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  • 1.
    Abboud, Mohamad Moulham
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Simulation of 3ph induction motor in Matlab with VVVF starting method2016Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Nowadays, three-phase induction motors are widely used on industrial and other types of processes. Therefore, accurate knowledge of an induction motor performance is very essential to have an idea of its operation conditions. This study is a sequel of a previous one, where Direct and Soft starting methods of three-phase motors has been simulated and compared. As in the previous study, the theory behind this one is based on representing the real motor by aset of equations and values in Matlab, forming a corresponding idealistic motor in a way where all the physical effects are similar. The motor is started under three different frequencies in the VVVF method using supporting simulation of the current, torque, speed,efficiency and power factor curves. The results of the three starting methods are then discussed and compared.

  • 2.
    Aftab, Mohammad Adnan
    Halmstad University, School of Business, Engineering and Science.
    Biofuel, An alternative source for jet fuel in Aviation2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The transport industry is one of the fastest growing industries with the sector playing a significant role in negative impact on global warming and pollution through the emission of greenhouse gases. Aviation in particular, has enjoyed growth especially in the few decades. New airlines and aircraft manufacturers are coming up with different innovations and technologies to ensure they make the best possible environmentally friendly aircraft. The new main area of focus has been on how to come up with fuel that will reduce the greenhouse gas-emissions. The stakeholders in the same effort include developed nations like the United States, United Kingdom, Russia, France, Germany, and Canada among others. Energy providers as well as jet fuel suppliers are also making efforts to conserve the environment. The purpose of this thesis is to explore the area of biofuel in aviation by looking into various stakeholders involved in the efforts of the transition from fossil fuel to biofuel. The conclusion of this thesis is that biofuels are viable options in the aviation industries since there have been positive results in the tests made. 

  • 3.
    Ahlbäck, David
    Halmstad University, School of Business, Engineering and Science.
    KONCEPTANALYS OCH DRIFTFALLSOPTIMERING AV "FREEPOWER – SOLAR BOAT"2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report aims to analyse the concept of Bjurtech AB:s ongoing development project “Freepower - Solar Boat”. Main focuses are technical optimization and usability from an end user perspective. Bjurtechs idea is to build an electric-powered 5-meter boat charged by integrated photovoltaic cells. The project´s intended pilot market is Sri Lankas coastal fishing fleet. A version for the Scandinavian market is also under consideration and both concepts are analysed in this report. Initially a 4.5-meter prototype was built and tested to try the concept in practise. Methods used are computer simulations in Matlab based on data collected from trail runs with the prototype combined with weather data from Sri Lanka and Sweden. The data and simulations were then used to try to determine whether the concept works for the intended target markets, as well as how the assumed user profiles affect usability and technical deterioration such as battery life. The approach used was to try to determine how to maximize the availability of the system in regards to battery charge level over the whole year at the same time as maximizing distance and boat speed per day. The systems CO2 emissions were then compared to an equivalent petrol-powered boat with the same amount of running hours over 25 years. The main findings of the study are, provided 12 to 14.5 nautical miles is regarded as a sufficient daily distance at 3 to 3.7 knots boat speed, that the system can deliver a high level of availability all year around for fishing operations in Sri Lanka. Considering the demand for daily availability is not as high for the assumed recreational use in Scandinavian markets the system is deemed to perform at a satisfactory level at these latitudes as well. The CO2 comparison showed a significant emissions decrease in the case of year around operations in Sri Lanka. In Scandinavia a reduction is obtained if there are a sufficient amount of operating hours per year. An increase of the installed rated power, Wp, was found to be the most cost efficient way of improving overall performance and that the prototypes photovoltaics of 580 Wp should in both the Sri Lankan and Scandinavian case be increased to a minimum of 800 Wp. Finally it was concluded that user awareness of how system operation impacts battery life can be of significant importance for a positive environmental result and long technical lifetime.

  • 4.
    Ahmed, Rizwan
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Abbas, Shahid
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Electrical and Optical Characteristics of InP Nanowires based p-i-n Photodetectors2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Photodetectors are a kind of semiconductor devices that convert incoming light to an electrical signal. Photodetectors are classified based on their different structure, fabrication technology, applications and different sensitivity. Infrared photodetectors are widely used in many applications such as night vision, thermal cameras, remote temperature sensing, and medical diagnosis etc.

     

    All detectors have material inside that is sensitive to incoming light. It will absorb the photons and, if the incoming photons have enough energy, electrons will be excited to higher energy levels and if these electrons are free to move, under the effect of an external electric field, a photocurrent is generated.

     

    In this project Fourier Transform Infrared (FT-IR) Spectroscopy is used to investigate a new kind of photodiodes that are based on self-assembled semiconductor nanowires (NWs) which are grown directly on the substrate without any epi-layer. The spectrally resolved photocurrent (at different applied biases) and IV curves (in darkness and illumination) for different temperatures have been studied respectively. Polarization effects (at low and high Temperatures) have been investigated.  The experiments are conducted for different samples with high concentration of NWs as well as with lower concentration of NWs in the temperature range from 78 K (-195ºC) to 300 (27ºC). These photodiodes are designed to work in near infrared (NIR) spectral range.

     

    The results show that the NW photodetectors indeed are promising devices with fairly high break down voltage, change of photocurrent spectra with polarized light, low and constant reverse saturation current (Is). The impact of different polarized light on photocurrent spectra has been investigated and an attempt has been made to clarify the observed double peak of InP photocurrent spectrum. Our investigations also include a comparison to a conventional planar InP p-i-n photodetector.

     

  • 5.
    Alhamarna, Ahmed
    et al.
    Halmstad University, School of Information Technology.
    Kjellgren, Simon
    Halmstad University, School of Information Technology.
    IDENTIFIERING AV ELEKTRONIKSKROT2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is the result of a survey carried out by two students at Halmstad University. The study was conducted at the request of the recycling company, with the purpose to explore opportunities for streamlining the screening pro- cess of electronic waste products. The question that was asked was if RFID could be used for identification of the scrap. The project members started their work to investigate if RFID was the best identification method where the advantages and disadvantages of various automated systems were com- pared. The conclusion drawn was that RFID could be a viable solution in the future, provided that manufacturers of electronics integrate RFID tags into their products. Given that increasingly more producers are using RFID to locate and identify their products during production and the falling price of passive tags, it is possible that labeling products with RFID tags could become a standard, both for more efficient logistics and a more efficient re- cycling process. 

