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  • 1.
    Abtahi, Farhad
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Aspects of Electrical Bioimpedance Spectrum Estimation2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electrical bioimpedance spectroscopy (EBIS) has been used to assess the status or composition of various types of tissue, and examples of EBIS include body composition analysis (BCA) and tissue characterisation for skin cancer detection. EBIS is a non-invasive method that has the potential to provide a large amount of information for diagnosis or monitoring purposes, such as the monitoring of pulmonary oedema, i.e., fluid accumulation in the lungs. However, in many cases, systems based on EBIS have not become generally accepted in clinical practice. Possible reasons behind the low acceptance of EBIS could involve inaccurate models; artefacts, such as those from movements; measurement errors; and estimation errors. Previous thoracic EBIS measurements aimed at pulmonary oedema have shown some uncertainties in their results, making it difficult to produce trustworthy monitoring methods. The current research hypothesis was that these uncertainties mostly originate from estimation errors. In particular, time-varying behaviours of the thorax, e.g., respiratory and cardiac activity, can cause estimation errors, which make it tricky to detect the slowly varying behaviour of this system, i.e., pulmonary oedema.

    The aim of this thesis is to investigate potential sources of estimation error in transthoracic impedance spectroscopy (TIS) for pulmonary oedema detection and to propose methods to prevent or compensate for these errors.   This work is mainly focused on two aspects of impedance spectrum estimation: first, the problems associated with the delay between estimations of spectrum samples in the frequency-sweep technique and second, the influence of undersampling (a result of impedance estimation times) when estimating an EBIS spectrum. The delay between frequency sweeps can produce huge errors when analysing EBIS spectra, but its effect decreases with averaging or low-pass filtering, which is a common and simple method for monitoring the time-invariant behaviour of a system. The results show the importance of the undersampling effect as the main estimation error that can cause uncertainty in TIS measurements.  The best time for dealing with this error is during the design process, when the system can be designed to avoid this error or with the possibility to compensate for the error during analysis. A case study of monitoring pulmonary oedema is used to assess the effect of these two estimation errors. However, the results can be generalised to any case for identifying the slowly varying behaviour of physiological systems that also display higher frequency variations.  Finally, some suggestions for designing an EBIS measurement system and analysis methods to avoid or compensate for these estimation errors are discussed.

  • 2.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Berndtsson, Andreas
    Abtahi, Shirin
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Development and preliminary evaluation of an Android based heart rate variability biofeedback system2014In: Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE, IEEE conference proceedings, 2014, 3382-3385 p.Conference paper (Refereed)
    Abstract [en]

    The reduced Heart Rate Variability (HRV) is believed to be associated with several diseases such as congestive heart failure, diabetes and chronic kidney diseases (CKD). In these cases, HRV biofeedback may be a potential intervention method to increase HRV which in turn is beneficial to these patients. In this work, a real-time Android biofeedback application based on a Bluetooth enabled ECG and thoracic electrical bioimpedance (respiration) measurement device has been developed. The system performance and usability have been evaluated in a brief study with eight healthy volunteers. The result demonstrates real-time performance of system and positive effects of biofeedback training session by increased HRV and reduced heart rate. Further development of the application and training protocol is ongoing to investigate duration of training session to find an optimum length and interval of biofeedback sessions to use in potential interventions.

  • 3.
    Ahmed, Tanvir Saif
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Markovic, Bratislav
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Distribuerade datalagringssystem för tjänsteleverantörer: Undersökning av olika användningsfall för distribuerade datalagringssystem2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis, a study of three different uses cases has been made within the field of data storage, which are as following: Cold Storage, High Performance Storage and Virtual Machine Storage. The purpose of the survey is to give an overview of commercial distributed file systems and a deeper study of open source codes distributed file systems in order to find the most optimal solution for these use cases. Within the study, previous works concerning performance, data protection and costs were an-alyzed and compared in means to find different functionalities (snapshotting, multi-tenancy, data duplication and data replication) which distinguish modern distributed file systems. Both commercial and open distributed file systems were examined. A cost estimation for commercial and open distrib-uted file systems were made in means to find out the profitability for these two types of distributed file systems.After comparing and analyzing previous works, it was clear that the open source distributed file sys-tem Ceph was proper as a solution in accordance to the objectives that were set for High Performance Storage and Virtual Machine Storage. The cost estimation showed that it was more profitable to im-plement an open distributed file system. This study can be used as guidance to choose between different distributed file systems.

  • 4.
    Akay, Altug
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Dragomir, A
    Erlandsson, Björn-Erik
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    A Novel Data-Mining Approach Leveraging Social Media to Monitor Consumer Opinion of Sitagliptin2015In: IEEE journal of biomedical and health informatics, ISSN 2168-2194, E-ISSN 2168-2208, Vol. 19, no 1, 389-396 p.Article in journal (Refereed)
    Abstract [en]

    A novel data mining method was developed to gauge the experience of the drug Sitagliptin (trade name Januvia) by patients with diabetes mellitus type 2. To this goal, we devised a two-step analysis framework. Initial exploratory analysis using self-organizing maps was performed to determine structures based on user opinions among the forum posts. The results were a compilation of user's clusters and their correlated (positive or negative) opinion of the drug. Subsequent modeling using network analysis methods was used to determine influential users among the forum members. These findings can open new avenues of research into rapid data collection, feedback, and analysis that can enable improved outcomes and solutions for public health and important feedback for the manufacturer.

  • 5.
    Akay, Altug
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    Dragomir, A.
    Erlandsson, Björn-Erik
    KTH, School of Technology and Health (STH), Health Systems Engineering, Systems Safety and Management.
    A novel data-mining platform leveraging social media to monitor outcomes of Januvia2013In: Engineering in Medicine and Biology Society (EMBC), 2013 35th Annual International Conference of the IEEE, IEEE conference proceedings, 2013, 7484-7487 p.Conference paper (Refereed)
    Abstract [en]

    A novel data-mining method was developed to gauge the experiences of the diabetes mellitus drug Januvia. Self-organizing maps were used to analyze forum posts numerically to infer user opinion of drug Januvia. Graph theory was used to discover influential users. The result is a word list compilation correlating positive and negative word cluster groups and a web of influential users on Januvia. The implications could open new research avenues into rapid data collection, feedback, and analysis that would enable improved solutions for public health.

  • 6.
    Alameddine, Raged
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Dashtbozorg, Sajad
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Utredning av för- och nackdelar med TN-S respektive TN-C system2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report analysis the advantages and disadvantages of the TN-C (four conductor system) and TN-S (five conductor system) system. There are different opinion about which system is most appropriate to use in the distribution network and the building main lines. With the help of literature studies and contacts with various power companies and electric companies different opinion have been discussed . TN-C is the most appropriate option in the distribution network and TN-S should be used in the building main lines. This for achieving high and stable electrical environment. This thesis will facilitate the choice of technology and hopefully increase the knowledge about the subject.

  • 7.
    Al-Breihi, Mohammed
    KTH, School of Technology and Health (STH).
    Utveckling av laboration om trefastransformatorn: En studie om transformatorer2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree project was carried out on behalf of the unit for Computer

    and Electrical engineering at the School of Technology and Health, KTH.

