Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to ...Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to degraded tracking performance,particularly around high-acceleration segments and trajectory inflection points.This study investigates machine learning-based predictive compensation for latency mitigation in soft-tissue tracking.Three models—autoregressive(AR),long short-term memory(LSTM),and temporal convolutional network(TCN)—were implemented and evaluated on both synthetic and real datasets.By aligning the prediction horizon with the end-to-end system delay,we demonstrate that prediction-based compensation significantly reduces tracking errors.Among the models,TCN achieved superior robustness and accuracy on complex motion patterns,particularly in multi-step prediction tasks,and exhibited better latency–horizon compatibility.The results suggest that TCN is a promising candidate for real-time latency compensation in teleoperated robotic systems involving dynamic soft-tissue interaction.展开更多
Colorectal cancer is the third most diagnosed cancer worldwide,and immune checkpoint inhibitors have shown promising therapeutic outcomes in selected patient groups.This study performed a comprehensive analysis of mul...Colorectal cancer is the third most diagnosed cancer worldwide,and immune checkpoint inhibitors have shown promising therapeutic outcomes in selected patient groups.This study performed a comprehensive analysis of multi-omics data from The Cancer Genome Atlas colorectal adenocarcinoma cohort(TCGA-COADREAD),accessed through cBioPortal,to develop machine learning models for predicting progression-free survival(PFS)following immunotherapy.The dataset included clinical variables,genomic alterations in Kirsten Rat Sarcoma Viral Oncogene Homolog(KRAS),B-Raf Proto-Oncogene(BRAF),and Neuroblastoma RAS Viral Oncogene Homolog(NRAS),microsatellite instability(MSI)status,tumor mutation burden(TMB),and expression of immune checkpoint genes.Kaplan–Meier analysis showed that KRAS mutations were significantly associated with reduced PFS,while BRAF and NRAS mutations had no significant impact.MSI-high tumors exhibited elevated TMB and increased immune checkpoint expression,reflecting their immunologically active phenotype.We developed both survival and classification models,with the Extra Trees classifier achieving the best performance(accuracy=0.86,precision=0.67,recall=0.70,F1-score=0.68,AUC=0.84).These findings highlight the potential of combining genomic and immune biomarkers with machine learning to improve patient stratification and guide personalized immunotherapy decisions.An interactive web application was also developed to enable clinicians to input patient-specific molecular and clinical data and visualize individualized PFS predictions,supporting timely,data-driven treatment planning.展开更多
Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyviny...Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyvinyl chloride(PVC)pipe waste polymers into nanofibers(NFs)optimized for TENG applications.We focused on optimizing the morphology of recycled PVC polymer to NFs and enhancing their piezoelectric properties by incorporating ZnO nanoparticles(NPs).The optimized PVC/0.5 wt%ZnO NFs were tested with Nylon-6 NFs,and copper(Cu)electrodes.The Nylon-6 NFs exhibited a power density of 726.3μWcm^(-2)—1.13 times higher than Cu and maintained 90%stability after 172800 cycles,successfully powering various colored LEDs.Additionally,a 3D-designed device was developed to harvest energy from biomechanical movements such as finger tapping,hand tapping,and foot pressing,making it suitable for wearable energy harvesting,automatic switches,and invisible sensors in surveillance systems.This study demonstrates that recycling polymers for TENG devices can effectively address energy,sensor,and environmental challenges.展开更多
The study aims to analyze the synergistic effect of hybrid fiber reinforcements on wear resistance of epoxy based natural fiber reinforced polymer composites(NFPCs).The study employed jute and sisal fibers as reinforc...The study aims to analyze the synergistic effect of hybrid fiber reinforcements on wear resistance of epoxy based natural fiber reinforced polymer composites(NFPCs).The study employed jute and sisal fibers as reinforcements.Two distinct reinforcements were incorporated in equal percentages to each type of composite sample.Five distinct composite specimens were identified as follows:NFPC⁃8(containing 4%sisal and jute fibers each),NFPC⁃16(containing 8%sisal and jute fibers each),NFPC⁃24(containing 12%sisal and jute fibers each),NFPC⁃32(containing 16%sisal and jute fibers each),and epoxy(EP)(containing 0%reinforcements).The hand layup technique was used for developing hybrid natural composites.In accordance with ASTM G99,pin⁃on⁃disc wear test rig was used for the dry sliding wear tests.The effect of applied load and sliding velocities on wear volume loss and specific wear rate was studied.The obtained results indicated that wear volume and specific wear rate are significantly affected by applied load and sliding velocity.NFPC⁃32 composite exhibited minimum wear loss and specific wear rate compared to other specimens.Besides,wear loss and specific wear rate were found to increase with the increase in applied load owing to the high contact stress at counterface during sliding.Further,wear volume and specific wear rate have increased with the increase in sliding velocity.It may be due to the fact that,high shearing force has resulted in sheared transfer layer at higher velocity.Worn surface analysis using scanning electron microscopy images showed the evidence of fragmented fibers and their pullout.展开更多
