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A machine learning-based strategy for predicting the mechanical strength of coral reef limestone using X-ray computed tomography
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作者 Kai Wu Qingshan Meng +4 位作者 Ruoxin Li Le Luo Qin Ke ChiWang Chenghao Ma 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2790-2800,共11页
Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL... Different sedimentary zones in coral reefs lead to significant anisotropy in the pore structure of coral reef limestone(CRL),making it difficult to study mechanical behaviors.With X-ray computed tomography(CT),112 CRL samples were utilized for training the support vector machine(SVM)-,random forest(RF)-,and back propagation neural network(BPNN)-based models,respectively.Simultaneously,the machine learning model was embedded into genetic algorithm(GA)for parameter optimization to effectively predict uniaxial compressive strength(UCS)of CRL.Results indicate that the BPNN model with five hidden layers presents the best training effect in the data set of CRL.The SVM-based model shows a tendency to overfitting in the training set and poor generalization ability in the testing set.The RF-based model is suitable for training CRL samples with large data.Analysis of Pearson correlation coefficient matrix and the percentage increment method of performance metrics shows that the dry density,pore structure,and porosity of CRL are strongly correlated to UCS.However,the P-wave velocity is almost uncorrelated to the UCS,which is significantly distinct from the law for homogenous geomaterials.In addition,the pore tensor proposed in this paper can effectively reflect the pore structure of coral framework limestone(CFL)and coral boulder limestone(CBL),realizing the quantitative characterization of the heterogeneity and anisotropy of pore.The pore tensor provides a feasible idea to establish the relationship between pore structure and mechanical behavior of CRL. 展开更多
关键词 Coral reef limestone(CRL) machine learning Pore tensor x-ray computed tomography(CT)
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Life Can’t Be Any Easier than This—Introduction of the Portable and Disposable V.A.C. Machines
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作者 Muhammad Ali Hussain Lalindra Kuruppu +2 位作者 Hardeep Jhattu Charlotte Ying Simon Wharton 《Modern Plastic Surgery》 2012年第2期24-27,共4页
The application of controlled levels of negative pressure on to a wound has been shown to accelerate evacuation of dead cells, debris and fluid which eventually encourages wound healing in a verity of surgical wounds.... The application of controlled levels of negative pressure on to a wound has been shown to accelerate evacuation of dead cells, debris and fluid which eventually encourages wound healing in a verity of surgical wounds. Vacuum Assisted Closure (V.A.C.) therapy—KCI Medical Limited, the terminology by which this is widely known, became popular, especially among the plastic surgery professionals in America and soon gained recognition worldwide. It is now widely used in the UK to manage and assist healing in a wide variety of wounds. Although KCI’s V.A.C. machines were the only ones on the market for a number of years, several wound management companies have now brought out their own machines and these are now known collectively as topical negative pressure therapy (TNPT). Traditional TNPT is often considered a relatively costly procedure. It is often used in patients with large wounds to facilitate dressing management and promote rapid cleaning and granulation. This may also allow them to be discharged to the community when they would otherwise remain inpatients, thereby saving bed days. Capital purchase of the machines is expensive and hospitals often rent or lease them on a short or long term basis. This can lead to difficulties in arranging the finances for discharge to the community. Subsequent dressing changes (recommended every 48 - 72 hrs) also incur high costs and involvement of the trained medical or nursing staff. As we all know;“Need is the mother of invention”. The disposable TNPT machine (V.A.C. ViaTM KCI Medical Ltd) has been introduced to help to solve these problems. It is a single use machine, inclusive of a dressing and canister and available off the shelf. It is very cost effective, easy to use and is used for small to moderate sized wounds. Senior author is using this machine which excellent results and illustrated the use of this machine with pictures in this paper. 展开更多
