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Automated evaluation of parapapillary choroidal microvasculature in crowded optic discs:a controlled,optical coherence tomography angiography study
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作者 Hatice Arda Hidayet Sener +5 位作者 Ozge Temizyurek Hatice Kubra Sonmez Duygu Gulmez Sevim Cem Evereklioglu Fatih Horozoglu Ayse Busra Gunay Sener 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第1期113-118,共6页
AIM:To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography(OCT-A).METHODS:Thirty patients with crowded discs,and 47 control... AIM:To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography(OCT-A).METHODS:Thirty patients with crowded discs,and 47 control subjects were enrolled in the study.One eye of each individual was included and OCT-A scans of optic discs were obtained in a 4.5×4.5 mm^(2) rectangular area.Radial peripapillary capillary(RPC)density,peripapillary retinal nerve fiber layer(pRNFL)thickness,cup volume,rim area,disc area,cup-to-disc(c/d)area ratio,and vertical c/d ratio were obtained automatically using device software.Automated parapapillary choroidal microvasculature(PPCMv)density was calculated using MATLAB software.When the vertical c/d ratio of the optic disc was absent or small cup,it was considered as a crowded disc.RESULTS:The mean signal strength index of OCT-A images was similar between the crowded discs and control eyes(P=0.740).There was no difference in pRNFL between the two groups(P=0.102).There were no differences in RPC density in whole image(P=0.826)and peripapillary region(P=0.923),but inside disc RPC density was higher in crowded optic discs(P=0.003).The PPCMv density in the inner-hemisuperior region was also lower in crowded discs(P=0.026).The pRNFL thickness was positively correlated with peripapillary RPC density(r=0.498,P<0.001).The inside disc RPC density was negatively correlated with c/d area ratio(r=-0.341,P=0.002).CONCLUSION:The higher inside disc RPC density and lower inner-hemisuperior PPCMv density are found in eyes with crowded optic discs. 展开更多
关键词 crowded optic disc ischemic optic neuropathy optical coherence tomography angiography parapapillary choroidal microvasculature
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Are China's Exports Crowding Out or Being Crowded Out? Evidence from Japan's Imports 被引量:4
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作者 Yan Liu Xunpeng Shi James Laurenceson, 《China & World Economy》 SCIE 2018年第4期1-23,共23页
Previous studies have investigated whether Chinese exports have crowaea oul mose from other countries. However, what has yet to be considered is the evidence based on different quality varieties. Using the most detail... Previous studies have investigated whether Chinese exports have crowaea oul mose from other countries. However, what has yet to be considered is the evidence based on different quality varieties. Using the most detailed Harmonized System 9-digit product- level data, the present paper provides evidence of crowding-out and crowded-out effects across different product quality segments and across manufacturing sectors by quality segments. The empirical evidence presented in this paper shows that the crowding-out effects of Chinese exports have been greatest at the lower end of the quality spectrum but less significant at the higher quality spectrum. Moreover, since 2007, China's own exports of lower quality manufactured goods have been increasingly crowded out. The key policy implication is that China's export path is in line with that taken by other Asian economies in previous decades; the crowded-out effect could achieve win-win outcomes for countries involved; and lower income countries would do well to be open to receive those relocated low value-added industries from China. However, the relocation policy in China is best implemented gradually as climbing up the product quality ladder takes time. 展开更多
关键词 constant market share analysis (CMS) crowded out crowding out industrial relocation
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Has China Crowded out Foreign Direct Investment from Its Developing East Asian Neighbors?
