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  • 201.
    Alabbasi, Abdulrahman
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Shihada, Basem
    Cavdar, Cicek
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    On Energy Efficiency of Prioritized IoT Systems2017In: Globecom 2017 - 2017 IEEE Global Communications Conference, IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    The inevitable deployment of 5G and the Internet of Things (IoT) sheds the light on the importance of the energy efficiency (EE) performance of Device-to- Device (DD) communication systems. In this work, we address a potential IoT application, where different prioritized DD system, i.e., Low-Priority (LP) and High-Priority (HP) systems, co-exist and share the spectrum. We maximize the EE of each system by proposing two schemes. The first scheme optimizes the individual transmission power and the spatial density of each system. The second scheme optimizes the transmission power ratio of both systems and the spatial density of each one. We also construct and analytically solve a multi- objective optimization problem that combines and jointly maximizes both HP and LP EE performance. Unique structures of the addressed problems are verified. Via numerical results we show that the system which dominates the overall EE (combined EEs of both HP and LP) is the system corresponding to the lowest power for low/high power ratio (between HP and LP systems). However, if the power ratio is close to one, the dominating EE corresponds to the system with higher weight.

  • 202.
    Alaei, Zohreh
    KTH, School of Information and Communication Technology (ICT).
    Power Enhancement in Piezoelectric Energy Harvesting2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Piezoelectric energy harvesting has been around for almost a decade to generate power from the ambient vibrations. Although the generated power is very small, but there are several ways to increase and enhance the generated power. This project presents different methods of optimizing the output power by changing the structural configuration of the energy harvesters, selection of piezoelectric material and circuit interface of these harvesters. To understand the different steps of the enhancement, the process of energy conversion by piezoelectric material has been first looked at.

    Different groups of piezoelectric material were studied to see what kind of materials have the ability of increasing the generated power. As mechanical configuration of the energy harvesters has a significant effect on the output voltage, their configuration such as Cantilever beam type, Cymbal type and Circular diaphragms has been described and compared. After the power generated in the piezoelectric crystal , the current is sent to through an interface circuit to get rectified and regulated. This circuit can be modified to increase the power as well. There are several types of circuits that can increase the output voltage significantly. Synchronized Switch Harvesting (SSH) techniques, Synchronous Electric Charge Extraction technique and voltage doubler are such examples. These techniques have been also studied and compared. Because of the outgrowing industry of piezoelectric energy harvesting in Medical field, their function and their progress has also been reviewed.

  • 203.
    Alagha, Alireza
    KTH, School of Information and Communication Technology (ICT).
    Requirements for improving Contemporary e-tourism Information systems in terms of customer satisfaction2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Who can ignore the impact of technology in different industries in 21st century? Various types of online tourism services have been offered by several firms who claim their services will be more accurate, more sufficient and better than traditional agencies’ offers. In this work, an investigation of a Tourism Information system will show how online services can bring value for each stakeholder in the firm and for others who interact with the e-tourism form.

    Data collection strategy for this work was survey and methods for data collection, included interviews and questionnaires.

    "Kano’s method" which shows how can bring "WOW "to the customer by adding unexpected features and make her satisfy by increasing her satisfaction. This work focused on IT’s impact to the current situation of the tourism industry in order to improve customers’ satisfaction. Optimized TIS

    1 may involve changes across many parts of a firm. In order to determine these factors, data collection using surveys of tourism experts in firm is needed. A complementary source of data includes literature, articles, and tourism brochure.

    Finally the collected data, analyses by Factor-Analysis method and the result of analyzed data shows the main factors of client satisfaction are convenience, specialization, accessibility and web design.

  • 204.
    Alas, Erkan
    KTH, School of Information and Communication Technology (ICT).
    EMC - Överhörning mellan ledare2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is about EMC in general and crosstalk in flat cable and wiring in particular. The task was to investigate the crosstalk in a flat cable and a circuit board.

    EMC, which stands for electromagnetic compatibility, describes the ability of electrical and electronic systems to operate without interfering with other systems. It also describes the ability to operate in a specified electromagnetic environment for electrical and electronic systems. The problem of crosstalk in cables and wires is already known and in PCB design, the crosstalk is an important EMC problem.

    Two surveys were carried out in which the first survey were performed on the flat cable. Measurements were made with an oscilloscope and then compared with the theory in the form of calculations and simulations. The same was done at the second survey with the circuit board where the following measurements were performed calculations to be able to simulate and compare the practice with theory.

    The beginning of the report begins with some theory of EMC and a few examples of what crosstalk can cause. Then the formulas used for the calculations in both surveys is shown.

    In the main part of the report, the results of the calculations for the measurements is shown which are then used in the simulations. After that, the measurements is compared with simulation values for both the flat cable and the circuit board. A small description of how the circuit board was designed are also discussed.

    The whole is rounded off with a conclusion were the results are discussed and the surveys are compared with each other.

  • 205.
    Alasali, Mohammad
    KTH, School of Information and Communication Technology (ICT).
    LTE MIMO Performance Measurements on Trains2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Providing passengers internet on board trains with continuous connectivity at high speeds and over large rural distances is a challenging issue. A promising solution to the problem is to use an on board WI-FI network combined with a cellular radio system connected to the LTE (long term evolution) 900/800MHz networks deployed outside the train. However, in order to reach the data rates that today's business traveller is expecting, \Multiple Input Multiple Output" (MIMO) may be needed. In this project the plausibility of achieving LTE MIMO functionality to moving trains is studied both theoretically and through measurements on a Swedish high speed train in a live LTE 900 network. The measurements were conducted along the main track between Stockholm and Gothenburg. Eight antennas were deployed at 4m height on the roof of a X2000 train that was moving at speeds between 100 and 200km/h. The average distance between the base stations and the track was 2.35km and the average base-station antenna height 45m. The measurement data was recorded using an LTE scanner provided by Rohde&Schwarz (TSMW). The simulations were conducted in Matlab and the above parameters were simulated for typical rural Line of Sight (LOS) radio channels. The simulation results show that MIMO may perform well on trains and reach higher rank in the above described radio channel, given that the inter-element distances are correctly chosen dependent on the base station-to-train distance. In the measurement a 2X2 MIMO system was tested and confirmed the model by showing that the condition number (CN), was less than 15 for 65% of the track covered by LTE. Hence, we find that it is indeed plausible to achieve MIMO functionality in LOS on the roof of a fast moving train. Furthermore, the report concludes that LTE-Advance with 8x8 MIMO functionality and carrier aggregation feature, may be a suitable solution in order to provide the internet capacity needed for all the passengers on board high speed trains.

  • 206.
    Alasali, Mohammad
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS. KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    LTE MIMO Performance Measurements on Board Passenger Trains2013Conference paper (Other academic)
    Abstract [en]

    Providing passenger internet on board trains with continuous connectivity at high speeds and over large rural distances is a challenging issue. A frequently used solution to the problem is to use an on board WiFi network connected to the 3G or 4G networks deployed outside the train. In order to be able to provide the capacity and the data rates that tomorrow's business travelers are expecting it has been suggested to use a combination of MIMO and carrier aggregation in the LTE-Advance standard. In this study, we practically investigate the plausibility of using MIMO functionality in an 900 LTE system when the receive antennas are mounted at a train roof about 4m above ground and the base stations antennas are on average placed 2.3km away from the track in towers with an average height of 45m and, hence, most of the time in line of site. It is found that along our test route MIMO is in practice supported by the radio channel at around 70% of the time when the train is travelling with an average speed of 185km/h and the MIMO antennas are mounted 10.5m apart.

  • 207.
    Alasali, Mohammad
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    LTE MIMO performance measurements on trains2013In: 2013 7th European Conference on Antennas and Propagation (EuCAP), New York: IEEE , 2013, p. 2327-2330Conference paper (Refereed)
    Abstract [en]

    Providing passenger internet on board trains with continuous connectivity at high speeds and over large rural distances is a challenging issue. A frequently used solution to the problem is to use an on board WiFi network connected to the 3G or 4G networks deployed outside the train. In order to be able to provide the capacity and the data rates that tomorrow's business travelers are expecting it has been suggested to use a combination of MIMO and carrier aggregation in the LTE-Advance standard. In this study, we practically investigate the plausibility of using MIMO functionality in an 900 LTE system when the receive antennas are mounted at a train roof about 4m above ground and the base stations antennas are on average placed 2.3km away from the track in towers with an average height of 45m and, hence, most of the time in line of site. It is found that along our test route MIMO is in practice supported by the radio channel at around 70% of the time when the train is travelling with an average speed of 185km/h and the MIMO antennas are mounted 10.5m apart.

