A new multi-phase active contour model is proposed for the image segmentation. It is a generalization of the C-V model with the following characteristics： （1） A key technique, called the technique of painting backg...A new multi-phase active contour model is proposed for the image segmentation. It is a generalization of the C-V model with the following characteristics： （1） A key technique, called the technique of painting background （TPBG）, is developed to remove the information of the background, which blocks the detection of weak boundaries in the object; （2） The two-phase level set is applied multiple times for getting the multi-phase segmentation model （n-1 times for the n-phase model, n〉1）; （3） A scaling-based method is introduced to improve the basic model. Experimental results show that the proposed model is effective for detecting weak boundaries.展开更多
The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-ob...The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-object obtained by PMLSF-TPBG are not variable since a specialcolor parameter is used in TPBG. To solve the problem, a new technique utilizing a varying parameter is proposed to ensure that PMLSF is effective for the detection of the desired boundaries of the sub-object. The interval of the variable color parameter is proved and the effects of the parameter are also discussed. Experimental results for the brain tumor detection show that different boundaries of the brain tumors can be detected with different color parameters. It is especially useful for clinical diagnoses.展开更多
In this letter,a multiphase level set approach unifying region and boundary-based infor-mation for multi-region segmentation of Synthetic Aperture Radar(SAR)image is presented.Anenergy functional that is applicable fo...In this letter,a multiphase level set approach unifying region and boundary-based infor-mation for multi-region segmentation of Synthetic Aperture Radar(SAR)image is presented.Anenergy functional that is applicable for SAR image segmentation is defined.It consists of two termsdescribing the local statistic characteristics and the gradient characteristics of SAR image respectively.A multiphase level set model that explicitly describes the different regions in one image is proposed.The purpose of such a multiphase model is not only to simplify the way of denoting multi-region by levelset but also to guarantee the accuracy of segmentation.According to the presented multiphase model,the curve evolution equations with respect to edge curves are deduced.The multi-region segmentationis implemented by the numeric solution of the partial differential equations.The performance of theapproach is verified by both simulation and real SAR images.The experiments show that the proposedalgorithm reduces the speckle effect on segmentation and increases the boundary alignment accuracy,thus correctly divides the multi-region SAR image into different homogenous regions.展开更多
Since the 1970s, according to the international pension system reform trend for old-age social security system, no single institutional arrangement can ensure the functions of endowment security system to achieve the ...Since the 1970s, according to the international pension system reform trend for old-age social security system, no single institutional arrangement can ensure the functions of endowment security system to achieve the optimal.Therefore,how to based on the present situation of development, and to accurately, thus promote the resources integration, comprehensive build multi-level old-age security system, has important policy and practice significance.展开更多
The waiting spectra of the sets consisting of pairs of sequences with prescribed quantitative waiting time indicators are determined. More precisely,let R(x,y) and R(x,y) be the lower and upper quantitative waiting ti...The waiting spectra of the sets consisting of pairs of sequences with prescribed quantitative waiting time indicators are determined. More precisely,let R(x,y) and R(x,y) be the lower and upper quantitative waiting time indicators of y by x respectively in the symbolic space Σm(integer m 2) and define the level sets Sα,β={(x,y)∈Σ2m:R(x,y)=α,R(x,y)=β},where 0αβ∞,it is shown that the sets Sα,βare all of Hausdorff dimension 2.Besides,some further extensions of this result are also made.展开更多
An assembly-to-order system, which at the end the buffer distinguishes its assembly stages of the system from the downstream systems, is considered in this paper. The system produces semi-finished products for the dow...An assembly-to-order system, which at the end the buffer distinguishes its assembly stages of the system from the downstream systems, is considered in this paper. The system produces semi-finished products for the downstream system and starts from a basic subassembly, and at each stage a component is assembled into the corresponding subassembly. The basic subassembly, components and buffer all follow a periodic-review, order up-to-level inventory policy. The buffer holds the semi-finished products to serve the specific demand from the downstream system. The service level of the system is determined by aggregate effects of the components held at stockpiles before the buffer and the basic subassembly. In order to measure the service level of the system, some notations and assumptions are made, on which the closed form expression of the service level of the system is achieved.展开更多
文摘A new multi-phase active contour model is proposed for the image segmentation. It is a generalization of the C-V model with the following characteristics： （1） A key technique, called the technique of painting background （TPBG）, is developed to remove the information of the background, which blocks the detection of weak boundaries in the object; （2） The two-phase level set is applied multiple times for getting the multi-phase segmentation model （n-1 times for the n-phase model, n〉1）; （3） A scaling-based method is introduced to improve the basic model. Experimental results show that the proposed model is effective for detecting weak boundaries.
