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  • 51.
    John, Shobin
    Halmstad University, School of Business, Engineering and Science.
    Solar PV Cell Utilization and Charging System Development2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is a result of master’s thesis in renewable engineering at Halmstad during spring term 2019.    The main contribution of the present work focuses on the development of a significant approach to identify best possible surfaces finish strategy in terms of solar battery charging. The aim of the thesis was to analyze, compare different battery charging method and implement PV cell system to run oil pump. I would like to emphasize my thanks Professor Jonny Hylander for his support guidance, opportunely posed questions that raised new lines of thought and motive to get good work on the thesis.     I would like to emphasis sincere thanks and gratitude to Mei Gong to guide throughout the thesis and support during urgent need.    I am grateful to other dissertation committee members for enlightening and inspiring discussion and their advice provided us guidelines in difficult times.    I would like as a final word of appreciation to thank the people of masters and research group at Halmstad University for their thoughtful comments and suggestion, which continually improve the quality of the dissertation

  • 52.
    Juneby, Hans
    et al.
    Halmstad University, School of Information Technology.
    Can, Mikael
    Halmstad University, School of Information Technology.
    Newtons andra vagn2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A problem of basic physics education in schools is that gravitation constantly interferes with experiments and demonstrations, making it difficult for students to understand Newton's first and second laws. The goal of this project is to improve the physics education in colleges and universities. To solve the problem we created a demonstration system that effectively demonstrates an inertial reference frame and Newton's second law by driving a specially designed train with constant velocity or constant acceleration. Students are able to perform three different experiments which are controlled via a webpage or by remote control, and analyse the output through plotted graphs. After extensive testing, the train and experiments proved successful and we concluded that physics education can be effectively improved with the help of practical experiments that students themselves can perform.

  • 53.
    Khan, Adnan
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Zahur, Hassan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Secure VPN solution in a converged network for Phoniro Systems, AB., an emerging SME2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With the advent of emerging communications technologies in today’s era of global computing, the significance of exploiting converged networks for the corporate sector has become all the more prudent. This thesis is a feasibility report for the implementation of a secure video-conference and VPN solution for an SME i.e. Phoniro Systems AB. Phoniro Systems provides health and welfare solutions. With offices in various locations throughout Sweden and active remote workers, it’s ever increasing needs and entering into new ventures; a secure, robust and reliable VPN and video-conference solution over a resilient converged network was needed. The proposed solution should integrate networks at different geographical locations. The solution should not only connect the offices but cater to the needs of remote clients providing secure and seamless connectivity. The accomplishment of the task required investigating various VPN and video conference technologies, while considering Phoniro's network infrastructure and requirements stated by the company. A balance between security, performance, ease of use and cost were some of the key considerations. Evaluating of different different technologies related to solution were done after testing them in the end a solution considering Phoniro’s requiremets was devised.

  • 54.
    Khosravi Bakhtiari, Mohsen
    Halmstad University, School of Information Technology. Theoretical computer science group at the School of Computer Science and Communication (CSC),KUNGLIGA TEKNISKA HÖGSKOLAN(KTH university ).
    Implementing and Evaluating Automaton Learning Algorithms for a Software Testing Platform2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Software Reliability group at KTH-CSC has designed and built a novel test platform LBTest for black-box requirements testing of reactive and embedded software systems (e.g. web servers, automobile control units, etc). The main concept of LBTest is to create a large number of test cases by incorporation of an automata learning algorithm with a model checking algorithm (NuSMV). This platform aims to support different learned automata, learning algorithms and different model checking algorithms which can be combined to implement the paradigm of learning-based testing (LBT).This thesis project investigates an existing published algorithm for learning deterministic finite automata (DFA)known as Kearns algorithm. The aimof this thesis is to investigate how effective Kearns algorithm is from a software testing perspective.Angluin’s well-known L* DFA learning algorithm has a simple structure and implementation. On the other hand, Kearnsalgorithm has more complex, difficult structure and harder implementation than L* algorithm, however it is more efficient and faster. For this reason, the plan is to implement an advanced DFA learning algorithm, Kearns algorithm[4], from a description in the literature (using Java).We consider a methodology to compare Kearns algorithm with Angluin’s DFA learning algorithm based on the master thesis of Czerny[8].The comparisonsbetween the Kearns and the L* algorithmsare based on the number of membership and equivalence queriesto investigate the difficulty of learning

  • 55.
    Liang, Xing
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sun, Lei
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    A Comparison Between Variational Inequality and Elrod-Adams Simulations of Reynolds Flow with Cavitation2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

      Despite considerable research related to lubrication with cavitation, significant simulation results and relative comparisons remain. To accomplish that, we make use of the finite element method which is seen as a better method to simulate lubrication with cavitation models such as the variational inequality model and the Elrod-Adams model. Different techniques are used during the process of resolution by the finite element method. A penalty method is used for the variational model and an iterative method is used for the Elrod-Adams model. Finally, some simulation results are presented to show dierent aspects of the two models. 

  • 56.
    Lindgren, Per-Olof
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Palmkvist, Adam
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Energieffektiv högtalare med trådlös kommunikation2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Music today is a big part of a person's everyday life and can influence emotions as wellas initiative and motivation. This effect together with development in technology hasled to that music today is accessible and can be played from a large amount of differentkinds of products. This in turn has meant that the demand for smaller audio playbackdevices is greater than ever.The goal of this project is to develop a concept for energy-efficient speakers withwireless communication that has the ability to obtain and play high quality music. Thespeakers will use the latest available technology and at the same time, using digitalsignal processing, have a low environmental impact through high energy efficiencyand low power consumption. Parallel to this work a pilot study will be conducted tosee trends in listener preference of sound.The result achieves the goals pledged while power consumption in sleep mode is solow that they meet the demands of tomorrow. It also shows that if the time and thewill, and if financial resources are available, it is possible to combine the reducedenvironmental impact with sound quality even for the discerning listener.

  • 57.
    Lundström, Jens
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Järpe, Eric
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Detecting and exploring deviating behaviour of smart home residents2016In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 55, p. 429-440Article in journal (Refereed)
    Abstract [en]

    A system for detecting deviating human behaviour in a smart home environment is the long-term goal of this work. Clearly, such systems will be very important in ambient assisted living services. A new approach to modelling human behaviour patterns is suggested in this paper. The approach reveals promising results in unsupervised modelling of human behaviour and detection of deviations by using such a model. Human behaviour/activity in a short time interval is represented in a novel fashion by responses of simple non-intrusive sensors. Deviating behaviour is revealed through data clustering and analysis of associations between clusters and data vectors representing adjacent time intervals (analysing transitions between clusters). To obtain clusters of human behaviour patterns, first, a random forest is trained without using beforehand defined teacher signals. Then information collected in the random forest data proximity matrix is mapped onto the 2D space and data clusters are revealed there by agglomerative clustering. Transitions between clusters are modelled by the third order Markov chain.

    Three types of deviations are considered: deviation in time, deviation in space and deviation in the transition between clusters of similar behaviour patterns.

    The proposed modelling approach does not make any assumptions about the position, type, and relationship of sensors but is nevertheless able to successfully create and use a model for deviation detection-this is claimed as a significant result in the area of expert and intelligent systems. Results show that spatial and temporal deviations can be revealed through analysis of a 2D map of high dimensional data. It is demonstrated that such a map is stable in terms of the number of clusters formed. We show that the data clusters can be understood/explored by finding the most important variables and by analysing the structure of the most representative tree. © 2016 Elsevier Ltd. All rights reserved.

