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  • 3101.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Dam, Mads
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Provably correct runtime monitoring (extended abstract)2008In: Fm 2008: Formal Methods, Proceedings / [ed] Cuellar, J; Maibaum, T; Sere, K, 2008, Vol. 5014, p. 262-277Conference paper (Refereed)
    Abstract [en]

    Runtime monitoring is an established technique for enforcing a wide range of program safety and security properties. We present a formalization of monitoring and monitor inlining, for the Java Virtual Machine. Monitors are security automata given in a special-purpose monitor specification language, ConSpec. The automata operate on finite or infinite strings of calls to a fixed API, allowing local dependencies on parameter values and heap content. We use a two-level class file annotation scheme to characterize two key properties: (i) that the program is correct with respect to the monitor as a constraint on allowed program behavior, and (ii) that the program has an instance of the given monitor embedded into it, which yields state changes at prescribed points according to the monitor's transition function. As our main application of these results we describe a concrete inliner, and use the annotation scheme to characterize its correctness. For this inliner, correctness of the level II annotations can be decided efficiently by a weakest precondition annotation checker, thus allowing on-device checking of inlining correctness in a proof-carrying code setting.

  • 3102.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    State Space Representation for Verification of Open Systems2006In: Algebraic Methodology And Software Technology, Proceedings / [ed] Johnson, M; Vene, V, Berlin: Springer , 2006, p. 5-20Conference paper (Refereed)
    Abstract [en]

    When designing an open system, there might be no implementation available for certain components at verification time. For such systems, verification has to be based on assumptions on the underspecified components. When component assumptions are expressed in Hennessy-Milner logic (HML), the state space of open systems can be naturally represented with modal transition systems (NITS), a graphical specification language equiexpressive with HML. Having an explicit state space representation supports state space exploration based verification techniques, Besides, it enables proof reuse and facilitates visualization for the user guiding the verification process. in interactive verification. As an intuitive representation of system behavior, it aids debugging when proof generation fails in automatic verification.

    However, HML is not expressive enough to capture temporal assumptions. For this purpose, we extend MTSs to represent the state space of open systems where component assumptions are specified in modal mu-calculus. We present a two-phase construction from process algebraic open system descriptions to such state space representations. The first phase deals with component assumptions, and is essentially a maximal model construction for the modal p-calculus. In the second phase, the models obtained are combined according to the structure of the open system to form the complete state space. The construction is sound and complete for systems with a single unknown component and sound for those-without dynamic process creation. For establishing open system properties based on the representation, we present a proof system which is sound and complete for prime formulae.

  • 3103.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Towards State Space Exploration Based Verification of Open Systems2005In: 4th International Workshop on Automated Verification of Infinite-State Systems (AVIS’05), April 2005, Edinburgh, Scotland, 2005Conference paper (Refereed)
  • 3104.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Naliuka, Katsiaryna
    University of Trento, Italy.
    ConSpec: A Formal Language for Policy Specification2008In: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 74, no 1-2, p. 2-12Article in journal (Refereed)
    Abstract [en]

    The paper presents ConSpec, an automata-based policy specification language. The language trades off clean semantics to language expressiveness: a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various Policy enforcement techniques.

  • 3105.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Naliuka, Katsiaryna
    University of Trento, Italy.
    ConSpec: A Formal Language for Policy Speci-fication2007In: Proceedings of The First International Workshop on Run Time Enforcement for Mobile and Distributed Systems (REM’07), 2007, p. 45-58Conference paper (Other academic)
    Abstract [en]

    The paper presents ConSpec, an automata based policy specification language. The language trades off clean semantics to language expressiveness; a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various policy enforcement techniques.

  • 3106. Akulich, A
    et al.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Laboratorieundersökningar av åldringsegenskaper hos dränerande asfaltbetong1992Report (Other academic)
  • 3107. Akyol, Z
    et al.
    Arbaugh, B
    Cleveland-Innes, Marta
    KTH, School of Computer Science and Communication (CSC), Media Technology and Graphic Arts, Media (closed 20111231).
    Garrison, R
    Ice, P
    Richardson, J
    Swan, K
    A response to the review of the community of inquiry framework2009In: Journal of distance education = Revue de l'enseignement à distance, ISSN 1916-6818, Vol. 23, no 2, p. 123-136Article in journal (Refereed)
    Abstract [en]

    The Community of Inquiry (CoI) framework has become a prominent model of teaching and learning in online and blended learning environments. Considerable research has been conducted which employs the framework with promising results, resulting in wide use to inform the practice of online and blended teaching and learning. For the CoI model to continue to grow and evolve, constructive critiques and debates are extremely beneficial, in so much as they identify potential problems and weaknesses in the model or its application, as well as provide direction for further research. In this context, the CoI framework was recently reviewed and critiqued by Rourke and Kanuka in their JDE article entitled “Learning in Communities of Inquiry: A Review of the Literature.” This paper is a response to this article and focuses on two main issues. The first issue is the focus of the review and critique on learning outcomes. The second issue concerns the representation, comprehensiveness, and methodology of the review.

  • 3108.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    The Least-Squares Identification of FIR Systems Subject to Worst-Case Noise1994In: 10th IFAC Symposium on System Identification, 1994, Vol. 2, p. 85-90Conference paper (Refereed)
  • 3109.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    The least-squares identification of FIR systems subject to worst-case noise1994In: System & Control Letters, Vol. 23, p. 329-338Article in journal (Refereed)
  • 3110.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    Ljung, Lennart
    Department of Electrical Engineering, Linköping University.
    On the choice of norms i system identification1994In: 10th IFAC Symposium on System Identification, 1994, Vol. 2, p. 103-108Conference paper (Refereed)
  • 3111.
    Al Abassi, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    The Possibilities for Establishing Agricultural Vocational Training Institutions in Kisumu2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3112.
    Al Ahad, Muhammed Abdullah
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Simmendinger, Christian
    T Syst Solut Res GmbH, D-70563 Stuttgart, Germany..
    Iakymchuk, Roman
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Laure, Erwin
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Markidis, Stefano
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Efficient Algorithms for Collective Operations with Notified Communication in Shared Windows2018In: PROCEEDINGS OF PAW-ATM18: 2018 IEEE/ACM PARALLEL APPLICATIONS WORKSHOP, ALTERNATIVES TO MPI (PAW-ATM), IEEE , 2018, p. 1-10Conference paper (Refereed)
    Abstract [en]

    Collective operations are commonly used in various parts of scientific applications. Especially in strong scaling scenarios collective operations can negatively impact the overall applications performance: while the load per rank here decreases with increasing core counts, time spent in e.g. barrier operations will increase logarithmically with the core count. In this article, we develop novel algorithmic solutions for collective operations such as Allreduce and Allgather(V)-by leveraging notified communication in shared windows. To this end, we have developed an extension of GASPI which enables all ranks participating in a shared window to observe the entire notified communication targeted at the window. By exploring benefits of this extension, we deliver high performing implementations of Allreduce and Allgather(V) on Intel and Cray clusters. These implementations clearly achieve 2x-4x performance improvements compared to the best performing MPI implementations for various data distributions.