关键词 Vacuum Assisted CLOSURE portable and DISPOSABLE machine Plastic Surgery
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Acme Portable Machines公司便携式服务器工作站
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《电子产品世界》 2004年第07B期23-24,共2页
关键词 Acme portable machines公司 Hercules系列 ATX 便携式服务器 工作站
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A Comprehensive Investigation of Machine Learning Feature Extraction and ClassificationMethods for Automated Diagnosis of COVID-19 Based on X-ray Images 被引量:7
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作者 Mazin Abed Mohammed Karrar Hameed Abdulkareem +6 位作者 Begonya Garcia-Zapirain Salama A.Mostafa Mashael S.Maashi Alaa S.Al-Waisy Mohammed Ahmed Subhi Ammar Awad Mutlag Dac-Nhuong Le 《Computers, Materials & Continua》 SCIE EI 2021年第3期3289-3310,共22页
The quick spread of the CoronavirusDisease(COVID-19)infection around the world considered a real danger for global health.The biological structure and symptoms of COVID-19 are similar to other viral chest maladies,whi... The quick spread of the CoronavirusDisease(COVID-19)infection around the world considered a real danger for global health.The biological structure and symptoms of COVID-19 are similar to other viral chest maladies,which makes it challenging and a big issue to improve approaches for efficient identification of COVID-19 disease.In this study,an automatic prediction of COVID-19 identification is proposed to automatically discriminate between healthy and COVID-19 infected subjects in X-ray images using two successful moderns are traditional machine learning methods(e.g.,artificial neural network(ANN),support vector machine(SVM),linear kernel and radial basis function(RBF),k-nearest neighbor(k-NN),Decision Tree(DT),andCN2 rule inducer techniques)and deep learningmodels(e.g.,MobileNets V2,ResNet50,GoogleNet,DarkNet andXception).A largeX-ray dataset has been created and developed,namely the COVID-19 vs.Normal(400 healthy cases,and 400 COVID cases).To the best of our knowledge,it is currently the largest publicly accessible COVID-19 dataset with the largest number of X-ray images of confirmed COVID-19 infection cases.Based on the results obtained from the experiments,it can be concluded that all the models performed well,deep learning models had achieved the optimum accuracy of 98.8%in ResNet50 model.In comparison,in traditional machine learning techniques, the SVM demonstrated the best result for an accuracy of 95% and RBFaccuracy 94% for the prediction of coronavirus disease 2019. 展开更多
关键词 Coronavirus disease COVID-19 diagnosis machine learning convolutional neural networks resnet50 artificial neural network support vector machine x-ray images feature transfer learning
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Rapid detection and risk assessment of soil contamination at lead smelting site based on machine learning
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作者 Sheng-guo XUE Jing-pei FENG +5 位作者 Wen-shun KE Mu LI Kun-yan QIU Chu-xuan LI Chuan WU Lin GUO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第9期3054-3068,共15页
A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model cor... A general prediction model for seven heavy metals was established using the heavy metal contents of 207soil samples measured by a portable X-ray fluorescence spectrometer(XRF)and six environmental factors as model correction coefficients.The eXtreme Gradient Boosting(XGBoost)model was used to fit the relationship between the content of heavy metals and environment characteristics to evaluate the soil ecological risk of the smelting site.The results demonstrated that the generalized prediction model developed for Pb,Cd,and As was highly accurate with fitted coefficients(R^(2))values of 0.911,0.950,and 0.835,respectively.Topsoil presented the highest ecological risk,and there existed high potential ecological risk at some positions with different depths due to high mobility of Cd.Generally,the application of machine learning significantly increased the accuracy of pXRF measurements,and identified key environmental factors.The adapted potential ecological risk assessment emphasized the need to focus on Pb,Cd,and As in future site remediation efforts. 展开更多
