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Infrared small target detection based on density peaks searching and weighted multi-feature local difference
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作者 JI Bin FAN Pengxiang +2 位作者 WANG Mengli LIU Yang XU Jiafeng 《Optoelectronics Letters》 2025年第4期218-225,共8页
To address the issues of unknown target size,blurred edges,background interference and low contrast in infrared small target detection,this paper proposes a method based on density peaks searching and weighted multi-f... To address the issues of unknown target size,blurred edges,background interference and low contrast in infrared small target detection,this paper proposes a method based on density peaks searching and weighted multi-feature local difference.Firstly,an improved high-boost filter is used for preprocessing to eliminate background clutter and high-brightness interference,thereby increasing the probability of capturing real targets in the density peak search.Secondly,a triple-layer window is used to extract features from the area surrounding candidate targets,addressing the uncertainty of small target sizes.By calculating multi-feature local differences between the triple-layer windows,the problems of blurred target edges and low contrast are resolved.To balance the contribution of different features,intra-class distance is used to calculate weights,achieving weighted fusion of multi-feature local differences to obtain the weighted multi-feature local differences of candidate targets.The real targets are then extracted using the interquartile range.Experiments on datasets such as SIRST and IRSTD-IK show that the proposed method is suitable for various complex types and demonstrates good robustness and detection performance. 展开更多
关键词 extract featur background clutter density peaks searching infrared small target detection weighted multi feature local difference capturing real targets density peak infrared small target detectionthis
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DFFMamba:A Novel Remote Sensing Change Detection Method with Difference Feature Fusion Mamba
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作者 PENG Daifeng DONG Fengxu GUAN Haiyan 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第6期728-748,共21页
Change detection(CD)plays a crucial role in numerous fields,where both convolutional neural networks(CNNs)and Transformers have demonstrated exceptional performance in CD tasks.However,CNNs suffer from limited recepti... Change detection(CD)plays a crucial role in numerous fields,where both convolutional neural networks(CNNs)and Transformers have demonstrated exceptional performance in CD tasks.However,CNNs suffer from limited receptive fields,hindering their ability to capture global features,while Transformers are constrained by high computational complexity.Recently,Mamba architecture,which is based on state space models(SSMs),has shown powerful global modeling capabilities while achieving linear computational complexity.Although some researchers have incorporated Mamba into CD tasks,the existing Mamba⁃based remote sensing CD methods struggle to effectively perceive the inherent locality of changed regions when flattening and scanning remote sensing images,leading to limitations in extracting change features.To address these issues,we propose a novel Mamba⁃based CD method termed difference feature fusion Mamba model(DFFMamba)by mitigating the loss of feature locality caused by traditional Mamba⁃style scanning.Specifically,two distinct difference feature extraction modules are designed:Difference Mamba(DMamba)and local difference Mamba(LDMamba),where DMamba extracts difference features by calculating the difference in coefficient matrices between the state⁃space equations of the bi⁃temporal features.Building upon DMamba,LDMamba combines a locally adaptive state⁃space scanning(LASS)strategy to enhance feature locality so as to accurately extract difference features.Additionally,a fusion Mamba(FMamba)module is proposed,which employs a spatial⁃channel token modeling SSM(SCTMS)unit to integrate multi⁃dimensional spatio⁃temporal interactions of change features,thereby capturing their dependencies across both spatial and channel dimensions.To verify the effectiveness of the proposed DFFMamba,extensive experiments are conducted on three datasets of WHU⁃CD,LEVIR⁃CD,and CLCD.The results demonstrate that DFFMamba significantly outperforms state⁃of⁃the⁃art CD methods,achieving intersection over union(IoU)scores of 90.67%,85.04%,and 66.56%on the three datasets,respectively. 展开更多
关键词 change detection state space model(SSM)change feature fusion deep learning difference Mamba(DMamba) local difference Mamba(LDMamba) spatial⁃channel token modeling SSM(SCTMS)
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A review of deep learning-based analyses of impact crater detection on different celestial bodies