  • 3113.
    Al Alam, Assad
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Optimally Fuel Ecient Speed Adaptation2008Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An optimal velocity trajectory for a heavy duty vehicle, obtained with the aid of modern GPS and digital map devices, depends on several variables. Curvature speed limitations, road grade, and posted road speed are common constraints imposed by the road travelled. This thesis presents a method for modelling and analysing a switching controller through the use of the former mentioned constraints. A non-linear model for the heavy duty vehicle is derived, enabling suitable control methods to be applied. Pontryagin’s Principal and LQR are discussed to get a profound understanding of how the controller should be designed. It is discovered that a switching controller based on optimal control and engineering experience is most favourable for the problem at hand. The controller is designed to address the main objectives set in this paper of minimising fuel consumption, travelling time, and brake wear.

    Gauss-Newtons’s algorithm for non-linear equations is used to estimate curve radii. Other input parameters are presumed to be available. GPS data error is discussed to perform a sensitivity analysis. An electronic horizon is produced on three road segments, entailed with data of the future road topology. Finally the switching controller is applied to the road segments. Experimental results show that the controller produces a velocity trajectory, which reduces fuel consumption by 5-15% and brake wear by 15-35%, while the travelling time is only increased by 1-2%.

  • 3114.
    Al Alam, Assad
    et al.
    Scania CV AB.
    Gattami, Ather
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    An experimental study on the fuel reduction potential of heavy duty vehicle platooning2010In: 13th International IEEE Conference on Intelligent Transportation Systems (ITSC), 2010, IEEE , 2010, p. 306-311Conference paper (Refereed)
    Abstract [en]

    Vehicle platooning has become important for the vehicle industry. Yet conclusive results with respect to the fuel reduction possibilities of platooning remain unclear. The focus in this study is the fuel reduction that heavy duty vehicle platooning enables and the analysis with respect to the influence of a commercial adaptive cruise control on the fuel consumption. Experimental results show that by using preview information of the road ahead from the lead vehicle, the adaptive cruise controller can reduce the fuel consumption. A study is undertaken for various masses of the lead vehicle. The results show that the best choice with respect to a heavier or lighter lead vehicle depends on the desired time gap. A maximum fuel reduction of 4.7-7.7% depending on the time gap, at a set speed of 70 km/h, can be obtained with two identical trucks. If the lead vehicle is 10 t lighter a corresponding 3.8-7.4% fuel reduction can be obtained depending on the time gap. Similarly if the lead vehicle is 10 t heavier a 4.3-6.9% fuel reduction can be obtained. All results indicate that a maximum fuel reduction can be achieved at a short relative distance, due to both air drag reduction and suitable control.

  • 3115.
    Al Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Gattami, Ather
    Electrical Engineering and Computer Sciences, UC Berkeley, Berkeley CA, 94720-1770, United States .
    Johansson, Karl Henrik
    Electrical Engineering and Computer Sciences, UC Berkeley, Berkeley CA, 94720-1770, United States .
    Tomlin, Claire Jennifer
    Scania CV AB, Södertälje, Sweden.
    Establishing safety for heavy duty vehicle platooning: a game theoretical approach2011In: IFAC Proceedings Volumes (IFAC-PapersOnline), 2011, p. 3818-3823Conference paper (Refereed)
    Abstract [en]

    It is fuel efficient to minimize the relative distance between vehicles to achievea maximum reduction in air drag. However, the relative distance can only be reduced to acertain extent without endangering a collision. Factors such as the vehicle velocity, the relativevelocity, and the characteristics of the vehicle ahead has a strong impact on what minimumrelative distance can be obtained. In this paper, we utilize optimal control and game theory toestablish safety criteria for heavy duty vehicle platooning applications. The derived results showthat a minimum relative distance of 1.2m can be obtained for two identical vehicles withoutendangering a collision, assuming that there is no delay present in the feedback system. If aworst case delay is present in the system, a minimum relative distance is deduced based uponthe vehicle’s maximum deceleration ability. The relative distance can be reduced if the followervehicle has a greater overall braking capability, which suggests that vehicle heterogeneity andorder has substantial impact. The findings are verified by simulations and the main conclusion isthat the relative distance utilized in commercial applications today can be reduced significantlywith a suitable advanced cruise control system.

  • 3116. Al Alawai, Reem
    et al.
    Laxman, karthik
    Dastgir, Sarim
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM. Sultan Qaboos University, , Oman.
    Role of bonding mechanisms during transfer hydrogenation reaction on heterogeneous catalysts of platinum nanoparticles supported on zinc oxide nanorods2016In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, p. 200-206Article in journal (Refereed)
    Abstract [en]

    For supported heterogeneous catalysis, the interface between a metal nanoparticle and the support plays an important role. In this work the dependency of the catalytic efficiency on the bonding chemistry of platinum nanoparticles supported on zinc oxide (ZnO) nanorods is studied. Platinum nanoparticles were deposited on ZnO nanorods (ZnO NR) using thermal and photochemical processes and the effects on the size, distribution, density and chemical state of the metal nanoparticles upon the catalytic activities are presented. The obtained results indicate that the bonding at Pt-ZnO interface depends on the deposition scheme which can be utilized to modulate the surface chemistry and thus the activity of the supported catalysts. Additionally, uniform distribution of metal on the catalyst support was observed to be more important than the loading density. It is also found that oxidized platinum Pt(IV) (platinum hydroxide) provided a more suitable surface for enhancing the transfer hydrogenation reaction of cyclohexanone with isopropanol compared to zero valent platinum. Photochemically synthesized ZnO supported nanocatalysts were efficient and potentially viable for upscaling to industrial applications.

