利用改进特征金字塔模型的SAR图像多目标船舶检测

深度学习模型中的特征金字塔网络（Feature Pyramid Network，FPN）常被用作合成孔径雷达（Synthetic Aperture Radar，SAR）图像中多目标船舶的检测。针对复杂场景下多目标船舶检测问题，提出了一种基于改进锚点框的FPN模型。首先将特征金字塔模型嵌入传统的RPN（Region Proposal Network）并映射成新的特征空间用于目标检测，然后利用基于形状相似度距离（Shape Similar Distance,SSD）度量的Kmeans聚类算法优化FPN的初始锚点框，并使用SAR船舶数据集测试。实验结果表明，所提算法目标检测精确率达到98.62%，在复杂场景下与YOLO、Faster RCNN、FPN based on VGG/ResNet等模型进行对比，模型准确率提高，整体性能更好。     

基于减缓热岛效应的公园绿地布局 优化研究

城市化进程加快导致城市热岛效应问题日益突出， 公园绿地在降温方面具有重要作用，如何通过公园绿地布局以 减缓热岛效应是当前值得思考的问题。以福州市主城区为研究 区，利用辐射传输方程和泰森多边形分析城市热岛情况及公园 绿地布局现状，采用P-中值模型结合城市用地规划确定公园 绿地布局优化方案，结果表明：1)福州市主城区的整体温度偏 高，其热岛范围达城市总面积的11.78%；2)共提取福州市主 城区公园绿地47个，总面积为11.11km2，占主城区总面积 的4.47%，公园绿地布局总体不能满足人们的需要；3)利用 P-中值模型对公园绿地供需情况进行分析，得出18个公园绿 地需要优化，其中包括福州动物园、环南公园等12个一级优化 公园绿地，以及屏山公园、琴亭湖公园等6个二级优化公园绿 地；4)结合福州市中心城区用地规划，得到50个潜在公园绿 地建设点，主要集中于城门镇、盖山镇及新店镇。     

基于共生理论的具有历史遗存的城市公园改造研究

具有历史遗存的城市公园是指在公园红线范围内含有一定文化价值的历史文化景点、文化遗产和文物保护单位等历史遗存的城市公园，其改造与更新的核心问题是平衡公园的保护传承与复兴发展，寻求二者的共生，如何科学有效地平衡协调两者之间的关系成为改造的关键。基于共生理论的解读与启示，以江西省南屏瀚峰文化公园为例，分别从文化、功能和空间3个方面深入分析了公园存在的主要问题，并结合实例，探讨了具有历史遗存的城市公园改造与更新的共生策略与实践措施。     

The political economy of Zimbabwean Urban informality since 2000 – A contemporary governance dilemma

ABSTRACT

The article explores the urban informality dilemma in Harare through the lens of a political economy theory. It examines the typologies of urban informality, the influence of political economy on urban informalities, and informs decision-making to address the urban informality dilemma. A qualitative approach was used where secondary data were collected through document analysis and primary data from interviews with 20 purposively selected key informants. Surveys and in-depth interviews were conducted with 585 individuals engaged in informal activities. It emerged that urban informality in Harare takes on different forms and aside from the economic crisis, politics played a role in the emergence and proliferation of urban informality. The article provides insight into, and raises awareness with regard to key areas of concern on how power influences decision-making relating to urban informality. Therefore, the article provides a basis for policy formulation and institutional reforms for effective measures to curb urban informality.     

试论城市轨道交通信号系统的运营维护管理要点

随着我国城市轨道的发展,在轨道交通动态发展过程中更加重视环境保护。信号系统是城市轨道交通最重要的设备之一,其稳定性对于有效的交通发展和人们出行的人身安全至关重要。但目前,在城市轨道交通信号系统的运营维护管理过程中仍存在问题,若不及时解决,可能会影响轨道交通信号系统的正常运营。因此,论文重点探讨了城市轨道交通信号系统的运营维护管理策略。     

简析数据加密技术在计算机网络安全中的应用

随着我国科学技术的不断发展,计算机被广泛应用于各行各业的发展建设以及人们日常生活和学习中,在给人们带来较大便利的同时,也存在安全隐患。网络安全问题威胁到了计算机信息的保密性,给计算机的可持续发展带来了安全隐患,若用户的信息被泄露会给用户带来巨大的财产损失及心理伤害。因此,出现了数据加密技术,其为计算机网络安全提供了很好的保障。基于此,论文对数据加密技术在提高网络安全性中的应用方面作了简要阐述。     

城市轨道交通运营管理专业三维立体人才培养模式构建的实证研究

论文以城市轨道交通运营管理专业为例,运用霍尔三维结构模式理论构建以知识体系、岗位技能、职业素养为坐标的三维立体人才培养模式维度体系,打破了传统仅以知识体系和岗位技能为重点的二维人才培养模式,丰富了交通类高职专业人才培养模式研究理论,为交通类相关专业在制定人才培养方案时提供参考依据。     

Dynamics of firm's network community associations and firm's innovation performance

ABSTRACT

R&D network structures have crucial impacts on firm's innovation performance. However, most previous studies have been based on the whole or ego network perspective, few studies have investigated the influence of community structure that a firm is engaged in on its innovation performance, and it is still unclear how a firm's relation to network community affect its innovation performance. This research aims to address this gap by focusing on the dynamics of firm's network community associations, empirically investigate the relationship between dynamics of firm's network community associations and its innovation performance. Based on the unbalanced panel data of smartphone R&D network during year 2004–2017, the results demonstrate that change in community member associations and movement across communities both have inverted-U-shaped effects on firm's innovation performance. Moreover, innovation openness depth has moderating effects on the relationships between dynamics of firm's network community associations and its innovation performance.     

The impact of dual network structure on firm performance: the moderating effect of innovation strategy

ABSTRACT

Firm innovation is embedded in a collaboration network among researchers and a knowledge network composed of knowledge elements; the two networks are decoupled. Guided by social network theory, this study puts forward the definition and the classification of firm dual network structure, probes into the influence of dual network structure on firm performance, and explores the alignment between innovation strategy and firm dual network structure. We conduct an empirical study of 183 listed companies in China from 2004 to 2018. It is found that the four types of dual network structure all have positive impacts on firm performance, and the impact of a collaboration network is slightly higher than that of a knowledge network. Besides, innovation strategy plays a positive moderating role in the relationship between dual network structure and firm performance. Our findings provide new ideas for firms to identify and optimise knowledge and collaboration network structures and match them with innovation strategy to improve performance.     

双边市场、不完全信息与二级价格歧视

本文研究了双边市场二级价格歧视问题。本文构建了包括广告商、消费者、垄断平台在内的两阶段博弈模型，研究了在最优与次优情况下平台的定价机制，分析了二级价格歧视对平台利润、社会福利等的影响。研究表明：（1）“顶部无扭曲”或“底部无扭曲”并不严格成立；（2）平台对观众提供的节目质量、广告插播量均可能出现类型逆转的情况；（3）二级价格歧视会增加社会总福利；（4）“会员制”是平台可能的占优定价机制之一。