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作者 Xu Zhang Jialong Lai +2 位作者 Feifei Cui Chunyu Ding Zhicheng Zhong 《Astronomical Techniques and Instruments》 2025年第3期127-147,共21页
Planetary surfaces,shaped by billions of years of geologic evolution,display numerous impact craters whose distribution of size,density,and spatial arrangement reveals the celestial body's history.Identifying thes... Planetary surfaces,shaped by billions of years of geologic evolution,display numerous impact craters whose distribution of size,density,and spatial arrangement reveals the celestial body's history.Identifying these craters is essential for planetary science and is currently mainly achieved with deep learning-driven detection algorithms.However,because impact crater characteristics are substantially affected by the geologic environment,surface materials,and atmospheric conditions,the performance of deep learning models can be inconsistent between celestial bodies.In this paper,we first examine how the surface characteristics of the Moon,Mars,and Earth,along with the differences in their impact crater features,affect model performance.Then,we compare crater detection across celestial bodies by analyzing enhanced convolutional neural networks and U-shaped Convolutional Neural Network-based models to highlight how geology,data,and model design affect accuracy and generalization.Finally,we address current deep learning challenges,suggest directions for model improvement,such as multimodal data fusion and cross-planet learning and list available impact crater databases.This review can provide necessary technical support for deep space exploration and planetary science,as well as new ideas and directions for future research on automatic detection of impact craters on celestial body surfaces and on planetary geology. 展开更多
关键词 Crater detection algorithms Deep learning different celestial bodies Impact crater databases
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A Moving IR Point Target Detection Algorithm Based on Reverse Phase Feature of Neighborhood in Difference Between Neighbor Frame Images 被引量:3
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作者 朱风云 秦世引 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第3期225-232,共8页
An algorithm for detecting moving IR point target in complex background is proposed, which is based on the Reverse Phase Feature of Neighborhood (RPFN) of target in difference between neighbor frame images that two ... An algorithm for detecting moving IR point target in complex background is proposed, which is based on the Reverse Phase Feature of Neighborhood (RPFN) of target in difference between neighbor frame images that two positions of the target in the difference image are near and the gray values of them are close to in absolute value but with inverse sign. Firstly, pairs of points with RPFN are detected in the difference image between neighbor frame images, with which a virtual vector graph is made, and then the moving point target can be detected by the vectors' sequence cumulated in vector graphs. In addition, a theorem for the convergence of detection of target contrail by this algorithm is given and proved so as to afford a solid guarantee for practical applications of the algorithm proposed in this paper. Finally, some simulation results with 1000 frames from 10 typical images in complex background show that moving point targets with SNR not lower than 1.5 can be detected effectively. 展开更多
关键词 pattern recognition target detection point target difference image RPFN
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Difference beam aided target detection in monopulse radar 被引量:1
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作者 Cai Fei Fan Hongqi +1 位作者 Song Zhiyong Fu Qiang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2015年第5期1485-1493,共9页
The classical detection step in a monopulse radar system is based on the sum beam only, the performance of which is not optimal when target is not at the beam center. Target detection aided by the difference beam can ... The classical detection step in a monopulse radar system is based on the sum beam only, the performance of which is not optimal when target is not at the beam center. Target detection aided by the difference beam can improve the performance at this case. However, the existing difference beam aided target detectors have the problem of performance deterioration at the beam center, which has limited their application in real systems. To solve this problem, two detectors are proposed in this paper. Assuming the monopulse ratio is known, a generalized likelihood ratio test (GLRT) detector is derived, which can be used when targeting information on target direction is available. A practical dual-stage detector is proposed for the case that the monopulse ratio is unknown. Simulation results show that performances of the proposed detectors are superior to that of the classical detector. 展开更多