  • 3117.
    Al Baghdady, Shayma
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Khan, Linnea
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Designing Roller compacted concrete (RCC) dams2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Concrete is the most common building material in the world and it consists of aggregates,cement and water that harden over time, it is also known as a composite material. The use ofconcrete is very versatile due to its resistance to wind and water and its ability to withstandhigh temperature. These qualities make concrete a suitable building material for largestructures such as dams.A dam is a huge construction that needs massive amount of concrete to build it with and thatleads to high cost, so alternative methods should be considered to minimize the cost ofconstructing the dams. One method is building the dams with Roller Compacted Concrete(RCC), which by definition is a composite construction material with no-slump consistency inits unhardened state and it has achieved its name from the construction method. The definitionfor a no-slump consistency is a freshly mixed concrete with a slump less than 6 mm. TheRCC is placed with the help of paving equipment and then it is compacted by vibrating rollerequipment. The RCC ingredients are the same as for the conventional concrete but it hasdifferent ratios in the materials that are blended to produce the concrete. It differs when itcomes to aggregates because both similar aggregates used in conventional concrete oraggregates that do not fulfill the normal standards can be used in the RCC mixtures. Thismeans, for example that aggregates found on the construction site can be used for the RCC.Compared to when constructing a conventional concrete dam, which is usually built in largeblocks, the RCC dam are usually built in thin, horizontal lifts, which allows rapidconstruction. This reduces the amount of formwork, but also the demand for man-hours areless due to the usage of machines for spreading and compacting, ultimately making it acheaper method. Building with RCC has become very popular around the world because of itsadvantages and new methods have been developed over the past two decades, adapted to theexperience gained after each project. All RCC dams that has been built, usually faceschallenges both during and after construction, and it includes everything from temperaturevariations, cracks to leakage.The main purpose of this master thesis is to create a guideline for how to design and constructdams with RCC and the idea is to be able to use it as a basis for future dams. Therequirements of Eurocode 2 and RIDAS are the basis of the criteria that the dam must fulfilland information of what is expected of the RCC is presented in this thesis. Furthermore anexample for design of an existing embankment dam to an RCC dam has been presented in thisthesis. The embankment dam needs to be rebuilt in order to increase the safety of the dam andthe goal of the case study was to determine the dimensions of the new RCC dam.

  • 3118.
    Al Dakkak, O.
    et al.
    Higher Institute of Applied Sciencenand Technology (HIAST).
    Ghneim, N.
    Higher Institute of Applied Sciencenand Technology (HIAST).
    Abou Zliekha, M.
    Damascus University/Faculty of Information Technology.
    Al Moubayed, Samer
    Damascus University/Faculty of Information Technology.
    Emotional Inclusion in An Arabic Text-To-Speech2005In: Proceedings of the 13th European Signal Processing Conference (EUSIPCO), Antalya, Turkey, 2005Conference paper (Refereed)
    Abstract [en]

    The goal of this paper is to present an emotional audio-visua lText to speech system for the Arabic Language. The system is based on two entities: un emotional audio text to speech system which generates speech depending on the input text and the desired emotion type, and un emotional Visual model which generates the talking heads, by forming the corresponding visemes. The phonemes to visemes mapping, and the emotion shaping use a 3-paramertic face model, based on the Abstract Muscle Model. We have thirteen viseme models and five emotions as parameters to the face model. The TTS produces the phonemes corresponding to the input text, the speech with the suitable prosody to include the prescribed emotion. In parallel the system generates the visemes and sends the controls to the facial model to get the animation of the talking head in real time.

  • 3119.
    Al Dakkak, O.
    et al.
    HIAST, Damascus, Syria.
    Ghneim, N.
    HIAST, Damascus, Syria.
    Abou Zliekha, M.
    Damascus University.
    Al Moubayed, Samer
    Damascus University.
    Prosodic Feature Introduction and Emotion Incorporation in an Arabic TTS2006In: Proceedings of IEEE International Conference on Information and Communication Technologies, Damascus, Syria, 2006, p. 1317-1322Conference paper (Refereed)
    Abstract [en]

    Text-to-speech is a crucial part of many man-machine communication applications, such as phone booking and banking, vocal e-mail, and many other applications. In addition to many other applications concerning impaired persons, such as: reading machines for blinds, talking machines for persons with speech difficulties. However, the main drawback of most speech synthesizers in the talking machines, are their metallic sounds. In order to sound naturally, we have to incorporate prosodic features, as close as possible to natural prosody, this helps to improve the quality of the synthetic speech. Actual researches in the world are towards better "automatic prosody generation".

  • 3120.
    al Ghatta, Amir
    KTH, School of Biotechnology (BIO).
    Matematisk modellering och analys av en ny process för metantillvaratagande2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 3121.
    Al Ghifary, Haider
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Hötorget Rooftop Hälsocenter & Restaurang - en takpotential2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An investigation of a rooftop potential of Hötorget Building 5 in Stockholm.

    This project proposes a program on floor 17, 18 and 19 (rooftop level) of the high-rise building containing a restaurant and a health centre with fitness facilities, group training and hamam-inspired steam sauna.

    The challenges have been to fit in a program in a space traditionally meant only for office use. The aim has been to provide a business that is useful for the place but at the same time provide architectural qualities by structural alterations to make vertical spaces with skylight, maximizing sightlines, keeping constant access to the façade and thereby access to the view outside. Other aims have been to create a brand and identity by adding an oriental hamam-theme into the project. Lastly the project intended to catch the “natural qualities” that are offered by a place of this height by giving access to the roof-top and letting the visitor experience the open sky and the city panorama throughout the year.

  • 3122.
    Al Hakim, Ezeddin
    KTH, School of Electrical Engineering and Computer Science (EECS).
    3D YOLO: End-to-End 3D Object Detection Using Point Clouds2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For safe and reliable driving, it is essential that an autonomous vehicle can accurately perceive the surrounding environment. Modern sensor technologies used for perception, such as LiDAR and RADAR, deliver a large set of 3D measurement points known as a point cloud. There is a huge need to interpret the point cloud data to detect other road users, such as vehicles and pedestrians.

    Many research studies have proposed image-based models for 2D object detection. This thesis takes it a step further and aims to develop a LiDAR-based 3D object detection model that operates in real-time, with emphasis on autonomous driving scenarios. We propose 3D YOLO, an extension of YOLO (You Only Look Once), which is one of the fastest state-of-the-art 2D object detectors for images. The proposed model takes point cloud data as input and outputs 3D bounding boxes with class scores in real-time. Most of the existing 3D object detectors use hand-crafted features, while our model follows the end-to-end learning fashion, which removes manual feature engineering.

    3D YOLO pipeline consists of two networks: (a) Feature Learning Network, an artificial neural network that transforms the input point cloud to a new feature space; (b) 3DNet, a novel convolutional neural network architecture based on YOLO that learns the shape description of the objects.

    Our experiments on the KITTI dataset shows that the 3D YOLO has high accuracy and outperforms the state-of-the-art LiDAR-based models in efficiency. This makes it a suitable candidate for deployment in autonomous vehicles.

