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Qatar Foundation Annual Research Forum Volume 2013 Issue 1
- Conference date: 24-25 Nov 2013
- Location: Qatar National Convention Center (QNCC), Doha, Qatar
- Volume number: 2013
- Published: 20 November 2013
421 - 440 of 541 results
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Hardware implementation of principal component analysis for gas identification systems on the Zynq SoC platform
More LessPrincipal component analysis (PCA) is a commonly used technique for data reduction in general as well as for dimensionality reduction in gas identification systems when a sensor array is being used. A complete PCA IP core for gas application has been designed and implemented on the Zynq programmable system on chip (SoC). The new heterogeneous Zynq platform with its ARM processor and programmable logic (PL) was used because it is becoming an interesting alternative to conventional field programmable gate array (FPGA) platforms. All steps of the learning and testing phases of PCA starting from the mean computation to the projection of data onto the new space, passing by the normalization process, covariance matrix and the eigenvectors computation were developed in C and synthesized using the new Xilinx VIVADO high level synthesis (HLS) tool. The eigenvectors were found using the Jacobi method. The implemented hardware of the presented PCA algorithm for a 16×30 matrix was faster than the software counterpart with a speed up of 1.41 times when executed on a desktop running a 64-bit Intel i7-3770 processor at 3.40GHz. The implemented IP core consumed an average of 23% of all on chip resources. The PCA algorithm used in the learning phase is to be executed first for the system to be trained to a specific data set and then produce the related vectors of means along with the eigenvectors that will be used in the testing part. The PCA algorithm used in the testing phase will also be used in real time identification. For testing purpose, a data set that represents the output of a 16-array gas sensor when exposed to three types of gases (CO, Ethanol and H2) in ten different concentrations (20, 40, 60, 80, 120, 140, 160, 180 and 200ppm) was used. The aim was to reduce the 30 samples of 16 dimensions to 30 vectors of 2 or 3 dimensions data depending on the need. The combination between the Zynq platform and the HLS tool showed many benefits, using Vivado HLS resulted in a considerable gain in terms of time spent on prototyping and this is due to the fact that the design was specified in a high level language such C or C++ and not a hardware description language such as VHDL or Verilog. While using the Zynq platform highlighted some interesting advantages compared with conventional FPGA platforms such us the possibility to split the design, executing the simple part in a software manner on the ARM processor and leaving the complex one for hardware acceleration. It is planned to further optimize the IP core using the Vivado HLS directives, the developed core is to be used in a larger gas identification system for dimensionality reduction purpose. The larger gas identification system will be used to identify a given gas and estimate its concentration and will be part of a Low Power Reconfigurable self-calibrated Multi‐Sensing Platform.
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Sonar placement and deployment in a maritime environment
By Selim BoraGiven a water-terrain area of interest (waterways, ports, etc.), this paper attempts to efficiently allocate underwater sonars to achieve a reasonable amount of coverage within a limited budget. Coverage is defined as the capability of sonars to detect threats. Though total coverage is desired, priority is given to the criticality/importance attached to the location of an area of interest on a grid-based system. Unlike other works in the literature, the developed model takes into consideration uncertainty inherent in the detection probability of sonars. Apart from issues of sonar reliability, underwater terrain, with its changing conditions, is bound to affect detection probabilities. While taking into consideration the specific physics of sonars in the model development, the model also adopts a hexagonal grid-based system to ensure more efficient placement of sonars. Based on an initially proposed mixed-integer program, a robust optimization model also is proposed to take care of uncertainties. With smaller scale problems, the model works adequately within a relatively short time period. However, large scale problems require extensive memory, taking much longer. As such, a heuristic is proposed as an alternative to the proposed model. Experimental results indicate the heuristic works effectively under most circumstances and performs less effectively under a few limited scenarios.
