• Journal of the Korean Data and Information Science Society
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• v.18 no.1
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• pp.107-121
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• 2007

An efficient encoding algorithm (or encryption algorithm) is essential for mobile devices since their resources such as computation power and battery capacity are very limited. This study is to propose an efficient encoding scheme for protecting mobile music. In the proposed scheme, server distributes each music file in a shuffled form or an encrypted one, then only authorized consumers can play the music after un-shuffling or decrypting it. We show the effectiveness of our proposed scheme by implementing and evaluating the prototype system on WIPI emulator. Experimental results show that our scheme can achieve much better performance than the standard encryption algorithm of OMA DRM.

• Information and Communications Magazine
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• v.28 no.10
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• pp.3-10
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• 2011

The increasing ubiquity of wireless networks and decreasing cost of hardware is fueling a proliferation of mobile devices. These devices are enabling a new revolution in mobile technology, not only running locally on them, but running on cloud as a service as well. From web browsing, email, or video conferencing, presentations to movie and music entertainment or games, multimedia applications, mobile cloud enables providing such diverse applications. Many technologies have been designed to address the limited hardware and performance in thin client PC. However, with the assorted network and graphic condition, those proposed technologies is obligated to alter aim to adapt mobile cloud. In this paper, we provide a survey of client technology on a Server that can be sufficed the requirements of Mobile Cloud. We also analyze each technology and classify with its individual difficulties and challenges.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.548-553
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• 2002

Most tasks of the large vertical or ceiling structures have been carried out by human power. Those tasks require us much operation costs and times, safety devices, etc. So the need of automation for those tasks have been rising. That automation needs a wall-climbing mobile vehicle. Most former researches are things about attachment devices and moving mechanisms. A wall-climbing mobile vehicle must be designed by a method different from the case of the vehicle of the horizontal environment. That is because gravity acts as a negative role on the stability of a wall-climbing vehicle. In this thesis, the particular shape characteristics of a wall-climbing mobile vehicle are derived by the wall-environment modeling. In addition, some design constraints of the permanent magnetic wheel as an attachment device was studied. According to those requirements and constraints, one specific wall-climbing mobile vehicle was designed and some experiments were made on the attachment ability of that vehicle.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.4
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• pp.1249-1265
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• 2022

Video streaming has become one of the most popular applications for mobile devices. The network bandwidth required for video streaming continues to exponentially increase as video quality increases and the user base grows. Multi-Path TCP (MPTCP), which allows devices to communicate simultaneously through multiple network interfaces, is one of the solutions for providing robust and reliable streaming of such high-definition video. However, mobile video streaming over MPTCP raises new concerns, e.g., power consumption and cellular data usage, since mobile device resources are constrained, and users prefer to minimize such costs. In this work, we propose a mobile video streaming framework over MPTCP (mDASH) to reduce the costs of energy and cellular data usage while preserving feasible streaming quality. Our evaluation results show that by utilizing knowledge about video behavior, mDASH can reduce energy consumption by up to around 20%, and cellular usage by 15% points, with minimal quality degradation.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.1422-1425
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• 2011

These days' mobile phones and their improved multimedia limits making it powerful enough to handle complicated tasks. Image processing related support for mobile devices is extremely comprehensive in mobile cyber museum. A key technical challenge is how to achieve the best-perceived image quality and transmitting data between client and server with given the limited screen size and display bit-depth of the mobile devices. This paper targets image processing features such as capturing rendering zooming, panning and image rotation for 360o view and customized algorithm related image processing with variety of search method i.e. alphabetical, visual search.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.23-32
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• 2013

As the mobile communication technology is developed, the services for communication between the mobile devices are provided, and the amount of usage is increasing tremendously. For the device-to-device communication, the device should be verified if it is a service member. The existing verification schemes include interactions with the third party, while this may cause the problems that the bandwidth is dissipated and the devices which are out of the communication range of the base station cannot communicate with other devices. To solve such problems, we propose a new scheme for verification between mobile devices without interaction of third party. For the proposed scheme, we develop and employ a new zero-knowledge proof protocol, which verifies the device's membership and its expiration time. Furthermore, the scheme guarantees privacy of the mobile device since it checks the encrypted verification message without decrypting, and protects replaying attack since it uses challenge-response method.

