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  • 251.
    Almgren, Mikael
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Ekström, Erik
    KTH, School of Information and Communication Technology (ICT).
    Utveckling av produktprototyp för hårdvaruaccelererad bildbehandling2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today's society there are embedded systems in almost everything from toasters to space rockets. In order to meet users’ ever-increasing demands for performance and functionality, the hardware of these systems must be utilized optimally. This can be done by designing hardware specifically for the task, or to use a more general hardware running customizable software. In many cases it may be suitable, and in some cases even necessary, to mix these methods to solve a given task. For example, a powerful processor could be complemented with special designed hardware, called an accelerator, to solve parts of the problem faster. The overall system performance can thus be increased by the use of the accelerators. One problem with this solution is that the connection between the processor and the accelerator may form a bottleneck.

    One way to reduce the effects of this bottleneck is to tightly integrate programmable logic (FPGA, Field Programmable Gate Array) and a processor on the same chip. This tight integration makes it possible to simplify and speed up the communication between the two units. For example, image processing could be accelerated in the FPGA and the result could then be used in some software application in the processor.

    This report describes how the work was carried out during this thesis. The main goal of the thesis was to study how a specific product prototype could be implemented using a Zynq-7000 based development board. The focus of this work was to study how the internal communication should be implemented, and there by how the solution should be partitioned between the software and hardware in Zynq-7000. The intended product was a system for image recognition of fruits or vegetables for use in a grocery store. During the work we used a Zynq-7000 based development board called ZedBoard to try our implementations.

  • 252.
    Almkvist, Magnus
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Wahren, Marcus
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Preserving Integrity inTelecommunication Networks Opened bythe Parlay Service Interface2002Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master’s Thesis in Electrical Engineering concerns the introduction of a Parlay gateway in Skanova’s public circuit switched telephone network, what network integrity problems this brings, and how to preserve the integrity of the network.

    There is a rising demand from the market on Skanova to be able to offer integrated and useful services via their network. Examples of such services are Web Controlled Call Forwarding and Virtual Call Centres. Until now, these services have been implemented with the Intelligent Network concept which is a technology for concentrating the service logic in the telephone network to centralised service platforms within the network operator’s domain. Developing new services in this environment is expensive and therefore, Skanova wants to open the network for third party service providers. The opening of the network is enabled by the introduction of a gateway implementing the open service interface Parlay.

    The crucial point when opening the network for third party service providers is to maintain the integrity of the network. Parlay is an object oriented Application Programming Interface that enables a third party service access to core network resources in a controlled manner.

    The authors’ definition of network integrity is: “the ability of a network to steadily remain in a safe state, while performing according to the expectations and specifications of its owner, i.e. delivering the expected functionality and providing means to charge for utilised network resources”.

    The thesis describes a few services implemented via the Parlay interface and points out examples of activities in these services that may jeopardise the integrity of the network. The described activities belong to one of the two categories: Call Control Functionality or Lack of Charging Instruments.

    The thesis also describes two important methods for addressing encountered integrity problems. The methods are: Parlay Service Level Agreement and Policy Management.</p> Finally, the solutions are compared and the conclusion is that Policy Management is a conformable and flexible method for addressing lots of integrity problems and that these are important qualities, since new integrity problems will arise all the time.

  • 253.
    Almlöf, Jonas
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Quantum Electronics and Quantum Optics, QEO (moved to SCI 2011-07-01).
    Björk, Gunnar
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics (Closed 20120101), Quantum Electronics and Quantum Optics, QEO (moved to SCI 2011-07-01).
    A short and efficient quantum-erasure code for polarization-coded photonic qubits2009In: CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference, 2009, p. 5191786-Conference paper (Refereed)
  • 254.
    Almlöf, Jonas
    et al.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    Björk, Gunnar G. E.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Quantum Electronics and Quantum Optics, QEO.
    A short and efficient error correcting code for polarization coded photonic qubits in a dissipative channel2011In: Optics Communications, ISSN 0030-4018, E-ISSN 1873-0310, Vol. 284, no 1, p. 550-554Article in journal (Refereed)
    Abstract [en]

    We propose a short and efficient non-degenerate quantum error correcting code that is adapted for qubits encoded on two orthogonal, single-photon states (e.g., horizontally and vertically polarized) subject to a dissipative channel. The proposed code draws its strength from the fact that it is adapted to the physical characteristics of the information-carrying basis states under the action of the channel. The code combines different energy manifolds and consists of only 3 spatio-temporal modes and on average 2 photons per code word.

  • 255.
    Almqvist, Daniel
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Jansson, Magnus
    KTH, School of Information and Communication Technology (ICT).
    Förbättrat informationsflöde med hjälp av Augmented Reality2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Augmented Reality is a technology where an object is introduced in front of a picture or a similar media using the camera on a mobile device. There are several different ways to use the Augmented Reality technology, research in the field has therefore been made. An example of an area where the technology can be used is advertisement. Since advertisement is something everyone is confronted with daily, but usually the advertisement can be seen as boring or is something many do not even notice. Through a Augmented Reality prototype, users can register both patterns and speech and get the required data from a database. It can create an interactive event that displays the information in a unique way, where everyone, even people with disabilities can take part of the information they usually can not take part of. This interactive event gives life to the previously tedious advertisement or information posters.

    The result of the report is a prototype on the mobile platform Android using Augmented Reality technology and the prototype has many features. It can use voice recognition and keywords to access additional information about the keyword. The testing of this prototype shows that many are in favour of the use of the prototype and they see it as an interesting way to get the information. That is why they are willing use the application themselves to get their own advertising in a unique and appealing way.

  • 256. Al-Naamani, Laila
    et al.
    Dobretsov, Sergey
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Chitosan-zinc oxide nanoparticle composite coating for active food packaging applications2016In: Innovative Food Science & Emerging Technologies, ISSN 1466-8564, E-ISSN 1878-5522, Vol. 38, p. 231-237Article in journal (Refereed)
    Abstract [en]

    In this study antimicrobial properties of chitosan and chitosan-zinc oxide (ZnO) nanocomposite coatings on PE films were studied. Oxygen plasma pretreatment of PE films led to increased adhesion by 2% of chitosan and the nanocomposite coating solutions to the packaging films. Scanning Electron Microscopy (SEM) revealed uniform coatings on PE surfaces. Incorporation of ZnO nanoparticles into the chitosan matrix resulted in 42% increase in solubility; swelling decreased by 80% while the water contact angle (WCA) increased from 60 to 95 compared to chitosan coating. PE coated with chitosan-ZnO nanocomposite films completely inactivated and prevented the growth of food pathogens, while chitosan-coated films showed only 10-fold decline in the viable cell counts of Salmonella enterica, Escherichia coli and Staphylococcus aureus after 24-h incubation compared to the control. Industrial relevance: One of the greatest challenges of food industry is microbial contamination. The present study suggests that PE coating with chitosan-ZnO nanocomposite is a promising technique to enhance antimicrobial properties of the films. Chitosan-ZnO nanocomposite coatings improved antibacterial properties of PE by inactivating about 99.9% of viable pathogenic bacteria. Hence, our results show the effectiveness of the nanocomposite coating in the development of active food packaging in order to prolong the shelf life of food products.