  • 58.
    Lundström, Jens
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Ourique de Morais, Wagner
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Cooney, Martin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    A Holistic Smart Home Demonstrator for Anomaly Detection and Response2015In: 2015 IEEE International Conference on Pervasive Computing and Communication Workshops (PerCom Workshops), Piscataway, NJ: IEEE Press, 2015, p. 330-335Conference paper (Refereed)
    Abstract [en]

    Applying machine learning methods in scenarios involving smart homes is a complex task. The many possible variations of sensors, feature representations, machine learning algorithms, middle-ware architectures, reasoning/decision schemes, and interactive strategies make research and development tasks non-trivial to solve.In this paper, the use of a portable, flexible and holistic smart home demonstrator is proposed to facilitate iterative development and the acquisition of feedback when testing in regard to the above-mentioned issues. Specifically, the focus in this paper is on scenarios involving anomaly detection and response. First a model for anomaly detection is trained with simulated data representing a priori knowledge pertaining to a person living in an apartment. Then a reasoning mechanism uses the trained model to infer and plan a reaction to deviating activities. Reactions are carried out by a mobile interactive robot to investigate if a detected anomaly constitutes a true emergency. The implemented demonstrator was able to detect and respond properly in 18 of 20 trials featuring normal and deviating activity patterns, suggesting the feasibility of the proposed approach for such scenarios. © IEEE 2015

  • 59.
    Lundström, Jens
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Synnott, Jonathan
    Ulster University, Jordanstown, United Kingdom.
    Järpe, Eric
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Nugent, Christopher
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research. Ulster University, Jordanstown, United Kingdom.
    Smart Home Simulation using Avatar Control and Probabilistic Sampling2015In: 2015 IEEE International Conference on Pervasive Computing and Communication Workshops (PerCom Workshops), Piscataway, NJ: IEEE Press, 2015, p. 336-341Conference paper (Refereed)
    Abstract [en]

    Development, testing and validation of algorithms for smart home applications are often complex, expensive and tedious processes. Research on simulation of resident activity patterns in Smart Homes is an active research area and facilitates development of algorithms of smart home applications. However, the simulation of passive infrared (PIR) sensors is often used in a static fashion by generating equidistant events while an intended occupant is within sensor proximity. This paper suggests the combination of avatar-based control and probabilistic sampling in order to increase realism of the simulated data. The number of PIR events during a time interval is assumed to be Poisson distributed and this assumption is used in the simulation of Smart Home data. Results suggest that the proposed approach increase realism of simulated data, however results also indicate that improvements could be achieved using the geometric distribution as a model for the number of PIR events during a time interval. © IEEE 2015

  • 60.
    Mahajumi, Abu Syed
    IDE, Microelectronics and Photonics.
    InAs/GaSb quantum well structures of Infrared Detector applications.: Quantum well structure2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The detection of MWIR (mid wavelength infrared radiation) is the important for industrial, biomedical and military applications.desirable for the radiation detector to operate in the middle wavelength IR (MWIR) band corresponding to a wavelength band ranging from about 3 microns to about 5 microns.Such MWIR detectors allow forobjects having a similar thermal signature. In addition, MWIR detectors may be used in low power applications such as in night vision for surveillance of personnel.

    Now a day commercially available uncooled IR sensors operating in MWIR region (2 – 5 μm) use microbolometric detectors which are inherently slow. The novel detector of InAs/GaSb quantum well structures overcomes this limitation. However, third-generation high-performance IR  FPAs are already an attractive proposition to the IR system designer. They covered such as multicolour (at least two, and maybe more different spectral bands) with the possibility of simultaneous detection in both space and time, and ever larger sizes of, say, 2000 × 2000, and operating at higher temperatures, even to room temperature, for all cut-off wavelengths.These hetero structures have a type-II band alignment such that the conduction band of InAs layer is lower than the valence band of GaSb layer. The effective bandgap of thesestructures can be adjusted from 0.4 eV to values below 0.1 eV by varying the thickness of constituent layers leading to an enormous range of detector cutoff wavelengths (3-20 This work is focused on the various key characteristics the optical (responsivity and detectivity) and electrical (surface leakage & dark current) of infrared detector and proof of concept is demonstrated on infrared P-I-N photodiodes based on InAs/GaSb superlattices with ~8.5 μm cutoff wavelength and bandgap energy ~150 meV operating at 78 K where supression of surface leakage currents is observed. In certain military applications, it isthermal imaging of airplanes, artillery tanks and otherμm).

  • 61.
    MALEKRAH, MEHDI
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Electrical and Optical Charactristics of InP Nanowire Photodetectors2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this project Fourier Transform Infrared Spectroscopy is used to investigate a new kind of photodiode that is based on nanowires. The photo current and I-V curves for different temperatures, different applied biases, in darkness and illumination condition have been studied. The experiment was conducted in the temperature range from 78 K (-195ºC) to 300 K (27ºC). These photo diodes are designed to work on NIR wavelengths. The results show some excellent properties, such as high break down voltage, and that is an important advantage for photo detectors, low and constant reverse saturation current (Is). The results show some defects, most of them come from fabrication. The design of the sample is also discussed.

  • 62.
    Mashad Nemati, Hassan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Data analytics for weak spot detection in power distribution grids2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This research aims to develop data-driven methods that extract information from the available data in distribution grids for detecting weak spots, including the components with degraded reliability and areas with power quality problems. The results enable power distribution companies to change from reactive maintenance to predictive maintenance by deriving benefits from available data. In particular, the data is exploited for three purposes: (a) failure pattern discovery, (b) reliability evaluation of power cables, and (c) analyzing and modeling propagation of power quality disturbances (PQDs) in low-voltage grids.

    To analyze failure characteristics it is important to discover which failures share common features, e.g., if there are any types of failures that happen mostly in certain parts of the grid or at certain times. This analysis provides information about correlation between different features and identifying the most vulnerable components. In this case, we applied statistical analysis and association rules to discover failure patterns. Furthermore, we propose a visualization of the correlations between different factors representing failures by using an approximated Bayesian network. We show that the Bayesian Network constructed based on the interesting rules of two items is a good approximation of the real dataset.

    The main focus of reliability evaluation is on failure rate estimation and reliability ranking. In case of power cables, the limited amount of recorded events makes it difficult to perform failure rate modeling. Therefore, we propose a method for interpreting the results of goodness-of-fit measures with confidence intervals, estimated using synthetic data.

    To perform reliability ranking of power cables, in addition to the age of cables, we consider other factors. Then, we use the proportional hazard model (PHM) to assess the impact of the factors and calculate the failure rate of each individual cable. In reliability evaluation, it is important to consider the fact that power cables are repairable components. We discuss that the conclusions about different factors in PHM and cables ranking will be misleading if one considers the cables as non-repairable components.

    In low-voltage distribution grids, analyzing PQDs is important as we are moving towards smart grids with the next generation of producers and consumers. Installing Power Quality and Monitoring Systems (PQMS) at all the nodes in the network, for monitoring the impacts of the new consumer/producer, is prohibitively expensive. Instead, we demonstrate that power companies can utilize the available smart meters, which are widely deployed in the low-voltage grids, for monitoring power quality events and identifying areas with power quality problems. In particular, several models for propagation of PQDs, within neighbor customers in different levels of the grid topology, are investigated. The results show that meters data can be used to detect and describe propagation in low-voltage grids.