关键词 detection difference beam Monopulse radar Sum beam Generalized likelihood ratiotest
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Smoke root detection from video sequences based on multi-feature fusion 被引量:1
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作者 Liming Lou Feng Chen +1 位作者 Pengle Cheng Ying Huang 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第6期1841-1856,共16页
Smoke detection is the most commonly used method in early warning of fire and is widely used in forest detection.Most existing smoke detection methods contain empty spaces and obstacles which interfere with detection ... Smoke detection is the most commonly used method in early warning of fire and is widely used in forest detection.Most existing smoke detection methods contain empty spaces and obstacles which interfere with detection and extract false smoke roots.This study developed a new smoke roots search algorithm based on a multi-feature fusion dynamic extraction strategy.This determines smoke origin candidate points and region based on a multi-frame discrete confidence level.The results show that the new method provides a more complete smoke contour with no background interference,compared to the results using existing methods.Unlike video-based methods that rely on continuous frames,an adaptive threshold method was developed to build the judgment image set composed of non-consecutive frames.The smoke roots origin search algorithm increased the detection rate and significantly reduced false detection rate compared to existing methods. 展开更多
关键词 Smoke detection multi-feature fusion Search strategy ViBe Choquet
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ADS-B Anomaly Data Detection Model Based on Deep Learning and Difference of Gaussian Approach 被引量:6
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作者 WANG Ershen SONG Yuanshang +5 位作者 XU Song GUO Jing HONG Chen QU Pingping PANG Tao ZHANG Jiantong 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第4期550-561,共12页
Due to the influence of terrain structure,meteorological conditions and various factors,there are anomalous data in automatic dependent surveillance-broadcast(ADS-B)message.The ADS-B equipment can be used for position... Due to the influence of terrain structure,meteorological conditions and various factors,there are anomalous data in automatic dependent surveillance-broadcast(ADS-B)message.The ADS-B equipment can be used for positioning of general aviation aircraft.Aim to acquire the accurate position information of aircraft and detect anomaly data,the ADS-B anomaly data detection model based on deep learning and difference of Gaussian(DoG)approach is proposed.First,according to the characteristic of ADS-B data,the ADS-B position data are transformed into the coordinate system.And the origin of the coordinate system is set up as the take-off point.Then,based on the kinematic principle,the ADS-B anomaly data can be removed.Moreover,the details of the ADS-B position data can be got by the DoG approach.Finally,the long short-term memory(LSTM)neural network is used to optimize the recurrent neural network(RNN)with severe gradient reduction for processing ADS-B data.The position data of ADS-B are reconstructed by the sequence to sequence(seq2seq)model which is composed of LSTM neural network,and the reconstruction error is used to detect the anomalous data.Based on the real flight data of general aviation aircraft,the simulation results show that the anomaly data can be detected effectively by the proposed method of reconstructing ADS-B data with the seq2seq model,and its running time is reduced.Compared with the RNN,the accuracy of anomaly detection is increased by 2.7%.The performance of the proposed model is better than that of the traditional anomaly detection models. 展开更多
关键词 general aviation aircraft automatic dependent surveillance-broadcast(ADS-B) anomaly data detection deep learning difference of Gaussian(DoG) long short-term memory(LSTM)
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Research on Facial Fatigue Detection of Drivers with Multi-feature Fusion 被引量:1
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作者 YE Yuxuan ZHOU Xianchun +2 位作者 WANG Wenyan YANG Chuanbin ZOU Qingyu 《Instrumentation》 2023年第1期23-31,共9页