  • 257. Al-Naamani, Laila
    et al.
    Dobretsov, Sergey
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Burgess, J. Grant
    Chitosan-zinc oxide nanocomposite coatings for the prevention of marine biofouling2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 168, p. 408-417Article in journal (Refereed)
    Abstract [en]

    Marine biofouling is a worldwide problem affecting maritime industries. Global concerns about the high toxicity of antifouling paints have highlighted the need to develop less toxic antifouling coatings. Chitosan is a natural polymer with antimicrobial, antifungal and antialgal properties that is obtained from partial deacetylation of crustacean waste. In the present study, nanocomposite chitosan-zinc oxide (chitosan-ZnO) nanoparticle hybrid coatings were developed and their antifouling activity was tested. Chitosan-ZnO nanoparticle coatings showed anti-diatom activity against Navicula sp. and antibacterial activity against the marine bacterium Pseudoalteromonas nigrifaciens. Additional antifouling properties of the coatings were investigated in a mesocosm study using tanks containing natural sea water under controlled laboratory conditions. Each week for four weeks, biofilm was removed and analysed by flow cytometry to estimate total bacterial densities on the coated substrates. Chitosan-ZnO hybrid coatings led to better inhibition of bacterial growth in comparison to chitosan coatings alone, as determined by flow cytometry. This study demonstrates the antifouling potential of chitosan-ZnO nanocomposite hybrid coatings, which can be used for the prevention of biofouling. (C) 2016 Elsevier Ltd. All rights reserved.

  • 258.
    Al-Naami, Nora
    KTH, School of Information and Communication Technology (ICT).
    Indoor navigation techniques for underground subway stations: Analyzing Suitable indoor navigation technologies for underground stations2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Indoor navigation has always been an interesting topic to look at since there are many use of it for example in airports, huge malls and underground transport stations. One interesting application area is the underground transportation since the current navigation in the underground stations in Sweden is proven to be insufficient to guide the user from the underground station to the final destination. GPS is a prominent solution for the outdoor navigation but no prominent solution has been found for the indoor navigation. Techniques used for navigation indoors vary depending on the infrastructure of the building. Therefore, this paper looks at the different indoor navigation techniques categorized based on a smartphone's sensors and find the techniques most suitable in implementing for the existing SL underground stations. The underground station is divided into two parts, the platform and the second floor. A combination of kinematic and visual navigation techniques is efficient to implement in the platform due to the environment of the platform. Wireless navigation is suitable to implement in the second floor due to the availability of WiFi access points in the second floor of the underground station. Those findings help in setting up an efficient navigation for the SL underground stations, which help in navigating users from one point to another.

  • 259.
    Alnoor, Ahmadullah
    KTH, School of Information and Communication Technology (ICT).
    State as a Service: Towards Stateful Cloud Services2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Cloud ERP or Enterprise Resource Planning (ERP) as a Cloud Service delivers value by reducing initial and long term operating costs since infrastructure, platform and (certain) application management tasks are delegated to a specialist provider. Questions present at intersection of the ERP challenge landscape and the Cloud Computing opportunity horizon include characterization of Cloud friendly ERP modules and adaptation of stateful (on-premises ERP) components to a stateless platform.

    Contributions of this thesis work include the R.A.I.N. Cloud fitness criteria that encompasses Responsiveness, Availability, I/O and Native support aspects of Cloud Services. More importantly, the State abstraction, a reliable and elastic state management framework employing Autonomic Computing and Redo Recovery constructs is introduced. Construction of abstraction properties, namely, affinity aware state preservation and recovery consider Cloud strengths of scaling out and reliability as well as peculiarities of Cloud billing model. Proof-of-concept implementation of State as a Service has been comprehensively detailed and evaluated advocating infrastructure layer support of the kind and associated tooling.

  • 260. Alonso, M. A.
    et al.
    Setala, T.
    Friberg, Ari T.
    KTH, School of Information and Communication Technology (ICT), Optics and Photonics, Optics.
    Optimal pulses for arbitrary dispersive media2011In: Journal of the European Optical Society - Rapid Publications, ISSN 1990-2573, E-ISSN 1990-2573, Vol. 6, p. 11035-Article in journal (Refereed)
    Abstract [en]

    A variational procedure is given for finding the pulses for which the initial temporal rms width and the rate of increase of this width are jointly minimized for propagation in non-absorbing media with arbitrary dispersive properties. We show that, while in linearly dispersive media the optimal pulses are Gaussian, in other situations such as a hollow metallic waveguide or for purely cubic dispersion departures from Gaussian behavior become evident. An interpretation of the results in terms of suitable phase-space representations is also given.

  • 261.
    Alpire, Adam
    KTH, School of Information and Communication Technology (ICT).
    Predicting Solar Radiation using a Deep Neural Network2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Simulating the global climate in fine granularity is essential in climate science research. Current algorithms for computing climate models are based on mathematical models that are computationally expensive. Climate simulation runs can take days or months to execute on High Performance Computing (HPC) platforms. As such, the amount of computational resources determines the level of resolution for the simulations. If simulation time could be reduced without compromising model fidelity, higher resolution simulations would be possible leading to potentially new insights in climate science research. In this project, broadband radiative transfer modeling is examined, as this is an important part in climate simulators that takes around 30% to 50% time of a typical general circulation model. This thesis project presents a convolutional neural network (CNN) to model this most time consuming component. As a result, swift radiation prediction through the trained deep neural network achieves a 7x speedup compared to the calculation time of the original function. The average prediction error (MSE) is around 0.004 with 98.71% of accuracy.

  • 262.
    Al-Qaysi, Ibrahim
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Ghidei, Yonas
    KTH, School of Information and Communication Technology (ICT).
    Tre-stegsmetod för att kvantifiera komplexitet för IT-förslag2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Modern enterprises are under constant change. Therefore, enterprises need to change, extend and modify the applications that support their businesses. Making changes in the architectures of large IT-systems however, are not straightforward. It is often very costly and time consuming. The problem is that there are no easy methods to quantify complexity and optimize an implementation in early phases of an application construction. Thus, many companies are in need of a method to quanitfy complexity of their IT-businessproposals in order to facilitate their decision-making process. One of them is the Swedish Armed Forces (sv. Försvarsmakten). The purpose of this study is therefore to present a simple method to quantify complexity and optimize implementation for IT-proposals. The purpose aligns with the goal, which is to present a model, which forms the basis for IT-proposals, for companies to consider in their process.

    This study uses a combination of a qualitative and quantitative research with an inductive research approach. Furthermore, this study evaluates in which ways Swedish Armed Forces application FMTK can be implemented and which implementations that are most optimal in terms of complexity. A method which incorporates the implementation is thereafter presented as a result of the study. Conclusively, the study shows with the help of analyses and evaluations that the presented method, namely the Three-stepmethod is superior to other methods.

  • 263.
    Alrup, Max
    KTH, School of Information and Communication Technology (ICT).
    Programutveckling för mobila enheter: Musikproduktionsapplikation för Android2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There are many applications that allow the user to produce music. Subsets of them are available on mobile devices such as smart phones and tablets. The majorities of these programs are well-made and offer many useful features. The problem is that it takes a long time to learn to use these programs.

    The goal of this project was to develop an easy to use music application for the Android platform. The development has been carried out using different a couple of different development techniques. Examples of these are the software development framework Scrum and the software development pattern Model, View, Controller (MVC). The code is written in the Java programming language with the integrated development environment Eclipse along with the Android Development Tools (ADT) plugin. The project resulted in a fully functioning music-production application. The application is a hybrid between static note input and real time input. Most of the functional requirements were implemented in the final product, but not all. Some low priority functionality was skipped due to time constraints.

  • 264.
    Al-Saadeh, Osama
    KTH, School of Information and Communication Technology (ICT).
    Performance of In-Band Full-Duplex for 5G Wireless Networks2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In-band full duplex is a new duplexing scheme that allows radio nodes to transmit and receive, utilizing the same frequency and time resources. The implementation of in-band full duplex was not feasible in practice, due to the effect of self-interference. But then, advances in signal processing made it possible to reduce this effect. However, the system level performance of in-band full duplex has not been investigated thoroughly.Through computer simulations, we investigate the performance of in-band full duplex, for indoor 5G small cell wireless networks. We examine the performance of in-band full duplex in comparison to dynamic and static time division duplexing. Additionally, we analyze the performance of the duplexing schemes with two interference mitigation techniques, namely beamforming and interference cancellation.Our results indicate that for highly utilized wireless networks, in-band full duplex should be combined with beamforming and interference cancellation, in order to achieve a performance gain over traditional duplexing schemes. Only then, in-band full duplex is considered advantageous, at any network utilization, and any downlink to uplink traffic demand proportion. Our results also suggest that in order to achieve a performance gain with in-band full duplex in both links, the transmit power of the access points should be comparable to the transmit power of the mobile stations.