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作者 Ligang Liu Kevin Chow Unias Li 《China & World Economy》 SCIE 2007年第3期70-88,共19页
This paper applies a gravity model to investigate the determinants of foreign direct investment (FDI) in East Asia. Economic fundamentals, such as market size, per capita income and country risk indicators, economic... This paper applies a gravity model to investigate the determinants of foreign direct investment (FDI) in East Asia. Economic fundamentals, such as market size, per capita income and country risk indicators, economic and cultural ties, exchange rate volatilities and information asymmetry are found to be important determinants for FDL Globally, the inward FDI among high-income OECD economies declined significantly on average over the period of 1990-2003, whereas the inward FDI of the high-income OECD economies in emerging market economies gained substantially. In the East Asian region, the ASEAN-4 (Indonesia, Malaysia, the Philippines and Thailand) received above-average inward FDI from the high-income OECD economies after controlling for their economic fundamentals. By contrast, China's FDl from the high-income OECD economies is below average relative to its economic fundamentals. Therefore, it is difficult to establish that China has crowded out FDI from its developing ASEAN neighbors. 展开更多
关键词 ASEAN China crowding out foreign direct investment
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Robust Counting in Overcrowded Scenes Using Batch-Free Normalized Deep ConvNet
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作者 Sana Zahir Rafi Ullah Khan +4 位作者 Mohib Ullah Muhammad Ishaq Naqqash Dilshad Amin Ullah Mi Young Lee 《Computer Systems Science & Engineering》 SCIE EI 2023年第9期2741-2754,共14页
The analysis of overcrowded areas is essential for flow monitoring,assembly control,and security.Crowd counting’s primary goal is to calculate the population in a given region,which requires real-time analysis of con... The analysis of overcrowded areas is essential for flow monitoring,assembly control,and security.Crowd counting’s primary goal is to calculate the population in a given region,which requires real-time analysis of congested scenes for prompt reactionary actions.The crowd is always unexpected,and the benchmarked available datasets have a lot of variation,which limits the trained models’performance on unseen test data.In this paper,we proposed an end-to-end deep neural network that takes an input image and generates a density map of a crowd scene.The proposed model consists of encoder and decoder networks comprising batch-free normalization layers known as evolving normalization(EvoNorm).This allows our network to be generalized for unseen data because EvoNorm is not using statistics from the training samples.The decoder network uses dilated 2D convolutional layers to provide large receptive fields and fewer parameters,which enables real-time processing and solves the density drift problem due to its large receptive field.Five benchmark datasets are used in this study to assess the proposed model,resulting in the conclusion that it outperforms conventional models. 展开更多
关键词 Artificial intelligence deep learning crowd counting scene understanding
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Using NMR-detected hydrogen-deuterium exchange to quantify protein stability in cosolutes,under crowded conditions in vitro and in cells
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作者 I-Te Chu Gary J.Pielak 《Magnetic Resonance Letters》 2023年第4期319-326,共8页
We review the use of nuclear magnetic resonance(NMR)spectroscopy to assess the exchange of amide protons for deuterons(HDX)in efforts to understand how high concentration of cosolutes,especially macromolecules,affect ... We review the use of nuclear magnetic resonance(NMR)spectroscopy to assess the exchange of amide protons for deuterons(HDX)in efforts to understand how high concentration of cosolutes,especially macromolecules,affect the equilibrium thermodynamics of protein stability.HDX NMR is the only method that can routinely provide such data at the level of individual amino acids.We begin by discussing the properties of the protein systems required to yield equilibrium thermodynamic data and then review publications using osmolytes,sugars,denaturants,synthetic polymers,proteins,cytoplasm and in cells. 展开更多
关键词 Amide proton exchange Cosolutes Equilibrium thermodynamics Macromolecular CROWDING OSMOLYTES Protein stability
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A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration
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作者 Yong-Chao Li Rui-Sheng Jia +1 位作者 Ying-Xiang Hu Hong-Mei Sun 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期965-981,共17页