In order to solve the shortcomings of current fatigue detection methods such as low accuracy or poor real-time performance,a fatigue detection method based on multi-feature fusion is proposed.Firstly,the HOG face dete... In order to solve the shortcomings of current fatigue detection methods such as low accuracy or poor real-time performance,a fatigue detection method based on multi-feature fusion is proposed.Firstly,the HOG face detection algorithm and KCF target tracking algorithm are integrated and deformable convolutional neural network is introduced to identify the state of extracted eyes and mouth,fast track the detected faces and extract continuous and stable target faces for more efficient extraction.Then the head pose algorithm is introduced to detect the driver’s head in real time and obtain the driver’s head state information.Finally,a multi-feature fusion fatigue detection method is proposed based on the state of the eyes,mouth and head.According to the experimental results,the proposed method can detect the driver’s fatigue state in real time with high accuracy and good robustness compared with the current fatigue detection algorithms. 展开更多
关键词 HOG Face Posture detection Deformable Convolution multi-feature Fusion Fatigue detection
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On-Line Detection of EDM Spark Locations Using Potential Difference Method
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作者 栗岩 狄士春 +1 位作者 冯晓光 赵万生 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1998年第3期82-85,共4页
The valuation relation of potential difference with discharging time in Electrical Discharge Machining (EDM) is analyzed theoretically and tested and verified by experiments designed in this paper and the relation bet... The valuation relation of potential difference with discharging time in Electrical Discharge Machining (EDM) is analyzed theoretically and tested and verified by experiments designed in this paper and the relation between potential difference and spark location is induced and analyzed, and proceed by experiments under the condition of onedimension. 展开更多
关键词 SPARK LOCATIONS POTENTIAL difference method on-line detection DISCHARGING time
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Evaluating the Effect of Tillage on Carbon Sequestration Using the Minimum Detectable Difference Concept 被引量:13
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作者 X. M. YANG C. F. DRURY +1 位作者 M. M. WANDER B. D. KAY 《Pedosphere》 SCIE CAS CSCD 2008年第4期421-430,共10页
Three long-term field trials in humid regions of Canada and the USA were used to evaluate the influence of soil depth and sample numbers on soil organic carbon (SOC) sequestration in no-tillage (NT) and moldboard plow... Three long-term field trials in humid regions of Canada and the USA were used to evaluate the influence of soil depth and sample numbers on soil organic carbon (SOC) sequestration in no-tillage (NT) and moldboard plow (MP) corn (Zea mays L.) and soybean (Glycine max L.) production systems. The first trial was conducted on a Maryhill silt loam (Typic Hapludalf) at Elora, Ontario, Canada, the second on a Brookston clay loam (Typic Argiaquoll) at Woodslee, Ontario, Canada, and the third on a Thorp silt loam (Argiaquic Argialboll) at Urbana, Illinois, USA. No-tillage led to significantly higher SOC concentrations in the top 5 cm compared to MP at all 3 sites. However, NT resulted in significantly lower SOC in sub-surface soils as compared to MP at Woodslee (10-20 cm, P = 0.01) and Urbana (20-30 cm, P < 0.10). No-tillage had significantly more SOC storage than MP at the Elora site (3.3 Mg C ha-1) and at the Woodslee site (6.2 Mg C ha-1) on an equivalent mass basis (1350 Mg ha-1 soil equivalent mass). Similarly, NT had greater SOC storage than MP at the Urbana site (2.7 Mg C ha-1) on an equivalent mass basis of 675 Mg ha-1 soil. However, these differences disappeared when the entire plow layer was evaluated for both the Woodslee and Urbana sites as a result of the higher SOC concentrations in MP than in NT at depth. Using the minimum detectable difference technique, we observed that up to 1500 soil sample per tillage treatment comparison will have to be collected and analyzed for the Elora and Woodslee sites and over 40 soil samples per tillage treatment comparison for the Urbana to statistically separate significant differences in the SOC contents of sub-plow depth soils. Therefore, it is impracticable, and at the least prohibitively expensive, to detect tillage-induced differences in soil C beyond the plow layer in various soils. 展开更多
关键词 carbon sequestration minimum detectable difference moldboard plow NO-TILLAGE soil depth
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TEMPO:Time-evolving multi-period observational anomaly detection method for space probes
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作者 Yiqun QIAO Tian WANG +1 位作者 Jinhu LÜ Kexin LIU 《Chinese Journal of Aeronautics》 2025年第9期271-282,共12页