  • 265. Al-Saadeh, Osama
    et al.
    Sung, Ki Won
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    A performance comparison of in-band full duplex and dynamic TDD for 5G indoor wireless networks2017In: EURASIP Journal on Wireless Communications and Networking, ISSN 1687-1472, E-ISSN 1687-1499, article id 50Article in journal (Refereed)
    Abstract [en]

    In-band full duplex has emerged as a solution for high data rate and low access delay for 5G wireless networks after its feasibility has been demonstrated. However, the impact of the in-band full duplex on the system-level performance of multi-cell wireless networks has not been investigated thoroughly. In this paper, we conduct an extensive simulation study to investigate the performance of in-band full duplex for indoor 5G small cell wireless networks. Particularly, we compare the in-band full duplex with static and dynamic time division duplexing schemes which require much less hardware complexity. We examine the effects of beamforming and interference cancellation under various traffic demands and asymmetry situations in the performance comparison. Our objective is to identify under which condition and with which technology support the in-band full duplex becomes advantageous over the simpler duplexing schemes. Numerical results indicate that for highly utilized wireless networks, in-band full duplex should be combined with interference cancellation and beamforming in order to achieve a performance gain over traditional duplexing schemes. Only then in-band full duplex is considered to be advantageous at any number of active mobile stations in the network and any downlink to uplink traffic proportion. Our results also suggest that in order to achieve a performance gain with the in-band full duplex in both links, the transmit power of the access points and the mobile stations should be comparable.

  • 266. Al-Saadi, Mubarak J.
    et al.
    Al-Harthi, Salim H.
    Kyaw, Htet H.
    Myint, Myo T. Z.
    Bora, Tanujjal
    Laxman, Karthik
    Al-Hinai, Ashraf
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Influence of Atomic Hydrogen, Band Bending, and Defects in the Top Few Nanometers of Hydrothermally Prepared Zinc Oxide Nanorods2017In: Nanoscale Research Letters, ISSN 1931-7573, E-ISSN 1556-276X, Vol. 12, article id 22Article in journal (Refereed)
    Abstract [en]

    We report on the surface, sub-surface (top few nanometers) and bulk properties of hydrothermally grown zinc oxide (ZnO) nanorods (NRs) prior to and after hydrogen treatment. Upon treating with atomic hydrogen (H*), upward and downward band bending is observed depending on the availability of molecular H2O within the structure of the NRs. In the absence of H2O, the H* treatment demonstrated a cleaning effect of the nanorods, leading to a 0.51 eV upward band bending. In addition, enhancement in the intensity of room temperature photoluminescence (PL) signals due to the creation of new surface defects could be observed. The defects enhanced the visible light activity of the ZnO NRs which were subsequently used to photocatalytically degrade aqueous phenol under simulated sunlight. On the contrary, in the presence of H2O, H* treatment created an electronic accumulation layer inducing downward band bending of 0.45 eV (similar to 1/7th of the bulk ZnO band gap) along with the weakening of the defect signals as observed from room temperature photoluminescence spectra. The results suggest a plausible way of tailoring the band bending and defects of the ZnO NRs through control of H2O/H* species.

  • 267. Al-Sabahi, Jamal
    et al.
    Bora, Tanujjal
    Al-Abri, Mohammed
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Controlled defects of zinc oxide nanorods for efficient visible light photocatalytic degradation of phenol2016In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 9, no 4, article id 238Article in journal (Refereed)
    Abstract [en]

    Environmental pollution from human and industrial activities has received much attention as it adversely affects human health and bio-diversity. In this work we report efficient visible light photocatalytic degradation of phenol using supported zinc oxide (ZnO) nanorods and explore the role of surface defects in ZnO on the visible light photocatalytic activity. ZnO nanorods were synthesized on glass substrates using a microwave-assisted hydrothermal process, while the surface defect states were controlled by annealing the nanorods at various temperatures and were characterized by photoluminescence and X-ray photoelectron spectroscopy. High performance liquid chromatography (HPLC) was used for the evaluation of phenol photocatalytic degradation. ZnO nanorods with high surface defects exhibited maximum visible light photocatalytic activity, showing 50% degradation of 10 ppm phenol aqueous solution within 2.5 h, with a degradation rate almost four times higher than that of nanorods with lower surface defects. The mineralization process of phenol during degradation was also investigated, and it showed the evolution of different photocatalytic byproducts, such as benzoquinone, catechol, resorcinol and carboxylic acids, at different stages. The results from this study suggest that the presence of surface defects in ZnO nanorods is crucial for its efficient visible light photocatalytic activity, which is otherwise only active in the ultraviolet region.

  • 268.
    Al-Sahaf, Hussein
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Susso, Madi
    KTH, School of Information and Communication Technology (ICT).
    Från- och närvaroplanering för Scania Sverige2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis was done with two-fold purpose, to give Scania a theoretical base for a new technology for management of the personnel presence and absence planning and to implement this new technology. Scanias former solution was utilized by using different Excel sheets and these have been perceived as inefficient and cumbersome to work with. This has led to a lot of additional administrative work and the need for a new solution was defined to this thesis.

    The initial phase of the project focused on understanding the relevant processes related to the presence and absence planning. When the processes were well understood, requirements on the new system were captured through qualitative methods and interviews with respondents of different positions from the enterprise. The requirements obtained from the interviews proved to be relatively consistent and was defined in a requirement specification. These requirements were used to evaluate different solutions chosen from the commercial stock. In addition, a make or buy analysis were created and made it possible to determine whether the solution would be bought or developed internally. After internal discussions within Scania, where the results from the alternative solution evaluation and the make or buy analysis was considered, it was decided that the new solution would be built in a Microsoft SharePoint environment.

    The environment was already available for Scania and the implementation was done as a pilot implementation. Two groups from Scanias enterprise was asked to act pilots, in order to evaluate the solution by strengths, weaknesses and desired functionalities. The pilot phase is planned to start in early September 2013.

  • 269.
    Al-Shishtawy, Ahmad
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Enabling and Achieving Self-Management for Large Scale Distributed Systems: Platform and Design Methodology for Self-Management2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Autonomic computing is a paradigm that aims at reducing administrative overhead by using autonomic managers to make applications self-managing. To better deal with large-scale dynamic environments; and to improve scalability, robustness, and performance; we advocate for distribution of management functions among several cooperative autonomic managers that coordinate their activities in order to achieve management objectives. Programming autonomic management in turn requires programming environment support and higher level abstractions to become feasible.

    In this thesis we present an introductory part and a number of papers that summaries our work in the area of autonomic computing. We focus on enabling and achieving self-management for large scale and/or dynamic distributed applications. We start by presenting our platform, called Niche, for programming self-managing component-based distributed applications. Niche supports a network-transparent view of system architecture simplifying designing application self-* code.  Niche provides a concise and expressive API for self-* code. The implementation of the framework relies on scalability and robustness of structured overlay networks. We have also developed a distributed file storage service, called YASS, to illustrate and evaluate Niche.

    After introducing Niche we proceed by presenting a methodology and design space for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to the design and development of an improved version of our distributed storage service YASS as a case study.

    We continue by presenting a generic policy-based management framework which has been integrated into Niche. Policies are sets of rules that govern the system behaviors and reflect the business goals or system management objectives. The policy based management is introduced to simplify the management and reduce the overhead, by setting up policies to govern system behaviors. A prototype of the framework is presented and two generic policy languages (policy engines and corresponding APIs), namely SPL and XACML, are evaluated using our self-managing file storage application YASS as a case study.