• Journal of the Korea Society of Computer and Information
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• v.12 no.2 s.46
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• pp.209-220
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• 2007

Mobile devices become a pak of our daily life due to their versatility, such as the wireless phone calls, the wireless accessibility to Internet, the display of multimedia content, and the communication with nearby mobile devices. Third generation telecommunication service provides an easy access to the Internet for nubile devices. Mobile users pay a fee charged by the telecommunication provider based on the amount of data transferred. This paper introduces a special ad hoc network in which mobile devices cooperate each other to download an interesting content from the Internet in order to reduce the telecommunication cost. The mobile devices, called the peers, in the ad hoc network are assigned a portion of the target file, and are responsible for downloading the portion using their 3G connection. Then, the peers exchange their downloaded portion with other participating peers using their cost-free ad hoc connection in order to reconstruct the whole content. According to the simulation results, large number of participating peers saves the telecommunication cost up to 90% with as few as 10 peers, although it slightly increase the overall content reconstruction time.

• Journal of the Korea Society for Simulation
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• v.15 no.4
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• pp.21-28
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• 2006

In this paper, we introduce the mobile grid architecture using kernel-based managements. Mobile grid paradigm is used to allow mobile users to access distributed resources in a transparent, secure and effective way. Each mobile grid user requests job submission, searches for suitable resources to run Job, executes the job to the allocated system resources, and receives the results of the requested job. There are a number of challenging issues when taking mobile environment into account, such as limited performance of mobile devices and mobility of mobile device. To resolve these issues, we design and implement the kernel-based management system for mobile grid application to overcome the limited resources of mobile devices. Also, we show the efficiency of the suggested architecture using the performance evaluation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8B
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• pp.786-796
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• 2009

Currently, web syndication is usually utilized in desktop environments, but not considering mobile environments. In this paper, we focus on the extension of the desktop based web syndication to the mobile internet. Simply adapting the desktop based web syndication to mobile devices can cause high wireless internet communication cost. We propose PMS(Proxy-based Mobile Syndication) model which achieves low cost mobile syndication. In the PMS model, MWProxy is defined as a proxy server between mobile devices and web sites. It can reduce the communication cost by peeking up modified items from the web sites and reducing the channel size. In this paper, we designed and implemented the PMS system in a mobile phone and evaluated the performance of the PMS system by conducting real experiments using mobile emulators.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.4961-4964
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• 2013

Greater use of mobile phone devices seems inevitable because the health industry and cancer care are facing challenges such as resource constraints, rising care costs, the need for immediate access to healthcare data of types such as audio video texts for early detection and treatment of patients and increasing remote aids in telemedicine. Physicians, in order to study the causes of cancer, detect cancer earlier, act in prevention measures, determine the effectiveness of treatment and specify the reasons for the treatment ineffectiveness, need to access accurate, comprehensive and timely cancer data. Mobile devices provide opportunities and can play an important role in consulting, diagnosis, treatment, and quick access to health information. There easy carriage make them perfect tools for healthcare providers in cancer care management. Key factors in cancer care management systems through a mobile phone health approach must be considered such as human resources, confidentiality and privacy, legal and ethical issues, appropriate ICT and provider infrastructure and costs in general aspects and interoperability, human relationships, types of mobile devices and telecommunication related points in specific aspects. The successful implementation of mobile-based systems in cancer care management will constantly face many challenges. Hence, in applying mobile cancer care, involvement of users and considering their needs in all phases of project, providing adequate bandwidth, preparation of standard tools that provide maximum mobility and flexibility for users, decreasing obstacles to interrupt network communications, and using suitable communication protocols are essential. It is obvious that identifying and reducing barriers and strengthening the positive points will have a significant role in appropriate planning and promoting the achievements of mobile cancer care systems. The aim of this article is to explain key points which should be considered in designing appropriate mobile health systems in cancer care as an approach for improving cancer care management.