In space probes,anomaly detection of sequence data collected by various sensors is essential to help detect potential faults promptly,improve the reliability of equipment operation,and ensure the smooth operation of t... In space probes,anomaly detection of sequence data collected by various sensors is essential to help detect potential faults promptly,improve the reliability of equipment operation,and ensure the smooth operation of the mission.However,sensors'signals often contain a superposition of various frequencies,changing fluctuations,and correlations between features.This complexity of data attributes makes building effective models challenging.This paper proposes a TimeEvolving Multi-Period Observational(TEMPO)anomaly detection method for space probes.First,fusing wavelet analysis and natural periods improves the ability to capture multi-period features in data.Then,the feature extraction framework proposed enhances the effectiveness of anomaly detection by comprehensively extracting the complex features of data through the multi-module synergy of temporal and channel.The results demonstrate that the proposed method enhances anomaly detection accuracy and its effectiveness is confirmed.Additionally,the ablation experiment results further validate the efficacy of each module.An evaluation of the algorithm's computational complexity confirms its suitability for real-time processing. 展开更多
关键词 Space probes Anomaly detection Time series data multi-feature extraction Period extraction
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Fault Detection of Yarn Congestion in Sizing Machine Based on Machine Vision
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作者 LI Jingwei ZOU Kun ZHAO Chen 《Journal of Donghua University(English Edition)》 2025年第3期292-300,共9页
During the sizing process,yarn congestion fault occurs at the reed teeth of a sizing machine.At present,the yarn congestion fault is generally handled by manual detection.The sizing production line operates on a large... During the sizing process,yarn congestion fault occurs at the reed teeth of a sizing machine.At present,the yarn congestion fault is generally handled by manual detection.The sizing production line operates on a large scale and runs continuously.Untimely handling of the yarn congestion fault causes a large amount of yarn waste.In this research,a machine vision-based algorithm for yarn congestion fault detection is developed.Through the analysis of the congestion fault and interference contour characteristics,the basic idea of image phase subtraction to identify the congestion fault is determined.To address the interference information appearing after image phase subtraction,the image pre-processing methods of Canny edge extraction and mean filtering are employed.According to the fault size and location characteristics,the fault contour detection algorithm based on inter-frame difference is designed.To mitigate the camera vibration interference,the anti-vibration interference algorithm based on affine transformation is studied,and the fault detection algorithm for the total yarn congestion fault is determined.The detection of 20 sets of field data is carried out,and the detection rate reaches 90%.This fault detection algorithm realizes the automatic detection of yarn congestion fault of sizing machine with certain real-time performance and accuracy. 展开更多
关键词 machine vision yarn congestion fault detection inter-frame difference affine transformation
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Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping, transcranial Doppler sonography and computer tomography examinations
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作者 Dongruo He Xiaoying Xu +1 位作者 Yinghui Zhang Guochao Han 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第4期379-381,共3页
BACKGROUND: It has been proved that brain electrical activity mapping (BEAM) and transcranial Doppler (TCD) detection can reflect the function of brain cell and its diseased degree of infant patients with moderat... BACKGROUND: It has been proved that brain electrical activity mapping (BEAM) and transcranial Doppler (TCD) detection can reflect the function of brain cell and its diseased degree of infant patients with moderate to severe hypoxic-ischemic encephalopathy (HIE). OBJECTIVE: To observe the abnormal results of HIE at different degrees detected with BEAM and TCD in infant patients, and compare the detection results at the same time point between BEAM, TCD and computer tomography (CT) examinations. DESIGN : Contrast observation SETTING: Departments of Neuro-electrophysiology and Pediatrics, Second Affiliated Hospital of Qiqihar Medical College. PARTICIPANTS: Totally 416 infant patients with HIE who received treatment in the Department of Newborn Infants, Second Affiliated Hospital of Qiqihar Medical College during January 2001 and December 2005. The infant patients, 278 male and 138 female, were at embryonic 37 to 42 weeks and weighing 2.0 to 4.1 kg, and they were diagnosed with CT and met the diagnostic criteria of HIE of newborn infants compiled by Department of Neonatology, Pediatric Academy, Chinese Medical Association. According to diagnostic criteria, 130 patients were mild abnormal, 196 moderate abnormal and 90 severe abnormal. The relatives of all the