It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimens...It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimensional(3D)models are relatively straightforward but time-consuming.One potential solution to enhance this process is to use machine learning algorithms to detect the 3D traces.In this study,a unique pixel-wise texture mapper algorithm generates a dense point cloud representation of an outcrop with the precise resolution of the original textured 3D model.A virtual digital image rendering was then employed to capture virtual images of selected regions.This technique helps to overcome limitations caused by the surface morphology of the rock mass,such as restricted access,lighting conditions,and shading effects.After AI-powered trace detection on two-dimensional(2D)images,a 3D data structuring technique was applied to the selected trace pixels.In the 3D data structuring,the trace data were structured through 2D thinning,3D reprojection,clustering,segmentation,and segment linking.Finally,the linked segments were exported as 3D polylines,with each polyline in the output corresponding to a trace.The efficacy of the proposed method was assessed using a 3D model of a real-world case study,which was used to compare the results of artificial intelligence(AI)-aided and human intelligence trace detection.Rosette diagrams,which visualize the distribution of trace orientations,confirmed the high similarity between the automatically and manually generated trace maps.In conclusion,the proposed semi-automatic method was easy to use,fast,and accurate in detecting the dominant jointing system of the rock mass.展开更多
The global population is rapidly expanding,driving an increasing demand for intelligent healthcare systems.Artificial intelligence(AI)applications in remote patient monitoring and diagnosis have achieved remarkable pr...The global population is rapidly expanding,driving an increasing demand for intelligent healthcare systems.Artificial intelligence(AI)applications in remote patient monitoring and diagnosis have achieved remarkable progress and are emerging as a major development trend.Among these applications,mouth motion tracking and mouth-state detection represent an important direction,providing valuable support for diagnosing neuromuscular disorders such as dysphagia,Bell’s palsy,and Parkinson’s disease.In this study,we focus on developing a real-time system capable of monitoring and detecting mouth state that can be efficiently deployed on edge devices.The proposed system integrates the Facial Landmark Detection technique with an optimized model combining a Bidirectional Gated Recurrent Unit(BiGRU)and Comprehensive Learning Particle Swarm Optimization(CLPSO).We conducted a comprehensive comparison and evaluation of the proposed model against several traditional models using multiple performance metrics,including accuracy,precision,recall,F1-score,cosine similarity,ROC–AUC,and the precision–recall curve.The proposed method achieved an impressive accuracy of 96.57%with an excellent precision of 98.25%on our self-collected dataset,outperforming traditional models and related works in the same field.These findings highlight the potential of the proposed approach for implementation in real-time patient monitoring systems,contributing to improved diagnostic accuracy and supporting healthcare professionals in patient treatment and care.展开更多
To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test ...To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.展开更多
Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,...Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.展开更多
In the process of piling ,there are many various defects in foundation pile of bridge such as mud-bearing,sediment-bearing, isolation, honeycomb, broken piles, and so on, showing physical and mechanical features of lo...In the process of piling ,there are many various defects in foundation pile of bridge such as mud-bearing,sediment-bearing, isolation, honeycomb, broken piles, and so on, showing physical and mechanical features of low-density and low-intensity. In fact, by using the comprehensive detection of acoustic transmission method, the reflected wave method as well as drill coring sample method, and the rational utilization of engineering geological condition in field, the characteristics, size and location of common defects of foundation pile of bridge can be accurately detected and judged and the integrity of piles and the quality of concrete can be impersonally estimated.comprehensive detecting and analyzing methods on this kind of piles are introduced briefly. The physical characters of defects and basic features of detecting curves and their corresponding relation are emphasized, and causes are analyzed in in detail in this paper.展开更多
The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in t...The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in two-dimensional space to position the microseismic events, as well as the accuracy of positioning microseismic events, may be reduced by the two-dimensional model and simple method, and ill-conditioned equations produced by TDOA location method will increase the positioning error. This article, based on inversion theory, studies the mathematical model of TDOA location method, polariza- tion analysis location method, and comprehensive difference location method of adding angle factor in the traditional TDOA location method. The feasibility of three methods is verified by numerical simulation and analysis of the positioning error of them. The results show that the comprehensive location method of adding angle difference has strong positioning stability and high positioning accuracy, and it may reduce the impact effectively about ill-conditioned equations to positioning results. Comprehensive location method with the data of actual measure may get better positioning results.展开更多