  • 208.
    Alasali, Mohammad
    et al.
    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).
    Beckman, Claes
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab). KTH, School of Information and Communication Technology (ICT), Centres, Center for Wireless Systems, Wireless@kth.
    Karlsson, M.
    Providing internet to trains using MIMO in LTE networks2014In: 2014 International Conference on Connected Vehicles and Expo, ICCVE 2014 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2014, p. 810-814Conference paper (Refereed)
    Abstract [en]

    Providing broadband passenger internet on board trains with continuous connectivity at high speeds and over large rural distances is a challenging issue. One solution to the problem is to use an onboard WiFi network connected to multiple 3G and 4G networks deployed outside the train and aggregate their combined capacity at the IP protocol level. In order to be able to provide the capacity and the data rates that tomorrow’s travelers are expecting, the future 4G standard (LTE-Advance) uses a combination of high order MIMO and carrier aggregation. In this study we use the Swedish company Icomera’s passenger internet system for our investigation. The system provides aggregation of multiple carrier and handover on an IP level. For about 10 years the system has in Sweden primarily been using multiple 3G communication links. However, here we present analysis and onboard measurements of a 2×2 MIMO channel to fast moving train in a live LTE 900 network. The results indicate that MIMO works surprisingly well and it is discussed that by combining 8×8 MIMO with carrier aggregation in future releases of 4G, it may be possible to bring gigabit internet connections to trains.

  • 209.
    Al-Askary, Omar
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Coding and Iterative Decoding of Concentrated Multi-level Codes for the Rayleigh Fading Channel2006Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    In this thesis we present the concept of concatenated multilevel codes. These codes are a combination of generalized concatenated codes with multilevel coding. The structure of these codes is simple and relies on the concatenation of two or more codes of shorter length. These codes can be designed to have large diversity which makes them attractive for use in fading channels. We also present an iterative decoding algorithm taylored to fit the properties of the proposed codes. The iterative decoding algorithm we present has a complexity comparable to the complexity of GMD decoding of the same codes. However, The gain obtained by using the iterative decoder as compared to GMD decdoing of these codes is quite high for Rayleigh fading channels at bit error rates of interest. Some bounds on the performance of these codes are given in this thesis. Some of the bounds are information theoretic bounds which can be used regardless of the code under study. Other bounds are on the error probability of concatenated multilevel codes.

    Finally we give examples on the implementation of these codes in adaptive coding of OFDM channels and MIMO channels.

  • 210.
    al-Askary, Omar
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Ben Slimane, Slimane
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Effect of error in CSI on the capacity of Rayleigh fading channels with QAM signalling and the design of robust signal constellations2007In: IET Communications, ISSN 1751-8628, E-ISSN 1751-8636, Vol. 1, no 6, p. 1118-1125Article in journal (Refereed)
    Abstract [en]

    The effects of channel estimation errors on the channel capacity of a discrete time, discrete input, infinite output Rayleigh fading channel are investigated. The case of conventional modulation methods such as phase shift keying (PSK) and quatrature amplitude modulation (QAM) is investigated at first where it was observed that the capacity degrades rapidly with increasing channel estimation errors. The effect of error in the channel estimation is similar to the effect of higher noise in the channel that depends on the transmitted signal. A genetic algorithm is used to optimise the signal constellation in order to maximise the capacity for a given finite number of signal points. The aim of trying to maximise the capacity is to estimate the remaining gap in performance between a traditional modulation scheme such as QAM and the best possible constellation that is optimised for the channel. The constellations obtained from the genetic algorithm are, in general, not directly implementable. A method to design practical robust signal constellations that overcome the effect of channel state information (CSI) error is presented. The robust signal constellations obtained show a performance that is very close to the optimal constellations. In this work, the probability distribution of the error in CSI is assumed to be known.

  • 211.
    Al-Askary, Omar
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Rizvi, Umar H.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Khormuji, Majid N.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Rate adaptive generalized concatenated codes for wireless communication2005In: Proceedings of the INMIC 2005: 9th International Multitopic Conference - Proceedings, 2005, p. 137-142Conference paper (Refereed)
    Abstract [en]

    This paper presents the construction and performance of rate adaptive generalized concatenated codes (GCCs) (sic) on linear block codes over Rayleigh fading Multi Input (sic) Output (MIMO) communication channels with N transmit (sic) N receive antennas. The code design criteria is chosen (sic) that it tries to follow the Shannon capacity of the MIMO (sic). It is envisaged that such codes provide a superior performance over systems that use Maximum Ratio Combining (sic) while maintaining the encoder/decoder complexity within acceptable level of practical usage. Furthermore it is expected (sic) these codes will provide good performance without an interver/deinterleaver because of their good burst error correction (sic).

  • 212.
    Al-Askary, Omar
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Sidiropoulos, Lazaros
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Kunz, Lukas
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Vouzas, Christos
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Nassif, Chafic
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Adaptive coding for OFDM based systems using generalized concatenated codes2005In: VTC2005-SPRING: 2005 IEEE 61ST VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-5, PROCEEDINGS, 2005, p. 649-653Conference paper (Refereed)
    Abstract [en]

    Orthogonal Frequency Division Multiplexing (OFDM) is considered to be a promising candidate for future high-speed wireless communication systems. In this paper we present an adaptive coding scheme for OFDM based systems using generalized concatenated codes. We study the performance of HIPERLAN/2 after encoding with the proposed coding scheme and compare it to the standard convolutional coding scheme currently used. The criteria of our study is the optimization of the throughput. Through the adaptive scheme, we propose a modulation selection based on the average quality of the channel, and a code assigning method for the different sub-channels, that adapts to the channel conditions. We argue that the proposed scheme protects the information better than the ones in the conventional systems, since the latter do not take advantage of the individual sub-channel condition. Our simulations show that lower packet error rate can be accomplished for even higher throughput.

  • 213. Al-Awis, S. N.
    et al.
    Schatz, Richard
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Fotonik och mikrovågsteknik, FMI.
    Pang, Xiaodan
    RISE ACREO AB.
    Ozolins, O.
    Jacobsen, Gunnar
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Fotonik och mikrovågsteknik, FMI.
    Popov, Sergei
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Fattah, A. Y.
    Chen, Jiajia
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Optical Network Laboratory (ON Lab).
    Phenomenological formula for modelling of physical layer impairments in elastic optical networks2015In: Asia Communications and Photonics Conference, ACPC 2015, 2015Conference paper (Refereed)
    Abstract [en]

    An empirical modelling technique is introduced to estimate impact of physical layer impairments in elastic optical networks, which can be used to evaluate transmission quality. The model has been verified experimentally with accuracy beyond (97.3%). © 2015 OSA.

  • 214.
    Albarrán Munoz, Isaac
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS.
    Parras Ruiz De Azúa, Manuel
    Telecommunication Services’ Migration to the Cloud: Network Performance analysis2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Nowadays, telecommunication services are commonly deployed in private networks, which are controlled and maintained by the telecommunication operators themselves, by co-location services providers, or, to some extent, by their hardware and software providers. However, with the present development of cloud computing resources, one might consider if these services could and should be implemented in the Cloud, thus taking advantage of cloud computing’s high availability, geographic distribution, and ease of usage. Additionally, this migration could reduce the telecommunication operators’ concerns in terms of hardware and network maintenance, leaving those to the Cloud computing providers who will need to supply a highly available and consistent service, to fulfill the telecommunication services’ requirements. Furthermore, virtualization provides the possibility of easily and rapidly changing the Cloud network topology facilitating the addition and removal of machines and services, allowing telecommunication services providers to adapt to their demands on the fly.

    The aim of this thesis project is to analyze and evaluate the level of performance, from the network point of view, that can be achieved when using Cloud computing resources to implement a telecommunication service, carrying out practical experiments both in laboratory and real environments. These measurements and analyses were conducted using an Ericsson prototype mobile switching center server (MSC-S) application, although the results obtained could be adapted to other applications with similar requirements.

