• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.4
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• pp.217-224
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• 2010

Nowadays, people perform their tasks anywhere anytime using their mobile devices. For this reason, data synchronization (DS) between mobile devices and a central server has become one of the most essential technologies in mobile environments. Currently, several mobile DS protocols are proposed and used. However, the existing DS protocols cannot guarantee interoperability between them. To solve the problem, an embedded DS gateway has been developed in our previous study. The gateway runs on a Windows Mobile-based emulator. It converts data on a mobile device into common data specified by OMA DS standard protocol and vice versa. The embedded gateway has been built to support the OMA DS standard protocol. In order to verify that the embedded gateway conforms to the OMA DS standard protocol, two kinds of OMA conformance tests have to be conducted - interoperability test with an OMA DS-based server and conformance test with SCTS (SyncML Conformance Test Suit). In this paper, some parts of the gateway previously built are modified and the modified gateway is installed on a Windows Mobile-based smart phone. And the interoperability test and the conformance test with the SCTS are conducted. The results of the tests show that the embedded DS gateway operates properly on the Windows Mobile-based smart phone and that the gateway passes the tests, verifying its conformity to the OMA DS standard protocol. In addition, DS performance tests show that DS delay times between a real smart phone and a DS server increase gently as the number of DS data increases. In other words, the embedded DS gateway built in this paper can be used for a real smart phone at a reasonable performance cost.

• Korean Journal of Human Ecology
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• v.23 no.2
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• pp.163-174
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• 2014

This study aimed to discriminate the groups clustered by mobile phone dependency and use type and to explore the quality of parent child-rearing attitudes and peer relationships predicting the types of groups. The subjects were the 688 fourth-grade students participating in the Korea Child Youth Panel Surveys. The data were analyzed with descriptive statistics, cluster analysis, One-way ANOVA and multinominal logistic regressions. The main results of this study were as follows. Firstly, as the result of cluster analysis inputting the mobile phone dependency and use type, the four clustered groups were produced. Secondly, the quality of parent child-rearing attitudes and peer relationships discriminating the four groups were parents' supervision, over-involvement, love, senses of non-alienation from peers and communicating with them. Therefore, this study suggested the parent education and peer-relationship improving program to form children's good habits of mobile phone use.

• Journal of Korean Society of Transportation
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• v.34 no.3
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• pp.222-233
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• 2016

Recently, mobile phone data was applied in travel demand modeling as a new source of dynamic population movement. This study is also aimed to estimate "occupancy population" during a given period of time within a given spatial region using mobile phone data. An occupancy population was defined as the number of people residing or moving within a given time and space. In case of Seoul Metropolitan area, we divided the area into a number of administrative districts as zones for analysis and estimated the occupancy population of each zone by mobile phone data collected by SK telecom Co., a wireless telecommunication provider in Korea. For the expansion of mobile phone data, a new concept of "communication probability" was introduced and applied in the estimation of occupancy population of each zone by the hour. We compared the estimated number with the daytime population and the daytime population index referred by the Statistics Korea. The results showed that a positive correlation existed between the estimated number and the statistical number by nationwide survey. It was concluded that mobile phone data could be more cost-effective sources than a conventional survey method to estimate the pattern of population movement by the hour or by the day.

• Journal of Information Technology Applications and Management
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• v.13 no.1
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• pp.39-66
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• 2006

In a few years, a variety of mobile devices are expected to be utilized as a necessity for business as well as personal communications. Thus it is needed to conduct a comprehensive study on the acceptance of mobile devices in the mature market like Korea. This paper develops an extended technology acceptance model by including functional attributes of cellular phone and examines the determinant factors causing accepting cellular phones. Our empirical analysis through the internet survey shows that 1) among the determinant factors, perceived usefulness, perceived enjoyment or fun, and social pressure have positive direct impacts on the intention of accepting cellular phone, and 2) functional attributes of cellular phone affect the determinant factors differently.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.289-294
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• 2011

In this paper, we developed a phone call display system or "alimi" for displaying the received phone data at limited space that can not carry a mobile phone and and its validity was confirmed. It consists of a data communication application transmitting the phone data via bluetooth, a RF data repeater to extend the range of data communication, and a display system part for displaying the received phone data to the phone user. It has economy in terms of system installation because the implementation of the proposed system is simple and low cost installation is possible. As ordinary mobile phones users using the system can easily utilize it by downloading the application on the app. store, it has economy and convenience checking whether a call is received.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.90-98
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• 2008

PKI (Public Key Infrastructure) which is used for the security of E-commerce (Electronic-commerce) in wired internet is not suitable for the mobile phone because of the fundamental limitation of performance such as less memory and less powerful CPU. Therefore, we need to develop a wireless PKI (WPKI) that provides the similar security level as the wired PKI supporting mobile phone. In this paper, we propose a lightweight and secure Wireless Certificate Management Protocol (WCMP) that is executable to the mobile phone that has a constrained communication environment and limitation of performance, and show the implementation results of the scheme based on the mobile phone. We minimize data sizes processed in mobile phone, and optimize protocols for the certificate management. This results in the reduced module sizes to be able to install in mobile phone and shows as the same level as the wired CMP.

