Identification of Air Traffic Flow Segments via Incremental Deterministic Annealing Clustering

Many of the traffic management decisions and initiatives in air traffic are based on "flows" of traffic in the National Airspace System (NAS), but the actual identification of the location and time of the flow segments are often left to interpretation based on observations of traffic data points over time. Having an automated method of identifying major flow segments can help to target traffic management initiatives, evaluate design of airspace, and enable actions to be taken on the collection of flights in a flow segment rather than on the flights individually. A novel approach is developed to identify the major flow segments of air traffic in the NAS that consists of a robust method for partitioning 4-dimensional traffic trajectories into a series of great circle segments, and clustering the segments using an Agglomerate Deterministic Annealing clustering algorithm. In addition, a very efficient algorithm to incrementally cluster the segments is developed that takes into account the spatial and temporal properties of the segments, and makes the method very suitable for real-time applications. Further, an enhancement to the algorithm is provided that requires only a small subset of the segments to be clustered, drastically reducing the run time. Results of the clustering technique are shown, highlighting various major traffic flow patterns in the NAS. In addition, organizing the traffic into the flow segments identified using the Incremental Clustering method is shown to have a potential reduction in the number of conflict points. An application of the flow information is presented in the form of a Decision Support Tool (DST) that aids traffic managers in establishing and managing Airspace Flow Programs. In addition, the flow segment information is applied to a low-level form of aggregated traffic management, showing that aggregating flights into the flow segments and rerouting the whole flow segment can be efficiently performed as compared to rerouting individual aircraft separately, and can reduce the number of conflict points. Considerations for implementing these techniques in real-time systems are also discussed

Trajectory Clustering for Air Traffic Categorisation

Availability of different types of data and advances in data-driven techniques open the path to more detailed analyses of various phenomena. Here, we examine the insights that can be gained through the analysis of historical flight trajectories, using data mining techniques. The goal is to learn about usual (or nominal) choices airlines make in terms of routing, and their relation with aircraft types and operational flight costs. The clustering is applied to intra-European trajectories during one entire summer season, and a statistical test of independence is used to evaluate the relations between the variables of interest. Even though about half of all flights are less than 1000 km long, and mostly operated by one airline, along one trajectory, the analysis shows that, for longer flights, there exists a clear relation between the trajectory clusters and the operating airlines (in about 49% of city pairs) and/or the aircraft types (30%), and/or the flight costs (45%)

Fuzzy Controllers

Trying to meet the requirements in the field, present book treats different fuzzy control architectures both in terms of the theoretical design and in terms of comparative validation studies in various applications, numerically simulated or experimentally developed. Through the subject matter and through the inter and multidisciplinary content, this book is addressed mainly to the researchers, doctoral students and students interested in developing new applications of intelligent control, but also to the people who want to become familiar with the control concepts based on fuzzy techniques. Bibliographic resources used to perform the work includes books and articles of present interest in the field, published in prestigious journals and publishing houses, and websites dedicated to various applications of fuzzy control. Its structure and the presented studies include the book in the category of those who make a direct connection between theoretical developments and practical applications, thereby constituting a real support for the specialists in artificial intelligence, modelling and control fields

Study and simulation of low rate video coding schemes

The semiannual report is included. Topics covered include communication, information science, data compression, remote sensing, color mapped images, robust coding scheme for packet video, recursively indexed differential pulse code modulation, image compression technique for use on token ring networks, and joint source/channel coder design

Identifying Anomalies in past en-route Trajectories with Clustering and Anomaly Detection Methods

International audienceThis paper presents a framework to identify and characterise anomalies in past en-route Mode S trajectories. The technique builds upon two previous contributions introduced in 2018: it combines a trajectory-clustering method to obtain the main flows in an airspace with autoencoding artificial neural networks to perform anomaly detection in flown trajectories. The combination of these two well-known Machine Learning techniques (ML) provides a useful reading grid associating cluster analysis with quantified level of abnormality. The methodology is applied to a sector of the French Bordeaux Area Control Center (ACC) during its 385 hours of operation over seven months of ADS-B traffic. The results provide a good taxonomy of deconfliction measures and weather-related ATC actions. The application of this work is manyfold, ranging from safety studies estimating risks of midair collision, to complexity and workload assessments of traffic when a sector is operated, or to the constitution of a database of ATC actions ensuring aircraft separation. This database could be used to train further ML techniques aimed at improving the state of the art of deconfliction algorithms

A Cooperative Approach for Autonomous Landing of UAVs

This dissertation presents a cooperative approach for the autonomous landing of MRVTOL UAVs (Multi Rotor-Vertical Take-off and Landing Unmanned Aerial Vehicles). Most standard UAV autonomous landing systems take an approach, where the UAV detects a pre-set pattern on the landing zone, establishes relative positions and uses them to perform the landing. These methods present some drawbacks such as all of the processing being performed by the UAV itself, requiring high computational power from it. An additional problem arises from the fact most of these methods are only reliable when the UAV is already at relatively low altitudes since the pattern’s features have to be clearly visible from the UAV’s camera. The method presented throughout this dissertation relies on an RGB camera, placed in the landing zone pointing upwards towards the sky. Due to the fact, the sky is a fairly stagnant and uniform environment the unique motion patterns the UAV displays can be singled out and analysed using Background Subtraction and Optical Flow techniques. A terrestrial or surface robotic system can then analyse the images in real-time and relay commands to the UAV. The result is a model-free method, i.e independent of the UAV’s morphological aspect or pre-determined patterns, capable of aiding the UAV during the landing manoeuvre. The approach is reliable enough to be used as a stand-alone method, or be used along traditional methods achieving a more robust system. Experimental results obtained from a dataset encompassing 23 diverse videos showed the ability of the computer vision algorithm to perform the detection of the UAV in 93,44% of the 44557 evaluated frames with a tracking error of 6.6%. A high-level control system that employs the concept of an approach zone to the helipad was also developed. Within the zone every possible three-dimensional position corresponds to a velocity command for the UAV, with a given orientation and magnitude. The control system was tested in a simulated environment and it proved to be effective in performing the landing of the UAV within 13 cm from the goal

Single Cell Proteomics in Biomedicine: High-dimensional Data Acquisition, Visualization and Analysis

New insights on cellular heterogeneity in the last decade provoke the development of a variety of single cell omics tools at a lightning pace. The resultant high-dimensional single cell data generated by these tools require new theoretical approaches and analytical algorithms for effective visualization and interpretation. In this review, we briefly survey the state-of-the-art single cell proteomic tools with a particular focus on data acquisition and quantification, followed by an elaboration of a number of statistical and computational approaches developed to date for dissecting the high-dimensional single cell data. The underlying assumptions, unique features, and limitations of the analytical methods with the designated biological questions they seek to answer will be discussed. Particular attention will be given to those information theoretical approaches that are anchored in a set of first principles of physics and can yield detailed (and often surprising) predictions