This work is focused on developing AA2124/4 wt.%B4 C nano-composite coatings on Ti-6 A1-4 V using friction surfacing to improve the wear resistance. The composite was produced using conventional stir casting method an...This work is focused on developing AA2124/4 wt.%B4 C nano-composite coatings on Ti-6 A1-4 V using friction surfacing to improve the wear resistance. The composite was produced using conventional stir casting method and coatings were laid using an indigenously-developed friction surfacing machine. The rotational speed of the mechtrode was varied. The microstructure of the composite coating was observed using conventional and advanced microscopic techniques. The sliding wear behavior was evaluated using a pin-on-disc apparatus. The coating geometry(thickness and width) increased with increased rotational speed. The interface was straight without thick intermetallic layer. Homogenous distribution of nano B4C particles and extremely fine grains was observed in the composite coating. The interfacial bonding between the aluminum matrix and B4C particles was excellent. The composite coating improved the wear resistance of the titanium alloy substrate due to the reduction in effective contact area,lower coefficient of friction and excellent interfacial bonding.展开更多
The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation...The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.展开更多
A mathematical model expressing the motion of a pair of multi-DOF robot fingers with hemi-spherical ends, grasping a 3-D rigid object with parallel fiat surfaces, is derived, together with non-holonomic constraints. B...A mathematical model expressing the motion of a pair of multi-DOF robot fingers with hemi-spherical ends, grasping a 3-D rigid object with parallel fiat surfaces, is derived, together with non-holonomic constraints. By referring to the fact that humans grasp an object in the form of precision prehension, dynamically and stably by opposable forces, between the thumb and another finger （index or middle finger）, a simple control signal constructed from finger-thumb opposition is proposed, and shown to realize stable grasping in a dynamic sense without using object information or external sensing （this is called ＂blind grasp＂ in this paper）. The stability of grasping with force/torque balance under non-holonomic constraints is analyzed on the basis of a new concept named ＂stability on a manifold＂. Preliminary simulation results are shown to verify the validity of the theoretical results.展开更多
Casting defects that are closely related to entrapped air bubbles and metallic oxides occur very frequently in the sand mold casting process. Many researchers have shown that these defects can be reduced by adopting a...Casting defects that are closely related to entrapped air bubbles and metallic oxides occur very frequently in the sand mold casting process. Many researchers have shown that these defects can be reduced by adopting an appropriate gating system design. However, it is difficult for field engineers to identify a specific gating system that is more appropriate for their products. In this study, we tried to draw a comparison between two gating system designs with and without a ceramic foam filter. The ceramic foam filter was added to the horizontal runner just after the down sprue to prevent air bubble generation and reduce turbulence without a change of gating system design. The water modeling experiment was conducted with four different amounts of the initial volumes of water in the reservoir to verify the effects of initial pouring velocity. The results of the experiment applying the filter showed remarkably changed flow characteristics. The use of the filter was found to convert the flow pattern of water in the desired direction. The ceramic foam filter performed well to reduce flow velocity and stabilize the water stream.The flow pattern without a filter can be improved significantly even with the the use of just a 10 PPI irregular filter. Although the study confirmed that use of the filter may change the flow characteristics, it needs to be noted that the use of the ceramic filter alone cannot solve all the problems caused by a poorly designed gating system.展开更多
Cross-project software defect prediction(CPDP)aims to enhance defect prediction in target projects with limited or no historical data by leveraging information from related source projects.The existing CPDP approaches...Cross-project software defect prediction(CPDP)aims to enhance defect prediction in target projects with limited or no historical data by leveraging information from related source projects.The existing CPDP approaches rely on static metrics or dynamic syntactic features,which have shown limited effectiveness in CPDP due to their inability to capture higher-level system properties,such as complex design patterns,relationships between multiple functions,and dependencies in different software projects,that are important for CPDP.This paper introduces a novel approach,a graph-based feature learning model for CPDP(GB-CPDP),that utilizes NetworkX to extract features and learn representations of program entities from control flow graphs(CFGs)and data dependency graphs(DDGs).These graphs capture the structural and data dependencies within the source code.The proposed approach employs Node2Vec to transform CFGs and DDGs into numerical vectors and leverages Long Short-Term Memory(LSTM)networks to learn predictive models.The process involves graph construction,feature learning through graph embedding and LSTM,and defect prediction.Experimental evaluation using nine open-source Java projects from the PROMISE dataset demonstrates that GB-CPDP outperforms state-of-the-art CPDP methods in terms of F1-measure and Area Under the Curve(AUC).The results showcase the effectiveness of GB-CPDP in improving the performance of cross-project defect prediction.展开更多
The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical informa...The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical information. In this research, two kinds of same leg movement are captured by simultaneous measurement; one is a leg movement with given strength, the other is a leg movement without strength on condition of basic experiment using optical motion capture and electromyography （EMG） equipment in order to quantitatively analyze characteristics of leg movement. Also, we measured the motion of the traditional Japanese dance using the constructed system. We can visualize leg movement of Japanese dance by displaying a 3D CG character animation with motion data and EMG data. In addition, we expect that our research will help dancers and researchers on dance through giving new information on dance movement which cannot be analyzed with only motion capture.展开更多
