Digital infrared thermography is suitable for monitoring the planar two-dimensional temperature distribution of curved surfaces of objects by sensing their infrared radiation. Cardiac infrared thermography also has a ...Digital infrared thermography is suitable for monitoring the planar two-dimensional temperature distribution of curved surfaces of objects by sensing their infrared radiation. Cardiac infrared thermography also has a thermal coronary angiography alias. This study proposes a digital image processing methodology for locating blood clot blockage. This methodology contains four consequent processes. The two-dimensional gray scale infrared thermograph pixels are first binarized and classified as background or coronary arteries using multi-thresh adaptive segmentation.The coronary artery contours are extracted from segmented raw pixels using continuous pepper-like pixel removal,erosion,subtraction,recursive neighborhood visiting,contour point-list construction and short edge deletion.In the third process one coronary artery branch is selected by physicians for calculating the longest curved central axis using morphological thinning and neighborhood analysis. In the last process the nearest left and right distances from each pixel along the directional central axis to its corresponding boundary contour are added as the coronary artery variable diameter at the current pixel's position. A variable diameter versus straighten length diagram along this axial curved path is plotted to provide useful physiological information to the physician. An obstruction rate equation is then defined to calculate the possible vascular blockage positions with the local minimal rates. Finally,preoperative cases are tested to prove the predictive positions are correct in comparison to individual patient myocardial perfusion imaging.展开更多
Due to the need for energy conservation in buildings and the simultaneous benefit of cost savings, the development of a low firing rate load modulating residential oil burner is very desirable. One of the two main req...Due to the need for energy conservation in buildings and the simultaneous benefit of cost savings, the development of a low firing rate load modulating residential oil burner is very desirable. One of the two main requirements of such a burner is the development of a burner nozzle that is able to maintain the particle size distribution of the fuel spray in the desirable (small) size range for efficient and stable combustion. The other being the ability to vary the air flow rate and air distribution around the fuel nozzle in the burner for optimal combustion at the current fuel firing rate. In this paper, which deals with the first requirement, we show that by using pulse width modulation in the bypass channel of a commercial off-the-shelf bypass nozzle, this objective can be met. Here we present results of spray patterns and particle size distribution for a range of fuel firing rates. The results show that a desirable fuel spray pattern can be maintained over a fuel firing rate turndown ratio (Maximum Fuel Flow Rate/Minimum Fuel Flow Rate) of 3.7. Thus here we successfully demonstrate the ability to electronically vary the fuel firing rate by more than a factor of 3 while simultaneously maintaining good atomization.展开更多
基金the financial support of this research under grant No.103-2218-E-234-001
文摘Digital infrared thermography is suitable for monitoring the planar two-dimensional temperature distribution of curved surfaces of objects by sensing their infrared radiation. Cardiac infrared thermography also has a thermal coronary angiography alias. This study proposes a digital image processing methodology for locating blood clot blockage. This methodology contains four consequent processes. The two-dimensional gray scale infrared thermograph pixels are first binarized and classified as background or coronary arteries using multi-thresh adaptive segmentation.The coronary artery contours are extracted from segmented raw pixels using continuous pepper-like pixel removal,erosion,subtraction,recursive neighborhood visiting,contour point-list construction and short edge deletion.In the third process one coronary artery branch is selected by physicians for calculating the longest curved central axis using morphological thinning and neighborhood analysis. In the last process the nearest left and right distances from each pixel along the directional central axis to its corresponding boundary contour are added as the coronary artery variable diameter at the current pixel's position. A variable diameter versus straighten length diagram along this axial curved path is plotted to provide useful physiological information to the physician. An obstruction rate equation is then defined to calculate the possible vascular blockage positions with the local minimal rates. Finally,preoperative cases are tested to prove the predictive positions are correct in comparison to individual patient myocardial perfusion imaging.
文摘Due to the need for energy conservation in buildings and the simultaneous benefit of cost savings, the development of a low firing rate load modulating residential oil burner is very desirable. One of the two main requirements of such a burner is the development of a burner nozzle that is able to maintain the particle size distribution of the fuel spray in the desirable (small) size range for efficient and stable combustion. The other being the ability to vary the air flow rate and air distribution around the fuel nozzle in the burner for optimal combustion at the current fuel firing rate. In this paper, which deals with the first requirement, we show that by using pulse width modulation in the bypass channel of a commercial off-the-shelf bypass nozzle, this objective can be met. Here we present results of spray patterns and particle size distribution for a range of fuel firing rates. The results show that a desirable fuel spray pattern can be maintained over a fuel firing rate turndown ratio (Maximum Fuel Flow Rate/Minimum Fuel Flow Rate) of 3.7. Thus here we successfully demonstrate the ability to electronically vary the fuel firing rate by more than a factor of 3 while simultaneously maintaining good atomization.