    Finally, we present a generic approach to achieve robust services that is based on finite state machine replication with dynamic reconfiguration of replica sets. We contribute a decentralized algorithm that maintains the set of resource hosting service replicas in the presence of churn. We use this approach to implement robust management elements as robust services that can operate despite of churn.

     

  • 270.
    Al-Shishtawy, Ahmad
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    Self-Management for Large-Scale Distributed Systems2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Autonomic computing aims at making computing systems self-managing by using autonomic managers in order to reduce obstacles caused by management complexity. This thesis presents results of research on self-management for large-scale distributed systems. This research was motivated by the increasing complexity of computing systems and their management.

    In the first part, we present our platform, called Niche, for programming self-managing component-based distributed applications. In our work on Niche, we have faced and addressed the following four challenges in achieving self-management in a dynamic environment characterized by volatile resources and high churn: resource discovery, robust and efficient sensing and actuation, management bottleneck, and scale. We present results of our research on addressing the above challenges. Niche implements the autonomic computing architecture, proposed by IBM, in a fully decentralized way. Niche supports a network-transparent view of the system architecture simplifying the design of distributed self-management. Niche provides a concise and expressive API for self-management. The implementation of the platform relies on the scalability and robustness of structured overlay networks. We proceed by presenting a methodology for designing the management part of a distributed self-managing application. We define design steps that include partitioning of management functions and orchestration of multiple autonomic managers.

    In the second part, we discuss robustness of management and data consistency, which are necessary in a distributed system. Dealing with the effect of churn on management increases the complexity of the management logic and thus makes its development time consuming and error prone. We propose the abstraction of Robust Management Elements, which are able to heal themselves under continuous churn. Our approach is based on replicating a management element using finite state machine replication with a reconfigurable replica set. Our algorithm automates the reconfiguration (migration) of the replica set in order to tolerate continuous churn. For data consistency, we propose a majority-based distributed key-value store supporting multiple consistency levels that is based on a peer-to-peer network. The store enables the tradeoff between high availability and data consistency. Using majority allows avoiding potential drawbacks of a master-based consistency control, namely, a single-point of failure and a potential performance bottleneck.

    In the third part, we investigate self-management for Cloud-based storage systems with the focus on elasticity control using elements of control theory and machine learning. We have conducted research on a number of different designs of an elasticity controller, including a State-Space feedback controller and a controller that combines feedback and feedforward control. We describe our experience in designing an elasticity controller for a Cloud-based key-value store using state-space model that enables to trade-off performance for cost. We describe the steps in designing an elasticity controller. We continue by presenting the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores that combines feedforward and feedback control.

  • 271.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Asif Fayyaz, Muhammad
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Popov, Konstantin
    Swedish Institute of Computer Science.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Achieving robust self-management for large-scale distributed applications2010Report (Other (popular science, discussion, etc.))
    Abstract [en]

    Autonomic managers are the main architectural building blocks for constructing self-management capabilities of computing systems and applications. One of the major challenges in developing self-managing applications is robustness of management elements which form autonomic managers. We believe that transparent handling of the effects of resource churn (joins/leaves/failures) on management should be an essential feature of a platform for selfmanaging large-scale dynamic distributed applications, because it facilitates the development of robust autonomic managers and hence improves robustness of self-managing applications. This feature can be achieved by providing a robust management element abstraction that hides churn from the programmer. In this paper, we present a generic approach to achieve robust services that is based on finite state machine replication with dynamic reconfiguration of replica sets. We contribute a decentralized algorithm that maintains the set of nodes hosting service replicas in the presence of churn. We use this approach to implement robust management elements as robust services that can operate despite of churn. Our proposed decentralized algorithm uses peer-to-peer replica placement schemes to automate replicated state machine migration in order to tolerate churn. Our algorithm exploits lookup and failure detection facilities of a structured overlay network for managing the set of active replicas. Using the proposed approach, we can achieve a long running and highly available service, without human intervention, in the presence of resource churn. In order to validate and evaluate our approach, we have implemented a prototype that includes the proposed algorithm.

     

  • 272.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Bao, Lin
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Policy based self-management in distributed environments2010In: 2010 Fourth IEEE International Conference on Self-Adaptive and Self-Organizing Systems Workshop (SASOW), IEEE Computer Society Digital Library, 2010, p. 256-260Conference paper (Refereed)
    Abstract [en]

      Currently, increasing costs and escalating complexities are primary issues in the distributed system management. The policy based management is introduced to simplify the management and reduce the overhead, by setting up policies to govern system behaviors. Policies are sets of rules that govern the system behaviors and reflect the business goals or system management objectives. This paper presents a generic policy-based management framework which has been integrated into an existing distributed component management system, called Niche, that enables and supports self-management. In this framework, programmers can set up more than one Policy-Manager-Group to avoid centralized policy decision making which could become a performance bottleneck. Furthermore, the size of a Policy-Manager-Group, i.e. the number of Policy-Managers in the group, depends on their load, i.e. the number of requests per time unit. In order to achieve good load balancing, a policy request is delivered to one of the policy managers in the group randomly chosen on the fly. A prototype of the framework is presented and two generic policy languages (policy engines and corresponding APIs), namely SPL and XACML, are evaluated using a self-managing file storage application as a case study.

  • 273.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Fayyaz, Muhammad Asif
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Popov, Konstantin
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Achieving Robust Self-Management for Large-Scale Distributed Applications2010In: Self-Adaptive and Self-Organizing Systems (SASO), 2010 4th IEEE International Conference on: SASO 2010, IEEE Computer Society, 2010, p. 31-40Conference paper (Refereed)
    Abstract [sv]

    Achieving self-management can be challenging, particularly in dynamic environments with resource churn (joins/leaves/failures). Dealing with the effect of churn on management increases the complexity of the management logic and thus makes its development time consuming and error prone. We propose the abstraction of robust management elements (RMEs), which are able to heal themselves under continuous churn. Using RMEs allows the developer to separate the issue of dealing with the effect of churn on management from the management logic. This facilitates the development of robust management by making the developer focus on managing the application while relying on the platform to provide the robustness of management. RMEs can be implemented as fault-tolerant long-living services. We present a generic approach and an associated algorithm to achieve fault-tolerant long-living services. Our approach is based on replicating a service using finite state machine replication with a reconfigurable replica set. Our algorithm automates the reconfiguration (migration) of the replica set in order to tolerate continuous churn. The algorithm uses P2P replica placement schemes to place replicas and uses the P2P overlay to monitor them. The replicated state machine is extended to analyze monitoring data in order to decide on when and where to migrate. We describe how to use our approach to achieve robust management elements. We present a simulation-based evaluation of our approach which shows its feasibility.

  • 274.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Höglund, Joel
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Popov, Konstantin
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Parlavantzas, Nikos
    INRIA, Grenoble, France.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Brand, Per
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Distributed Control Loop Patterns for Managing Distributed Applications2008In: SASOW 2008: SECOND IEEE INTERNATIONAL CONFERENCE ON SELF-ADAPTIVE AND SELF-ORGANIZING SYSTEMS WORKSHOPS, PROCEEDINGS / [ed] Serugendo GD, LOS ALAMITOS: IEEE Computer Society, 2008, p. 260-265Conference paper (Refereed)
    Abstract [en]

    In this paper we discuss various control loop patterns for managing distributed applications with multiple control loops. We introduce a high-level framework, called DCMS, for developing, deploying and managing component-based distributed applications in dynamic environments. The control loops, and interactions among them, are illustrated in the context of a distributed self-managing storage service implemented using DCMS to achieve various self-* properties. Different control loops are used for different self-* behaviours, which illustrates one way to divide application management, which makes for both ease of development and for better scalability and robustness when managers are distributed. As the multiple control loops are not completely independent, we demonstrate different patterns to deal with the interaction and potential conflict between multiple managers.