  • 3123. Al Hasib, Abdullah
    Design and implementation of Wireless Packet Level Authentication2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Secure user authentication, authorization and access control have become the major challenges in any wireless security system, often due to certain wireless network characteristics such as lack of infrastructure, low power availability and mobility. Taking advantage of such network characteristics, an attacker can launch several security attacks like Denial of Service (DoS) attacks, packet spoofing and session hijacking attacks. Packet Level Authentication (PLA) provides an elegant network level solution to the aforementioned attacks by allowing every node in the network to validate the authenticity and integrity of a packet without any prior contact with the originator of the packet.

    The cornerstone of PLA is public key cryptography based digital signature which is added do every outgoing packet by the packet originator. Therefore, signature generation and verification schemes of PLA become infeasible in resource-constrained devices if dedicated hardware accelerator is not used.

    In this thesis, we present Wireless Packet Level Authentication (WPLA) that extends PLA to offer an adaptive hop-by-hop signature verification scheme. WPLA includes a lightweight signature verification approach for resource-constrained devices while retaining the public key cryptography based signature verification scheme for strong authentication. Furthermore, to ensure end-to-end data confidentiality over the unsecured channels, we integrate a symmetric encryption scheme along with secret key generation and distribution process. Finally, we implement the proposed solution and evaluate the performance of our implementation.

  • 3124. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    Interdisciplinary Centre for Security, Reliability and Trust, Universtity of Luxembourg, Luxembourg.
    Depth super-resolution by enhanced shift and add2013In: Computer Analysis of Images and Patterns: 15th International Conference, CAIP 2013, York, UK, August 27-29, 2013, Proceedings, Part II, Springer, 2013, Vol. 8048 LNCS, no PART 2, p. 100-107Conference paper (Refereed)
    Abstract [en]

    We use multi-frame super-resolution, specifically, Shift & Add, to increase the resolution of depth data. In order to be able to deploy such a framework in practice, without requiring a very high number of observed low resolution frames, we improve the initial estimation of the high resolution frame. To that end, we propose a new data model that leads to a median estimation from densely upsampled low resolution frames. We show that this new formulation solves the problem of undefined pixels and further allows to improve the performance of pyramidal motion estimation in the context of super-resolution without additional computational cost. As a consequence, it increases the motion diversity within a small number of observed frames, making the enhancement of depth data more practical. Quantitative experiments run on the Middlebury dataset show that our method outperforms state-of-the-art techniques in terms of accuracy and robustness to the number of frames and to the noise level.

  • 3125. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    Advanced Engineering - IEE S.A., Luxembourg .
    Dynamic super resolution of depth sequences with non-rigid motions2013In: 2013 IEEE International Conference on Image Processing, ICIP 2013 - Proceedings, IEEE Signal Processing Society, 2013, p. 660-664Conference paper (Refereed)
    Abstract [en]

    We enhance the resolution of depth videos acquired with low resolution time-of-flight cameras. To that end, we propose a new dedicated dynamic super-resolution that is capable to accurately super-resolve a depth sequence containing one or multiple moving objects without strong constraints on their shape or motion, thus clearly outperforming any existing super-resolution techniques that perform poorly on depth data and are either restricted to global motions or not precise because of an implicit estimation of motion. The proposed approach is based on a new data model that leads to a robust registration of all depth frames after a dense upsampling. The textureless nature of depth images allows to robustly handle sequences with multiple moving objects as confirmed by our experiments.

  • 3126. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    SnT - Universtity of Luxembourg, Luxembourg .
    Multi-frame super-resolution by enhanced shift & add2013In: 2013 8th International Symposium on Image and Signal Processing and Analysis (ISPA), IEEE , 2013, p. 171-176Conference paper (Refereed)
    Abstract [en]

    A critical step in multi-frame super-resolution is the registration of frames based on their motion. We improve the performance of current state-of-the-art super-resolution techniques by proposing a more robust and accurate registration as early as in the initialization stage of the high resolution estimate. Indeed, we solve the limitations on scale and motion inherent to the classical Shift & Add approach by upsampling the low resolution frames up to the super-resolution factor prior to estimating motion or to median filtering. This is followed by an appropriate selective optimization, leading to an enhanced Shift & Add. Quantitative and qualitative evaluations have been conducted at two levels; the initial estimation and the final optimized superresolution. Results show that the proposed algorithm outperforms existing state-of-art methods.

  • 3127. Al Ismaeil, Kassem
    et al.
    Aouada, Djamila
    Mirbach, Bruno
    Ottersten, Björn
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Bilateral Filter Evaluation Based on Exponential Kernels2012Conference paper (Refereed)
    Abstract [en]

    The well-known bilateral filter is used to smooth noisy images while keeping their edges. This filter is commonly used with Gaussian kernel functions without real justification. The choice of the kernel functions has a major effect on the filter behavior. We propose to use exponential kernels with L1 distances instead of Gaussian ones. We derive Stein's Unbiased Risk Estimate to find the optimal parameters of the new filter and compare its performance with the conventional one. We show that this new choice of the kernels has a comparable smoothing effect but with sharper edges due to the faster, smoothly decaying kernels.

  • 3128.
    Al Jallad, Mohannad
    KTH, School of Information and Communication Technology (ICT).
    REA Business Modeling Language: Toward a REA based Domain Specific Visual Language2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Resources Events Agents (REA) ontology is a profound business modeling ontology that was developed to define the architecture of accounting information systems. Nevertheless, REA did not manage to get the same attention as other business modeling ontologies. One reason of such abandon is the absence of a meaningful visual notation for the ontology, which has resulted in an abstruse ontology to non-academic audience. Another reason for this abandon is the fact that REA does not have a standard formal representation. This has resulted in a humble amount of researches which have focused on defining meta-models of the ontology while neglecting the wider purpose of REA-based information systems development. Consequently, the ontology was deviated away from its original purpose, and rather used in business schools.

    To solve the aforementioned issues, this research presents a Model Driven Development (MDD) technique in the form of a REA-based Domain Specific Visual Language (DSVL) that is implemented within a modeling and code generation editor. This effort was taken in order to answer the question of “How would a REA-DSVL based tool make the REA ontology implementable in the domain of information systems development?”

    In order to answer the research question, a design science methodology (DSRM) was implemented as the structure of this research. The DSRM was chosen because this research aims to develop three main artifacts. These are; a meta-model of REA, a visual notation of REA, and a REA-DSVL-based modeling and code generation tool.

    The first phase of the DSRM was to identify the problems which were mentioned earlier, followed by the requirements identification phase which drew the outline of the; meta-model, the visual notation, and the tool. After that, the development phase was conducted in order to develop the aforementioned artifacts. The editor was then demonstrated using a case study of a local company in Stockholm-Sweden. Finally, the resulted artifacts were evaluated based on the collected requirements and the results from the case study.

