• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.1023-1026
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• 2005

본 논문에서는 SDR(Software Defined Radio) 시스템을 위한 Digital IF(Intermediate Frequency) Up/Down 변환기를 설계하고 성능을 평가하였다. 설계한 시스템은 AD 변환부, DA 변환부 및 Up-Down conversion 기능을 수행하는 FPGA로 구성된다. AD 변환부는 Analog Device 사의 AD6645를 사용하였으며, DA 변환부는 Analog Device 사의 AD9775를 사용하였다. Up-Down conversion 기능을 수행하는 FPGA부는 샘플된 IF 입력을 혼합기와 NCO에 의해 기저대역(DC)으로 다운 시키는 역할을 하며, 14bit의 기저대역(DC) 신호를 혼합기와 NCO에 의해 IF 출력으로 올려주는 역할을 한다. 이러한 설계는 기존의 아날로그 헤테로다인 방식에 비하여 높은 유연성 및 우수한 성능 향상을 보여준다.

• Journal of The Korean Association of Information Education
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• v.19 no.3
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• pp.287-298
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• 2015

Digital textbook is noted as a new education materials to realize a new education paradigm with changes in digitalized society. The purposes of this study is investigation of key factors on digital textbook satisfaction by selecting of the three factors(domestic environment factor, teachers factor, school environment factor), analysis of awareness of effect factors on digital textbook satisfaction, and verification for each effect factors' influence on elementary school. 201 elementary school students, 201 their parents, and 12 teachers in Chung-nam were surveyed and factors which influenced on digital textbook satisfaction were analyzed. According to the results, firstly, there was a statistical significant difference in domestic internet environment, device owned environments, the utilization of the internet for the purpose of education and using time, device type of teachers, lesson time of digital textbook used in class and time ratio. Secondly, multiple regression analysis was conducted to find out the influence on digital textbook, the Awareness of parents about digital textbook, The lesson time using digital textbook by teacher, The utilization of the internet for the purpose of education affected satisfactions significantly in the order. This study has significant implications about which we have provided the effort needed to use digital textbook.

• Journal of The Korean Association of Information Education
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• v.8 no.1
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• pp.91-99
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• 2004

According to get ubiquitous environment, it is suggested to environment to get information with whichever terminal at any time wherever. Advancement of ability of mobile device increase requirement of wireless internet base solution. In this paper We developed distance education system based on wireless internet. This system has no problem of bandwidth and resolution of pocket pc because of using SWF(Shockwave Flash). It can maintain readability of high quality when size of resolution is changed but another graphic format can't maintain it.

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.221-242
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• 1996

The purpose of this study is to investigate the teaching methods a n.0, pplied to the basic reference education. Especially, the independent study method in reference education-PSI, AT and PI method used in 1970s at the library schools in the United States was examined in detail. The conclusions and suggestions drawn from this study are as follows : 1) The studies concerned with the teaching method in library and information science education in Korea is very scarce. Studies in this area are needed. 2) In order to improve and innovate the teaching method, instructor' knowledge and understanding of the various teaching methods are essential. The library and information science instructors' efforts should be made in this respect. 3) Instructional materials developed through the research activities concerned with teaching method should be shared among the instructors of the reference education and the device for such sharing should be made.

• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.161-169
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• 2015

In this paper, we propose an smart device based robot programming education program and analyzing students' perceptions such as satisfaction, Expectancy-Value of IT convergence learning after the robot education program according to elementary gifted students' level. Smart device based robot programming education program designed based on schematic of the convergence suggested by WTEC and consist of creative phase, integration/fusion phase, innovation phase, outcome phase for learning practical process of the IT convergence. We are conducting a smart device based robot programming education class to consist of 126 gifted students and analysing the difference of perception. According to analysis of the result, core and advanced students' perception on satisfaction score shows also high. However, advanced level students' satisfaction score shows higher than core students' satisfaction score. Also, advanced level students' expectancy-value score on IT convergence learning shows higher than core students' score.

