Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.Howev...Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.However,the increasing demand for higher resolution and real-time imaging results in significant data volume,limiting data storage,transmission and processing efficiency of system.Therefore,there is an urgent need for an effective method to compress the raw data without compromising image quality.This paper presents a photoacoustic-computed tomography 3D data compression method and system based on Wavelet-Transformer.This method is based on the cooperative compression framework that integrates wavelet hard coding with deep learning-based soft decoding.It combines the multiscale analysis capability of wavelet transforms with the global feature modeling advantage of Transformers,achieving high-quality data compression and reconstruction.Experimental results using k-wave simulation suggest that the proposed compression system has advantages under extreme compression conditions,achieving a raw data compression ratio of up to 1:40.Furthermore,three-dimensional data compression experiment using in vivo mouse demonstrated that the maximum peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)values of reconstructed images reached 38.60 and 0.9583,effectively overcoming detail loss and artifacts introduced by raw data compression.All the results suggest that the proposed system can significantly reduce storage requirements and hardware cost,enhancing computational efficiency and image quality.These advantages support the development of photoacoustic-computed tomography toward higher efficiency,real-time performance and intelligent functionality.展开更多
The photoacoustic imaging of lipid is intrinsically constrained by the feeble nature of endogenous lipid signals,posing a persistent sensitivity challenge that demands innovative solutions.Although adopting high-effic...The photoacoustic imaging of lipid is intrinsically constrained by the feeble nature of endogenous lipid signals,posing a persistent sensitivity challenge that demands innovative solutions.Although adopting high-efficiency excitation and detection elements may improve the imaging sensitivity to a certain extent,the application of the elements is inevitably subject to various limitations in practical applications,particularly during in vivo imaging and endoscopic imaging.In this study,we propose a multi-combinatorial approach to enhance the sensitivity of lipid photoacoustic imaging.The approach involves wavelet transform processing of one-dimensional A-line signals,gradient-based denoising of two-dimensional B-scan images,and finally,threedimensional spatial weighted averaging of the data processed by the previous two steps.This method not only significantly improves the signal-to-noise ratio(SNR)in distinguished feature regions of the image by around 10 dB,but also efficiently extracts weak signals with no distinct features in the original image.After processing with this method,the images acquired under single scanning were compared with those obtained under multiple scanning.The results showed highly consistent image features,with the structural similarity index increasing from 0.2 to 0.8,confirming the accuracy and reliability of the multi-combinatorial approach.展开更多
Abstract： In order to improve the accuracy of vertical handoff decision for radio heterogeneous network, this paper proposes an intelligent adaptive multi-criteria vertical handoff （AMVHO） decision algorithm. This ...Abstract： In order to improve the accuracy of vertical handoff decision for radio heterogeneous network, this paper proposes an intelligent adaptive multi-criteria vertical handoff （AMVHO） decision algorithm. This algo- rithm uses a fuzzy inference system （FIS） and a modified Elman neural network （MENN）. The FIS adopts the crucial criteria of vertical handoff as input variables and makes handoff decision based on the defined rule base. The MENN helps to predict the number of users of the after-handoff network, which is a pivotal variable of the FIS. Simulation results show that, compared with the conventional method, the AMVHO decision algorithm a- chieves better performance in guaranteeing the quality of service （QoS） of the after-handoff communication.展开更多
Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in wh...Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in which nodes represent various tasks and edges denote the resources exchanged among tasks. Using the properties of node degree distribution, strength distribution and other weighted quantities, we demonstrate the heterogeneity of the network and point out the relation between structural characters of vertices and the functionality of correspond- ing tasks. The above phenomena indicate that the design requirements and principles of production process contrib- ute to the heterogeneous features of the network. Besides, betweenness centrality of nodes can be used as an impor- tance indicator to provide additional information for decision making. The correlations between structure and weighted properties are investigated to further address the influence brought by production schemes in system con- nectivity patterns. Cascading failures model is employed to analyze the robustness of the network when targeted at- tack happens. Two capacity assignment strategies are compared in order to improve the robustness of the network at certain cost. The refinery system displays more reliable behavior when the protecting strategy considers heteroge- neous properties. This phenomenon further implies the structure-activity relationship of the refinery system and provides insightful suggestions for process system design. The results also indicate that robustness analysis is a _promising applicat!on of methodologies from complex networks to process system engineering..展开更多
