Article Article types Articles commonly fall into one of three main categories:Full-length articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of...Article Article types Articles commonly fall into one of three main categories:Full-length articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of work that has been published previously in short form such as a Communication are usually acceptable.展开更多
Introduction Types of paper Contributions falling into the following categories will be considered for publication: Original research papers, reviews, Research Notes, Short Communication, New technologies, News and Vi...Introduction Types of paper Contributions falling into the following categories will be considered for publication: Original research papers, reviews, Research Notes, Short Communication, New technologies, News and Views, Commentary on significant events and topics in global horticultural fields with international interests.展开更多
INTRODUCTION Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriat...INTRODUCTION Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.展开更多
INTRODUCTION.Types of paper.Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriat...INTRODUCTION.Types of paper.Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.展开更多
Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thi...Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.展开更多
Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate art...Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.展开更多
Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate art...Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.展开更多
Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe seve...Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe severely affects its pressure-holding capacity,hence the early detection of internal cracks is crucial for effective pipeline maintenance strategies.This study extends the scope of guided wave-based ultrasonic testing to detect the growth of internal cracks in a natural gas distribution PE pipe.Laboratory experiments and a finite element model were planned to study the wave-crack interaction at different stages of axially oriented internal crack growth with a piezoceramic transducer-based setup arranged in a pitch-catch configuration.Mode dispersion analysis supplemented with preliminary experiments was performed to isolate the optimal inspection frequency,leading to the selection of the T(0,1)mode at 50-kHz for the investigation.A transmission index based on the energy of the T(0,1)mode was developed to trace the extent of simulated crack growth.The findings revealed an inverse linear correlation between the transmission index and the crack depth for crack growth beyond 20%crack depth.展开更多
The present work proposed a new method for the modeling by the finite element method of the acoustic propagation problems in infinite axisymmetric cylindrical guides lined with locally reacting absorbent materials wit...The present work proposed a new method for the modeling by the finite element method of the acoustic propagation problems in infinite axisymmetric cylindrical guides lined with locally reacting absorbent materials without flow. The method deals with the development of an efficient transparent boundary condition based on DtN operators. The method developed in this study is successfully applied to a straight axisymmetric lined guide by imposing a mode on one of the artificial boundaries of the truncated guide. The results are in good agreement with analytical solutions. Applying the method for a non-uniform axisymmetric lined guide which is a complex case, proved its effectiveness and the results compared to those of PML layers are in very good agreement.展开更多
Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.M...Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions.展开更多
Introduction: Prostate cancer (PCa) is the third most prevalent cancer among Malaysian males, often diagnosed at advanced stages, leading to suboptimal outcomes. While transrectal ultrasound-guided systematic biopsy (...Introduction: Prostate cancer (PCa) is the third most prevalent cancer among Malaysian males, often diagnosed at advanced stages, leading to suboptimal outcomes. While transrectal ultrasound-guided systematic biopsy (TRUS-SB) is the primary diagnostic method, prebiopsy multiparametric magnetic resonance imaging (mpMRI) is gaining popularity in identifying suspicious lesions. This study addresses the lack of comprehensive investigations into the efficacy of cognitive registration TRUS targeted biopsy (COG-TB) compared to conventional TRUS-SB, considering the resource limitations of the Malaysian healthcare system. Materials and Methods: A retrospective cohort study was conducted in two Malaysian healthcare facilities. 116 adult patients with a prostate-specific antigen (PSA) level of more than 4 ng/mL who underwent both COG-TB and TRUS-SB between October 2020 and March 2022 were included. Primary outcomes were cancer detection rate and histopathological outcomes, including Gleason score. Results: COG-TB showed a higher overall cancer detection rate (50%) compared to TRUS-SB (44%). Clinically significant cancer detection rates were similar between COG-TB and TRUS-SB (37.1%). Further analysis revealed that both COG-TB and TRUS-SB detected clinically significant cancer in 30.2% of patients, did not detect it in 56.0%, and had conflicting findings in 16 patients (p Conclusion: COG-TB and TRUS-SB have comparable detection rates for clinically significant prostate cancer, with COG-TB showing a higher tendency to detect insignificant prostate cancer. Further studies comparing these methods are warranted.展开更多