• Anxiety and mood
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• v.8 no.2
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• pp.127-132
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• 2012

Objective : This study aims to investigate the relationship between addictive mobile phone use and post-traumatic stress disorder (PTSD) symptoms in bullies who experienced school violence. Methods : The study subjects consisted of 97 adolescents in The Foundation for Preventing Youth Violence after school violence. The participants conducted self-report questionnaire for addictive mobile phone use and Impacted Event Scale-revised-Korean version (IES-R-K). Partial correlation and multiple logistic regressions were performed. Results : The scores related to addictive mobile phone use were correlated with total score (r=0.21, p=0.04), avoidance score (r=0.21, p=0.04) and intrusive score (r=0.26, p=0.01) related to PTSD symptoms on the IES-R-K. Intrusive score related to PTSD symptoms on the IES-R-K were significant risk factor for addictive mobile phone use (O.R=1.25, 95% CI=1.12-1.39). Conclusion : This data supports that PTSD intrusive symptoms could be predictable factor of addictive mobile phone use. An appropriate intervention about PTSD symptoms might play a useful role in preventing addictive mobile phone use in bullies of school violence.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.87-96
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• 2009

In u-GIS environments, a geographic information service system for mobile phone is consumer(user) oriented service system based on existing GIS and LBS considering characteristic of mobile phone. In the past, development of a geographic information service system for mobile phone dependent on various hardware specification of mobile phones and mobile operators. From now on, the geographic information service system for mobile phone independents on hardware specification of mobile phones and mobile operators. Also, it changes from service oriented GIS provider(specialist) to service oriented consumer. For the satisfaction of this requirement, we propose a design of geographic information service system for mobile phone using FLEX for creates standard execution file. The standard execution file is able to apply various mobile phone. And we propose a management method of picture contents combination of location information that geographic information service system for mobile phone is provided it firstly. In this system, it provides facilities that display map, manage location, manage contents, manage mash-up, manage map data. And then it provide facility of swf generation for display result map on mobile phone. In this paper, we are implemented the proposed system and seen same results in various mobile phone. The created *.swf file provides same result at any time, anywhere, anyone in spite of different zoom level and different display screen.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.185-190
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• 2009

Biomedical mobile devices for ubiquitous healthcare consist of biomedical sensors and communication terminal. They have two types of configuration. One is the sensor-network type device using wired or wireless communication with intelligent sensors to acquire biomedical data. The other is the sensor embedded type device, where the data can be acquired directly by itself. There are many examples of sensor network type, such as, fall detection sensor, blood glucose sensor, and ECG sensors networked with commercial PDA phone and commercial phone terminal for ubiquitous healthcare. On the other hand, sensor embedded type mounts blood glucose sensor, accelerometer, and etc. on commercial phone. However, to enable true ubiquitous healthcare, motion sensing is essential, because users go around anywhere and their signals should be measured and monitored, when they are affected by the motion. Therefore, in this paper, two biomedical mobile devices with motion monitoring function were addressed. One is sensor-network type with motion monitoring function, which uses Zigbee communication to measure the ECG, PPG and acceleration. The other is sensor-embedded type with motion monitoring function, which also can measure the data and uses the built-in cellular phone network modem for remote connection. These devices are expected to be useful for ubiquitous healthcare in coming aged society in Korea.

• Journal of Information Technology Services
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• v.11 no.2
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• pp.19-47
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• 2012

Contemporary smartphone competition is generally described as the battle between Apple's proprietary platform and Google's open platform. However, this competition is not limited within smartphone adoption itself. User's pre-adoption of one mobile platform via smartphone can be connected to the post-adoption of the same mobile platform based on the other smart devices (e.g. smart pad). In this study, we investigate whether user's preference to a certain platform is persistent over mobile ecology, from the pre-adoption of one smart device to the post-adoption of following devices. For this investigation, we adopt the dual-model as the ground theory, where post-adoption of IT product is explained by both dedication and constraint factors. The empirical testing first evidences that dual model works well as our research model for identifying the reasons of post-adoption. Next, we group our data into two parts in order to compare the switching behavior of iPhone users and Android phone users. iPhone users show much lower switching rate to Android based smart pads, while Android phone users show higher churn rate to iPad (49.3% : 96.3%). Especially, satisfaction showed much stronger effect than switching cost on the continuing intention of existing platform, when the analysis is given to the iPhone user's group. From this result, we can conjecture the relatively stronger loyalty of iPhone users. More managerial implications on the mobile platform strategy are driven.