BACKGROUND Laparoscopic cervical cerclage is performed for patients with abnormal cervical anatomy and/or transvaginal cervical cerclage failure.However,the method of removing the stitches to allow labour induction re...BACKGROUND Laparoscopic cervical cerclage is performed for patients with abnormal cervical anatomy and/or transvaginal cervical cerclage failure.However,the method of removing the stitches to allow labour induction remains controversial.According to published literature,stitches are removed through laparoscopic or transvaginal methods.Herein,we report,for the first time,a case of a patient who had undergone laparoscopic cerclage,and then underwent removal of stitches by laparotomy and labour induction in the third trimester of pregnancy.CASE SUMMARY A patient who underwent laparoscopic cervical cerclage due to cervical insufficiency became pregnant naturally following the operation.At 31 wk of pregnancy,severe foetal malformations were found.To successfully induce labour,cerclage stitches were removed via laparotomy,and rivanol was injected directly into the uterus.Following successful induction of labour,the patient delivered a dead foetus.CONCLUSION This report provides a reliable scheme of removing cerclage stitches for patients who have undergone laparoscopic cerclage but experience severe foetal malformations.展开更多
Guided by the All-China Women’s Federation(ACWF),the China Children and Teenagers’Fund(CCTF)and Hengyuanxiang Group launched Heng’ai Action in 2005.This public-welfare initiative called on caring people to knit swe...Guided by the All-China Women’s Federation(ACWF),the China Children and Teenagers’Fund(CCTF)and Hengyuanxiang Group launched Heng’ai Action in 2005.This public-welfare initiative called on caring people to knit sweaters for orphans and/or children with disabilities.During the past two decades,more than 465,000 kilograms of wool and 147 million yuan(US$21 million)in funding and materials have been donated to the program.Further,1.5 million sweaters have been knitted and presented to children in need,warming their bodies and hearts.展开更多
With the development of computer vision technology,panoramic image stitching has been widely used in fields such as scene reconstruction.A single traditional image cannot fully capture the panoramic view of the iconic...With the development of computer vision technology,panoramic image stitching has been widely used in fields such as scene reconstruction.A single traditional image cannot fully capture the panoramic view of the iconic East Gate of the South Campus of Shaanxi University of Technology.Therefore,this project aims to technically fuse multiple partial images into a complete panoramic image,enabling comprehensive recording and visual presentation of the architectural landscapes and spatial environments in this area.This report first introduces the technical background and application scenarios,clarifying the necessity of panoramic image stitching in campus landscape recording.It then elaborates on the core objectives and practical values,highlighting the role of technical solutions in improving image quality.Technically,a modular system design based on OpenCV is adopted,including modules such as image preprocessing,feature extraction and matching,image registration,fusion,and post-processing.Specifically,the SIFT algorithm is applied for feature extraction,KNN combined with ratio testing is used for feature matching,image registration is achieved by calculating the homography matrix,the fusion process utilizes multiband blending and Laplacian pyramid,and post-processing includes operations such as black area filling and CLAHE contrast enhancement.The experiment was conducted in a specific hardware and software environment using five overlapping images.After preprocessing,stitching,detail enhancement,and black edge repair,a panoramic image was successfully generated.The results show that the panoramic image fully presents the relevant scenery,with concealed seams,balanced exposure differences,and strong hierarchical details.This report provides a systematic description of the project’s technical implementation and achievement application.展开更多
There is still a dearth of systematic study on picture stitching techniques for the natural tubular structures of intestines,and traditional stitching techniques have a poor application to endoscopic images with deep ...There is still a dearth of systematic study on picture stitching techniques for the natural tubular structures of intestines,and traditional stitching techniques have a poor application to endoscopic images with deep scenes.In order to recreate the intestinal wall in two dimensions,a method is developed.The normalized Laplacian algorithm is used to enhance the image and transform it into polar coordinates according to the characteristics that intestinal images are not obvious and usually arranged in a circle,in order to extract the new image segments of the current image relative to the previous image.The improved weighted fusion algorithm is then used to sequentially splice the segment images.The experimental results demonstrate that the suggested approach can improve image clarity and minimize noise while maintaining the information content of intestinal images.In addition,the method's seamless transition between the final portions of a panoramic image also demonstrates that the stitching trace has been removed.展开更多
