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  • 201.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Haziza, Frédéric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Holík, Lukás
    Brno Univ Technol, Brno, Czech Republic.
    Parameterized verification through view abstraction2016Inngår i: International Journal on Software Tools for Technology Transfer, ISSN 1433-2779, E-ISSN 1433-2787, Vol. 18, nr 5, s. 495-516Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a simple and efficient framework for automatic verification of systems with a parametric number of communicating processes. The processes may be organized in various topologies such as words, multisets, rings, or trees. Our method needs to inspect only a small number of processes in order to show correctness of the whole system. It relies on an abstraction function that views the system from the perspective of a fixed number of processes. The abstraction is used during the verification procedure in order to dynamically detect cut-off points beyond which the search of the state space need not continue. We show that the method is complete for a large class of well quasi-ordered systems including Petri nets. Our experimentation on a variety of benchmarks demonstrate that the method is highly efficient and that it works well even for classes of systems with undecidable verification problems. In particular, the method handles the fine-grained and full version of Szymanski's mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.

  • 202.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Haziza, Frédéric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Holík, Lukáš
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    All for the price of few: (Parameterized verification through view abstraction)2013Inngår i: Verification, Model Checking, and Abstract Interpretation, Springer Berlin/Heidelberg, 2013, s. 476-495Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    vmcai2013
  • 203.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datorteknik.
    Liang, Chencheng
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Rümmer, Philipp
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för datorteknik. Univ Regensburg, Regensburg, Germany.
    Boosting Constrained Horn Solving by Unsat Core Learning2024Inngår i: Verification, Model Checking, and Abstract Interpretation / [ed] Rayna Dimitrova; Ori Lahav; Sebastian Wolff, Springer Nature, 2024, s. 280-302Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Relational Hyper-Graph Neural Network (R-HyGNN) was introduced in [1] to learn domain-specific knowledge from program verification problems encoded in Constrained Horn Clauses (CHCs). It exhibits high accuracy in predicting the occurrence of CHCs in counterexamples. In this research, we present an R-HyGNN-based framework called MUSHyperNet. The goal is to predict the Minimal Unsatisfiable Subsets (MUSes) (i.e., unsat core) of a set of CHCs to guide an abstract symbolic model checking algorithm. In MUSHyperNet, we can predict the MUSes once and use them in different instances of the abstract symbolic model checking algorithm. We demonstrate the efficacy of MUSHyperNet using two instances of the abstract symbolic modelchecking algorithm: Counter-Example Guided Abstraction Refinement (CEGAR) and symbolic model-checking-based (SymEx) algorithms. Our framework enhances performance on a uniform selection of benchmarks across all categories from CHC-COMP, solving more problems (6.1% increase for SymEx, 4.1% for CEGAR) and reducing average solving time (13.3% for SymEx, 7.1% for CEGAR).

  • 204.
    Abdulla, Parosh
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Jonsson, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Trinh, Cong Quy
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Automated Verification of Linearization Policies2016Inngår i: Automated Verification of Linearization Policies: 23rd International Symposium, SAS 2016, Edinburgh, UK, September 8-10, 2016, Proceedings, 2016Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We present a novel framework for automated verification of linearizability for concurrent data structures that implement sets, stacks, and queues. The framework requires the user to provide a linearization policy, which describes how linearization point placement in different concurrent threads affect each other; such linearization policies are often provided informally together with descriptions of new algorithms. We present a specification formalism for linearization policies which allows the user to specify, in a simple and concise manner, complex patterns including non-fixed linearization points. To automate verification, we extend thread-modular reasoning to bound the number of considered threads, and use a novel symbolic representation for unbounded heap structures that store data from an unbounded domain. We have implemented our framework in a tool and successfully used it to prove linearizability for a wide range of algorithms, including all implementations of concurrent sets, stacks, and queues based on singly-linked lists that are known to us from the literature.

  • 205.
    Abdullah, Jakaria
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Dai, Gaoyang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Mohaqeqi, Morteza
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Yi, Wang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Schedulability Analysis and Software Synthesis for Graph-Based Task Models with Resource Sharing2018Inngår i: Proc. 24th Real-Time and Embedded Technology and Applications Symposium, IEEE Computer Society, 2018, s. 261-270Konferansepaper (Fagfellevurdert)
  • 206.
    Abdullah, Muhammad
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Mobile Robot Navigation using potential fields andmarket based optimization2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A team of mobile robots moving in a shared area raises the problem of safe and autonomous navigation. While avoiding static and dynamic obstacles, mobile robots in a team can lead to complicated and irregular movements. Local reactive approaches are used to deal with situations where robots are moving in dynamic environment; these approaches help in safe navigation of robots but do not give optimal solution. In this work a 2-D navigation strategy is implemented, where a potential field method is used for obstacle avoidance. This potential field method is improved using fuzzy rules, traffic rules and market based optimization (MBO). Fuzzy rules are used to deform repulsive potential fields in the vicinity of obstacles. Traffic rules are used to deal situations where two robots are crossing each other. Market based optimization (MBO) is used to strengthen or weaken repulsive potential fields generated by other robots based on their importance. For the verification of this strategy on more realistic vehicles this navigation strategy is implemented and tested in simulation. Issues while implementing this method and limitations of this navigation strategy are also discussed. Extensive experiments are performed to examine the validity of MBO navigation strategy over traditional potential field (PF) method.

    Fulltekst (pdf)
    fulltext
  • 207.
    Abdullah, Nazri
    et al.
    Universiti Tun Hussien Onn Malaysia, Malaysia .
    Kounelis, Ioannis
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Security Extensions for Mobile Commerce Objects2014Inngår i: SECURWARE 2014, The Eighth International Conference on Emerging Security Information, Systems and Technologies, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Electronic commerce and its variance mobile commerce have tremendously increased their popularity in the last several years. As mobile devices have become the most popular mean to access and use the Internet, mobile commerce and its security are timely and very hot topics. Yet, today there is still no consistent model of various m–commerce applications and transactions, even less clear specification of their security. In order to address and solve those issues, in this paper, we first establish the concept of mobile commerce objects, an equivalent of virtual currencies, used for m–commerce transactions. We describe functionalities and unique characteristics of these objects; we follow with security requirements, and then offer some solutions – security extensions of these objects. All solutions are treated within the complete lifecycle of creation and use of the m–commerce objects.

  • 208. Abdullah, Omed Gh.
    et al.
    Tahir, Dana A.
    Kadir, K.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för material- och miljökemi (MMK). Kurdistan Institution for Strategic Studies and Scientific Research, Iraq.
    Optical and structural investigation of synthesized PVA/PbS nanocomposites2015Inngår i: Journal of materials science. Materials in electronics, ISSN 0957-4522, E-ISSN 1573-482X, Vol. 26, nr 9, s. 6939-6944Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polymer nanocomposite based on polyvinyl alcohol (PVA) and lead sulfide (PbS) in the average radius of (1.88-2.23) nm, have been synthesized using the chemical reduction rote and solution casting technique for different concentrations of PbS. The characterization of the polymer nanocomposite films were carried out using UV-visible spectroscopy, SEM, and XRD. The effect of various concentration of PbS NP on the optical properties of the composite has been studied to understand the optimum conditions for the synthesis process. The nanocomposite film shows high UV and visible light absorptions in the wavelength range of (200-500) nm, which correspond to the characteristics of the PbS NPs. The significant decreasing trend of the direct allowed band gap of the nanocomposite was observed upon increasing the Pb source concentration, from (6.27 eV) for pure PVA to (2.34 eV) for 0.04 M PbS concentration, which is much higher than the energy gap of bulk PbS value (0.41 eV). The calculated values of the static refractive index of Cauchy dispersion model were in the range of (1.09-1.20). X-ray diffraction analysis confirmed the cubic nanocrystalline PbS phase formation.

