GPS沉桩定位系统及应用

通过介绍GPS沉桩定位系统主要构成、基本工作原理、主要数据处理、精度分析及实际应用效果比对等,揭示了用GPS沉桩定位系统替代传统控制方法进行水上沉桩定位的可行性、优越性及广泛的应用前景。     

GPS在杭州湾跨海大桥变形监测中的应用

杭州湾跨海特大桥全长36km,针对其跨度大、海上作业时间长等特点,重点论述了利用GPS对其进行变形监测的方案设计,对具体监测过程和数据处理方法进行了阐述。实践表明,这种GPS变形监测方案能够满足杭州湾跨海特大桥变形监测的需要,可以为确保桥梁安全运营提供有效的监测手段。     

考虑能源类型的城市出租车运营效率评价研究

以分析西安市燃气型、电动型及甲醇型3种能源类型出租车在运营中的既有期望运营投入和非期望运营投入，既有期望产出和非期望产出为基础，本文构建基于DEA-Malmquist的考虑能源类型的出租车运营效率评价模型。从西安市出租车管理处提取西安市 2020 年 9~12 月期间 14946辆出租车的GPS轨迹数据，并随机选取1000辆甲醇型出租车、1000 辆电动型出租车及 1000辆燃气型出租车作为样本进行实例分析。通过处理3000辆出租车GPS数据，得到乘客在工作日和双休日不同时段的出行需求和特征，分析3种不同能源类型出租车的运营效率差异。所得结论可为西安政府部门对不同能源类型出租车的管理运营提供决策支持。     

Integrating GIS concepts into transportation network data structures

Transportation network data structures must be designed to meet the requirements of the analyses being conducted and must be compatible with the selected graphical user interface. Increasing interest in geographic information systems (GIS) and intelligent transportation systems (ITS) have further burdened the network data structure. It is possible to implement object oriented programming (OOP) technology to satisfy these needs, without making the data structure excessively complicated.

This paper shows how a well‐developed network data structure can incorporate major capabilities normally associated with stand‐alone GIS's. The design of a network data structure derives from both theoretical and practical considerations. A design of a network data structure, composed entirely of objects, is presented. Examples of its implementation, limitations, advantages, and possible extensions are drawn from experience with the General Network Editor (GNE).     

A Participatory Approach to Marine Habitat Mapping in the Grenadine Islands

Increasing interest in implementing an ecosystem-based management approach has made stakeholder involvement vital and has highlighted the need for an effective participatory framework. In this study we used a participatory geographic information systems (PGIS) framework to collaboratively map the marine resources of the transboundary Grenadine Islands with a broad range of stakeholders from the two sovereign nations. We found the application of PGIS allowed the collective resolution of an appropriate mapping scale and a locally relevant habitat classification scheme that would not only serve the needs of resource managers, but could also be understood by resource users. Furthermore, multi-level stakeholder involvement in the mapping process captured resource use profiles and other fishing-related attributes, gave credibility to local knowledge and ownership of information, and was instrumental in building capacity to access and use the produced information. Lessons learned included the importance of investing considerable time early in the participatory process, which was later rewarded by stakeholder buy-in and led to financial and in-kind support. Furthermore, hosting the information in multiple formats on a project website has resulted in easy access and use by a wide range of stakeholders over a cross-country scale. We believe our experiences will be valuable to other practitioners considering using PGIS, particularly for those working in similar resource-limited, developing nation contexts.     

数据存储和GPS定位在冷藏机组控制器中的应用

本文研究了一种基于ATMEGA644PA-AU单片机的具有数据存储和GPS定位功能的冷藏机组控制器,其将冷藏运输车辆在运行过程中冷藏箱体内温度、冷藏制冷机组运行时各参数、GPS定位信息以逗号分隔文档的形式存储于USB闪存盘中,用以实现冷藏机组运行时的全过程参数的存储与查询,为冷藏机组的维修、运输货物的保存、品质的查询提供详实、可靠数据。     

向家坝库区滑坡特征参数统计分析

向家坝水电站位于四川省与云南省交界的金沙江峡谷处。从地层岩性以及地貌特征2方面,分析向家坝库区滑坡的发育规律,并基于GIS空间分析方法,使用滑坡面积与滑坡数量2个参数对滑坡地层岩性、相对高差及岸坡结构等进行统计分析,结果表明:滑坡多发育在1)泥页岩为主夹粉砂岩和砂岩地层中;2)地形相对高差在0~100m之间;3)岸坡结构为缓倾顺向岸坡与缓倾斜向岸坡处。     

Identifying multiclass vehicles using global positioning system data

It has been previously evidenced that global positioning system (GPS) data can be used to distinguish passenger cars from delivery trucks. In this paper, a machine learning approach is proposed to use GPS data to identify multiclass vehicles, including passenger cars, single unit trucks, and multi-trailer trucks. The method is acceleration and deceleration-based since it considers the variations of acceleration and deceleration as the most effective features to classify vehicles. The overall classification result for the three vehicle classes is about 75%. The major challenge is to distinguish single unit trucks from multitrailer trucks due to their somewhat similar mobility patterns. The paper also explores the impacts of GPS sampling frequency on vehicle classification. It is found that the proposed multiclass vehicle classification can be reasonably conducted if the data are collected frequently enough (i.e., every five seconds or more frequently) to capture the major acceleration and deceleration processes. The proposed method can be considered as a low-cost and non-intrusive approach to collect vehicle class information and to potentially supplement the existing classification schemes in urban areas.     

GIS在城市轨道交通中的功能分析

地理信息系统技术应用于城市轨道交通成为一种新的趋势,它能够提高轨道交通管理的快速反应能力和综合协调控制能力。本文针对地理信息系统应用于城市轨道交通建设、运营等阶段的功能进行分析,首先对地理信息系统在国内外轨道交通中的应用进行简介,再着重对地理信息系统在城市轨道交通建设、城市轨道交通调度指挥以及城市轨道交通应急处理中的功能进行总结并加以简单的分析,最后基于GIS在城市轨道交通中的功能分析,对GIS在该领域的发展趋势进行预测,得出地理信息系统在城市轨道交通中的应用应朝多功能综合一体化、多信息技术融合及三维可视化方向发展的结论。     

考虑空驶距离的出租汽车空气污染排放模型

为合理、准确量化空驶状态下出租汽车空气污染排放总量及比例,基于深圳市出租汽车GPS数据,构建考虑空驶距离的出租汽车空气污染排放模型。经过数据筛选,以深圳市3 198辆出租汽车为分析对象,识别出租汽车空驶和载客状态,进而计算载客距离和空驶距离。结合已有的三类出租汽车空气污染排放模型,考虑出租汽车空驶距离分别构建改进模型。参考已有研究成果设定空气污染排放因子,计算得到三类模型对应的空驶过程中出租汽车空气污染排放量占各自污染排放总量的比例分别为25.4%,34.2%和18.9%。最后,从排放因子、行驶距离、燃油经济性等方面探讨出租汽车空气污染减排策略。