The proliferation of low-altitude economic activities has precipitated a significant expansion in the application domains of Unmanned Aerial Vehicle(UAV),transcending the constraints of singular platform operation.Mul...The proliferation of low-altitude economic activities has precipitated a significant expansion in the application domains of Unmanned Aerial Vehicle(UAV),transcending the constraints of singular platform operation.Multi-UAV cooperative online remote sensing image stitching involves several challenges,including image blurriness and deformation caused by platform vibrations,as well as managing vast amounts of data and addressing transmission delays.This paper introduces a real-time system for multi-UAV video stitching that integrates hardware acceleration,pose-guided ROI filtering,and temporal consistency constraints.Data from the onboard GPS and Inertial Measurement Unit(IMU)are used to estimate the overlap between two aerial images.Subsequently,the Graphics Processing Unit(GPU)within an edge computing platform is tasked with swiftly detecting SIFT features within the overlapping image sectors.Feature point matching is performed using a position-guided matching algorithm to compute the homography matrix.The results demonstrate that the RK3588-based edge computing platform exhibits rapid image decoding and stitching capabilities,with an average stitching latency of 36.43ms.Furthermore,this study developed a ground-based human-machine interaction system to present stitched video streams in realtime,thereby improving the operational efficiency and visual quality of multi-UAV aerial surveillance.展开更多
This paper designs and implements a single-camera 360°panoramic imaging system based on motor-driven fisheye rotation.The system utilizes a stepper motor for precise angular control,enabling the camera to rotate ...This paper designs and implements a single-camera 360°panoramic imaging system based on motor-driven fisheye rotation.The system utilizes a stepper motor for precise angular control,enabling the camera to rotate around its optical center to capture multi-view images,thereby avoiding the parallax and geometric mismatch problems inherent in traditional multi-camera configurations.To address the strong distortion characteristics of fisheye images,an equidistant projection model is adopted for distortion correction.On this basis,a brightness normalization method combining global linear brightness correction and local illumination compensation is proposed to enhance stitching consistency.By establishing a geometry model constrained by camera rotation and integrating cylindrical projection with cosine-weighted blending,the system achieves high-precision panoramic stitching and seamless visual transitions.展开更多
BACKGROUND Wound management is an essential part of emergency medicine practice.A good suture technique should deal a complex irregular traumatic wound without any complications of dehiscence/gaping,infection,delayed ...BACKGROUND Wound management is an essential part of emergency medicine practice.A good suture technique should deal a complex irregular traumatic wound without any complications of dehiscence/gaping,infection,delayed wound healing,frequent dressings and further stay in hospital.There is no ideal technique of suturing for any wound.In pursuit of the new techniques,we have introduced a new suturing technique called combined oblique and vertical everting running(COVER)stitch which has showed good healing with less complications.AIM To compare the outcomes between the COVER stitch and conventional suturing group.METHODS In this study,we included 40 cases which were divided into two groups.Group 1 patients were managed by COVER stitch,and group 2 patients underwent conventional suturing for their wounds.The outcomes were measured in terms of scar quality,suturing duration and length of suture material used,suturing related complications and suture removal time which were compared by t-test usingχ^(2) test.RESULTS Better results were seen in COVER stitch than the conventional suturing.COVER group had significantly better results in terms of time taken for suture,amount suture material used and time taken for suture removal compared to the conventional group.No wound related complications were seen in this group.Moreover,scar formed was also better in COVER group.CONCLUSION COVER stitch is another new technique which can be used to deal simple to complex wounds and it is an emerging idea with good healthy scars with less complications.展开更多
Optical microscopes are essential tools for scientific research,but traditional microscopes are restricted to capturing only two-dimensional(2D)texture information,lacking comprehensive three-dimensional(3D)morphology...Optical microscopes are essential tools for scientific research,but traditional microscopes are restricted to capturing only two-dimensional(2D)texture information,lacking comprehensive three-dimensional(3D)morphology capabilities.Additionally,traditional microscopes are inherently constrained by the limited space-bandwidth product of optical systems,resulting in restricted depth of field(DOF)and field of view(FOV).Attempts to expand DOF and FOV typically come at the cost of diminished resolution.In this paper,we propose a texture-driven FOV stitching algorithm specifically designed for extended depth-of-field(EDOF)microscopy,allowing for the integration of 2D texture and 3D depth data to achieve high-resolution,high-throughput multimodal imaging.Experimental results demonstrate an 11-fold enhancement in DOF and an 8-fold expansion in FOV compared to traditional microscopes,while maintaining axial resolution after FOV extension.展开更多
Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production metho...Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production methods on their mechanical properties and their failure mechanism. It is concluded from test results that, in terms of mechanical properties, the RTM-made cross-joint holds superiority over other two, and both stitch-RTM and cobonding methods have significant adverse effects on mechanical proper- t...展开更多
A multi layer gridless area router is reported.Based on corner stitching,this router adopts tile expansion to explore path for each net.A heuristic method that penalizes nodes deviating from the destination is devise...A multi layer gridless area router is reported.Based on corner stitching,this router adopts tile expansion to explore path for each net.A heuristic method that penalizes nodes deviating from the destination is devised to accelerate the algorithm.Besides,an enhanced interval tree is used to manage the intermediate data structure.In order to improve the completion rate of routing,a new gridless rip up and rerouting algorithm is proposed.The experimental results indicate that the completion rate is improved after the rip up and reroute process and the speed of this algorithm is satisfactory.展开更多
According to the bio-characteristics of the lower and upper cavity surfaces of dental restoration, a stitching approach is proposed based on a virtual zipper working mechanism and a minimization of the surface total c...According to the bio-characteristics of the lower and upper cavity surfaces of dental restoration, a stitching approach is proposed based on a virtual zipper working mechanism and a minimization of the surface total curvature energy, which is used to resolve the stitching problems existing during computer-aided design for dental restorations. First, the two boundaries corresponding to the lower and upper surfaces are triangulated based on the zipper working mechanism to generate the initial stitching surface patch, of which the edges are distributed uniformly between the boundaries. Secondly, the initial stitching surface patch is subdivided and deformed to reconstruct an optimized surface patch according to the bio-characteristics of the teeth. The optimized surface patch is minimally distinguishable from the surrounding mesh in smoothness and density, and it can stitch the upper and lower cavity surfaces naturally. The experimental results show that the dental restorations obtained by the proposed method can satisfy both the shape aesthetic and the fitting accuracy, and meet the requirements of clinical oral medicine.展开更多
Stitch welding of plate covered skeleton structure of Ti-6Al-4V titanium alloys has a variety of applications in aerospace vehicle manufacture. The laser stitch welding of Ti-6Al-4V titanium alloys was carried out by ...Stitch welding of plate covered skeleton structure of Ti-6Al-4V titanium alloys has a variety of applications in aerospace vehicle manufacture. The laser stitch welding of Ti-6Al-4V titanium alloys was carried out by a 4 kW ROFIN fiber laser. Influences of laser welding parameters on the macroscopic geometry, porosity, microstructure and mechanical properties of the stitch welded seams were investigated by digital microscope, optical microscope, scanning electron microscope and universal tensile testing machine. The results showed that the three-pipe nozzle with gas flow rate larger than 5 L/min could avoid oxidization, presenting better shielding effect in comparison with the single-pipe nozzle. Porosity formation could be suppressed with the gap between plate and skeleton less than 0.1 mm, while the existing porosity can be reduced with remelting. The maximum shear strength of stitch welding joint with minimal porosity was obtained by employing laser power of 1700 W, welding speed of 1.5 m/min and defocusing distance of ＋8 ram.展开更多
We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects...We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects are first exposed with a small exposure step size （less than 10nm）. With the introduction of the additional proximity effect to compensate the original proximity effect, the shape, size, and position of the holes can be well controlled. The second step is the exposure of the access waveguides at a larger step size （about 30nm） to improve the scan speed of the EBL. The influence of write-field stitching error can be alleviated by replacing the original waveguides with tapered waveguides at the joint of adjacent write-fields. It is found experimentally that a higher exposure efficiency is achieved with a larger step size;however,a larger step size requires a higher dose.展开更多
Experimental and analytical investigation is conducted to explore the effects of stitching on plain （without hole） and open-hole compressive and tensile strength of uniweave T300/QY9512 laminates under different env...Experimental and analytical investigation is conducted to explore the effects of stitching on plain （without hole） and open-hole compressive and tensile strength of uniweave T300/QY9512 laminates under different environmental conditions （20 ℃/dry and wet, 150 ℃/dry and wet）. Strength performance of stitched composite laminates is also studied using finite element analysis （FEA） model and compared with the experimental results to validate the model. It is found that under similar environmental conditions, the open-hole compressive strength of stitched laminate is decreased and open-hole tensile strength increased as compared to the unstitched laminates. Predicted tensile and compressive strengths are found to be in a good agreement with the test results and the relative error in all cases is less than 15%.展开更多