Trunk roads play an important role in undertaking high-grade roads and connecting Qixia County, township and rural roads in road traffic. At present, it has been transformed from the decline of construction bonus to a...Trunk roads play an important role in undertaking high-grade roads and connecting Qixia County, township and rural roads in road traffic. At present, it has been transformed from the decline of construction bonus to a new era of increased maintenance. As the manager and maintainer of road traffic, how to do a good job in the comprehensive and three-dimensional maintenance of the road itself and the surrounding environment, so as to achieve the real meaning of "Chang'an, Shu'Mei",It is one of the important issues that highway managers and maintainers should consider as highway high-quality development. This paper shares the management experience in recent years for peer reference only.展开更多
The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and ha...The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and harmful substances, which will cause a certain degree of threat to their own health, forming a certain harm. Therefore, the disease type of occupational disease will often bring serious physical and mental trauma to the workers, and even cause great harm and impact on their families. To this end, this needs the relevant departments to cause enough attention. The detection and evaluation of occupational diseases is an important way to effectively avoid occupational diseases. For this reason, this paper mainly starts with the routine detection and evaluation of occupational-disease-inductive factors, and from the perspective of a new health investigation. In addition, by combining the 130 researcher cases selected from January 2019 to January 2021, the comprehensive field investigation in the detection and evaluation of occupational-disease-inductive factors is a more comprehensive and objective analysis.展开更多
The casing damage has been a big problem in oilfield production. The current detection methods mostly are used after casing damage, which is not very effective. With the rapid development of China's offshore oil i...The casing damage has been a big problem in oilfield production. The current detection methods mostly are used after casing damage, which is not very effective. With the rapid development of China's offshore oil industry, the number of offshore oil wells is becoming larger and larger. Because the cost of offshore oil well is very high, the casing damage will cause huge economic losses. What's more, it can also bring serious pollution to marine environment. So the effective methods of detecting casing damage are required badly. The accumulation of stress is the main reason for the casing damage. Magnetic anisotropy technique based on counter magnetostriction effect can detect the stress of casing in real time and help us to find out the hidden dangers in time. It is essential for us to prevent the casing damage from occurring. However, such technique is still in the development stage. Previous studies mostly got the relationship between stress and magnetic signals by physical experiment, and the study of physical mechanism in relative magnetic permeability connecting the stress and magnetic signals is rarely reported. The present paper uses the ANSYS to do the three-dimensional finite element numerical simulation to study how the relative magnetic permeability works for the oil casing model. We find that the quantitative relationship between the stress' s variation and magnetic induction intensity's variation is: Δδ =K* ΔB, K = 8.04×109, which is proved correct by physical experiment.展开更多
Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional sp...Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional space graph for constructing applied algorithms and an improved GridOf algorithm were proposed in terms of analyzing the existing outlier detection algorithms from criterion and theory. Key words outlier - detection - three-dimensional space graph - data mining CLC number TP 311. 13 - TP 391 Foundation item: Supported by the National Natural Science Foundation of China (70371015)Biography: ZHANG Jing (1975-), female, Ph. D, lecturer, research direction: data mining and knowledge discovery.展开更多
Based on radon gas properties and its existing projects applications, we firstly attempted to apply geo- physical and chemical properties of radon gas in the field of mining engineering, and imported radioac- tive mea...Based on radon gas properties and its existing projects applications, we firstly attempted to apply geo- physical and chemical properties of radon gas in the field of mining engineering, and imported radioac- tive measurement method to detect the development process of the overlying strata mining-induced fractures and their contained water quality in underground coal mining, which not only innovates a more simple-fast-reliable detection method, but also further expands the applications of radon gas detection technology in mining field. A 3D simulation design of comprehensive testing system for detecting strata mining-induced fractures on surface with radon gas (CTSR) was carried out by using a large-scale 3D solid model design software Pro/Engineer (Pro/E), which overcame three main disadvantages of ''static design thought, 2D planar design and heavy workload for remodification design'' on exiting design for mining engineering test systems. Meanwhile, based on the simulation design results of Pro/E software, the sta- bility of the jack-screw pressure bar for the key component in CTSR was checked with a material mechan- ics theory, which provided a reliable basis for materials selection during the latter machining process.展开更多
