Uniform Dispersal of Robots with Minimum Visibility Range

2017 ◽  
pp. 155-167 ◽  
Author(s):  
Attila Hideg ◽  
Tamás Lukovszki
Keyword(s):  
Visibility Range

The Statistical Evaluations of Transmission Characteristics, Limits of Ranges and Speeds of Transmission of Information Via the Pulsed Atmospheric Bistatic Optical Channels

2019 ◽  
pp. 97-104
Author(s):  
Mikhail V. Tarasenkov ◽  
Egor S. Poznakharev ◽  
Vladimir V. Belov
Keyword(s):  
Communication Systems ◽  
Estimation Algorithm ◽  
Transmission Characteristics ◽  
Radiation Beam ◽  
Optical Channels ◽  
The Monte Carlo Method ◽  
Wide Range ◽  
Transmission Of Information ◽  
Optical Axes ◽  
Visibility Range

The simulation program by the Monte Carlo method of pulse reactions of bistatic atmospheric aerosol-gas channels of optical-electronic communication systems (OECS) is created on the basis of the modified double local estimation algorithm. It is used in a series of numerical experiments in order to evaluate statistically the transfer characteristics of these channels depending on the optical characteristics of an atmosphere plane-parallel model for wavelengths λ = 0.3, 0.5, and 0.9 μm at a meteorological visibility range SM = 10 and 50 km. The results are obtained for a set of basic distances between the light source and the light receiver up to 50 km and for the angular orientations of the optical axes of a laser radiation beam and of the receiving system in a wide range of their values. The dependences of the pulse reactions maximum values over-the-horizon channels of the OECS on the variations of these parameters are established.

SIMPLE FIRE MODEL FOR COMPARATIVE STUDIES OF CRITICAL CONDITIONS DURING COMBUSTION OF CHOSEN POLYMER MATERIALS

2009 ◽  
Vol 15 (3) ◽  
pp. 247-257 ◽  
Author(s):  
Marek Konecki ◽  
Marzena Półka
Keyword(s):  
Reduction Rate ◽  
Polymer Materials ◽  
Critical Conditions ◽  
Toxic Species ◽  
Smoke Layer ◽  
Epoxy Material ◽  
Life Threatening ◽  
Visibility Range ◽  
Thermal Influence ◽  
The Given

The time taken to evacuate space inside a building (required time for evacuation) must be shorter than the time for the environment in that space to become life threatening (available safe egress time ‐ ASET). That time is the time, when certain tenability limits of smoke filling, toxicity and thermal influence of the building environment are exceeded. As a consequence of lost visibility in smoke, people loose their orientation, and consequently evacuation is slowed down or becomes impossible. In such conditions inhaling of an excessive volume of toxins may lead to loss of consciousness or death. In the paper are discussed the influences of visibility through a smoke layer (or smoke obscuration) and concentration of toxic products of combustion on ASET, in well ventilated fires. Apart from the visibility range, also CO and CO2 concentrations have been chosen for the analysis. The given simple formulas show the dependency of rate of combustion and yields of smoke and toxic species on visibility reduction rate and increasing of concentration of toxic products evolved during combustion of selected materials. Epoxy materials were used for the analysis: pure Epoxy material 561 and epoxy with the following admixtures: MoO3, Roflam P and Melamine, as well as 2 types of polyurethane form. Santrauka Laikas, reikalingas žmonėms evakuotis iš pastato (evakuacijos laikas), turi būti trumpesnis už laiką, per kurį konkreti pastato erdvė tampa pavojinga gyvybei (leistinas saugios evakuacijos laikas – angl. ASET). Šis laikas apibrėžia priimtinų dūmų plitimo, toksiškumo ir šiluminio poveikio pastato erdvei ribų viršijimą. Dėl dūmų žmonės praranda orientaciją, todėl evakuacija užsitęsia arba tampa neįmanoma. Dėl tokiomis aplinkos sąlygomis įkvepiamo didelio toksinų kiekio galima prarasti sąmonę ar net mirti. Straipsnyje apžvelgiama matomumo per dūmų sluoksnį ir toksiškų produktų koncentracijos įtaka evakuacijos laikui (ASET), kai degančioje patalpoje gaisro metu užtikrinama gera oro ventiliacija. Greta matomumo buvo tiriama CO ir CO2 koncentracijos įtaka evakuacijos laikui. Pateiktos formulės rodo degimo intensyvumo ir dūmų bei toksiškų priedų išsiskyrimo įtaką matomumo mažėjimui ir toksinių produktų koncentracijos didėjimui įvertinant konkrečios medžiagos degimą. Tyrimams naudotos šios medžiagos: epoksidinė medžiaga 561 be priemaišų, epoksidinė medžiaga su MoO3 , Roflam P ir Melamine priedais, dvi poliuretano detalės.

