• KIPS Transactions on Computer and Communication Systems
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• v.6 no.1
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• pp.25-30
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• 2017

The influence of the data deletion method which is one of anti-forensic techniques is substantial in terms of forensic analysis compared to its simplicity of the act. In academic world, recovery techniques on deleted files have been continuously studied in response to the data deletion method and representatively, the file system-based file recovery technique and file format based recovery technique exist. If there's metadata of deleted file in file system, the file can be easily recovered by using it, but if there's no metadata, the file is recovered by using the signature-based carving technique or the file format based recovery technique has to be applied. At this time, in the file format based recovery technique, the file structure analysis and possible recovery technique should be provided. This paper proposes the page recovery technique on deleted PDF file based on the structural characteristics of PDF file. This technique uses the tag value of page object which constitutes one page of PDF file. Object is extracted by utilizing each tag value as a kind of signature and by analyzing extracted object, the metadata of PDF file is recombined and then it's reconfigured page by page. Recovering by page means that even if deleted PDF file is damaged, even some pages consisting of PDF file can be recovered. Generally, if the file system based file is not recoverable, deleted file is recovered by applying the signature based carving technique. The technique which we proposed in this paper can recover PDF files that are damaged. In the digital forensic perspective, it can be utilized to recover more data than previously.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.900-911
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• 2009

This paper analyzes user preferences on the basic structure of digital textbook contents based on the PDF and HTML formats. This was conducted by analysing the data from an online survey on user preferences for the representative structures of the PDF- and HTML-based digital textbook contents that are currently used on the Web. Results show that in the PDF format, the structure with TOC(Table Of Contents) links on the left screen and the main content on the right was most preferred by 82% of the respondents. In terms of the viewing method, the one that presents one page of the textbook fitted to the width of the computer screen in a single-page view was regarded as the best. Similarly, in the HTML format, the structure with TOC links on the left frame and the main content on the right using 2-frames was revealed as the most preferred by 84% of the respondents. However, the structures of the PDF- and HTML-based digital textbook contents employed by most existing Web sites go against the users' preferences. Accordingly, for digital textbook development in the future, user preferences must be considered to allow students to read the contents more easily and conveniently.

• Proceedings of the Korean Printing Society Conference
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• 2001.06a
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• pp.63-77
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• 2001

PDF(Portable Document Format) is a file format that Adobe advances postscritp technique and use in managing document information or electric publishing(internet, CD-ROM, DVD). PDF is a devised document type for being able to read and print anywhere, independent of OS, printer type, resolution, and the kind of computer etc. Because this includes a compressing function, it transfers document through a small size of file in internet or intranet. In addition, that is a file format has various advantages-sharing of information and transfering documents in on line or off line environment. In this paper, we developed electronic document system using PDF format. Electronic document system consists of filter, automatic indexing, special searching system and web server. The information used in this paper is database made using Zwon\`s DocuCom. The filter recognizes various kinds of document structure. And according to property of document, it produces ASCII output. In addition to processing various formats of document, the filter can extract keywords in documents of MS WORD, Excel, Powerpoint, PDF, CAD etc. This filter uses the structure of window printer drive and can extract the information for text, page, font type and size from relevant document. The automatic indexing recognizes the formatted tag of document form ASCII text produced by filter and extracts adequate keyword to structure and property of document. PDF electronic document systems proposed in this paper can be used in Internet, PC communication. Users can choose and read electronic documents by two ways. First, users can choose and read relevant books using PDF electronic document homepage. Second, users can use PDF integrated-search system. User can search after inputing keyword and choose reference field and type of data. But, now, PDF products of Adobe can\`t support the Korean character. If this problem is resolved, we thick that PDF applications system looks active. Although there is limited function in case of using Zwon DocuCom used in this study, we think that there isn\`t a great deal of difficulty in electronic document and building digital database.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.120-125
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• 1999

