system that dispenses material. In vitro cell proliferation and chondrogenic differentiation tests were carried out using nasal septal chondrocytes.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.85-88
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• 2024

Electroencephalography (EEG) is a test that diagnoses epilepsy and measures brain function. During EEG, the space between the electrode and the skin is filled with a conductive paste to reduce the impedance between the electrode and the scalp, which helps measure the EEG signals. This study compared the artifacts of the two representative conductive pastes (Ten20 and Elefix). The artifacts, noise, and satisfaction were surveyed after using the two conductive pastes. The two conductive pastes had similar artifacts and noise, but the survey results showed that the Elefix conductive paste had better satisfaction and adhesion. This result may be explained by the imprinting effect according to the experience of using the Elefix conductive paste first in the EEG class. Hence, further research is needed.

• Journal of Korean Living Environment System
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• v.16 no.2
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• pp.89-100
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• 2009

The present study was designed to observe the thermal dynamics of core and skin temperatures during sub-maximal treadmill exercise; to investigate the effect of regional body cooling during short rest after the treadmill exercise on the thermal dynamics. Three conditions (No cooling, Head/Hand cooling, Leg cooling) were simulated in a climatic chamber at 24±1℃ and 50±5%RH. Subjects performed two bouts of treadmill exercise at a rate of 80%HR_max followed by rest. Body cooling with a hood, long gloves, and a blanket that circulated water set at 15℃ was assigned during two bouts of rest. The results showed that (1) rectal temperature (T_re) did not show significant difference between three conditions; (2) Skin temperatures had specific features, depending on body regions. In particular, the initial fall phenomena of skin temperatures at the onset of exercise were noteworthy in the chest, thigh, calf, and finger tip. Of these, the most significant initial fall was found in finger temperature (T_fing). (3) During the period of the initial fall in skin temperatures, T_re gradually increased. (4) The magnitude of the fall of T_fing at the onset of 2^nd running was on average 4.8, 5.1 and 3.4℃ for Control, HH cooling, and Leg cooling, respectively (p<0.05). The initial drop of T_fing at the onset of running was maintained for an average of 8.1, 7.9 and 6.3 minutes for Control, HH cooling, and Leg cooling, with no significant differences. In conclusion, the initial fall phenomena at the onset of treadmill exercise reflected non-thermal factors, as opposed to internal thermal status. The magnitude of the initial fall in T_fing was affected by legs cooling. Therefore, the initial fall phenomenon should be considered when interpreting the thermal status of the shell during heavy works/exercises that assigned with intermittent regional body cooling.