Background:Coronary artery disease(CAD)is a major global health concern requiring efficient and accurate diagnostic methods.Manual interpretation of coronary computed tomography angiography(CTA)images is time-consumin...Background:Coronary artery disease(CAD)is a major global health concern requiring efficient and accurate diagnostic methods.Manual interpretation of coronary computed tomography angiography(CTA)images is time-consuming and prone to interobserver variability,underscoring the need for automated segmentation and stenosis detection tools.Methods:This study presents a hybrid multi-scale 3D segmentation framework utilizing both 3D U-Net and Enhanced 3D U-Net architectures,designed to balance computational efficiency and anatomical precision.Processed CTA images from the ImageCAS dataset underwent data standardization,normalization,and augmentation.The framework applies ensemble learning to merge coarse and fine segmentation masks,followed by advanced post-processing techniques,including connected component analysis and centerline extraction,to refine vessel delineation.Stenosis regions are detected using the Enhanced 3D U-Net and morphological operations for accurate localization.Results:The proposed pipeline achieved near-perfect segmentation accuracy(0.9993)and a Dice similarity coefficient of 0.8539 for coronary artery delineation.Precision,recall,and F1 scores for stenosis detection were 0.8418,0.8289,and 0.8397,respectively.The dual-model approach demonstrated robust performance across varied anatomical structures and effectively localized stenotic regions,indicating clear superiority over conventional models.Conclusion:This hybrid framework enables highly reliable and automated coronary artery segmentation and stenosis detection from 3D CTA images.By reducing reliance on manual interpretation and enhancing diagnostic consistency,the proposed method holds strong potential to improve clinical workflows for CAD diagnosis and management.展开更多
An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, clo...An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.展开更多
The skewed symmetry detection plays an improtant role in three-dimensional（3-D） reconstruction. The skewed symmetry depicts a real symmetry viewed from some unknown viewing directions. And the skewed symmetry detect...The skewed symmetry detection plays an improtant role in three-dimensional（3-D） reconstruction. The skewed symmetry depicts a real symmetry viewed from some unknown viewing directions. And the skewed symmetry detection can decrease the geometric constrains and the complexity of 3-D reconstruction. The detection technique for the quadric curve ellipse proposed by Sugimoto is improved to further cover quadric curves including hyperbola and parabola. With the parametric detection, the 3-D quadric curve projection matching is automatical- ly accomplished. Finally, the skewed symmetry surface of the quadric surface solid is obtained. Several examples are used to verify the feasibility of the algorithm and satisfying results can be obtained.展开更多
The intelligent detection technology driven by X-ray images and deep learning represents the forefront of advanced techniques and development trends in flaw detection and automated evaluation of light alloy castings.H...The intelligent detection technology driven by X-ray images and deep learning represents the forefront of advanced techniques and development trends in flaw detection and automated evaluation of light alloy castings.However,the efficacy of deep learning models hinges upon a substantial abundance of flaw samples.The existing research on X-ray image augmentation for flaw detection suffers from shortcomings such as poor diversity of flaw samples and low reliability of quality evaluation.To this end,a novel approach was put forward,which involves the creation of the Interpolation-Deep Convolutional Generative Adversarial Network(I-DCGAN)for flaw detection image generation and a comprehensive evaluation algorithm named TOPSIS-IFP.I-DCGAN enables the generation of high-resolution,diverse simulated images with multiple appearances,achieving an improvement in sample diversity and quality while maintaining a relatively lower computational complexity.TOPSIS-IFP facilitates multi-dimensional quality evaluation,including aspects such as diversity,authenticity,image distribution difference,and image distortion degree.The results indicate that the X-ray radiographic images of magnesium and aluminum alloy castings achieve optimal performance when trained up to the 800th and 600th epochs,respectively.The TOPSIS-IFP value reaches 78.7%and 73.8%similarity to the ideal solution,respectively.Compared to single index evaluation,the TOPSIS-IFP algorithm achieves higher-quality simulated images at the optimal training epoch.This approach successfully mitigates the issue of unreliable quality associated with single index evaluation.The image generation and comprehensive quality evaluation method developed in this paper provides a novel approach for image augmentation in flaw recognition,holding significant importance for enhancing the robustness of subsequent flaw recognition networks.展开更多
In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based ...In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based on the combination of the single unit infrared detector.The surface dimension features of ground armored targets are identified by size calculating solution algorithm.The signal response value and the value of size calculating are identified by the method of fuzzy recognition to make the fuzzy classification judgment for armored target.According to the characteristics of the target signal,a custom threshold de-noising function is proposed to solve the problem of signal preprocessing.The multi-line array infrared detection can complete the scanning detection in a large area in a short time with the characteristics of smart munition in the steady-state scanning stage.The method solves the disadvantages of wide scanning interval and low detection probability of single unit infrared detection.By reducing the scanning interval,the number of random rendezvous in the infrared feature area of the upper surface is increased,the accuracy of the size calculating is guaranteed.The experiments results show that in the fuzzy recognition method,the size calculating is introduced as the feature operator,which can improve the recognition ability of the ground armor target with different shape size.展开更多