关键词 smelting site potentially toxic elements x-ray fluorescence potential ecological risk machine learning
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Robust Malicious Executable Detection Using Host-Based Machine Learning Classifier
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作者 Khaled Soliman Mohamed Sobh Ayman M.Bahaa-Eldin 《Computers, Materials & Continua》 SCIE EI 2024年第4期1419-1439,共21页
The continuous development of cyberattacks is threatening digital transformation endeavors worldwide and leadsto wide losses for various organizations. These dangers have proven that signature-based approaches are ins... The continuous development of cyberattacks is threatening digital transformation endeavors worldwide and leadsto wide losses for various organizations. These dangers have proven that signature-based approaches are insufficientto prevent emerging and polymorphic attacks. Therefore, this paper is proposing a Robust Malicious ExecutableDetection (RMED) using Host-based Machine Learning Classifier to discover malicious Portable Executable (PE)files in hosts using Windows operating systems through collecting PE headers and applying machine learningmechanisms to detect unknown infected files. The authors have collected a novel reliable dataset containing 116,031benign files and 179,071 malware samples from diverse sources to ensure the efficiency of RMED approach.The most effective PE headers that can highly differentiate between benign and malware files were selected totrain the model on 15 PE features to speed up the classification process and achieve real-time detection formalicious executables. The evaluation results showed that RMED succeeded in shrinking the classification timeto 91 milliseconds for each file while reaching an accuracy of 98.42% with a false positive rate equal to 1.58. Inconclusion, this paper contributes to the field of cybersecurity by presenting a comprehensive framework thatleverages Artificial Intelligence (AI) methods to proactively detect and prevent cyber-attacks. 展开更多
关键词 portable executable MALWARE intrusion detection CYBERSECURITY zero-day threats Host IntrusionDetection System(HIDS) machine learning Anomaly-based Intrusion Detection System(AIDS) deep learning
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Use of portable X-ray fluorescence in the analysis of surficial sediments in the exploration of hydrothermal vents on the Southwest Indian Ridge 被引量:5
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作者 LIAO Shili TAO Chunhui +3 位作者 LI Huaiming ZHANG Guoyin LIANG Jin YANG Weifang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第7期66-76,共11页
Hydrothermal plumes released from the eruption of sea floor hydrothermal fluids contain large amounts of oreforming materials. They precipitate within certain distances from the hydrothermal vent. Six surficial sedime... Hydrothermal plumes released from the eruption of sea floor hydrothermal fluids contain large amounts of oreforming materials. They precipitate within certain distances from the hydrothermal vent. Six surficial sediment samples from the Southwest Indian Ridge(SWIR) were analyzed by a portable X-ray fluorescence(PXRF) analyzer on board to find a favorable method fast and efficient enough for sea floor sulfide sediment geochemical exploration. These sediments were sampled near, at a moderate distance from, or far away from hydrothermal vents. The results demonstrate that the PXRF is effective in determining the enrichment characteristics of the oreforming elements in the calcareous sediments from the mid-ocean ridge. Sediment samples(〉40 mesh) have high levels of elemental copper, zinc, iron, and manganese, and levels of these elements in sediments finer than 40 mesh are lower and relatively stable. This may be due to relatively high levels of basalt debris/glass in the coarse sediments, which are consistent with the results obtained by microscopic observation. The results also show clear zoning of elements copper, zinc, arsenic, iron, and manganese in the surficial sediments around the hydrothermal vent. Sediments near the vent show relatively high