An approach of distane map based imageenhancement (DMIE) is proposed. It is applied toconventional interpolations to get sharp images. Edgedetection is performed after images are interpolatedby linear interpolations. ...An approach of distane map based imageenhancement (DMIE) is proposed. It is applied toconventional interpolations to get sharp images. Edgedetection is performed after images are interpolatedby linear interpolations. To meet the two conditionsset for DMIE, i. e., no abrupt changes and no over-boosting, different boosting rate should be used inadjusting pixel intensities. When the boosting rate isdetermined by using the distance from enhancedpixels to nearest edges, edge-oriented imageenhancement is obtained. By using Erosion technique,the range for pixel intensity adiustment is set.Over-enhancement is avoided by limiting the pixel iutensities in enhancement within the range. A unifled linear-time algoritiml for disance transform is adopted to deal with the calculation of Euelidean distance of the images.Its computation complexity is 0(N).After the preparation,i.e.,distance transforming and erosion,the images get more and more sharpened while no over.boosting.Occurs by repeating the enhancement procedure ,The simplicity of the enhancement operation makes DMIE suitable for enhancement rate adjusting展开更多
A novel approach to realistic collision-free animation of the upper limb was proposed.According to the obstacle-avoidance strategy of human hand,the movement trajectory was computed by manipulability model and minimum...A novel approach to realistic collision-free animation of the upper limb was proposed.According to the obstacle-avoidance strategy of human hand,the movement trajectory was computed by manipulability model and minimum-jerk based interpolation.In each key frame,an improved in～verse kinematics method was adopted to obtain a believable posture of the upper limb.By comparing with the real movement data obtained from the motion capture device,the resultant animation was testified to be natural.This method can be performed in interactive time,and therefore is applicable in animation edit and control of virtual humans.展开更多
This paper provides several linear isomorphism theorems for certain nonsymmetric differential operators of sixth order under proper topologies about some complex parameters. From these results, one can, to a large ext...This paper provides several linear isomorphism theorems for certain nonsymmetric differential operators of sixth order under proper topologies about some complex parameters. From these results, one can, to a large extent, explain and control the stability of some objects in their moving processes.展开更多
This paper considers geometric error control in the parabola-blending linear interpolation method(Zhang,et al.,2011).Classical model of chord error by approximation with contact circle on the parabolas leads to incorr...This paper considers geometric error control in the parabola-blending linear interpolation method(Zhang,et al.,2011).Classical model of chord error by approximation with contact circle on the parabolas leads to incorrect result.By computing the geometric error directly without accumulating the approximation error and chord error,the authors realize correct geometric error control by establishing inequality constraints on the accelerations of the motion.展开更多
Using linear interpolation method, VIRE algorithm simply treats the signal strength value and distance of the reference tag as a linear relationship, leading to the inaccuracy of signal strength value for virtual refe...Using linear interpolation method, VIRE algorithm simply treats the signal strength value and distance of the reference tag as a linear relationship, leading to the inaccuracy of signal strength value for virtual reference tags. The threshold in VIRE algorithm is a fixed value that needs repeatedly adjustment through experiments, which results in the complicated algorithm. To solve these problems, an improved algorithm is proposed in this paper, including nonlinear interpolation algorithm, dynamic threshold setting and tag self-correction of fuzzy map, which builds an indoor positioning system based on reference tags. The experimental results show that the improved algorithm can improve the positioning accuracy and improve the stability of positioning results under bad environmental conditions without increasing the number of reference tags.展开更多
One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promisin...One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method.展开更多
This paper presents simple and fast algorithms for computing very tight upper and lower bounds on the prices of American Asian options in the binomial model.The authors choose two types sets of the actual arithmetic a...This paper presents simple and fast algorithms for computing very tight upper and lower bounds on the prices of American Asian options in the binomial model.The authors choose two types sets of the actual arithmetic average prices,instead of the simulated values in other existing models,as the representative average prices at each node of the binomial tree.This approach simplifies effectively the computation and reduces the error caused by the linear interpolation.Numerical results show that the approach produces accurate upper and lower bounds compared to the other existing methods based on the binomial tree.展开更多
文摘An approach of distane map based imageenhancement (DMIE) is proposed. It is applied toconventional interpolations to get sharp images. Edgedetection is performed after images are interpolatedby linear interpolations. To meet the two conditionsset for DMIE, i. e., no abrupt changes and no over-boosting, different boosting rate should be used inadjusting pixel intensities. When the boosting rate isdetermined by using the distance from enhancedpixels to nearest edges, edge-oriented imageenhancement is obtained. By using Erosion technique,the range for pixel intensity adiustment is set.Over-enhancement is avoided by limiting the pixel iutensities in enhancement within the range. A unifled linear-time algoritiml for disance transform is adopted to deal with the calculation of Euelidean distance of the images.Its computation complexity is 0(N).After the preparation,i.e.,distance transforming and erosion,the images get more and more sharpened while no over.boosting.Occurs by repeating the enhancement procedure ,The simplicity of the enhancement operation makes DMIE suitable for enhancement rate adjusting
基金Supported by Science and Technology Project of Tianjin(No.06YFGZGX06200).
