In this work,we mainly study Bell nonlocality and quantum steerability of two-coupled double quantum dots(DQDs)system via local filtering operation.We compare and analyze the influence of the Coulomb potential,tempera...In this work,we mainly study Bell nonlocality and quantum steerability of two-coupled double quantum dots(DQDs)system via local filtering operation.We compare and analyze the influence of the Coulomb potential,temperature,tunneling parameter and local filtering operation on quantum steering and Bell nonlocality in the system.The results show that quantum steering and nonlocality first increase and then decrease but never vanish even for the stronger value of the Coulomb potential.Quantum steering and Bell nonlocality would degrade with the increase of temperature.The filtering process does not increase the degree of steerability,but decreases the range of quantum steerability.In addition,it is noteworthy that a peculiar phenomenon exists:the Einstein-Podolsky-Rosen(EPR)steering asymmetry between Alice and Bob first increase,then decrease to zero and finally increases as the tunneling strength increases.However,this phenomenon does not appear with no operation between Alice and Bob.展开更多
Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewi...Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.展开更多
Combining beamlet transform with steerable filters, a new edge detection method based on line gradient is proposed. Compared with operators based on point local properties, the edge-detection results with this method ...Combining beamlet transform with steerable filters, a new edge detection method based on line gradient is proposed. Compared with operators based on point local properties, the edge-detection results with this method achieve higher SNR and position accuracy, and are quite helpful for image registration, object identification, etc. Some edge-detection experiments on optical and SAR images that demonstrate the significant improvement over classical edge operators axe also presented. Moreover, the template matching result based on edge information of optical reference image and SAR image also proves the validity of this method.展开更多
A new iris feature extraction approach using both spatial and frequency domain is presented. Steerable pyramid is adopted to get the orientation information on iris images. The feature sequence is extracted on each su...A new iris feature extraction approach using both spatial and frequency domain is presented. Steerable pyramid is adopted to get the orientation information on iris images. The feature sequence is extracted on each sub-image and used to train Support Vector Machine (SVM) as iris classifiers. SVM has drawn great interest recently as one of the best classifiers in machine learning, although there is a problem in the use of traditional SVM for iris recognition. It cannot treat False Accept and False Reject differently with different security requirements. Therefore, a new kind of SVM called Non-symmetrical SVM is presented to classify the iris features. Experimental data shows that Non-symmetrical SVM can satisfy various security requirements in iris recognition applications. Feature sequence combined with spatial and frequency domain represents the variation details of the iris patterns properly. The results in this study demonstrate the potential of our new approach, and show that it performs more satis- factorily when compared to former algorithms.展开更多
Image fusion should consider the priori knowledge of the source images to be fused, such as the characteristics of the images and the goal of image fusion, that is to say, the knowledge about the input data and the ap...Image fusion should consider the priori knowledge of the source images to be fused, such as the characteristics of the images and the goal of image fusion, that is to say, the knowledge about the input data and the application plays a crucial role. This paper is concerned on multiresolution （MR） image fusion. Considering the characteristics of the multisensor （SAR and FLIR etc） and the goal of fusion, which is to achieve one image in possession of the contours feature and the target region feature. It seems more meaningful to combine features rather than pixels. A multisensor image fusion scheme based on K-means duster and steerable pyramid is presented. K-means cluster is used to segment out objects in FLIR images. The steerable pyramid is a multiresolution analysis method, which has a good property to extract contours information at different scales, Comparisons are made with the relevant existing techniques in the literature. The paper concludes with some examples to illustrate the efficiency of the proposed scheme.展开更多
Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing fo...Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing forces of the rotary ribs on the wellbore wall influence the weight-on-bit(WOB)transmission efficiency and the rate of penetration(ROP).In this paper,analytical models of the WOB transmission efficiency were established for the wellbore wall with and without ladders respectively based on the structure and working principle of the SRSS.And the variation rules of the WOB transmission efficiency with the nominal WOB,the frictional coefficient of wellbore wall,the pushing force and the front chamfer of the steerable rib were analyzed.And the following research results were obtained.First,the nominal WOB of this SRSS has to satisfy the minimum requirement and it is conducive to the increase of WOB transmission efficiency by increasing the nominal WOB appropriately.Second,whether there are ladders on the wellbore wall or not,the WOB transmission efficiency decreases as the total pushing forces of steerable ribs and the frictional coefficient of wellbore wall increase.And the WOB transmission efficiency in the case of wellbore wall with ladders is much lower than that without ladders.Third,if there are ladders on the wellbore wall,the front chamfer of steerable rib has a significant effect on the WOB transmission efficiency.The larger the front chamfer is,the lower the WOB transmission efficiency is(even self-locking).In conclusion,the research results play an important role in guiding the rational selection and control of the WOB at drilling site.展开更多
