첨가물에 따른 고온 초전도 후막의 특성

소대화,전용우,이영매,김태완,Korobova, Natalya 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

In this study, by using the electrophoresis, preparation of YBCO superconducting wire deposited on metal Ag base wire was studied with its properties. YBCO powder could be prepared by solid state reactions with calcining and sintering processes. Superconducting wire prepared on metal Ag wire used as cathode of deposition base could be also fabricated in the YBCO/acetone-dispersed solution to obtain several tens of ㎛ thick films. In the process of film deposition, a catalyst I₂added into the suspension solution was very useful for preparing thick film of YBCO, and BaF₂ of additive material was also necessary for preparing crack-free wire of YBCO superconductor. As a result, YBCO superconducting wire added 2~3wt.% of BaF₂with catalyst, I₂had better deposition condition for uniform and dense YBCO wires, and critical current density, Jc was calculated at the value of 1,458A/㎠ (more than 10³A/㎠, 77K, 0[T]) of 30㎛ thick sample by 4-point prove method.

전기영동 초전도후막의 전착밀도 개선

소대화,전용우,이영매,임병제,Korobova, Natalya 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

YBCO superconducting thick films were perpared on Ag wire by electrophoresis in acetone and ethanol with chemically modified suspension. The addition of organic compounds, such a PEG into suspension solution for improving critical current density was investigated. Surfac state, deposition conditions, pore distribution and cracks were investigated by using SEM photographs. Controlling preparation conditions were studied for reducing these defects. As a results, in acetone slolution, the surface crack of samples was decreased with increasing PEG. To develop optimum microstructures for samples processes affect the microstructure and hence the properties of ceramic superconductors.

난소 적출 백서에 식립된 마이크로스크류에 교정력 부여 시 나타난 초기 경조직 변화에 관한 연구

이대승,이진우,,장문정 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.2

중년 이후의 여성의 경우 칼슘 섭취가 부족하거나, 인위적인 난소 적출 또는 폐경 등으로 인하여 골밀도가 감소하는 경향이 있다. 이 경우 교정 치료 시, 골내 고정원으로 마이크로스크류를 이용할 수 있는지를 알아보기 위하여, 생후 4개월 된 Sprague-Dawley계 백서를 실험군으로 난소 적출(Ovariectomy Screw, OS)군, 대조군으로 Sham operation 시행한(Sham operation Screw, SS)군의 두 군으로 나누었다. OS군과 SS군 모두 상악 대구치 사이 구개골에 마이크로스크류를 식립하였고, NiTi coil spring을 이용하여, 상악 중절치 2개를 견인하였다. 각 군당 3일, 7일 후 7마리씩 희생시켰다. 희생 3일전 Alizarin red S를 주입하고, 상악골, 장골, 심장혈을 채득한 후, 심장혈을 성분분석하고, 상악골과 장골은 비탈회 레진표본을 제작하여, 편광현미경, 형광현미경으로 관찰하였다. 심장혈을 통한 성분 조사 결과 OS군, SS군 모두 7일째 alkaline phosphatase (ALP)의 농도가 높게 나타나 골개조의 가능성을 보였고, 편광현미경 사진에서 OS, SS군에서 모두 마이크로스크류의 압박측, 긴장측, 치아의 긴장측에서 3일 보다 7일에서 기존골에 비하여 골밀도가 낮은 영역이 적었고, 치아의 압박측에서는 골밀도가 낮은 영역이 증가하였다. 형광현미경 관찰결과는 3일째 보다 7일째에 더 Alizarin red S로 침착된 골이 나타난 것으로 보아, 새로운 골의 형성이 있었음을 나타내었다. 골다공증이 유도된 백서에서 계속된 골의 흡수보다는 골개조의 가능성이 증가하고, 신생골의 형성이 증가함을 확인할 수 있었고, 이는 골다공증에서도 마이크로스크류의 식립으로 고정원 확보가 가능한 것으로 생각한다. Most elderly women experience a decrease in their bone density due to a deficiency of calcium intake, ovariectomy, or menopause. This study evaluated the usability of the microscrew as a skeletal anchorage system in these orthodontic treatment cases, using rats as a research group. The 4 month old sprague-dawley species rats were divided into two groups, the OS (Ovariectomy Screw), and the SS (Sham operation Screw) group. In both the OS and SS groups, microscrews were implanted into the palatal bone between the upper molar teeth and two upper incisors were retracted using NiTi coil spring with 75g of force. After 3days, the again after 7days, 7rats in each group were sacrificed. Three days before they were sacrificed, Alizarin red S was intraperitoneally injected, and their maxillary bone, tibia and blood from their hearts were taken. The components of the extracted blood were biochemically analyzed and non-decalcified grinding resin sections for maxillary bone and tibia were made. The sections were examined with a polarization microscope, and fluorescent microscope. Smaller concentrations of Ca and P, the inorganic substances closely related to bone density, were found in the extracted blood of the OS group. Both OS and SS groups showed a possibility of bone remodeling with a high concentration of ALP after 7days. An increase in bone density on the tension and compression sides of the microscrew and the tension side of the tooth or both OS and SS groups was confirmed with a polarization microscope. However, the bone density of the pressure side of the tooth and apical side was decreased. More deposits of Alizarin red S in the bone after 7 days rather than 3 days seen with a fluorescent microscope suggested the existence of new bone formation.

