Search results for "Aloha"
showing 4 items of 4 documents
Underwater Wireless Communications for Cooperative Robotics with UWSim-NET
2019
The increasing number of autonomous underwater vehicles (AUVs) cooperating in underwater operations has motivated the use of wireless communications. Their modeling can minimize the impact of their limited performance in real-time robotic interventions. However, robotic frameworks hardly ever consider the communications, and network simulators are not suitable for HIL experiments. In this work, the UWSim-NET is presented, an open source tool to simulate the impact of communications in underwater robotics. It gathers the benefits of NS3 in modeling communication networks with those of the underwater robot simulator (UWSim) and the robot operating system (ROS) in modeling robotic systems. Thi…
Smaku piesārņojuma izplatība Ventspils brīvostas teritorijas apkārtnē
2019
Viens no gaisa kvalitātes rādītājiem ir tā smarža, kuras uztvere nereti ir subjektīva. Aktīvas saimnieciskās darbības rezultātā bieži tiek emitētas dažādas smakas. Bakalaura darbā “Smaku piesārņojuma izplatība Ventspils brīvostas teritorijas apkārtnē” apkopota informācija par galvenajiem smaku piesārņojuma avotiem, izplatību ietekmējošiem faktoriem, novērtēšanas metodēm, normatīviem un kontroles instrumentiem. Darba pētnieciskā daļā veikta potenciālo smaku piesārņojuma avotu identifikācija, analizējot 2016. gada valsts statistiskos pārskatus 2-Gaiss, Ventspils brīvostas teritorijā, izvērtētas galvenās potenciālās vielas. Eksperimentālā daļā veikta smaku izplatības modelēšana dažādas atmosfē…
Letter Throughput and Delay Analysis of the Ideal Window
1999
We consider the problem of random access communications over a time slotted channel with feedback of infinitely multiplicity at the beginning of each collision resolution interval (CRI), i.e., users know via instantaneous feedback the number of users involved in that collision. Once this is known, the resolution algorithm (CRA) operates with binary (successful / non successful, s/ns) feedback. The analysis of this simple full feedback sensing window random access algorithm, named ideal window stabilized ALOHA, (IWSA), algorithm, provides a throughput of 0.5052 packets/slot, Its delay is also analyzed and compared with similar algorithms.
Influence of the input-stage architecture on the in-laboratory test of a mid-infrared interferometer: application to the ALOHA up-conversion interfer…
2020
ABSTRACT In the framework of the Astronomical Light Optical Hybrid Analysis (ALOHA) laboratory mid-infrared (MIR) up-conversion fibred interferometer in the L band, we report on the influence of the input-stage architecture. Using an amplitude division set-up in the visible or near-infrared is a straightforward choice in most cases. In the MIR context, the results are slightly different and we show that a wavefront division set-up is needed. These in-laboratory principle experiments allow us to measure a reliable 88 per cent instrumental contrast with high flux and to obtain fringes from faint sources at 3.5 μm with a spectral bandwith of 37 nm converted to 817 nm. An equivalent limiting L-…