마이크로 팩토리를 위한 방전 가공 시스템 개발

유병한,김태곤,정재원,허세곤,고석훈,박성수,정영훈,민병권,이상조 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

마이크로 팩토리 시스템에서 마이크로 방전 가공 시스템은 많은 장점을 가진다. 전통적인 가공 시스템과 달리 비접촉 가공 방식이기 때문에 소형화에 따른 강성저하 문제에서 자유로우며, 정밀 가공이 가능하다. 그러나 방전가공에서 사용하는 전극에서, 가공 중 발생하는 마모 문제는 생산성뿐만 아니라 가공 정밀도를 떨어뜨리는 문제를 발생시킨다. 이번 연구에서는 전극의 마모 문제를 보완할 수 있는 방전 드릴링 가공과 밀링 가공에서의 공정 제어기법을 제안하였다. 또한, 마이크로 팩토리 용 테스트베드의 방전 가공 모듈로 디스크형 미세 전극 드레싱 가공 시스템, 자동 공구 교환 장치 시스템, 소형 유체 순환 시스템 등도 개발하였다.

악성 섬유성조직구종에서 ras 유전자의 돌연변이

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

전기분사법을 이용한 키틴/키토산 미세입자의 제조

유용,박원호,민병무,이승진 梨花女子大學校 藥學硏究所 2003 藥學硏究論文集 Vol.- No.12

최근 의약학용 바이오 소재로 각광을 받고 있는 키틴과 키토산을 전기적인 힘을 이용하는 전기방사장치를 이용하여 미세입자 형태로 제조하였다. 키틴 또는 키토산 시료에 대하여 고분자 농도가 일정한 수준(사슬 간의 엉킴이 본격적 일어나는 농도) 이상에서는 초극세 섬유의 형태를 보였으며, 그 농도 이하에서는 비교적 균일하고 미세한 입자를 형성하였다. 키토산의 경우, 5% 초산 수용액에 녹여 4~5 wt%로 분사하였을 경우 200~400 ㎚ 크기의 미세입자를 제조할 수 있었다. 또한 농도가 증가할수록 입자의 크기가 커지면서 다소 불균일해지는 경향을 보였다. 수용성 글리콜 키토산은 분자량이 작기 때문에 높은 농도인 약 55 wt% 까지 미세입자가 생성되었다. 이 입자의 평균 크기는 약 300~500 ㎚ 정도를 나타내었다. 키토산을 초산 수용액에 녹여서 ???? 아세토산으로 ??????이 얻어진 N-아세틸화 키틴의 경우에는 ???????? ?????? 녹여 전기분사를 하였는데 7wt% 이하에서 균일한 미세입자가 생성되었다. 따라서, 키틴이나 키토산의 미세입자를 제조하기 위해서는 용매에 따라 일정한 농도와 점도와의 관계곡선으로부터 사슬 간의 엉킴현상에 의해 섬유상이 형성되지 않은 낮은 농도에서 전기분사를 실시하는 것이 무엇보다도 중요하다는 것을 알 수 있었다. Electrospray method is a new technique lo fabricate the polymer nanoparticles. Nanoparticles of chitin and chitosan were prepared by electrospray and characterized by scanning electron microscope (SEM). In general, the increase in the concentration of chitosan solution induced the increase in its solution viscosity. In addition, the solution viscosity increased rapidly at above the critical concentration, due to formation of entanglement between chitosan chains. From the plot of polymer concentration vs. solution viscosity, it was found that chitosan or chitin nanoparticles, with, particle size in the range of 200-600 nm, could be easily formed at below the critical concentration associated with the formation of chain entanglement. Therefore, we concluded that the plot of polymer concentration vs. solution viscosity was important to investigate the concentration range in which polymer nanoparticles could be prepared.

인체 연부조직 육종에서 Cyclin D1, CDK4,p16 및 Rb 단백의 발현

유진영,이아원,강석진,김병기 대한병리학회 2001 Journal of Pathology and Translational Medicine Vol.35 No.3

건조효과를 고려한 준설매립토의 압밀거동

유남재,박병수,이명욱,이주원 강원대학교 산업기술연구소 2000 産業技術硏究 Vol.20 No.A

This research is to investigate the self-weight consolidation settlement and desiccation shrinkage settlement of soft marine dredging clay by performing numerical and experimental works. Large column test were carried out investigate the consolidation settlement considering effect of the self-weight and desiccation shrinkage, and centrifuge model test was also carried out investigate self-weight consolidation settlement. Results of centrifuge model and large column experiments about changes of settlement with time were analyzed by using the numerical technique of explicit finite difference method considering effect of the self-weight and desiccation based on the finite strain consolidation theory. Centrifuge model test results were in relatively good agreements with analyzed results in terms of self-weight consolidation settlement with time. Large column test results showed quite different values from the numerically estimated one, carried by experimental conditions.

