scholarly journals FEASIBILITY OF SMARTPHONE BASED PHOTOGRAMMETRIC POINT CLOUDS FOR THE GENERATION OF ACCESSIBILITY MAPS

2018 ◽  
Vol XLII-2 ◽  
pp. 35-41 ◽  
Author(s):  
E. Angelats ◽  
M. E. Parés ◽  
P. Kumar
Keyword(s):  
Feasible Solution ◽  
Image Acquisition ◽  
Point Clouds ◽  
Test Cases ◽  
Public Parks ◽  
Real Situation ◽  
Starting Point ◽  
Smartphone Technology ◽  
Near Term ◽  
Reduced Mobility

Accessible cities with accessible services are an old claim of people with reduced mobility. But this demand is still far away of becoming a reality as lot of work is required to be done yet. First step towards accessible cities is to know about real situation of the cities and its pavement infrastructure. Detailed maps or databases on street slopes, access to sidewalks, mobility in public parks and gardens, etc. are required. In this paper, we propose to use smartphone based photogrammetric point clouds, as a starting point to create accessible maps or databases. This paper analyses the performance of these point clouds and the complexity of the image acquisition procedure required to obtain them. The paper proves, through two test cases, that smartphone technology is an economical and feasible solution to get the required information, which is quite often seek by city planners to generate accessible maps. The proposed approach paves the way to generate, in a near term, accessibility maps through the use of point clouds derived from crowdsourced smartphone imagery.

scholarly journals PEDESTRIAN PATHFINDING IN URBAN ENVIRONMENTS: PRELIMINARY RESULTS

2017 ◽  
Vol IV-5/W1 ◽  
pp. 35-41 ◽  
Author(s):  
G. López-Pazos ◽  
J. Balado ◽  
L. Díaz-Vilariño ◽  
P. Arias ◽  
M. Scaioni
Keyword(s):  
Path Planning ◽  
Spatial Information ◽  
Point Clouds ◽  
Urban Environments ◽  
Dijkstra Algorithm ◽  
Starting Point ◽  
Outdoor Environments ◽  
Main Components ◽  
Representative Points ◽  
Reduced Mobility

With the rise of urban population, many initiatives are focused upon the <i>smart city</i> concept, in which mobility of citizens arises as one of the main components. Updated and detailed spatial information of outdoor environments is needed to accurate path planning for pedestrians, especially for people with reduced mobility, in which physical barriers should be considered. This work presents a methodology to use point clouds to direct path planning. The starting point is a classified point cloud in which ground elements have been previously classified as roads, sidewalks, crosswalks, curbs and stairs. The remaining points compose the obstacle class. The methodology starts by individualizing ground elements and simplifying them into representative points, which are used as nodes in the graph creation. The region of influence of obstacles is used to refine the graph. Edges of the graph are weighted according to distance between nodes and according to their accessibility for wheelchairs. As a result, we obtain a very accurate graph representing the as-built environment. The methodology has been tested in a couple of real case studies and Dijkstra algorithm was used to pathfinding. The resulting paths represent the optimal according to motor skills and safety.

scholarly journals Efficiency of Commercial Banking in Developing Countries

Mathematics ◽  
2021 ◽  
Vol 9 (14) ◽  
pp. 1597
Author(s):  
Violeta Cvetkoska ◽  
Katerina Fotova Čiković ◽  
Marija Tasheva
Keyword(s):  
Developing Countries ◽  
Commercial Banks ◽  
Feasible Solution ◽  
Banking System ◽  
Efficiency Score ◽  
Commercial Banking ◽  
Real Situation ◽  
Super Efficiency ◽  
Bank Management ◽  
The Stability

The aim of this paper is to evaluate the relative efficiency of commercial banks in three developing countries in Europe (North Macedonia, Serbia, and Croatia) in the period from 2015 to 2019, and to provide targets for improvement for the inefficient banks by using DEA. The variables are selected under the income-based approach. Based on the output-oriented BCC model, unusual results are obtained for a few commercial banks in each country, that is, they are BCC relative efficient, which is contrary to the real situation. In order to identify outliers that can affect the efficiency results, a super-efficiency procedure is applied so that banks with a super-efficiency score higher than 1.2 (outliers) or for which a feasible solution was not found are considered in detail and removed, and then the output-oriented BCC model is rerun. Based on the obtained results, the Macedonian commercial banking system shows the highest efficiency (91.1%), followed by the Croatian (90.9%) and the Serbian (81.9%) banking system. The estimated targets for improvement of the inefficient commercial banks could help their top bank management in better resource allocation and making fact-based and faster decisions by which they can improve the operation of the banks they lead and contribute to the stability of the financial system.

scholarly journals Automated Measurement of Heart Girth for Pigs Using Two Kinect Depth Sensors

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3848
Author(s):  
Xinyue Zhang ◽  
Gang Liu ◽  
Ling Jing ◽  
Siyao Chen
Keyword(s):  
Mirror Symmetry ◽  
Point Cloud ◽  
Point Clouds ◽  
Depth Image ◽  
View Point ◽  
Important Indicator ◽  
Depth Sensors ◽  
Starting Point ◽  
Feature Based ◽  
Girth Measurement