  • 6.
    ALRimawi, Mohammed
    Halmstad University, School of Information Technology.
    Doppler Wheel for Emulation of Automotive Radar Target2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Automotive radar is an emerging field of research and development. Technological ‎advancements in this field will improve safety for vehicles, pedestrians, and ‎bicyclists, and enable the development of autonomous vehicles. Usage of the ‎Automotive radar is expanding ‎in car and road areas to reduce collisions and ‎accident. Automotive radar ‎developers face a problem to test their radar sensor in ‎the street since there are a lot of interferences ‎signals, noise and unpredicted ‎situations. This thesis provides a part of the solution for this problem by designing a ‎device can demonstrate a different speeds value. This device will help the developer ‎to test their radar sensor inside an anechoic chamber room that provides accurate ‎control of the environmental conditions. This report shows how to ‎build the ‎measuring setup device, step by step to demonstrate the people and vehicle’s speed ‎‎in the street by a Doppler emulator using the wheel for millimetre FWMC radar. ‎Linear speed system needs a large space for testing, but using the rotational wheel ‎allow the developer to test the radar sensor in a small area. It begins with the wheel ‎design specifications and the relation between the ‎rotational speed (RPM) of the ‎wheel and the Doppler frequency. The Doppler ‎frequency is changed by varying the ‎speed of the wheel. Control and power circuit ‎was carefully designed to control the ‎wheel speed accurately. All the measuring ‎setup device parts were assembled in one ‎box. Also, signal processing was done by ‎MATLAB to measure the Doppler frequency ‎using millimetre FMCW radar sensor. ‎The measuring setup device was tested in the ‎anechoic chamber room for different speeds. the ‎manual and automatic tests show ‎good results to measure the different wheel speeds ‎with high accuracy.‎

  • 7.
    Alvarado, Cristian
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Ibrahim, Ayad
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Fjärrstyrning av videokamera2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On some occasions it may be inappropriate with a cameraman behind the camera. In somecases there is no cameraman available or it is a smaller event, like a family celebration, to befilmed. It can also be difficult for a cameraman to shoot from certain angles. One solution forthis kind of situations can be to remotely control the camera movements. There are thosekinds of solutions on the market today but they either address professional filmmakers or thefunctionality is limited, for example by the absence of wireless remote control.This project aims to develop a solution to the problem with absence of wireless remote controland also a solution with more flexibility and less complexity than today’s solutions. The maindifference between this and existing solutions is the use of Bluetooth technology ascommunication between the devices. The project resulted in a solution consisting of twounits; one operating unit where the camera is mounted and a remote unit for control of theoperating unit. The remote unit is managed by the filmmaker. The remote unit consist of anAndroid application on a smart and which communicates with the control unit via Bluetooth.

  • 8.
    Amin, Mohammed Nurul
    et al.
    Halmstad University, School of Information Technology. amin _ m 154@yahoo.com.
    Alam, Md. Obaidul
    Halmstad University, School of Information Technology. obai_ aust@yahoo.com.
    Landin, Lars
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Electrical and optical characteristics of Infrared Photodetectors based on InP nanowire2011In: 14th International Conference on Computer and Information Technology, ICCIT 2011, p. 629-634, article id 6164864Article in journal (Refereed)
    Abstract [en]

    High speed photodetectors are most sophisticated optoelectronic devices, because it has high photo sensitivity, and allow a large wavelength range of detection as a receiver from 750 nm to 1.3-1.55 μm in the optical communication system. Since the last decade, the electrical and optical characteristics of photodetectors have been investigated to improve their performance and price. We have worked on two different type of infrared photodetectors based on nanowire. One photodetector was p-n photodiode, and the other one was p-i-n structure. We investigated the detector performance at 77K-300K temperature corresponding with wavelength in darkness and under illumination as regarding breakdown voltage, sensitivity, and quantum efficiency. We have also compared the differences between the two photodetectors performance characteristics. © 2011 IEEE.

  • 9.
    Amin, Muhammed Nurul
    et al.
    Halmstad University, School of Information Technology. amin_m154@yahoo.com.
    Alam, Md. Obaidul
    Halmstad University, School of Information Technology. obai_aust@yahoo.com.
    Electro-optical characterisation of inp nanowire based p-n, p-i-n infrared photodetectors2012In: Journal of Communications, ISSN 1796-2021, E-ISSN 1796-2021, Vol. 7, no 11, p. 808-820Article in journal (Refereed)
    Abstract [en]

    High speed photodetectors are most sophisticated optoelectronic devices, because it has high photo sensitivity, low noise, high conversion efficiency and allow a large wavelength range of detection from 750 nm to 1.3-1.55 pm in the optical communication system. These photodetector is used as an optical receiver which transforms the energy of optical radiation such as infrared, visible or ultraviolet into the electrical signal that is convenient for measurement. Since the last decade, the electro-optical characterisation of photodetectors has been investigated to improve their performance and price. In this paper, we are going to discuss the characterisation of the two different type infrared photodectors based on nanowire that we have worked on our project. One photodetector is p- n nanowire structure, and another is p-i-n structure. Both photodetectors is worked based on internal photoelectric effect and on the theory of p-n junction. We investigated the detector performance at 77K-300K temperature corresponding with wavelength in darkness and under illumination as regarding breakdown voltage, sensitivity, and quantum efficiency. We have also compared the differences between the two photodetectors performance characteristics. © 2012 ACADEMY PUBLISHER.

  • 10.
    Andersen, Niklas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ismail, Zahir
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Solel från ljudbarriär: längs Annetorpsvägen i Hyllie, Malmö2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    City of Malmö has ambitions for the district Hyllie to become a demonstrative area ofsustainable urban development. As a part of this the following report aims to investigate the potential in using noise barriers combined with photovoltaics along Annetorpsvägen to generate solar electricity. To quantify the losses that shadows from buildings along the roadmight cause, a 3D-model of the area was constructed in SketchUp. This digital model made it possible to simulate shadows and how they change over the year. A reference model of a photovoltaic noise barrier (PVNB) was constructed and used to find the dates on which the solar cells are shadowed depending on building heights and positioning of the barrier.

    The results show that two lengths with a total distance of 400 meters is appropriate for applying photovoltaic noise barriers. Along distance A, a PVNB with a total capacity of 19 kWp is expected to generate 18 000 kWh per year assuming realistic shadowing, which equals 6% losses compared to production without shadows. The PVNB along distance B with installed capacity of 37 kWp has no considerable problems with shadowing and is expected to generate 37 500 kWh per year. This gives a total production of 56 500 kWh per year.

    The combined investment costs (excluding costs for the actual noise barrier) for both power plants are assumed to be approximately one million SEK. Expected economical outcome is a negative capital value after 25 years, although a change of critical factors such as investment aid, investment cost, electricity prices and cost of capital may result in a more positive outcome. Production losses from shadowing and dirt seem to have a minimal effect on the outcome

    Despite uncertainty in the economical outcome, realizing the project would have several other positive effects such as reduction of carbon dioxide emissions and a positive impact on the public view of renewable energy.

  • 11.
    Andersson, Gustav
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ericsson, Emil
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Dark Ages Interferometer (DALI) Deployment Rover: Energy System2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The cosmic “Dark Ages” is the cosmic era between the epochs of recombination of cosmic microwave background and the formation of the first stars. The only signal from this epoch is from neutral hydrogen, which could represent one of the richest data sets in cosmology. In order to extract this data, NASA/JPL has proposed a rover mission to the farside of the moon to deploy several radio arrays. Here the arrays would gather data undisturbed by human interference. This thesis examines the possibility of using photovoltaic and electric batteries as an energy solution for a rover on the moon. The requirement for such a system to survive on the moon is discussed in a literature study. A proof of concept simulation using a Simulink model has also been done. The thesis concludes that a rover can deploy the radio array using solar energy. It would be able to hibernate through the night using radioisotope heating. It would need to wait for its batteries to charge before each night.

