• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.9-13
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• 2011

The purpose of this study was to investigate the effects of the secondary tasks such as sending text message (STM) and searching navigation (SN) on skin conductance level (SCL) and deviation of vehicle speed during driving. The participants included 30 healthy adults; 14 males aged $25.2{\pm}0.9$ with $1.9{\pm}1.8$ years of driving experiences and 16 females aged $22.6{\pm}1.9$ with $1.2{\pm}0.8$ years of driving experiences. All subjects were instructed to keep a constant speed (80km/h or 100km/h). SCL and deviation of vehicle speed were measured during driving only and driving with secondary tasks. SCL and deviation of vehicle speed were more increased during the driving with secondary tasks than driving only. Secondary tasks increased an activation of sympathetic nerve system and decreased driving performance. However, there were no significant differences in the SCL and deviation of vehicle speed according to gender and speed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.4
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• pp.49-56
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• 2013

KakaoTalk, a Korean mobile instant messenger service launched by KAKAO Inc., has grown remarkably popular in a short period of time, with its number of subscribers exceeding 100 million as of July 2013. Today, KakaoTalk is an everyday communication tool among most Korean mobile users. Although KAKAO has been the subject of many business and consumer studies, the KakaoTalk platform strategy has not been studied thoroughly. In this study, we analyze its platform strategy through the lens of several widely utilized frameworks such as Platform Leadership (Gawer & Cusumano 2002, 2008), Winner-take-all dynamics (Eisenmann et al. 2006), and Open Service Innovation (Chesbrough 2011). Our results show that Eisenmann et al (2006)'s "Winner-Take-All" platform best explains how KakaoTalk dominated its rivals, Mypeople by Daum Communications and Line by Naver Corporation. In surpassing its rivals, KAKAO delivered a solution to the 'essential problem' that mobile social communication should be upgraded from mobile companies' paid "Short Message Service" (SMS). By doing so, KakaoTalk fulfilled the first requirement of Gawer & Cusumano (2008)'s "Coring" strategy, which explains how a new platform is created. KakaoTalk also satisfied the second requirement of "Coring" by providing economic incentives for KakaoTalk members to interact through its Games and Items store. Actively accepting its customers' ideas and upgrading its services, KAKAO reinforced its platform leadership to its customers and put Chesbrough (2011)'s "Outside In - Open Service" innovation strategy into practice.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.1 s.343
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• pp.79-88
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• 2006

In this paper, we designed and implemented ubiquitous u-Health system using RFE and ZigBee. We made a wireless protocol Kit which combines RFE Tag recognition and ZigBee data communication capability. The software is designed and developed on the TinyOS. Wireless communication technologies which hold multi-protocol stacks with RFID and result in the wireless ubiquitous world could be Bluetooth, ZigBee, 802.11x WLAN and so on. The environments that the suggested u-Health system may be used is un-manned nursing, which would be utilized in dense sensor networks such as a hospital. The the size of devices with RFID and ZigBee will be so smaller and smaller as a bracelet, a wrist watch and a ring. The combined wireless RFID-ZigBee system could be applied to applications which requires some actions corresponding to the collected (or sensed) information in WBAN(Wireless Body Area Network) and/or WPAN(Wireless Person Area Network). The proposed ubiquitous u-Health system displays some text-type alert message on LCD which is attached to the system or gives voice alert message to the adequate node users. RFE will be used as various combinations with other wireless technologies for some application-specific purposes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.7-16
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• 2020

The mobile electronic notification service delivers notifications through mobile phone text or app-based message push to solve various problems of the paper-based mail service. And it is a service that an electronic document relay company proves to prove delivery. In order for public and administrative agencies to provide mobile electronic notification service, the user's identification information of the mobile phone number or the subscribed app is required. To overcome these limitations, ICT-regulated sandbox system was used to allow collective conversion of users' resident registration numbers into connecting information (CI). Therefore, in this paper, we propose a technical method for safe management of user CI in mobile electronic notice service, identity verification of electronic notice readers, and prevention of forgery and forgery of electronic notices. Through the proposed method, it is confirmed that the service can be activated by minimizing the adverse function of the mobile electronic notification service by securing the user's convenience and technical safety for the CI.

