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  • 1. Abourraja, Mohamed Nezar
    et al.
    Oudani, Mustapha
    Samiri, Mohamed Yassine
    Boudebous, Dalila
    El Fazziki, Abdelaziz
    Najib, Mehdi
    Bouain, Abdelhadi
    Rouky, Naoufal
    A multi-agent based simulation model for rail–rail transshipment: An engineering approach for gantry crane scheduling2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, p. 13142-13156Article in journal (Refereed)
    Abstract [en]

    Le Havre Port Authority is putting into service a multimodal hub terminal with massified hinterland links (trains and barges) in order to restrict the intensive use of roads, to achieve a more attractive massification share of hinterland transportation and to provide a river connection to its maritime terminals that do not currently have one. This paper focuses on the rail-rail transshipment yard of this new terminal. In the current organizational policy, this yard is divided into two equal operating areas, and, in each one, a crane is placed, and it is equipped with reach stackers to enable container moves across both operating areas. However, this policy causes poor scheduling of crane moves, because it gives rise to many crane interference situations. For the sake of minimizing the occurrence of these undesirable situations, this paper proposes a multi-agent simulation model including an improved strategy for crane scheduling. This strategy is inspired by the ant colony approach and it is governed by a new configuration for the rail yard's working area that eliminates the use of reach stackers. The proposed simulation model is based on two planner agents, to each of which a time-horizon planning is assigned. The simulation results show that the model developed here is very successful in significantly reducing unproductive times and moves (undesirable situations), and it outperforms other existing simulation models based on the current organizational policy.

  • 2.
    Almas, Muhammad Shoaib
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Vanfretti, Luigi
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems. Statnett.
    A Hybrid Synchrophasor and GOOSE-Based Power System Synchronization Scheme2016In: IEEE Access, E-ISSN 2169-3536, Vol. 4, p. 4659-4668Article in journal (Refereed)
    Abstract [en]

    The design and real-time hardware-in-the-loop implementation of a hybrid synchrophasors and GOOSE-based automatic synchronization algorithm are presented in this paper. Automatic synchronization is performed by utilizing the synchrophasor measurements from two commercial phasor measurement units (PMUs), while the coordinated control commands to automatic voltage regulator and/or turbine governor control and trip command to the circuit breaker are issued using IEC 61850-8-1 GOOSE messages. The algorithm is deployed inside the PMU using the protection logic equations, and direct communication between the PMUs is established to minimize the communication latencies. In addition, the algorithm is tested using a standard protection relay test-set, and automatic test sequences are executed to validate its performance. It is concluded that the hybrid synchrophasor and GOOSE-based automatic synchronization scheme ensures minimum communication latencies, reduces equipment cost, facilitates interoperability, and performs automatic reconnection adequately.

  • 3.
    Arfaoul, Ghada
    et al.
    Orange Labs, F-75015 Paris, France..
    Bisson, Pascal
    Thales, F-45400 Fleury Les Aubrais, France..
    Blom, Rolf
    RISE SICS, Secur Lab, S-16480 Stockholm, Sweden..
    Borgaonkar, Ravishankar
    Univ Oxford, Dept Comp Sci, Oxford OX1 2JD, England..
    Englund, Hakan
    Ericsson AB, Ericsson Res, S-16480 Stockholm, Sweden..
    Felix, Edith
    Thales, F-45400 Fleury Les Aubrais, France..
    Klaedtke, Felix
    NEC Labs Europe, D-69115 Heidelberg, Germany..
    Nakarmi, Prajwol Kumar
    Ericsson AB, Ericsson Res, S-16480 Stockholm, Sweden..
    Näslund, Mats
    KTH.
    O'Hanlon, Piers
    Univ Oxford, Dept Comp Sci, Oxford OX1 2JD, England..
    Papay, Juri
    Univ Southampton, IT Innovat Ctr, Southampton SO16 7NS, Hants, England..
    Suomalainen, Jani
    VTT Tech Res Ctr Finland, Espoo 02044, Finland..
    Surridge, Mike
    Univ Southampton, IT Innovat Ctr, Southampton SO16 7NS, Hants, England..
    Wary, Jean-Philippe
    Orange Labs, F-75015 Paris, France..
    Zahariev, Alexander
    Nixu Corp, Espoo 02150, Finland..
    A Security Architecture for 5G Networks2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 22466-22479Article in journal (Refereed)
    Abstract [en]

    5G networks will provide opportunities for the creation of new services, for new business models, and for new players to enter the mobile market. The networks will support efficient and cost-effective launch of a multitude of services, tailored for different vertical markets having varying service and security requirements, and involving a large number of actors. Key technology concepts are network slicing and network softwarization, including network function virtualization and software-defined networking. The presented security architecture builds upon concepts from the 3G and 4G security architectures but extends and enhances them to cover the new 5G environment. It comprises a toolbox for security relevant modeling of the systems, a set of security design principles, and a set of security functions and mechanisms to implement the security controls needed to achieve stated security objectives. In a smart city use case setting, we illustrate its utility; we examine the high-level security aspects stemming from the deployment of a large number of IoT devices and network softwarization.

  • 4.
    Azari, Amin
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Miao, Guowang
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Network Life time Maximization for Cellular-Based M2M Networks2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, p. 18927-18940, article id 8045999Article in journal (Refereed)
    Abstract [en]

    High energy efficiency is critical for enabling massive machine-type communications (MTC) over cellular networks. This paper is devoted to energy consumption modeling, battery lifetime analysis, lifetime-aware scheduling, and transmit power control for massive MTC over cellular networks. We consider a realistic energy consumption model for MTC and model network battery-lifetime. Analytic expressions are derived to demonstrate the impact of scheduling on both the individual and network battery lifetimes. The derived expressions are subsequently employed in the uplink scheduling and transmit power control for mixed-priority MTC traffic in order to maximize the network lifetime. Besides the main solutions, low complexity solutions with limited feedback requirement are investigated, and the results are extended to existing LIE networks. In addition, the energy efficiency, spectral efficiency, and network lifetime tradeoffs in resource provisioning and scheduling for MTC over cellular networks are investigated. The simulation results show that the proposed solutions can provide substantial network lifetime improvement and network maintenance cost reduction in comparison with the existing scheduling schemes.

  • 5.
    Azari, Amin
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Miao, Guowang
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Network Lifetime Maximization for Cellular-Based M2M Networks2017In: IEEE Access, E-ISSN 2169-3536Article in journal (Refereed)
    Abstract [en]

    High energy efficiency is critical for enabling massivemachine-type communications (MTC) over cellular networks.This work is devoted to energy consumption modeling,battery lifetime analysis, lifetime-aware scheduling and transmitpower control for massive MTC over cellular networks. Weconsider a realistic energy consumption model for MTC andmodel network battery-lifetime. Analytic expressions are derivedto demonstrate the impact of scheduling on both the individualand network battery lifetimes. The derived expressions aresubsequently employed in uplink scheduling and transmit powercontrol for mixed-priority MTC traffic in order to maximizethe network lifetime. Besides the main solutions, low-complexitysolutions with limited feedback requirement are investigated,and the results are extended to existing LTE networks. Also,the energy efficiency, spectral efficiency, and network lifetimetradeoffs in resource provisioning and scheduling for MTC overcellular networks are investigated. The simulation results showthat the proposed solutions can provide substantial networklifetime improvement and network maintenance cost reductionin comparison with the existing scheduling schemes.

  • 6.
    Bogodorova, Tetiana
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power and Energy Systems.
    Vanfretti, Luigi
    Model Structure Choice for a Static VAR Compensator Under Modeling Uncertainty and Incomplete Information2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, article id UNSP 22657Article in journal (Refereed)
    Abstract [en]

    To simulate the complex behavior of power systems, operators frequently rely on models. The task of model identification and validation becomes important in this context. The validity of the models has a direct influence on operator's decisions and actions. In other words, erroneous or imprecise models lead to erroneous predictions of the systems' behavior which may result in unwanted operator's actions. This paper addresses the challenge of model structure choice for modeling and parameter identification in power systems. Three types of model structures are analyzed: 1) physical principle-based modeling; 2) black-box modeling (NARX, transfer function, Hammerstein Wiener model); and 3) combination of physical and black-box modeling. This analysis has been performed using real grid measurements and available knowledge about a static VAR compensator (SVC) connected to the U.K.'s transmission network and operated by National Grid. The SVC's modeling is presented in the context of a generalized modeling and identification algorithm, that is offered as a guideline for engineers. The model validity issues of the identified SVC models that include modeling uncertainty are discussed.

  • 7.
    Bogodorova, Tetiana
    et al.
    KTH.
    Vanfretti, Luigi
    Peric, Vedran S.
    Turitsyn, Konstantin
    Identifying Uncertainty Distributions and Confidence Regions of Power Plant Parameters2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5Article in journal (Refereed)
    Abstract [en]

    Power system operators, when obtaining a model's parameter estimates; require additional information to guide their decision on a model's acceptance. This information has to establish a relationship between the estimates and the chosen model in the parameter space. For this purpose, this paper proposes to extend the usage of the particle filter (PF) as a method for the identification of power plant parameters; and the parameters' confidence intervals, using measurements. Taking into consideration that the PF is based on the Bayesian filtering concept, the results returned by the filter contain more information about the model and its parameters than usually considered by power system operators. In this paper the samples from the multi-modal posterior distribution of the estimate are used to identify the distribution shape and associated confidence intervals of estimated parameters. Three methods [rule of thumb, least-squares cross validation, plug-in method (HSJM)] for standard deviation (bandwidth) selection of the Gaussian mixture distribution are compared with the uni-modal Gaussian distribution of the parameter estimate. The applicability of the proposed method is demonstrated using field measurements and synthetic data from simulations of a Greek power plant model. The distributions are observed for different system operation conditions that consider different types of noise. The method's applicability for model validation is also discussed.