    The developed methods of (a) failure pattern discovery are applied on data from Halmstad Energi och Miljö (HEM Nät), Öresundskraft, Göteborg Energy, and Växjö Energy, four different distribution system operators in Sweden. The developed methods of (b) reliability evaluation of power cables and (c) analyzing and modeling propagation of PQDs are applied on data from HEM Nät.

  • 63.
    Mashad Nemati, Hassan
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Laso, A.
    Department of Electrical and Energy Engineering, University of Cantabria, Santander, Spain.
    Manana, M.
    Department of Electrical and Energy Engineering, University of Cantabria, Santander, Spain.
    Pinheiro Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Stream Data Cleaning for Dynamic Line Rating Application2018In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 11, no 8, article id 2007Article in journal (Refereed)
    Abstract [en]

    The maximum current that an overhead transmission line can continuously carry depends on external weather conditions, most commonly obtained from real-time streaming weather sensors. The accuracy of the sensor data is very important in order to avoid problems such as overheating. Furthermore, faulty sensor readings may cause operators to limit or even stop the energy production from renewable sources in radial networks. This paper presents a method for detecting and replacing sequences of consecutive faulty data originating from streaming weather sensors. The method is based on a combination of (a) a set of constraints obtained from derivatives in consecutive data, and (b) association rules that are automatically generated from historical data. In smart grids, a large amount of historical data from different weather stations are available but rarely used. In this work, we show that mining and analyzing this historical data provides valuable information that can be used for detecting and replacing faulty sensor readings. We compare the result of the proposed method against the exponentially weighted moving average and vector autoregression models. Experiments on data sets with real and synthetic errors demonstrate the good performance of the proposed method for monitoring weather sensors.

  • 64.
    Mashad Nemati, Hassan
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Pinheiro Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Jürgensen, Jan Henning
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Hilber, Patrik
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Reliability Evaluation of Power Cables Considering the Restoration Characteristic2019In: International Journal of Electrical Power & Energy Systems, ISSN 0142-0615, E-ISSN 1879-3517, Vol. 105, p. 622-631Article in journal (Refereed)
    Abstract [en]

    In this paper Weibull parametric proportional hazard model (PHM) is used to estimate the failure rate of every individual cable based on its age and a set of explanatory factors. The required information for the proposed method is obtained by exploiting available historical cable inventory and failure data. This data-driven method does not require any additional measurements on the cables, and allows the cables to be ranked for maintenance prioritization and repair actions.

    Furthermore, the results of reliability analysis of power cables are compared when the cables are considered as repairable or non-repairable components. The paper demonstrates that the methods which estimate the time-to-the-first failure (for non-repairable components) lead to incorrect conclusions about reliability of repairable power cables.

    The proposed method is used to evaluate the failure rate of each individual Paper Insulated Lead Cover (PILC) underground cables in a distribution grid in the south of Sweden. © 2018 Elsevier Ltd

  • 65.
    Mashad Nemati, Hassan
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    Overview of Smart Grid Challenges in Sweden2014In: The SAIS Workshop 2014 Proceedings, Swedish Artificial Intelligence Society (SAIS) , 2014, p. 155-164Conference paper (Refereed)
    Abstract [en]

    Smart grids are advanced power grids that use modern hardware and software technologies to provide clean, safe, secure, reliable, ecient and sustainable energy. However, there are many challenges in the eld of smart grids in terms of communication, reliability, interoperability, and big data that should be considered. In this paper we present a brief overview of some of the challenges and solutions in the smart grids, focusing especially on the Swedish point of view. We discuss thirty articles, from 2006 until 2013, with the main interest on datarelated challenges.

  • 66.
    Moshiri, Hesam
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Implementation of a Generic Gateway as a Multipurpose Communication Node2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Steering and navigation systems play an essential role in governing today’s leisure boats. CPAC Systems AB, a subsidiary of Volvo AB, satisfies a large part of the global market needs for this kind of products. CPAC Systems, among others, manufactures a well-known “steer-by-wire” (SBW) control system, the “Electronic Vessel Control” (a.k.a. EVC). The need to connect the EVC to systems and devices designed by other companies resulted in the development of “gateway” devices, which have a primary role in preserving the integrity of the overall system architecture. Whenever the SBW communicates with external products, gateways are used as electric isolators and protocol translators, in order to protect the integrity of the SBW function. Today, a number of different gateway devices are required to match the different interfaces to which the CPAC’s EVC system has to be connected. This thesis aims to tackle the huge diversification of the requirements and evaluates the possibility of designing a “single” product that satisfies most of the requirements. In addition to that, the work aims to design a flexible device that could be easily updated to comply with the potential needs of the incoming applications. This isbeneficial in terms of both technology and cost-efficiency. Existing gateway products are designed to fulfill the assigned tasks or just to do a specific protocol conversion and apart from this significant difference with a generic gateway, they have some limitations concerning environmental conditions and prospective upgrades. Therefore designing, testing and implementation of one multifunctional gateway to be applicable as a multipurpose communication node to cover several functionalities, would be beneficial. Several challenges arose in designing the generic gateway device, such as: hardware design with a limited number of connection I/Os (solution is limited to 20 I/Os, whereas current gateway products require as many as 35 I/Os), robustness, final cost and power consumption. The contribution of the thesis was to analyse current gateway products, to design the hardware (Schematic and PCB), to implement the software, to debug the operation, to verify of the designed hardware to ensure the operation of each part. For gathering test results and investigation of communication or instruction signals, industrial equipment like digital oscilloscope and CAN analyser have been used to prove the operation of the device which are demonstrated in the “design tests” part. In addition, robustness of the gateway has been tested against several industrial test parameters, such as temperature variations, isolation, power supply robustness and typical power consumption. The results of these tests are iscussed in the “robustness tests” part. By fulfilling all of these steps and collaboration with the company team, satisfactory results have been achieved.

  • 67.
    Muzamil, Sohail
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Perveiz, Muhammad Shoaib
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Simulation of Volume Measurement of Glass Gob2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    We present a geometrical and mathematical solution to a problem faced in the glass industry in this work. Volume measurement of the glass gob is vital in making glassware. Geometric models were used to represent the glass gob.

    A line scan camera system takes the images of the glass gob and the volume information of the glass gob is obtained by the image processing in the industry. This work is carried out to implement a simulator which estimates the change in the volume measurement of glass gob through line scan when it is rotated or when its shape is changed. A mixture of graphical and mathematical approaches is used to carry out this study. Geometric models have been used to represent the different gob models. Geometric models facilitate the manipulation of volumetric data.A simple and effective technique is used in this work. The problem is divided into steps. Volume measurement through a line scan technique is simulated. An easy to use graphical user interface (GUI) is designed to interact with the gob model and check the results of volume measurements.We present a geometrical and mathematical solution to a problem faced in the glass industry in this work. Volume measurement of the glass gob is vital in making glassware. Geometric models were used to represent the glass gob.A line scan camera system takes the images of the glass gob and the volume information of the glass gob is obtained by the image processing in the industry.This work is carried out to implement a simulator which estimates the change in the volume measurement of glass gob through line scan when it is rotated or when its shape is changed. A mixture of graphical and mathematical approaches is used to carry out this study. Geometric models have been used to represent the different gob models. Geometric models facilitate the manipulation of volumetric data.

