• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.217-227
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• 2005

In this paper, we present the result of an efficient implementation of DirectX-based multichannel visual monitoring system and the performance analysis of it. Our proposed system mainly consists of three subsystems: display, storage, and retrieval/playback. The display subsystem is designed to utilize efficiently H/W acceleration, overlay and flip of DirectX for faster real-time display, display synchronization among channels, and improvement of tearing artifact. For the performance improvement of storage speed, the storage subsystem is designed and implemented in DirectShow Filter-based multithreading architecture so that it can store multichannel video streams efficiently in each channel with minimizing data bottleneck among channels. In the retrieval and playback subsystem, efficient index file architecture and video data storage architecture, efficient playback architecture which can make playback be processed parallel among channels are designed and implemented for faster retrieval and playback,. Through experiments, our proposed system is shown to be maximally 2 times as fast in storaging speed and maximally 3.5 times as fast in retrieval and playback speed as the previous system.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.351-354
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• 2002

DVR(Digital Video Recorder), a recently popular visual monitoring system, is required to support multi camera channel display(upto 16 channels) with various display modes in real-time. For such a multichannel display system, it is well known that tearing artifacts become more serious. Thus, one needs to design a display system for DVR so that it does not show tearing artifacts as much as possible, but keeps real-time display speed. In this paper, we present our efforts in designing and implementing a display system which rarely ever shows tearing artifacts, but without degradation of required real-time display speed, and which displays character information stably without blinking.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2116-2119
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• 2003

In this paper, we present a DirectShow-based retrieval and playback subsystem of DVR(Digital Video Recorder), which supports real-time playback of stored video data and synchronized playback among several video channel data. The effectiveness of out proposed design is verified through experiments with a DVR system implementing the proposed design.

• Progress in Medical Physics
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• v.16 no.3
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• pp.148-154
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• 2005

Since the output of retina for visual stimulus is carried by neurons of very diverse functional properties, it is not adequate to use conventional single electrode for recording the retinal action potential. For this purpose, we used newly developed multichannel recording system for monitoring the simultaneous electrical activities of many neurons in a functioning piece of retina. Retinal action potentials are recorded with an extra-cellular planar array of 60 microelectrodes. In studying the collective activity of the ganglion cell population it is essential to recognize basic functional distinctions between individual neurons. Therefore, it is necessary to detect and to classify the action potential of each ganglion cell out of mixed signal. We programmed M-files with MATLAB for this sorting process. This processing is mandatory for further analysis, e.g. poststimulus time histogram (PSTH), auto-correlogram, and cross-correlogram. We established MATLAB based protocol for waveform classification and verified that this approach was effective as an initial spike sorting method.