  • 8. Bonetto, Riccardo
    et al.
    Rossi, Michele
    Tomasin, Stefano
    Fischione, Carlo
    KTH, School of Electrical Engineering (EES), Network and Systems engineering. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Joint Optimal Pricing and Electrical Efficiency Enforcement for Rational Agents in Microgrids2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, p. 19782-19798Article in journal (Refereed)
    Abstract [en]

    In electrical distribution grids, the constantly increasing number of power generation devices based on renewables demands a transition from a centralized to a distributed generation paradigm. In fact, power injection from distributed energy resources (DERs) can be selectively controlled to achieve other objectives beyond supporting loads, such as the minimization of the power losses along the distribution lines and the subsequent increase of the grid hosting capacity. However, these technical achievements are only possible if alongside electrical optimization schemes, a suitable market model is set up to promote cooperation from the end users. In contrast with the existing literature, where energy trading and electrical optimization of the grid are often treated separately, or the trading strategy is tailored to a specific electrical optimization objective, in this paper, we consider their joint optimization. We also allow for a modular approach, where the market model can support any smart grid optimization goal. Specifically, we present a multi-objective optimization problem accounting for energy trading, where: 1) DERs try to maximize their profit, resulting from selling their surplus energy; 2) the loads try to minimize their expense; and 3) the main power supplier aims at maximizing the electrical grid efficiency through a suitable discount policy. This optimization problem is proved to be non-convex, and an equivalent convex formulation is derived. Centralized solutions are discussed and a procedure to distribute the solution is proposed. Numerical results to demonstrate the effectiveness of the so obtained optimal policies are finally presented, showing the proposed model results in economic bene fits for all the users (generators and loads) and in an increased electrical efficiency for the grid.

  • 9.
    Della Penda, Demia
    et al.
    Ericsson AB, S-16480 Kista, Sweden..
    Abrardo, Andrea
    Univ Siena, Dept Informat Engn, I-53100 Siena, Italy.;Consorzio Nazl Interuniv Telecomunicaz, I-43124 Parma, Italy..
    Moretti, Marco
    Consorzio Nazl Interuniv Telecomunicaz, I-43124 Parma, Italy.;Univ Pisa, Dept Informat Engn, I-56122 Pisa, Italy..
    Johansson, Mikael
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Distributed Channel Allocation for D2D-Enabled 5G Networks Using Potential Games2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 11195-11208Article in journal (Refereed)
    Abstract [en]

    Frequency channel allocation is a key technique for improving the performance of cellular networks. In this paper, we address the channel allocation problem for a 5G multi-cell system. We consider a heterogeneous network in which cellular users, micro-cell users, and device-to-device (D2D) communications coexist within the radio footprint of the macro cell. We maximize the aggregate transmission rate, exploiting channel diversity and managing both the inter-cell interference, typical of cellular networks and the intra-cell interference generated by the nonorthogonal transmissions of the small-cell and D2D users. By modeling the allocation problem as a potential game, whose Nash equilibria correspond to the local optima of the objective function, we propose a new decentralized solution. The convergence of our scheme is enforced by using a better response dynamic based on a message passing approach. The simulation results assess the validity of the proposed scheme in terms of convergence time and achievable rate under different settings.

  • 10.
    Fodor, Gábor
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control. Ericsson Research, Sweden.
    Parkvall, S.
    Sorrentino, S.
    Wallentin, P.
    Lu, Q.
    Brahmi, N.
    Device-to-device communications for national security and public safety2014In: IEEE Access, E-ISSN 2169-3536, Vol. 2, p. 1510-1520, article id 6985517Article in journal (Refereed)
    Abstract [en]

    Device-to-device (D2D) communications have been proposed as an underlay to long-term evolution (LTE) networks as a means of harvesting the proximity, reuse, and hop gains. However, D2D communications can also serve as a technology component for providing public protection and disaster relief (PPDR) and national security and public safety (NSPS) services. In the United States, for example, spectrum has been reserved in the 700-MHz band for an LTE-based public safety network. The key requirement for the evolving broadband PPDR and NSPS services capable systems is to provide access to cellular services when the infrastructure is available and to efficiently support local services even if a subset or all of the network nodes become dysfunctional due to public disaster or emergency situations. This paper reviews some of the key requirements, technology challenges, and solution approaches that must be in place in order to enable LTE networks and, in particular, D2D communications, to meet PPDR and NSPS-related requirements. In particular, we propose a clustering-procedure-based approach to the design of a system that integrates cellular and ad hoc operation modes depending on the availability of infrastructure nodes. System simulations demonstrate the viability of the proposed design. The proposed scheme is currently considered as a technology component of the evolving 5G concept developed by the European 5G research project METIS.

  • 11.
    Fodor, Gábor
    et al.
    Ericsson Research, Sweden.
    Roger, Sandra
    Rajatheva, Nandana
    Ben Slimane, Slimane
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Svensson, Tommy
    Popovski, Petar
    B. da Silva Jr., Jose Mairton
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Ali, Samad
    An Overview of Device-to-Device Communications Technology Components in METIS2016In: IEEE Access, E-ISSN 2169-3536, Vol. 4, p. 3288-3299Article in journal (Refereed)
    Abstract [en]

    As the standardization of network-assisted deviceto-device (D2D) communications by the 3 rd Generation Partnership Project progresses, the research community has started to explore the technology potential of new advanced features that will largely impact the performance of 5G networks. For 5G, D2D is becoming an integrative term of emerging technologies that take advantage of the proximity of communicating entities in licensed and unlicensed spectra. The European 5G research project Mobile and Wireless Communication Enablers for the 2020 Information Society (METIS) has identified advanced D2D as a key enabler for a variety of 5G services, including cellular coverage extension, social proximity and communicating vehicles. In this paper, we review the METIS D2D technology components in three key areas of proximal communications – network-assisted multi-hop, full-duplex, and multi-antenna D2D communications – and argue that the advantages of properly combining cellular and ad hoc technologies help to meet the challenges of the information society beyond 2020.

  • 12.
    Ghasemifard, Fatemeh
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Analyzing Glide-Symmetric Holey Metasurfaces Using a Generalized Floquet Theorem2018In: IEEE Access, E-ISSN 2169-3536Article in journal (Refereed)
  • 13.
    Gu, Song
    et al.
    Chengdu Aeronaut Polytech, Dept Aeronaut Engn, Chengdu 610100, Sichuan, Peoples R China..
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Production Systems.
    Hao, Wei
    Chengdu Aeronaut Polytech, Dept Aeronaut Engn, Chengdu 610100, Sichuan, Peoples R China..
    Du, Yingjie
    Chengdu Aeronaut Polytech, Dept Aeronaut Engn, Chengdu 610100, Sichuan, Peoples R China..
    Wang, Jian
    Chengdu Aeronaut Polytech, Dept Aeronaut Engn, Chengdu 610100, Sichuan, Peoples R China..
    Zhang, Weirui
    Chengdu Aeronaut Polytech, Dept Aeronaut Engn, Chengdu 610100, Sichuan, Peoples R China..
    Online Video Object Segmentation via Boundary-Constrained Low-Rank Sparse Representation2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 53520-53533Article in journal (Refereed)
    Abstract [en]

    Graphcut-based algorithm is adopted in many video object segmentation systems because different terms can be probabilistically fused together in a framework. Constructing spatio-temporal coherences is an important stage in segmentation systems. However, many steps are involved when computing a key term with good discriminative power. If the cascade steps are adopted, the inaccurate output of the previous step will definitely affect the next step, leading to inaccurate segmentation. In this paper, a key term that is computed by a single framework referred to as boundary-constrained low-rank sparse representation (BCLRSR) is proposed to achieve the accurate segmentation. By treating the elements as linear combinations of dictionary templates, low-rank sparse optimization is adopted to achieve the spatio-temporal saliency. For adding the spatial information to the low-rank sparse model, a boundary constraint is adopted in the framework as a Laplacian regularization. A BCLRSR saliency is then obtained by the represented coefficients, which measure the similarity between the elements in the current frame and the ones in the dictionary. At last, the object is segmented by minimizing the energy function, which is formalized by the spatio-temporal coherences. The experiments on some public datasets show that our proposed algorithm outperforms the state-of-the-art methods.

