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International Conference on Intelligent Computing, Automation and Systems (ICICAS)

作者： Weixiang Xu Jiamin Zhao School of Traffic and Transportation Beijing Jiaotong University Beijing China National Demonstration Center for Experimental Traffic and Transportation Education

ISBN: (数字)9781728161068

ISBN: (纸本)9781728161075

The Development and popularization of the vehicle navigation technology, automatic driving technology, GPS technology and big data technology, provide conditions for the transparency and sharing of traffic data in the future. Meanwhile, the innovation of the 5G technology and cloud computing also create conditions for the calculation of massive data. To effectively alleviate traffic congestion in modern cities, the authors proposed a traffic flow time series model and shortest path algorithm of urban traffic based on travel plans. Travel plans, namely, are the information about users' planning travel, including the starting point, destination, departure time, etc. Adopting lots of users' travel plans as the main source data, the authors constructed a traffic flow time series model with dynamic future traffic flow. Based on this model, the improved Floyd algorithm was used to calculate the shortest path. After the shortest path is adopted by users, update the traffic flow time series model to obtain more accurate future traffic flow data. Travel plans have the characteristics of real-time and reliability, the traffic flow data based on real-time travel plans is more realistic than the traditional traffic flow prediction methods which are based on historical data. Likewise, the optimal path algorithm based on the traffic flow time series model is also more scientific than the traditional optimal path algorithms theoretically.

关键词： 5G mobile communication Big Data cloud computing Global Positioning System navigation road traffic time series traffic engineering computing transportation travel Traffic flow shortest path algorithms big data traffic in cities Cloud Computing Global Positioning Systems Road traffic Time series navigation engineering computing transport shortest path Consumers

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On algorithms for permuting large entries to the diagonal of a sparse matrix

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SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS 2001年第4期22卷 973-996页

作者： Duff, IS Koster, J Rutherford Appleton Lab Didcot OX11 0QX Oxon England CERFACS Toulouse France

We consider bipartite matching algorithms for computing permutations of a sparse matrix so that the diagonal of the permuted matrix has entries of large absolute value. We discuss various strategies for this and consider their implementation as computer codes. We also consider scaling techniques to further increase the relative values of the diagonal entries. Numerical experiments show the effect of the reorderings and the scaling on the solution of sparse equations by a direct method and by preconditioned iterative techniques.

关键词： sparse matrices bipartite weighted matching shortest path algorithms direct methods iterative methods preconditioning

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Minimum cost multi-product flow lines

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ANNALS OF OPERATIONS RESEARCH 2007年第1期150卷 31-46页

作者： Alfieri, Arianna Nicosia, Gaia Politecn Torino Dipt Sistemi Prod & Econ I-10129 Turin Italy Univ Roma Tre Dipartimento Informat & Automaz I-00146 Rome Italy

In this paper, the problem of finding the minimum cost flow line able to produce different products is considered. This problem can be formulated as a shortest path problem on an acyclic di-graph when the machines graph associated with each product family is a chain or a comb. These graphs are relevant in production planning when dealing with pipelined assembly systems. We solve the problem using A* algorithm which can be efficiently exploited when there is a good estimate on the value of an optimal solution. Therefore, we adapt a known bound for the shortest Common Supersequence problem to our case and show the effectiveness of the approach by presenting an extensive computational experience.

关键词： flow lines optimization shortest path algorithms

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A Fresh Look at Zones and Octagons

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ACM TRANSACTIONS ON PROGRAMMING LANGUAGES AND SYSTEMS 2021年第3期43卷 1–51页

作者： Gange, Graeme Ma, Zequn Navas, Jorge A. Schachte, Peter Sondergaard, Harald Stuckey, Peter J. Monash Univ Fac IT Clayton Vic 3800 Australia Univ Melbourne Sch Comp & Informat Syst Parkville Vic 3010 Australia SRI Int Comp Sci Lab Menlo Pk CA 94025 USA

Zones and Octagons are popular abstract domains for static program analysis. They enable the automated discovery of simple numerical relations that hold between pairs of program variables. Both domains are well understood mathematically but the detailed implementation of static analyses based on these domains poses many interesting algorithmic challenges. In this article, we study the two abstract domains, their implementation and use. Utilizing improved data structures and algorithms for the manipulation of graphs that represent difference-bound constraints, we present fast implementations of both abstract domains, built around a common infrastructure. We compare the performance of these implementations against alternative approaches offering the same precision. We quantify the differences in performance by measuring their speed and precision on standard benchmarks. We also assess, in the context of software verification, the extent to which the improved precision translates to better verification outcomes. Experiments demonstrate that our new implementations improve the state of the art for both Zones and Octagons significantly.