In mausoleum murals, existing bubbles are one kind of the most harmful defects for the repair and protection of relics. For this reason, it is necessary to detect bubbles, especially the ones with small size. A method...In mausoleum murals, existing bubbles are one kind of the most harmful defects for the repair and protection of relics. For this reason, it is necessary to detect bubbles, especially the ones with small size. A method to detect the small bubbles with enhanced terahertz （THz） images is proposed. To simulate the bubbles in the mausoleum murals, circular grooves have been hidden in the plaster and then measured by the THz reflected time domain spectroscopy imaging system. To observe the small bubbles in murals, a comprehensive enhancement algorithm is adopted to process the obtained THz images. With the enhanced method, the circular grooves in the murals can be observed clearly, even for the circular groove with a diameter of 1.5 mm. The results indicate that the proposed comprehensive method can be used to detect the tiny defects of murals.展开更多
Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrat...Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.展开更多
The multi-level modeling technology of Building Information Modeling(BIM),combined with Three-dimensional Geographic Information System(3DGIS)macro-scene visualization technology and location information,can realize t...The multi-level modeling technology of Building Information Modeling(BIM),combined with Three-dimensional Geographic Information System(3DGIS)macro-scene visualization technology and location information,can realize the transmission of decentralized information from various disciplines to multi-disciplinary collaborative information sharing services.It can be applied independently for the whole life cycle,which plays a positive role in reducing the cost and improving the efficiency of engineering planning,design,construction,operation,and maintenance.In this paper,the data integration and function integration methods of 3DGIS and BIM are designed.In order to avoid the breaking problems caused by attribute information loss and excessive simplification in the process of BIM data integration,the attribute mapping between 3DGIS and BIM based on Industry Foundation Classes(IFC)and City Geography Markup Language(CityGML)and the data simplification method considering the geometric characteristics of BIM are designed.By setting the relevant preconditions and thresholds of patch merging,on the premise of maintaining the structural characteristics of BIM data surface,reduce the amount of model data to improve the efficiency of BIM data loading,rendering and display effect in 3D geospatial scene.Through the data and function integration of 3DGIS and BIM,we can effectively manage the data of large-scale model,and calculate and obtain the geospatial location and direction of key parts of buildings through the coordinate transformation of BIM,which can effectively assist the rapid and accurate positioning of BIM in virtual 3D scene and expand the visualization ability of 3DGIS.By effectively integrating 3DGIS and BIM,this paper gives full play to the spatial management advantages of 3DGIS and the component management advantages of BIM.The rationality and operability of the method are verified by its application in the operation and maintenance management project of concealed facilities in actual buildings.展开更多
基金supported by grants from the Human Resources Development program (Grant No.20204010600250)the Training Program of CCUS for the Green Growth (Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning (KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government (MOTIE).
文摘It is of great importance to obtain precise trace data,as traces are frequently the sole visible and measurable parameter in most outcrops.The manual recognition and detection of traces on high-resolution three-dimensional(3D)models are relatively straightforward but time-consuming.One potential solution to enhance this process is to use machine learning algorithms to detect the 3D traces.In this study,a unique pixel-wise texture mapper algorithm generates a dense point cloud representation of an outcrop with the precise resolution of the original textured 3D model.A virtual digital image rendering was then employed to capture virtual images of selected regions.This technique helps to overcome limitations caused by the surface morphology of the rock mass,such as restricted access,lighting conditions,and shading effects.After AI-powered trace detection on two-dimensional(2D)images,a 3D data structuring technique was applied to the selected trace pixels.In the 3D data structuring,the trace data were structured through 2D thinning,3D reprojection,clustering,segmentation,and segment linking.Finally,the linked segments were exported as 3D polylines,with each polyline in the output corresponding to a trace.The efficacy of the proposed method was assessed using a 3D model of a real-world case study,which was used to compare the results of artificial intelligence(AI)-aided and human intelligence trace detection.Rosette diagrams,which visualize the distribution of trace orientations,confirmed the high similarity between the automatically and manually generated trace maps.In conclusion,the proposed semi-automatic method was easy to use,fast,and accurate in detecting the dominant jointing system of the rock mass.
