• Journal of the Korea Society of Computer and Information
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• v.24 no.8
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• pp.51-58
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• 2019

In this paper, we propose to characteristics of mobile phone dance live broadcast platform and the second-generation technology acceptance model TAM2, this paper established the user acceptance model of mobile phone dance live broadcast platform, aiming to study the influencing factors of users' acceptance on mobile phone dance live broadcast platform. Based on the empirical analysis of user survey, the model is validated, and the relationship between variables in the model is clarified. It is also confirmed that human-computer interaction, scene interaction, relationship interaction and other factors will affect the user's acceptance on mobile phone dance live broadcast platform. At the same time, based on the relationship among variables obtained in the research, this paper tries to analyze how the variables affect each other based on the actual practice of mobile phone dance live broadcast platform. In addition, the video design strategy and marketing strategy for further development of mobile phone dance live broadcast platform are given to help the platform and dance creators to carry out better promotion on the mobile side. In the end, this paper summarizes the shortcomings of this study and points out further research directions in the future, providing a reference for researchers in the field of mobile phone dance live broadcast platform acceptance.

• Journal of information and communication convergence engineering
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• v.8 no.3
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• pp.277-280
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• 2010

We report that broadcast messages in Mobile WiMAX networks should be synchronized throughout all the base stations to gain the benefit of beamforming technique. A simple synchronization implementation of broadcast messages in Mobile WiMAX networks is presented. Using this technique, the interference between broadcast messages and beamformed messages can be reduced.

• Journal of KIISE:Databases
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• v.32 no.4
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• pp.394-404
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• 2005

Battery capacity of mobile clients in wireless mobile computing environments is one of the important resources that determine the availability of mobile clients. So, data broadcast techniques in mobile computing environments need not only rapid delivery of requested data but also efficient data delivery mechanisms which can reduce battery consumption of mobile clients. This paper proposes organization of an index and broadcast data for on-demand data broadcast. It organizes an index containing broadcast time of each data using some of high-priority data in a broadcast server. By sending such index information prior to the corresponding data, the proposed approach reduces tuning time of mobile clients. It also includes when the next index information will be broadcasted in each data broadcast. This can reduce tuning time of mobile clients waiting for an index to be broadcasted. Experiments show that the proposed approach effectively reduces tuning time of mobile clients.

• Journal of Information Technology Services
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• v.8 no.1
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• pp.179-192
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• 2009

In wireless environments, it is very effective to introduce a data broadcast system for providing a number of clients with mobile data services. In particular, an efficient broadcast scheduling and a caching strategy are very important for performance of data broadcast systems in wireless environments which have such inherent restrictions as low bandwidth, frequent disconnections, and short battery life. In this paper, we present a data broadcast scheduling strategy using bit vectors to cope with dynamic request patterns of clients. In addition, we also propose an efficient caching strategy, 2FWT, that takes characteristics of the broadcast scheduling strategy into account. Finally, we evaluate performance of the data broadcast system. According to the results, the proposed system generally shows better performance than others.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.69-85
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• 2006

Broadcast has been often used to disseminate the frequently requested data efficiently to a large volume of mobile clients over a single or multiple channels. Conventional concurrency control protocols for mobile transactions are not suitable for the wireless broadcast environments due to the limited bandwidth of the up-link communication channel. In wireless broadcast environments, the server often broadcast different data items with different frequency to incorporate the data access patterns of mobile transactions. The previously proposed concurrency control protocols for mobile transactions in wireless broadcast environments are focused on the mobile transactions with uniform data access patterns. However, these protocols perform poorly when the data access pattern of update mobile transaction are not uniform but skewed. The update mobile transactions with skewed data access patterns will be frequently aborted and restarted due 4o the update conflict of the same data items with a high access frequency. In this paper, we propose an energy-efficient concurrence control protocol for mobile transactions with skewed data access as well as uniform data access patterns. Our protocol use a random back-off technique to avoid the frequent abort and restart of update mobile transactions. We present in-depth experimental analysis of our method by comparing it with existing concurrency control protocols. Our performance analysis show that it significantly decrease the average response time, the amount of upstream and downstream bandwidth usage over existing protocols.