    A simple and effective technique is used in this work. The problem is divided into steps. Volume measurement through a line scan technique is simulated. An easy to use graphical user interface (GUI) is designed to interact with the gob model and check the results of volume measurements.

  • 68.
    Nilsson, Emil
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Svensson, Christer
    ISY, Linköping University, Linköping, Sweden.
    Envelope Detector Sensitivity and Blocking Characteristics2011In: 2011 20th European Conference on Circuit Theory and Design (ECCTD), Piscataway, NJ: IEEE Press, 2011, p. 773-776, article id 6043845Conference paper (Refereed)
    Abstract [en]

    This paper presents analytical expressions for the sensitivity of a low power envelope detector driven by a weak RF signal in the presence of a blocking signal. The envelope detector has been proposed for low power Wake-Up radios in applications such as RFID and wireless sensor systems. The theoretical results are verified with simulations of a modern short channel MOS transistor in a commonly used circuit topology. A discussion around a tutorial example of a radio frontend, consisting of an LNA and a detector, is presented. It is shown that the sensitivity of a low power envelope detector can reach -62 dBm with a low power LNA and in presence of a CW blocker. © 2011 IEEE.

  • 69.
    Nilsson, Emil
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Svensson, Christer
    Linkoping Univ, Dept Elect Engn ISY, SE-58183 Linkoping, Sweden..
    Ultra Low Power Wake-Up Radio Using Envelope Detector and Transmission Line Voltage Transformer2013In: IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS, ISSN 2156-3357, Vol. 3, no 1, p. 5-12Article in journal (Refereed)
    Abstract [en]

    An ultra-low power wake-up radio receiver using no oscillators is described. The radio utilizes an envelope detector followed by a baseband amplifier and is fabricated in a 130-nm complementary metal-oxide-semiconductor process. The receiver is preceded by a passive radio-frequency voltage transformer, also providing 50 Omega antenna matching, fabricated as transmission lines on the FR4 chip carrier. A sensitivity of -47 dBm with 200 kb/s on-off keying modulation is measured at a current consumption of 2.3 mu A from a 1 V supply. No trimming is used. The receiver accepts a dBm continuous wave blocking signal, or modulated blockers 6 dB below the sensitivity limit, with no loss of sensitivity.

  • 70.
    Nilsson, Jimmy
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Testbänk för motorbåtsdrev2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Marinediesel has, to meet there customers needs for a suitable sterndrive to powerboats, developed a prototype. The prototype is currently in the testing phase. The opportunity to test the sterndrive under load inside the workshop has not previously been possible. Until now the drive has been tested in a test bench without any load on the propeller axle. The prototype has also been tested under real conditions mounted on a boat.The idea with my thesis was to create a test bench that can run around the clock in order to be able to test things like wear and service intervals and other things that require that the test interval is long. In this report, I have deepened me in how to measure the torque on a rotating shaft. This specialization has led to that the torque is not measured directly on a shaft. Instead the torque is calculated from the oil pressure in the hydraulic cylinders which manages the application of simulated resistance of the propeller shaft. This simulated resistance is created by hydraulic cylinders, belts and pulleys that are stretched and released depending on the desired clamping. The output and input signals is handled by a PLC with integrated touch screen. The choice of mechanic drive finally ended with an inverter drive controlled asynchronous motor of 75kW. In this report there is also a piece about some ways to reduce the unwanted noise that occurs with inverter drives. Enjoy the reading.

  • 71.
    Nordmark, Viktor
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Kolmodin, Tobias
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Trådlös multimeter för smarta terminaler2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 72.
    Pentakota, Uday Kumar
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Cost estimation and procedure to setup 1MW waste-to-energy gasification plant in India2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    With an increasing demand for electrical energy, it is certain that the production will also increase,especially in rapid developing countries like India. Rapid industrialization is carving for more electrical energy, investment and suitable space for its infrastructure. But this development has to be sustainable keeping in mind the increasing global temperature due to pollution.

    India is the second largest population in the world and hence produces a lot of waste daily. As of now, most of the waste goes to the landfills and gets burnt there or decomposed, either way releasing greenhouse gases in the process and degrading the environment. The municipal waste management is a challenging process in developing countries because of non-availability of proper infrastructure. There are some methods to manage this waste, such as scientific landfills,Incineration, Biomethanation, Gasification, Pyrolysis and Plasma Arc Gasification.By Gasification the solid waste is converted into synthesis gas which can be used for chemical industries, power generation, transportation and industrial heating etc. This process shrinks the solid waste to slag or ash which can either be used to manufacture eco bricks or can be disposed of on landfill. Thus saving a lot of place from land filling and if used for power generation it does not release any considerable harmful gases into the environment making it a sustainable process and partially renewable source of energy.

    This project will estimate the capital requirement and procedure to setup a 1 MW gasification plant in Indian state of Telangana. In the study, the generation, composition, treatment and energy potential of solid waste have been studied. The technologies for waste-to-energy conversion have also been studied and the feasibility comparison of two leading technologies has been done.

  • 73.
    Pettersson, Håkan
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Trägårdh, Johanna
    Solid State Physics and the Nanometer Consortium, Lund University, Lund, SUEDE.
    Persson, Ann I.
    Solid State Physics and the Nanometer Consortium, Lund University, Lund, SUEDE.
    Landin, Lars
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Hessman, Dan
    Solid State Physics and the Nanometer Consortium, Lund University, Lund, SUEDE.
    Samuelson, Lars E.
    Solid State Physics and the Nanometer Consortium, Lund University, Lund, SUEDE.
    Infrared Photodetectors in Heterostructure Nanowires2006In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 6, no 2, p. 229-232Article in journal (Refereed)
    Abstract [en]

    We report on spectrally resolved photocurrent measurements on single self-assembled nanowire heterostructures. The wires, typically 3 μm long with an average diameter of 85 nm, consist of InAs with a 1 μm central part of InAsP. Two different sets of wires were prepared with phosphorus contents of 15 ±3% and 35 ±3%, respectively, as determined by energy-dispersive spectroscopy measurements made in transmission electron microscopy. Ohmic contacts are fabricated to the InAs ends of the wire using e-beam lithography. The conduction band offset between the InAs and InAsP regions virtually removes the dark current through the wires at low temperature. In the optical experiments, interband excitation in the phosphorus-rich part of the wires results in a photocurrent with threshold energies of about 0.65 and 0.82 eV, respectively, in qualitative agreement with the expected band gap of the two compositions. Furthermore, a strong polarization dependence is observed with an order of magnitude larger photocurrent for light polarized parallel to the wire than for light polarized perpendicular to the wire. We believe that these wires form promising candidates as nanoscale infrared polarization-sensitive photodetectors.

  • 74.
    Ramazanali, Hawar
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). Saab Training and Simulation, Huskvarna, Sweden.
    Vinel, Alexey
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Tuning of LTE/LTE-A DRX parameters2016In: 2016 IEEE 21st International Workshop on Computer Aided Modelling and Design of Communication Links and Networks (CAMAD), Piscataway, NJ: IEEE, 2016, p. 95-100Conference paper (Refereed)
    Abstract [en]

    The tradeoff between the power saving and the queuing delay in LTE/LTE-A radio devices with Discontinuous Reception (DRX) Mechanism is discussed. Two optimization problems to tune the DRX parameters are formulated. An optimal performance determined by exhaustive search over a large parameter set and a reduced parameter set, obtained by disabling short DRX cycles, is compared.