    This study about transformers, their function and uses, the way they’re

    built, how the core and windings, which are the most important parts of a

    transformer, are made and what kind of materials are used to make them.

    Several types of transformers and their functions are described. A crucial

    part of the study has been to search for different ways to develop

    transformers to make them environmentally safer and to increase their

    life-span. As such this work describes different transformer oils, what

    advantages and disadvantages they have compared to mineral oils, what

    properties they have and in what way they’re less harmful for the

    environment. HVDC units transform high voltages from Alternating

    Current to Direct Current to lessen the resistive losses and energy losses

    which lead to a cleaner environment.

    The theory examination of the transformer is the basis for the formation

    of a lab for educational use, among others in a course about electrical

    power that’s included in Bachelor of Science in Electrical Engineering at

    KTH.

  • 8.
    Alsén, Caroline
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Kostnadsfördelar med IoT för hissystem2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Internet of things is today a development that is strongly moving forward to make society more con-trolled by technology, modern and it will be easier for many people. This technology can be used in many diffrent industries and work areas, such as elevator monitoring. This report evaluates the benefits with Internet of things within elevator monitoring. The company Safeline Sweden AB has developed a product that will make it easier to monitor elevators from a distance. An investigation of this product has been done and what their advantages were. After that, a buisness model was formed for Safelines new product IMS. By interviewing potential customers, the information about the sitaution today and the approach for new technology was discovered. The information from the interviews was then used to create a good and sustainable business model for Safeline.A buisness model was created for Safeline Sweden AB and the produkt IMS. The business model describes how the company should launch the new product, how the customer relations should be created, developed and retained. The information from the interviews made it clear that the IMS should be sold as a system solution because it is considered to be more attractive and be more valu-able for the customers.

  • 9.
    Andersson, Dan
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Implementation av prototyp för inomhuspositionering2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Development of technology constantly creates new opportunities but it can also mean major chang-es for companies and organizations. Today phones, tablets, laptops, mobile communications and cloud technology make it possible to be no longer bound by the time, location or device in order to work. The change means that a new office type that is more flexible and space efficient due to no fixed workplaces, is becoming more common. A problem with this type of offices that are known as flex-offices is that it is not obvious where or when a colleague is in the office, especially if it is large office with multiple floors.

    The aim of this work is to develop and implement a Location-Based Service for the company Connecta AB. The service will enable users to use their mobile phone to share their current workplace location in an office environment.

    The result of this work is a Location-Based Service that enables a user to use an Android phone with support for Near Field Communcication to share their current workplace position. The cloud-based server solution, Windows Azure is used to store indexed workplace positions.

  • 10.
    Atefi, Seyed Reza
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Buendia, Ruben
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS) (Closed 20130701).
    Cole Function and Conductance-Based Parasitic Capacitance Compensation for Cerebral Electrical Bioimpedance Measurements2012In: Engineering in Medicine and Biology Society (EMBC), 2012 Annual International Conference of the IEEE, San Diego: IEEE press , 2012, 3368-3371 p.Conference paper (Refereed)
    Abstract [en]

    One of the most common measurement artifacts present in Electrical Bioimpedance Spectroscopy measurements (EBIS) comes from the capacitive leakage effect resulting from parasitic stray capacitances. This artifact produces a deviation in the measured impedance spectrum that is most noticeable at higher frequencies. The artifact taints the spectroscopy measurement increasing the difficulty of producing reliable EBIS measurements at high frequencies. In this work, an approach for removing such capacitive influence from the spectral measurement is presented making use of a novel method to estimate the value of the parasitic capacitance equivalent that causes the measurement artifact. The proposed method has been tested and validated theoretically and experimentally and it gives a more accurate estimation of the value of the parasitic capacitance than the previous methods. Once a reliable value of parasitic capacitance has been estimated the capacitive influence can be easily compensated in the EBIS measured data. Thus enabling analysis of EBIS data at higher frequencies, i.e. in the range of 300-500 kHz like measurements intended for cerebral monitoring, where the characteristic frequency is remarkably higher than EBIS measurements i.e. within the range 30 to 50 kHz, intended for body composition assessment.

  • 11.
    Azhari, Mohammad
    et al.
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    Raghothama, Jayanth
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    Meijer, Sebastiaan
    KTH, School of Technology and Health (STH), Health Systems Engineering, Health Care Logistics.
    A Design and Implementation of Interactive Visualizations and Simulation in Transportation2014In: The Shift from Teaching to Learning: Individual, Collective and Organizational Learning Through Gaming Simulation: Proceedings of the 45th Conferenceof the International Simulation and Gaming Association, 2014Conference paper (Refereed)
    Abstract [en]

    Transportation Planners have a long history of using Geographical Information Systems, Simulation Models and Visualizations for decision support. A frame-work that integrates all three can provide enhanced decision support, opportuni-ties for training and planning future scenarios. In the current paper, we describe the concept of such a framework and the first steps toward its development.

  • 12.
    Baltoglou, Georgios
    et al.
    KTH, School of Technology and Health (STH).
    Karapistoli, Eirini
    Chatzimisios, Periklis
    Real-World IPTV Network Measurements2011In: 2011 IEEE SYMPOSIUM ON COMPUTERS AND COMMUNICATIONS (ISCC), 2011Conference paper (Refereed)
    Abstract [en]

    Internet Protocol Television or IPTV is defined as an alternate method of distributing television content over IP by a telecom carrier or an Internet service provider (ISP) and it is increasingly gaining market share in modern communication networks. IPTV poses specific requirements on the network infrastructure and at the same time it requires that several network performance characteristics are maintained under defined levels in order for the end user to have an assured viewing experience. In this paper, our main motivation is to investigate how a real life network performs in terms of distributing this inelastic and high-bandwidth type of service utilizing traffic measurements. Furthermore, our goal is to verify and analyze whether the studied network is suited for multicast IPTV traffic.

  • 13.
    Björklund, Johan
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Prestandautvärdering av permanentmagnetmotor2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The project was to evaluate a synchronous three-phase permanent magnet motor with brushless outrunner. It is supposed to be a part of an electric drive system for equipment onboard sailing boats. The goal was to investigate the performance of the motor and find the construction weaknesses and to come up with suggestions how to optimize the performance of the motor.

     

    Tests and measurements were made with a test setup that consisted of inverter, motor and a generator connected to the shaft. The generator stator winding had a short circuit when the load current reached 106,1 A and the tests therefore had to end. The copper wire used in the windings temperature became to high and the isolation of the wire melted.  The tests showed that the motor could handle up to 92,1 A with an efficiency of 70%. It was how much current the winding could withstand together with the power losses that was the limiting factor of the motor construction.

     

    Forced cooling with water cooled stator or improving the winding wires ability to handle higher currents by increasing the cable area are both alternatives to get a better efficiency and motor performance.

  • 14.
    Björnström, Tommie
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Cederqvist, Reidar
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Comparison and Implementation of Software Frameworks for Internet of Things2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is no established standard for how Internet of Things devices are communicating with each other, every manufacturer uses their own proprietary software and protocols. This makes it difficult to ensure the best possible user experience. There are several projects that can become a standard for how devices discovering, communicating, networking etc. The goal for this thesis work was to compare such software frameworks in some areas and investigate how Inteno’s operating system Iopsys OS can be complemented by implement one of these frameworks. A literature study gave two candidates for the comparison, AllJoyn and Bonjour. The result of the comparison showed that AllJoyn was the most appropriate choice for Inteno to implement into their OS. AllJoyn was chosen because it has a potential to become an established standard and includes tools for easy implementation. To make a proof of concept, an AllJoyn application was created. The application together with a JavaScript web page, can show and control options for an AllJoyn Wi-Fi manager application and AllJoyn enabled lamps.