In this study, high velocity impact behaviour of friction stir welded AA7075-T651 25 mm thick plates were investigated using a 7.62 mm × 51 mm lead core and 7.62 mm × 39 mm steel core projectiles. Prior to b...In this study, high velocity impact behaviour of friction stir welded AA7075-T651 25 mm thick plates were investigated using a 7.62 mm × 51 mm lead core and 7.62 mm × 39 mm steel core projectiles. Prior to ballistic trails, mechanical and metallurgical properties of friction stir welded AA 7075-T651 25 mm thick plates were studied. Microstructural and hardness studies revealed that friction stir welds constituted three distinct regions namely Weld Nugget(WN), Thermo-Mechanically Affected Zone(TMAZ) and Heat Affected Zone(HAZ). Base Material(BM) and all three weld regions were ballistically tested as per military standard NIJ.0108.01 using lead and steel core bullets at maximum permissible velocities of 830 ± 20 and 700 ± 30 m/s, respectively. It has been found that base material(AA7075-T651)and all three weld regions of 25 mm thick plates were able to resist perforation by both types of projectiles used. However depth of penetration has been found to increase from BM to WN, HAZ and TMAZ for both types of projectiles. In all cases steel core projectiles caused higher depth of penetration compared to those caused by lead core projectiles. TMAZs of the friction stir welds were found to be the weakest zone. The fracture that occurred in the base material was spall fragmentation indicating brittle failure, whereas all zones of friction stir welded AA7075-T651 targets with a front petalling, indicating ductile failure. The post-ballistic tested samples showed no significant change in the microstructure of the BM and WN. On the other hand, TMAZ and HAZ showed severe grain deformation in the direction of projectile penetration, and the formation of adiabatic shear bands(ASB). This work showed that 25 mm thick friction stir welded AA7075-T651 joints responded well to ballistic impact loads, making them a good choice for light combat vehicles.展开更多
Marvi et al(Science,2014,vol.346,p.224)concluded a sidewinder rattlesnake increases the body contact length with the sand when granular incline angle increases.They also claimed the same principle should work on robot...Marvi et al(Science,2014,vol.346,p.224)concluded a sidewinder rattlesnake increases the body contact length with the sand when granular incline angle increases.They also claimed the same principle should work on robotic snake too.We have evidence to prove that this conclusion is only partial in describing the snake body-sand interaction.There should be three phases that fully represent the snake locomotion behaviors during ascent of sandy slopes,namely lifting,descending,and ceasing.The snake body-sand interaction during the descending and ceasing phases helps with the climbing while such interaction during the lifting phase in fact contributes resistance.展开更多
Citrus fruit crops are among the world’s most important agricultural products,but pests and diseases impact their cultivation,resulting in yield and quality losses.Computer vision and machine learning have been widel...Citrus fruit crops are among the world’s most important agricultural products,but pests and diseases impact their cultivation,resulting in yield and quality losses.Computer vision and machine learning have been widely used to detect and classify plant diseases over the last decade,allowing for early disease detection and improving agricultural production.This paper presented an automatic system for the early detection and classification of citrus plant diseases based on a deep learning(DL)model,which improved accuracy while decreasing computational complexity.The most recent transfer learning-based models were applied to the Citrus Plant Dataset to improve classification accuracy.Using transfer learning,this study successfully proposed a Convolutional Neural Network(CNN)-based pre-trained model(EfficientNetB3,ResNet50,MobiNetV2,and InceptionV3)for the identification and categorization of citrus plant diseases.To evaluate the architecture’s performance,this study discovered that transferring an EfficientNetb3 model resulted in the highest training,validating,and testing accuracies,which were 99.43%,99.48%,and 99.58%,respectively.In identifying and categorizing citrus plant diseases,the proposed CNN model outperforms other cuttingedge CNN model architectures developed previously in the literature.展开更多
OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real ...OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real time.We applied cupping at the following five Bladder Meridian acupoints.To investigate optimal intensity,negative pressure intensity was increased every 2 min up to 80 k Pa.To investigate optimal time,10 measurement sites were selected and negative pressure intensities of 30,60,and 80 k Pa were applied for 5 min each.Skin color information was analyzed by the following skin color values:red color saturation,erythema index,and melanin index.RESULTS:The red color saturation and erythema index increased steadily up to 60 kpa negative pressure intensity,then decreased between 60 and 80 k Pa.Therefore,maximal values were observed at 60 k Pa.The melanin index consistently increased with increasing negative pressure intensity.The red color saturation and erythema index did not change after 20 s at 60 k Pa negative pressure intensity.For negative pressure intensities below 80 k Pa,significant changes in melanin index were not observed after 20 s.At 80 k Pa negative pressure intensity,the melanin index exhibited an increasing pattern for200 s,then showed no changes.CONCLUSIONS:To minimize skin deformation,60 k Pa and 20 s were the appropriate intensity and duration when using red color saturation and erythema index as diagnostic indexes.Because of the increasing pattern up to 80 k Pa negative pressure intensity,the optimal intensity of melanin index could not be determined.When applying 80 k Pa negative pressure intensity and using melanin index as the diagnostic index,we recommend a duration of 200 s.展开更多
