• The Journal of Korean Association of Computer Education
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• v.3 no.2
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• pp.87-94
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• 2000

Software productivity doesn't satisfy the need of service of software users and software quality isn't improved. Moreover, we still have difficulty in software maintenance. As a plan to counteract solving this crisis, the technology that is called CBSE or Componentware is introduced. Componet Based Software Architecture, one of the technologies associated with CBSE, as a structural description of system, describes both the components composed system of and interaction among these components. Software Architecture provides the technology and the methodology of composition among components in the field of CBSE. is accepted one of core technologies. In this thesis, we analyse information necessary for component specification and then proposed that component specificaton activities using formal specification language Z which is verified with the ability of analysis and logicality. The proposed activities are composed of 9 tasks. By presenting specific 11 products, it is also proposed that component specification activities which is the base of CBSD(ComponentBased Software Development) for reusing.

• The Journal of Korean Association of Computer Education
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• v.6 no.2
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• pp.9-21
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• 2003

This paper proposes an automatic construction system for transliteration dictionary from English-Korean parallel corpus. The system works in 3 steps: it extracts all nouns from Korean documents as the first step, filters transliterated foreign word nouns out of them with the language identification method as the second step, and extracts the corresponding English words by using a probabilistic alignment method as the final step. Specially, the fact that there is a corresponding English word in most cases, is utilized to extract the purely transliterated part from a Koreans word phrase, which is usually used in combined forms with Korean endings(Eomi) or particles(Josa). Moreover, the direct phonetic comparison is done to the words in two different alphabet systems without converting them to the same alphabet system. The experiment showed that the performance was influenced by the first and the second preprocessing steps; the most efficient model among manually preprocessed ones showed 85.4% recall, 91.0% precision and the most efficient model among fully automated ones got 68.3% recall, 89.2% precision.

• The Journal of Korean Association of Computer Education
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• v.13 no.1
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• pp.53-64
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• 2010

In this paper, we tried to enable a mobile device as a resource to access to mobile grid networks. By advanced Internet techniques, the use of mobile devices has been rapidly increased. Some researches in mobile grid computing tried to combine grid computing with mobile devices. However, according to intrinsic properties of mobile environments, mobile devices have many considerations, such as mobility management, disconnected operation, device heterogeneity, service discovery, resource sharing, security, and so on. To solve these problems, there are two trends for mobile grid computing: a proxy-based mobile grid architecture and an agent-based mobile grid architecture. We focus on a proxy-based mobile grid architecture with IP-paging, which can easily manage idle mobile devices and grid resource status information. Also, we use SIP(Session Initiation Protocol)to support mobility management, mobile grid services. We manage variation of mobile device state and power by paging cache. Finally, using the candidate set and the reservation set of resources, we perform task migration. The performance evaluation by simulation, shows improvement of efficiency and stability during execution.

• The Journal of Korean Association of Computer Education
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• v.13 no.1
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• pp.45-52
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• 2010

With rapid increase in the number of web documents, the problem of information overload in Internet search is growing seriously. In order to improve web search results, previous research studies employed user queries/preferred words and the number of links in the web documents. In this study, performance of the search results exploiting these two criteria is examined and other preference criteria for web documents are analyzed. Experimental results show that personalized web search results employing queries and preferred words yield up to 1.7 times better performance over the current search engine and that the search results using the number of links gives up to 1.3 times better performance. Although it is found that the first of the user's preference criteria for web documents is the contents of the document, readability and images in the document are also given a large weight. Therefore, performance of web search personalization algorithms will be greatly improved if they incorporate objective data reflecting each user's characteristics in addition to the number of queries and preferred words.

• The Journal of Korean Association of Computer Education
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• v.13 no.4
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• pp.41-50
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• 2010

So far, the researches about the Internet addiction testing are diverse and enormous. However, since the testing factors have the same importance, there is no discrimination among the factors. In our paper, we analyze the problems of the existing researches by using Lisrel and data mining algorithms. Next, we propose an alternative for the Internet addiction testing. In order to accomplish these, we make an questionnaire consisted of Young's test and then, we asked to 440 primary and secondary school students. In addition, we analyzed the problems of Young's test with factor analysis and then, we distinguish more important items from others with J48 and PART. Finally, based on this analysis, we propose a method to diagnose addicted students and prescribe them.