  • 209.
    Abdullah, Saad
    et al.
    Mälardalens universitet, Akademin för innovation, design och teknik, Inbyggda system. Department of Biomedical Engineering, Riphah International University, Lahore, Pakistan.
    Abdelakram, Hafid
    Mälardalens universitet, Akademin för innovation, design och teknik, Inbyggda system.
    Kristoffersson, Annica
    Mälardalens universitet, Akademin för innovation, design och teknik, Inbyggda system.
    Bilal Saeed, Muhammad
    Biomedical Engineering Department, NED University of Engineering and Technology, Karachi, Pakistan..
    Saad, Samreen
    Department of Biochemistry, Karachi University, Karachi, Pakistan.
    Real-Time Portable Raspberry Pi-Based System for Sickle Cell Anemia Detection2023Inngår i: Abstracts: Medicinteknikdagarna 2023, 2023, s. 118-118Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    fulltext
  • 210.
    Abdullah, Saad
    et al.
    Mälardalens universitet, Akademin för innovation, design och teknik, Inbyggda system.
    Kanwal, Kehkashan
    Mälardalens universitet, Akademin för innovation, design och teknik.
    Hafid, A.
    Ziauddin University, Department of Electrical Engineering, Karachi, Pakistan.
    Difallah, S.
    University of Science and Technology Houari Boumediene, Instrumentation Laboratory, Algiers, Algeria.
    Low-cost BLE based intravenous monitoring and control infusion system2023Inngår i: Int. Conf. Adv. Electron., Control Commun. Syst., ICAECCS, Institute of Electrical and Electronics Engineers Inc. , 2023Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Administering the medications and fluids intravenously is a frequent practice in modern medical procedures, which plays a vital role in the treatment of certain acute conditions which require immediate action by drugs or fluids. This paper covers the design of a low-cost, wireless drip monitoring system for use in the hospital environment. The device is equipped with the Bluetooth low energy based battery-operated microcontroller, an infrared based drops counting system and a digital servo motor to control the drip flow rate, and it is attached to an existing intravenous stand. A LabView graphical user interface has also been developed to provide sets of input to the system to calculate the desired drip rate and the amount of pressure that digital servo motor must apply to achieve it. The system shows an average accuracy of 96% when compared with the measured and calculated values. This allows accurate computation of the level of the drip.

  • 211. Abdullah, Zaid
    et al.
    Kisseleff, Steven
    Alves Martins, Wallace
    Chen, Gaojie
    Sanguinetti, Luca
    Ntontin, Konstantinos
    Papazafeiropoulos, Anastasios
    Chatzinotas, Symeon
    Ottersten, Björn
    University of Luxembourg, Luxembourg.
    Cooperative Hybrid Networks with Active Relays and RISs for B5G: Applications, Challenges, and Research Directions2022Inngår i: IEEE Wireless Communications, ISSN 15361284, s. 1-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Among the recent advances and innovations in wireless technologies, reconfigurable intelligent surfaces (RISs) have received much attention and are envisioned to be one of the enabling technologies for beyond 5G (B5G) networks. On the other hand, active (or classical) cooperative relays have played a key role in providing reliable and power-efficient communications in previous wireless generations. In this article, we focus on hybrid network architectures that amalgamate both active relays and RISs. The operation concept and protocols of each technology are first discussed. Subsequently, we present multiple use cases of cooperative hybrid networks where both active relays and RISs can coexist harmoniously for enhanced rate performance. Furthermore, a case study is provided which demonstrates the achievable rate performance of a communication network assisted by either an active relay, an RIS, or both, and with different relaying protocols. Finally, we provide the reader with the challenges and key research directions in this area.

  • 212.
    Abdullah, Zaid
    et al.
    Interdisciplinary Centre for Security, Reliability and Trust (Sn T), University of Luxembourg, L-1855, Luxembourg..
    Papazafeiropoulos, Anastasios
    Communications and Intelligent Systems Research Group, University of Hertfordshire, Hatfield AL10 9AB, U.K., and also with the SnT, University of Luxembourg, Luxembourg..
    Kisseleff, Steven
    Interdisciplinary Centre for Security, Reliability and Trust (Sn T), University of Luxembourg, L-1855, Luxembourg..
    Chatzinotas, Symeon
    Interdisciplinary Centre for Security, Reliability and Trust (Sn T), University of Luxembourg, L-1855, Luxembourg..
    Ottersten, Björn
    Interdisciplinary Centre for Security, Reliability and Trust (Sn T), University of Luxembourg, L-1855, Luxembourg..
    Impact of Phase-Noise and Spatial Correlation on Double-RIS-Assisted Multiuser MISO Networks2022Inngår i: IEEE Wireless Communications Letters, ISSN 2162-2337, E-ISSN 2162-2345, s. 1-1Artikkel i tidsskrift (Fagfellevurdert)
  • 213.
    Abdulrazzak, Shahm
    et al.
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Mattsson, Tor
    Högskolan i Halmstad, Akademin för informationsteknologi.
    Java Auto Grader2023Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The process of grading code submissions in programming courses is time-consuming and error-prone. To address this issue, we propose a project that automates the testing and grading process for Java code submissions at Halmstad University. Our approach leverages property-based testing using the JUnit Quick-Check library to generate tests and test reports automatically.

     

    The tool we demonstrate in this project is designed to provide students with immediate feedback on their code submissions and reduce the workload for instructors. By automatically generating tests and test reports, our approach ensures that code submissions meet the required specifications and are free from common errors. The com.pholser library is utilized to implement the property-based testing approach.

     

    We believe that our project has the potential to improve the grading process for programming courses and provide a more efficient and effective way of assessing student code submissions. Our implementation can be easily extended to support other programming languages and can be integrated with existing learning management systems to provide a seamless experience for instructors and students alike.

    Fulltekst (pdf)
    fulltext
  • 214. Abe, K.
    et al.
    Iwana, B. K.
    Holmer, Viktor Gösta
    KTH.
    Uchida, S.
    Font creation using class discriminative deep convolutional generative adversarial networks2018Inngår i: Proceedings - 4th Asian Conference on Pattern Recognition, ACPR 2017, Institute of Electrical and Electronics Engineers Inc. , 2018, s. 238-243Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this research, we attempt to generate fonts automatically using a modification of a Deep Convolutional Generative Adversarial Network (DCGAN) by introducing class consideration. DCGANs are the application of generative adversarial networks (GAN) which make use of convolutional and deconvolutional layers to generate data through adversarial detection. The conventional GAN is comprised of two neural networks that work in series. Specifically, it approaches an unsupervised method of data generation with the use of a generative network whose output is fed into a second discriminative network. While DCGANs have been successful on natural images, we show its limited ability on font generation due to the high variation of fonts combined with the need of rigid structures of characters. We propose a class discriminative DCGAN which uses a classification network to work alongside the discriminative network to refine the generative network. This results of our experiment shows a dramatic improvement over the conventional DCGAN.

  • 215.
    Abebe, Zelalem Teffera
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik.
    Process Control over Wireless Sensor Networks2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    A signicant growth was witnessed in the led of Wireless Sensor Networks (WSNs), the previous decade. Advances in hardware miniaturization coupled with increased processing capabilities and memory capacity have extended the application domains of WSNs. In light of this, standardization organizations led by academia and industries initiated activities for the design of protocols such as IEEE 802.15.4 and IETF RPL (Routing Protocol for Low power and Lossy Networks). IEEE 802.15.4 denes physical and media access layers for WSNs while IETF RPL denes the functionality of the routing layer.

