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Visual Quality Analysis of Urban Park Landscapes Based on Eye Tracking: A Case Study of Nanjing Xiaohong Stone Carving Park
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作者 LIU Ruoxi WANG Xiaojun 《Journal of Landscape Research》 2024年第4期5-12,共8页
The landscape quality of urban parks is an important aspect of tourists'landscape experience.A full understanding of their relationship is beneficial to the park design,construction and management.In this paper,Xi... The landscape quality of urban parks is an important aspect of tourists'landscape experience.A full understanding of their relationship is beneficial to the park design,construction and management.In this paper,Xiaohong Stone Carving Park in Nanjing was selected as a case study.Firstly,the subjective landscape visual quality evaluation of tourists was obtained through the scenic beauty evaluation,and the objective landscape visual preference of users was obtained through eye movement experiment and analysis.Secondly,the values of various park landscape elements were measured respectively.And then the correlation between the subjective and objective evaluation and the values of park landscape elements was analyzed.The results showed that:(1)The visual preference of plant cluster landscape with beautiful shape,distinct layers and significant color contrast is high;(2)The preference for waterfront scenes with significant terrain differences,rich background vegetation levels,and clear and vivid water side reflections is high;(3)The designed artificial structures often become the focus of attention in the whole scene,which can improve the beauty of the scene;(4)The overall landscape composition is very important for the beauty of the scene.Finally,through the comprehensive analysis with the design expectation,the optimization strategy was proposed. 展开更多
关键词 Urban park Landscape visual evaluation eye tracking
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A new real-time eye tracking based on nonlinear unscented Kalman filter for monitoring driver fatigue 被引量:6
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作者 Zutao ZHANG 1 , 2 , Jiashu ZHANG 2 (1.School of Mechanical Engineering, Southwest Jiaotong University, Chengdu Sichuan 610031, China 2.Sichuan Key Lab of Signal and Information Processing, Southwest Jiaotong University, Chengdu Sichuan 610031, China) 《控制理论与应用(英文版)》 EI 2010年第2期181-188,共8页
A new scheme for driver fatigue detection is presented, which is based on the nonlinear unscented Kalman filter and eye tracking. Assuming a probability distribution than to approximate an arbitrary nonlinear function... A new scheme for driver fatigue detection is presented, which is based on the nonlinear unscented Kalman filter and eye tracking. Assuming a probability distribution than to approximate an arbitrary nonlinear function or transformation, eye nonlinear tracking can be achieved using an unscented transformation (UT), which adopts a set of deterministic sigma points to match the posterior probability density function of the eye movement. Driver fatigue can be detected using the percentage of eye closure (PERCLOS) framework in a realistic driving condition after the eye nonlinear tracking. This system was tested adequately in realistic driving environments with subjects of different genders, with/without glasses, in day/night driving, being commercial/noncommercial drivers, in continuous driving time, and under different road conditions. The last experimental results show that the proposed method not only improves the robustness for nonlinear eye tracking, but also can provide more accurate estimation than the traditional Kalman filter. 展开更多
关键词 eye tracking Unscented Kalman filter (UKF) Fatigue detection PERCLOS
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Neurocode-Tracking Based on Quantitative Fast Dynamic EEG Recording in Combination with Eye-Tracking 被引量:3
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作者 Wilfried Dimpfel Hans Carlos Hofmann 《World Journal of Neuroscience》 2014年第2期106-119,共14页
Information processing within the brain relies on electro-chemical features. Electric events are accessible by recording of the EEG. These electric oscillations might be regarded as a neuronal code carrying informatio... Information processing within the brain relies on electro-chemical features. Electric events are accessible by recording of the EEG. These electric oscillations might be regarded as a neuronal code carrying information on important motor, cognitive and emotional events. A new approach of quantitative assessment of very short time epochs of 364 ms has been developed on the base of particularly defined frequency ranges and called “Neurocode-Tracking”. The new method was technically validated by the use of