The heart girth parameter is an important indicator reflecting the growth and development of pigs that provides critical guidance for the optimization of healthy pig breeding. To overcome the heavy workloads and poor adaptability of traditional measurement methods currently used in pig breeding, this paper proposes an automated pig heart girth measurement method using two Kinect depth sensors. First, a two-view pig depth image acquisition platform is established for data collection; the two-view point clouds after preprocessing are registered and fused by feature-based improved 4-Point Congruent Set (4PCS) method. Second, the fused point cloud is pose-normalized, and the axillary contour is used to automatically extract the heart girth measurement point. Finally, this point is taken as the starting point to intercept the circumferential perpendicular to the ground from the pig point cloud, and the complete heart girth point cloud is obtained by mirror symmetry. The heart girth is measured along this point cloud using the shortest path method. Using the proposed method, experiments were conducted on two-view data from 26 live pigs. The results showed that the heart girth measurement absolute errors were all less than 4.19 cm, and the average relative error was 2.14%, which indicating a high accuracy and efficiency of this method.

User-Driven Computer-Assisted Reverse Engineering of Editable CAD Assembly Models

2021 ◽  
pp. 1-16
Author(s):  
Ghazanfar Ali Shah ◽  
Jean-Philippe Pernot ◽  
Arnaud Polette ◽  
Franca Giannini ◽  
Marina Monti
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Point Clouds ◽  
Geometric Constraints ◽  
Computer Assisted ◽  
Reconstruction Process ◽  
Mechanical Parts ◽  
Starting Point ◽  
Cad Models ◽  
Incomplete Datasets

Abstract This paper introduces a novel reverse engineering technique for the reconstruction of editable CAD models of mechanical parts' assemblies. The input is a point cloud of a mechanical parts' assembly that has been acquired as a whole, i.e. without disassembling it prior to its digitization. The proposed framework allows for the reconstruction of the parametric CAD assembly model through a multi-step reconstruction and fitting approach. It is modular and it supports various exploitation scenarios depending on the available data and starting point. It also handles incomplete datasets. The reconstruction process starts from roughly sketched and parameterized geometries (i.e 2D sketches, 3D parts or assemblies) that are then used as input of a simulated annealing-based fitting algorithm, which minimizes the deviation between the point cloud and the reconstructed geometries. The coherence of the CAD models is maintained by a CAD modeler that performs the updates and satisfies the geometric constraints as the fitting process goes on. The optimization process leverages a two-level filtering technique able to capture and manage the boundaries of the geometries inside the overall point cloud in order to allow for local fitting and interfaces detection. It is a user-driven approach where the user decides what are the most suitable steps and sequence to operate. It has been tested and validated on both real scanned point clouds and as-scanned virtually generated point clouds incorporating several artifacts that would appear with real acquisition devices.

scholarly journals A metaheuristic penalty approach for the starting point in nonlinear programming

2020 ◽  
Vol 54 (2) ◽  
pp. 451-469
Author(s):  
David R. Penas ◽  
Marcos Raydan
Keyword(s):  
Nonlinear Programming ◽  
Feasible Solution ◽  
Packing Problem ◽  
Merit Function ◽  
Test Problems ◽  
Huge Amount ◽  
Novel Approach ◽  
Starting Point ◽  
Metaheuristic Techniques ◽  
Optimization Schemes

Solving nonlinear programming problems usually involve difficulties to obtain a starting point that produces convergence to a local feasible solution, for which the objective function value is sufficiently good. A novel approach is proposed, combining metaheuristic techniques with modern deterministic optimization schemes, with the aim to solve a sequence of penalized related problems to generate convenient starting points. The metaheuristic ideas are used to choose the penalty parameters associated with the constraints, and for each set of penalty parameters a deterministic scheme is used to evaluate a properly chosen metaheuristic merit function. Based on this starting-point approach, we describe two different strategies for solving the nonlinear programming problem. We illustrate the properties of the combined schemes on three nonlinear programming benchmark-test problems, and also on the well-known and hard-to-solve disk-packing problem, that possesses a huge amount of local-nonglobal solutions, obtaining encouraging results both in terms of optimality and feasibility.

Effects of Wind Environment on Propeller Performance of Multirotor Drone in Hover

2019 ◽  
Author(s):  
Motonao Murakami ◽  
Hiroyuki Abe ◽  
Hikaru Aono ◽  
Hitoshi Ishikawa
Keyword(s):  
Flow Velocity ◽  
Figure Of Merit ◽  
Cross Flow ◽  
Force Transducer ◽  
Test Cases ◽  
Torque Measurement ◽  
Propeller Design ◽  
Starting Point ◽  
Cross Flow Velocity ◽  
Propeller Performance

Abstract The purpose of this study is to understand the effect of cross flow and fluctuating flow on the propeller performance of MAV. This study especially has focused on the propeller performance during hovering flight under several cross flow velocity in actual flight conditions. We investigated four test cases of propellers with different starting point of design. The thrust and the torque of each propeller were experimentally measured by using the force transducer in wind tunnel. Figure of Merit (FM) of each propeller were evaluated based on the thrust and the torque measurement. The results showed that low cross flow velocity reduced FM. However, high cross flow velocity improved FM. Fluctuating flow yielded the change of FM with time. Furthermore, it was found that the starting point of the propeller design had a great effect on FM under wind environments.