content of the ore-forming elements and either high ratios of copper to iron content and zinc to iron content or high ratios of copper to manganese content and zinc to manganese content. These findings show that the content of the ore-forming elements in the sediments around hydrothermal vents are mainly influenced by the distance of sediments to the vent, rather than grain size. In this way, the PXRF analysis of surface sediment geochemistry is found to satisfy the requirements of recognition geochemical anomaly in mid-ocean ridge sediments. Sediments with diameters finer than 40 mesh should be used as analytical samples in the geochemical exploration for hydrothermal vents on mid-oceanic ridges. The results concerning copper, zinc, arsenic, iron, and manganese and their ratio features can be used as indicators in sediment geochemical exploration of seafloor sulfides. 展开更多
关键词 mid-ocean ridge sediments hydrothermal activity portable x-ray fluorescence geochemical exploration
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Application of a Portable XRF Spectrometer for <i>In-Situ</i>and Nondestructive Investigation of Pigments in Two 15th Century Icons 被引量:1
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作者 Eglantina Merkaj Nikolla Civici 《Open Journal of Applied Sciences》 2020年第6期305-317,共13页
<span style="font-family:Verdana;">A simple </span><span style="font-family:Verdana;">portable X-Ray Fluorescence (</span><span style="font-family:;" "=&qu... <span style="font-family:Verdana;">A simple </span><span style="font-family:Verdana;">portable X-Ray Fluorescence (</span><span style="font-family:;" "=""><span style="font-family:Verdana;">XRF) spectrometer was successfully used for </span><i><span style="font-family:Verdana;">in-situ</span></i><span style="font-family:Verdana;"> and nondestructive identification of the painting materials in two 15</span><sup><span style="font-family:Verdana;">th</span></sup><span style="font-family:Verdana;"> century icons from the Onufri Museum in Beart, Albania. </span></span><span style="font-family:Verdana;">The spectrometer is based on a low power X-ray tube, a thermoelectrically cooled Si PIN detector and the spectrum acquisition system. It was assembled and adjusted at our laboratory for the investigation of the icons. </span><span style="font-family:Verdana;">A small number of pigments were clearly identified by </span><span style="font-family:Verdana;">X-Ray Fluorescence (</span><span style="font-family:Verdana;">XRF) measurements in both icons. This include</span><span style="font-family:Verdana;">s</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> Lead white for the white color, gold and yellow ochre for the yellow color, red lead, cinnabar and red ochre for the red color, as well as cooper based pigments for the green color. At the same time, the investigation raised some new questions that need further investigations by </span><span style="font-family:Verdana;">the use of additional analytical techniques. The results show that in both</span><span style="font-family:Verdana;"> icons are used similar pigments, which are in accordance with the Byzantine icon painting tradition.</span></span> 展开更多
关键词 portable x-ray Fluorescence (XRF) Spectrometer Pigment Analysis Icons Albanian Icons Berat Albania
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Automatic Detection and Measurement of Fetal Biparietal Diameter and Femur Length —Feasibility on a Portable Ultrasound Device
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作者 Naiad Hossain Khan Eva Tegnander +3 位作者 Johan Morten Dreier Sturla Eik-Nes Hans Torp Gabriel Kiss 《Open Journal of Obstetrics and Gynecology》 2017年第3期334-350,共17页