    Based on the analyses of the artifacts and the case study, this research was concluded with the result that a REA-based DSVL tool can help in boosting the planning and analysis phases of the software development lifecycle (SDLC). This is achieved by automating some of the conventional software planning and design tasks, which would lead to more accurate systems’ designs; thus, minimizing the time of the planning and design phases. And it can be achieved by abstracting the direct logic of REA through providing functionalities that help users from different backgrounds (academic and professional) to embrace a business modeling editor rather than an ontology; thus, attracting a wider users base for implementing REA.

  • 3129.
    Al Karim, Miftah
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    PMU Data Mining in and analysis of suitable algorithm for fault pattern recognition.2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Phasor measurement unit (PMU) is getting much attention in recent days to acquire power system data. It is because PMU provides the opportunity to collect high resolution system. Having a high resolution data provides scopes to monitor a system with different computational methods. Data mining is one of the effective methods. In the age of power system automation high resolution power system data storage and management has become more feasible. Data mining can be implemented on high resolution PMU data and many advantages can be achieved from such an operation.  

    Data mining is a scientific process through which a knowledge or patterns are identified from a large amount of data base. Data mining in power system based on PMU data is getting much focus in the recent years. Some of the prominent research on mining power system data and finding pattern is already going on in this field.

    There are different pattern recognition algorithms deployed in data mining field. Research has also been done to check the efficacy of those algorithms in action.

    In this thesis implementation of existing pattern recognition algorithms based on background study is carried out. Along with it one work-process is proposed to check out the possibilities of data mining in power system regarding fault pattern recognition. The mining process proposed here is a mixture of different existing algorithms and a new algorithm for fault classification. The work here mostly offers a broad perspective of data mining in power system rather than dealing with a specific application.

  • 3130.
    Al Karim, Miftah
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Synchrophasor-based data mining for power system fault analysis2012In: Innovative Smart Grid Technologies (ISGT Europe), 2012 3rd IEEE PES International Conference and Exhibition on, IEEE , 2012, p. 6465843-Conference paper (Refereed)
    Abstract [en]

    Phasor measurement units can provide high resolution and synchronized power system data, which can be effectively utilized for the implementation of data mining techniques. Data mining, based on pattern recognition algorithms can be of significant help for power system analysis, as high definition data is often complex to comprehend. In this paper three pattern recognition algorithms are applied to perform the data mining tasks. The deployment is carried out firstly for fault data classification, secondly for checking which faults are occurring more frequently and thirdly for identifying the root cause of a fault by clustering the parameters behind each scenario. For such purposes three algorithms are chosen, k-Nearest Neighbor, Naïve Bayes and the k-means Clustering.

  • 3131.
    Al Khatib, Iyad
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Performance Analysis of Application-Specific Multicore Systems on Chip2008Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    The last two decades have witnessed the birth of revolutionary technologies in data communications including wireless technologies, System on Chip (SoC), Multi Processor SoC (MPSoC), Network on Chip (NoC), and more. At the same time we have witnessed that performance does not always keep pace with expectations in many services like multimediaservices and biomedical applications. Moreover, the IT market has suffered from some crashes. Hence, this triggered us to think of making use of available technologies and developing new ones so that the performance level is suitable for given applications and services. In the medical field, from a statistical viewpoint, the biggest diseases in number of deaths are heart diseases, namely Cardiovascular Disease (CVD) and Stroke. The application with the largest market for CVD is the electrocardiogram (ECG/EKG) analysis. According to the World Health Organization (WHO) report in 2003, 29.2% of global deaths are due to CVD and Stroke, half of which could be prevented if there was proper monitoring. We found in the new advance in microelectronics, NoC, SoC, and MPSoC, a chance of a solution for such a big problem. We look at the communication technologies, wireless networks, and MPSoC and realize that many projects can be founded, and they may affect people's lives positively, as for example, curing people more rapidly, as well as homecare of such large scale diseases. These projects have a medical impact as well as economic and social impacts. The intention is to use performance analysis of interconnected microelectronic systems and combine it with MPSoC and NoC technologies in order to evolve to new systems on chip that may make a difference. Technically, we aim at rendering more computations in less time, on a chip with smaller volume, and with less expense. The performance demand and the vision of having a market success, i.e. contributing to lower healthcare costs, pose many challenges on the hardware/software co-design to meet these goals. This calls upon the development of new integrated circuits featuring increased energy efficiency while providing higher computation capabilities, i.e. better performance. The biomedical application of ECG analysis is an ideal target for an application-specific SoC implementation. However, new 12-lead ECG analyses algorithms are needed to meet the aforementioned goals. In this thesis, we present two novel algorithms for ECG analysis, namely the Autocorrelation-Function (ACF) based algorithm and the Fast Fourier Transform (FFT) based algorithm. In this respect, we explore the design space by analyzing different hardware and software architectures. As a result, we realize a design with twelve processors that can compute 3.5 million arithmetic computations and respect the real time hard deadline for our biomedical application (3.5-4seconds), and that can deploy the ACF-based and FFT-based algorithms. Then, we investigate the configuration space looking for the most effective solution, performance and energy-wise. Consequently, we present three interconnect architectures (Single Bus, Full Crossbar, and Partial Crossbar) and compare them with existing solutions. The sampling frequencies of 2.2 KHz and 4 KHz, with 12 DSPs, are found to be the critical points for our Shared-Bus design and Crossbar architecture, respectively. We also show how our performance analysis methods can be applied to such a field of SoC design and with a specific purpose application in order to converge to a solution that is acceptable from a performance viewpoint, meets the real-time demands, and can be implemented with the present technologies while at the same time paving the way for easier and faster development. In order to connect our MPSoC solution to communication networks to transmit the medical results to a healthcare center, we come up with new protocols that will allow the integration of multiple networks on chips in a communication network. Finally, we present a methodology for HW/SW Codesign for application-specific systems (with focus on biomedical applications) that require a large number of computations since this will foster the convergence to solutions that are acceptable from a performance point of view.