The use of intelligent machines to work and react like humans is vital in emerging smart cities.Computer-aided analysis of complex and huge MRI(Mag-netic Resonance Imaging)scans is very important in healthcare applica...The use of intelligent machines to work and react like humans is vital in emerging smart cities.Computer-aided analysis of complex and huge MRI(Mag-netic Resonance Imaging)scans is very important in healthcare applications.Among AI(Artificial Intelligence)driven healthcare applications,tumor detection is one of the contemporary researchfields that have become attractive to research-ers.There are several modalities of imaging performed on the brain for the pur-pose of tumor detection.This paper offers a deep learning approach for detecting brain tumors from MR(Magnetic Resonance)images based on changes in the division of the training and testing data and the structure of the CNN(Convolu-tional Neural Network)layers.The proposed approach is carried out on a brain tumor dataset from the National Centre of Image-Guided Therapy,including about 4700 MRI images of ten brain tumor cases with both normal and abnormal states.The dataset is divided into test,and train subsets with a ratio of the training set to the validation set of 70:30.The main contribution of this paper is introdu-cing an optimum deep learning structure of CNN layers.The simulation results are obtained for 50 epochs in the training phase.The simulation results reveal that the optimum CNN architecture consists of four layers.展开更多
In clinical practice,brain death is the irreversible end of all brain activity.Compared to current statistical methods for the determination of brain death,we focus on the approach of complex networks for real-world e...In clinical practice,brain death is the irreversible end of all brain activity.Compared to current statistical methods for the determination of brain death,we focus on the approach of complex networks for real-world electroencephalography in its determination.Brain functional networks constructed by correlation analysis are derived,and statistical network quantities used for distinguishing the patients in coma or brain death state,such as average strength,clustering coefficient and average path length,are calculated.Numerical results show that the values of network quantities of patients in coma state are larger than those of patients in brain death state.Our findings might provide valuable insights on the determination of brain death.展开更多
This study explores the mechanical properties of a novel composite material,blending polylactic acid(PLA)with sea shells,through a comprehensive tensile test analysis.The tensile test results offer valuable insights i...This study explores the mechanical properties of a novel composite material,blending polylactic acid(PLA)with sea shells,through a comprehensive tensile test analysis.The tensile test results offer valuable insights into the material’s behavior under axial loading,shedding light on its strength,stiffness,and deformation characteristics.The results suggest that the incorporation of sea shells decrease the tensile strength of 14.55%and increase the modulus of 27.44%for 15 wt%SSP(sea shell powder)into PLA,emphasizing the reinforcing potential of the mineral-rich sea shell particles.However,a potential trade-off between decreased strength and reduced ductility is noted,highlighting the need for a delicate balance in material composition.The study underscores the importance of uniform sea shell particle distribution within the PLA matrix for consistent mechanical performance.These results offer a basis for additional PLA-sea shell blend optimization,directing future efforts to balance strength,flexibility,and other critical attributes for a range of applications,including biomedical devices and sustainable packaging.This investigation opens the door to more sustainable and mechanically strong materials in the field of additive manufacturing by demonstrating the positive synergy between nature-inspired materials and cutting-edge testing techniques.展开更多
Finger Braille is one of the tactual communication media of deafblind people. In one-handed Finger Braille, a sender dots the left part of the Braille code on the Distal Interphalangeal （DIP） joints of the index, mi...Finger Braille is one of the tactual communication media of deafblind people. In one-handed Finger Braille, a sender dots the left part of the Braille code on the Distal Interphalangeal （DIP） joints of the index, middle and ring fingers of a receiver, and subsequently dots the right part of the Braille code on the Proximal Interphalangeal （PIP）joints of the same fingers. Because there is a small number of non-disabled people who are skilled in Finger Braille, deafblind people communicate in this medium only through an interpreter. We have been developing a Finger Braille recognition system using small piezoelectric accelerometers worn by the receiver To recognize the dotted positions （DIP or PIP joints）, we have made a hypothesis that the dotting on the DIP joints causes a hard impact, and the dotting on the PIP joints causes a soft impact, when the receiver＇s hand forms a natural longitudinal arch on the desk. The difference of each impact is indicated by its damping amplitude ratio. In this paper, a measurement experiment about the postures of the receiver＇s hand was conducted. The postures of the receiver＇s hand were as follows： forming the natural longitudinal arch on the desk and fully contacting the desk. As a result, the dotting on the DIP joints of both postures caused the hard impacts; the dotting on the PIP joints caused the soft impact when the receiver＇s hand formed the natural longitudinal arch; the dotting on the PIP joints caused the hard impact when the receiver＇s hand fully contacted the desk. Therefore, we could verify the hypothesis.展开更多
基金Support by Sichuan Science and Technology Program[2023YFSY0026,2023YFH0004]Guangzhou Huashang University[2024HSZD01,HS2023JYSZH01].
