bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix acid stimulation: What are the gaps to bridge from lab to field?
Authors: Goedeke Stefan , Gharbi Oussama , Al-Sammarraie Mohammed , Giraldo Carlos , Fakhroo Abdulrahman , Ulumuddin Bidin , Bermejo Nelson , Saqer Al-Shahwani Saqer , Cheneviere Pascal
Published: November 2013

Acidizing core flooding experiments in carbonates are typically performed in the laboratory in order to observe different physical phenomena and to design acid stimulation jobs in the field. The experiments are usually well defined in terms of mineralogy, permeability, porosity, pressure, temperature and salinity. During the tests, key parameters are analyzed such as the pore volume of acid needed to create wormholes and breakthrough as well as pressure and permeability time-evolution. In reality, the result of an acid stimulation in the field is difficult to predict because of the heterogeneous nature of carbonate formations, complexity of such reactive transport phenomenon, and more importantly the uncertainties related to subsurface well conditions. Stimulation models and numerical tools can help bridge the gap between the laboratory observations and real field applications. We utilize selected core flooding results obtained from the QP - TOTAL collaboration on acid stimulation and use these measurements as input for different acid stimulation software. Subsequently, a benchmarking of commercial and academic acid stimulation software at the well scale is performed. The main criteria for this comparison are the capacity of modeling improved acid stimulation under constant or varying pumping rates, the capability of modeling complex fluids such as chemical diverters and relative permeability modifiers and the ability to simulate different well configurations. Then, a sensitivity analysis on selected key parameters such as the dissolution model, pore volume to breakthrough and solute velocities is conducted. Finally, predictions from numerical models are compared to acid stimulation field results from literature, for Middle Eastern carbonate. We try to history match the results and we identify main areas of improvement for future development of acid stimulation software.
Environmentally-friendly smart coatings for materials protection: State of the art and future perspectives
Authors: Hamdy Makhlouf Abdel Salam
Published: November 2013

The huge economic impact of the corrosion of metallic structures is a very important issue for all modern societies. Reports on the corrosion failures of bridges, buildings, aircrafts, automobiles, and gas and oil pipelines are not unusual. It is estimated that corrosion and its consequences cost developed nations between 3% and 5% of their gross domestic product. The process involving hexavalent chromates is the most effective and most widely used conversion coatings for corrosion protection for many metals and alloys. However, the carcinogenic effect and environmental waste due to chromates are well documented. The concept of 'self-healing', 'self-repairing' or 'smart' materials has in recent years been developed experimentally in new types of manufactured materials creating a new class of multifunctional materials of self healing properties. Such properties add functionality to the materials to heal themselves automatically after mechanical, physical or chemical damages caused, for example, by scratch, impact, abrasion, erosion, friction, corrosion, wear, fire, ice, etc. The development of active corrosion protection systems for steels, Al and Mg substrates is an issue of prime importance in key industries, including petroleum, chemicals, transportation. The present work provides new insights towards the development of new protective systems with self-healing functionality. The proposed coatings characterize with the self-healing ability, ease of application at low cost and safety. When the new chromate-free surface treatments are applied prior to Fluoropolymer top coating, the coatings exceed 2000-hour salt spray tests. The approach described herein can be used in many industrial applications where active corrosion protection of materials is required.
Composition and origins of polycyclic aromatic hydrocarbons (PAHs) in the coastal sediments of Qatar
Authors: Soliman Yousria
Published: November 2013

The spatial distribution of Polycyclic Aromatic Hydrocarbons (PAHs)was investigated in sediments from 16 sites from the east coast of the Arabian Gulf of Qatar. Sixteen US-EPA priority PAHs and their alkylated homolog were determined. The highest PAHs concentrations were found in sediments inside fishing Harbors as well as at offshore locations close to an oil fields. Most inshore coastal locations showed low PAHs concentrations (95.4- 27.88 ng.g-1). Concentrations of PAHs in Qatar coastal sediments indicated that the area has low contaminate concentrations (<100 ng/g-1) except inside the fishing Harbor and offshore where moderate levels of pollution were detected (100=SPAHs=1000 ng.g-1). The spatial distribution of the concentrations of 16 parent PAHs and their alkyl homologs are presented and the possible sources of the PAHs have been elucidated using diagnostic ratios. Contaminant patterns and diagnostic ratios indicated that the PAHs were mainly from petrogenic sources, with higher contributions of pyrogenic PAHs near industrialized and urban areas.
Managing of invasive species of red palm weevil (Rhynchophorus ferrugienus)
Authors: Al-Turaihi Emad
Published: November 2013