  • 12.
    Andersson, Robin
    Halmstad University, School of Business and Engineering (SET).
    Electric power quality in low voltage grid: Office buildings and rural substation2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The modern society uses more and more electronic devices needed to being able to function together. This put higher demands on the electrical grid together with that the typical load have changed from the past. Therefore utility companies are obliged to keep the voltage within certain limits for this to function. What exact these limits have been have not always been clear since they have not been gathered in one single document. 

    This thesis is a cooperation with Kraftringen who also has been the initiator. Kraftringen would like to become more proactive in their work regarding electric power quality. For becoming more proactive continuously measurements have to be done but the locations have to be carefully selected in the beginning to get a wider perspective of the grid.

    Energy markets inspectorate (EI) is supervisory of the electric power quality in Sweden and since 2011 they have published a code of statutes (EIFS 2011:2 later 2013:1) intended to summarize limits on voltage. Some of the electrical power quality aspects are not mentioned in EIFS 2013:1 and standards have to be used to find limited values. Flicker and interharmonics are not mentioned in EIFS 2013:1 and for values on flicker the standard SS-EN 50160 has to be used and for interharmonics the standard SS-EN 61000-2-2 state limit values. Besides all this there are standards with stricter limits than EIFS 2013:1 e.g. for total harmonic distortion on voltage were SS-EN 61000-2-2 suggest 6 % instead of 8 %.

    Three different field studies have been conducted in order to get some perception of the present situation regarding electric power quality. Two measurements were conducted on a typical office building because they represents a large part of the typical load in Lund. The third measurement was conducted on a substation in a rural area to get a perception of the situation outside urban areas. 

    These measurements shown that the overall electric power quality was within given limits according to EIFS 2013:1 and different standards. However, conducted measurements shown some interesting results. Both the typical office buildings have a slightly capacitive power factor which results in that the voltage inside the building is going to be slightly higher than at the substation. Since the voltage level at the measured urban substation was above nominal voltage level with about 2-5 % this could be problematic. Another eventual problem with a load with a capacitive power factor is resonance with the inductive parts of the grid like transformers leading to magnified harmonic levels.

    It is suggested that Kraftringen expand their number of permanent electric power quality measurement locations to get a better overview of the present situation. The best suited locations to start with are such that have received complaints earlier, preferably measured on the low voltage side of the transformer for also register the amount of zero sequence harmonics. Next step in the measurement expansion would be substations known to be under higher load than others or substations with a PEN-conductor in a smaller area than the phase conductors, supplying a typical office load with high amounts of third harmonics and unbalance. From this it would be appropriate to spread out the measurement locations geographically to better get to know the grids behaviour. 

  • 13.
    Aramrattana, Maytheewat
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). The Swedish National Road and Transport Research Institute (VTI), Göteborg, Sweden.
    A Simulation-Based Safety Analysis of CACC-Enabled Highway Platooning2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cooperative Intelligent Transport Systems (C-ITS) enable actors in the transport systems to interact and collaborate by exchanging information via wireless communication networks. There are several challenges to overcome before they can be implemented and deployed on public roads. Among the most important challenges are testing and evaluation in order to ensure the safety of C-ITS applications.

    This thesis focuses on testing and evaluation of C-ITS applications with regard to their safety using simulation. The main focus is on one C-ITS application, namely platooning, that is enabled by the Cooperative Adaptive Cruise Control (CACC) function. Therefore, this thesis considers two main topics: i) what should be modelled and simulated for testing and evaluation of C-ITS applications? and ii) how should CACC functions be evaluated in order to ensure safety?

    When C-ITS applications are deployed, we can expect traffic situations which consist of vehicles with different capabilities, in terms of automation and connectivity. We propose that involving human drivers in testing and evaluation is important in such mixed traffic situations. Considering important aspects of C-ITS including human drivers, we propose a simulation framework, which combines driving-, network-, and traffic simulators. The simulation framework has been validated by demonstrating several use cases in the scope of platooning. In particular, it is used to demonstrate and analyse the safety of platooning applications in cut-in situations, where a vehicle driven by a human driver cuts in between vehicles in platoon. To assess the situations, time-to-collision (TTC) and its extensions are used as safety indicators in the analyses.

    The simulation framework permits future C-ITS research in other fields such as human factors by involving human drivers in a C-ITS context. Results from the safety analyses show that cut-in situations are not always hazardous, and two factors that are the most highly correlated to the collisions are relative speed and distance between vehicles at the moment of cutting in. Moreover, we suggest that to solely rely on CACC functions is not sufficient to handle cut-in situations. Therefore, guidelines and standards are required to address these situations properly.

  • 14.
    Aramrattana, Maytheewat
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Modelling and Simulation for Evaluation of Cooperative Intelligent Transport System Functions2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Future vehicles are expected to be equipped with wireless communication tech- nology, that enables them to be “connected” to each others and road infras- tructures. Complementing current autonomous vehicles and automated driving systems, the wireless communication allows the vehicles to interact, cooperate, and be aware of its surroundings beyond their own sensors’ range. Such sys- tems are often referred to as Cooperative Intelligent Transport Systems (C-ITS), which aims to provide extra safety, efficiency, and sustainability to transporta- tion systems. Several C-ITS applications are under development and will require thorough testing and evaluation before their deployment in the real-world. C- ITS depend on several sub-systems, which increase their complexity, and makes them difficult to evaluate.

    Simulations are often used to evaluate many different automotive appli- cations, including C-ITS. Although they have been used extensively, simulation tools dedicated to determine all aspects of C-ITS are rare, especially human fac- tors aspects, which are often ignored. The majority of the simulation tools for C-ITS rely heavily on different combinations of network and traffic simulators. The human factors issues have been covered in only a few C-ITS simulation tools, that involve a driving simulator. Therefore, in this thesis, a C-ITS simu- lation framework that combines driving, network, and traffic simulators is pre- sented. The simulation framework is able to evaluate C-ITS applications from three perspectives; a) human driver; b) wireless communication; and c) traffic systems.

    Cooperative Adaptive Cruise Control (CACC) and its applications are cho- sen as the first set of C-ITS functions to be evaluated. Example scenarios from CACC and platoon merging applications are presented, and used as test cases for the simulation framework, as well as to elaborate potential usages of it. Moreover, approaches, results, and challenges from composing the simulation framework are presented and discussed. The results shows the usefulness of the proposed simulation framework.

  • 15.
    Aramrattana, Maytheewat
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Larsson, Tony
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jansson, Jonas
    The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Nåbo, Arne
    The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    A simulation framework for cooperative intelligent transport systems testing and evaluation2019In: Transportation Research Part F: Traffic Psychology and Behaviour, ISSN 1369-8478, E-ISSN 1873-5517, Vol. 61, p. 268-280Article in journal (Refereed)
    Abstract [en]

    Connected and automated driving in the context of cooperative intelligent transport systems (C-ITS) is an emerging area in transport systems research. Interaction and cooperation between actors in transport systems are now enabled by the connectivity by means of vehicle-to-vehicle and vehicle-to-infrastructure (V2X) communication. To ensure the goals of C-ITS, which are safer and more efficient transport systems, testing and evaluation are required before deployment of C-ITS applications. Therefore, this paper presents a simulation framework—consisting of driving-, traffic-, and network-simulators—for testing and evaluation of C-ITS applications. Examples of cooperative adaptive cruise control (CACC) applications are presented, and are used as test cases for the simulation framework as well as to elaborate on potential use cases of it. Challenges from combining the simulators into one framework, and limitations are reported and discussed. Finally, the paper concludes with future development directions, and applications of the simulation framework in testing and evaluation of C-ITS. © 2017 Elsevier Ltd. All rights reserved.

