For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory n...For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory networks(GRNs)that achieve superior performance in forming trapping pattern towards targets require accurate global positional information to guide swarm robots.This article presents a gene regulatory network with Self-organized grouping and entrapping method for swarms(SUNDER-GRN)to achieve adequate trapping performance with a large-scale swarm in a confined multitarget environment with access to only local information.A hierarchical self-organized grouping method(HSG)is proposed to structure subswarms in a distributed way.In addition,a modified distributed controller,with a relative coordinate system that is established to relieve the need for global information,is leveraged to facilitate subswarms entrapment toward different targets,thus improving the global multi-target entrapping performance.The results demonstrate the superiority of SUNDERGRN in the performance of structuring subswarms and entrapping 10 targets with 200 robots in an environment confined by obstacles and with only local information accessible.展开更多
Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neur...Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neurodegenerative diseases has developed a pressing need to design multitarget-directed ligands to address the complementary pathways involved in these diseases. The major enzyme targets for development of therapeutics for Alzheimer's disease are cholinesterase and β-secretase enzymes. In this review, we discuss recent advances in profiling single target inhibitors based on these enzymes to multitarget-directed ligands as potential therapeutics for this devastating disease. In addition, therapeutics based on iron chelation strategy are discussed as well.展开更多
Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).T...Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).The United States Preventive Services Task Force(USPSTF) October 2015 draft recommendation for CRC screening included mt-s DNA as an "alternative" screening test that "may be useful in select clinical circumstances",despite its very high sensitivity for early stage CRC.The evidence supporting mt-s DNA for routine screening use is robust.The clinical efficacy of mt-s DNA as measured by sensitivity,specificity,life-years gained(LYG),and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document,especially those requiring annual testing adherence.In a population with primarily irregular screening participation,tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence.This paper reviews the evidence supporting mt-s DNA for routine screening and demonstrates,using USPSTF's modeling data,that mt-s DNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing,high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening.展开更多
AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office...AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office-based study examined mt-s DNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-s DNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-s DNA compliance and diagnostic colonoscopy compliance on positive cases.RESULTS Over 12 mo, 77 providers ordered 393 mt-sD NA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sD NA was negative in 85.3%(296/347) and positive in 14.7%(51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer(4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas(15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage Ⅰ(2) and Stage Ⅱ (2), three were located in the proximal colon and one was located in the distal colon.CONCLUSION Mt-s DNA provided medical benefit to screening noncompliant Medicare population. High compliance with mt-s DNA and subsequent follow-up diagnostic colonoscopy identified patients with clinically critical advanced colorectal neoplasia.展开更多
A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation ...A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation functions. According to values of βi^t(K), N events with larger joint probabilities can be searched out as the events with guiding joint probabilities, tiros, the number of searching nodes will be greatly reduced. As a result, this method effectively reduces the calculation load and nnkes it possible to be realized on real-thne, Theoretical ,analysis and Monte Carlo simulation results show that this method is efficient.展开更多
For data association in multisensor and multitarget tracking, a novel parallel algorithm is developed to improve the efficiency and real-time performance of FGAs-based algorithm. One Cluster of Workstation (COW) wit...For data association in multisensor and multitarget tracking, a novel parallel algorithm is developed to improve the efficiency and real-time performance of FGAs-based algorithm. One Cluster of Workstation (COW) with Message Passing Interface (MPI) is built. The proposed Multi-Deme Parallel FGA (MDPFGA) is run on the platform. A serial of special MDPFGAs are used to determine the static and the dynamic solutions of generalized m-best S-D assignment problem respectively, as well as target states estimation in track management. Such an assignment-based parallel algorithm is demonstrated on simulated passive sensor track formation and maintenance problem. While illustrating the feasibility of the proposed algorithm in multisensor multitarget tracking, simulation results indicate that the MDPFGAs-based algorithm has greater efficiency and speed than the FGAs-based algorithm.展开更多
In this paper, an adaptive digital filter algorithm is presented to optimize the signal-to-noise ratio of an antenna array with multiuser signal inputs. These synchronous communication signals have constant envelope p...In this paper, an adaptive digital filter algorithm is presented to optimize the signal-to-noise ratio of an antenna array with multiuser signal inputs. These synchronous communication signals have constant envelope property and are transmitted through a Multiple-Input/Multiple-Output (MIMO) linear channel. This Multiuser Constant Modulus Algorithm (MU-CMA) using an antenna array can compensate for both Interuser Interference (IUI) and Intersymbol Interference (ISI). The method is derived by minimizing the cost function of the constant modulus signals as well as cross-correlations between them. The simulation result in this paper shows the performance of this algorithm.展开更多
