In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and ...In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and disturbance of non-flame phenomena further more, the average changing pixel number of the first-order moments of consecutive flames has been defined in the moment analysis as well. The first-order moments of all kinds of flames used in our experiments present irregularly flickering, and their average changing pixel numbers of first-order moments are greater than fire-like disturbances. For the analysis of flicker frequency of flame, which is extracted and calculated in spatial domain, and therefore it is computational simple and fast. The method of extracting flicker frequency from video images is not affected by the catalogues of combustion material and distance. In experiments, we adopted two kinds of flames, i. e. , fixed flame and movable flame. Many comparing and disturbing experiments were done and verified that the methods can be used as criteria for early fire detection.展开更多
Gas-liquid two-phase slug exist in numerous industrial flow phenomena widely processes and practical applications. Furthermore, heat and mass transfer rates, pressure prediction and momentum loss greatly depend on the...Gas-liquid two-phase slug exist in numerous industrial flow phenomena widely processes and practical applications. Furthermore, heat and mass transfer rates, pressure prediction and momentum loss greatly depend on the slug flow structure. Hence, the study of slug flow has attracted considerable research inter- est. Meanwhile, uncovering the dynamic behaviors and flow structure of slug flow has also become a sig- nificant problem, especially for the measurement of two-phase flow parameters.展开更多
基金Supported by " Experimental Scale Studies in Smoke Control Strategy in Large Linear Atria in HKSAR" (B Q372)
文摘In this paper, motion analysis methods based on the moment features and flicker frequency features for early fire flame from ordinary CCD video camera were proposed, and in order to describe the changing of flame and disturbance of non-flame phenomena further more, the average changing pixel number of the first-order moments of consecutive flames has been defined in the moment analysis as well. The first-order moments of all kinds of flames used in our experiments present irregularly flickering, and their average changing pixel numbers of first-order moments are greater than fire-like disturbances. For the analysis of flicker frequency of flame, which is extracted and calculated in spatial domain, and therefore it is computational simple and fast. The method of extracting flicker frequency from video images is not affected by the catalogues of combustion material and distance. In experiments, we adopted two kinds of flames, i. e. , fixed flame and movable flame. Many comparing and disturbing experiments were done and verified that the methods can be used as criteria for early fire detection.
基金Supported by the National Natural Science Foundation of China under Grant Nos 41174109 and 61473203, and the National Science and Technology Major Project of China under Grant No 2011ZX05020-006.
文摘Gas-liquid two-phase slug exist in numerous industrial flow phenomena widely processes and practical applications. Furthermore, heat and mass transfer rates, pressure prediction and momentum loss greatly depend on the slug flow structure. Hence, the study of slug flow has attracted considerable research inter- est. Meanwhile, uncovering the dynamic behaviors and flow structure of slug flow has also become a sig- nificant problem, especially for the measurement of two-phase flow parameters.
