Topic
Keying
About: Keying is a research topic. Over the lifetime, 6598 publications have been published within this topic receiving 82943 citations.
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Papers
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TL;DR: In this paper, the effect of atmospheric turbulence-induced fading on the symbol decision position in the on-off keying (OOK) and the binary phase shift keying(BPSK) subcarrier intensity modulated (SIM) laser communication link is investigated.
Abstract: This paper shows the impact of atmospheric turbulence-induced fading on the symbol decision position in the on-off keying (OOK) and the binary phase shift keying (BPSK) subcarrier intensity modulated (SIM) laser communication link. Weak turbulence is simulated in the laboratory using a chamber equipped with heating elements and fans. We have shown that in atmospheric turbulence, it is advantageous to employ modulation schemes such as pulse time and subcarrier intensity modulations that do not directly impress data on the optical irradiance as is the case with the OOK. For the OOK-modulated laser communication system, atmospheric turbulence imposes complexity on the symbol decision subsystem and by extension places a limit on the achievable bit error rate (BER) performance.
71 citations
TL;DR: Substantial performance improvements are obtained with a number of recently proposed modulation formats for 1980-km 42.7-Gb/s single-channel transmission over standard single-mode fiber.
Abstract: We experimentally compare nonreturn-to-zero and return-to-zero on-off keying with a number of recently proposed modulation formats for 1980-km 42.7-Gb/s single-channel transmission over standard single-mode fiber. Substantial performance improvements are obtained with the new formats.
71 citations
TL;DR: A study of potential of brainwaves and their computing for providing higher security in robotic environment and selected and employed the neural network based on learning vector quantization for correct classification.
71 citations
Patent•
IBM1
TL;DR: In this paper, a key-in method including a manual keying in phase, and an automatic accuracy enhancement phase, where at least one of the manual phase, the automatic phase and the interaction there between is dependent, at least, on data generated previous to said dataflow point.
Abstract: This invention discloses a key-in method including a manual keying in phase, and an automatic accuracy enhancement phase, wherein at least one of the manual phase, the automatic phase and the interaction therebetween is dependent, at least one dataflow point, on data generated previous to said dataflow point.
71 citations
Patent•
23 Aug 1999TL;DR: An efficient chroma key-based coding technique for digital video with an optimized binary keying threshold is provided in this article, where the shape information of a foreground object is embedded in the keyed output, so there is no need to carry an explicit alpha plane, or use alpha plane coding.
Abstract: An efficient chroma key-based coding technique for digital video with an optimized switching threshold. An optimized binary keying threshold (T) is provided for switching between a first image region (such as a background region) (B) and second image region (such as a foreground object) (A) video picture. The threshold optimizes a PSNR of a quantization error Q of a key color K. A chroma key technique is also provided for representing the shape of a video object, where the shape information (alpha plane) of a foreground object is embedded in the keyed output, so there is no need to carry an explicit alpha plane, or use alpha plane coding. The chroma key shape representation technique provides a smooth transition at the boundary (500, 505) between objects without the need for special switching patterns, such as a general gray scale shape coding tool, or post-processing, e.g., using feathering filters.
71 citations