• Title/Summary/Keyword: 김철환

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Dental Treatment of an AIDS Patient with Cerebral Infarction History and Hepatitis Type B Under General Anesthesia (뇌경색 및 B형 간염을 동반한 후천성 면역 결핍증 환자의 전신 마취 하 치과치료)

  • Ji, Sang-Eun;Kim, Jong-Soo;Kim, Chul-Hwan;Kim, Seung-Oh
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.4
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    • pp.237-241
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    • 2014
  • Acquired Immune Deficiency Syndrome is the state which develops after complications with the infection from HIV. Irrespective of their state, all HIV infections have infectivity. According to a 2013 U.N. AIDS global report, the number of reported newly infected with HIV is constantly falling, while that of Korea has been increasing over recent years and it surpassed 10,000 in 2013. This phenomenon might be attributed to the unusualness of the blood test for early detection of HIV infection. From this fact, we can assume that we have strong possibilities for encounters with infections in the office. But many misconceptions about the disease makes patients try to hide their medical history, which can lead to a nationwide spread of the infection without proper management. Even though it may be difficult to take care of HIV patients in smaller dental offices, large scale hospitals have the means to arrange protocols to treat them. We present a case about dental treatment of a patient with AIDS that has a history of cerebral infarction and hepatitis type B under general anesthesia. The purpose of this case report was to discuss the special considerations of dental care for patients with HIV.

A Study on the Strength Evaluation and Defect Detection Capability of Adhesive Joint with CNTs (CNT를 첨가한 접착조인트의 결함탐지능 및 강도 평가에 관한 연구)

  • Kim, Tae-Hyeong;Kim, Cheol-Hwan;Choi, Jin-Ho
    • Composites Research
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    • v.31 no.4
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    • pp.151-155
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    • 2018
  • Mechanical joint and adhesive joint are two typical joining methods for structures. The adhesive joints distribute the load over a larger area than mechanical joints and have excellent fatigue properties. However, the strength of adhesive joint greatly depends on the environmental conditions and the skill of the operator. Therefore, there is a need for techniques to evaluate the quality of the adhesive joints. The electric resistance method is a very promising technique for detecting defects by measuring the electrical resistance of an adhesive joint in which CNTs are dispersed in an adhesive. In this study, Aluminium-Aluminium adhesive single lap joint specimens were fabricated by using the adhesive dispersing CNTs using a sonicator and a 3-roll mill, and the static strengths and defect detection capabilities of the joints using the electrical resistance method were evaluated according to the CNTs content.

EXPRESSION OF CARTILAGE DERIVED MORPHOGENIC PROTEIN IN PLEOMORPHIC ADENOMA (다형성선종에서 연골유래형성단백의 발현)

  • Lee, Hwang-Jae;Kim, Chul-Hwan;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.33 no.3
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    • pp.247-255
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    • 2007
  • The bone morphogenic protein(BMP) can promote migration and growth of mesenchymal cells and initiate process for bone and cartilage formation. Cartilage-derived morphogenic protein(CDMP)-1 and -2 belong to the bone morphogenetic protein family in the transforming growth factor(TGF)-${\beta}$ superfamily. Although pleomorphic adenoma of the salivary glands is an epithelial tumor, it frequently shows ectopic cartilaginous formation with biomolecular studies. The mechanism of pathogenesis in cartilaginous formation is still controversy. We examined the expression and localization of CDMP-1 and -2, in comparison with the localization of cartilaginous matrix proteins, in human normal salivary glands and 20 cases of pleomorphic adenoma using immunohistochemical methods. The results were followed. 1. CMP-1 was immunolocalized in the striated ducts and the intercalated ducts, but not expressed in excretory duct, CDMP-2 was not expressed in the normal salivary glands. 2. CMP-1 was immunolocalized in the ductal cell and cuboidal neoplastic myoepithelial cells around the chondroid areas of the pleomorphic adenomas, whereas these molecules were not localized in the spindle-shaped neoplastic myoepithelial cells of the myxoid element in these tumors. CDMP-2 was expressed neither in normal salivary glands nor in any elements of the pleomorphic adenomas. 3. In transmission electron microscopic view, the tumor cells are composed of modifed myoepithelial cells between hyaline and myxoid stroma. 4. In Immuno-blot analysis, strong overexpression of CDMP-1 was frequently seen in pleomorphic adenomas, but the level of CDMP-2 was expressed minimally in pleomorphic adenoma. From the these results, it should be suggested that undifferentiated neoplastic myoepithelial cells around the chondroid areas expressed CDMP-1 and suggested that this molecule may play a role in the differentiation of neoplastic myoepithelial cells in pleomorphic adenoma, but not CDMP-2.