A novel automatic seamless stitching method is presented. Compared to the traditional method, it can speed the processing and minimize the utilization of human resources to produce global lunar map. Meanwhile, a new g...A novel automatic seamless stitching method is presented. Compared to the traditional method, it can speed the processing and minimize the utilization of human resources to produce global lunar map. Meanwhile, a new global image map of the Moon with spatial resolution of -120 m has been completed by the proposed method from Chang＇E-1 CCD image data.展开更多
For the purpose of identifying the stern of the SWATH （Small Waterplane Area Twin Hull） availably and perfecting the detection technique of the SWATH ship＇s performance, this paper presents a novel bidirectional im...For the purpose of identifying the stern of the SWATH （Small Waterplane Area Twin Hull） availably and perfecting the detection technique of the SWATH ship＇s performance, this paper presents a novel bidirectional image registration strategy and mosaicing technique based on the scale invariant feature transform （SIFT） algorithm. The proposed method can help us observe the stern with a great visual angle for analyzing the performance of the control fins of the SWATH. SIFT is one of the most effective local features of the scale, rotation and illumination invariant. However, there are a few false match rates in this algorithm. In terms of underwater machine vision, only by acquiring an accurate match rate can we find an underwater robot rapidly and identify the location of the object. Therefore, firstly, the selection of the match ratio principle is put forward in this paper; secondly, some advantages of the bidirectional registration algorithm are concluded by analyzing the characteristics of the unidirectional matching method. Finally, an automatic underwater image splicing method is proposed on the basis of fixed dimension, and then the edge of the image＇s overlapping section is merged by the principal components analysis algorithm. The experimental results achieve a better registration and smooth mosaicing effect, demonstrating that the proposed method is effective.展开更多
In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced...In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt （LM） method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.展开更多
This contribution attempts to model the alteration of the in-plane elastic properties in laminates caused by stitching, and to predict the in-plane effective tensile strength of the stitched composite laminates. The d...This contribution attempts to model the alteration of the in-plane elastic properties in laminates caused by stitching, and to predict the in-plane effective tensile strength of the stitched composite laminates. The distortion of in-plane fibers is considered to be the main cause that affects the in-plane mechanical properties. A fiber distortion model is proposed to characterize the fiber misalignment and the fiber content concentration due to stitching. The undistorted region, the fiber distortion region, the resin-rich pocket and the through-thickness reinforcement section are taken into account. The fiber misalignment and inhomogeneous fiber content due to stitching have been formulated by introducing two parameters, the distortion width and maximum misalignment. It has been found that the ply stress concentration in stitched laminates is influenced by the two concurrent factors, the stitch hole and inhomogeneous fiber content. The stitch hole brings about the stress concentration whereas the higher fiber content at the local region induced by stitching restrains the local deformation of the composite. The model is used to predict the tensile strength of the [0/45/0/-45/90/45/0/-45]58 T300/QY9512 composite laminate stitched by Kevlar 29 yarn with different stitching configurations, showing an acceptable agreement with experimental data.展开更多
Rotator cuff tear is a common medical condition.We introduce various suture methods that can be used for arthroscopic rotator cuff repair,review the single row rotator cuff repair method with modified technique,and in...Rotator cuff tear is a common medical condition.We introduce various suture methods that can be used for arthroscopic rotator cuff repair,review the single row rotator cuff repair method with modified technique,and introduce the Ulsan-University(UU)stich.We compare the UU stitch with the modified Mason-Allen(MA)suture method.The UU stitch configuration is a simple alternative to the modified MA suture configuration for rotator cuff repair.展开更多
文摘BACKGROUND Laparoscopic cervical cerclage is performed for patients with abnormal cervical anatomy and/or transvaginal cervical cerclage failure.However,the method of removing the stitches to allow labour induction remains controversial.According to published literature,stitches are removed through laparoscopic or transvaginal methods.Herein,we report,for the first time,a case of a patient who had undergone laparoscopic cerclage,and then underwent removal of stitches by laparotomy and labour induction in the third trimester of pregnancy.CASE SUMMARY A patient who underwent laparoscopic cervical cerclage due to cervical insufficiency became pregnant naturally following the operation.At 31 wk of pregnancy,severe foetal malformations were found.To successfully induce labour,cerclage stitches were removed via laparotomy,and rivanol was injected directly into the uterus.Following successful induction of labour,the patient delivered a dead foetus.CONCLUSION This report provides a reliable scheme of removing cerclage stitches for patients who have undergone laparoscopic cerclage but experience severe foetal malformations.