a signal generator and was found to correspond to classical quantitative EEG analysis except for some smudging during the transition from one frequency range to the next. Real data from a subject were obtained during relaxation and performance of three mental tasks. Data were time averaged for 180 s using the classical method and compared to data averaging during 16.4 s. Results were nearly identical with respect to spectral signatures showing the expected midline frontal theta increases during performance of three cognitive tests but not during relaxation. Collection of very short time epochs of 728 ms duration confirmed task dependent frontal theta increases, most prominent during calculation performance test (CPT), less during d2-concentration and memory test, none during relaxation. Finally, the new technique was combined with eye-tracking. Capture of the EEG mapping video of Neurocode-Tracking and synchronization with the gaze overlay video by starting recording with an audio signal (gong) allowed a match of gazes precisely with the corresponding electric events. Use of this technical combination in research will hopefully lead to a new understanding of spectral signatures of electric activity called enkephaloglyphs. 展开更多
关键词 Neurocode tracking eye tracking QUANTITATIVE EEG ATTENTION
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Eye-Tracking Based Autism Spectrum Disorder Diagnosis Using Chaotic Butterfly Optimization with Deep Learning Model 被引量:1
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作者 Tamilvizhi Thanarajan Youseef Alotaibi +1 位作者 Surendran Rajendran Krishnaraj Nagappan 《Computers, Materials & Continua》 SCIE EI 2023年第8期1995-2013,共19页
Autism spectrum disorder(ASD)can be defined as a neurodevelopmental condition or illness that can disturb kids who have heterogeneous characteristics,like changes in behavior,social disabilities,and difficulty communi... Autism spectrum disorder(ASD)can be defined as a neurodevelopmental condition or illness that can disturb kids who have heterogeneous characteristics,like changes in behavior,social disabilities,and difficulty communicating with others.Eye tracking(ET)has become a useful method to detect ASD.One vital aspect of moral erudition is the aptitude to have common visual attention.The eye-tracking approach offers valuable data regarding the visual behavior of children for accurate and early detection.Eye-tracking data can offer insightful information about the behavior and thought processes of people with ASD,but it is important to be aware of its limitations and to combine it with other types of data and assessment techniques to increase the precision of ASD detection.It operates by scanning the paths of eyes for extracting a series of eye projection points on images for examining the behavior of children with autism.The purpose of this research is to use deep learning to identify autistic disorders based on eye tracking.The Chaotic Butterfly Optimization technique is used to identify this specific disturbance.Therefore,this study develops an ET-based Autism Spectrum Disorder Diagnosis using Chaotic Butterfly Optimization with Deep Learning(ETASD-CBODL)technique.The presented ETASDCBODL technique mainly focuses on the recognition of ASD via the ET and DL models.To accomplish this,the ETASD-CBODL technique exploits the U-Net segmentation technique to recognize interested AREASS.In addition,the ETASD-CBODL technique employs Inception v3 feature extraction with CBO algorithm-based hyperparameter optimization.Finally,the long-shorttermmemory(LSTM)model is exploited for the recognition and classification of ASD.To assess the performance of the ETASD-CBODL technique,a series of simulations were performed on datasets from the figure-shared data repository.The experimental values of accuracy(99.29%),precision(98.78%),sensitivity(99.29%)and specificity(99.29%)showed a better performance in the ETASD-CBODL technique over recent approaches. 展开更多
关键词 eye tracking ASD diagnosis deep learning butterfly optimization algorithm behavior analysis
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Navigation technology/eye-tracking in ophthalmology:principles,applications and benefits-a narrative review 被引量:1
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作者 Igor Kozak Ulrike Rahn 《Annals of Eye Science》 2021年第1期33-45,共13页
