This paper describes the itmlogic package, which provides a Python implementation of the Longley-Rice Irregular Terrain Model. It implements the classic model, enabling the quantification of propagation loss over irregular terrain. itmlogic is capable of predicting the the statistics of propagation loss given input parameters such as transmitter and receiver heights, frequency, surface permittivity, climate zone, and terrain information.
April 29, 2020John Ahlgren, Maria Eugenia Berezin, Kinga Bojarczuk, Elena Dulskyte, Inna Dvortsova, Johann George, Natalija Gucevska, Mark Harman, Ralf Lämmel, Erik Meijer, Silvia Sapora, Justin Spahr-Summers
We introduce the Web-Enabled Simulation (WES) research agenda, and describe FACEBOOK’s WW system. We describe the application of WW to reliability, integrity and privacy at FACEBOOK1, where it is used to simulate social media interactions on an infrastructure consisting of hundreds of millions of lines of code.
Solar-powered high-altitude long endurance aircraft that harvest and store solar energy can fly indefinitely if they are able to close a 24-hour energy cycle. Perpetual endurance is possible when energy consumption does not exceed energy storage.
An aero-structural optimization framework is presented to derive cost-optimal designs for communication tower structures. Preliminary designs are sought given certain high-level requirements such as tower height, wind speed and antenna loading. In order to rapidly search the design space, low-order modeling is emphasized for computational efficiency.
This paper proposes to use Gabor frames to lower the memory and CPU costs of split-step Fourier PE solvers and allow for the easy implementation of RBCs. Gabor transforms have been used before for PE-based modeling of geophysical problems (Chen et al, Geophysics, 2006, 71(2), S37-S52), but they have not yet been extensively used in electromagnetics
This paper proposes a new framework for modeling NLOS propagation using a PE - IE hybrid. The framework’s PE component simulates field propagation from the transmitting antenna through the atmosphere/ionosphere, and uses a wide-angle split-step Fourier method enhanced by Gabor-Daubechies sparsification techniques that produce significant computational savings over earlier PE solution methods.
We propose and study a task we name panoptic segmentation (PS). Panoptic segmentation unifies the typically distinct tasks of semantic segmentation (assign a class label to each pixel) and instance segmentation (detect and segment each object instance). The proposed task requires generating a coherent scene segmentation that is rich and complete, an important step toward real-world vision systems.
June 2, 2019Qi Tang, Abhishek Tiwari, Inigo del Portillo, Michael Reed, Hongyu Zhou, Dudi Shmueli, Gunnar Ristroph, Steven Cashion, Dawei Zhang, Joseph Stewart, Pratheep Bondalapati, Qi Qu, Yan Yan, Bob Proctor, Hamid Hemmati
We describe the design, development, and field demonstration of a high-throughput E-band communication link between a ground station and a Cessna aircraft flying at an altitude of 7km and a top speed of 463km/h.
In this paper, we describe the data and methodology that power Facebook Disaster Maps. These maps utilize information about Facebook usage in areas impacted by natural hazards, producing aggregate pictures of how the population is affected by and responding to the hazard. The maps include insights into evacuations, cell network connectivity, access to electricity, and long-term displacement.
We assess the viability of a state-of-the-art 100G/200G commercial optical coherent DSP ASIC (16 nm FinFET CMOS technology) for space applications through heavy ion testing to (1) screen for destructive SELs and (2) observe for nondestructive heavy ion SEEs on the ASIC.