文摘Soft-tissue motion introduces significant challenges in robotic teleoperation,especially in medical scenarios where precise target tracking is critical.Latency across sensing,computation,and actuation chains leads to degraded tracking performance,particularly around high-acceleration segments and trajectory inflection points.This study investigates machine learning-based predictive compensation for latency mitigation in soft-tissue tracking.Three models—autoregressive(AR),long short-term memory(LSTM),and temporal convolutional network(TCN)—were implemented and evaluated on both synthetic and real datasets.By aligning the prediction horizon with the end-to-end system delay,we demonstrate that prediction-based compensation significantly reduces tracking errors.Among the models,TCN achieved superior robustness and accuracy on complex motion patterns,particularly in multi-step prediction tasks,and exhibited better latency–horizon compatibility.The results suggest that TCN is a promising candidate for real-time latency compensation in teleoperated robotic systems involving dynamic soft-tissue interaction.
基金funded by the Research,Development,and Innovation Authority(RDIA)—Kingdom of Saudi Arabia(Grant No.13292-psu-2023-PSNU-R-3-1-EF-).
文摘Colorectal cancer is the third most diagnosed cancer worldwide,and immune checkpoint inhibitors have shown promising therapeutic outcomes in selected patient groups.This study performed a comprehensive analysis of multi-omics data from The Cancer Genome Atlas colorectal adenocarcinoma cohort(TCGA-COADREAD),accessed through cBioPortal,to develop machine learning models for predicting progression-free survival(PFS)following immunotherapy.The dataset included clinical variables,genomic alterations in Kirsten Rat Sarcoma Viral Oncogene Homolog(KRAS),B-Raf Proto-Oncogene(BRAF),and Neuroblastoma RAS Viral Oncogene Homolog(NRAS),microsatellite instability(MSI)status,tumor mutation burden(TMB),and expression of immune checkpoint genes.Kaplan–Meier analysis showed that KRAS mutations were significantly associated with reduced PFS,while BRAF and NRAS mutations had no significant impact.MSI-high tumors exhibited elevated TMB and increased immune checkpoint expression,reflecting their immunologically active phenotype.We developed both survival and classification models,with the Extra Trees classifier achieving the best performance(accuracy=0.86,precision=0.67,recall=0.70,F1-score=0.68,AUC=0.84).These findings highlight the potential of combining genomic and immune biomarkers with machine learning to improve patient stratification and guide personalized immunotherapy decisions.An interactive web application was also developed to enable clinicians to input patient-specific molecular and clinical data and visualize individualized PFS predictions,supporting timely,data-driven treatment planning.
基金supported by the research projects AP23486880 from the Ministry of Higher EducationScience of the Republic of Kazakhstan and 111024CRP2010,20122022FD4135 from Nazarbayev University.
文摘Recycling plastic waste into triboelectric nanogenerators(TENGs)presents a sustainable approach to energy harvesting,self-powered sensing,and environmental remediation.This study investigates the recycling of polyvinyl chloride(PVC)pipe waste polymers into nanofibers(NFs)optimized for TENG applications.We focused on optimizing the morphology of recycled PVC polymer to NFs and enhancing their piezoelectric properties by incorporating ZnO nanoparticles(NPs).The optimized PVC/0.5 wt%ZnO NFs were tested with Nylon-6 NFs,and copper(Cu)electrodes.The Nylon-6 NFs exhibited a power density of 726.3μWcm^(-2)—1.13 times higher than Cu and maintained 90%stability after 172800 cycles,successfully powering various colored LEDs.Additionally,a 3D-designed device was developed to harvest energy from biomechanical movements such as finger tapping,hand tapping,and foot pressing,making it suitable for wearable energy harvesting,automatic switches,and invisible sensors in surveillance systems.This study demonstrates that recycling polymers for TENG devices can effectively address energy,sensor,and environmental challenges.
文摘The study aims to analyze the synergistic effect of hybrid fiber reinforcements on wear resistance of epoxy based natural fiber reinforced polymer composites(NFPCs).The study employed jute and sisal fibers as reinforcements.Two distinct reinforcements were incorporated in equal percentages to each type of composite sample.Five distinct composite specimens were identified as follows:NFPC⁃8(containing 4%sisal and jute fibers each),NFPC⁃16(containing 8%sisal and jute fibers each),NFPC⁃24(containing 12%sisal and jute fibers each),NFPC⁃32(containing 16%sisal and jute fibers each),and epoxy(EP)(containing 0%reinforcements).The hand layup technique was used for developing hybrid natural composites.In accordance with ASTM G99,pin⁃on⁃disc wear test rig was used for the dry sliding wear tests.The effect of applied load and sliding velocities on wear volume loss and specific wear rate was studied.The obtained results indicated that wear volume and specific wear rate are significantly affected by applied load and sliding velocity.NFPC⁃32 composite exhibited minimum wear loss and specific wear rate compared to other specimens.Besides,wear loss and specific wear rate were found to increase with the increase in applied load owing to the high contact stress at counterface during sliding.Further,wear volume and specific wear rate have increased with the increase in sliding velocity.It may be due to the fact that,high shearing force has resulted in sheared transfer layer at higher velocity.Worn surface analysis using scanning electron microscopy images showed the evidence of fragmented fibers and their pullout.