    This thesis investigates research issues in wireless sensor networks and network controlled systems that control micro-biological processes for water treatment plants. By choosing a process model that can relate to an industrial process, feasibility of control over IEEE 802.15.4 and RPL protocols is evaluated for stability with regards to network delay and packet loss. Settling time and overshoot are measured to indicate control performance. Control messages related to routing and routing table lengths are measured to indicate network stability and scalability. The system model used is a centralized discrete controller controlling a thermal processes running on the sensors. This model is chosen for representing wide industrial networked control systems while adding a WSN dimension based on IEEE 802.15.4 and RPL. The main contribution of this thesis is an experimental study where both the network and controller performance is validated while utilizing commercial o-theshelf sensor platforms. The results from this experimental work include rst the use of established theorems for analyzing control using WSNs. Moreover, the ability of IEEE 802.15.4 and RPL to provide stable communication that is reliable enough for actual industrial control implementation is validated.

    Fulltekst (pdf)
    XR-EE-RT_2013-025_Zelalem Teffera
  • 216.
    Abedan Kondori, Farid
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Bring Your Body into Action: Body Gesture Detection, Tracking, and Analysis for Natural Interaction2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Due to the large influx of computers in our daily lives, human-computer interaction has become crucially important. For a long time, focusing on what users need has been critical for designing interaction methods. However, new perspective tends to extend this attitude to encompass how human desires, interests, and ambitions can be met and supported. This implies that the way we interact with computers should be revisited. Centralizing human values rather than user needs is of the utmost importance for providing new interaction techniques. These values drive our decisions and actions, and are essential to what makes us human. This motivated us to introduce new interaction methods that will support human values, particularly human well-being.

    The aim of this thesis is to design new interaction methods that will empower human to have a healthy, intuitive, and pleasurable interaction with tomorrow’s digital world. In order to achieve this aim, this research is concerned with developing theories and techniques for exploring interaction methods beyond keyboard and mouse, utilizing human body. Therefore, this thesis addresses a very fundamental problem, human motion analysis.

    Technical contributions of this thesis introduce computer vision-based, marker-less systems to estimate and analyze body motion. The main focus of this research work is on head and hand motion analysis due to the fact that they are the most frequently used body parts for interacting with computers. This thesis gives an insight into the technical challenges and provides new perspectives and robust techniques for solving the problem.

    Fulltekst (pdf)
    fulltext
  • 217.
    Abedan Kondori, Farid
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Human Motion Analysis for Creating Immersive Experiences2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    From an early age, people display the ability to quickly and effortlessly interpret the orientation and movement of human body parts, thereby allowing one to infer the intentions of others who are nearby and to comprehend an important nonverbal form of communication. The ease with which one accomplishes this task belies the difficulty of a problem that has challenged computational systems for decades, human motion analysis.

    Technological developments over years have resulted into many systems for measuring body segment positions and angles between segments. In these systems human body is typically considered as a system of rigid links connected by joints. The motion is estimated by the use of measurements from mechanical, optical, magnetic, or inertial trackers. Among all kinds of sensors, optical sensing encompasses a large and varying collection of technologies.

    In a computer vision context, human motion analysis is a topic that studies methods and applications in which two or more consecutive images from an image sequences, e.g. captured by a video camera, are processed to produce information based on the apparent human body motion in the images.

    Many different disciplines employ motion analysis systems to capture movement and posture of human body for applications such as medical diagnostics, virtual reality, human-computer interaction etc.

    This thesis gives an insight into the state of the art human motion analysissystems, and provides new methods for capturing human motion.

    Fulltekst (pdf)
    fulltext
  • 218.
    Abedan Kondori, Farid
    et al.
    Department of Applied Physics and Electronics, Umeå University, Umea, Sweden.
    Yousefi, Shahrouz
    Department of Applied Physics and Electronics, Umeå University, Umea, Sweden.
    Smart Baggage in Aviation2011Inngår i: Proceedings - 2011 IEEE International Conferences on Internet of Things and Cyber, Physical and Social Computing, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Nowadays, the Internet has dramatically changed the way people take the normal course of actions. By the recent growth of the Internet, connecting different objects to users through mobile phones and computers is no longer a dream. Aviation industry is one of the areas which have a strong potential to benefit from the Internet of Things. Among many problems related to air travel, delayed and lost luggage are the most common and irritating. Therefore, this paper suggests anew baggage control system, where users can simply track their baggage at the airport to avoid losing them. Attaching a particular pattern on the bag, which can be detected and localized from long distance by an ordinary camera, users are able to track their baggage. The proposed system is much cheaper than previous implementations and does not require sophisticated equipment.

  • 219.
    Abedan Kondori, Farid
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Yousefi, Shahrouz
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Kouma, Jean-Paul
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Liu, Li
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Li, Haibo
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Direct hand pose estimation for immersive gestural interaction2015Inngår i: Pattern Recognition Letters, ISSN 0167-8655, E-ISSN 1872-7344, Vol. 66, s. 91-99Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a novel approach for performing intuitive gesture based interaction using depth data acquired by Kinect. The main challenge to enable immersive gestural interaction is dynamic gesture recognition. This problem can be formulated as a combination of two tasks; gesture recognition and gesture pose estimation. Incorporation of fast and robust pose estimation method would lessen the burden to a great extent. In this paper we propose a direct method for real-time hand pose estimation. Based on the range images, a new version of optical flow constraint equation is derived, which can be utilized to directly estimate 3D hand motion without any need of imposing other constraints. Extensive experiments illustrate that the proposed approach performs properly in real-time with high accuracy. As a proof of concept, we demonstrate the system performance in 3D object manipulation On two different setups; desktop computing, and mobile platform. This reveals the system capability to accommodate different interaction procedures. In addition, a user study is conducted to evaluate learnability, user experience and interaction quality in 3D gestural interaction in comparison to 2D touchscreen interaction.

  • 220. Abedan Kondori, Farid
    et al.
    Yousefi, Shahrouz
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Li, Haibo
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Direct Head Pose Estimation Using Kinect-type Sensors2014Inngår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911XArtikkel i tidsskrift (Fagfellevurdert)
  • 221.
    Abedan Kondori, Farid
    et al.
    Umeå universitet.
    Yousefi, Shahrouz
    KTH Royal Institute of Technology.
    Li, Haibo
    KTH Royal Institute of Technology.
    Direct three-dimensional head pose estimation from Kinect-type sensors2014Inngår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 50, nr 4, s. 268-270Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A direct method for recovering three-dimensional (3D) head motion parameters from a sequence of range images acquired by Kinect sensors is presented. Based on the range images, a new version of the optical flow constraint equation is derived, which can be used to directly estimate 3D motion parameters without any need of imposing other constraints. Since all calculations with the new constraint equation are based on the range images, Z(xyt), the existing techniques and experiences developed and accumulated on the topic of motion from optical flow can be directly applied simply by treating the range images as normal intensity images I(xyt). In this reported work, it is demonstrated how to employ the new optical flow constraint equation to recover the 3D motion of a moving head from the sequences of range images, and furthermore, how to use an old trick to handle the case when the optical flow is large. It is shown, in the end, that the performance of the proposed approach is comparable with that of some of the state-of-the-art approaches that use range data to recover 3D motion parameters.