  • 15.
    Boongerd, Sanhawad
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lindstein, Fredrik
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Analys av datakommunikationssäkerhet för VoIP-protokoll2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Voice over IP (VoIP) is a relatively new technology that enables voice calls over data networks.With VoIP it is possible to lower expenses, and increase functionality and flexibility. FromSwedish Armed Forces point of view, the security issue is of great importance, why the focus inthis report is on the security aspect of the two most common open-source VoIP-protocols H.323and SIP, some of the most common attacks, and counter-measures for those attacks.Because of the level of complexity with a network running H.323 or SIP, and the fact that it hasyet to stand the same level of trial as of traditional telephony, a VoIP-system includes manyknown security-issues, and probably at present many unknown security flaws.

    The conclusion is that it takes great knowledge and insight about a VoIP-network based onH.323 or SIP to make the network satisfyingly safe as it is today, and is therefore perhaps not asuitable solution for the Swedish Armed Forces today for their more sensitive communications.

  • 16.
    Borgström, Fredrik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Acceleration of FreeRTOS withSierra RTOS accelerator: Implementation of a FreeRTOS software layer onSierra RTOS accelerator2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today, the effect of the most common ways to improve the performance of embedded systems and real-time operating systems is stagnating. Therefore it is interesting to examine new ways to push the performance boundaries of embedded systems and real-time operating systems even further. It has previously been demonstrated that the hardware-based real-time operating system, Sierra, has better performance than the software-based real-time operating system, FreeRTOS. These real-time operating systems have also been shown to be similar in many aspects, which mean that it is possible for Sierra to accelerate FreeRTOS. In this thesis an implementation of such acceleration has been carried out. Because existing real-time operating systems are constantly in development combined with that it was several years since an earlier comparison between the two real-time operating systems was per-formed, FreeRTOS and Sierra were compared in terms of functionality and architecture also in this thesis. This comparison showed that FreeRTOS and Sierra share the most fundamental functions of a real-time operating system, and thus can be accelerated by Sierra, but that FreeRTOS also has a number of exclusive functions to facilitate the use of that real-time operating system. The infor-mation obtained by this comparison was the very essence of how the acceleration would be imple-mented. After a number of performance tests it could be concluded that all of the implemented functions, with the exception of a few, had shorter execution time than the corresponding functions in the original version of FreeRTOS.

  • 17.
    Brenning, Magnus
    et al.
    KTH, School of Technology and Health (STH).
    Olander, Björn
    KTH, School of Technology and Health (STH).
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Medical Engineering.
    Vennberg, Johan
    KTH, School of Technology and Health (STH).
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering. 2Laboratory for communication networks, School of Electrical Engineering, KTH.
    NeTraWeb - A Web-Based Traffic Flow Performance Meter2006In: 4th Swedish National Computer Networking Workshop SNCNW 2006, 2006Conference paper (Refereed)
    Abstract [en]

    This paper presents a web-based traffic flow performance meter. The NeTraWeb tool configures and automates the measurement activities, including storage and presentation of the main performance parameters.

  • 18.
    Buendia, Ruben
    et al.
    University of Borås, Sweden.
    bogonez-franco, Paco
    Technical University of Catalonia.
    Nescolarde, Lexa
    Technical University of Catalonia.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Influence of electrode mismatch on Cole parameter estimation from Total Right Side Electrical Bioimpedance Spectroscopy measurements2012In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34, no 7, 1024-1028 p.Article in journal (Refereed)
    Abstract [en]

    Applications based on measurements of Electrical Bioimpedance (EBI) spectroscopy analysis, like assessment of body composition, have proliferated in the past years. Currently Body Composition Assessment (BCA) based in Bioimpedance Spectroscopy (BIS) analysis relays on an accurate estimation of the Cole parameters R-0 and R-infinity. A recent study by Bogonez-Franco et al. has proposed electrode mismatch as source of remarkable artefacts in BIS measurements. Using Total Right Side BIS measurements from the aforementioned study, this work has focused on the influence of electrode mismatch on the estimation of R-0 and R-infinity using the Non-Linear Least Square curve fitting technique on the modulus of the impedance. The results show that electrode mismatch on the voltage sensing electrodes produces an overestimation of the impedance spectrum leading to a wrong estimation of the parameters R-0 and R-infinity, and consequently obtaining values around 4% larger that the values obtained from BIS without electrode mismatch. The specific key factors behind electrode mismatch or its influence on the analysis of single and spectroscopy measurements have not been investigated yet, no compensation or correction technique is available to overcome the deviation produced on the EBI measurement. Since textile-enabled EBI applications using dry textrodes, i.e. textile electrodes with dry skin-electrode interfaces and potentially large values of electrode polarization impedance are more prone to produce electrode mismatch, the lack of a correction or compensation technique might hinder the proliferation of textile-enabled EBI applications for personalized healthcare monitoring.

  • 19.
    Buendia, Ruben
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Gil-Pita, Roberto
    Department of Theory of the Signal and Communications.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Cole Parameter Estimation from the Modulus of the Electrical Bioimpeadance for Assessment of Body Composition: A Full Spectroscopy Approach2011In: Journal of Electrical Bioimpedance, ISSN 1891-5469, E-ISSN 1891-5469, Vol. 2, 72-78 p.Article in journal (Refereed)
    Abstract [en]

    Activities around applications of Electrical Bioimpedance Spectroscopy (EBIS) have proliferated in the past decade significantly. Most of these activities have been focused in the analysis of the EBIS measurements, which eventually might enable novel applications. In Body Composition Assessment (BCA) the most common analysis approach currently used in EBIS is based on the Cole function, which most often requires curve fitting. One of the most implemented approaches for obtaining the Cole parameters is performed in the impedance plane through the geometrical properties that the Cole function exhibit in such domain as depressed semi-circle. To fit the measured impedance data to a semi-circle in the impedance plane, obtaining the Cole parameters in an indirect and sequential manner has several drawbacks. Applying a Non-Linear Least Square (NLLS) iterative fitting on the spectroscopy measurement, obtains the Cole parameters considering the frequency information contained in the measurement. In this work, from experimental total right side EBIS measurements, the BCA parameters have been obtained to assess the amount and distribution of whole body fluids. The values for the BCA parameters have been obtained using values for the Cole parameters estimated with both approaches: circular fitting on the impedance plane and NLLS impedance-only fitting. The comparison of the values obtained for the BCA parameters with both methods confirms that the NLLS impedance-only is an effective alternative as Cole parameter estimation method in BCA from EBIS measurements. Using the modulus of the Cole function as the model for the fitting would eliminate the need for performing a phase detection in the acquisition process, simplifying the hardware specifications of the measurement instrumentation when implementing a bioimpedance spectrometer.