An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for... An automatic method able to recognize a presented section through the biparietal plane of the fetal head and a section through the fetal femur in ultrasound images is developed. Once the correct anatomical section for measurement is identified by the machine, the placement of the measurement calipers is automatically determined by fitting an active contour model to the structure of interest. The fetal biparietal diameter (BPD) and femur length (FL) are then measured automatically. The validation data set contained 167 and 197 B-mode images for BPD and FL measurements, respectively. The images were acquired using 4 different ultrasound scanners, which resulted in varied image quality and gain settings. The mean gestational age (GA) of the fetuses was 19.4 weeks, range 16 to 41 weeks. A measurement success rate of 90% was achieved for both BPD and FL. The correlation coefficients between the manual and automatic measurements were 0.995 (BPD) and 0.967 (FL), mean errors were 0.5 mm (BPD) and -1.7 mm (FL) and error range with 95% confidence interval (CI) were ﹣3.8 - 4.8 mm (BPD) and ﹣11.4 - 8.1 mm (FL). The automatic measurement results were consistent in both high and low gain settings. The intraclass correlation coefficients between manual and automatic measurements were 0.995 (95% CI;0.981 - 0.999) for BPD in high gain, 1.0 (95% CI;0.998 - 1.0) for BPD in low gain, 0.998 (95% CI;0.991 - 0.999) for FL in high gain and 0.999 (95% CI;0.996 - 1.0) for FL in low gain settings. The method was implemented on a prototype, portable ultrasound machine designed to be used in low- and middle-income countries (LMIC). The overall performance of the method supports our hypothesis that automated methods can be used and are beneficial in a clinical setting. 展开更多
关键词 FETAL DATING Biparietal DIAMETER FEMUR Length portable Ultrasound machine Automatic Measurement
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Efficiency of Portable Electronic Vulcanizer
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作者 Eduardo Zeta Ramis 《World Journal of Engineering and Technology》 2015年第1期15-23,共9页
This research was aimed at finding out the efficiency of the portable electronic vulcanizer. The old vulcanizing equipment was upgraded to save time, investment, manpower and to eliminate the problem of gas emission i... This research was aimed at finding out the efficiency of the portable electronic vulcanizer. The old vulcanizing equipment was upgraded to save time, investment, manpower and to eliminate the problem of gas emission in vulcanization. The study also determined the accurate temperature setting and duration of vulcanizing process using electronic vulcanizer which eliminated the problem of gas emission produced by the conventional (gas fired) vulcanizer of about 2.772 kg of carbon dioxide for 1 liter of diesel fuel and/or 2.331 kg of carbon dioxide for 1 liter of petrol into the atmosphere. In constructing this vulcanizer, a letter G body configuration made of GI pipe with 31.5 cm long lag bolt with some electronic parts were installed, like the analog temperature gauge, digital timer, relay, LED, buzzer, switch, and heating element. Specifically, the product is divided into three components: base or body, control panel board and the heating unit. The effectiveness level of the equipment was tested utilizing five different temperatures at a constant and variable time. For Class A gum, the best temperature which bonded the gum exactly to the rubber tire was 60℃ in 1 minute while Class B gum was bonded at 60℃ in 2 minutes. The rate of energy consumed by the electronic vulcanizer for Class A gum was Php 0.0757 with an efficiency of 85.22% and for Class B gum was Php 0.15 with an efficiency of 85.22% and for conventional vulcanizer for Class A gum was Php 1.08 with an efficiency of 43.38% and for Class B gum was Php 1.52, with an efficiency of 78.08%. The study revealed that more tires could be vulcanized in a short period of time, therefore providing greater income over time. It is also environment-friendly since it does not emit carbon dioxide as compared to the conventional vulcanizing. 展开更多
关键词 ELECTRIC Vulcanizer portable ELECTRONIC Vulcanizer ENVIRONMENT-FRIENDLY machine
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X-ray image distortion correction based on SVR
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作者 袁泽慧 李世中 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第3期302-306,共5页