• Journal of KIISE:Databases
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• v.35 no.3
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• pp.257-271
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• 2008

Wireless broadcast environments has character that a number of mobile client can receive data streaming from central server no matter how they are so many. Because it is asymmetric bandwidth in that uplink and downlink bandwidth are different. This advantage helps wireless broadcast environments is used in many applications. These applications work almost read operation and need control concurrency using transaction unit. Previous concurrency control scheme in single channel is not adapted in multi channel environments because consistency of data are broken when a mobile client tunes in a broadcast cycle in a channel and then move into another channel and listen to different broadcast cycle with already accessed broadcast cycle. In this paper, we propose concurrency control for read-only mobile transactions in multiple wireless broadcast channel. First of all, we adapt index and data dedicated channel and propose LBCPC(Longest Broadcast Cycle Per Channel) as new unit of consistency. In index dedicated channel, it is repeatedly broadcasted data in same BCPC(Broadcast Cycle Per Channel) until LBCPC. And mobile transaction executes validation using control information every LBCPC. As a result, consistency of data is kept and average response time is shorter than one in single channel because waiting time for restart reduces. And as control information is broadcasted more frequently than in single channel, it is guaranteed currency about data accessed by transaction. Finally, according to the simulation result, we verify performance of our scheme in multi channel as comparing average response time with single channel.

• Journal of Broadcast Engineering
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• v.14 no.6
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• pp.676-691
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• 2009

Recently mobile broadcast standards that have IP layer between transport layer and service layer such as DVB-IPDC, OMA-BCAST have been commercialized. Specially, IP abstract layer of OMA-BCAST makes it possible to interface diverse transport layers. Service guide, that is important for user interface, of these mobile broadcast standards has complex structure and heterogeneous schema. ESG schema is not interoperable, therefore terminals should have various implementations of service layer to support more than one service layer at a time. In this paper, not only for enabling interoperability of DVB-IPDC and OMA-BCAST but for supporting basic scenarios of mobile broadcast, simple ESG schema was developed. This new schema can be used as an independent ESG schema, especially for the integrated mobile broadcast middleware environment.

• Journal of KIISE:Databases
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• v.30 no.5
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• pp.476-493
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• 2003

Data broadcast is an effective data transmission method from a data base server to numerous mobile clients due to the restrictions on mobile environment such as low wireless communication bandwidth and energy shortage of mobile devices. There are various broadcast methods based on clients' data access frequencies or semantic relationship of data. The broadcast schedule based only on the access frequencies does not consider semantic relations of data, so that when a client needs to access a series of semantically related data, the client has to listen to the wireless channel for a long time. On the other hand, the broadcast schedule based only on semantic relationship of data makes data access time longer when clients highly request specific data which are not semantically related but frequently accessed. In this paper, we present an efficient data broadcast method based on not only data access frequencies but also semantic relationship to improve mobile clients' query response time. The new hybrid broadcast method we propose creates a data broadcast schedule according to the data access frequencies and then the schedule is adjusted to reflect semantic relationship of data. We show our method is efficient by experimental performance analysis.

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.395-400
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• 2019

The CBS and the AEAS functionalities are defined in cellular systems and T-DMB systems, respectively. In the case that communication facilities are disabled in indoor environments, it is impossible for the residents to receive the emergency messages. In this paper, a novel collaborative technology of intelligent mobile robots is proposed, which relies on cooperative communications among the intelligent mobile robots. In order to improve the performance, the intelligent mobile robots exploit their location information. Simulation results confirm that the proposed method is very suitable for reliable emergency alert broadcast.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1245-1253
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• 2009

Since 2000, the demand for multimedia content consumption has been continuously increasing. The research and standardization for the mobile broadcast service has been done to deliver multimedia contents to the huge number of users with the minimum cost. A few commercial services started after the related standards were released. We call this mobile broadcast service the 1st generation service. Now, many experts are researching and developing the technologies for 3Screens(TV, PC, and Mobile) Services that an user can enjoy multimedia contents at every place with the various networks and devices. To enable this service, two main technical areas exist. The first is a core network technology that can support the various access network and the second is a common application layer technology. To resolve these technical areas, we propose IMS(IP Multimedia Subsystem) based OMA BCAST(Open Mobile Alliance Mobile Broadcast Service Enabler Suite) as the technical solution for 3 Screen Services in the paper. In addition, we propose application layer multicast that is enable to implement IMS based OMA BCAST to the existing network with the minimum cost. Finally, we show how we can save the implementation cost of IMS based OMA BCAST with the simulation results.