A Generalization of the Knaster-Kuratowski-Mazurkiewicz Theorem on H-Spaces

Bae, Jong-Sook,Chae, Soo-Seon 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

In 1961, Fan[5] showed an infinite dimensional version of the classical Knaster-Kuratowski-Mazurkiewicz theorem (briefly KKM theorem) [12]. The significance of KKM theorem) [12]. The significance of KKM theorem was reinforced by Fan who gave a variety of its applications in a series of papers(see[6]). And also Fan's results were developed by many authors and applied in studying fixed point theorems, minimax and variational inequalities, matching theorems, intersection theorems for sets with convex sections and many other fields.

ON THE PROPERTIES OF THE EXACT SEQUENCE OF MODULES OVER RING

Kim, Gi-Ik,Kim, Young-Cheol 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

The notion of a module is obtain essentially by generalization of a vector space. Modules are also of great importance in the higher reaches of group theory and ring theory and are fundamental to the study of advanced topics such as algebraic top-ology, category theory, and homological algebra

n차원 호모로지 R-기군들의 완전열에 관하여

Kim,Gi Ik,Kim,Keon Ho 명지대학교자연과학연구소 1989 자연과학논문집 Vol.7 No.-

Let h be a homomorphism of a lower sequence S into a lower sequence T of R-modules. For every integer n, let ?? and define a function ?? ?? for every ?? and every ?? We can have that the following sequence is exact : ?? Where ?? is induced by h, ?? is induced by the injection ?? defined by ?? for every ?? and ?? is induced by the projection ?? defined by ?? for every (s,t)??

고온 초전도체 Y₁-x Gdx Ba₂Cu₃O7-y의 임계전류밀도에 관한 연구

전인,송승기,최덕,김영호 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

고온 초전도체 Y₁-??Nd??Ba₂Cu₃O??-??(x=00.1, 0.2, 0.3,...,1.0)를 고상 반응법을 이용하여 제작하였다. 온도에 따른 전기적 비저항의 측정과 자기적 감수율의 측정을 통하여 구한 초전도 전이온도는 92.1∼93.5K 사이에 존재하였다. 77K에서 시료의 자기적 감수율은 -5.06∼-6.83Χ10??emu/㎤ㆍOe 사이에 존재하였으며, 상온에서의 비저항은 x=0.6인 시료를 제외하고 x가 증가함에 따라 감소하였다. 수송 임계전류밀도는 자기장이 0일때 51.6∼80.6 A/㎠사이에서 측정되었으며 x가 증가함에 따라 대체로 증가하였다. 자기장을 가해준 상태에서 측정한 수송 임계전류밀도 는 자기장이 증가함에 따라 급격히 감소하였다. 자기 이력곡선으로부터 Bean의 공식을 이용하여 구한 임계전류밀도는 수송 임계전류밀도의 0.8∼2.7Χ10??배로 크게 나타났다. High-Tc superconductors Y₁-??Nd??Ba₂Cu₃O??-??(x=0.1, 0.2, 0.3,…,1.0) have been prepared by solid state reaction method. The superconduction transition temperatures determined by the temperature dependence of electric resistivity and magnetic susceptibility are in the range between 92.1 and -6.83Χ10??emu/㎤·Oe and the resistivities at room temperature are decreased as increasing Gd contents except for the value of x=0.6 sample. Transport critical current densities have the value of 51.6∼80.6 A/㎠ and are generally increased with increasing the magnetic field. Magnetic critical current densities obtained from the magnetization curve using the Bean's law are about 0.8∼2.7Χ10??times of the transport J??.

Amplification of c-erb-B-1 Proto-Oncogene in Hamster Buccal Pouch Carcinoma Cell Lines

Kim, Kyung-Soon 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

We have observed that type 1 herpes simplex virus(HSV-1) and 7, 12-dimet-hylbenz(a)anthracene (DMBA) synergistically increase carcinogenesis in hamster buccal pouch tissues. Two epithelioid cell lines from the pouch squamous cell carcinomas derived with DMBA and DMBA plus HSV-1 were established and named HBPC-1(hamster buccal pouch cell-1) and HBPC-2(hamster buccal pouch cell-2), respectively. Furthermore, hamster skin tumor cell(HSTC) line was established from a skin tumor of hamster receiving DMBA in conjunction with HSV-1 infection. During the past two decades much effort has been given to the search of molecular events in carcinogenesis. the notion that cancer is a genetic disease has led the finding a set of genes that can become tumorigenic "oncogenes." The term "oncogene" is given to the group of genes originally identified as being directly responsible for the initiation and maintenance of tumors caused by mammalian retoviruses. It is generally accepted that these viral oncogenes are derived from normal cellular genes, "proto-oncogenes." A frequent activation of ras, myc and abl proto-oncogenes in human cancers, along with their well known tumorigenic properties when transduced by retroviruses, strongly supports the concept that these oncogenes are involved in the genesis of human cancers. Amplification of cellular erb-B-1 proto-oncogene is commonly found in human squamous cell carcinoma cell lines and squamous cancer tissues. Furthermore, several chemical carcinogens ere reported to activate cellular proto-oncogenes in the process of carcinogenesis in laboratory animals. Whereas cellular ras proto-oncogenes are activated by DMBA and benzo(a)pyrene in rats and mice, amplification of erb-B-1 oncogene expressing epidermal growth factor receptors has been found to be linked to invasiveness of epidermoid cell carcinoma developed by topical DMBA in hamster buccal pouches. In the present study we have examined the possible presence of activated cellular proto-oncogenes from the established three cell lines.