0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing c...0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing coronary lesion characteristics of patients aged<≥80 years to those≥80 years undergoing PCI,the octogenarians have a higher prevalence of calcified and ostial lesions,tortuous coronary anatomy,multi-vessel disease and left main stem(LMS)stenosis.⑶Furthermore,they often have greater ischemic burden than their younger counterparts,suggesting an even greater benefit following revascularization.展开更多
BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter clo...BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.展开更多
A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a di...A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a distance of 5.6 mm from the antenna centre. These feeding points when excited one by one generate four tilted beams in four different space quadrants, thus yielding a beam steerable antenna, Importantly, since the proposed antenna is symmetrical in the structure, all the four tilted beams have the same radiation pattern characteristics. A further enhancement of the antenna bandwidth is also achieved using 100-μn capacitive coupling between the feed and the antenna strip.展开更多
The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coinci...The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coincides exactly with the planned path, which is usually a plane curve with straight, building, holding, and dropping sections in succession. The drilling direction is of course dependant on the direction of the resultant forces acting on the bit and it is quite a tough job to hit the optimum target at the hole bottom as required. The traditional passive methods for correcting the drilling path have not met the demand to improve the techniques of deviation control. A method for combining wellbore surveys to obtain a composite, more accurate well position relies on accepting the position of the well from the most accurate survey instrument used in a given section of the wellbore. The error in each position measurement is the sum of many independent root sources of error effects. The relationship between surveys and other influential factors is considered, along with an analysis of different points of view. The collaborative work describes, establishes a common starting point of wellbore position uncertainty model, definition of what constitutes an error model, mathematics of position uncertainty calculation and an error model for basic directional service.展开更多
High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With ...High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio(CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.展开更多
Bio-inspired design translates the knowledge of natural or biological structures or behaviors into novel theories and technologies,providing new directions for research and developments.Although the medical needles fo...Bio-inspired design translates the knowledge of natural or biological structures or behaviors into novel theories and technologies,providing new directions for research and developments.Although the medical needles for percutaneous intervention technology appear to be mature,biomimetic solutions become popular to further facilitate the performance of the medical needles.In this paper,we review the current state of bio-inspired medical needle designs for percutaneous interventions,including a variety of biomimetic mechanisms and insertion strategies.Existing and experimental designs of biomimetic medical needles are classified into five groups with respect to the applications,while their characteristics are identified and discussed.Such classification and discussion will not only provide technical insights into previous studies but also identify undiscovered directions for future research.展开更多
基金supported by the University-Industry Collaborative Education Program(Project No.220506627183928).
文摘In this work,we mainly study Bell nonlocality and quantum steerability of two-coupled double quantum dots(DQDs)system via local filtering operation.We compare and analyze the influence of the Coulomb potential,temperature,tunneling parameter and local filtering operation on quantum steering and Bell nonlocality in the system.The results show that quantum steering and nonlocality first increase and then decrease but never vanish even for the stronger value of the Coulomb potential.Quantum steering and Bell nonlocality would degrade with the increase of temperature.The filtering process does not increase the degree of steerability,but decreases the range of quantum steerability.In addition,it is noteworthy that a peculiar phenomenon exists:the Einstein-Podolsky-Rosen(EPR)steering asymmetry between Alice and Bob first increase,then decrease to zero and finally increases as the tunneling strength increases.However,this phenomenon does not appear with no operation between Alice and Bob.
基金the National Natural Science Foundation of China(No.52375293)the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(Nanjing University of Aeronautics and astronautics,Nos.1005-IZD2300225 and IZD2400217)+2 种基金the Nanjing Life and Health Technology Special Project(No.202305031)the Clinical Competence Enhancement Project in Healthcare(No.JSPH-MB-2022-4)the Medical Engineering Translational Fund of Jiangsu Province Hospital(No.NM202402).
文摘Minimally invasive interventional surgery techniques using guidewire-based catheters are widely adopted to treat vascular diseases.However,commonly used interventional catheters lack active guidance.The use of guidewires is associated with risks,including increased exposure to X-rays and potential vascular damage during withdrawal from complex vessels.Herein,we developed sub-millimeter microtubular ionic actuators(0.6-0.8 mm outer diameter)integrated into steerable interventional catheters.These actuators can generate large deformations(>10 mm)under 7 V direct current due to enhanced ion migration,enabling precise navigation without the need for guidewires.The designed catheters achieved active bending and accurate positioning in complex arterial vascular branches within a human model.They were also able to navigate within different arterial locations(e.g.,the innominate,subclavian,and carotid arteries)in pigs without the use of guidewires,and even access the ventricle and deliver contrast medium,indicating their great potential for future endovascular therapy.