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Cloud-based development life cycle: Software testing as service
More LessCloud computing is an emerging paradigm, which is changing the way computing resources are provisioned, accessed, utilized, maintained and managed. The SWOT analysis for the Cloud is depicted in Table 1. Cloud computing is increasingly changing the way software products and services are produced and consumed; thereby implying the need for a change in the ways, methods, tools and concepts by which these products are tested. Software testing is an important quality control activity stage within the Software Development Lifecycle. Software testing involves both function (eg. bugs) and non-functional testing (eg. regression). It verifies and validates the finished product to ensure that development effort meets up with requirements specification. This process often requires consumption of resources over a limited period of time. These resources could be costly, or, not readily available, which in turn, can have an effect on the efficiency of the testing process. Though this process is important, nevertheless it is not a business critical process because it does not contain overly sensitive business data, which makes it an ideal case for migration to the cloud. The increasing complexity and distribution of teams, applications, processes and services, along with the need for adequate testing approaches for cloud-based applications and services creates a convincing case for the need for cloud-based software testing. Cloud-based testing or Software Testing as a Service is a new way of carrying out testing as a service, using the cloud as the underlying platform to provide on-demand software testing services via the internet. Table 2 below shows a SWOT analysis for cloud-based testing, from which a comparison between traditional software testing with cloud-based testing can be made and advantages of the cloud approach can be drawn. A number of major industrial players like IBM, HP, UTest, SOASTA, Sogetti, and SauceLabs, to mention a few, now offer various cloud-based testing services which presents a lot of advantages to customers. Though cloud-based testing presents a lot of advantages and benefits over traditional testing, it cannot overly replace traditional testing because areas of testing and scenarios of testing for synergy and trade-offs exist. For example, some testing areas requiring implicit domain knowledge about the customer's business (like insurance business); or areas where hardware or software is an integral and essential part of the other and directly dependent on each other (like programmable logic controllers), may require the adoption of traditional testing practices over cloud-based testing. This represents an area for further research: developing intelligent/context aware Cloud-based testing services with the ability to recreate or mimic areas/scenarios requiring implicit domain knowledge. Furthermore, there is a lack of adequate support tools cloud-based testing services. These tools include: self-learning test case libraries and tools for measuring cloud-based testing services. This paper will present our research efforts in the area of Cloud based collaborative software development life cycle, with particular focus on the feasibility of provisioning software testing as a cloud service. This research has direct industrial implication and holds huge research and business potentials.
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Grand Challenges For Sustainable Growth: Irish Presidency Of The Eu Council 2013 In Review
By Soha MaadThe presetation will overview the outcomes of the Irish Presidency of the EU Council for 2013 in addressing grand challenges for sustainable Growth with special emphasis on the digital (IT) agenda for Europe. The Irish Presidency of the EU council for 2013 made great achievements including the agreement of the 7 years EU Budget (including the budget to tackle youth unemploymen, the €70 billions Horizon 2020 program for research and innovation; the €30 billions budget for connecting Europe facility targeting enhancement in transport, energy and telecoms; and the €16 billions budget for the Erasmus programme), the reform of Common Agriculture Policy (CAP) and Common Fisheries Policy (CFP), and the brokerage of various partnerships and trade agreements (the most important ones are the EU-US agreement of €8 billions, and the EU-Japan agreement). An estimated number of 200 policy commitments were achieved including more than 80 in legislative form. The presentation will put a particular emphasis on the digital agenda for Europe and the horizon for international collaboration to tackle grand challenges for sustainable growth and the application of ICT to address these challenges. A brief overview of key related events held during the Irish Presidency of the EU council will be covered and the announcement of a book launch event elaborating on the topic and content of the presentation will be made.
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ChiQat: An intelligent tutoring system for learning computer science
More LessFoundational topics in Computer Science (CS), such as data structures and algorithmic strategies, pose particular challenges to learners and teachers. The difficulty of learning these basic concepts often discourages students from further study, and leads them to lower success. In any discipline, students' interaction with skilled tutors is one of the most effective strategies to address the problem of weak learning. However, human tutors are not always available. Technology can compensate here: Intelligent Tutoring Systems (ITSs) are systems designed to simulate the teaching of human tutors. ITSs use artificial intelligence techniques to guide learners through problem solving exercises using pedagogical strategies similar to those employed by human tutors. ChiQat-Tutor, a novel ITS that we are currently developing, aims at facilitating learning of basic CS data structures (e.g., linked lists, trees, stacks) and algorithmic strategies (e.g., recursion). The system will use a number of effective pedagogical strategies in CS education, including positive and negative feedback, learning from worked-out examples, and learning from analogies. ChiQat will support linked lists, trees, stacks, and recursion. The ChiQat linked list module builds on iList, our previous ITS that provenly helps students learn linked lists. This module provides learners with a simulated environment where linked lists can be seen, constructed, and manipulated. Lists are represented graphically and can be manipulated interactively using programming commands (C++ or Java). The system can currently follow the solution strategy of a student, and provides personalized positive and negative feedback. Our next step is to add support for worked-out examples. The recursion module provides learners with an animated and interactive environment, where they can trace recursion calls of a given recursive problem. This is one of the most challenging tasks students face when learning the concept of recursion. In the near future, students will be aided in breaking down recursive problems into their basic blocks (base case and recursive case) through interactive dialogues. ChiQat employs a flexible, fault-tolerant, distributed plug-in architecture, where each plug-in fulfills a particular role. This configuration allows different system types to be defined, such as all-in-one applications or distributed ones. The system is composed of separate front and back ends. The back-end will house the main logic for heavy computational tasks such as problem knowledge representation and tutor feedback generation. The front-end (user interface) collects users input and sends it to the back-end, while displaying the current state of the problem. Due to this flexible architecture, it will be possible to run the system in two modes; online and offline. Offline mode will run all client and server components on the same machine, allowing the user to use the system in a closed environment. The online mode will allow running the back-end on a server as a web service which can communicate with a front-end running on the client machine. This allows wider and greater reachability for users using lower powered connected devices such as mobile devices, as well as traditional laptops and desktop computers which are connected to the Internet.