Navigation technology in ophthalmology,colloquially called“eye-tracking”,has been applied to various areas of eye care.This approach encompasses motion-based navigation technology in both ophthalmic imaging and trea... Navigation technology in ophthalmology,colloquially called“eye-tracking”,has been applied to various areas of eye care.This approach encompasses motion-based navigation technology in both ophthalmic imaging and treatment.For instance,modern imaging instruments use a real-time eye-tracking system,which helps to reduce motion artefacts and increase signal-to-noise ratio in imaging acquisition such as optical coherence tomography(OCT),microperimetry,and fluorescence and color imaging.Navigation in ophthalmic surgery has been firstly applied in laser vision corrective surgery and spread to involve navigated retinal photocoagulation,and positioning guidance of intraocular lenses(IOL)during cataract surgery.It has emerged as one of the most reliable representatives of technology as it continues to transform surgical interventions into safer,more standardized,and more predictable procedures with better outcomes.Eye-tracking is essential in refractive surgery with excimer laser ablation.Using this technology for cataract surgery in patients with high preoperative astigmatism has produced better therapeutic outcomes.Navigated retinal laser has proven to be safer and more accurate compared to the use of conventional slit lamp lasers.Eye-tracking has also been used in imaging diagnostics,where it is essential for proper alignment of captured zones of interest and accurate follow-up imaging.This technology is not routinely discussed in the ophthalmic literature even though it has been truly impactful in our clinical practice and represents a small revolution in ophthalmology. 展开更多
关键词 Navigation technology eye tracking imaging:refractive surgery excimer laser cataract surgery navigated retinal laser
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Evaluation of Product Placement with Attention on Eye-Tracking and EEG
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作者 Wanzeng Kong Xinyu Zhang +3 位作者 Luyun Wang Qiaonan Fan Yuanming Dai Yunxi Miao 《Journal of Beijing Institute of Technology》 EI CAS 2019年第1期42-50,共9页
Advertising evaluation can not only evaluate the subconscious behavior of consumers and help consumers to avoid irrational consumption,but also improve the utilization of advertising resources.To deal with this topic,... Advertising evaluation can not only evaluate the subconscious behavior of consumers and help consumers to avoid irrational consumption,but also improve the utilization of advertising resources.To deal with this topic,electroencephalogram(EEG)data and eye movement data from18 subjects is collected.The power spectra of beta band and theta band are used to calculate the EEG attention index,while the eye attention index is calculated by the statistics at fixation on the interesting area.Therefore the fusion attention index is obtained by fusing the EEG signal and eye movement data in the feature level.The results indicate that the memory of the advertisements is synced up with the attention of the products.And the fusion attention index has a higher significant difference than the other two indexes. 展开更多
关键词 NEUROMARKETING electroencephalogram(EEG) eye track ATTENTION ADVERTISING EVALUATION
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The Influence of the Food Images on Consumers' Attention by Using the Eye-Tracking Technology
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作者 WANG Hui-ya 《Journal of Literature and Art Studies》 2018年第4期680-686,共7页
This study used an eye-tracking methodology to investigate consumers' gazing behavior by focusing on how assessment design influences gazing behavior and decision time. Only one factor of test design was investigated... This study used an eye-tracking methodology to investigate consumers' gazing behavior by focusing on how assessment design influences gazing behavior and decision time. Only one factor of test design was investigated and each test contained three images. Eight participants were recruited. This study answered three questions: (1) Does the color of food influence gazing behavior? (2) Does the color of food influence decision-making? (3) Is gazing behavior related to decision-making behavior? The results demonstrated that gazing behavior and decision time have a positive relationship with the image selected. Future research should consider the relationships between eye movements, cognitive goals, and tasks 展开更多
关键词 eye tracking gazing behavior decision time food image
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Comparison of Anticancer Drug Preparation Techniques between Chemotherapy Specialist Pharmacists and Non-Chemotherapy Pharmacists Using Eye-Tracking Techniques
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作者 Yuka Miyachi Yukina Miyagi +5 位作者 Saori Gocho Chika Nakayama Masayuki Ejiri Masayuki Takeuchi Masafumi Ohnishi Taeyuki Oshima 《Pharmacology & Pharmacy》 2023年第8期229-238,共10页