  • 275.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Höglund, Joel
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Popov, Konstantin
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Parlavantzas, Nikos
    INRIA, Grenoble, France.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Brand, Per
    Swedish Institute of Computer Science (SICS), Kista, Sweden.
    Enabling Self-Management Of Component Based Distributed Applications2008In: FROM GRIDS TO SERVICE AND PERVASIVE COMPUTING, Springer-Verlag New York, 2008, p. 163-174Conference paper (Refereed)
    Abstract [en]

    Deploying and managing distributed applications in dynamic Grid environments requires a high degree of autonomous management. Programming autonomous management in turn requires programming environment support and higher level abstractions to become feasible. We present a framework for programming self-managing component-based distributed applications. The framework enables the separation of application’s functional and non-functional (self-*) parts. The framework extends the Fractal component model by the component group abstraction and one-to-any and one-to-all bindings between components and groups. The framework supports a network-transparent view of system architecture simplifying designing application self-* code. The framework provides a concise and expressive API for self-* code. The implementation of the framework relies on scalability and robustness of the Niche structured p2p overlay network. We have also developed a distributed file storage service to illustrate and evaluate our framework.

  • 276.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Khan, Tareq Jamal
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Robust Fault-Tolerant Majority-Based Key-Value Store Supporting Multiple Consistency Levels2011In: 2011 IEEE 17TH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS), 2011, p. 589-596Conference paper (Refereed)
    Abstract [en]

    The wide spread of Web 2.0 applications with rapidly growing amounts of user generated data, such as, wikis, social networks, and media sharing, have posed new challenges on the supporting infrastructure, in particular, on storage systems. In order to meet these challenges, Web 2.0 applications have to tradeoff between the high availability and the consistency of their data. Another important issue is the privacy of user generated data that might be caused by organizations that own and control datacenters where user data are stored. We propose a large-scale, robust and fault-tolerant key-value object store that is based on a peer-to-peer network owned and controlled by a community of users. To meet the demands of Web 2.0 applications, the store supports an API consisting of different read and write operations with various data consistency guarantees from which a wide range of web applications would be able to choose the operations according to their data consistency, performance and availability requirements. For evaluation, simulation has been carried out to test the system availability, scalability and fault-tolerance in a dynamic, Internet wide environment.

  • 277.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    ElastMan: Autonomic elasticity manager for cloud-based key-value stores2013In: HPDC 2013 - Proceedings of the 22nd ACM International Symposium on High-Performance Parallel and Distributed Computing, 2013, p. 115-116Conference paper (Refereed)
    Abstract [en]

    The increasing spread of elastic Cloud services, together with the pay-as-you-go pricing model of Cloud computing, has led to the need of an elasticity controller. The controller automatically resizes an elastic service in response to changes in workload, in order to meet Service Level Objectives (SLOs) at a reduced cost. However, variable performance of Cloud virtual machines and nonlinearities in Cloud services complicates the controller design. We present the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores. ElastMan combines feedforward and feedback control. Feedforward control is used to respond to spikes in the workload by quickly resizing the service to meet SLOs at a minimal cost. Feedback control is used to correct modeling errors and to handle diurnal workload. We have implemented and evaluated ElastMan using the Voldemort key-value store running in a Cloud environment based on OpenStack. Our evaluation shows the feasibility and effectiveness of our approach to automation of Cloud service elasticity.

  • 278.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    ElastMan: Autonomic Elasticity Manager for Cloud-Based Key-Value Stores2012Report (Other academic)
    Abstract [en]

    The increasing spread of elastic Cloud services, together with the pay-asyou-go pricing model of Cloud computing, has led to the need of an elasticity controller. The controller automatically resizes an elastic service, in response to changes in workload, in order to meet Service Level Objectives (SLOs) at a reduced cost. However, variable performance of Cloud virtual machines and nonlinearities in Cloud services, such as the diminishing reward of adding a service instance with increasing the scale, complicates the controller design. We present the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores. ElastMan combines feedforward and feedback control. Feedforward control is used to respond to spikes in the workload by quickly resizing the service to meet SLOs at a minimal cost. Feedback control is used to correct modeling errors and to handle diurnal workload. To address nonlinearities, our design of ElastMan leverages the near-linear scalability of elastic Cloud services in order to build a scale-independent model of the service. Our design based on combining feedforward and feedback control allows to efficiently handle both diurnal and rapid changes in workload in order to meet SLOs at a minimal cost. Our evaluation shows the feasibility of our approach to automation of Cloud service elasticity.

  • 279.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    ElastMan: Elasticity manager for elastic key-value stores in the cloud2013In: Proceedings of the 2013 ACM Cloud and Autonomic Computing Conference, New York, NY, USA: Association for Computing Machinery (ACM), 2013, p. 7:1-7:10Conference paper (Refereed)
    Abstract [en]

    The increasing spread of elastic Cloud services, together with the pay-as-you-go pricing model of Cloud computing, has led to the need of an elasticity controller. The controller automatically resizes an elastic service in response to changes in workload, in order to meet Service Level Objectives (SLOs) at a reduced cost. However, variable performance of Cloud Virtual Machines and nonlinearities in Cloud services, such as the diminishing reward of adding a service instance with increasing the scale, complicates the controller design. We present the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores. ElastMan combines feedforward and feedback control. Feedforward control is used to respond to spikes in the workload by quickly resizing the service to meet SLOs at a minimal cost. Feedback control is used to correct modeling errors and to handle diurnal workload. To address nonlinearities, our design of ElastMan leverages the near-linear scalability of elastic Cloud services in order to build a scale-independent model of the service. We have implemented and evaluated ElastMan using the Voldemort key-value store running in an OpenStack Cloud environment. Our evaluation shows the feasibility and effectiveness of our approach to automation of Cloud service elasticity.

  • 280.
    Al-Shishtawy, Ahmad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Vlassov, Vladimir
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Brand, Per
    Swedish Institute of Computer Science.
    Haridi, Seif
    Swedish Institute of Computer Science.
    A design methodology for self-management in distributed environments2009In: IEEE International conference on Computational Science and Engineering, 2009, p. 430-436Conference paper (Refereed)
    Abstract [en]

      Autonomic computing is a paradigm that aims at reducing administrative overhead by providing autonomic managers to make applications selfmanaging. In order to better deal with dynamic environments, for improved performance and scalability, we advocate for distribution of management functions among several cooperative managers that coordinate their activities in order to achieve management objectives. We present a methodology for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to design and development of a distributed storage service as a case study. The storage service prototype has been developed using the distributing component management system Niche. Distribution of autonomic managers allows distributing the management overhead and increased management performance due to concurrency and better locality.

  • 281. Altincekic, T. G.
    et al.
    Boz, I.
    Baykal, A.
    Kazan, S.
    Topkaya, R.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Synthesis and characterization of CuFe2O4 nanorods synthesized by polyol route2010In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 493, no 1-2, p. 493-498Article in journal (Refereed)
    Abstract [en]

    Uniform, high quality, CuFe2O4 nanorods with high aspect ratios were synthesized by a surfactant-free single step polyol process at 220 degrees C. The structure of the product was characterized by XRD and FT-IR, and the morphology of the product was analyzed by SEM. The results showed that the as-prepared nanorods have a uniform cross-section and with average diameter of similar to 100 nm and aspect ratio in the range of 13-52. X-ray line profile fitting resulted in crystallite size of 15 nm, which reveals the polycrystalline nature of these nanorods. Magnetic characterization of product was performed by EPR and VSM techniques and the results show that the CuFe2O4 nanorods are ferromagnetic. The line width of the resonance lines in FMR is about 1.8 kOe which may originate from different resonance fields of randomly distributed nanocrystals which have different orientation of magnetic easy axes.

