• Journal of The Korean Association For Science Education
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• v.29 no.4
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• pp.400-413
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• 2009

The purpose of this study was to investigate middle school students' processes of argumentation in science lessons and to compare students' argumentation in different contexts (socioscientific context/scientific context). An argumentation-based teaching-learning strategy was used to enhance quality in students' arguments in science lessons. Data were collected from five lessons by video- and audio-recording eight groups of four students each engaging in argumentation. The quality and frequency of students' argumentation was analyzed using an assessment framework based on the work of Toulmin. The findings showed that: (a) there was improvement in the quality of students' argumentation; (b) there were no differences in the structure of argumentation and percentage of explanatory argumentation components as well as dialogic argumentation components in different argumentation contexts. The results of this study showed that students' argumentation can be enhanced with strategic argumentation teaching-learning.

• Journal of The Korean Association For Science Education
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• v.19 no.3
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• pp.428-440
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• 1999

The colorful overhead projector films, named as Bio-cosmos II, including photographs, pictures, concept maps, and diagrams, were developed and manufactured as audio-visual teaching aids and teaching resources for students' biology learning in high school, and the CD-ROM and web sites for their application to the school were also constructed. The content of the films was organized based upon the analysis of seven different biology textbooks approved by the Ministry of Education. The films were designated based on various instructional strategies and manufactured using multimedia with various educational softwares. The CD-ROM was composed of the scenes as logo, initial main, chapters list, contents, and quit. Initial main scene indicated various chapters according to the texts of biology areas in General Science, Biology I, and II. Each chapters linked with the scenes for detailed concept maps, the downstream real subjects, and contents. The subject screens were composed of various types of summarized diagrams including lesson contents, figures, pictures, photographs, and their explanation, experimental procedures and results, tables for summarized contents, and additional animation with video captures, explanations, glossary, etc. Most files were manufactured in software Adobe Photoshop by scanning the pictures, figures and photographs, and then the explanation, modification, storing with PICT or PSD files, and transformation with JPG files, were processed in the aspect of high quality in terms of instructional strategies and graphic skills on gracefulness, clearness, colorfulness, brightness, and distinctness. A 14 films for biology areas in General Science, 80 for Biology I, and 142 for Biology II were manufactured and loaded to the CD-ROM and web site, and the files had been attempted to opened with an internet home-page of http://gic.kyungpook.ac.kr/biocosmos.

• Journal of the Korean School Mathematics Society
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• v.10 no.2
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• pp.263-288
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• 2007

The purpose of this study is to search the effective teaching-learning program by considering how affect on formation of the process-object perspective of linear function using Excel. In this study we analyzed function units in textbook and examined how Excel affect on the formation of the process-object perspective of linear function. Teaching experiment was based on qualitative case study and performed for five classes with five 8th graders. Data were gathered through observations, audio-taped interviews, video recording of the students 'work, students' worksheets, and detailed field notes. Findings indicate that exploration learning environment using Excel could supplement paper-and-pencil environment. We found that intuitive, dynamic, explorative, feedback skills via Excel can play the role of scaffolding supporting formation of process perspective object perspective of linear function.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.247-249
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• 2005

최근 디지털 TV, DVD 플레이어, 홈시어터와 같은 디지털 A/V 기기들을 통합하여 멀티미디어 컨텐츠를 서비스 받는 홈 네트워크 기술에 대한 관심이 높아지고 있다. 이러한 환경에서 UpnP를 이용한 디지털 기기들의 상태를 모니터링하고, 사용자의 요청과 제어 명령을 전달하여, 멀티미디어 컨텐츠를 서비스 받을 수 있도록 하는 연구는 매우 중요하다. 그러나 UPnP는 TCP/IP 기반의 프로토콜을 사용하기 때문에 사용자 인터랙션에 의한 전송 지연 시간이 발생한다. 그러므로 본 논문에서는 셋탑 박스에 최적화된 UPnP AV 시스템을 구현하고 AV 컨텐츠의 효율적인 재생을 위한 UPnP프레임워크의 재생 기법을 제안한다. UPnP AV 시스템은 미디어 서버가 있고, 미디어 서버에 저장된 비디오/오디오 파일 등을 전송받아 재생하기 위한 셋탑 박스에는 컨트롤 포인트와 UPnP 미디어 렌더러의 통합 모델이 탑재된다. 이러한 기법은 다양한 기기를 제어하고 호환성을 제공하는 UPnP프레임워크가 될 수 있다.

