Osteogenesis imperfecta(OI)is a disorder of low bone mass and increased fracture risk due to a range of genetic variants that prominently include mutations in genes encoding typeⅠcollagen.While it is well known that ...Osteogenesis imperfecta(OI)is a disorder of low bone mass and increased fracture risk due to a range of genetic variants that prominently include mutations in genes encoding typeⅠcollagen.While it is well known that OI reflects defects in the activity of bone-forming osteoblasts,it is currently unclear whether OI also reflects defects in the many other cell types comprising bone,including defects in skeletal vascular endothelium or the skeletal stem cell populations that give rise to osteoblasts and whether correcting these broader defects could have therapeutic utility.展开更多
This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT w...This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT was the Center for Display Research(CDR)which was started in 1995.Thus display research has a long history at HKUST.展开更多
Robotic computing systems play an important role in enabling intelligent robotic tasks through intelligent algo-rithms and supporting hardware.In recent years,the evolution of robotic algorithms indicates a roadmap fr...Robotic computing systems play an important role in enabling intelligent robotic tasks through intelligent algo-rithms and supporting hardware.In recent years,the evolution of robotic algorithms indicates a roadmap from traditional robotics to hierarchical and end-to-end models.This algorithmic advancement poses a critical challenge in achieving balanced system-wide performance.Therefore,algorithm-hardware co-design has emerged as the primary methodology,which ana-lyzes algorithm behaviors on hardware to identify common computational properties.These properties can motivate algo-rithm optimization to reduce computational complexity and hardware innovation from architecture to circuit for high performance and high energy efficiency.We then reviewed recent works on robotic and embodied AI algorithms and computing hard-ware to demonstrate this algorithm-hardware co-design methodology.In the end,we discuss future research opportunities by answering two questions:(1)how to adapt the computing platforms to the rapid evolution of embodied AI algorithms,and(2)how to transform the potential of emerging hardware innovations into end-to-end inference improvements.展开更多
Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of tu...Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of turn-on voltage(VON),and dual-gate TFTs for acquiring sensor signals and modulating VON have been deployed to improve the robustness and performance of the systems in which they are deployed.Digital circuit building blocks based on fluorinated TFTs have been designed,fabricated,and characterized,which demonstrate the utility of the proposed low-temperature TFT technologies for implementing flexible electronic systems.The construction and characterization of an analog front-end system for the acquisition of bio-potential signals and an active-matrix sensor array for the acquisition of tactile images have been reported recently.展开更多
Dear Editor,This paper is concerned with the underwater localization based on acoustic signals. Specifically, we will focus on the search of an underwater target that can constantly broadcast a beacon signal, such as ...Dear Editor,This paper is concerned with the underwater localization based on acoustic signals. Specifically, we will focus on the search of an underwater target that can constantly broadcast a beacon signal, such as a black box. Common measurements for localization are Doppler shift [1], time of arrival(ToA) [2]–[4], time difference of arrival(TDoA) [5], [6], angle of arrival(AoA) [7], etc.展开更多
As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indi...As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indicating the elderly＇s growing fatal accident rates and their different behaviours compared to younger drivers. However, few research has focused on design-led practical solutions to mitigate the elderly＇s growing fatal accidents, by consid- ering their usability and body conditions, afflicting the elderly, such as decreased vision, hearing, and reaction times. In this paper, first, current worldwide situations on growing fatal accident rates for elderly drivers is reviewed and the key impact factors are identified and discussed with regarding to usability and design trend in the automotive technology for elderly. Second, existing smart vehicle technology-based solutions to promote safe driving are explored and their pros and cons are discussed and anal- ysed. Most of solutions are not created by people with driving difficulties, which are caused by health problems most commonly afflicting the elderly. Thirdly, diverse design-led research activities are taken, such as a survey, observation, and interviews to gain new understanding of what kinds of driving problems elderly drivers have and demonstrate how new system concepts could be developed for the elderly＇s benefits. Finally, it is found that the elderly＇s low vision and late reaction are main factors causing their driving difficulties. Based on this finding, usable vehicle system design ideas have been proposed, by utilising facial expression sensing technology as a solution. The proposed solutions would ensure reducing both the elderly＇s driving problems and high fatal accident rates and provide a more enjoyable driving environment for the elderly population.展开更多
