백서 척수후근절로부터 슈반세포의 효과적인 체외 배양법

김성민,이종호,김남열,안강민,최원재,최시호,차미주,이주영,황순정,장정원,명훈,최진영,서병무,정필훈,김명진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Schwann cells(SCs), an important component of the peripheral nervous system, intract with nerous to mutually support growth and replication for the peripheral nerve regentation. Recently, ading SCs to the lumen of guidance channel is widely tried to improve regeneration or to make regeneration possible over otherwise irreparable gaps. however, it is not easy to isolate and multiplicate SCs as much as enough to help the axonal regeneration. For the allogeneic SCs source for tubular nerve guidance, we developed a little bit improved technique of harvesting and multiplicating SCs. by culturing dispersed dorsal root ganglia in specially designed medium with growth factors and serial processing, we repeatedlly generate relatively homogenous SC cultures. Our technique was compared with other methods of literature using immunostaining methods such as GFAP, S100, BDNF and the total SC count assessment at different time interval after primary culture.

산업부산물인 Fly Ash의 라이닝콘크리트에의 적용에 관한 실험적 연구

최세진,임정열,정우성,김완영,김무한 공주대학교 자원재활용신소재지역협력센터 2000 2차년도 센터 사업 성과집 Vol.2000 No.1

This is an experimental study to analyze the usability of fly ash in the tunnel lining concrete. For this purpose, the mix proportion of plain concrete and concrete using fly ash(the replacement of 15 and 30% by weight of cement) to satisfy slump 15cm, air content 5% and compressive strength 270kgf/cm2, was selected. And then tests for slump, setting time, compressive strength, tensile strength, drying shrinkage and adiabatic temperature rise were performed. According to test results, it was found that the concrete using fly ash 15% (FA 15 concrete) was better than the plain concrete and FA 30 concrete. FA 15 concrete was more useful than the others in reducing the drying shrinkage : the drying shrinkage strains of FA 15 concrete after 20 weeks of air drying was lower about 10% than the plain concrete, and lower 6% than FA 30 concrete. And the highest compressive strength after curing for 28 days of 365kgf/cm2 was obtained from FA 15 concrete. This was almost 10-20% improvement in compressive sterngth, compare to the plain concrete and FA 30 concrete. And the effect of 5~7.5℃ of concrete using fly ash for hydration heat reducing was calculated. Therefore, concrete using fly ash 15% (FA 15) was expected to improve the performance of lining concrete.

군위지역 오이 시설 재배지의 토양특성 변화

이동훈,최충렬,김광섭,김평열,서정우,박만 경북대학교 농업과학기술연구소 2006 慶北大農學誌 Vol.24 No.-

군위군 오이재배지역을 정밀토양도를 이용하며 토양특성을 조사하구 군위군 노지 및 시설오이 재배지토양의 물리화학적 특성을 조사하여, 연작과 관행적인 토양관리로 인하여 저하된 토양의 이화학적 특성을 오이재배에 적합한 토양으로 개량하기 위한 기초자료로 이용하고자 토양조사를 실시하였다. 조사지역은 군위군 군위읍 외랑리 오이재배단지로서 주요토양통은 토양토에 나타난 단북통과 신정들이 가장 넓게 분포하였으며, 점토함량은 시설재배지내 토양의 경우 양토이었으며, 시설재배지의 외부 토양의 경우 23.8%로 높게 나타났다. 오이 재배지 토양의 화학적 특성 결과에 대한 오이재배지 토양의 적정범위와비교하여 보면 일반적인 화학적 성질에서 서는 유효인산의 함량이 적정범위보다 높은 것을 알 수 있으며, 치환성 양이온 함량은 시설재배지의 외부토양은 적정범위에 속하나 시설재배지 내부토양은 모두 높은 것으로 나타났으며, 최상부 토양은 매우 높으나 l0cm이하는 깊이에 따라 뚜렷한 차이는 없었다. 오이 재배지 토양 중 중금속 함량은 모두 기준치보다 높게 나타났는데, 구리의 함량이 시설재배지가 노지재배지보다 높게 나타났다. The soils of plastic film houses in which intensive cultivation takes place suffer from the serious problems such as severe salinity and accumulation of heavy metals etc. The objective of this research was to examine the change in soil properties with repeated cucumber cultivation under plastic film house at Gunwi-Gun area. The soils were classified mainly to Danbuk and SinJung series. Clay content is lower in the soils of plastic film house than in the field soil. Available P205 and exchangeable cations were accumulated at the level higher than the optimum range. The content of extractable heavy metals were higher in the soils of plastic film house than in those of the field. For optimum yield, much attention should be paied to the management of soils by the pre-soil survey.

우관상동맥 개구부 완전 폐쇄가 동반된 대동맥 판상부 협착증 1례

임상현,김종진,김희열,진승원,전희경,노태호,채장성,김재형,홍순조,최규보,윤정섭,김치경 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

압축성 코드에서 예조건화 코드로의 이진

한상훈(Sang-Hoon Han),김명호(Myeong-Ho Kim),최정열(Jeong-Yeol Choi) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.3

이차원 범프 유동에 대한 다양한 예조건화 행렬의 수렴 특성을 살펴 Choi와 Merkle의 예조건화 행렬을 선택하여, 압축성 및 예조건화 Roe의 Riemann 해법의 수치 소산항을 수학적으로 비교하였다. 이 결과 코드의 구조는 동일하게 유지한 채, 고유치의 작은 수정만으로 압축성 해법을 예조건화 해법으로 이전할 수 있는 방법을 알 수 있었다. 아울러 점성 유동 영역에서의 안정성 및 정확성을 향상시키기 위하여 von Neumann 안정 조건 및 점성 자코비안을 고려하였으며, 개발된 코드는 표준 검증 문제에 적용하여 검증을 수행하였다. Comprehensive mathematical comparison of numerical dissipation vector was made for a compressible and the preconditioned version Roe's Riemann solvers. Choi and Merkle type preconditioning method was selected from the investigation of the convergence characteristics of the various preconditioning methods for the flows over a two-dimensional bump. The investigation suggests a way of migration from a compressible code to a preconditioning code with a minor changes in Eigenvalues while maintaining the same code structure. Von Neumann stability condition and viscous Jacobian were considered additionally to improve the stability and accuracy for the viscous flow analysis. The developed code was validated through the applications to the standard validation problems.

