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
Traditional feature-based image stitching techniques often encounter obstacles when dealing with images lackingunique attributes or suffering from quality degradation. The scarcity of annotated datasets in real-life s...Traditional feature-based image stitching techniques often encounter obstacles when dealing with images lackingunique attributes or suffering from quality degradation. The scarcity of annotated datasets in real-life scenesseverely undermines the reliability of supervised learning methods in image stitching. Furthermore, existing deeplearning architectures designed for image stitching are often too bulky to be deployed on mobile and peripheralcomputing devices. To address these challenges, this study proposes a novel unsupervised image stitching methodbased on the YOLOv8 (You Only Look Once version 8) framework that introduces deep homography networksand attentionmechanisms. Themethodology is partitioned into three distinct stages. The initial stage combines theattention mechanism with a pooling pyramid model to enhance the detection and recognition of compact objectsin images, the task of the deep homography networks module is to estimate the global homography of the inputimages consideringmultiple viewpoints. The second stage involves preliminary stitching of the masks generated inthe initial stage and further enhancement through weighted computation to eliminate common stitching artifacts.The final stage is characterized by adaptive reconstruction and careful refinement of the initial stitching results.Comprehensive experiments acrossmultiple datasets are executed tometiculously assess the proposed model. Ourmethod’s Peak Signal-to-Noise Ratio (PSNR) and Structure Similarity Index Measure (SSIM) improved by 10.6%and 6%. These experimental results confirm the efficacy and utility of the presented model in this paper.展开更多
Stomachache is one of the most common diseases of digestive system, among which stomach pain of deficiency cold of spleen and stomach is the most common. Acupuncture and moxibustion therapy as an external treatment of...Stomachache is one of the most common diseases of digestive system, among which stomach pain of deficiency cold of spleen and stomach is the most common. Acupuncture and moxibustion therapy as an external treatment of traditional Chinese medicine for relieving stomach pain due to deficiency of spleen and stomach, has the advantages of convenient operation, small adverse reactions and remarkable curative effect, which is easy for patients to accept. In this paper, acupuncture and moxibustion therapy such as moxibustion and warm acupuncture therapy for stomach pain of spleen and stomach deficiency cold type is summarized to provide evidence-based basis for clinical treatment of stomach pain of spleen and stomach deficiency cold type.展开更多
Stitch density is one of the critical quality parameters of knit fabrics. This parameter is closely related to other physical quality parameters like fabric weight, fabric tightness factor, fiber types, blend ratio, y...Stitch density is one of the critical quality parameters of knit fabrics. This parameter is closely related to other physical quality parameters like fabric weight, fabric tightness factor, fiber types, blend ratio, yarn diameter and linear density, and fabric structure. Selecting stitch density (wales per inch, course per inch) is essential to getting the appropriate fabric weight and desired quality. Usually, no rules or assumptions exist to get the desired stitch density in the finished fabric stage. Fifteen types of blended knit fabrics were prepared to conduct the study. The varying percentages of cotton, polyester, and elastane are incorporated in the blends. Regression analysis and regression ANOVA tests were done to predict the stitch density of finished fabrics. A suitable regression equation is established to get the desired results. The study also found that the stitch density value in the finished stage fabric decreases by approximately 15% compared to the stitch density in the grey fabric stage. This study will help the fabric manufacturers get the finished fabric stitch density in advance by utilizing the grey fabric stitch density data set. The author expects this research to benefit the knitting and dyeing industry, new researchers, and advanced researchers.展开更多
Ceramic matrix composites (CMCs) are the preferred materials for solving advanced aerospace high-temperature structural components;it has the comprehensive advantages of higher temperature (~1500˚C) and low density. I...Ceramic matrix composites (CMCs) are the preferred materials for solving advanced aerospace high-temperature structural components;it has the comprehensive advantages of higher temperature (~1500˚C) and low density. In service environments, CMCs exhibit complex damage mechanisms and failure modes, which are affected by constituent materials, meso-architecture and inhere defects. In this paper, the in-plane tensile mechanical behavior of a plain-woven SiCf/SiC composite at room and elevated temperatures was investigated, and the factors affecting the tensile strength of the material were discussed in depth. The results show that the tensile modulus and strength of SiCf/SiC composites at high temperature are lower, but the fracture strain increases and the toughness of the composites is enhanced;the stitching holes significantly weaken the tensile strength of the material, resulting in the material is easy to break at the cross-section with stitching holes.展开更多