The outage probability of a composite microscopic and macroscopic diversity system is evaluated over correlated shadowed fading channels.The correlations on both a microlevel and macrolevel are taken into account for ...The outage probability of a composite microscopic and macroscopic diversity system is evaluated over correlated shadowed fading channels.The correlations on both a microlevel and macrolevel are taken into account for the evaluations.The expression of the desired outage probability is explicitly presented,and two evaluation approaches,i.e.a compact Gaussian-Hermite quadrature method and an effective iterative algorithm,are proposed.The accuracy and efficiency of the proposed approaches are analysed,and a guideline is provided for their application.By employing the proposed evaluation approaches,results and demonstrations are presented,which display the implied effects of the corresponding parameters on the system outage performance,and reveal the potential to facilitate the design and analysis of such composite diversity systems.展开更多
β-Ga_(2)O_(3) Schottky barrier diodes have undergone rapid progress in research and development for power electronic applications.This paper reviews state-of-the-art β-Ga_(2)O_(3) rectifier technologies,including ad...β-Ga_(2)O_(3) Schottky barrier diodes have undergone rapid progress in research and development for power electronic applications.This paper reviews state-of-the-art β-Ga_(2)O_(3) rectifier technologies,including advanced diode architectures that have enabled lower reverse leakage current via the reduced-surface-field effect.Characteristic device properties including onresistance,breakdown voltage,rectification ratio,dynamic switching,and nonideal effects are summarized for the different devices.Notable results on the high-temperature resilience of β-Ga_(2)O_(3) Schottky diodes,together with the enabling thermal packaging solutions,are also presented.展开更多
In this paper,we review existing approaches to integrating small gain and small phase analysis for feedback stability of dynamical systems,and give a brief outlook for possible future directions in exploring this topi...In this paper,we review existing approaches to integrating small gain and small phase analysis for feedback stability of dynamical systems,and give a brief outlook for possible future directions in exploring this topic.Small gain analysis has been very successful and popular in control theory since 1960s,while the small phase analysis for multiple-input-multiple-output systems has not been well understood until recently and is now gradually taking shape.Nevertheless,there have been attempts to analyzing feedback stability via the integration of gain and phase information over decades,including the combination of small gain with positive realness as well as that with negative imaginariness.Such combinations can be subsumed into a recently proposed framework for gain-phase integration,which brings in new geometrical methods and also sheds new lights on several future directions.展开更多
This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered ...This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered by mobile communication.First,the principles and techniques of speech enhancement are analyzed,and a fast lateral recursive least square method(FLRLS method)is adopted to process sound data.Then,the convolutional neural networks(CNNs)-based noise recognition CNN(NR-CNN)algorithm and speech enhancement model are proposed.Finally,related experiments are designed to verify the performance of the proposed algorithm and model.The experimental results show that the noise classification accuracy of the NR-CNN noise recognition algorithm is higher than 99.82%,and the recall rate and F1 value are also higher than 99.92.The proposed sound enhance-ment model can effectively enhance the original sound in the case of noise interference.After the CNN is incorporated,the average value of all noisy sound perception quality evaluation system values is improved by over 21%compared with that of the traditional noise reduction method.The proposed algorithm can adapt to a variety of voice environments and can simultaneously enhance and reduce noise processing on a variety of different types of voice signals,and the processing effect is better than that of traditional sound enhancement models.In addition,the sound distortion index of the proposed speech enhancement model is inferior to that of the control group,indicating that the addition of the CNN neural network is less likely to cause sound signal distortion in various sound environments and shows superior robustness.In summary,the proposed CNN-based speech enhancement model shows significant sound enhancement effects,stable performance,and strong adapt-ability.This study provides a reference and basis for research applying neural networks in speech enhancement.展开更多
Macrophages and neutrophils are key components of myeloid cells and play critical roles in innate immune responses,organ formation,and tissue homeostasis.The integrity of their functions heavily relies on the generati...Macrophages and neutrophils are key components of myeloid cells and play critical roles in innate immune responses,organ formation,and tissue homeostasis.The integrity of their functions heavily relies on the generation of a proper number of mature macrophages and neutrophils through embryonic and adult myelopoiesis.In mammalian adult myelopoiesis,oligopotent common myeloid progenitors(CMPs)are known to be the earliest myeloid progenitors,which give rise to granulocyte-macrophage progenitors(GMPs),subsequently differentiate into unipotent neutrophil and macrophage precursors,and finally,mature macrophages and neutrophils(Orkin and Zon,2008).In contrast,the ontogeny of embryonic myelopoiesis and the mechanism underlying the formation of macrophages and neutrophils remainless understood.展开更多