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Logic as a ground for effective and reliable web applications
More LessUnderstanding 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.
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On green planning and management of cellular networks in urban cities
By Zaher DawyEnergy is becoming a main concern nowadays due to the increasing demands on natural energy resources. Base stations (BS) consume up to 80% of the total energy expenditure in a cellular network. The energy-efficiency of the BSs decreases significantly at off-peak hours since the power amplifiers' energy-efficiency degrades at lower output power. Thus, power savings methods should focus on the access network level by trying to manipulate the BSs power consumption. This could be done by reducing the number of active elements (e.g., BSs) in the network for lower traffic states by switching some BSs off. In this case, network management should allow smooth transition between different network topologies based on the traffic demands. In this work, we evaluate a green radio network planning approach by jointly optimizing the number of active BSs and the BS on/off switching patterns based on the changing traffic conditions in the network in an effort to reduce the total energy consumption of the BSs. Planning is performed based on two approaches: a reactive and a proactive approach. In the proactive approach, planning will be performed starting with the lowest traffic demand until reaching the highest traffic demand whereas in the reactive approach, the reverse way is considered. Performance results are presented for various case studies and evaluated taking into account practical network planning considerations. Moreover, we present real planning results in an urban city environment using the ICS telecom tool from ATDI in order to perform coverage calculations and analysis for LTE networks.
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Cooperative relaying for idle band integration in spectrum sharing systems
By Syed HussainRecent developments in wireless communications and the emergence of high data rate services have consumed almost all the accessible spectrum making it a very scarce radio resource. Spectrum from very low frequencies to several GHz range has been either dedicated to a particular service or licensed to its providers. It is very difficult to find sufficient bandwidth for new technologies and services within accessible spectrum range. Contrarily, studies in different parts of the world reveal that the licensed and/or dedicated spectrum is underutilized leaving unused bands at different frequencies. These idle bands; however, cannot be used by non-licensed users due to current spectrum management practices throughout the world. This fact forced the regulatory authorities and academia to rethink the spectrum allocation policies. This resulted in the idea of spectrum sharing systems, generally known as cognitive radio, in which non-licensed or secondary users can access the spectrum licensed to the primary users. Many techniques and procedures have been suggested in the recent years for smooth and transparent spectrum sharing among the primary and secondary users. The most common approach suggests that the secondary users should perform spectrum sensing to identify the unused bands and exploit them for their own transmission. However, as soon as the primary user becomes active in that band, secondary transmission should be switched off or moved to some other idle band. A major problem faced by the secondary users is that the average width of the idle bands available at different frequencies is not large enough to support high data rate wireless applications and services. A possible solution is to integrate few idle bands together to generate a larger bandwidth. This technique is also known as spectrum aggregation. Generally, it is proposed to build the transmitter with multiple radio frequency chains which are activated according to the availability of idle bands. A combiner or aggregator is then used to transmit the signal through the antenna. Similarly, a receive antenna can be realized through multiple receive RF chains through a separator or splitter. Another option is to use orthogonal frequency division multiplexing in which sub-carriers can be switched on and off based on unused and active primary bands, respectively. These solutions are developed and analyzed for direct point to point links between the nodes. In this work, we analyze spectrum aggregation for indirect links through multiple relays. We propose a simple mechanism for idle band integration in a secondary cooperative network. Few relays in the system partly facilitate the source to aggregate available idle bands and collectively all the involved relays provide an aggregated larger bandwidth for the source to destination link. We analyze two commonly used forwarding schemes at the relays; namely, amplify-and-forward and decode-and-forward. We focus on outage probability of the scheme and derive a generalized closed form expression applicable to both scenarios. We analyze the system performance under different influential factors and reveal some important trade-offs.