  • 16.
    Aramrattana, Maytheewat
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES). The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Larsson, Tony
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Jansson, Jonas
    The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Nåbo, Arne
    The Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    Cooperative Driving Simulation2016In: Proceedings of the Driving Simulation Conference 2016, 2016, p. 123-132Conference paper (Refereed)
    Abstract [en]

    For a few decades, driving simulators have been supporting research and development of advanced driver assistance systems (ADAS). In the near future, connected vehicles are expected to be deployed. Driving simulators will need to support evaluation of cooperative driving applications within cooperative intelligent transportation systems (C-ITS) scenarios. C-ITS utilize vehicle-to-vehicle and vehicle-to-infrastructure (V2X) communication. Simulation of the inter vehicle communication is often not supported in driving simulators. On the other hand, previous efforts have been made to connect network simulators and traffic simulators, to perform C-ITS simulations. Nevertheless, interactions between actors in the system is an essential aspect of C-ITS. Driving simulators can provide the opportunity to study interactions and reactions of human drivers to the system. This paper present simulation of a C-ITS scenario using a combination of driving, network, and traffic simulators. The architecture of the solution and important challenges of the integration are presented. A scenario from Grand Cooperative Driving Challenge (GCDC) 2016 is implemented in the simulator as an example use case. Lastly, potential usages and future developments are discussed.

  • 17.
    Arashlouzadeh, Amir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Surface Roughness Measurment: Multi-bandFrequency Shift Interferometer based onPolarization Measurement2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Optical measurement techniques have been gaining ground for their vast applications in industry and scientific purposes. These techniques are beneficial comparing to the mechanical methods. Non-intrusive, robust, high accuracy and small measurement volume are some of the advantages of the optical metrology. However, these approaches are expensive. Interferometry is one of the most prominent principles of these optical measurements. It employs the study of fringe patterns in order to model surface roughness with a high precision up to nano-meter scale. In this thesis, we mainly focus on the multi-band frequency shifting interferometry based on polarization measurement for 3D surface modeling. The system has advantages such as it is very accurate and there is no need of a phase unwrapping algorithm. Like the conventional phase shifting interferometry, four intensity images are recorded for the four polarization states correspondingly and then the images are processed by MATLAB and the final results are provided. In this technique the need for three cameras and offset correction between the cameras has been revised and optimized by using only one camera. In the first setup trial, a fiber optic switch has been used which does not lead to the desired results and then the switch has been removed and the corresponding images are satisfactory.

  • 18.
    Assarsson, Fredrik
    et al.
    Halmstad University, School of Information Technology.
    Nilsson, Felix
    Halmstad University, School of Information Technology.
    Utredning av övertoners effekter på transformatorer2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is a study of how one of Halmstad Energi och Miljö Nät AB’s transformers is affected by current harmonics. The study is mostly about how much the transformer's nominal power must be derated. The study shows the theory of both what is harmonics, how harmonics affect transformers and calculation models for derating transformers. The methods used and compared for the transformer power write-down are factor K, which is described in SS-EN 50464-3 and K-factor, which is described in ANSI / IEEE C57.100.

    In order to realistically investigate how the different standards affect the transformer, three cases have been tested.

    • The mean effect of the harmonics over a month, based on collected measurement data.
    • The maximum effect of the harmonics over a month, based on collected measurement data.
    • The effects of harmonics if the harmonic levels increase in the future.

    The result of the study shows that in the cases based on measurement data the nominal power of the transformer should be reduced by about 6-17% for the K-factor method. For factor K, the figures are about 2.5-7.5%. However, the measurement data from all cases shows that the load rate of the tested transformer is far below the maximum impaired effect. If the amount of current harmonics would increase in the future, a write-down of 30% of the maximum effect is not unreasonable.

  • 19.
    Barkstedt, Patrik
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Bizzarri, Sandro
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Forensisk  analys av smartphones: - fokus på sociala medier2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dagens samhälle är trenden att fler och fler människor införskaffar smartphones för att när som helst kunna vara uppkopplade mot internet. Detta gör att informationen en smartphone hanterar och sparar är viktigare och mer intressant för båda sidorna av lagen. Med denna ökning av smartphones har användandet av applikationer till sociala medier så som facebook ökat.I denna rapport utreds det vad en facebookapplikation lagrar för typ av information efter den har använts och hur pass noga det går att kartlägga vart applikationen har används. För att kunna göra detta krävs först en utredning på vilka sätt de går att hämta ut information ifrån en smartphone. I denna rapport har det alltså utretts huruvida de går att utvinna samma information med hjälp av flera metoder och om de går att uppnå samma resultat med hjälp av en utvinning med de olika metoderna. Vid analys av den utvunna datan visar det sig att applikationen lagrade den intressanta datan i databasfiler. Allt från meddelanden och statusuppdateringar till platsdata sparades i dessa databasfiler, vilket gjorde att enheten gick att kartlägga.

  • 20.
    Behramaj, Fisnik
    et al.
    Halmstad University.
    Albinsson, Daniel
    Halmstad University.
    Modern Träningsmaskin2015Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    This project intends to solve the problem with a training machine with the aim of reducing injuriesamong users. The users themselves shall not be applying the weights on this so calledSmithmachine. The project's primary goal is to generate a force via a technical solution to createresistance on the bar that can be used for e.g. bench press. The project aims to create a safe exercisemachine designed for users regardless of age, gender or physical condition. The goal of the projectis to create a prototype of an already existing exercise machine but for a small fee. The method isapplicable to the project's testing and exploration of the area of knowledge concerning the study.The project team has gathered knowledge and facts from Internet sources and through conversationswith two lecturers: Hans-Erik Eldemark and Thomas Munther to then apply this information in theirwork. The project resulted in a modified exercise machine designed to produce weight via an ACmotor in which the user can select the weight of 5 kg range via an user-friendly interface. Theconclusion shows that the project is practisable, that all high-priority targets in the specifications aremet and that the group got the expected results of the project.

  • 21. Berg, Jacob
    et al.
    Landin, Niclas
    Kommunikationskort2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Raytelligence har utvecklat en radar som kan registrera rörelse och hjärtfrekvens hos människor. Datan från radarn skickas över Universal Serial Bus (USB) till en extern dator. För att produkten ska bli mer användarvänlig krävs en bättre kommunikationslösning. Projektet går ut på att implementera en trådlös kommunikation i form av bluetooth och Wireless Local Area Network (WLAN) som kan skicka datan från radarn trådlöst till en extern dator eller mobil enhet. I rapporten beskrivs de olika metoderna som använts för att åstadkomma den trådlösa kommunikationen. Det beskrivs passande gränssnitt, val av passande kommunikationsmodul, implementering och kalibrering av antenn, val av komponenter och olika sätt att motverka Elektromagnetisk Interferens (EMI) för att få bra förutsättningar för en Elektromagnetisk kompatibilitet (EMC)-certifiering. Resultatet av projektet är en produkt som bygger på kommunikationsmodulen RS9113 och Raytelligence radarkort.

