Preferred Language
Articles
/
bRZFBocBVTCNdQwCCC9i
Calibrating Range Measurements of Lidars Using Fixed Landmarks in Unknown Positions
...Show More Authors

We consider the problem of calibrating range measurements of a Light Detection and Ranging (lidar) sensor that is dealing with the sensor nonlinearity and heteroskedastic, range-dependent, measurement error. We solved the calibration problem without using additional hardware, but rather exploiting assumptions on the environment surrounding the sensor during the calibration procedure. More specifically we consider the assumption of calibrating the sensor by placing it in an environment so that its measurements lie in a 2D plane that is parallel to the ground. Then, its measurements come from fixed objects that develop orthogonally w.r.t. the ground, so that they may be considered as fixed points in an inertial reference frame. Moreover, we consider the intuition that moving the distance sensor within this environment implies that its measurements should be such that the relative distances and angles among the fixed points above remain the same. We thus exploit this intuition to cast the sensor calibration problem as making its measurements comply with this assumption that “fixed features shall have fixed relative distances and angles”. The resulting calibration procedure does thus not need to use additional (typically expensive) equipment, nor deploy special hardware. As for the proposed estimation strategies, from a mathematical perspective we consider models that lead to analytically solvable equations, so to enable deployment in embedded systems. Besides proposing the estimators we moreover analyze their statistical performance both in simulation and with field tests. We report the dependency of the MSE performance of the calibration procedure as a function of the sensor noise levels, and observe that in field tests the approach can lead to a tenfold improvement in the accuracy of the raw measurements.

Scopus Clarivate Crossref
View Publication
Publication Date
Sun Dec 19 2021
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
FIRST PHOTOGRAPHIC RECORDS AND NEW DISTRIBUTION RANGE OF THE ENDANGERED LONG-TAILED NESOKIA NESOKIA BUNNII (KHAJURIA, 1981)
...Show More Authors

In the 1970s, the world knew the long-tailed nesokia Nesokia bunnii (Khajuria, 1981) (Rodentia, Muridae) from the Mesopotamian marshes of Garden of Eden in Southern Iraq. This distinct rodent was known from only five voucher specimens collected at the confluence of Tigris and Euphrates Rivers in southern Iraq while its occurrence in Southwestern Iran had
never been reported. In the 1990s, a large extent of its natural habitat was catastrophically desiccated and the animal was last seen in the 1970s. Since then, the status of this elusive rodent was shrouded in mystery. In 2007, an extraordinary photograph of a carcass of this species came to the light from Hawizeh Marsh which was interpreted as concrete evidence of the species’ pers

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Thu Jul 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Simulation and Analysis the Attenuation Effect of Atmospheric Layers on a Laser Beam Within the Visible Range
...Show More Authors

Abstract: The power and the size of the final spot of the laser beam reaching the target are very important requirements in most of the laser applications and fields such as medical, military, and scientific, so studying laser propagation in the atmosphere is a very important topic. The propagation of the laser beam through the atmosphere is subject to several attenuation processes that deplete the power and expand the beam. Through the simulation results of the free electron laser within the visible region of the electromagnetic spectrum (400-700nm), it was found that the attenuation increases with decreasing wavelength. Laser propagation in the presence of rain and snow leads to a very large l

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Engineering
Experimental Evaluation of the Performance of One-Axis Daily Tracking and Fixed PV Module in Baghdad, Iraq
...Show More Authors

An attempt was made to evaluate the PV performance of one-axis daily tracking and fixed system for Baghdad, Iraq. Two experimental simulations were conducted on a PV module for that purpose. Measurements included incident solar radiation, load voltage and load current. The first experiment was carried out for six months of winter half of year to simulate the one-axis daily tracking. The azimuth angle was due south while the tilt angle was being set to optimum according to each day of simulation. The second experiment was done at one day to simulate the PV module of fixed angles. It is found that there is a significant power gain of 29.6% for the tracking system in respect to the fixed one. The one-axis daily tracking was much more effect

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Sep 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Radon-Distribution Measurements With CR-39, LR-115 And CN-85 DeteCtors
...Show More Authors

