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发表还是出局?——“Tenure-track”机制下青年教师发表国际学术期刊论文的压力 被引量:22
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作者 田美 陆根书 《复旦教育论坛》 CSSCI 北大核心 2016年第5期14-20,34,共8页
为了增加研究成果产出,我国高校逐渐加强了对教师发表国际学术期刊论文的要求。为探讨这种压力对青年教师的影响,本研究组对我国西部地区某研究型大学青年教师进行了半结构化访谈研究。研究发现,在"tenure-track"机制下,青年... 为了增加研究成果产出,我国高校逐渐加强了对教师发表国际学术期刊论文的要求。为探讨这种压力对青年教师的影响,本研究组对我国西部地区某研究型大学青年教师进行了半结构化访谈研究。研究发现,在"tenure-track"机制下,青年教师面临巨大的发表国际学术期刊论文的压力;被访者指出,加速发表国际学术期刊论文,有损高质量与创新性学术论文的产出;发表国际学术期刊论文的压力还导致青年教师普遍产生"重科研、轻教学"的态度;同时,过度的压力也可能对青年教师的健康及家庭关系产生消极影响。 展开更多
关键词 发表 出局 tenure—track 青年学者 发表压力
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基于改进Tracktor的行人多目标跟踪算法 被引量:1
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作者 谌海云 黄忠义 +1 位作者 王海川 余鸿皓 《计算机工程与应用》 CSCD 北大核心 2024年第8期242-249,共8页
在多目标视频跟踪中,针对受交互遮挡等影响导致检测偏差从而致使目标身份丢失的问题,提出一种基于改进Tracktor的行人多目标跟踪算法DUTracktor。在检测框回归中设计一个动态更新模块,利用孪生网络对建议框进一步检测定位;利用时序信息... 在多目标视频跟踪中,针对受交互遮挡等影响导致检测偏差从而致使目标身份丢失的问题,提出一种基于改进Tracktor的行人多目标跟踪算法DUTracktor。在检测框回归中设计一个动态更新模块,利用孪生网络对建议框进一步检测定位;利用时序信息增强模块更新当前帧更适合的模板,建立全局上下文关系;并通过像素相关进行特征融合,从而增强目标边缘信息和尺度信息;利用相机运动补偿和融合相似矩阵构建二级关联跟踪机制,建立检测框和轨迹更强大的关联性,提高目标跟踪的鲁棒性。在公开的MOT16数据集上进行实验测试,并与当前主流算法相比,该算法跟踪精度表现较优,具有良好的鲁棒性,FPS稳定在24帧。 展开更多
关键词 计算机视觉 多目标跟踪 tracktor 孪生网络
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BEVTrack:基于难例挖掘训练的端到端三维多目标跟踪方法 被引量:1
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作者 张弘 万家旭 +2 位作者 陈海波 张健 李旭亮 《信号处理》 CSCD 北大核心 2024年第1期152-165,共14页
多目标跟踪已经成为自动驾驶系统中的一个关键组成部分,其目的是在连续的视频流与点云流中识别、定位并标识所有感兴趣的目标。目前三维多目标跟踪方法多依赖人工多阶段调参以保证整体跟踪性能,难以对复杂遮挡或运动进行有效建模。而现... 多目标跟踪已经成为自动驾驶系统中的一个关键组成部分,其目的是在连续的视频流与点云流中识别、定位并标识所有感兴趣的目标。目前三维多目标跟踪方法多依赖人工多阶段调参以保证整体跟踪性能,难以对复杂遮挡或运动进行有效建模。而现有的三维端到端多目标跟踪方法,如MUTR等,精度普遍较低。其核心原因为三维空间中的特征聚合和感知相对于二维图像更具挑战性,简单的网络难以实现复杂的三维特征聚合,并大量的噪声信息与难例信息干扰严重,影响模型的特征提取能力。针对以上问题,本文提出了一种基于难例挖掘训练的端到端多目标跟踪框架BEVTrack。针对三维特征关联问题,本文设计了基于鸟瞰图(BEV)位置编码的三维跟踪查询。通过基于BEV特征的三维跟踪查询,本文方法能够更好地将跟踪查询与实际三维特征进行有效关联,从而大幅度提升了跟踪精度。同时,模型依靠BEV数据进行特征关联,仅需轻量化的网络便可以实现快速有效的跟踪。针对数据噪声问题,本文提出了面向多目标跟踪的难例挖掘训练,通过针对检测难例与跟踪难例分别处理,训练模型去除检测错误噪声与跟踪匹配的能力,从而提升在真实场景下模型处理噪声信息与难例干扰的能力。在实验结果方面,基于Nuscenes数据集,我们进行了大量的对比实验与模型消融实验,实验结果证明本文的方法在该数据集上取得了领先的性能。 展开更多
关键词 多目标跟踪 端到端 难例挖掘 TRANSFORMER
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基于改进CStrack关联策略的多目标跟踪算法
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作者 苏佳 冯康康 +2 位作者 孟俊彤 梁奔 张明 《无线电工程》 2024年第3期597-606,共10页
针对复杂场景下目标外观变化明显、运动不规律易导致轨迹中断和身份切换频繁等问题,从重识别(Re-Identification,Re-ID)特征、数据关联和插值等方面对跟踪器进行改进,提出基于改进CStrack关联策略的多目标跟踪算法。使用外观特征更新模... 针对复杂场景下目标外观变化明显、运动不规律易导致轨迹中断和身份切换频繁等问题,从重识别(Re-Identification,Re-ID)特征、数据关联和插值等方面对跟踪器进行改进,提出基于改进CStrack关联策略的多目标跟踪算法。使用外观特征更新模块,减小因视角改变、目标移动导致特征剧烈变化而产生的影响,增强特征间的关联。提出二次关联方法,根据高低置信度检测结果的特点,使用不同的度量方式进行二次关联:第一次关联使用IoU距离融合外观特征作为关联的代价矩阵,第二次使用扩展IoU关联,缓解运动估计偏差、外观不可区分导致度量失效的问题;采用高斯回归算法,考虑运动信息,通过插值补偿漏检。在MOT17、MOT20数据集上进行测试,跟踪精度分别达到73.9%、64.2%。实验结果表明,该方法在跟踪精度上有明显优势,能够较好地适应复杂场景。 展开更多
关键词 多目标跟踪 CStrack 重识别 数据关联
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基于Bytetrack的多目标跟踪算法在斑马鱼毒性行为识别中的应用 被引量:2
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作者 赵海翔 崔鸿武 +4 位作者 黄桢铭 王磊 李皓 崔正国 曲克明 《渔业科学进展》 CSCD 北大核心 2024年第2期136-149,共14页
利用计算机视觉技术识别斑马鱼(Danio rerio)在不同污染物暴露下的行为变化是水质毒性评价的常用方法之一,但传统方法存在效率低、面对遮挡和复杂环境时性能差等缺陷。针对这些问题,本研究使用基于Bytetrack的多目标跟踪算法追踪斑马鱼... 利用计算机视觉技术识别斑马鱼(Danio rerio)在不同污染物暴露下的行为变化是水质毒性评价的常用方法之一,但传统方法存在效率低、面对遮挡和复杂环境时性能差等缺陷。针对这些问题,本研究使用基于Bytetrack的多目标跟踪算法追踪斑马鱼在4种污染物(Zn、Pb、Cr和苯酚)暴露2 h后的行为变化,对斑马鱼在4种浓度梯度中的平均速度、最大速度、最低速度、平均碰撞次数和行为轨迹等指标进行分析。结果显示,算法的追踪精度、漏检率和检测时间(每300帧)分别能达到90.26%、16.33%和0.19 min,检测时间和精度相比于传统目标检测方法有较大提升。同时,根据污染物不同,该方法能准确识别特定污染物环境中斑马鱼相应的运动状态及轨迹变化,可实现精确识别和实时响应,在鱼类毒性行为识别领域具有重要参考意义。 展开更多
关键词 计算机视觉 多目标跟踪 斑马鱼 行为分析
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On the Restricting Factors & System Arrangements of Chinese Land Tenure Marketization
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作者 YU Peng-yi,ZHANG Wei-dong(Business School of Huazhong University of Science and Technology Wuhan,Hubei,430074,PRC) 《Journal of Northeast Agricultural University(English Edition)》 CAS 2003年第2期166-172,共7页
