• The Journal of Information Technology
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• v.7 no.1
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• pp.57-67
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• 2004

Data broadcast has attracted a lot of attention as an efficient way of disseminating data to very large client populations. The main motivation of data broadcast systems is that the number of clients that they serve can grow arbitrarily large without any effect on their performance. The performance of broadcast system depends mainly on client caching strategies and on data broadcast scheduling mechanisms. This paper addresses the latter issue and proposes a new broadcast scheduling scheme, named RxW$^{\alpha}$, that is suitable to data broadcast systems. This paper also evaluates the performance of RxW$^{\alpha}$ on the basis of a simulation model. The performance results indicate that RxW$^{\alpha}$ is capable of improving the performance in the variance of response time significantly, showing a reasonable performance in the response time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.6B
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• pp.199-206
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• 2008

Broadcast encryption is a cryptographical primitive which is designed for a content provider to distribute contents to only privileged qualifying users through an insecure channel. Anyone who knows public keys can distribute contents by means of public key broadcast encryption whose technique can also be applicable to many other applications. In order to design public key broadcast encryption scheme, it should devise some methods that convert a broadcast encryption scheme based on symmetric key cryptosystem to a public key broadcast encryption. Up to this point, broadcast encryption scheme on trial for converting from symmetric key setting to asymmetric public key setting has been attempted by employing the Hierarchical Identity Based Encryption (HIBE) technique. However, this converting method is not optimal because some of the properties of HIBE are not quite fitting for public key broadcast schemes. In this paper, we proposed new converting method and an efficient public key broadcast encryption scheme Pub-PI which is obtained by adapting the new converting method to the PI scheme [10]. The transmission overhead of the Pub-PI is approximately 3r, where r is the number of revoked users. The storage size of Pub-PI is O($c^2$), where c is a system parameter of PI and the computation cost is 2 pairing computations.

• 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 Communications and Networks
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• v.18 no.3
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• pp.375-386
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• 2016

Most existing studies on broadcast services in orthogonal frequency division multiplexing (OFDM) systems have focused on how to allocate the transmission power to the subcarriers. However, because a broadcasting system must guarantee quality of service to all users, the performance of the broadcast service dominantly depends on the channel state of the user who has the lowest received signal-to-noise ratio among users. To reduce the effect of the worst user on the system performance, we propose a joint delivery scheme of unicast and broadcast transmissions in OFDM systems with broadcast and unicast best-effort users. In the proposed joint delivery scheme, the BS delivers the broadcast information using both the broadcast and unicast subcarriers at the same time in order to improve the performance of the broadcast service. The object of the proposed scheme is to minimize the outage probability of the broadcast service while maximizing the sum-rate of best-effort users. For the proposed joint delivery scheme, we develop an adaptive power and subcarrier allocation algorithm under the constraint of total transmission power. This paper shows that the optimal power allocation over each subcarrier in the proposed scheme has a multi-level water filling form. Because the power allocation and the subcarrier assignment problems should be jointly solved, we develop an iterative algorithm to find the optimal solution. Numerical results show that the proposed joint delivery scheme with adaptive power and subcarrier allocation outperforms the conventional scheme in terms of the outage probability of the broadcast service and the sum-rate of best-effort users.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.276-283
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• 2006

This paper analyzes metadata workflow from creation to browsing, and discusses metadata authoring and browsing technology. Unlike usual multimedia authoring, broadcast metadata authoring means metadata editing synchronized with video. In order to make practical application of other systems, the result is in XML or MXF(Material eXchange Format) based on common metadata scheme. The MXF Browser developed with the consideration of broadcast metadata that is time-synchronized with AV content provides not only metadata authoring capability but also advanced content browsing services such as summary playback and highlight browsing based on metadata multi-track.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.131-140
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• 2018

A broadcast scheduling scheme is an essential technique to improve the performance of data broadcast systems. This paper explores the problem of data broadcast over multiple channels to reduce query response time, and proposes a new hybrid data broadcast scheduling scheme named HDAMA. The proposed scheme employs the strategy that combines the advantages of push-based broadcast and pull-based broadcast. HDAMA could enhance the performance of query response time since it is capable of controlling the influence of access probability properly reflecting the characteristics of multi-data queries and broadcasting pull data items relatively on time. Simulation is performed to evaluate the performance of the proposed scheme. The simulation results show that the performance of HDAMA is superior to other schemes in terms of the average response time.

• 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 Broadcast Engineering
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• v.12 no.4
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• pp.321-332
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• 2007

The digitalization of a broadcast has caused the oversupply of the contents in order to fit the user's needs for various broadcast services. The massive contents could not help demanding one-sided watching without considering a taste and preference of a user. This situation is enlarging the demand about the personalized broadcast service to enable user to watch broadcast contents in anytime according to surplus provision of broadcast contents. TV-Anytime standard could be a solution for broadcast service to enable users to watch personalized broadcast contents according to their preference. The paper proposes the personalized broadcasting system for authoring, receiving and transmission of TV-Anytime metadata, the detailed information about the broadcast contents so that user could efficiently search a large of broadcast contents stored in the PDR(Personal Digital Recorder)receiver under the DCATV(Digital Cable Television) environment.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.107-117
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• 2017

Recently, IoT applications are being deployed in Smart TVs, and these IoT applications are using smart TVs as application platforms rather than broadcast platforms. With the advent of Hybrid broadcast technologies, now it becomes available to develop IoT applications which are coupled to the broadcast information. However, the existing IoT services are not suitable for Hybrid broadcast application since they are built on cloud and require various protocol implementations. In this paper, a Fog Computing-based architecture for hybrid broadcast application is proposed. Instead of accessing IoT services from hybrid broadcast app directly, the proposed architecture places Fog Applet Server between them and distribute loads of hybrid broadcast app to the Fog Applet. The proposed architecture is implemented as a service to control IoT device with hybrid application.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.45-52
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• 2017

According to the change in media environment, a support plan for local broadcast has been required. In terms of legal and institutional support for the development of local broadcast, the enactment of special Act for local broadcast has become a breakthrough. In this point of view, we analyzed the performance and the limitation of the special Act. As a literature research, analyzing the literature and related-ordinances, we have sought legal and institutional support plans for the local broadcast. As a result, with the Local Broadcast Development Council being in charge of legislative right and responsibility, a plan to empower them to have legal and institutional authority should be drawn; another plan to secure independence in operating a fund and to promote the capability to produce local broadcast programs and the distribution system should be drawn; the other elaborate plan for the locality index that assesses the locality is required. Local broadcast should be on a way to secure not only public interest and concern but locality and diversity; legal and institutional plans should be sought.