• Title/Summary/Keyword: 환경자기

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Study on the Thermal Properties of Epoxy Resin Compositions having Conjugated Double Bond in Backbone (공액이중결합의 골격구조를 갖는 에폭시수지 경화물의 열특성에 관한 연구)

  • Lee, KyoungEun;Yoo, Min Jae;Kim, Young Chul
    • Journal of Adhesion and Interface
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    • v.14 no.3
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    • pp.135-145
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    • 2013
  • Epoxy resin compositions were studied on the view of self-extinguishing properties without retardant additives and suitability as materials of eco-friendly EMC (Epoxy molding compound). Cured epoxy and phenolic resin composition having conjugated double bond of aromatic structure exhibited self-extinguishing properties and low heat release capacity. In this study, the structure of long conjugated double bond of hetero-atom type azomethyne group between conjugated double bonds of aromatic structure showed lower heat release capacity. Low heat release capacity seemed to be related with high reaction enthalpy, $T_g$ and reactivity affected by hetero-atom structure in azomethyne group.

Attitude Learning of Swarm Robot System using Bluetooth Communication Network (블루투스 통신 네트워크를 이용한 군집합로봇의 행동학습)

  • Jin, Hyun-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.3
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    • pp.137-143
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    • 2009
  • Through the development of techniques, robots are becomes smaller, and many of robots needed for application are greater and greater. Method of coordinating large number of autonomous robots through local interactions has becoming an important research issue in robot community. Swarm Robot System is a system that independent autonomous robots in the restricted environment infer their status from preassigned conditions and operate their jobs through the coorperation with each other. Within the SRS,a robot contains sensor part to percept the situation around them, communication part to exchange information, and actuator part to do a work. Specially, in order to cooperate with other robots, communicating with other robot is one of the essential elements. In such as Bluetooth has many adventages such as low power consumption, small size module package, and various standard procotols, it is rated as one of the efficent communcating system for autonomous robot is developed in this paper. and How to construct and what kind of procedure to develop the communicatry system for group behavior of the SRS under intelligent space is discussed in this paper.

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Moderating Effect of Learning styles on the relationship of quality and satisfaction of e-Learning context (이러닝의 품질특성과 만족도에 관한 학습유형의 조절효과)

  • Ahn, Tony Donghui
    • Journal of Digital Convergence
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    • v.15 no.12
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    • pp.35-45
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    • 2017
  • This study aims to explore the effect of quality factors and learning styles on users' satisfaction in e-Learning context. For this purpose, statistical methods such as reliability test, factor analysis, ANOVA, regression analysis were carried out using the survey data from university students. The quality factors of e-Learning were classified into contents, system, service, and interpersonal activities while learning styles were classified into positive-cooperative, self-directed, environmental-dependent, and passive styles. The results showed that each quality factors of e-Learning has a strong positive effect on user satisfaction, and self-directed group has higher satisfaction than other groups. Learning styles have moderating effects on the quality-satisfaction relationship, and especially, the group of passive learning style has a strong moderating effect on the interpersonal activities. Theoretical and practical implications and future research directions are drawn from these findings.

Intrusion Detection System of Network Based on Biological Immune System (생체 면역계를 이용한 네트워크 침입탐지 시스템)

  • Sim, Kwee-Bo;Yang, Jae-Won;Lee, Dong-Wook;Seo, Dong-Il;Choi, Yang-Seo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.5
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    • pp.411-416
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    • 2002
  • Recently, the trial and success of malicious cyber attacks has been increased rapidly with spreading of Internet and the activation of a internet shopping mall and the supply of an online internet, so it is expected to make a problem more and more. Currently, the general security system based on Internet couldn't cope with the attack properly, if ever, other regular systems have depended on common softwares to cope with the attack. In this paper, we propose the positive selection mechanism and negative selection mechanism of T-cell, which is the biological distributed autonomous system, to develop the self/non-self recognition algorithm, the anomalous behavior detection algorithm, and AIS (Artificial Immune System) that is easy to be concrete on the artificial system. The proposed algorithm can cope with new intrusion as well as existing one to intrusion detection system in the network environment.

Engineering Properties of Self-healing Smart Grouting Method (자기치유 기능을 이용하는 SSG공법의 공학적 특성)

  • Moon, In-Jong;Kim, Byoung-Il;Heo, June;Choi, Yong-Sung;Choi, Yong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.32 no.3
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    • pp.29-37
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    • 2016
  • SSG (self-healing smart grouting) method, which is developed recently, has the characteristics such as an improvement of durability and waterproofing, prevention of leaching and pollution. In this study, we performed several tests such as gel-time measurement, uniaxial compression test, permeability test, fish poison test and chemical resistance test to compare the engineering properties of SSG with the other chemical grouting method (LW, SGR). As results of tests, the SSG method has low possibility of groundwater and ground pollution caused by leaching, furthermore, it has advantages like long/short term waterproofing, strength and durability. Therefore the SSG method can be applicable in the fields as an alternative of existing chemical grouting methods with problems.