Impulse Generation Mechanisms in a Laser-Driven In-Tube Accelerator

CHOI, Jeong-Yeol,KANG, Ki-Ha,SASOH, Akihiro,JEUNG, In-Seuck,URABE, Naohide,KLEINE, Harald 日本航空宇宙学会 2008 Transactions of the Japan Society for Aeronautical Vol.51 No.172

<P>To enhance laser-propulsion thrust performance, a unique Laser-driven In-Tube Accelerator (LITA) has been developed. This paper numerically analyzes the impulse generation mechanisms in LITA. For this purpose, a LITA performance experiment was conducted in atmospheric air with a projectile installed on a ballistic pendulum to calibrate the numerical approximations. We conducted experimental flow visualization by framing shadowgraph and computational fluid dynamics solving the axi-symmetric Euler equation applied to an ideal gas. The results show that a laser-driven blast wave is generated by a spherical hot gas core where the supplied laser energy is absorbed first. The effect of confinement by the tube or shroud wall is confirmed. The impulse production is established not only from the interaction between the incident blast wave and projectile, but also from the following repetitive pressure waves. Assuming that about 30% of the input laser energy is absorbed by the working air, both the impulse and peak pressure agrees quantitatively between the experiment and numerical simulation.</P>

DECOMPOSITION SPACES OF TOPOLOGICAL SPACES

Choi, Jeong-yeol 全北大學校 文理科大學 1976 論文集 Vol.4 No.-

Irreducible Representations of the Groups D2n

Choi, Jeong-yeol 圓光大學校 1980 論文集 Vol.14 No.2

群 ?? (regular dihedral group)은 한 平面上의 正 n 角形의 回轉群이다. 즉, ?? 은 degree 2n 를 갖는데, i) n 個의 元素는 주어진 平面에서의 回轉이며, ii) n 個의 元素는 對稱軸을 中心으로 角 π만큼의 回轉이다. 2π a=주어진 平面에서의 角 ---- 만큼의 回轉, n b=對稱軸을 中心으로 角 π만큼의 回轉 이라 하면, 1, a, ..., ?? 은 (i)에 屬하는 n 個의 元素이며, b,ba, ..., ?? 은 (ii)에 屬하는 n 個의 元素이다. 따라서, ?? 은 aⁿ=1, b₂=1, ?? 를 滿足시키는 a와 b에 依해 生成되는 群이다. 一般的으로, 모든 有限群의 irreducible representations 를 計算하기는 어렵지만, 여기서는 ?? 의 모든 irreducible representations 를 計算하고자 한다(§2). 그러기 爲해, §1에서는 §2에서 必要한 몇 가지 定理를 證明하고자 한다. The group ?? (regular dihedral group)is a rotation group of a regular n polygon on a plane. That is, ?? has its degree 2n such that (i) n elements of rotations on a given plane, (ii) n elements of rotations of angle πaround symmetric axes. Let us put 2π a=a rotation of angle ---- on a given plane, n b=a rotation of angle πaround a symmetric axis, then 1, a, ..., ?? are n elements belonging to (i), and b, ba, ..., ?? are n elements belonging to (ii). Therefore, D₂?? is a group generated by a and b having the relations aⁿ=1, b₂=1, ?? In general, it is difficult to calculate all irreducible representations of a finite group. In this note, we shall try to calculate of all irreducible representations ?? (§2). In order to do this, in §1 some theorems which are needed in §2 will be proved.

A note on Differentiable G-manifolds

Choi, Jeong-yeol 圓光大學校 1981 論文集 Vol.15 No.1

G를 緊迫 Lie群이라 하자. 이 論文에서는 다음 것을 證明하고자 한다. ⅰ) M가 境界를 갖지 않는 緊追微分可能 G-多樣體 이면, imbedding G-寫像 f : M → V가 存在한다. 여기서 V는 有限次元 G-벡타 空間이다.(定理 9) ⅱ) M가 境界 əM를 갖는 緊追 G-多樣體이면, əM의 G-不變開近傍 U와 各 x∈əM에 對해 h(x)=(x, 0)인 G-diffeomorphism h : U → əM×(0,1)이 存在한다. 여기서 G의 action은 (0,1)上에서 自明하다.(定理 10)

Some Properties of Banach Algebras

Choi, Jeong-Yeol,Park, Chan-Ho 圓光大學校 基礎自然科學硏究所 1989 基礎科學硏究誌 Vol.8 No.2

함수해석론은 주로 노-옴 공간, 바나크 공간, 바나크 환, 힐버트 공간 및 그 활용에 관해 연구하는수학의 한 분야인데, 해석학에서의 많은 바나크 공간이, 그 자체적으로 중요한 승법연산하에서 바나크환이 된다. 본 논문에서는 바나크 환의 일반션형군과 리졸벤트 및 스텍트럼에 대한 몇가지 성질을 고찰한다.