scholarly journals Study on Relative Accuracy and Verification Method of High-Definition Maps for Autonomous Driving

2021 ◽  
Vol 10 (11) ◽  
pp. 761
Author(s):  
Tengfei Yu ◽  
He Huang ◽  
Nana Jiang ◽  
Tri Dev Acharya
Keyword(s):  
Accuracy Assessment ◽  
A Priori ◽  
Autonomous Driving ◽  
Relative Accuracy ◽  
Accuracy Evaluation ◽  
High Definition ◽  
Verification Method ◽  
Road Signs ◽  
Point Set ◽  
Priori Information

High-definition maps (HDM) for autonomous driving (AD) are an important component of AD systems. HDMs accurately provide a priori information, including lane lines, and road signs, for AD systems. It is an important task to make a reasonable accuracy assessment of the HDM. The current methods for relative accuracy evaluation of general maps in the field of mapping are not fully applicable to HDMs. In this study, a method based on point set alignment and resampling is used to evaluate the relative accuracy of lane lines, and experiments are conducted based on relevant real HDM data. The results show that the relative accuracy of the lane lines is more detailed and relevant than the traditional method. This has implications for the quality control of HDM production.

scholarly journals On the Improvement of Multiple Circles Detection from Images Using Hough Transform

2019 ◽  
Vol 20 (2) ◽  
pp. 331
Author(s):  
Wesley Oliveira Barbosa ◽  
Antonio Wilson Vieira
Keyword(s):  
Hough Transform ◽  
A Priori ◽  
False Positives ◽  
Multiple Objects ◽  
Efficient Tool ◽  
Robust Detection ◽  
Point Set ◽  
Priori Information ◽  
The Individual ◽  
Set Of Points

The automatic detection of lines and curves from color images is a very important task in many applications, such as object recognition and scene reconstruction. Although there are closed formulation for curve fitting to a set of points, if the point set describes more than one instance of the object, as two circles for example, there is no closed formulation for obtaining the individual set of parameters without a priori information of which points belong to each object. However, it is usual the presence of multiple instances of objects such as lines and circles on an image. The well known Hough Transform is an efficient tool for recovering multiple objects from images using a voting process where the usual presence of false positives is an issue. In our work, we present an improvement on the voting process to detect multiple circles using Hough Transform in order to avoid false positives. Our experiments show that our voting process leads to a more robust detection, reducing the number of false positive and providing a more accurate detection even with large number of circles.

Transom Flow Elevations in the Partially Ventilated Condition

2015 ◽  
Author(s):  
Richard A. Royce ◽  
Patrick J. Doherty
Keyword(s):  
Potential Flow ◽  
A Priori ◽  
Static Condition ◽  
A Priori Information ◽  
Model Data ◽  
High Definition ◽  
Sinkage And Trim ◽  
Priori Information ◽  
Wake Sheet ◽  
Vessel Speed

Predicting separation from a transom stern presents a problem for potential flow calculations. As the vessel speed increases, the transom flow elevation progressively deviates from the static condition. In the absence of viscosity, potential theory is not able to adequately capture this process. Without a priori information regarding the transom flow elevation, potential flow calculations either under or over-predict the resistance. The under-prediction results from placement of the wake sheet at the static condition waterline, and over-prediction results from placement of the wake sheet at the transom/keel intersection (the fully ventilated condition). This paper expands the investigation of transom flow elevations by experimentally measuring the deflection of the flow from the static condition for five different transom configurations ranging from round bilge to deep-vee sections. The models use a common forebody of the vessel. The models were effectively fixed in sinkage and trim. High definition video was used to capture the flow elevations for a range of speeds. This paper presents the findings in terms of the transom Froude number and ventilation factors, and makes comparisons to prior empirical equations. Model data is also provided.

scholarly journals Predicting forest stand variables from airborne LiDAR data using a tree detection method in Central European forests