文摘Guided by the All-China Women’s Federation(ACWF),the China Children and Teenagers’Fund(CCTF)and Hengyuanxiang Group launched Heng’ai Action in 2005.This public-welfare initiative called on caring people to knit sweaters for orphans and/or children with disabilities.During the past two decades,more than 465,000 kilograms of wool and 147 million yuan(US$21 million)in funding and materials have been donated to the program.Further,1.5 million sweaters have been knitted and presented to children in need,warming their bodies and hearts.
文摘With the development of computer vision technology,panoramic image stitching has been widely used in fields such as scene reconstruction.A single traditional image cannot fully capture the panoramic view of the iconic East Gate of the South Campus of Shaanxi University of Technology.Therefore,this project aims to technically fuse multiple partial images into a complete panoramic image,enabling comprehensive recording and visual presentation of the architectural landscapes and spatial environments in this area.This report first introduces the technical background and application scenarios,clarifying the necessity of panoramic image stitching in campus landscape recording.It then elaborates on the core objectives and practical values,highlighting the role of technical solutions in improving image quality.Technically,a modular system design based on OpenCV is adopted,including modules such as image preprocessing,feature extraction and matching,image registration,fusion,and post-processing.Specifically,the SIFT algorithm is applied for feature extraction,KNN combined with ratio testing is used for feature matching,image registration is achieved by calculating the homography matrix,the fusion process utilizes multiband blending and Laplacian pyramid,and post-processing includes operations such as black area filling and CLAHE contrast enhancement.The experiment was conducted in a specific hardware and software environment using five overlapping images.After preprocessing,stitching,detail enhancement,and black edge repair,a panoramic image was successfully generated.The results show that the panoramic image fully presents the relevant scenery,with concealed seams,balanced exposure differences,and strong hierarchical details.This report provides a systematic description of the project’s technical implementation and achievement application.
基金the Special Research Fund for the Natural Science Foundation of Chongqing(No.cstc2019jcyjmsxm1351)the Science and Technology Research Project of Chongqing Education Commission(No.KJQN2020006300)。
文摘There is still a dearth of systematic study on picture stitching techniques for the natural tubular structures of intestines,and traditional stitching techniques have a poor application to endoscopic images with deep scenes.In order to recreate the intestinal wall in two dimensions,a method is developed.The normalized Laplacian algorithm is used to enhance the image and transform it into polar coordinates according to the characteristics that intestinal images are not obvious and usually arranged in a circle,in order to extract the new image segments of the current image relative to the previous image.The improved weighted fusion algorithm is then used to sequentially splice the segment images.The experimental results demonstrate that the suggested approach can improve image clarity and minimize noise while maintaining the information content of intestinal images.In addition,the method's seamless transition between the final portions of a panoramic image also demonstrates that the stitching trace has been removed.
基金funded by Graduate innovation program of National University of Defense Technology,grant number:XJZH2024016.