  • 222.
    Abedan Kondori, Farid
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Yousefi, Shahrouz
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Li, Haibo
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Direct three-dimensional head pose estimation from Kinect-type sensors2014Inngår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 50, nr 4, s. 268-270Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A direct method for recovering three-dimensional (3D) head motion parameters from a sequence of range images acquired by Kinect sensors is presented. Based on the range images, a new version of the optical flow constraint equation is derived, which can be used to directly estimate 3D motion parameters without any need of imposing other constraints. Since all calculations with the new constraint equation are based on the range images, Z(xyt), the existing techniques and experiences developed and accumulated on the topic of motion from optical flow can be directly applied simply by treating the range images as normal intensity images I(xyt). In this reported work, it is demonstrated how to employ the new optical flow constraint equation to recover the 3D motion of a moving head from the sequences of range images, and furthermore, how to use an old trick to handle the case when the optical flow is large. It is shown, in the end, that the performance of the proposed approach is comparable with that of some of the state-of-the-art approaches that use range data to recover 3D motion parameters.

  • 223.
    Abedan Kondori, Farid
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Yousefi, Shahrouz
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Liu, Li
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Li, Haibo
    KTH Royal Institute of Technology, Department of Media Technology and Interaction Design.
    Head operated electric wheelchair2014Inngår i: IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI 2014), IEEE , 2014, s. 53-56Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Currently, the most common way to control an electric wheelchair is to use joystick. However, there are some individuals unable to operate joystick-driven electric wheelchairs due to sever physical disabilities, like quadriplegia patients. This paper proposes a novel head pose estimation method to assist such patients. Head motion parameters are employed to control and drive an electric wheelchair. We introduce a direct method for estimating user head motion, based on a sequence of range images captured by Kinect. In this work, we derive new version of the optical flow constraint equation for range images. We show how the new equation can be used to estimate head motion directly. Experimental results reveal that the proposed system works with high accuracy in real-time. We also show simulation results for navigating the electric wheelchair by recovering user head motion.

  • 224. Abedan Kondori, Farid
    et al.
    Yousefi, Shahrouz
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Liu, Li
    Li, Haibo
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID. Nanjing University of Posts and Telecommunications, Nanjing, China .
    Head Operated Electric Wheelchair2014Inngår i: Proceedings of the IEEE Southwest Symposium on Image Analysis and Interpretation, 2014, s. 53-56Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Currently, the most common way to control an electric wheelchair is to use joystick. However, there are some individuals unable to operate joystick-driven electric wheelchairs due to sever physical disabilities, like quadriplegia patients. This paper proposes a novel head pose estimation method to assist such patients. Head motion parameters are employed to control and drive an electric wheelchair. We introduce a direct method for estimating user head motion, based on a sequence of range images captured by Kinect. In this work, we derive new version of the optical flow constraint equation for range images. We show how the new equation can be used to estimate head motion directly. Experimental results reveal that the proposed system works with high accuracy in real-time. We also show simulation results for navigating the electric wheelchair by recovering user head motion.

  • 225.
    Abedan Kondori, Farid
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Yousefi, Shahrouz
    Ostovar, Ahmad
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för datavetenskap.
    Liu, Li
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Li, Haibo
    A Direct Method for 3D Hand Pose Recovery2014Inngår i: 22nd International Conference on Pattern Recognition, 2014, s. 345-350Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a novel approach for performing intuitive 3D gesture-based interaction using depth data acquired by Kinect. Unlike current depth-based systems that focus only on classical gesture recognition problem, we also consider 3D gesture pose estimation for creating immersive gestural interaction. In this paper, we formulate gesture-based interaction system as a combination of two separate problems, gesture recognition and gesture pose estimation. We focus on the second problem and propose a direct method for recovering hand motion parameters. Based on the range images, a new version of optical flow constraint equation is derived, which can be utilized to directly estimate 3D hand motion without any need of imposing other constraints. Our experiments illustrate that the proposed approach performs properly in real-time with high accuracy. As a proof of concept, we demonstrate the system performance in 3D object manipulation. This application is intended to explore the system capabilities in real-time biomedical applications. Eventually, system usability test is conducted to evaluate the learnability, user experience and interaction quality in 3D interaction in comparison to 2D touch-screen interaction.

  • 226.
    Abedi, Amin
    et al.
    UNIGE, Inst Environm Sci, Geneva, Switzerland.;UNIGE, Comp Sci Dept, Geneva, Switzerland..
    Hesamzadeh, Mohammad Reza
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Romerio, Franco
    UNIGE, Inst Environm Sci, Geneva, Switzerland.;UNIGE, Geneva Sch Econ & Management, Geneva, Switzerland..
    Adaptive robust vulnerability analysis of power systems under uncertainty: A multilevel OPF-based optimization approach2022Inngår i: International Journal of Electrical Power & Energy Systems, ISSN 0142-0615, E-ISSN 1879-3517, Vol. 134, artikkel-id 107432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With the growing level of uncertainties in today's power systems, the vulnerability analysis of a power system with uncertain parameters becomes a must. This paper proposes a two-stage adaptive robust optimization (ARO) model for the vulnerability analysis of power systems. The main goal is to immunize the solutions against all possible realizations of the modeled uncertainty. In doing so, the uncertainties are defined by some predetermined intervals defined around the expected values of uncertain parameters. In our model, there are a set of first-stage decisions made before the uncertainty is revealed (attacker decision) and a set of second-stage decisions made after the realization of uncertainties (defender decision). This setup is formulated as a mixedinteger trilevel nonlinear program (MITNLP). Then, we recast the proposed trilevel program to a single-level mixed-integer linear program (MILP), applying the strong duality theorem (SDT) and appropriate linearization approaches. The efficient off-the-shelf solvers can guarantee the global optimum of our final MILP model. We also prove a lemma which makes our model much easier to solve. The results carried out on the IEEE RTS and modified Iran's power system show the performance of our model to assess the power system vulnerability under uncertainty.

  • 227.
    Abedi, Amin
    et al.
    Institute for Environmental Sciences, University of Geneva, Switzerland.
    Hesamzadeh, Mohammad Reza
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Romerio, Franco
    Institute for Environmental Sciences, University of Geneva, Switzerland.
    An ACOPF-based bilevel optimization approach for vulnerability assessment of a power system2021Inngår i: International Journal of Electrical Power & Energy Systems, ISSN 0142-0615, E-ISSN 1879-3517, Vol. 125, artikkel-id 106455Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper examines the effects of reactive power dispatch, losses, and voltage profile on the results of the interdiction model to analyze the vulnerability of the power system. First, an attacker-defender Stackelberg game is introduced. The introduced game is modeled as a bilevel optimization problem where the attacker is modeled in the upper level and the defender is modeled in the lower level. The AC optimal power flow (ACOPF) is proposed as the defender's tool in the lower-level problem to mitigate the attack consequences. Our proposed ACOPF-based mathematical framework is inherently a mixed-integer bilevel nonlinear program (MIBNLP) that is NP-hard and computationally challenging. This paper linearizes and then transforms it into a one-level mixed-integer linear program (MILP) using the duality theory and some proposed linearization techniques. The proposed MILP model can be solved to the global optimum using state-of-the-art solvers such as Cplex. Numerical results on two IEEE systems and Iran's 400-kV transmission network demonstrate the performance of the proposed MILP for vulnerability assessment. We have also compared our MILP model with the DCOPF-based approach proposed in the relevant literature. The comparative results show that the reported damage measured in terms of load shedding for the DCOPF-based approach is always lower than or equal to that for the ACOPF-based approach and these models report a different set of critical lines, especially in more stressed and larger power systems. Also, the effectiveness and feasibility of the proposed MILP model for power-system vulnerability analysis are discussed and highlighted. 

  • 228. Abedifar, V.
    et al.
    Furdek, Marija
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Muhammad, Ajmal
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Eshghi, M.
    Wosinska, Lena
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Routing, modulation format, spectrum and core allocation in SDM networks based on programmable filterless nodes2018Inngår i: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    An RMSCA approach based on binary particle swarm optimization is proposed for programmable filterless SDM networks, aimed at minimizing core and spectrum usage. Nearoptimal resource consumption.