  • 22.
    Bergholm, Johan
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Gallardo, Sascha
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Svensson, Jonny
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Positionering och Spårning av mobila enheter, ur ett IT–forensiskt perspektiv2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dagens Sverige så har de mobila enheterna en självklar plats i våra fickor, likväl som i vårt samhälle och i dess brottslighet, vilket gör att det sedan några år är att anse självklart att de även har en central roll i IT–forensiska utredningar inom våra polismyndigheter. Men vid sidan av konkreta bevis för begångna brott lagrar enheterna dessutom ofta data som kan användas för att spåra enheten, och därmed också dess brukare, över tid, vilket givetvis är av intresse av polismyndigheter men skulle även kunna vara av stort intresse för exempelvis försäkringsbolag och andra delar av den 'civila sektorn' som driver utredningar men som saknar polisens befogenheter. För att ge ett så brett användningsområde som möjligt fokuserar därför rapporten inte bara på datat som är tillgängligt från den faktiska enheten och hur de kan användas för spårning och positionering, utan försöker även på praktiskt väg undersöka i vilken grad dessa metoder kan utföras med allmänt tillgänglig mjuk- och hårdvara.

  • 23.
    Borg, Richard
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Svensson, Timmy
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Assistansrobot "Slangaren"2011Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This project is a step towards automatic firefighting. The goal is to decrease the number of personal injuries by replacing the human firefighter with robots or similar technical tools. Especially in very hostile environments due to risk of explosions or building collapse. A robot is easy to replace and can be maneuvered from a safe distance. The idea of the project comes from the company Drones Networking which aims for developing a totally autonomous firefighting system. The result of this project is a prototype of a robot which handles the hose during firefighting.

  • 24.
    Borgström, Roger
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Enesten, Daniel
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Uv-ljus som vattenrening i kylanläggning2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective with this project has been to purify water in the Aqua Interiör in Laholm proprietary water furniture using uv-light. These furnitures are rent out to customers to get moderately cold water, with or without sparkling. The water furnitures is directly connected to the water system. A problem with the water furniture is that it is not suitable for hospitals because there is an increased bacterial content in the water, however, below the prescribed limits. In hospitals there is a higher requirement for water quality. The objective with the uv-radiation is to solve this problem. A reactor has been developed in which the water is uv-radiated in a spiral made of quartz glass. A control system controls the radiation of the water and that no problem occurs during the radiation.A display with touch-function has been used to get an attractive way to present important information about lamp status and temperature inside the reactor. This is how the service personnel receive information on the lamp if it needs replacing or not. A log of the system was created to ensure that no unauthorized person would be able to delete the log data that is created. The touch-display made it a solid feeling of quality and new technology.The use of the uv filter has resulted in a positive result, with purified water. An ambition is that further development of this project will lead to a finished product that will be sold / out rented by Aqua Interiör i Laholm .

  • 25.
    BOZKURT, Ugur
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Aslan, Mustafa
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Assembly of a UAV: hardware design of a UAV2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis is dedicated to assemble the hardware system of a UAV (Unmanned Aerial Vehicle) in order to prepare the platform for an autonomous flight in the air for a given path through the pre-programmed check points. A UAV is an aircraft that contains sensors, GPS, radio system, servomechanisms and computers, which provide the capability of an autonomous flight without a human pilot in the cockpit. A stable flight requires sensing the roll, pitch, and yaw angles of aircraft. Roll and pitch angles were ensured by a sensor system of FMA Direct Company called co-pilot flight stabilization system (CPD4), which allows controlling ailerons and elevator manually.

    An autopilot is required for steering the aircraft autonomously according the GPS data and the establish waypoints that the airplane have to pass by. The GPS gives heading information to the autopilot, and this uses the information of the next waypoint to decide which direction to go. Hereby an autonomous flight is provided. In this project a lego mindstorm NXT was used as an autopilot that is product of LEGO Company [1]. The output of the autopilot is used to control the airplane servos to fly in the desired direction. A software and hardware interface was designed to allow the autopilot to receive the data from the co-pilot sensor and to transmit data to the co-pilot processor, which will finally steer the actuator servos. Experiments were performed with different parts of the system and the results reported.

  • 26.
    Calikus, Ece
    et al.
    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.
    Pinheiro Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Gadd, Henrik
    Halmstad University, School of Business, Engineering and Science. Öresundskraft, Helsingborg, Sweden.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    A data-driven approach for discovering heat load patterns in district heating2019In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 252, article id 113409Article in journal (Refereed)
    Abstract [en]

    Understanding the heat usage of customers is crucial for effective district heating operations and management. Unfortunately, existing knowledge about customers and their heat load behaviors is quite scarce. Most previous studies are limited to small-scale analyses that are not representative enough to understand the behavior of the overall network. In this work, we propose a data-driven approach that enables large-scale automatic analysis of heat load patterns in district heating networks without requiring prior knowledge. Our method clusters the customer profiles into different groups, extracts their representative patterns, and detects unusual customers whose profiles deviate significantly from the rest of their group. Using our approach, we present the first large-scale, comprehensive analysis of the heat load patterns by conducting a case study on many buildings in six different customer categories connected to two district heating networks in the south of Sweden. The 1222 buildings had a total floor space of 3.4 million square meters and used 1540 TJ heat during 2016. The results show that the proposed method has a high potential to be deployed and used in practice to analyze and understand customers’ heat-use habits. © 2019 Calikus et al. Published by Elsevier Ltd.

  • 27.
    Chaath, Alaaeddin
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science. PRIVATE.
    Improving the Design of Wind Turbine Plants: Future Design of Wind Turbine Plants2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Applying the new ideas developed by the present study on the current design of WTP can lead to satisfactory results and give flexibility in terms of producing more electrical power during periods of low/medium wind velocity. The innovative ideas and methods included in the present work reveal the features of the future renewable energy designs that could, in the few coming years, revolutionize the field of wind turbine designs worldwide. Also, increase the capacity factor significantly, since the application of these ideas in areas where wind class II and III blows have proven to be very effective. Especially, when compares the result of new ideas with the current wind turbine designs.

    Testing the innovative ideas regarding the future wind turbines on a current WTP achieved a good results in increasing electric energy production over the year. For example applies the new ideas on a WTP model Enercon (E-101) will achieve an annual increase around 20% of electric power generation (wind class II, Cp = 36), i.e. when wind speed is ranging from 0-10 m/s (Level C – option 02) the production improved at the highest value, reaching up to +46%. Also, in Level B the generation of electricity witnessed an increase up to 10% when the wind velocity being always between level C with a minimum of 10 meters per second and Level A (Level A is the maximum output value, which is changing from one turbine type to the other). 