As a general rule of Economics of Development,economic growth and development require rational institution guarantee.Land Tenure.As a main institution factor in agricultural development,closely relates to the reform o... As a general rule of Economics of Development,economic growth and development require rational institution guarantee.Land Tenure.As a main institution factor in agricultural development,closely relates to the reform of Chinese agriculture.Based on the relevant theories of Economics of Institution and Economics of Development,and combined with the marketization process of Chinese Land Tenure of Property Rights,the article studied the effects of institutional factors and put forward some choices in the development of agriculture,which is of both significant and practical importance. 展开更多
关键词 land tenure of property rights institution choice rural reform
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Innovation in Bio-disaster Prevention and Control Mechanism after Forest Tenure Reform at County Level
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作者 ZHAN Zu-ren 《Asian Agricultural Research》 2012年第11期85-88,93,共5页
Taking Youxi County of Fujian Province as an example,the author introduced basic situations of new bio-disaster prevention and control mechanism for forest resource protection and social service works after the forest... Taking Youxi County of Fujian Province as an example,the author introduced basic situations of new bio-disaster prevention and control mechanism for forest resource protection and social service works after the forest tenure reform.Then,the author analyzed new problems faced by bio-disaster prevention and control in forestry.Finally,the author present the existing problems of bio-disaster prevention and control at the county level from five aspects:innovating upon plant quarantine management mechanism;innovation upon survey methods and service modes of bio-disaster monitoring;strengthening and improving construction of bio-disaster monitoring and forecasting network;innovating upon management system for bio-disaster prevention and control;speeding up construction of service system for social prevention and control of bio-disasters. 展开更多
关键词 FOREST tenure system REFORM PREVENTION and control
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Forest Tenure Transfer and Assessment of Dayi County
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作者 Qinghao GAO Huafeng ZENG Ying NIE 《Asian Agricultural Research》 2013年第7期41-45,共5页
According to analysis of basic situations and achievements of forest tenure transfer in Dayi County,this paper points out problems in the assessment of forest tenure transfer in Dayi County,including few specialized o... According to analysis of basic situations and achievements of forest tenure transfer in Dayi County,this paper points out problems in the assessment of forest tenure transfer in Dayi County,including few specialized organizations and personnel of forest tenure transfer value assessment,outmoded forest tenure assessment operating specifications,low charges of forest tenure assessment,and weak awareness of forest tenure assessment. In line with these problems,it presents ideas of increasing specialized forest tenure assessment organization,strengthening training of specialized forest tenure assessment personnel,promoting guiding price of forest tenure transfer,and energetically developing forest tenure transfer market. It is hoped to promote development of forest tenure transfer in Dayi County. 展开更多
关键词 Dayi COUNTY FOREST tenure TRANSFER ASSESSMENT Deve
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System Change of Collective Forest Tenure Oriented to Deepening the Reform
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作者 PAN Wu-lin,ZHAO Meng,LIU Jing School of Business,Agricultural University of Hebei,Baoding 071000,China 《Asian Agricultural Research》 2011年第11期12-15,共4页