Branch identification technology is a key technology to achieve automated pruning of fruit tree branches, and one of its technical bottlenecks lies in the stitching of branch images. To this end, we propose a set of b...Branch identification technology is a key technology to achieve automated pruning of fruit tree branches, and one of its technical bottlenecks lies in the stitching of branch images. To this end, we propose a set of branch image stitching technology algorithms. The algorithm is based on the grey-scale prime centroid method to determine the detection feature points, and uses the coordinate transformation matrix H of the corresponding points of the image to carry out the image geometric transformation, and realises the feature matching through sample comparison and classification methods. The experimental results show that the matched point images are more correct and less time-consuming.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
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
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
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
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
Automatic video mosaicking is a challenging task in computer vision. Current researches consider either panoramic or mapping tasks on short videos. In this paper, an automatic mosaicking algorithm is proposed for both...Automatic video mosaicking is a challenging task in computer vision. Current researches consider either panoramic or mapping tasks on short videos. In this paper, an automatic mosaicking algorithm is proposed for both mapping and panoramic tasks based on the adapted key-frame on videos of any length.The speeded up robust features(SURF) and the grid motion statistic(GMS) algorithm are used for feature extraction and matching between consecutive frames, which are used to compute the transformation. In order to reduce the influence of the accumulated error during image stitching, an evaluation metric is put forward for the transformation matrix. Besides, a self-growth method is employed to stitch the global image for long videos. The algorithm is evaluated by using aerial-view and panoramic videos respectively on the graphic processing unit(GPU) device, which can satisfy the real-time requirement. The experimental results demonstrate that the proposed algorithm is able to achieve a better performance than the state-of-art.展开更多
In this paper, the tensile properties of the MWK structures produced with different basic stitches for composite reinforcement were experimentally studied. The results show that the MWK structures with the double loop...In this paper, the tensile properties of the MWK structures produced with different basic stitches for composite reinforcement were experimentally studied. The results show that the MWK structures with the double loop pillar stitches have better mechanical properties.展开更多
Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off (Scan Line Corrector) ga...Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off (Scan Line Corrector) gap-filling methods of LLHM (Local Linear Histogram Matching) and AWLHM (Adaptive Window Linear Histogram Matching), which leave stripes as a byproduct. To improve Landsat SLC-off images with stripes,we propose an algorithm involving some hypothetical stripe-crossing stitch lines using the mean pixel value of the stitch lines.展开更多
This paper presented a method of fabricating radio frequency( RF) transmission lines by embroidering conductive thread on fabric. A digital embroidery machine was selected to fabricate transmission lines. Effects of t...This paper presented a method of fabricating radio frequency( RF) transmission lines by embroidering conductive thread on fabric. A digital embroidery machine was selected to fabricate transmission lines. Effects of the typical process parameters on the S-parameter of these RF transmission lines were tested and discussed. And the results showed that embroidery process parameters such as stitch direction,stitch spacing,stitch length and embroidered tension had significant effects on the RF performance of embroidered transmission lines,of which stitch type was the most important factor for the measured S-parameter of transmission lines.展开更多
The study sought to investigate the historical background of the traditional hand-made embroidery technique, the production process, and its changing trends amongst the Asantes of Ghana. Interview and observation were...The study sought to investigate the historical background of the traditional hand-made embroidery technique, the production process, and its changing trends amongst the Asantes of Ghana. Interview and observation were used in collecting the needed data at selected craft centres in the Kwabre East District, Ejisu-Juaben municipality, Kumasi sub-metro and metropolitan in the Ashanti region of Ghana. The study employed both descriptive and experimental research methods based on the qualitative research approach. It was revealed that Kente and Adinkra enjoy wide reputation and therefore are considered as prestigious clothes. However, Nwomu cloth does not have this fame, only indigenes understand its usage and the philosophy behind its production. In view of this, it is recommended that the elders who are endowed with this unique craft must open their doors to the youth to learn the craft.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.
