• Journal of Information Technology Applications and Management
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• v.23 no.3
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• pp.49-59
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• 2016

Rapid technological advancements and widespread adoption of smart phones in recent years provide students with new opportunities for getting knowledge and making researches in innovation century. As the penetration of smart phone devices in education increases, there is a large growth in the use of these devices especially among the youth. In spite of increasing importance of smart devices in education, the significant features of these technology devices for general learning have not been experientially addressed. In this study we are going to investigate the comparison of smart phone devices and find the necessary conditions for using mobile devices as an educational tool by a conjoint method. There will be five attributes: screen size, batter type, mobile OS, memory capacity and price. By surveying we got the results which showed us the respondents' desire of using specific smart phone; thus, we defined that screen size attribute is the most important device characteristic.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.360-370
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• 2013

As the mobile telecommunications service market grows rapidly, interconnection opportunities from the fixed network to the mobile network increase and the land-to-mobile (LM) interconnection charge becomes critical factor in competition between fixed and mobile telecommunications service providers. This paper aims to evaluate the LM interconnection charge level in Korea in comparison with those of 36 foreign countries and suggest the regression model for the LM interconnection charge. Based on the regression analysis, we found that regulation, GDP per capita, wire telephone penetration, liberalization are identified as significantly affecting factors on the LM interconnection charge level, and the level of the LM interconnection charge is comparatively low.

• The Journal of Korea Robotics Society
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• v.11 no.3
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• pp.156-162
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• 2016

For the underwater localization, acoustic sensor systems are widely used due to greater penetration properties of acoustic signals in underwater environments. On the other hand, the good penetration property causes multipath and interference effects in structured environment too. To overcome this demerit, a localization method using the attenuation of electro-magnetic(EM) waves was proposed in several literatures, in which distance estimation and 2D-localization experiments show remarkable results. However, in 3D-localization application, the estimation difficulties increase due to the nonuniform (doughnut like) radiation pattern of an omni-directional antenna related to the depth direction. For solving this problem, we added a depth sensor for improving underwater 3D-localization with the EM wave method. A micro scale pressure sensor is located in the mobile node antenna, and the depth data from the pressure sensor is calibrated by the curve fitting algorithm. We adapted the depth(z) data to 3D EM wave pattern model for the error reduction of the localization. Finally, some experiments were executed for 3D localization with the fast calculation and less errors.

• Laser Solutions
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• v.8 no.1
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• pp.27-37
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• 2005

During laser spot welding of the braun tube electron gun, phenomena such as serious spattering and oxidative reaction, etc. were occurred. The spatter occurred from weld pool affects the braun tube, namely it blocks up a very small hole on the shadow mask and causes short circuit between two poles of the electron gun. We guessed that high power density and oxidative reaction are main sources of these problems. So, we studied to prevent and to reduce spatter occurring in spot welding of the braun tube electron gun using pulsed Nd:YAG laser. The characteristics of laser output power was estimated, and the loss of laser energy by optical parameter and spatter was measured by powermeter. The effects of welding parameters, laser defocused distance and incident angle, were investigated on the shape and penetration depth of the laser welded bead in flare and flange joints. From these results, the laser peak power was a major factor to control penetration depth and to occur spatter. It was found that the losses of laser energy by optic parameter and sticked spatter affect seriously laser weldability of thin sheets.

• 한국벤처창업학회:학술대회논문집
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• 2018.11a
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• pp.277-281
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• 2018

Information system has been at center of economic development in several developed countries, and as Africa envision to improve its global economic competitiveness it is important to assess penetration rate the digital divide and catch-up effect over the years. This paper examined whether there exists digital divide and if so, is it narrowing over time and whether the ICT is converging with time in the African countries. Three technologies namely mobile-cellular, internet and fixed broadband were used to measure the digital divide and the catch-up effect. Gamma and sigma convergence methodology together with averaged penetration ratios were used to assess the cross-country performance of each technology. This study confirms both the narrowing of digital divide and convergence of ICT in all three technologies for both total group and subgroups. The digital gap was narrowing over time and the low-income countries were catching up faster to the middle-income countries in all three technologies. However, there are marked differences exhibited in the speed of narrowing digital divide and the speed of convergence between the total groups and the subgroups of countries. Some policy implications were discussed in the conclusion and they can be utilized in designing developmental ICT policies in each technology case for individual countries.

