濟州道內 高等學校 物理敎育 正常化에 關한 硏究

李相法,尹志洪 제주대학 1980 논문집 Vol.12 No.2

In this stuay we investigated the status of physics education at high schools in Jeju-do and measured the experimental experiences of students graduated from high schools. We collected the data from 20 science or physics teachers and 383 freshmen in natural science classes in Jeju national college. The results of the investigations are as follows. (1) Most students and school administrators thought physics as an unimportant subject, and none of the students selected physics as an optional subject among those offered as natural sciences. (2) Experimental apparatus was not sufficiently availabie in each school and the students hardly made any physical experiments in the high schools. (3) The mean teaching hours assigned to physics teachers were nearly 21 hours per week. Many teachers were charged two or more subjectsin addition to physics. (4) Most teachers thought that an effective physics education was possible only through experimental study, but the lack of experimental apparatus made it impossible. Given these data we suggested that : (1) The necessity of physics education should be explained to the students and school administrators. (2) The teaching methods should be changed from those traditional ones to methods based on experiments and observations. (3) The physics teachers and school administrators should make an effort to improve all of the experimental equipment. (4) The physics teachers must be rid of their overload, and henceforth teach only their own major subjects.

퍼콜레이션 감수율의 진폭비의 보편성

이상법 경북대학교 과학교육연구소 1997 科學敎育硏究誌 Vol.21 No.-

We study the universality of two off-lattice percolation models, i.e., the continuum percolation of randomly centered disks and spheres for penetrable concentric shell(PCS) model and the randomly bonded percolation of uniformly distributed points, and also of the irreversible kinetic gelation model. We specifically consider the amplitude ratio of percolation susceptibilities R=C_-/C_+ (C_- and C_+ being the amplitudes below and above the percolation susceptibilities which is supposed to be universal but found to be different from the ordinary lattice percolation values in both two and three dimensions. By numerical investigation, we find that R depends strongly on the size of system for the former two off-lattice percolation models; after a finite size effect is carefully taken into account, R is found to be consistent with the known lattice value, indicating a strong universality between lattice and off-lattice percolation models. For the kinetic gelation model, on the other hand, we find that R does not depend strongly upon the size of system and is close to the lattice value, again indicating a strong universality between these two models. We point out that the primary cause of such differences may be the different (approximate) sampling techniques for the percolation susceptibilities. We discuss some subtleties of finite size scaling analyses.

연속 퍼콜레이션 모형의 감수율의 진폭비의 보편성

安駿浩,李相法 경북대학교 과학교육연구소 1994 科學敎育硏究誌 Vol.18 No.-

We study the universality-related problem of continuum percolations. We specifically consider the amplitude ratio of susceptibilities, R=C_-/C_+, which is supposed to be universal but found to be different from the lattice value. We discuss several possible sources of errors in estimating R by computer simulations and present simulation data for penetrable-concentric-shell model, with the finite size effect being carefully taken into account. Results from any finite-sized system were found to be significantly larger than the known lattice values: however, after taking extrapolations to the infinite-system-limit, we obtained R very close to the lattice values for both two and three dimensions. Based upon these, we conclude the strong universality between continuum and lattice percolation models for at least PCS model.

중등학교 에너지 보존 실험의 검증 및 새로운 실험 방법의 고안

서종식,기대연,이상법 慶北大學校 師範大學 科學敎育硏究所 1999 科學敎育硏究誌 Vol.23 No.-

We examined experiments for kinetic energy conservation in the high school textbook of Physics I and Physics II for the 6th National Science Curriculum and designed a new kit which enables to reduce experimental errors. Most experiments in the existing textbooks deal with the energy conservation for gravitational potential energy transforming to kinetic energy of the same object. We carried out the most commonly used two experiments and found that the experimental errors exceed more than 10~20 percent if carried out without carefulness. This may possibly make students suspect the mechanical energy conservation law. Our new kit, on the other hand, exhibits that the mechanical energy conserves with an error of less than 6% even in the process of transferring the elastic potential energy of one object to the kinetic energy of an another object.