  • 14.
    Gómez, Francisco José
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Aguilera, Miguel
    Instituto Costaricense de Electricidad (ICE), San José, Costa Rica.
    Vanfretti, Luigi
    Olsen, Svein Harald
    Statnett SF, Oslo, Norway.
    Multi-Domain Semantic Information and Physical Behavior Modeling of Power Systems and Gas Turbines Expanding the Common Information Model2018In: IEEE Access, E-ISSN 2169-3536Article in journal (Refereed)
    Abstract [en]

    The rapid increase of Intermittent Energy Resources (IER) there is a need to have dispatchable production available to ensure secure operation and increase opportunity for energy system flexibility. Gas turbine-based power plants offer flexible operation that is being improved with new technology advancements. Those plants provide in general, quick start together with significant ramping capability, which can be exploited to balance IERs. Consequently, to understand this potential source of flexibility, better models for gas turbines are required for power systems studies and analysis. In this work both the required semantic information and physical behavior models of such multi-domain systems are considered. First, UML class diagrams and RDF schemas based on the Common Information Model (CIM) standards are used to describe the semantic information of the electrical power grid. An extension that exploits the ISO 15926 standard is herein proposed to derive the multi-domain semantics required by integrated electrical power grid with detailed gas turbine dynamic models. Second, the Modelica language is employed to create the equation-based models which represent the behavior of a multi-domain physical system. A comparative simulation analysis between the power system domain model and the multi-domain model has been performed. Some differences between the turbine dynamics representation of the commonly used GGOV1 standard model and a more detailed gas turbine model are shown.

  • 15. He, Wang
    et al.
    Xu, Bo
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering.
    Gustafsson, Mats
    Ying, Zhinong
    He, Sailing
    KTH, School of Electrical Engineering and Computer Science (EECS), Electromagnetic Engineering.
    RF Compliance Study of Temperature Elevation in Human Head Model Around 28 GHz for 5G User Equipment Application: Simulation Analysis2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6Article in journal (Refereed)
    Abstract [en]

    The crowdedness of current cellular bands and the demand for higher transmission speed prompt the use of the millimeter-wave spectrum for the next-generation mobile communication. In the millimeter-wave frequencies, the dosimetric quantity for human exposure to electromagnetic fields changes from the specific absorption rate to incident power density. In this paper, we used 28-GHz beam-steering patch arrays, a dipole antenna, and plane waves to investigate the temperature elevation in a multi-layer model of human head and its correlation with power density metrics. The power density averaged over one square-centimeter in free space and the peak temperature elevation in tissue at 28 GHz have good correlation. The peak temperature elevation indicated by the power density averaged one square-centimeter also agrees well with the peak temperature elevation induced by the plane waves. The results show that the averaging area of a few square-centimeters may be a good candidate for the spatial-average power density. The findings provide valuable input to the ongoing revision and updating of relevant safety standards and guidelines.

  • 16.
    Ji, Wei
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Yin, S.
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    A Virtual Training Based Programming-Free Automatic Assembly Approach for Future Industry2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 43865-43873, article id 8425978Article in journal (Refereed)
    Abstract [en]

    Currently, the automated assembly depends on advance programming, which is suitable to large-batch products assembly; however, it does not fit in the assembly of small-batch products due to the large amount of preparatory work including assembly planning and robot programming. Therefore, those assemblies in small batch largely rely on human interventions, which is a system-level problem. Targeting the problem, this paper presents a novel programming-free automated assembly planning and control approach based on virtual training. Within the context, the 3-D models of products are used, including general assembly features of each component. The features are used in a search-based planner to generate assembly sequence, and to plan assembly path. Then the virtual assembly simulation is carried out based on the generated assembly plan, where the collisions and contacts are captured and passed to the planner to regenerate a new path. The new path is simulated in the virtual world. The simulation process is repeated until an executable strategy is obtained. In the real world, the physical robots perform the actual assembly by following the trained sequences and paths that are calibrated according to the real positions and orientations of the components. A proof-of-concept case study is carried out in robot operating system environment to validate this approach.

  • 17.
    Jinzhi, Lu
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Wang, Jiqiang
    Nanjing Aeronaut & Astronaut Univ, Coll Energy & Power Engn, Nanjing 210016, Jiangsu, Peoples R China..
    Chen, DeJiu
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Wang, Jian
    Univ Elect Sci & Technol China, Sch Informat & Commun Engn, Chengdu 611731, Sichuan, Peoples R China..
    Törngren, Martin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    A Service-Oriented Tool-Chain for Model-Based Systems Engineering of Aero-Engines2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 50443-50458Article in journal (Refereed)
    Abstract [en]

    This paper proposes a service-oriented tool-chain with an emphasis on domain-specific views, simulation automation, and process management to support model-based system engineering of aero-engines. In the tool-chain, a domain-specific modeling approach is adopted to facilitate the descriptions of co-design workflows and the related development information. The relevant domain-specific models are the basis for automated creation of a Web-based process management system consolidating and controlling service-oriented technical resources (models, data, and tools). In particular, the system also provides support for automated orchestration of tool operations, model, and simulation configurations. In order to promote the model and tool interoperability, the tool-chain adopts open standards for integrations, including open services for lifecycle collaboration and functional mock-up interface. Finally, through a case study of simulation-based aero-engine performance analysis, we evaluate the flexibility and efficiency of this tool chain by comparing it with a traditional simulation process both qualitatively and quantitatively.

  • 18.
    Khodaee, Alireza
    et al.
    KTH.
    Melander, Arne
    KTH. Swerea KIMAB AB, S-16440 Kista, Sweden..
    Haglund, Sven
    Swerea KIMAB AB, S-16440 Kista, Sweden..
    The Effects of Blank Geometry on Gear Rolling for Large Gear Modules: Experiments and Finite Element Simulations2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 33344-33352Article in journal (Refereed)
    Abstract [en]

    Gear rolling is a forming process to produce gear wheels by plastic deformation. The advantage of the process is to eliminate the chip formation during production and also to improve the product properties since the non-metallic inclusions will be oriented along the cog surface and not perpendicular to it. The method has been developed in the past years for gear production for automobile application with modules up to 3 mm. The successful application of gear rolling in those cases raises the question regarding the feasibility of using cold rolling to manufacture gears with larger modules which can be used for heavy vehicles. In this paper, a gear wheel with normal module of 4 mm has been studied in order to investigate if such large modules can be manufactured by gear rolling. One of the issues in rolling of gears is the design of the blank geometry in order to obtain the right gear geometry after the rolling process. Blank shape modifications are necessary to control and to reduce the undesired shape deviations caused by the large plastic deformations in rolling. The blank modifications also help the process designer to control the forming force and torque. In this paper, the process has been modeled by finite element simulation and the influence of different blanks has been simulated. The validity of the FE model has been checked through several experiments. Both the numerical and experimental results revealed favorable blank modifications to apply for further developments of the gear rolling process.

  • 19.
    Kim, Jeemin
    et al.
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 03722, South Korea..
    Park, Jihong
    Univ Oulu, Ctr Wireless Commun, Oulu 90014, Finland..
    Kim, Seunghwan
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 03722, South Korea..
    Kim, Seong-Lyun
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 03722, South Korea..
    Sung, Ki Won
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Center for Wireless Systems, Wireless@kth.
    Kim, Kwang Soon
    Yonsei Univ, Sch Elect & Elect Engn, Seoul 03722, South Korea..
    Millimeter-Wave Interference Avoidance via Building-Aware Associations2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 10618-10634Article in journal (Refereed)
    Abstract [en]

    Signal occlusion by building blockages is a double-edged sword for the performance of millimeter-wave (mmW) communication networks. Buildings may dominantly attenuate the useful signals, especially when mmW base stations (BSs) are sparsely deployed compared with the building density. In the opposite BS deployment, buildings can block the undesired interference. To enjoy only the benefit, we propose a building-aware association scheme that adjusts the directional BS association bias of the user equipments (UEs), based on a given building density and the concentration of UE locations around the buildings. The association of each BS can thereby be biased: 1) toward the UEs located against buildings for avoiding interference to other UEs or 2) toward the UEs providing their maximum reference signal received powers. The proposed association scheme is optimized to maximize the downlink average data rate derived by stochastic geometry. Its effectiveness is validated by simulation using real building statistics.

  • 20. Krivochiza, J.
    et al.
    Duncan, J. Merlano
    Andrenacci, S.
    Chatzinotas, S.
    Ottersten, Björn
    FPGA Acceleration for Computationally Efficient Symbol-Level Precoding in Multi-User Multi-Antenna Communication Systems2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 15509-15520Article in journal (Refereed)
  • 21.
    Laakso, Miku J.
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Bleiker, Simon J.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Liljeholm, Jessica
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Mårtensson, Gustaf E.
    Mycronic AB, S-18353 Taby, Sweden..
    Asiatici, Mikhail
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems. Ecole Polytech Fed Lausanne, Sch Comp & Commun Sci, CH-1015 Lausanne, Switzerland..
    Fischer, Andreas C.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Ebefors, Thorbjorn
    Silex Microsyst AB, S-17543 Jarfalla, Sweden.;MyVox AB, S-12938 Hagersten, Sweden..
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Through-Glass Vias for Glass Interposers and MEMS Packaging Applications Fabricated Using Magnetic Assembly of Microscale Metal Wires2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 44306-44317Article in journal (Refereed)
    Abstract [en]

    A through-glass via (TGV) provides a vertical electrical connection through a glass substrate. TGVs are used in advanced packaging solutions, such as glass interposers and wafer-level packaging of microelectromechanical systems (MEMS). However, TGVs are challenging to realize because via holes in glass typically do not have a sufficiently high-quality sidewall profile for super-conformal electroplating of metal into the via holes. To overcome this problem, we demonstrate here that the via holes can instead be filled by magnetically assembling metal wires into them. This method was used to produce TGVs with a typical resistance of 64 m Omega, which is comparable with other metal TGV types reported in the literature. In contrast to many TGV designs with a hollow center, the proposed TGVs can be more area efficient by allowing solder bump placement directly on top of the TGVs, which was demonstrated here using solder-paste jetting. The magnetic assembly process can be parallelized using an assembly robot, which was found to provide an opportunity for increased wafer-scale assembly speed. The aforementioned qualities of the magnetically assembled TGVs allow the realization of glass interposers and MEMS packages in different thicknesses without the drawbacks associated with the current TGV fabrication methods.

