한국산업기술대학교의 산학일체형 교육제도

박철우,Park, Cheol-U 한국대학교육협의회 2004 大學敎育 Vol.127 No.-

하악 편측 유리단 가철성 국소의치의 설계에 따른 광탄성 응력 분석

박철우,계기성,Park, Cheol-Woo,Kay, Kee-Sung 대한치과보철학회 2009 대한치과보철학회지 Vol.47 No.2

연구목적: 하악 우측 제1, 2 대구치가 결손된 Kennedy 분류 II급 증례에서 임상적으로 적용할 수 있는 편측 유리단 가철성 국소의치의 종류에 따른 응력 분포 양상을 비교하는 것이다. 연구 재료 및 방법: Kennedy 분류 II급 증례의 광탄성 모형에서 클라스프를 이용한 국소의치, 코너스 치관을 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치, 탄성 레진을 이용한 국소의치를 편측성으로 제작하였다. 응력 동결로에서 응력 주기에 맞춰 각 국소의치의 제1 대구치 중심와에 6 kg의 수직하중을 가하면서 응력을 동결하였다. 광탄성 모형을 절단하여 만든 시편을 광탄성 실험 장치로 광탄성 등색선의 흑백 무늬를 관찰하고 디지털 카메라로 촬영하였다. 촬영된 사진에서 8개의 측정점을 정하여 육안으로 무늬차수를 계측하고 비교하였다. 결과: 각 절단 시편의 최대 무늬차수와 하중점 직하방의 잔존 치조제에 발생한 무늬차수는 탄성 레진을 이용한 국소의치, 클라스프를 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치, 코너스 치관을 이용한 국소의치 순으로 높게 관찰되었다. 제2 소구치 치근단에 발생한 무늬차수는 클라스프를 이용한 국소의치, 탄성 레진을 이용한 국소의치, 코너스 치관을 이용한 국소의치, 완압형 어태치먼트를 이용한 국소의치 순으로 높게 관찰되었다. 결론: 코너스 치관을 이용한 국소의치가 수직하중시 지대치 주위 치조골과 잔존 치조제에 대하여 응력을 가장 균형있게 분산시켰고, 탄성 레진을 이용한 국소의치는 지대치보다 잔존 치조제의 상태가 더 양호한 경우에 적용 가능할 것이다. Statement of problem: There are common clinical cases in which the mandibular first and second molars are missing unilaterally. Purpose: This study was designed to compare and evaluate the magnitude and distribution of stress produced by four kinds of mandibular unilateral free-end removable partial dentures that could be applied clinically in Kennedy class II cases. Material and methods: Four unilateral free-end removable partial dentures using clasp, Konus crown, resilient attachment, and flexible resin were fabricated on the photoelastic models of the Kennedy class II cases. The vertical load of 6㎏ was applied on the central fossa of the first molar of every removable partial denture in the stress freezing furnace and the photoelastic models were frozen according to the stress freezing cycle. After these models were sliced mesio-distally to a thickness of 6mm, the photoelastic isochromatic white and black lines of the sliced specimens were examined with the transparent photoelastic experiment device and photographs were taken with a digital camera. The fringe order numbers at eight measuring points in the photograph were measured with the naked eye. Results: The maximum fringe order number of each sliced specimen and the fringe order number at the residual ridge just below the loading point were in the decreasing order of the unilateral removable partial dentures using flexible resin followed by clasp, resilient attachment, and Konus crown. The fringe order number at the root apex of the second premolar was in the decreasing order of the unilateral removable partial dentures using clasp followed by flexible resin, Konus crown, and resilient attachment. Conclusion: The removable partial denture using Konus crown showed the most equalized stress distribution to the supporting alveolar bone of abutment teeth and residual ridge under the vertical loads. The removable partial denture using flexible resin can be applied to the case that has a better state of residual ridge than abutment teeth.