    In order to potentially test this approach in a real environment, a prior providers’ survey was utilized to evaluate their services based on our requirements in terms of hardware and network characteristics, and thus select a suitable candidate environment for our purposes. One cloud provider was selected and its service was further evaluated based on the MSC-S application requirements. We report the results of our bench-marking process in this environment and compare them to the results of testing in a laboratory environment. The results of both sets of testing were well correlated and indicate potential for hosting telecommunication services in a Cloud environment, providing the Cloud meets the requirements imposed by the telecom services.

  • 215.
    Albertsson, Peter
    KTH, School of Information and Communication Technology (ICT).
    Entreprenörskap och programutveckling2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At the end of 2005 a new application was developed. The new application had an innovational potential to be markets international, which later led to a patent application and the business Mobisma AB was invented. The technical solutions meet the requirements for a patent application and it got novelty, inventive and an industrial application. The intent of this invention was to guide the user from commodity status in to a telephone exchange from their cell phones. At the year end of 2005/2006 it was unique with this type of applications for a cell phone. There were plenty of telecommunications industry businesses that showed interest in the solution of their system. The business Mobisma is today silver partners with Panasonic World Wide.

    This report describes the completed development with an emphasis on entrepreneurship and patents. Two very important areas that are important for an engineer to know about of this sorts of ambitions. This history and its experiences that are described are very important to know about.

  • 216.
    Albrecht, Steffen
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Sigma-delta based techniques for future multi-standard wireless radios2005Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Improvements in process technology and design innovations have resulted in compact and cost effective digital baseband solutions. The radio part, however, has remained a bottleneck in terms of chip area and power consumption as the feature size of analog devices does not directly benefit from scaling. With the addition of yet more standards into emerging products, the requirements of future radios will extend over characteristic performance features into demands of programmable and reconfigurable hardware for radios covering multiple frequency bands. Hence, a guideline in the design of such radios is a large degree of hardware sharing.

    The thesis investigates the application of sigma-delta modulation to arising multistandard wireless radios. First, it reviews principles in wireless radios, such as selected modulation and access techniques. It also examines several communication standards of personal wireless radios as well as common receiver architectures for their implementation. This is followed by general considerations and background information about sigma-delta modulators. In the third and fourth chapter, implementations to two blocks of a wireless radio receiver system are suggested: An architecture for a frequency synthesizer and an implementation of an analog-to-digital converter.

    In the first contribution, the thesis develops a novel concept for frequency synthesis that is more suitable for multi-band, multi-standard radio architectures, achieving a large amount of hardware sharing among different wireless standards. As a second pillar, the thesis contributes with the design of a dual-standard sigma-delta modulator for data conversion within a radio receiver. Parts of the work concerning the dual-standard modulator are embodied in a granted swedish patent.

  • 217.
    Alcala, Yvonne
    et al.
    New York Medical College .
    Olivecrona, Henrik
    Karolinska.
    Olivecrona, Lotta
    Karolinska.
    Noz, Marilyn E.
    New York University.
    Maguire Jr., Gerald Q.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Zeleznik, Michael P.
    Sollerman, Christer
    Sahlgrenska University Hospital, Göteborg, Sweden.
    Qualifying CT for wrist arthroplasty: Extending techniques for total hip arthroplasty to total wrist arthroplasty2005In: Medical Imaging 2005: Image Processing, Pt 1-3 / [ed] Fitzpatrick, JM; Reinhardt, JM, SPIE - The International Sooceity for Optical Engineeering , 2005, Vol. 5747, p. 1155-1164Conference paper (Refereed)
    Abstract [en]

    The purpose of this study was to extend previous work to detect migration of total wrist arthroplasty non-invasively, and with greater accuracy. Two human cadaverous arms, each with a cemented total wrist implant, were used in this study. In one of the arms, I mm tantalum balls were implanted, six in the carpal bones and five in the radius. Five CT scans of each arm were acquired, changing the position of the arm each time to mimic different positions patients might take on repeated examinations. Registration of CT volume data sets was performed using an extensively validated, 3D semi-automatic volume fusion tool in which co-homologous point pairs (landmarks) are chosen on each volume to be registered. Three sets of ten cases each were obtained by placing landmarks on 1) bone only (using only arm one), 2) tantalum implants only, and 3) bone and tantalum implants (both using only arm two). The accuracy of the match was assessed visually in 2D and 3D, and numerically by calculating the distance difference between the actual position of the transformed landmarks and their ideal position (i.e., the reference landmark positions). All cases were matched visually within one width of cortical bone and numerically within one half CT voxel (0.32 mm, p = 0.05). This method matched only the bone/arm and not the prosthetic component per se, thus making it possible to detect prosthetic movement and wear. This method was clinically used for one patient with pain. Loosening of the carpal prosthetic component was accurately detected and this was confirmed at surgery.

  • 218.
    Alci, Kenan
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    TFTP loading of programs into a Microcontroller’s flash memory and evaluation of Microchip’s TCP/IP stack with ENC28J602014Report (Other academic)
    Abstract [en]

    This project began with a microprocessor platform developed by two master’s students: Albert López and Francisco Javier Sánchez. Their platform was designed as a gateway for sensing devices operating in the 868 MHz band. The platform consists of a Texas Instruments MSP430F5437A microcontroller and a Microchip ENC28J60 Ethernet cont roller connected to the MSP430 processor by a Serial Peripheral Interface.

    Javier Lara Peinado implemented prototype white space sensors using the platform developed by the earlier two students. As part of his effort, he partially implemented a Trivial File Transfer Protocol (TFTP) system for loading programs in to the flash memory of the microcontroller using Microchip’s TCP/IP stack.  However, he was not successful in loading programs into the flash as the TFTP transfer got stuck at the first block.

    The first purpose of this project was to find and fix the error(s) in the TFTP loading of programs into the MSP430’s flash memory. The second purpose of this project was to evaluate Microchip’s TCP/IP stack in depth.  This report describes measurements of UDP transmission rates. Additionally, the TFTP processing rate is measured and the TFTP program loading code is documented.  The report concludes with suggestions for possible improvements of this system.

  • 219.
    Aldabbagh, Haimen
    KTH, School of Information and Communication Technology (ICT).
    Provinsgenerering med postprocess2014Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor's thesis is a part of a larger project carried out at Paradox Interactive. The project aims to improve a map generator for the strategy game Europa Universalis IV. This work addresses the creation and implementation of a province generator that divides a pregenerated landscape in provinces. The provinces in the game are the regions on the game map that the game mechanics are based upon. The improvements that are expected of the new province generator includes the following properties:

    • The provinces that are created have more logically placed boundaries that are affected by the structure of the landscape.

    • The program gives the user more control over how the end result should look like by letting the user set the values of input parameters.

    • The execution should not exceed an approximate time limit. This time limit is set by Paradox Interactive.

    The work began with research on the topics map creation and map division to give enough knowledge to plan the implementation of the program. The programming language that is used is Java. The implementation of the program is based on many well-known algorithms in which the most remarkable one is Fortune's algorithm which performs the main task of the provincial division of the program, the creation of Voronoi diagrams. The Voronoi diagrams are used to divide the map into regions which by using a post-process results in the creation of the provinces.

    Other well-known algorithms and methods used or addressed in this report include the Lloyd relaxation, Bresenham's line algorithm, Scan Line Flood Fill, Delaunay triangulation and Bowyer-Watson's algorithm. The result of this work is a Java application that can load a map file containing information of a landscape structure and create a division of provinces with provincial boundaries that depend on the structure of the landscape. The results of the provincial division may be controlled by a number of user defined parameters. The program could not be fully calibrated during the time of the project because the landscape generator was not ready in time to be able to provide a map of a generated landscape. The generated provinces can be saved as an image file on the hard disk.

  • 220.
    Aldana Pulido, Rafael
    KTH, School of Information and Communication Technology (ICT).
    Ophthalmic Diagnostics Using Eye Tracking Technology2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Human eyes directly reflect brain activity and cognition. The study of eye movements and gaze patterns can therefore say a lot about the human brain and human behavior. Today eye tracking technology is being used to measure acuity of toddlers, to rehabilitate patients in intensive care, to detect if a person is lying or not, and to understand the cognitive level of a non-verbal person.

    Current vision testing is mostly based on manual observation and subjective methods. With eye tracking technology eye movements can be tested in an automated way that increases reliability and reduces variability and subjectivity.

    Eye tracking technology allows for measuring eye movements and therefore quantitative comparisons of the progress in treatment can be made over the course of a patient’s therapy –enabling more effective therapy. This technology also enables standardized and automated processes that are more time- and cost-efficient. The most important advantages of this technology is that it is non-invasive and it is not necessary to stabilize the subject’s head during testing. These advantages greatly extend the set of subjects that can be studied and reduce the cost and skills required for studying eye movements and gaze patterns.