  • 28.
    Chen, Kunru
    Halmstad University, School of Information Technology.
    Recurrent Neural Networks for Fault Detection: An exploratory study on a dataset about air compressor failures of heavy duty trucks2018Independent thesis Advanced level (degree of Master (Two Years)), 80 credits / 120 HE creditsStudent thesis
  • 29.
    Dahlgren, Patrik
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Heehrle, Emil
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Persson, Jim
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Analys av Örkelljunga Utbildningscentrums IT-miljö2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I dagens samhälle där tillgången till information är nästintill obegränsad och nätverkfinns överallt ökar kraven på IT-säkerhet. Gratis programvaror och information omhur man använder dessa finns enkelt tillgängliga för vem som helst på Internet idag.Då många av dessa programsviter har full support och de är mycket användarvänligainnebär det också att fler kan utföra intrång och attacker mot olika IT-miljöer utanatt behöva inneha expertis inom området. Ett hjälpmedel mot dessa hot ärpenetrationstesting, där man kan identifiera eventuella brister och sårbarheter i ettgivet IT-system.Den här rapportens mål har varit att utreda om Örkelljunga Utbildningscentrums ITsäkerhetstår i proportion till känsligheten på informationen som de innehar ochbehandlar.Detta har gjorts genom ett penetrationstest, där man på plats har skannat skolansnätverk efter sårbarheter och möjliga intrångsvägar.Därefter har sårbarheterna utvärderats och rankats efter hur kritiska de anses varaoch utifrån detta teoretiskt bevisat hur man som attackerare hade kunnat gå till vägaför att komma åt eller förstöra känslig information.Resultaten visade på ett flertal kritiska brister som vid närmare analys hade kunnatutnyttjas för att ta sig in i systemet och eventuellt komma åt känslig information.Slutsats blev därför att Örkelljunga Utbildningscentrums IT-miljö för närvarande intehar tillräcklig säkerhet i proportion till känsligheten på information som de innehar.

  • 30.
    Dalati, Fares
    et al.
    Halmstad University, School of Information Technology.
    Martinez Lopez, Pablo Enrique
    Halmstad University, School of Information Technology.
    Vital Sign Radar Redesign: Further Development of a Compact, Highly integrated 60 GHz Radar for Human Vital Sign Monitoring2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, thanks to the modern technologies, the human being has been able todevelop new techniques to solve problems present in the past. Regarding the medicalfield, it is common to use several apparatus in order to measure the vital signs. Themain drawback about the traditional methods employed for this purpose is that theyare invasive towards the patient. However, in this thesis it has been developed afurther design of a radar system so as to be able to measure these vital signs in awireless way.

    Based on a 60 GHz frequency modulated continuous wave radar chip, it has been ableto increase the performance of the measurements by adding a second radar chip.Because of this new feature, the radar system is now having a better precision byprocessing greater data matrix to analyse the targets positions and theirmeasurements. In addition, an enhanced MCU has been incorporated in order toavoid performance bottlenecks because it is necessary to handle the processing of thedata received by the two radar chips. Lastly, reducing the sweeping time (periodbetween the lowest frequency broadcast to linearly reach the highest frequencybroadcast) from 20 ms the previous design to 1 ms, which requires higher samplingrate to cover the fast sweep and provide higher flow of information that leads to fasterdetection process.

    A 3D design of the prototype has been designed to show the physical appearance itwould have once entering in production. The result is a compact and highlyintegrated radar system which will be able to monitor the heart beating andrespiration frequency of a human being in a range of ten meters.

  • 31.
    D'Ambrosio, Marco
    et al.
    Halmstad University, School of Business and Engineering (SET). Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Medaglia, Marco
    Halmstad University, School of Business and Engineering (SET). Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Vertical Axis Wind Turbines: History, Technology and Applications2010Independent thesis Advanced level (degree of Master (Two Years)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In  this  Master Thesis  a  review  of  different  type  of  vertical  axis  wind turbines (VAWT)  and  a preliminary investigation of a new kind of VAWT are presented.

    After an introduction about the historical background of wind power, the report deals with a more accurate analysis of the main type of VAWT, showing their characteristics and their operations. The aerodynamics of the wind turbines and a review of different type on generators that can be used to connect the wind mill to the electricity grid are reported as well.

    Several statistics are also presented, in order to explain how the importance of the wind energy has grown  up  during  the  last  decades  and  also  to  show  that  this development  of  the  market  of  wind power  creates  new  opportunity  also  for VAWT,  that  are  less  used  than  the  horizontal  axis  wind turbine (HAWT).

    In the end of 2009 a new kind of vertical axis wind turbine, a giromill 3 blades type, has been built in Falkenberg, by the Swedish company VerticalWind. The tower of this wind turbine is made by wood,  in  order  to  get  a  cheaper  and  more environment  friendly  structure,  and  a  direct  driven synchronous multipole with permanent magnents generator is located at its bottom. This 200 kW VAWT represents the intermediate step between the 12 kW prototype, built in collaboration with the Uppsala University, and the common Swedish commercial size of 2 MW, which is the goal of the company.

    A  preliminary  investigation  of  the  characteristics  of  this  VAWT  has  been done, focusing  in particular on the value of the frequency of resonance of the tower, an important value that must be never reached during the operative phase in order to avoid serious damage to all the structure, and on the power curve, used to evaluate the coefficient of power (Cp) of the turbine. The results of this investigation and  the steps  followed  to  get  them  are  reported.  Moreover  a  energy production analysis of the turbine has been done using WindPro, as well as a comparison with and older type on commercial VAWT.

  • 32.
    Davidsson, Martin
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Karlsson, Jonas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Mätning och analys av elkvalité2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 33.
    Druyts, Jan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Control induction motor by frequency converter: Simulation electric vehicle2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Summary

     Today we are probably on a point of change for the car industry. The last century was the century of vehicles with internal combustion engines. Fossil fuels were relative cheap, easy accessible and they have a high specific energy. The pollution and dependency on oil caused the last decade an increasing demand for alternatives. Alternatives for electric power plants and for car drives. Yet the turnover to hybrids is a fact and much research is done for pure electric vehicles. Research about the control of electric motors is by that become a hot topic.

    To simulate an electric vehicle drive with an induction motor, a frequency converter is needed. This combination of motor and converter led to many possible experiments. With a few experiments already done and a broad theoretical background report this thesis provides a good bundle of information to start with further experiments. The experiments can become even broader when a flywheel is added as mass inertia momentum and a DC source on the DC-link. Both elements contribute for a better simulation of an electric motor in an electric vehicle.

    What is described in this theoretical report about the combination of an induction motor and converter is only the tip of the iceberg. I had too less time to begin experimenting with the flying wheel. The DC-link voltage becomes ca. 540V. From the perspective of safety I could never work alone with the DC-link. Even with a companion it was too dangerous because the equipment of the Halmstad University is not made for such dangerous voltages. That’s why this thesis contains more theoretical background and less actual practical data.

  • 34.
    Ebers, Lucas
    et al.
    Halmstad University, School of Information Technology.
    Eriksson, Niklas
    Halmstad University, School of Information Technology.
    Projektering av lokalnät med fördjupning i selektivitet2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    In power system, when a local network with over head lines is replaced by a network laid underground, itchanges the characteristics of the material used and gives an opportunity for an updated sizing. The goal withthe project was to present a proposal of a reconstruction of a old local network to a modern local network andpresent a selective coordination plan for all the branches in the new network. The methods that are used isthe Velanders method for interleaver of the maximum power, sizing according to “SvenskStandard”(Swedish Standards) and curve fit of trip curves to present digital produced selective coordinationplan. The new underground local network delivers a better electrical quality, that fulfills the triggerconditions and obtains a good selective coordination.