  • 75.
    Ramsten, Johannes
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Klum, Markus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Implementation av fältbuss ASIC i FPGA2010Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    HMS Industrial Networks AB is in need of changing a communications solution that iscurrently based on an ASIC. This will be achieved by moving the communications solution toa FPGA with the help of the programming language VHDL. By doing this, it is possible toreduce the need for specific circuits, get a more flexible platform and thus get a cheapersolution.

    This report describes a solution for how to move a network protocol from an ASIC to anFPGA. The report shows that the network slave device is working under the guidelines forthis project. This means that it is quite realistic to implement a fieldbus protocol on an FPGA,using VHDL and to maintain the same functionality as the earlier communications solution.

  • 76.
    Razzaghi, Elyas
    et al.
    Halmstad University, School of Information Technology.
    Van Hoek, Arno
    Halmstad University, School of Information Technology.
    Micro-Shivering Detection: Detection of human micro-shivering using a 77 GHz radar2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Radars have been under steady development to track, identify, image, and classify targets. Modern radar systems, with the help of embedded systems, have additional comprehensive signal processing capabilities. They can extract useful information from very noisy data, e.g. interference from the environment and unwanted echoes which is collectively known as clutter in radar terms. Concerning the healthcare industry, radar applications for detection of vital signs, i.e. breathing and heart rate, have been extensively developed during the last few decades. Modern radar systems are expected to be a large part of non-intrusive monitoring in the coming smart home industry, where vital signs need to be monitored in the currently aging population.

    The research presented here is to break new ground in the radar-based healthcare technology, enabling detection of cold-induced shivering to such level that the micro-shivering can be clearly identified. To simplify the radar software optimization, a commercially available radar kit with demo application and a muscle model system using a vibration generator is used.

    The model is quantified through precise measurements. A simulated human body vital sign plus shivering is applied. By optimizing the radar software, the shivering amplitude and frequency are measured.

  • 77.
    Rickard, Hoff
    et al.
    Halmstad University, School of Information Technology.
    Besfort, Berisha
    Halmstad University, School of Information Technology.
    BWave PowerAmp2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project is about developing a complete amplifier that can integrate with three differentclass-D amplifier modules. With the thought so that the product can later be sold on themarket.Where the use of the product can be used for either home or cinema audio systems.We have designed and reused existing schematic solutions and the company has assisted indeveloping some of the schematics. The result of this report is the development and design ofcircuit boards with EMC guidelines.

  • 78.
    Roos, Fredrik
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Sundvall, Kristian
    Halmstad University, School of Business and Engineering (SET).
    Jämförelse av verklig och modellerad elproduktion från en solcellsanläggning: En utvärdering av två simuleringsverktyg.2012Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out in New Zealand in collaboration with the University of Waikato. In association with Dr. Mike Duke the purpose of this work is to investigate whether two different software for modeling of photovoltaic systems are useful in the teaching of solar energy.The next ten years grid-connected photovoltaic systems are assumed to increase and therefore also a rising demand for people with engineering knowledge are to be predicted. For engineer students with a focus on solar energy a more practical teaching with design software´s can be a good method to make the students comprehend more when it comes to large scale photovoltaic systems and be more prepared for working life.The software´s used is called Transient System Simulation (TRNSYS) and Photovoltaic Systems (PVSYST) which are both well used throughout the world. To assess the reliability of the software´s, a reference solar power plant at 16.1 kWp installed capacity are used, which consists of photovoltaic modules from four different manufacturers. This reference plant owned by the University of Waikato is installed on the library roof and is the point of reference for both software´s in the calculation of electricity production.The subject of the thesis concerns the solar energy with a focus on grid-connected photovoltaic systems and beyond that the work has also led to an investigation of solar radiation, solar cells and how to use information from different weather databases. In this project a widely used database "Typical Meteorological Year 2" with 20 years of age measurements of solar radiation is used and compared to the latest information available. The handiness and suitability of both software´s were also evaluated to see if the software´s are good enough for teaching at the University of Waikato.The conclusion made by the writers is that TRNSYS can be used in teaching at the University of Waikato but PVSYST need further investigation. TRNSYS is suitable because of its performance accuracy and detail in the building modeling. The writers cannot recommend PVSYST as the investigation of the software was not completed due to the lack of time. PVSYST does likely have the potential to be an educational tool, but it remains to be investigated.

  • 79.
    Rosenberg, Pontus
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Henriksson, Angelica
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Elektronisk träffmarkör2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Företaget Jakt & Skyttesystem AB har ett portabelt viltmålsskyttesystem som de vill utrusta med elektronisk träffmarkering som klarar av vapen av olika kaliber. Målet för projektet är att utvärdera och utveckla metoder för träfflokalisering i tavelskytte. Vi valde att utreda sensorsystem som inte begränsas av vapen med låg anslagsenergi. Därför har vi valt att endast utreda teknikerna ljudlokalisering i luft och fasta material samt bildlokalisering. Som utgångspunkt för projektet studerades hur befintliga skyttesystem fungerar, vilken sensorteknik och vilka material som används. Ett flertal olika gummimaterial testades på militära skyttebanorna vid Lv6 för att se vilket material som passar bäst. För att utveckla sensorsystemet användes datainsamlingsinstrument från National Instruments, (Daqpad 6070e). De sensorer som testats är piezoelement, accelerometrar, elektretmikrofoner och kamera. För ljudlokalisering utformades algoritmer som baseras på tidsdifferanser mellan sensorerna och bildlokaliseringsalgoritmen baseras på kantdetektion samt perspektivkompensering. Resultatet visar att bildlokalisering ger en högre precision än ljudlokalisering men tekniken är svår att anpassa till fältmässiga förhållanden då den exempelvis kräver en tydlig träffbild och en hög prestanda på hårdvaran. Slutsatsen är att ljudlokalisering i luft är det bästa alternativet med en träffyta av ett slitstarkt material, exempelvis neoprengummi eller naturgummi. Bästa sensorkonfigurationen är en mikrofon i varje hörn med en numerisk lösningsmetod till TDOA-ekvationerna.

  • 80.
    Sadoon, Sarah
    Halmstad University, School of Information Technology.
    Mätsystem för en säkrare vandring2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today there are many books and equipment that contribute to a safe journey in the wildness. But the market still has a great potential for development. In this project two prototypes has been developed to control the users hydration level when hiking in wildness. The measurement system shows a warning signal when the water level is too low. The two prototypes have been compared and a conclusion has been drawn for which prototype is themost optimal for the projects purposes.

  • 81.
    Saj, Damian
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Saj, Izabela
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Nanowire-based InP solar cell materials2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this project, a new type of InP solar cell was investigated. The main idea is that light is converted to electrical current in p-i-n photodiodes formed in thin InP semiconductor nanowires epitaxially grown on an InP substrate. Two different types of samples were investigated. In the first sample type (series C03), the substrate was used as a common p-type electrode, whereas a short p-segment was included in all nanowires for the second sample type (B07).

    Current – voltage (I-V) characteristics with and without illumination were measured, as well as spectrally resolved photocurrents with and without bias. The main conclusion is that the p-i-n devices showed good rectifying behavior with an onset in photocurrent that agrees with the corresponding energy band gap of InP. An interesting observation was that in series B07 (with included p-segments) the photocurrent was determined by the band gap of hexagonal Wurtzite crystal structure, whereas series C03 (without p-segments) displayed a photocurrent dominated by the InP substrate which has a Zincblende crystal structure. We found that the overall short-circuit current was ten as large for the latter sample, stressing the importance of the substrate as a source of photocurrent.