This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filt...This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filter. We first derive the stability condition and steady-state predicted errors as fundamental properties of the VM-α-β filter. The optimal gains for representative motion models are then derived from the Kalman filter equations. Theoretical and numerical analyses verify that VM-α-β filters with these optimal gains realize more accurate tracking than conventional α-β filters when the filter gains are relatively large. Our study reveals the conditions under which the predicted errors of the VM-α-β filters are less than those of conventional α-β filters. Moreover, numerical simulations clarify that the variance of the tracking error of the VM-α-β filters is approximately 3/4 of that of the conventional α-β filters in realistic situations, even when the accuracy of the position/velocity measurements is the same.展开更多
Architectural distortion is an important ultrasonographic indicator of breast cancer. However, it is difficult for clinicians to determine whether a given lesion is malignant because such distortions can be subtle in ...Architectural distortion is an important ultrasonographic indicator of breast cancer. However, it is difficult for clinicians to determine whether a given lesion is malignant because such distortions can be subtle in ultrasonographic images. In this paper, we report on a study to develop a computerized scheme for the histological classification of masses with architectural distortions as a differential diagnosis aid. Our database consisted of 72 ultrasonographic images obtained from 47 patients whose masses had architectural distortions. This included 51 malignant (35 invasive and 16 non-invasive carcinomas) and 21 benign masses. In the proposed method, the location of the masses and the area occupied by them were first determined by an experienced clinician. Fourteen objective features concerning masses with architectural distortions were then extracted automatically by taking into account subjective features commonly used by experienced clinicians to describe such masses. The k-nearest neighbors (k-NN) rule was finally used to distinguish three histological classifications. The proposed method yielded classification accuracy values of 91.4% (32/35) for invasive carcinoma, 75.0% (12/16) for noninvasive carcinoma, and 85.7% (18/21) for benign mass, respectively. The sensitivity and specificity values were 92.2% (47/51) and 85.7% (18/21), respectively. The positive predictive values (PPV) were 88.9% (32/36) for invasive carcinoma and 85.7% (12/14) for noninvasive carcinoma whereas the negative predictive values (NPV) were 81.8% (18/22) for benign mass. Thus, the proposed method can help the differential diagnosis of masses with architectural distortions in ultrasonographic images.展开更多
Large-scale indoor 3D reconstruction with multiple robots faces challenges in core enabling technologies.This work contributes to a framework addressing localization,coordination,and vision processing for multi-agent ...Large-scale indoor 3D reconstruction with multiple robots faces challenges in core enabling technologies.This work contributes to a framework addressing localization,coordination,and vision processing for multi-agent reconstruction.A system architecture fusing visible light positioning,multi-agent path finding via reinforcement learning,and 360°camera techniques for 3D reconstruction is proposed.Our visible light positioning algorithm leverages existing lighting for centimeter-level localization without additional infrastructure.Meanwhile,a decentralized reinforcement learning approach is developed to solve the multi-agent path finding problem,with communications among agents optimized.Our 3D reconstruction pipeline utilizes equirectangular projection from 360°cameras to facilitate depth-independent reconstruction from posed monocular images using neural networks.Experimental validation demonstrates centimeter-level indoor navigation and 3D scene reconstruction capabilities of our framework.The challenges and limitations stemming from the above enabling technologies are discussed at the end of each corresponding section.In summary,this research advances fundamental techniques for multi-robot indoor 3D modeling,contributing to automated,data-driven applications through coordinated robot navigation,perception,and modeling.展开更多
The blood system originates from hematopoietic stem cells(HSCs),capable of self-renewal and differentiation,generating diverse blood cell types(Eaves,2015;Lucas,2021).The concept of the hematopoietic niche was first p...The blood system originates from hematopoietic stem cells(HSCs),capable of self-renewal and differentiation,generating diverse blood cell types(Eaves,2015;Lucas,2021).The concept of the hematopoietic niche was first proposed in 1978(Schofield,1978),which is crucial for maintaining hematopoietic balance.The following studies,particularly in mammals,have utilized targeted genetic manipulation to identify and define these niches.展开更多