文摘The pyramidal multiphase level set framework （PMLSF） based on the technique of painting background （TPBG） and the Chan-Vese model can detect multiple objects on a given image. However, the boundaries of the sub-object obtained by PMLSF-TPBG are not variable since a specialcolor parameter is used in TPBG. To solve the problem, a new technique utilizing a varying parameter is proposed to ensure that PMLSF is effective for the detection of the desired boundaries of the sub-object. The interval of the variable color parameter is proved and the effects of the parameter are also discussed. Experimental results for the brain tumor detection show that different boundaries of the brain tumors can be detected with different color parameters. It is especially useful for clinical diagnoses.
文摘In this letter,a multiphase level set approach unifying region and boundary-based infor-mation for multi-region segmentation of Synthetic Aperture Radar(SAR)image is presented.Anenergy functional that is applicable for SAR image segmentation is defined.It consists of two termsdescribing the local statistic characteristics and the gradient characteristics of SAR image respectively.A multiphase level set model that explicitly describes the different regions in one image is proposed.The purpose of such a multiphase model is not only to simplify the way of denoting multi-region by levelset but also to guarantee the accuracy of segmentation.According to the presented multiphase model,the curve evolution equations with respect to edge curves are deduced.The multi-region segmentationis implemented by the numeric solution of the partial differential equations.The performance of theapproach is verified by both simulation and real SAR images.The experiments show that the proposedalgorithm reduces the speckle effect on segmentation and increases the boundary alignment accuracy,thus correctly divides the multi-region SAR image into different homogenous regions.
文摘Since the 1970s, according to the international pension system reform trend for old-age social security system, no single institutional arrangement can ensure the functions of endowment security system to achieve the optimal.Therefore,how to based on the present situation of development, and to accurately, thus promote the resources integration, comprehensive build multi-level old-age security system, has important policy and practice significance.
文摘The waiting spectra of the sets consisting of pairs of sequences with prescribed quantitative waiting time indicators are determined. More precisely,let R(x,y) and R(x,y) be the lower and upper quantitative waiting time indicators of y by x respectively in the symbolic space Σm(integer m 2) and define the level sets Sα,β={(x,y)∈Σ2m:R(x,y)=α,R(x,y)=β},where 0αβ∞,it is shown that the sets Sα,βare all of Hausdorff dimension 2.Besides,some further extensions of this result are also made.
基金This research is supported by the National Natural Science Foundation of China(No. 70332001).
文摘An assembly-to-order system, which at the end the buffer distinguishes its assembly stages of the system from the downstream systems, is considered in this paper. The system produces semi-finished products for the downstream system and starts from a basic subassembly, and at each stage a component is assembled into the corresponding subassembly. The basic subassembly, components and buffer all follow a periodic-review, order up-to-level inventory policy. The buffer holds the semi-finished products to serve the specific demand from the downstream system. The service level of the system is determined by aggregate effects of the components held at stockpiles before the buffer and the basic subassembly. In order to measure the service level of the system, some notations and assumptions are made, on which the closed form expression of the service level of the system is achieved.