Red palm weevil-RPW (Rhynchophorus ferrugienus Olive, Coleoptera, Curculionidae) was first observed in India in 1917 as a serious pest on date palm (Phoenix dactylifera L.). It was introduced in Arabian Gulf countries in the mid-1980s and now considered to be one of the most destructive insects on date palm. The larvae are responsible for damaging and they cause the death of palm tree. There is no data available about the loss caused by this insect. This study showed the strategies used to control invasive species of RPW. These strategies include the following methods: (1) Declare the infested area as a quarantine or isolated area prohibiting the movement of plants, persons, animals or others. (2) Eradicate invasive species as soon as it is discovered quickly and population levels remain low. (3) Mechanical control involves using machinery or fire to remove the insect. (4) Keeping potentially damaging out in the first place where it was observed. (5) Biological control involves introducing a predator or parasite in an attempt to lower the population dynamic. (6) Chemical control involves using chemical pesticides to kill all the stages. (7) The newest technology for managing invaders species of RPW is using pheromone traps.
Size-dependent elemental analysis of particulate matter pollutants in the UAE
Authors: Hamdan Nasser
Published: November 2013

We report on the study of industrial and natural aerosol pollutants in various UAE locations. Both indoor and outdoor atmospheres were sampled at residential and work places. The eventual goal of this study is to identify potential health risks of airborne pollutants. The size-dependent distributions of various elements and source apportionment of aerosol particulate matter was determined. Sampling was done using a multi-stage cascade impactor capable of sorting sizes with aerodynamic cut-off diameters ranging from 16 to .0625 micro-m in 9 steps. The samples collected on membrane filters, were studied using X-ray fluoresce (XRF), micro-XRF, Scanning Electron Microscopy (SEM), and optical microscopy. Results obtained so far show the main two sources of particulate matter pollutants are: airborne desert dust and airborne dust from building materials. Trace elements on the other hand are related to industrial pollution. Microscopy methods show that mass concentration of fine particles is considerably higher than that of coarse particles. Elemental analysis obtained with micro-XRF show that Ca, Si, Al, and Fe are present on all membranes but dominant on large cut-off membranes ( > 2 micro-m) while Si, P, Zn, S, Cu, K, and Ti are found on small cut-off membranes (< 1 micro-m). Elements appearing in trace quantities are: Zn, Fe, Cu, Br, Pb, Mn and mainly attributed to industrial pollution. It is noted that Ti, for example, is found mainly indoors possibly resulting from wall paints. On the other hand, elements such as Mg, Na, Cl, are originating from sea salts and hence are found both indoors and outdoors. Future work is underway to include complimentary methods such as ion beam techniques such as Proton Induced X-ray Emission(PIXE) and Proton Induced Gamma-ray Emission (PIGE) to identify lighter elements and synchrotron X-ray Absorption Spectroscopy( XAS) for chemical analysis.
Assessment of a SIFT-based DEM extraction approach using GEOEYE-1 satellite stereo-pairs in flood mapping of an ungauged basin
Authors: Tsanis Ioannis , Daliakopoulos Ioannis N.
Published: November 2013

A module for Digital Elevation Model (DEM) extraction from Very High Resolution (VHR) satellite stereo-pair imagery is developed and used for a flood plain mapping applications at an ungauged basin. A procedure for parallel processing of cascading image tiles is used for handling the large datasets requirements of VHR satellite imagery. The Scale-Invariant Feature Transform (SIFT) algorithm is used to detect potentially homogeneous features in the members of the stereo-pair. The resulting feature pairs are filtered using the RANdom SAmple Consensus (RANSAC) algorithm by using a variable distance threshold. Finally, homogeneous pairs are converted to point cloud ground coordinates for DEM generation. A 0.5 m × 0.5 m Geoeye-1 stereo-pair acquired over an area of 25 km2 in the island of Crete, Greece is used as input for the module. The resulting 1.5 m × 1.5 m DEM has superior detail over previously developed 2 m and 5 m DEMs that are used as reference, and yields a Root Mean Square Error (RMSE) of about 1 m compared to ground truth measurements. 1D and 2D hydraulic models are used to simulate the rainfall-runoff characteristics and the flood wave kinematics, of the flash flood event of October 17th, 2006 that occurred in Almirida basin, by using the 1.5 m VHR-DEM as an input. Results show that the hydraulic simulation based on the generated VHR-DEM, calibrated and validated via field data, produces an accurate extent and water level of the flooded area, proving that Remote Sensing stereo reconstruction is a promising alternative to the traditional survey methods in flood mapping applications.
Techniques for isolation and purification of marine microalgae from the coast of Qatar
Authors: Bacha Sarah
Published: November 2013