infant patients were informed of the experiment. METHOOS: BEAM and TCD examinations were performed in the involved 416 infant patients with HIE at different degrees with DYD2000 16-channel BEAM instrument and EME-2000 ultrasonograph before preliminary diagnosis treatment (within 1 month after birth) and 1,3,6,12 and 24 months after birth, and detected results were compared between BEAM, TCD and CT examinations. MAIN OUTCOME MEASURES: Comparison of detection results of HIE at different time points in infant patients between BEAM. TCD and CT examinations. RESULTS: All the 416 infant patients with HIE participated in the result analysis. (1) Comparison of the detected results in infant patients with mild HIE at different time points after birth between BEAM, TCD and CT examinations: BEAM examination showed that the recovery was delayed, and the abnormal rate of BEAM examination was significantly higher than that of CT examination 1 and 3 months after birth [55.4%(72/130)vs. 17.0% (22/130 ),x^2=41.66 ;29.2% ( 38/130 ) vs. 6.2% ( 8/130 ), x^2=23.77, P 〈 0.01 ], exceptional patients had mild abnormality and reached the normal level in about 6 months. TCD examination showed that the disease condition significantly improved and infant patients with HIE basically recovered 1 or 2 months after birth, while CT examination showed that infant patients recovered 3 or 4 months after birth. (2) Comparison of detection results of infant patients with moderate HIE at different time points between BEAM, TCD and CT examinations: The abnormal rate of BEAM examination was significantly higher than that of CT examination 1,3,6 and 12 months after birth [90.8% (178/196),78.6% (154/196),x^2=4.32,P 〈 0.05;64.3% (126/196),43.9% (86/196) ,x^2=16.44 ;44.9% (88/196) ,22.4% (44/196),x^2=22.11 ;21.4% (42/196), 10.2% (20/196),x^2=9.27, P 〈 0.01]. BEAM examination showed that there was still one patient who did not completely recovered in the 24^th month due to the relatives of infant patients did not combine the treatment,. TCD examination showed that the abnormal rate was 23.1%(30/196)in the 1^st month after birth, and all the patients recovered to the normal in the 3^rd month after birth, while CT examination showed that mild abnormality still existed in the 24^th month after birth (1.0% ,2/196). (3) Comparison of detection results of infant patients with severe HIE at different time points between BEAM, TCD and CT examinations: The abnormal rate of BEAM examination was significantly higher than that of CT examination in the 1^st, 3^rd, 6^th and 12^th months after birth[86.7% (78/90),44.4% (40/90),x^2=35.53;62.2% (56/90),31.1% (28/90),x^2=17.51 ;37.8% (34/90),6.7% (6/90), x^2=27.14, P 〈 0.01]. BEAM examination showed that mild abnormality still existed in 4 infant patients in the 24^th month after birth. TCD examination showed that the abnormal rate was 11.1% (10/90) in the 3^rd month after birth, and all the infant patients recovered in the 6^th month after birth. CT examination showed that the abnormal rate was 6.7%(6/90) in the 12^th month after birth, and all of infant patients recovered to the normal in the 24^th month after birth.CONCLUSION : BEAM is the direct index to detect brain function of infant patients with HIE, and positive reaction is still very sensitive in the tracking detection of convalescent period. The positive rate of morphological reaction in CT examination is superior to that in TCD examination, and the positive rate is very high in the acute period of HIE in examination. 展开更多
关键词 HIE Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping transcranial Doppler sonography and computer tomography examinations
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Application of Different Detection Methods in The Diagnosis of Hepatitis C
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作者 CAO Shuangzhan 《外文科技期刊数据库(文摘版)医药卫生》 2021年第10期981-983,共5页
Objective: To explore the application and effect evaluation of different laboratory detection methods in the diagnosis of hepatitis C.Methods 100 patients with hepatitis C clinically diagnosed from January 2018 to Jan... Objective: To explore the application and effect evaluation of different laboratory detection methods in the diagnosis of hepatitis C.Methods 100 patients with hepatitis C clinically diagnosed from January 2018 to January 2020 were collected. Hepatitis C antibody was detected by enzyme-linked immunosorbent assay, magnetic particle chemiluminescence, colloidal gold method, and hepatitis C virus ribonucleic acid (HCV-RNA) was detected by real-time fluorescence quantitative polymerase chain reaction (PCR), To evaluate the value of different detection methods in the clinical diagnosis of hepatitis C.Results hepatitis C is an infectious disease. The etiology refers to the infection of hepatitis C virus (HCV), which is mainly transmitted by blood. HCV is an RNA virus with high heterogeneity. It is mostly hidden in the early stage of infection. The infection rate of HCV is high all over the world, which seriously threatens the safety of human life. With the continuous development and progress of clinical testing technology, In clinical diagnosis and treatment of hepatitis C disease, more and more attention is paid to laboratory testing technology. 展开更多