文摘The proliferation of low-altitude economic activities has precipitated a significant expansion in the application domains of Unmanned Aerial Vehicle(UAV),transcending the constraints of singular platform operation.Multi-UAV cooperative online remote sensing image stitching involves several challenges,including image blurriness and deformation caused by platform vibrations,as well as managing vast amounts of data and addressing transmission delays.This paper introduces a real-time system for multi-UAV video stitching that integrates hardware acceleration,pose-guided ROI filtering,and temporal consistency constraints.Data from the onboard GPS and Inertial Measurement Unit(IMU)are used to estimate the overlap between two aerial images.Subsequently,the Graphics Processing Unit(GPU)within an edge computing platform is tasked with swiftly detecting SIFT features within the overlapping image sectors.Feature point matching is performed using a position-guided matching algorithm to compute the homography matrix.The results demonstrate that the RK3588-based edge computing platform exhibits rapid image decoding and stitching capabilities,with an average stitching latency of 36.43ms.Furthermore,this study developed a ground-based human-machine interaction system to present stitched video streams in realtime,thereby improving the operational efficiency and visual quality of multi-UAV aerial surveillance.
基金Graduate Innovation Ability Training Program of the Hebei Provincial Department of Education,2025(Project No.:CXZZSS2025095)。
文摘This paper designs and implements a single-camera 360°panoramic imaging system based on motor-driven fisheye rotation.The system utilizes a stepper motor for precise angular control,enabling the camera to rotate around its optical center to capture multi-view images,thereby avoiding the parallax and geometric mismatch problems inherent in traditional multi-camera configurations.To address the strong distortion characteristics of fisheye images,an equidistant projection model is adopted for distortion correction.On this basis,a brightness normalization method combining global linear brightness correction and local illumination compensation is proposed to enhance stitching consistency.By establishing a geometry model constrained by camera rotation and integrating cylindrical projection with cosine-weighted blending,the system achieves high-precision panoramic stitching and seamless visual transitions.
文摘BACKGROUND Wound management is an essential part of emergency medicine practice.A good suture technique should deal a complex irregular traumatic wound without any complications of dehiscence/gaping,infection,delayed wound healing,frequent dressings and further stay in hospital.There is no ideal technique of suturing for any wound.In pursuit of the new techniques,we have introduced a new suturing technique called combined oblique and vertical everting running(COVER)stitch which has showed good healing with less complications.AIM To compare the outcomes between the COVER stitch and conventional suturing group.METHODS In this study,we included 40 cases which were divided into two groups.Group 1 patients were managed by COVER stitch,and group 2 patients underwent conventional suturing for their wounds.The outcomes were measured in terms of scar quality,suturing duration and length of suture material used,suturing related complications and suture removal time which were compared by t-test usingχ^(2) test.RESULTS Better results were seen in COVER stitch than the conventional suturing.COVER group had significantly better results in terms of time taken for suture,amount suture material used and time taken for suture removal compared to the conventional group.No wound related complications were seen in this group.Moreover,scar formed was also better in COVER group.CONCLUSION COVER stitch is another new technique which can be used to deal simple to complex wounds and it is an emerging idea with good healthy scars with less complications.
基金supported by Science Foundation of Donghai Lab-oratory(No.DH-2022KF01001).
文摘Optical microscopes are essential tools for scientific research,but traditional microscopes are restricted to capturing only two-dimensional(2D)texture information,lacking comprehensive three-dimensional(3D)morphology capabilities.Additionally,traditional microscopes are inherently constrained by the limited space-bandwidth product of optical systems,resulting in restricted depth of field(DOF)and field of view(FOV).Attempts to expand DOF and FOV typically come at the cost of diminished resolution.In this paper,we propose a texture-driven FOV stitching algorithm specifically designed for extended depth-of-field(EDOF)microscopy,allowing for the integration of 2D texture and 3D depth data to achieve high-resolution,high-throughput multimodal imaging.Experimental results demonstrate an 11-fold enhancement in DOF and an 8-fold expansion in FOV compared to traditional microscopes,while maintaining axial resolution after FOV extension.
文摘Tension and shear tests are carried out on composite cross-joints, produced by resin transfer moulding (RTM), stitch-RTM and cobonding techniques separately, to investigate the influences of different production methods on their mechanical properties and their failure mechanism. It is concluded from test results that, in terms of mechanical properties, the RTM-made cross-joint holds superiority over other two, and both stitch-RTM and cobonding methods have significant adverse effects on mechanical proper- t...