Background Unicellular algae, at the base of aquatic food chains, are particularly sensitive to a wide range of pollutants and are therefore important in toxicity tests for hazard assessment and aquatic environment protection. EMRQ (ExxonMobil Research Qatar) in collaboration with ESC (Environmental Studies Center, Qatar) and the Ministry of Environment, Qatar, is investigating the impact of common toxicants on the performance (growth and survival) of microalgae found in the coastal regions of Qatar. The present work was undertaken to establish the techniques for the isolation and purification of four microalgal species in order to culture them under specific laboratory conditions. Objectives * To conduct laboratory experiments to determine the most appropriate method for the isolation and purification of different microalgal species found in the coastal waters of Qatar. * To establish axenic cultures of the purified unialgae at EMRQ. * To conduct chronic toxicity tests of certain toxicants commonly found in seawaters on the microalgal species isolated and cultured. Methodology Different phytoplankton species were identified and isolated from freshly collected seawater from various sites around the coast of Qatar. * Unialgal isolates were obtained by four major techniques: streaking, spraying, serial dilution, and single-cell isolations by capillary method * Purifications of the unialgal samples to obtain axenic cultures were realized by micropipette washing technique followed by streak-plating technique and using antibiotics. Results The isolation by streak-plating showed to be the most suitable method for the small non motile microalgal species (<10mm) that grow well on a substrate. The serial-dilution technique looked to be ideal for all types of microalgae, specially the small motile species. The isolation by picking-up a single cell was found to be more adequate for the large phytoplankton species. A mixture of antibiotics showed to be more effective than the use of any individual antibiotic. Conclusion and Discussion A few microalgae have been successfully isolated and purified using the techniques mentioned above. The streak-plating method seems to be the most promising technique for the species found in Qatari waters. At present we are doing experiments to determine the specific biological and physical conditions for culturing the purified microalgae species for optimum growth at EMRQ. The purpose of obtaining axenic cultures of phytoplankton is to study the impact of specific toxicants on these species by performing chronic toxicity tests.
Regional hydrodynamic modelling for environmental impact assessment due to desalination plants of Qatar
Authors: Qiblawey Hazim
Published: November 2013

Desalination of Arabian Gulf is intense. But the environmental issues as not yet addressed on regional scale. Key issues are the concentrate and chemical discharges to the marine environment, the emissions of air pollutants and the energy demand of the processes. For sustainable use of desalination technology, the impacts of each major desalination project should be investigated and mitigated by means of a project- and location-specific environmental impact assessment (EIA) study and long term impact based on the global climate change. In this context, this study is aimed to address the impact of desalination with global climate change on a regional scale. A hydrodynamic model covering the Arabian Gulf driven by Arabian Sea tidal levels was setup to establish the hydrodynamic condition of the Gulf. The model was driven with level and velocity components from the global tidal model TPXO. The results are compared with the predicted tides from ATT (Admiralty Tide Table) of standard ports as well as secondary ports and available tidal streams at the Diamond Points. This is an attempt to make a calibrated working model that drive the coastal Qatar hydrodynamic model which ultimately drive dispersion model with long term climate parameters to assess the impact of climate change on the dispersion of concentrated brine. The model validity compares well with the ATT predicted tides and tidal steams of Admiralty Chart No. 3787. The regional model is shows very good agreement on predicted tides along the regional model and velocity vectors at the admiralty diamonds on chart. Free surface of the model was compared with the ATT predicted tides at ports Mesaieed, Al Wakra, Doh, ras laffan, Jabal Al Fuwarit, mina salman, MINA Saud, Khowr E Musa Bar, Bharder E Shaid Rajai and Port sultan Qaboos. As the bathymetry and coastline near south east part of Qatar were not well resolved, model comparison could not be carried out at this site. The model was run with an updated bathymetry from the navigational charts to resolve the tides of coastal Qatar. Except at Al Wakra, the predicted levels were in good agreement with the model results. Tidal streams on BHO Chart No. 3787 were also compared against the model velocities during spring and neap stages of the tide. The velocity values obtained from Admiralty Diamonds during spring and neap tides are based on very short-term observations. Since the estimates are based on data collected during different periods, it could be used as an estimate of the tidal currents only in the absence of other data. Comparisons between model current speeds and BHO chart values of tidal streams indicate good matching during spring tides while during neap tides the model over-estimates the current speeds at all Diamond points. Variations in tidal current velocities between peak flood and peak ebb at different parts of the gulf convincingly indicate diurnal reversal of the tidal streams.
Five-Phase Sensorless Induction Motor Drives With Lc Filter For High Power Applications
Authors: Abduallah Ahmad
Published: November 2013

