CHEAP AND IMMERSIVE VIRTUAL REALITY: APPLICATION IN CARTOGRAPHY

In this paper, we analysed and tested the possibilities for the use of low-cost VR (Virtual Reality) headsets, with a focus on cartographic visualization. Low-cost devices were compared and classified into three categories (low-end, mid-range and high-end). We also created a pilot virtual environment, called “Carthoreality”, and conducted simple pilot user testing using this virtual environment and the three low-end headsets. Our pilot test shows a few drawbacks to these devices, including weight of the headset and penetrating light. Some problems in terms of user aspects were also identified, such as nausea while wearing headsets or disorientation after removing them, which occurred for all users

Atypical transistor-based chaotic oscillators: Design, realization, and diversity

In this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predominantly anti-persistent monofractal dynamics. Notably, we recurrently found a circuit comprising one resistor, one transistor, two inductors, and one capacitor, which generates a range of attractors depending on the parameter values. We also found a circuit yielding an irregular quantized spike-train resembling some aspects of neural discharge and another one generating a double-scroll attractor, which represent the smallest known transistor-based embodiments of these behaviors. Through three representative examples, we additionally show that diffusive coupling of heterogeneous oscillators of this kind may give rise to complex entrainment, such as lag synchronization with directed information transfer and generalized synchronization. The replicability and reproducibility of the experimental findings are good. Published by AIP Publishing