루프형 낙석방지안전시설의 구조적 안전성 검토 연구

박철우,이학용,Park, Cheol-U,Lee, Hak-Yong 한국건설안전협회 2009 建設 安全技術 Vol.50 No.-

Road is typically constructed along ridge area of mountain because of topographical and economic reasons. Therefore, road may face lots of open cut slope which can easily cause rock falling. This study evaluates the structural safety of newly developed falling rock protection system which has a roof deck plate. The structural performance under self-weight, snow load and load from failing rock was investigated using a finite element numerical analysis method. From the analysis results, the H-beam space was limited not to exceed 2.2m. The deck plate was also safe under the examined loading condition. A hinge and connection in the system were investigated through detailed modelling and analysis. The results showed that the hinge was safe enough and that the connection should strengthened with appropriate stiffeners.

강유전 고분자 박막의 저차원 전기광학 특성

박철우,정치섭,Park, Chul-Woo,Jung, Chi-Sup 한국전기전자재료학회 2014 전기전자재료학회논문지 Vol.27 No.3

The electro-optic properties in Langmuir Blodgett films of poly (vinylidene fluoride trifluoroethylene) are investigated in the crossover region between two and three dimensions. The absence of finite size effect is observed in the films thinner than 20 nm, which confirms that these films are two dimensional ferroelectrics. The copolymer LB film of P(VDF-TrFE) exhibits the largest electro-optic response(26 pm/V) at 10 layer thickness. The cross-over behavior of electro-optic effect around the 10 layer thickness was discussed with the formation of nanomesa after thermal annealing.

방사선치료 암 환자의 대체요법 경험실태 조사연구

박철우,박태진,Park Cheol Woo,Park Tae-Jin 대한방사선치료학회 2001 大韓放射線治療技術學會誌 Vol.13 No.1

Although it is presumed that cancer patients take various alternative therapies, the present status is not well recognized. The purpose of this study is to survey alternative therapies used by cancer patients receiving radiation therapy and then, find associated factors of taking alternative therapies. The study subjects were composed of those who receiving radiation therapy in the department of radiation oncology in 5 hospitals located at Extended Busan city and who were on follow-up after medical cure. They were 394 male and female patients over 20 years old. The mean age of the subjects was 53.2 years old and the age ranged from 23 to 83 years old. 188 patients($47.7\%$) used alternative therapies. Total 68 different kinds of alterative therapies were used, average 7.3 kinds per patient were experienced, and average total cost expenditure was 2,830,000 won. Among the alternative therapies, black bean($38.8\%$) was the most commonly used and brown rice($38.3\%$), ganoderm lucidum($37.8\%$), elm tree($33.5\%$), and phellinus linteus($30.8\%$) were followed in order of frequency. However in considering the time, cost and effort spent, phellinus linteus was the first. In terms of cost, phellinus linteus was the highest with average expenditure of 2,740,000 won. Among the motivation of using alternative therapies, expecting auxiliary help for the hospital therapy was the highest ($31.4\%$). About half of users($56.9\%$) of alternative therapies were recommended by their relatives to use alternative therapies. In comparing the characteristics of experienced and unexperienced groups, alternative therapy was experienced significantly more in patients of younger age(p=0.001), in patient of higher educational level(p=0.001), and in patients of higher income(p=0.030) The proportion of using alternative therapies was significantly higher in the group treated with chemotherapy(p=0.005), and in the patients who did not satisfy with radiation therapy(p=0.001). The frequency of drinking was significantly higher tendency in the inexperienced group(p=0.046), There was no significant difference in marital status, job, religion, other disease, surgical operation of the cancer and smoking staus between the two groups. Among the unexperienced group, $34.0\%$ of the patients did not take the alternative therapies because they did not have know]edge for the alternatives, and $22.3\%$ worried about negative effects on hospital-based therapy $58.7\%$ of them were willing to take the alternative therapies if the effects and safety were proven by the government or research institutes. $21.9\%$ of the patients wanted to take the alternatives if they were affordable. $72.3\%$ of the patients was willing to take them if their families recommend, but $27.2\%$ responded they would not take them in any situation. Conclusively, various kinds of alternative therapies which were not proved medically were exposed to patients, In these circumstances, it is required to investigate, study and evaluate the medical effects and safety of the alternative therapies.