• Information Systems Review
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• v.7 no.2
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• pp.41-59
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• 2005

Mobile games have emerged as the most innovative entertainment technology adding new revenue streams, taking advantage of the potential of wireless consumer applications and service offerings. Mobile games, like any other types of computer game, offer a unique value for users in providing an exciting digital experience in virtual worlds. Players can become empowered through the development of new characters and strategies within games to achieve rewarding successes against the computers and other players. In this paper, we attempt to investigate the factors influencing the usage and acceptance of the mobile games in Korea, based on the extended version of the Technology Acceptance Model(TAM). Based on data collected from survey, we show that perceived usefulness is the major determinant for users to play mobile games. Two factors, including perceived enjoyment and self-expressiveness, are empirically shown to determine perceived usefulness. In addition, perceived ease of use, rewards, operational quality of device, and design/story have been showed to significantly and directly affect perceived enjoyment. It was also confirmed that self-efficacy and operational quality of device are the antecedents of perceived ease of use. Based upon the statistical results, some useful guidelines for game development and market penetration strategies are also provided.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.303-317
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• 2020

As the penetration rate of smart phones has spread and functions have been developed variously, a new advertising medium called mobile advertising has emerged. In addition, various mobile advertisements targeting teenagers, where most of their daily lives are conducted using smartphones, have been activated. Adolescents in the modern society called Generation Z have the longest time to use a smartphone among age groups. Even during the economic downturn, adolescent consumers are an important consumer group that can overcome the economic recession, so mobile advertisements targeting their purchasing power are being created like a flood. Therefore, in this study, the influence of mobile advertisement characteristics and personal characteristics on purchasing attitudes for adolescents using smartphones was identified, and how this was linked to purchasing behavior again. To conduct the research, a survey was conducted on 324 high school students using smartphones, and the results are as follows: First, the higher the recognition of convenience in mobile advertising characteristics and brand preferences, the higher the brand preference. Characteristics and brand trust had a positive effect on acceptance as the awareness of convenience, information, and entertainment increased. Third, the influence of adolescents' personal characteristics on purchasing attitudes had a positive effect on brand preferences by pursuit of fashion, pursuit of personality, and practical pursuit. Fourth, as a result of analyzing the relationship between purchase attitude and purchase behavior, it was verified that brand preference and brand trust among purchase attitude have a positive influence on purchase behavior. This study has significance in that it has grasped the influence of mobile advertising on purchasing behavior among teenagers who are rapidly growing as mobile consumers.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.281-290
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• 2020

The purpose of this study was to examine how the consumer's entertainment, information, relevance, reliability, and perceived invasion affect the avoidance of advertising. Besides, the purpose of this study was to examine whether there is a difference according to the country and age in the effect of advertisement characteristics on the evasion. This study investigated the avoidance of mobile advertising among 254 Koreans and Chinese publics in their 20's and 40's, evaluated the results in terms of comparative analysis. Collected data were verified by multiple regression analysis and hierarchical regression analysis. The higher the advertising entertainment and relevance, the lower the avoidance of advertising. The higher the perceived penetration, the higher the avoidance of advertising. Besides, there were differences by country and age in the effects of advertising entertainment, information, relevance, and reliability on ad avoidance. The implications of this study are to find out how to reduce the mobile advertising avoidance of consumers by identifying the predictive factors that cause the avoidance of advertisements by country and age.

• Journal of Korea Multimedia Society
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• v.17 no.1
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• pp.94-103
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• 2014

Asthma is a chronical disease which could be controled by constant management and the patients may lead their daily lives if they are properly supervised. South Korea is one of the most wired nations, and its penetration rate of smart phones will exceed 80% of entire population this year, so managing asthma and communicating with medical staffs with mobile applications, will be very reasonable solution. In this study, medical staffs, developers and UI/UX experts co-worked developed an Android-based application for asthma management. To tell the effectiveness and availability, we made asthma sufferers use this mobile application for more than six months. After six months we surveyed and interviewed the patients. We could find merits and demerits of the applications and we finally suggested new guidelines for version 2.0.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.669-674
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• 2017

Due to the depletion of fossil fuels and the increase in environmental pollution, electric vehicles are attracting attention as next-generation transportation and are becoming popular all over the world. As the interest in electric vehicles and the penetration rate increase, studies on the charging infrastructure with vehicle-to-grid (V2G) technology and information technology are actively under way. In particular, communication with the grid network is the most important factor for stable charging and load management of electric vehicles. However, with the existing centralized infrastructure, there are problems when control-message requests increase and the charging infrastructure cannot efficiently operate due to slow response speed. In this paper, we propose a new charging infrastructure using mobile edge computing (MEC) that mitigates congestion and provides low latency by applying distributed cloud computing technology to wireless base stations. Through a performance evaluation, we confirm that the proposed charging infrastructure (with low latency) can cope with peak conditions more efficiently than the existing charging infrastructure.