In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation metrics.In this paper,we aim to reduce the annotation cost of crowd dat... In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation metrics.In this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised information.For this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the network.Specifically,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd images.In addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density estimation.The experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++. 展开更多
关键词 Crowd density estimation linear feature calibration vision transformer weakly-supervision learning
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Investigation on Breakdown Characteristics of Various Surface Terminal Structures for GaN-Based Vertical P-i-N Diodes
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作者 Song Shi Guanyu Wang +5 位作者 Yingcong Xiang Chuan Guo Xing Wang Yinlin Pu Huilan Li Zhixian Li 《Journal of Applied Mathematics and Physics》 2024年第2期554-568,共15页
GaN-based vertical P-i-N diode with mesa edge terminal structure due to electric field crowding effect, the breakdown voltage of the device is significantly reduced. This work investigates three terminal structures, i... GaN-based vertical P-i-N diode with mesa edge terminal structure due to electric field crowding effect, the breakdown voltage of the device is significantly reduced. This work investigates three terminal structures, including deeply etched, bevel, and stepped-mesas terminal structures, to suppress electric field crowding effects at the device and junction edges. Deeply-etched mesa terminal yields a breakdown voltage of 1205 V, i.e., 89% of the ideal voltage. The bevel-mesa terminal achieves about 89% of the ideal breakdown voltage, while the step-mesa terminal is less effective in mitigating electric field crowding, at about 32% of the ideal voltage. This work can provide an important reference for the design of high-power, high-voltage GaN-based P-i-N power devices, finding a terminal protection structure suitable for GaNPiN diodes to further enhance the breakdown performance of the device and to unleash the full potential of GaN semiconductor materials. 展开更多
关键词 GaN P-I-N Mesa Edge Terminal Electric Field Crowding
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An attending physician float shift for the improvement of physician productivity in a crowded emergency department 被引量:6
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作者 Muhammad Umer Nasim Chintan Mistry +2 位作者 Robert Harwood Erik Kulstad Laura Tommaso 《World Journal of Emergency Medicine》 CAS 2013年第1期10-14,共5页
BACKGROUND:Patients backlogged in the emergency department(ED) waiting for an inpatient bed(boarders) continue to require the attention of ED physicians,exacerbating crowding in the ED.To address this problem,we added... BACKGROUND:Patients backlogged in the emergency department(ED) waiting for an inpatient bed(boarders) continue to require the attention of ED physicians,exacerbating crowding in the ED.To address this problem,we added a "float shift" to our winter schedule solely to care for boarders.We sought to quantify the effect of this float shift,hypothesizing greater physician productivity.METHODS:We performed a retrospective observational study in our community hospital ED,measuring the number of new patients seen in each 10-hour shift in the presence or absence of a float shift physician.We calculated the number of new patients seen per shift for each of the 7 daily shifts,during February(float shift scheduled) and May(float shift unscheduled) of 2008.We then compared the mean number of patients seen per shift in February with May.RESULTS:Total monthly patient volume was 6 656 for February and 6 775 for May,with the mean daily census being 230 and 219 patients,respectively.The number of new patients seen during each shift was greater in February than in May,with a mean increase of 1.1 patients per shift(with the float shift).Surveying participants about intervention effectiveness showed 92%of residents,but only 65%of attending physicians,in favor of maintaining the float shift.CONCLUSION:The presence of a "float shift" physician caring only for boarding patients allows other physicians to maintain and even increase their productivity in our ED,despite the presence of longer throughput times and increased time on diversion. 展开更多
关键词 CROWDING Physician staffing Boarding patients Float shift
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Simulation-based optimization of inner layout of a theater considering the effect of pedestrians
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作者 高庆飞 陶亦舟 +2 位作者 韦艳芳 吴成 董力耘 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第3期285-291,共7页