  • 229. Abedifar, Vahid
    et al.
    Furdek, Marija
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Muhammad, Ajmal
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Eshghi, Mohammad
    Wosinska, Lena
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Routing, Modulation and Spectrum Assignment in Programmable Networks based on Optical White Boxes2018Inngår i: Journal of Optical Communications and Networking, ISSN 1943-0620, E-ISSN 1943-0639, Vol. 10, nr 9, s. 723-735Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Elastic optical networks (EONs) can help overcome the flexibility challenges imposed by emerging heterogeneous and bandwidth-intensive applications. Among the different solutions for flexible optical nodes, optical white box switches implemented by architecture on demand (AoD) have the capability to dynamically adapt their architecture and module configuration to the switching and processing requirements of the network traffic. Such adaptability allows for unprecedented flexibility in balancing the number of required nodal components in the network, spectral resource usage, and length of the established paths. To investigate these trade-offs and achieve cost-efficient network operation, we formulate the routing, modulation, and spectrum assignment (RMSA) problem in AoD-based EONs and propose three RMSA strategies aimed at optimizing a particular combination of these performance indicators. The strategies rely on a newly proposed internal node configuration matrix that models the structure of optical white box nodes in the network, thus facilitating hardware-aware routing of connection demands. The proposed strategies are evaluated in terms of the number of required modules and the related cost, spectral resource usage, and average path length. Extensive simulation results show that the proposed RMSA strategies can achieve remarkable cost savings by requiring fewer switching modules than the benchmarking approaches, at a favorable trade-off with spectrum usage and path length.

  • 230.
    Abedin, Ahmad
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Germanium layer transfer and device fabrication for monolithic 3D integration2021Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Monolithic three-dimensional (M3D) integration, it has been proposed,can overcome the limitations of further circuits’ performance improvementand functionality expansion. The emergence of the internet of things (IoT) isdriving the semiconductor industry toward the fabrication of higher-performancecircuits with diverse functionality. On the one hand, the scaling of devices isreaching critical dimensions, which makes their further downscaling techno-logically difficult and economically challenging, whereas, on the other hand,the field of electronics is no longer limited only to developing circuits thatare meant for data processing. Sensors, processors, actuators, memories, andeven power storage units need to be efficiently integrated into a single chip tomake IoT work. M3D integration through stacking different layers of deviceson each other can potentially improve circuits’ performance by shorteningthe wiring length and reducing the interconnect delay. Using multiple tiersfor device fabrication makes it possible to integrate different materials withsuperior physical properties. It offers the advantage of fabricating higher-performance devices with multiple functionalities on a single chip. However,high-quality layer transfer and processing temperature budget are the majorchallenges in M3D integration. This thesis involves an in-depth explorationof the application of germanium (Ge) in monolithic 3D integration.Ge has been recognized as one of the most promising materials that canreplace silicon (Si) as the channel material for p-type field-effect transistors(pFETs) because of its high hole mobility. Ge pFETs can be fabricated atsubstantially lower temperatures compared to Si devices which makes theformer a good candidate for M3D integration. However, the fabrication ofhigh-quality Ge-on-insulator (GOI) layers with superior thickness homogene-ity, low residual doping, and a sufficiently good interface with buried oxide(BOX) has been challenging.This thesis used low-temperature wafer bonding and etch-back techniquesto fabricate the GOI substrate for M3D applications. For this purpose, aunique stack of epitaxial layers was designed and fabricated. The layer stackcontains a Ge strain relaxed buffer (SRB) layer, a SiGe layer to be used asan etch stop, and a top Ge layer to be transferred to the handling wafer.The wafers were bonded at room temperature, and the sacrificial wafer wasremoved through multiple etching steps leaving 20 nm Ge on the insulatorwith excellent thickness homogeneity over the wafer. Ge pFET devices werefabricated on the GOI substrates and electrically characterized to evaluatethe layer quality. Finally, the epitaxial growth of the highly doped SiGeand sub-nm Si cap layers have been investigated as alternatives for improvedperformance Ge pFETs.The Ge buffer layer was developed through the two-step deposition tech-nique resulting in defect density of107cm−3and surface roughness of 0.5 nm.The fully strainedSi0.5Ge0.5film with high crystal quality was epitaxiallygrown at temperatures below 450°C. The layer was sandwiched between theGe buffer and the top 20 nm Ge layer to be used as an etch-stop in the etch- back process. A highly selective etching method was developed to remove the3μm Ge buffer and 10nm SiGe film without damaging the 20 nm transferringGe layer.The Ge pFETs were fabricated at temperatures below 600°C so that theycould be compatible with the M3D integration. The back interface of thedevices depleted atVBG= 0V, which confirmed the small density of fixedcharges at the Ge/BOX interface along with a low level of residual doping inthe Ge channel. The Ge pFETs with 70 % yield over the whole wafer showed60 % higher carrier mobility than Si reference devices.Low-temperature epitaxial growth of Si passivation layer on Ge was de-veloped in this thesis. For electrical evaluation of the passivation layer,metal-oxide-semiconductor (MOS) capacitors were fabricated and character-ized. The capacitors showed an interface trap density of3×1011eV−1cm−2,and hysteresis as low as 3 mV at Eox of 4MV/cm corresponding to oxide trapdensity of1.5×1010cm−2. The results indicate that this Si passivation layersubstantially improves the gate dielectric by reducing the subthreshold slopeof Ge devices while increasing their reliability. The in-situ doped SiGe layerwith a dopant concentration of2.5×1019cm−3and resistivity of 3.5 mΩcmwas selectively grown on Ge to improve the junction formation.The methods developed in this thesis are suitable for large-scale M3Dintegration of Ge pFET devices on the Si platform. The unique Ge layertransfer and etch-back techniques resulted in the fabrication of GOI substrateswith high thickness homogeneity, low residual doping, and sufficiently goodGe/BOX interface. The process temperatures for Ge transfer and pFETsfabrication are kept within the range of the M3D budget. Integration of theSi cap for gate dielectric formation and SiGe layers in the source/drain regionmay increase device performance and reliability

    Fulltekst (pdf)
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  • 231.
    Abedin, Ahmad
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik, Integrerade komponenter och kretsar.
    Asadollahi, Ali
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik, Integrerade komponenter och kretsar.
    Garidis, Konstantinos
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Integrerade komponenter och kretsar.
    Hellström, Per-Erik
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Integrerade komponenter och kretsar.
    Östling, Mikael
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Elektronik.
    Epitaxial growth of Ge strain relaxed buffer on Si with low threading dislocation density2016Inngår i: ECS Transactions, Electrochemical Society, 2016, nr 8, s. 615-621Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Epitaxial Ge with low dislocation density is grown on a low temperature grown Ge seed layer on Si substrate by reduced pressure chemical vapor deposition. The surface topography measured by AFM shows that the strain relaxation occurred through pit formation which resulted in freezing the defects at Ge/Si interface. Moreover a lower threading dislocation density compared to conventional strain relaxed Ge buffers on Si was observed. We show that by growing the first layer at temperatures below 300 °C a surface roughness below 1 nm can be achieved together with carrier mobility enhancement. The different defects densities revealed from SECCO and Iodine etching shows that the defects types have been changed and SECCO is not always trustable.