基金Department of Science and Technology [DST-WOS-A, No.SR/WOS-A/ET-1093/2015 (G)] for funding the project
文摘This work is focused on developing AA2124/4 wt.%B4 C nano-composite coatings on Ti-6 A1-4 V using friction surfacing to improve the wear resistance. The composite was produced using conventional stir casting method and coatings were laid using an indigenously-developed friction surfacing machine. The rotational speed of the mechtrode was varied. The microstructure of the composite coating was observed using conventional and advanced microscopic techniques. The sliding wear behavior was evaluated using a pin-on-disc apparatus. The coating geometry(thickness and width) increased with increased rotational speed. The interface was straight without thick intermetallic layer. Homogenous distribution of nano B4C particles and extremely fine grains was observed in the composite coating. The interfacial bonding between the aluminum matrix and B4C particles was excellent. The composite coating improved the wear resistance of the titanium alloy substrate due to the reduction in effective contact area,lower coefficient of friction and excellent interfacial bonding.
基金the Research Fund of Istanbul University under grant FAB-2017-25658.
文摘The objective of this study is to investigate the improvement possibilities of the floatability of galena with ultrasonic application in the presence of potassium ethyl xanthate(KEX). For this purpose, micro-flotation experiments were carried out in addition to surface chemistry studies including zeta potential, contact angle, and bubble-particle attachment time measurements at various ultrasonic power levels and conditioning time. The results showed that, the maximum micro-flotation recovery of 77.5% was obtained with 30 W ultrasound power and 2 min conditioning time. In addition, more negative zeta potential values were obtained with ultrasound as well as higher contact angle and lower bubble-particle attachment time, which indicated the increased hydrophobicity of galena with ultrasound.
基金This work was supported in part by the Grant-in-Aid for Exploratory Research of the JSPS (No. 16656085).
文摘A mathematical model expressing the motion of a pair of multi-DOF robot fingers with hemi-spherical ends, grasping a 3-D rigid object with parallel fiat surfaces, is derived, together with non-holonomic constraints. By referring to the fact that humans grasp an object in the form of precision prehension, dynamically and stably by opposable forces, between the thumb and another finger （index or middle finger）, a simple control signal constructed from finger-thumb opposition is proposed, and shown to realize stable grasping in a dynamic sense without using object information or external sensing （this is called ＂blind grasp＂ in this paper）. The stability of grasping with force/torque balance under non-holonomic constraints is analyzed on the basis of a new concept named ＂stability on a manifold＂. Preliminary simulation results are shown to verify the validity of the theoretical results.
文摘Casting defects that are closely related to entrapped air bubbles and metallic oxides occur very frequently in the sand mold casting process. Many researchers have shown that these defects can be reduced by adopting an appropriate gating system design. However, it is difficult for field engineers to identify a specific gating system that is more appropriate for their products. In this study, we tried to draw a comparison between two gating system designs with and without a ceramic foam filter. The ceramic foam filter was added to the horizontal runner just after the down sprue to prevent air bubble generation and reduce turbulence without a change of gating system design. The water modeling experiment was conducted with four different amounts of the initial volumes of water in the reservoir to verify the effects of initial pouring velocity. The results of the experiment applying the filter showed remarkably changed flow characteristics. The use of the filter was found to convert the flow pattern of water in the desired direction. The ceramic foam filter performed well to reduce flow velocity and stabilize the water stream.The flow pattern without a filter can be improved significantly even with the the use of just a 10 PPI irregular filter. Although the study confirmed that use of the filter may change the flow characteristics, it needs to be noted that the use of the ceramic filter alone cannot solve all the problems caused by a poorly designed gating system.
基金supported by Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.RS-2022-00155885).
文摘Cross-project software defect prediction(CPDP)aims to enhance defect prediction in target projects with limited or no historical data by leveraging information from related source projects.The existing CPDP approaches rely on static metrics or dynamic syntactic features,which have shown limited effectiveness in CPDP due to their inability to capture higher-level system properties,such as complex design patterns,relationships between multiple functions,and dependencies in different software projects,that are important for CPDP.This paper introduces a novel approach,a graph-based feature learning model for CPDP(GB-CPDP),that utilizes NetworkX to extract features and learn representations of program entities from control flow graphs(CFGs)and data dependency graphs(DDGs).These graphs capture the structural and data dependencies within the source code.The proposed approach employs Node2Vec to transform CFGs and DDGs into numerical vectors and leverages Long Short-Term Memory(LSTM)networks to learn predictive models.The process involves graph construction,feature learning through graph embedding and LSTM,and defect prediction.Experimental evaluation using nine open-source Java projects from the PROMISE dataset demonstrates that GB-CPDP outperforms state-of-the-art CPDP methods in terms of F1-measure and Area Under the Curve(AUC).The results showcase the effectiveness of GB-CPDP in improving the performance of cross-project defect prediction.
基金This work was partly supported by the"21st Century COE program",the"Open Research Center program"the"Grantin-in-Aid for Scientific Research"of the Ministry of Education,Science,Sports and Culture(No.(B)16300035).