We propose an extended cellular automaton model based on the floor field. The floor field can be changed accordingly in the presence of pedestrians. Furthermore, the effects of pedestrians with different speeds are di... We propose an extended cellular automaton model based on the floor field. The floor field can be changed accordingly in the presence of pedestrians. Furthermore, the effects of pedestrians with different speeds are distinguished, i.e., still pedestrians result in more increment of the floor field than moving ones. The improved floor field reflects impact of pedestrians as movable obstacles on evacuation process. The presented model was calibrated by comparing with previous studies. It is shown that this model provides a better description of crowd evacuation both qualitatively and quantitatively.Then we investigated crowd evacuation from a middle-size theater. Four possible designs of aisles in the theater are studied and one of them is the actual design in reality. Numerical simulation shows that the actual design of the theater is reasonable.Then we optimize the position of the side exit in order to reduce the evacuation time. It is shown that the utilization of the two exits at bottom is less than that of the side exits. When the position of the side exit is shifted upwards by about 1.6 m,it is found that the evacuation time reaches its minimum. 展开更多
关键词 cellular AUTOMATON floor field crowd EVACUATION optimization of PEDESTRIAN facilities
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An Intelligent Cluster Verification Model Using WSN to Avoid Close Proximity and Control Outbreak of Pandemic in a Massive Crowd
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作者 Naeem Ahmed Nawaz Norah Saleh Alghamdi +1 位作者 Hanen Karamti Mohammad Ayoub Khan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第11期327-350,共24页
Assemblage at public places for religious or sports events has become an integral part of our lives.These gatherings pose a challenge at places where fast crowd verification with social distancing(SD)is required,espec... Assemblage at public places for religious or sports events has become an integral part of our lives.These gatherings pose a challenge at places where fast crowd verification with social distancing(SD)is required,especially during a pandemic.Presently,verification of crowds is carried out in the form of a queue that increases waiting time resulting in congestion,stampede,and the spread of diseases.This article proposes a cluster verification model(CVM)using a wireless sensor network(WSN),single cluster approach(SCA),and split cluster approach(SpCA)to solve the aforementioned problem for pandemic cases.We show that SD,cluster approaches,and verification by WSN can overcome the management issues by optimizing the cluster size and verification time.Hence,our proposed method minimizes the chances of spreading diseases and stampedes in large events such as a pilgrimage.We consider the assembly points in the annual pilgrimage to Makkah Al-Mukarmah and Umrah for verification using Contiki/Cooja tool.We compute results such as verified cluster members(CMs)to define cluster size,success rate to determine the best success rate,and verification time to determine the optimal verification time for various scenarios.We validate ourmodel by comparing the results of each approach with the existing model.Our results showthat the SpCAwith SD is the best approach with a 96% success rate and optimization of verification time as compared to SCA with SD and the existing model. 展开更多
关键词 Cluster verification model wireless sensor network social distancing crowd single approach split approach
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Crowdedness estimation approach based on stereovision for bus passengers
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作者 朱秋煜 江毅凭 +1 位作者 邓伟俊 唐利 《Journal of Shanghai University(English Edition)》 2010年第1期17-23,共7页
An estimation approach is proposed in this paper based on the binocular stereovision to collect the degree of crowdedness in public transports. The proposed method combines the disparity with frame differences to extr... An estimation approach is proposed in this paper based on the binocular stereovision to collect the degree of crowdedness in public transports. The proposed method combines the disparity with frame differences to extract the foreground object. An adaptive window normalized cross correlation (NCC) matching and interpolated method is applied to get the sub-pixel image disparity value. Then, the foreground object is projected to the horizontal plane to eliminate the influence of the occlusion and perspective effect. Finally the degree of crowdedness is calculated from the area and the perimeter of the foreground objects. Experimental results show that the proposed method can obtain good estimation results in the simulated scenes in the laboratory and on parking or moving buses. This approach is effective to illumination changes, shadows and occlusion of passengers. 展开更多
关键词 PASSENGER degree of crowdedness binocular stereovision DISPARITY foreground object detection
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Adaptive Scheme for Crowd Counting Using off-the-Shelf Wireless Routers
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作者 Wei Zhuang Yixian Shen +3 位作者 Chunming Gao Lu Li Haoran Sang Fei Qian 《Computer Systems Science & Engineering》 SCIE EI 2022年第4期255-269,共15页