Compared to the last decade when the convolution neu-ral network(CNN)dominated the research field,machine learn-ing(ML)algorithms have reached a pivotal moment called the generative artificial intelligence(AI)era.With...Compared to the last decade when the convolution neu-ral network(CNN)dominated the research field,machine learn-ing(ML)algorithms have reached a pivotal moment called the generative artificial intelligence(AI)era.With the emer-gence of large-scale foundation models[1],such as large multi-modal model(LMM)GPT-4[2]and text-to-image generative model DALL·E[3].展开更多
Mixed integer linear programming(MILP)is an NP-hard problem,which can be solved by the branch and bound algorithm by dividing the original problem into several subproblems and forming a search tree.For each subproblem...Mixed integer linear programming(MILP)is an NP-hard problem,which can be solved by the branch and bound algorithm by dividing the original problem into several subproblems and forming a search tree.For each subproblem,linear programming(LP)relaxation can be solved to find the bound for making the following decisions.Recently,with the increasing dimension of MILPs in different applications,how to accelerate the solution process becomes a huge challenge.In this survey,we summarize techniques and trends to speed up MILP solving from two perspectives.First,we present different approaches in simplex initialization,which can help to accelerate the solution of LP relaxation for each subproblem.Second,we introduce the learning-based technologies in branch and bound algorithms to improve decision making in tree search.We also propose several potential directions and extensions to further enhance the efficiency of solving different MILP problems.展开更多
The terahertz band lies between the microwave and infrared regions of the electromagnetic spectrum.This radiation has very low photon energy and thus it does not pose any ionization hazard for biological tissues.It is...The terahertz band lies between the microwave and infrared regions of the electromagnetic spectrum.This radiation has very low photon energy and thus it does not pose any ionization hazard for biological tissues.It is strongly attenuated by water and very sensitive to water content.Unique absorption spectra due to intermolecular vibrations in this region have been found in different biological materials.These unique features make tera-hertz imaging very attractive for medical applications in order to provide complimentary information to existing imaging techniques.There has been an increasing interest in terahertz imaging and spectroscopy of biologically related applications within the last few years and more and more terahertz spectra are being reported.This paper introduces terahertz technology and provides a short review of recent advances in terahertz imaging and spectroscopy techniques,and a number of applications such as molecular spectroscopy,tissue characterization and skin imaging are discussed.展开更多
Lower limb exoskeleton robots offer an effective treatment for patients with lower extremity dysfunction.In order to improve the rehabilitation training effect based on the human motion mechanism,this paper proposes a...Lower limb exoskeleton robots offer an effective treatment for patients with lower extremity dysfunction.In order to improve the rehabilitation training effect based on the human motion mechanism,this paper proposes a humanoid sliding mode neural network controller based on the human gait.A humanoid model is constructed based on the human mechanism,and the parameterised gait trajectory is used as target to design the humanoid control system for robots.Considering the imprecision of the robot dynamics model,the neural network is adopted to compensate for the uncertain part of the model and improve the model accuracy.Moreover,the sliding mode control in the system improves the response speed,tracking performance,and stability of the control system.The Lyapunov stability analysis proves the stability of the control system theoretically.Meanwhile,an evaluation method using the similarity function is improved based on joint angle,velocity,and acceleration to evaluate the comfort of humans in rehabilitation training more reasonably.Finally,to verify the effectiveness of the proposed method,simulations are carried out based on experimental data.The results show that the control system could accurately track the target trajectory,of which the robot is highly similar to the human.展开更多
基金supported by the National Natural Science Foundation of China (81972034,92068104 and 82002262 to R.X.)the National Key R&D Program of China (2020YFA0112900 to R.X.)+5 种基金Project of Xiamen Cell Therapy Research Center (3502Z20214001 to R.X.)supported by a the NIH grant of US (R01AR075585,R01HD115274,R01CA282815 to M.B.G.)Career Award for Medical Scientists from the Burroughs Wellcome Funda Pershing Square Sohn Cancer Research Alliance and the Maximizing Innovation in Neuroscience Discovery (MIND)Prizesupported by a Jump Start Research Career Development Award from Weill Cornell Medicinea Study Abroad Scholarships from the Mogam Science Scholarship Foundation。
文摘Osteogenesis imperfecta(OI)is a disorder of low bone mass and increased fracture risk due to a range of genetic variants that prominently include mutations in genes encoding typeⅠcollagen.While it is well known that OI reflects defects in the activity of bone-forming osteoblasts,it is currently unclear whether OI also reflects defects in the many other cell types comprising bone,including defects in skeletal vascular endothelium or the skeletal stem cell populations that give rise to osteoblasts and whether correcting these broader defects could have therapeutic utility.