关键词 different detection C virus Hepatitis diagnosis APPLICATION
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Fracture identification based on remote detection acoustic reflection logging 被引量:10
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作者 张宫 李宁 +2 位作者 郭宏伟 武宏亮 罗超 《Applied Geophysics》 SCIE CSCD 2015年第4期473-481,626,共10页
Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away fr... Fracture identification is important for the evaluation of carbonate reservoirs. However, conventional logging equipment has small depth of investigation and cannot detect rock fractures more than three meters away from the borehole. Remote acoustic logging uses phase-controlled array-transmitting and long sound probes that increase the depth of investigation. The interpretation of logging data with respect to fractures is typically guided by practical experience rather than theory and is often ambiguous. We use remote acoustic reflection logging data and high-order finite-difference approximations in the forward modeling and prestack reverse-time migration to image fractures. First, we perform forward modeling of the fracture responses as a function of the fracture-borehole wall distance, aperture, and dip angle. Second, we extract the energy intensity within the imaging area to determine whether the fracture can be identified as the formation velocity is varied. Finally, we evaluate the effect of the fracture-borehole distance, fracture aperture, and dip angle on fracture identification. 展开更多
关键词 remote detection acoustic wave reverse-time migration finite difference wave iequation reflection wave imaging i
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Land use/land cover classification and its change detection using multi-temporal MODIS NDVI data 被引量:26
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作者 M USMAN R LIEDLI +1 位作者 M A SHAHID A ABBAS 《Journal of Geographical Sciences》 SCIE CSCD 2015年第12期1479-1506,共28页
Detailed analysis of Land Use/Land Cover (LULC) using remote sensing data in complex irrigated basins provides complete profile for better water resource management and planning. Using remote sensing data, this stud... Detailed analysis of Land Use/Land Cover (LULC) using remote sensing data in complex irrigated basins provides complete profile for better water resource management and planning. Using remote sensing data, this study provides detailed land use maps of the Lower Chenab Canal irrigated region of Pakistan from 2005 to 2012 for LULC change detection. Major crop types are demarcated by identifying temporal profiles of NDVI using MODIS 250 m × 250 m spatial resolution data. Wheat and rice are found to be major crops in rabi and kharif seasons, respectively. Accuracy assessment of prepared maps is performed using three dif- ferent techniques: error matrix approach, comparison with ancillary data and with previous study. Producer and user accuracies for each class are calculated along with kappa coeffi- cients (K). The average overall accuracies for rabi and kharif are 82.83% and 78.21%, re- spectively. Producer and user accuracies for individual class range respectively between 72.5% to 77% and 70.1% to 84.3% for rabi and 76.6% to 90.2% and 72% to 84.7% for kharif. The K values range between 0.66 to 0.77 for rabi with average of 0.73, and from 0.69 to 0.74 with average of 0.71 for kharif. LULC change detection indicates that wheat and rice have less volatility of change in comparison with both rabi and kharif fodders. Transformation be- tween cotton and rice is less common due to their completely different cropping conditions. Results of spatial and temporal LULC distributions and their seasonal variations provide useful insights for establishing realistic LULC scenarios for hydrological studies. 展开更多
关键词 land use/land cover remote sensing normalized difference vegetation index accuracy assessment change detection hydrological modeling
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TDOA-based Sybil attack detection scheme for wireless sensor networks 被引量:5
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作者 温蜜 李辉 +1 位作者 郑燕飞 陈克非 《Journal of Shanghai University(English Edition)》 CAS 2008年第1期66-70,共5页
