Three Tiered Self-Localization of Two Position Estimation Using Three Dimensional Environment Map and Gyro-Odometry

2014 ◽  
Vol 26 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Kazuya Okawa ◽  
Keyword(s):  
Three Dimensional ◽  
Position Estimation ◽  
Map Matching ◽  
Localization Method ◽  
Challenge Course ◽  
Environment Map ◽  
Improve Accuracy ◽  
Environment Maps ◽  
Using Data ◽  
Map Data

As in the Tsukuba Challenge, any robot that autonomously moves around outdoors must be capable of accurate self-localization. Among many existing methods for robot self-localization, the most widely used is for the robot to estimate its position by comparing it with prior map data actually acquired using its sensor while it moves around. Although we use such a self-localization method in this study, this paper proposes a new method to improve accuracy in robot self-localization. In environments with few detected objects, a lack of acquired data very likely will lead to a failure in map matching and to erroneous robot self-localization. Therefore, a method for robot self-localization that uses three-dimensional environment maps and gyro-odometry depending on the situation is proposed. Moreover, the effectiveness of the proposed method is confirmed by using data from the 2013 Tsukuba Challenge course.

scholarly journals Spectrum Awareness for Cognitive Radios Supported by Radio Environment Maps: Zonal Approach

2021 ◽  
Vol 11 (7) ◽  
pp. 2910
Author(s):  
Paweł Kaniewski ◽  
Janusz Romanik ◽  
Edward Golan ◽  
Krzysztof Zubel
Keyword(s):  
Situational Awareness ◽  
Cognitive Radios ◽  
Field Tests ◽  
Radio Networks ◽  
Map Construction ◽  
Environment Map ◽  
Construction Techniques ◽  
Interpolation Techniques ◽  
Environment Maps ◽  
Radio Environment Maps

In this paper, we present the concept of the Radio Environment Map (REM) designed to ensure electromagnetic situational awareness of cognitive radio networks. The map construction techniques based on spatial statistics are presented. The results of field tests done for Ultra High Frequency (UHF) range with different numbers of sensors are shown. Exemplary maps with selected interpolation techniques are presented. Control points where the signal from licensed users is correctly estimated are identified. Finally, the map quality is assessed, and the most promising interpolation techniques are selected.

Three-Dimensional Computerized Anthropometry of the Nose: Landmark Representation Compared to Surface Analysis

2007 ◽  
Vol 44 (3) ◽  
pp. 278-285 ◽  
Author(s):  
Virgilio F. Ferrario ◽  
Fabrizio Mian ◽  
Redento Peretta ◽  
Riccardo Rosati ◽  
Chiarella Sforza
Keyword(s):  
Three Dimensional ◽  
Digital Data ◽  
Limits Of Agreement ◽  
B Splines ◽  
Surface Areas ◽  
Using Data ◽  
Difference Volume ◽  
T Values ◽  
Plaster Models ◽  
Plaster Casts

Objective: To compare three-dimensional nasal measurements directly made on subjects to those made on plaster casts, and nasal dimensions obtained with a surface-based approach to values obtained with a landmark representation. Methods: Soft-tissue nasal landmarks were directly digitized on 20 healthy adults. Stone casts of their noses were digitized and mathematically reconstructed using nonuniform rational B-splines (NURBS) curves. Linear distances, angles, volumes and surface areas were computed using facial landmarks and NURBS-reconstructed models (surface-based approach). Results: Measurements on the stone casts were somewhat smaller than values obtained directly from subjects (differences between −0.05 and −1.58 mm). Dahlberg's statistic ranged between 0.73 and 1.47 mm. Significant (p < .05) t values were found for 4 of 15 measurements. The surface-based approach gave values 3.5 (volumes) and 2.1 (surface area) times larger than those computed with the landmark-based method. The two values were significantly related (volume, r = 0.881; surface, r = 0.924; p < .001), the resulting equations estimated actual values well (mean difference, volume −0.01 mm3, SD 1.47, area 0.05 cm2, SD 1.44); limits of agreement between −2.89 and 2.87 mm3 (volume); −2.88 and 2.78 cm2 (area). Conclusions: Considering the characteristics of the two methods, and for practical purposes, nasal distances and angles obtained on plaster models were comparable to digital data obtained directly from subjects. Surface areas and volumes were best obtained using a surface-based approach, but could be estimated using data provided by the landmark representation.

scholarly journals Dynamics of Three-Dimensional Turbulent Wall Plumes and Implications for Estimates of Submarine Glacier Melting

2018 ◽  
Vol 48 (9) ◽  
pp. 1941-1950 ◽  
Author(s):  
Ekaterina Ezhova ◽  
Claudia Cenedese ◽  
Luca Brandt
Keyword(s):  
Three Dimensional ◽  
Characteristic Parameters ◽  
Buoyant Plumes ◽  
Tidewater Glaciers ◽  
Glacier Melting ◽  
Order Of Magnitude ◽  
Layer Flow ◽  
Using Data ◽  
Turbulent Wall ◽  
Wall Plume

AbstractSubglacial discharges have been observed to generate buoyant plumes along the ice face of Greenland tidewater glaciers. These plumes have been traditionally modeled using classical plume theory, and their characteristic parameters (e.g., velocity) are employed in the widely used three-equation melt parameterization. However, the applicability of plume theory for three-dimensional turbulent wall plumes is questionable because of the complex near-wall plume dynamics. In this study, corrections to the classical plume theory are introduced to account for the presence of a wall. In particular, the drag and entrainment coefficients are quantified for a three-dimensional turbulent wall plume using data from direct numerical simulations. The drag coefficient is found to be an order of magnitude larger than that for a boundary layer flow over a flat plate at a similar Reynolds number. This result suggests a significant increase in the melting estimates by the current parameterization. However, the volume flux in a wall plume is found to be one-half that of a conical plume that has 2 times the buoyancy flux. This finding suggests that the total entrainment (per unit area) of ambient water is the same and that the plume scalar characteristics (i.e., temperature and salinity) can be predicted reasonably well using classical plume theory.