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PhosphoSiteAnalyzer: Analyzing complex cell signalling networks
More LessPhosphoproteomic experiments are routinely conducted in laboratories worldwide, and because of the fast development of mass spectrometric techniques and efficient phosphopeptide enrichment methods, life-science researchers frequently end up having lists with tens of thousands of phosphorylation sites for further interrogation. To answer biologically relevant questions from these complex data sets, it becomes essential to apply computational, statistical, and predictive analytical methods. Recently we have provided an advanced bioinformatic platform termed “PhosphoSiteAnalyzer” to the scientific community to explore large phosphoproteomic data sets that have been subjected to kinase prediction using the previously published NetworKIN algorithm. NetworKIN applies sophisticated linear motif analysis and contextual network modeling to obtain kinase-substrate associations with high accuracy and sensitivity. PhosphoSiteAnalyzer provides an algorithm for retrieval of kinase predictions from the public NetworKIN webpage in a semi-automated way and applies hereafter advanced statistics to facilitate a user-tailored in-depth analysis of the phosphoproteomic data sets. The interface of the software provides a high degree of analytical flexibility and is designed to be intuitive for most users. Network biology and in particular kinase-substrate network biology provides an adequate conceptual framework to describe and understand diseases and for designing targeted biomedicine for personalized medicine. Hence network biology and network analysis are absolutely essential to translational medical research. PhosphoSiteAnalyzer is a versatile bioinformatics tool to decipher such complex networks and can be used in the fight against serious diseases such as psychological disorders, cancer and diabetes that arise as a result of dysfunctional cell signalling networks.
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Opportunistic Cooperative Communication Using Buffer-Aided Relays
More LessSpectral efficiency of a communication system refers to the information rate that the system can transmit reliably over the available bandwidth (spectrum) of the communication channel. Enhancing the spectral efficiency is without doubt a major objective for the designers of next generation wireless systems. It is evident that the telecommunications industry is rapidly growing due to the high demands for ubiquitous connectivity and the popularity of high data rate multimedia services. As well-known, wireless channels are characterized by temporal and spectral fluctuations due to physical phenomena such as fading and shadowing. A well-established approach to exploit the variations of the fading channel is opportunistic communication, which means transmitting at high rates when the channel is good and at low rates or not at all when the channel is poor. Furthermore, in the last few years, the research focus has turned into exploiting the broadcast nature of the wireless medium and the potential gains of exploiting the interaction (cooperation) between neighboring nodes in order to enhance the overall capacity of the network. Cooperative communication will be one of the major milestones in the next decade for the emerging fourth and fifth generation wireless systems. Cooperative communication can take several forms such as relaying the information transmitted by other nodes, coordinated multi-point transmission and reception techniques, combining several information flows together using network coding in order to exploit side information available at the receiving nodes, and interference management in dense small cell networks and cognitive radio systems to magnify the useful information transmission rates. We propose to exploit all sources of capacity gains jointly. We want to benefit from old, yet powerful, and new transmission techniques. Specifically, we want to examine optimal resource allocation and multiuser scheduling in the context of the emerging network architectures that involve relaying, network coding and interference handling techniques. We like to call this theme opportunistic cooperative communication. With the aid of opportunistic cooperative communication we can jointly exploit many sources of capacity gains such as multiuser diversity, multihop diversity, the broadcast nature of the wireless medium and the side-information at the nodes. We suggest exploring opportunistic cooperative communication as the choice for future digital communications and networking. In this direction, we introduce the topic of buffer-aided relaying as an important enabling technology for opportunistic cooperative communication. The use of buffering at the relay nodes enables storing the received messages temporarily before forwarding them to the destined receivers. Therefore, buffer-aided relaying is a prerequisite in order to apply dynamic opportunistic scheduling in order to exploit the channel diversity and obtain considerable throughput gains. Furthermore, these capacity gains can be integrated with other valuable sources of capacity gains that can be obtained using, e.g., multiuser scheduling, network coding over bidirectional relays, and interference management and primary-secondary cooperation in overlay cognitive radios systems. The gains in the achievable spectral efficiency are valuable and hence they should be considered for practical implementation in next generation broadband wireless systems. Furthermore, this topic can be further exploited in other scenarios and applications.
