• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.75-81
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• 2012

In this paper, we design and implementation of effective integrated broadcast contents transmission System based on single server system. Because of previous broadcast contents transmission system is consist of various individual functional equipment. And it is not easy to use and not effective to manage for broadcast contents transmission. In this paper, we evaluated and analysed of developed system in the test environment. As a result of performance test, It showed that it was well performed without any data error in the performance test, and It showed that it was well managed, controled, scheduled, processed of the integrated broadcast contents transmission environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.61-69
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• 2021

On-demand broadcast is an effective data dissemination technique in mobile computing environments. This paper explores the issues for scheduling multi-data queries in on-demand broadcast environments, and proposes a new broadcast scheduling scheme named CASS. The proposed scheme prioritizes queries by reflecting the characteristics of multi-data queries, and selects the data that has not been broadcast in the query for the longest time as the broadcast data according to the query priority. Simulation is performed to evaluate the performance of CASS. The simulation results show that the proposed scheme outperforms other schemes in terms of the average response time since it can show highly desirable characteristics in the aspects of query data adjacency and data conflict rate.

• 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.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.236-246
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• 2017

As a research on culinary staffs' subjective perception of star chefs' appearance in cooking broadcast, this study analyzed the subjective tendency targeting culinary staffs in hotels & restaurants by applying Q methodology. Three research questions of this study were set up like below. First, what are the culinary staffs' acceptance types of subjective perception of star chefs' appearance in cooking broadcast? Second, what are the characteristics of homogeneous type of culinary staffs' subjective perception of star chefs' appearance in cooking broadcast? Third, what are the things in common and differences of culinary staffs' each subjective perception type of star chefs' appearance in cooking broadcast? In the results of typological analysis based on such research questions, total four types were drawn such as Acquiring expertise through cooking broadcast type(Type1, N=8), New broadcast genre recognition type(Type2, N=10), The profession of the chef reality recognition type(Type3, N=2), and Profession image of chef synergy type(Type4, N=2). Each type showed its own distinctive characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.1043-1049
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• 2009

Broadcast of sink node is used for network management, data collection by query and synchronization in wireless sensor networks. Simple flooding scheme induces the broadcast storm problem. The MPR based broadcast schemes reduce redundant retransmission of broadcast packets. MPR is a set of one hop neighbor nodes which have to relay broadcast message to cover all two hop neighbors. Though MPR can reduce redundant retransmission remarkably, it still suffers from energy waste problem caused by collision and duplicate packets reception. This paper proposes a new MPR based sink broadcast scheme using 3-channel. The proposed scheme reduces energy consumption by avoiding duplicate packet reception, while increases reliability by reducing collision probability remarkably. The results of analysis and simulation show that the proposed scheme is more efficient in energy consumption compared to the MPR based scheme. The result also shows that the proposed scheme reduces delivery latency by evading a contention with other relay nodes and improves reliability of broadcast message delivery by reducing collision probability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.17-27
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• 2012

Broadcast-based data dissemination has become a widely accepted approach of communication in the mobile computing environment. However, with a large set of data items, the expected delay of receiving a desired data increases due to the sequential nature of the broadcast channel. This paper explores the issue of designing proper data allocation on multiple broadcast channels to reduce this wait time, and proposes a new data allocation scheme named near optimal data allocation(NODA). The proposed scheme first partitions all data items in K group based on the theoretical lower-bound of the average expected delay to determine data items which each broadcast channel has to broadcast. Then, NODA further partitions each group of data items in B groups using extended dynamic programming algorithm to broadcast data items allocated on the same broadcast channel in different frequencies. The proposed scheme is capable of minimizing the average expected delay time since it can broadcast data items allocated on the same channel reflecting their popularities.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.37-52
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• 2004

Broadcast has been often used to disseminate the frequently requested data efficiently to a large volume of mobile units over a single or multiple channels. Since the mobile units have limited battery power, the minimization of the access time for the broadcast data is an important problem. There have been many research efforts that focus on the improvement if the broadcast techniques by providing indexes on the broadcast data. In this paper, we studied an efficient index allocation method for the broadcast data over multiple physical channels, which cannot be coalesced into a single high bandwidth channel. Previously proposed index allocation techniques either require the equal size of index and data or have a performance degradation problem when the number of given physical channels is not enough. These two problems will result in the increased average access time for the broadcast data. To cope with these problems, we propose an efficient tree- structured index allocation method for the broadcast data with different access frequencies over multiple physical channels. Our method minimizes the average access time for the broadcast data by broadcasting the hot data and their indexes more often than the less hot data and their indexes. We present an in-0e0th experimental and theoretical analysis of our method by comparing it with other similar techniques. Our performance analysis shows that it significantly decrease the average access time for the broadcast data over existing methods.

• 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.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.7-9
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• 2006

본 논문에서는 정적인(static) 무선 애드 혹 네트워크상에서 에너지 효율적으로 broadcast하는 문제에 대한 새로운 "Broadcast by iterative Coverage sequence Adjustment with Hitch-hiking (BCAH)" 알고리즘을 제안한다. BCAH는 에너지 효율적인 broadcast알고리즘 중 가장 대표적인 Broadcast Incremental Power(BIP)와 같은 시간 복잡도를 가지면서 BIP에 비해 적은 에너지를 소모해 broadcast를 수행한다. 또한 BCAH는 각 노드의 인접한 노드들의 정보만을 이용해 동작하기 때문에 노드들의 이동성을 고려한 동적인 네트워크에 좋은 확장성을 가진다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.164-167
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• 2010

`신호 공간 다이버시티(Signal Space Diversity)'기술은 DVB-T2 표준에 포함된 기술로써, 추가적인 전력이나 대역폭의 희생없이 검파에 있어 성능 이득을 얻을 수 있어 DVB-T2 물리계층 핵심적인 기술 중 하나로 평가받으며, 후속 표준인 DVB-NGH 에도 적용 가능성이 높은 기술이다. 본 논문에서는 '신호 공간 다이버시티' 기술을 MIMO 시스템으로 확장하기 위해서 발생하는 문제점에 대해서 분석한 뒤, 이를 해결하기 위해 제안된 '성분 맞교환(Component-Swapping)' 기술을 현재 논의 중에 있는 DVB-NGH 시스템에 적용하여 주어진 실험 환경에서 2.2~3.0dB 가량의 이득을 가짐을 실험적으로 확인하였다.