The synthetic apert ure based linear array photoacoustic tomography(PAT)was proposed to address the limited-view shortcomings of the single aperture,but the detection field of view(FOV)determined by the apert ure orie...The synthetic apert ure based linear array photoacoustic tomography(PAT)was proposed to address the limited-view shortcomings of the single aperture,but the detection field of view(FOV)determined by the apert ure orientation efect was not fully considered yet,leading to the limited-view observation and image resolution degradation.Herein,the aperture orientation effect was proposed from the theoretical model and then it was verified via both the numerical simulation and phantom experiment.Different orientations were enumerated sequentially in the simulation to approximate the ideal fullview case for the optimal detection FOV,considering the detect.ion pattern of the linear array transducer.As a result,the corresponding optimal aperture orientation was 60°if the synthetic aperture was seamlessly established by three single linear arrays,where the overlapped detection pattern was optimized from the individual linear-array transducer at the adjacent positions.Therefore,the limited view artifacts were minimized and the image resolution was enhanced in this aperture orientation.This study showed that the aperture orientation had great influence on the optimal detection FOV in the synthetic aperture configuration,where the full-view imaging quality and enhanced image resolution could be achieved.展开更多
A new approach to the simultaneous registration of multiple medical images is proposed using shared chain mutual information （SCMI） as the matching measure. The presented method applies SCMI to measure the shared in...A new approach to the simultaneous registration of multiple medical images is proposed using shared chain mutual information （SCMI） as the matching measure. The presented method applies SCMI to measure the shared information between the multiple images. Registration is achieved by adjusting the relative position of the floating image until the SCMI between all the images is maximized. Using this measure, we registered three and four simulated magnetic resonance imaging （MRI） images using downhill simplex optimization to search for the optimal transformation parameters. Accuracy and validity of the proposed method for multiple-image registration are testified by comparing the results with that of twoimage registration. Furthermore, the performance of the proposed method is validated by registering the real ultrasonic image sequence.展开更多
This paper considers the scenario where multiple robots collaboratively cover a region in which the exact distribution of workload is unknown prior to the operation.The workload distribution is not uniform in the regi...This paper considers the scenario where multiple robots collaboratively cover a region in which the exact distribution of workload is unknown prior to the operation.The workload distribution is not uniform in the region,meaning that the time required to cover a unit area varies at different locations of the region.In our approach,we divide the target region into multiple horizontal stripes,and the robots sweep the current stripe while partitioning the next stripe concurrently.We propose a distributed workload partition algorithm and prove that the operation time on each stripe converges to the minimum under the discrete-time update law.We conduct comprehensive simulation studies and compare our method with the existing methods to verify the theoretical results and the advantage of the proposed method.Flight experiments on mini drones are also conducted to demonstrate the practicality of the proposed algorithm.展开更多
In this paper,we consider a cone problem of matrix optimization induced by spectral norm(MOSN).By Schur complement,MOSN can be reformulated as a nonlinear semidefinite programming(NLSDP)problem.Then we discuss the con...In this paper,we consider a cone problem of matrix optimization induced by spectral norm(MOSN).By Schur complement,MOSN can be reformulated as a nonlinear semidefinite programming(NLSDP)problem.Then we discuss the constraint nondegeneracy conditions and strong second-order sufficient conditions of MOSN and its SDP reformulation,and obtain that the constraint nondegeneracy condition of MOSN is not always equivalent to that of NLSDP.However,the strong second-order sufficient conditions of these two problems are equivalent without any assumption.Finally,a sufficient condition is given to ensure the nonsingularity of the Clarke’s generalized Jacobian of the KKT system for MOSN.展开更多
基金supported by the National Key R&D Program of China[Grant No.2023YFF0713600]the National Natural Science Foundation of China[Grant No.62275062]+3 种基金Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments[Grant No.2023-SGTTXM-002 and 2024-SGTTXM-005]the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)[Grant No.YDZX2023115]the Taishan Scholar Special Funding Project of Shandong Provincethe Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai[Grant No.ZL202402].