Multi-phase IM drive systems are nowadays seen as a possible alternative to the three-phase drives due to their features that are especially suited for high power applications such as Oil & Gas industries, electric vehicles, traction drive, ship propulsion, robotics and mining and huge number of application. The main advantages of the multi-phase machines are higher power density with reduced volume, lower torque pulsation at higher frequency, lower dc link current harmonics and lower noise and keep going. This fault tolerance capability of the multi-phase machines makes them highly attractive for safety critical applications listed above. The trend in the drive industry is to employ sensorless topology to make the system more reliable, robust, lower hardware count, reduced cabling, reduced cost and less maintenance. The purpose of this project is to design and develop five-phase speed sensorless induction motor drive system with inverter output LC filter. The drive system are supplied using PWM voltage source inverter and the growing switching speed of IGBTs pose additional problem of high dv/dt. The high dv/dt of the inverter output leads to several problems in the drive systems such as doubling of motor applied voltage (especially for drive with long cable), high voltage stress on motor, leakage and bearing currents leading to the bearing failure and high electromagnetic interference (EMI) etc. To mitigate these issues particularly passive filters are used. This paper focuses on using an LC filter at the output of the five-phase inverter. This paper investigate the design issues of output LC in conjunction with five-phase drive system. The LC filter causes delay and phase shift in the output voltages that affect adversely the motor control especially in sensorless vector controlled drive system. The presence of LC filter is to be incorporated in the speed estimator system. Hence the modification is necessary in the control structure. The effect of inverter output LC filter on the behavior of a sensorless vector controlled five-phase induction motor drive system investigated in this paper. Modification in the control structure and algorithm will be implemented. The whole approach based on theoretical study, simulation verification and experimental implementation. The work on existing Five-phase induction motor drive system at QU. The effect of LC filters on long cable length drive system and the use of composite type of filters will be evaluated in future project cycles.
Performance Improvement Of Grid-Interfaced Renewable Energy Sources In Smart Grids During Faults
Authors: El Deeb Hisham
Published: November 2013

Performance improvement of grid-interfaced renewable energy sources in smart grids during faults
Reduced Switch Count Asymmetrical Flying Capacitor Multi-Level Inverter For Variable Speed Drives Application
Authors: Iqbal Atif
Published: November 2013

Reduced Switch Count Asymmetrical Flying Capacitor Multi-level Inverter for Variable Speed Drives Application
Sensitive Detection Of Oil/Gas-Related Organic Contamination In Soil Around Selected Industrial Hotspots Of Qatar
Authors: Mahmoud Khaled
Published: November 2013

The State of Qatar is a major oil/gas producer in the world which renders its local environment vulnerable to carcinogenic and toxic chemical species resulting from direct and indirect contact with petroleum products. The current level of environmental contamination as direct result of oil/gas industry in Qatar is unknown and there is an urgent need to understand the associated risks on the local population and natural wildlife. This research project was aiming to selectively detect and identify oil/gas-related contaminants, specifically polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), in the soil and marine regions of Qatar. PAHs and PCBs are considered toxic and carcinogenic. They are classified as persistent organic pollutants (POPs). Soils can be contaminated with POPs due to the air pollution from the heavy traffic or from the waste discharged from industries. Fifty soil samples were collected from different residential and industrial areas in Qatar and were extracted through accelerated solvent extraction (ASE) technique. Gas chromatograph - Flame ionization detector (GC-FID) was used to find the 16 common PAHs in each sample and gas chromatograph - electron capture detector (GC-ECD) was used to find PCBs with the aid of deuterated internal and surrogate standards. It was found that some of the samples contain high amounts of benzo[a]pyrene which is the most carcinogenic hydrocarbon. Also, soil samples collected near coastal areas close to industrial activities show higher percentages of PAHs and PCBs (1.1- 1.9 µg/g and 10.4-17.4 µg/g for PAHs and PCBs respectively) as compared to other soil samples. This study helps in identifying environmental hotspots and various risks associated with these contaminants and provide decision makers with preventive and protective measures.
The Diversity Of Darkling Beetles (Coleoptera: Tenebrionidae) In Qatar Is Understimated
Authors: Mas-Peinado Paloma
Published: November 2013

As part of the biodiversity surveys conducted recently in Qatar, we studied the darkling beetles of the family Tenebrionidae (Coleoptera). We have started the analyses of the geographic distribution of the species, followed by studies on systematics, genetics, and evolution of the most diversified group of Coleoptera in desert environments. We have already produced relevant new results such as the discovery of the presence of Scaurus puncticollis Solier, 1838 in Qatar, and preliminary phylogeographic analyses of the populations of Adesmia cancellata distributed across Qatar. Together with these findings, we are currently updating the check-list of Qatar beetles of the family Tenebrionidae. In addition, several species of the genus Pimelia, Thriptera, and Gonocephalum are currently under taxonomic study, and we will add new records that will be included for the first time in the Biodiversity report of insect species for Qatar. The geographic range of darkling beetles in Qatar is being expanded along with current new biodiversity surveys. This suggest that the fauna of darkling beetles of Qatar is still underestimated despite previous efforts conducted by many researchers locally (e.g., Ministry of the Environment, Qatar University, Friends of the Environmental Centre) and internationally. To document and report the actual Biodiversity Heritage of Qatar, new exhaustive field biodiversity surveys should be conducted to complete the catalogue of Tenebrionoidae for the State of Qatar. This abstract is a contribution for the Qatar Foundation Annual Research Conference (QF-ARC-2013).
Service-based Internet Infrastructure for the Qatar World Cup 2022
Authors: Anan Muhammad
Published: November 2013

