• Title, Summary, Keyword: 극한지

Search Result 3,379, Processing Time 0.052 seconds

Effects of Teaching of Limit Using GeoGebra to High School Students' Mathematics Learning (GeoGebra를 활용한 극한 지도가 고등학생들의 수학 학습에 미치는 영향)

  • Kong, Min Sook;Kang, Yun Soo
    • Journal of the Korean School Mathematics Society
    • /
    • v.17 no.4
    • /
    • pp.697-716
    • /
    • 2014
  • The purpose of this paper is to investigate high school students' learning characteristics which revealed in their learning process of limit using GeoGebra. And we are going to analyze effects of teaching of limit using GeoGebra to high school students' interesting and attitudes for mathematics learning. To do this, we selected three high school students as participants and ask them performing limit learning using GeoGebra. We recorded their problem solving process. Through analyzing their problem solving process relate to their solution, we found the followings: First, students did not logically approach based on mathematical properties or given materials, rather showing tendency decide with self-conscious and intuition. Second, it is possible that former reasoning strategies disturb following reasoning in the process of high school students' mathematics learning. Third, learning process of limit using GeoGebra help high school students to identify and correct their errors relate to limit learning. Forth, learning process of limit using GeoGebra positively effects to high school students' interesting and attitudes for mathematics learning.

  • PDF

A Study on Visual Acuity According to Color Temperature and Color Rendering of Light Soureces (광원의 색온도 및 연색성에 따른 밝음의 느낌에 관한 연구)

  • 이진우;지철근;조경애
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • /
    • pp.261-266
    • /
    • 2002
  • 본 연구에서는 광원의 색온도와 연색성의 차이에 의한 밝음의 느낌과 조도와의 관계를 밝히기 위하여 이종 램프간, 또한 동종 램프 간의 비교 실험을 시각 대상물로 흑백 인쇄문자지와 색상지를 사용하여 수행하였다. 현재 널리 사용되고 있는 백열전구, 형광램프, 고압 나트륨램프, 메탈핼라이드램프, 무전극 방전램프를 대상으로 실험을 수행하여, 램프 간 실험 결과의 통계처리 결과, 백열전구와 무전극 방전램프, 주광색 형광램프와 무전극 방전램프, 고압 나트륨램프와 무전극 방전램프, 메탈핼라이드램프와 무전극 방전램프는 유의수준 5[%] 이내에서 결과에 분명한 차이가 있음이 밝혀졌다.

  • PDF

A study on the performance strategies and the composition of the performing works in Baegooja musical dance theater group through Violate (배구자무용연구소의 가무극 <파계> 연구)

  • Kim, Nam Seok
    • (The) Research of the performance art and culture
    • /
    • no.33
    • /
    • pp.165-193
    • /
    • 2016
  • 배구자는 1920~30년대 조선에서 큰 인기를 확보한 무용수이자 연극인이었다. 그녀는 배구자악극단을 창립하여 조선과 해외(일본)를 오가면서 공연을 펼쳤고, 대중들은 그녀의 작품을 보기 위해서 극장으로 몰려들었다. 그녀와 그녀의 극단이 인기를 확보하고 있을 무렵, 그러니까 1931년 배구자무용연구소는 '혁신 공연'을 선언하고 일련의 작품을 발표했다. 당시 공연 작품 중에는 가무극 <파계>가 포함되어 있었는데, 다행히 <파계>는 공연 대본으로 기록되어 현재까지 전해질 수 있었다. 남아 있는 가무극 <파계>를 통해, 배구자무용연구소(나아가서는 '배구자악극단')의 공연 전략과 레퍼토리의 실체를 파악할 수 있을 것으로 기대된다. 조선 근대연극(사)의 주요한 축을 담당한 배구자악극단에 대한 연구는, 일제강점기 조선의 대중극의 다양한 갈래와 그 특성에 대한 이해를 제고할 것으로 전망된다.

극한지 자원 개발을 위한 소재 개발

  • Gwon, Yong-Nam;Kim, Sang-Sik;Kim, Yeong-Ju;U, Nam-Seop
    • Journal of the KSME
    • /
    • v.54 no.11
    • /
    • pp.42-45
    • /
    • 2014
  • 이 글에서는 최근 자원개발이 북극과 같은 극한지로 확대됨에 따라 해양구조물에 요구되는 소재의 특성 향상 연구 동향에 대해 소개하고자 한다.

  • PDF

The effect of Novel gravitational fields on early Amphibian Morphogenesis (중력장의 변화가 양서류 초기 발생에 미치는 영향)

  • 이은정;정해문
    • The Korean Journal of Zoology
    • /
    • v.35 no.4
    • /
    • pp.518-525
    • /
    • 1992
  • 본 연구에서는 horizontal clinostat과 원심분리 방법의 이용으로 각각 저중력 상태($\mu$G)와 고중력 상태(3G)를 유도하여, 중력장의 변화가 양서류 수정란의 초기 형태 형성에 미치는 영향을 북방산개구리(Rano dybows비름를 대상으로 조사하였다. 중력장의 변화는 첫번째 수평 분열인 제3분열면의 위치에 영향을 미쳤다. 즉 저중력 상태에서는 분열면이 적도면 근처에서, 또 고중력 상태에서는 분열면이 동물극 근처에서 형성되었다. 이와 같은 변화는 포배기로 이어져 할강의 위치와 동물극 정단 세포층 수에 영향을 미쳤다. 즉 저중력에 노출된 포배는 정상배(1G)에 비해 할강이 중앙에 위치했으며 동물극 정단의 세포층 수가 증가하는 반면 고중력에 노출된 포배는 할강이 보다 동물극 폭에 위치했으며 동물극 정단의 세포층 수도 감소하였다. 그러나 낭배기에 도달하면 동물극 정단 세포층 수의 차이는 정상 상태로 조절되었다. 한편 중력장의 변화는 낭배기에 이르는 발생 속도와 원구상순부의 위치를 변경시켰다. 낭배기 이후의 발생 단계에서 중력에 의한 변화로는 tail fin circulation(stage 22)시기의 머리크기의 변화를 들 수 있다. 이상의 결과로 무미 양서류의 초기 형태 형성은 중력장에 의해 변형될 수 있으며 이러한 변화는 발생이 진행됨에 따라 조절되는 것으로 보인다.