    This thesis has developed and evaluated a novel calibration procedure for an eye tracker. The development phase has included programming and integration with the existing application programming interfaces. The evaluation phase included reliability and validity testing, as well as statistical analysis in terms of repeatability, objectivity, comprehension, relevance, and independence of the performance of the Tobii T60/T120 Eye Tracker on healthy  subjects.

    The experimental results have shown that the prototype application gives the expected benefits in a clinical  setting. A conclusion of this thesis is that eye tracking technology could be an improvement over existing methods for screening of eye alignment and diagnostics of ophthalmic disorders, such as strabismus (crossed eyes) or amblyopia (lazy eye). However, applying this technology to clinical cases will require further development. This development is suggested as future work.

  • 221. Aldinucci, Marco
    et al.
    Brorsson, Mats
    KTH, School of Information and Communication Technology (ICT), Software and Computer systems, SCS.
    D'Agostino, Daniele
    Daneshtalab, Masoud
    KTH, School of Information and Communication Technology (ICT), Electronics, Electronic and embedded systems.
    Kilpatrick, Peter
    Leppanen, Ville
    Preface2017In: The international journal of high performance computing applications, ISSN 1094-3420, E-ISSN 1741-2846, Vol. 31, no 3, p. 179-180Article in journal (Refereed)
  • 222.
    Aleksandrian, Arsen
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Sigrén Vinblad, Emil
    KTH, School of Information and Communication Technology (ICT).
    Wearables and the potential of Google Glass2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Mobile Life (TML) is a company with great passion for mobile devices that has set its primary focus on developing tailor-made mobile applications. Some of their bigger clients consist of airlines where TML designs, develops and delivers applications, in which travelers who travel with the airline can use to browse through, reserve and book flights.

    Wearable Technology is being more and more embraced as the future big addition to the ecosystem of mobile devices and exploring what some of the more prominent wearables have to offer is very much in the interest of aspiring companies like TML. To understand more in-depth what it means to develop applications for devices that might suffer from vast limitations in regards to interaction and feedback, we would first investigate what coming wearables could be recognized as prominent. The wearables that we concluded as suitable to investigate closer were Google Glass, Android Wear and various smartwatches. Out of these, Google Glass was the device chosen to act as our platform when exploring the potential of a wearable. A suitable way of understanding the possibilities and limitations of user interaction for Google Glass was to develop our own flight booking application for Glass.

    The realization we got was that there are various aspects of Glass that limits the kind of applications that can be made for it. The two primary things are the limits of the hardware and the fact that user interaction has taken a step back. From the graphical directmanipulation interaction that we nowadays are so used to in smartphones, to a simple menu system with limitations to how much the user can interact and how much feedback the program can show the user.

  • 223.
    Aleo Monteagudo, Francisco
    KTH, School of Information and Communication Technology (ICT).
    Motion Recognition: Generating real - time feedback based upon movement of a gaming controller2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Today motion recognition has become popular for human computer interaction in areas, such as health care, computer games, and robotics. Although many research projects have investigated this field, there are still some challenges remaining, especially in real-time environments.

    In real-time environments, the amount of data needed to compute the user’s motion and the time required to collect and process this data are crucial parameters in the performance of a motion recognition system. Moreover, the nature of the data (accelerometer, gyroscope, camera, . . . ) determines the design of the motion recognition system. One of the most important challenges is to reduce the delay between sensing and recognizing the motion, while, at the same time, achieving acceptable levels of accuracy.

    In this thesis we present a solution using Nintendo’s Wii Remote that solves several problems, such as permitting multiple device interaction and synchronization. In addition, this thesis addresses the performance challenge of realizing motion recognition for such a device. Finally, this thesis introduces a Java architecture which contains a set of interfaces that can be re-used in future projects.

    One of the most important achievements of this project is enabling interaction among different users and devices in a real-time environment, as, our application deals with multiple devices at the same time, with an acceptable delay. The resulting application provides smooth interaction to the user. As a consequence, our application enables collaborative and competitive activities which in this thesis project were evaluated in a educational process context. In this specific context, the main goal of the researchers with whom I was collaborating was to extend traditional methods of teaching children about some abstract concepts, such as energy.

    In addition, this thesis shows how to achieve different levels of accuracy and performance, by implementing two different algorithms. The first one is a static algorithm based on heuristics. The second algorithm, called k-Means, is based on data clustering. The heuristics based algorithm provides a result in less than 2 milliseconds, while k-Means takes roughly 4 milliseconds to converge. A comparison of the performance and flexibility of these two algorithms is presented.

    This project has resulted in a multi-threaded high level architecture based on Java, which enables interaction between Wiimote devices. The Application Programming Interface, can be easily extended for future projects, via several interfaces that provide basic mechanisms, such as an event listener, message delivery, and synchronization module. Moreover, the two different motion recognition algorithms offer different performances and different flexibility features, a crucial parameter closely related with motion recognition accuracy.

  • 224.
    Alexandru, Iordan
    et al.
    Norwegian University of Science and Technology Trondheim.
    Podobas, Artur
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Natvig, Lasse
    Norwegian University of Science and Technology Trondheim.
    Brorsson, Mats
    KTH, School of Information and Communication Technology (ICT), Communication: Services and Infrastucture, Software and Computer Systems, SCS.
    Investigating the Potential of Energy-savings Using a Fine-grained Task Based Programming Model on Multi-cores2011Conference paper (Refereed)
    Abstract [en]

    In this paper we study the relation between energy-efficiencyand parallel executions when implemented with a fine-grained task-centricprogramming model. Using a simulation framework comprised of an ar-chitectural simulator and a power and area estimation tool, we haveinvestigated the potential energy-savings when employing parallelism onmulti-cores system. In our experiments with 2 - 8 multi-cores systems,we employed frequency and voltage scaling in order to keep the relativeperformance of the systems constant and measured the energy-efficiencyusing the Energy-delay-product. Also, we compared the energy consump-tion of the parallel execution against the serial one. Our results showthat through judicious choice of load balancing parameters, significantimprovements of around 200 % in energy consumption can be acheived.

  • 225. Alfieri, G.
    et al.
    Monakhov, E. V.
    Svensson, B. G.
    Hallén, Anders.
    KTH, School of Information and Communication Technology (ICT), Material Physics.
    Defect energy levels in hydrogen-implanted and electron-irradiated n-type 4H silicon carbide2005In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 98, no 11Article in journal (Refereed)
    Abstract [en]

    Using deep level transient spectroscopy (DLTS), we have studied the energy position and thermal stability of deep levels in nitrogen doped 4H-SiC epitaxial layers after 1.2 MeV proton implantation and 15 MeV electron irradiation. Isochronal annealing was performed at temperatures from 100 to 1200 degrees C in steps of 50 degrees C. The DLTS measurements, which were carried out in the temperature range from 120 to 630 K after each annealing step, reveal the presence of ten electron traps located in the energy range of 0.45-1.6 eV below the conduction band edge (E-c). Of these ten levels, three traps at 0.69, 0.73, and 1.03 eV below E-c, respectively, are observed only after proton implantation. Dose dependence and depth profiling studies of these levels have been performed. Comparing the experimental data with computer simulations of the implantation and defects profiles, it is suggested that these three new levels, not previously reported in the literature, are hydrogen related. In particular, the E-c-0.73 eV level displays a very narrow depth distribution, confined within the implantation profile, and it originates most likely from a defect involving only one H atom.

  • 226. Alfieri, G.
    et al.
    Monakhov, E. V.
    Svensson, B. G.
    Linnarsson, Margareta K.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Applied Physics, MAP.
    Annealing behavior between room temperature and 2000 degrees C of deep level defects in electron-irradiated n-type 4H silicon carbide2005In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 98, no 4Article in journal (Refereed)
    Abstract [en]

    The annealing behavior of irradiation-induced defects in 4H-SiC epitaxial layers grown by chemical-vapor deposition has been systematically studied by means of deep level transient spectroscopy (DLTS). The nitrogen-doped epitaxial layers have been irradiated with 15-MeV electrons at room temperature and an isochronal annealing series from 100 to 2000 degrees C has been performed. The DLTS measurements, which have been carried out in the temperature range from 120 to 630 K after each annealing step, revealed the presence of six electron traps located in the energy range of 0.45-1.6 eV below the conduction-band edge (E-c). The most prominent and stable ones occur at E-c-0.70 eV (labeled Z(1/2)) and E-c-1.60 eV(EH6/7). After exhibiting a multistage annealing process over a wide temperature range, presumably caused by reactions with migrating defects, a significant fraction of both Z(1/2) and EH6/7 (25%) still persists at 2000 degrees C and activation energies for dissociation in excess of 8 and similar to 7.5 eV are estimated for Z(1/2) and EH6/7, respectively. On the basis of these results, the identity of Z(1/2) and EH6/7 is discussed and related to previous assignments in the literature.