  • 22.
    Lan, Dapeng
    et al.
    Univ Oslo, Dept Informat, N-0316 Oslo, Norway..
    Pang, Zhibo
    ABB Corp Res, S-72226 Vasteras, Sweden..
    Fischione, Carlo
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Liu, Yu
    Linkoping Univ, Dept Sci & Technol, S-58183 Linkoping, Sweden..
    Taherkordi, Amir
    Univ Oslo, Dept Informat, N-0316 Oslo, Norway..
    Eliassen, Frank
    Univ Oslo, Dept Informat, N-0316 Oslo, Norway..
    Latency Analysis of Wireless Networks for Proximity Services in Smart Home and Building Automation: The Case of Thread2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 4856-4867Article in journal (Refereed)
    Abstract [en]

    Proximity service (ProSe), using the geographic location and device information by considering the proximity of mobile devices, enriches the services we use to interact with people and things around us. ProSe has been used in mobile social networks in proximity and also in smart home and building automation (Google Home). To enable ProSe in smart home, reliable and stable network protocols and communication infrastructures are needed. Thread is a new wireless protocol aiming at smart home and building automation (BA), which supports mesh networks and native Internet protocol connectivity. The latency of Thread should be carefully studied when used in user-friendly and safety-critical ProSe in smart home and BA. In this paper, a system level model of latency in the Thread mesh network is presented. The accumulated latency consists of different kinds of delay from the application layer to the physical layer. A Markov chain model is used to derive the probability distribution of the medium access control service time. The system level model is experimentally validated in a multi-hop Thread mesh network. The outcomes show that the system model results match well with the experimental results. Finally, based on an analytical model, a software tool is developed to estimate the latency of the Thread mesh network, providing developers more network information to develop user-friendly and safety-critical ProSe in smart home and BA.

  • 23.
    Lavenius, Jan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Vanfretti, Luigi
    Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA..
    PMU-Based Estimation of Synchronous Machines' Unknown Inputs Using a Nonlinear Extended Recursive Three-Step Smoother2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 57123-57136Article in journal (Refereed)
    Abstract [en]

    Knowledge of the synchronous machines' control input signals and internal states can provide valuable insight to system operators for assessing security margins and the stability of the power system. For example, during disturbances in a stressed power system, it can be of great value to monitor the performance of the machine's control system, e.g., the response of the field voltage, mechanical power, and the field current. As there are often no real-time power plant measurements available to power system operators, internal states, and unknown inputs of generator units would need to be estimated from synchrophasor measurements. This paper proposes a new estimation algorithm, the nonlinear extended recursive three-step smoother (NERTSS), to simultaneously estimate the states and the unknown inputs of the synchronous machine using data from phasor measurement units. These quantities can then be used to monitor the performance of the machine's controls. The case studies presented in the paper compare the estimation performance of the NERTSS with the extended Kalman filter with unknown inputs (EKF-UI) when noisy synchrophasor measurements are used. The simulation results show that the proposed estimation method compares favorably with respect to the EKF-UI in terms of the achieved estimation accuracy.

  • 24.
    Laya, Andres
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Kalalas, Charalampos
    Vazquez-Gallego, Francisco
    Alonso, Luis
    Alonso-Zarate, Jesus
    Goodbye, ALOHA!2016In: IEEE Access, E-ISSN 2169-3536, Vol. 4, p. 2029-2044Article in journal (Refereed)
    Abstract [en]

    The vision of the Internet of Things (IoT) to interconnect and Internet-connect everyday people, objects, and machines poses new challenges in the design of wireless communication networks. The design of medium access control (MAC) protocols has been traditionally an intense area of research due to their high impact on the overall performance of wireless communications. The majority of research activities in this field deal with different variations of protocols somehow based on ALOHA, either with or without listen before talk, i.e., carrier sensing multiple access. These protocols operate well under low traffic loads and low number of simultaneous devices. However, they suffer from congestion as the traffic load and the number of devices increase. For this reason, unless revisited, the MAC layer can become a bottleneck for the success of the IoT. In this paper, we provide an overview of the existing MAC solutions for the IoT, describing current limitations and envisioned challenges for the near future. Motivated by those, we identify a family of simple algorithms based on distributed queueing (DQ), which can operate for an infinite number of devices generating any traffic load and pattern. A description of the DQ mechanism is provided and most relevant existing studies of DQ applied in different scenarios are described in this paper. In addition, we provide a novel performance evaluation of DQ when applied for the IoT. Finally, a description of the very first demo of DQ for its use in the IoT is also included in this paper.

  • 25. Lee, Giwon
    et al.
    Ko, Haneul
    Pack, Sangheon
    Pacifici, Valentino
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems Engineering.
    Dán, György
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems Engineering.
    Fog-Assisted Aggregated Synchronization Scheme for Mobile Cloud Storage Applications2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 56852-56863Article in journal (Refereed)
    Abstract [en]

    Cloud storage applications, such as Dropbox and Google Drive, have recently become very popular among mobile users. In these applications, a cloud server is responsible for synchronizing updates to files among mobile users, and thus if files are shared by many mobile users and are frequently updated then the resulting synchronization traffic can be significant. In order to reduce the synchronization traffic with providing acceptable access latency, we propose a fog-assisted aggregated synchronization (FAS) scheme in which the fog computing server and the cloud server conduct localized and aggregated synchronizations, respectively. We develop an analytical model of the FAS scheme based on renewal-reward theory and use it for model-based adjustment of the timer that controls the trade-off between access latency and synchronization traffic. We use analytical and simulation results to give insight into the effects of the timer, the update-to-access ratio, the number of mobile users, and the sensitivity to the arrival process. The analytical and simulation results demonstrate that the FAS scheme can reduce the synchronization traffic significantly with acceptable access latency compared to conventional schemes.

  • 26. Lema, Maria A.
    et al.
    Laya, Andres
    Mahmoodi, Toktam
    Cuevas, Maria
    Sachs, Joachim
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Dohler, Mischa
    Business Case and Technology Analysis for 5G Low Latency Applications2017In: IEEE Access, E-ISSN 2169-3536, Vol. 5, p. 5917-5935Article in journal (Refereed)
    Abstract [en]

    A large number of new consumer and industrial applications are likely to change the classic operator's business models and provide a wide range of new markets to enter. This paper analyzes the most relevant 5G use cases that require ultra-low latency, from both technical and business perspectives. Low latency services pose challenging requirements to the network, and to fulfill them, operators need to invest in costly changes in their network. In this sense, it is not clear whether such investments are going to be amortized with these new business models. In light of this, specific applications and requirements are described and the potential market benefits for operators are analyzed. Conclusions show that the operators have clear opportunities to add value and position themselves strongly with the increasing number of services to be provided by 5G.

  • 27. Li, J.
    et al.
    Sun, J.
    Qian, Y.
    Shu, F.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Xiang, W.
    A Commercial Video-Caching System for Small-Cell Cellular Networks Using Game Theory2016In: IEEE Access, E-ISSN 2169-3536, Vol. 4, p. 7519-7531, article id 7496825Article in journal (Refereed)
    Abstract [en]

    Evidence indicates that requesting video clips on demand accounts for a dramatic increase in data traffic over cellular networks. Caching part of popular videos in the storage of small-cell base stations (SBS) in cellular networks is an efficient method to reduce transmission latency and mitigate redundant transmissions. In this paper, we propose a commercial caching system consisting of a video retailer (VR) and multiple network service providers (NSPs). Each NSP leases its SBSs, with some price, to the VR for the purpose of making profits, and the VR, after storing popular videos in the rented SBSs, can provide better local video services to the mobile users, thereby gaining more profits. We conceive this system within the framework of a Stackelberg game by treating the SBSs as a specific type of resources. Then, we establish the profit models for both the NSPs and the VR based on stochastic geometry. We further investigate the Stackelberg equilibrium by solving the optimization problems in two cases, i.e., whether or not the VR has a budget plan on renting the SBSs. Numerical results are provided for quantifying the proposed framework by showing its efficiency on pricing and resource allocation.