We firstly introduce development background of new collective forest tenure reform.The situations indicate that the collective forest tenure reform has already stepped into comprehensive and in-depth stage.However,due... We firstly introduce development background of new collective forest tenure reform.The situations indicate that the collective forest tenure reform has already stepped into comprehensive and in-depth stage.However,due to neglect of local demands and actual conditions,there appear problems of low operating efficiency of supporting measures and relevant policies and little effect of in-depth reform.Therefore,it is required to strictly distinguish the relation between system change of collective forest tenure and the in-depth reform.For the purpose of in-depth reform,in accordance with local situations of forest farmers and forestry organizations,requirements for system,as well as local reform conditions,we strictly divide system change of collective forest tenure into three types:induced institutional change,hidden induced institutional change and imposed institutional change.Then,we divide the imposed institutional change into weak institutional change and pure strong institutional change. 展开更多
关键词 In-depth REFORM of COLLECTIVE forest tenure INDUCE
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Ecological Hidden Troubles and Countermeasures under Reform of Collective Forest Tenure
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作者 REN Yang1,LI Yuan-hui1,JIANG Guo-hua2 1.Faculty of Humanities and Social Sciences,Beijing Forestry University,Beijing 100083,China 2.Division of Legal Affairs,Beijing Municipal Bureau of Landscape and Forestry,Beijing 100013,China 《Asian Agricultural Research》 2011年第11期46-49,共4页
Three stages of reform of collective forest tenure after reform and opening up are reviewed.The reform of forest tenure brings sharp increase of economic benefit.However,due to forest farmers' subjective pursuit f... Three stages of reform of collective forest tenure after reform and opening up are reviewed.The reform of forest tenure brings sharp increase of economic benefit.However,due to forest farmers' subjective pursuit for economic benefit and objective lack of necessary economic,financial and technical support,ecological hidden troubles are created.Based on these,we put forward countermeasures,including strengthening forest farmers' awareness of ecological protection and solving ecological problems in accordance with actual conditions of the region. 展开更多
关键词 REFORM of FOREST tenure Economic BENEFIT Ecologica
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Forest Tenure and Sustainable Forest Management
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作者 Jacek P. Siry Kathleen McGinley +1 位作者 Frederick W. Cubbage Pete Bettinger 《Open Journal of Forestry》 2015年第5期526-545,共20页
We reviewed the principles and key literature related to forest tenure and sustainable forest management, and then examined the status of sustainable forestry and land ownership at the aggregate national level for maj... We reviewed the principles and key literature related to forest tenure and sustainable forest management, and then examined the status of sustainable forestry and land ownership at the aggregate national level for major forested countries. The institutional design principles suggested by Ostrom are well accepted for applications to public, communal, and private lands. The analyses of countries as a whole suggest that problems of forest land loss and sustainable forest management are related to the amount of public lands owned, as well as the difference between developed and developing countries. Developed countries have largely achieved a stable level of land use and resource extraction after centuries of exploitation of forests and natural resources. Many developed countries do have greater amounts of private forest land than developing countries, which have occurred as the countries transfer lands to private owners in the course of development. Public lands and management approaches require diligence, but can be developed to meet the design criteria suggested by tenure rights theorists. Private or communal ownership is often considered superior, but also must meet the criteria suggested above in order to foster sustainable forest management in poor countries. 展开更多
关键词 FOREST tenure PROPERTY RIGHTS SUSTAINABLE FOREST MANAGEMENT
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Experimental and numerical settlement analysis of railway track over geogrid reinforced ballast 被引量:1
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作者 Mohammed Y.Fattah Mahmood R.Mahmood Mohammed F.Aswad 《Railway Sciences》 2024年第3期311-331,共21页