Anticancer drug preparation by pharmacists is a critical task directly related to medical incidents. This study examined the factors influencing medical errors in chemotherapy, that is, errors by specialist pharmacist... Anticancer drug preparation by pharmacists is a critical task directly related to medical incidents. This study examined the factors influencing medical errors in chemotherapy, that is, errors by specialist pharmacists (CPh) and pharmacists in other departments (NCPh), by measuring their gaze during the preparation of anticancer drugs. The eye-tracking results showed that the gazing time of NCPh was significantly longer than that of CPh for items such as “preparation of a closed-system device” and “preparation of the syringe” and all preparation times (P < 0.05). The NCPh were not assigned to prepare drugs on a regular basis, indicating their lack of familiarity with the process. There was no significant difference in gaze ratio between CPh and NCPh. This outcome was suggested to be a result of the use of an anticancer drug preparation support system. The results for the pupil diameter variation rate showed that NCPh were significantly more mydriatic in the “mixing injections” category than CPh. However, CPh tended to be more mydriatic in the “checking” category. CPh exhibited a smooth workflow and focused on the important items to be checked. This study showed that the differences in procedure flow and concentration points may lead to errors. Furthermore, the results are of interest from the perspective of medical incident prevention. They will be useful in identifying potential human factors, such as where the pharmacist focuses their attention by measuring eye movements. 展开更多
关键词 eye tracking Medicine Inspection Anticancer Drug PHARMACISTS
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Eye Tracking during High Speed Navigation at Sea--Field Trial in Search of Navigational Gaze Behaviour
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作者 Fredrik Forsman Anna Sjors-Dahlman +2 位作者 Joakim Dahlman Torbjorn Falkmer Hoe C.Lee 《Journal of Transportation Technologies》 2012年第3期277-283,共7页
Purpose: Professional high speed sea navigational procedures are based on turn points, courses, dangers and steering cues in the environment. Since navigational aids have become less expensive and due to the fact that... Purpose: Professional high speed sea navigational procedures are based on turn points, courses, dangers and steering cues in the environment. Since navigational aids have become less expensive and due to the fact that electronic sea charts can be integrated with both radar and transponder information, it may be assumed that traditional navigation by using paper based charts and radar will play a less significant role in the future, especially among less experienced navigators. Possible navigational differences between experienced and non-experienced boat drivers is thus of interest with regards to their use of navigational aids. It may be assumed that less experienced navigators rely too much on the information given by the electronic sea chart, despite the fact that it is based on GPS information that can be questioned, especially in littoral waters close to land. Method: This eye tracking study investigates gaze behaviour from 16 ex perienced and novice boat drivers during high speed navigation at sea. Results: The results show that the novice drivers look at objects that are close to themselves, like instrumentation, while the experienced look more at objects far away from the boat. This is in accordance with previous research on car drivers. Further, novice boat drivers used the electronic navigational aids to a larger extent than the experienced, especially during high speed conditions. The experienced drivers focused much of their attention on objects outside the boat. Conclusions: The findings verify that novice boat drivers tend to rely on electronic navigational aids. Experienced drivers presumably use the navigational aids to verify what they have observed in the surrounding environment and further use the paper based sea chart to a larger extent than the novice drivers. 展开更多
关键词 eye tracking NAVIGATION Driving Experience VISION
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A strong tracking nonlinear robust filter for eye tracking 被引量:9
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作者 Zutao ZHANG Jiashu ZHANG 《控制理论与应用(英文版)》 EI 2010年第4期503-508,共6页
Non-intrusive methods for eye tracking are important for many applications of vision-based human computer interaction.However,due to the high nonlinearity of eye motion,how to ensure the robustness of external interfe... Non-intrusive methods for eye tracking are important for many applications of vision-based human computer interaction.However,due to the high nonlinearity of eye motion,how to ensure the robustness of external interference and accuracy of eye tracking pose the primary obstacle to the integration of eye movements into today's interfaces.In this paper,we present a strong tracking unscented Kalman filter (ST-UKF) algorithm,aiming to overcome the difficulty in nonlinear eye tracking.In the proposed ST-UKF,the Suboptimal fading factor of strong tracking filtering is introduced to improve robustness and accuracy of eye tracking.Compared with the related Kalman filter for eye tracking,the proposed ST-UKF has potential advantages in robustness and tracking accuracy.The last experimental results show the validity of our method for eye tracking under realistic conditions. 展开更多