X-ray image has been widely used in many fields such as medical diagnosis,industrial inspection,and so on.Unfortunately,due to the physical characteristics of X-ray and imaging system,distortion of the projected image... X-ray image has been widely used in many fields such as medical diagnosis,industrial inspection,and so on.Unfortunately,due to the physical characteristics of X-ray and imaging system,distortion of the projected image will happen,which restrict the application of X-ray image,especially in high accuracy fields.Distortion correction can be performed using algorithms that can be classified as global or local according to the method used,both having specific advantages and disadvantages.In this paper,a new global method based on support vector regression(SVR)machine for distortion correction is proposed.In order to test the presented method,a calibration phantom is specially designed for this purpose.A comparison of the proposed method with the traditional global distortion correction techniques is performed.The experimental results show that the proposed correction method performs better than the traditional global one. 展开更多
关键词 x-ray image distortion correction support vector regression machine
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Covid-19 Detection from Chest X-Ray Images Using Advanced Deep Learning Techniques 被引量:3
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作者 Shubham Mahajan Akshay Raina +2 位作者 Mohamed Abouhawwash Xiao-Zhi Gao Amit Kant Pandit 《Computers, Materials & Continua》 SCIE EI 2022年第1期1541-1556,共16页
Like the Covid-19 pandemic,smallpox virus infection broke out in the last century,wherein 500 million deaths were reported along with enormous economic loss.But unlike smallpox,the Covid-19 recorded a low exponential ... Like the Covid-19 pandemic,smallpox virus infection broke out in the last century,wherein 500 million deaths were reported along with enormous economic loss.But unlike smallpox,the Covid-19 recorded a low exponential infection rate and mortality rate due to advancement inmedical aid and diagnostics.Data analytics,machine learning,and automation techniques can help in early diagnostics and supporting treatments of many reported patients.This paper proposes a robust and efficient methodology for the early detection of COVID-19 from Chest X-Ray scans utilizing enhanced deep learning techniques.Our study suggests that using the Prediction and Deconvolutional Modules in combination with the SSD architecture can improve the performance of the model trained at this task.We used a publicly open CXR image dataset and implemented the detectionmodelwith task-specific pre-processing and near 80:20 split.This achieved a competitive specificity of 0.9474 and a sensibility/accuracy of 0.9597,which shall help better decision-making for various aspects of identification and treat the infection. 展开更多
关键词 machine learning deep learning object detection chest x-ray medical images Covid-19
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Multi-Label Chest X-Ray Classification via Deep Learning
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作者 Aravind Sasidharan Pillai 《Journal of Intelligent Learning Systems and Applications》 2022年第4期43-56,共14页
In this era of pandemic, the future of healthcare industry has never been more exciting. Artificial intelligence and machine learning (AI & ML) present opportunities to develop solutions that cater for very specif... In this era of pandemic, the future of healthcare industry has never been more exciting. Artificial intelligence and machine learning (AI & ML) present opportunities to develop solutions that cater for very specific needs within the industry. Deep learning in healthcare had become incredibly powerful for supporting clinics and in transforming patient care in general. Deep learning is increasingly being applied for the detection of clinically important features in the images beyond what can be perceived by the naked human eye. Chest X-ray images are one of the most common clinical method for diagnosing a number of diseases such as pneumonia, lung cancer and many other abnormalities like lesions and fractures. Proper diagnosis of a disease from X-ray images is often challenging task for even expert radiologists and there is a growing need for computerized support systems due to the large amount of information encoded in X-Ray images. The goal of this paper is to develop a lightweight solution to detect 14 different chest conditions from an X ray image. Given an X-ray image as input, our classifier outputs a label vector indicating which of 14 disease classes does the image fall into. Along with the image features, we are also going to use non-image features available in the data such as X-ray view type, age, gender etc. The original study conducted Stanford ML Group is our base line. Original study focuses on predicting 5 diseases. Our aim is to improve upon previous work, expand prediction to 14 diseases and provide insight for future chest radiography research. 展开更多