关键词： Abstract interpretation shortest path algorithms difference-bounds matrix numerical abstract domains program analysis static analysis variable packing weakly relational domains

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Design of a Human-in-the-Loop Aircraft Taxi Optimisation System Using Autonomous Tow Trucks

Design of a Human-in-the-Loop Aircraft Taxi Optimisation Sys...

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AIAA Aviation Forum and Exposition

作者： Zaninotto, Stefano Gauci, Jason Farrugia, Geoffrey Debattista, Johan Univ Malta Inst Aerosp Technol Msida 2080 Msd Malta HandsOn Syst Ltd Mosta 3000 Mst Malta Malta Air Traff Serv Ltd Luqa 4000 Lqa Malta

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

One of the solutions proposed by the aerospace industry to reduce fuel consumption, air pollution and noise at an airport consists of using electric tow trucks to tow aircraft from the gate to the runway (or vice-versa). However, the introduction of tow trucks would result in an increase in vehicle traffic at the airport, potentially increasing the workload of Air Traffic Controllers (ATC). This paper proposes an algorithm - based on Dijkstra's algorithm - and a Human Machine Interface (HMI) concept to optimise airport taxi operations with autonomous tow trucks at a strategic level, while keeping ATC in the loop. Preliminary tests of the algorithm have been carried out using simulated traffic data for Malta International Airport (MIA) and the results show that the algorithm can be tuned to minimise the average vehicle taxi delay or the number of unresolved vehicle conflicts. It is also shown that, in certain cases, both the taxi delay and the number of conflicts can be reduced through a minor adjustment of the Off-Block Time (OBT) of departing aircraft.

关键词： Commercial Aircraft Human In The Loop Runway Holding Position shortest path algorithms Air Traffic Controller Aerospace Industry Fuel Consumption Aircraft Hangars Optimization Algorithm Aircraft Stand

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Efficient Distance Sensitivity Oracles for Real-World Graph Data 36

Efficient Distance Sensitivity Oracles for Real-World Graph ...

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IEEE 36th International Conference on Data Engineering (ICDE)

作者： Lee, Jong-Ryul Chung, Chin-Wan Korea Adv Inst Sci & Technol KAIST Sch Comp Daejeon South Korea Chongqing Univ Technol CQUT Chongqing Liangjiang KAIST Int Program Chongqing Peoples R China

ISBN: (数字)9781728129037

ISBN: (纸本)9781728129037

A distance sensitivity oracle is a data structure answering queries that ask the shortest distance from a node to another in a network expecting node/edge failures. It has been mainly studied in theory literature, but all the existing oracles for a directed graph suffer from prohibitive preprocessing time and space. Motivated by this, we develop two practical distance sensitivity oracles for directed graphs as variants of Transit Node Routing, and effective speed-up techniques with a slight loss of accuracy. Extensive experiments demonstrate that our oracles greatly outperform all of competitors in most cases. To the best of our knowledge, our oracles are the first distance sensitivity oracles that handle real-world graph data with million-level nodes.

关键词： Graph algorithms path and circuit problems Graphs and networks Distance sensitivity oracle Distance query shortest distance shortest path algorithms

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ORRP: Optimal reactive routing protocol for mobile Ad-Hoc networks

ORRP: Optimal reactive routing protocol for mobile Ad-Hoc ne...

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6th International Conference on Computer Information Systems and Industrial Management Applications

作者： Chaki, Nabendu Chaki, Rituparna Univ Calcutta Kolkata 700009 W Bengal India West Bengal Univ Technol Kolkata 700064 West Bengal India

ISBN: (纸本)9780769528946

An ad-hoc network is a self-supporting collection of mobile nodes that happen to exist within a close proximity in an interval of time. In this paper, a reactive routing protocol has been proposed that computes the shortest path in between any source-destination pair on demand. The approach, unlike other reactive protocols, finds a loop-free, optimal path between the end nodes. It does not use broadcasting like DSR or some other reactive protocols. In fact ORRP exchanges only (n-1) control packets, in the best case. A comparative performance evaluation establishes the advantages of ORRP. The paper is a substantial extension of our earlier work reported in [14].

关键词： mobile ad hoc network routing protocol reactive routing shortest path algorithms loop-free routing

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On Integration of Any Factor with Distance for Navigation : Walk Safely and Fast Enough 23

On Integration of Any Factor with Distance for Navigation : ...