文摘The purpose of this research is a quantitative analysis of movement patterns of dance, which cannot be analyzed with a motion capture system alone, using simultaneous measurement of body motion and biophysical information. In this research, two kinds of same leg movement are captured by simultaneous measurement; one is a leg movement with given strength, the other is a leg movement without strength on condition of basic experiment using optical motion capture and electromyography （EMG） equipment in order to quantitatively analyze characteristics of leg movement. Also, we measured the motion of the traditional Japanese dance using the constructed system. We can visualize leg movement of Japanese dance by displaying a 3D CG character animation with motion data and EMG data. In addition, we expect that our research will help dancers and researchers on dance through giving new information on dance movement which cannot be analyzed with only motion capture.
基金funding from the Armament Research Board(ARMREB),Defence Research and Development Organization(DRDO),Ministry of Defence,Government of India (Grant no.:ARMREB/MAA/2018/200)。
文摘In this study, high velocity impact behaviour of friction stir welded AA7075-T651 25 mm thick plates were investigated using a 7.62 mm × 51 mm lead core and 7.62 mm × 39 mm steel core projectiles. Prior to ballistic trails, mechanical and metallurgical properties of friction stir welded AA 7075-T651 25 mm thick plates were studied. Microstructural and hardness studies revealed that friction stir welds constituted three distinct regions namely Weld Nugget(WN), Thermo-Mechanically Affected Zone(TMAZ) and Heat Affected Zone(HAZ). Base Material(BM) and all three weld regions were ballistically tested as per military standard NIJ.0108.01 using lead and steel core bullets at maximum permissible velocities of 830 ± 20 and 700 ± 30 m/s, respectively. It has been found that base material(AA7075-T651)and all three weld regions of 25 mm thick plates were able to resist perforation by both types of projectiles used. However depth of penetration has been found to increase from BM to WN, HAZ and TMAZ for both types of projectiles. In all cases steel core projectiles caused higher depth of penetration compared to those caused by lead core projectiles. TMAZs of the friction stir welds were found to be the weakest zone. The fracture that occurred in the base material was spall fragmentation indicating brittle failure, whereas all zones of friction stir welded AA7075-T651 targets with a front petalling, indicating ductile failure. The post-ballistic tested samples showed no significant change in the microstructure of the BM and WN. On the other hand, TMAZ and HAZ showed severe grain deformation in the direction of projectile penetration, and the formation of adiabatic shear bands(ASB). This work showed that 25 mm thick friction stir welded AA7075-T651 joints responded well to ballistic impact loads, making them a good choice for light combat vehicles.
基金the Natural Science Foundation of China(51175494,61128008)Newton Research Collaboration Programme(NRCP/1415/89)
文摘Marvi et al(Science,2014,vol.346,p.224)concluded a sidewinder rattlesnake increases the body contact length with the sand when granular incline angle increases.They also claimed the same principle should work on robotic snake too.We have evidence to prove that this conclusion is only partial in describing the snake body-sand interaction.There should be three phases that fully represent the snake locomotion behaviors during ascent of sandy slopes,namely lifting,descending,and ceasing.The snake body-sand interaction during the descending and ceasing phases helps with the climbing while such interaction during the lifting phase in fact contributes resistance.
基金supported by the“Human Resources Program in Energy Technology”of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and granted financial resources from the Ministry of Trade,Industry,and Energy,Republic of Korea(No.20204010600090)The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University for funding this work through Small Groups.Project under grant number(R.G.P.1/257/43).
文摘Citrus fruit crops are among the world’s most important agricultural products,but pests and diseases impact their cultivation,resulting in yield and quality losses.Computer vision and machine learning have been widely used to detect and classify plant diseases over the last decade,allowing for early disease detection and improving agricultural production.This paper presented an automatic system for the early detection and classification of citrus plant diseases based on a deep learning(DL)model,which improved accuracy while decreasing computational complexity.The most recent transfer learning-based models were applied to the Citrus Plant Dataset to improve classification accuracy.Using transfer learning,this study successfully proposed a Convolutional Neural Network(CNN)-based pre-trained model(EfficientNetB3,ResNet50,MobiNetV2,and InceptionV3)for the identification and categorization of citrus plant diseases.To evaluate the architecture’s performance,this study discovered that transferring an EfficientNetb3 model resulted in the highest training,validating,and testing accuracies,which were 99.43%,99.48%,and 99.58%,respectively.In identifying and categorizing citrus plant diseases,the proposed CNN model outperforms other cuttingedge CNN model architectures developed previously in the literature.
基金Supported by the Industrial Technology Innovation Program(Development of Safe and Comfortable Human augmentation Hybrid Robot Suit)Funded by the Ministry of Trade,Industry&Energy,No.20007058,MOTIE,Korea)。
文摘OBJECTIVE:To identify the optimal intensity and duration of cupping that would minimize mechanical skin deformation.METHODS:We developed an optical measurement probe and system for measuring skin color values in real time.We applied cupping at the following five Bladder Meridian acupoints.To investigate optimal intensity,negative pressure intensity was increased every 2 min up to 80 k Pa.To investigate optimal time,10 measurement sites were selected and negative pressure intensities of 30,60,and 80 k Pa were applied for 5 min each.Skin color information was analyzed by the following skin color values:red color saturation,erythema index,and melanin index.RESULTS:The red color saturation and erythema index increased steadily up to 60 kpa negative pressure intensity,then decreased between 60 and 80 k Pa.Therefore,maximal values were observed at 60 k Pa.The melanin index consistently increased with increasing negative pressure intensity.The red color saturation and erythema index did not change after 20 s at 60 k Pa negative pressure intensity.For negative pressure intensities below 80 k Pa,significant changes in melanin index were not observed after 20 s.At 80 k Pa negative pressure intensity,the melanin index exhibited an increasing pattern for200 s,then showed no changes.CONCLUSIONS:To minimize skin deformation,60 k Pa and 20 s were the appropriate intensity and duration when using red color saturation and erythema index as diagnostic indexes.Because of the increasing pattern up to 80 k Pa negative pressure intensity,the optimal intensity of melanin index could not be determined.When applying 80 k Pa negative pressure intensity and using melanin index as the diagnostic index,we recommend a duration of 200 s.