Purpose-The main objective of the present research is to investigate the benefits of using geogrid reinforcement in minimizing the rate of deterioration of ballasted rail track geometry resting on soft clay and to exp... Purpose-The main objective of the present research is to investigate the benefits of using geogrid reinforcement in minimizing the rate of deterioration of ballasted rail track geometry resting on soft clay and to explore the effect of load amplitude,load frequency,presence of geogrid layer in ballast layer and ballast layer thickness on the behavior of track system.These variables are studied both experimentally and numerically.This paper examines the effect of geogrid reinforced ballast laying on a layer of clayey soil as a subgrade layer,where a half full scale railway tests are conducted as well as a theoretical analysis is performed.Design/methodologylapproach-The experimental tests work consists of laboratory model tests to investigate the reduction in the compressibility and stress distribution induced in soft clay under a ballast railway reinforced by geogrid reinforcement subjected to dynamic load.Experimental model based on an approximate half scale for general rail track engineering practice is adopted in this study which is used in Iraqi railways.The investigated parameters are load amplitude,load frequency and presence of geogrid reinforcement layer.A half fuli-scale railway was constructed for carrying out the tests,which consists of two rails 800 mm in iength with three w00den sleepers(900 mm×90 mm×90 mm).The ballast was overlying 500 mm thick clay layer.The tests were carried out with and without geogrid reinforcement,the tests were carried out in a well tied steel box of 1.5 m length X 1 m width X 1 m height.A series of laboratory tests were conducted to investigate the response of the ballast and the clay layers where the ballast was reinforced by a geogrid.Settlement in ballast and clay,was measured in reinforced and unreinforced ballast cases.In addition to the laboratory tests,the application of numerical analysis was made by using the finite element program PLAXIS 3D 2013.Findings-It was concluded that the settlement increased with increasing the simulated train load amplitude,there is a sharp increase in settlement up to the cycle 500 and after that,there is a gradual increase to level out between,2,500 and 4,500 cycles depending on the load frequency.There is a little increase in the induced settlement when the load amplitude increased from 0.5 to i ton,but it is higher when the load amplitude increased to 2 ton,the increase in settlement depends on the geogrid existence and the other studied parameters.Both experimental and numerical results showed the same behavior.The effect of load frequency on the settlement ratio is almost constant after 500 cycles.In general,for reinforced cases,the effect of load frequency on the settlement ratio is very small ranging between 0.5 and 2%compared with the unreinforcedcase.Originalitylvalue-Increasing the ballast layer thickness from 20 cm to 30 cm leads to decrease the settlement by about 50%.This ascertains the efficiency of ballast in spreading the waves induced by the track. 展开更多
关键词 track ettlement BALLAST FINITEELEMENTS
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Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints 被引量:1
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作者 Jin-Xi Zhang Kai-Di Xu Qing-Guo Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第7期1557-1565,共9页
The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requ... The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this paper.Herein, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings. 展开更多
关键词 Nonlinear systems output constraints prescribed performance reference tracking time delays
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Label-free in-vivo classi-cation and tracking of red blood cells and platelets using Dynamic-YOLOv4 network 被引量:1
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作者 Caizhong Guan Bin He +6 位作者 Hongting Zhang Shangpan Yang Yang Xu Honglian Xiong Yaguang Zeng Mingyi Wang Xunbin Wei 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第5期89-103,共15页