  • 20.
    Buendia, Ruben
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Harris, Matthew
    Phillips Research.
    Caffarel, Jeniffer
    Phillips Research.
    Gil-Pita, Roberto
    Department of Theory of the Signal and Communications, University of Alcala, Madrid, Spain.
    Hook Effect correction & resistance-based Cole fitting prior Cole model-based analysis: Experimental validation2010In: Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2010, IEEE Engineering in Medicine and Biology , 2010, 6563-6566 p.Conference paper (Refereed)
    Abstract [en]

    The analysis of measurements of Electrical Bioimpedance (EBI) is on the increase for performing non-invasive assessment of health status and monitoring of pathophysiological mechanisms. EBI measurements might contain measurements artefacts that must be carefully removed prior to any further analysis. Cole model-based analysis is often selected when analysing EBI data and might lead to miss-conclusion if it is applied on data contaminated with measurement artefacts. The recently proposed Correction Function to eliminate the influence of the Hook Effect from EBI data and the fitting to the real part of the Cole model to extract the Cole parameters have been validated on experimental measurements. The obtained results confirm the feasible experimental use of these promising pre-processing tools that might improve the outcome of EBI applications using Cole model-based analysis.

  • 21.
    Camling, Johan
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Lönnegren, Fredrik
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Karttillämpningar för rikstäckande accessnät2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes the process of analyzing and evaluating geographic services, and the development of map applications for nationwide networks. The project was performed at DGC, a datacommunications-, telephony- and networks operator which distributes customer access across Sweden where consumers are connected to the backbone network. In whole, the task consisted of an analysis regarding the possibilities of address-to-coordinate lookup for established customer sites, displaying the access network in a map interface and developing one or more tools, aimed at supporting order processes. Architecture patterns, use-cases construed from user requests and analysis of external provider services for geocoding determined the design of the solution. Software was partially integrated in existing systems, and partially distributed as stand-alone applications. The product was finalized with a release. Read further to get a description of the monitoring tool, network mapping with KML, dealing with geographic data, and also the process of fetching coordinates for addresses.

  • 22. Campo, A. B.
    et al.
    Dirckx, J. J.
    Widman, Erik
    KTH, School of Technology and Health (STH), Medical Engineering, Medical Imaging.
    Waz, A. T.
    Dudzik, G.
    Abramski, K. M.
    Application of a new four-channel vibrometer for determination of atherosclerosis: Further advances towards a handheld device2016In: 2016 IEEE International Symposium on Medical Measurements and Applications, MeMeA 2016 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2016Conference paper (Refereed)
    Abstract [en]

    Cardiovascular diseases (CD) are the leading cause of death worldwide and their prevalence is expected to rise. Important in the etiology of CD is the stiffening of the large arteries (arteriosclerosis) and plaque formation (atherosclerosis) in the common carotid artery (CCA). Increasing evidence shows that both arteriosclerosis and atherosclerosis can be detected by assessing pulse wave velocity (PWV) in the CCA, and several techniques focus on the detection of PWV in this structure. In previous studies, laser Doppler vibrometry (LDV) was proposed as an approach to detect arterial stiffness. In the present work, a compact four-channel LDV system is introduced for PWV detection. Four phantom arteries were assessed mimicking real life cardiovascular pathologies. Due to the high sensitivity and the increased spatial and temporal resolution of the LDV system, PWV could be assessed, and even local changes in phantom architecture could be detected. The system could potentially be used to detect arteriosclerosis and arterial plaque during cardiovascular screening.

  • 23. Cippitelli, E.
    et al.
    Gasparrini, S.
    Gambi, E.
    Spinsante, S.
    Wåhslén, Jonas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Time synchronization and data fusion for RGB-Depth cameras and inertial sensors in AAL applications2015In: 2015 IEEE International Conference on Communication Workshop, ICCW 2015, IEEE conference proceedings, 2015, 265-270 p.Conference paper (Refereed)
    Abstract [en]

    Ambient Assisted Living applications often need to integrate data from multiple sensors, to provide consistent information on the observed phenomena. Data fusion based on samples from several sensors requires accurate time synchronization with sufficient resolution, depending on the sensor sampling frequency. This work presents a technical platform for the efficient and accurate synchronization of the data captured from RGB-Depth cameras and wearable inertial sensors, that can be integrated in AAL solutions. A case study of sensor data fusion for Timed Up and Go test is also presented and discussed.

  • 24.
    Cronebäck, Alexandra
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Input interface requirements on board mounted DC/DC converters2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out on behalf of the department of Power Modules at Ericsson.

    In a telecom system interface A is a physical point between the power supply system and the telecommunication equipment described in a European standard called ETSI EN 300 132-2. This interface is also described in the American standard ATIS-0600315.2007. For board-mounted products, such as DC/DC converters, a well-defined input interface description is lacking.

    The goal of this thesis was to evaluate if the requirements in the standards ETSI EN 300 132-2 and ATIS-0600315.2007 are viable for the input interface of DC/DC converters. A part of this goal was also to investigate and analyze how the systems, in which the DC/DC converters operate, works.

    To be able to determine if any of the two standards, ETSI and ATIS, are viable for use for the input interface, both were reviewed and described with focus on voltage levels and transients.

    In the information gathering phase it became clear that an extended limitation was needed. Therefore, in order to investigate what happens from interface A to the input interface of DC/DC converters, the system used in this thesis is the EBS LOD (Ericsson Blade System – Low Ohmic Distribution). EBS is one of the systems in Core sites.

    The report describes the construction of EBS where in the PFM (Power Fan Module), backplanes and various boards are important parts. Furthermore some key principles within Core sites, such as HOD (High Ohmic Distribution), LOD, Two-wire system and Three-wire system, are also described in order to explain how the EBS system works.

    EBS (including PIM (Power Interface Module)) was modeled in OrCad PSpice, with both one board and 26 boards, and was simulated with different transients at an input to the system. The simulation results show that the high voltages never reach the DC/DC converter and that they therefore are well protected from transients in an EBS LOD system.

    In order to determine whether the standards ETSI and ATIS are viable for the input interface of DC/DC converters, it is concluded that more investigations, tests and simulations are needed.

  • 25.
    Dahlberg, Axel
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Francén, Jonas
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    IPv6-adresshantering och prefixdelegering i MPLS VPN-nät2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Full migration to IPv6 brings the need to adjust datacommunication services for the new generationof IP protocols with maintained or expanded functionality. This thesis’ goals is to submitone or more solutions that meets requirements and the technical conditions that enables thecompany DGC:s to expand the service IP-VPN for IPv6. This includes address assignmenttechniques like prefix delegation and automatic address configuration in existing network infrastructure.Solutions are presented in six scenarios that have been investigated considering tests, analysis andexperienced problems. The investigation formed the criteria scalability, configuration complexity,compatibility, support by RFC:s and requirements stated by DGC that adds to the evaluationof the most suitable solution.The evaluation has resulted in a recommended scenario that is implementable according to givengoals.Techniques that may influence the choice of most suitable solution, but that is not yet available,are discussed and presented to point out what may needed to be considered in the future.

