A Particle Image Velocimetry (PIV) method based on the image separation andreconstruction with the median filter and triangular Bezier patch was proposed to measure multiplevelocity fields from single-camera images in...A Particle Image Velocimetry (PIV) method based on the image separation andreconstruction with the median filter and triangular Bezier patch was proposed to measure multiplevelocity fields from single-camera images in the present study. The method was examined on syntheticPIV images with the Green-Taylor two-phase vortex flows and the test results showed high accuracyand highly correct tracking percent compared with the exact solution. An experiment of the bubblyjet flow was also conducted as a practical demonstration of the present method. As a result, it isconfirmed from the simulation image examination and the experimental measurement that the proposedmethod shows a good performance in the measurement of bubble and particle phases.展开更多
The flow field of pulsing air separation is normally in an unsteady turbulence state.With the application of the basic principles of multiphase turbulent flows,we established the dynamical computational model,which sh...The flow field of pulsing air separation is normally in an unsteady turbulence state.With the application of the basic principles of multiphase turbulent flows,we established the dynamical computational model,which shows a remarkable variation of the unstable pulsing air flow field.CFD(computational fluid dynamics) was used to conduct the numerical simulation of the actual geometric model of the classifier.The inside velocity of the flowing fields was analyzed later.The simulation results indicate that the designed structure of the active pulsing air classifier provided a favorable environment for the separation of the particles with different physical characters by density.We shot the movement behaviors of the typical tracer grains in the active pulsing flow field using a high speed dynamic camera.The displacement and velocity curves of the particles in the continuous impulse periods were then analyzed.The experimental results indicate that the effective separation by density of the particles with the same settling velocity and different ranges of the density and particle size can be achieved in the active pulsing airflow field.The experimental results provide an agreement with the simulation results.展开更多
Organizing unstructured information from books into a well-defined structure is a significant challenge in digital libraries.Most digital libraries can provide only search services at the granularity of books and few ...Organizing unstructured information from books into a well-defined structure is a significant challenge in digital libraries.Most digital libraries can provide only search services at the granularity of books and few libraries allow books to be accessed at the granularity of chapters,as manually constructing directory information for books is time-consuming.Extracting structured data from scanned books thus remains an urgent and important work.In this paper,we propose a novel structured data organization framework called CMSOF to organize scanned data automatically,and apply it to a Chinese medicine digital library. In the framework,image blocks and text blocks on the scanned page of books are separated based on the gray histogram projection method or a hybrid method of region growth and the Ada-Boosting classifier at first,and then the text structure is obtained from text blocks by text size and font type recognition.Finally,image blocks and structured OCRed text are correlated at the semantic level.By integrating the structured data into a Chinese medicine information system(CMIS) ,we can organize the Chinese medicine books well and users can access the books with flexibility,which indicates that CMSOF is an efficient framework to organize books mixed with images and text.展开更多
文摘A Particle Image Velocimetry (PIV) method based on the image separation andreconstruction with the median filter and triangular Bezier patch was proposed to measure multiplevelocity fields from single-camera images in the present study. The method was examined on syntheticPIV images with the Green-Taylor two-phase vortex flows and the test results showed high accuracyand highly correct tracking percent compared with the exact solution. An experiment of the bubblyjet flow was also conducted as a practical demonstration of the present method. As a result, it isconfirmed from the simulation image examination and the experimental measurement that the proposedmethod shows a good performance in the measurement of bubble and particle phases.
基金the financial support provided by the National Natural Science Foundation of China (No.51074156)the Natural Science Foundation of China for InnovativeResearch Group (No. 50921002)+1 种基金the Natural Science Foundation of Jiangsu Province of China (No. BK2010002)the Fundamental Research Funds for the Central Universities (No. 2010ZDP01A06)
文摘The flow field of pulsing air separation is normally in an unsteady turbulence state.With the application of the basic principles of multiphase turbulent flows,we established the dynamical computational model,which shows a remarkable variation of the unstable pulsing air flow field.CFD(computational fluid dynamics) was used to conduct the numerical simulation of the actual geometric model of the classifier.The inside velocity of the flowing fields was analyzed later.The simulation results indicate that the designed structure of the active pulsing air classifier provided a favorable environment for the separation of the particles with different physical characters by density.We shot the movement behaviors of the typical tracer grains in the active pulsing flow field using a high speed dynamic camera.The displacement and velocity curves of the particles in the continuous impulse periods were then analyzed.The experimental results indicate that the effective separation by density of the particles with the same settling velocity and different ranges of the density and particle size can be achieved in the active pulsing airflow field.The experimental results provide an agreement with the simulation results.
基金Project supported by the China Academic Digital Associative Library(CADAL)
文摘Organizing unstructured information from books into a well-defined structure is a significant challenge in digital libraries.Most digital libraries can provide only search services at the granularity of books and few libraries allow books to be accessed at the granularity of chapters,as manually constructing directory information for books is time-consuming.Extracting structured data from scanned books thus remains an urgent and important work.In this paper,we propose a novel structured data organization framework called CMSOF to organize scanned data automatically,and apply it to a Chinese medicine digital library. In the framework,image blocks and text blocks on the scanned page of books are separated based on the gray histogram projection method or a hybrid method of region growth and the Ada-Boosting classifier at first,and then the text structure is obtained from text blocks by text size and font type recognition.Finally,image blocks and structured OCRed text are correlated at the semantic level.By integrating the structured data into a Chinese medicine information system(CMIS) ,we can organize the Chinese medicine books well and users can access the books with flexibility,which indicates that CMSOF is an efficient framework to organize books mixed with images and text.