文摘This year marks the tenth anniversary of the State Key Laboratory of Advanced Displays and Optoelectronics Technologies(SKLADOT)at the Hong Kong University of Science and Technology(HKUST).The predecessor of SKLADOT was the Center for Display Research(CDR)which was started in 1995.Thus display research has a long history at HKUST.
基金supported in part by NSFC under Grant 62422407in part by RGC under Grant 26204424in part by ACCESS–AI Chip Center for Emerging Smart Systems, sponsored by the Inno HK initiative of the Innovation and Technology Commission of the Hong Kong Special Administrative Region Government
文摘Robotic computing systems play an important role in enabling intelligent robotic tasks through intelligent algo-rithms and supporting hardware.In recent years,the evolution of robotic algorithms indicates a roadmap from traditional robotics to hierarchical and end-to-end models.This algorithmic advancement poses a critical challenge in achieving balanced system-wide performance.Therefore,algorithm-hardware co-design has emerged as the primary methodology,which ana-lyzes algorithm behaviors on hardware to identify common computational properties.These properties can motivate algo-rithm optimization to reduce computational complexity and hardware innovation from architecture to circuit for high performance and high energy efficiency.We then reviewed recent works on robotic and embodied AI algorithms and computing hard-ware to demonstrate this algorithm-hardware co-design methodology.In the end,we discuss future research opportunities by answering two questions:(1)how to adapt the computing platforms to the rapid evolution of embodied AI algorithms,and(2)how to transform the potential of emerging hardware innovations into end-to-end inference improvements.
基金supported by Grant RGC 16215720 from the Science and Technology Program of Shenzhen under JCYJ20200109140601691Grant GHP/018/21SZ from the Innovation and Technology Fund+1 种基金Grant SGDX20211123145404006 from the Science and Technology Program of ShenzhenFundamental and Applied Fundamental Research Fund of Guangdong Province 2021B1515130001。
文摘Here we review two 300℃metal–oxide(MO)thin-film transistor(TFT)technologies for the implementation of flexible electronic circuits and systems.Fluorination-enhanced TFTs for suppressing the variation and shift of turn-on voltage(VON),and dual-gate TFTs for acquiring sensor signals and modulating VON have been deployed to improve the robustness and performance of the systems in which they are deployed.Digital circuit building blocks based on fluorinated TFTs have been designed,fabricated,and characterized,which demonstrate the utility of the proposed low-temperature TFT technologies for implementing flexible electronic systems.The construction and characterization of an analog front-end system for the acquisition of bio-potential signals and an active-matrix sensor array for the acquisition of tactile images have been reported recently.
基金supported by the National Natural Science Foundation of China(62201162)the HKUST(GZ)(Start-Up Founding,G0101000066)+3 种基金the Natural Sciences and Engineering Research Council(NSERC)of Canada(RGPIN-201803792)the IET Sensor TECH(5404-2061-101)the Natural Science Foundation of Jiangsu Province(BK20190733)the NUPTSF(NY219166)。
文摘Dear Editor,This paper is concerned with the underwater localization based on acoustic signals. Specifically, we will focus on the search of an underwater target that can constantly broadcast a beacon signal, such as a black box. Common measurements for localization are Doppler shift [1], time of arrival(ToA) [2]–[4], time difference of arrival(TDoA) [5], [6], angle of arrival(AoA) [7], etc.
文摘As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indicating the elderly＇s growing fatal accident rates and their different behaviours compared to younger drivers. However, few research has focused on design-led practical solutions to mitigate the elderly＇s growing fatal accidents, by consid- ering their usability and body conditions, afflicting the elderly, such as decreased vision, hearing, and reaction times. In this paper, first, current worldwide situations on growing fatal accident rates for elderly drivers is reviewed and the key impact factors are identified and discussed with regarding to usability and design trend in the automotive technology for elderly. Second, existing smart vehicle technology-based solutions to promote safe driving are explored and their pros and cons are discussed and anal- ysed. Most of solutions are not created by people with driving difficulties, which are caused by health problems most commonly afflicting the elderly. Thirdly, diverse design-led research activities are taken, such as a survey, observation, and interviews to gain new understanding of what kinds of driving problems elderly drivers have and demonstrate how new system concepts could be developed for the elderly＇s benefits. Finally, it is found that the elderly＇s low vision and late reaction are main factors causing their driving difficulties. Based on this finding, usable vehicle system design ideas have been proposed, by utilising facial expression sensing technology as a solution. The proposed solutions would ensure reducing both the elderly＇s driving problems and high fatal accident rates and provide a more enjoyable driving environment for the elderly population.