Numerical test of Flory formulas for true self-avoiding walks on fractal lattices

Lee, Sang Bub 서울대학교 이론물리학연구센터 1993 연구논문집 Vol.2 No.-

퍼콜레이션 감수율의 진폭비의 보푠성

( Sang Bub Lee ) 경북대학교 과학교육연구소 1997 科學敎育硏究誌 Vol.21 No.-

We study the universality of two off-lattice percolation models, i.e., the continuum percolation of randomly cenyered disks and spheres for oenetrable concentric shell(PCS) model and the randomly bonded percolation of uniformly distributed points, and also of the irreversible kinetic gelation model. We specifically consider the amplitude ratio of percolation susceptibilities R=C_/C+ (C_ and C+ being the amplitudes below and above the percolation threshold) which is supposed to be universal but found to be different from the ordinary lattice percolation values in both two and three dimensions. By numerical investigation, we find that R depends strongly on the size of system for the former two off-lattice percolation models; after a finite size effect is carefully taken in to account, R is found be consistent with the known lattice valusm indicating a strong universality between lattice and off-lattice percolation models. For the kinetic gelation model, on the other hand, we find that R does not depend strongly upon the size of system and is close to the lattice value, again indicating a strong universality between these two models. We point out that the primary cause of such differences may be the different subtleties of finite size scaling analyses.

Analysis of Fuel Options in TRIGA Reactor

Lee, Un-Chul,Lee, Chang-Kun,Lee, Ji-Bok,Kim, Jin-Soo,Lee, Sang-Kun,Jun, Byung-Jin,Chung, Bub-Dong Korean Nuclear Society 1979 Nuclear Engineering and Technology Vol.11 No.1

In this paper. nuclear characteristics of TRIGA Mark-III has been analyzed in detail for six different fuel options. Presently, 70 w/o enriched FLIP fuels are adopted for TRIGA core to improve fuel lifetime. However, such highly enriched fuels are not easily obtained due to nonproliferation treaty. This research examines the possible substitution for FLIP fuels with high density fuels without reducing the nuclear performance. This work will provide long-time plan for TRIGA operation.

Two-point Cluster Function for Continuum Percolation in One Dimension

Lee, Sang-Bub 慶北大學校 師範大學 1989 敎育硏究誌 Vol.31 No.-

서로 다른 두 상으로 구성된 혼합매질에서, 같은 클러스터 내에서 서로 연결된 두 점을 동시에 발견할 확률로 정의되는 두 점간의 연결함수를 일차원 저밀도영역에서 계산하였다. 계산에 사용된 모형은 길이가 σ이고 중심에 길이 λσ인 서로 중복될 수 없는 선소가 들어있는 막대들로 구성된 일차원 매질로서 소위 Penetrable-concentric-shell (PCS)model이라 일컬어 지는 모형을 이용하였다. 얻어진 결과는 전산 시뮬래이션을 통하여 검증되었으며, 임의의 밀도에 대한 시뮬래이션 결과도 아울러 발표되었다.

Invasion Percolation Between Two Wells in Continuous Media

Sang Bub Lee 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.6

Invasion percolation between two wells was studied in continuous media consisted of overlapping disks and spheres. The invasion percolation between injection and extraction wells occurs when a fluid injected through the injection well invades less pressurized neighboring pores until it reaches the extraction well. Attention was paid to whether the probability distribution of the invading mass m and the fractal dimension of the clusters of invaded pore particles remain similar to those of the lattice model. Our results indicated that the power characterizing the probability distribution via P(m) / m− was considerably larger than that of the lattice model for a reduced volume density = c of pore particles, c being the percolation critical density, and that it converged to the value for the lattice model for pe = 0 as was increased, where pe is the pressure of an extraction site for the lattice model. The fractal dimension of the invaded clusters was found to be similar to that of the ordinary lattice percolation clusters generated at the percolation threshold. The scaling of the invaded clusters was also examined, and it held in both two and three dimensions.

Coplanar Waveguide를 이용한 광대역 평형 저잡음 증폭기

윤법상(Bub-Sang Yun),윤태순(Tae-Soon Yun),김종호(Jong-ho Kim),김종헌(Jong-Heon Kim),이병제(Byungje Lee),김남영(Nam-Young Kim),이종철(Jong-Chul Lee) 한국통신학회 2001 한국통신학회 학술대회논문집 Vol.2001 No.7