    Fulltekst (pdf)
    fulltext
  • 232.
    Abedin, Ahmad
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Garidis, Konstantinos
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Asadollahi, Ali
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Hellström, Per-Erik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Östling, Mikael
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system.
    Growth of epitaxial SiGe alloys as etch-stop layers in germanium-on-insulator fabricationManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    In this study, the application of epitaxially grown SixGe1-x films as etch stop layers in a germanium-on-insulator substrate fabrication flow is investigated. Layers with Ge contents from 15% to 70% were epitaxially grown on Si (1 0 0) using silane and germane. It was found that the Ge content in the films is independent of the growth temperature for fixed partial pressure ratios. At low growth temperatures the activation energy is found to be 1.8 eV which points to a hydrogen desorption limited growth rate mechanism. At growth temperatures of less than 500℃, the surface roughness is <1 nm. This surface roughness does not change when the films are grown on Ge substrates. Finally, a fully strained Si0.5Ge0.5 film was grown on Ge strain relaxed buffer at 450℃. This layer demonstrates etch selectivity of >400:1 towards Ge in diluted SC-1. This result enables the integration of the Si0.5Ge0.5 film as an etch stop layer for single crystalline germanium-on-insulator substrate fabrication.

    Fulltekst (pdf)
    fulltext
  • 233.
    Abedin, Ahmad
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar.
    Zurauskaite, Laura
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar.
    Asadollahi, Ali
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elektronik och inbyggda system, Integrerade komponenter och kretsar. KTH.
    GOI fabrication for Monolithic 3D integrationInngår i: Artikkel i tidsskrift (Annet vitenskapelig)
  • 234.
    Abedin, Sarder
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationssystem och –teknologi. Kyung Hee University, Yongin 17104, South Korea.
    Munir, M. S.
    Tran, N. H.
    Han, Z.
    Hong, C. S.
    Data Freshness and Energy-Efficient UAV Navigation Optimization: A Deep Reinforcement Learning Approach2021Inngår i: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 22, nr 9, s. 5994-6006Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, we design a navigation policy for multiple unmanned aerial vehicles (UAVs) where mobile base stations (BSs) are deployed to improve the data freshness and connectivity to the Internet of Things (IoT) devices. First, we formulate an energy-efficient trajectory optimization problem in which the objective is to maximize the energy efficiency by optimizing the UAV-BS trajectory policy. We also incorporate different contextual information such as energy and age of information (AoI) constraints to ensure the data freshness at the ground BS. Second, we propose an agile deep reinforcement learning with experience replay model to solve the formulated problem concerning the contextual constraints for the UAV-BS navigation. Moreover, the proposed approach is well-suited for solving the problem, since the state space of the problem is extremely large and finding the best trajectory policy with useful contextual features is too complex for the UAV-BSs. By applying the proposed trained model, an effective real-time trajectory policy for the UAV-BSs captures the observable network states over time. Finally, the simulation results illustrate the proposed approach is 3.6 &#x0025; and 3.13 &#x0025; more energy efficient than those of the greedy and baseline deep Q Network (DQN) approaches. 

  • 235. Abel, Olubunmi
    et al.
    Shatunov, Aleksey
    Jones, Ashley R.
    Andersen, Peter M.
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Neurologi.
    Powell, John F.
    Al-Chalabi, Ammar
    Development of a Smartphone App for a Genetics Website: The Amyotrophic Lateral Sclerosis Online Genetics Database (ALSoD)2013Inngår i: JMIR mhealth and uhealth, E-ISSN 2291-5222, Vol. 1, nr 2, artikkel-id e18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The ALS Online Genetics Database (ALSoD) website holds mutation, geographical, and phenotype data on genes implicated in amyotrophic lateral sclerosis (ALS) and links to bioinformatics resources, publications, and tools for analysis. On average, there are 300 unique visits per day, suggesting a high demand from the research community. To enable wider access, we developed a mobile-friendly version of the website and a smartphone app. Objective: We sought to compare data traffic before and after implementation of a mobile version of the website to assess utility. Methods: We identified the most frequently viewed pages using Google Analytics and our in-house analytic monitoring. For these, we optimized the content layout of the screen, reduced image sizes, and summarized available information. We used the Microsoft. NET framework mobile detection property (HttpRequest. IsMobileDevice in the Request. Browser object in conjunction with HttpRequest. UserAgent), which returns a true value if the browser is a recognized mobile device. For app development, we used the Eclipse integrated development environment with Android plug-ins. We wrapped the mobile website version with the WebView object in Android. Simulators were downloaded to test and debug the applications. Results: The website automatically detects access from a mobile phone and redirects pages to fit the smaller screen. Because the amount of data stored on ALSoD is very large, the available information for display using smartphone access is deliberately restricted to improve usability. Visits to the website increased from 2231 to 2820, yielding a 26% increase from the pre-mobile to post-mobile period and an increase from 103 to 340 visits (230%) using mobile devices (including tablets). The smartphone app is currently available on BlackBerry and Android devices and will be available shortly on iOS as well. Conclusions: Further development of the ALSoD website has allowed access through smartphones and tablets, either through the website or directly through a mobile app, making genetic data stored on the database readily accessible to researchers and patients across multiple devices.

    Fulltekst (pdf)
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  • 236.
    Abelsson, Sara
    Blekinge Tekniska Högskola, Sektionen för teknik, Avdelningen för signalbehandling.
    Propagation Measurements at 3.5 GHz for WiMAX2007Independent thesis Advanced level (degree of Master (One Year))Oppgave
    Abstract [en]

    Propagation measurements at the frequency 3.5 GHz for the WiMAX technology have been conducted. The purpose of these measurements is that a coverage analysis should be accomplished. The mathematical software package MATLAB has been used to analyze the collected data from the measurement campaign. Path loss models have also been used and a comparison between these models and the collected data has been performed. An analysis prediction tool from an application called WRAP has also been used in the comparison with the collected data. In this thesis, diff

    Fulltekst (pdf)
    FULLTEXT01
  • 237.
    Aberger, Martin
    Linköpings universitet, Institutionen för systemteknik, Reglerteknik. Linköpings universitet, Tekniska högskolan.
    Effects of Nonlinearities in Black Box Identification of an Industrial Robot2000Rapport (Annet vitenskapelig)
    Abstract [en]

    This paper discusses effects of nonlinearities in black box identification of one axis of a robot. The used data come from a commercial ABB robot, IRB1400. A three-mass flexible model for the robot was built in MathModelica. The nonlinearities in the model are nonlinear friction and backlash in the gear box.

    Fulltekst (pdf)
    FULLTEXT01
  • 238. Abermann, S.
    et al.
    Efavi, J.
    Sjöblom, Gustaf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Lemme, Max
    Olsson, Jörgen
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Bertagnolli, E.
    Processing and evaluation of metal gate/high-k/Si capacitors incorporating Al, Ni, TiN, and Mo as metal gate, and ZrO2 and HfO2 as high-k dielectric2006Inngår i: Presented at Int. Conf. on Micro- and Nano-Engineering, 2006Konferansepaper (Annet vitenskapelig)
  • 239.
    Abewardhana, Ruwan
    et al.
    Univ Colombo, Dept Phys, Colombo, Sri Lanka.
    Abegunawardana, Sidath
    Univ Colombo, Dept Phys, Colombo, Sri Lanka.
    Fernando, Mahendra
    Univ Colombo, Dept Phys, Colombo, Sri Lanka.
    Sonnadara, Upul
    Univ Colombo, Dept Phys, Colombo, Sri Lanka.
    Cooray, Vernon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Lightning Localization Based on VHF Broadband Interferometer Developed in Sri Lanka2018Inngår i: 2018 34th international conference on lightning protection (ICLP 2018), New York: IEEE, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A basic broadband digital interferometer was developed, which is capable of locating Very High Frequency (VHF) radiation sources in two spatial dimensions and time. Three antennas sensed the time series of broadband electromagnetic (EM) signals and digitized with 4 ns sampling interval for a duration of several milliseconds. A technique based on cross-correlations has been implemented for mapping lightning source locations. A map of the first return stroke (RS) and the preceding stepped leader was mapped successfully, using the system with a time resolution of few milliseconds. The result was compared with the visible events of the ground flash to validate the system.