Case analysis for constructing a homogeneous learning group in programming lessons for non-specialists (비전공자를 대상으로 한 프로그래밍 수업에서 동질적 학습 집단 구성을 위한 사례 분석)

  • Lee, Kyung-Sook
    • Journal of Digital Convergence
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    • v.17 no.12
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    • pp.59-65
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    • 2019
  • The purpose of this study is to investigate the effects of the learning environment on the learning achievement of the learners and to improve the learning achievement of the learners while accepting the fact that it is difficult to change the class environment in which the middle and large group. Among the learner's positive and cognitive factors, we examined the factors that can classify learners into homogeneous groups in programming learning. The difficulty level of the learning contents influenced factors that classify the homogeneous group, and the factors were analyzed by dividing the intermediate difficulty and the final achievement. In addition, we examined the factors that affect the difference between two grades in order to analyze factors affecting steady learning regardless of difficulty level. It was found that the learners' personal motivation influenced the learning achievement of easy learning contents, and the performance self - efficacy had influence on the learning achievement and achievement of difficult learning contents.

Case Study on Flip Learning Application to Preparatory Childhood Teachers (예비유아교사의 플립러닝 적용 사례 연구)

  • Pyo, Chang-woo
    • Journal of the Korea society of information convergence
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    • v.8 no.1
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    • pp.39-47
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    • 2015
  • This study was conducted to identify the experience that applied Flip Learning to preparatory childhood teachers. The target of study is 76 students who were in the first semester of the first year of three-year early childhood education major and took teaching profession subjects for 2 credits. The semester was run for 13 week-course from the beginning of March to the middle of June. Flip Learning was applied to all the classes. Data was collected through qualitative analysis of participants' journals and was concluded with the category of three strengths and four weaknesses. The strengths were firstly active class participation, secondly repetition learning, and thirdly self directed learning. The weaknesses were firstly a burden on class time, secondly improvement on Flip Learning methods, and thirdly a need of ability for self-directed learning and fourthly the experience of environmental unstability for prior learning. It suggests application examples of more effective teaching and learning methods for college professors and students through the case that applied Flip Learning to preparatory early childhood teachers.

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A Study on Analysis of Learning Activity in Class of Engineering College Students (공과대학 학생의 수업 내 학습활동 분석 연구)

  • Song, Myung hyun;Kim, Kyeong Eon;Kang, Sueng Chan
    • Journal of Practical Engineering Education
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    • v.8 no.1
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    • pp.69-73
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    • 2016
  • While growing interest about university education and quality enhancement, learner's scholastic achievement, learning process, various of learning activity work variable performance of university education. In this context, for quality enhancement of engineering education, it is necessary to pay attention not only learning achievement, educational conditions and environment, but also how students learn. The purpose of this study is checking learning activity in class of Engineering college students and proposing teaching and learning support for promoting learning activity in class. The result of this study is engineering college students were participate in highly only activity is called to professor, but self-directed learning engagements was less than. Activity of promoted thinking about task execution implemented frequently, but activity of critical thinking and applied everyday life were less than. In class students cooperated with colleague learner actively, they had sincere attitude about class. Based on these results, in order to promote learning activity in class, it is necessary sufficient teaching-learning support for learner's self-directed learning and enhancing thinking skills.

A study on ACF Comparsion to Various Spreading Sequence for T-DMB Emergency Broadcasting (T-DMB 재난방송을 위한 다양한 확산 수열 자기상관특성 비교 연구)

  • Lee, Seung-Ho;Lee, Yong-Tae;Kim, Geon;Yang, Chung-Mo;Kim, Wan-Sik;Cho, Ju-Phil;Park, Yong-Woon;Cha, Jae-Sang
    • Journal of Satellite, Information and Communications
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    • v.6 no.2
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    • pp.125-130
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    • 2011
  • In this paper, there was compared to the performance of the Auto Correlation Feature of each code using Spreading code for improving the data transmission technology in T-DMB disaster broadcasting. Generally, wireless mobile communication environment such as DMB occur the Inter Code Interference and the Multi-Path Interference in the process of the identification of the transmitter from the receiver. To solve this problem, spreading code technology was able to improve the security property. Also, it will be able to use in many fields of signal processing, because to control a period of the code can be variable. Therefore, in this paper, we studied to compare the performance of excellent orthogonal Golay code, Kasami code and ZCD(Zero Correlation Duration) code.

A Study on the Improvement of Evaluation Indicators for Small Library Operations (작은도서관 운영평가 지표 개선에 관한 연구)

  • Kim, Bo-il
    • Journal of the Korean Society for Library and Information Science
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    • v.52 no.1
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    • pp.5-34
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    • 2018
  • The small library evaluation index, which was previously developed and is currently in use, needs to be improved because of two major reasons: inefficient allocation of points along with evaluation items and detailed indicators that are different from the actual environment of small libraries; and the lack of value as basic data for preparing policies relevant to small libraries. Therefore, the present study proposed a small library operation evaluation index (draft) that includes not only a quantitative evaluation but also a qualitative evaluation that allows the evaluation of the basic purpose and value of small libraries by reflecting the demands of the small libraries that are being evaluated. The proposed small library operation evaluation index (draft) was made to be an evaluation for self-inspection that enables small libraries to autonomously conduct operation evaluation and gauge their level by diversifying the evaluation methods and the evaluation scale of detailed indicators.