关键词 eye tracking Strong tracking unscented Kalman filter (ST-UKF) Unscented Kalman filter (UKF) Strong tracking filtering (STF)
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Sampling strong tracking nonlinear unscented Kalman filter and its application in eye tracking 被引量:2
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作者 张祖涛 张家树 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第10期324-332,共9页
The unscented Kalman filter is a developed well-known method for nonlinear motion estimation and tracking. However, the standard unscented Kalman filter has the inherent drawbacks, such as numerical instability and mu... The unscented Kalman filter is a developed well-known method for nonlinear motion estimation and tracking. However, the standard unscented Kalman filter has the inherent drawbacks, such as numerical instability and much more time spent on calculation in practical applications. In this paper, we present a novel sampling strong tracking nonlinear unscented Kalman filter, aiming to overcome the difficulty in nonlinear eye tracking. In the above proposed filter, the simplified unscented transform sampling strategy with n+ 2 sigma points leads to the computational efficiency, and suboptimal fading factor of strong tracking filtering is introduced to improve robustness and accuracy of eye tracking. Compared with the related unscented Kalman filter for eye tracking, the proposed filter has potential advantages in robustness, convergence speed, and tracking accuracy. The final experimental results show the validity of our method for eye tracking under realistic conditions. 展开更多
关键词 unscented Kalman filter strong tracking filtering sampling strong tracking nonlinearunscented Kalman filter eye tracking
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Implementation System of Human Eye Tracking Algorithm Based on FPGA 被引量:2
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作者 Zhong Liu Xin’an Wang +1 位作者 Chengjun Sun Ken Lu 《Computers, Materials & Continua》 SCIE EI 2019年第3期653-664,共12页
With the high-speed development of transportation industry,highway traffic safety has become a considerable problem.Meanwhile,with the development of embedded system and hardware chip,in recent years,human eye detecti... With the high-speed development of transportation industry,highway traffic safety has become a considerable problem.Meanwhile,with the development of embedded system and hardware chip,in recent years,human eye detection eye tracking and positioning technology have been more and more widely used in man-machine interaction,security access control and visual detection.In this paper,the high parallelism of FPGA was utilized to realize an elliptical approximate real-time human eye tracking system,which was achieved by the series register structure and random sample consensus(RANSAC),thus improving the speed of image processing without using external memory.Because eye images acquired by the camera often generate a lot of noises due to uneven light and dark background,the preprocessing technologies such as color conversion,image filtering,histogram modification and image sharpening were adopted.In terms of feature extraction of images,the eye tracking algorithm in this paper adopted seven-section rectangular eye tracking characteristic method,which increased a section between the mouth and the nose on the basis of the traditional six-section method,so its recognition accuracy is much higher.It is convenient for the realization of hardware parallel system in FPGA.Finally,aiming at the accuracy and real-time performance of the design system,a more comprehensive simulation test was carried out.The human eye tracking system was verified on DE2-115 multimedia development platform,and the performance of VGA(resolution:640×480)images of 8-bit grayscale was tested.The results showed that the detection speed of this system was about 47 frames per second under the condition that the detection rate of human face(front face,no inclination)was 93%,which reached the real-time detection level.Additionally,the accuracy of eye tracking based on FPGA system was more than 95%,and it has achieved ideal results in real-time performance and robustness. 展开更多
关键词 Human eye tracking FPGA real-time performance PREPROCESSING elliptic approximation.