基金Science and Technology Research Project of the Henan Province(222102240014).
文摘Traditional feature-based image stitching techniques often encounter obstacles when dealing with images lackingunique attributes or suffering from quality degradation. The scarcity of annotated datasets in real-life scenesseverely undermines the reliability of supervised learning methods in image stitching. Furthermore, existing deeplearning architectures designed for image stitching are often too bulky to be deployed on mobile and peripheralcomputing devices. To address these challenges, this study proposes a novel unsupervised image stitching methodbased on the YOLOv8 (You Only Look Once version 8) framework that introduces deep homography networksand attentionmechanisms. Themethodology is partitioned into three distinct stages. The initial stage combines theattention mechanism with a pooling pyramid model to enhance the detection and recognition of compact objectsin images, the task of the deep homography networks module is to estimate the global homography of the inputimages consideringmultiple viewpoints. The second stage involves preliminary stitching of the masks generated inthe initial stage and further enhancement through weighted computation to eliminate common stitching artifacts.The final stage is characterized by adaptive reconstruction and careful refinement of the initial stitching results.Comprehensive experiments acrossmultiple datasets are executed tometiculously assess the proposed model. Ourmethod’s Peak Signal-to-Noise Ratio (PSNR) and Structure Similarity Index Measure (SSIM) improved by 10.6%and 6%. These experimental results confirm the efficacy and utility of the presented model in this paper.
文摘Stomachache is one of the most common diseases of digestive system, among which stomach pain of deficiency cold of spleen and stomach is the most common. Acupuncture and moxibustion therapy as an external treatment of traditional Chinese medicine for relieving stomach pain due to deficiency of spleen and stomach, has the advantages of convenient operation, small adverse reactions and remarkable curative effect, which is easy for patients to accept. In this paper, acupuncture and moxibustion therapy such as moxibustion and warm acupuncture therapy for stomach pain of spleen and stomach deficiency cold type is summarized to provide evidence-based basis for clinical treatment of stomach pain of spleen and stomach deficiency cold type.
文摘Stitch density is one of the critical quality parameters of knit fabrics. This parameter is closely related to other physical quality parameters like fabric weight, fabric tightness factor, fiber types, blend ratio, yarn diameter and linear density, and fabric structure. Selecting stitch density (wales per inch, course per inch) is essential to getting the appropriate fabric weight and desired quality. Usually, no rules or assumptions exist to get the desired stitch density in the finished fabric stage. Fifteen types of blended knit fabrics were prepared to conduct the study. The varying percentages of cotton, polyester, and elastane are incorporated in the blends. Regression analysis and regression ANOVA tests were done to predict the stitch density of finished fabrics. A suitable regression equation is established to get the desired results. The study also found that the stitch density value in the finished stage fabric decreases by approximately 15% compared to the stitch density in the grey fabric stage. This study will help the fabric manufacturers get the finished fabric stitch density in advance by utilizing the grey fabric stitch density data set. The author expects this research to benefit the knitting and dyeing industry, new researchers, and advanced researchers.