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Security-Smart-Seamless (Sss) Public Transportation Framework For Qatar Using Tv White Space (Tvws)
More LessThe present Qatarian government has a long term vision of introducing intelligent transport, logistics management and road safety services in Qatar. Studies have shown that the public transport system in Qatar, and Doha in particular, is developing, but is not yet as comprehensive as in many renowned world cities (Pernin et al., 2008; Henry et al., 2012). Furthermore, with hosting rights of FIFA 2022 World Cup being granted to Qatar, a seminar paper was recently discussed by 2030 Qatar National Vision aim at world-class transport system for Qatar which meets the requirements of the country's long term goal (Walker, 2013). The introduction of intelligent public transport system involves the incorporation of technology into transportation system so as to improve public safety, conserve resources through seamless transport hub and introduce smartness for maximum utility in public transportation. The aforementioned goals of 2030 Qatar National Vision can be achieved through TVWS technology. TVWS technology was created to make use of sparsely used VHF and UHF spectra bands as indicated in Figure 1. The project focuses on IEEE 802.22 to enhance the Security, Smart, Seamless (SSS) transportation system in Qatar as shown in Figure 2 below. It is sub-divided as: (i) Security- TVWS to provide surveillance camera in public bus and train system. The bus/train system will be fitted with micro-camera. The project will provide the city center management team the ability to monitor and track the public transportation system in-case of accident, terrorism and other social issues. (ii) Seamless-TVWS will be made available for anyone who can purchase a down/up converter terminal to access the internet services for free. The need for up/down converter arises because the current mobile devices operate in ISM bands, whereas TVWS operates in VHF/UHF bands. (iii) Smart-The city center management can seat in their office and take control of eventuality. If there is such a project in the past, it might be using satellite technology. We are all aware of the limitations of satellite technology such as round delay trip. (iv) Novelty- Spectrum sensing by using Grey prediction algorithm is proposed to achieve optimal result. From academic point of view, Grey prediction algorithm has been used in predicting handoff in cellular communication and in stock market prediction, with high prediction accuracy of 95~98% (Sheu and Wu, 2000; Kayacan et al. 2010). The proposal methodology is as shown in Figure 3. Wireless Rural Area Network (WRAN) with cell radius varies from 10 - 100 km leaning towards macro cell architecture. Hence, the roll-out will require less base station infrastructure. In addition, the VHF-UHF bands offer desirable propagation qualities when compared to other frequency bands thereby ensuring wider and reliable radio coverage.
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Visualization Methods And Computational Steering Of The Electron Avalanches In The High-Energy Particle Detector Simulators
More LessThe 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.
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Kernel collaborative label power set system for multi-label classification
More LessA traditional multi-class classification system assigns each example x a single label l from a set of disjoint labels L. However, in many modern applications such as text classification, image/video categorization, music categorization etc [1, 2], each instance can be assigned to a subset of labels Y ⊆ L. In text classification, news document can cover several topics such as the name of movie, box office ratings, and/or critic reviews. In image/video categorization, multiple objects can appear in the same image/video. This problem is known as multi-label learning. Figures 1 shows some examples of the multi-label images. Collaborative Representation with regularized least square (CRC-RLS) is a state-of-the-art face recognition method that exploits this collaborative representation between classes in representing the query sample [3]. The basic idea is to code the testing sample over a dictionary, and then classify it based on the coding vector. While the benefits of collaborative representation are becoming well established for face recognition or in general multi-class classification, the corresponding use for multi-label classification needs to be investigated. In this research, a kernel collaborative label power set multi-label classifier (ML-KCR) based on regularized least square principle is proposed. ML-KCR directly introduces the discriminative information of the samples using l2-norm\sparsity" and uses the class specified representation residual for classification. Further, in order to capture co-relation among classes, the multi-label problem is transformed using label power set which is based on the concept of handling sets of labels as single labels and thus allowing the classification process to inherently take into account the correlations between labels. The proposed approach is applied to six publicly available multi-label data sets from different domains using 5 different multi-label classification