Did They Mind the Gap? Voter/Party Ideological Proximity between the BQ, the NDP and Quebec Voters, 2006–2011

2016 ◽  
Vol 49 (2) ◽  
pp. 289-310 ◽  
Author(s):  
Jean-Philippe Gauvin ◽  
Chris Chhim ◽  
Mike Medeiros
Keyword(s):  
Political Party ◽  
Three Dimensional ◽  
Election Study ◽  
Federal Election ◽  
Party Manifestos ◽  
Longitudinal Approach ◽  
The Face ◽  
Election Results ◽  
Using Data ◽  
Over Time

AbstractThe 2011 Canadian federal election results changed the face of federal politics in Quebec. In a sudden and spectacular reversal of electoral fortunes, BQ support crumbled while that of the NDP surged. While most commentators focused exclusively on the 2011 election itself to explain what had happened, we offer an interpretation that takes a longitudinal approach. Using data from the Canadian Election Study and political party manifestos from 2006 to 2011, we propose a three-dimensional proximity model of voter/party congruence to explore the evolution of the ideological stances of Quebec voters and parties. Empirical results suggest these ideological distances between the NDP and Quebec voters decreased over time, whereas the BQ has distanced itself from voters. Furthermore, ideological distances between party and voters are a significant predictor of vote.

scholarly journals Data assimilation for volcanic ash plumes using a satellite observational operator: a case study on the 2010 Eyjafjallajökull volcanic eruption

2017 ◽  
Vol 17 (2) ◽  
pp. 1187-1205 ◽  
Author(s):  
Guangliang Fu ◽  
Fred Prata ◽  
Hai Xiang Lin ◽  
Arnold Heemink ◽  
Arjo Segers ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Volcanic Ash ◽  
Three Dimensional ◽  
Forecast Accuracy ◽  
Improve Model ◽  
Powerful Approach ◽  
Using Data ◽  
D Model

Abstract. Using data assimilation (DA) to improve model forecast accuracy is a powerful approach that requires available observations. Infrared satellite measurements of volcanic ash mass loadings are often used as input observations for the assimilation scheme. However, because these primary satellite-retrieved data are often two-dimensional (2-D) and the ash plume is usually vertically located in a narrow band, directly assimilating the 2-D ash mass loadings in a three-dimensional (3-D) volcanic ash model (with an integral observational operator) can usually introduce large artificial/spurious vertical correlations.In this study, we look at an approach to avoid the artificial vertical correlations by not involving the integral operator. By integrating available data of ash mass loadings and cloud top heights, as well as data-based assumptions on thickness, we propose a satellite observational operator (SOO) that translates satellite-retrieved 2-D volcanic ash mass loadings to 3-D concentrations. The 3-D SOO makes the analysis step of assimilation comparable in the 3-D model space.Ensemble-based DA is used to assimilate the extracted measurements of ash concentrations. The results show that satellite DA with SOO can improve the estimate of volcanic ash state and the forecast. Comparison with both satellite-retrieved data and aircraft in situ measurements shows that the effective duration of the improved volcanic ash forecasts for the distal part of the Eyjafjallajökull volcano is about 6 h.

scholarly journals A simple, high-resolution, non-destructive method for determining the spatial gradient of the elastic modulus of insect cuticle

2018 ◽  
Vol 15 (145) ◽  
pp. 20180312 ◽  
Author(s):  
S h. Eshghi ◽  
M. Jafarpour ◽  
A. Darvizeh ◽  
S. N. Gorb ◽  
H. Rajabi
Keyword(s):  
Elastic Modulus ◽  
High Resolution ◽  
Three Dimensional ◽  
Insect Cuticle ◽  
Spatial Gradient ◽  
Engineering Systems ◽  
Small Complex ◽  
Load Carrying ◽  
Using Data ◽  
Non Destructive

Nature has evolved structures with high load-carrying capacity and long-term durability. The principles underlying the functionality of such structures, if studied systematically, can inspire the design of more efficient engineering systems. An important step in this process is to characterize the material properties of the structure under investigation. However, direct mechanical measurements on small complex-shaped biological samples involve numerous technical challenges. To overcome these challenges, we developed a method for estimation of the elastic modulus of insect cuticle, the second most abundant biological composite in nature, through simple light microscopy. In brief, we established a quantitative link between the autofluorescence of different constituent materials of insect cuticle, and the resulting mechanical properties. This approach was verified using data on cuticular structures of three different insect species. The method presented in this study allows three-dimensional visualisation of the elastic modulus, which is impossible with any other available technique. This is especially important for precise finite-element modelling of cuticle, which is known to have spatially graded properties. Considering the simplicity, ease of implementation and high-resolution of the results, our method is a crucial step towards a better understanding of material–function relationships in insect cuticle, and can potentially be adapted for other graded biological materials.

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