Space decomposition based on visible objects in an indoor environment

2021 ◽  
pp. 239980832110373
Author(s):  
Kimia Amoozandeh ◽  
Stephan Winter ◽  
Martin Tomko
Keyword(s):  
Indoor Environment ◽  
Verbal Description ◽  
Two Dimensional ◽  
Space Decomposition ◽  
Visibility Polygons ◽  
Visual Range

When a person moves, the set of objects in their visual range changes. Hence, the set of objects perceived from a specific range of locations may be considered as a signature (possibly non-unique) of this region and be used for the localization of this person. In the case of fixed objects, the number of regions with a set of specific visible objects is limited. A verbal description containing references to elements of this set of visible objects could then be used to localize a person in the space. This paper proposes an approach for decomposing a space into regions that are characterized by such sets of visible objects. In our approach, at least a portion of partial surfaces of an object must be visible (beyond single points) to make part of the signature. Our method calculates two-dimensional visibility polygons for a portion of an object’s surface. Overlaying these polygons, we partition the space in regions of visibility signatures. The approach has been implemented, and we demonstrate how to represent space by qualitative locations using these visibility signatures. We further show how this representation can be used to locate a person within a space by a set of visible objects.

scholarly journals Parametric study on the hygrothermal performance of timber frame walls with external airtightness membranes in a temperate maritime climate

2019 ◽  
Vol 282 ◽  
pp. 02080
Author(s):  
Valentina Marincioni ◽  
Federico Lorenzetti ◽  
Hector Altamirano-Medina
Keyword(s):  
Parametric Study ◽  
Indoor Environment ◽  
Moisture Transfer ◽  
Wall Structure ◽  
Two Dimensional ◽  
Mould Growth ◽  
Timber Frame ◽  
Maritime Climate ◽  
Hygrothermal Performance ◽  
Control Layer

In recent years, external airtightness membranes have become an option for timber frame wall systems, as they allow high levels of air- and wind-tightness with an easy installation and provide rainwater protection during construction. This opens up the option of removing the internal air and vapour control layer. However, the hygrothermal risks associated to this option could be higher than in conventional construction, because vapour transfer can occur from the indoor environment into the timber frame wall not just via diffusion but also advection. This can lead to moisture accumulation and mould growth risk within the wall structure. This paper presents a parametric study that aims at identifying the moisture risk when external airtightness membranes are installed on a timber frame wall in a temperate maritime climate. The parametric study considered the two-dimensional heat, air and moisture transfer within a timber frame wall. Parameters having higher influence on moisture risk were identified and should be considered when designing robust wall systems.

Antenna System and Architecture-Circular Polarized UWB Antenna for Indoor Positioning Application

2016 ◽  
pp. 340-361
Author(s):  
Rupesh Kumar ◽  
Bernard Huyart ◽  
Jean-Christophe Cousin
Keyword(s):  
Indoor Environment ◽  
Indoor Positioning ◽  
Antenna System ◽  
Future Perspective ◽  
Two Dimensional ◽  
Radio Waves ◽  
Uwb Antenna ◽  
Localization System ◽  
Recent Developments ◽  
Waves Propagation

Indoor environment can be characterized as sever attenuating and depolarizing medium for electromagnetic (radio) waves propagation. These signals are radiated from transmitters to space (free-space propagation channel) and received from space to receivers through antennas. These signals are commonly radiated or received with pre-defined signal's polarization schemes and these schemes are always controlled by the antenna. In this chapter, the two-dimensional antenna designs and its polarization schemes are presented for minimizing the sever effects of an indoor environment. Emphasis is on understanding the special attention required for designing an antenna dedicated to an Indoor Positioning/Localization System. Some recent developments in antenna designs are presented as an example for the better understanding and its future perspective.

scholarly journals Noise space decomposition method for two-dimensional sinusoidal model

2013 ◽  
Vol 58 ◽  
pp. 147-161 ◽  
Author(s):  
Swagata Nandi ◽  
Debasis Kundu ◽  
Rajesh Kumar Srivastava
Keyword(s):  
Decomposition Method ◽  
Two Dimensional ◽  
Sinusoidal Model ◽  
Space Decomposition

A Robust and Efficient 3D LADAR Odometer with Outlier Detection

2017 ◽  
Vol 71 (2) ◽  
pp. 317-338
Author(s):  
Zhen Zhu ◽  
Maarten Uijt de Haag
Keyword(s):  
Outlier Detection ◽  
Field Test ◽  
Indoor Environment ◽  
Detection Method ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Test Results ◽  
Estimation Algorithms ◽  
Laser Scanners ◽  
Autonomous Aircraft

This paper discusses the estimation algorithms for Three-Dimensional (3D) displacement and 3D rotation using Two-Dimensional (2D) laser scanners. An efficient outlier detection method is proposed for both algorithms to help protect the integrity of navigation. The algorithms have been evaluated using both simulation and field test results. They are able to produce a robust odometry solution for an autonomous aircraft in an indoor environment.