文摘Combining beamlet transform with steerable filters, a new edge detection method based on line gradient is proposed. Compared with operators based on point local properties, the edge-detection results with this method achieve higher SNR and position accuracy, and are quite helpful for image registration, object identification, etc. Some edge-detection experiments on optical and SAR images that demonstrate the significant improvement over classical edge operators axe also presented. Moreover, the template matching result based on edge information of optical reference image and SAR image also proves the validity of this method.
基金Project supported by the National Natural Science Foundation of China (No. 60272031), Educational Department Doctor Foundation of China (No. 20010335049), and Zhejiang Provincial Natural ScienceFoundation (No. ZD0212), China
文摘A new iris feature extraction approach using both spatial and frequency domain is presented. Steerable pyramid is adopted to get the orientation information on iris images. The feature sequence is extracted on each sub-image and used to train Support Vector Machine (SVM) as iris classifiers. SVM has drawn great interest recently as one of the best classifiers in machine learning, although there is a problem in the use of traditional SVM for iris recognition. It cannot treat False Accept and False Reject differently with different security requirements. Therefore, a new kind of SVM called Non-symmetrical SVM is presented to classify the iris features. Experimental data shows that Non-symmetrical SVM can satisfy various security requirements in iris recognition applications. Feature sequence combined with spatial and frequency domain represents the variation details of the iris patterns properly. The results in this study demonstrate the potential of our new approach, and show that it performs more satis- factorily when compared to former algorithms.
基金This project was supported by National "863" High Technology Research and Development Program of China(2001AA135091) National Science Foundation of China +2 种基金Shanghai Key Scientific Project (02DZ15001) China PH.D. DisciplineSpecial Foundation (20020248029) China Aviation Science Foundation (02D57003) .
文摘Image fusion should consider the priori knowledge of the source images to be fused, such as the characteristics of the images and the goal of image fusion, that is to say, the knowledge about the input data and the application plays a crucial role. This paper is concerned on multiresolution （MR） image fusion. Considering the characteristics of the multisensor （SAR and FLIR etc） and the goal of fusion, which is to achieve one image in possession of the contours feature and the target region feature. It seems more meaningful to combine features rather than pixels. A multisensor image fusion scheme based on K-means duster and steerable pyramid is presented. K-means cluster is used to segment out objects in FLIR images. The steerable pyramid is a multiresolution analysis method, which has a good property to extract contours information at different scales, Comparisons are made with the relevant existing techniques in the literature. The paper concludes with some examples to illustrate the efficiency of the proposed scheme.
基金Project supported by the National Research Council of Science and Technology Major Project“Rotary Steering System Research and Development”(No.:2016ZX05022-002)the Surface Project of the National Natural Science Foundation of China“Study on Borehole Collission Prevention Mechanism Based on Magnetic Field Distribution and Passive Magnetic Ranging of Downhole Casing String”(No.:51674284)the Changjiang Scholars and Innovative Team Development Program of the Ministry of Education of the People's Republic of China.
文摘Now,the static push-the-bit rotary steerable system(SRSS)developed in China is being put into field tests and primary applications.During its normal drilling,higher frictional forces generated by the static pushing forces of the rotary ribs on the wellbore wall influence the weight-on-bit(WOB)transmission efficiency and the rate of penetration(ROP).In this paper,analytical models of the WOB transmission efficiency were established for the wellbore wall with and without ladders respectively based on the structure and working principle of the SRSS.And the variation rules of the WOB transmission efficiency with the nominal WOB,the frictional coefficient of wellbore wall,the pushing force and the front chamfer of the steerable rib were analyzed.And the following research results were obtained.First,the nominal WOB of this SRSS has to satisfy the minimum requirement and it is conducive to the increase of WOB transmission efficiency by increasing the nominal WOB appropriately.Second,whether there are ladders on the wellbore wall or not,the WOB transmission efficiency decreases as the total pushing forces of steerable ribs and the frictional coefficient of wellbore wall increase.And the WOB transmission efficiency in the case of wellbore wall with ladders is much lower than that without ladders.Third,if there are ladders on the wellbore wall,the front chamfer of steerable rib has a significant effect on the WOB transmission efficiency.The larger the front chamfer is,the lower the WOB transmission efficiency is(even self-locking).In conclusion,the research results play an important role in guiding the rational selection and control of the WOB at drilling site.