An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as dron...An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.展开更多
BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study repo...BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.展开更多
This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiven...This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiveness of the probability hypothesis density (PHD) filter. Firstly, a measurement-driven mechanism based on this gating technique is designed to classify the measure- ments. In this mechanism, only the measurements for the existing targets are considered in the update step of the existing targets while the measurements of newborn targets are used for exploring newborn targets. Secondly, the gating strategy enables the development of a heuristic state estima- tion algorithm when sequential Monte Carlo (SMC) implementation of the PHD filter is investi- gated, where the measurements are used to drive the particle clustering within the space gate. The resulting PHD filter can achieve a more robust and accurate estimation of the existing targets by reducing the interference from clutter. Moreover, the target birth intensity can be adaptive to detect newborn targets, which is in accordance with the birth measurements. Simulation results demonstrate the computational efficiency and tracking performance of the proposed algorithm.展开更多
Multiple sources localization is an important technique applied in many areasl such as sonar, radar, biomedical, and geology exploration. High resolution localization needs to employ jointly two sorts of high resoluti...Multiple sources localization is an important technique applied in many areasl such as sonar, radar, biomedical, and geology exploration. High resolution localization needs to employ jointly two sorts of high resolution estimators, time-delay estimator and Direction Of Arrival (DOA) estimator, both of which are tough problems attracting many signal processing researchers. There is also another difficulty that is to pair two groups of parameters in timedelay and DOA domains. In underwater environment, multiple sources localization research faces more difficulties because of the long duration emitted wave, limit aperture of array, and short data record of echoes. In this paper, an new extended ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique) method is presented. With a single echo wave, both time-delay and DOA parameters of multiple sources are estimated simultaneously.No additional pairing algorithm is needed to obtain the source locations. The performance of the new estimators and the probability of correct pairing is given by computer simulations, andthe results shows that good estimation can be obtained in low SNR (Signal to Noise Ratio) for multiple sources localization.展开更多
In this paper, the sharp threshold properties of a (2n + 1)-dimensional delayed viral infection model are investigated. This model combines with n classes of uninfected tar- get cells, n classes of infected cells a...In this paper, the sharp threshold properties of a (2n + 1)-dimensional delayed viral infection model are investigated. This model combines with n classes of uninfected tar- get cells, n classes of infected cells and nonlinear incidence rate h(x,v). Two kinds of distributed time delays are incorporated into the model to describe the time needed for infection of uninfected target cells and virus replication. Under certain conditions, it is shown that the basic reproduction number is a threshold parameter for the existence of the equilibria, uniform persistence, as well as for global stability of the equilibria of the model.展开更多
基金supported in part by National Key R&D Program of China(Grant Nos.2021ZD0111501,2021ZD0111502)the Key Laboratory of Digital Signal and Image Processing of Guangdong Province+8 种基金the Key Laboratory of Intelligent Manufacturing Technology(Shantou University)Ministry of Education,the Science and Technology Planning Project of Guangdong Province of China(Grant No.180917144960530)the Project of Educational Commission of Guangdong Province of China(Grant No.2017KZDXM032)the State Key Lab of Digital Manufacturing Equipment&Technology(grant number DMETKF2019020)National Natural Science Foundation of China(Grant Nos.62176147,62002369)STU Scientific Research Foundation for Talents(Grant No.NTF21001)Science and Technology Planning Project of Guangdong Province of China(Grant Nos.2019A050520001,2021A0505030072,2022A1515110660)Science and Technology Special Funds Project of Guangdong Province of China(Grant Nos.STKJ2021176,STKJ2021019)Guangdong Special Support Program for Outstanding Talents(Grant No.2021JC06X549)。
文摘For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory networks(GRNs)that achieve superior performance in forming trapping pattern towards targets require accurate global positional information to guide swarm robots.This article presents a gene regulatory network with Self-organized grouping and entrapping method for swarms(SUNDER-GRN)to achieve adequate trapping performance with a large-scale swarm in a confined multitarget environment with access to only local information.A hierarchical self-organized grouping method(HSG)is proposed to structure subswarms in a distributed way.In addition,a modified distributed controller,with a relative coordinate system that is established to relieve the need for global information,is leveraged to facilitate subswarms entrapment toward different targets,thus improving the global multi-target entrapping performance.The results demonstrate the superiority of SUNDERGRN in the performance of structuring subswarms and entrapping 10 targets with 200 robots in an environment confined by obstacles and with only local information accessible.