基金supported by the National Science and Technology Council,Taiwan,with grant numbers NSTC 114-2622-8-992-007-TD1 and 112-2811-E-992-003-MY3.
文摘The global population is rapidly expanding,driving an increasing demand for intelligent healthcare systems.Artificial intelligence(AI)applications in remote patient monitoring and diagnosis have achieved remarkable progress and are emerging as a major development trend.Among these applications,mouth motion tracking and mouth-state detection represent an important direction,providing valuable support for diagnosing neuromuscular disorders such as dysphagia,Bell’s palsy,and Parkinson’s disease.In this study,we focus on developing a real-time system capable of monitoring and detecting mouth state that can be efficiently deployed on edge devices.The proposed system integrates the Facial Landmark Detection technique with an optimized model combining a Bidirectional Gated Recurrent Unit(BiGRU)and Comprehensive Learning Particle Swarm Optimization(CLPSO).We conducted a comprehensive comparison and evaluation of the proposed model against several traditional models using multiple performance metrics,including accuracy,precision,recall,F1-score,cosine similarity,ROC–AUC,and the precision–recall curve.The proposed method achieved an impressive accuracy of 96.57%with an excellent precision of 98.25%on our self-collected dataset,outperforming traditional models and related works in the same field.These findings highlight the potential of the proposed approach for implementation in real-time patient monitoring systems,contributing to improved diagnostic accuracy and supporting healthcare professionals in patient treatment and care.
基金supported by Project of the National Natural Science Foundation of China (No.62073256, 61773305)the Key Science and Technology Program of Shaanxi Province (No.2020GY-125)Xi’an Science and Technology Innovation talent service enterprise project (No.2020KJRC0041)。
文摘To objectively obtain the three-dimensional coordinates of the projectile fuze proximity explosion when projectile intersects the head of missile target, we propose a dynamic seven photoelectric detection screen test method, which is made up of six plane detection screens and a flash photoelectric dynamic detection screen. The three-dimensional coordinates calculation model of the projectile proximity explosion position based on seven plane detection screens with dynamic characteristics is established.According to the relation of the dynamic seven photoelectric detection screen planes and the time values,the analytical function of the projectile proximity explosion position parameters under non-linear motion is derived. The projectile signal filtering method based on discrete wavelet transform is explored in this work. Additionally, the projectile signal recognition algorithm using an improved particle swarm is proposed. Based on the characteristics of the time duration and the signal peak error for the projectile passing through the detection screen, the signals attribution of the same projectile passing through six detection screens are analyzed for obtaining precise time values of the same projectile passing through the detection screens. On the basis of the projectile fuze proximity explosion test, the linear motion model and the proposed non-linear motion model are used to calculate and compare the same group of projectiles proximity explosion position parameters. The comparison of test results verifies that the proposed test method and calculation model in this work accurately obtain the actual projectile proximity explosion position parameters.
基金This research was jointly funded by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0103 and 2019QZKK0105)the National Natural Science Foundation of China(Grant Nos.91837208 and 42075085).
文摘Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.
文摘In the process of piling ,there are many various defects in foundation pile of bridge such as mud-bearing,sediment-bearing, isolation, honeycomb, broken piles, and so on, showing physical and mechanical features of low-density and low-intensity. In fact, by using the comprehensive detection of acoustic transmission method, the reflected wave method as well as drill coring sample method, and the rational utilization of engineering geological condition in field, the characteristics, size and location of common defects of foundation pile of bridge can be accurately detected and judged and the integrity of piles and the quality of concrete can be impersonally estimated.comprehensive detecting and analyzing methods on this kind of piles are introduced briefly. The physical characters of defects and basic features of detecting curves and their corresponding relation are emphasized, and causes are analyzed in in detail in this paper.