文摘Ceramic matrix composites (CMCs) are the preferred materials for solving advanced aerospace high-temperature structural components;it has the comprehensive advantages of higher temperature (~1500˚C) and low density. In service environments, CMCs exhibit complex damage mechanisms and failure modes, which are affected by constituent materials, meso-architecture and inhere defects. In this paper, the in-plane tensile mechanical behavior of a plain-woven SiCf/SiC composite at room and elevated temperatures was investigated, and the factors affecting the tensile strength of the material were discussed in depth. The results show that the tensile modulus and strength of SiCf/SiC composites at high temperature are lower, but the fracture strain increases and the toughness of the composites is enhanced;the stitching holes significantly weaken the tensile strength of the material, resulting in the material is easy to break at the cross-section with stitching holes.
文摘Branch identification technology is a key technology to achieve automated pruning of fruit tree branches, and one of its technical bottlenecks lies in the stitching of branch images. To this end, we propose a set of branch image stitching technology algorithms. The algorithm is based on the grey-scale prime centroid method to determine the detection feature points, and uses the coordinate transformation matrix H of the corresponding points of the image to carry out the image geometric transformation, and realises the feature matching through sample comparison and classification methods. The experimental results show that the matched point images are more correct and less time-consuming.
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.
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.
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.
基金supported by the National Science Foundation of China(61603040,61973036,61433003)。
文摘Automatic video mosaicking is a challenging task in computer vision. Current researches consider either panoramic or mapping tasks on short videos. In this paper, an automatic mosaicking algorithm is proposed for both mapping and panoramic tasks based on the adapted key-frame on videos of any length.The speeded up robust features(SURF) and the grid motion statistic(GMS) algorithm are used for feature extraction and matching between consecutive frames, which are used to compute the transformation. In order to reduce the influence of the accumulated error during image stitching, an evaluation metric is put forward for the transformation matrix. Besides, a self-growth method is employed to stitch the global image for long videos. The algorithm is evaluated by using aerial-view and panoramic videos respectively on the graphic processing unit(GPU) device, which can satisfy the real-time requirement. The experimental results demonstrate that the proposed algorithm is able to achieve a better performance than the state-of-art.
文摘In this paper, the tensile properties of the MWK structures produced with different basic stitches for composite reinforcement were experimentally studied. The results show that the MWK structures with the double loop pillar stitches have better mechanical properties.
文摘Stripes are artifacts in satellite images caused by various factors such as hardware defects. In some cases, these artifacts are introduced by some mitigating algorithms like Landsat SLC-off (Scan Line Corrector) gap-filling methods of LLHM (Local Linear Histogram Matching) and AWLHM (Adaptive Window Linear Histogram Matching), which leave stripes as a byproduct. To improve Landsat SLC-off images with stripes,we propose an algorithm involving some hypothetical stripe-crossing stitch lines using the mean pixel value of the stitch lines.
基金National Natural Science Foundation of China(No.51405079)the Fundamental Research Funds for the Central Universities,China
文摘This paper presented a method of fabricating radio frequency( RF) transmission lines by embroidering conductive thread on fabric. A digital embroidery machine was selected to fabricate transmission lines. Effects of the typical process parameters on the S-parameter of these RF transmission lines were tested and discussed. And the results showed that embroidery process parameters such as stitch direction,stitch spacing,stitch length and embroidered tension had significant effects on the RF performance of embroidered transmission lines,of which stitch type was the most important factor for the measured S-parameter of transmission lines.
文摘The study sought to investigate the historical background of the traditional hand-made embroidery technique, the production process, and its changing trends amongst the Asantes of Ghana. Interview and observation were used in collecting the needed data at selected craft centres in the Kwabre East District, Ejisu-Juaben municipality, Kumasi sub-metro and metropolitan in the Ashanti region of Ghana. The study employed both descriptive and experimental research methods based on the qualitative research approach. It was revealed that Kente and Adinkra enjoy wide reputation and therefore are considered as prestigious clothes. However, Nwomu cloth does not have this fame, only indigenes understand its usage and the philosophy behind its production. In view of this, it is recommended that the elders who are endowed with this unique craft must open their doors to the youth to learn the craft.