고온 초전도체 Y₁-x Ndx Ba₂Cu₃O7-y의 임계 전류밀도에 관한 연구

박영민,전인,송승기 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

고온 초전도체 Y₁-??Nd??Ba₂Cu₃O??-??(x=0.0,0.2,0.4,0.6,0.8,1.0)를 고상 반응법을 이용하여 제작하여 제작하였다. X-ray 회절실험 결과로 부터 격자상수를 구했다. x가 증가함에 따라 a,b,c값이 증가하였고 x=0.6과 x=1.0에서 anomaly 현상을 보였다. SEM 사진을 통한grain size는 x= 0.0,1.0에서 2∼3μm, x=0.6,0.8에서 4/μm, x=0.2,0.4에서 5μm 정도로 나타났다. 온도 변화에 따른 비저항 측정으로 구한 초전도 전이온도는 모든 시료에 대해 85∼92K 사이에 존재하였고 x가 증가함에 따라 감소하였다. 수송 임계전류밀도는 20-92 A/㎠사이에서 측정 되었으며 시료내의 Nd 치환량이 증가하면 J?는 증가하였고 x=0.4에서 anomaly 현상이 나타났다. 자기장을 가해준 상태엣 측정한 수송 임계전류밀도는 자기 장이 증가함에 따라 x=0.0 시료에서 급격히 감소하였고 Nd가 많이 치환된 시료에서는 감소율이 작았다. High-T??superconductor Y₁-??Nd??Ba₂Cu₃O??-??(0.0, 0.2, 0.4, 0.6, 0.8, 1.0)has been prepared by the solid state reaction method. Lattice constants are calculated from the result of X-ray diffraction pattern. The lattice constant a, b, and c are increased as increasing x except for x=0.6 and 1.0 samples. SEM photograph showed that the grain size is 2∼3μm for x=0.0 and 1.0 samples, 4μm for x=0.6, 0.8 and 5μm for x=0.2, 0.4 samples. The superconducting transition temperature determined by the temperature dependence of resistivity are detected between 85K and 95K decreased as increasing x. Transport current density was observed between 20 and 92 A/㎠ and J?? increased as increasing Nd concentration in the sample except for the x=0.4 sample. Transport current density of x=0.0 sample decreased abruptly with increasing applied magnetic field and the smaple of large Nd concentration has the slowly decreasing transport current density with inereasing magnetic field.

On the Nearly Periodic and Prolongation Flows

Kim, Young-Key,Min, Kyung-Jin 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

龍仁地域의 資源植物 調査 硏究

兪在殷 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

The survey aims to investigate the distribution of plant resources in the Yong-in area, to furnish fundamental academic data for this field of discipline and to stimulate the residents in the region to increase their income with the exploitation of useful plants as an income source and in case of war, as emergency rations for soldier. This surveying study will be summaried as follows; 1. Plant resources distributed along the area were totally 91 families, 260 genera and 416 species. 2. Epimedium koreanum Nakai and Acanthopanax sessiliforum etx. medicinal Plants were distrbuted. 3. The surveyed area was consist mixed that deciduous broad-leaved trees including Quercus acutissima, Quercus mongolica and Quercus serrata.

원자의 선택적 2광자 공명성 3광자 이온화 과정에 관한 밀도행렬의 수치해

오완영,남백일,강석찬,김영순 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-

2광자 공명성 3광자 이온화 과정에서 밀도행렬의 시간에 대한 미적분방정식을 수치해 석적으로 계산하여 기저상태와 2광자 공명 여기상태의 전자밀도 행렬요소 σ??와 σ??,이온화율 P, 그리고 동위원소 선택율 S를 Li과 Sr원자들에 대하여 계산하였고, Rate Approximation에 기초한 준정상해의 결과와 비교하였다. 비교적 큰 동위원소이동 값을 갖는 ??Li와 ??Li의 경우 레이저의 세기가 매우 작은 영역과 큰 여역에서는 P와 s의 수치해의 계산결과와 준정상해법 계산결과는 비교적 잘 맞는 경향을 볼 수 있었으며, ??Sr와 ??Sr의 경우 즉, 동위원소 이동값이 700MH?에 불과한 경우 Li원자보다 민감하여 준정상해법의 결과는 제한적으로 적용됨을 볼 수 있었다. We present results of numerical calculations obtained through solving integro-differential equations for the electron density matrices ?? and?? and the ionization rate P in two-photon resonant three-photon ionization of Li and Sr, as well as the selectivity S for the isotope separation. We also compare our results with the predictions from quasi-stationary solutions based on the rate approximation. Our numerical results for P and S show that the quasi-stationary solutions are valid at very high and very low laser intensities when the isotope shift is large as in the case with 4s of ??Li and ??Li, and that the validity is rather limited in the cases with small isotope shift as in 5p? ?S of ??Sr and ??Sr.

STUDY ON PROJECTIVE MODULES OVER R

Kim, Gi-Ik,Seo, Bog-Won 명지대학교자연과학연구소 1991 자연과학논문집 Vol.9 No.-