  • 227. Alfieri, G
    et al.
    Monakhov, EV
    Linnarsson, Margareta K.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Semiconductor Materials, HMA.
    Svensson, BG
    Capacitance spectroscopy study of high energy electron irradiated and annealed 4H-SIC2005In: SILICON CARBIDE AND RELATED MATERIALS 2004 / [ed] Nipoti, R; Poggi, A; Scorzoni, A, ZURICH-UETIKON: TRANS TECH PUBLICATIONS LTD , 2005, Vol. 483, p. 365-368Conference paper (Refereed)
    Abstract [en]

    Deep level transient spectroscopy (DLTS) was employed to investigate the annealing behaviour and thermal stability of radiation induced defects in nitrogen doped 4H-SiC epitaxial layers, grown by chemical vapor deposition (CVD). The epilayers have been irradiated with 15 MeV electrons and an isochronal annealing series has been carried out. The measurements have been performed after each annealing step and six electron traps located in the energy band gap range of 0.42-1.6 eV below the conduction band edge (E-c) have been detected.

  • 228. Al-Hamdi, A. M.
    et al.
    Sillanpää, M.
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM. Sultan Qaboos University, Oman.
    Intermediate formation during photodegradation of phenol using lanthanum doped tin dioxide nanoparticles2016In: Research on chemical intermediates (Print), ISSN 0922-6168, E-ISSN 1568-5675, Vol. 42, no 4, p. 3055-3069Article in journal (Refereed)
    Abstract [en]

    Lanthanum (La)-doped tin dioxide (SnO<inf>2</inf>) nanoparticles were synthesized by a modified sol–gel method at room temperature. The samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The photocatalytic activity of La:SnO<inf>2</inf> samples were investigated by studying the degradation profile of phenol and its by-products in water. The treated samples were analyzed by HPLC–UV and a UV–Vis spectrophotometer. Benzoquinone, catechol, resorcinol, hydroquinone, acetic acid, and 2-propanol were identified as phenol degradation intermediates. Maximum concentration acquired was in the order of catechol, resorcinol, hydroquinone, and benzoquinone, which was observed in the beginning stages while iso-propanol and acetic acid were observed in the final stages of phenol degradation. We achieved a complete photodegradation of a 10 ppm aqueous phenol solution and intermediates with 0.6 % of SnO<inf>2</inf>:La nanoparticles in 120 min under artificial solar irradiation. A maximum degradation rate constant of 0.02228 min−1 of propanol and a minimum of acetic acid 0.013412 min−1 were recorded at 37 °C.

  • 229. Al-Hamdi, Abdullah M.
    et al.
    Sillanpaa, Mika
    Bora, Tanujjal
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Efficient photocatalytic degradation of phenol in aqueous solution by SnO2:Sb nanoparticles2016In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 370, p. 229-236Article in journal (Refereed)
    Abstract [en]

    Photodegradation of phenol in the presence of tin dioxide (SnO2) nanoparticles under UV light irradiation is known to be an effective photocatalytic process. However, phenol degradation under solar light is less effective due to the large band gap of SnO2. In this study antimony (Sb) doped tin dioxide (SnO2) nanoparticles were prepared at a low temperature (80 degrees C) by a sol-gel method and studied for its photo catalytic activity with phenol as a test contaminant. The catalytic degradation of phenol in aqueous media was studied using high performance liquid chromatography and total organic carbon measurements. The change in the concentration of phenol affects the pH of the solution due to the by-products formed during the photo-oxidation of phenol. The photoactivity of SnO2:Sb was found to be a maximum for 0.6 wt.% Sb doped SnO2 nanoparticles with 10 mg L-1 phenol in water. Within 2 h of photodegradation, more than 95% of phenol could be removed under solar light irradiation.

  • 230. Al-Hamdi, Abdullah M.
    et al.
    Sillanpaa, Mika
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Gadolinium doped tin dioxide nanoparticles: an efficient visible light active photocatalyst2015In: Journal of Rare Earths, ISSN 1002-0721, Vol. 33, no 12, p. 1275-1283Article in journal (Refereed)
    Abstract [en]

    Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide (SnO2) nanoparticles was reported. Gadolinium doped tin dioxide (SnO2:Gd) nanoparticles were found to absorb higher visible light compared to lanthanum, neodymium and cerium doped materials that were studied in detail. Photocatalytic degradation of phenol under artificial white light and sunlight in the presence of SnO2: Gd nanoparticles was studied with high performance liquid chromatography (HPLC), capillary electrophoresis (CE), total organic carbon (TOC) measurements and the determination of chemical oxygen demand (COD). Clear correlations between the results obtained from these multiple measurements were found, and a kinetic pathway for the degradation process was proposed. Within 150 min of solar irradiation, the TOC of a 10 ppm phenol solution in water was reduced by 95%-99%, thus demonstrating that SnO2: Gd nanoparticles are efficient visible light photocatalysts.

  • 231. Alhammouri, M.
    et al.
    Muftic, Sead
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    A design of an access control model for multilevel-security documents2008Conference paper (Refereed)
    Abstract [en]

    In this paper we describe an access control model for multilevel-security documents, those structured into multiple sections based on certain security classifications. Our access control system uses XACML policies to allow documents, whose contents have varying sensitivity levels, to be created, viewed, and edited by groups that have members with varying clearance levels, while enforcing the required security constraints.

  • 232. Alhammouri, M.
    et al.
    Muftic, Sead
    KTH, School of Information and Communication Technology (ICT), Computer and Systems Sciences, DSV.
    Management of groups and group keys in multi-level security environments2007In: Computer Safety, Reliability, and Security, Proceedings, Springer Berlin/Heidelberg, 2007, p. 75-80Conference paper (Refereed)
    Abstract [en]

    This paper describes techniques and solutions for management of groups and cryptographic keys when sharing secure documents protected at different classification levels. Such access control environment enforces access to documents at multiple security classification levels, starting from the membership in the group, then access to particular group applications, then access to individual documents and finally even their sections.

  • 233. Ali, Amjad
    et al.
    Jafri, Syeda I.
    Habib, Ayesha
    Amin, Yasar
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. University of Engineering and Technology (UET), Pakistan.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronics, Integrated devices and circuits. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    RFID Humidity Sensor Tag for Low-cost Applications2017In: APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL, ISSN 1054-4887, Vol. 32, no 12, p. 1083-1088Article in journal (Refereed)
    Abstract [en]

    This article presents a low-cost, flexible, chipless Radio Frequency Identification (RFID) tag for humidity monitoring applications. The tag exhibits moisture sensing feature within a compact geometrical dimension of 20mm x 17.6mm. The design is loaded with 12 resonators, where each resonator represents 1 bit in the frequency domain. For the designed 12-bit tag, 11 inverted C-shaped resonators are dedicated for encoding 11-bit information in their spectral signature. An integrated meandered-shaped resonator, covered with moisture sensitive Kapton (R) HN film, functions as a 1-bit moisture sensor. It is deployed for monitoring relative humidity (RH) levels, simultaneously. The passive RFID tag is realized on Taconic TLX-0 and has an operational bandwidth of 2.62 GHz. Furthermore, the design is modeled and analyzed for multiple substrates. The performance of the sensor tag for various humidity levels indicates that it is a potential solution for inexpensive sensing applications.