Since the outbreak of the world-wide novel coronavirus pandemic,crowd counting in public areas,such as in shopping centers and in commercial streets,has gained popularity among public health administrations for preven... Since the outbreak of the world-wide novel coronavirus pandemic,crowd counting in public areas,such as in shopping centers and in commercial streets,has gained popularity among public health administrations for preventing the crowds from gathering.In this paper,we propose a novel adaptive method for crowd counting based on Wi-Fi channel state information(CSI)by using common commercial wireless routers.Compared with previous researches on device-free crowd counting,our proposed method is more adaptive to the change of environ-ment and can achieve high accuracy of crowd count estimation.Because the dis-tance between access point(AP)and monitor point(MP)is typically non-fixed in real-world applications,the strength of received signals varies and makes the tra-ditional amplitude-related models to perform poorly in different environments.In order to achieve adaptivity of the crowd count estimation model,we used convo-lutional neural network(ConvNet)to extract features from correlation coefficient matrix of subcarriers which are insensitive to the change of received signal strength.We conducted experiments in university classroom settings and our model achieved an overall accuracy of 97.79%in estimating a variable number of participants. 展开更多
关键词 CSI device-free deep learning crowd counting WI-FI wireless sensing
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Design and Availability Research of a Flammable and Explosive Volatiles Monitoring and Early Warning System (FEVMEW) for the Bus Crowded Places
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作者 Cen Yu Weibin Guo +2 位作者 Ruyi Li Qiang Chen Tianping Xu 《Journal of Computer and Communications》 2020年第12期83-90,共8页
<div style="text-align:justify;"> In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded p... <div style="text-align:justify;"> In order to reduce the arson or accidental fire losses, we developed a gas sensitive detector used for the rapid detection and early warning of flammables in crowded places such as buses. A MEMS (Micro-Electro-Mechanical System) based thin film semiconductor was fabricated as the gas sensor. To obtain the target gas selective response, the surface of the sensitive film was modified with highly active metal catalytic nano-particles. Thus the anti-interference ability was improved and the false alarm rate was effectively reduced. Furthermore, the modular embedded system for information acquisition and transmission was developed. Supported by the Airflow Precision control system (APs), the rapid warning of volatile gas of flammable substances was realized. Experiments showed that RAs has satisfied selectivity to volatiles of usual flammable liquid, such as the output voltage reaches 3 V (0 - 3.3 V). With simulation about the actual installation state in bus, MWs sounds an alarm at 2 minutes after splashing 50 mL 92# petrol to the floor. For the last two years, FEVMEW has been integrated into more than 4000 buses in Hefei. This design has been proved feasible according to the actual operation. </div> 展开更多
关键词 Flammable and Explosive Volatiles Monitoring and Early Warning Bus crowded Places Gas Sensitive MEMS Chip Airflow Regulating
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SOEs urged not to profit by crowding out private economy
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作者 王永强 张一君 《China Economist》 2010年第3期5-7,共3页
Hu Deping,68,is the oldest son of Hu Yaobang,a late Party secretary general. His name has recently appeared in the press not because of his father’s reputation but for his own
关键词 SOEs urged not to profit by crowding out private economy GNP
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Participants Recruitment for Coverage Maximization by Mobility Predicting in Mobile Crowd Sensing 被引量:1
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作者 Yuanni Liu Xi Liu +2 位作者 Xin Li Mingxin Li Yi Li 《China Communications》 SCIE CSCD 2023年第8期163-176,共14页
Mobile Crowd Sensing(MCS)is an emerging paradigm that leverages sensor-equipped smart devices to collect data.The introduction of MCS also poses some challenges such as providing highquality data for upper layer MCS a... Mobile Crowd Sensing(MCS)is an emerging paradigm that leverages sensor-equipped smart devices to collect data.The introduction of MCS also poses some challenges such as providing highquality data for upper layer MCS applications,which requires adequate participants.However,recruiting enough participants to provide the sensing data for free is hard for the MCS platform under a limited budget,which may lead to a low coverage ratio of sensing area.This paper proposes a novel method to choose participants uniformly distributed in a specific sensing area based on the mobility patterns of mobile users.The method consists of two steps:(1)A second-order Markov chain is used to predict the next positions of users,and select users whose next places are in the target sensing area to form a candidate pool.(2)The Average Entropy(DAE)is proposed to measure the distribution of participants.The participant maximizing the DAE value of a specific sensing area with different granular sub-areas is chosen to maximize the coverage ratio of the sensing area.Experimental results show that the proposed method can maximize the coverage ratio of a sensing area under different partition granularities. 展开更多
