Travel Patterns and Street Networks: A Novel Visualization Methodology of City-Level Traffic Flows and Network Usability

Street Networks, knitted in the urban fabric, facilitate spatial movement and control the flow of urbanization. The interrelation between a city’s spatial network and how the residents travel over it has always been of high interest to scholars. Over the years, multifaceted visualization methods have emerged to better express this travel trend from small to large scale. This study proposes a novel approach to 1) visualize city-wide travel patterns with respect to the street network orientation and 2) analyze the discrepancies between travel patterns and streets to evaluate network usability. The visualizations adopt histograms and rose diagrams to provide several insights into network-wide traffic flows. The visualization of four New York City (NYC) boroughs including Queens, Brooklyn, Bronx, and Staten Island was generated for the daily traffic and the average hourly flows in the morning and evening rush hours. Then the contrasts between built-in street network topology and travel orientation were drawn to show where people travel over the network, travel demand, and finally which segments experience high or light traffic, revealing the true picture of network usability. The findings of the study provide an insight into the novel and innovative approach that can help better understand the travel behavior lucidly and assist policymakers in decision making to maintain a balance between urban topology and travel demands. In addition, the study demonstrates how to further investigate city street networks and urbanization from different diverse dimensions.

Sustainability-oriented configurational analysis of the street network of China's superblocks:Beyond Marshall's model

The duality in China's traffic planning has given rise to the basic unit of urban form and function called the superblock,which is defined and bound by an arterial street network.The street network of China's superblock un derpins the coexiste nee and in teraction of global and local movement,the public and daily space,and affects place diversity and local characteristics.However,its configuration remains to be articulated because of the lack of a systematic representation method,and the associations between configuration and performance,cognition and design cannot be determi ned.This study proposes an improved representation method for the street network of China's superblocks based on Marshall's route structure analysis to explore the configurational characteristics and sustainability of the network.To fit local conditions,this study improves Marshall's route structure analysis from four perspectives,namely,the judgement of relative hierarchy,the node construction principle,and the deletion and addition of the original indicators.The improved method is then applied to calculate and compare the depth,connectivity,and complexity of the street networks of 10 sample superblocks in Nanjing,which are classified into six types by construction backgrounds,each having two seenarios differing by the level of publicity.Results indicate that the types formed in accordance with the"The Capital Plan"of the Republic of China,which presents a combination of fine orthogonal grids and radiations,and by the renewal of the traditional street-andlane network,which has the"characteristic structure" defined by Marshall,perform best in terms of configurational sustainability.The an alysis also reveals that the addition of semipublic streets formed mainly from the bottom up narrows the sustainability gap among the samples.This study provides a tool for elaborate urban study and design and provides in sights into the cognitive and practical aspects of China's urban planning and design.

Evolution of the commercial blocks in ancient Beijing city from the street network perspective

The synergistic relationship between urban functions and street networks has al-ways been a focus in the field of urban research and practice.From the perspective of street networks,by adopting space syntax,this study analyzed the deep structural characteristics and potential evolution rules of commercial blocks attached to street networks in different periods,as well as the corresponding economic,political,and cultural characteristics of an-cient Beijing city over the past 800 years.By combining these with changes in the street network,we further explained the function mechanism of layout and level adjustment in commercial blocks,and the influence of the street network on commercial blocks in the process of historical change.The main conclusions included the following:(1)The urban centripetal-centrifugal siphon effect:the layout form,topological structure,and traffic mode changes in the street network had corresponding guidance for the layout and hierarchical system of commercial blocks,while the centripetal development of the street network could guide the agglomeration effect of commercial blocks,although centrifugal development caused commercial blocks to display outward evacuation.(2)Stage transformation from mu-tation node to smooth development:the layout of commercial blocks came to depend on the ability to cross the commuting flow center,which originally relied on the accessibility of transportation nodes as local centers.Changes in traffic modes mainly affected the adjust-ment of the first-level commercial blocks,which easily led to overall layout mutation.Traffic levels have an obvious positive hierarchical relation with the second-and third-level com-mercial blocks.(3)The adaptation of traditional commercial blocks to the needs of a modern city:affected by the different emerging times and unevenness of the original commercial foundation,commercial blocks have formed various developmental models that meet the needs of modernization,and reach a balance between cultural continuity and functional ad-aptation.