  • 3132.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Bertozzi, Davide
    Poletti, Francesco
    Benini, Luca
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Bechara, Mohamed
    Khalifeh, Hasan
    Hajjar, Mazen
    Nabiev, Rustam
    Jonsson, Sven
    Hardware/Software architecture for real-time ECG monitoring and analysis leveraging MPSoC technology2007In: Transactions on High-Performance Embedded Architectures and Compilers I / [ed] tenstrom, P; OBoyle, M; Bodin, F; Cintra, M; McKee, SA, 2007, Vol. 4050, p. 239-258Conference paper (Refereed)
    Abstract [en]

    The interest in high performance chip architectures for biomedical applications is gaining a lot of research and market interest. Heart diseases remain by far the main cause of death and a challenging problem for biomedical engineers to monitor and analyze. Electrocardiography (ECG) is an essential practice in heart medicine. However, ECG analysis still faces computational challenges, especially when 12 lead signals are to be analyzed in parallel, in real time, and under increasing sampling frequencies. Another challenge is the analysis of huge amounts of data that may grow to days of recordings. Nowadays, doctors use eyeball monitoring of the 12-lead ECG paper readout, which may seriously impair analysis accuracy. Our solution leverages the advance in multi-processor system-on-chip architectures, and it is centered on the parallelization of the ECG computation kernel. Our Hardware- Software (HW/SW) Multi-Processor System-on-Chip (MPSoQ design improves upon state-of-the-art mostly for its capability to perform real-time analysis of input data, leveraging the computation horsepower provided by many concurrent DSPs, more accurate diagnosis of cardiac diseases, and prompter reaction to abnormal heart alterations. The design methodology to go from the 12-lead ECG application specification to the final HW/SW architecture is the focus of this paper. We explore the design space by considering a number of hardware and software architectural variants, and deploy industrial components to build up the system.

  • 3133.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. iITC, Sweden .
    Ismail, M.
    WNoC: A microelectronic system architecture suitable for biomedical wireless sensor networks2005Conference paper (Refereed)
    Abstract [en]

    This paper presents a low-cost microelectronic system architecture suitable for single chip CMOS integration. The system architecture consists of a large set of on-chip processing-cores, sensors, and four multi-standard wireless border cores that are interconnected to form an ultra-fast microelectronic network of distributed-computing systems. Our main application areas are: biomedical emergency monitoring systems and healthcare. The hardware platform is based on Network-on-Chip (NoC) design and RF circuitry for wireless connectivity. We focus on the design of this Wireless Network-on-Chip (WNoC). WNoC faces several challenges. A main issue of concern from the application point of view is to have the design support the convergence to a decision within acceptable periods of time, because time is critical in many medical healthcare applications. We define a mechanism to enable many WNoCs to interact together over the wireless media. A key result is a design and protocol for internal and external WNoC communications between the main and backup wireless cores. We run simulations on a biomedical monitoring system for emergency situations, and our results show that the time to converge to a medical warning is in the range of milliseconds, which is acceptable for the related medical scenarios.

  • 3134.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Nabiev, Rustam
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    ECG-BIONET: A global biomedical network for human heart monitoring and analysis: Performance needs of an electrocardiogram Telemedicine platform for medical aid at the point-of-need2006In: 25TH IEEE INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS: VOLS 1-7, PROCEEDINGS IEEE INFOCOM 2006, New York: IEEE , 2006, p. 3282-3283Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a Tele-medicine application platform as a medical aid for patients suffering from Heart malfunction. We focus on heart diseases since they remain by far the major cause of death in the globe. Our solution utilizes the Satellite communication protocol DVB-RCS (Digital Video Broadcast- Return Channel Satellite), Wi-Fi, and the Network-on-Chip (NoC) technology. We utilize the 12-lead ECG biomedical technique to detect heart disorders via the biomedical NoC, which transmits the medical alarm and results via the biomedical network, ECG-BIONET. We do not investigate the DVB-RCS standard or Wi-Fi technology, but rather we try to utilize this technology, and we look at it from a performance point of view for our application by investigating three parameters, namely: delay, packet loss, and reliability. We follow a top down approach by looking at the needs of the application from a performance guarantee for our specific-purpose network.

  • 3135.
    Al Khatib, Lyad
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Performance anaalysis of wireless LAN access points2003Licentiate thesis, comprehensive summary (Other scientific)
  • 3136. Al Moubayed, S.
    et al.
    Bohus, D.
    Esposito, A.
    Heylen, D.
    Koutsombogera, M.
    Papageorgiou, H.
    Skantze, Gabriel
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    UM3I 2014 chairs' welcome2014In: UM3I 2014 - Proceedings of the 2014 ACM Workshop on Understanding and Modeling Multiparty, Multimodal Interactions, Co-located with ICMI 2014, 2014, p. iii-Conference paper (Other (popular science, discussion, etc.))
  • 3137.
    Al Moubayed, Samer
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Bringing the avatar to life: Studies and developments in facial communication for virtual agents and robots2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The work presented in this thesis comes in pursuit of the ultimate goal of building spoken and embodied human-like interfaces that are able to interact with humans under human terms. Such interfaces need to employ the subtle, rich and multidimensional signals of communicative and social value that complement the stream of words – signals humans typically use when interacting with each other.

    The studies presented in the thesis concern facial signals used in spoken communication, and can be divided into two connected groups. The first is targeted towards exploring and verifying models of facial signals that come in synchrony with speech and its intonation. We refer to this as visual-prosody, and as part of visual-prosody, we take prominence as a case study. We show that the use of prosodically relevant gestures in animated faces results in a more expressive and human-like behaviour. We also show that animated faces supported with these gestures result in more intelligible speech which in turn can be used to aid communication, for example in noisy environments.

    The other group of studies targets facial signals that complement speech. As spoken language is a relatively poor system for the communication of spatial information; since such information is visual in nature. Hence, the use of visual movements of spatial value, such as gaze and head movements, is important for an efficient interaction. The use of such signals is especially important when the interaction between the human and the embodied agent is situated – that is when they share the same physical space, and while this space is taken into account in the interaction.

    We study the perception, the modelling, and the interaction effects of gaze and head pose in regulating situated and multiparty spoken dialogues in two conditions. The first is the typical case where the animated face is displayed on flat surfaces, and the second where they are displayed on a physical three-dimensional model of a face. The results from the studies show that projecting the animated face onto a face-shaped mask results in an accurate perception of the direction of gaze that is generated by the avatar, and hence can allow for the use of these movements in multiparty spoken dialogue.

    Driven by these findings, the Furhat back-projected robot head is developed. Furhat employs state-of-the-art facial animation that is projected on a 3D printout of that face, and a neck to allow for head movements. Although the mask in Furhat is static, the fact that the animated face matches the design of the mask results in a physical face that is perceived to “move”.

    We present studies that show how this technique renders a more intelligible, human-like and expressive face. We further present experiments in which Furhat is used as a tool to investigate properties of facial signals in situated interaction.

    Furhat is built to study, implement, and verify models of situated and multiparty, multimodal Human-Machine spoken dialogue, a study that requires that the face is physically situated in the interaction environment rather than in a two-dimensional screen. It also has received much interest from several communities, and been showcased at several venues, including a robot exhibition at the London Science Museum. We present an evaluation study of Furhat at the exhibition where it interacted with several thousand persons in a multiparty conversation. The analysis of the data from the setup further shows that Furhat can accurately regulate multiparty interaction using gaze and head movements.

