• 한국건설순환자원학회논문집
• /
• 제8권1호
• /
• pp.143-151
• /
• 2020

최근 자기치유 콘크리트의 연구가 활발히 진행되고 있으며, 구조물의 유지관리에 활용하기 위한 다양한 방법이 시도되고 있다. 하지만 자기치유 콘크리트의 기술적인 발전과는 달리, 성능을 평가하기 위한 방법은 불충분한 실정이다. 비록 표면관찰과 투수실험을 통해서 균열의 치유를 관찰하는 방법이 널리 실행되고 있지만, 현미경 관찰을 통한 표면관찰 방법은 국부적인 지점의 관찰은 전체적인 성능을 평가하기에는 불충분할 수 있으며, 투수실험의 경우에는 물질용출 및 점성으로 인한 손실을 고려해야 한다. 상기의 두 실험방법의 단점을 보완한 기체확산실험이 개발되었지만, 실제 치유가 발생한 시편을 대상으로의 검증은 이루어지지 않았다. 따라서 본 연구에서는 치유가 발생한 모르타르 시편에 대해 기체확산실험을 진행하였고, 기체확산실험에 의한 자기치유 평가의 적정성을 검증하였다.

• 천문학회보
• /
• 제45권1호
• /
• pp.47.2-47.2
• /
• 2020

The Experiment to Detect the Global EoR Signature (EDGES) has probed the status of the early Universe through the global 21cm observation. The claimed (brightness temperature) of ~ 500 mK absorption dip at z~17 against the continuum background cannot be explained in the standard LambdaCDM framework. In the meantime, the Planck 2018 Legacy Data, especially the E-mode polarization power spectrum, puts rather strong constraints on the high-redshift reionization process. We show how these two observational contraints can be accomodated in a series of reionization scenarios, with a special focus on the strongly self-regulated reionization by first stars.

• 마이크로전자및패키징학회지
• /
• 제18권3호
• /
• pp.53-57
• /
• 2011

In the modern packaging technologies highly condensed metal interconnects are typically formed by highcost processes. These methods inevitably require the precise controls of mutually dependant process parameters, which usually cause the difficulty of the change in the layout design for interconnects of chip to-chip, or chip-to-substrate. In order to overcome these problems, the unique concept and methodology of self-assembly even in micro-meter scale were developed. In this report we focus on the factors which influenced the self-formed bumps by analyzing the phenomenon experimentally. In case of RMA flux, homogenous pattern was obtained in both plain surface and cross-section surface observation. By using RA flux, the phenomena were accelerated although the self-formtion results was inhomogenous. With ussage of moderate RA flux, reaction rate of the self-formation was accelerated with homogeneous pattern.

• 아동학회지
• /
• 제20권1호
• /
• pp.165-176
• /
• 1999

The purpose of this study was to investigate whether children's temperament and maternal control strategies were related to the self-control behaviors of 3-year-old children. The sample was comprised of 50 young children, ranging from 37 to 50 months of age, and their mothers. Mothers were asked to complete a questionnaire on children's temperament. Situational observation was conducted for obtaining data on maternal control strategies and for children's self-control behaviors in a resistance to temptation situation. All the subjects' activities were videotaped for 20 minutes. Differences were found in maternal control strategies and children's self-control behaviors by gender of child and by age and education of mothers. Relationships were found between children's temperament and maternal control strategies. However, children's temperament had an indirect effect on their self-control behaviors through maternal control strategies. The findings indicated that the self-control development of children in this sample were in a transitional stage.

• 수산해양교육연구
• /
• 제20권3호
• /
• pp.343-357
• /
• 2008

Generally, schooling is implemented by instruction in the classroom. And instruction is made progress by concrete interaction through teacher's question and students' answer or presentation. According to a lot of researches on teacher-student interaction, student's opportunity of class presentation is influenced by students' self-esteem, learning attitude, academic achievement, and relationships. And students' opportunity of class presentation is very important not only students but also social equality and democracy. Therefore, teachers have to recognize the importance of students' opportunity of class presentation. However, according to many referential researches, students' opportunity of class presentation is differentiated by students' academic ability and social-economic status. The purpose of this study was to ascertain whether students' opportunity of class presentation was differentiated by students' academic ability and social-economic status or not. The method of this study was used checklist, interview, and class observation for a month. This study indicates that in spite of some exceptional cases, many students were taken the opportunity of class presentation differently by his/her academic ability and social-economic status. And teacher does not recognize that whether she gives student's opportunity of class presentation differently or not. To be a good teacher, teacher should reflect that teaching students is not easy, and teaching students is very important. And teacher should recognize that her speaking, action, and interaction with students including students' opportunity of class presentation influences students' self-esteem, learning attitude, academic achievement, and relationships.