In-vivo flow cytometry is a noninvasive real-time diagnostic technique that facilitates continuous monitoring of cells without perturbing their natural biological environment,which renders it a valuable tool for both ... In-vivo flow cytometry is a noninvasive real-time diagnostic technique that facilitates continuous monitoring of cells without perturbing their natural biological environment,which renders it a valuable tool for both scientific research and clinical applications.However,the conventional approach for improving classification accuracy often involves labeling cells with fluorescence,which can lead to potential phototoxicity.This study proposes a label-free in-vivo flow cytometry technique,called dynamic YOLOv4(D-YOLOv4),which improves classification accuracy by integrating absorption intensity fluctuation modulation(AIFM)into YOLOv4 to demodulate the temporal features of moving red blood cells(RBCs)and platelets.Using zebrafish as an experimental model,the D-YOLOv4 method achieved average precisions(APs)of 0.90 for RBCs and 0.64 for thrombocytes(similar to platelets in mammals),resulting in an overall AP of 0.77.These scores notably surpass those attained by alternative network models,thereby demonstrating that the combination of physical models with neural networks provides an innovative approach toward developing label-free in-vivoflow cytometry,which holds promise for diverse in-vivo cell classification applications. 展开更多
关键词 LABEL-FREE in-vivoflow cytometry cell classification and tracking D-YOLOv4
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基于改进YOLOv7-ByteTrack的干制哈密大枣缺陷检测与计数系统 被引量:1
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作者 刘鑫 马本学 +2 位作者 李玉洁 陈金成 喻国威 《农业工程学报》 EI CAS CSCD 北大核心 2024年第3期303-312,共10页
针对目前无法同时对随机多列排布干制哈密大枣进行快速缺陷检测和统计计数问题,该研究设计了一款干制哈密大枣在线检测与计数系统。以干制哈密大枣为研究对象,利用工业相机拍摄传送带上随机排列的多类别缺陷干制哈密大枣视频为数据源,... 针对目前无法同时对随机多列排布干制哈密大枣进行快速缺陷检测和统计计数问题,该研究设计了一款干制哈密大枣在线检测与计数系统。以干制哈密大枣为研究对象,利用工业相机拍摄传送带上随机排列的多类别缺陷干制哈密大枣视频为数据源,采用改进的YOLOv7模型进行干制哈密大枣多类别缺陷检测并将检测结果作为后续多目标跟踪算法的输入;考虑到传送带上干制哈密大枣的外观相似性高以及排列密集等特点,该研究结合ByteTrack多目标跟踪算法的思想,设计了一种多类别干制哈密大枣的画线计数方法,实现了随机排布多类别干制哈密大枣的缺陷检测、准确定位及计数。试验结果表明:1)改进的YOLOv7模型浮点计算量为64.6 G,在干制哈密大枣目标检测数据的测试集上的平均检测精度、召回率、F_(1)平衡分数分别达到了98.03%、93.43%和95.00%,相比YOLOv7模型分别提高了4.40、6.88和7.00个百分点,浮点计算量下降了38.6%;2)基于改进YOLOv7为目标检测器开发的ByteTrack算法计数模型对干制哈密大枣计数的准确率为90.12%。该研究可为干制哈密大枣检测计数和分选分级提供技术支持。 展开更多
关键词 图像处理 目标检测 干制哈密大枣 多目标跟踪 YOLOv7
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Land tenure security,place satisfaction and loyalty in the peri-urban area of Ibadan City,Nigeria
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作者 Taiwo Oladapo BABALOLA 《Regional Sustainability》 2022年第4期346-355,共10页
Land tenure security is pertinent to achieving the sustainable development agenda in cities where land is needed and useful for development purposes.Sufficient empirical research has been done to prove the importance ... Land tenure security is pertinent to achieving the sustainable development agenda in cities where land is needed and useful for development purposes.Sufficient empirical research has been done to prove the importance of tenure security for investment,resilience,conservation,food security,as well as health and well-being,but it has not been clarified if and how land tenure security could adequately influence place loyalty and satisfaction with the residential environment,as it is clear that place loyalty and satisfaction are pertinent to inclusive development.Using the case of Ibadan City,the study examined how different dimensions of tenure security could determine residents’place loyalty and satisfaction.The study employed a survey cross-sectional research design to distribute 514 structured questionnaires to household heads across 4 sampled peri-urban local government areas while 452 were retrieved for analysis.Hierarchical regression analysis model was employed to understand the association between tenure security dimensions and satisfaction(as model I)and loyalty(as model II).For model I,F=8.640,P=0.000,R=0.555,and R^(2)=0.308 were obtained;while for model II,F=9.157,P=0.001,R=0.415,and R^(2)=0.173 were acquired.This thus means that residents’place loyalty and satisfaction can partly be explained by tenure security.In particular,respondents with no eviction experience,recognized property rights,and invulnerable to eviction have higher odds of being satisfied and loyal.Therefore,we recommend protection,improvement,and upgrading of land tenure security as one of the means to promote place loyalty and satisfaction,which is essential to achieving inclusive and sustainable development. 展开更多