文摘Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neurodegenerative diseases has developed a pressing need to design multitarget-directed ligands to address the complementary pathways involved in these diseases. The major enzyme targets for development of therapeutics for Alzheimer's disease are cholinesterase and β-secretase enzymes. In this review, we discuss recent advances in profiling single target inhibitors based on these enzymes to multitarget-directed ligands as potential therapeutics for this devastating disease. In addition, therapeutics based on iron chelation strategy are discussed as well.
文摘Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).The United States Preventive Services Task Force(USPSTF) October 2015 draft recommendation for CRC screening included mt-s DNA as an "alternative" screening test that "may be useful in select clinical circumstances",despite its very high sensitivity for early stage CRC.The evidence supporting mt-s DNA for routine screening use is robust.The clinical efficacy of mt-s DNA as measured by sensitivity,specificity,life-years gained(LYG),and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document,especially those requiring annual testing adherence.In a population with primarily irregular screening participation,tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence.This paper reviews the evidence supporting mt-s DNA for routine screening and demonstrates,using USPSTF's modeling data,that mt-s DNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing,high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening.
文摘AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office-based study examined mt-s DNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-s DNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-s DNA compliance and diagnostic colonoscopy compliance on positive cases.RESULTS Over 12 mo, 77 providers ordered 393 mt-sD NA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sD NA was negative in 85.3%(296/347) and positive in 14.7%(51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer(4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas(15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage Ⅰ(2) and Stage Ⅱ (2), three were located in the proximal colon and one was located in the distal colon.CONCLUSION Mt-s DNA provided medical benefit to screening noncompliant Medicare population. High compliance with mt-s DNA and subsequent follow-up diagnostic colonoscopy identified patients with clinically critical advanced colorectal neoplasia.
文摘A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation functions. According to values of βi^t(K), N events with larger joint probabilities can be searched out as the events with guiding joint probabilities, tiros, the number of searching nodes will be greatly reduced. As a result, this method effectively reduces the calculation load and nnkes it possible to be realized on real-thne, Theoretical ,analysis and Monte Carlo simulation results show that this method is efficient.
基金Supported by National Defence Scientific Research Foundation
文摘For data association in multisensor and multitarget tracking, a novel parallel algorithm is developed to improve the efficiency and real-time performance of FGAs-based algorithm. One Cluster of Workstation (COW) with Message Passing Interface (MPI) is built. The proposed Multi-Deme Parallel FGA (MDPFGA) is run on the platform. A serial of special MDPFGAs are used to determine the static and the dynamic solutions of generalized m-best S-D assignment problem respectively, as well as target states estimation in track management. Such an assignment-based parallel algorithm is demonstrated on simulated passive sensor track formation and maintenance problem. While illustrating the feasibility of the proposed algorithm in multisensor multitarget tracking, simulation results indicate that the MDPFGAs-based algorithm has greater efficiency and speed than the FGAs-based algorithm.
