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Enriching the Restoration and Utilization of Architectural Heritage Sites: An Augmented Reality Approach (Makkah Al-Mukarramah as a case study)

Research Authors
Reffat, R. M.
Research Journal
Proceedings of the National Built Heritage Forum, Research & heritage: Research Papers on Architectural Heritage, Saudi Commission for Tourism and Antiquities, Jeddah, Saudi Arabia
Research Member
Research Pages
PP. 115-129
Research Year
2011

A Framework for Developing an intelligent Computational Real-Time Virtual Environment Model for Efficient Crowd Management in Hajj (Pilot Case: Nafrah of Pilgrims from Arafat)

Research Authors
Reffat, R. M.
Research Journal
Proceedings Book of the First Forum of Traffic Safety, College of Architecture and Planning, Dammam, Saudi Arabia
Research Member
Research Pages
PP.150-161.
Research Year
2011

CAAD| Innovation | Practice

Research Authors
Sidaw, B., Reffat, R. M., Elmarsafawy, H., El-Wageeh, S. and Bennadji, A. (Eds.)
Research Journal
Proceedings of the 5th International Conference of ASCAAD (Arab Society of Computer Aided Architectural Design), The Kingdom University, Manama, Bahrain,
Research Member
Research Vol
ISBN 978-99958-2-063-3.
Research Year
2012

On the design of multiband transmission functions synthesized by one wave digital lattice structure

Research Abstract
In this contribution, the design of multiband transmission functions is considered. Independent and arbitrary number of bands can be designed. Moreover, the whole transmission function is synthesized by one wave digital lattice structure. The approximation process starts by extracting the scattering matrix properties of multiband reference lattice structures. Consequently, the approximation problem reduces to generating a polynomial Q of degree n, which is the degree of the filter. The degree n is depending on the number of the designed bands. Hence, if the number of bands is even, n will be odd, and if the number of bands is odd, n will be even. The polynomial Q will approximate the difference phase function of the two branch polynomials. It is composed of two subpolynomials, one of them is Hurwitz and the other is anti-Hurwitz. The degrees of these subpolynomials differ by odd number if the number of bands is even and differ by even number if the number of bands is odd. Q is generated according to iterative interpolation and using explicit recursive formulas. After obtaining Q, the two subpolynomials are calculated and the two branch all-pass functions are constructed. Consequently, the filter is synthesized in the digital frequency domain. The method is applied through an illustrative example. Copyright © 2011 John Wiley & Sons, Ltd.
Research Authors
M. Yaseen
Research Department
Research Journal
INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS
Research Rank
2
Research Year
2013

On the State-Space Realization of LPV Input-Output Models: Practical Approaches

Research Abstract
A common problem in the context of linear parameter- varying (LPV) systems is how input-output (IO) models can be efficiently realized in terms of state-space (SS) representations. The problem originates from the fact that in the LPV literature discrete-time identification and modeling of LPV systems is often accomplished via IO model structures. However, to utilize these LPV-IO models for control synthesis, commonly it is required to transform them into an equivalent SS form. In general, such a transformation is complicated due to the phenomenon of dynamic dependence (dependence of the resulting representation on time-shifted versions of the scheduling signal). This conversion problem is revisited and practically applicable approaches are suggested which result in discrete-time SS representations that have only static dependence (dependence on the instantaneous value of the scheduling signal). To circumvent complexity, a criterion is also established to decide when an linear-time invariant (LTI)-type of realization approach can be used without introducing significant approximation error. To reduce the order of the resulting SS realization, an LPV Ho-Kalman-type of model reduction approach is introduced, which, besides its simplicity, is capable of reducing even non-stable plants. The proposed approaches are illustrated by application oriented examples.
Research Authors
Roland Tóth, Hossam Seddik Abbas, and Herbert Werner
Research Department
Research Journal
IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
Research Pages
PP.139-153
Research Vol
VOL. 20, NO. 1
Research Year
2012