  • 282.
    Altinel, Ekrem
    KTH, School of Information and Communication Technology (ICT).
    A DESIGN FLOW FOR PREDICTABLE COMPOSABLE SYSTEMS2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    MPSoCs serve for the needs of the modern embedded systems by providing computationally powerful and flexible platforms. However, due to the design productivity gap and some architectural and methodological challenges, the successful design of real-time applications on these platforms is becoming a pressing concern. Methodologies starting with models at low levels of abstractions often are limited in their design space exploration. One way to improve the situation is by introducing formally analyzable models and entering the design process at a high level of abstraction. This approach enables the creation of correct-by-construction designs. ForSyDe is a modeling framework for embedded systems based on the theory of formal models of computation and it allows specification of systems at a high abstraction level. On the other hand, architectural challenges such as unpredictable timing behavior and interference between applications call for predictable and composable architectures. The CompSOC platform has a predictable and composable architecture and its design flow can map analyzable data-flow applications to an MPSoC in a way that guarantees the real-time requirements of the applications. Methodological challenges such as the automation of the design flows and tool interoperability are other major contributers of the design productivity gap, hence these aspects of a design flow are of paramount importance. By combining the ForSyDe and the CompSOC design flows, this thesis proposes a design flow that starts with a high level model of the system. By formal analysis, this design flow can produce a mapping of application tasks to an MPSoC platform. The design flow can implement an FPGA prototype of the system. The design flow is automated and as case studies, two image processing applications are implemented. These two applications are used to validate the design flow.

  • 283.
    Altinkaya, Martin
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Ahmedi, Saman
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    SIP in an Interconnector and Service Provider Role2001Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This Master’s Thesis concerns the technical problems and solutions in the Telia Mobile’s Golden Gate Architecture. The Golden Gate project will bridge service control from the IPnetwork to the circuit switched network. Connecting the different users of PSTN, GSM, W-LAN, and GPRS networks together will require solutions to many problems. Most of the problems have already been defined by Telia. Our task is to evaluate two parts of the Golden Gate architecture, namely the Interconnect- and Service Provider roles.

    The Interconnector provider connects networks of different technical standards and enables other network operators to reach Service Providers on the Internet or other IP-based networks. The role concerns mainly mapping between SS7 signaling and the Session Initiation Protocol (SIP), charging and billing. Via the Interconnector the Service Provider can connect different services to any network.

    We will describe the SIP-protocol in detail and then we will look into the mapping between SS7 and SIP. We will also propose a charging model. It is important to have a solution that supports roaming between the different networks, we will evaluate such a solution. Most of the protocols (INAP, ENUM, MAP and ISUP) that are involved in the Golden Gate architecture are not completely defined. There are many Internet Drafts that discuss the possible functionality of the protocols and the interworking between them. Many different Internet-workgroups are working with these issues. No one seems to have the right answers for the interconnection between the protocols involved.

    Since the IP-telephony will probably replace today’s telephony systems, it is important to ensure a suitable Quality of Service (QoS), security that guarantees privacy, and a fair billing function. These are the three major problems in the IP-telephony world. IP-Telephony or Voice over IP (VoIP) has been on the market for a long time, there are many 'free IP-call sites' that use VoIP, but the quality of the calls are not yet good enough to replace traditional telephony. Our task here is to make sure that the necessary quality of service is provided, and a reliable charging model is used.

  • 284.
    Alvarez Alvarez, Oscar
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Ghanbari, Amirhossein
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth. KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    A COMPARATIVE STUDY OF SMART GRID DEVELOPMENT IN DEVELOPED AND DEVELOPING COUNTRIES2014Conference paper (Refereed)
    Abstract [en]

    During recent years, there has been an increasing interest in the potential opportunities that can be attained with the use of smart devices in order to gather data or automate processes. This type of communications between devices with minimal human intervention is referred to as Machine-to-machine (M2M) communications that can be applied to optimize resources and improve service delivery applications. Smart Grid is one of the M2M communications applications that is attaining more attention during recent years, because of its potential to change the complete energy ecosystem; going from a unidirectional system to a bidirectional one where customers will have an important role in the ecosystem.Depending on the country and its characteristics and situation, Smart Grid development can be very different. This article identifies commonalities and differences in Smart Grid communication development considering the current status in developed and developing countries. The process is done by evaluating the following techno-economic aspects: Technology development, Public initiatives, Regulator policies and Economic situation/Business perspective of the country. The article is concluded by showing that regulator policies regarding the level of liberalization in the energy market are a key element when defining business strategies and different stages of Smart Grid communications development has a critical influence in the definition of business models, as it defines the key activities, partners and value proposition for the business.

  • 285.
    Alvarez Alvarez, Oscar
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Ghanbari, Amirhossein
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Markendahl, Jan
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth. KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Smart Energy: Competitive Landscape and Collaborative Business Models2015In: 2015 18th International Conference on Intelligence in Next Generation Networks, ICIN 2015, IEEE Communications Society, 2015Conference paper (Refereed)
    Abstract [en]

    During the recent years several technologies and services based in Internet of Things (IoT) and Machine-to-Machine communications (M2M) have appeared in many different sectors, like healthcare, transport, logistics, media or utilities. When new technologies (like Smart Grid or Smart Energy) appear two types of challenges can be defined: technical and business challenges, therefore innovation has to be applied in both of them. Too often innovation is focus on the technical evolution and underestimated on the business field, however it is a key aspect for new technologies and services to reach commercial success. Traditional business models in the energy sector will suffer big changes in the next years, as the Smart Grid concept is developed.By the advent of new services and applications, horizontal and vertical partnerships with competitors and other actors will take place. In this context collaboration between actors, partnerships and agreements will be of key importance. This paper investigates the different actors involved in a Smart Energy ecosystem, its possible activities and suitable business models for the different Smart Grid building blocks or milestones.

  • 286.
    Alvarez Jörgensen, Kristian
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Chlebek, Michael
    KTH, School of Information and Communication Technology (ICT).
    Near ultrasonic close range communication for modern smartphones2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    NFC is a technology that allows close-range communication between mobile devices. Unfortunately, not all modern smartphones have the required API’s or hardware to utilize it. This thesis seeks therefore to develop a viable alternative to NFC for close range communication (less than 10 cm) between mobile smart phones. The goal is to evaluate the feasibility of using a novel scheme that utilizes near ultrasonic frequencies for close range communication for both Android and iOS.An iPhone and an Android device were used to test our proposed scheme. Range test were preformed on a quiet and noisy environment (food court in a shopping mall), and an interference test was done in the quiet environment. The scheme was shown to work in the tested quiet and noisy environment for ranges less than 1 cm. In the noisy environment, significant data loss happened at 5 cm for the tested android device, while data was somewhat reliably received at up to 10 cm in a quiet environment among both tested devices. Our tests also show that concurrently communicating devices spaced at least 110 cm away will not interfere with each other.Our findings show that the proposed scheme could be a viable alternative for close range communication. By employing an error correcting code, tolerance to data loss could be improved. Using a different modulation technique is also advisable in order to improve the data transfer rate.For future work, we suggest testing the near ultrasonic capabilities of a wider array of devices in order to determine the usefulness of the proposed scheme.

  • 287.
    Aly, Mazen
    KTH, School of Information and Communication Technology (ICT).
    Automated Bid Adjustments in Search Engine Advertising2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In digital advertising, major search engines allow advertisers to set bid adjustments on their ad campaigns in order to capture the valuation differences that are a function of query dimensions. In this thesis, a model that uses bid adjustments is developed in order to increase the number of conversions and decrease the cost per conversion. A statistical model is used to select campaigns and dimensions that need bid adjustments along with several techniques to determine their values since they can be between -90% and 900%. In addition, an evaluation procedure is developed that uses campaign historical data in order to evaluate the calculation methods as well as to validate different approaches. We study the problem of interactions between different adjustments and a solution is formulated. Real-time experiments showed that our bid adjustments model improved the performance of online advertising campaigns with statistical significance. It increased the number of conversions by 9%, and decreased the cost per conversion by 10%.