  • 82.
    Sant'Anna, Anita
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent Systems´ laboratory.
    A Symbolic Approach to Human Motion Analysis Using Inertial Sensors: Framework and Gait Analysis Study2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Motion analysis deals with determining what and how activities are being performed by a subject, through the use of sensors. The process of answering the what question is commonly known as classification, and answering the how question is here referred to as characterization. Frequently, combinations of inertial sensor such as accelerometers and gyroscopes are used for motion analysis. These sensors are cheap, small, and can easily be incorporated into wearable systems.

    The overall goal of this thesis was to improve the processing of inertial sensor data for the characterization of movements. This thesis presents a framework for the development of motion analysis systems that targets movement characterization, and describes an implementation of the framework for gait analysis. One substantial aspect of the framework is symbolization, which transforms the sensor data into strings of symbols. Another aspect of the framework is the inclusion of human expert knowledge, which facilitates the connection between data and human concepts, and clarifies the analysis process to a human expert.

    The proposed implementation was compared to state of practice gait analysis systems, and evaluated in a clinical environment. Results showed that expert knowledge can be successfully used to parse symbolic data and identify the different phases of gait. In addition, the symbolic representation enabled the creation of new gait symmetry and gait normality indices. The proposed symmetry index was superior to many others in detecting movement asymmetry in early-to-mid-stage Parkinson's Disease patients. Furthermore, the normality index showed potential in the assessment of patient recovery after hip-replacement surgery. In conclusion, this implementation of the gait analysis system illustrated that the framework can be used as a road map for the development of movement analysis systems.

  • 83.
    Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Activity monitoring as a tool for person-centered care: preliminary report2014In: 2014 IEEE International Conference on Bioinformatics and Biomedicine (BIBM) / [ed] Huiru (Jane) Zheng, Werner Dubitzky, Xiaohua Hu, Jin-Kao Hao, Daniel Berrar, Kwang-Hyun Cho, Yadong Wang & David Gilbert, Piscataway, NJ: IEEE Press, 2014, p. 48-51Conference paper (Refereed)
    Abstract [en]

    The Person-Centered Care (PCC) paradigm advocates that instead of being the passive target of a medical intervention, patients should play an active part in their care and in the decision-making process, together with clinicians. Although new mobile and wearable technologies have created a new wave of personalized health-related applications, it is still unclear how these technologies can be used in health care institutions in order to support person-centered care. In order to investigate this matter, we undertook a pilot study aimed at determining if and how activity monitoring can support person-centered care routines for patients undergoing total hip replacement surgery. This is a preliminary report describing the methodology, preliminary results, and some practical challenges. We present here an orientation-invariant, accelerometer-based activity monitoring method, especially designed to address the requirements of monitoring in-patients in a real clinical setting. We also present and discuss some practical issues related to complying with hospital requirements and collaborating with hospital staff. © 2014 IEEE.

  • 84.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Bass, Robert
    Portland State University, Portland, OR, USA.
    A New Two-Degree-of-Freedom Space Heating Model for Demand Response2014In: SMARTGREENS 2014: Proceedings of the 3rd International Conference on Smart Grids and Green IT Systems, [S. l.]: SciTePress, 2014, p. 5-13Conference paper (Refereed)
    Abstract [en]

    In today’s fast changing electric utilities sector demand response (DR) programs are a relatively inexpensive means of reducing peak demand and providing ancillary services. Advancements in embedded systems and communication technologies are paving the way for more complex DR programs based on transactive control. Such complex systems highlight the importance of modeling and simulation tools for studying and evaluating the effects of different control strategies for DR. Considerable efforts have been directed at modeling thermostatically controlled appliances. These models however operate with only one degree of freedom, typically, the thermal mass temperature. This paper proposes a two-degree-of-freedom residential space heating system composed of a thermal storage unit and forced convection system. Simulation results demonstrate that such system is better suited for maintaining thermal comfort and allows greater flexibility for DR programs. The performance of several control strategies are evaluated, as well as the effects of model and weather parameters on thermal comfort and power consumption.

  • 85.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    A linguistic approach to the analysis of accelerometerdata for gait analysis2010In: Proceedings of the seventh IASTED International Conference on Biomedical Engineering: February 17-19, 2010, Innsbruck, Austria / [ed] A. Hierlemann, Anaheim, CA: ACTA Press, 2010, p. 8-Conference paper (Refereed)
    Abstract [en]

    There is evidence that many cognitive conditions affect the human motor system. Gait analysis has lately been used as a means of studying this physical-cognitive correlation. The development of gait analysis systems, able to record and analyze gait during normal daily activities and in uncontrolled environment, is an important addition to this area of research. Lately, linguistic approaches have been studied as means to achieve activity classification from vision sensors. The present work aims to extend the linguistic approach to achieve quantitative analysis of gait from accelerometer data. The proposed method can be used to extend the Human Activity Language framework to include the analysis of inertial sensors such as accelerometers. Results show that the proposed method is more accurate and robust than previous methods and can be used to extract a number of clinically relevant gait measurements. A novel symmetry index is presented to exemplify how the proposed method is able to extract more information from accelerometer signals than previous methods.

  • 86.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    A Symbol-Based Approach to Gait Analysis From Acceleration Signals: Identification and Detection of Gait Events and a New Measure of Gait Symmetry2010In: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, E-ISSN 1558-0032, Vol. 14, no 5, p. 1180-1187Article in journal (Refereed)
    Abstract [en]

    Gait analysis can convey important information about one’s physical and cognitive condition. Wearable inertial sensor systems can be used to continuously and unobtrusively assess gait during everyday activities in uncontrolled environments. An important step in the development of such systems is the processing and  analysis of the sensor data. This paper presents a symbol-based method used to detect the phases of gait and convey important dynamic information from accelerometer signals. The addition of expert knowledge substitutes the need for supervised learning techniques, rendering the system easy to interpret and easy to improve incrementally. The proposed method is compared to an approach based on peak-detection. A new symbol-based symmetry index is created and compared to a traditional temporal symmetry index and a symmetry measure based on cross-correlation. The symbol-based symmetry index exemplifies how the proposed method can extract more information from the acceleration signal than previous approaches

  • 87.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Developing a Motion Language: Gait Analysis from Accelerometer Sensor Systems2009In: Pervasive Health 2009: 3rd International Conference on Pervasive Computing Technologies for Healthcare, Piscataway, N.J.: IEEE Press, 2009, p. 1-8Conference paper (Refereed)
    Abstract [en]

    The advances in sensing technology provide us with the opportunity to develop mobile and unobtrusive systems to continuously gather gait data. Accelerometers have been shown to be an adequate choice for recording human motion data. For that reason, many previous works have investigated the use of accelerometers for gait analysis. Previous works were able to extract either static temporal information or dynamic general information about the gait patterns. This work aims at extracting both static and dynamic information from acceleration signals. The ability to extract information about the dynamics of gait is exemplified with a novel symmetry measure. The method presented here is based on the motion language approach. A method based on peak detection was chosen as a reference, which we compare to our method. A Gait Rite pressure sensitive mat was used to detect heel-strike and toe-off ground truths. Results show that the proposed approach is as accurate as, more robust than, and conveys more information than the reference method.