Effect of Wind Speed on Ventilation Flow Through a Two Dimensional Room Fitted With a Windcatcher

2018 ◽  
Author(s):  
Rahil Taghipour ◽  
Peter Abdo ◽  
B. P. Huynh
Keyword(s):  
Indoor Environment ◽  
Natural Ventilation ◽  
Air Flow ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Indoor Space ◽  
Wind Speeds ◽  
Flow Through ◽  
Convergent Inlet ◽  
Natural Means

Natural ventilation is the process of supplying and removing air through an indoor space by natural means. Windcatcher has been used over centuries for providing natural ventilation using wind power, it is an effective passive method to provide healthy and comfortable indoor environment by decreasing moisture content in the air and reducing pollutants concentration. The windcatcher’s function is based on the wind and on the stack effect resulting from temperature differences. Generally, it is difficult for wind to change its direction, and enter a room through usual openings, the windcatcher is designed to overcome such problems since they have vertical columns aimed at helping wind to channel down to the inside of a building. The efficiency of a windcatcher is maximized by applying special forms of opening and exit. The openings depend on the windcatcher’s location and on its cross sectional area and shape such as square, rectangular, hexagonal or circular. In this study the effect of different wind speeds on the total air flow captured by different inlet designs is investigated. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a two dimensional room fitted with a windcatcher applying wind speeds from 1 m/s up to 14 m/s and based on different inlet designs such as a uniform inlet, a divergent inlet and a bulging-convergent inlet.

Effect of Windcatcher’s Inlet Shape on Ventilation Flow Through a Two Dimensional Room

2018 ◽  
Author(s):  
Peter Abdo ◽  
Rahil Taghipour ◽  
B. P. Huynh
Keyword(s):  
Indoor Environment ◽  
Natural Ventilation ◽  
Air Flow ◽  
Two Dimensional ◽  
Sectional Area ◽  
Cross Sectional ◽  
Indoor Space ◽  
Flow Through ◽  
Convergent Inlet ◽  
Natural Means

Natural ventilation is the process of supplying and removing air through an indoor space by natural means. Windcatcher has been used over centuries for providing natural ventilation using wind power, it is an effective passive method to provide healthy and comfortable indoor environment by decreasing moisture content in the air and reducing pollutants concentration. The windcatcher’s function is based on the wind and on the stack effect resulting from temperature differences. Generally, it is difficult for wind to change its direction, and enter a room through usual openings, the windcatcher is designed to overcome such problems since they have vertical columns aimed at helping wind to channel down to the inside of a building. The efficiency of a windcatcher is maximized by applying special forms of opening and exit. The openings depend on the windcatcher’s location and on its cross sectional area and shape such as square, rectangular, hexagonal or circular. In this study the effect of the inlet design is investigated to achieve better air flow and increase the efficiency of windcatchers. To achieve this, CFD (computational fluid dynamics) tool is used to simulate the air flow in a two dimensional room fitted with a windcatcher based on different inlet designs such as a uniform inlet, a divergent inlet and a bulging-convergent inlet.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

Introductory paper

1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan
Keyword(s):  
Line Intensity ◽  
Classification Scheme ◽  
Two Dimensional ◽  
Spectral Classification ◽  
Dimensional Array ◽  
Rr Lyrae ◽  
Metallic Line ◽  
Introductory Paper ◽  
Parameter Varying ◽  
Definition Of

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.

A one-dimensional self-gravitating stellar gas

1966 ◽  
Vol 25 ◽  
pp. 46-48 ◽  
Author(s):  
M. Lecar
Keyword(s):  
Gravitational Field ◽  
Phase Space ◽  
Motion Picture ◽  
Space Distribution ◽  
Two Dimensional ◽  
One Dimensional ◽  
Phase Space Distribution ◽  
Dimensional Phase Space ◽  
The Mean

“Dynamical mixing”, i.e. relaxation of a stellar phase space distribution through interaction with the mean gravitational field, is numerically investigated for a one-dimensional self-gravitating stellar gas. Qualitative results are presented in the form of a motion picture of the flow of phase points (representing homogeneous slabs of stars) in two-dimensional phase space.

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