• Journal of Educational Research in Mathematics
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• v.20 no.2
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• pp.185-202
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• 2010

This study was designed to investigate the possibility that the optimization problem solving activities based on the instrumented CAS can have an influence on the sequence of mathematics curriculum in secondary mathematics education. Some optimization problem solving activities based on CAS were constructed and executed to eleventh grade(the penultimate year of Korean high school) 7 students for nine class hours. They have experienced using CAS in mathematics class for three months, but never learned calculus. The data which consists of classroom observations(audio and video taped) and post-unit interviews with students were analyzed. In the analysis, with CAS, students can highly deal with the applied optimization problems made up of calculus, cubic equation, solution of radical equation, and graph analysis which never learned. This result shows CAS may have an influence on the sequence of mathematics curriculum in secondary mathematics education.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.1
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• pp.22-32
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• 2003

Many of multimedia applications in distributed environments generate the packets which have the real-time characteristics for continuous audio/video data and transmit them according to the teal-time task scheduling theories. In this paper, we model the traffic for continuous media in the distributed multimedia applications based on the high-bandwidth networks and introduce the PDMA algorithm which is the hard real-time task scheduling theory for guaranteeing QoS requested by the clients. Furthermore, we propose the admission control to control the new request not to interfere the current services for maintaining the high quality of services of the applications. Since the proposed admission control is sufficient for the PDMA algorithm, the PDMA algorithm is always able to find the feasible schedule for the set of messages which satisfies it. Therefore, if the set of messages including the new request to generate the new traffic. Otherwise, it rejects the new request. In final, we present the simulation results for showing that the scheduling with the proposed admission control is of practical use.

• The Mathematical Education
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• v.56 no.3
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• pp.257-280
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• 2017

The purpose of this study is to analyze middle school students' learning characteristics they showed on the inquiry-based learning process of circumcenter using various teaching tools, and then to identify the effects of using teaching tools in the middle school students' learning process of circumcenter. For this purpose, we developed teaching materials for inquiry-based learning of circumcenter using textbook, origami, ruler and compass, GeoGebra and sand experiment. Then we applied them on the learning process of circumcenter for five groups of middle school students. From the analyzing of audio/video materials and documents which are collected from the process of participants' inquiry-based learning of circumcenter, we identified the following results. First, inquiry-based learning of circumcenter using various teaching tools promoted mathematical discourses among participants of this study. For example, they conjectured mathematical properties or justified their opinions after manipulated teaching tools in the process of learning circumcenter. Second, inquiry-based learning of circumcenter using various teaching tools promoted participants' divergent thinking. They tried many inquiry methods to find new mathematical properties relate to circumcenter. For example, they tried many inquiry methods to know whether there is unique circle containing four vertices of given quadrangles. Third, we found several didactic implications relate to inquiry-based learning of circumcenter using various teaching tools which are due to characteristics of teaching tools themselves. Participants showed several misconceptions about mathematical properties during they participated inquiry-based activity for learning of circumcenter using various teaching tools. We identified their misconceptions were not due to any other variables containing their learning characteristics but to characteristics of teaching tools.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3885-3895
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• 2000

The emergence of digital imaging and digital networks has made duplication of original artwork easier. In order to protect these creations, new methods for signing and copyrighting visual data are needed. In the last few years, a large number of schemes have heen proposed for hiding copyright marks and other information in digital image, video, audio and other multimedia objects. In this paper, we propose a technique for embedding the watermark of visually recognizable patterns into the frequency domain of images. The embedded watermark can be retrieved from the decoded sequence witbout knowledge of the original. Because the source image is not required to extract the watermark, one cannot make the fake original that is invertible to watermarking scheme from the waternlarked image. In order to recover the embedded signature data without knowledge of the original, a prediction of the original value of the pixel containing the information is needed. The prediction is based on a averaging of amplitude values in a neighborhood around the pixel itself. Additionally the projxJsed technique could survive several kinds of image processings including JPEG lossy compression.

• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.3139-3149
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• 1997

E-mail system has been widely used for information transmission. As multimedia technologies are developed, many Internet services support multimedia. E-mail system only transmits 7bit ASCII data using simple mail transfer protocol(SMTP) specified in RFC 821. E-mail system can't support the authoring and the transmission of multimedia data. In this study multimedia mail authoring system has been designed and implemented in order to provide message integration. Multimedia messages can be authored and transformed into text types with this system. Transformed messages are transmitted from sender's mail transfer agent (MTA) to receiver's MTA by means of SMTP. Messages can be authored in hypertext markup language (HTML) including text, image, audio and video. This system provides integrated messages which consist or various media. BASE64 Encoding method is used in order to transform multimedia messages into text types. Received mails are managed by multimedia user agent (MUA) which is proposed in this study. Convenience for user is improved in this system.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.69-78
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• 2007

In recent years, embedded mobile systems have been expanding their application domains from embedded portable devices which only execute a specialized application such as MP3 player or digital camcoder to digital convergence devices which execute more complicated applications converged various functionalities such as video and audio play, digital dictionary, DMB, games, phone, etc. As it requires the increasing hardware performance such as more faster CPU and more larger RAM, display, disk size, it has brought about a corresponding increase in power consumption. However, coupled with relatively small gains in battery capacity over recent years, the importance of software architecture including intelligent power management has become paramount. In this paper, we have ported UbiFOSTM with energy saving techniques on the ARM9-based MBA2440 platform. For energy savings, we adapted the dynamic power management and the device power management schemes based on monitoring workload. Experimental results with some well-known applications show that proposed low power technique could save energy up to 24 %.