Street networks in relation to landforms： Implications for fast-growing cities

In addition to socio-economic factors, major landforms may affect the city structure and urban form. Here we show that landforms have significant effects on the city shape and street patterns of the fast-growing Iranian cities of Dezful （a river） and Khorramabad （moun- tains and valleys）, but no clear effects on the cities of Yazd and Nain. Also, where the street orientation is peaked, the Gibbs/Shannon entropy （a measure of dispersion or spread） is low, but increases as the distribution becomes more uniform because of landform constraints. The streets in the old inner parts of all the cities are, on average, shorter and denser （more streets per unit area） than the streets of the newer outer parts. The entropies of the outer parts are also greater than those of the inner parts, implying that the street-length distribution gradually becomes more dispersed or spread as the city expands. All these cities have been fast growing in the past decades, with the newer outer parts expanding rapidly. As shown here, the rapidly formed outer parts （with greater dispersion in street patterns） have significantly different textures from those of the older inner parts, indicating different functionality and growth processes. These quantitative methods for street-network analysis can be used worldwide, particularly for analysing the effects of landforms on city shape and texture.

Street network patterns for mitigating urban heat islands in arid climates

This study explores the impact of street pattern measurements on urban heat islands(UHI)in the arid climate of Mashhad,Iran.The Landsat-8 top-of-the-atmosphere(TOA)brightness images from 2013 to 2021,average values of normalized difference vegetation index(NDvI)and land surface temperature(LST)were calculated.Street pattern measurements,including closeness-centrality,straightness,and street orientation,were employed to analyse the patterns in each district.The results indicated that districts with higher straightness and lower closeness-centrality exhibit,cooler surface temperatures.Strong correlations were observed between LST and NDVl,straightness,and local closeness-centrality.The research highlighted the importance of considering street network measurements in long-term urban planning and design to mitigate the UHI effect in arid regions.A moderate grid street pattern with a reasonable distribution of green spaces throughout the region is suggested to reduce surface temperatures sustainably.Street pattern indexes,such as straightness and local closeness-centrality,are identified as significant factors in urban design to mitigate UHl.These findings have implications for urban planners,who can use this information to create street network patterns with lower UHI effects by reducing local closeness-centrality and increasing straightness.

A congestion bottleneck analysis model for tourist block street network

The development of the tourism industry has led to increased pressure of people flow in tourist blocks.Therefore,it is critical to ease the traffic pressure in these blocks.This paper aims to identify the bottleneck links of street networks in tourist blocks to achieve the effective prevention of congestion accidents.A logit stochastic user equilibrium model combined with spatial syntax is presented to study the travelers’route choice behavior.The nonlinear Bureau of Public Roads function is applied to calculate the time impedance of each street.A case analysis of the Chongqing Ciqikou tourist block shows that the bottleneck link has the features of high integration and a large degree of negative time impedance evolution.The research’s results are more consistent with practical circumstances because the influence of the road network topological structure on pedestrian path selection has been considered.

基于Walnut Street修正模型的短波信道仿真算法

传统短波信道Watterson模型只能模拟信道短期变化规律。为模拟短波信道在各种长度时间段内的变化,针对短波信道接收端信噪比统计特性,提出了一种基于信噪比重放的短波信道仿真算法。该算法以Walnut Street信道模型为基础,通过对实际观测数据进行分析处理,建立接收端信噪比变化的中期和长期变化统计模型,联合Watterson模型实现信道模拟。仿真结果表明,该算法可反映实际信噪比变化规律,为短波网络仿真提供精确的信道质量模拟。

Exploring Location Pattern of Commercial Stores in Shichahai, Beijing from a Street Centrality Perspective

The location pattern of different commercial stores in Shichahai, a historic conservation area in Beijing, was investigated from a street centrality perspective. Many previous studies have investigated the relationship between street centrality and land use patterns or commercial activities at interurban or intraurban scales. We considered Shichahai in this study to determine if street centrality applied at the street scale and if the street network was the only factor influencing the selection of store location. First, the nearest neighbor index, nearest neighbor hierarchical spatial cluster(NNHSC), and kernel density estimation(KDE) methods were used to provide baseline spatial distributions of commercial stores. Second, urban network analysis(UNA) tools were used to measure the street centrality indices under two conditions, with and without the weighting of cultural relics calculated by a principal component analysis(PCA). Finally, both store locations and centrality values at nodes were transformed to one unit(raster pixel) for a correlation analysis.The results showed that three of the four store types were clustered and had their own hotspots that were mostly located in the eastern and central parts of city blocks. The most momentous findings were determined from the street centrality indices. Among the three store types with correlation coefficients above 0.5, all centrality indices with landmark weighting, except straightness, had higher correlations,with closeness with landmark weighting having the highest correlation, followed by betweenness with landmark weighting. Therefore,we statistically concluded that street centrality could apply at the street scale and that the street network was not the only factor that influenced store location pattern, with landmarks also playing a significant role. The results provide guidance in determining the selection strategy for stores in a historic conservation area.