2019 ◽  
Vol 65 (3-4) ◽  
pp. 191-197 ◽  
Author(s):  
Ivan Sačkov ◽  
Ľubomír Scheer ◽  
Tomáš Bucha
Keyword(s):  
Accuracy Assessment ◽  
A Priori ◽  
Forest Stand ◽  
Airborne Lidar ◽  
Individual Tree ◽  
Tree Detection ◽  
Detection Approach ◽  
Mean Diameter ◽  
Priori Information ◽  
The Individual

Abstract In this study, the individual tree detection approach (ITD) was used to estimate forest stand variables, such as mean height, mean diameter, and total volume. Specifically, we applied the multisource-based method implemented in reFLex software (National Forest Centre, Slovakia) which uses all the information contained in the original point cloud and a priori information. For the accuracy assessment, four reference forest stands with different types of species mixture and the area of 7.5 ha were selected and measured. Furthermore, independent measurements of 1 372 trees were made for the construction of allometric models. The author’s ITD-based method provided slightly more accurate estimations for stands with substantial or moderate dominance of coniferous trees. However, no statistically significant effect of species mix on the overall accuracy was confirmed (p < 0.05). The root mean square error did not exceed 1.9 m for mean height, 3.0 cm for mean diameter, and 12.88 m3 ha−1 for total volume.

Innovative Approach to Information Search by Example of a Patent Analysis of an Important Substitution Plan

2020 ◽  
pp. 143-157
Author(s):  
Maria A. Milkova
Keyword(s):  
Information Search ◽  
Topic Modeling ◽  
Cognitive Biases ◽  
A Priori ◽  
Import Substitution ◽  
Innovative Approach ◽  
Iterative Search ◽  
Comprehensive Picture ◽  
Priori Information ◽  
Selection Of

Nowadays the process of information accumulation is so rapid that the concept of the usual iterative search requires revision. Being in the world of oversaturated information in order to comprehensively cover and analyze the problem under study, it is necessary to make high demands on the search methods. An innovative approach to search should flexibly take into account the large amount of already accumulated knowledge and a priori requirements for results. The results, in turn, should immediately provide a roadmap of the direction being studied with the possibility of as much detail as possible. The approach to search based on topic modeling, the so-called topic search, allows you to take into account all these requirements and thereby streamline the nature of working with information, increase the efficiency of knowledge production, avoid cognitive biases in the perception of information, which is important both on micro and macro level. In order to demonstrate an example of applying topic search, the article considers the task of analyzing an import substitution program based on patent data. The program includes plans for 22 industries and contains more than 1,500 products and technologies for the proposed import substitution. The use of patent search based on topic modeling allows to search immediately by the blocks of a priori information – terms of industrial plans for import substitution and at the output get a selection of relevant documents for each of the industries. This approach allows not only to provide a comprehensive picture of the effectiveness of the program as a whole, but also to visually obtain more detailed information about which groups of products and technologies have been patented.

scholarly journals Computational Method for Wavefront Sensing Based on Transport-Of-Intensity Equation

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 177
Author(s):  
Iliya Gritsenko ◽  
Michael Kovalev ◽  
George Krasin ◽  
Matvey Konoplyov ◽  
Nikita Stsepuro
Keyword(s):  
A Priori ◽  
Spherical Wave ◽  
Computational Method ◽  
Optical Systems ◽  
Radius Of Curvature ◽  
Imaging Method ◽  
Wavefront Sensing ◽  
Phase Imaging ◽  
Transport Of Intensity Equation ◽  
Priori Information

Recently the transport-of-intensity equation as a phase imaging method turned out as an effective microscopy method that does not require the use of high-resolution optical systems and a priori information about the object. In this paper we propose a mathematical model that adapts the transport-of-intensity equation for the purpose of wavefront sensing of the given light wave. The analysis of the influence of the longitudinal displacement z and the step between intensity distributions measurements on the error in determining the wavefront radius of curvature of a spherical wave is carried out. The proposed method is compared with the traditional Shack–Hartmann method and the method based on computer-generated Fourier holograms. Numerical simulation showed that the proposed method allows measurement of the wavefront radius of curvature with radius of 40 mm and with accuracy of ~200 μm.

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