  • 3138.
    Al Moubayed, Samer
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Prosodic Disambiguation in Spoken Systems Output2009In: Proceedings of Diaholmia'09: 2009 Workshop on the Semantics and Pragmatics of Dialogue / [ed] Jens Edlund, Joakim Gustafson, Anna Hjalmarsson, Gabriel Skantze, Stockholm, Sweden., 2009, p. 131-132Conference paper (Refereed)
    Abstract [en]

    This paper presents work on using prosody in the output of spoken dialogue systems to resolve possible structural ambiguity of output utterances. An algorithm is proposed to discover ambiguous parses of an utterance and to add prosodic disambiguation events to deliver the intended structure. By conducting a pilot experiment, the automatic prosodic grouping applied to ambiguous sentences shows the ability to deliver the intended interpretation of the sentences.

  • 3139.
    Al Moubayed, Samer
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Towards rich multimodal behavior in spoken dialogues with embodied agents2013In: 4th IEEE International Conference on Cognitive Infocommunications, CogInfoCom 2013 - Proceedings, IEEE Computer Society, 2013, p. 817-822Conference paper (Refereed)
    Abstract [en]

    Spoken dialogue frameworks have traditionally been designed to handle a single stream of data - the speech signal. Research on human-human communication has been providing large evidence and quantifying the effects and the importance of a multitude of other multimodal nonverbal signals that people use in their communication, that shape and regulate their interaction. Driven by findings from multimodal human spoken interaction, and the advancements of capture devices and robotics and animation technologies, new possibilities are rising for the development of multimodal human-machine interaction that is more affective, social, and engaging. In such face-to-face interaction scenarios, dialogue systems can have a large set of signals at their disposal to infer context and enhance and regulate the interaction through the generation of verbal and nonverbal facial signals. This paper summarizes several design decision, and experiments that we have followed in attempts to build rich and fluent multimodal interactive systems using a newly developed hybrid robotic head called Furhat, and discuss issues and challenges that this effort is facing.

  • 3140.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Alexanderson, Simon
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Granström, Björn
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    A robotic head using projected animated faces2011In: Proceedings of the International Conference on Audio-Visual Speech Processing 2011 / [ed] Salvi, G.; Beskow, J.; Engwall, O.; Al Moubayed, S., Stockholm: KTH Royal Institute of Technology, 2011, p. 71-Conference paper (Refereed)
    Abstract [en]

    This paper presents a setup which employs virtual animatedagents for robotic heads. The system uses a laser projector toproject animated faces onto a three dimensional face mask. This approach of projecting animated faces onto a three dimensional head surface as an alternative to using flat, two dimensional surfaces, eliminates several deteriorating effects and illusions that come with flat surfaces for interaction purposes, such as exclusive mutual gaze and situated and multi-partner dialogues. In addition to that, it provides robotic heads with a flexible solution for facial animation which takes into advantage the advancements of facial animation using computer graphics overmechanically controlled heads.

  • 3141.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Ananthakrishnan, Gopal
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Acoustic-to-Articulatory Inversion based on Local Regression2010In: Proceedings of the 11th Annual Conference of the International Speech Communication Association, INTERSPEECH 2010, Makuhari, Japan, 2010, p. 937-940Conference paper (Refereed)
    Abstract [en]

    This paper presents an Acoustic-to-Articulatory inversionmethod based on local regression. Two types of local regression,a non-parametric and a local linear regression have beenapplied on a corpus containing simultaneous recordings of positionsof articulators and the corresponding acoustics. A maximumlikelihood trajectory smoothing using the estimated dynamicsof the articulators is also applied on the regression estimates.The average root mean square error in estimating articulatorypositions, given the acoustics, is 1.56 mm for the nonparametricregression and 1.52 mm for the local linear regression.The local linear regression is found to perform significantlybetter than regression using Gaussian Mixture Modelsusing the same acoustic and articulatory features.

  • 3142.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Ananthakrishnan, Gopal
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Enflo, Laura
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Music Acoustics. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Automatic Prominence Classification in Swedish2010In: Proceedings of Speech Prosody 2010, Workshop on Prosodic Prominence, Chicago, USA, 2010Conference paper (Refereed)
    Abstract [en]

    This study aims at automatically classifying levels of acoustic prominence on a dataset of 200 Swedish sentences of read speech by one male native speaker. Each word in the sentences was categorized by four speech experts into one of three groups depending on the level of prominence perceived. Six acoustic features at a syllable level and seven features at a word level were used. Two machine learning algorithms, namely Support Vector Machines (SVM) and memory based Learning (MBL) were trained to classify the sentences into their respective classes. The MBL gave an average word level accuracy of 69.08% and the SVM gave an average accuracy of 65.17 % on the test set. These values were comparable with the average accuracy of the human annotators with respect to the average annotations. In this study, word duration was found to be the most important feature required for classifying prominence in Swedish read speech

  • 3143.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT. KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Baklouti, M.
    Chetouani, M.
    Dutoit, T.
    Mahdhaoui, A.
    Martin, J. -C
    Ondas, S.
    Pelachaud, C.
    Urbain, J.
    Yilmaz, M.
    Generating Robot/Agent Backchannels During a Storytelling Experiment: 2009 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-72009In: ICRA: 2009 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, 2009, p. 3749-3754Conference paper (Refereed)
    Abstract [en]

    This work presents the development of a real-time framework for the research of Multimodal Feedback of Robots/Talking Agents in the context of Human Robot Interaction (HRI) and Human Computer Interaction (HCI). For evaluating the framework, a Multimodal corpus is built (ENTERFACE_STEAD), and a study on the important multimodal features was done for building an active Robot/Agent listener of a storytelling experience with Humans. The experiments show that even when building the same reactive behavior models for Robot and Talking Agents, the interpretation and the realization of the behavior communicated is different due to the different communicative channels Robots/Agents offer be it physical but less-human-like in Robots, and virtual but more expressive and human-like in Talking agents.

  • 3144.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    A novel Skype interface using SynFace for virtual speech reading support2011In: Proceedings from Fonetik 2011, June 8 - June 10, 2011: Speech, Music and Hearing, Quarterly Progress and Status Report, TMH-OPSR, Volume 51, 2011, Stockholm, Sweden, 2011, p. 33-36Conference paper (Other academic)
    Abstract [en]

    We describe in this paper a support client interface to the IP telephony application Skype. The system uses a variant of SynFace, a real-time speech reading support system using facial animation. The new interface is designed for the use by elderly persons, and tailored for use in systems supporting touch screens. The SynFace real-time facial animation system has previously shown ability to enhance speech comprehension for the hearing impaired persons. In this study weemploy at-home field studies on five subjects in the EU project MonAMI. We presentinsights from interviews with the test subjects on the advantages of the system, and onthe limitations of such a technology of real-time speech reading to reach the homesof elderly and the hard of hearing.