  • 240.
    Abeynanda, Hansi
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Nätverk och systemteknik.
    Weeraddana, Chathuranga
    Univ Oulu, Ctr Wireless Commun, Oulu 90014, Finland..
    Lanel, G. H. J.
    Univ Sri Jayewardenepura, Dept Math, Nugegoda 10250, Sri Lanka..
    Fischione, Carlo
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Datavetenskap, Nätverk och systemteknik.
    On the Primal Feasibility in Dual Decomposition Methods Under Additive and Bounded Errors2023Inngår i: IEEE Transactions on Signal Processing, ISSN 1053-587X, E-ISSN 1941-0476, Vol. 71, s. 655-669Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With the unprecedented growth of signal processing and machine learning application domains, there has been a tremendous expansion of interest in distributed optimization methods to cope with the underlying large-scale problems. Nonetheless, inevitable system-specific challenges such as limited computational power, limited communication, latency requirements, measurement errors, and noises in wireless channels impose restrictions on the exactness of the underlying algorithms. Such restrictions have appealed to the exploration of algorithms' convergence behaviors under inexact settings. Despite the extensive research conducted in the area, it seems that the analysis of convergences of dual decomposition methods concerning primal optimality violations, together with dual optimality violations is less investigated. Here, we provide a systematic exposition of the convergence of feasible points in dual decomposition methods under inexact settings, for an important class of global consensus optimization problems. Convergences and the rate of convergences of the algorithms are mathematically substantiated, not only from a dual-domain standpoint but also from a primal-domain standpoint. Analytical results show that the algorithms converge to a neighborhood of optimality, the size of which depends on the level of underlying distortions.

  • 241.
    Abeywickrama, K. G. Nilanga B.
    et al.
    Chalmers, Div High Voltage Engn, Dept Mfg & Mat Technol, SE-41296 Gothenburg, Sweden..
    Daszczynski, Tadeusz
    Warsaw Univ Technol, PL-00611 Warsaw, Poland..
    Serdyuk, Yuriy V.
    Chalmers, Div High Voltage Engn, Dept Mfg & Mat Technol, SE-41296 Gothenburg, Sweden.;Natl Acad Sci Ukraine, Inst Electrodynam, Kiev, Ukraine.;ABB High Voltage Technol Ltd, R&D HV Lab, Zurich, Switzerland..
    Gubanski, Stanislaw M.
    KTH.
    Determination of complex permeability of silicon steel for use in high-frequency modeling of power transformers2008Inngår i: IEEE transactions on magnetics, ISSN 0018-9464, E-ISSN 1941-0069, Vol. 44, nr 4, s. 438-444Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Information about frequency dependence of complex permeability of silicon steel is a vital input parameter in calculations of transformer winding inductance used for modeling. high-frequency behavior (100 Hz-1 MHz). We present two ways of determining small signal complex permeability spectra in frequency domain and compare and discuss the results. The first method is based on an optimization procedure, in which inductance of a winding is measured and calculated by analytical formulas and finite-element modeling. The second method makes use of a single sheet tester. We show that the magnitude of effective permeability of the silicon steel laminations remains significant up to about 100 kHz. We also report on the effect of magnetic viscosity on complex permeability.

  • 242. Abeywickrama, Sandu
    et al.
    Furdek, Marija
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Monti, Paolo
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wosinska, Lena
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS, Optical Network Laboratory (ON Lab).
    Wong, Elaine
    Protecting core networks with dual-homing: A study on enhanced network availability, resource efficiency, and energy-savings2016Inngår i: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 381, s. 327-335Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Core network survivability affects the reliability performance of telecommunication networks and remains one of the most important network design considerations. This paper critically examines the benefits arising from utilizing dual-homing in the optical access networks to provide resource-efficient protection against link and node failures in the optical core segment. Four novel, heuristic-based RWA algorithms that provide dedicated path protection in networks with dual-homing are proposed and studied. These algorithms protect against different failure scenarios (i.e. single link or node failures) and are implemented with different optimization objectives (i.e., minimization of wavelength usage and path length). Results obtained through simulations and comparison with baseline architectures indicate that exploiting dual-homed architecture in the access segment can bring significant improvements in terms of core network resource usage, connection availability, and power consumption.

  • 243.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik.
    García Martín, Eva
    Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik.
    Johansson, Christian
    NODA Intelligent Systems AB, Sweden.
    Lavesson, Niklas
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Datateknik och informatik, JTH, Jönköping AI Lab (JAIL). Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Institutionen för datalogi och datorsystemteknik.
    Trend analysis to automatically identify heat program changes2017Inngår i: Energy Procedia, Elsevier, 2017, s. 407-415Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The aim of this study is to improve the monitoring and controlling of heating systems located at customer buildings through the use of a decision support system. To achieve this, the proposed system applies a two-step classifier to detect manual changes of the temperature of the heating system. We apply data from the Swedish company NODA, active in energy optimization and services for energy efficiency, to train and test the suggested system. The decision support system is evaluated through an experiment and the results are validated by experts at NODA. The results show that the decision support system can detect changes within three days after their occurrence and only by considering daily average measurements.

    Fulltekst (pdf)
    fulltext
  • 244.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    García Martín, Eva
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Johansson, Christian
    NODA Intelligent Systems AB, SWE.
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Trend analysis to automatically identify heat program changes2017Inngår i: Energy Procedia, Elsevier, 2017, Vol. 116, s. 407-415Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The aim of this study is to improve the monitoring and controlling of heating systems located at customer buildings through the use of a decision support system. To achieve this, the proposed system applies a two-step classifier to detect manual changes of the temperature of the heating system. We apply data from the Swedish company NODA, active in energy optimization and services for energy efficiency, to train and test the suggested system. The decision support system is evaluated through an experiment and the results are validated by experts at NODA. The results show that the decision support system can detect changes within three days after their occurrence and only by considering daily average measurements.

    Fulltekst (pdf)
    fulltext
  • 245.
    Abid, Fahim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Busatto, Tatiano
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Intermodulation due to interaction of photovoltaic inverter and electric vehicle at supraharmonic range2016Inngår i: 2016 17th International Conference on Harmonics and Quality of Power, Piscataway. NJ, 2016, s. 685-690, artikkel-id 7783471Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Advent of power electronic switching is introducing more and more non-linear loads in the low voltage grid. Besides harmonic current generation in the frequency range below 2 kHz, these non-linear loads are also responsible for current emission in the range of 2 kHz to 150 kHz, commonly known as supraharmonic emission. Supraharmonic currents mainly flow between nearby appliances and heavily influence the overall emission of neighboring devices. This paper presents an analysis of supraharmonic interaction between a photovoltaic inverter and an electric vehicle. It has been noticed that intermodulation distortion arises as a result of interaction between different switching frequencies used by the devices. Later, additional household equipment were added to photovoltaic and electric vehicle to observe their effect on intermodulation distortion. All the measurements were conducted in a controlled laboratory environment imitating a domestic customer.