关键词 data average entropy human mobility prediction markov chain mobile crowd sensing
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A Novel Collaborative Evolutionary Algorithm with Two-Population for Multi-Objective Flexible Job Shop Scheduling 被引量:1
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作者 CuiyuWang Xinyu Li Yiping Gao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第11期1849-1870,共22页
Job shop scheduling(JS)is an important technology for modern manufacturing.Flexible job shop scheduling(FJS)is critical in JS,and it has been widely employed in many industries,including aerospace and energy.FJS enabl... Job shop scheduling(JS)is an important technology for modern manufacturing.Flexible job shop scheduling(FJS)is critical in JS,and it has been widely employed in many industries,including aerospace and energy.FJS enables any machine from a certain set to handle an operation,and this is an NP-hard problem.Furthermore,due to the requirements in real-world cases,multi-objective FJS is increasingly widespread,thus increasing the challenge of solving the FJS problems.As a result,it is necessary to develop a novel method to address this challenge.To achieve this goal,a novel collaborative evolutionary algorithmwith two-population based on Pareto optimality is proposed for FJS,which improves the solutions of FJS by interacting in each generation.In addition,several experimental results have demonstrated that the proposed method is promising and effective for multi-objective FJS,which has discovered some new Pareto solutions in the well-known benchmark problems,and some solutions can dominate the solutions of some other methods. 展开更多
关键词 Multi-objective flexible job shop scheduling Pareto archive set collaborative evolutionary crowd similarity
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Abnormal Crowd Behavior Detection Using Optimized Pyramidal Lucas-Kanade Technique 被引量:1
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作者 G.Rajasekaran J.Raja Sekar 《Intelligent Automation & Soft Computing》 SCIE 2023年第2期2399-2412,共14页
Abnormal behavior detection is challenging and one of the growing research areas in computer vision.The main aim of this research work is to focus on panic and escape behavior detections that occur during unexpected/u... Abnormal behavior detection is challenging and one of the growing research areas in computer vision.The main aim of this research work is to focus on panic and escape behavior detections that occur during unexpected/uncertain events.In this work,Pyramidal Lucas Kanade algorithm is optimized using EME-HOs to achieve the objective.First stage,OPLKT-EMEHOs algorithm is used to generate the opticalflow from MIIs.Second stage,the MIIs opticalflow is applied as input to 3 layer CNN for detect the abnormal crowd behavior.University of Minnesota(UMN)dataset is used to evaluate the proposed system.The experi-mental result shows that the proposed method provides better classification accu-racy by comparing with the existing methods.Proposed method provides 95.78%of precision,90.67%of recall,93.09%of f-measure and accuracy with 91.67%. 展开更多
关键词 Crowd behavior analysis anomaly detection Motion Information
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Toward Optimal Periodic Crowd Tracking via Unmanned Aerial Vehicle
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作者 Khalil Chebil Skander Htiouech Mahdi Khemakhem 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期233-263,共31页
Crowd management and analysis(CMA)systems have gained a lot of interest in the vulgarization of unmanned aerial vehicles(UAVs)use.Crowd tracking using UAVs is among the most important services provided by a CMA.In thi... Crowd management and analysis(CMA)systems have gained a lot of interest in the vulgarization of unmanned aerial vehicles(UAVs)use.Crowd tracking using UAVs is among the most important services provided by a CMA.In this paper,we studied the periodic crowd-tracking(PCT)problem.It consists in usingUAVs to follow-up crowds,during the life-cycle of an open crowded area(OCA).Two criteria were considered for this purpose.The first is related to the CMA initial investment,while the second is to guarantee the quality of service(QoS).The existing works focus on very specified assumptions that are highly committed to CMAs applications context.This study outlined a new binary linear programming(BLP)model to optimally solve the PCT motivated by a real-world application study taking into consideration the high level of abstraction.To closely approach different real-world contexts,we carefully defined and investigated a set of parameters related to the OCA characteristics,behaviors,and theCMAinitial infrastructure investment(e.g.,UAVs,charging stations(CSs)).In order to periodically update theUAVs/crowds andUAVs/CSs assignments,the proposed BLP was integrated into a linear algorithm called PCTs solver.Our main objective was to study the PCT problem fromboth theoretical and numerical viewpoints.To prove the PCTs solver effectiveness,we generated a diversified set of PCTs instances with different scenarios for simulation purposes.The empirical results analysis enabled us to validate the BLPmodel and the PCTs solver,and to point out a set of new challenges for future research directions. 展开更多