关键词 Data Science Deep Learning x-ray machine Learning Artificial Intelligence Health Care CNN Neural Network
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手持式近红外光谱仪测定梨三种品质指标通用模型建模方法研究 被引量:2
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作者 毛欣然 夏静静 +5 位作者 徐惟馨 韦芸 陈玥瑶 陈月飞 闵顺耕 熊艳梅 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第2期406-412,共7页
梨是生活中非常常见的水果,梨的糖度、酸度(pH)、硬度是评价梨品质的重要指标。近红外光谱技术因快速、无损和高效等优点,广泛应用于检测水果品质指标。手持式近红外光谱仪可以应用于现场无损检测梨品质,梨的大小不同会对梨的光谱和建... 梨是生活中非常常见的水果,梨的糖度、酸度(pH)、硬度是评价梨品质的重要指标。近红外光谱技术因快速、无损和高效等优点,广泛应用于检测水果品质指标。手持式近红外光谱仪可以应用于现场无损检测梨品质,梨的大小不同会对梨的光谱和建模产生一定影响。因此,采集大小不同的5个品种梨果(雪梨、红香酥、蜜梨、红肖梨、酸梨)的近红外光谱,最大的雪梨平均赤道周长27.64 cm,重量为362.84 g,最小的蜜梨平均赤道周长18.35 cm,重量为112.67 g,共197个样品。光谱范围为900~1700 cm^(-1),并在梨的赤道上选取三个点测量梨果的可溶性固形物、酸度(pH)与硬度三个化学指标。采集光谱发现,小梨吸光度较大,而大梨吸光度较小。采用三点平均光谱代表样品光谱和一阶导预处理,改善了光谱的一致性,解决了样品不均匀性、不同梨大小不同等因素的影响。线性回归模型PLS可溶性固形物、酸度(pH)和硬度的校正集决定系数依次为0.7394、0.9335、0.8866,预测集决定系数依次为0.7559、0.8734、0.7874,校正集RMSEC依次为0.5504、0.1941、0.5181。预测集RMSEP依次为0.6564、0.2420、0.6692。非线性回归LSSVM模型可溶性固形物、酸度(pH)和硬度的校正集决定系数依次为0.9763、0.9999、0.9960,预测集决定系数依次为0.9234、0.9777、0.9394,校正集RMSEC依次为0.1949、0.0033、0.0894。预测集RMSEP依次为0.3169、0.1089、0.3613。对比线性算法和非线性算法,LS-SVM建模效果明显优于PLS,LS-SVM算法适用于更多的品种、更宽的品质指标范围的样品预测,模型的准确度和稳定性有了显著提高,可以建立不同品种大小的梨的通用模型。手持式近红外光谱仪可用于梨果的糖度、硬度和pH值的快速无损高效检测,并摆脱了实验室的限制,可以实现现场快速检测。 展开更多
关键词 手持式近红外仪 偏最小二乘法 最小二乘支持向量机
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人机携行外骨骼负重上楼梯的动态建模与仿真
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作者 邓蓉 刘放 +2 位作者 黄文建 杨明发 李晨晖 《机械科学与技术》 CSCD 北大核心 2024年第8期1304-1312,共9页
研究外骨骼在不同负重情况下上楼梯时各关节驱动力矩变化规律。基于西南交通大学第三代人机携行助力外骨骼机器人,首先运用D-H法推导了外骨骼的运动学模型,研究外骨骼各个连杆之间的相对运动与位姿关系;其次,基于拉格朗日方法构建了外... 研究外骨骼在不同负重情况下上楼梯时各关节驱动力矩变化规律。基于西南交通大学第三代人机携行助力外骨骼机器人,首先运用D-H法推导了外骨骼的运动学模型,研究外骨骼各个连杆之间的相对运动与位姿关系;其次,基于拉格朗日方法构建了外骨骼动力学模型,并进行了动力学仿真分析;最后,将拟合得到的人体步态周期数据作为基于Adams环境中外骨骼在不同负重情况下上楼梯动力学仿真中的驱动函数,得到各关节驱动力矩数据。所得结果验证了运用拟人建模方法辨识外骨骼机器人动力学模型的有效性,为外骨骼在负重上楼梯环境下的系统驱动和控制提供了理论基础,增加了人机携行性。 展开更多
关键词 助力外骨骼 动力学仿真 拟人建模 人机携行
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Characterization of the Convoluted 3D Internetallic Phases in a Recycled Al Alloy by Synchrotron X-ray Tomography and Machine Learning 被引量:1
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作者 Zhenhao Li Ling Qin +4 位作者 Baisong Guo Junping Yuan Zhiguo Zhang Wei Li Jiawei Mi 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2022年第1期115-123,共9页
Fe-rich intermetallic phases in recycled Al alloys often exhibit complex and 3D convoluted structures and morphologies.They are the common detrimental intermetallic phases to the mechanical properties of recycled Al a... Fe-rich intermetallic phases in recycled Al alloys often exhibit complex and 3D convoluted structures and morphologies.They are the common detrimental intermetallic phases to the mechanical properties of recycled Al alloys.In this study,we used synchrotron X-ray tomography to study the true 3D morphologies of the Ferich phases,Al_(2)Cu phases and casting defects in an ascast Al-5Cu-1.5Fe-1Si alloy.Machine learning-based image processing approach was used to recognize and segment the diff erent phases in the 3D tomography image stacks.In the studied condition,theβ-Al_(9)Fe_(2)Si_(2)andω-Al_(7)Cu_(2)Fe are found to be the main Fe-rich intermetallic phases.Theβ-Al_(9)Fe_(2)Si_(2)phases exhibit a spatially connected 3D network structure and morphology which in turn control the 3D spatial distribution of the Al_(2)Cu phases and the shrinkage cavities.The Al_(3)Fe phases formed at the early stage of solidification aff ect to a large extent the structure and morphology of the subsequently formed Fe-rich intermetallic phases.The machine learning method has been demonstrated as a powerful tool for processing big datasets in multidimensional imaging-based materials characterization work. 展开更多
关键词 Recycled Alalloy Solidifi cation Synchrotron x-ray tomography machine learning Fe-rich intermetallic phases
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便携式麻醉机应用及研究进展