scholarly journals Development and Certification of A Visibility-Range Monitor By Image Processing

1989 ◽  
Vol 13 ◽  
pp. 117-119
Author(s):  
Keishi Ishimoto ◽  
Masao Takeuchi ◽  
Shigeyuki Naitou ◽  
Haruki Furusawa
Keyword(s):  
Image Processing ◽  
Vertical Distribution ◽  
Video Camera ◽  
Measuring System ◽  
Blowing Snow ◽  
Snow Surface ◽  
Charge Coupled Device ◽  
Visibility Range ◽  
A Charge ◽  
The Vertical Distribution

A new visibility-range measuring system has been developed which uses a video camera, and with which visibility can be estimated by measuring the brightness contrast of a black target against a standardized background. This principle has been applied to development of the new visibility-range monitor described in this paper. In this monitor, a charge-coupled device (CCD) video camera measures the brightness of an arbitrary area in its range of vision, and visibility range measured by the video camera in blowing snow can be compared with that measured by the transmissometer-type visibility-range monitor and can also be calculated by direct observation using optical targets. The new sytem can monitor visibility and record information about traffic on highways at 1 s intervals for a maximum of six separate positions. The vertical distribution of visibilities over a snow surface has been observed, and it has been found that the fluctuation in visibility is greatest at lower levels above the ground in blowing snow.

Evaluation of A16 Motorway Fog-Signaling System with Respect to Driving Behavior

1997 ◽  
Vol 1573 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Jeroen H. Hogema ◽  
Richard van der Horst
Keyword(s):  
Evaluation Study ◽  
Driving Behavior ◽  
Maximum Speed ◽  
Signaling System ◽  
Loop Detectors ◽  
Road Section ◽  
The Matrix ◽  
Visibility Range ◽  
Positive Effect ◽  
Traffic Measurements

On the A16 Motorway in the Netherlands, the Dutch Ministry of Transport implemented an automatic fog-signaling system to elicit safer driving behavior during fog. Along a road section 12 km (7.4 mi) long, 20 sensors were placed to continuously measure the visibility range. During fog, the system displays an explicit fog warning on overhead matrix signs together with a maximum speed limit that depends on the actual available visibility range. An evaluation study in terms of driving behavior was carried out for a period of more than 2 years. Continuous traffic measurements for individual vehicles were obtained via inductive loop detectors at six locations (four experimental and two control locations). Data on the local visibility conditions and on the messages displayed on the matrix signs were available on a 1-min basis. The results reveal that the system has a positive effect on speed choice in fog: on top of a lower mean speed caused by the reduced visibility, the system results in an additional decrease of speed of about 8 to 10 kph

Consistency between backscatter lidar products and visibility range

2011 ◽  
Vol 24 (3) ◽  
pp. 231-234
Author(s):  
V. Mitev ◽  
R. Matthey
Keyword(s):  
Visibility Range

The modern theory of black object visibility and meteorological visibility range

1994 ◽  
Vol 28 (5) ◽  
pp. 763-767 ◽  
Author(s):  
I.L. Katsev ◽  
E.P. Zege
Keyword(s):  
Modern Theory ◽  
Visibility Range

Self-deployment of mobile robotic networks: an algorithm for decentralized sweep boundary coverage

Robotica ◽  
2016 ◽  
Vol 35 (9) ◽  
pp. 1816-1844 ◽  
Author(s):  
Anna A. Semakova ◽  
Kirill S. Ovchinnikov ◽  
Alexey S. Matveev
Keyword(s):  
Computer Simulations ◽  
Minimum Distance ◽  
A Priori ◽  
Safety Margin ◽  
The Other ◽  
Robotic Networks ◽  
Wheeled Robots ◽  
Visibility Range ◽  
Current Minimum ◽  
Unknown Region

SUMMARYSeveral non-holonomic Dubins-car-like robots travel over paths with bounded curvatures in a plane that contains an a priori unknown region. The robots are anonymous to one another and do not use communication facilities. Any of them has access to the current minimum distance to the region and can determine the relative positions and orientations of the other robots within a finite and given visibility range. We present a distributed navigation and guidance strategy under which every robot autonomously converges to the desired minimum distance to the region with always respecting a given safety margin, the robots do not collide with one another and do not get into clusters, and the entire team ultimately sweeps over the respective equidistant curve at a speed exceeding a given threshold, thus forming a kind of a sweeping barrier at the perimeter of the region. Moreover, this strategy provides effective sub-uniform distribution of the robots over the equidistant curve. Mathematically rigorous justification of the proposed strategy is offered; its effectiveness is confirmed by extensive computer simulations and experiments with real wheeled robots.

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