합병증이 동반된 Meckel씨 게실 2례 보고

정병욱,박동일,이준희,서정욱,원유홍,김웅,신현종,권영무 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

합병증이 동반된 Meckel씨 게실을 가진 환자의 치료에 대한 필요성은 과정이 문제이다. 하지만 우연히 만나는 게실의 처치는 논란 중이다. 부수적인 게실 절제술(incidental diverticulectomy)의 제안자는 증상이 있는 게실의 외과적 처치는 중요한 이환 및 사망률은 지적한다. 이를 반대하는 사람들은 전 생애를 통해 합병증의 위험성이 낮게 나타나므로 필요가 없다고한다. 게실의 예방적 제거는 개복술시 우연히 발견 될 때 시행한다. 이는 남아있는 게실이 나중에 합병증을 일으키는 것보다 술후 합병증의 위험성이 매우 적음을 알 수 있다. 저자들은 합병증이 동반된 Meckel씨 게실 2예를 경험하였기에 문헌 고찰과 더불어 보고하는 바이다. The necessity for therapy with complicated Meckel's diverticular is a matter of course.However, management of the incidentally encountered diverticulum is controversial. Proponents of incidental diverticulectomy point to the significant morbidity and mortality rates of surgical treatment of symptomatic divenicular. Other authors base their opposition to incidental diveniculectomy on the low risk of complications developing during lifetime. Prophyillctic removal of the diveniculum is indicated when it is found incidentally at laparotomy, because there are few postoperative complications and the risk exists that the remaining diverticulum may be the cause of later complication. The 2 cases of complicated Meckel's diverticulum are reported with a brief review of literature.

골프지도자의 자격유형에 따른 교육적 기반과 생활환경에 관한 연구

백병주,유승원 龍仁大學校 體育科學硏究所 2003 體育科學硏究論叢 Vol.13 No.1

This study aims to provide cultural and technical information and data on golf instructors' educational and personal life and their social status by closely examining their lifestyle revolving mostly around the golf range. After entering into the world of golf, many, if not all, of them commit themselves fully to golf in terms of money and effort over a long period of time in order to improve skills as a golfer. And after playing in a number of amateur golf tournaments and passing a sort of exams designed to test their qualification, they eventually get into the world of professional golf. Their life pattern changes gradually to suit a particular league or tournament. Through the change that often entails anguish and conflicts, golf players become more mature and develop ability to teach others. Starting fresh as an instructor, they attempt to teach students based on strategies and skills, which are systemized to some extent but focused mainly on practical training at the same time. In this period of their life, golf instructors usually try to rectify personal shortcomings and improve financial conditions while bracing for a second life as a player. These efforts, however, bring both positive and negative emotions to them. Consequently, they become confused as to what their own identity really is. And they instinctively try to get over this hardship through self rationalization. But the anguish and conflicts bothering them are not easily removed. The study result mentioned above gives us problems as well as implications to consider from the viewpoint of pedagogy, and they are as follows: First, as the function of a golf range and golf-related policies is tilted overly toward profit-making not just in terms of the substitution effect relating to physical education and workout practiced in daily life but also in terms of "money earning more money," golf is largely commercial and private. That commercial motivation prevails over educational functionality when it comes to a golf range or related policies is a serious matter. Therefore, a large sum of investment is absolutely necessary to nurture an excellent player. And this is why golf is regarded by many ordinary people as something very different from other sports. In view of this peculiar aspect, agencies and organizations responsible for raising and training golf players and instructors must offer programs that are designed to provide effective and practical training to those aspiring to become a player or an instructor. In so doing, they need to pay attention to cost saving and other productive measures so as to ultimately transform golf education into a complementary/substitute means to traditional physical education and daily physical exercise. Second, in most cases, golf ranges and instructors seem to devote too much of their time and resources to teaching practical skills and tips rather than to developing intellectual capability and educational acumen of students and trainees. This problematic aspect or trend, which stems largely from Korea's elitist physical-education policy, can be wiped out only when we do away with excessive commercialism and materialism noted by endless pursuit of mundane fame and wealth and instead assign a higher level of value to the education designed to teach true knowledge and morality. Also, a systematic educational foundation should be prepared so that golf can be accepted and played more widely in the future. Third, the job insecurity and low social status of golf instructors make their attempt at second life as a player all the more difficult. The two problems also push golf instructors to focus increasingly on money-making. The unstable identity of golf instructors is directly related to the current educational environment in which a golf instructor is perceived to be teaching practical skills for a particular sport instead of teaching physical-education in a broad sense. Solving the less-than-desirable situation requires institutional support in the form of proper environment for various physical activities and feedback, seminars on continuing education, public space for self development, education-related public offices offering space, assistance and incentives, and job security. Fourth, we are living in the era of "education inflation" here in Korea. Educational background must not mean everything in and for one's life. But it may be necessary for an instructor to gain confidence and respect from the public. In this regard, if it is deems that the overall level of education for golf instructors is low, it is important to add more programs and classes to the existing curriculum so as to help instructors develop intellectual strength to work comfortably with complicated topics. It is true that the word 'golf instructor' still sounds strange to ordinary people and even some of those involved in physical education. But this much is true. Golf instructors are shouldering their share of the burden for physical education, and their endeavor is making golf become more and more popular. confused due to irrational circumstances and policies, golf instructors in Korea, however, will surely play a pioneering role for the nation's future education. In consideration of this, the government must actively lend a helping hand to them.