고 에너지 광자선의 조사선량 측정 시 전리함의 스템효과 보정계수

박철우,이재승,권대철,차동수,김진수,김경근,Park, Cheol-Woo,Lee, Jae-Seung,Kweon, Dae-Chel,Cha, Dong-Soo,Kim, Jin-Soo,Kim, Kyoung-Keun 대한디지털의료영상학회 2010 대한디지털의료영상학회논문지 Vol.12 No.1

Ionization chambers often exhibit a stem effect, caused by interactions of radiation with air near the chamber end, or with dielectric in the chamber stem or cable. In this study measured stem effect correction factor for length of ionization chamber from medical linear accelerator recommend to with the use of stem correction method. For a model of the Farmer-type chamber, were used to calculate the beam quality correction factor. These interactions contribute to the apparent measured exposure. Additionally, it needs to consider ionization chamber use of small volume and stem effect of cable by a large field. Linear accelerator generated photons energy and increased dose repeatedly measured by using stem correction method. Stem effect was dependence of the energy and increases with photon energy conditions improved of beam quality. In conclusion, stem effect correction factor was measured within 0.4% calculated according to the exposures stem length and also supposed to determined below 1% of another stem correction method.

한국인 모유와 조제분유 중의 공액리놀레산

박철우,반경녀,이영남,김정옥,김민석,하영래,Park, Cherl-Woo,Bahn, Kyeong-Nyeo,Lee, Young-Nam,Kim, Jeong-Ok,Kim, Min-Seok,Ha, Yeong-Lae 한국식품영양과학회 2007 한국식품영양과학회지 Vol.36 No.3

The concentrations of conjugated linoleic acid (CLA) in twelve Korean mothers' milk samples collected in October 2006 and four infant formula samples produced by Korean manufacturers were determined. CLA detected from both mothers' milk and infant formula samples was only cis-9, trans-11 CLA isomer. The amount of cis-9, trans-11 CLA in Korean mothers' milk (100 mL) ranged from 4.32 to 10.12 mg ($6.27{\pm}0.28\;mg$). Infant formula (13 g), which is the manufacturers' recommended amount to make up 100 mL with water, contained cis-9, trans-11 CLA isomer in amounts ranging from 1.61 to 2.97 mg ($2.27{\pm}0.31\;mg$). 한국인 모유에는 cis-9, trans-11 CLA 이성체만 동정되었고, 그 함량은 $4.32{\sim}10.12\;mg/100\;mL$(평균 $6.27{\pm}0.28\;mg/100\;mL$)이었고, 지방함량 중에는 $1.35{\sim}3.13\;mg/g$(평균 $1.96{\pm}0.06\;mg/g$)으로 개인에 따라 큰 차이가 있었다. 한국인 모유에 함유된 CLA의 함량은 외국의 CLA 함량에 비해 낮았고, 그 이유는 식사의 차이 때문인 것으로 추정되었다. 국내에서 제조된 조제분유에서도 cis-9, trans-11 CLA만 동정되었는데, 그 함량은 $2.35{\sim}22.82\;mg/100\;g$으로 평균치는 $17.45{\pm}1.24\;mg/100\;g$이었고, 지방에 함유된 cis-9, trans-11 CLA 함량은 $0.45\;mg/g{\sim}0.85\;mg/g$으로 그 평균치는 $0.65{\pm}0.02\;mg/g$이었다. 영유아가 조제분유 제조사의 지시된 13% 조제분유를 섭취할 경우 cis-9, trans-11 CLA를 2.27 mg 섭취하는 것으로 모유 100 mL에 함유되어 있는 양에 비해 낮다. 따라서 조제분유를 조제할 때 모유와 동일한 cis-9, trans-11 CLA를 섭취할 수 있도록 조제분유를 제조하는 것이 바람직하다.