• 한국건축시공학회지
• /
• 제7권2호통권24호
• /
• pp.99-106
• /
• 2007

The purpose of this study presents in Relations between cracks in self-leveling material and quality of floor groundwork surface are experimentally examined. As the first stage, the experiment to observe cracks in self-leveling material constructed on floor groundwork made from various kinds of concrete was carried. As a result, following basic findings were obtained. First, observation of cracks should be continued until an increase in width of cracks stop, without constructing any finishing material. Second, degree of cracks may be indicated quantitatively by the product of length and width. Finally, Cracks and separation is not be influenced by specimen size. Based on these findings, the method of predicting cracks by evaluating surface layer quality of floor groundwork will be established.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제54권2호
• /
• pp.51-54
• /
• 2005

In this work, the attempt has been made to investigate the morphology of self-assembled dipyridinium dithioacetate on Au(111) substrate by Scanning Tunneling Microscopy(STM). Also, we measured electrical properties(I-V) using Scanning Tunneling Spectroscopy(STS). Sample used in this experiment is dipyridinium dithioacetate, which contains thiol functional group, this structure that can be self-assembled easily to Au(111) substrate. The self-assembly procedure was used for two different concentrations, 0.5 mM/ml and 1 mM/ml. Dilute density of sample by 0.5 mM/ml, 1 mM/ml and observed dipyridinium dithioacetate's image by STM after self-assembled on Au(111) substrate. The structure of STM tip-SAMs-Au(111) substrate has been used measurement for electrical properties(I-V) using STS. The current-voltage(I-V) measurement result, observed negative differential resistance(NDR) properties.

• 과학교육연구지
• /
• 제34권1호
• /
• pp.105-112
• /
• 2010

본 연구의 목적은 탐구 과제에 대한 사전지식이 초등 과학 영재의 관찰방법과 의문에 미치는 영향을 알아보기 위한 것이다. 이를 위해 '거미와 거미줄' 이라는 과제를 해결하는 과정에서의 학생들의 관찰방법과 의문이 사전지식에 의해 어떻게 영향을 받는지 연구하였다. 사전지식이 상대적으로 높은 집단의 학생들은 사전지식이 낮은 집단에 비해서 관찰의 방법과 양이 높게 나타났다. 그러나 사전지식이 양이 높은 집단이나 낮은 집단 모두 관찰 방법에서는 오감을 이용한 단순 관찰을 주로 하였다. 이는 사전지식의 양이 관찰의 양에는 영향을 미치나 관찰 방법에는 영향을 주지 못하는 것으로 볼 수 있다. 사전지식이 높은 집단에서는 보다 높은 수준의 관찰이 나타났다. 이는 관찰의 수준이 높아지기 위해서는 사전에 충분한 교육이 필요함을 의미한다. 따라서 교사들이 관찰을 이용한 수업을 수행할 경우에 사전에 관련된 지식에 대하여 충분한 수업이 이루어져야 보다 효율적인 관찰이 일어난다고 볼 수 있다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.96.3-96
• /
• 2001

In this paper the self-organized and fuzzy inference used stochastic gradient ascent method is proposed. Fuzzy rule and fuzzy set increase as occasion demands autonomously according to the observation information. And two rules(or two fuzzy sets)becoming to be similar each other as progress of learning are unified. This unification causes the reduction of a number of parameters and learning time. Using fuzzy inference and making a rule with an appropriate state division, our proposed method makes it possible to construct a robust reinforcement learning system.

• 한국초등과학교육학회지:초등과학교육
• /
• 제35권2호
• /
• pp.253-264
• /
• 2016

The purpose of this study was to investigate implications of self-directed learning experiments in elementary science education through understanding elementary school students' awareness of their experiences in self-directed learning experiments. Twenty students joined the school science club voluntarily and conducted self-directed learning experiments. We collected data through observation of the experiments, interviews, and questionnaires. The students who participated in the club showed high satisfaction with self-directed learning experiments. The participants were aware that their scientific interest and knowledge, and the confidence in conducting experiments were increased. The students felt positive about the inquiry process of conducting self-directed learning experiments with their own subjects. They also felt a sense of achievement in attempting their experiments in defiance of several failures. The participants realized that the self-directed inquires led to increased declarative and procedural knowledge of science. The students stated that they had some difficulties in coping with the different results contrary to expectations and preparing laboratory materials and instruments. Nonetheless, they showed the promotion of their scientific literacy during overcoming those difficulties. We suggest that self-directed learning experiments can be a more effective way in science learning to make students experience the nature of science than existing school experiments. This can be implemented through a creative experience activities such as science clubs.