  • 35.
    Emanuelsson, Petter
    Halmstad University, School of Information Technology.
    Metodframtagning för hastighetsberoende tester på stillastående bil2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 36.
    Eriksson, Hannes
    et al.
    Halmstad University.
    Brange Sollie, Ivan
    Halmstad University.
    Wireless IO: A wireless accessory for integration of an Axis Communications camera in a sensor network.2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When installing new network security cameras in buildings, the cameras are often connected to sensors via signal wires. Since most building already have internet and electricity drawn throughout the structure, the procedure of routing a new signal wire can be costly and time demanding. By replacing this wire with a wireless link, the cost and time it takes for the customer to install a camera could be reduced.

    The objective for this thesis is to investigate different wireless technologies used in short range, low power wireless communication networks such as PANs and LANs. Focusing on technologies used in the surveillance segment a decision will be made on which wireless technology that would suit as a link between a sensor and a camera for transmitting trigger signals. The technology will then be implemented in a proof-of-concept accessory, which can give an Axis Communications camera wireless functionality through it’s IO port.

  • 37.
    Ernst, Robert
    et al.
    Halmstad University, School of Information Technology.
    Nilsson, Emil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab.
    Viberg, Per-Arne
    Swedish Adrenaline AB, Halmstad, Sweden..
    60GHz Vital Sign Radar using 3D-printed Lens2016In: 2016 IEEE SENSORS, Piscataway: IEEE, 2016, article id 7808774Conference paper (Refereed)
    Abstract [en]

    There is an increased interest in contact-less vital sign monitoring methods as they offer higher flexibility to the individual being observed. Recent industrial development enabled radar functionality to be packed in single-chip solutions, decreasing application complexity and speeding up designs. Within this paper, a vital sign radar has been developed utilizing a recently released 60GHz frequency modulated continuous wave single-chip radar in combination with 3D-printed quasi-optics. The electronics development has been focused on compactness and high system integration using a low cost design process. The final experiments prove that the radar is capable of tracking human respiration rate and heartbeat at the same time from a distance of 1m.

  • 38.
    Friel, Ross
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Gerling-Gedin, Maria
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Nilsson, Emil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab. Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Embedded Systems (CERES).
    Andreasson, Björn Pererik
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    3D Printed Radar Lenses with Anti-Reflective Structures2019In: Designs, E-ISSN 2411-9660, Vol. 3, no 2, article id 28Article in journal (Refereed)
    Abstract [en]

    Background: The purpose of this study was to determine if 3D printed lenses with wavelength specific anti-reflective (AR) surface structures would improve beam intensity and thus radar efficiency for a Printed Circuit Board (PCB)-based 60 GHz radar. This would have potential for improved low-cost radar lenses for the consumer product market. Methods: A hyperbolic lens was designed in 3D Computer Aided Design (CAD) software and was then modified with a wavelength specified AR structure. Electromagnetic computer simulation was performed on both the ‘smooth’ and ‘AR structure’ lenses and compared to actual 60 GHz radar measurements of 3D printed polylactic acid (PLA) lenses. Results: The simulation results showed an increase of 10% in signal intensity of the AR structure lens over the smooth lens. Actual measurement showed an 8% increase in signal of the AR structure lens over the smooth lens. Conclusions: Low cost and readily available Fused Filament Fabrication (FFF) 3D printing has been shown to be capable of printing an AR structure coated hyperbolic lens for millimeter wavelength radar applications. These 3D Printed AR structure lenses are effective in improving radar measurements over non-AR structure lenses.

  • 39.
    Gao, Yang
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Article identification for inventory list in a warehouse environment2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this paper, an object recognition system has been developed that uses local image features. In the system, multiple classes of objects can be recognized in an image. This system is basically divided into two parts: object detection and object identification. Object detection is based on SIFT features, which are invariant to image illumination, scaling and rotation. SIFT features extracted from a test image are used to perform a reliable matching between a database of SIFT features from known object images. Method of DBSCAN clustering is used for multiple object detection. RANSAC method is used for decreasing the amount of false detection. Object identification is based on 'Bag-of-Words' model. The 'BoW' model is a method based on vector quantization of SIFT descriptors of image patches. In this model, K-means clustering and Support Vector Machine (SVM) classification method are applied.

  • 40.
    Goncalves, Dulce
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Bergquist, Magnus
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Bunk, Richard
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS). Future Mobility Center, Halmstad University, Halmstad, Sweden.
    Alänge, Sverker
    Institute for Management of Innovation and Technology (IMIT), Gothenburg, Sweden.
    The Influence of Cultural Values on Organizational Agility2019In: AMCIS 2019 Proceedings, 2019, p. 1-10Conference paper (Refereed)
    Abstract [en]

    Organizational agility, a firm’s ability to manage dynamic change, has become strategically important for companies in their innovation work. In this context cultural aspects are especially important, as they can both support and hamper organizational agility. Differences can generate innovation ability but they can also create conflicts between competing value systems, thus reducing the firm’s ability to develop organizational agility to support innovation processes. We conducted a comparative study in incumbent firms and startups in the automotive industry to identify the influence of entrepreneurial cultural values on organizational agility. The Competing Values Framework was applied to identify the relationship between cultural values and organizational agility. The result shows that cultural differences affect the companies ability to develop organizational agility for innovation work. In particular incumbents struggled to enable a change towards organizational agility. We found that startups integrated Clan and Adhocracy into an agile culture, which enabled continuous innovation growth.

  • 41.
    Habibi, Shiva
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Sprei, Frances
    Chalmers University of Technology, Gothenburg, Sweden.
    Englund, Cristofer
    RISE Viktoria, 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.
    Comparison of free-floating car-sharing services in cities2017Conference paper (Refereed)
    Abstract [en]

    In recent years, free-floating car sharing services (FFCS) have been offered by many organizations 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. FFCS can provide a high degree of utilization of vehicles and less usage of infrastructure in the form of parking lots and roads and thus has the potential to increase the efficiency of the transport sector. However, there is also a concern that these compete with other efficient modes of transport such as biking and public transport. The aim of this paper is to better understand how, when and where the vehicles are utilized through logged data of the vehicles movements. We have access to data collected on FFCS services in 22 cities in Europe and North America which allows us to compare the usage pattern in different cities and examine whether or not there are similar trends. In this paper, we use the collected data to compare the different cities based on utilization rate, length of trip and time of day that the trip is made. We find that the vehicle utilization rates differ between cities with Madrid and Hamburg having some of the highest utilization levels for the FFCS vehicles. The result form a first step of a better understanding on how these services are being used and can provide valuable input to local policy makers as well as future studies such as simulation models.

  • 42.
    Hagström, A. L.
    et al.
    Halmstad University, School of Information Technology.
    Vass, L.A.M.
    Halmstad University, School of Information Technology.
    Liu, F.
    Halmstad University, School of Information Technology.
    Gerling, M.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Karlsson, P-O
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Nilsson, Emil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Andreasson, Björn Pererik
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    An iterative approach to determine the refractive index of 3D printed 60GHz PLA lenses2018In: Proceedings of the 14th Loughborough Antennas and Propagation Conference (LAPC 2018), Piscataway, N.J.: IEEE, 2018Conference paper (Refereed)
    Abstract [en]

    This paper describes an iterative approach to determine quasi-optical properties of standard 3D printer filament material to, in an inexpensive and fast way, construct focusing lenses for millimetre wave systems. Results from three lenses with different focal lengths are shown and discussed. The real part of the permittivity at 60GHz for polylactic acid (PLA) is in this paper determined to be εr=2.74. © 2018 Institution of Engineering and Technology. All rights reserved.