基金funded and supported by the Taif University Researchers,Taif University,Taif,Saudi Arabia,under Project TURSP-2020/147.
文摘The use of intelligent machines to work and react like humans is vital in emerging smart cities.Computer-aided analysis of complex and huge MRI(Mag-netic Resonance Imaging)scans is very important in healthcare applications.Among AI(Artificial Intelligence)driven healthcare applications,tumor detection is one of the contemporary researchfields that have become attractive to research-ers.There are several modalities of imaging performed on the brain for the pur-pose of tumor detection.This paper offers a deep learning approach for detecting brain tumors from MR(Magnetic Resonance)images based on changes in the division of the training and testing data and the structure of the CNN(Convolu-tional Neural Network)layers.The proposed approach is carried out on a brain tumor dataset from the National Centre of Image-Guided Therapy,including about 4700 MRI images of ten brain tumor cases with both normal and abnormal states.The dataset is divided into test,and train subsets with a ratio of the training set to the validation set of 70:30.The main contribution of this paper is introdu-cing an optimum deep learning structure of CNN layers.The simulation results are obtained for 50 epochs in the training phase.The simulation results reveal that the optimum CNN architecture consists of four layers.
基金by the National Natural Science Foundation of China under Grant Nos 10672057 and 10872068the Fundamental Research Funds for the Central Universities and Japan Society for the Promotion of Science(22560425).
文摘In clinical practice,brain death is the irreversible end of all brain activity.Compared to current statistical methods for the determination of brain death,we focus on the approach of complex networks for real-world electroencephalography in its determination.Brain functional networks constructed by correlation analysis are derived,and statistical network quantities used for distinguishing the patients in coma or brain death state,such as average strength,clustering coefficient and average path length,are calculated.Numerical results show that the values of network quantities of patients in coma state are larger than those of patients in brain death state.Our findings might provide valuable insights on the determination of brain death.
文摘This study explores the mechanical properties of a novel composite material,blending polylactic acid(PLA)with sea shells,through a comprehensive tensile test analysis.The tensile test results offer valuable insights into the material’s behavior under axial loading,shedding light on its strength,stiffness,and deformation characteristics.The results suggest that the incorporation of sea shells decrease the tensile strength of 14.55%and increase the modulus of 27.44%for 15 wt%SSP(sea shell powder)into PLA,emphasizing the reinforcing potential of the mineral-rich sea shell particles.However,a potential trade-off between decreased strength and reduced ductility is noted,highlighting the need for a delicate balance in material composition.The study underscores the importance of uniform sea shell particle distribution within the PLA matrix for consistent mechanical performance.These results offer a basis for additional PLA-sea shell blend optimization,directing future efforts to balance strength,flexibility,and other critical attributes for a range of applications,including biomedical devices and sustainable packaging.This investigation opens the door to more sustainable and mechanically strong materials in the field of additive manufacturing by demonstrating the positive synergy between nature-inspired materials and cutting-edge testing techniques.
文摘Finger Braille is one of the tactual communication media of deafblind people. In one-handed Finger Braille, a sender dots the left part of the Braille code on the Distal Interphalangeal （DIP） joints of the index, middle and ring fingers of a receiver, and subsequently dots the right part of the Braille code on the Proximal Interphalangeal （PIP）joints of the same fingers. Because there is a small number of non-disabled people who are skilled in Finger Braille, deafblind people communicate in this medium only through an interpreter. We have been developing a Finger Braille recognition system using small piezoelectric accelerometers worn by the receiver To recognize the dotted positions （DIP or PIP joints）, we have made a hypothesis that the dotting on the DIP joints causes a hard impact, and the dotting on the PIP joints causes a soft impact, when the receiver＇s hand forms a natural longitudinal arch on the desk. The difference of each impact is indicated by its damping amplitude ratio. In this paper, a measurement experiment about the postures of the receiver＇s hand was conducted. The postures of the receiver＇s hand were as follows： forming the natural longitudinal arch on the desk and fully contacting the desk. As a result, the dotting on the DIP joints of both postures caused the hard impacts; the dotting on the PIP joints caused the soft impact when the receiver＇s hand formed the natural longitudinal arch; the dotting on the PIP joints caused the hard impact when the receiver＇s hand fully contacted the desk. Therefore, we could verify the hypothesis.
