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류성림 ( Sung Rim Ryu ) 한국수학교육학회 1998 수학교육 Vol.37 No.1
The purpose of this study is to investigate the understanding of middle school students on the meaning of proof and to suggest a teaching method to improve their understanding based on three levels identified by Kunimune as follows: Level I to think that experimental method is enough for justifying proof, Level II to think that deductive method is necessary for justifying proof, Level III to understand the meaning of deductive system. The conclusions of this study are as follows: First, only 13% of 8th graders and 22% of 9th graders are on level II. Second, although about 50% students understand the meaning of hypothesis, conclusion, and proof, they can`t understand the necessity of deductive proof. This conclusion implies that the necessity of deductive proof needs to be taught to the middle school students. One of the teaching methods on the necessity of proof is to compare the nature of experimental method and deductive proof method by providing their weak and strong points respectively.
ZnO가 첨가된 (Na,K)NbO<sub>3</sub>계 세라믹스의 압전 특성
류성림,권순용,어순철,김시철,류주현,Ryu Sung-Lim,Kweon Soon-Yong,Ur Soon-Chul,Kim Si-Chul,Yoo Ju-Hyun 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.8
ZnO was doped up to 0.3 wt% for improving the electrical properties of lead-free $[Li_{0.04}(Na_{0.44}Ko_{0.52})-(Nb_{0.86}\;Ta_{0.10}\;Sb_{0.04})]O_3$ piezoelectric ceramics. The ceramics were fabricated with the conventional sintering processes. Crystal structure of the samples was tetragonal phase regardless of ZnO amount. However, the piezoelectric properties were varied with the ZnO amount. The electro-mechanical coupling factor $(k_p)$ was with the ZnO amount up to 0.2 wt% but decreased with the further addition. the maximum value of $k_p$ was 0.475. Density, piezoelectric charge constant and relative dielectric constant was also showed maximum value at 0.2 wt%. The maximum values are $4.75g/cm^3$, 275 pC/N, 1403, respectively. In contrast, the mechanical quality factor $(Q_m)$ was not varied with increasing the ZnO addition up to 0.2 wt% but rapidly increased at 0.3 wt%.
2009 개정 교육과정에 따른 초등수학교과서의 STEAM 요소 분석: 3~4학년군을 중심으로
류성림 ( Sung Rim Ryu ) 한국수학교육학회 2015 初等 數學敎育 Vol.18 No.3
본 연구에서는 2009 개정 초등수학 3~4학년군 교과서에 포함된 STEAM 요소를 학년별, 내용 영역별로 분석하여 어떤 요소가 어떻게 분포되어 있는지를 알아보고자 하였다. 연구 결과 STEAM 요소의 학년별 분포는 4학년 1학기 184개(27.7%), 3학년 2학기 164개(24.8%), 3학년 1학기 162개(24.4%), 4학년 2학기 153개(23.1%)의 순으로 나타났고, 3학년과 4학년의 차이는 거의 없다고 볼 수 있다. 내용 영역별 분포는 STEAM 요소가 내용 영역의 분포 비율과 비슷하게 분포되어 있음을 알 수 있었다. 그러나 STEAM 요소별로는 편차가 심하다는 것을 알 수 있었다. 예술(A) 요소가 448개(67.6%)로 가장 많았는데, 표현예술이 344개(51.9%)로 문화예술의 104개(15.7%)보다 3배 정도많았다. 표현예술이 약 절반을 차지하고 있는 것은 하위요소로 수학 교과서에 만화, 글쓰기, 이야기 만들기 등의 의사소통 요소가 많이 포함된 것이 주된 이유라고 볼 수 있다. 다음으로 기술공학(T-E) 요소가 160개(24.1%) 포함되었고, 과학(S) 요소가 55개(8.3%)가 포함되어 있었다. 다음교육과정의 교과서 개발 시 상대적으로 적은 과학 요소도보다 적극적으로 융합하려는 노력을 기울일 필요가 있다. This study analyzed what STEAM elements, except mathematical content, are contained in 2009 revised elementary school 3rd and 4th grade group mathematics textbooks. STEAM elements in the textbooks were examined by grade and by content area in the elementary school mathematics curriculum. According to the results, the difference between 3rd and 4th grade in the number of STEAM elements is almost not visible. Distribution of specific content areas could be seen that the distribution STEAM element is similar to the percentage distribution of the content area. However, the number of STEAM elements are different depending on the type of STEAM. The number of arts element is 448(67.6%) and this elements are seen the most. The number of representative art and cultural art is 344(51.9%) and 104(15.7%), respectively. The number of technology-engineering and science is 160(24.1%) and 55(8.3%), respectively. We need to developed to promote use of science element in next mathematics curriculum.
하소온도변화에 따른 (Na,K)NbO<sub>3</sub>계 무연 압전세라믹스의 압전 및 유전특성
류성림,정광현,류주현,이병률,정영호,Ryu, Sung-Lim,Chung, Kwang-Hyun,Yoo, Ju-Hyun,Lee, Byung-Youl,Jeong, Yeong-Ho 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.9
In this paper, in order to develop lead-free piezoelectric ceramics, $(Li_{0.04}Na_{0.44}K_{0.52)(Nb_{0.86}Ta_{0.10}Sb_{0.04})O_3$ ceramics were fabricated with the variation of calcination temperature and sintering temperature. The ceramics couldn't be sintered at temperature less than $1110^{\circ}C$ and showed the highest density at calcination temperature of $800^{\circ}C$. Crystal structure of the ceramics showed pseudo-tetragonal phase. At the calcination temperature of $800^{\circ}C$ and sintering temperature of $1110^{\circ}C$, the optimal values of $density=4.64g/cm^3,\;kp=0.45,\;{\varepsilon}r=1336,\;d_{33}=254pC/N\;and\;Tc=335^{\circ}C$ were obtained.
압전 액츄에이터에 활용할 저온소결 압전 세라믹스에 관한 연구
류성림,이상호,류주현,Ryu, Sung-Lim,Lee, Sang-Ho,Yoo, Ju-Hyun 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.3
In this study, in order to develop the composition ceramics for multilayer piezoelectric actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$, $Na_2CO_3$, ZnO as sintering aids and their piezoelectric and dielectric properties were investigated according to the Bi substitution, Bi substitution induced grain growth and increase of sinterablity, And also, Bi substitution suppress secondary phase due to the liquid phase sintering effect. Bi substitution enhanced electromechanical coupling factor ($k_p$) and dielectric constant ($\varepsilon_r$), However, mechanical quality factor($Q_m$) was deteriorated, At the sintering temperature of 870 $^{\circ}C$ and Bi substitution of 1 mol%, density, electromechanical coupling factor ($k_p$), mechanical quality factor ($Q_m$), Dielectric constant ($\varepsilon_r$) and piezoelectric constant ($d_{33}$) of specimen showed the optimum values of 7,878 $g/cm^3$, 0,608, 835, 1603 and 397 pC/N, respectively for multilayer piezoelectric actuator application.