  • 28.
    Li, Jun
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Shen, Xiaoman
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Chen, Lei
    RISE Viktoria, S-41756 Gothenburg, Sweden..
    Van, Dung Pham
    Ou, Jiannan
    South China Normal Univ, South China Acad Adv Optoelect, MOE Int Lab Opt Informat Technol, Guangzhou 511400, Guangdong, Peoples R China..
    Wosinska, Lena
    Chalmers Univ Technol, Dept Elect Engn, S-41296 Gothenburg, Sweden..
    Chen, Jiajia
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Service Migration in Fog Computing Enabled Cellular Networks to Support Real-Time Vehicular Communications2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 13704-13714Article in journal (Refereed)
    Abstract [en]

    Driven by the increasing number of connected vehicles and related services, powerful communication and computation capabilities are needed for vehicular communications, especially for real-time and safety-related applications. A cellular network consists of radio access technologies, including the current long-term evolution (LTE), the LTE advanced, and the forthcoming 5th generation mobile communication systems. It covers large areas and has the ability to provide high data rate and low latency communication services to mobile users. It is considered the most promising access technology to support real-time vehicular communications. Meanwhile, fog is an emerging architecture for computing, storage, and networking, in which fog nodes can be deployed at base stations to deliver cloud services close to vehicular users. In fog computing-enabled cellular networks, mobility is one of the most critical challenges for vehicular communications to maintain the service continuity and to satisfy the stringent service requirements, especially when the computing and storage resources are limited at the fog nodes. Service migration, relocating services from one fog server to another in a dynamic manner, has been proposed as an effective solution to the mobility problem. To support service migration, both computation and communication techniques need to be considered. Given the importance of protocol design to support the mobility of the vehicles and maintain high network performance, in this paper, we investigate the service migration in the fog computing-enabled cellular networks. We propose a quality-of-service aware scheme based on the existing handover procedures to support the real-time vehicular services. A case study based on a realistic vehicle mobility pattern for Luxembourg scenario is carried out, where the proposed scheme, as well as the benchmarks, are compared by analyzing latency and reliability as well as migration cost.

  • 29.
    Li, Wei
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Vanfretti, Luigi
    Chow, Joe H.
    Pseudo-Dynamic Network Modeling for PMU-Based State Estimation of Hybrid AC/DC Grids2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 4006-4016Article in journal (Refereed)
    Abstract [en]

    This paper presents a PMU-based state estimation (SE) algorithm that uses a pseudo-dynamic network modeling approach. The pseudo-dynamic network model combines different equations with static network equations. Then it applies the weighted least squares algorithm to solve an over-determined least squares estimation problem. The proposed method can improve SE accuracy during both steady state and transient conditions without increasing the computational burden. In addition, the proposed modeling approach is applied to networks containing both a STATCOM and a voltage source converter-HVdc to demonstrate how to develop and apply a pseudo-dynamic SE model. Case studies aim to illustrate and verify the performance of the proposed method under steady state and transient conditions.

  • 30.
    Liu, Dong
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Wang, Chao
    Tongji Univ, Dept Informat & Commun Engn, Shanghai 201804, Peoples R China.;Univ Exeter, Dept Comp Sci, Exeter EX4 4QF, Devon, England..
    Rasmussen, Lars Kildehöj
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Discontinuous Reception for Multiple-Beam Communication2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 46931-46946Article in journal (Refereed)
    Abstract [en]

    Discontinuous reception (DRX) techniques have successfully been proposed for energy savings in 4G radio access systems, which are deployed on legacy 2GHz spectrum bands with signal features of omnidirectional propagation. In upcoming 5G systems, higher frequency spectrum bands will also be utilized. Unfortunately higher frequency bands encounter more significant path loss, thus requiring directional beamforming to aggregate the radiant signal in a certain direction. We, therefore, propose a DRX scheme for multiple beam (DRXB) communication scenarios. The proposed DRXB scheme is designed to avoid unnecessary energy-and-time-consuming beam-training procedures, which enables longer sleep periods and shorter wake-up latency. We provide an analytical model to investigate the receiver-side energy efficiency and transmission latency of the proposed scheme. Through simulations, our approach is shown to have clear performance improvements over the conventional DRX scheme where beam training is conducted in each DRX cycle.

  • 31.
    Liu, Hongyi
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Fang, Tongtong
    KTH, School of Electrical Engineering and Computer Science (EECS), Software and Computer systems, SCS.
    Zhou, Tianyu
    KTH, School of Electrical Engineering and Computer Science (EECS), Software and Computer systems, SCS.
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Production Systems.
    Towards Robust Human-Robot Collaborative Manufacturing: Multimodal Fusion2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 74762-74771Article in journal (Refereed)
    Abstract [en]

    Intuitive and robust multimodal robot control is the key toward human-robot collaboration (HRC) for manufacturing systems. Multimodal robot control methods were introduced in previous studies. The methods allow human operators to control robot intuitively without programming brand-specific code. However, most of the multimodal robot control methods are unreliable because the feature representations are not shared across multiple modalities. To target this problem, a deep learning-based multimodal fusion architecture is proposed in this paper for robust multimodal HRC manufacturing systems. The proposed architecture consists of three modalities: speech command, hand motion, and body motion. Three unimodal models are first trained to extract features, which are further fused for representation sharing. Experiments show that the proposed multimodal fusion model outperforms the three unimodal models. This paper indicates a great potential to apply the proposed multimodal fusion architecture to robust HRC manufacturing systems.

  • 32.
    Ma, Ruixiang
    et al.
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China..
    Wu, Fei
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China.;Huazhong Univ Sci & Technol, Shenzhen Res Inst, Shenzhen 518000, Peoples R China..
    Zhang, Meng
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China..
    Lu, Zhonghai
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Electronic and embedded systems.
    Wan, Jiguang
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China..
    Xie, Changsheng
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Wuhan 430074, Hubei, Peoples R China.;Huazhong Univ Sci & Technol, Shenzhen Res Inst, Shenzhen 518000, Peoples R China..
    RBER-Aware Lifetime Prediction Scheme for 3D-TLC NAND Flash Memory2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 44696-44708Article in journal (Refereed)
    Abstract [en]

    NAND flash memory is widely used in various computing systems. However, flash blocks can sustain only a limited number of program/erase (P/E) cycles, which are referred to as the endurance. On one hand, in order to ensure data integrity, flash manufacturers often define the maximum P/E cycles of the worst block as the endurance of flash blocks. On the other hand, blocks exhibit large endurance variations, which introduce two serious problems. The first problem is that the error correcting code (ECC) is often over-provisioned, as it has to be designed to tolerate the worst case to ensure data integrity, which causes longer decoding latency. The second problem is the underutilized block's lifespan due to conservatively defined block endurance. Raw bit error rate (RBER) of most blocks have not arrived the allowable RBER based on the nominal endurance point, which implies that the conventional P/E cycle-based block retirement policies may waste large flash storage space. In this paper, to exploit the storage capacity of each flash block, we propose an RBER-aware lifetime prediction scheme based on machine learning technologies. We consider the problem that the model can lose prediction effectiveness over time and use incremental learning to update the model for adapting the changes at different lifetime stages. At run time, trained data will be gradually discarded, which can reduce memory overhead. For evaluating our purpose, four well-known machine learning techniques have been compared in terms of predictive accuracy and time overhead under our proposed lifetime prediction scheme. We also compared the predicted values with the tested values obtained in the real NAND flash-based test platform, and the experimental results show that the support vector machine (SVM) models based on our proposed lifetime prediction scheme can achieve as high as 95% accuracy for flash blocks. We also apply our proposed lifetime prediction scheme to predict the actual endurance of flash blocks at four different retention times, and the experimental results show that it can significantly improve the maximum P/E cycle of flash blocks from 37.5% to 86.3% on average. Therefore, the proposed lifetime prediction scheme can provide a guide for block endurance prediction.

  • 33.
    Mahmood, Farhan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electric Power and Energy Systems.
    Vanfretti, Luigi
    Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA..
    Pignati, Marco
    Ecole Polytech Fed Lausanne, Distributed Elect Syst Lab, CH-1015 Lausanne, Switzerland..
    Hooshyar, Hossein
    Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA..
    Sossan, Fabrizio
    Ecole Polytech Fed Lausanne, Distributed Elect Syst Lab, CH-1015 Lausanne, Switzerland..
    Paolone, Mario
    Ecole Polytech Fed Lausanne, Distributed Elect Syst Lab, CH-1015 Lausanne, Switzerland..
    Experimental Validation of a Steady State Model Synthesis Method for a Three-Phase Unbalanced Active Distribution Network Feeder2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 4042-4053Article in journal (Refereed)
    Abstract [en]

    This paper presents the field validation of a method that performs steady-state model synthesis (SSMS) of active distribution networks using syncrophasor measurements. The validation is performed by applying the SSMS method on a real active distribution feeder network by utilizing the measurements from real phasor measurement units (PMUs) installed at the EPFL campus. An extended version of total vector error and a power flow comparison at the PMU buses are used as performance assessment metrics. A real-time hardware-in-the-loop simulations set up at the Distributed Energy System Laboratory is used for further performance assessment of the SSMS application. The effectiveness of the SSMS application is demonstrated by testing it extensively for several different case studies.