基金Supported by the National Natural Science Foundation ofChina (60671040)
文摘In this paper, an adaptive digital filter algorithm is presented to optimize the signal-to-noise ratio of an antenna array with multiuser signal inputs. These synchronous communication signals have constant envelope property and are transmitted through a Multiple-Input/Multiple-Output (MIMO) linear channel. This Multiuser Constant Modulus Algorithm (MU-CMA) using an antenna array can compensate for both Interuser Interference (IUI) and Intersymbol Interference (ISI). The method is derived by minimizing the cost function of the constant modulus signals as well as cross-correlations between them. The simulation result in this paper shows the performance of this algorithm.
基金supported by the National Natural Science Foundation of China (61773142)。
文摘An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.
基金Supported by Guangxi Guilin Science and Technology Fund,No.20190218-7-6.
文摘BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.
基金supported by the Aeronautical Science Foundation of China(No.201401P6001)
文摘This paper studies the dynamic estimation problem for multitarget tracking. A novel gat- ing strategy that is based on the measurement likelihood of the target state space is proposed to improve the overall effectiveness of the probability hypothesis density (PHD) filter. Firstly, a measurement-driven mechanism based on this gating technique is designed to classify the measure- ments. In this mechanism, only the measurements for the existing targets are considered in the update step of the existing targets while the measurements of newborn targets are used for exploring newborn targets. Secondly, the gating strategy enables the development of a heuristic state estima- tion algorithm when sequential Monte Carlo (SMC) implementation of the PHD filter is investi- gated, where the measurements are used to drive the particle clustering within the space gate. The resulting PHD filter can achieve a more robust and accurate estimation of the existing targets by reducing the interference from clutter. Moreover, the target birth intensity can be adaptive to detect newborn targets, which is in accordance with the birth measurements. Simulation results demonstrate the computational efficiency and tracking performance of the proposed algorithm.
文摘Multiple sources localization is an important technique applied in many areasl such as sonar, radar, biomedical, and geology exploration. High resolution localization needs to employ jointly two sorts of high resolution estimators, time-delay estimator and Direction Of Arrival (DOA) estimator, both of which are tough problems attracting many signal processing researchers. There is also another difficulty that is to pair two groups of parameters in timedelay and DOA domains. In underwater environment, multiple sources localization research faces more difficulties because of the long duration emitted wave, limit aperture of array, and short data record of echoes. In this paper, an new extended ESPRIT (Estimation of Signal Parameters via Rotational Invariance Technique) method is presented. With a single echo wave, both time-delay and DOA parameters of multiple sources are estimated simultaneously.No additional pairing algorithm is needed to obtain the source locations. The performance of the new estimators and the probability of correct pairing is given by computer simulations, andthe results shows that good estimation can be obtained in low SNR (Signal to Noise Ratio) for multiple sources localization.
基金The authors would like to thank the anonymous referees and the editor for very helpful suggestions and comments which led to improvements of our orig- inal paper. J. Wang was supported by National Natural Science Foundation of China (Nos. 11401182 and 11471089), Natural Science Foundation of Heilongjiang Province (No. A201415), Science and Technology Innovation Team in Higher Edu- cation Institutions of Heilongjiang Province (No. 2014TD005), Project funded by China Postdoctoral Science Foundation (No. 2014M552295) and Project funded by Chongqing Postdoctoral Foundation (No. Xm2014024). X. Wang is supported by the National Natural Science Foundation of China (No. 11301453), Postdoctoral Science Foundation of China (No. 2014M562366), Postdoctoral Science Foundation of Shaanxi Province (No. 2014010), the Universities Young Teachers Program of Henan Province (No. 2014GGJS-093).
文摘In this paper, the sharp threshold properties of a (2n + 1)-dimensional delayed viral infection model are investigated. This model combines with n classes of uninfected tar- get cells, n classes of infected cells and nonlinear incidence rate h(x,v). Two kinds of distributed time delays are incorporated into the model to describe the time needed for infection of uninfected target cells and virus replication. Under certain conditions, it is shown that the basic reproduction number is a threshold parameter for the existence of the equilibria, uniform persistence, as well as for global stability of the equilibria of the model.