보조전계 BSCCO 전기영동 전착막의 현탁용매 영향 : Influences of Suspension Solution on Field-assisted EPD Films of BSCCO

소대화,전용우,박정철 明知大學校 産業技術硏究所 2003 産業技術硏究所論文集 Vol.22 No.-

Abstract - In the electrophoresis for fabrication of a superconducting wire and film, the enough deposition and formal sustain of a film condition affect to superconducting state of samples. In this paper, a superconducting film was fabricated with various suspension solution such as acetone, buthanol, and ethanol. As a results, the best deposition condition with d.c 250 V and a.c 25 V of applied voltage, and 90 sec of applied time for BSCCO superconducting film by electrophoresis was investigated.

학생의 체질, 체력변화에 관한 종단적 조사 분석 : 초, 중, 고 학생을중심으로

김대건,한찬우 東國大學校 敎育硏究院 1997 교육문제연구 Vol.12 No.-

This study, the status of physique development, physical condition, physical strength by years, ages, and sexs, provided by the department of school physical education, local support bureau, ministry of education resulted from physique for 10 years from 1995 to 1995, change status of a physical condition and a physical strength for 10 years from 1985 to 1995 with the object of 100,580 students in total of 450 sample school for 10 years based on the result of physique, physical condition and six items of physical charter investigated by above mentioned authorities with the view of the examing the change of physique, physical condition, physical strength for the students' between the age of through 17 of the county wide elementary, middle, and high school vertically. 1. The change of the of physical condition A number of students' weak sight increased from 1.47% in 1985 to 3.40% in 1995 or 2.3 times. This means that it has increased 2.3 times compared with 10 years. Refracting deficiency increased from 8.16% in 1985 to 21.49% in 1995. This indicated that it has abruptly increased 2.6 times as many as 10 years period. As the result of 1995 investigation 3.4% of the country wide students' for 0.2 to 0.4% were proved to have the weak sight and 21.49% students' for 0.3% to 0.6% of the whole students', on top of these other students' proved to have the refracting deficiency including long sight and astigmatism students. Students' sight weakenization was more serious with the height of school years. The study was indication that about 13 students wore glasses in the case of the elementary school students', 32 students', and 32 in the case of the middle school and 42 of 100 students' in the case of the high school students' it was necessary for than to remedy their eye sight. The statistics of deceases about nose and neck including emphysema and the swollening of tonsil increased a little from 21% to 2.75% compared with 10 years ago. The study also showed diseases including caries increased a little to 51.2% from 50.06% in 1980. 1 can conclude the physical condition for students' continuesly go wrong. 2. The aspect of physical strength Change The change for the worse of all the events of students' over all the sports events shows the gradual of for all students'. Compared with 10 years before l00m running the male average record decreased 0.38sec, while it decreased to 0.71sec in the case of the female students', male students' pule-up decreased to 1.52 times and the record for female students' decreased to 2.91sec. The record of Hand throwing in the case of the male students' decreased 01.9m while in he case of female students' decreased to 1.66m and only the sit-up for the students' indicated the smiler number of it exceptionaly, However this part also indicated inferity compared with Ole record one year before. Standing broad jump indicated 3.16m Hl the case of male students' and 9.7cm decreas respectively in the case of female students' The physical measurement fields the list showing remarkable difference was the distance run. It's difference showed 24sec in the case of male students' and 25.Isec in the case of female students, compared with 10 years. This is the indication that the sustained power of adolescent's heart and lungs remarkably decreased.

