• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.81-94
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• 2005

Recently, wireless LAN circumstance is being widely deployed in Public spots. Many People use Portable equipments such as PDA and laptop computer for multimedia applications, and also demand of mobility support is increasing. However, handoff latency is inevitably occurred between both APs when clients move from one AP to another. To reduce handoff latency. in this paper, we suggest WFH(Weighted Frequent Handoff) using effective data structure. WFH improves cache hit ratio using a new cache replacement algorithm considering the movement pattern of users. It also reduces unessential duplicate traffics. Our algorithm uses FHR(Frequent Handoff Region) that can change pre-authentication lesion according to QoS based user level, movement Pattern and Neighbor Graph that dynamically captures network movement topology.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.10 no.4
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• pp.21-32
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• 2000

We have seen a lot of developments on computer application areas with the wide spread use of computers and the rapid growth of communication network. It is necessary to use a cryptographic technique for electronic voting, but, at present, despite of its importance electronic voting protocols so far have many shortcomings. In this paper, with the assumption of a trustable voting centers we propose a large-scale and practical electronic voting protocol satisfying protocol requirements, such as secureness, fairness, privacy of voter and correctness. Voters are able to get a vote without revealing their voted information by using the blinding technique. We can find the injustice between a voter and the tallier by using undeniable challenge and responsible protocol. Also, we proposes a secure protocol that compensates a integrity of electronic voting and protects a privacy of voter from outer attacks as using a anonymity of voter.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.667-677
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• 2012

Vulnerable web applications have been the primary method used by the attackers to spread their malware to a large number of victims. Such attacks commonly make use of malicious links to remotely execute a rather advanced malicious code. The attackers often deploy malwares that utilizes unknown vulnerabilities so-called "zero-day vulnerabilities." The existing computer vaccines are mostly signature-based and thus are effective only against known attack patterns, but not capable of detecting zero-days attacks. To mitigate such limitations of the current solutions, there have been a numerous works that takes a behavior-based approach to improve detection against unknown malwares. However, behavior-based solutions arbitrarily introduced a several limitations that made them unsuitable for real-life situations. This paper proposes an advanced web browser based malicious behavior detection system that solves the problems and limitations of the previous approaches.

• The Journal of Korean Institute of Information Technology
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• v.17 no.6
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• pp.17-25
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• 2019

Accurate tracking of the sinkholes that are appearing frequently now is an important method of protecting human and property damage. Although many sinkhole detection systems have been proposed, it is still far from completely solved especially in-depth area. Furthermore, detection of sinkhole algorithms experienced the problem of unstable result that makes the system difficult to fire a warning in real-time. In this paper, we proposed a method of sinkhole tracking by deep learning and data association, that takes advantage of the recent development of CNN transfer learning. Our system consists of three main parts which are binary segmentation, sinkhole classification, and sinkhole tracking. The experiment results show that the sinkhole can be tracked in real-time on the dataset. These achievements have proven that the proposed system is able to apply to the practical application.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.151-156
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• 2020

Various institutions provide various welfare-related services, and accordingly, the quantity and quality of welfare-related services are improved. Along with the improvement of welfare services, the rate of fraudulent and redundant supply and demand due to inappropriate applicants is also increasing. In particular, in the case of similarly promoted projects by various institutions, confirmation of duplicate applications may be insufficient due to system inconsistency between institutions and delays in qualification verification, which may result in duplicate supply and demand. In this paper, in order to prevent the redundant supply and demand related to welfare service similar projects in various institutions, the problem of data management and sharing between institutions was reviewed and a method of applying blockchain technology was proposed step by step. Through the proposal of this paper, transparent data management of recipients is possible, and through this, trust-based welfare benefit management will be possible.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.6
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• pp.41-50
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• 2020

This paper deals with the Braille Education System which complements the shortcomings of the existing Braille Learning Products. An application dedicated to the blind is configured to perform full functions through touch gestures and voice guidance for user convenience. Braille kit is produced for educational purposes through Arduino and 3D printing. The system supports the following functions. First, the learning of the most basic braille, such as initial consonants, final consonant, vowels, abbreviations, etc. Second, the ability to check learned braille by solving step quizzes. Third, translation of braille. Through the experiment, the recognition rate of touch gestures and the accuracy of braille expression were confirmed, and in case of translation, the translation was done as intended. The system allows blind people to learn braille efficiently.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.100-109
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• 2020

At the beginning of the discussion of early childhood software education, the study was conducted to apply an early childhood software education program based on computational thinking and analyze the effects of early childhood software education programs. In this study, a balanced distribution of software education, content elements and computing thinking elements was applied to achieve the ultimate goal of software education, which is to improve computing thinking. As early as possible, it's a good idea to start teaching to remind themselves how to think through experiences and play activities and to discover problems and find solutions by themselves. In the analysis results, early childhood software education program we applied affected positive impacts on software education effect, computational thinking of early childhood. Based on these results, a program was proposed for systematic early childhood software education that effective develope of computational thinking.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1117-1123
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• 2021

Object recognition is to identify the location and class of a specific object by analyzing the given image when a specific image is input. One of the fields in which object recognition technology is actively applied in recent years is autonomous vehicles, and this paper describes the trend of image-based object recognition artificial intelligence technology in autonomous vehicles. The image-based object detection algorithm has recently been narrowed down to two methods (a single-step detection method and a two-step detection method), and we will analyze and organize them around this. The advantages and disadvantages of the two detection methods are analyzed and presented, and the YOLO/SSD algorithm belonging to the single-step detection method and the R-CNN/Faster R-CNN algorithm belonging to the two-step detection method are analyzed and described. This will allow the algorithms suitable for each object recognition application required for autonomous driving to be selectively selected and R&D.

• Journal of Industrial Convergence
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• v.20 no.7
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• pp.37-50
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• 2022

This study intends to analyze the learning effect of asynchronous online classes used in education fields around the world after the COVID-19 pandemic. To this end, we compared and analyzed the lecture evaluation and final exam questions of the HTML5 web programming course, which was conducted offline in 2019 and asynchronously online in 2020 due to COVID-19. As a result of the analysis, no significant difference was drawn between the two teaching methods in the lecture evaluation score and final exam score. However, contrary to concerns about the application of online classes to the entire curriculum, the lecture evaluation and final exam scores of the video-based online classes were high, suggesting the possibility that online classes could be more effective than offline classes if well organized and managed in the future.

• Journal of The Korean Association of Information Education
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• v.26 no.3
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• pp.219-227
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• 2022

Students are always preparing for remote classes while taking face-to-face classes due to COVID-19. However, it is true that the class satisfaction with distance learning is not high for students and teachers. The idea that even if remote classes are conducted at home, it would be nice to have classes together like real ones, the need for a virtual world education program that utilizes augmented reality and virtual reality based on the metaverse has emerged. However, there are very few studies that teachers try to apply them to their classes. In this study, a metaverse application curriculum was presented for elementary science and 'space' domains. To implement the metaverse, ZEPETO and COSPACIS EDU were used. In the analysis of content creation with students and evaluation with schoolmates, this study showed that the concentration of learning was increased and creativity improved in the 'real', 'individual', and 'society' domains.