文摘Photoacoustic-computed tomography is a novel imaging technique that combines high absorption contrast and deep tissue penetration capability,enabling comprehensive three-dimensional imaging of biological targets.However,the increasing demand for higher resolution and real-time imaging results in significant data volume,limiting data storage,transmission and processing efficiency of system.Therefore,there is an urgent need for an effective method to compress the raw data without compromising image quality.This paper presents a photoacoustic-computed tomography 3D data compression method and system based on Wavelet-Transformer.This method is based on the cooperative compression framework that integrates wavelet hard coding with deep learning-based soft decoding.It combines the multiscale analysis capability of wavelet transforms with the global feature modeling advantage of Transformers,achieving high-quality data compression and reconstruction.Experimental results using k-wave simulation suggest that the proposed compression system has advantages under extreme compression conditions,achieving a raw data compression ratio of up to 1:40.Furthermore,three-dimensional data compression experiment using in vivo mouse demonstrated that the maximum peak signal-to-noise ratio(PSNR)and structural similarity index(SSIM)values of reconstructed images reached 38.60 and 0.9583,effectively overcoming detail loss and artifacts introduced by raw data compression.All the results suggest that the proposed system can significantly reduce storage requirements and hardware cost,enhancing computational efficiency and image quality.These advantages support the development of photoacoustic-computed tomography toward higher efficiency,real-time performance and intelligent functionality.
基金supported by the National Key Research and Development Program of China(2022YFC2402400)the National Natural Science Foundation of China(82027803,62275062)+7 种基金the Guangdong Provincial Key Laboratory of Biomedical Optical Imaging Technology(2020B121201010)the Shenzhen Science and Technology Innovation Committee under Grant(JCYJ20220818101417039)the Shenzhen Key Laboratory for Molecular lmaging(ZDSY20130401165820357)the Shenzhen Medical Research Fund(D2404002)the Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments(2023-SGTTXM-002 and 2024-SGTTXM-005)the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)(YDZX2023115)the Taishan Scholar Special Funding Project of Shandong Provinceand the Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai(ZL202402).
文摘The photoacoustic imaging of lipid is intrinsically constrained by the feeble nature of endogenous lipid signals,posing a persistent sensitivity challenge that demands innovative solutions.Although adopting high-efficiency excitation and detection elements may improve the imaging sensitivity to a certain extent,the application of the elements is inevitably subject to various limitations in practical applications,particularly during in vivo imaging and endoscopic imaging.In this study,we propose a multi-combinatorial approach to enhance the sensitivity of lipid photoacoustic imaging.The approach involves wavelet transform processing of one-dimensional A-line signals,gradient-based denoising of two-dimensional B-scan images,and finally,threedimensional spatial weighted averaging of the data processed by the previous two steps.This method not only significantly improves the signal-to-noise ratio(SNR)in distinguished feature regions of the image by around 10 dB,but also efficiently extracts weak signals with no distinct features in the original image.After processing with this method,the images acquired under single scanning were compared with those obtained under multiple scanning.The results showed highly consistent image features,with the structural similarity index increasing from 0.2 to 0.8,confirming the accuracy and reliability of the multi-combinatorial approach.
基金Sponsored by the National Natural Science Foundation of China(Grant No.60802030)the Foundation for Outstanding Young Scientist in Shandong Province(2007BSC01002)the Foundation of Key Program of Science and Technology in Shandong Province(2007GG2QT01007)
文摘Abstract： In order to improve the accuracy of vertical handoff decision for radio heterogeneous network, this paper proposes an intelligent adaptive multi-criteria vertical handoff （AMVHO） decision algorithm. This algo- rithm uses a fuzzy inference system （FIS） and a modified Elman neural network （MENN）. The FIS adopts the crucial criteria of vertical handoff as input variables and makes handoff decision based on the defined rule base. The MENN helps to predict the number of users of the after-handoff network, which is a pivotal variable of the FIS. Simulation results show that, compared with the conventional method, the AMVHO decision algorithm a- chieves better performance in guaranteeing the quality of service （QoS） of the after-handoff communication.