As wireless sensor networks (WSN) are deployed in fire monitoring, object tracking applications, security emerges as a central requirement. A case that Sybil node illegitimately reports messages to the master node w... As wireless sensor networks (WSN) are deployed in fire monitoring, object tracking applications, security emerges as a central requirement. A case that Sybil node illegitimately reports messages to the master node with multiple non-existent identities (ID) will cause harmful effects on decision-making or resource allocation in these applications. In this paper, we present an efficient and lightweight solution for Sybil attack detection based on the time difference of arrival (TDOA) between the source node and beacon nodes. This solution can detect the existence of Sybil attacks, and locate the Sybil nodes. We demonstrate efficiency of the solution through experiments. The experiments show that this solution can detect all Sybil attack cases without missing. 展开更多
关键词 attack detection Sybil attack.time difference of arrival (TDOA) wireless sensor networks (WSN)
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Camera-based Basketball Scoring Detection Using Convolutional Neural Network 被引量:3
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作者 Xu-Bo Fu Shao-Long Yue De-Yun Pan 《International Journal of Automation and computing》 EI CSCD 2021年第2期266-276,共11页
Recently,deep learning methods have been applied in many real scenarios with the development of convolutional neural networks(CNNs).In this paper,we introduce a camera-based basketball scoring detection(BSD)method wit... Recently,deep learning methods have been applied in many real scenarios with the development of convolutional neural networks(CNNs).In this paper,we introduce a camera-based basketball scoring detection(BSD)method with CNN based object detection and frame difference-based motion detection.In the proposed BSD method,the videos of the basketball court are taken as inputs.Afterwards,the real-time object detection,i.e.,you only look once(YOLO)model,is implemented to locate the position of the basketball hoop.Then,the motion detection based on frame difference is utilized to detect whether there is any object motion in the area of the hoop to determine the basketball scoring condition.The proposed BSD method runs in real-time with satisfactory basketball scoring detection accuracy.Our experiments on the collected real scenario basketball court videos show the accuracy of the proposed BSD method.Furthermore,several intelligent basketball analysis systems based on the proposed method have been installed at multiple basketball courts in Beijing,and they provide good performance. 展开更多
关键词 Computer vision convolutional neural network(CCN) frame difference motion detection object detection real-time system
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Identifying influential nodes in social networks via community structure and influence distribution difference 被引量:4
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作者 Zufan Zhang Xieliang Li Chenquan Gan 《Digital Communications and Networks》 SCIE CSCD 2021年第1期131-139,共9页
This paper aims to effectively solve the problem of the influence maximization in social networks.For this purpose,an influence maximization method that can identify influential nodes via the community structure and t... This paper aims to effectively solve the problem of the influence maximization in social networks.For this purpose,an influence maximization method that can identify influential nodes via the community structure and the influence distribution difference is proposed.Firstly,the network embedding-based community detection approach is developed,by which the social network is divided into several high-quality communities.Secondly,the solution of influence maximization is composed of the candidate stage and the greedy stage.The candidate stage is to select candidate nodes from the interior and the boundary of each community using a heuristic algorithm,and the greedy stage is to determine seed nodes with the largest marginal influence increment from the candidate set through the sub-modular property-based Greedy algorithm.Finally,experimental results demonstrate the superiority of the proposed method compared with existing methods,from which one can further find that our work can achieve a good tradeoff between the influence spread and the running time. 展开更多
关键词 Social network Community detection Influence maximization Network embedding Influence distribution difference
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Automatic Detection of Moving Target with an Active Camera 被引量:1
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作者 冯秉瑞 杨威 +2 位作者 张田文 黄庆明 师海峰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1995年第4期18-23,共6页
AutomaticDetectionofMovingTargetwithanActiveCameraFENGBingri;YANGWei;ZHANGTianwen;HUANGQingming;SHIHaifeng冯秉... AutomaticDetectionofMovingTargetwithanActiveCameraFENGBingri;YANGWei;ZHANGTianwen;HUANGQingming;SHIHaifeng冯秉瑞,杨威,张田文,黄庆明,师海峰(... 展开更多
关键词 ss:Moving target detection BACKGROUND compensation difference PICTURE
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