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同构视阈下的异构治理:市辖区体制的优化进路 被引量:1
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作者 邱实 《深圳社会科学》 2022年第2期50-60,共11页
市辖区是现代城市治理的重要政区,其在城市基础性管理和公共服务供给方面发挥了重要作用。市辖区是现代市制的产物,受政策主观性和要素客观性的双重影响。基于我国市制变迁背景,改革开放以来的市辖区体制发展可以归纳为四个阶段:非规律... 市辖区是现代城市治理的重要政区,其在城市基础性管理和公共服务供给方面发挥了重要作用。市辖区是现代市制的产物,受政策主观性和要素客观性的双重影响。基于我国市制变迁背景,改革开放以来的市辖区体制发展可以归纳为四个阶段:非规律变动期(1949—1982)、数量增长期(1983—2003)、平稳控制期(2004—2013)、规模拓展期(2014至今)。市辖区体制的这四个时期并非是自发产生的,而是根据市制的客观发展和主观调控形成的,并具有前后衔接的波动性,形成了当前市辖区体制的基本形态。同时,在职责同构化的政府过程中,城市发展的非均衡性使市辖区在分配发展资源时出现了明显的差异性,进而引发市辖区体制的职责偏差。在同构化治理的背景下,市辖区体制出现设置高度"同构化"、调整自主性偏弱和城市治理"模糊化"等难点,引发城市治理现代化的障碍。在充分考量"职责同构"发生的必然性和合理性的基础上,尝试以"异构"治理作为市辖区体制优化的理念创新,即在"同构"的现实中以"异构"治理为视角创新市辖区体制的优化理念。基于此,分别从政区治理的适域化、治理单元的多维化和区际治理的协同化三个方面出发,探索市辖区"异构"治理的实践策略。 展开更多
关键词 城市发展 市辖区体制 职责同构 异构治理 适域化 协同
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Tomato detection method using domain adaptive learning for dense planting environments
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作者 LI Yang HOU Wenhui +4 位作者 YANG Huihuang RAO Yuan WANG Tan JIN Xiu ZHU Jun 《农业工程学报》 EI CAS CSCD 北大核心 2024年第13期134-145,共12页
This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy ... This study aimed to address the challenge of accurately and reliably detecting tomatoes in dense planting environments,a critical prerequisite for the automation implementation of robotic harvesting.However,the heavy reliance on extensive manually annotated datasets for training deep learning models still poses significant limitations to their application in real-world agricultural production environments.To overcome these limitations,we employed domain adaptive learning approach combined with the YOLOv5 model to develop a novel tomato detection model called as TDA-YOLO(tomato detection domain adaptation).We designated the normal illumination scenes in dense planting environments as the source domain and utilized various other illumination scenes as the target domain.To construct bridge mechanism between source and target domains,neural preset for color style transfer is introduced to generate a pseudo-dataset,which served to deal with domain discrepancy.Furthermore,this study combines the semi-supervised learning method to enable the model to extract domain-invariant features more fully,and uses knowledge distillation to improve the model's ability to adapt to the target domain.Additionally,for purpose of promoting inference speed and low computational demand,the lightweight FasterNet network was integrated into the YOLOv5's C3 module,creating a modified C3_Faster module.The experimental results demonstrated that the proposed TDA-YOLO model significantly outperformed original YOLOv5s model,achieving a mAP(mean average precision)of 96.80%for tomato detection across diverse scenarios in dense planting environments,increasing by 7.19 percentage points;Compared with the latest YOLOv8 and YOLOv9,it is also 2.17 and 1.19 percentage points higher,respectively.The model's average detection time per image was an impressive 15 milliseconds,with a FLOPs(floating point operations per second)count of 13.8 G.After acceleration processing,the detection accuracy of the TDA-YOLO model on the Jetson Xavier NX development board is 90.95%,the mAP value is 91.35%,and the detection time of each image is 21 ms,which can still meet the requirements of real-time detection of tomatoes in dense planting environment.The experimental results show that the proposed TDA-YOLO model can accurately and quickly detect tomatoes in dense planting environment,and at the same time avoid the use of a large number of annotated data,which provides technical support for the development of automatic harvesting systems for tomatoes and other fruits. 展开更多
关键词 PLANTS MODELS domain adaptive tomato detection illumination variation semi-supervised learning dense planting environments
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Sustainable Intervention Plans for Igbo Cultural Region of Nigeria
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作者 Bartho Ekweruo Nnezi Uduma-Olugu 《Journal of Civil Engineering and Architecture》 2014年第2期231-241,共11页
The Igbos are one of the major tribes of Nigeria. Over the years, their distinct way of living have further accentuated their culture. The paper discusses the Igbo cultural landscape region which comprises of rural au... The Igbos are one of the major tribes of Nigeria. Over the years, their distinct way of living have further accentuated their culture. The paper discusses the Igbo cultural landscape region which comprises of rural autonomous communities made up of clusters of kindred and villages. In spite of the existence of the townships serving as trade, political and administrative centers for more than one century, the rate of urbanization has been very slow thereby affecting the development of the communities physically, economically and socially at astonishing rates consuming farmlands and traditional community boundaries. This paper is aimed at creating awareness on the unique regional growth pattern in Igbo land heavily dependent on cultural and natural heritages for purpose of determining adaptable regional planning strategies for such vibrant cultural region. It has examined the key issues and suggested a way forward to a more sustainable development of the region. 展开更多
关键词 Igbo cultural landscape sustainable interventions EROSION ecological consequences urban growth patterns Nigeria.
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AN ADAPTIVE TRUST REGION METHOD FOR EQUALITY CONSTRAINED OPTIMIZATION 被引量:1
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作者 ZHANGJuliang ZHANGXiangstm ZHUOXinjian 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2003年第4期494-505,共12页
In this paper, a trust region method for equality constrained optimizationbased on nondifferentiable exact penalty is proposed. In this algorithm, the trail step ischaracterized by computation of its normal component ... In this paper, a trust region method for equality constrained optimizationbased on nondifferentiable exact penalty is proposed. In this algorithm, the trail step ischaracterized by computation of its normal component being separated from computation of itstangential component, i.e., only the tangential component of the trail step is constrained by trustradius while the normal component and trail step itself have no constraints. The other maincharacteristic of the algorithm is the decision of trust region radius. Here, the decision of trustregion radius uses the information of the gradient of objective function and reduced Hessian.However, Maratos effect will occur when we use the nondifferentiable exact penalty function as themerit function. In order to obtain the superlinear convergence of the algorithm, we use the twiceorder correction technique. Because of the speciality of the adaptive trust region method, we usetwice order correction when p = 0 (the definition is as in Section 2) and this is different from thetraditional trust region methods for equality constrained optimization. So the computation of thealgorithm in this paper is reduced. What is more, we can prove that the algorithm is globally andsuperlinearly convergent. 展开更多
关键词 equality constrained optimization global convergence trust region method superlinear convergence nondifferentiable exact penalty function maratos effect
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