  • 234.
    Ali, Kamran
    KTH, School of Information and Communication Technology (ICT).
    Web scraping to monitor the client and the competitor’s brands performance and product offering in an online space2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the advent of an internet and advancement in digitalization, there is an increasing trend in an online shopping. Online shopping makes it easier for the customers to buy their favorite product in a very convenient and with the best price available in the market. Before buying a brand product, customer look for the product price on the price comparison website (Amazon, Ebay, Skyscanner), read the customer reviews left on various blogs (Yelp, Yahoo, Trustpilot) and also about which brand people are talking the most on social media. So the internet and the social media are playing a huge role in the recognition of a brand and product price competitiveness. There are several methods (analyzing the social network data, sentiment analysis of user reviews and advertisement analysis) used previously in an e-commerce industry to monitor the brand performance and price offering. But now as almost every retailer has their online presence and the transparent information is available on the retailer website. So scraping the data from the retailer website and doing a comprehensive analysis at the brand and product level can provide more valuable insights to have a competitive edge. This method can help the e-commerce organizations to easily scrape all the useful information to see the gap in their product catalog, price difference, competitor promotion strategies, brand popularity and the estimated revenue for their brands. In this thesis project, we have used this approach to address the problem for the e-commerce client who has a lot of competitors sells the same type of products in an online space. The presented solution will help the e-commerce client by providing new ways of measuring the brand’s performances and see the development of product offerings and product prices under a longer period of time.

  • 235.
    Ali, Mai
    et al.
    Alfaisal Univ, Dept Elect Engn, Riyadh, Saudi Arabia..
    Gia, Tuan Nguyen
    Taha, Abd-Elhamid
    Alfaisal Univ, Dept Elect Engn, Riyadh, Saudi Arabia..
    Rahmani, Amir M.
    Univ Calif Irvine, Dept Comp Sci, Irvine, CA USA.;Vienna Univ Technol, Vienna, Austria..
    Westerlund, Tomi
    Univ Turku, Dept Future Technol, Turku, Finland..
    Liljeberg, Pasi
    Univ Turku, Dept Future Technol, Turku, Finland..
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronics.
    Autonomous Patient/Home Health Monitoring powered by Energy Harvesting2017In: Globecom 2017 - 2017 IEEE Global Communications Conference, Institute of Electrical and Electronics Engineers (IEEE), 2017Conference paper (Refereed)
    Abstract [en]

    This paper presents the design of an autonomous smart patient/home health monitoring system. Both patient physiological parameters as well as room conditions are being monitored continuously to insure patient safety. The sensors are connected on an IoT regime, where the collected data is wirelessly transferred to a nearby gateway which performs preliminary data analysis, commonly referred to as fog computing, to make sure emergency personnel and healthcare providers are notified in case patient being monitored is at risk. To achieve power autonomy three energy harvesting sources are proposed, namely, solar, RF and thermal. The design of the RF energy harvesting system is demonstrated, where novel multiband antenna is fabricated as well as an efficient RF-DC rectifier achieving maximum conversion efficiency of 84%. Finally, the sensor node is tested with different type of sensors and settings while being solely powered by a Photovoltaic (PV) solar cell.

  • 236.
    Ali, Mirza Maaz
    KTH, School of Information and Communication Technology (ICT).
    Adaptable Information and Data Security Process: A Secure Yet Employee Friendly Process Proposal of IT Security Implementation in Organizations.2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Organizations have been changing their IT structure due to several reasons such as merger of two companies, acquisition of one company by another or IT consolidation within a company. IT policies are one of the areas which get redefined during such changes. However the lack of test facilities, time, funds, or human resources and expertise for change assessment of reengineering IT infrastructure such as integration of independently working systems or switching from on premises IT resources to cloud based IT resources, can be left unassessed. The absence of forthcoming changes' assessment can cause trouble at many levels of any organization, depending on which business operation is affected. Since every employee with a workstation is an end user, it is safe to say that end users or employees are the target of those unforeseen impacts. This situation can be handled by a working process which is able to adapt the changes made to IT systems security.

    This thesis presents a process that highlights post change issues and can help organizations to adapt to the changes in the environment and minimizes highlighted issues hence called Adaptable Information and Data Security Process. A system or entity is adaptable if it can adapt to changes.

    The results of this research are derived by putting the proposed process in use to calculate monetary and time loss in any project using different variables. Those results can encourage and support middle management to propose investment in user training and local support staff when presenting their case to upper management. Our results show the loss of 0.24% of a 200,000 kroner project to be completed in 44 weeks due to lack of adequate training of technical staff and users training to use IT systems. Another dimension of loss is calculated to show 4.2 hour of time loss on top of monetary loss given a total of 44 weeks of project period. The proposal suggests that the calculations of those loses can help management invest the time and money on users’ training and onsite technical support which will result in less investment and long lasting results as oppose to conventional approach that is lack of users training and off shore support that may reduce expenses in short term but causes significant long term losses.

  • 237.
    Ali Mohamed, Iqram
    KTH, School of Information and Communication Technology (ICT).
    Wireless mesh networking for the Outdoor Sports (Orienteering)2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Orienteering is played at different terrain lands. Competitors are allowed to carry a topograph-ical map and a magnetic compass. Map has standard signs and sequence of number signifies as the check points one who accomplish all the check points in sequence in shortest period of time is a winner and it requires good map navigational skill. Real time online analysis of orienteering sports is the one still doesn’t exist and tracking orienteering competitors is challenging thing to implement using passive RFID wireless mesh network. Tracking the competitors using wireless mesh network makes this sport attractive and interesting to global online viewers. Existing devices provides only the offline analysis.

    This will allow viewers to view live progress of participants’ positions. Currently existing available systems for monitoring Orienteering competitors unable to facilitate online analysis feature so this feature is easier for spectators to track the competitor’s position. In this project, I described about my implementation, designing and testing of designed wire-less mesh hardware device to NEP AB Company and this device can be used in other outdoor sports for tracking the competitors and also be used in other tracking applications like mili-tary, medical and asset tracking. Wireless device is implemented using two ISM band 915MHz and 434MHz lowest frequency is to cover the longest range.

    Hardware device designed, which communicate from one node to other node performs receiv-ing, transmitting and forwarding the packet. I defined the protocol standard which is com-pliance of IEEE 805.15.4 for the WPAN the communication pattern is to provide reliable and robust communication between the transmitter and receiver. Idea is to print the passive 13.56 MHz RFID tag behind the map, so competitors no need to carry anything apart from map and compass. Instead of RFID reader, in this project I have given the interrupt from the button and integrate reader part is considered as the future work.

    Passive RFID and wireless mesh network is the emerging field and reliable way of tracking competitors. In which data collected from the each check point with real-time data transmis-sion and all nodes information is monitored from the main control unit. This thesis describes a functional prototype of device which is used in tracking the outdoor sports competitors and the main target is to track the Orienteering competitors in the terrain land.

  • 238.
    Ali, Muhammad Ahmed
    KTH, School of Information and Communication Technology (ICT).
    Mobile Trillium Engine2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mobile trillium engine development, integration and deployment in clustered environment“The air transport industry has a constantly growing mobile workforce and a complex, dynamic workflow that requires workers to access and act on the real time information. Rapid mobilization and automation of the key workflow process will allow air transport industry to reduce business cost, better management and improved customer services.” [1]The aim of this thesis is to develop a backend system that integrates an existing asset, incident and change management system which is widely used in air transport industry to a mobility platform. The solution enables the field engineers to do limited incident and change management on hand held devices using a mobile application. The business data required by the mobile application is extracted from the legacy incident management system and injected into the mobility platform which makes it readily available for the mobile application. Any updates made by field engineers using the mobile application are synchronized back to the incident management system via this solution.

  • 239.
    Ali, Murad
    KTH, School of Information and Communication Technology (ICT).
     Performance Evaluation of an Open-source Multicast Router2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Open-source routing has gained momentum in the last few years due to expensive proprietary network hardware and software. People and organizations want more control on routing hardware and software. Inspired by the success of open-source software, and contributions by researchers and many volunteer developers across the globe, there are two open-source routing stacks in the market which are quite promising in terms of performance and features, namely Quagga and XORP. These routing daemons can run on many different hardware and operating systems, and are free to download and customize according to personal preference. Today, assembling a router from off-the-shelf hardware and open-source software is a matter of a few minute efforts. Nowadays, open-source software has become an integral part of many commercial network products.

    This thesis presents a performance evaluation study of an open-source multicast router. Open-source routing software is used to build a fully functional, high-performing open-source multicast router. The multicast router is running the XORP (pronounced as Zorp) routing software installed on the Debian Linux operating system. A testbed which consisted of three open-source routers was created, where different performance and operational tests were conducted. The tests mainly concerned the evaluation of the multicast routing functionality of an open-source router in a production-like environment where triple-play services were provided to the customers. Linux Differentiated Services were used to provide quality of service to three different traffic classes. Besides these tests, reliability, router management and interoperability with proprietary routers were also evaluated.