关键词 Land tenure security Place satisfaction Place loyalty Urban governance Peri-urban area Sustainability African city
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Masked Autoencoders as Single Object Tracking Learners 被引量:1
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作者 Chunjuan Bo XinChen Junxing Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第7期1105-1122,共18页
Significant advancements have beenwitnessed in visual tracking applications leveragingViT in recent years,mainly due to the formidablemodeling capabilities of Vision Transformer(ViT).However,the strong performance of ... Significant advancements have beenwitnessed in visual tracking applications leveragingViT in recent years,mainly due to the formidablemodeling capabilities of Vision Transformer(ViT).However,the strong performance of such trackers heavily relies on ViT models pretrained for long periods,limitingmore flexible model designs for tracking tasks.To address this issue,we propose an efficient unsupervised ViT pretraining method for the tracking task based on masked autoencoders,called TrackMAE.During pretraining,we employ two shared-parameter ViTs,serving as the appearance encoder and motion encoder,respectively.The appearance encoder encodes randomly masked image data,while the motion encoder encodes randomly masked pairs of video frames.Subsequently,an appearance decoder and a motion decoder separately reconstruct the original image data and video frame data at the pixel level.In this way,ViT learns to understand both the appearance of images and the motion between video frames simultaneously.Experimental results demonstrate that ViT-Base and ViT-Large models,pretrained with TrackMAE and combined with a simple tracking head,achieve state-of-the-art(SOTA)performance without additional design.Moreover,compared to the currently popular MAE pretraining methods,TrackMAE consumes only 1/5 of the training time,which will facilitate the customization of diverse models for tracking.For instance,we additionally customize a lightweight ViT-XS,which achieves SOTA efficient tracking performance. 展开更多
关键词 Visual object tracking vision transformer masked autoencoder visual representation learning
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Tenure of Urban Land: Structure, Form and Transformation in Ribeirao Preto, Brazil
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作者 Ivone Salgado Dirceu Piccinato Junior 《Journal of Civil Engineering and Architecture》 2016年第1期108-121,共14页
The purpose of this study is to explore the urban morphological aspects of cities governed by the juridical regime of emphyteusis, a recurrent situation in the northeastern part of the state of Silo Paulo, Brazil, wit... The purpose of this study is to explore the urban morphological aspects of cities governed by the juridical regime of emphyteusis, a recurrent situation in the northeastern part of the state of Silo Paulo, Brazil, with special attention to the city of Ribeirao Preto. The concession of lands to the Catholic Church was a recurring practice in Brazil during the colonial and imperial periods, when the cities were being established. As these lands were intended for the formation of patrimonial goods to show the devotion of the residents to a Catholic saint, the lands were not allowed to be commercialized. The tenure reveals a relation in which there is an owner--the landlord--who has direct control of the urban land. This owner allows another--the leaseholder--the useful domain of the land, thus giving the latter the right to use the land, the obligation to pay an annual tax and the responsibility to give the owner a percentage of the sales generated from the land. In 1845, farmers donated a tract of land to be used to glorify Silo Sebastiao. This land is now the city of Ribeirao Preto, and it is this conjuncture that defined the structure and the transformation of the original urban form of the current city. 展开更多
关键词 tenure emphyteusis urban land Catholic Church urban morphology concession of lands.