  • 26. Daudi, M.
    et al.
    Hauge, Jannicke
    KTH, School of Technology and Health (STH). University of Bremen, Germany.
    Thoben, K. -D
    Effects of decision synchronization on trust in collaborative networks2016In: 17th IFIP WG 5.5 Working Conference on Virtual Enterprises, PRO-VE 2016, Springer-Verlag New York, 2016, 215-227 p.Conference paper (Refereed)
    Abstract [en]

    In collaborative networks, individual and organizational entities encounter many disagreements over many decisions rights. These disagreements procreate conflicting preferences, which in turn, affect trustworthy amongst partners. To that end, it becomes necessary that partners assume a degree of fairness on decision rights by calibrating positions which they initially consider a final. This calibration involves synchronizing partners’ conflicting preferences to a compromise. The objective of this paper, therefore, is to analyze and evaluate the effect of both, compromised and uncompromised preferences on trust. To achieve this, a corresponding behavioral trust model is proposed and evaluated empirically using a logistics collaboration scenario. This evaluation applies a multi-agent systems simulation method. The simulation involves 360 observations with three preferences set as predictor variables. Results show that irrespective of a degree to which conflicting preferences are synchronized, a magnitude of the generated effect on trust, depends as well on other factors like transport cost and extent to which vehicles are loaded. Additionally, if other factors are kept constant, compromised preferences affects trust more positively than uncompromised ones.

  • 27.
    Duvheim Bruce, Adam
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Indreeide, Ole Martn
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Beräkning av återmatad bromsenergi på Malmbanan2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Energy is a limited recourse and the use of energy has to be as effective as possible to avoid harmful effects on the environment and to cut spending. Reusing the energy the ore train uses to climb the mountains of northern Sweden through regenerative breaking leads to a more effective use of energy. Calculation of energy uses the trains’ stored energy and the losses during its journey along Malmbanan. This results in a total power save of 20 % for single track and between 20 % and 21 % for double track. Traffic on double track can increase but the relationship between regenerated and consumed energy will be the same. Regenerating energy on the railway reduces today’s negative impact on the environment and leads to savings in energy cost for the company.

  • 28.
    Edlund, Fredrik
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Sarker, Saqib
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Smart Kitchen: Automatisk inventering av föremål2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Internet of Things is growing fast and is predicted to become a part of everyday life. This can be used to create products which will make everyday life easier. Automated object detection combined with an automated inventory check can make it easier to manage what is in stock, this is something that can be used in smart refrigerators as an example, to make life more convenient through Internet of Things. This Bachelor thesis studies methods regarding object detection with the purpose to build a system which automatically identifies objects and manages the inventory status. A prototype was built and tested to see what the possibilities there is with such a system. The Prototype uses a Raspberry Pi as core unit, which uses Dlib libraries to identify predefined objects. The user will identify unknown objects via the mobile phone application, which makes it possible for the system to learn how to identify new objects. The same application is used to check the inventory status for the different objects that has been identified by the system. The prototype can identify objects and learn to identify new ones, according to the goals of the project.

  • 29.
    Engström, Magnus
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Soheily, Nadia
    EKG-analys och presentation2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The interpretation of the ECG is an important method in the diagnosis of abnormal heart conditions and can be used proactively to discover previ-ously unknown heart problems. Being able to easily measure the ECG and get it analyzed and presented in a clear manner without having to consult a doctor is improtant to satisfy consumer needs.

    This report describes how an ECG signal is treated with different algo-rithms and methods to detect the heartbeat and its various parameters. This information is used to classify each heartbeat separately and thus determine whether the user has a normal or abnormal cardiac function. To achieve this a software prototype was developed in which the algorithms were implemented. A questionnaire survey was done in order to examine how the output of the software prototype should be presented for a user with no medical training.

    Seven ECG files from MIT-BIH Arrhythmia database were used for validation of the algorithms. The developed algorithms could detect of if any abnormality of heart function occurred and informed the users to consult a physician. The presentation of the heart function was based on the result from the questioner.

  • 30.
    Eriksson, Martin
    et al.
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Sturm, Dennis
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Halvorsen, Kjartan
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Gullstrand, Lennart
    Swedish Sports Confederation.
    Wireless Vertical Displacement Measurement during Running using an Accelerometer and a Mobile Phone2011Conference paper (Refereed)
    Abstract [en]

    The purpose of this study was to investigate in the usability of a wireless accelerometer linked to a mobile phone via Bluetooth radio for measuring vertical displacement in running athletes. Five experienced runners were monitored during lactate threshold testing at three to five different velocities. Accelerometer data was received, processed and stored on the phone to be compared to simultaneous position transducer (ground truth) recordings after data collection. A paired t-test and statistical analysis show no significant differences in the reliability of the recordings. While further investigations are encouraged, the accelerometer and algorithm (running in J2ME on the mobile phone) proof as aflexible, easy-to-use tool for out-of-the-lab monitoring and to provide real-time feedback for running technique experiments.

  • 31.
    Eriksson, Niklas
    et al.
    KTH, School of Technology and Health (STH).
    Lifvendahl, Patrik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Utbildningssimulator av funktioner i spårfordon: Hårdvarusimulator med felsökning på dörrsystem2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor. The components are used for illustration of the functions in a door system on a rail vehicle. The educational simulator is controlled with a control unit and with pushbuttons for manual control. For demonstration of the boarding security an optical sensor is used as symbolize for the obstacle detection.

    The educational simulation has two embedded common faults: cable fault and ground fault. The instruction manual consists of a circuit diagram and is used for troubleshooting. The circuit diagram over the door system is used to find the faults and to correct them. The fault analysis includes the factors, which is the reason for the most common faults to occur in a rail vehicle. Door system receives diagnostic code from a door computer that control priori- tizing for arrangements that will be made.

    Keywords

    Educational simulator, rail vehicle, hardware-based, door system, prototype, obstacle detec- tion, instruction manual, troubleshooting, fault analysis and diagnostic code. 

  • 32.
    Eriksson, Niklas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lifvendahl, Patrik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Utbildningssimulator av funktioner i spårfordon: Hårdvarusimulator med felsökning på dörrsystem2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor. The components are used for illustration of the functions in a door system on a rail vehicle. The educational simulator is controlled with a control unit and with pushbuttons for manual control. For demonstration of the boarding security an optical sensor is used as symbolize for the obstacle detection.

    The educational simulation has two embedded common faults: cable fault and ground fault. The instruction manual consists of a circuit diagram and is used for troubleshooting. The circuit diagram over the door system is used to find the faults and to correct them. The fault analysis includes the factors, which is the reason for the most common faults to occur in a rail vehicle. Door system receives diagnostic code from a door computer that control priori- tizing for arrangements that will be made. 

  • 33.
    Ernmark, Niklas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Utveckling av en CAN-adapter i ett sensorsystem för övervakning av däcktryck.: Development of a CAN-adapter in a sensor system for tire pressure monitoring.2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes a degree project at the Royal Institute of Technology. The purpose was to create a unique system solution in which a CAN adapter card (Controller Area Network) was to be integrated with an air pressure monitoring system for heavy duty vehicles. The goal was to present measurement values ​​from valve sensors on a personal computer. The air pressure monitoring system is called J1939 - TPMS and is a finished product. J1939 - TPMS sends CAN-frames to a CAN-bus in J1939 format. These frames are to be read by the adapter card and presented on a terminal program on a personal computer. The job has been to investigate how the J1939 - TPMS system works in detail. The role of the J1939 protocol and its relationship with CAN has been clarified. Also, a detailed description of how J1939 frames are interpreted and how the measuring data TPMS is decoded is done. Principles for how a CAN node works has been clarified. Based on this, a CAN adapter card has been designed. The design has included component selection, design of electronics schema, design of computer cards and development of embedded software. The result was a ready-to-use CAN adapter card tested with J1939-TPMS. Requirements for the project were met. However, more work with the card will be needed to make it a finished product. The work was carried out at Motion Control in Västerås AB in cooperation with Transeco Däckservice (Transeco Tire Service).