  • 288.
    Alyafawi, Islam
    KTH, School of Information and Communication Technology (ICT).
    Network Coding Strategies and Performance Evaluation for Bidirectional Relaying2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The ambitious of researchers to reach the maximum capacity of data network lead them to network coding. The simplicity of applying network coding and the improvement to achieve the maximum possible information flow in a network lead to apply network coding in many applications. Network coding was implemented first in wired medium, and then moved to the wireless one. Due to the special characteristics of the wireless medium and the less reliability compared with the wired one, this created wide research area of network coding applications for wireless systems.

    In this work, the main focus will be on practical implementation problem when network coding is applied in a two way relay networks. A new proposed method of performing network coding will be presented. Our proposed method can achieve better network performance than conventional network coding. We will also provide our own method to generate the coded message. The main feature of the proposed method is to multiply the received packets together inside the relay node. The packets multiplication is at the symbol level in the complex domain. The resulted packet will be broadcasted to both receivers.

    The receivers will be able to recover the other node packet by dividing the broadcasted packet with their own packets. Analytical and experimental analysis show that the proposed method has better performance and more robust for channel asymmetry than conventional network coding.

  • 289. Alzaher, H.
    et al.
    Al-Ghamdi, M.
    Ismail, Mohammed
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    CMOS low-power bandpass IF filter for Bluetooth2007In: Iet Circuits Devices & Systems, ISSN 1751-858X, Vol. 1, no 1, p. 7-12Article in journal (Refereed)
    Abstract [en]

    Design of a CMOS 18th-order IF (intermediate frequency) bandpass filter for integrated low-IF Bluetooth receivers is presented. The centre frequency and bandwidth of the filter are 3 and 1 MHz, respectively. The proposed filter is based on unity gain fully differential voltage buffers and provides efficient, low power and a small area design solution. The filter, including its automatic tuning circuit, occupies an area of 0.6 mm(2) in a standard 0.5 mu m-CMOS chip. Experimental results show that the filter satisfies the selectivity and dynamic range requirements of Bluetooth while operating from a total supply current of 0.9 mA.

  • 290.
    Amaya de la Pena, Ignacio
    KTH, School of Information and Communication Technology (ICT).
    Fraud detection in online payments using Spark ML2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Frauds in online payments cause billions of dollars in losses every year. To reduce them, traditional fraud detection systems can be enhanced with the latest advances in machine learning, which usually require distributed computing frameworks to handle the big size of the available data.

    Previous academic work has failed to address fraud detection in real-world environments. To fill this gap, this thesis focuses on building a fraud detection classifier on Spark ML using real-world payment data.

    Class imbalance and non-stationarity reduced the performance of our models, so experiments to tackle those problems were performed. Our best results were achieved by applying undersampling and oversampling on the training data to reduce the class imbalance. Updating the model regularly to use the latest data also helped diminishing the negative effects of non-stationarity.

    A final machine learning model that leverages all our findings has been deployed at Qliro, an important online payments provider in the Nordics. This model periodically sends suspicious purchase orders for review to fraud investigators, enabling them to catch frauds that were missed before.

  • 291. Amer, Wael A.
    et al.
    Wang, Li
    Amin, Abid M.
    Yu, Haojie
    Zhang, Lei
    Li, Chao
    Wang, Yang
    KTH, School of Information and Communication Technology (ICT).
    Liquid-crystalline azobenzene-containing ferrocene-based polymers: study on synthesis and properties of main-chain ferrocene-based polyesters with azobenzene in the side chain2013In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 24, no 2, p. 181-190Article in journal (Refereed)
    Abstract [en]

    Ferrocene-based polymers are characterized by their electrochemical activity, good redox properties, thermal, photochemical stability, and liquid crystallinity, and thus they have various applications in different fields. A comprehensive investigation on the synthesis and properties of three novel main-chain ferrocene-based polyesters with azobenzene in the side chain (MFPAS) was carried out. The main-chain ferrocene-based polyester, poly(N-phenyldiethanolamine 1,1'-ferrocene dicarboxylate (PPFD), was synthesized via the solution polycondensation reaction of 1,1'-ferrocenedicarbonyl chloride with phenyldiethanolamine (PDE). The novel MFPAS were synthesized via the post-polymerization azo-coupling reaction of PPFD with three different 4-substituted anilines including 4-nitroaniline, 4-aminobenzoic acid, and 4-aminobenzonitrile to produce 4-nitrophenylazo-functionalized-PPFD (PPFD-NT), 4-carboxyphenylazo-functionalized-PPFD (PPFD-CA), and 4-cyanophenylazo-functionalized-PPFD (PPFD-CN), respectively. All the synthesized polymers were characterized by 1H NMR spectroscopy, Fourier transform infrared spectroscopy, and UVvisible spectroscopy. In addition, powder X-ray diffraction patterns were measured for the synthesized polymers. The photoisomerization of the MFPAS was studied. The thermal properties of the MFPAS were studied using thermogravimetric analysis and differential scanning calorimetry. PPFD-CA and PPFD-CN were found to be more thermally stable than PPFD-NT. Finally, the liquid-crystalline properties of PPFD and the MFPAS were examined using polarized optical microscope. It was found that all the polymers possessed nematic phases and exhibited textures with schlieren disclinations.

  • 292. Amer, Wael A.
    et al.
    Wang, Li
    Yu, Haojie
    Amin, Abid M.
    Wang, Yang
    KTH, School of Information and Communication Technology (ICT).
    Synthesis and Properties of a Ferrocene-based Metallomesogenic Polymer Containing Bis(4-hydroxyoctoxyphenyl)sulfone2012In: Journal of Inorganic and Organometallic Polymers and Materials, ISSN 1574-1443, Vol. 22, no 6, p. 1229-1239Article in journal (Refereed)
    Abstract [en]

    Poly[bis(4-hydroxyoctoxyphenyl)sulfone 1,1'-ferrocene dicarboxylate] (PHOSFD) was synthesized by solution polycondensation reaction of bis(4-hydroxyoctoxyphenyl)sulfone with 1,1'-ferrocenyl chloride. The synthesized polymer was characterized via the measurement of its H-1 NMR spectrum, UV-Vis spectrum and FTIR spectrum. X-ray diffraction pattern was measured to investigate the crystallinity of the synthesized polymer and it was found that the polymer is mostly amorphous. The molecular weight of the polymer was determined by gel permeation chromatography. In addition, the electrochemical, the thermal, and the liquid crystalline properties of the synthesized polymer were examined and compared with the properties of poly(diethyleneglycol 1,1'-ferrocene dicarboxylate) (PDEFD) that was synthesized in our earlier study. The electrochemical processes of PHOSFD in CH2Cl2 were confirmed neither to be totally reversible nor completely irreversible. Generally, the electrochemical properties of PHOSFD and PDEFD were found to be similar to each other. PHOSFD was found to be thermally stable but its thermal stability is lower than that of PDEFD. Both of PHOSFD and PDEFD showed liquid crystalline properties and they possessed nematic phase textures with schlieren disclinations during heating and cooling.

  • 293.
    Amin, Yasar
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Printable Green RFID Antennas for Embedded Sensors2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the recent years, radio-frequency identification (RFID) technology has been widely integrated into modern society applications, ranging from barcode successor to retail supply chain, remote monitoring, detection and healthcare, for instance. In general, an RFID tag or transponder is composed of an antenna and an application-specific integrated circuit chip. In a passive UHF RFID system (which is the focus of presented research), the communication between the transponder tag and the reader is established by modulating the radar cross section (RCS) of the transponder tag. The need for flexible RFID tags has recently been increased enormously; particularly the RFID tags for the UHF band ensure the widest use but in the meantime face considerable challenges of cost, reliability and environmental friendliness.