The shortcomings of today's Internet and the high demand for complex and sophisticated applications and services drive a very interesting and novel research area called Future Internet. The area of Future Internet research focuses on developing a new network with similar magnitude as today's Internet but with more demanding and complex design goals and specifications. It strives to solve the issues identified in today's Internet by capitalizing on the advantages of emerging new technologies in the area of computer networking such as Software Defined Networking (SDN), autonomic computing, and cloud computing. SDN represents an extraordinary opportunity to rethink computer networks, enabling the design and deployment of a future Internet. Utilizing these technologies leads to a significant progress in the development of an enhanced, secure, reliable, and scalable Internet. In 2022, Qatar will host the world cup where more than 5 Million people from all over the world are expected to attend. This event is expected to put the host country, Qatar, under massive pressure and huge challenges in terms of providing high quality Internet service especially with the increasing demand for emerging applications such as video streaming service over mobile devices. It is vital to evaluate and deploy state-of-the-art technologies based on a promising future Internet infrastructure in order to provide high-quality Internet services unique to this event and to the continuing rapid growth of the country. The main goal in this paper is to present a new network design with similar magnitude as today's Internet but with more demanding and complex design goals and specifications defined by the knowledge and experience gathered from four decades of using the current Internet. This research focuses on the development of a complete system, designed with the new requirements of the Future Internet in mind, and aims to provide, monitor and enhance the increasing demand for popular video streaming service. The testing environment was built using the Global Environment for Network Innovations (GENI) testbed (see Figure 1). GENI, a National Science Foundation (NSF) funded research and development effort, aims to build a collaborative and exploratory network experimentation platform for the design, implementation and evaluation of future networks. Because GENI is meant to enable experimentation with large-scale distributed systems, experiments will in general always contain multiple communicating software entities. Large experiments may well contain tens of thousands of such communicating entities, spread across continental or transcontinental distances. The conducted experiments illustrate how such a system can function under unstable and changing network conditions, dynamically learn its environment, recognize potential service degradation problems, and react to these challenges in an autonomic manner without the need for human intervention.
MobiBots: Towards detecting distributed mobile botnets
Authors: Mtibaa Abderrahmen , Alnuweiri Hussein , Harras Khaled A
Published: November 2013

It is widely known that the state of a patient's coronary heart disease can be better assessed using intravascular ultrasound (IVUS) than with more conventional angiography. Recent work has shown that segmentation and 3D reconstruction of IVUS pull-back sequence images can be used for computational fluid dynamic simulation of blood flow through the coronary arteries. This map of shear stress in the blood vessel walls can be used to predict susceptibility of a region of the arteries to future arteriosclerosis and disease. Manual segmentation of images is time consuming as well as cost prohibitive for routine diagnostic use. Current segmentation algorithms do not achieve a high enough accuracy because of the presence of speckle due to blood flow, relatively low resolution of images and presence of various artifacts including guide-wires, stents, vessel branches, and some other growth or inflammations. On the other hand, the image may be induced with additional blur due to movement distortions, as well as resolution-related mixing of closely resembling pixels thus forming a type of out-of-focus blur.. Robust automated segmentation achieving high accuracy of 95% or above has been elusive despite of work by a large community of researchers in the machine vision field. We propose a comprehensive approach where a multitude of algorithms are applied simultaneously to the segmentation problem. In an initial step, pattern recognition methods are used to detect and localize artifacts. We have achieved a high accuracy of 95% or better in detecting frames with stents and location of guide-wire in a large data-set consisting of 15 pull-back sequences with about 1000 image frames each. Our algorithms for lumen segmentation using spatio-temporal texture detection and active contour models have achieved accuracies approaching 70% in the same data-set which is on the high-side of reported accuracies in the literature. Further work is required to combine these methods to increase segmentation accuracy. One approach we are investigating is to combine algorithms using a meta-algorithmic approach. Each segmentation algorithm computes along with the segmentation a measure of confidence in the segmentation which can be biased on prior information about the presence of artifacts. A meta-algorithm then runs a library of algorithms on a sub-sequence of images to be segmented and chooses the segmentation based on computed confidence measures. Machine learning and testing is performed on a large data base. This research is in collaboration with Brigham and Women Hospital in Boston that provides well over 45,000 frames of data for the study.
Distributed algorithms in wireless sensor networks: An approach for applying binary consensus in large testbeds
Authors: Al-Nakhala Noor
Published: November 2013