文摘The essential for microseismic monitoring is fast and accurate calculation of seismic wave source location. The precision of most traditional microseismic monitoring processes of mines, using TDOA location method in two-dimensional space to position the microseismic events, as well as the accuracy of positioning microseismic events, may be reduced by the two-dimensional model and simple method, and ill-conditioned equations produced by TDOA location method will increase the positioning error. This article, based on inversion theory, studies the mathematical model of TDOA location method, polariza- tion analysis location method, and comprehensive difference location method of adding angle factor in the traditional TDOA location method. The feasibility of three methods is verified by numerical simulation and analysis of the positioning error of them. The results show that the comprehensive location method of adding angle difference has strong positioning stability and high positioning accuracy, and it may reduce the impact effectively about ill-conditioned equations to positioning results. Comprehensive location method with the data of actual measure may get better positioning results.
文摘Trunk roads play an important role in undertaking high-grade roads and connecting Qixia County, township and rural roads in road traffic. At present, it has been transformed from the decline of construction bonus to a new era of increased maintenance. As the manager and maintainer of road traffic, how to do a good job in the comprehensive and three-dimensional maintenance of the road itself and the surrounding environment, so as to achieve the real meaning of "Chang'an, Shu'Mei",It is one of the important issues that highway managers and maintainers should consider as highway high-quality development. This paper shares the management experience in recent years for peer reference only.
文摘The so-called occupational disease, in fact, refers to enterprises and institutions or individual workers, because in the daily process of employment, contact with radioactive substances or dust and other toxic and harmful substances, which will cause a certain degree of threat to their own health, forming a certain harm. Therefore, the disease type of occupational disease will often bring serious physical and mental trauma to the workers, and even cause great harm and impact on their families. To this end, this needs the relevant departments to cause enough attention. The detection and evaluation of occupational diseases is an important way to effectively avoid occupational diseases. For this reason, this paper mainly starts with the routine detection and evaluation of occupational-disease-inductive factors, and from the perspective of a new health investigation. In addition, by combining the 130 researcher cases selected from January 2019 to January 2021, the comprehensive field investigation in the detection and evaluation of occupational-disease-inductive factors is a more comprehensive and objective analysis.
基金supported by the National Natural Science Foundation of China(No.41174157)
文摘The casing damage has been a big problem in oilfield production. The current detection methods mostly are used after casing damage, which is not very effective. With the rapid development of China's offshore oil industry, the number of offshore oil wells is becoming larger and larger. Because the cost of offshore oil well is very high, the casing damage will cause huge economic losses. What's more, it can also bring serious pollution to marine environment. So the effective methods of detecting casing damage are required badly. The accumulation of stress is the main reason for the casing damage. Magnetic anisotropy technique based on counter magnetostriction effect can detect the stress of casing in real time and help us to find out the hidden dangers in time. It is essential for us to prevent the casing damage from occurring. However, such technique is still in the development stage. Previous studies mostly got the relationship between stress and magnetic signals by physical experiment, and the study of physical mechanism in relative magnetic permeability connecting the stress and magnetic signals is rarely reported. The present paper uses the ANSYS to do the three-dimensional finite element numerical simulation to study how the relative magnetic permeability works for the oil casing model. We find that the quantitative relationship between the stress' s variation and magnetic induction intensity's variation is: Δδ =K* ΔB, K = 8.04×109, which is proved correct by physical experiment.
文摘Outlier detection has very important applied value in data mining literature. Different outlier detection algorithms based on distinct theories have different definitions and mining processes. The three-dimensional space graph for constructing applied algorithms and an improved GridOf algorithm were proposed in terms of analyzing the existing outlier detection algorithms from criterion and theory. Key words outlier - detection - three-dimensional space graph - data mining CLC number TP 311. 13 - TP 391 Foundation item: Supported by the National Natural Science Foundation of China (70371015)Biography: ZHANG Jing (1975-), female, Ph. D, lecturer, research direction: data mining and knowledge discovery.
基金support for this work provided by the Fundamental Research Funds for the Central Universities(China University of Mining & Technology) (No. 2010ZDP02B02)the State Key Laboratory of Coal Resources and Safe Mining(No. SKLCRSM08X02)
文摘Based on radon gas properties and its existing projects applications, we firstly attempted to apply geo- physical and chemical properties of radon gas in the field of mining engineering, and imported radioac- tive measurement method to detect the development process of the overlying strata mining-induced fractures and their contained water quality in underground coal mining, which not only innovates a more simple-fast-reliable detection method, but also further expands the applications of radon gas detection technology in mining field. A 3D simulation design of comprehensive testing system for detecting strata mining-induced fractures on surface with radon gas (CTSR) was carried out by using a large-scale 3D solid model design software Pro/Engineer (Pro/E), which overcame three main disadvantages of ''static design thought, 2D planar design and heavy workload for remodification design'' on exiting design for mining engineering test systems. Meanwhile, based on the simulation design results of Pro/E software, the sta- bility of the jack-screw pressure bar for the key component in CTSR was checked with a material mechan- ics theory, which provided a reliable basis for materials selection during the latter machining process.