  • 34.
    Masoudi, Meysam
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Khafagy, Mohammad Galal
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Conte, Alberto
    Nokia Bell Labs, Cloud Nat Telecom Platforms Automat Dept, F-91620 Nozay, France..
    El-Amine, Ali
    IMT Atlantique, Dept Syst Reseaux Cybersecurite & Droit Numer SRC, CS 17607, F-35576 Cesson Sevigne, France..
    Francoise, Brian
    Orange Gardens, F-92320 Chatillon, France..
    Nadjahi, Chayan
    Normandie Univ, LUSAC, UNICAEN, F-14000 Caen, France..
    Salem, Fatma Ezzahra
    Orange Gardens, F-92320 Chatillon, France..
    Labidi, Wael
    Inst Polytech Paris, Telecom SudParis, UMR CNRS Samovar, F-91011 Evry, France..
    Sural, Altug
    Polaran Ltd, TR-06800 Ankara, Turkey..
    Gati, Azeddine
    Orange Gardens, F-92320 Chatillon, France..
    Bodere, Dominique
    Orange Gardens, F-92320 Chatillon, France..
    Arikan, Erdal
    Polaran Ltd, TR-06800 Ankara, Turkey..
    Aklamanu, Fred
    Nokia Bell Labs, F-91620 Nozay, France..
    Louahlia-Gualous, Hasna
    Normandie Univ, LUSAC, UNICAEN, F-14000 Caen, France..
    Lallet, Julien
    Nokia Bell Labs, F-91620 Nozay, France..
    Pareek, Kuldeep
    MIC Nordic AB, S-16432 Kista, Sweden..
    Nuaymi, Loutfi
    IMT Atlantique, Dept Syst Reseaux Cybersecurite & Droit Numer SRC, CS 17607, F-35576 Cesson Sevigne, France..
    Meunier, Luc
    Sverige AB, Tele2, S-16494 Kista, Sweden..
    Silva, Paulo
    Univ Porto, INESC TEC, P-4200465 Porto, Portugal.;Univ Porto, Fac Engn, P-4200465 Porto, Portugal..
    Almeida, Nuno T.
    Univ Porto, INESC TEC, P-4200465 Porto, Portugal.;Univ Porto, Fac Engn, P-4200465 Porto, Portugal..
    Chahed, Tijani
    Inst Polytech Paris, Telecom SudParis, UMR CNRS Samovar, F-91011 Evry, France..
    Sjolund, Tord
    MIC Nordic AB, S-16432 Kista, Sweden..
    Cavdar, Cicek
    KTH, School of Electrical Engineering and Computer Science (EECS), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Green Mobile Networks for 5G and Beyond2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 107270-107299Article in journal (Refereed)
    Abstract [en]

    The heated 5G network deployment race has already begun with the rapid progress in standardization efforts, backed by the current market availability of 5G-enabled network equipment, ongoing 5G spectrum auctions, early launching of non-standalone 5G network services in a few countries, among others. In this paper, we study current and future wireless networks from the viewpoint of energy efficiency (EE) and sustainability to meet the planned network and service evolution toward, along, and beyond 5G, as also inspired by the findings of the EU Celtic-Plus SooGREEN Project. We highlight the opportunities seized by the project efforts to enable and enrich this green nature of the network as compared to existing technologies. In specific, we present innovative means proposed in SooGREEN to monitor and evaluate EE in 5G networks and beyond. Further solutions are presented to reduce energy consumption and carbon footprint in the different network segments. The latter spans proposed virtualized/cloud architectures, efficient polar coding for fronthauling, mobile network powering via renewable energy and smart grid integration, passive cooling, smart sleeping modes in indoor systems, among others. Finally, we shed light on the open opportunities yet to be investigated and leveraged in future developments.

  • 35. Mehrizi, S.
    et al.
    Tsakmalis, A.
    Chatzinotas, S.
    Ottersten, Björn
    A Bayesian Poisson-Gaussian Process Model for Popularity Learning in Edge-Caching Networks2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 92341-92354Article in journal (Refereed)
  • 36. Mohamed, S. A. S.
    et al.
    Haghbayan, M. -H
    Westerlund, T.
    Heikkonen, J.
    Tenhunen, Hannu
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits. Department of Future Technologies, University of Turku (UTU), Turku, 20500, Finland.
    Plosila, J.
    A Survey on Odometry for Autonomous Navigation Systems2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 97466-97486, article id 8764393Article in journal (Refereed)
    Abstract [en]

    The development of a navigation system is one of the major challenges in building a fully autonomous platform. Full autonomy requires a dependable navigation capability not only in a perfect situation with clear GPS signals but also in situations, where the GPS is unreliable. Therefore, self-contained odometry systems have attracted much attention recently. This paper provides a general and comprehensive overview of the state of the art in the field of self-contained, i.e., GPS denied odometry systems, and identifies the out-coming challenges that demand further research in future. Self-contained odometry methods are categorized into five main types, i.e., wheel, inertial, laser, radar, and visual, where such categorization is based on the type of the sensor data being used for the odometry. Most of the research in the field is focused on analyzing the sensor data exhaustively or partially to extract the vehicle pose. Different combinations and fusions of sensor data in a tightly/loosely coupled manner and with filtering or optimizing fusion method have been investigated. We analyze the advantages and weaknesses of each approach in terms of different evaluation metrics, such as performance, response time, energy efficiency, and accuracy, which can be a useful guideline for researchers and engineers in the field. In the end, some future research challenges in the field are discussed.

  • 37.
    Naqvi, Syeda, I
    et al.
    Univ Engn & Technol, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Naqvi, Aqeel H.
    Chung Ang Univ, Sch Elect & Elect Engn, Seoul 06974, South Korea..
    Arshad, Farzana
    Univ Engn & Technol, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Riaz, Muhammad A.
    Univ Engn & Technol, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Azam, Muhammad A.
    Univ Engn & Technol, Dept Comp Engn, Taxila 47050, Pakistan..
    Khan, Mansoor S.
    COMSATS Univ Islamabad, Math Dept, Islamabad 45550, Pakistan..
    Amin, Yasar
    Univ Engn & Technol, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Loo, Jonathan
    Univ West London, Sch Comp & Engn, London W5 5RF, England..
    Tenhunen, Hannu
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics. Univ Turku, TUCS, Dept Informat Technol, FIN-20520 Turku, Finland..
    An Integrated Antenna System for 4G and Millimeter-Wave 5G Future Handheld Devices2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 116555-116566Article in journal (Refereed)
    Abstract [en]

    In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm x 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 x 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST(R)MWS(R). The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.

  • 38.
    Nomikos, Nikolaos
    et al.
    Univ Aegean, Dept Informat & Commun Syst Engn, Samos 83200, Greece..
    Poulimeneas, Dimitrios
    KTH, School of Electrical Engineering and Computer Science (EECS), Automatic Control.
    Charalambous, Themistoklis
    Aalto Univ, Sch Elect Engn, Dept Elect Engn & Automat, Espoo 02150, Finland..
    Krikidis, Ioannis
    Univ Cyprus, Elect & Comp Engn Dept, CY-1678 Nicosia, Cyprus..
    Vouyioukas, Demosthenes
    Univ Aegean, Dept Informat & Commun Syst Engn, Samos 83200, Greece..
    Johansson, Mikael
    Univ Cyprus, Elect & Comp Engn Dept, CY-1678 Nicosia, Cyprus..
    Delay- and Diversity-Aware Buffer-Aided Relay Selection Policies in Cooperative Networks2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 73531-73547Article in journal (Refereed)
    Abstract [en]

    Buffer-Aided (BA) relaying has shown tremendous performance improvements in terms of throughput and outage probability, although it has been criticized of suffering from long delays that are restrictive for applications, such as video streaming, Web browsing, and file sharing. In this paper, we propose novel relay selection policies aiming at reducing the average delay by incorporating the buffer size of the relays into the decision making of the relay selection process. More specifically, we first propose two new delay-aware policies. One is based on the hybrid relay selection algorithm, where the relay selection takes into account the queue sizes so that the delay is reduced and the diversity is maintained. The other approach is based on the max - link relay selection algorithm. For the max - link algorithm, a delay-aware only approach starves the buffers and increases the outage probability of the system. Thus, for max - link, we propose a delay- and diversity-aware BA relay selection policy targeting the reduction of the average delay, while maintaining the diversity of the transmission. The proposed policies are analyzed by means of Markov Chains and expressions for the outage, throughput, and delay are derived. The asymptotic performance of the policies is also discussed. The improved performance in terms of delays and the use of the proposed algorithms are demonstrated via extensive simulations and comparisons, signifying, at the same time, the need for adaptive mechanisms to handle the interplay between delay and diversity.

  • 39.
    Pan, Fei
    et al.
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Pang, Zhibo
    ABB Corp Res, S-72226 Vasteras, Sweden..
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Wen, Hong
    Univ Elect Sci & Technol China, Dept Aeronaut & Astronaut, Chengdu 611731, Sichuan, Peoples R China..
    Liao, Run-Fa
    Univ Elect Sci & Technol China, Natl Key Lab Sci & Technol Commun, Chengdu 611731, Sichuan, Peoples R China..
    Clone Detection Based on Physical Layer Reputation for Proximity Service2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 3948-3957Article in journal (Refereed)
    Abstract [en]

    Proximity-based service (ProSe) provides direct communications among smart sensor nodes in proximity which aims at reserving resource consumption and alleviating the load in base stations, which is a promising solution for smart sensor systems that possess limited computing and energy resources. During the ProSe direct communications, most of the prior art security methods are usually provided by the ProSe function and are based on complex cryptography. However, despite the computing complexity, it is difficult for cryptographic methods to detect clone attack which is a common kind of attack in sensor systems. Clone nodes feature different physical positions but claim colliding IDs with captured nodes. Thus, clone nodes can be detected by spatial differences, in particular, by the surveillance of physical layer channel state information (CSI). However, CSI is not absolute static due to the random noise in wireless propagation environment. Accordingly, the detection accuracy varies with the stability of CSI. To address this challenge, we take the first attempt to introduce physical layer reputation and then elaborate the physical layer reputation based clone detection protocol to detect clone attack in multiple scenarios. The proposed protocol significantly improves the detection rate and false alarm rate and it is validated both by simulations and realizations.