Our work represents a new starting point for a wireless sensor network implementation of a cooperative algorithm called the binary consensus algorithm. Binary consensus is used to allow a collection of distributed entities to reach consensus regarding the answer to a binary question and the ﬁnal decision is based on the majority opinion. Binary consensus can play a basic role in increasing the accuracy of detecting event occurrence. Existing work on binary consensus focuses on simulation of the algorithm in a purely theoretical sense. We have adapted the binary consensus algorithm for use in wireless sensor networks. This is achieved by specifying how motes ﬁnd partners to update state with as well as by adding a heuristic for individual motes to determine convergence. In traditional binary consensus, individual nodes do not have a stop condition, meaning nodes continue to transmit even after convergence has occurred. In WSNs however, this is unacceptable since it will consume power. So in order to save power sensor motes should stop the communication when the whole network converges. For that reason we have designed a tunable heuristic value N that will allow motes to estimate when convergence has occurred. We have evaluated our algorithm successfully in hardware using 139 IRIS sensor motes and have further supported our results using the TOSSIM simulator. We were able to minimize the convergence time reaching optimal results. The results also show that as the network gets denser the convergence time will lower. In addition, convergence speed depends on the number of motes present in the network. During the experiments none of the motes failed and our algorithm converged correctly. The hardware as well as the simulation results demonstrate that the convergence speed depends on the topology type, the number of motes present in the network, and the distribution of the initial states.
Logic as a ground for effective and reliable web applications
Authors: Geneves Pierre
Published: November 2013

Understanding modern query languages provides key insights for the design of secure, effective and novel web applications. With the ever expanding volume of web data, two data shapes have clearly emerged as flexible ways of representing information: trees (such as most XML documents) and graphs (such as sets of RDF triples). Web applications that process, extract and filter such input data structures often rely on query languages such as XPath and SPARQL for that purpose. This has notably triggered research initiatives such as NoSQL aimed towards a better understanding and more effective implementations of these languages. In parallel, the increasing availability of surging volumes of data urges the finding of techniques to make these languages scale in order to query data of higher orders of magnitude in size. The development of big-data-ready efficient and scalable query evaluators is challenging in several interdependent aspects: one is parallelization -- or how to evaluate a query by leveraging a cluster of machines. Another critical aspect consists in finding techniques for placing data on the cloud in a clever manner so as to limit data communication and thus diminish the global workload. In particular, one difficulty resides in optimizing data partitioning for the execution of subqueries, possibly taking into account additional information on data organization schemes (such as XML Schemas or OWL descriptions). At the same time, growing concerns about data privacy urge the development of analyzers for web data access control policies. We believe that static analysis of web query languages will play an increasingly important role especially in all the aforementioned situations. In this context, we argue that modal logic can give useful yardsticks for characterizing these languages in terms of expressive power and also in terms of complexity for the problem of query answering and for the problems of static analysis of queries. Furthermore, model-checkers and satisfiability-checkers for modal logics such as the mu-calculus can serve as a robust ground for respectively designing scalable query evaluators and powerful static analyzers.
Visualization Methods And Computational Steering Of The Electron Avalanches In The High-Energy Particle Detector Simulators
Authors: Sheharyar Ali
Published: November 2013

The traditional cycle in the simulation of the electron avalanches and any scientific simulation is to prepare input, execute a simulation, and to visualize the results as a post-processing step. Usually, such simulations are long running and computationally intensive. It is not unusual for a simulation to keep running for several days or even weeks. If the experiment leads to the conclusion that there is incorrect logic in the application, or input parameters were wrong, then simulation has to be restarted with correct parameters. A most common method of analyzing the simulation results is to gather the data on disk and visualize after the simulation finishes. The electron avalanche simulations can generate millions of particles that can require huge amount of disk I/O. The disk being inherently slow can become the bottleneck and can degrade the overall performance. Furthermore, these simulations are commonly run on the supercomputer. The supercomputer maintains a queue of researchers' programs and executes them as time and priorities permit. If the simulation produces incorrect results and there is a need to restart it with different input parameters, it may not be possible to restart it immediately because supercomputer is typically shared by several other researchers. The simulations (or jobs) have to wait in the queue until they are given a chance to execute again. It increases the scientific simulation cycle time and hence reduces the researcher's productivity. This research work proposes a framework to let researchers visualize the progress of their experiments so they could detect the potential errors at early stages. It will not only enhance their productivity but will also increase efficiency of the computational resources. This work focuses on the simulations of the propagation and interactions of electrons with ions in particle detectors known as Gas Electron Multipliers (GEMs). However, the proposed method is applicable to any scientific simulation from small to very large scale.
Simultaneous estimation of multiple phase information in a digital holographic configuration
Authors: Rastogi Pramod
Published: November 2013

The automated and simultaneous extraction of multiple phase distributions and their derivatives continue to pose major challenges. A possible reason is the lack of proper data processing concepts to support the multiple wave mixing that needs to be introduced to make the configuration at a time sensitive to multiple phase components and yet be able to decrypt each component of the phase efficiently and robustly, in absence of any cross-talk. The paper demonstrates a phase estimation method for encoding and decoding the phase information in a digital holographic configuration. The proposed method relies on local polynomial phase approximation and subsequent state-space formulation. The polynomial approximation of phase transforms multidimensional phase extraction into a parameter estimation problem, and the state-space modeling allows the application of Kalman filtering to estimate these parameters. The prominent advantages of the method include high computational efficiency, ability to handle rapid spatial variations in the fringe amplitude, and non-requirement of two-dimensional unwrapping algorithms. The performance of the proposed method is evaluated using numerical simulation.
Automatic long audio alignment for conversational Arabic speech
Authors: Elmahdy Mohamed
Published: November 2013