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EasyGaze:Hybrid eye tracking approach for handheld mobile devices 被引量:2
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作者 Shiwei CHENG Qiufeng PING +1 位作者 Jialing WANG Yijian CHEN 《Virtual Reality & Intelligent Hardware》 2022年第2期173-188,共16页
Background Eye-tracking technology for mobile devices has made significant progress.However,owing to limited computing capacity and the complexity of context,the conventional image feature-based technology cannot extr... Background Eye-tracking technology for mobile devices has made significant progress.However,owing to limited computing capacity and the complexity of context,the conventional image feature-based technology cannot extract features accurately,thus affecting the performance.Methods This study proposes a novel approach by combining appearance-and feature-based eye-tracking methods.Face and eye region detections were conducted to obtain features that were used as inputs to the appearance model to detect the feature points.The feature points were used to generate feature vectors,such as corner center-pupil center,by which the gaze fixation coordinates were calculated.Results To obtain feature vectors with the best performance,we compared different vectors under different image resolution and illumination conditions,and the results indicated that the average gaze fixation accuracy was achieved at a visual angle of 1.93°when the image resolution was 96×48 pixels,with light sources illuminating from the front of the eye.Conclusions Compared with the current methods,our method improved the accuracy of gaze fixation and it was more usable. 展开更多
关键词 eye movement Gaze estimation FIXATION Human-computer interaction eye tracking
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Examining the Impact of Web Advertising on Reading: An Eye Tracking Study
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作者 Mike Z. Yao Jeffrey Ho Minjun Xu 《Journalism and Mass Communication》 2012年第2期343-354,共12页
This study measures visual attention to examine the impact of banner ads on reading and information processing on the Web. Using a 2 × 3 experimental design, 120 students were randomly assigned to read a series o... This study measures visual attention to examine the impact of banner ads on reading and information processing on the Web. Using a 2 × 3 experimental design, 120 students were randomly assigned to read a series of either short or long articles on webpages presented with no banner ads, a static banner ad, or an animated banner ad. Visual attention was recorded by an eye-tracking device. Results from our study show that when there is too little information presented on a Webpage with no banner ads, the readers might become less attentive to the paper, while a long paper presented with too many visual stimuli may overload viewers' cognitive capacity. While these findings are generally consistent with past research that compared the impact of static ads against animated ads, the addition of a control condition and the varying of article length in our study extended previous research by revealing more complex visual processing and cognitive processes. 展开更多
关键词 READING visual attention web advertising eye tracking
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A DUAL-CAMERA VIDEO-TRACKING SYSTEM USING PROJECTION ALGORITHM
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作者 Liu Xiaojun Zou Mouyan (Institute of Electronics, Chinese Academy of Sciences, Beijing 100080) 《Journal of Electronics(China)》 2001年第2期174-180,共7页
This paper presents a video-tracking system composed of two cameras. One camera acts for producing an in-focus image of the object and the other one ensures an extended vision field under monitoring. Such a system sch... This paper presents a video-tracking system composed of two cameras. One camera acts for producing an in-focus image of the object and the other one ensures an extended vision field under monitoring. Such a system scheme can achieve an excellent tracking performance,especially under various unfavorable conditions. A projection algorithm is used for the calculation of the displacement of the moving object. As a result, the computational cost is reduced greatly.In order that the tracking action of the system persists even if the object is sheltered or ns acceleration is larger than a specified threshold, a dedicated tracking algorithm on the basis of the α-β filtering is designed. Experiments show that the algorithm is efficient and the system works very well. 展开更多
关键词 VIDEO monitoring VIDEO tracking α-β FILTERS
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Fundamental Properties and Optimal Gains of a Steady-State Velocity Measured <i>α</i>-<i>β</i>Tracking Filter
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作者 Kenshi Saho 《Advances in Remote Sensing》 2014年第2期61-76,共16页
This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filt... This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filter. We first derive the stability condition and steady-state predicted errors as fundamental properties of the VM-α-β filter. The optimal gains for representative motion models are then derived from the Kalman filter equations. Theoretical and numerical analyses verify that VM-α-β filters with these optimal gains realize more accurate tracking than conventional α-β filters when the filter gains are relatively large. Our study reveals the conditions under which the predicted errors of the VM-α-β filters are less than those of conventional α-β filters. Moreover, numerical simulations clarify that the variance of the tracking error of the VM-α-β filters is approximately 3/4 of that of the conventional α-β filters in realistic situations, even when the accuracy of the position/velocity measurements is the same. 展开更多