关键词 Unmanned aerial vehicles periodic crowd-tracking problem open crowded area optimization binary linear programming crowd management and analysis system
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Sparrow Search Optimization with Transfer Learning-Based Crowd Density Classification
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作者 Mohammad Yamin Mishaal Mofleh Almutairi +1 位作者 Saeed Badghish Saleh Bajaba 《Computers, Materials & Continua》 SCIE EI 2023年第3期4965-4981,共17页
Due to the rapid increase in urbanization and population,crowd gatherings are frequently observed in the form of concerts,political,and religious meetings.HAJJ is one of the well-known crowding events that takes place... Due to the rapid increase in urbanization and population,crowd gatherings are frequently observed in the form of concerts,political,and religious meetings.HAJJ is one of the well-known crowding events that takes place every year in Makkah,Saudi Arabia.Crowd density estimation and crowd monitoring are significant research areas in Artificial Intelligence(AI)applications.The current research study develops a new Sparrow Search Optimization with Deep Transfer Learning based Crowd Density Detection and Classification(SSODTL-CD2C)model.The presented SSODTL-CD2C technique majorly focuses on the identification and classification of crowd densities.To attain this,SSODTL-CD2C technique exploits Oppositional Salp Swarm Optimization Algorithm(OSSA)with EfficientNet model to derive the feature vectors.At the same time,Stacked Sparse Auto Encoder(SSAE)model is utilized for the classification of crowd densities.Finally,SSO algorithm is employed for optimal fine-tuning of the parameters involved in SSAE mechanism.The performance of the proposed SSODTL-CD2C technique was validated using a dataset with four different kinds of crowd densities.The obtained results demonstrated that the proposed SSODTLCD2C methodology accomplished an excellent crowd classification performance with a maximum accuracy of 93.25%.So,the proposed method will be highly helpful in managing HAJJ and other crowded events. 展开更多
关键词 Crowd management crowd density classification artificial intelligence deep learning computer vision
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Dataset of Large Gathering Images for Person Identification and Tracking
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作者 Adnan Nadeem Amir Mehmood +7 位作者 Kashif Rizwan Muhammad Ashraf Nauman Qadeer Ali Alzahrani Qammer H.Abbasi Fazal Noor Majed Alhaisoni Nadeem Mahmood 《Computers, Materials & Continua》 SCIE EI 2023年第3期6065-6080,共16页
This paper presents a large gathering dataset of images extracted from publicly filmed videos by 24 cameras installed on the premises of Masjid Al-Nabvi,Madinah,Saudi Arabia.This dataset consists of raw and processed ... This paper presents a large gathering dataset of images extracted from publicly filmed videos by 24 cameras installed on the premises of Masjid Al-Nabvi,Madinah,Saudi Arabia.This dataset consists of raw and processed images reflecting a highly challenging and unconstraint environment.The methodology for building the dataset consists of four core phases;that include acquisition of videos,extraction of frames,localization of face regions,and cropping and resizing of detected face regions.The raw images in the dataset consist of a total of 4613 frames obtained fromvideo sequences.The processed images in the dataset consist of the face regions of 250 persons extracted from raw data images to ensure the authenticity of the presented data.The dataset further consists of 8 images corresponding to each of the 250 subjects(persons)for a total of 2000 images.It portrays a highly unconstrained and challenging environment with human faces of varying sizes and pixel quality(resolution).Since the face regions in video sequences are severely degraded due to various unavoidable factors,it can be used as a benchmark to test and evaluate face detection and recognition algorithms for research purposes.We have also gathered and displayed records of the presence of subjects who appear in presented frames;in a temporal context.This can also be used as a temporal benchmark for tracking,finding persons,activity monitoring,and crowd counting in large crowd scenarios. 展开更多
关键词 Large crowd gatherings a dataset of large crowd images highly uncontrolled environment tracking missing persons face recognition activity monitoring
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