    The multidimensional focus of the aforementioned research encompasses the production of low-cost and reliable RFID tags. The state-of-the-art fabrication methods and materials for proposed antennas are evaluated in order to surmount the hurdles for realization of flexible green electronics. Moreover, this work addresses the new rising issues interrelated to the field of economic and eco-friendly tags comprising of paper substrate. Paper substrates offer numerous advantages for manufacturing RFID tags, not only is paper extensively available, and inexpensive; it is lightweight, recyclable and can be rolled or folded into 3D configurations.

    The most important aspect of an RFID system's performance is the reading range. In this research several pivotal challenges for item-level tagging, are resolved by evolving novel structures of progressive meander line, quadrate bowtie and rounded corner bowtie antennas in order to maximize the reading distance with a prior selected microchip under the various constraints (such as limited antenna size, specific antenna impedance, radiation pattern requirements). This approach is rigorously evolved for the realization of innovative RFID tag antenna which has incorporated humidity sensor functionality along with calibration mechanism due to distinctiveness of its structural behavior which will be an optimal choice for future ubiquitous wireless sensor network (WSN) modules.

    The RFID market has grown in a two-dimensional trend, one side constitutes standalone RFID systems. On the other side, more ultramodern approach is paving its way, in which RFID needs to be integrated with broad operational array of distinct applications for performing different functions including sensors, navigation, broadcasting, and personal communication, to mention a few. Using different antennas to include all communication bands is a straightforward approach, but at the same time, it leads to increase cost, weight, more surface area for installation, and above all electromagnetic compatibility issues. The indicated predicament is solved by realization of proposed single wideband planar spirals and sinuous antennas which covers several bands from 0.8-3.0GHz. These antennas exhibit exceptional performance throughout the operational range of significance, thus paving the way for developing eco-friendly multi-module RF industrial solutions.

  • 294.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Shao, Botao
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Hållstedt, Julius
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Design and Analysis of Efficient and Compact Antenna for Paper Based UHF RFID Tags2008In: ISAPE 2008: THE 8TH INTERNATIONAL SYMPOSIUM ON ANTENNAS, PROPAGATION AND EM THEORY, PROCEEDINGS, VOLS 1-3 / [ed] Su D; Yan Z, NEW YORK: IEEE , 2008, p. 62-65Conference paper (Refereed)
    Abstract [en]

    Paper substrate is one of the paramount nominees for Radio Frequency Identification (RFID) tags but at the same time it is extremely prone towards environmental changes. In this paper, antennas for UHF RFID tags on paper based substrate are investigated and analyzed for the first time to evaluate the effect of change in dielectric constant on the antenna parameters and performance. On the basis of analysis a concrete meander line antenna is proposed, designed and evaluated which has tremendous immunity towards variation in dielectric constant.

  • 295.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Evolutionary Versatile Printable RFID Antennas For "Green" Electronics2012In: Journal Electromagnetic Waves and Applications, ISSN 0920-5071, E-ISSN 1569-3937, Vol. 26, no 2-3, p. 264-273Article in journal (Refereed)
    Abstract [en]

    The development of low cost directly printable RFID tag antennas is essential for item level tracking. We present evolutionary design approach to achieve robust extremely versatile RFID antennas on paper/flexible substrates which allow a simple integration directly on, e.g., paperboard in a roll-to-roll production line. Fully integrated printed tags for "green" electronics are designed for operability in frequencies 866-868 MHz & 902-928 MHz. We present benchmarking results for various challenges of antennas in terms of ruggedness, reliability and flexing performance.

  • 296.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Performance-Optimized Quadrate Bowtie RFID Antennas For Cost-Effective and Eco-Friendly Industrial Applications2012In: Progress in Electromagnetics Research-PIER, ISSN 1559-8985, Vol. 126, p. 49-64Article in journal (Refereed)
    Abstract [en]

    Fully integrated printed RFID antennas show potential solution for item level labeling applications. In order to accommodate the antenna during the package printing process, it is vastly preferred that antenna structures are printed on paper substrates. However, the electromagnetic properties and thickness of paper substrates are susceptible to change due to various environmental effects. Thus, adequately consistent in performance and material insensitive printed Quadrate Bowtie RFID antennas are proposed. This paper presents an in-depth efficient optimization for high performance tag antenna designs for operability in frequencies 866-868MHz & 902-928MHz. It is demonstrated that the proposed antennas can tolerate a considerable variation in the permittivity on thin paper substrates, and present benchmarking results when n across metal and water containing objects.

  • 297.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Design and Fabrication of Wideband Archimedean Spiral Antenna Based Ultra-Low Cost "Green" Modules for RFID Sensing and Wireless Applications2012In: Progress In Electromagnetics Research-PIER, ISSN 1559-8985, Vol. 130, p. 241-256Article in journal (Refereed)
    Abstract [en]

    A parametric analysis is performed for a wideband Archimedean spiral antenna in recognition of an emerging concept to integrate RFID along with several applications by using a single antenna. The antenna is fabricated using state-of-the-art inkjet printing technology on various commercially available paper substrates to provide the low-cost, flexible RF modules for the next generation of "green" electronics. The effects on electromagnetic characteristics of the planar Archimedean spiral antenna, due to the use of paper are investigated besides other parameters. The proposed antenna is evaluated and optimized for operational range from 0.8-3.0GHz. It exhibits exceptional coverage throughout numerous RFID ISM bands so do for other wireless applications.

  • 298.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Development and Analysis of Flexible UHF RFID Antennas For "Green" Electronics2012In: Progress In Electromagnetics Research-PIER, ISSN 1070-4698, Vol. 130, p. 1-15Article in journal (Refereed)
    Abstract [en]

    In this paper, novel Bowtie antennas which cover complete UHF RFID band (860-960MHz), fabricated on various ultra-low-cost substrates using state-of-the-art printing technologies are investigated as an approach that aims to accommodate the antenna during the package printing process whilst faster production on commercially available paper. The proposed antenna structures are evaluated in reference to circuit and field concepts, to exhibit extreme degree of functional versatility. These antennas are developed to cater the variations which appear in electromagnetic properties and thickness of paper substrate due to various environmental effects. Computed (simulated) and well-agreed measurement results confirm a superior performance of the tag modules while stepping towards next generation of "green" tags.

  • 299.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    "Green" Wideband Log-Spiral Antenna for RFID Sensing and Wireless Applications2012In: Journal of Electromagnetic Waves and Applications, ISSN 0920-5071, Vol. 26, no 14-15, p. 2043-2050Article in journal (Refereed)
    Abstract [en]

    The novel idea of integrating RFID with sensors along with other wireless applications by using single tag antenna is implemented, by fabricating proposed antenna using state-of-the-art inkjet printing technology on commercially available paper substrates. For the first time, a parametric analysis is performed for realization of planar log-spiral antenna on paper for operational range from 0.8-3.0GHz, which also exhibits excellent coverage throughout numerous RFID ISM bands, and for other wireless applications. The ANSYS HFSS tool is used to design and predict the performance of the proposed antenna in terms of radiation pattern and input impedance.

  • 300.
    Amin, Yasar
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Two-arm Sinuous Antenna for RFID Ubiquitous Sensors and Wireless Applications2012In: Journal Electromagnetic Waves and Applications, ISSN 0920-5071, E-ISSN 1569-3937, Vol. 26, no 17-18, p. 2365-2371Article in journal (Refereed)
    Abstract [en]

    For the first time, two-arm planar sinuous antenna is demonstrated to realize the emerging concept of integrating RFID functionalities along with sensors and other wireless applications for "green" electronics. In-depth, parametric analysis is performed for the proposed antenna which is fabricated on a paper substrate using revolutionary inkjet printing technology to develop a system-level solution for ultra-low-cost mass production of multipurpose wireless tags in an approach that could be easily expanded to other microwave and wireless "cognition" applications. The proposed antenna exhibits excellent performance throughout several RFID ISM bands and for other wireless applications in its operational range from 0.8 to 3.0 GHz.

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