This paper is a study on the cyber education center, OpenEdu, developing on internet. The conventional cyber university is allowed for ID user only, but OpenEdu is opened all internet user for open education and it has a various content. free of charge and high quality. Also. in this system, we support the various 500 contents, other efficiently services and it is a self-learning(asynchronous) distance education application(HTML, PDF. Front Page) on cyber-space using the information super highway It will make the cyber education center from new paradigm of distance education. The purpose of OPenEdu provides a async. distance education service, free of charge to obtain many various contents on internet. The future study is enhanced user interface and upgraded content quality.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.1
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• pp.65-74
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• 2004

This study analyzed the main bodies, sizes of litters, spaces between letters, Words, lines, length of lines, sizes of main body and margin, Position of the main bodies of PDF(Portable Document Format) in high schools and "the criteria of reading system for the textbooks" which was suggested by the Department of Education and Provided some suggestions for the improvement. First, it is judged that spaces of the main body of textbooks should be shrunken to make the ratio of 50:50 between the main body and space margin. Second, it is judged that the main body should be placed in the center of text page. Third, the results of the above findings showed that it would be difficult to deal with the task of deciding space and position or the main body and marginal space in a form of single project, because there are many variables involved and psychologically complicated elements which can not be measured objectively.

• Journal of Korean Library and Information Science Society
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• v.54 no.1
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• pp.221-240
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• 2023

This study proposes a medium-specific reading instruction method for digital natives exposed to various reading media with the development of information and communication technology. For this purpose, an elementary school located in H-si, Gyeonggi-do was selected and the readability and literacy tests according to the media were conducted for 6th graders. In the experiment, the same article contents were divided into three groups, and the time required to read and read using different media was measured, and the literacy according to the media was confirmed through quizzes. As a result of the measurement, the average reading time of the web-page was 3 minutes 28 seconds, the quiz correct answer rate (average) 3.99 questions, the average reading time of the pdf file in the form of an e-book was 5 minutes 23 seconds, the correct answer rate (average) 4.35 questions, the average reading time of the printed text was 7 minutes 14 seconds, and the correct answer rate (average) 6.26 questions. The number of students who participated in the experiment is 144, and there is a limit to generalizing the reading method according to the media type only with the results of the researcher's experiment.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.113-119
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• 2006

The Korean Astronomical Data Center(KADC) in Korea Astronomy and Space Science Institute(KASI) has developed a database of astronomical journals published by the Korean Astronomical Society and the Korean Space Science Society. It consists of all bibliographic records of the Journal of the Korean Astronomical Society(JKAS), Publication of the Korean Astronomical Society(PKAS), and Journal of Astronomy & Space Sciences(JASS). The KADC provides useful search functions in the search page such as search criterion of bibcode, publication date, author names, title words, or abstract words. The journal name is one of the search criterion in which more than one journal can be designated at the same time. The criterion of author name is provided bilingually: English or Korean. The abstract and full text can be downloaded as PDF files. It is also possible to search papers related to a specific research topic published in Korean astronomical journals, provided by the KADC, which often cannot be found the worldwide, Astrophysics Data System(ADS) services. The KADC will become basic infrastructure for the systematic construction of bibliographic records, and hence, make the society of Korean astronomers more interactive and collaborative.

• The Journal of the Korea Contents Association
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• v.20 no.9
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• pp.1-10
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• 2020

National R & D data covers information in all fields from basic science research to industrialization, but it is expressed in technical terms, which make it difficult for the public to use. Accordingly, NTIS developed and launched the data curation service 'R&D issue service', which selects national R&D information on national and social issues and provides them to the public. Therefore, this study aims to analyze the effect of a data curation service on NTIS users' access to R&D data and suggest how to develop the curation service. The R&D issue service extracts issue from the news article and provide related national R&D projects, achievements and major research institute. All raw data used for the service are open to the public, organized in a report format and provided as PDF files. In addition, automative process is developed for all NTIS users to make individual issue packaging like administrator. The results show that 'R&D issue service' launching increases users' access and convenience to R&D data related to major issues, and the number of page views of users increased after the service was opened.