AlN 단결정의 품질평가를 위한 molten KOH/NaOH eutectic alloy의 화학적 습식에칭

박철우,박재화,홍윤표,오동근,최봉근,이성국,심광보,Park, Cheol Woo,Park, Jae Hwa,Hong, Yoon Pyo,Oh, Dong Keun,Choi, Bong Geun,Lee, Seong Kuk,Shim, Kwang Bo 한국결정성장학회 2014 한국결정성장학회지 Vol.24 No.6

본 연구에서는 상용화되는 AlN 웨이퍼(wafer)를 이용하여 molten KOH/NaOH 화학적 습식 에칭(Wet Chemical Etching)에 따른 표면변화 특성 및 최적의 에칭 조건을 조사하였다. AlN 웨이퍼를 $350^{\circ}C$에서 5분간 에칭 시 Al-face, N-face는 서로 다른 관찰되었다. 특히, Al-face는 에치핏의 형상을 파악하여 결함특성을 관찰하였고, 이로부터 결함 밀도를 계산하여 $2{\times}10^6/cm^2{\sim}10^{10}/cm^2$의 결과를 얻었다. N-face의 경우 육각 뿔(hexagonal pyramids) 형태의 격자결함이 형성되었다. 또한 AlN 웨이퍼의 성장 시 배향을 관찰하기 위해 XRD(X-Ray Diffraction, Rigaku, JAPAN)를 이용하여 분석한 결과 육방정 AlN의 C축 방향에 해당되는 (0002) 및 (0004) 면으로 배향된 상태임을 알 수 있었고, DC-XRD(Double Crystal X-ray Diffraction, bruker, Germany)를 이용하여 rocking curve의 위치에 따라 곡률 반경을 측정했을 때 1.6~17 m의 곡률을 가지고 있는 것으로 나타났다. We investigated the optimal etching conditions and properties of the surface change due to molten KOH/NaOH chemical wet etching using an AlN wafer which has been put to practical use in the present study. Results were observed using a scanning electron microscope after 5 minutes etching at $350^{\circ}C$, was found to have a surface form of the respective other Al-face, the N-face. In particular, etch-pit in the form of a hexagon, which is observed in the Al-face appeared, It was calculated at $2{\times}10^6/cm^2{\sim}10^{10}/cm^2$ dislocation density. In the case of N-face, lattice defects in the form of the hexagonal pyramids is formed. It was discovered that in order to observe the orientation of the wafer, which corresponds to the C-axis direction of the resulting hexagonal AlN which was analyzed using XRD (0002) and is a state of being oriented in the (0004) plane. The Radius of curvature of AlN wafer was 1.6~17 m measured by DC-XRD rocking curve position.

새 정부에 바란다 - '신성장동력을 중심으로'

박철우,Park, Cheol-Woo 한국과학기술단체총연합회 2013 과학과 기술 Vol.526 No.-

하악 제1대구치 단일 수복을 위한 발치 즉시 임플란트의 임상증례

박철우,Park, Cheol-Woo 대한심미치과학회 2021 Journal of the Korean Academy of Esthetic Dentistr Vol.30 No.1

Immediate implantation is widely applied as it is recognized as a useful implant treatment in dental clinic due to its various advantages as well as being able to shorten the treatment period. Immediate implant treatment was performed on 5 patients who needed extraction of the mandibular first molar for various reasons, shortening the overall treatment period, and obtaining satisfactory results. Immediate implantation after extraction is a high-level treatment that requires proper initial fixation at the exact location of the extraction socket and the surrounding soft tissues, but is considered to be a clinically very useful prosthetic restoration method 발치 즉시 임플란트는 치료 기간을 단축할 수 있을 뿐만 아니라 여러 가지 장점으로 인해서 치과임상에서 유용한 임플란트 치료법으로 인식되면서 널리 적용되고 있다. 다양한 이유로 인해서 하악 제1대구치의 발치가 필요한 5명의 환자에게 발치 즉시 임플란트 치료를 진행하여 전체 치료 기간을 단축하면서 만족스러운 결과를 얻었다. 발치 즉시 임플란트는 발치와 내 정확한 위치에 적절한 초기고정을 얻어야 하고 주위 연조직도 개선해야 하는 고난도 치료법이지만 임상적으로 매우 유용한 보철 수복 방법이라고 판단된다.