文摘0ctogenarians represent the fastest growing group of patients undergoing percutaneous coronary intervention(PCI),now constituting more than one in five patients treated with PCI in real-world practice.[1,2]Comparing coronary lesion characteristics of patients aged<≥80 years to those≥80 years undergoing PCI,the octogenarians have a higher prevalence of calcified and ostial lesions,tortuous coronary anatomy,multi-vessel disease and left main stem(LMS)stenosis.⑶Furthermore,they often have greater ischemic burden than their younger counterparts,suggesting an even greater benefit following revascularization.
文摘BACKGROUND Paravalvular leak(PVL),also known as paravalvular prosthetic regurgitation,is not a rare complication after surgical valve replacement,and it may cause varying degrees of heart failure.The transcatheter closure of PVL is technically demanding and challenging.CASE SUMMARY A 68-year-old man presented with degenerative mitral regurgitation with heart failure,New York Heart Association functional class 3.He received bioprosthetic mitral valve replacement in December 2019.PVL was noted at the location of the aorto-mitral curtain in transesophageal echocardiography without signs of endocarditis or dehiscence of the bioprosthetic valve.Transseptal transcatheter closure of the mitral PVL was performed efficiently using the EchoNavigator virtual marker and Agilis NxT steerable introducer.CONCLUSION This case highlights that the EchoNavigator virtual marker and Agilis NxT steerable introducer can facilitate transseptal transcatheter closure of mitral PVL by reducing the procedure time and contrast media.
基金the European Union through the Welsh As-sembly Government
文摘A dual S shaped micro strip antenna with a realistic feed is proposed for generation of tilted beam radiation pattern pertaining for beam steering applications. To achieve this, four feeding points are located at a distance of 5.6 mm from the antenna centre. These feeding points when excited one by one generate four tilted beams in four different space quadrants, thus yielding a beam steerable antenna, Importantly, since the proposed antenna is symmetrical in the structure, all the four tilted beams have the same radiation pattern characteristics. A further enhancement of the antenna bandwidth is also achieved using 100-μn capacitive coupling between the feed and the antenna strip.
文摘The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually drilled, namely, the inclination and azimuth. In directional drilling the bit trajectory never coincides exactly with the planned path, which is usually a plane curve with straight, building, holding, and dropping sections in succession. The drilling direction is of course dependant on the direction of the resultant forces acting on the bit and it is quite a tough job to hit the optimum target at the hole bottom as required. The traditional passive methods for correcting the drilling path have not met the demand to improve the techniques of deviation control. A method for combining wellbore surveys to obtain a composite, more accurate well position relies on accepting the position of the well from the most accurate survey instrument used in a given section of the wellbore. The error in each position measurement is the sum of many independent root sources of error effects. The relationship between surveys and other influential factors is considered, along with an analysis of different points of view. The collaborative work describes, establishes a common starting point of wellbore position uncertainty model, definition of what constitutes an error model, mathematics of position uncertainty calculation and an error model for basic directional service.
文摘High Altitude Platform(HAP) must compensate for relative motion with respect to the ground because of the stratosphere complexity,which is important to guarantee Quality of Service(QoS) in intended coverage area.With analysis on HAP movement models for predicting the geographical coverage in the cases of shift horizontally and vertically,yaw,roll and pitch,the mechanisms of steerable antennas movement compensation are investigated.The mechanism is applied to a scenario of 127 cell architecture,with a cell cluster size of four.By the simulation results of Carrier to Interference Ratio(CIR),the steerable antenna movement compensation mechanism decrease influence of HAP movement and guarantee effective coverage of the service area.
基金supported by Shenzhen Key Laboratory of Robotics Perception and Intelligence(ZDSYS20200810171800001)Southern University of Science and Technology,Shenzhen 518055.
文摘Bio-inspired design translates the knowledge of natural or biological structures or behaviors into novel theories and technologies,providing new directions for research and developments.Although the medical needles for percutaneous intervention technology appear to be mature,biomimetic solutions become popular to further facilitate the performance of the medical needles.In this paper,we review the current state of bio-inspired medical needle designs for percutaneous interventions,including a variety of biomimetic mechanisms and insertion strategies.Existing and experimental designs of biomimetic medical needles are classified into five groups with respect to the applications,while their characteristics are identified and discussed.Such classification and discussion will not only provide technical insights into previous studies but also identify undiscovered directions for future research.