基金Supported by the National High Technology Research and Development Program of China (2012AA041102)the State Key Development Program for Basic Research of China (2012CB720500)
文摘Refinery system, a typical example of process systems, is presented as complex network in this paper. The topology of this system is described by task-resource network and modeled as directed and weighted graph, in which nodes represent various tasks and edges denote the resources exchanged among tasks. Using the properties of node degree distribution, strength distribution and other weighted quantities, we demonstrate the heterogeneity of the network and point out the relation between structural characters of vertices and the functionality of correspond- ing tasks. The above phenomena indicate that the design requirements and principles of production process contrib- ute to the heterogeneous features of the network. Besides, betweenness centrality of nodes can be used as an impor- tance indicator to provide additional information for decision making. The correlations between structure and weighted properties are investigated to further address the influence brought by production schemes in system con- nectivity patterns. Cascading failures model is employed to analyze the robustness of the network when targeted at- tack happens. Two capacity assignment strategies are compared in order to improve the robustness of the network at certain cost. The refinery system displays more reliable behavior when the protecting strategy considers heteroge- neous properties. This phenomenon further implies the structure-activity relationship of the refinery system and provides insightful suggestions for process system design. The results also indicate that robustness analysis is a _promising applicat!on of methodologies from complex networks to process system engineering..
基金the National Natural Science Foundation of China(Grant No.61371045)Science and Technology Development Plan Project of Shandong Province,China(Grant No.2016GGX103032)+1 种基金China Postdoctoral Science Foundation(Grant No.2015M571413)Shenzhen Science&Technology Program(No.JCYJ20160429115309834).
文摘The synthetic apert ure based linear array photoacoustic tomography(PAT)was proposed to address the limited-view shortcomings of the single aperture,but the detection field of view(FOV)determined by the apert ure orientation efect was not fully considered yet,leading to the limited-view observation and image resolution degradation.Herein,the aperture orientation effect was proposed from the theoretical model and then it was verified via both the numerical simulation and phantom experiment.Different orientations were enumerated sequentially in the simulation to approximate the ideal fullview case for the optimal detection FOV,considering the detect.ion pattern of the linear array transducer.As a result,the corresponding optimal aperture orientation was 60°if the synthetic aperture was seamlessly established by three single linear arrays,where the overlapped detection pattern was optimized from the individual linear-array transducer at the adjacent positions.Therefore,the limited view artifacts were minimized and the image resolution was enhanced in this aperture orientation.This study showed that the aperture orientation had great influence on the optimal detection FOV in the synthetic aperture configuration,where the full-view imaging quality and enhanced image resolution could be achieved.
基金This work was supported by the National Natural Science Foundation of China under Grant No.60604021.
文摘A new approach to the simultaneous registration of multiple medical images is proposed using shared chain mutual information （SCMI） as the matching measure. The presented method applies SCMI to measure the shared information between the multiple images. Registration is achieved by adjusting the relative position of the floating image until the SCMI between all the images is maximized. Using this measure, we registered three and four simulated magnetic resonance imaging （MRI） images using downhill simplex optimization to search for the optimal transformation parameters. Accuracy and validity of the proposed method for multiple-image registration are testified by comparing the results with that of twoimage registration. Furthermore, the performance of the proposed method is validated by registering the real ultrasonic image sequence.
文摘This paper considers the scenario where multiple robots collaboratively cover a region in which the exact distribution of workload is unknown prior to the operation.The workload distribution is not uniform in the region,meaning that the time required to cover a unit area varies at different locations of the region.In our approach,we divide the target region into multiple horizontal stripes,and the robots sweep the current stripe while partitioning the next stripe concurrently.We propose a distributed workload partition algorithm and prove that the operation time on each stripe converges to the minimum under the discrete-time update law.We conduct comprehensive simulation studies and compare our method with the existing methods to verify the theoretical results and the advantage of the proposed method.Flight experiments on mini drones are also conducted to demonstrate the practicality of the proposed algorithm.
基金This research is mainly supported by the National Natural Science Foundation of China(Nos.91130007 and 91330206).
文摘In this paper,we consider a cone problem of matrix optimization induced by spectral norm(MOSN).By Schur complement,MOSN can be reformulated as a nonlinear semidefinite programming(NLSDP)problem.Then we discuss the constraint nondegeneracy conditions and strong second-order sufficient conditions of MOSN and its SDP reformulation,and obtain that the constraint nondegeneracy condition of MOSN is not always equivalent to that of NLSDP.However,the strong second-order sufficient conditions of these two problems are equivalent without any assumption.Finally,a sufficient condition is given to ensure the nonsingularity of the Clarke’s generalized Jacobian of the KKT system for MOSN.