Low-complexitylinearparameter-varyingmodelingandcontrol of aroboticmanipulator

Research Abstract
In thispaper,apracticalprocedureforlinearparameter-varying(LPV)modelingandidentificationof a roboticmanipulatorispresented,whichleadstoasuccessfulexperimentalimplementationofan LPV gain-scheduledcontroller.Anonlineardynamicmodelofatwo-degrees-of-freedommanipulator containingallimportanttermsisobtainedandunknownparameterswhicharerequiredtoconstructan LPV modelareidentified.Animportanttoolforobtainingamodelofcomplexitylowenoughtobe suitableforcontrollersynthesisistheprinciple-component-analysis-basedtechniqueofparameterset mapping.Sincetheresultingquasi-LPVmodelhasalargenumberofaffineschedulingparametersanda large overbounding,parametersetmappingisusedtoreduceconservatismandcomplexityin controllerdesignbyfindingtighterparameterregionswithfewerschedulingparameters.Asufficient a posteriori condition isderivedtoassessthestabilityoftheresultingclosed-loopsystem.Toevaluate the applicabilityandefficiencyoftheapproximatedmodel,apolytopicLPVgain-scheduledcontrolleris synthesizedandimplementedexperimentallyonanindustrialrobotforatrajectorytrackingtask.The experimentalresultsillustratethatthedesignedLPVcontrolleroutperformsanindependentjointPD controllerintermsoftrackingperformanceandachievesaslightlybetteraccuracythanamodel-based inverse dynamicscontroller,whilehavingasimplerstructure.Moreover,itisshownthattheLPV controllerismorerobustagainstdynamicparameteruncertainty.
Research Authors
Seyed MahdiHashemi , HossamSeddikAbbas , HerbertWerner
Research Department
Research Journal
Control EngineeringPractice
Research Pages
PP.248-257
Research Year
2012

Analysis and Modeling of Traffic Accidents Causes for Main Rural Roads in Egypt

Research Abstract
The purpose of this research is to investigate traffic accidents causes and major factors that would be the main reasons for accidents, and to develop a model for accidents on Main National Egyptian Rural Roads. Accidents models would help decision makers to develop the road network to be more safe and minimize the accidents rate. Models were calibrated using accidents records data collected from 19 rural roads from previous studies, and 7 rural roads from filed surveys in Assiut region, "General Authority for Roads & Bridges". The data was splittied in two different types of road sections in location and engineering properties, namely; "Agriculture roads undivided sections", "Desert roads undivided sections”. Simple, Stepwise, and multiple regression analysis have been used to find the effect of each parameter on the accident rate value. Several functional forms are explored and tested in the calibration process. Before proceeding to the development of models, ANOVA statistical tests are conducted to establish whether there are any significant differences in the data used for models’ calibration as a result of differences among the considered roads. The results indicated that exponential model formula represents the highest correlation for all road types .Average daily traffic (ADT), Shoulder width, pedestrian crossing and percentage of trucks have highest effects of traffic accidents on agriculture roads undivided sections, Shoulder width, Radius of horizontal curves and percentage of trucks have the highest effects of traffic accidents on desert roads undivided sections.
Research Authors
A. M. ismail, H. Y. Ahmed, M. A. owais
Research Department
Research Journal
JES
Research Member
Research Rank
2
Research Vol
38(4)
Research Year
2010

Analysis and Modeling of Traffic Accidents Causes for Main Rural Roads in Egypt

Research Abstract
The purpose of this research is to investigate traffic accidents causes and major factors that would be the main reasons for accidents, and to develop a model for accidents on Main National Egyptian Rural Roads. Accidents models would help decision makers to develop the road network to be more safe and minimize the accidents rate. Models were calibrated using accidents records data collected from 19 rural roads from previous studies, and 7 rural roads from filed surveys in Assiut region, "General Authority for Roads & Bridges". The data was splittied in two different types of road sections in location and engineering properties, namely; "Agriculture roads undivided sections", "Desert roads undivided sections”. Simple, Stepwise, and multiple regression analysis have been used to find the effect of each parameter on the accident rate value. Several functional forms are explored and tested in the calibration process. Before proceeding to the development of models, ANOVA statistical tests are conducted to establish whether there are any significant differences in the data used for models’ calibration as a result of differences among the considered roads. The results indicated that exponential model formula represents the highest correlation for all road types .Average daily traffic (ADT), Shoulder width, pedestrian crossing and percentage of trucks have highest effects of traffic accidents on agriculture roads undivided sections, Shoulder width, Radius of horizontal curves and percentage of trucks have the highest effects of traffic accidents on desert roads undivided sections.
Research Authors
A. M. ismail, H. Y. Ahmed, M. A. owais
Research Department
Research Journal
JES
Research Member
Research Rank
2
Research Vol
38(4)
Research Year
2010
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