measures. We validate the advocated approach experimentally and demonstrate that it yields significant performance gains when compared with the state-of-the art multi-label methods. In summary, following are our main contributions * A kernel collaborative label powerset classifier (ML-KCR) based on regularized least square principle is proposed for multi-label classification. ML-KCR directly introduces the discriminative information and aim to maximize the margins between the samples of di_erent classes in each local area. * In order to capture correlation among labels, the multi-label problem is transformed using label powerset (LP). The main disadvantage associated with LP is the complexity issue arise due to many distinct label sets. We will show that this complexity issue can be avoided using collaborative representation with regularization. * We applied the proposed approach to publicly available multi-label data sets and compared with state-of-the-art multi-label methods. The proposed EML method is compared with the state-of-the-art multi-label classifiers: RAkEL, ECC, CLR, MLkNN, IBLR [2]. References [1] Tsoumakas, G., Katakis, I., Vlahavas, I., 2009. Data Mining and Knowledge Discovery Handbook. Springer, 2nd Edition, Ch. Mining Multilabel Data. [2] Zhang, M.-L., Zhou, Z.-H., 2013. A review on multi-label learning algorithms. IEEE Transactions on Knowledge and Data Engineering (preprint). [3] Zhang, L., Yang, M., 2011. Sparse representation or collaborative representation: Which helps face recognition? In: IEEE International Conference on Computer Vision (ICCV).
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Simultaneous estimation of multiple phase information in a digital holographic configuration
More LessThe 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.
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Automatic long audio alignment for conversational Arabic speech
More LessLong 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.
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Simultaneous fault detection, isolation and tracking design using a single observer-based module
By Nader MeskinFault diagnosis (FD) has received much attention for complex modern automatic systems such as car, aircraft, rockets, unmanned vehicles, and so on since 1970s. In the FD research field, the diagnostic systems are often designed separately from the control algorithms, although it is highly desirable that both the control and diagnostic modules are integrated into one system module. Hence, the problem of simultaneous fault detection and control (SFDC) has attracted a lot of attention in the last two decades, both in research and application domains. The simultaneous design unifies the control and detection units into a single unit which results in less complexity as compared with the case of separate design; so, it is a reasonable approach. However, the current literature in the field of SFDC suffers from the following limitations and drawbacks. First, most of the literature that considers the problem of SFDC, can achieve the control objective of "regulation" but none of them consider the problem of "tracking" in SFDC design. Therefore, considering the problem of tracking in SFDC design methodology is of great significance and importance. Second, although most of the current references in the field of SFDC can achieve acceptable fault detection, they cannot achieve fault isolation. Hence, although there are certain published works in the field of SFDC, none of them is capable of detecting and isolating simultaneous faults in the system as well as tracking the specified reference input. In this paper, the problem of simultaneous fault detection, isolation and tracking (SFDIT) design for linear continuous-time systems is considered. An H_infty/H_index formulation of the SFDIT problem using a dynamic observer detector and state feedback controller is developed. Indeed, a single module based on dynamic observer is designed which produces two signals, namely the residual and the control signals. The SFDIT module is designed such that the effects of disturbances and reference inputs on the residual signals are minimized (for accomplishing fault detection) subject to the constraint that the transfer matrix function from the faults to the residuals is equal to a pre assigned diagonal transfer matrix (for accomplishing fault isolation), while the effects of disturbances, reference inputs and faults on the specified control output are minimized (for accomplishing fault-tolerant control and tracking problems). Sufficient conditions for solvability of the problem are obtained in terms of linear matrix inequality (LMI) feasibility conditions. On the other hand, it is shown that by applying our methodology, the computational complexity from the view point of the number and size of required observers is significantly reduced in comparison with all of the existing methodologies. Moreover, using this approach the system can not only detect and isolate the occurred faults but also able to track the specified reference input. The proposed method can also handle isolation of simultaneous faults in the system. Simulation results for an autonomous unmanned underwater vehicle (AUV) illustrate the effectiveness of our proposed design methodology.