Long Audio Alignment is a known problem in speech processing in which the goal is to align a long audio input with the corresponding text. Accurate alignments help in many speech processing tasks such as audio indexing, speech recognizer's acoustic model training, audio summarizing and retrieving, etc. In this work, we have collected more than 1400 hours of conversational Arabic speech extracted from Al-Jazeerah podcasts besides the corresponding non-aligned text transcriptions. Podcast's length varies from 20-50 minutes each. Five episodes have been manually aligned that meant to be used in evaluating alignment accuracy. For each episode, a split and merge segmentation approach is applied to segment audio file into small segments of average length of 5 sec. having filled pauses on the boundary of each segment. A pre-processing stage in applied on the corresponding raw transcriptions to remove titles, headings, images, speaker's names, etc. A biased language model (LM) is trained on the fly using the processed text. Conversational Arabic speech is mostly spontaneous and influenced by dialectal Arabic. Since phonemic pronunciation modeling is not always possible for non-standard Arabic words, a graphemic pronunciation model (PM) is utilized to generate one pronunciation variant for each word. Unsupervised acoustic model adaptation in applied on a pre-trained Arabic acoustic model using the current podcast audio. The adapted AM along with the biased LM and the graphemic PM are used in a fast speech recognition pass applied on the current podcast's segments. Recognizer's output is aligned with the processed transcriptions using Levenshtein distance algorithm. This way we can ensure error recovery where miss-alignment of a certain segment does not affect alignment of later segments. The proposed approach resulted in an alignment accuracy of 97% on the evaluation set. Most of miss-alignment errors were found to be with segments having significant background noise (music, channel noise, cross-talk, etc.) or significant speech disfluencies (truncated words, repeated words, hesitations, etc.). For some speech processing tasks like acoustic model training, it is required to eliminate miss-aligned segments from the training data. That is why a confidence scoring metric is proposed to accept/reject aligner output. The score is provided for each segment and it is basically the Min-Edit distance between recognizer's output and the aligned text. By using confidence scores, it was possible to reject the majority of miss-aligned segments resulting in 99% alignment accuracy. This work was funded by a grant from the Qatar National Research Fund under its National Priorities Research Program (NPRP) award number NPRP 09-410-1-069. Reported experimental work was performed at Qatar University in collaboration with University of Illinois.
A routing protocol for smart cities: RPL robustness under study
Authors: Heurtefeux Karel
Published: November 2013

Smart cities could be defined as developed urban areas, creating sustainable economic development and high quality of life by excelling in multiple key areas such as transportation, environment, economy, living, and government. This excellence could be reached through efficiency based on the intelligent management and integrated Information and Communication Technologies (ICT). Motivations. In the near future (2030), two thirds of the world population will reside on a city, thus increasing drastically demands on city infrastructures. As a result, urbanization is becoming a crucial issue. The Internet of Things (IoT) vision foresees billions of devices to form a worldwide network of interconnected objects including computers, mobile phones, RFID tags and wireless sensors. In this study, we focus on Wireless Sensor Networks (WSNs). The WSNs are a specific technology suitable to create Smart Cities. A distributed network of intelligent sensor nodes could measure numerous parameters and communicate them wirelessly and in real-time and makes possible a more efficient management of the city. For example, the pollution concentration in each street can be monitored, water leaks can be detected or noise maps of the city obtained. The number of applications with WSNs available for smart cities is only bounded by imagination: environmental care, sustainable development, healthcare, efficient traffic management, energy supply, water management, green buildings, etc. In short, WSN could improve the quality of life in a city. Scope. However, such urban applications often use multi-hop wireless networks with high density to obtain sufficient area coverage. As a result, they need networking stacks and routing protocols that can scale with network size and density, while remaining energy-efficient and lightweight. To this end, the IETF RoLL working group has designed the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL). This paper presents experimental results on the RPL protocol. The RPL properties in terms of delivery ratio, control packet overhead, dynamics and robustness are studied. The results are obtained by several experimentations conducted on two large WSNs testbeds composed of more than 100 sensor nodes each. In this real-life scenario (high density and convergecast traffic), several intrinsic characteristics of RPL are underlined: path length stability but reduced delivery ratio and important overhead (Fig. 1). However, the routing metrics, as defined by default, favor the creation of "hubs", aggregating most of 2-hops nodes (Fig. 2). To investigate the RPL robustness, we observe its behavior when facing a sudden death of several sensors and when several sensors are redeployed. RPL shows good abilities to maintain the routing process despite such events. However, the paper highlights that this ability can be reduced if only few critical nodes fail. To the best of our knowledge, it is the first study of RPL on such large platform.
Development of a spontaneous large vocabulary speech recognition system for Qatari Arabic
Authors: Elmahdy Mohamed
Published: November 2013