• The Journal of Korean Association of Computer Education
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• v.13 no.5
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• pp.103-110
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• 2010

If an exterior computer wants to join the Grid/cloud computing platform for a while, all of the related firewalls' filtering rule should be immediately updated. As the platform of Internet application is gradually evolving into the Grid/Cloud environment, the R&D requirement for the dynamic traversing of the multiple firewalls by a single try is also increasing. In this paper, we introduce the new mechanism for the dynamic traversing of the multiple firewalls using the concept of the one-time master key that can dynamically unlock the tiers of firewalls simultaneously instead of the existed filtering rule based method like a lock management at each firewall. The proposed master keys are like one-time password, consisted of IP addresses, port numbers, and TCP's initial sequence numbers, and generated by end users not administrators. They're exchanged mutually in advance and used to make a hole at local-side firewalls for the other's packet incoming. Therefore, the proposed mechanism can function regardless of the number or type of firewalls.

• The Journal of Korean Association of Computer Education
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• v.18 no.4
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• pp.55-62
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• 2015

Recommender systems through collaborative filtering has been utilized successfully in various areas by providing with convenience in searching information. Measuring similarity is critical in determining performance of these systems, because it is the criteria for the range of recommenders. This study analyzes distributions of similarity from traditional measures and investigates relations between similarities and the number of co-rated items. With this, this study suggests a method for selecting reliable recommenders by restricting similarities, which compensates for the drawbacks of previous measures. Experimental results showed that restricting similarities of neighbors by upper and lower thresholds yield superior performance than previous methods, especially when consulting fewer nearest neighbors. Maximum improvement of 0.047 for cosine similarity and that of 0.03 for Pearson was achieved. This result tells that a collaborative filtering system using Pearson or cosine similarities should not consult neighbors with very high or low similarities.

• The Journal of Korean Association of Computer Education
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• v.18 no.4
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• pp.31-40
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• 2015

The objective of this study is to develop and implement a smart device based instructional analysis application to enhance the efficiency of teaching in class. The main design features for this application are as follows: first, User Interface(UI) has been simplified to provide teachers a clear and easy-to-understand way to utilize the application. Second, the characteristics of Korean language were considered, such as sentence structure. Third, multi-aspect analysis is possible through adopting three analysis types - Flanders' interaction analysis, Tuckman's analysis, Mcgraw's concentration of instruction analysis. The practical instructional analysis application has been developed through this study, and this user-oriented application will be able to help teachers improve the quality of teaching in class. Also, this study can be a starting point for further researches on design principles of instructional analysis, especially with the recent technology and theories, such as a voice-recognition system, an edutainment applied instruction and an experiential learning.

• The Journal of Korean Association of Computer Education
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• v.16 no.1
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• pp.73-80
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• 2013

Government promotes that the strategy of national R&D converts from catch-up R&D type to leading R&D type for the future growth and national competitiveness according to the recent paradigm shift in the research and development. So the many national researches about foundation, source and core technology are actively being made. As a result of these researches, the security has become an important part of success factor in R&D. And so various security diagnosis and evaluation is being conducted about national R&D program. Existing the research security evaluation models are classified domains in terms of security management and created evaluation indicators according to the domains. However the models are inappropriate in case of researchers doing self-diagnosis of research security. This paper set up the domains in aspect of research management and then proposed the evaluation indicator of research security according to the domains. The evaluation indicator model that is suggested can be utilized in self-diagnosis of research security effectively.

• The Journal of Korean Association of Computer Education
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• v.14 no.1
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• pp.175-185
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• 2011

Recently RFID systems have been introduced in place of barcode systems to industries such as logistics, distribution, and manufacturing. Due to security vulnerabilities in wireless communication between the reader and tags, however, the authentication protocols for the communication have also been researched extensively. In order to solve the vulnerability of previously proposed protocols, this paper thus proposes an authentication protocol that satisfies the security requirements in the RFID system and minimizes the quantity of computation such as random number generation, transmitting the micro-time of databases. In addition, it is expected that the proposed cross authentication protocol is safe against replay attack, spoofing attack, traffic analysis, and eavesdropping attack when it is applied to the RFID system. Also, it has advantages such as providing a high level of security at a lower manufacturing cost.