  • 34.
    Ezzeddine, Kassem
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Oskarsson, Robert
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Analys av kondensatorbatteriers tillkopplingsfenomen: Undersökning av de kopplingsfenomen som uppstår vid tillkoppling av kondensatorbatterier och deras påverkan på närliggande komponenter2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Many electrical devices need reactive power to operate. Transmission of reactive power occupies a proportion of the available capacity in the power system and therefore capacitor banks are used near to the end user to generate reactive power. Thus, the reactive effect is generated and consumed in a separate part of the power system. Capacitor banks switching causes transients which may damage the surrounding components.

    Based on the real substation Stallbacka in Trollhättan, this study has analysed capacitor banks switching transients within the medium voltage level. The analysis has covered the size of these transients according to different conditions and scenarios. The result showed that the transients in this case never reached serious levels, thus there was no impact on the components. It is not clear whether the transients affect the power quality because there are no defined limits. 

    A calculation tool to the predicted transients was supposed to be created in the process. This calculation tool was never completed due to the unmanageable solution that was obtained.

  • 35.
    Favero, Federico
    KTH, School of Technology and Health (STH), Ergonomics (Closed 20130701).
    Natural light lighting qualities for the design of future spaces development of a methodology2011In: 27TH SESSION OF THE CIE, VOL. 1, PTS 1 AND 2, C I E CENTRAL BUREAU , 2011, 482-487 p.Conference paper (Refereed)
    Abstract [en]

    This paper wants to contribute to the development of a novel methodology in which daylight and artificial light are combined in the definition of the user's experience of architectural space. This experience is based upon the three systems that are triggered by light, visual, biological and perceptual/psychological. Natural Light is an attempt to deal with the issue of quality in spaces under a human perspective. This paper resumes the theoretical question that is leading a PhD research work, the result of a workshop developed in the city of Stockholm and the practical and methodological applications that will follow.

  • 36.
    Ferreira Gonzalez, Javier
    KTH, School of Technology and Health (STH), Medical sensors, signals and systems (MSSS).
    Textile-enabled Bioimpedance Instrumentation for Personalised Health Monitoring Applications2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A growing number of factors, including the costs, technological advancements, an ageing population, and medical errors are leading industrialised countries to invest in research on alternative solutions to improving their health care systems and increasing patients’ life quality. Personal Health System (PHS) solutions envision the use of information and communication technologies that enable a paradigm shift from the traditional hospital-centred healthcare delivery model toward a preventive and person-centred approach. PHS offers the means to follow patient health using wearable, portable or implantable systems that offer ubiquitous, unobtrusive bio-data acquisition, allowing remote access to patient status and treatment monitoring.

    Electrical Bioimpedance (EBI) technology is a non-invasive, quick and relatively affordable technique that can be used for assessing and monitoring different health conditions, e.g., body composition assessments for nutrition. EBI technology combined with state-of-the-art advances in sensor and textile technology are fostering the implementation of wearable bioimpedance monitors that use functional garments for the implementation of personalised healthcare applications.

    This research studies the development of a portable EBI spectrometer that can use dry textile electrodes for the assessment of body composition for the purposes of clinical uses. The portable bioimpedance monitor has been developed using the latest advances in system-on-chip technology for bioimpedance spectroscopy instrumentation. The obtained portable spectrometer has been validated against commercial spectrometer that performs total body composition assessment using functional textrode garments.

    The development of a portable Bioimpedance spectrometer using functional garments and dry textile electrodes for body composition assessment has been shown to be a feasible option. The availability of such measurement systems bring closer the real implementation of personalised healthcare systems.

  • 37.
    Fredrik, Nilsson
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Bodin, Arvid
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Ombyggnad av en statisk webbsida till en responsiv2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today ́s society people are working more and more while travelling, which makes them use smartphones and tablets instead of laptops. These screens are usually smaller than a laptop screen. That is why a more dynamic web design has been re- quested in order to fit the screen on the device being used. The static webpage’s width was 1000 pixels and the goal was to fit all the tables and information in the respon- sive version with a width of 320 pixels. Important information also had to be moved to a different page in order to make it more visible. A new CSS-template was imple- mented and several new Java Scripts followed by finer adjustments to the HTML code. Since some information had to be more visible to the user, a new tab was cre- ated in order to fulfill this demand. The new tab contained information about “Net- work Status” only related to the signed in user. After simulating the webpage in Chrome the responsiveness of the page was confirmed on all screen sizes. Sending the webpage asynchronously made the slow pages respond instantly but the total loading time was still slow. To fix this, back-end programming would have been re- quired. The project’s webpage fulfilled all the requirements. 

  • 38.
    Gabrail, Philip
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Samuelsson, Sam
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Analys av fältfördelning i kabelavslut av linjära och icke linjära material: Analysis of the field distribution in cable termination by linear and nonlinear material2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays XLPE high voltage cables are used in transmission and distribution of electrical power and has an important role in the electrical system. Power transmission that occurs over long distances is diverted from one point to another and is done with the help of cable terminations. These cable terminations have some vulnerabilities that affect the entire power system.

    The theoretical part of the report was carried out with the help of FEM software Comsol Multiphysics. Results showed that the highest field concentration occurs at the insulation of the cable and caused malfunction and vulnerabilities. In the linear case for the electrical part resulted a high permittivity that the potential and the electric field was reduced, which showed the same result for low conductivity. For the nonlinear material the conductivity changes with the electric field and time.

    The temperature of the linear case showed that at high temperatures the material became more conductive. In the nonlinear case the conductive material was reduced. This could be controlled with different threshold value (Eb) which cannot in the linear case.

    The practical part was done in E.ON:s laboratory for different type of cable terminations that were tested with 33kV. Some of the tested cable terminations were used for testing purposes and was picked out of operation because of a malfunction in the cable. An attempt to control field concentration was carried out in the laboratory and resulted to a reduced field  istribution in the cable termination. The result of the practical part showed how the field concentration was distributed in the cable termination and that the field distribution led to the collapse of the cable.

  • 39. Gasparrini, S.
    et al.
    Cippitelli, E.
    Gambi, E.
    Spinsante, S.
    Wåhslén, Jonas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Orhan, Ibrahim
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Proposal and experimental evaluation of fall detection solution based on wearable and depth data fusion2016In: ICT Innovations 2015: Emerging Technologies For Better Living, Springer, 2016, Vol. 399, 99-108 p.Conference paper (Refereed)
    Abstract [en]

    Fall injury issues represent a serious problem for elderly in our society. These people want to live in their home as long as possible and technology can improve their security and independence. In this work we study the joint use of a camera based system and wearable devices, in the so called data fusion approach, to design a fall detection solution. The synchronization issues between the heterogeneous data provided by the devices are properly treated, and three different fall detection algorithms are implemented. Experimental results are also provided, to compare the proposed solutions.