In this work, we develop a spontaneous large vocabulary speech recognition system for Qatari Arabic (QA). A major problem with dialectal Arabic speech recognition is due to the sparsity of speech resources. So, we propose an Automatic Speech Recognition (ASR) framework to jointly use Modern Standard Arabic (MSA) data and QA data to improve acoustic and language modeling by orthographic normalization, cross-dialectal phone mapping, data sharing, and acoustic model adaptation. A wide-band speech corpus has been developed for QA. The corpus consists of 15 hours speech data collected from different TV series and talk-show programs. The corpus was manually segmented and transcribed. A QA tri-gram language model (LM) was linearly interpolated with a large MSA LM in order to decrease Out-Of-Vocabulary (OOV) rate and to improve perplexity. The vocabulary consists of 21K words extracted from the QA training set with additional 256K MSA vocabulary. The acoustic model (AM) was trained with a data pool of QA data and additional 60 hours of MSA data. In order to boost the contribution of QA data, Maximum-A-Posteriori (MAP) adaptation was applied on the resulted AM using only the QA data, effectively increasing the weight of dialectal acoustic features in the final cross-lingual model. All trainings were performed with Maximum Mutual Information Estimation (MMIE) and with Speaker Adaptive Training (SAT) applied on top of MMIE. Our proposed approach achieves more than 16% relative reduction in WER on QA testing set compared to a baseline system trained with only QA data. This work was funded by a grant from the Qatar National Research Fund under its National Priorities Research Program (NPRP) award number NPRP 09-410-1-069. Reported experimental work was performed at Qatar University in collaboration with University of Illinois.
Random projections and haar cascades for accurate real-time vehicle detection and tracking
Authors: ElHelw Mohamed
Published: November 2013

This paper presents a robust real-time vision framework that detects and tracks vehicles from stationary traffic cameras with certain regions of interest. The framework enables intelligent transportation and road safety applications such as road-occupancy characterization, congestion detection, traffic flow computation, and pedestrian tracking. It consists of three main modules:1) detection, 2) tracking, and 3) data association. To this end, vehicles are first detected using Haar-like features. In the second phase, a light-weight appearance-based model is built using random projections to keep track of the detected vehicles. The data association module fuses new detections and existing targets for accurate tracking. The practical value of the proposed framework is demonstrated with evaluation involving several real-world experiments and variety of challenges.
Humanitarian Computing Library
Authors: Abo Eita Nada
Published: November 2013

Humanitarian Computing Library
Veiling in the courtroom: Muslim women's credibility and perceptions
Authors: Ammar Nawal , Ammar Nawal
Published: November 2013

This presentation provides systematic evidence on an emergent debate about a Muslim woman's dress and her perceived credibility as a witness in a court context. The objective of this research is to understand how Muslim women's dress impacts their perceived credibility. The issue of testifying in western courts while wearing either a head veil (hijab) or a face veil (niqab) has been strongly contested on the grounds that physically seeing the witness's face helps observers judge her credibility (e.g., R. v. N.S., 2010). Canada's Supreme Court (N.S. v. Her Majesty the Queen, et al., 2012) ruled that judges will disallow the niqab "whenever the effect of wearing it would impede an evaluation of the witness's credibility." In 2010, an Australian judge ruled that a Muslim woman must remove her full veil while giving evidence before a jury. In 2007, the UK guidance on victims also indicated that the niqab may affect the quality of evidence given in the court room. All of those decisions and opinions run contrary to systematic research. Psychological studies suggest that nonverbal cues are not only poor indicators of veracity, but that they are the least useful indicators of deception (e.g., DePaulo et al., 2003, Vrij, 2008). This presentation discusses results of a research project that examined Muslim women's credibility. Using a quasi-experimental design, three groups of Muslim women lied or told the truth while testifying about a mock crime: 1) women without any coverings (safirat), 2) women wearing hijab (muhjabat) and 3) women wearing niqab (munaqabat). Videos of these women were then shown to audiences who assessed the credibilityof the witnesses. The research further explored the witness's general perceptions of being an eyewitness within the court system, and to what extent (if any) their dress impacted their perceptions. The presentation fits within the Social Sciences, Arts and Humanities thematic pillar of Qatar's National Research Strategy. It more particularly fits within two of the grand challenges: Managing Transition to a Diversified Knowledge- based Society: Build a knowledge-based society by emphasizing a robust research culture, and Holistic and Systematic Assessment of the Rapidly Changing Environment: Foster motivation, scholarship, and prosperity among Qatari nationals and expatriates along with cultural accommodations that are in-sync with modern practice.