• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6214-6242
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• 2019

Routing in mobile ad hoc networks is performed in a distributed fashion where each node acts as host and router, such that it forwards incoming packets for others without relying on a dedicated router. Nodes are mostly resource constraint and the users are usually inclined to conserve their resources and exhibit selfish behaviour by not contributing in the routing process. The trust and reputation models have been proposed to motivate selfish nodes for cooperation in the packet forwarding process. Nodes having bad trust or reputation are detected and secluded from the network, eventually. However, due to the lack of proper identity management and use of non-persistent identities in ad hoc networks, malicious nodes can pose various threats to these methods. For example, a malicious node can discard the bad reputed identity and enter into the system with another identity afresh, called whitewashing. Similarly, a malicious node may create more than one identity, called Sybil attack, for self-promotion, defame other nodes, and broadcast fake recommendations in the network. These identity-based attacks disrupt the overall detection of the reputation systems. In this paper, we propose a reputation-based scheme that detects selfish nodes and deters identity attacks. We address the issue in such a way that, for normal selfish nodes, it will become no longer advantageous to carry out a whitewash. Sybil attackers are also discouraged (i.e., on a single battery, they may create fewer identities). We design and analyse our rationale via game theory and evaluate our proposed reputation system using NS-2 simulator. The results obtained from the simulation demonstrate that our proposed technique considerably diminishes the throughput and utility of selfish nodes with a single identity and selfish nodes with multiple identities when compared to the benchmark scheme.

• Journal of Digital Contents Society
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• v.17 no.5
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• pp.401-407
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• 2016

In the smart education era, it is crucial for the teacher to make lecture materials in the form of 3D convergence contents for themselves. In this study, we developed an interactive authoring tool to create 3D convergence contents for the teacher. The proposed system was implemented based on a commercial 3D engine for practicality. To evaluate the usability of the tool, we conducted a satisfaction survey of a focus group. As a result, we concluded that the proposed authoring tool was useful to create desired contents but rather complicated to use due to the text-based script editor. In the following research we will improve the editor so that it can be used in a more intuitive manner.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.43-50
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• 2022

For high-quality education of the modern generation of students, forms of organizing the educational process and the latest methods of obtaining knowledge that differ from traditional ones are necessary. The importance of multimedia teaching tools is shown, which are promising and highly effective tools that allow the teacher not only to present an array of information in a larger volume than traditional sources of information, but also to include text, graphs, diagrams, sound, animation, video, etc. in a visually integrated form. Approaches to the classification of multimedia learning tools are revealed. Special features, advantages of multimedia, expediency of use and their disadvantages are highlighted. A comprehensive analysis of the capabilities of multimedia teaching tools gave grounds for identifying the didactic functions that they perform. Several areas of multimedia application are described. Multimedia technologies make it possible to implement several basic methods of pedagogical activity, which are traditionally divided into active and passive principles of student interaction with the computer, which are revealed in the article. Important conditions for the implementation of multimedia technologies in the educational process are indicated. The feasibility of using multimedia in education is illustrated by examples. Of particular importance in education are game forms of learning, in the implementation of which educational elements based on media material play an important role. The influence of the game on the development of attention by means of works of media culture, which are very diverse in form and character, is shown. The importance of the role of multimedia in student education is indicated. In the educational process of multimedia students, a number of educational functions are implemented, which are presented in the article. Recommendations for using multimedia are given.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.1
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• pp.71-85
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• 2004

Many online content providers who use the Internet to distribute contents, such as news, music, games, books, and other types of information, have been experiencing an extremely competitive business environment. To survive in this environment, they have started charging a fee for the contents that they provide. However, there have been very few success stories in commercializing online contents. One of the biggest hurdles may be customers' psychological resistance against paying a fee for the contents that have been free of charge previously. Without examining customers' perceived prices for online contents, many online content providers have tended to decide their prices by themselves. Online games are not exceptional cases. Although many online game-related research works have focused on psychological and technical aspects, very few works have examined online garners' preference carefully. This study alms at exploring online garners' preference by measuring their WTP (willingness to pay) for online games.