  • 40.
    Gatu, Andreas
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Svensson, Alexander
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Justerbar modell av transmissionsledning för elkraftsöverföring2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This diploma work has been carried out on behalf of Terco. TercosPST 2220 Transmission Line and Distribution Module works as a physicalmodel of a real transmission and distribution grid where five different typesof networks based on length, voltage and apparent effect are available. Thereis today a need of a model where the user self can adjust these parameters sothat the model more precisely can reflect the characteristics that the specificgrid has. Here it’s investigated how the length and its impact on a line canbe varied in a model.A presentation of how the transmission and distribution grid works andare described theoretically provides the basics for the different models thatcan describe a whole network and its properties.Since the R, L and C components needs to be able to be varied to be ableto physically realize this theoretical model, the different methods that thiscan be realized through are investigated. Two approaches are investigated,the cascaded pi-model and variable active-passive reactance (VAPAR).A number of aspects like space, cost and variability makes the variableactive-passive reactance the most suited solution. Its function as a variablevoltage source, made out of an four switches, operated with control techno-logy and pulse width modulation, makes it possible to imitate R, L and Csproperties and effect on a transmission line. The result is that the necessaryR,L,C components are made adjustable in order to be incorporated in aadjustable transmission lin model.The result and the goal are verified with simulations where variableactive-passive reactance is proved able for further development and practicaltests to model transmission and distribution lines with different length.

    Keywords. Variability, Inverter, Impedance, DC-AC, Pulse width modula-tion, Harmonics, H-bridge, Transmission line, Voltage drop, Reactive effect.

  • 41.
    Gerkens, Rick
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Berg, David
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Elkvalitéproblem vid varvtalsstyrd motordrift i industrimiljö2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Harmonics caused by variable speed drives create problems in industrial systems. The purpose of this study is to identify these problems and give recommendations to avoid them. The study was conducted as a bachelor thesis at the Royal Technical University in Stockholm, Sweden for the consultant company Ramboll Energy. A literature review was combined with electrical power quality measurements on variable speed motor operations conducted at Sandvik Mining in Sandviken, Sweden.

    Electrical quality problems caused by variable speed drives origin mainly from frequency inverter control that gives a non-linear current usage which, if the grid is not strong enough, affects voltage quality. Examples of problems are production downtime, disruption and malfunction of equipment and increased wear of equipment.

    This study shows that when making changes in systems containing harmonics, future harmonic levels can be approximated in some cases. Measurements before the change provide input data to model the system, describing the load as a harmonic current generator. With some assumptions on the grid impedance, calculating an approximation on harmonic after the change is possible.

    This study has used a simplified model for the prediction of harmonic levels after a change in the system. The purpose is to propose a cost effective way to approximate so that information on how to prevent problems …in the decision making. Electrical power quality problems could be prevented more often and not doing that is a waste of economical, environmental and social resources.

  • 42.
    Gidlöf Örnerfors, Linus
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Testautomatisering av linjärmotorer2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This diploma work has been carried out on behalf of Stegia AB. Stegia manufacturesand sells linear motors that are tested in a test bench before shipped to thecustomer. Today there is a need for a test bench that collects test results from theperformed tests. The company would like to lower the risk of falsely made tests,and to make the test bench easier for the production staff to use. At this moment,the test of the linear motors is made up of several manual tasks before the test iscompleted. This increases the risk of wrong results because of incorrectly madetests, with no traceability of the results. The goal with this diploma work is to lowerthe risk of incorrect test result by automating the testing process for the productionstaff. The result is presented as a prototype, that should increase the reliability ofthe test result of the motors. The result is then validated and analyzed in this report.

  • 43.
    Grahn, Erik
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Evaluation of MEMS accelerometer and gyroscope for orientation tracking nutrunner functionality2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the production industry, quality control is of importance. Even though today's tools provide a lot of functionality and safety to help the operators in their job, the operators still is responsible for the final quality of the parts. Today the nutrunners manufactured by Atlas Copco use their driver to detect the tightening angle. There- fore the operator can influence the tightening by turning the tool clockwise or counterclockwise during a tightening and quality cannot be assured that the bolt is tightened with a certain torque angle. The function of orientation tracking was de- sired to be evaluated for the Tensor STB angle and STB pistol tools manufactured by Atlas Copco. To be able to study the orientation of a nutrunner, practical exper- iments were introduced where an IMU sensor was fixed on a battery powered nutrunner. Sensor fusion in the form of a complementary filter was evaluated. The result states that the accelerometer could not be used to estimate the angular dis- placement of tightening due to vibration and gimbal lock and therefore a sensor fusion is not possible. The gyroscope by itself can be used to provide the angular displacement around every axis with high accuracy without taking into account the gimbal lock phenomena or external forces in the form of vibration of the tool. The gyroscope provided data with a probability to measure ±1° in future tightenings by 69,76%. The gyroscope provided data with high accuracy and stability and can be used in real world application and production for true angle functionality of the tools. 

  • 44.
    Grip, Johan
    et al.
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Djampou, Serge
    KTH, School of Technology and Health (STH), Data- och elektroteknik.
    Elkraftsystem för fälttest av Polygeneration system EXC2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In a modern society electricity is a key component for the development of the individual, industry, and society. Natural disaster areas where the electricity has been knocked out face great trials in order to get vital public functions working again. With the help of the mobile eco-friendly energy device Emergency Energy Module (EEM) electricity needs can be eased.

    The goal of thesis was to produce an electrical power system description for the upcoming Export container (EXC), and to generate a correct circuit diagram for the existing Emergency energy module (EEM).

    The electric power description must take into account EXC's specifications and include Bills of Material (BoM) and circuit diagram. The problems lies in getting the various sources of energy (solar, wind and biomass gasifier) to work together in a power system where DC, AC, three-phase and single-phase are mixed. Great emphasis is also given to obtain a flexible electricity systems that can be relatively easily changed for different customer needs.

    The making of this thesis was carried out initially with a gathering facts phase. This was followed by a review and analysis of the EEM's electrical system which resulted in a circuit diagram and a manual.

    Weaknesses in EEM's electrical system was considered to be the lack of overvoltage protection and residual current device, measuring point 5 was misplaced, measuring equipment should for safety reasons be firmly attached and 1-phase generator should be used in biomass gasifier to remove uneven load problems. The existing Power router, whose task is to control the energy flow in the system, was limited because it could only receive one AC power source, handle only one-phase and had a relatively low maximum output power of 5.5 kW.

    Whit the help of the analysis improvement suggestions above and with EXC's specification taking into account was then an electric power system for EXC constructed. with associated BoM, circuit diagram, specifications for subsystems and proposals for candidates that meet these.

    The electrical system is recommended to be built around the Power router Quattro which provides great opportunities for flexibility in terms of being able to scale up the system if such more power would be desired by the customer, or if there is a need for 3-phase systems. A variety of programming settings can then be made which facilitates the construction of specific electrical systems for varying customer needs.