关键词 α-β FILTER Moving Target tracking VELOCITY Measurement KALMAN FILTER OPTIMAL Gain
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Comparison of three fluorescence labeling and tracking methods of endothelial progenitor cells in laser-injured retina
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作者 Hui Shi Xin-Rui Wang +8 位作者 Ming-Chao Bi Wei Yang Dan Wang Hai-Le Liu Ling-Ling Liang Xiao-Hong Li Qian Hao Zhi-Hua Cui E Song 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第4期580-588,共9页
AIM: To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells(EPCs) in a mouse model of laser-induced retinal injury.METHODS: EPCs were isolated from ... AIM: To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells(EPCs) in a mouse model of laser-induced retinal injury.METHODS: EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes: 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester(CFSE), 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein(Di I-Ac LDL), and green fluorescent protein(GFP). The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS: EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION: The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study. 展开更多
关键词 endothelial progenitor cells cell tracking 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester 1 1′-dilinoleyl-3 3 3′ 3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein green fluorescent protein retinal laser photocoagulation
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Optimization of the carrier tracking loop for GPS high dynamic receivers 被引量:6
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作者 李传军 杨树兴 《Journal of Beijing Institute of Technology》 EI CAS 2012年第2期164-171,共8页
A carrier tracking loop which can adjust the loop parameters adaptively is proposed for high dynamic application. Three modules, called the α-β-γT filter model, adaptive loop structure mod- el and adaptive loop ban... A carrier tracking loop which can adjust the loop parameters adaptively is proposed for high dynamic application. Three modules, called the α-β-γT filter model, adaptive loop structure mod- el and adaptive loop bandwidth model respectively, are added in the presented tracking loop com- pared with the traditional carrier tracking loop based on the second-order frequency lock loop (FLL) assisting third-order phase lock loop (PLL) loop filter. And the optimization methods for the track- ing bandwidth and the carrier loop order are analyzed. The real-time estimation methods of the dy- namic parameters, the velocity, acceleration and jerk along the line of sight (LOS) between the sat- ellite and the receiver' s antenna, and the measurement parameters are discussed based on the pres- ented α-β-γ filter algorithm. A method is introduced to improve the filter' s dynamic response to meet high dynamic application by self-adjusted α-β-γ filter coefficient used in the tracking loop. The performance of three cases with different carrier tracking loop is compared by simulation. 展开更多
关键词 OPTIMIZATION carrier tracking loop α-β-γ filter high dynamic receiver
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3D Track-keeping Method for Autonomous Underwater Vehicle 被引量:1
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作者 WANG Wei, Bian Xin-Qian, Chang Zong-HuCollege of Power and Nuclear Engineering, Harbin Engineering University, Harbin 150001, China 《哈尔滨工程大学学报(英文版)》 2002年第2期18-22,共5页
In this paper, 3D track-keeping control method for autonomous underwater vehicle (AUV) with and without the influence of ocean current is investigated. Because the system to be controlled is highly nonlinear and stron... In this paper, 3D track-keeping control method for autonomous underwater vehicle (AUV) with and without the influence of ocean current is investigated. Because the system to be controlled is highly nonlinear and strong coupled, an approach is used to divide it into two subsystems. One is to control the heading and the track error on the horizontal plane. The other is to control the pitch and the track error on the vertical plane. The results of computer simulation show that the autopilot works properly, it can capture the current waypoint and turns to track the next path automatically. 展开更多
关键词 AUV SLIDING MODE CONTROL 3D track - keeping
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Pupil center detection with a single webcam for gaze tracking
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作者 Ralph Oyini Mbouna Seong G Kong 《Journal of Measurement Science and Instrumentation》 CAS 2012年第2期133-136,共4页
This paper presents a user friendly approach to localize the pupil center with a single web camera.Several methods have been proposed to determine the coordinates of the pupil center in an image,but with practical lim... This paper presents a user friendly approach to localize the pupil center with a single web camera.Several methods have been proposed to determine the coordinates of the pupil center in an image,but with practical limitations.The proposed method can track the user’s eye movements in real time under normal image resolution and lighting conditions using a regular webcam,without special equipment such as infrared illuminators.After the pre-processing steps used to deal with illumination variations,the pupil center is detected using iterative thresholding by applying geometric constraints.Experimental results show that robustness and speed in determining the pupil’s location in real time for users of various ethnicities,under various lighting conditions,at different distances from the webcam and with standard resolution images. 展开更多
关键词 pupil detection eye gaze tracking feature extraction facial features tracking
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