文摘A multi layer gridless area router is reported.Based on corner stitching,this router adopts tile expansion to explore path for each net.A heuristic method that penalizes nodes deviating from the destination is devised to accelerate the algorithm.Besides,an enhanced interval tree is used to manage the intermediate data structure.In order to improve the completion rate of routing,a new gridless rip up and rerouting algorithm is proposed.The experimental results indicate that the completion rate is improved after the rip up and reroute process and the speed of this algorithm is satisfactory.
基金The National High Technology Research and Development Program of China(863 Program)(No.2005AA420240)the Key Science and Technology Program of Jiangsu Province (No.BE2005014)
文摘According to the bio-characteristics of the lower and upper cavity surfaces of dental restoration, a stitching approach is proposed based on a virtual zipper working mechanism and a minimization of the surface total curvature energy, which is used to resolve the stitching problems existing during computer-aided design for dental restorations. First, the two boundaries corresponding to the lower and upper surfaces are triangulated based on the zipper working mechanism to generate the initial stitching surface patch, of which the edges are distributed uniformly between the boundaries. Secondly, the initial stitching surface patch is subdivided and deformed to reconstruct an optimized surface patch according to the bio-characteristics of the teeth. The optimized surface patch is minimally distinguishable from the surrounding mesh in smoothness and density, and it can stitch the upper and lower cavity surfaces naturally. The experimental results show that the dental restorations obtained by the proposed method can satisfy both the shape aesthetic and the fitting accuracy, and meet the requirements of clinical oral medicine.
基金Project(2012BAF08B02)supported by Key Project in the National Science and Technology Pillar Program During the Twelfth Five-year Plan Period,China
文摘Stitch welding of plate covered skeleton structure of Ti-6Al-4V titanium alloys has a variety of applications in aerospace vehicle manufacture. The laser stitch welding of Ti-6Al-4V titanium alloys was carried out by a 4 kW ROFIN fiber laser. Influences of laser welding parameters on the macroscopic geometry, porosity, microstructure and mechanical properties of the stitch welded seams were investigated by digital microscope, optical microscope, scanning electron microscope and universal tensile testing machine. The results showed that the three-pipe nozzle with gas flow rate larger than 5 L/min could avoid oxidization, presenting better shielding effect in comparison with the single-pipe nozzle. Porosity formation could be suppressed with the gap between plate and skeleton less than 0.1 mm, while the existing porosity can be reduced with remelting. The maximum shear strength of stitch welding joint with minimal porosity was obtained by employing laser power of 1700 W, welding speed of 1.5 m/min and defocusing distance of ＋8 ram.
文摘We present an all-e-beam lithography （EBL） process for the patterning of photonic crystal waveguides. The whole device structures are exposed in two steps. Holes constituting the photonic crystal lattice and defects are first exposed with a small exposure step size （less than 10nm）. With the introduction of the additional proximity effect to compensate the original proximity effect, the shape, size, and position of the holes can be well controlled. The second step is the exposure of the access waveguides at a larger step size （about 30nm） to improve the scan speed of the EBL. The influence of write-field stitching error can be alleviated by replacing the original waveguides with tapered waveguides at the joint of adjacent write-fields. It is found experimentally that a higher exposure efficiency is achieved with a larger step size;however,a larger step size requires a higher dose.
基金National Natural Science Foundation of China(10672009)Basic Science Foundation of Aviation(05B51044)"FanZhou" Youth Scientific Funds(20060501)
文摘Experimental and analytical investigation is conducted to explore the effects of stitching on plain （without hole） and open-hole compressive and tensile strength of uniweave T300/QY9512 laminates under different environmental conditions （20 ℃/dry and wet, 150 ℃/dry and wet）. Strength performance of stitched composite laminates is also studied using finite element analysis （FEA） model and compared with the experimental results to validate the model. It is found that under similar environmental conditions, the open-hole compressive strength of stitched laminate is decreased and open-hole tensile strength increased as compared to the unstitched laminates. Predicted tensile and compressive strengths are found to be in a good agreement with the test results and the relative error in all cases is less than 15%.