scholarly journals Women´s images in «Telva», a women´s magazine

Comunicar ◽  
2006 ◽  
Vol 13 (26) ◽  
pp. 149-154 ◽  
Author(s):  
Meritxell Roca-i-Sales
Keyword(s):  
Real Situation ◽  
The Real ◽  
Social Stereotypes ◽  
Starting Point ◽  
The Press

Taking the field of specialized press as a starting point, this study aims at determining and understanding the mechanisms of representation employed by the press for women, also known as women´s magazines and women´s pages. Stereotypes, understood as a representation tool, determine the actual models and icones for women in women´s magazines, and besides, permit comparison with the real situation of the contemporary Spanish woman. This paper also argues about the correspondence between media stereotypes and social stereotypes used in the interviews published by «Telva» in almost 40 years. Tomando como punto de partida el campo de la prensa especializada, este estudio trata de determinar y de estudiar los mecanismos de representación usados por la prensa para mujeres o prensa femenina. Los estereotipos, entendidos como una herramienta de representación, determinan los actuales modelos e iconos de género en la prensa femenina y, a su vez, permiten la comparación con la situación real de la mujer española contemporánea. Este artículo también versa sobre la correspondencia entre los estereotipos mediáticos y los estereotipos sociales usados en las entrevistas publicadas en «Telva» durante casi 40 años.

New visibility-based path-planning approach for covert robotic navigation

Robotica ◽  
2006 ◽  
Vol 24 (6) ◽  
pp. 759-773 ◽  
Author(s):  
Mohamed S. Marzouqi ◽  
Ray A. Jarvis
Keyword(s):  
Path Planning ◽  
Test Cases ◽  
Cluttered Environment ◽  
Environment Map ◽  
Descent Trajectory ◽  
Physical Experiments ◽  
Planning Approach ◽  
Starting Point ◽  
Visibility Distance ◽  
Planning Problems

A new promising approach for visibility-sensitive path-planning problems is presented. The paper focuses on covert navigation where a mobile robot needs to plan a stealthy path to approach a designated destination in a cluttered environment. The aim is to minimize the robot's exposure to hostile sentries within the same environment. The approach can be adapted to work with different levels of initial knowledge the robot may have about both the environment map and the sentries' locations. The approach depends on estimating a cost value at each free-space location that presents the risk of being seen by any sentry. Based on the distance transform algorithm methodology, the minimum visibility–distance cost to a goal is calculated at each cell in the grid-based environment map. Moving along the steepest descent trajectory from any starting point generates an optimal covert path to a goal. The approach has been evaluated with both simulated and physical experiments. A number of test cases are presented. In each case, a path with considerable covertness, compared to a short path to the same destination, is generated. In addition to covert navigation, the approach is introduced briefly as a potential solution for other visibility-based path-planning problems.

scholarly journals On the Simplex Algorithm Initializing

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Nebojša V. Stojković ◽  
Predrag S. Stanimirović ◽  
Marko D. Petković ◽  
Danka S. Milojković
Keyword(s):  
Feasible Solution ◽  
Numerical Test ◽  
Optimal Solution ◽  
Simplex Algorithm ◽  
Initial Solution ◽  
Test Problems ◽  
Basic Feasible Solution ◽  
Cpu Time ◽  
Starting Point ◽  
Number Of Iterations

This paper discusses the importance of starting point in the simplex algorithm. Three different methods for finding a basic feasible solution are compared throughout performed numerical test examples. We show that our two methods on theNetlibtest problems have better performances than the classical algorithm for finding initial solution. The comparison of the introduced optimization softwares is based on the number of iterative steps and on the required CPU time. It is pointed out that on average it takes more iterations to determine the starting point than the number of iterations required by the simplex algorithm to find the optimal solution.

A numerical investigation of flux-limited approximations for pedestrian dynamics

2017 ◽  
Vol 27 (06) ◽  
pp. 1177-1197 ◽  
Author(s):  
L. Müller ◽  
A. Meurer ◽  
F. Schneider ◽  
A. Klar
Keyword(s):  
Eikonal Equation ◽  
Particle System ◽  
Mean Field ◽  
Test Cases ◽  
Pedestrian Flow ◽  
Mean Velocity ◽  
Pedestrian Dynamics ◽  
Interacting Particle ◽  
Starting Point ◽  
Scalar Equations

A hierarchy of models for pedestrian flow with fixed speed is numerically investigated. The starting point is a microscopic model based on a stochastic interacting particle system coupled to an eikonal equation. Starting from this model a nonlocal and nonlinear flux-limited maximum-entropy equation for density and mean velocity is derived via a mean field kinetic equation. Finally, associated classical scalar equations for the density are considered for comparison. These models are compared to each other for different test cases showing the superiority of the flux-limited approach, in particular for situations with smaller values of the stochastic noise.

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