• Management & Information Systems Review
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• v.31 no.4
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• pp.109-137
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• 2012

This Research focuses on the effect of location-based mobile advertisement considering both of product involvement and advertising expression. The product involvement is classified as high and low involvement and forms of text and picture advertising, which are commonly used in mobile advertising, are chose in this research. To verify the advertising effect for location-based mobile advertisement, advertising attitude, brand attitude, and purchase intention are assessed by conducting survey experiment, which is stimulated for the location-based mobile advertisement including product involvement and advertising expressions. The results presented in this research indicate that the low-involvement product shows lower advertising effect rather than high-involvement product, because consumers recognize the mobile advertisement with low-involvement. The Second finding is that the effect of picture mobile advertising is more effective than that of text mobile advertising and this result is consistent with previous researchers. Finally, the favorable effects for location-based mobile advertisement is more effective than that of non-location-based mobile advertisement, because location-based mobile advertising can cause the immediate response for consumer to react with given advertising.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.4
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• pp.503-508
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• 2010

Recently, the advance of mobile devices has made various services possible beyond simple communication. One of services is the predicting the future path of users and providing the most suitable location based service based on the prediction results. Almost of these prediction methods are based on previous path data. Thus, calculating similarities between current location information and the previous trajectories for path prediction is an important operation. The collected trajectory data have a huge amount of location information generally. These information needs the high computational cost for calculating similarities. For reducing computational cost, the meaningful location based trajectory model approaches are proposed. However, most of the previous researches are considering only the physical information such as stay time and the distance for extracting the meaningful locations. Thus, they will probably ignore the characteristics of users for meaningful location extraction. In this paper, we suggest a meaningful location extracting and trajectory simplification approach considering the stay time, distance, and additionally interaction information of user. The method collects the location information using GPS device and interaction information between the user and the others. Using these data, the proposed method defines the proximity of the people who are related with the user. The system extracts the meaningful locations based on the calculated proximities, stay time and distance. Using the selected meaningful locations the trajectories are simplified. For verifying the usability of the proposed method, we collect the behavioral data of smart phone users. Using these data, we measure the suitability of meaningful location extraction method, and the accuracy of prediction approach based on simplified trajectories. Following these result, we confirmed the usability of proposed method.

• Journal of Digital Forensics
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• v.12 no.3
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• pp.1-8
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• 2018

A random chat application is a type of social dating application that helps people find a lover or spouse by randomly connecting and providing services such as text, voice and video chat. Recently, there has been globally a rapid increase in its use due to the fact that it provides people to quick and convenient encounters at low cost. However, it is used as one of method to prostitute or to trade drugs and become a cause of violent crimes due to various criminal occurring after actual meeting between app users. For this reason, a random chat application is likely to provide proof of prostitution or drug trade and clues to arrest rape, kidnapping and murder suspects. Thus, it is necessary to analyse random chat applications from the viewpoint of digital forensics investigation, but there is no related research at all. Therefore, in this paper, we analyzed artifacts of 6 Korea random chat application's user behaviors; Ranchat, AngTalk, SsumgThing, DaTalk, EveryTalk and Sail. As a result, we found that it is remain on mobile device that time and contents of message transmission/reception, sender/receiver, friend profile and user account creation time when user is using the applications.

• Journal of Korean Home Economics Education Association
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• v.21 no.3
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• pp.29-43
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• 2009

The purposes of this study were to examine effective variables influencing on adolescents' mobile phone addiction. The subjects were the 666 middle or high school students who had their own mobile phone in Gwangju. Data were analyzed with frequency, percentage, cronbach's ${\alpha}$, mean, SD, pearson's correlation and multiple regression using SPSS/PC WIN 14.0 program. The major findings were as follows: 1. The most frequently used function of student mobile phones was text message and they used text message more than 41 times a day. Mostly they were talking to the same sex friends on the phone and the monthly charges ranged from 20,000 to 30,000 won. In general, they called to their friends after school. Their parents' attitudes toward their mobile phone using showed that the most of their parents did not care about their children's mobile phone use. The restriction of using their mobile phone at school was normal. 2. The average scores of mobile phone addiction were lower than median(3.0) and self esteem, self control, family strengths, peer conformity and school life adaptation were higher than median. 3. The adolescence's mobile phone additions were influenced by peer conformity, school life adaptation, school levels, sex and self control. And these variables explained to the adolescence's mobile phone additions about 28%.