基金supported by the Natural Sciences and Engineering Research Council of Canada under Grant No. STPGP 396756partly supported by the National Natural Science Foundation of China under Grant No. 6110-1096the Natural Science Foundation of Hunan Province under Grant No. 11JJ4055.
文摘The outage probability of a composite microscopic and macroscopic diversity system is evaluated over correlated shadowed fading channels.The correlations on both a microlevel and macrolevel are taken into account for the evaluations.The expression of the desired outage probability is explicitly presented,and two evaluation approaches,i.e.a compact Gaussian-Hermite quadrature method and an effective iterative algorithm,are proposed.The accuracy and efficiency of the proposed approaches are analysed,and a guideline is provided for their application.By employing the proposed evaluation approaches,results and demonstrations are presented,which display the implied effects of the corresponding parameters on the system outage performance,and reveal the potential to facilitate the design and analysis of such composite diversity systems.
文摘β-Ga_(2)O_(3) Schottky barrier diodes have undergone rapid progress in research and development for power electronic applications.This paper reviews state-of-the-art β-Ga_(2)O_(3) rectifier technologies,including advanced diode architectures that have enabled lower reverse leakage current via the reduced-surface-field effect.Characteristic device properties including onresistance,breakdown voltage,rectification ratio,dynamic switching,and nonideal effects are summarized for the different devices.Notable results on the high-temperature resilience of β-Ga_(2)O_(3) Schottky diodes,together with the enabling thermal packaging solutions,are also presented.
基金supported in part by the Shenzhen Science and Technology Innovation Committee,China(SGDX20201103094600006)the Foshan-HKUST Projects Program(FSUST20-FYTRI12F)+1 种基金the National Natural Science Foundation of China(62103303)the Shanghai Municipal Science and Technology,China Major Project(2021SHZDZX0100).
文摘In this paper,we review existing approaches to integrating small gain and small phase analysis for feedback stability of dynamical systems,and give a brief outlook for possible future directions in exploring this topic.Small gain analysis has been very successful and popular in control theory since 1960s,while the small phase analysis for multiple-input-multiple-output systems has not been well understood until recently and is now gradually taking shape.Nevertheless,there have been attempts to analyzing feedback stability via the integration of gain and phase information over decades,including the combination of small gain with positive realness as well as that with negative imaginariness.Such combinations can be subsumed into a recently proposed framework for gain-phase integration,which brings in new geometrical methods and also sheds new lights on several future directions.
基金supported by General Project of Philosophy and Social Science Research in Colleges and Universities in Jiangsu Province(2022SJYB0712)Research Development Fund for Young Teachers of Chengxian College of Southeast University(z0037)Special Project of Ideological and Political Education Reform and Research Course(yjgsz2206).
文摘This study aims to reduce the interference of ambient noise in mobile communication,improve the accuracy and authenticity of information transmitted by sound,and guarantee the accuracy of voice information deliv-ered by mobile communication.First,the principles and techniques of speech enhancement are analyzed,and a fast lateral recursive least square method(FLRLS method)is adopted to process sound data.Then,the convolutional neural networks(CNNs)-based noise recognition CNN(NR-CNN)algorithm and speech enhancement model are proposed.Finally,related experiments are designed to verify the performance of the proposed algorithm and model.The experimental results show that the noise classification accuracy of the NR-CNN noise recognition algorithm is higher than 99.82%,and the recall rate and F1 value are also higher than 99.92.The proposed sound enhance-ment model can effectively enhance the original sound in the case of noise interference.After the CNN is incorporated,the average value of all noisy sound perception quality evaluation system values is improved by over 21%compared with that of the traditional noise reduction method.The proposed algorithm can adapt to a variety of voice environments and can simultaneously enhance and reduce noise processing on a variety of different types of voice signals,and the processing effect is better than that of traditional sound enhancement models.In addition,the sound distortion index of the proposed speech enhancement model is inferior to that of the control group,indicating that the addition of the CNN neural network is less likely to cause sound signal distortion in various sound environments and shows superior robustness.In summary,the proposed CNN-based speech enhancement model shows significant sound enhancement effects,stable performance,and strong adapt-ability.This study provides a reference and basis for research applying neural networks in speech enhancement.