BONE HEALING CAPACITY OF THE COLLAGEN BONE FILLER ($TERUPLUG^{(R)}$) AND RHBMP-2 IN THE RABBIT CRANIUM DEFECT (가토 두개골 결손부에 이식된 Collagen bone filler ($TERUPLUG^{(R)}$) 및 rhBMP-2의 골치유 능력)

  • Kim, Ju-Hoon;Kim, Chul-Hwan;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.2
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    • pp.119-130
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    • 2008
  • Absorbable atelo-collagen sponge $TERUPLUG^{(R)}$, Termo Co. Tokyo, Japan) is inserted in the extraction wound where alveolar bone is exposed. It protects wounds and promotes the formation of granulation. This is made of atelo-collagen, to minimize antigenicity, which is cross-linked by heat treatment for biocompatibility. $TERUPLUG^{(R)}$ consists of between 85 and 95 % of collagen type I and between 5 to 15 % of collagen type III. The raw material for the collagen is derived from bovine skin. It features a sponge block design and is shaped for easy insertion in the extraction wound. This study was designed to find out the bone healing capacity of $TERUPLUG^{(R)}$. We implanted $TERUPLUG^{(R)}$ (experimental group I) and $TERUPLUG^{(R)}$ with rhBMP-2 (experimental group II) in the rabbit cranium defect and then histologically analysed the specimen. The results were as follows. 1. In the 4 weeks, a lot of the newly formed collagen fibers around material of the experimental group I implanted $TERUPLUG^{(R)}$ were observed. But, in the experimental group II implanted $TERUPLUG^{(R)}$ with rhBMP-2, a little of newly formed collagen fibers around material were observed. The cell proliferating activity and apoptosis of the experimental group I, II was positive in and around the implanted material. 2. In the 8 weeks, the amount of newly formed and matured bone in the experimental group II was more observed than the experimental group I and control group. The results of this study indicate that absorbable atelo-collagen sponge ($TERUPLUG^{(R)}$) is relatively favorable bone void filler with biocompatibility and has the better bone healing capacity in case of application with rhBMP-2.

Investigation of Electrical and Optical Properties of ITO Film on Polymer Substrates Grown by Roll to Roll Sputtering Process

  • Kim, Cheol-Hwan;Lee, Sang-Jin;Baek, Jong-Hyeon;Jo, Seong-Geun;Ham, Dong-Seok;Choe, U-Jin;Kim, Gwang-Je;Lee, Jae-Heung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.336.1-336.1
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    • 2014
  • 대표적인 TCO 물질인 ITO는 디스플레이 패널이나 태양 전지 등과 같은 소자에 널리 사용되고 있다. 최근에는 대량생산 및 대면적화, 그리고 유연 디스플레이 응용을 위해 롤투롤 스퍼터링(roll to roll sputtering) 공정을 이용하여 플라스틱 기판에 ITO박막을 증착하여 ITO 필름을 제작하고 있다. 롤투롤 방식으로 ITO 필름의 제작 시 공정 변수에 따라 ITO 박막의 전기적 광학적 물성 변화가 매우 크기 때문에, 공정 변수에 따른 ITO 박막의 전기적, 광학적 특성 변화에 대한 연구의 필요성이 매우 높아지고 있다. 따라서 본 연구에서는 롤투롤 스퍼터링 방법으로 PET 기판 위에 다양한 조건으로 ITO 박막을 증착하여 공정변수에 따른 ITO 박막의 물성을 조사 하였다. 이를 위해 ITO (In/Sn=95/5 wt.%) 타겟을 사용하여 DC 파워와 산소 분압비, 열처리 온도 등을 변화시켜 낮은 면저항과 높은 광투과도를 가지는 최적의 ITO 증착 조건을 찾은 후 ITO 박막을 PET 기판 위에 두께 별로 증착 하였다. ITO 박막의 두께와 열처리 온도에 따른 전기적 특성은 면저항 측정기와 홀 측정 장치를 이용하여 분석하였고, 분광광도계와 탁도 측정기를 이용하여 광학적 특성을 관찰하였다. 또한, GIXD를 이용하여 이들 박막의 구조와 결정성에 대한 조사를 수행하였다. 이 결과들로부터 산소 분압비에 따른 ITO/PET 박막의 저항 특성 변화와 ITO 박막의 두께와 열처리 온도에 따른 구조적, 전기적, 광학적 특성을 조사하여, 롤투롤 스퍼터링법에서 공정 조건에 따른 ITO/PET 필름의 물성변화를 보고하고자 한다.

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A Study on the Activation of Dual Use Technology Program (민.군겸용기술사업 활성화 방안 연구)

  • Kim, Chul-Whan;Choi, Eun-Ho;Heo, Whan
    • Journal of the military operations research society of Korea
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    • v.32 no.1
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    • pp.13-35
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    • 2006
  • This study aims to propose alternative suggestions for practical and efficient implementation of Dual Use Technology Programs(CUTP) in Korea which can strengthen both national security and industrial competitiveness. DUTP of Korea has suffered from inefficiency and inactivity. This study analyzes the Inefficiency and negative factors of DUTP of Korea by examining the previous cases of the advanced countries. It also examines individual problems of DUTP carefully and attempts to derive alternative solutions to improve the current situation. First, a global government plan should be made considering Korea's weapon system and Korea's industrial characteristics. Second, DUTP should begin to develop core technology in connection with technology level evaluation and technology exchange project should establish a comprehensive information network system which links any civilian and military technology data. Third, technology transfer project should be promoted by utilizing cyber technology exchange market and military defense venture center. Fourth, standardization project should be expanded by establishing a national standard information system.