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Towards computational offloading in mobile device clouds
More LessWith the rise in mobile device adoption, and growth in mobile application market expected to reach $30 billion by the end of 2013, mobile user expectations for pervasive computation and data access are unbounded. Yet, various applications, such as face recognition, speech and object recognition, and natural language processing, exceed the limits of standalone mobile devices. Such applications resort to exploiting larger resources in the cloud, which sparked researching problems arising from data and computational offloading to the cloud. Research in this area has mainly focused on profiling and offloading tasks to remote cloud resources, automatically transforming mobile applications by provisioning and partitioning its execution into offloadable tasks, and more recently, bringing computational resources (e.g. Cloudlets) closer to task initiators in order to save mobile device energy. In this work, we argue for environments in which computational offloading is performed among mobile devices forming what we call a Mobile Device Cloud (MDC). Our contributions are: (1) Implementing an emulation testbed for quantifying the potential gain, in execution time or energy consumed, of offloading tasks to an MDC. This testbed includes a client offloading application, an offloadee server receiving tasks, and a traffic shaper situated between the client and server emulating different communication technologies (Bluetooth 3.0, Bluetooth 4.0, WiFi Direct, WiFi, and 3G). Our evaluation for offloading tasks with different data and computation characteristics to an MDC registers up to 80% and 90% savings in time or energy respectively, as opposed to offloading to the cloud. (2) Providing an MDC experimental platform to enable future evaluation and assessment of MDC-based solutions. We create a testbed, shown in Figure 1, to measure the energy consumed by a mobile device when running or offloading tasks using different communication technologies. We build an offloading Android-based mobile application and measure the time taken to offload tasks, execute them, and receive the results from other devices within an MDC. Our experimental results show gains in time and energy savings, up to 50% and 26% respectively, by offloading within MDCs, as opposed to locally executing tasks. (3) Providing solutions that address two major MDC challenges. First, due to mobility, offloadee devices leaving an MDC would seriously compromise performance. Therefore, we propose several social-based offloadee selection algorithms that exploit contact history between devices, as well as friendship relationships or common interests between device owners or users. Second, we provide solutions for balancing power consumption by distributing computational load across MDC members to elongate and MDC's life time. This need occurs when users need to maximize the lifetime of an ensemble of devices that belong to the same user or household. We evaluate the algorithms we propose for addressing these two challenges using the real datasets that contain contact mobility traces and social information for conference attendees over the span of three days. Our results show the impact of choosing the suitable offloadee subset, the gain from leveraging social information, and how MDCs can live longer by balancing power consumption across their members.
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QALB: Qatar Arabic language bank
More LessAutomatic text correction has been attracting research attention for English and some other western languages. Applications for automatic text correction vary from improving language learning for humans and reducing noise in text input to natural language processing tools to correcting machine translation output for grammatical and lexical choice errors. Despite the recent focus on some Arabic language technologies, Arabic automatic correction is still a fairly understudied research problem. Modern Standard Arabic (MSA) is a morphologically and syntactically complex language, which poses multiple writing challenges not only to language learners, but also to Arabic speakers, whose dialects differ substantially from MSA. We are currently creating resources to address these challenges. Our project has two components: first is QALB (Qatar Arabic Language Bank), a large parallel corpus of Arabic sentences and their corrections, and second is ACLE (Automatic Correction of Language Errors), an Arabic text correction system trained and tested on the QALB corpus. The QALB corpus is unique in that: a) it will be the largest Arabic text correction corpus available, spanning two million words; b) it will cover errors produced by native-speakers, non-native speakers, and machine translation systems; and c) it will contain a trace of all the actions performed by the human annotators to achieve the final correction. This presentation describes the creation of two major components of the project: the web-based annotation interface and the annotation guidelines. QAWI (QALB Annotation Web Interface) is our web-based, language-independent annotation framework used for manual correction of the QALB corpus. Our framework provides intuitive interfaces for annotating text, managing a large number of human annotators and performing quality control. Our annotation interface, in particular, provides a novel token-based editing model for correcting Arabic text that allows us to reliably track all modifications. We demonstrate details of both the annotation and the administration interfaces as well as the back-end engine. Furthermore, we show how this framework is able to speed up the annotation process by employing automated annotators to correct basic Arabic spelling errors. We also discuss the evolution of our annotation guidelines from its early developments through its actual usage for group annotation. The guidelines cover a variety of linguistic phenomena, from spelling errors to dialectal variations and grammatical considerations. The guidelines also include a large number of examples to help annotators understand the general principles behind the correction rules and not simply memorize them. The guidelines were written in parallel to the development of our web-based annotation interface and involved several iterations and revisions. We periodically provided new training sessions to the annotators and measured their inter-annotator agreement. Furthermore, the guidelines were updated and extended using feedback from the annotators and the inter-annotator agreement evaluations. This project is supported by the National Priority Research Program (NPRP grant 4-1058-1-168) of the Qatar National Research Fund (a member of the Qatar Foundation). The statements made herein are solely the responsibility of the authors.