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IEEE 23rd International Enterprise Distributed Object Computing Workshop (EDOCW)

作者： Zhao, Yizhou Xie, Yuetian Ahvar, Shohreh ISEP Paris France

ISBN: (纸本)9781728145983

With the popularization of personal navigation systems and mobile devices, multifarious location-based services and datasets are being advanced. In this paper, we propose a new method for navigating based on combination of any factor (e.g. safety, enjoyment, air quality, etc.) with distance. A data structure based on intensity of the factor is introduced. This data structure can be extended easily to cover different sources of data (e.g. government open data, users' feedback). Any kind of shortest path algorithm can be used in proposed method. We apply this method to a situation where travelers are seeking safer routes. The incoming traffic data of each station from Paris in 2017 is utilized to model a location-based safety status of the city. The shortest route is then modulated to a safer route to help pedestrians bypass unsafe zones in the city, thereby reducing the risk of encountering incidents. As a proof-of-concept, we produce a web application based on Google Maps API, which illustrates the performance of our method and application.

关键词： Location-Based Data Navigation Urban Safety Modeling shortest path algorithms

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Agent-Based Modeling of Uncrewed Aircraft System Flight Planning for Airspace Fairness

Agent-Based Modeling of Uncrewed Aircraft System Flight Plan...

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AIAA Aviation Forum

作者： Yang, Rebekah Walker, Simone Prebble, Matthew Lesko, Mark Landry, Glen Hales, Shaelynn CNA Corp Ctr Data Management & Analyt Arlington VA 22201 USA

ISBN: (数字)9781624107047

ISBN: (纸本)9781624107047

The number of uncrewed aircraft systems (UAS) and corresponding UAS operations is expected to increase dramatically soon. Regulatory agencies are currently designing and piloting UAS traffic management concepts that rely on federated protocols and a cooperative, community-based approach. As demand increases, the need to ensure fair usage of airspace among operators will be an important challenge. Currently, there are no widely agreed upon definitions or guidelines for UAS airspace fairness. The objective of this work was to evaluate the fairness implications of using a first-filed-first-served protocol for flight planning. We developed UAS Cooperative Airspace Traffic Simulation (UCATS), an agent-based modeling simulation tool, to evaluate different UAS package delivery scenarios using a first-filed-first-served approach to UAS flight planning. We defined key metrics to measure fairness, including average delay, maximum delay, and percentages of flights as planned, replanned, and canceled. Our results showed that a first-filed-first-served approach may cause flights having a departure time later in the day and flights that are filed with less advanced time have a higher probability of experiencing more negative flight outcomes. We also evaluated the sensitivity of fairness metrics to different traffic levels, different flight densities, and the addition of food delivery operations.

关键词： Aircraft Systems Flight Planning Airspace Federal Aviation Administration Air Taxi Conflict Detection and Resolution Department of Transportation shortest path algorithms Air Traffic Management Flight Trajectory

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Finding routes in a public transport network. A case study 19

Finding routes in a public transport network. A case study

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19th International Conference on Methods and Models in Automation and Robotics (MMAR)

作者： Olczyk, Adrian Galuszka, Adam Silesian Tech Univ Inst Automat Control PL-44100 Gliwice Poland

ISBN: (纸本)9781479950812

There is a need for reliable and trustworthy public transport planner services. Mass transits are trying to solve problems as traffic jams or increasing pollution in densely populated city agglomerations. Passengers are looking for travel information on-line and companies providing public transport solutions often struggle with providing modern trip planner platforms. We address this problem by providing simple and easy to implement solution for shortest paths computation in public transport network of any size. In first part of the paper we present our approach to building time-expanded graph model of public transportation network. We use a structure with multiple vertices within one stop identified by triple (stop, time, line) and edges with constant travel times. Second part introduces k-shortest paths algorithm for created graph. We provide step by step explanation along with code samples. Average algorithm response time is around 1.5s for a public transport network of the size over 2800 stops. This is accepted query time for a web application. None additional speed-up techniques has been used to keep implementation and explanations simple and leaving room for further improvements. Algorithm has been successfully tested in Upper Silesian Industrial District (GOP) in cooperation with main public transport provider in the area (KZK GOP). This real instance is the biggest one in Poland and contains 370 lines and over 2800 stops.

关键词： graph theory public transport Upper Silesian Industrial District k-shortest path algorithm mass transit public transport planner service public transportation network time-expanded graph model travel information trip planner platform Data structures Educational institutions Mobile communication Planning Reliability Routing Transportation Travel information Transport networks Public Transit Mass transit public transport network Educational institutions Data structures mobile communication shortest path algorithms Graph theory Network routing transport FINDINGS

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