• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.9
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• pp.3043-3067
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• 2022

With the mobile traffic in the network increases exponentially, multi-access edge computing (MEC) develops rapidly. MEC servers are deployed geo-distribution, which serve many mobile terminals locally to improve users' QoE (Quality of Experience). When the cache space of a MEC server is full, how to replace the cached videos is an important problem. The problem is also called the cache replacement problem, which becomes more complex due to the dynamic video popularity and the varied video sizes. Therefore, we proposed a new cache replacement scheme based on local video popularity and video size to solve the cache replacement problem of MEC servers. First, we built a local video popularity model, which is composed of a popularity rise model and a popularity attenuation model. Furthermore, the popularity attenuation model incorporates a frequency-dependent attenuation model and a frequency-independent attenuation model. Second, we formulated a utility based on local video popularity and video size. Moreover, the weights of local video popularity and video size were quantitatively analyzed by using the information entropy. Finally, we conducted extensive simulation experiments based on the proposed scheme and some compared schemes. The simulation results showed that our proposed scheme performs better than the compared schemes in terms of hit rate, average delay, and server load under different network configurations.

• The Journal of Society for e-Business Studies
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• v.8 no.1
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• pp.71-83
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• 2003

Nowadays on-line services based on Internet are being popularized and there are lots of E-Commerce applications using Internet. So we can use lots of information on anytime. To maximize the convenience of the network, the platform of the service is moving from E-Commerce to M-Commerce. In this paper we developed the application system for mobile environment. Therefore applicants can apply their applications and see the competition rate of the applying departments anytime and anywhere even if in the network disconnection regions. And we can manage more economically the application system because we use the network only the time when we syncronize the mobile device to mobile server.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.245-247
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• 2011

For the mobile meteorological services, sensed data should be gathered at a server from various clients like as USN, mobile phone or public traffic vehicle by wireless network. The gathered data have huge volume and increase continuously, a special query method and data structure are considered. This paper studies on all query type and processing steps for the mobile meteorological services and proposes effective system structure.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.2
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• pp.23-32
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• 2013

The purpose of this study is to make effective mobile grid considered general environment, which can be summarized as irregular mobility, service exploration, data sharing, variety of machines, limit to the battery duration, etc. The data was extracted from the Dartmouth College. We analysed mobile use pattern of a specific group and applied pattern using hybrid method. As a result, we could adjust infra usage effectively and appropriately and cost cutting and increase satisfaction of user. In this study, by applying weighting method based on access time interval, we analysed use pattern added time variation with association rule during users in mobile grid environment. We proposed more stable way to manage patterns in a mobile grid environment that is being used as a hybrid form to process the data value received from the server in real time. Further studies are needed to get appropriate use pattern by group using use patterns of various groups.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.269-273
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• 2006

In this paper, a remote screen control by mobile networks on embedded system is implemented. For this system a server program is ported on the embedded system connected with internet. And on the side of a mobile phone, a client program is ported using GVM. The embedded system can display the text and image from the mobile phone on its LCD. In the implemented embedded system the text and image data from GVM emulator is sent to the system for display on its LCD. The realization of the proposed embedded system can display the text :md image from a working mobile phone.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.4098-4116
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• 2020

Mobile devices such as smartphones are very attractive targets for augmented reality (AR) services, but their limited resources make it difficult to increase the number of objects to be recognized. When the recognition process is scaled to a large number of objects, it typically requires significant computation time and memory. Therefore, most large-scale mobile AR systems rely on a server to outsource recognition process to a high-performance PC, but this limits the scenarios available in the AR services. As a part of realizing large-scale standalone mobile AR, this paper presents a solution to the problem of accuracy, memory, and speed for large-scale object recognition. To this end, we design our own basic feature and realize spatial locality, selective feature extraction, rough pose estimation, and selective feature matching. Experiments are performed to verify the appropriateness of the proposed method for realizing large-scale standalone mobile AR in terms of efficiency and accuracy.

• ETRI Journal
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• v.29 no.1
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• pp.107-109
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• 2007

In location-based services, most trigger technologies have been implemented on the server side by periodically requesting the locations of mobile phones from mobile network servers. However, bottlenecks and communication interruptions occur when the servers are overloaded by trigger requests. In this letter, we propose a new multilevel location trigger specification which distributes the event detecting role to mobile phones and redesigns the location triggering into a multilevel step. Our suggested location trigger specification can reduce bottlenecks caused by triggers in a mobile core network and reduce power consumption caused by embedded GPS devices in mobile phones.

• Spatial Information Research
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• v.10 no.4
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• pp.567-578
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• 2002

The success of gCRM depends on the availability of adequate, real-time data about customers' location and the provision of diverse value-added services utilizing it. In the existing gCRM systems, however, it seems that the positional precision of customers' location is very low, and further that the services based on real-time location data are not provided. In order to overcome these weaknesses and extend the limited scope of gCRM, we suggest a new design of gCRM system integrated with LBS. We also describe in some detail the system prototype for such an integration.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.72-77
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• 2006

In this paper, a remote screen control by mobile networks on embedded system is implemented. For this system a server program is ported on the embedded system connected with internet. And on the side of a mobile phone, a client program is ported using GVM. The embedded system can display the text from the mobile phone on its LCD. In the implemented embedded system, the text data from GVM emulator is sent to the system for display on its LCD. The realization of the proposed embedded system can display the text from a working mobile phone.