Smart Street Lighting Control and Monitoring System for Electrical Power Saving by Using VANET

The huge amount of electrical power of many countries is consumed in lighting the streets. However, vehicles pass with very low rate in specific periods of time and parts of the streets are not occupied by vehicles over time. In this paper, we propose a system that automatically switches off the light for the parts of the streets having no vehicles and turns on the light for these parts once there are some vehicles that are going to come. Logically, this system may save a large amount of the electrical power. In addition, it may increase the lifetime of the lamps and reduce the pollutions. This system automatically controls and monitors the light of the streets. It can light only the parts that have vehicles and help on the maintenance of the lighting equipments. Vehicular Ad-Hoc Networks (VANET) make it possible to propose such system. VANET enables the possibility to know the presence of vehicles, their locations, their directions and their speeds in real time. These quantities are what are needed to develop this system. An advantage of using VANET is that there is no need to use specific network and equipments to design the system, but VANET infrastructure will be used. This decreases the cost and speed up the deployment of such system. This paper focuses on the proposal of different possible architectures of this system. Results show that the saved energy may reach up to 65% and an increase of the lifetime of the lamps of 53%.

哈尔滨城建初期中东铁路附属地城市街道网络形态的演进与基因解析(1898-1926)

本文基于哈尔滨城建史界定城建初期的时间范围,利用历史舆图与sDNA技术分析城建初期中东铁路附属地城市街道网络形态的演进逻辑,并运用“特征识别-共性归纳-基因解析”的方法解析街道网络形态基因。研究表明.城建初期(1898-1926)附属地先后形成了老哈尔滨、新市街、埠头区等区域的街道网络,本文将其归类为五种形态特征单元,以及它们组合形成的“枝干形”与“放射形”两类街道网络形态基因,体现出西方规划思想与本土地域特征的双重影响。

街道界面与街道网络的形态关联性研究——以武汉市中心城区为例

街道是城市物质空间形态的基本构成要素,与人们的生活息息相关。文章以武汉市中心城区为例,分析其街道界面与街道网络的形态关联性。街道界面形态的测度参数为界面密度与近线率,街道网络形态的测度参数为整合度与选择度。结果显示:界面密度与整合度、选择度在全局尺度下均呈现正相关关系,在分区尺度下仅与整合度呈现正相关关系;而近线率与整合度、选择度在全局尺度下均未呈现出相关性,但在分区尺度下与整合度呈现正相关关系。总体而言,街道可达性越高,则对应的街道界面也越密集;但街道界面是否也越整齐则因不同的城市肌理类型而呈现出差异性。研究进一步揭示了城市形态要素间的内在联系,以及各项形态要素在不同城市尺度上与城市空间活力的关联性,可为我国建设充满活力的街道空间提供助力。

复杂场景下自适应注意力机制融合实时语义分割

实现高准确度和低计算负担是卷积神经网络(CNN)实时语义分割面临的严峻挑战。针对复杂城市街道场景目标种类众多、光照变化大等特点,该文设计了一种高效的实时语义分割自适应注意力机制融合网络(AAFNet)分别提取图像空间细节和语义信息,再经过特征融合网络(FFN)获得准确语义图像。AAFNet采用扩展的深度可分离卷积(DDW)可增大语义特征提取感受野,提出自适应平均池化(Avp)和自适应最大池化(Amp)构成自适应注意力机制融合模块(AAFM),可细化目标边缘分割效果并降低小目标的漏分率。最后在复杂城市街道场景Cityscapes和CamVid数据集上分别进行了语义分割实验,所设计的AAFNet以32帧/s(Cityscapes)和52帧/s(CamVid)的推理速度获得73.0%和69.8%的平均分割精度(mIoU),且与扩展的空间注意力网络(DSANet)、多尺度上下文融合网络(MSCFNet)以及轻量级双边非对称残差网络(LBARNet)相比,AAFNet平均分割精度最高。

“双碳”目标下光储技术在城市照明行业的融合应用探究

随着“双碳”目标的深入实施,照明行业作为城市市政基础设施亟需向低碳、智能方向升级。本文结合光储技术的发展趋势,梳理了其在城市基础设施能源底座中的应用场景,着重阐述了基于城市照明体系构建路灯专网的可行性并探讨了与光储技术融合应用的趋势和展望,对城市传统照明体系向多元化、场景化、绿色化发展具有参考意义。

