• Journal of Positioning, Navigation, and Timing
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• v.7 no.4
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• pp.217-226
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• 2018

According to the Korea Coast Guard's maritime disaster statistics (Korea Coast Guard 2017, Korean Statistical information Service 2018), an average of 2,140 marine accidents occurred every year for the past 6 years and the number of accidents is increasing every year. Among them, maritime accidents of fishing vessels are the most frequent, and recently accidents involving fishing boat and leisure vessels are rapidly increasing as well. In particular, the number of accidents involving leisure vessels increased to about one-third of the accidents of fishing vessels, and emergency rescue requests are increasing every year accordingly. However, the number of crash accidents involving users of small vessels and marine leisure activities are increasing because of the difficulties of installing navigation equipment and electronic navigation charts. Recently, the demand for precise positioning using mobile devices is increasing in the fields of maritime safety, piloting support, and coastal survey. Although various applications of smart devices provide location-based services for users, the measurement results are discontinuous when using the position coordinates of the National Marine Electronics Association (NMEA) calculated by smartphone. Recently, Google announced that they will provide GPS raw data to developers from Android 7.0 Nougat. As a result, developers have an opportunity to receive precise carrier phase and code measurements to make more accurate positioning according to the performance of Android devices. This study analyzed GPS positioning performance using Android devices, and compared and analyzed the positioning performance at sea with high-performance GPS receivers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.171-174
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• 2014

Increasingly important user based service on the smart media era, and increasing awareness about the user experience. In this study, by considering these realities, what impact location based constructs on smartphone environment, continuous intention to use you want to identification. Thus, this study conducted of preference the influencing factors for location based constructs. First steps, based constructs known empirical studies were categorized information, entertainment, safe&emergency, navigation&tracking and advertising& commerce. Second Steps, the categorized factors were analyzed preference relationship between constructs using AHP(analytic hierarchy process) technique. Questionnaire survey was conducted to those who employees S Telecom in Busan city and Gyeongnam province during 2000. 4. 15 and 2014. 4. 30. The result of the analysis might be summarized that the navigation(0.133) has the highest preference ran in the constructs. Based on these findings, several theoretical and practical implications were suggested and discussed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1067-1073
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• 2021

Participants in the virtual environment will have an immersive and memorable perceived experience through interacting with virtual objects. Recently, commercial virtual reality technologies have released simple and cost-effective smartphone-based head-mounted displays (HMD) and high-quality wide field-of-view (FOV) HMDs. However, due to the vergence-accommodation conflict structure of HMD and the learned cognition mechanism in real, side effects such as dizziness and nausea remain challenging to overcome. This study focuses on consistent size perception among various cognitive difference factors, which are essential for interaction with virtual objects. We verified whether the visual angle, which affects the size perception of an object in real, is also the main factor in the virtual environment. Our experiments derived the relation between the visual angle and the environmental components, shadow, and grid, which help perceive a virtual object. As a result of the regression analysis, we presented that in the small FOV HMD environment, the visual angle affects size perception, and the relation between the shadow and the grid is statistically significant.

• Proceedings of the Korean Society of Community Living Science Conference
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• 2011.10a
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• pp.81-81
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• 2011

• Spatial Information Research
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• v.20 no.4
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• pp.57-67
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• 2012

Recently, market of mobile spatial information service is increasing along with enlargement of geo-spatial information utilization area and spread of smartphone. In particular, smartphone users look forward to utilizing spatial information service more easily and conveniently. Korea has the potential for spatial information technology development, but does not have enough governmental support to develop various spatial information service in mobile network environment. Hence, it is need to make governmental support plans for utilizing mobile services and promoting the related industry base on mobile spatial information. In this paper, we propose governmental action plans for utilizing mobile services and promoting the related industry by surveying mobile application/web services and analyzing demands of mobile spatial information experts.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.149-154
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• 2012

This paper aims to design and realize android smartphone mobile webapp office JPetStore order system based Seam framework. Currently in production until the lightweight container architecture, known commonly architecture is Seam framework. However, there is no design and implementation research of mobile webapp office with the Seam framework environment. In this study, the Seam environment based on the android mobile webapp office JPetStore order system implementation after analyzing the mobile webapp office development productivity with the objective is to provide guidance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.869-876
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• 2011

Recently, use of Smartphones is growing at an extremely rapid pace. Many researchers have recognized the importance of developing Smartphones applications under these circumstances, and they have been conducted many studies to develop apps efficiently. The Smartphones middleware has become a focus of recent research to develop efficient Smartphones apps on a server-client environment in particular. In this study, for enhancing portability, expandability and convenience in the development of apps on the various platforms of Smartphones, We have proposed XML based Open API optimized in the Smartphones middleware. We also evaluated the performance, by applying it in Smartphone middleware environment.

• Journal of Digital Contents Society
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• v.13 no.3
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• pp.401-412
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• 2012

Communication through smartphones is creating a new paradigm of mobile communication beyond the restrictions of mobility and space. The mobile instant messengers of the smartphone, which began on the desktop environment, are providing various communication features, including multimedia contents, texts, and voice. Kindergartens and nurseries are using Websites, phones, SMS, printed materials, handwritten notifications, etc. to communicate with the parents. IsPlus was developed to facilitate the communication between the parents and the teachers, including exchanges of pictures and videos, chatting, and attendance management using smartphones. This is meaningful in that it is an early smartphone mobile messenger for educational institutions for infants and preschoolers. This study presented a new approach to the development of a mobile messenger for a specific group of users by analyzing the user environment, communication types, application planning process and interface design development using storytelling.

• The Journal of the Korea Contents Association
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• v.13 no.9
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• pp.49-57
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• 2013

Recently, in spite of fast development of smartphone, recording technology has saved, listened and searched in server based on PSTN and wired network. We introduce a mobile transcript recording system for mobile office environment. All calls using smartphone are automatically saved on memory in mobile device with this system. Thereafter, recording files are encrypted and uploaded to recording server by user authority. Beside recording data in database on web server is saved and managed efficiently and economically through web application. This system is able to be used in legal corroborative facts and the prevention of crime such as voice phishing.

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.121-136
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• 2011

With the rapid growth of GPS-enable Smartphones, the interest on using Location Based Services (LBSs) has increased significantly. The evolution in the functionalities provided by those smartphones has enabled them to accurately pinpoint the location of a user. Because location information is what all LBSs depend on to process user's request, it should be properly protected from attackers or malicious service providers (SP). Additionally, maintaining user's privacy and confidentiality are imperative challenges to be overcome. A possible solution for these challenges is to provide user anonymity, which means to ensure that a user initiating a request to the SP should be indistinguishable from a group of people by any adversary who had access to the request. Most of the proposals that maintain user's anonymity are based on location obfuscation. It mainly focuses on adjusting the resolution of the user's location information. In this paper, we present a new protocol that is focused on using cryptographic techniques to provide anonymity for LBSs users in the smartphone environment. This protocol makes use of a trusted third party called the Anonymity Server (AS) that ensures anonymous communication between the user and the service provider.