  • 88.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Eklund, Helene
    Sahlgrenska Academy, Göteborg, Sweden.
    Zügner, Roland
    Sahlgrenska Academy, Göteborg, Sweden.
    Tranberg, Roy
    Sahlgrenska Academy, Göteborg, Sweden.
    Assessment of Gait Symmetry and Gait Normality Using Inertial Sensors: In-Lab and In-Situ Evaluation2013In: Biomedical Engineering Systems and Technologies: 5th International Joint Conference, BIOSTEC 2012, Vilamoura, Portugal, February 1-4, 2012, Revised Selected Papers / [ed] Joaquim Gabriel et al., Heidelberg: Springer Berlin/Heidelberg, 2013, p. 239-254Chapter in book (Refereed)
    Abstract [en]

    Quantitative gait analysis is a powerful tool for the assessment of a number of physical and cognitive conditions. Unfortunately, the costs involved in providing in-lab 3D kinematic analysis to all patients is prohibitive. Inertial sensors such as accelerometers and gyroscopes may complement in-lab analysis by providing cheaper gait analysis systems that can be deployed anywhere. The present study investigates the use of inertial sensors to quantify gait symmetry and gait normality. The system was evaluated in-lab, against 3D kinematic measurements; and also in-situ, against clinical assessments of hip-replacement patients. Results show that the system not only correlates well with kinematic measurements but it also corroborates various quantitative and qualitative measures of recovery and health status of hip-replacement patients

  • 89.
    Sathiamoorthy, Karthick
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Ahmed, Tanjim
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Construction and Validation of a White Light Interferometer2011Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    White light interferometry is a well-developed and very old technique for optical measurements. The thesis describes the design of a vertical scan interferometer system to study the surface topography of surfaces down to nanometers. The desired properties of the system are its simplicity, portability and compact size, making it suitable for use in general labs and for educational purposes. By acquiring a sequence of images of the deformed fringe pattern, the surface topography can be observed, giving greater understanding of the surface roughness.

    The principle behind the system is coherence peak sensing where the resulting fringe pattern of the object gets changed in accordance with its surface topography. To accomplish this, individual components of the interferometer were studied and a prototype was built in the lab. A series of experiments were performed which validate the working of the system. The results of the validation which are produced in the report give the accuracy of the system. The output from the prototype interferometer is processed by MATLAB to decode the surface topography of the object under measurement. The design of the prototype is also discussed. Possible application of this device for sensing the surface topography of a cylindrical object is also put forward.

    Even-though the white light interferometer is more common, making them simple and cost effective will be more advantageous for the whole research community.

  • 90.
    Saveski, Stefan
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Venturi Rios, Jack Peter
    Halmstad University, School of Business, Engineering and Science.
    Smart Heating System for Residential Apartments2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    HFAB is always striving to satisfy their customers energy demand and at the same time followdirectives within the company, where saving a certain amount of energy every year is included.For this reason, the heating system in their apartments is set to deliver about 21ºC. However, thereare some customers who feel that 21 °C is not warm enough, and therefore choose to plug in anelectrical radiator to raise the temperature. This solution often results in an expensive electricitybill and a poorly optimized temperature increase, due to the manner of how the mechanicalthermostats are configured by the landlord. Thus, the aim of this study was to find a solutionsystem for HFAB where the customers had the option to pay for the extra heat in addition to the 21°C, which in turn would lead to lower electricity consumption and cost for the consumers.To achieve this goal, test methods were created to acquire temperature data from various solutionsystems, provided by different companies and also from the current solution that the customershave been using. Calculations about how much heat (power) was needed to achieve temperaturesabove 21ºC in a room were made. Cost evaluations of the electricity consumed by the solutionsystems and different heat packages were also estimated.The study showed that, the temperature set range value from digital thermostats was higher (upto 28°C) compared to the mechanical ones (21ºC) when such solution systems were installed inthe hot-water radiators. That allowed the use of an electrical radiator in a room to raise thetemperature without shutting the hot-water radiators off. When it comes to the electricityconsumption, one test showed that the customer had an option to save up to 42% of the electricalcost when using these solution systems. The indicated cost saving has been possible due to theautomatically operation of the electrical radiator via wireless relays.

  • 91.
    Siddiqui, Muhammad Saad
    et al.
    Halmstad University. Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Iqbal, Tahseen
    Halmstad University. Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Development of PDI plates for Industrial Applications2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The aim of this Master’s Degree thesis project is to design and develop point diffraction interferometer plates. In this project the PDI plates are re-designed, changing the design which was used in previous projects in Halmstad University. The transparency of PDI plates can be controlled by coating them with NiCr film. Firstly, four plates with coating of different thickness of NiCr were developed. The relationship between transmittance and the thickness of NiCr was established by testing these plates for transmittance and reflectance with the help of a laser and an optical power meter.

    The absorption coefficient of clear substrates and reflection of light is also taken into account to achieve the correct results. The parameters like the diameter of semi-transparent area around the pinholes and the size of pinholes is chosen after fully understanding its application. The lay-out and description of design is also included in the report.

  • 92.
    Sidén, Göran
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Development of New Wind Power in Falkenberg2010Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Within Energy in Minds H-Uni has made a scientific study of the technology, practicability and potential of running cogeneration plants fuelled with rape-seed oil on farms and rural industries. As the cost for the made investigations were lower than planned, three additional studies on topics and activities carried out within Energy in Minds has been made.Within Energy in Minds the municipality of Falkenberg has realized 5 new turbines of 2.3 MW each by the sea shore of Falkenberg. This wind power park gives valuable experience for the planning of the future expansion of wind power, especially for the planned off-shore park with 30 turbines som e 8 km out in the sea.Falkenberg has since the 80-ties actively contributed to the utilisation of wind power in Sweden, both in terms of careful planning of where and how wind turbines should be placed in the landscape but also in terms of participating in the technical competence and manufacturing of turbines.

  • 93.
    Sidén, Göran
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS).
    Utveckling av nya vindkraftverk i Falkenberg2010Report (Other (popular science, discussion, etc.))
  • 94.
    Solberg, Amanda
    et al.
    Halmstad University, School of Information Technology.
    Ohrzén, Christoffer
    Halmstad University, School of Information Technology.
    Projektering av allmänt lokalnät i landsbygdsmiljö med analys av kapacitivaströmmar2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A general local powerline has implemented to mimic a lifelike powerline build around 1960s in thecountryside. Since reconstruction is needed a new projection is made of the area to improve the powerquality. The projection includes the old transmission lines will be replaced with underground powercables to make it weatherproof. The implication of underground power cables leads to smaller distancebetween the phases which generates greater capacitance. Due the increase will make the capacitivecurrents greater as well which affect the power quality for the costumers in the area.

    The projectionmust be adapted to the increase of earth fault currents which the capacitive currents contribute. The regeneration of the old and new power lines consists a sketch of terrain, merge of the powerconsumption, electrical fuses, line diagram, sizing transformers and right dimensions of cables. Calculations on capacitive fault current, voltage drop as well as neutral grounding reactor (a resistanceparallel with an inductor) was executed. Calculations of the powerline followed Swedish standard andthe neutral ground reactor after the norms of Swedish electrical industry.

    Regard to the projection, including underground cables, the capacitive fault currents increased with 46,75 times compared to transmission powerlines at 10 kV. Calculations of the neutral ground reactorresulted in 5,25 Henry for the inductor and 1154 Ohm for the resistor to compensate the gain. The conclusion is that weatherproofing the powerline at 10 kV leads to compensating otherwise the powerquality and selectivity will be affected. That result in a more expensive arrangement cost forunderground cables compared to transmission.