PTT단위를 갖는 액정중합체의 합성 및 블렌드

김원,최유성,이태양,최재곤,홍완해,조병욱 조선대학교 생산기술연구소 2003 生産技術硏究 Vol.25 No.1

This study explores the potential of improving the physical properties of poly(trimethylene terephthalate) (PTT) by inducing thermotropic liquid crystalline polymers. The TLCP was synthesized by polycondensation reaction of terephthaloyl chloride with corresponding diols. The TLCP used was copolymers containing random PTT groups on the polymer backbone. The PTT moieties were used to increse compatibility between the PTT and the TLCP. The TLCP showed the nematic phase above those melting temperature(T_m) The TLCP seems to act as plasticizers and nucleating agents in the matrix polymers Liquid crystalline phase did not reaveal any significant macrophase separation and thermal degradaton under the temperature of processing condition.

간암세포에서 저산소증에 의해 유도되는 VEGF의 발현기작에 대한 연구

권유욱,배수경,김정애,김규원,박병채 부산대학교 유전공학연구소 1997 분자생물학 연구보 Vol.13 No.-

Purpose: Hepatocellular carcinoma(HCC),a typical hypervasculized tumor is very sensitive to hypoxia and vascular endothelial growth factor(VEGF) has previously been identified to be up-regulated in response to hypoxia in several cell types. However, the molecular mechanisma by which hypoxia is sensed by the cells remain enigmatic. To investigate whether calcium and AP-1 are involved in hypoxia-sensing mechanism, we performed following eaperiments. Materials and Methods: Hep3B cells were grown in hypoxia condition. To assess cell viability, MTT assay was performed. To investigate the effect of calcium and AP-1,northern blot analysis was performed after treatment with BAPTA/AM. Results: The expression of VEGF was significantly up-regulated by hypoxia in Hep3B, hepatocellular carcinoma cell line. The increased expression of VEGF induced by hypoxia was blocked by the addition of BAPTA/AM, a cytosolic calcium chelator to the media. In addition, we found that the expression of c-jun protooncogene was also-regulated by hypoxia. Hypoxia increase of c-jun expression was also normalized by the treatment with BAPTA/AM. Conclusion: These results suggest that the increased expression of VEGF by hypoxia is mediated through the calcium and c-jun signalling pathway in the Hep3B human hepatoma cell lines.

항진균제 알릴아민류의 합성과 생물학적 평가

정병호,조원제,천승훈,박면지,유진철,천문우 朝鮮大學校 1998 藥學硏究誌 Vol.19 No.2

For the development of antifungal agents. modification of naftifine which exhibits significant antimycotic activity was performed by replacing the naphthalene ring of it to hetero cyclic rings such as morpholine. benzothiazole. piperidine and pyridine derivatives. The synthesized compounds were tested in vitro antifungal activity against five different fungi with naftifine as a comparative antimycotic molecule. From the biological evaluation two compounds. (E)-N-(3-phenyl-2-propenyl)-N-(4-piperidinylmethyl)amine(3d) and (E)-N-(3-phenyl-2-propenyl)-N-(3-pyndylmethyl)amine(3D) showed relatively noticeable activity(MIC=50㎍/㎖). On the other hand. the other compounds had no activity.