  • 3145.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology. KTH, School of Computer Science and Communication (CSC), Centres, Centre for Speech Technology, CTT.
    Effects of Visual Prominence Cues on Speech Intelligibility2009In: Proceedings of Auditory-Visual Speech Processing AVSP'09, Norwich, England, 2009Conference paper (Refereed)
    Abstract [en]

    This study reports experimental results on the effect of visual prominence, presented as gestures, on speech intelligibility. 30 acoustically vocoded sentences, permutated into different gestural conditions were presented audio-visually to 12 subjects. The analysis of correct word recognition shows a significant increase in intelligibility when focally-accented (prominent) words are supplemented with head-nods or with eye-brow raise gestures. The paper also examines coupling other acoustic phenomena to brow-raise gestures. As a result, the paper introduces new evidence on the ability of the non-verbal movements in the visual modality to support audio-visual speech perception.

  • 3146.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Perception of Nonverbal Gestures of Prominence in Visual Speech Animation2010In: Proceedings of the ACM/SSPNET 2nd International Symposium on Facial Analysis and Animation, Edinburgh, UK, 2010, p. 25-Conference paper (Refereed)
    Abstract [en]

    It has long been recognized that visual speech information is important for speech perception [McGurk and MacDonald 1976] [Summerfield 1992]. Recently there has been an increasing interest in the verbal and non-verbal interaction between the visual and the acoustic modalities from production and perception perspectives. One of the prosodic phenomena which attracts much focus is prominence. Prominence is defined as when a linguistic segment is made salient in its context.

  • 3147.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Prominence Detection in Swedish Using Syllable Correlates2010In: Proceedings of the 11th Annual Conference of the International Speech Communication Association, INTERSPEECH 2010, Makuhari, Japan, 2010, p. 1784-1787Conference paper (Refereed)
    Abstract [en]

    This paper presents an approach to estimating word level prominence in Swedish using syllable level features. The paper discusses the mismatch problem of annotations between word level perceptual prominence and its acoustic correlates, context, and data scarcity. 200 sentences are annotated by 4 speech experts with prominence on 3 levels. A linear model for feature extraction is proposed on a syllable level features, and weights of these features are optimized to match word level annotations. We show that using syllable level features and estimating weights for the acoustic correlates to minimize the word level estimation error gives better detection accuracy compared to word level features, and that both features exceed the baseline accuracy.

  • 3148.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Blomberg, Mats
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Granström, Björn
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Gustafson, Joakim
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Mirning, N.
    Skantze, Gabriel
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Talking with Furhat - multi-party interaction with a back-projected robot head2012In: Proceedings of Fonetik 2012, Gothenberg, Sweden, 2012, p. 109-112Conference paper (Other academic)
    Abstract [en]

    This is a condensed presentation of some recent work on a back-projected robotic head for multi-party interaction in public settings. We will describe some of the design strategies and give some preliminary analysis of an interaction database collected at the Robotville exhibition at the London Science Museum

  • 3149.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Bollepalli, Bajibabu
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Gustafson, Joakim
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Hussen-Abdelaziz, A.
    Johansson, Martin
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Koutsombogera, M.
    Lopes, J. D.
    Novikova, J.
    Oertel, Catharine
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Skantze, Gabriel
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Stefanov, Kalin
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Varol, G.
    Human-robot Collaborative Tutoring Using Multiparty Multimodal Spoken Dialogue2014Conference paper (Refereed)
    Abstract [en]

    In this paper, we describe a project that explores a novel experi-mental setup towards building a spoken, multi-modally rich, and human-like multiparty tutoring robot. A human-robotinteraction setup is designed, and a human-human dialogue corpus is collect-ed. The corpus targets the development of a dialogue system platform to study verbal and nonverbaltutoring strategies in mul-tiparty spoken interactions with robots which are capable of spo-ken dialogue. The dialogue task is centered on two participants involved in a dialogueaiming to solve a card-ordering game. Along with the participants sits a tutor (robot) that helps the par-ticipants perform the task, and organizes and balances their inter-action. Differentmultimodal signals captured and auto-synchronized by different audio-visual capture technologies, such as a microphone array, Kinects, and video cameras, were coupled with manual annotations. These are used build a situated model of the interaction based on the participants personalities, their state of attention, their conversational engagement and verbal domi-nance, and how that is correlated with the verbal and visual feed-back, turn-management, and conversation regulatory actions gen-erated by the tutor. Driven by the analysis of the corpus, we will show also the detailed design methodologies for an affective, and multimodally rich dialogue system that allows the robot to meas-ure incrementally the attention states, and the dominance for each participant, allowing the robot head Furhat to maintain a well-coordinated, balanced, and engaging conversation, that attempts to maximize the agreement and the contribution to solve the task. This project sets the first steps to explore the potential of us-ing multimodal dialogue systems to build interactive robots that can serve in educational, team building, and collaborative task solving applications.

  • 3150.
    Al Moubayed, Samer
    et al.
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Beskow, Jonas
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Bollepalli, Bajibabu
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Hussen-Abdelaziz, A.
    Johansson, Martin
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Koutsombogera, M.
    Lopes, J.
    Novikova, J.
    Oertel, Catharine
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Skantze, Gabriel
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Stefanov, Kalin
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH, Speech Communication and Technology.
    Varol, G.
    Tutoring Robots: Multiparty Multimodal Social Dialogue With an Embodied Tutor2014Conference paper (Refereed)
    Abstract [en]

    This project explores a novel experimental setup towards building spoken, multi-modally rich, and human-like multiparty tutoring agent. A setup is developed and a corpus is collected that targets the development of a dialogue system platform to explore verbal and nonverbal tutoring strategies in multiparty spoken interactions with embodied agents. The dialogue task is centered on two participants involved in a dialogue aiming to solve a card-ordering game. With the participants sits a tutor that helps the participants perform the task and organizes and balances their interaction. Different multimodal signals captured and auto-synchronized by different audio-visual capture technologies were coupled with manual annotations to build a situated model of the interaction based on the participants personalities, their temporally-changing state of attention, their conversational engagement and verbal dominance, and the way these are correlated with the verbal and visual feedback, turn-management, and conversation regulatory actions generated by the tutor. At the end of this chapter we discuss the potential areas of research and developments this work opens and some of the challenges that lie in the road ahead.

60616263646566 3101 - 3150 of 122673
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