• Journal of Advanced Navigation Technology
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• v.9 no.2
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• pp.192-199
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• 2005

Adaptive Modulation & Coding (AMC) is the method of varying the modulation and coding scheme for the changeable wireless channel environment. WiBro use AMC method because it has a very large variation caused by mobility interference and other cell interference. In this paper, we will compare and analysis the method of selecting the optimum MCS level for the efficiently use of mobile power consumption.

• Communications for Statistical Applications and Methods
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• v.13 no.1
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• pp.11-17
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• 2006

The spacing of inspection times in intermittent inspection is of great interest, and several ways for the determination of inspection times have been proposed. In most inspection schemes including equally spaced inspection and optimally spaced inspection, the best inspection times in each inspection scheme depend on the unknown parameter, and we need an initial guess of the unknown parameter for practical use. Thus it is evident that the efficiency of the resulting inspection scheme highly depends on the choice of the initial value. However, since we can obtain some information about the unknown parameter at each inspection, we may use the accumulated information and adjust the next inspection time. In this paper, we study this sequential determination of the inspection times in optimally spaced inspection.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5182-5199
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• 2017

Recently, Internet of Things (IoT) drives a large variety of research, development, and new type of markets. All type of devices and sensors will be part of the Internet of Things and will be able to communicate not only plain data, but also audio-visual, olfactory, and haptic media data. In addition, as the devices and sensors getting smarter, it is highly probable that they can process acquired media and metadata to extract higher level of information (e.g., semantics). To support such enhanced functionalities, ISO/IEC SC29 WG11 (MPEG) starts a new standard project, ISO/IEC 23093, called Internet of Media Things (IoMT) to provide standard data formats and APIs for media things. This paper presents the standardization activities of IoMT focusing on explaining terms, standard scopes, and major media things with their use cases. One of the use cases, an IoT system for a blind pedestrian navigation assistance, is evaluated to prove its effectiveness.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.542-547
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• 2003

This paper proposes the method to develop information system for maintenance of urban transit using wireless LAM. Wireless LAN communication provides very useful method to maintain urban transit vehicle. We will use wireless LAN to transmit driving data, operational data and trace data from vehicle to wayside. And also we will use wireless LAN to refer various information concerning to work in real time. Proposed method may prevent loss of maintenance manpower and provide effective maintenance process.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.177-188
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• 2013

Since the world entered the age called "Smart Revolution", there has also been a lot of changes in the field of education. In educational environment, there is a growing interest in smart learning based on mobile contents, with the development of Smart Devices and ubiquitous technology. This paper is about a research on what effects smart learning has on leaner side when learners make active use of mobile contents in this age of Smart Revolution. First, we embodied teaching plans for some practical classes in forms of mobile contents using M-bizmaker. After the learning process based on the embodied contents for students, we analyzed the survey results on 4 sections-their use of apps, screen composition, technical support, interactions. We also studied the results of a questionnaire on 4 sections-contents, information offering, feedback systems, learner assessment-to evaluate their satisfaction. The research suggests that learner satisfaction can be improved with smart learning based on mobile contents embodied for leaners.

• Journal of Information Technology Applications and Management
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• v.25 no.4
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• pp.171-184
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• 2018

Social media has been integrated into a part of travel industry. Subsequently, it has influenced tourists' travel behavior. Prior studies claim that individuals have different behaviors regarding the use of social media for travel purposes. With lack of studies focusing on age group, the objective of this study is to determine whether there is a difference in the motivation among three generations in using social media for the sake of sharing travel experiences. Finding shows that all generations use social media with similar motivation for travel purposes. They have high motivation in obtaining travel information before the trip and in sharing memorable travel experiences through social media. They also wanted to keep such information as personal document during and after the traveling.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.1064-1079
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• 2019

Information security has become increasingly important with the rapid development of mobile devices and internet. An efficient encryption system is a key to this end. In this paper, we propose an image encryption method based on the cross diffusion of two chaotic maps. We use two chaotic sequences, namely the Logistic map and the Chebyshev map, for key generation which has larger security key space than single one. Moreover, we use these two sequences for further image encryption diffusion which decreases the correlation of neighboring pixels significantly. We conduct extensive experiments on several well-known images like Lena, Baboon, Koala, etc. Experimental results show that our algorithm has the characteristics of large key space, fast, robust to statistic attack, etc.

• Asian Journal for Public Opinion Research
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• v.10 no.2
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• pp.76-101
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• 2022

Despite the increasing use of digital media and their powerful impact on risk management during recent outbreaks of emerging infectious diseases, the question of how digital media exposure influences preventive behaviors has not been fully explained. Using the appraisal tendency framework and protection motivation theory as theoretical frameworks, we theorized the affective and cognitive mechanisms under which the differential roles of three negative emotions (fear, anger, worry) on two cognitive appraisals (perceived threat and perceived efficacy) were examined. Based on data collected from a survey of 1,500 South Koreans during the COVID-19 pandemic, we found that while worry and anger increased perceived efficacy, fear reduced perceived efficacy. The results also showed that although exposure to COVID-19 information via digital formats increased preventive behavioral intention in general, digital media use for COVID-19 information had a negative influence on preventive behavioral intention through the sequential mediation of fear and perceived efficacy.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.205-218
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• 2013

Recently, due to the proliferation of smartphones, users of mobile banking services which are based in wireless Internet without constraint of the time and places are significantly increased. In the study, considering the characteristics of mobile banking services based on the smartphone and the user behavior. we analyse the factors which have an effect on the behavioral intention to use mobile banking services based on the smartphone. For this purpose, we use the model which is based on Technology Acceptance Model (TAM) and add two constructs:the perceived enjoyment and the perceived risk. A survey data for 194 students at the K cyber university is used for statistical analysis. As a result, the perceived ease of use affects the perceived usefulness and the perceived enjoyment, and the perceived ease of use. And the perceived usefulness and perceived enjoyment affect continuous intention to use. On the other hand, the hypothesis which the perceived risk would affect adversely the continuous intention to use is rejected. Through this study, we expect to provide the useful implications for the smartphone banking services and contribute to the development of strategy for them.

• Journal of Information Technology Services
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• v.12 no.2
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• pp.243-256
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• 2013

Recently, due to the proliferation of smartphones, users of mobile multimedia services which are based on wireless internet without constraint of the time and places are significantly increased. In this study, considering the characteristics of mobile multimedia and the user behavior, we analyse the factors which have an effect on the behavioral intention to use the mobile multimedia services. For this purpose, we use the model which is based on Technology Accepted Model (TAM) and add two constructs; the perceived enjoyment and the perceived risk. A survey data for 280 students at the K cyber university is used for statistical analysis As a result, the perceived ease of use affects the perceived usefulness and the perceived enjoyment, and the perceived ease of use. And the perceived usefulness and perceived enjoyment affect continuous intention to use. On the other hand, the hypothesis which the perceived risk would affect adversely the continuous intention to use is rejected. Through this study, we expect to provide the useful implications for the mobile multimedia services and contribute to the development of strategy for them.