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Land Tenure and Land Consolidation Issues in Bosnia and Herzegovina and Croatia
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作者 Zeljko Obradovic 《Journal of Geodesy and Geomatics Engineering》 2016年第2期8-17,共10页
Bosnia and Herzegovina and Croatia are post-war and post-socialist countries having partly common history and problems regarding land tenure and land consolidation, but, due to the different recent development, they a... Bosnia and Herzegovina and Croatia are post-war and post-socialist countries having partly common history and problems regarding land tenure and land consolidation, but, due to the different recent development, they are tackling detected problems in different manner. Internal problems regarding land ownership, privatization and corruption, together with negative consequences of globalization and economic crisis resulted in the downfall of land usage for food production having visible impact on prosperity of the nations. The expansion of farming area represents therefore one of the priorities for both countries. Without well kept and well managed land registers, and without the development of efficient land tenure mechanisms, the mentioned problems can hardly be solved, hence, both countries are paying great attention to solving these problems. Bosnia and Herzegovina fighting with the reducing size of uncultivated land, initiated the land consolidation activities on pilot locations in Oragje, Ravno and Trebinje after twenty years. Croatia has focused its activities on dealing with the issues related to the registration of state-owned agricultural land and on developing the efficient system for land tenure. For this purpose, different kinds of projects related to land registration, land consolidation, and finally the State agricultural land IT system establishment project have been executed. In this paper, an overview of the executed activities, the achieved results and detected problems is given indicating also further activities. 展开更多
关键词 Land consolidation land tenure OWNERSHIP state-owned agricultural land.
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Adaptive Trajectory Tracking Control for Nonholonomic Wheeled Mobile Robots:A Barrier Function Sliding Mode Approach 被引量:1
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作者 Yunjun Zheng Jinchuan Zheng +3 位作者 Ke Shao Han Zhao Hao Xie Hai Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期1007-1021,共15页
The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external disturbances.This paper proposes a barrier function-base... The trajectory tracking control performance of nonholonomic wheeled mobile robots(NWMRs)is subject to nonholonomic constraints,system uncertainties,and external disturbances.This paper proposes a barrier function-based adaptive sliding mode control(BFASMC)method to provide high-precision,fast-response performance and robustness for NWMRs.Compared with the conventional adaptive sliding mode control,the proposed control strategy can guarantee that the sliding mode variables converge to a predefined neighborhood of origin with a predefined reaching time independent of the prior knowledge of the uncertainties and disturbances bounds.Another advantage of the proposed algorithm is that the control gains can be adaptively adjusted to follow the disturbances amplitudes thanks to the barrier function.The benefit is that the overestimation of control gain can be eliminated,resulting in chattering reduction.Moreover,a modified barrier function-like control gain is employed to prevent the input saturation problem due to the physical limit of the actuator.The stability analysis and comparative experiments demonstrate that the proposed BFASMC can ensure the prespecified convergence performance of the NWMR system output variables and strong robustness against uncertainties/disturbances. 展开更多
关键词 Adaptive sliding mode barrier function nonholonomic wheeled mobile robot(NWMR) trajectory tracking control
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