Extracting commuter-specific destination hotspots from trip destination data – comparing the boro taxi service with Citi Bike in NYC     

Andreas Keler  Jukka M. Krisp  Linfang Ding 《地球空间信息科学学报》2020,23(2):141-152

ABSTRACT

Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics. It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities. Previous research shows that due to service restrictions, boro taxis have typical customer destination locations on selected Saturdays: many drop-off clusters appear near the restricted zone, where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing. Detected crossings imply recent infrastructural modifications. We want to follow up on these results and add one additional group of commuters: Citi Bike users. For selected Saturdays in June 2015, we want to compare the destinations of boro taxi and Citi Bike users. This is challenging due to manifold differences between active mobility and motorized road users, and, due to the fact that station-based bike sharing services are restricted to stations. Start and end points of trips, as well as the volumes in between rely on specific numbers of bike sharing stations. Therefore, we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods.  相似文献   

X线CT机选型的依据     

丁文奎  张国桢 《CT理论与应用研究》1993,(1)

本文描述了X 线CT 机的几个主要技术特性,并根据这些特性,计论如何去选择一台价格低、图像质量高的CT 扫描机。  相似文献   

德都地震前湾井水位的四步段映震异常及其预报意义     

丁成儒 《地震》1993,(3)

本文归纳了德都中强地震发生前湾_1井水位动态异变的基本特征,指出湾,井水位的四步段映震异常:骤然陡降—缓慢回升—高位跳动—高位稳定发震。并对短、临异常作了对比分析,探讨四步段映震异常对地震短临预报的重要意义。还就区域应力异常场和灵敏性问题进行了讨论。  相似文献   

A laboratory study of teleseismic Pn waves     

Shi-Yu Gao  Shan Ding 《地震学报(英文版)》1993,6(2):511-516

In this paper, the influences of mechanical properties of low velocity layers and thickness of high velocity layers in the lower lithosphere on the horizontal propagaties of seismic waves are discussed by means of altrasonic seismic model experiments; It is shown that the structure of the lower lithosphere consisting of soft low velocity layers and thin high velocity layers is favourable for the horizontal propagation of seismic energy, therefore, it is a very possible structure pattern of the lower lithosphere responsible for Pn and later high velocity arrivals observed in long range distances; Such pattern is also consistent with studies of rheological stratification of the lower lithosphere beneath mid-ocean-ridges and continental rifts. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 97–102, 1993. The project is supported by the Chinese joint Seismological Science Foundation.  相似文献   

HO x production due to radon decay in air     

Huiling Ding  Philip K. Hopke 《Journal of Atmospheric Chemistry》1993,17(4):375-390

The HO _x (OH and HO₂) production rate in indoor air caused by radon decay was measured by the chemical amplification technique. The average HO _x production rate was found to be (4.31±0.07)×10⁵ HO _x per Rn decay per second (Bq) within the range of relative humidity from 3.4 to 55.0 percent at 22 °C. This work providedG(HO _x )-value, 7.86±0.13 #/100 eV in air by directly measuring [HO _x ] from radiolysis of water vapor. It is also found that there is no obvious relationship between the HO _x production rate and the relative humidity in this range. Therefore, this work provides both the basic data for the evaluation of radioactive pollution in indoor air as well as a potentially useful way to produce HO _x concentrations in air.  相似文献   

具有门限的一种非线性随机-动力模式   总被引：3，自引：0，他引：3       下载免费PDF全文

丁裕国  江志红 《热带气象学报》1993,9(2):97-104

提出一种附加门限控制的具有非线性反馈作用的随机-动力模式,从而对具有线性反馈的随机-动力气候模式加以改进。从理论上说,这种具有门限的随机气候模式可使气候系统内部反馈机制中的非线性特征更为明显,以便更加客观地模拟和预报短期的气候变化。  相似文献   

青海湖流域水量平衡要素的估算   总被引：4，自引：0，他引：4  

丁永建  刘风景 《干旱区地理》1993,16(4):25-30

本文对青海湖流域水量平衡各要素进行了讨论，并根据现有实测资料和经验公式着重对液域水量平衡起关键作用的流域平等降水，陆面蒸发和地表径流进行了计算。  相似文献   

努和廷式铀矿床地质特征及其油气水与铀成矿作用探讨   总被引：11，自引：4，他引：11  

张如良  丁万烈 《铀矿地质》1994,10(5):257-265,274

本文应用有机地球化学原理探索油气水与铀矿化的关系，并总结了“努和廷式”铀矿床的地质特征和成矿机理。“努和廷式”铀矿床产于中新生代陆相盆地油气田的顶部或边部，矿床规模巨大。铀矿床形成与油气田中油气水渗漏所造成的地球化学环境及物质参与有关。据此提出“以油找铀”的找矿思路。  相似文献   

水文水资源系统贝叶斯分析现状与前景   总被引：17，自引：2，他引：17       下载免费PDF全文

黄传军  丁晶 《水科学进展》1994,5(3):242-247

简介了贝叶斯分析的基本原理,综述了它在水文水资源系统中考虑不确定性和风险的特点及其在径流预报、洪水分析与地区综合、水资源规划与管理等问题中的应用,并分析了其发展前景,着重指出将灰色先验分布、模糊似然函数在贝叶斯定理框架中耦合的综合途径.  相似文献   

暴雨和中尺度气象学问题   总被引：86，自引：8，他引：86  

丁一汇 《气象学报》1994,52(3):274-284

对近年来暴雨和中尺度气象学的进展进行了综合评述，这包括（１）暴雨发生的条件；（２）强风暴和中尺度对流系统概念模式；（３）中尺度系统的数值模拟；（４）中尺度动力学问题；（５）暴雨预报等。对于暴雨和中尺度气象学将来研究的问题也作了讨论。  相似文献