  • 240.
    Ali, Noman Mumtaz
    et al.
    KTH, School of Information and Communication Technology (ICT).
    Potys, Róbert Attila
    KTH, School of Information and Communication Technology (ICT).
    Implementation and Evaluation of NetInf TP, an Information-centric Transport Protocol2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In recent times, there has been a signicant growth in the number of Internet users, resulting in an increased demand for dierent types and amounts of content. As content distribution over the Internet has become a key issue, one proposal is that the Internet architecture could evolve to a more \Information-Centric" paradigm instead of the currently designed\Host-Centric" paradigm. In the host-based architecture, the data is often restricted to a location and will become unavailable if the host holding the data (or network connection) becomes unreachable.

    With the Information-centric data approach, the requestor requests data and receives it regardless of where the data actually originated from. Hence, the focus moves from \where" to \what" one is interested in. The heterogeneity of access methods and devices makes this type of approach even more appealing, especially when caching of data at intermediate points can be achieved. The prototype developed in the thesis builds an important part of the Information-Centric vision, that is a receiver-driven transport protocol. This is in contrast to the host-centric transport protocols which are always source driven. The advantage of having the receiver driven feature is to allow for multiple senders or receivers of the same data. That is, onereceiver may ask more than one holder to send different pieces of the same file.

    We have implemented, simulated and assessed the performance of the proposed protocol, hereby called NetInf TP. Since the protocol may have to co-exist with existing sender driven TCP implementations for some time, we have looked at the inter-operation of NetInf TP with TCP variants from both qualitative and quantitative perspectives.

  • 241.
    Ali, Raja Hashim
    et al.
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST).
    Bark, Mikael
    KTH, School of Information and Communication Technology (ICT).
    Miro, Jorge
    KTH, School of Information and Communication Technology (ICT).
    Muhammad, Sayyed Auwn
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST).
    Sjöstrand, Joel
    Stockholm University.
    Zubair, Syed Muhammad
    KTH, School of Electrical Engineering (EES), Communication Networks. University of Balochistan, Pakistan.
    Abbas, Raja Manzar
    Arvestad, Lars
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST).
    VMCMC: a graphical and statistical analysis tool for Markov chain Monte Carlo tracesManuscript (preprint) (Other academic)
    Abstract [en]

    Motivation: MCMC-based methods are important for Bayesian inference of phylogeny and related parameters. Although being computationally expensive, MCMC yields estimates of posterior distributions that are useful for estimating parameter values and are easy to use in subsequent analysis. There are, however, sometimes practical diculties with MCMC, relating to convergence assessment and determining burn-in, especially in large-scale analyses. Currently, multiple software are required to perform, e.g., convergence, mixing and interactive exploration of both continuous and tree parameters.

    Results: We have written a software called VMCMC to simplify post-processing of MCMC traces with, for example, automatic burn-in estimation. VMCMC can also be used both as a GUI-based application, supporting interactive exploration, and as a command-line tool suitable for automated pipelines.

    Availability: VMCMC is available for Java SE 6+ under the New BSD License. Executable jar les, tutorial manual and source code can be downloaded from https://bitbucket.org/rhali/visualmcmc/.

  • 242.
    Ali, Raja Hashim
    et al.
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST). KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, Centres, SeRC - Swedish e-Science Research Centre.
    Bark, Mikael
    KTH, School of Information and Communication Technology (ICT).
    Miró, Jorge
    KTH, School of Information and Communication Technology (ICT).
    Muhammad, Sayyed Auwn
    KTH, School of Computer Science and Communication (CSC), Computational Science and Technology (CST). KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, Centres, SeRC - Swedish e-Science Research Centre.
    Sjöstrand, J.
    Zubair, Syed M.
    KTH, School of Electrical Engineering (EES), Communication Networks. University of Balochistan, Pakistan.
    Abbas, R. M.
    Arvestad, L.
    VMCMC: A graphical and statistical analysis tool for Markov chain Monte Carlo traces2017In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 18, no 1, article id 97Article in journal (Refereed)
    Abstract [en]

    Background: MCMC-based methods are important for Bayesian inference of phylogeny and related parameters. Although being computationally expensive, MCMC yields estimates of posterior distributions that are useful for estimating parameter values and are easy to use in subsequent analysis. There are, however, sometimes practical difficulties with MCMC, relating to convergence assessment and determining burn-in, especially in large-scale analyses. Currently, multiple software are required to perform, e.g., convergence, mixing and interactive exploration of both continuous and tree parameters. Results: We have written a software called VMCMC to simplify post-processing of MCMC traces with, for example, automatic burn-in estimation. VMCMC can also be used both as a GUI-based application, supporting interactive exploration, and as a command-line tool suitable for automated pipelines. Conclusions: VMCMC is a free software available under the New BSD License. Executable jar files, tutorial manual and source code can be downloaded from https://bitbucket.org/rhali/visualmcmc/.

  • 243.
    Ali Tandra, Sabrina
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Rizvi, S.M. Sarwarul Islam
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Security for Cloud Based Services2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Cloud computing is a new buzzword in the modern information technology world. Today cloud computing can be considered as a service, similar to the way that electricity is considered a service in urban areas. A cloud user can utilize different computing resources (e.g. network, storage, software application), whenever required, without being concerned with the complex underlying technology and infrastructure architecture. The most important feature is that the computing resources are available whenever they are needed. Additionally, users pay only for the resource they actually use. As a result, cloud users can easily scale their information technology infrastructure, based on their business policy and requirements. This scalability makes the business process more agile.

    The motivation for this thesis was the need for a suitable set of security guidelines for ifoodbag (and similar companies) when implementing web applications in the cloud. The goal of this thesis is to provide security in a system, being developed in another Master’s thesis project, to implement the ifoodbag web application in a cloud. To achieve this goal, we began by identifying the risks, threats, and vulnerabilities in the system model proposed by these other students for their implementation. A study was made of several different security mechanisms that might reduce or eliminate risks and secure the most vulnerable points in the proposed system’s design. Tests of these alternatives were conducted to select a set of mechanisms that could be applied to the proposed system’s design. Justification for why these specific mechanisms were selected is given. The tests allowed the evaluation of how each of these different security mechanisms affected the performance of the system. This thesis presents the test results and their analysis. From this analysis a set of mechanisms were identified that should be included in the prototype of the system. In conclusion, we found that DNSSEC, HTTPS, VPN, AES, Memcached with SASL authentication, and elliptic curve cryptography gave the most security, while minimizing the negative impact on the system. Additionally, client & server mutual authentication and a multi-level distributed database security policy were essential to provide the expected security and privacy that users would expect under the Swedish Data Protection law and other laws and regulations.

  • 244.
    Ali, Waqas Liaqat
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Securing Safebook: Secure Data Access Control and Key Management for Safebook2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Online social networks have become a fast and efficient way of sharing information and experiences. Over the past few years the trend of using social networks has drastically increased with an enormous amount of users’ private contents injected into the providers’ data centers. This has raised concerns about how the users’ contents are protected and how the privacy of users is preserved by the service providers. Moreover, current social networks have been subject to much criticism over their privacy settings and access control mechanism. The providers own the users’ contents and these contents are subject to potential misuse. Many socially engineered attacks have exposed user contents due to the lack of sufficient privacy and access control. These security and privacy threats are addressed by Project Safebook, a distributed peer-to-peer online social networking solution leveraging real life trust. By design Safebook decentralizes data storage and thus the control over user content is no longer in the service provider’s hands. Moreover, Safebook uses an anonymous routing technique to ensure communication privacy between different users.

