• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.145-150
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• 2010

In this paper, we propose additional data transmission system for spectrum efficiency improvement and derive channel capacity formula as a approximated closed-form. Spread spectrum watermarking scheme is selected for the watermarking embedder. Nakagami-q (Hoyt) model is considered as a multipath fading channel. Numerical results show the channel capacity variation of the proposed system in wireless fading channel. From the results, we confirm that the channel capacity of the watermarking system is affected by the fading coefficient and system parameters such that host sampling frequency, host-to-watermark ratio, watermark-to-noise ratio, and PN sequence length.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.382-385
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• 2003

Introduction of digital broadcasting service does not only mean the change of information transmission method but also the change of total broadcasting system. In past day, Television was only received one-sided information from broadcasting station, but digital broadcasting means that digital television becomes the most important means of information transmission by the introduction of new programming, lots of channels, data service, multi communication. In the age of the digital broadcasting, the recording and replay medium's interest is getting higher. The medium is able to record more than 24 hours' digital broadcasting programs without additional tapes. In this paper the recording and replay device using HDD was implemented and device driver based on linux was programmed. It has Intel PXA250 processor and hard disk is used as storage equipment. And transport Stream is saved on hard disk through PXA250's data bus. FIFO is added to solve the different saving speed and FPGA is also added to display the saved data.

• Journal of Korea Multimedia Society
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• v.24 no.1
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• pp.67-74
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• 2021

As IoT(Internet Of Things) devices like a smart sensor have constrained power sources, a power strategy is critical in WSN(Wireless Sensor Networks). Therefore, it is necessary to figure out the residual power of each sensor node for managing power strategies in WSN, which, however, requires additional data transmission, leading to more power consumption. In this paper, a residual power estimation method was proposed, which uses ignorantly small amount of power consumption in the resource-constrained wireless networks including WSN. A residual power prediction is possible with the least data transmission by using Machine Learning method with some training data in this proposal. The performance of the proposed scheme was evaluated by machine learning method, simulation, and analysis.

• Journal of the Korea Society of Computer and Information
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• v.14 no.2
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• pp.37-44
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• 2009

In this paper, we propose an efficient method which improves the performance of transmission of PGA which is essential data for real-time earthquake monitoring system. Currently, above 120 earthquake stations were installed nationwide and additional installation is expected because the social interesting of earthquake hazard is rising. Real-time earthquake monitoring system checks earthquake occurrence by using PGA were calculated from acceleration data of each seismic station. An efficient method of PGA data transmission is key factor of real-time monitoring. The key idea of proposed method is to deal with each seismic station using an unique ID, to assign one bit to indicate whether a packet include a station's data or not. Proposed method can contain more station data and decrease the data loss compared to current method. To verify proposed method, we investigate the turnaround time and ratio of data loss using above 91000 packets. As results of experiment. the proposed method is proven that the method need more time about 50% but reduce the data loss about 87% as compared to previous method.

• Journal of Broadcast Engineering
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• v.14 no.3
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• pp.332-341
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• 2009

Terrestrial digital multimedia broadcasting(T-DMB) is one of mobile broadcasting services, and the commercial service was started in December 2005 in Korea. The performance targets of T-DMB are providing VCD(video CD) quality video and FM radio quality audio. In recent years, the researches for providing high quality video or audio service on T-DMB environments have been being carried out. To provide high-quality video or audio service, some additional data should be transmitted to the receiver as well as T-DMB video and audio data. Since the data rate for one T-DMB program is low, it is important to transmit the additional data at a low bit rate. In this paper, we propose a packetizing method for efficient transmission of the additional data to provide multichannel audio service on T-DMB environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.93-99
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• 2008

Most of the current research works on high-technology is being carried on to provide ubiquitous services to people. To make that possible, ubiquitous computing networks should be deployed in the first place, where ubiquitous sensor network (USN) will take a very big role. This paper is devoted to introduce a new transmission technique to make USN more independent and reliable as an infra-structure for ubiquitous services. The proposed scheme can elevate the network performance by ensuring the reliability of data transmission. Especially, the proposed scheme can reduce network traffic and communication cost by detecting data error without additional data and communication. In addition, it has an advantage of using the legacy routing protocols.

• Journal of Korea Multimedia Society
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• v.21 no.11
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• pp.1237-1243
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• 2018

In the HDTV video codec, conventional the padding method of DEPA(DTV essential padding area) region is aimed at minimizing the redundant information to be transmitted. This article propose a method to transmit additional data by using DEPA region. The proposed method is effective for the channel and storage because it can reduce the amount of bits while preventing deterioration of image quality by inserting binary gray image blocks into the DEPA region. Additionally this algorithm can be used in various fields because it conforms to the standards of MPEG-2, ATSC, and DVB encoders.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.2
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• pp.82-102
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• 2008

Packet losses tend to occur during short error bursts separated by long periods of relatively error-free transmission. There is also a significant spatial correlation in loss among the receiver nodes in a multicast session. To recover packet transmission errors at the transport layer, tree-based protocols construct a logical tree for error recovery before data transmission is started. The current tree construction scheme does not scale well because it overloads the sender node. We propose a scalable recovery tree construction scheme considering these properties. Unlike the existing tree construction schemes, our scheme distributes some tasks normally handled by the sender node to specific nodes acting as repair node distributors. It also allows receiver nodes to adaptively re-select their repair node when they experience unacceptable error recovery delay. Simulation results show that our scheme constructs the logical tree with reduced message and time overhead. Our analysis also indicates that it provides fast error recovery, since it can reduce the number of additional retransmissions from its upstream repair nodes or sender node.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.79-90
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• 2015

Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient concurrent multipath routing protocol with a small number of paths based on interaction between paths. The interaction between paths helps to reinforce the multipath reliability by making efficient use of resources. The protocol selects several nodes located in the radio overlapped area between a pair of paths as bridge nodes for the path-interaction. In order to operate the bridge node efficiently, when the transmission failure has detected by overhearing at each path, it performs recovery transmission to recover the path failure. Simulation results show that proposed protocol is superior to the existing multipath protocols in terms of energy consumption and delivery reliability.

• International journal of advanced smart convergence
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• v.1 no.2
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• pp.16-19
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• 2012

A modified 4-coil magnetic resonance wireless power transfer (MRWPT) system is proposed. Four coils based on 2-coil system with additional two matching coils were used in this topology. When Tx-Rx distance is changed, the input impedance is changed. However, it can be adjusted by coil parameters of matching coils to maintain impedance matching for maximum efficiency. The equivalent circuit of MRWPT system was analyzed for both transmission function and optimum coupling coefficient of the matching coils. By using four spiral resonant coils, these design considerations was experimentally verified. The measured data agreed well with the calculated data and the transmission function of the proposed system was more efficient than that of conventional 2-coil system.