• Journal of Digital Contents Society
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• v.13 no.1
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• pp.111-118
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• 2012

The burst is to require abruptly high transmission rate in case of transmitting pre-stored variable bit rate video data, and it causes to be inefficient use of network resource, resource reservation. To avoid these problems, smoothing is transmission plan where variable rate video data is converted to a constant bit rate stream. These smoothing algorithms include CBA, MCBA, MVBA and others. To evaluate amount of burst reduction in the existing CBA, MCBA, MVBA algorithm, this paper compares the burst-related-factors of transmission plan in smoothing algorithms with original video sources which were stored Variable Bit Rate. There are maximum frame bytes, maximum GOP bytes, transmission rate variability per frame, transmission rate variability per GOP in burst-related evaluation factors. Experimental result shows burst-related factors of smoothing algorithms which were used for experiment lower than that of pre-stored video data, except special case.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.9-15
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• 2007

Smoothing is a transmission plan where variable rate video data is converted to a constant bit rate stream. Among them are CBA, MCBA, MVBA, e-PCRTT and others. e-PCRTT algorithm, which was improved from PCRTT, restricts the number of rate changes with fixed-size run. This causes unnecessary rate changes when run size is small and buffer size is large. In this paper, to overcome a shortcoming of e-PCRTT algorithm, a smoothing algorithm is proposed, which is improved from e-PCRTT, where a transmission rate transmits more intervalsl as possible. Experiments demonstrated that the proposed algorithm outperformed e-PCRTT algorithm. In order to show the performance, various evaluation factors were used such as the number of transmission rate changes, peak rate, transmission rate variability and so on.

• Journal of Advanced Navigation Technology
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• v.24 no.1
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• pp.53-60
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• 2020

In this paper, We have studied the structure of a Telemetry Transmitter capable of transmitting variable data rates. This paper proposed a structure combining variable pre-modulation filter with cutoff characteristic with variable input sample rate converter. Variable pre-modulation filter has the same characteristics as pre-modulation filter and is converted to a constant sampling rate without structural changes according to the variable input data rate. We propose a software program that actively controls variable pre-modulation filter and variable input sample rate converter to respond to real-time changing data.

• The KIPS Transactions:PartC
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• v.9C no.5
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• pp.679-686
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• 2002

The transmission of prerecorded and compressed video data without degradation of picture quality requires video servers to cope with large fluctuations in bandwidth requirement. Bandwidth smoothing techniques can reduce the burst of a variable-bit rate stream by prefetching data at a series of fixed rates and simplifying the allocation of resources in the video servers and the network. In this paper, the proposed smoothing algorithm results in the optimal transmission plans for (1) the smallest bandwidth requirements, (2) the minimum number of changes in transmission rate, and (3) the minimum amount of the server process overhead. The advantages of the proposed smoothing algorithm have been verified through the comparison with the existing smoothing algorithms in diverse environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1473-1478
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• 2005

In this paper, we proposed UWB system with variable rate in piconet environment that several wireless devices moves as variable. And, we analyzed the performance of UWB system according to multiple access interference and transmission rate. Also, we have evaluated the performance of m system with Truncated Type-II Hybrid ARQ scheme fer achieving high qualify data transmission.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.189-198
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• 2002

Precoder has been shown to be able to provide source diversity and design flexibility. In this paper we employ precoding techniques for block transmission based on a multirate filterbank structure. To accommodate multiuser communication with variable data rates, different precoders with corresponding coefficients and up/down sampling rates are used. However, due to unknown multipath distortion, different interferences may exist in the received data, such as multiuser interference, intersymbol interference and interblock interference. To estimate channel parameters for a desired user, we employ all structured signature waveforms associated with different symbols of that user and apply subspace techniques. Therefore better performance of channel estimator can be achieved than the conventional subspace method based only on the signature of the current symbol. The delay for that user can also be jointly estimated. Channel identifiability conditions and asymptotic channel estimation error are investigated in detail. Numerical examples are provided to justify the proposed method. gest either multicode (MC) or multiple processing gain (MPG) mechanism [2], while requiring data rates to be integral multiples of some basic low-rate. In order to support variable rate transmission however, a comprehensive scheme needs to be investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2326-2333
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• 2009

In the adaptable bandwidth allocation technique, a transmission plan for variable rate video data is made by smoothing algorithms such as CBA algorithm and the data is sent by the transmission plan considering network traffic. But the CBA algorithm, the MCBA algorithm, MVBA algorithm and the other smoothing algorithms produce a transmission plan where the size of the increasing interval of transmission rate is generally larger than the size of the decreasing interval. And the transmission rate in CBA algorithm, the MCBA algorithm, the MVBA algorithm is changed in overflow curve during the increasing interval of transmission rate. This may cause many frames to be discarded when available transmission rate is larger than transmission rate by the transmission plan. In this paper, the smoothing algorithm, where transmission rate is changed in the middle of underflow curve and overflow curve to decrease the number of discarded frames, but the transmission rate increases at the minimum, and the CBA algorithm, the MCBA algorithm, the MVBA algorithm are applied to a transmission plan in the adaptable bandwidth allocation technique, and the minimum frame rates, the average frame rates, the variation of frame rates, and the numbers of discarded frames are compared in among algorithms.

• The KIPS Transactions:PartC
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• v.14C no.3 s.113
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• pp.285-292
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• 2007

In the adaptable bandwidth allocation technique, a transmission plan for variable rate video data is made by the CBA algorithm and the data is transmitted by considering network traffic. But the CBA algorithm produces a transmission plan where the size of the increasing interval of transmission rate is generally larger than the size of the decreasing interval. And the transmission rate in CBA algorithm is changed in overflow curve during the increasing interval of transmission rate. This ぉy cause many frames to be discarded when available transmission rate is small. In this paper, a smoothing algorithm is proposed, where transmission rate is changed in the middle of underflow curve and overflow curve, but the transmission rate increases at the minimum. In order to show the performance, the proposed algorithm and a CBA algorithm were applied to a transmission plan in the adaptable bandwidth allocation technique, and the minimum frame rates, the average frame rates, the variation of frame rates, and the numbers of discarded frames were compared in both algorithms.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2971-2973
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• 2000

In this paper, we proposed the implementation of multiple access serial communications with improved transmission control. For serial communications. RS232 protocol is used and the transmitting data and is merged to form data channel. Multiple host access is configures by using the common data channel and ground channel. 8bit data transfer with variable frame size is transferred by using the 16bit host ID. Packet is composed of HEADER, receiver ID. variable length data frame, TAIL and CRC informations. Multiple hosts are allowed to transfer packet with the other hosts through the common communication channel. Byte-stuffing is used to differentiate the transfer rate of PC is performed.

• Journal of Korea Game Society
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• v.6 no.2
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• pp.51-60
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• 2006

Smoothing is a transmission plan where variable rate video data is converted to a constant bit rate stream. Among them are CBA, MCBA, MVBA, PCRTT and others. But, in these algorithm, a transmission plan is made in according to stored frame sequence in these algorithms. In case that the number of bytes in frames in GOP differs greatly each other, this may cause unnecessary transmission rate changes and may require high transmission rates abruptly when frame's byte is large. In result, it is difficult to use efficient network resource. In this paper, we proposed a smoothing algorithm that find the optimal frame sequence in short time by using backtracking method and smoothing's structure for the proposed smoothing algorithm. This algorithm decides the sequence of frames which requires the lowest variance of frame's bytes in GOP and make a transmission plan. In order to show the performance, we compared with MVBA algorithm by various evaluation factors such as the number of rate changes, peak rate, rate variability.