基金supported by grants from the National Natural Science Foundation of China/Research Grants Council Joint Research Scheme(31961160726)the National Key Research and Development Program of China(2018YFA0800200)+1 种基金the Major Program of Shenzhen Bay Laboratory(S201101002)the Research Grants Council of Hong Kong(RGC/NFSC N_HKUST603/19,16102022,16101621,T13-605/18-W,T13-602/21-N).
文摘Macrophages and neutrophils are key components of myeloid cells and play critical roles in innate immune responses,organ formation,and tissue homeostasis.The integrity of their functions heavily relies on the generation of a proper number of mature macrophages and neutrophils through embryonic and adult myelopoiesis.In mammalian adult myelopoiesis,oligopotent common myeloid progenitors(CMPs)are known to be the earliest myeloid progenitors,which give rise to granulocyte-macrophage progenitors(GMPs),subsequently differentiate into unipotent neutrophil and macrophage precursors,and finally,mature macrophages and neutrophils(Orkin and Zon,2008).In contrast,the ontogeny of embryonic myelopoiesis and the mechanism underlying the formation of macrophages and neutrophils remainless understood.
文摘This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filter. We first derive the stability condition and steady-state predicted errors as fundamental properties of the VM-α-β filter. The optimal gains for representative motion models are then derived from the Kalman filter equations. Theoretical and numerical analyses verify that VM-α-β filters with these optimal gains realize more accurate tracking than conventional α-β filters when the filter gains are relatively large. Our study reveals the conditions under which the predicted errors of the VM-α-β filters are less than those of conventional α-β filters. Moreover, numerical simulations clarify that the variance of the tracking error of the VM-α-β filters is approximately 3/4 of that of the conventional α-β filters in realistic situations, even when the accuracy of the position/velocity measurements is the same.
文摘Architectural distortion is an important ultrasonographic indicator of breast cancer. However, it is difficult for clinicians to determine whether a given lesion is malignant because such distortions can be subtle in ultrasonographic images. In this paper, we report on a study to develop a computerized scheme for the histological classification of masses with architectural distortions as a differential diagnosis aid. Our database consisted of 72 ultrasonographic images obtained from 47 patients whose masses had architectural distortions. This included 51 malignant (35 invasive and 16 non-invasive carcinomas) and 21 benign masses. In the proposed method, the location of the masses and the area occupied by them were first determined by an experienced clinician. Fourteen objective features concerning masses with architectural distortions were then extracted automatically by taking into account subjective features commonly used by experienced clinicians to describe such masses. The k-nearest neighbors (k-NN) rule was finally used to distinguish three histological classifications. The proposed method yielded classification accuracy values of 91.4% (32/35) for invasive carcinoma, 75.0% (12/16) for noninvasive carcinoma, and 85.7% (18/21) for benign mass, respectively. The sensitivity and specificity values were 92.2% (47/51) and 85.7% (18/21), respectively. The positive predictive values (PPV) were 88.9% (32/36) for invasive carcinoma and 85.7% (12/14) for noninvasive carcinoma whereas the negative predictive values (NPV) were 81.8% (18/22) for benign mass. Thus, the proposed method can help the differential diagnosis of masses with architectural distortions in ultrasonographic images.
基金supported by Bright Dream Robotics and the HKUSTBDR Joint Research Institute Funding Scheme under Project HBJRI-FTP-005(Automated 3D Reconstruction using Robot-mounted 360-Degree Camera with Visible Light Positioning Technology for Building Information Modelling Applications,OKT22EG06).
文摘Large-scale indoor 3D reconstruction with multiple robots faces challenges in core enabling technologies.This work contributes to a framework addressing localization,coordination,and vision processing for multi-agent reconstruction.A system architecture fusing visible light positioning,multi-agent path finding via reinforcement learning,and 360°camera techniques for 3D reconstruction is proposed.Our visible light positioning algorithm leverages existing lighting for centimeter-level localization without additional infrastructure.Meanwhile,a decentralized reinforcement learning approach is developed to solve the multi-agent path finding problem,with communications among agents optimized.Our 3D reconstruction pipeline utilizes equirectangular projection from 360°cameras to facilitate depth-independent reconstruction from posed monocular images using neural networks.Experimental validation demonstrates centimeter-level indoor navigation and 3D scene reconstruction capabilities of our framework.The challenges and limitations stemming from the above enabling technologies are discussed at the end of each corresponding section.In summary,this research advances fundamental techniques for multi-robot indoor 3D modeling,contributing to automated,data-driven applications through coordinated robot navigation,perception,and modeling.