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Pfmt-Dnclcpa Theory For Ballistic Spin Wave Transport Across Iron-Gadolinium Nanojunctions Presenting Structural Interfacial Disorder Between Iron Leads
More LessIt is widely accepted at present that the electronics based information-processing technology has fundamental limitations. A promising alternative to electronic excitations are the spin waves on magnetically ordered systems, which usher a potentially powerful solution towards fabricating devices that transmit and process information (Khitun and Wang 2006). This approach to information-processing technology, known as magnonics, is rapidly growing (Kruglyak and Hicken 2006, Choi et al. 2007), and key magnonic components such as wave guides, emitters, nanojunctions and ï¬lters (Khater et al. 2011) are currently explored as basic elements of magnonic circuitry. This paper deals with the theory for ballistic spin wave transport across ultrathin iron-gadolinium nanojunctions, ..-Fe] [Gd]nML [Fe-.. , which are known to present structural interfacial disorder; n is the number of gadolinium monoatomic planes between the iron leads. It is shown that our PFMT-DNCLCPA theory gives a detailed and complete analysis for the properties of the ballistic transmission, and the corresponding reflection and absorption spectra across the structurally disordered nanojunction. We have developed the dynamic non-local coherent phase approximation (DNLCPA), and the phase field matching theory (PFMT) methods (Ghader and Khater 2013), and fully integrate them to study the ballistic spin wave transport across such nanojunctions. The DNCLPA method yields a full description of the dynamics of the spin wave excitations localized on the nanojunction, and their corresponding life-times and local density of states. These are excitations propagating laterally in the nanojunction atomic planes with finite life-times, but their fields are localized along the direction normal to the nanojunction. Moreover, the calculations determine the reflection, transmission, and absorption spectra for the spin waves incident at any arbitrary angle from the iron leads onto the nanojunction. The PFMT-DNCLCPA calculated results vary with nanojunction thickness. In particular, the normal incidence transmission spectra present no absorption effects and resonance assisted maxima are identified, notably at low frequencies at microscopic and submicroscopic wavelengths, which shift to lower frequencies with increasing nanojunction thickness. The results render these systems interesting for potential applications in magnonic circuitry. Fig.1 Calculated DNLCPA-PFMT reflection and transmission spectra for spin waves at normal incidence from the iron leads onto the magnetic ..-Fe] [Gd]3ML [Fe-.. nanojunction, as a function of the spin wave energies in units J(Fe-Fe)S(Fe) of the iron exchange and its spin. Note the transmission assisted maxima. Fig.2 Calculated absorption spectra for obliquely incident spin waves at the nanojunction cited in Fig.1, due to its structural interfacial disorder. Acknowledgements: The authors acknowledge QNRF financial support for the NPRP 4-184-1-035 project. References - S. Choi, K.S. Lee, K.Y. Guslienko, S.K. Kim, Phys. Rev. Lett. 98, 087205 (2007) - D. Ghader and A. Khater, to be published (2013) - A. Khater, B. Bourahla, M. Abou Ghantous, R. Tigrine, R. Chadli, Eur. Phys. J. B: Cond. Matter 82, 53 (2011) - A. Khitun and K. L. Wang, Proceedings of the Third International Conference on Information Technology, New Generations ITNG, 747 (2006) - V.V. Kruglyak and R.J. Hicken, J. Magn. Magn. Mater. 306, 191 (2006)
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The Gas Electron Multiplier For Charged Particle Detection
By Maya Abi AklThe Gas Electron Multiplier (GEM) has emerged as a promising tool for charged particle detection. It is being developed as a candidate detection system for muon particles for the future upgrade of Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It consists of a thin polymer foil, metal coated on each side and pierced by a high density of holes (see figure). The potential difference between the electrodes and the high electric field generated by the holes will further amplify the electrons released in the gas of the detector by the ionizing radiation or the charged particle crossing the detector. In this work, we will report on the results of the performance of the GEM prototype at the tests conducted at the CERN acceleration facilities using pion and muon beams. The main issues under study are efficiency, gain uniformity, and spatial resolution of the detector.
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