Automated Guided Vehicles(AGVs)have been introduced into various applications,such as automated warehouse systems,flexible manufacturing systems,and container terminal systems.However,few publications have outlined pr...Automated Guided Vehicles(AGVs)have been introduced into various applications,such as automated warehouse systems,flexible manufacturing systems,and container terminal systems.However,few publications have outlined problems in need of attention in AGV applications comprehensively.In this paper,several key issues and essential models are presented.First,the advantages and disadvantages of centralized and decentralized AGVs systems were compared;second,warehouse layout and operation optimization were introduced,including some omitted areas,such as AGVs fleet size and electrical energy management;third,AGVs scheduling algorithms in chessboardlike environments were analyzed;fourth,the classical route-planning algorithms for single AGV and multiple AGVs were presented,and some Artificial Intelligence(AI)-based decision-making algorithms were reviewed.Furthermore,a novel idea for accelerating route planning by combining Reinforcement Learning(RL)andDijkstra’s algorithm was presented,and a novel idea of the multi-AGV route-planning method of combining dynamic programming and Monte-Carlo tree search was proposed to reduce the energy cost of systems.展开更多
With the wide application of automated guided vehicles(AGVs) in large scale outdoor scenarios with complex terrain,the collaborative work of a large number of AGVs becomes the main trend.The effective multi-agent path...With the wide application of automated guided vehicles(AGVs) in large scale outdoor scenarios with complex terrain,the collaborative work of a large number of AGVs becomes the main trend.The effective multi-agent path finding(MAPF) algorithm is urgently needed to ensure the efficiency and realizability of the whole system. The complex terrain of outdoor scenarios is fully considered by using different values of passage cost to quantify different terrain types. The objective of the MAPF problem is to minimize the cost of passage while the Manhattan distance of paths and the time of passage are also evaluated for a comprehensive comparison. The pre-path-planning and real-time-conflict based greedy(PRG) algorithm is proposed as the solution. Simulation is conducted and the proposed PRG algorithm is compared with waiting-stop A^(*) and conflict based search(CBS) algorithms. Results show that the PRG algorithm outperforms the waiting-stop A^(*) algorithm in all three performance indicators,and it is more applicable than the CBS algorithm when a large number of AGVs are working collaboratively with frequent collisions.展开更多
Article Article types Articles commonly fall into one of three main categories:Fulllength articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of ...Article Article types Articles commonly fall into one of three main categories:Fulllength articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of work that has been published previously in short form such as a Communication are usually acceptable.Short communications must contain original and highly significant work whose high novelty warrants rapid publication.展开更多
文摘Article Article types Articles commonly fall into one of three main categories:Full-length articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of work that has been published previously in short form such as a Communication are usually acceptable.
文摘Introduction Types of paper Contributions falling into the following categories will be considered for publication: Original research papers, reviews, Research Notes, Short Communication, New technologies, News and Views, Commentary on significant events and topics in global horticultural fields with international interests.
文摘INTRODUCTION Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.
文摘INTRODUCTION.Types of paper.Contributions falling into the following categories will be considered for publication:Original research papers,reviews and short communications.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.
基金Project supported by the Natural Science Foundation of Jilin Province of China(Grant Nos.20240402081GH and 20220101012JC)the National Natural Science Foundation of China(Grant No.42074139)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA202308)。
文摘Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.
文摘Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.
文摘Introduction Types of paper Contributions falling into the following categories will be considered for publication:Original research papers,Reviews,Short communication.Please ensure that you select the appropriate article type from the list of options when making your submission.Authors contributing to special issues should ensure that they select the special issue article type from this list.
基金the financial support provided by USDOT Pipeline and Hazardous Materials Safety Administration (PHMSA)through the Competitive Academic Agreement Program (CAAP)。
文摘Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe severely affects its pressure-holding capacity,hence the early detection of internal cracks is crucial for effective pipeline maintenance strategies.This study extends the scope of guided wave-based ultrasonic testing to detect the growth of internal cracks in a natural gas distribution PE pipe.Laboratory experiments and a finite element model were planned to study the wave-crack interaction at different stages of axially oriented internal crack growth with a piezoceramic transducer-based setup arranged in a pitch-catch configuration.Mode dispersion analysis supplemented with preliminary experiments was performed to isolate the optimal inspection frequency,leading to the selection of the T(0,1)mode at 50-kHz for the investigation.A transmission index based on the energy of the T(0,1)mode was developed to trace the extent of simulated crack growth.The findings revealed an inverse linear correlation between the transmission index and the crack depth for crack growth beyond 20%crack depth.