基金supported by the National Key Research and Development Program of China(2018YFA0800200)the National Natural Science Foundation of China/ResearchGrantsCouncilJointResearchScheme(31961160726)+1 种基金the National Natural Science Foundation of China(32170827 and 32370886)the Research Grants Council of Hong Kong(RGC/NFSC N_HKUST603/19).
文摘The blood system originates from hematopoietic stem cells(HSCs),capable of self-renewal and differentiation,generating diverse blood cell types(Eaves,2015;Lucas,2021).The concept of the hematopoietic niche was first proposed in 1978(Schofield,1978),which is crucial for maintaining hematopoietic balance.The following studies,particularly in mammals,have utilized targeted genetic manipulation to identify and define these niches.
基金This research was supported in part by ACCESS-AI Chip Center for Emerging Smart Systems,sponsored by InnoHK funding,Hong Kong SAR,and HKUST-HKUST(GZ)20 for 20 Cross-campus Collaborative Research Scheme C031.
文摘Compared to the last decade when the convolution neu-ral network(CNN)dominated the research field,machine learn-ing(ML)algorithms have reached a pivotal moment called the generative artificial intelligence(AI)era.With the emer-gence of large-scale foundation models[1],such as large multi-modal model(LMM)GPT-4[2]and text-to-image generative model DALL·E[3].
文摘Mixed integer linear programming(MILP)is an NP-hard problem,which can be solved by the branch and bound algorithm by dividing the original problem into several subproblems and forming a search tree.For each subproblem,linear programming(LP)relaxation can be solved to find the bound for making the following decisions.Recently,with the increasing dimension of MILPs in different applications,how to accelerate the solution process becomes a huge challenge.In this survey,we summarize techniques and trends to speed up MILP solving from two perspectives.First,we present different approaches in simplex initialization,which can help to accelerate the solution of LP relaxation for each subproblem.Second,we introduce the learning-based technologies in branch and bound algorithms to improve decision making in tree search.We also propose several potential directions and extensions to further enhance the efficiency of solving different MILP problems.
基金Supported by in part for this work from the Research Grants Council of the Hong Kong Government and the Shun Hing Institute of Advanced Engineering, Hong Kong
文摘The terahertz band lies between the microwave and infrared regions of the electromagnetic spectrum.This radiation has very low photon energy and thus it does not pose any ionization hazard for biological tissues.It is strongly attenuated by water and very sensitive to water content.Unique absorption spectra due to intermolecular vibrations in this region have been found in different biological materials.These unique features make tera-hertz imaging very attractive for medical applications in order to provide complimentary information to existing imaging techniques.There has been an increasing interest in terahertz imaging and spectroscopy of biologically related applications within the last few years and more and more terahertz spectra are being reported.This paper introduces terahertz technology and provides a short review of recent advances in terahertz imaging and spectroscopy techniques,and a number of applications such as molecular spectroscopy,tissue characterization and skin imaging are discussed.
基金National Natural Science Foundation of China,Grant/Award Numbers:No.62073297,No.U1813201。
文摘Lower limb exoskeleton robots offer an effective treatment for patients with lower extremity dysfunction.In order to improve the rehabilitation training effect based on the human motion mechanism,this paper proposes a humanoid sliding mode neural network controller based on the human gait.A humanoid model is constructed based on the human mechanism,and the parameterised gait trajectory is used as target to design the humanoid control system for robots.Considering the imprecision of the robot dynamics model,the neural network is adopted to compensate for the uncertain part of the model and improve the model accuracy.Moreover,the sliding mode control in the system improves the response speed,tracking performance,and stability of the control system.The Lyapunov stability analysis proves the stability of the control system theoretically.Meanwhile,an evaluation method using the similarity function is improved based on joint angle,velocity,and acceleration to evaluate the comfort of humans in rehabilitation training more reasonably.Finally,to verify the effectiveness of the proposed method,simulations are carried out based on experimental data.The results show that the control system could accurately track the target trajectory,of which the robot is highly similar to the human.