IMO의 선박안정수 규제와 외래침입생물체의 전기화학적 처리기술

소대화,전용우 明知大學校 産業技術硏究所 2005 産業技術硏究所論文集 Vol.24 No.-

The introduction of invasive marine species into new environments by ship's ballast water, attached to ships' hulls and via other vectors has been identified as one of the four greatest threats to the world's oceans by Global Environment Facility (GEF). IMO (International Maritime Organization) is carrying out the international restriction of the effluence suppression and treatment of Ship's ballast water by Ballast Water Management Convention. In this paper, to deal with this international restriction convention and to consider economic potential of ship's ballaster treatment market near future, the equipment and technology of ship's ballaster water treatment was studied.

에어볼 발파공법의 현장적용 사례연구

강대우,이신,김상욱 東亞大學校 建設技術硏究所 2005 硏究論文集 Vol.28 No.2

발파로 인한 환경적 문제는 주로 진동과 폭음에 대한 영향이나, 발파로 인한 파쇄도 및 경제성에 관해서도 효율적인 발파공법들이 많이 개발되고 있다. 이러한 문제를 해결하기 위한 방법으로 선진국에서 많이 사용되는 방법이 air decking을 이용하는 발파방법이다. 이미 선진국의 발파현장에서는 air decking 기술을 이용한 다양한 발파방법으로 VARI-STEM, GAS-BAG, POWER DECK 등이 이용되어지고 있다. 본 연구에서는 이들 중에서 Air ball 제품을 이용한 발파공법에 대하여 연구하고 국내 현장적용과 효과에 대하여 분석하였다. 그 결과 발파진동의 경우에는 약 30 ~ 40% 정도의 감쇄효과가 나타났고, 화약량의 경우 20 ~ 25%정도의 감소를 보였다. 또한 폭음의 경우에도 Air ball을 이용한 발파가 효과적이었으나 분석결과의 결정계수가 낮아 이는 더 많은 실험을 통하여 다시 분석해야 할 것으로 생각된다.

Response Strategy for Cyber-Attack Origin

Dea-woo Park 한국정보통신학회 2018 2016 INTERNATIONAL CONFERENCE Vol.10 No.1

Function and Technology Analysis of Cyber-attack Weapons

Dea-woo Park 한국정보통신학회 2018 2016 INTERNATIONAL CONFERENCE Vol.10 No.1

Act on the National Cybersecurity

Dea-woo Park 한국정보통신학회 2015 2016 INTERNATIONAL CONFERENCE Vol.7 No.1

The cyberattack weapons (malicious codes) including Stuxnet and Duqu paralyzed the nuclear system of Iran to steal national secrets. Information about the F-35 fighters was stolen through a subcontractor of the US Department of Defense. In December, 2014, a hacker stole the nuclear power data including key nuclear power technology like ‘Safety and Performance Analysis Code’ managed by KHNP to infringe people’s assets and further increased damages and people’s uneasiness about cyber terror attacks against national infrastructure. The National Cybersecurity Act in response to cybercrime and cyber terrorism and cyber warfare citizens, public agencies, and experts in the military to establish a comprehensive response system for participation. National Cybersecurity Council should respond to cyberattacks, defense, media psychological warfare. National Cybersecurity Council is mutually share relevant information and real-time analysis, information sharing and coordination support. In addition, the permanent council of the national constitution, government, and military operations.