文摘The present work proposed a new method for the modeling by the finite element method of the acoustic propagation problems in infinite axisymmetric cylindrical guides lined with locally reacting absorbent materials without flow. The method deals with the development of an efficient transparent boundary condition based on DtN operators. The method developed in this study is successfully applied to a straight axisymmetric lined guide by imposing a mode on one of the artificial boundaries of the truncated guide. The results are in good agreement with analytical solutions. Applying the method for a non-uniform axisymmetric lined guide which is a complex case, proved its effectiveness and the results compared to those of PML layers are in very good agreement.
文摘Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions.
文摘Introduction: Prostate cancer (PCa) is the third most prevalent cancer among Malaysian males, often diagnosed at advanced stages, leading to suboptimal outcomes. While transrectal ultrasound-guided systematic biopsy (TRUS-SB) is the primary diagnostic method, prebiopsy multiparametric magnetic resonance imaging (mpMRI) is gaining popularity in identifying suspicious lesions. This study addresses the lack of comprehensive investigations into the efficacy of cognitive registration TRUS targeted biopsy (COG-TB) compared to conventional TRUS-SB, considering the resource limitations of the Malaysian healthcare system. Materials and Methods: A retrospective cohort study was conducted in two Malaysian healthcare facilities. 116 adult patients with a prostate-specific antigen (PSA) level of more than 4 ng/mL who underwent both COG-TB and TRUS-SB between October 2020 and March 2022 were included. Primary outcomes were cancer detection rate and histopathological outcomes, including Gleason score. Results: COG-TB showed a higher overall cancer detection rate (50%) compared to TRUS-SB (44%). Clinically significant cancer detection rates were similar between COG-TB and TRUS-SB (37.1%). Further analysis revealed that both COG-TB and TRUS-SB detected clinically significant cancer in 30.2% of patients, did not detect it in 56.0%, and had conflicting findings in 16 patients (p Conclusion: COG-TB and TRUS-SB have comparable detection rates for clinically significant prostate cancer, with COG-TB showing a higher tendency to detect insignificant prostate cancer. Further studies comparing these methods are warranted.
文摘Automated Guided Vehicles(AGVs)have been introduced into various applications,such as automated warehouse systems,flexible manufacturing systems,and container terminal systems.However,few publications have outlined problems in need of attention in AGV applications comprehensively.In this paper,several key issues and essential models are presented.First,the advantages and disadvantages of centralized and decentralized AGVs systems were compared;second,warehouse layout and operation optimization were introduced,including some omitted areas,such as AGVs fleet size and electrical energy management;third,AGVs scheduling algorithms in chessboardlike environments were analyzed;fourth,the classical route-planning algorithms for single AGV and multiple AGVs were presented,and some Artificial Intelligence(AI)-based decision-making algorithms were reviewed.Furthermore,a novel idea for accelerating route planning by combining Reinforcement Learning(RL)andDijkstra’s algorithm was presented,and a novel idea of the multi-AGV route-planning method of combining dynamic programming and Monte-Carlo tree search was proposed to reduce the energy cost of systems.
基金Supported by the National Key Research and Development Program of China(No.2020YFC1807904).
文摘With the wide application of automated guided vehicles(AGVs) in large scale outdoor scenarios with complex terrain,the collaborative work of a large number of AGVs becomes the main trend.The effective multi-agent path finding(MAPF) algorithm is urgently needed to ensure the efficiency and realizability of the whole system. The complex terrain of outdoor scenarios is fully considered by using different values of passage cost to quantify different terrain types. The objective of the MAPF problem is to minimize the cost of passage while the Manhattan distance of paths and the time of passage are also evaluated for a comprehensive comparison. The pre-path-planning and real-time-conflict based greedy(PRG) algorithm is proposed as the solution. Simulation is conducted and the proposed PRG algorithm is compared with waiting-stop A^(*) and conflict based search(CBS) algorithms. Results show that the PRG algorithm outperforms the waiting-stop A^(*) algorithm in all three performance indicators,and it is more applicable than the CBS algorithm when a large number of AGVs are working collaboratively with frequent collisions.
文摘Article Article types Articles commonly fall into one of three main categories:Fulllength articles,Review articles and Short communications.Full-length articles are original,unpublished primary research.Extensions of work that has been published previously in short form such as a Communication are usually acceptable.Short communications must contain original and highly significant work whose high novelty warrants rapid publication.