  • PDF

Analysis of the Electrodeless Fluorescent Lamps' Radio Interference Characteristics by Operating Frequencies and Structures (무전극 형광등 시스템의 구동 주파수 및 방식에 따른 특성 분석)

  • Mok, Jin-Dam;Jeon, Sang-Bong;Park, Seung-Keun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • /
    • pp.45-48
    • /
    • 2011
  • The electrodeless fluorescent lamp is relatively new luminaire and has been known as the high energy saving lamp which has long life and environment-friendly. But these kind of lamps have some risks to cause harmful radio interference unavoidably due to its own inductive characteristics. In this paper we measured the radio disturbance characteristics of the induction lamp with the operating frequency at 250 kHz, and compared the values with the limits of relevant standards. Finally we have estimated the interference protection distance between the induction lamps and some services around their operating frequencies, and considered the desirable future scopes and limits of the applications for these kind of lamps.

  • PDF

Analysis on the Induction Effects by Separation Distance between the Power Feeding Station and the Telecommunication Cables (3점 전위강하법과 2극 측정법에 대한 접지저항 측정 결과 분석)

  • Choi, Mun-hwan;Lee, Snag-mu;Cho, Pyung-dong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • /
    • pp.577-580
    • /
    • 2012
  • RRA Notification No.2010-36 suggests the 3-point method(fall-of-Potential) using 2 auxiliary poles only as a test method of earth resistance. However this method needs to much space to install auxiliary poles so it is very difficult to measure the earth resistance in spots such as a mountain district, rocky district. So, we have analyzed the methods of 2-point method and loop resistance method in IEEE std. 81 and ITU-handbook(Earthing and Bonding) and applied these methods in test bed with 3-point method. In this paper we have compared and analyzed the earth resistance value using these 3 methods.

  • PDF

Student Satisfaction and Achievement after Role-playing in a Pediatric Dentistry Class (소아치과 역할극 수업에 대한 학생들의 만족도와 성취도)

  • Kim, Min Jin;Song, Ji-Soo;Shin, Teo Jeon;Kim, Young-Jae;Kim, Jung-Wook;Jang, Ki-Taeg;Lee, Sang-Hoon;Hyun, Hong-Keun
    • THE JOURNAL OF THE KOREAN ACADEMY OF PEDTATRIC DENTISTRY
    • /
    • v.45 no.3
    • /
    • pp.280-289
    • /
    • 2018
  • This study aimed to investigate the effects of learning with role-playing on student satisfaction and achievement regarding behavior management teaching in pediatric dentistry. 93 students were divided into 19 groups and randomly assigned to role-play as a doctor, patient, parent, assistant, or narrator. Their performances were evaluated by the instructor and the satisfaction survey was conducted. All participants took the written test and were asked to compare lecture and role-playing with regard to the effectiveness of learning. Statistical analysis was performed with Mann-Whitney U test, Independent T-test, and Kruskal-Wallis test. 68 students (73.1%) who believed that the role-playing was more helpful than lecture showed higher level of satisfaction than students who believed lecture was more helpful. But there were no differences in the tutor evaluation score and the written test scores. Participants in the patient management scenario showed higher level of descriptive question scores of the written test and tutor evaluation score than those who participate in the parent management scenario. There were no differences between the role groups. Role-playing may help students to become more interested and participatory in learning behavior management. The level of satisfaction may differ by the design and content of the scenario.

Preparation and Characteristics of High Performance Cathode for Anode-Supported Solid Oxide Fuel Cell (연료극 지지체식 고체산화물 연료전지용 고성능 공기극 제조 및 특성 연구)

  • Song, Rak-Hyun
    • Journal of the Korean Electrochemical Society
    • /
    • v.8 no.2
    • /
    • pp.88-93
    • /
    • 2005
  • Anode-supported solid oxide fuel cell (SOFC) was investigated to increase the cell power density at intermediate temperature through control of the cathode structure. The anode-supported SOFC cell were fabricated by wet process, in which the electrolyte of $8mol\%\;Y_2O_3-stabilized\;ZrO_2 (YSZ)$ was coated on the surface of anode support of Ni/YSA and then the cathode was coated. The cathode has two- or three- layered structure composed of $(La_{0.85}Sr_{0.15})_{0.9}MnO_{3-x}(LSM),\;LSM/YS$ composite (LY), and $La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3{LSCF)$ with different thickness. Their single cells with different cathode structures were characterized by measuring the cell performance and ac impedance in the temperature range of 600 to $800^{\circ}C$ in humidified hydrogen with $3\%$ water and air. The cell with $LY\;9{\mu}m/LSM\;9{\mu}m/LSCF\;17{\mu}m$ showed best performance of $590mW/cm^2$, which was attributed to low polarization resistance due to LY and to low interfacial resistance due to LSCF.