linus: Conveniently explore, share, and present large-scale biological trajectory data in a web browser

In biology, we are often confronted with information-rich, large-scale trajectory data, but exploring and communicating patterns in such data can be a cumbersome task. Ideally, the data should be wrapped with an interactive visualisation in one concise packet that makes it straightforward to create and test hypotheses collaboratively. To address these challenges, we have developed a tool, linus, which makes the process of exploring and sharing 3D trajectories as easy as browsing a website. We provide a python script that reads trajectory data, enriches them with additional features such as edge bundling or custom axes, and generates an interactive web-based visualisation that can be shared online. linus facilitates the collaborative discovery of patterns in complex trajectory data.

Sound Systems

The story of Tudor’s transition from performer to composer is undermined by the observation of archival material which reveals he continued to realize other composers’ works even after he supposedly became a composer. A list of ten realizations Tudor retrospectively selected in the early 1970s provides a preliminary guide to reflect on the complex trajectory of his musical activity in the 1960s which departed from the traditional format of score and its performance, giving birth to “sound systems” as a tentative coordination of modular instruments in which the composer’s material served as a mere pre-text or a point of departure. In order to understand the nature of Tudor’s realization of this period it is necessary to also delve into the technical specificity of equipment. A case study of Fontana Mix, a material composed by John Cage, which Tudor realized as late as 1968 is presented, triggering a discussion on the complex entanglement between the acts of realization and composition.

ON ALGORITHM FOR DETECTING CHANGES IN THE OBJECT MOTION MODE

The article deals with the solution to the problem of determining the motion mode of an object along a complex trajectory. A hybrid stochastic model is used to describe a complex trajectory. The solution of the problem is based on the application of a sequential decision rule about the choice at an unknown time of the hypothesis about the current mode of motion, with a limited size of the bank of competing Kalman filters. An algorithm is constructed for calculating the average size of the Kalman filter bank in the case of M-possible motion modes. The algorithm is developed in a general form, therefore, it can be used not only for the four types of object motion models considered in this paper, but also for any linear discrete-time models with Gaussian noise presented by equations in the state space. The algorithm for a priori estimation of the average size of a bank of competing Kalman filters for M-possible modes of motion is implemented in MATLAB, the results of computer simulation are presented.

Kinematics of the disk working body for ground development

High rates of growth in the volume of earthworks in winter, with a lack of funds for the purchase of new equipment, determine the relevance of work to improve the existing and create new working bodies for the development of frozen grounds and snow-ice formations to increase the efficiency of their destruction without increasing the power of the base machine. This can be done by installing a fundamentally new cutting tool in the form of elliptical circular knives on the working bodies. The article deals with the kinematics of an ellipsoidal disk working body. Expressions for determining the displacement, velocity and acceleration of the point of the cutting edge of the disk are obtained analytically. It was found that the points of the cutting edge of the disk move in space along a complex trajectory, and the absolute values of velocity and acceleration are variable parameters. The regularity of the change in the angle of entry of the disk into the ground at different values of the angle of its attachment to the shaft of the working battery was revealed, and the main design and technological parameters were determined and substantiated.

Effects of High Fidelity Modeling of Multirotor Drones

This paper examines two different factors that will affect energy consumption for multi-rotor drones with more than four rotors. First, the choice of aerodynamic model for the rotor blades is examined. Two aerodynamic models, the blade element theory (BET) model and lumped blade (LB) model, are compared using vertical, roll, pitch, and yaw trajectories. The BET and LB models produced very different trajectories with identical inputs, especially in the vertical and yaw trajectories which differed by 87.9% and 52.5%, respectively. The BET and LB models also result in different energy usages with the LB model consistently predicting 36% more energy consumption. The second factor studied is the choice of rotor groupings. For a multi-rotor drone, different rotor groupings may result in different energy usages; two groupings are considered. The same four basic trajectories are compared. The results show that the two groupings have an energy difference of 4.7–4.9% for each of the roll, pitch, and yaw directions which implies that each grouping has a base energy consumption inherent to it. Then, possible energy compounding effects are explored by examining a complex trajectory. The complex trajectory yields a 9.26% energy difference between the two groupings but further examination reveals that the difference is due to differences in the final trajectory not energy compounding effects. Thus, it is concluded that the aerodynamic model and rotor groupings are two important factors that must be considered when energy consumption needs to be minimized.