Trip Planning Queries in Road Networks

能动性是人类的基本特征。作为一个物种，我们总是因为各种各样的原因而四处迁徙。在移动通信设备丰富的今天，移动数据的收集相对容易，从而提供了大量的时空数据。智能地使用这些数据可以使人们在几个方面更有效地移动，例如通过更有效和高效地拼车来减少燃料消耗，减少交通时间等，从而走向所谓的智慧城市。大量的流量监控应用、社交网络等，都可以利用这些数据源，进一步聚合其价值。此外，考虑到非时空数据，例如公共事件、天气模式和路径受欢迎程度，这些数据可能变得相当复杂和丰富。鉴于这一总体主题，提出的研究计划将集中在道路网络中的旅行规划查询主题上。旅行计划查询考虑一个道路网络、一个起点和一个终点，以及旅行者（或其团队）想要访问的一组兴趣点。旅行计划查询可以有几种变体：兴趣点可能属于不同的兴趣点类别（可能需要以任意、全部或部分顺序穿越），或者可能需要考虑兴趣点的开放时间、交通状况或公共交通时间表、兴趣点之间的最大距离或从预定路径到潜在兴趣点的最大距离。等******拟议的研究计划将有助于推进最先进的领域，在旅行规划查询一般通过调查三个相关方面：(a)多式联运。到目前为止，在文献中，绝大多数旅行计划查询都考虑了单一的交通方式。考虑旅行者在一次旅行中使用多种交通方式的可能性是很有实际意义的。(b)道路网丰富。道路网络本身相对简单，容易理解。尽管如此，还是有大量的信息可以从它们的上下文环境以及它们的历史使用中考虑进来，以丰富它们并提供语义上更有趣的答案。(c)时间依赖性。时间是规划中的一个内在因素，例如，一天/一年中的旅行时间不同，旅行者可能需要考虑特定的出发或到达时间。在旅行规划查询中，这些方面还没有得到广泛的考虑。此外，考虑到这些方面（单独或组合）的普遍重要性，进一步理解它们将有助于广义时空研究的知识体系，并使这些方面也能够考虑到其他问题

Mobility is a basic human characteristic. As a species we have always been moving about for a plethora of reasons. With today's abundance of mobile communication devices, data about mobility can be collected relatively easily, thus providing large amounts of spatio-temporal data. Using such data intelligently can enable people to move more efficiently in several aspects, e.g., consuming less fuel by sharing rides more effectively and efficiently, spending less time in traffic, etc., thus moving towards so-called smart cities. A large number of traffic monitoring applications, social networks, etc., can leverage such data sources and aggregate further value to it. Moreover, this data can become rather complex and richer by considering non-spatio-temporal data, e.g., public events, weather patterns and path-popularity. Given this overarching theme, the proposed research program will focus on the topic of trip planning queries in road networks. A trip planning query considers a road network, a starting and a destination point, and a set of points-of-interest a traveller (or group thereof) wants to visit. There can be several variations of trip planning queries: points-of-interest may belong to different categories-of-interest (which may be needed to be traversed in an arbitrary, full or partial order) or one may have to account for opening hours of points-of-interest along with traffic conditions or public transportation schedules, maximum distance between point-of-interest or from pre-determined paths to potential points-of-interest, etc. ******The proposed research program will contribute to advancing the state-of-the-art in the domain of trip planning queries in general by investigating three relevant aspects thereof: (a) Multi-modal transportation. Thus far in the literature, the vast majority of trip planning queries have considered a single mode of transportation. It is of practical importance to consider the possibility of travellers using more than one transportation mode in a single trip. (b) Enriched road networks. Road networks themselves are relatively simple and well understood. Nonetheless, there is a large amount of information that can be taken into account from their contextual environment as well as their historical use in order to enrich them and provide semantically more interesting answers. (c) Temporal dependency. Time is an intrinsic factor in planning, e.g., travel times vary during the day/year and travellers may need to consider a particular departure or arrival time. Those aspects have not been widely considered in the context of trip planning queries. Furthermore, given the general importance of those aspects, individually or in combination), furthering their understanding will contribute to the body of knowledge in spatio-temporal research broadly defined and enable the consideration of those aspects with respect to other queries as well.**