  • 40.
    Pan, Gaofeng
    et al.
    Southwest Univ, Chongqing Key Lab Nonlinear Circuits & Intelligen, Chongqing 400715, Peoples R China. iamantoulakis, Panagiotis D.; Ma, Zheng; Karagiannidis, George K..
    Diamantoulakis, Panagiotis D.
    Ma, Zheng
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering. Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
    Ding, Zhiguo
    Karagiannidis, George K.
    Simultaneous Lightwave Information and Power Transfer: Policies, chniques and Future Directions2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 28250-28257, article id 8653294Article in journal (Refereed)
    Abstract [en]

    Harvesting energy from the surrounding environment is an important and practical solution to prolong the life of the energy-constrained Internet-of-Things (IoT) devices, e.g., wireless sensors. Visible light communications (VLC) has been proved able to provide high-speed data links while meeting the illumination requirement. Thereby, the energy of VLC signals may be harvested by the energy-constrained IoT terminals, such as indoor sensors and portable/wearable devices. This paper presents the concept of simultaneous lightwave information and power transfer (SLIPT) with a particular focus on the design of the receiver and the practical methods to realize SLIPT in the domains of time, signal components, and photoelectric converters. Furthermore, this paper also introduces the applications of SLIPT to various network topologies and communication technologies, e.g., multiple input multiple output, hybrid VLC-radio frequency, and secure communications. Finally, a detailed discussion of future research directions and challenges for the design of SLIPT systems is also presented.

  • 41.
    Pham, Cong-Toan
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electromagnetic Engineering.
    Månsson, Daniel
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electromagnetic Engineering.
    A Study on Realistic Energy Storage Systems for the Privacy of Smart Meter Readings of Residential Users2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 150262-150270Article in journal (Refereed)
    Abstract [en]

    The introduction of smart meters sparked concerns about privacy breach through real-time monitoring of electric power consumption. Valuable private information about occupancy, behaviour, health, religion and wealth can be extracted from the user’s power profile which urges measurements to protect the integrity of the user. One physical mitigation technique to assure privacy is explored using energy storage systems. Real energy storage technologies are limited in their energy capacities and power capabilities, which have to be appropriately sized to fulfil their role. This paper analyses and compares different energy storage technologies (li-ion, lead-acid, electric double layer capacitor and flywheel) for the protection of residential users by estimating the minimal required capacities and costs for both single and multiple user cases. The analysis is based on actual measured user data from the REDD data set. The results show that the integrity can be protected with reasonable capacities and investments ranging in the margin of market available products.

  • 42.
    Qin, Tian
    et al.
    Department of Electrical and Electronic Engineering, University of Bristol.
    Bleiker, Simon J.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Rana, Sunil
    Department of Electrical and Electronic Engineering, University of Bristol.
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Pamunuwa, Dinesh
    Department of Electrical and Electronic Engineering, University of Bristol.
    Performance Analysis of Nanoelectromechanical Relay-Based Field-Programmable Gate Arrays2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 15997-16009Article in journal (Refereed)
    Abstract [en]

    The energy consumption of field-programmable gate arrays (FPGA) is dominated by leakage currents and dynamic energy associated with programmable interconnect. An FPGA built entirely from nanoelectromechanical (NEM) relays can effectively eliminate leakage energy losses, reduce the interconnect dynamic energy, operate at temperatures >225 °C and tolerate radiation doses in excess of 100 Mrad, while hybrid FPGAs comprising both complementary metal-oxide-semiconductor (CMOS) transistors and NEM relays (NEM-CMOS) have the potential to realize improvements in performance and energy efficiency. Large-scale integration of NEM relays, however, poses a significant engineering challenge due to the presence of moving parts. We discuss the design of FPGAs utilizing NEM relays based on a heterogeneous 3-D integration scheme, and carry out a scaling study to quantify key metrics related to performance and energy efficiency in both NEM-only and NEM-CMOS FPGAs. We show how the integration scheme has a profound effect on these metrics by changing the length of global wires. The scaling regime beyond which net performance and energy benefits is seen in NEM-CMOS over a baseline 90 nm CMOS technology is defined by an effective relay beam length of 0.5 μm , on-resistance of 200 kΩ , and a via pitch of 0.4 μm , all achievable with existing process technology. For ultra-low energy applications that are not performance critical, NEM-only FPGAs can provide close to 15× improvement in energy efficiency.

  • 43.
    Saeed, Ayesha
    et al.
    Univ Engn & Technol Taxila, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Fawad,
    Khan, Muhammad Jamil
    Univ Engn & Technol Taxila, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Riaz, Muhammad Ali
    Univ Engn & Technol Taxila, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Shahid, Humayun
    Univ Engn & Technol Taxila, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Khan, Mansoor Shaukat
    COMSATS Univ Islamabad, Math Dept, Islamabad 45550, Pakistan..
    Amin, Yasar
    Univ Engn & Technol Taxila, Telecommun Engn Dept, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Loo, Jonathan
    Univ West London, Sch Comp & Engn, London W5 5RF, England..
    Tenhunen, Hannu
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics.
    Robustness-Driven Hybrid Descriptor for Noise-Deterrent Texture Classification2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 110116-110127Article in journal (Refereed)
    Abstract [en]

    A robustness-driven hybrid descriptor (RDHD) for noise-deterrent texture classification is presented in this paper. This paper offers the ability to categorize a variety of textures under challenging image acquisition conditions. An image is initially resolved into its low-frequency components by applying wavelet decomposition. The resulting low-frequency components are further processed for feature extraction using completed joint-scale local binary patterns (CJLBP). Moreover, a second feature set is obtained by computing the low order derivatives of the original sample. The evaluated feature sets are integrated to get a final feature vector representation. The texture-discriminating performance of the hybrid descriptor is analyzed using renowned datasets: Outex original, Outex extended, and KTH-TIPS. The experimental results demonstrate a stable and robust performance of the descriptor under a variety of noisy conditions. An accuracy of 95.86%, 32.52%, and 88.74% at noise variance of 0.025 is achieved for the given datasets, respectively. A comparison between performance parameters of the proposed paper with its parent descriptors and recently published paper is also presented.

  • 44.
    Shabbir, Ghulam
    et al.
    Univ Engn & Technol Taxila, Taxila 47050, Pakistan..
    Ahmad, Jamil
    Univ Engn & Technol Taxila, Taxila 47050, Pakistan..
    Raza, Waseem
    Univ Lahore, Lahore 54000, Pakistan..
    Amin, Yasar
    Univ Engn & Technol Taxila, Taxila 47050, Pakistan..
    Akram, Adeel
    Univ Engn & Technol Taxila, Taxila 47050, Pakistan..
    Loo, Jonathan
    Univ West London, London W5 5RF, England..
    Tenhunen, Hannu
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics, Integrated devices and circuits.
    Buffer-Aided Successive Relay Selection Scheme for Energy Harvesting IoT Networks2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 36246-36258Article in journal (Refereed)
    Abstract [en]

    In this paper, we analyze the impact of buffer-aided full-duplex successive relay selection schemes with energy harvesting capability of relay nodes in amplifying and forward (AF) and decode and forward (DF) relaying environments for the Internet of Things networks. We propose to select a relay pair based on the energy harvested and signal strength at relay and destination to receive and transmit in the same time slot, respectively. Contrary to the previous relay pair selection schemes which are based on the signal strength only and cause the relay overuse problem, the proposed scheme ensures the balanced use of energy of relay nodes. The proposed relay selection scheme is implemented with the time switching (TS) and power splitting (PS)-based energy harvesting models in AF and DF relaying environments separately. Furthermore, we derive the closed-form expression of the outage probability and average throughput for both the TS and PS approaches in the DF and AF relaying modes. We compare the proposed relay selection scheme with the S-MMRS scheme and prove that the proposed scheme significantly reduces the outage probability and improves the average throughput. Furthermore, the analytical findings are reinforced with the extensive Monte Carlo simulations.

  • 45.
    Sun, Peng
    et al.
    Zhejiang Univ, State Key Lab Ind Control Technol, Hangzhou 310027, Zhejiang, Peoples R China..
    Wu, Liantao
    Shanghai Huawei Technol Corp Campus, Shanghai 200040, Peoples R China..
    Wang, Zhibo
    Wuhan Univ, Sch Cyber Sci & Engn, Wuhan 430072, Hubei, Peoples R China.;Nanjing Univ, State Key Lab Novel Software Technol, Nanjing 210023, Jiangsu, Peoples R China..
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering. KTH, School of Electrical Engineering and Computer Science (EECS), Centres, ACCESS Linnaeus Centre.
    Wang, Zhi
    Zhejiang Univ, State Key Lab Ind Control Technol, Hangzhou 310027, Zhejiang, Peoples R China..
    Sparsest Random Sampling for Cluster-Based Compressive Data Gathering in Wireless Sensor Networks2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 36383-36394Article in journal (Refereed)
    Abstract [en]

    Compressive data gathering (CDG) has been recognized as a promising technique to collect sensory data in wireless sensor networks (WSNs) with reduced energy cost and better traffic load balancing. Besides, clustering is often integrated into CDG to further facilitate the network performance. However, existing cluster-based CDG methods generally require a large number of sensor nodes to participate in each compressive sensing (CS) measurement gathering and rarely consider possible node failures due to power depletion or malicious attacks, leading to insufficient energy efficiency and poor system robustness. In this paper, we propose a sparsest random sampling scheme for cluster-based CDG (SRS-CCDG) in WSNs to achieve energy efficient and robust data collection. Specifically, sensor nodes are organized into clusters. In each round of data gathering, a random subset of sensor nodes sense the monitored field and transmit their measurements to the corresponding cluster heads (CHs). Then, each CH transmits the data gathered within its cluster to the sink. In SRS-CCDG, each sensor reading is regarded as one CS measurement, and both intra-cluster and inter-cluster data transmissions can be realized by two methods, i.e., relaying or direct transmission. Furthermore, we propose analytical models that study the relationship between the size of clusters and the energy cost when using different intra-cluster and inter-cluster transmission schemes, aimed at finding the optimal size of clusters and transmission schemes that could lead to minimum energy cost. Then, we present a centralized clustering algorithm based on the theoretical analysis. Finally, we investigate the robustness of signal recovery performance of SRS-CCDG when node failures happen. Extensive simulations demonstrate that SRS-CCDG can significantly reduce the energy cost and improve the system robustness to node failures.