文摘Background:Coronary artery disease(CAD)is a major global health concern requiring efficient and accurate diagnostic methods.Manual interpretation of coronary computed tomography angiography(CTA)images is time-consuming and prone to interobserver variability,underscoring the need for automated segmentation and stenosis detection tools.Methods:This study presents a hybrid multi-scale 3D segmentation framework utilizing both 3D U-Net and Enhanced 3D U-Net architectures,designed to balance computational efficiency and anatomical precision.Processed CTA images from the ImageCAS dataset underwent data standardization,normalization,and augmentation.The framework applies ensemble learning to merge coarse and fine segmentation masks,followed by advanced post-processing techniques,including connected component analysis and centerline extraction,to refine vessel delineation.Stenosis regions are detected using the Enhanced 3D U-Net and morphological operations for accurate localization.Results:The proposed pipeline achieved near-perfect segmentation accuracy(0.9993)and a Dice similarity coefficient of 0.8539 for coronary artery delineation.Precision,recall,and F1 scores for stenosis detection were 0.8418,0.8289,and 0.8397,respectively.The dual-model approach demonstrated robust performance across varied anatomical structures and effectively localized stenotic regions,indicating clear superiority over conventional models.Conclusion:This hybrid framework enables highly reliable and automated coronary artery segmentation and stenosis detection from 3D CTA images.By reducing reliance on manual interpretation and enhancing diagnostic consistency,the proposed method holds strong potential to improve clinical workflows for CAD diagnosis and management.
基金Project(51274250)supported by the National Natural Science Foundation of ChinaProject(2012BAK09B02-05)supported by the National Key Technology R&D Program during the 12th Five-year Plan of China
文摘An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.
基金Supported by the National Natural Science Foundation of China(10377007)~~
文摘The skewed symmetry detection plays an improtant role in three-dimensional（3-D） reconstruction. The skewed symmetry depicts a real symmetry viewed from some unknown viewing directions. And the skewed symmetry detection can decrease the geometric constrains and the complexity of 3-D reconstruction. The detection technique for the quadric curve ellipse proposed by Sugimoto is improved to further cover quadric curves including hyperbola and parabola. With the parametric detection, the 3-D quadric curve projection matching is automatical- ly accomplished. Finally, the skewed symmetry surface of the quadric surface solid is obtained. Several examples are used to verify the feasibility of the algorithm and satisfying results can be obtained.
基金funded by the National Key R&D Program of China(2020YFB1710100)the National Natural Science Foundation of China(Nos.52275337,52090042,51905188).
文摘The intelligent detection technology driven by X-ray images and deep learning represents the forefront of advanced techniques and development trends in flaw detection and automated evaluation of light alloy castings.However,the efficacy of deep learning models hinges upon a substantial abundance of flaw samples.The existing research on X-ray image augmentation for flaw detection suffers from shortcomings such as poor diversity of flaw samples and low reliability of quality evaluation.To this end,a novel approach was put forward,which involves the creation of the Interpolation-Deep Convolutional Generative Adversarial Network(I-DCGAN)for flaw detection image generation and a comprehensive evaluation algorithm named TOPSIS-IFP.I-DCGAN enables the generation of high-resolution,diverse simulated images with multiple appearances,achieving an improvement in sample diversity and quality while maintaining a relatively lower computational complexity.TOPSIS-IFP facilitates multi-dimensional quality evaluation,including aspects such as diversity,authenticity,image distribution difference,and image distortion degree.The results indicate that the X-ray radiographic images of magnesium and aluminum alloy castings achieve optimal performance when trained up to the 800th and 600th epochs,respectively.The TOPSIS-IFP value reaches 78.7%and 73.8%similarity to the ideal solution,respectively.Compared to single index evaluation,the TOPSIS-IFP algorithm achieves higher-quality simulated images at the optimal training epoch.This approach successfully mitigates the issue of unreliable quality associated with single index evaluation.The image generation and comprehensive quality evaluation method developed in this paper provides a novel approach for image augmentation in flaw recognition,holding significant importance for enhancing the robustness of subsequent flaw recognition networks.