基金supported by the Science and Technology Development Fund of Macao (Nos. 004/2011/A1 and 015/2010/A)the National High Technology Research and Development Program (No. 2010AA122202)
文摘A novel automatic seamless stitching method is presented. Compared to the traditional method, it can speed the processing and minimize the utilization of human resources to produce global lunar map. Meanwhile, a new global image map of the Moon with spatial resolution of -120 m has been completed by the proposed method from Chang＇E-1 CCD image data.
基金Supported by the "Liaoning Baiqianwan" Talents Program(No.200718625)the Program of Scientific Research Project of Liao Ning Province Education Commission(No.LS2010046)the National Commonweal Industry Scientific Research Project(No.201003024)
文摘For the purpose of identifying the stern of the SWATH （Small Waterplane Area Twin Hull） availably and perfecting the detection technique of the SWATH ship＇s performance, this paper presents a novel bidirectional image registration strategy and mosaicing technique based on the scale invariant feature transform （SIFT） algorithm. The proposed method can help us observe the stern with a great visual angle for analyzing the performance of the control fins of the SWATH. SIFT is one of the most effective local features of the scale, rotation and illumination invariant. However, there are a few false match rates in this algorithm. In terms of underwater machine vision, only by acquiring an accurate match rate can we find an underwater robot rapidly and identify the location of the object. Therefore, firstly, the selection of the match ratio principle is put forward in this paper; secondly, some advantages of the bidirectional registration algorithm are concluded by analyzing the characteristics of the unidirectional matching method. Finally, an automatic underwater image splicing method is proposed on the basis of fixed dimension, and then the edge of the image＇s overlapping section is merged by the principal components analysis algorithm. The experimental results achieve a better registration and smooth mosaicing effect, demonstrating that the proposed method is effective.
基金supported by the National Natural Science Foundation of China(61473100)
文摘In order to achieve a high precision in three-dimensional（3D） multi-camera measurement system, an efficient multi-cameracalibration method is proposed. A stitching method of large scalecalibration targets is deduced, and a fundamental of multi-cameracalibration based on the large scale calibration target is provided.To avoid the shortcomings of the method, the vector differencesof reprojection error with the presence of the constraint conditionof the constant rigid body transformation is modelled, and mini-mized by the Levenberg-Marquardt （LM） method. Results of thesimulation and observation data calibration experiment show thatthe accuracy of the system calibrated by the proposed methodreaches 2 mm when measuring distance section of 20 000 mmand scale section of 7 000 mm × 7 000 mm. Consequently, theproposed method of multi-camera calibration performs better thanthe fundamental in stability. This technique offers a more uniformerror distribution for measuring large scale space.
基金Project supported by the Excellent Young Teachers Program of the Ministry of Education of Chinathe Shu-Guang Program of the City of Shanghai+1 种基金the National Natural Sciences Foundation of China(No.10372120)Shanghai Leading Academic Discipline Project(No.Y0103).
文摘This contribution attempts to model the alteration of the in-plane elastic properties in laminates caused by stitching, and to predict the in-plane effective tensile strength of the stitched composite laminates. The distortion of in-plane fibers is considered to be the main cause that affects the in-plane mechanical properties. A fiber distortion model is proposed to characterize the fiber misalignment and the fiber content concentration due to stitching. The undistorted region, the fiber distortion region, the resin-rich pocket and the through-thickness reinforcement section are taken into account. The fiber misalignment and inhomogeneous fiber content due to stitching have been formulated by introducing two parameters, the distortion width and maximum misalignment. It has been found that the ply stress concentration in stitched laminates is influenced by the two concurrent factors, the stitch hole and inhomogeneous fiber content. The stitch hole brings about the stress concentration whereas the higher fiber content at the local region induced by stitching restrains the local deformation of the composite. The model is used to predict the tensile strength of the [0/45/0/-45/90/45/0/-45]58 T300/QY9512 composite laminate stitched by Kevlar 29 yarn with different stitching configurations, showing an acceptable agreement with experimental data.
文摘Rotator cuff tear is a common medical condition.We introduce various suture methods that can be used for arthroscopic rotator cuff repair,review the single row rotator cuff repair method with modified technique,and introduce the Ulsan-University(UU)stich.We compare the UU stitch with the modified Mason-Allen(MA)suture method.The UU stitch configuration is a simple alternative to the modified MA suture configuration for rotator cuff repair.