The  aim  of this  work  is to determine radon and  its decay  product concentratiQns  indoor   and  outdoor   in  different   areas   in  north   and middle  are·a of Iraq by using nuclear  trak detectors  , CR-39  , CN- 85 andLR-115.                        -

For   CR-39    detectors   ,   the   highest    radon    concentration  was

(64.07Bq/m3)indoor and  (52.4  Bq/m3)

outdoor &n

... Show More
View Publication Preview PDF
Publication Date
Mon May 20 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Convergence Comparison of two Schemes for Common Fixed Points with an Application
...Show More Authors

      Some cases of common fixed point theory for classes of generalized nonexpansive maps are studied. Also, we show that the Picard-Mann scheme can be employed to approximate the unique solution of a mixed-type Volterra-Fredholm functional nonlinear integral equation.

View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Journal Of International Dental And Medical Research
Evaluation of selection criteria for patients indicated for fixed orthodontic appliance treatment
...Show More Authors

Scopus (1)
Scopus
Publication Date
Wed Dec 01 2021
Journal Name
Baghdad Science Journal
Some Results on Normalized Duality Mappings and Approximating Fixed Points in Convex Real Modular Spaces
...Show More Authors

  In this paper, the concept of normalized duality mapping has introduced in real convex modular spaces. Then, some of its properties have shown which allow dealing with results related to the concept of uniformly smooth convex real modular spaces. For multivalued mappings defined on these spaces, the convergence of a two-step type iterative sequence to a fixed point is proved

View Publication Preview PDF
Scopus (4)
Scopus Clarivate Crossref
Publication Date
Fri Mar 31 2017
Journal Name
Journal Of Engineering
Experimental Measurements of Viscosity and Thermal Conductivity of Single Layer Graphene Based DI-water Nanofluid
...Show More Authors

Experimental measurements of viscosity and thermal conductivity of single layer of graphene . based DI-water nanofluid are performed as a function of  concentrations (0.1-1wt%) and temperatures between (5 to 35ºC). The result reveals that the thermal conductivity of GNPs nanofluids was increased with increasing the nanoparticle weight fraction concentration and temperature, while the maximum enhancement was about 22% for concentration of 1 wt.% at
35ºC. These experimental results were compared with some theoretical models and a good agreement between Nan’s model and the experimental results was observed. The viscosity of the graphene nanofluid displays Newtonian and Non-Newtonian behaviors with respect to nanoparticles concen

... Show More
View Publication Preview PDF
Publication Date
Fri Apr 21 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees22fr
Effect of Ag doping on optical constant and hall effect measurements of SnS thin films
...Show More Authors

In this report Silver doped Tin Sulfide (SnS) thin films with ratio of (0.03) were prepared using thermal evaporation with a vacuum of 4*10-6 mbar on glass with (400) nm thickness and the sample annealing with ( 573K ). The optical constants for the wavelengths in the range (300-900) nm and Hall effect for (SnS and SnS:3% Ag) films are investigated and calculated before and after annealing at 573 K. Transition metal doped SnS thin films the regular absorption 70% in the visible region, the doping level intensification the optical band gap values from 1.5- 2 eV. Silver doped tin sulfide (SnS) its direct optical band gap. Hall Effect results of (SnS and SnS:3% Ag) films show all films were (p-type) electrical conductivity with resistivity of

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Wed Jun 01 2022
Journal Name
Journal Of Engineering
Assessment Strategies of Fixed Firefighting system in Residential Multi-Story Building for Improving Fire Safety: A Review
...Show More Authors

A fixed firefighting system is a key component of fire safeguarding and reducing fire danger. It is installed as a permanent component in a structure to protect the entire or a portion of the building and its contents. The study aims to review the previous studies that deal with the evaluation of fire safety measures and their use in resolving problems associated with fire threats in buildings. For this reason, a number of previous studies in this field were reviewed compared with the NFPA code. The findings revealed that regulatory developments over the last several decades had created an atmosphere conducive to innovation. This has resulted in a growth in the number of fixed firefighting system types now obtainable. Th

... Show More
View Publication Preview PDF
Crossref