  • 46.
    Sun, Tao
    et al.
    Tianjin University.
    Lian, Binbin
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Mechatronics.
    Zhang, Jiateng
    Tianjin University.
    Song, Yimin
    Tianjin Univeristy.
    Kinematic calibration of a2-DoF over-constrained parallel mechanism using real inverse kinematics2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 67752-67761Article in journal (Refereed)
  • 47.
    Tahvili, Sahar
    et al.
    RISE SICS Vasteras, S-72212 Vasteras, Sweden..
    Pimentel, Rita
    RISE SICS Vasteras, S-72212 Vasteras, Sweden..
    Afzal, Wasif
    Malardalen Univ, Sch Innovat Design & Engn, S-72220 Vasteras, Sweden..
    Ahlberg, Marcus
    KTH. ..
    Fornander, Eric
    KTH.
    Bohlin, Markus
    RISE SICS Vasteras, Ind Efficiency, S-72212 Vasteras, Sweden..
    sOrTES: A Supportive Tool for Stochastic Scheduling of Manual Integration Test Cases2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 12928-12946Article in journal (Refereed)
    Abstract [en]

    The main goal of software testing is to detect as many hidden bugs as possible in the final software product before release. Generally, a software product is tested by executing a set of test cases, which can be performed manually or automatically. The number of test cases which are required to test a software product depends on several parameters such as the product type, size, and complexity. Executing all test cases with no particular order can lead to waste of time and resources. Test optimization can provide a partial solution for saving time and resources which can lead to the final software product being released earlier. In this regard, test case selection, prioritization, and scheduling can be considered as possible solutions for test optimization. Most of the companies do not provide direct support for ranking test cases on their own servers. In this paper, we introduce, apply, and evaluate sOrTES as our decision support system for manual integration of test scheduling. sOrTES is a Python-based supportive tool which schedules manual integration test cases which are written in a natural language text. The feasibility of sOrTES is studied by an empirical evaluation which has been performed on a railway use-case at Bombardier Transportation, Sweden. The empirical evaluation indicates that around 40% of testing failure can be avoided by using the proposed execution schedules by sOrTES, which leads to an increase in the requirements coverage of up to 9.6%.

  • 48.
    Tariq, Nimra
    et al.
    Univ Engn & Technol Taxila, Dept Telecommun Engn, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Riaz, Muhammad Ali
    Univ Engn & Technol Taxila, Dept Telecommun Engn, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Shahid, Humayun
    Univ Engn & Technol Taxila, Dept Telecommun Engn, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Khan, Muhammad Jamil
    Univ Engn & Technol Taxila, Dept Telecommun Engn, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Khan, Mansoor Shaukat
    COMSATS Univ Islamabad, Math Dept, Islamabad 45550, Pakistan..
    Amin, Yasar
    Univ Engn & Technol Taxila, Dept Telecommun Engn, ACTSENA Res Grp, Taxila 47050, Pakistan..
    Loo, Jonathan
    Univ West London, Sch Comp & Engn, London W5 5RF, England..
    Tenhunen, Hannu
    KTH, School of Electrical Engineering and Computer Science (EECS), Electronics. Univ Turku, Dept Informat Technol, TUCS, FIN-20520 Turku, Finland..
    Orientation Independent Chipless RFID Tag Using Novel Trefoil Resonators2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 122398-122407Article in journal (Refereed)
    Abstract [en]

    In this paper, a compact and fully passive bit encoding circuit, capable of operating as a chipless radio frequency identification (RFID) tag is presented. The structure consists of novel concentric trefoil-shaped slot resonators realized using Rogers RT/duroid (R) 5880 laminate, occupying a physical footprint of 13.55 x 13.55 mm(2). Each resonating element is associated with a particular data bit, having a 1:1 resonator-to-bit correspondence. Bit sequences are configured through introducing modifications in the geometric structure either by addition or exclusion of each nested slot resonator. Such changes manifest directly in the electromagnetic signature of the tag as presence or absence of corresponding resonant peaks. The proposed 10-bit tag offers minimized inter-resonator mutual coupling and insensitivity to changes in polarization and incident angles thereby demonstrating orientation independent functionality. Moreover, error-free encoding is achieved through stabilizing the shift in resonant frequencies for a variety of different geometric configurations and orientation of the structure. The tag operates within the license-free ultrawideband ranging from 5.4 to 10.4 GHz, providing spectral bit capacity and bit density of 2 bits/GHz and 5.44 bits/cm(2) respectively.

  • 49.
    Turchet, Luca
    et al.
    Queen Mary Univ London, Ctr Digital Mus, London E1 4NS, England..
    Fischione, Carlo
    KTH, School of Electrical Engineering and Computer Science (EECS), Network and Systems engineering.
    Essl, Georg
    Univ Wisconsin, Coll Letters & Sci, Milwaukee, WI 53211 USA..
    Keller, Damian
    Univ Fed Acre, Amazon Ctr Mus Res NAP, BR-69920900 Rio Branco, Brazil..
    Barthet, Mathieu
    Queen Mary Univ London, Ctr Digital Mus, London E1 4NS, England..
    Internet of Musical things: Visit and Challenges2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 61994-62017Article in journal (Refereed)
    Abstract [en]

    The Internet of Musical Things (IoMusT) is an emerging research field positioned at the intersection of Internet of Things, new interfaces for musical expression, ubiquitous music, human-computer interaction, artificial intelligence, and participatory art. From a computer science perspective, IoMusT refers to the networks of computing devices embedded in physical objects (musical things) dedicated to the production and/or reception of musical content. Musical things, such as smart musical instruments or wearables, are connected by an infrastructure that enables multidirectional communication, both locally and remotely. We present a vision in which the IoMusT enables the connection of digital and physical domains by means of appropriate information and communication technologies, fostering novel musical applications and services. The ecosystems associated with the IoMusT include interoperable devices and services that connect musicians and audiences to support musician-musician, audience-musicians, and audience-audience interactions. In this paper, we first propose a vision for the IoMusT and its motivations. We then discuss five scenarios illustrating how the IoMusT could support: 1) augmented and immersive concert experiences; 2) audience participation; 3) remote rehearsals; 4) music e-learning; and 5) smart studio production. We identify key capabilities missing from today's systems and discuss the research needed to develop these capabilities across a set of interdisciplinary challenges. These encompass network communication (e.g., ultra-low latency and security), music information research (e.g., artificial intelligence for real-time audio content description and multimodal sensing), music interaction (e.g., distributed performance and music e-learning), as well as legal and responsible innovation aspects to ensure that future IoMusT services are socially desirable and undertaken in the public interest.

  • 50.
    Vega Barbas, Mario
    et al.
    KTH. ESNE Escuela Univ Diseno Innovac & Tecnol, Madrid 28016, Spain..
    Pau, Ivan
    Univ Politecn Madrid, E-28040 Madrid, Spain..
    Augusto, Juan Carlos
    Middlesex Univ, Sch Sci & Technol, London NW4 4BT, England..
    Seoane, Fernando
    Univ Boras, Swedish Sch Text, S-50190 Boras, Sweden.;Karolinska Inst, Inst Clin Sci Intervent & Technol, S-17177 Stockholm, Sweden.;Karolinska Univ Hosp, Dept Biomed Engn, S-14186 Stockholm, Sweden..
    Interaction Patterns for Smart Spaces: A Confident Interaction Design Solution for Pervasive Sensitive IoT Services2018In: IEEE Access, E-ISSN 2169-3536, Vol. 6, p. 1126-1136Article in journal (Refereed)
    Abstract [en]

    Smart spaces represent a powerful tool for deploying the new pervasive sensitive services based on Internet of Things products and developed in current information society close to users. Researchers have focused their efforts on new techniques to improve systems and products in this area but neglecting the human factors related to psychological aspects of the user and their psycho-social relationship with the deployment space where they live. This research proposes to take into account these cognitive features in early stages of the design of smart spaces by defining a set of interaction patterns. By using this set of interaction patterns it is possible to influence over the confidence that users can develop during the use of IoT products and services based on them. An evaluative verification has been carried out to assess how this design engineering approach provides a real impact on the generation of confidence in the users of this kind of technology.

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