• Journal of the Korea Society of Computer and Information
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• v.23 no.4
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• pp.17-24
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• 2018

This paper proposes data mining models relevant to the serial publication periods and mobile gamification likelihood of webtoon contents which were either serialized or completed in platform. The size of the cartoon industry including webtoon takes merely 1% of the total entertainment contents industry in Korea. However, the significance of webtoon business is rapidly growing because its intellectual property can be easily used as an effective OSMU (One Source Multi-Use) vehicle for multiple types of contents such as movie, drama, game, and character-related merchandising. We suggested a set of data mining classifiers that are deemed suitable to provide prediction models for serial publication periods and mobile gamification likelihood for the sake of webtoon contents. As a result, the balanced accuracies are respectively recorded as 85.0% and 59.0%, from the two models.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.21-34
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• 2005

The purpose of this study was to suggest strategies for the development of mushroom associated tour villages with the aged. Mushroom has many strong points to use a theme for making a park and tour village. Especially it can be easily cultivated by the aged and a popularist commodity. The 5 days work system in a week enlarge the chance for the people to get a weekend tour. The number of the people who want to live in rural area after retire is getting increased also. This trend needs the development of tour villages as a kind of the silver agricultural industry in rural area. "Work & Play" concepts should be considered as a pivotal strategy to develope mushroom associated tour villages with the aged workforce. Mushroom can be a good theme attracting the tourist when the cultivating, showing, processing and marketing mushroom are welly connected in a village. And the traditional family game and culture must be adjusted for the tourist.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.151-156
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• 2017

In case of massive water leakage, it's crucial for field manager to quickly positioning the problematic valve and related ones. However, it's not easy for the system to find the corresponding valve and even if it's found, it can not respond quickly because it can't know the relevant information immediately. In this paper, we implement the system for identifying sluice valve positions using GPS and AR techniques. The proposed system is composed of hand held android device, remote database server and data acquisition device for DB creation. We utilize the android device's sensors including GPS, gyro, accelerometer, magnetic sensor. The system identifies the valve with matching between the position data from the remote database server, and current GPS locations of device. We use AR techniques to overlay the graphics pattern of valve positions and some additional informations on captured real scene. With this system, it will be fast and accurate for maintenance of sluice valve of municipal water system.

• Journal of Korea Game Society
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• v.8 no.4
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• pp.65-73
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• 2008

In this paper, we designed and implemented edutainment platform that can be effectively applied to developmental disabilities for their education and treatment of sensibility and intelligence training. We developed embedded hardware and contents authoring tool to make multimedia contents operated on the hardware, a management tool to provide result of training, and a real-time monitoring tool for observing the state of study. The hardware is designed by considering the characteristics of developmental disabilities and provides visual, auditory and tactile sense to assist sensibility training for their attention. User-friendly and easy-to-use authoring tool enable teachers and non-specialist to make educational contents. Also the real-time monitoring tool make us to observe user's status even in the outside of classroom. The management tool stores result of training and make us to review the result for further steps. Using this edutainment platform, efficient repetitive training is possible without restriction of time and location. Also when it applied to practical education, we can recognize that our system is effective on improving the ability of attention and studying.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.1-8
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• 2013

As yet the use of 3D projection mapping facade has been limited to advertising and performance in the outside. And interactive elements are lacking. In this paper, propose a interaction system which control of projection mapping facade for multi-audience participation using smart devices. The system can be interaction for the multi-façade. And single or multiple can participate in the game. A user test based on the result confirmed an effectiveness of the proposed method. This research showed a practical method in which interaction of projection facade system can be used to user devices. The results of this study can be used as a base module for projection facade interaction system. In addition, It can be utilized for converged content development such as performances, games, education and various applications services.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.278-287
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• 1998

The halophytes are considered less important in our field, as the land reclamation executed continuously by public or individual. So this research is to use plants more active on the reclaimed land and to verify their utility in the aspect of the landscape planning, design and complementaton. This research is performed at the construction site of Incheon International Airport in Youngjong-do located in West-sea of Korea. Following proposals are the major conclusions drawn from the research:1. The halophytes to be used in the vicinity of the water reservoir in orer to improve the ground for the introduction of new plants and prevent the water contaminatioin. 2. The halophytes to be used as a gound-cover which protects major structures nearby from being damaged by the salt content in the air. 3. Thd halophytes to be used as a unique and panoramic landscape element. They have various colors which change throughout a year. 4. Thd halophytes to be considered as a outdoor recreation resource. The halophytes planted area may be utilized as picnic area, outdoor event plaza, ball game ground, rough in the golf cource and etc. Additional usage of the land include the future rearch site for sea fronted ecological studies and pasture for cows and other livestock.