  • 95.
    Sopi, Jeton
    Halmstad University.
    NFC Door Lock2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 96.
    Sporrong, Kristofer
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Harrysson, Mattias
    Halmstad University, School of Business and Engineering (SET).
    Elektrisk integrering och projektering av förnybar energi i svagt lokalt elnät2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    To achieve a reliable and qualitative power conversion from the wind into electric power, a variety of factors and demands need to be obtained. Climatological and technological factors requires proper dimensioning and adjustment of the conversion technology, to harvest the greatest possible amount of energy and to be converted in a reliable and energy efficient way, that windmill owners, power grid owners require. The wind is as familiar an unpredictable power supply. The variations in intensity over time could mean a number of drive optimization problems with after-effects of the wind turbine, power grid and load. The consequences may depend on which type of technology that is installed in the different parts of the energy system. The area's power grid and varying power needs with characteristics over time, also has a significant importance. The turbulent wind gives deviations of voltage and power flow, especially in various extreme situations in weak power grids. Good interaction between the wind turbine and power grid with varying active and reactive power demand for the energy users, provides conditions for a good power quality and thus, an optimal and safe operation with few interruptions over time. It can be, and often is the mechanics, electro-technical choices in the wind turbine and associated electrical systems that play a critical role in how profitable installation is during the wind turbines technological life. The power grid owner strives for a good interaction between the power grid and electrical generation which rise for few faults between interruptions and errors. In the branch this is known as "Mean time between failures" MTBF. 

    According to the Swedenergy, harmonics, slow and fast voltage variations including required short-circuit power should be investigated and compared with those requirements and terms that prevails with electrical integration of power into the grid. The feasibility study has concluded two suitable power connection proposals including wind mapping research, later in this report it is described and suggested two related Smart Grid variants with energy storage for the two power connection proposals in the existing weak local grid. 

  • 97.
    Sprei, Frances
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Englund, Cristofer
    RISE Viktoria, Gothenburg, Sweden.
    Habibi, Shiva
    Chalmers University of Technology, Gothenburg, Sweden.
    Pettersson, Stefan
    RISE Viktoria, Gothenburg, Sweden.
    Voronov, Alexey
    RISE Viktoria, Gothenburg, Sweden.
    Wedlin, Johan
    RISE Viktoria, Gothenburg, Sweden.
    Engdahl, Henrik
    Nimling AB, Askim, Sweden.
    Comparing electric vehicles and fossil driven vehicles in free-floating car sharing services2017Conference paper (Refereed)
    Abstract [en]

    In recent years, free-floating car sharing (FFCS) services have been offered as a more flexible option compared to traditional car sharing. FFCS allows users to pick up and return cars anywhere within a specified area of a city. These can be either electric or fossil driven vehicles. We analyze the difference in usage of these two types of vehicles. The analysis is based on a dataset consisting of vehicle availability data sampled between 2014 and 2016 for 9 cities with EVs in the FFCS fleet. We find that there is no statistical difference in how EVs and fossil driven FFCS vehicles are used. When it comes to charging of EVs two main strategies are identified: widespread “slow charging” versus tailored fast-charging.

  • 98.
    Stude, Joan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Design and Implementation of an Ion Beam Profiling System2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The work describes the development of a reliable device for profiling anion beam in the intensity cross section. A sensor head consisting of a Faradaycup in combination with a Channel Electron Multiplier was designedand built together with electronics including power supply and front endelectronics. The design was chosen considering financial and long term lifeaspects. Testing, first calibration and error analysis were done using the ionbeam facilities where the unit is supposed to be installed permanently. Theprofiling system performed as designed and the profile of the ion beam couldbe measured reliably with an accuracy down to the femto ampere range.

  • 99.
    Sun, Gao
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    ISO26262 impact on vehicle level variant handling for embedded systems testing2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    ISO 26262 is an international standard about functional safety published on 2011, aiming to avoid failure in safety related electrical and electronic systems in passenger cars. A corresponding standard for heavy vehicles is expected to be published in a few years’ time. In order to be well-prepared, the heavy vehicle manufacturer Scania decides to start investigating what impact ISO26262 can bring.

    At Scania, modularization is one of the most important features of the product, which means several modules can be combined together into a vehicle in a variety of ways, so that highly configurable products can be provided for the customer. Huge number of unique module combinations bring big challenges to systems integration testing department REST/I in Scania because of limited time and resource availability for testing. Nowadays, people in REST/I deal with the variant mainly based on human experience, which is quite difficult to obtain the exact complete variant information and concrete testing coverage. In order to fulfill the requirement related with variant handling in ISO26262, better variant handling methods are proposed in this thesis, which can mainly be divided into two parts: method for variant generating and method for configuration selecting. To simplify the implementation work of this thesis, only the ECU components are focused on (other components such as sensors are ignored), and the risk-based feature is not added to the configuration selecting. Variant generating is to generate variant information from Allocation Element Diagram in Sesamm database systematically. According to the generated variant information, the configuration can be selected automatically by using Greedy best-first-search algorithm based on the proposed testing coverage metrics. Since all these work can be done automatically by computer, REST/I not only can work more efficiently by saving a lot of labor resource, but also can avoid mistakes caused by anthropogenic factors. However, not all the data needed for the automation are existed today, so the suggestions for consummation of the data to be ready for implementing the proposed methods are also mentioned in this thesis.

  • 100.
    Svendsen, Toni
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    End of line test: En studie av företaget Emotrons linjetestning i produktionen2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Emotron is a company specialised in developing, producing and marketing equipment to con-trol, monitor and protect processes and machinery driven by electric motors, with an applica-tion focus. Examples of uses for their products are fans, pumps, lifts and cranes.

    The project is to look at Emotrons end of line test. The company has seen that at the final test-ing there is a bottleneck that restricts the outflow and prevents an increase in the number of tested products.

    The purpose of this project is to review how Emotrons end-of-line test works today and if there is a possibility to make the test more efficient in such a way that the quality is not at risk, while increasing the outflow of tested products.

    The projects first step is to look at and analyse what is causing the bottleneck at the end-of-line. When the analysis is complete, the next step is to review whether there is a possibility to solve the bottleneck and if so in what way can this be done. Emotrons most overall objective of the project is to increase the outflow of the number of tested products without jeopardizing the quality.

    An analysis has been made on frequency inverters, soft starters and shaft power monitors. Fail reports for the year 2007 have been reviewed. Faults that have been detected have been sub-mitted by type and size. The testing has been divided into various phases of error. A time pre-cision has been established to show the time of the test stages. The distinction has been made to provide a picture of where and when errors occur during the testing.

    A logging test has been carried out on the largest frequency inverter types to determine the characteristics of frequency inverters when tested with load by today's test method. It has also carried out a logging test with an artificial load. An analysis is made on a test machine that is under construction, which today is called PEBB test.

    The conclusions to be drawn from the analyses and tests carried out, in order to meet the company's objectives, and answer the project's problem is that it is possible to make the end of line test more efficient. The end of line test can be more efficient by combining the strength of the PEBB test, which is its measurement equipment, with the artificial load method where the frequency inverter is tested as it is expected to serve at the final customer. This can in-crease the outflow of tested products and maintain Emotrons requirements for quality.

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