文摘A novel approach to realistic collision-free animation of the upper limb was proposed.According to the obstacle-avoidance strategy of human hand,the movement trajectory was computed by manipulability model and minimum-jerk based interpolation.In each key frame,an improved in～verse kinematics method was adopted to obtain a believable posture of the upper limb.By comparing with the real movement data obtained from the motion capture device,the resultant animation was testified to be natural.This method can be performed in interactive time,and therefore is applicable in animation edit and control of virtual humans.
文摘This paper provides several linear isomorphism theorems for certain nonsymmetric differential operators of sixth order under proper topologies about some complex parameters. From these results, one can, to a large extent, explain and control the stability of some objects in their moving processes.
基金supported partially by the National Natural Science Foundation of China under Grant Nos.10871195 and 60821002/F02National Center for Mathematics and Interdisciplinary Sciences of Chinese Academy of Sciences
文摘This paper considers geometric error control in the parabola-blending linear interpolation method(Zhang,et al.,2011).Classical model of chord error by approximation with contact circle on the parabolas leads to incorrect result.By computing the geometric error directly without accumulating the approximation error and chord error,the authors realize correct geometric error control by establishing inequality constraints on the accelerations of the motion.
文摘Using linear interpolation method, VIRE algorithm simply treats the signal strength value and distance of the reference tag as a linear relationship, leading to the inaccuracy of signal strength value for virtual reference tags. The threshold in VIRE algorithm is a fixed value that needs repeatedly adjustment through experiments, which results in the complicated algorithm. To solve these problems, an improved algorithm is proposed in this paper, including nonlinear interpolation algorithm, dynamic threshold setting and tag self-correction of fuzzy map, which builds an indoor positioning system based on reference tags. The experimental results show that the improved algorithm can improve the positioning accuracy and improve the stability of positioning results under bad environmental conditions without increasing the number of reference tags.
文摘One of the main aspects in computed tomography (CT) development is to make CT rapidly scan a large longitudinal volume with high z-axis resolution. The combination of helical scanning with multi-slice CT is a promising approach. Image reconstruction in multi-slice CT becomes, therefore, the major challenge. Known algorithms need to derive the complementary data or work only for certain range of pitches. A reconstruction algorithm was presented that works with the direct data as well as arbitrary pitches. Filter interpolation based on the proposed method was implemented easy. The results of computer simulations under kinds of conditions for four-slice CT were presented. The proposed method can obtain higher efficiency than the conventional method.
基金partially supported by China Postdoctoral Science Foundation under Grant No.2012M510377National Natural Science Foundation of China under Grant Nos.71373043,71331006,and 71171119+2 种基金the National Social Science Foundation of China under Grant No.11AZD010Program for New Century Excellent Talents in University under Grant No.NCET-10-0337Program for Excellent Talents,UIBE
文摘This paper presents simple and fast algorithms for computing very tight upper and lower bounds on the prices of American Asian options in the binomial model.The authors choose two types sets of the actual arithmetic average prices,instead of the simulated values in other existing models,as the representative average prices at each node of the binomial tree.This approach simplifies effectively the computation and reduces the error caused by the linear interpolation.Numerical results show that the approach produces accurate upper and lower bounds compared to the other existing methods based on the binomial tree.