基金This work was supported by the National Natural Science Foundation of China(No.11804263)the Program for Innovative Science and Research Team of Xi’an Technological University.
文摘In order to improve the infrared detection and discrimination ability of the smart munition to the dynamic armor target under the complex background,the multi-line array infrared detection system is established based on the combination of the single unit infrared detector.The surface dimension features of ground armored targets are identified by size calculating solution algorithm.The signal response value and the value of size calculating are identified by the method of fuzzy recognition to make the fuzzy classification judgment for armored target.According to the characteristics of the target signal,a custom threshold de-noising function is proposed to solve the problem of signal preprocessing.The multi-line array infrared detection can complete the scanning detection in a large area in a short time with the characteristics of smart munition in the steady-state scanning stage.The method solves the disadvantages of wide scanning interval and low detection probability of single unit infrared detection.By reducing the scanning interval,the number of random rendezvous in the infrared feature area of the upper surface is increased,the accuracy of the size calculating is guaranteed.The experiments results show that in the fuzzy recognition method,the size calculating is introduced as the feature operator,which can improve the recognition ability of the ground armor target with different shape size.
基金supported by the 973 Program of China under Grant No.2013CBA01702National Natural Science Foundation of China under Grant No.11474206,No.91233202,No.11374216,and No.11404224+3 种基金Program for New Century Excellent Talents in University under Grant No.NCET-12-0607Scientific Research Project of Beijing Education Commission under Grant No.KM201310028005Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20121108120009the Beijing Youth Top-Notch Talent Training Plan under Grant No.CIT&TCD201504080
文摘In mausoleum murals, existing bubbles are one kind of the most harmful defects for the repair and protection of relics. For this reason, it is necessary to detect bubbles, especially the ones with small size. A method to detect the small bubbles with enhanced terahertz （THz） images is proposed. To simulate the bubbles in the mausoleum murals, circular grooves have been hidden in the plaster and then measured by the THz reflected time domain spectroscopy imaging system. To observe the small bubbles in murals, a comprehensive enhancement algorithm is adopted to process the obtained THz images. With the enhanced method, the circular grooves in the murals can be observed clearly, even for the circular groove with a diameter of 1.5 mm. The results indicate that the proposed comprehensive method can be used to detect the tiny defects of murals.
文摘Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.
基金supported by the Open Fund of Key Laboratory of Urban Land Resources Monitoring and Simulation,Ministry of Land and Resources[grant number KF-2018-03-050]China Postdoctoral Science Foundation[grant number 2018M642800].
文摘The multi-level modeling technology of Building Information Modeling(BIM),combined with Three-dimensional Geographic Information System(3DGIS)macro-scene visualization technology and location information,can realize the transmission of decentralized information from various disciplines to multi-disciplinary collaborative information sharing services.It can be applied independently for the whole life cycle,which plays a positive role in reducing the cost and improving the efficiency of engineering planning,design,construction,operation,and maintenance.In this paper,the data integration and function integration methods of 3DGIS and BIM are designed.In order to avoid the breaking problems caused by attribute information loss and excessive simplification in the process of BIM data integration,the attribute mapping between 3DGIS and BIM based on Industry Foundation Classes(IFC)and City Geography Markup Language(CityGML)and the data simplification method considering the geometric characteristics of BIM are designed.By setting the relevant preconditions and thresholds of patch merging,on the premise of maintaining the structural characteristics of BIM data surface,reduce the amount of model data to improve the efficiency of BIM data loading,rendering and display effect in 3D geospatial scene.Through the data and function integration of 3DGIS and BIM,we can effectively manage the data of large-scale model,and calculate and obtain the geospatial location and direction of key parts of buildings through the coordinate transformation of BIM,which can effectively assist the rapid and accurate positioning of BIM in virtual 3D scene and expand the visualization ability of 3DGIS.By effectively integrating 3DGIS and BIM,this paper gives full play to the spatial management advantages of 3DGIS and the component management advantages of BIM.The rationality and operability of the method are verified by its application in the operation and maintenance management project of concealed facilities in actual buildings.