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作者 王彬华 李远洋 李晓雪 《生物医学工程研究》 2024年第3期256-260,共5页
重大灾害事故瞬间将产生批量危重症伤员,开展损伤控制手术是灾害事故现场有效降低伤员死亡率和致残率的关键。便携式麻醉机是灾害事故现场实施损伤控制手术的重要医疗装备。本文回顾了国内外麻醉机的研究现状,结合灾害救援特点,重点分... 重大灾害事故瞬间将产生批量危重症伤员,开展损伤控制手术是灾害事故现场有效降低伤员死亡率和致残率的关键。便携式麻醉机是灾害事故现场实施损伤控制手术的重要医疗装备。本文回顾了国内外麻醉机的研究现状,结合灾害救援特点,重点分析了便携式麻醉机的性能特点和关键技术,并对未来发展方向进行了展望。 展开更多
关键词 便携式麻醉机 监护 麻醉深度 精准麻醉 一体化
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Radiography Image Classification Using Deep Convolutional Neural Networks
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作者 Ahmad Chowdhury Haiyi Zhang 《Journal of Computer and Communications》 2024年第6期199-209,共11页
Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can b... Research has shown that chest radiography images of patients with different diseases, such as pneumonia, COVID-19, SARS, pneumothorax, etc., all exhibit some form of abnormality. Several deep learning techniques can be used to identify each of these anomalies in the chest x-ray images. Convolutional neural networks (CNNs) have shown great success in the fields of image recognition and image classification since there are numerous large-scale annotated image datasets available. The classification of medical images, particularly radiographic images, remains one of the biggest hurdles in medical diagnosis because of the restricted availability of annotated medical images. However, such difficulty can be solved by utilizing several deep learning strategies, including data augmentation and transfer learning. The aim was to build a model that would detect abnormalities in chest x-ray images with the highest probability. To do that, different models were built with different features. While making a CNN model, one of the main tasks is to tune the model by changing the hyperparameters and layers so that the model gives out good training and testing results. In our case, three different models were built, and finally, the last one gave out the best-predicted results. From that last model, we got 98% training accuracy, 84% validation, and 81% testing accuracy. The reason behind the final model giving out the best evaluation scores is that it was a well-fitted model. There was no overfitting or underfitting issues. Our aim with this project was to make a tool using the CNN model in R language, which will help detect abnormalities in radiography images. The tool will be able to detect diseases such as Pneumonia, Covid-19, Effusions, Infiltration, Pneumothorax, and others. Because of its high accuracy, this research chose to use supervised multi-class classification techniques as well as Convolutional Neural Networks (CNNs) to classify different chest x-ray images. CNNs are extremely efficient and successful at reducing the number of parameters while maintaining the quality of the primary model. CNNs are also trained to recognize the edges of various objects in any batch of images. CNNs automatically discover the relevant aspects in labeled data and learn the distinguishing features for each class by themselves. 展开更多
关键词 CNN RADIOGRAPHY Image Classification R Keras Chest x-ray machine Learning
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基于机器学习的恶意PNG图像识别方法
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作者 马秋豪 《电视技术》 2024年第4期203-206,共4页
为避免网络病毒借助便携式网络图形(Portable Network Graphics,PNG)传播恶意代码,应用机器学习技术,提出一套行之有效的恶意PNG图像识别方法。该识别方法采用动态分析的方式,评估PNG图像和加载器行为,同时结合基于传统调用特征的机器... 为避免网络病毒借助便携式网络图形(Portable Network Graphics,PNG)传播恶意代码,应用机器学习技术,提出一套行之有效的恶意PNG图像识别方法。该识别方法采用动态分析的方式,评估PNG图像和加载器行为,同时结合基于传统调用特征的机器学习算法,分类并识别恶意PNG图像。结果表明,提出的恶意PNG图像识别方法具有较高的可靠性和可行性,可以保证对多种恶意PNG图像的识别效果,还能避免用户隐写处理健康图像信息,完全符合图像水印隐秘传输应用需求。 展开更多
关键词 机器学习 恶意图像识别 便携式网络图形(PNG) 动态分析
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基于SPEI指数的河北省夏秋两季干旱预测研究
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作者 张冉 王海兴 +4 位作者 张照娜 陆禹阔 史东旭 许超前 贾悦 《科学技术创新》 2024年第8期70-73,共4页
为获得河北省夏、秋两季干旱预测模型,本文以标准化降雨蒸散指数(SPEI)为基础,基于极限学习机模型(ELM),采用麻雀搜索算法(SSA)、蜂群算法(ABC)、蝙蝠算法(BA)、粒子群算法(PSO)、遗传算法(GA)共5种优化算法构建了优化ELM模型用于建立区... 为获得河北省夏、秋两季干旱预测模型,本文以标准化降雨蒸散指数(SPEI)为基础,基于极限学习机模型(ELM),采用麻雀搜索算法(SSA)、蜂群算法(ABC)、蝙蝠算法(BA)、粒子群算法(PSO)、遗传算法(GA)共5种优化算法构建了优化ELM模型用于建立区域SPEI指数估算模型,结果表面:SSA-ELM模型在所有模型中精度最高,同时可移植性较好,可作为河北省夏、秋两季的干旱预测模型使用。 展开更多
关键词 河北省 标准化降雨蒸散指数 极限学习机模型 麻雀搜索算法 模型可移植性
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