• Journal of Information Processing Systems
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• v.6 no.3
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• pp.347-358
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• 2010

This paper presents a measurement system for 3D hand-drawn gesture motion. Many pen-type input devices with Inertial Measurement Units (IMU) have been developed to estimate 3D hand-drawn gesture using the measured acceleration and/or the angular velocity of the device. The crucial procedure in developing these devices is to measure and to analyze their motion or trajectory. In order to verify the trajectory estimated by an IMU-based input device, it is necessary to compare the estimated trajectory to the real trajectory. For measuring the real trajectory of the pen-type device, a PHANToMTM haptic device is utilized because it allows us to measure the 3D motion of the object in real-time. Even though the PHANToMTM measures the position of the hand gesture well, poor initialization may produce a large amount of error. Therefore, this paper proposes a calibration method which can minimize measurement errors.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.7
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• pp.573-577
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• 2002

A tape feeder of a SMD(Surface Mount Device) mounter is a device that sequentially feeds electronic components on a tape reel to the pick-up system of the mounter. As components are getting much smaller, feeding accuracy of a feeder becomes one of the most important factors for successful component pick-up. Therefore, it is critical to keep the feeding accuracy to a specified level in the assembly and production of tape feeders. This paper describes a tape feeder inspection system that was developed to automatically measure and inspect feeding accuracy using machine vision. It consists of a feeder base, an image acquisition system, and a personal computer. The image acquisition system is composed of CCD cameras with lens, LED illumination systems, and a frame grabber inside the PC. This system loads up to six feeders at a time and inspects them automatically and sequentially. The inspection software was implemented using Visual C++on Windows NT with easily usable GUI. Using this system, we can automatically measure and inspect the quality of all feeders in production process by analyzing the measurement results statistically.

• Journal of information and communication convergence engineering
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• v.8 no.4
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• pp.399-404
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• 2010

We propose a seamless IPTV transport technology of mobile device. This technology uses multiple interfaces of wireless communication on mobile device. This proposal for transportation of mobile IPTV contents is more mobile and adaptable than other wireless technologies that are currently being used. Algorithm of proposed technology is as follow. When the signal strength of the connected wireless network interface of mobile device is getting lower than specified level, another wireless network interface is connected to continue downloading the IPTV contents in advance. Another connection is maintained until the signal strength of the first connected interface is stable or the interface is connected to another base station (or AP) that have good signal strength. For more seamless services, we consider classifying the packets of mobile IPTV and using dynamic content quality select techniques. Dynamic content quality selection is based on notifying transfer rate to the content delivery network (CDN) server. The proposed technology is expected to use efficiently with both mobile IPTV and the transportation of mobile P2P/P4P.

• The Journal of Information Systems
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• v.30 no.1
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• pp.85-104
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• 2021

Purpose This study aims to verify the mediating effect of the utilization performance of digital device on the relationship between user attitude and life satisfaction. Design/methodology/approach Using the data of 2018 Digital Divide Survey conducted by the National Information Society Agency(NIA), the mediating effect was verified by Baron & Kenny (1986)'s 3 step process, targeting 1,662 adults older than 55. Findings The result is as follows: first, the user attitude of middle and older aged people has a positive effect on their life satisfaction. Second, the effect of user Attitude towards Digital Device of middle and older citizens is partially mediated by the utilization performance of digital device. The results of this study indicate that when providing informatization education in the local community to promote the use of digital devices for the elderly, efforts should be made to grasp the level and inclination of informatization individually, and furthermore present improvements for wireless devices that the elderly can easily access in their daily lives. This study is expected to be a groundwork for a practical intervention to boost positive attitude towards using digital device to enhance the utilization performance of digital device and the life satisfaction of middle and older aged people.

• Research in Mathematical Education
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• v.1 no.1
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• pp.13-22
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• 1997

Cognitive psychology has provided valuable theoretical perspectives on learning mathematics. Based on the metaphor of the mind as an information processing device, educators and psychologists have developed detailed models of competence in a variety of areas of mathematical skill and understanding. Unquestionably, these models are an asset in thinking about the curriculum we want our students to follow. But any psychological paradigm has aspects of learning and knowledge that it accounts for well, and others that it accounts for less well. For instance, the paradigm of cognitive science gives us valuable models of the knowledge we want our students to acquire; but in picturing the mind as a computational device it reduces us to conceiving of learning in individualist terms. It is less useful in helping us develop effective learning communities in our classrooms. In this paper I review some of the significant accomplishments of cognitive psychology for mathematics education, and some of the directions that situated cognition theorists are taking in trying to understand knowing and learning in terms that blend individual and social perspectives.