    This thesis project addresses privacy aware data management for Safebook users and a data access control solution to preserve users’ data privacy and visibility utilizing a peer to peer paradigm. The solution focuses on three sub-problems: (1) preserving the user’s ownership of user data, (2) providing an access control scheme which supports fine grained access rights, and (3) secure key management. In our proposed system, the user profile is defined over a collection of small data artifacts. An artifact is the smallest logical entity of a profile. An artifact could be a user’s status tweak, text comment, photo album metadata, or multimedia contents. These artifacts are then logically arranged to form a hierarchical tree, call the User Profile Hierarchy. The root of the profile hierarchy is the only entry point exposed by Safebook from where the complete user profile can be traversed. The visibility of portions of the user profile can be defined by exposing a subset of profile hierarchy. This requires limiting access to child artifacts, by encrypting the connectivity information with specific access keys. Each artifact is associated with a dynamic access chain, which is an encrypted string and contains the information regarding the child nodes. A dynamic access chain is generated using a stream cipher, where each child’s unique identifier is encrypted with its specific access key and concatenated to form the dynamic access chain. The decryption process will reveal only those child artifacts whose access keys are shared. The access keys are managed in a hierarchical manner over the profile hierarchy. Child artifacts inherit the parent’s access key or their access key can be overridden with a new key. In this way, fine grained access rights can be achieved over a user’s artifacts. Remote users can detect changes in a specific branch of a profile hierarchy and fetch new artifacts through our proposed profile hierarchy update service. On top of the proposed access control scheme, any social networking abstraction (such as groups, circles, badges, etc.) can be easily implemented.

  • 245.
    Alisauskas, Saulius
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Community based testing2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Currently, Android is the most popular operating system for mobile devices, but at the same time, the market for Android devices is heavily fragmented in terms of available versions, types of devices, models, form-factors and manufactures. As a result, it is virtually impossible to test applications on all existing devices. Testing on a set of the most popular devices is more realistic but can be expensive, which makes it much more difficult for individual developers to create high quality applications.

    Fortunately, each Android application developer around the world typically owns at least one device which is not used all the time and could be shared with other developers. This way, a community shared pool of Android devices can be created for automated test execution.

    This master thesis reviews existing testing frameworks that are used for testing Android applications and analyzes existing services that in one way or another try to solve the problem of providing affordable ways of performing testing on real devices.  Main result of this thesis project is a working distributed community based testing service that enables developers to easily connect, share, and execute automated test cases on devices that use Android operating system. Moreover, it provides ways of decreasing overall test execution time by executing parts of tests in parallel on multiple devices and aggregating received results.

  • 246.
    Al-Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Bertozzi, Davide
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Benini, Luca
    Performance Analysis and Design Space Exploration for High-End Biomedical Applications: Challenges and Solutions2007In: Proceedings of the International Conference on Hardware - Software Codesign and System Synthesis, 2007, p. 217-226Conference paper (Refereed)
    Abstract [en]

    High-end biomedical applications are a good target for specific-purpose system-on-chip (SoC) implementations. Human heart electrocardiogram (ECG) real-time monitoring andanalysis is an immediate example with a large potential market. Today, the lack of scalable hardware platforms limits real-time analysis capabilities of most portable ECG analyzers, and prevents the upgrade of analysis algorithms for better accuracy. Multiprocessor system-on-chip (MPSoC) technology, which is becoming main-stream in the domain of high-performance microprocessors, is becoming attractive even for power-constrained portable applications, due to the capability to provide scalable computation horsepower at an affordable power cost. This paper illustrates one of the first comprehensive HW/SW exploration frameworks to fully exploit MPSoC technology to improve the quality of real-time ECG analysis.

  • 247.
    Al-Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Poletti, Francesco
    Bertozzi, Davide
    Benini, Luca
    Bechara, Mohamed
    Khalifeh, Hasan
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Nabiev, Rustam
    A Multiprocessor System-on-Chip for Real-Time Biomedical Monitoring and Analysis: Architectural Design Space Exploration2006In: DAC '06: Proceedings of the 43rd annual Design Automation Conference, 2006, p. 125-130Conference paper (Refereed)
    Abstract [en]

    In this paper we focus on MPSoC architectures for human heart ECGreal-time monitoring and analysis. This is a very relevant bio-medicalapplication, with a huge potential market, hence it is an ideal targetfor an application-specific SoC implementation. We investigate asymmetric multi-processor architecture based on STMicroelectronicsVLIW DSPs that process in real-time 12-lead ECG signals. Thisarchitecture improves upon state-of-the-art SoC designs for ECGanalysis in its ability to analyze the full 12 leads in real-time, evenwith high sampling frequencies, and ability to detect heartmalfunction. We explore the design space by considering a number ofhardware and software architectural options.

  • 248.
    Alm, Karl-Johan
    KTH, School of Information and Communication Technology (ICT).
    Evaluation of a Prototype for Relevance Profiling2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Only a small portion of the amounts of information generated online are relevant to a given person.

    In this thesis, a prototype for determining a relevance value based on sets of data for some topic is evaluated to determine its viability in a future product called Votia.

    To achieve this, an evaluation model was dened based on \accuracy" and \eciency" for various machine learning algorithms applied to various types of data found in a tweet - a short user message on the Twitter platform | such as the message, relations between users and the tweeter, users' general behavior characteristics, and geographic data. A system was set up to fetch and convert Twitter data into data tting the prototype, with the hypothesis that (1) the Twitter data model could be mapped into the Votia data model, from which user behavior could be predicted at an adequate accuracy, and that (2) user behavior could be predicted to some degree from isolated sets of data.

    Data from Twitter was obtained by taking a random sample of users - the main actors - and then loading their and their friends' timelines. The data was processed, identifying interactivity between the set of users and their friends, in particular in who retweeted what. A number of machine learning algorithms, such as Nave Bayes classier, were tested on this data and evaluated according to the model.

    In the case of user relation, data was instead obtained by identifying a number of the top Twitter users, and the evaluation revolved around grouping their followers based on how similarly they behaved.

    The evaluation shows that predicting user behavior from isolated sets of data is not applicable in the given environment, and that the data set must be analyzed in a more integrated manner, e.g. by grouping similar users together. As the input data sets are arbitrary, each being analyzed in specic ways, a pipeline with processing modules that not only analyze the data sets in terms of relevance, but also perform preprocessing, is suggested. Examples of preprocessing might be ltering, adjusting data for use by subsequent modules, or at out rejecting the data prematurely.

  • 249. Almeida, J. M. P.
    et al.
    Tribuzi, V.
    Fonseca, R. D.
    Otuka, A. J. G.
    Ferreira, P. H. D.
    Mastelaro, V. R.
    Brajato, P.
    Hernandes, A. C.
    Dev, Apurba
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Semiconductor Materials, HMA. Universidade de São Paulo, Brazil.
    Voss, T.
    Correa, D. S.
    Mendonca, C. R.
    Femtosecond laser processing of glassy and polymeric matrices containing metals and semiconductor nanostructures2013In: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 35, no 12, p. 2643-2648Article in journal (Refereed)
    Abstract [en]

    Tailoring properties of materials by femtosecond laser processing has been proposed in the last decade as a powerful approach for technological applications, ranging from optics to biology. Although most of the research output in this field is related to femtosecond laser processing of single either organic or inorganic materials, more recently a similar approach has been proposed to develop advanced hybrid nanomaterials. Here, we report results on the use of femtosecond lasers to process hybrid nanomaterials, composed of polymeric and glassy matrices containing metal or semiconductor nanostructures. We present results on the use of femtosecond pulses to induce Cu and Ag nanoparticles in the bulk of borate and borosilicate glasses, which can be applied for a new generation of waveguides. We also report on 3D polymeric structures, fabricated by two-photon polymerization, containing Au and ZnO nanostructures, with intense two-photon fluorescent properties. The approach based on femtosecond laser processing to fabricate hybrid materials containing metal or semiconductor nanostructures is promising to be exploited for optical sensors and photonics devices.

  • 250.
    Almgren, Mikael
    KTH, School of Information and Communication Technology (ICT).
    Evaluation and Implementation of Dominance Breaking Presolving Techniques in the Unison Compiler Back-End2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Constraint-based compiler back-ends use constraint programming to solve some of the translation stages that a compiler back-end typically is constructed of. Using constraint programming enables the compiler to generate optimal target code that is faster and more robust compared to code generated by a traditional compiler back-end. With constraint programming, problems are modeled and automatically solved by a constraint solver. A method to make the solving less time-consuming is presolving. Presolving derives new information about a problem that can be applied to its model before the actual solving. This thesis focuses on evaluating a set of dominance breaking presolving techniques in a constraint-based compiler back-end. A dominance relation in constraint programming is two assignments that are in some sense equivalent. Based on the evaluation some of the presolving techniques are re-implemented in an open source constraint-solving toolkit, to remove dependencies on proprietary, but commonly available, systems inside the constraint-based compiler. The re-implemented techniques show similar or better performance than the original implementations of the techniques. In the best case, the re-implemented techniques shows an efficiency increase of 50 % compared to the original implementations.

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