60dB 0.18μm CMOS Low-Power Programmable Gain Amplifier (60dB 0.18μm CMOS 저전력 이득 조절 증폭기)

  • Park, Seung-Hun;Lee, Jung-Hoon;Kim, Cheol-Hwan;Ryu, Jee-Youl
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.349-351
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    • 2013
  • This research paper presents a low-power programmable gain amplifier (PGA) to facilitate signal processing of the detection of defects in steel plates. This circuit is able to adjust a gain in the range of 6 to 60dB in 7 steps using different signal types for various defects from hall sensors. The gain of PGA is designed by operating on-resistors of switches and passive components. The proposed PGA ($0.18{\mu}m$ CMOS process with 1.8 supply voltage) showed excellent gain error of less than -0.2dB, and low power consumption of 0.47mW.

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Inelastic and Local Buckling Behavior of H-Beams with Web Opening under Cyclic Loadings (반복하중을 받는 H형강 유공보의 소성 및 국부좌굴 거동)

  • Lee, Eun Taek;Kim, Cheol Hwan;Oh, Woo Hun
    • Journal of Korean Society of Steel Construction
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    • v.15 no.3
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    • pp.271-279
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    • 2003
  • Many researches have been conducted to describe the elastic and inelastic behavior of H-shaped beams with web openings, and were generally concentrated on the uniaxial loading conditions. With previous research results, the formulae for the design of beams with web openings, considering local buckling, have been proposed by Darwin. Although the formulae are so simple and useful to apply to real situations, it needs more research on cyclic loading conditions. In this experimental study, a total of seven H-shaped beams with circular web openings under cyclic loading conditions were investigated. The dimension criteria were based on the formulae proposed by Darwin. The suitability of the existing design formulae, the effects of plastic hinges on beams with web openings, and the local bucking around the web openings to the beam strength under cyclic loading were also investigated through by the observations of the behavior of these beams with various dimensional openings.

Optimization Technology of Thermomechanical Pulp Made from Pinus densiflora (II) - Quantification of Pitch Contents in TMP - (국내산 소나무로 제조되는 열기계펄프 제조 기술 최적화 연구 (II) - TMP 펄프의 피치 정량 연구 -)

  • Nam, Hyegeong;Kim, Chul-Hwan;Lee, Ji-Young;Park, Hyunghun;Kwon, Sol
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.33-42
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    • 2015
  • Pitches contained in thermomechanical pulp negatively influence paper qaulity and pulp and papermaking process. Without controlling TMP pitches suitably, it is hard to make a certain quality of paper. In order to control pitches in TMP, they must be quantitatively recognized by proper tools. One of the most widely used way to detecting TMP pitches is a staining method using a hydrophobic dye such as Sudan IV. Sudan IV could be used with three different protocols including different application of its dissolution, washing, dyeing time, etc. The dyeing protocols were classified into three categories including Stain I, Stain II, and Stain III. In dyeing time, Stain I required more than 24 hours to dye pitches. On the other hand, Stain III could stain TMP pitches with the most brief way. The images of red-stained pitches could be captured by a stereomicroscope with ${\times}35$ and ${\times}45$ magnifications, and then quantitatively analysed measuring their numbers and areas by Carl Zeiss AxioVision (ver. 4.8.2) program. Among three protocols, both Stain I and Stain III were the most ideal methods to detect TMP pitches because they detected more pitches and bigger pitch areas compared to Stain II against the same specimen. In particular, it was recognized that Stain III could be used as the most useful tool to detect TMP pitches accurately within several minutes.

Effect of Electron Beam Irradiation on the Properties of Softwood Unbleached Kraft Pulp (전자선 전처리에 따른 침엽수 미표백 크라프트 펄프의 특성평가)

  • Kim, Eun Hea;Lee, Ji Young;Jeun, Joon Pyo;Kim, Sun Young;Kim, Chul Hwan;Park, Jong Hye
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.5
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    • pp.68-73
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    • 2015
  • Electron beam irradiation is also an eco-friendly treatment compared to other physical and chemical treatments. In this study, we attempted to evaluate the possibilities of energy savings by applying electron beam irradiation to the refining process. After softwood unbleached kraft pulp (UKP) was irradiated with electron beams at 50 and 100 kGy, it was beaten in a laboratory beater, and then its freeness and fiber properties were analyzed. The physical properties of their fiber handsheet were also and measured. As the irradiation dose of the electron beam and the beating time increased, lower freeness and fiber lengths of the UKP were observed. Handsheets made from UKP that was irradiated by electron beam and beaten showed a reciprocal relationship with the irradiation dose of the electron beam, in particular, the strength of the handsheets decreased dramatically at 100 kGy of irradiation. Therefore, it was confirmed that electron beam irradiation is effective in reducing the beating time or beating energy. But the irradiation dose must be controlled under 50 kGy to minimize the loss of paper strength.