  • 43.
    Hajji, Maryam
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    A comparative study of Nanowire-based InP and Planar ITO/InP Photodetectors2011Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Photodetectors are a kind of semiconductor devices that convert incoming light to an electrical signal. Photodetectors have different applications in sensors and fiber optic communication systems, and medical diagnosis etc.

    In this project  Fourier Transform Infrared (FTIR) Spectroscopy is used to investigate a new version  of photodiodes for near-infrared radiation that is based on self-assembled semiconductor nanowires (NWs) which are grown directly on the substrate without any epi-layer. The spectrally resolved photocurrent (at different applied biases) and IV curves (in darkness and illumination) for different temperatures have been studied, respectively.

    The thesis work also includes a comparison to a planar photodetector based on Indium Tin Oxide (ITO) deposited directly on an InP substrate.

     

     

  • 44.
    Hansen, Kevin
    et al.
    Halmstad University.
    Edlert, Robin
    Halmstad University.
    Doorwatch2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 45.
    Harrysson, Mattias
    Halmstad University, School of Business and Engineering (SET).
    Fault Location Algorithms in Transmission Grids2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The rapid growth of the electric power system has in recent decades resulted in an increase of the number of transmission lines and total power outage in Norway. The challenge of a fast growing electrical grid has also resulted in huge increases of overhead lines and their total length. These lines are experiencing faults due to various reasons that cause major disruptions and operating costs of the transmission system operator (TSO). Thus, it’s important that the location of faults is either known or can be estimated with reasonably high accuracy. This allows the grid owner to save money and time for inspection and repair, as well as to provide a better service due to the possibility of faster restoration of power supply and avoiding blackouts. 

    Fault detection and classification on transmission lines are important tasks in order to protect the electrical power system. In recent years, the power system has become more complicated under competitive and deregulated environments and a fast fault location technique is needed to maintain security and supply in the grid.

    This thesis compares and evaluates different methods for classification of fault type and calculation of conventional one-side and two-side based fault location algorithms for distance to fault estimation.  Different algorithm has been implemented, tested and verified to create a greater understanding of determinants facts that affect distance to faults algorithm’s accuracy.  Implemented algorithm has been tested on the data generated from a number of simulations in Simulink for a verification process in implemented algorithms accuracy. Two types of fault cases have also been simulated and compared for known distance to fault estimation. 

  • 46.
    Hellring, Magnus
    et al.
    Volvo.
    Rögnvaldsson, Thorsteinn
    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).
    Larsson, Magnus
    Mecel AB.
    Ion current based pressure peak detection under different air humidity conditions2000In: Advanced Microsystems for Automotive Applications 2000 / [ed] Sven Krüger, Wolfgang Gessner, New York: Springer , 2000, p. 125-138Conference paper (Other academic)
    Abstract [en]

    A model based soft sensor that estimates the location of the in-cylinder pressure peak from the ion current is described. The soft sensor uses a neural network algorithm and has been implemented in a SAAB 9000 low-pressure turbo production car. It estimates the pressure peak location, in real time, during normal highway driving with an error of 2-3 crank angle degrees. The soft sensor has been tested during normal Scandinavian weather conditions, with a relative air humidity of about 50%, as well as when water is sprayed into the intake manifold, resulting in approximately 100% relative humidity. The neural network based soft sensor is significantly better than that of another method, based on nonlinear Gaussian curve fits, for the same task.

  • 47.
    Hertz, Erik
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Svensson, Bertil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Nilsson, Peter
    Department of Electrical and Information Technology, Lund University, Lund, Sweden.
    Combining the Parabolic Synthesis Methodology with Second-Degree Interpolation2016In: Microprocessors and microsystems, ISSN 0141-9331, E-ISSN 1872-9436, Vol. 42, p. 142-155Article in journal (Refereed)
    Abstract [en]

    The Parabolic Synthesis methodology is an approximation methodology for implementing unary functions, such as trigonometric functions, logarithms and square root, as well as binary functions, such as division, in hardware. Unary functions are extensively used in baseband for wireless/wireline communication, computer graphics, digital signal processing, robotics, astrophysics, fluid physics, games and many other areas. For high-speed applications as well as in low-power systems, software solutions are not sufficient and a hardware implementation is therefore needed. The Parabolic Synthesis methodology is a way to implement functions in hardware based on low complexity operations that are simple to implement in hardware. A difference in the Parabolic Synthesis methodology compared to many other approximation methodologies is that it is a multiplicative, in contrast to additive, methodology. To further improve the performance of Parabolic Synthesis based designs, the methodology is combined with Second-Degree Interpolation. The paper shows that the methodology provides a significant reduction in chip area, computation delay and power consumption with preserved characteristics of the error. To evaluate this, the logarithmic function was implemented, as an example, using the Parabolic Synthesis methodology in comparison to the Parabolic Synthesis methodology combined with Second-Degree Interpolation. To further demonstrate the feasibility of both methodologies, they have been compared with the CORDIC methodology. The comparison is made on the implementation of the fractional part of the logarithmic function with a 15-bit resolution. The designs implemented using the Parabolic Synthesis methodology – with and without the Second-Degree Interpolation – perform 4x and 8x better, respectively, than the CORDIC implementation in terms of throughput. In terms of energy consumption, the CORDIC implementation consumes 140% and 800% more energy, respectively. The chip area is also smaller in the case when the Parabolic Synthesis methodology combined with Second-Degree Interpolation is used. © 2016 Elsevier B.V. All rights reserved.

  • 48.
    Hudji, Muadh
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sarris, Imad
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Utvärdering av en generator med permanentmagneter avsedd för ett vindkraftverk2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 49.
    Islam, Raihan
    et al.
    Halmstad University, School of Information Technology.
    Tomy, Kiran
    Halmstad University, School of Information Technology.
    Study on Reverberation Chamber for High-Frequency2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 50.
    Jebur, Mariam
    Halmstad University, School of Business, Engineering and Science.
    Övervakningssystem för vindkraftverk: Monitoring system for wind turbines2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report describes how a new and modern monitoring system is crea- ted for a wind turbine.

    Elvira Vind AB is a company that has an old operating surveillance system manufactured in 1992. A need has arisen with the owner of the company and are looking for a simple and smooth system that monitors the situation in a wind turbine. Therefore, a system is created that can transmit data wireless- ly through a GSM-module. The system must be able to sense temperature, vibration and sound levels. Also a camera has to take a picture when it de- tects vibration and display the values of the sensors in a web site. The system must also be powered during a power failure, therefore a voltage regulator and a charging circuit was made in the circuit board.

    The goal of this project is to create a sensor-based monitoring system for a wind turbine and to see the sensor readings wirelessly and displayed in a web site. The report describes how the electronic circuit board has been created and which methods have been used for each sensor in this project. There is also a description of how to use the system for both software and hardware. 

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