  • 246.
    Abid, Fahim
    et al.
    KTH.
    Ghorbani, Hossein
    Pourrahimi, Amir Masoud
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Edin, Hans Ezz
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Differences in morphology and polarization properties of heat-treated XLPE and LDPE insulation2016Inngår i: 2016 IEEE CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA (IEEE CEIDP), IEEE conference proceedings, 2016, s. 113-116Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cross-linked polyethylene (XLPE) is the most commonly used insulating material for extruded high voltage cable applications. Degassing is a heat-treatment process that is performed to remove methane from XLPE insulation which is formed during the crosslinking reactions as a by-product. Apart from removing methane, heat-treatment influences the electrical properties through changing the morphology due to annealing and also removal of polar crosslinking by-products. Scanning electron microscopy (SEM) is generally used to observe the changes in crystalline structure of the polymer. Frequency domain spectroscopy (FDS) is widely used to study polarization properties of dielectric materials. In this study these two methods are used for a comparative analysis of XLPE and LDPE subjected to different heat-treatment time, with or without a diffusion barrier. Electrical measurements are performed at room temperature. From the SEM imaging conducted after permanganate acid etching, formation of spherulites due to heat-treatment is not obvious in neither LDPE nor in XLPE. However, distinctions between LDPE and XLPE in SEM micrographs are evident. From studies with dielectric polarization spectroscopy, it is found that the LDPE samples are less sensitive to heat-treatment in comparison to the XLPE samples while dissipation factor of XLPE samples are influenced by the choice of pressing film used during sample preparation.

  • 247.
    Abid, Muhammad Adil
    et al.
    Malmö universitet, Fakulteten för teknik och samhälle (TS), Institutionen för datavetenskap och medieteknik (DVMT).
    Amouzad Mahdiraji, Saeid
    Malmö universitet, Fakulteten för teknik och samhälle (TS), Institutionen för datavetenskap och medieteknik (DVMT).
    Lorig, Fabian
    Malmö universitet, Fakulteten för teknik och samhälle (TS), Institutionen för datavetenskap och medieteknik (DVMT). Malmö universitet, Internet of Things and People (IOTAP).
    Holmgren, Johan
    Malmö universitet, Fakulteten för teknik och samhälle (TS), Institutionen för datavetenskap och medieteknik (DVMT).
    Mihailescu, Radu-Casian
    Malmö universitet, Fakulteten för teknik och samhälle (TS), Institutionen för datavetenskap och medieteknik (DVMT).
    Petersson, Jesper
    Department of Health Care Management, Region Skåne, 21428 Malmö, Sweden; Department of Neurology, Lund University, 22242 Malmö, Sweden.
    A Genetic Algorithm for Optimizing Mobile Stroke Unit Deployment2023Inngår i: Procedia Computer Science, ISSN 1877-0509, Vol. 225, s. 3536-3545Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A mobile stroke unit (MSU) is an advanced ambulance equipped with specialized technology and trained healthcare personnel to provide on-site diagnosis and treatment for stroke patients. Providing efficient access to healthcare (in a viable way) requires optimizing the placement of MSUs. In this study, we propose a time-efficient method based on a genetic algorithm (GA) to find the most suitable ambulance sites for the placement of MSUs (given the number of MSUs and a set of potential sites). We designed an efficient encoding scheme for the input data (the number of MSUs and potential sites) and developed custom selection, crossover, and mutation operators that are tailored according to the characteristics of the MSU allocation problem. We present a case study on the Southern Healthcare Region in Sweden to demonstrate the generality and robustness of our proposed GA method. Particularly, we demonstrate our method's flexibility and adaptability through a series of experiments across multiple settings. For the considered scenario, our proposed method outperforms the exhaustive search method by finding the best locations within 0.16, 1.44, and 10.09 minutes in the deployment of three MSUs, four MSUs, and five MSUs, resulting in 8.75x, 16.36x, and 24.77x faster performance, respectively. Furthermore, we validate the method's robustness by iterating GA multiple times and reporting its average fitness score (performance convergence). In addition, we show the effectiveness of our method by evaluating key hyperparameters, that is, population size, mutation rate, and the number of generations.

    Fulltekst (pdf)
    fulltext
  • 248.
    Abideen, Amar
    KTH, Skolan för elektroteknik och datavetenskap (EECS).
    Dielectric Response and Partial Discharge Characteristics of Stator Winding Insulation System with SiC Stress Grading2020Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The typical construction of a stator coil includes the use of end corona protection (ECP)coating, which is made of semi-conductive materials like silicon carbide (SiC). Thepurpose of ECP is to smooth the electric stress distribution near the slot exit, limitingthe electric field and partial discharge (PD) activity within the insulation system. Thisthesis investigates how ECP affects the dielectric response of a stator coil in highvoltagemeasurements, both in the time-domain and frequency-domain. It also studieshow well time-domain results transformed to the frequency-domain correspond to directmeasurements. As a further point, the effect of the ECP on PD activity was demonstrated.Measurements of dielectric response and PD were made on new coil-halves producedin the usual way in a production run for a motor. The results show that applying theECP design significantly reduces the PD activity and increases the inception voltage. Inaddition, the dielectric response of the coil with ECP tape has shown to have a nonlinearvoltage dependent characteristic due to the presence of ECP. As the voltage goes higher,this causes a shift of the loss peak toward higher frequency. A distributed-element modelof the end section of a stator coil was used to model the nonlinear effect due to ECP, andits results are compared to the measured results. Lastly, FEM simulation of a stator coilend section is presented, showing the contribution of ECP tape in evenly distributing theelectric stress near the slot exit.

    Fulltekst (pdf)
    fulltext
  • 249.
    Abidin, Aysajan
    et al.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska högskolan.
    Larsson, Jan-Åke
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska högskolan.
    Direct proof of security of Wegman-Carter authentication with partially known key2014Inngår i: Quantum Information Processing, ISSN 1570-0755, E-ISSN 1573-1332, Vol. 13, nr 10, s. 2155-2170Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Information-theoretically secure (ITS) authentication is needed in Quantum Key Distribution (QKD). In this paper, we study security of an ITS authentication scheme proposed by Wegman& Carter, in the case of partially known authentication key. This scheme uses a new authentication key in each authentication attempt, to select a hash function from an Almost Strongly Universal2 hash function family. The partial knowledge of the attacker is measured as the trace distance between the authentication key distribution and the uniform distribution; this is the usual measure in QKD. We provide direct proofs of security of the scheme, when using partially known key, first in the information-theoretic setting and then in terms of witness indistinguishability as used in the Universal Composability (UC) framework. We find that if the authentication procedure has a failure probability ε and the authentication key has an ε´ trace distance to the uniform, then under ITS, the adversary’s success probability conditioned on an authentic message-tag pair is only bounded by ε +|Ƭ|ε´, where |Ƭ| is the size of the set of tags. Furthermore, the trace distance between the authentication key distribution and the uniform increases to |Ƭ|ε´ after having seen an authentic message-tag pair. Despite this, we are able to prove directly that the authenticated channel is indistinguishable from an (ideal) authentic channel (the desired functionality), except with probability less than ε + ε´. This proves that the scheme is (ε + ε´)-UC-secure, without using the composability theorem.

    Fulltekst (pdf)
    fulltext
  • 250.
    Abidin, Aysajan
    et al.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    Larsson, Jan-Åke
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    New Universal Hash Functions2012Inngår i: Lecture Notes in Computer Science, Vol. 7242 / [ed] Frederik Armknecht and Stefan Lucks, Springer Berlin Heidelberg , 2012, s. 99-108Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Universal hash functions are important building blocks for unconditionally secure message authentication codes. In this paper, we present a new construction of a class of Almost Strongly Universal hash functions with much smaller description (or key) length than the Wegman-Carter construction. Unlike some other constructions, our new construction has a very short key length and a security parameter that is independent of the message length, which makes it suitable for authentication in practical applications such as Quantum Cryptography.

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