基于跨层次聚合网络的实时城市街景语义分割

随着自动驾驶技术的迅速发展,精确高效的场景理解显得尤为重要。城市街景语义分割旨在准确识别并分割出行人、障碍物、道路和标志物等要素,为自动驾驶技术提供必要的道路信息。然而,当前的语义分割算法在城市街景分割中仍然面临一些挑战,主要表现为不同类别的像素区分不够清晰、对于复杂场景结构的理解不够精准以及对小尺度对象或大尺度结构的分割不准确等问题。为此,本文提出一种基于跨层次聚合网络的实时城市街景语义分割算法。首先,在编码器末端设计了结合跨层次聚合的金字塔池化模块,用于高效提取多尺度上下文信息;其次,在编码器和解码器之间设计了跨层次聚合模块,通过引入通道注意力机制增强信息的表征能力,逐级聚合编码器阶段的特征以充分实现特征复用;最后,在解码器阶段设计了多尺度融合模块,在通道维度聚合全局信息与局部信息,促进深层特征与浅层特征的融合。将所提算法在两个通用的城市街景数据集上进行了验证。在一张RTX3090显卡上(TensorRT测速环境),本文算法在Cityscapes测试集以294 FPS的实时性达到73.0%mIoU的准确性,在更高分辨率的图像上以164 FPS的实时性达到75.8%mIoU的准确性;在CamVid数据集以239 FPS的实时性达到74.8%mIoU的准确性。实验结果表明,本文算法在准确性与实时性之间取得了有效平衡,对比其他算法的语义分割性能具有显著提升,为实时城市街景语义分割领域带来了新的突破。

基于网络点评的游憩体验质量与包装设计关系探究——以杭州清河坊街为例

近年来,游憩体验质量被提出并用于衡量游客满意水平,同时大众对旅游产品包装设计的要求也与日俱增。本文以杭州清河坊街区游客的网络点评为研究对象,运用网络文本分析方法,对游憩体验质量与包装设计的关系进行了探究。研究发现包装设计与游憩体验质量有显著联系,与包装设计有关的点评总体呈现积极的情感色彩,消极体验主要由于包装设计的潜在欺骗性与辨识度缺失。基于发现,提出可持续的旅游产品包装设计建议。

基于步行网络修补的街道空间更新模式研究

新的时代背景下,“以车为本”的发展模式已不再适宜,城市步行网络的建设日益得到重视。而相较于宏观视角下的步行网络整体规划,对既有步行网络进行修补优化更加切实可行。研究对重庆市步行网络的发展趋势和街道使用主体的需求进行了分析,指出修补重庆旧城传统山地步行网络的价值,提出了通过街道公共空间更新来修补旧城步行网络这一方法。进一步从总体思路、目标、原则与策略四个方面构建了街道公共空间更新的具体模式。

结合生成对抗网络与混合注意力机制的街景图像语义分割

街景图像语义分割是自动驾驶领域的主要研究任务之一,对于路径规划和行人安全保障具有重要意义。目前,街景图像语义分割主要存在小目标物体分割不精确、模型容易出现过拟合的问题。为此,提出一种结合生成对抗网络与混合注意力机制的街景图像语义分割模型。具体而言,提出一种多尺度混合注意力模块,用于增强上下文语义信息、提高特征表征能力和对多尺度目标的适应性。同时,为了降低过拟合,引入BN层,结合DCGAN网络构建生成对抗网络分割模型,通过判别损失和分割损失共同约束训练,以增强模型稳定性、提高分割精度。实验结果表明,与DeepLabV3+相比,所提模型在Cityscapes数据集上的分割精度提高了2.4个百分点,mIoU值达到73.4%。

基于POI数据的城市功能区识别及其空间分布特征——以珠海市中心城区为例

为了探究城市功能区的空间分布特点,基于兴趣点(POI)数据构建城市功能区定量识别体系,分析珠海市中心城区城市功能区的空间分布特征.结果表明:①珠海市中心城区的功能区普遍具有明确的主导功能,且呈现“中心居住,外围工业,混合分散”的分布格局.②“单一”和“混合”功能区交错分布的地区主要集中在珠海市中心城区北部.③混合功能区多表现为居住和商业服务设施功能的混合,呈现出“商住联动”特征.

基于ZigBee网络和自适应PSD算法的路灯分布式节能控制方法

当前照明系统缺乏分布式路灯动态化控制,浪费大量能源,为此,提出了基于ZigBee网络和自适应PSD算法的路灯分布式节能控制方法。通过ZigBee网络通信连接系统传感器、控制中心和照明终端,协调设备通信功能,实现信息快速传输储存。利用神经网络处理信号数据,提高系统信号检测和处理效率。在此基础上,利用自适应PSD算法识别路灯信号动态特征,进行自适应信号检测,调节信号数据偏差,精确检测数据结果,增强系统节能控制稳定程度,实现路灯分布式节能控制。由实验结果可知,研究方法将分布式路灯检测精准度提高到99%,熔池宽度稳定在3.5W/mm,具有良好的检测精准度和控制稳定性,可以对路灯进行节能控制。

探析医院建筑柱网柱跨的合理确定

介绍了国内医院建筑柱网柱跨相关研究进展;分析了地下室停车位、“双通道”设计、未来开设公共服务空间的需求等因素对医院建筑柱网柱跨的影响;对8100 mm和8400 mm柱跨形成的诊室、病房进行了对比,并对柱跨选择提出了具体建议。