  • 45.
    Gustavsson, Robert
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering. KTH.
    Lind, Alexander
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering. KTH.
    Utvärdering av energiförbrukning av ett IoT-system för övervakning av hundars rörelsemönster2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Tracy Trackers is currently developing an AI platform which purpose is to monitor a dog's movement pattern. The platform consists of hardware with accelerometer, gyroscope, temperature and humidity sensors attached to the dog. The hardware is connected to a mobile through Bluetooth. A study was conducted to investigate which batteries that are available on the market and which ones that fit best for the prototype. The aim of the study was to find a rechargeable battery with long operat-ing hours that is economically and environmentally viable for future production. Hardware for monitoring the battery voltage characteristics was built to determine differences between kinds of batteries and if there was an optimal type of battery for the specific product. The sensors used by the prototype were studied using os-cilloscopes and a self-constructed circuit in order to be able to determine power consumption at different sampling frequencies. Furthermore, a circuit was built for filtering out certain frequencies to determine the current consumption of the DC-components. The current consumption measured by the tests in this study refers to what draws current in the prototype. The developed hardware can be used for measurements of future prototypes

  • 46.
    Ha, Minkeun
    et al.
    KTH, School of Technology and Health (STH).
    Lindh, Thomas
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Distributed Performance Management of Internet of Things as a Service for Caregivers2017Conference paper (Refereed)
    Abstract [en]

    This paper presents a multi-layer distributed performancemanagement model for Internet of Things (IoT) as aservice for caregivers. Performance monitoring and control ofIoT devices and services are vital functions for e-health systems.Cloud-based IoT systems with centralized data centers furtherunderline the need for distributed management. The main contributionof this paper is a model and prototype implementation thatcombines low-complexity policy-based and conventional networkmanagement with cloud computing paradigm, lightweight IoTprotocols, and their data models. A case study on monitoringof heart activity demonstrates interworking between OMALightweight M2M protocol, Bluetooth low energy GATT services,and Azure IoT hub cloud platform to enable distributed policybasedperformance management.

  • 47.
    Haidari, Bahaman
    et al.
    KTH, School of Technology and Health (STH).
    Holm, Isak
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Verifiering av ERTMS-signalprojektering: Tillämpning mot Estland2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    EU has a framework that strives to interoperability to make it easy to travel and do business with all nations in the EU without the need to change trains or drivers. This report discribes the various laws and regulations that issued and specified by the EU Commission, UNISIG and the Swedish national rules that apply for ERTMS signalling project planning for trackside equipment. Today there is a need to more efficient the signal project planning. To achieve this, a checklist for signaling project planning will be developed that clear show, for example, where an Eurobalise in relation to a signal point should be located by referring to the correct subchapter in the right document.

    The mission of the project is to make it easier to design new production of ERTMS signalling project planning. To make this be possible studies has been done to TSI, SUBSET (the documents that controls and regulates the ERTMS signalling), relevant documents and analysis already implemented signalling project planning on Ådallines.

    The report presents a compilation of the signal project and how the different phases will occur, how they will be implemented and their significance.

    In this report, the group has produced a complete compilation of the processed documents for ERTMS signalling project and a checklist for verification of the ERTMS signalling project.

  • 48.
    Hamid Muhammed, Hamed
    KTH, School of Technology and Health (STH), Health Systems Engineering.
    Using Weighted Fixed Neural Networks for Unsupervised Fuzzy Clustering2002In: International Journal of Neural Systems (IJNS), ISSN 1793-6462, Vol. 12, no 6, 425-434 p.Article in journal (Refereed)
    Abstract [en]

    A novel algorithm for unsupervised fuzzy clustering is introduced. The algorithm uses a so-called Weighted Fixed Neural Network (WFNN) to store important and useful information about the topological relations in a given data set. The algorithm produces a weighted connected net, of weighted nodes connected by weighted edges, which reflects and preserves the topology of the input data set. The weights of the nodes and the edges in the resulting net are proportional to the local densities of data samples in input space. The connectedness of the net can be changed, and the higher the connectedness of the net is chosen, the fuzzier the system becomes. The new algorithm is computationally efficient when compared to other existing methods for clustering multi-dimensional data, such as color images.

  • 49.
    Herrlin, Emma
    KTH, School of Technology and Health (STH), Medical Engineering, Computer and Electronic Engineering.
    Alternativa reglermetoder för en energieffektiv byggnad2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Ungefär 60 % av den totala energianvändningen för uppvärmning (inklusive varmvatten) i Sverige går åt till att värma upp flerbostäder och lokaler, vilket ger en indikation på att det finns potential att minska energianvändningen ytterligare genom att hitta alternativa metoder för styr- och reglering av befintliga värmesystem. En viktig faktor oberoende av vilken metod som används är att veta byggnadens dynamiska egenskaper. Det finns en rad olika metoder på marknaden för att kunna minska energianvändningen och en del av dem är välbeprövande medan andra fortfarande är på forskningsnivå. Den beprövade metoden är prognosstyrning vilket också utvärderades vidare i examensarbetet genom en studie av tidigare utförda arbeten inom området. En gemensam och viktig faktor för att kunna spara energi för uppvärmning i byggnader är att veta byggnadens tidskonstant, även kallad värmetröghet. För att påvisa dess betydelse utfördes simuleringar i ett program som heter TEKNOsim som är utvecklat av Chalmers tekniska högskola. Resultatet från simuleringarna som utfördes för 6 olika scenarier visade att den stora faktorn som påverkade byggnaden var internvärmen från belysning, apparater och personer. En yttre påverkande faktor som också hade betydelse var solavskärmning för fönsterna vilket gav en jämnare rumstemperatur. Då simuleringarna anpassades till två olika driftfall för ventilationssystemet till ”kontorstid” och ”utanför kontorstid” höll sig rumstemperaturen inom ramen för högsta och lägsta temperatur under tiden då kontoret var bemannat. En annan metod som användes var en litteraturstudie för arbeten inom området prognosstyrning. För de arbeten som valdes ut undersöktes två olika leverantörer som är marknadsledande i Sverige, eGain och Kabona. I snitt visade resultaten en besparing på 10–15% för uppvärmningskostnaderna men den individuella spridningen för eGains prognosstyrning var stor. Vissa fastigheter hade ingen besparing alls medan andra hade en besparing på 26%. Den stora spridningen berodde antagligen på att det nya systemet endast varit igång i 6 månader då studiens utfördes, vilket är för kort tid för att få några tillförlitliga resultat. För Kabonas tjänst Ecopilot var resultaten mer jämna.

  • 50.
    Hjalmarsson, Håkan
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Lindqvist, Kristian
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Identification of performance limitations in control2001In: 2001 European Control Conference, ECC 2001, IEEE conference proceedings, 2001, 1446-1451 p.Conference paper (Refereed)
    Abstract [en]

    Non-minimum phase zeros and poles of a process put upper and lower constraints on the bandwidth of a closed loop system. It is thus of great interest to be able to identify these quantities. In this contribution it is shown that non-minimum phase zeros and unstable poles can be identified using high order models without the standard o(n) (n is the model order) variance penalty for over modeling. An asymptotic, in the model order and the number of data, expression for the variance of non-minimum phase zeros is derived. This result shows that the problem of determining the performance limits of a system from experimental data is considerably easier than identifying the complete system. As a direct application of this an optimal experiment design problem for identification of performance limits is posed and solved.

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