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  • Boldt, Martin
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Borg, Anton
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Evaluating Temporal Analysis Methods UsingResidential Burglary Data2016In: ISPRS International Journal of Geo-Information, Special Issue on Frontiers in Spatial and Spatiotemporal Crime Analytics, ISSN 2220-9964, Vol. 5, no 9, 1-22 p.Article in journal (Refereed)
    Abstract [en]

    Law enforcement agencies, as well as researchers rely on temporal analysis methods in many crime analyses, e.g., spatio-temporal analyses. A number of temporal analysis methods are being used, but a structured comparison in different configurations is yet to be done. This study aims to fill this research gap by comparing the accuracy of five existing, and one novel, temporal analysis methods in approximating offense times for residential burglaries that often lack precise time information. The temporal analysis methods are evaluated in eight different configurations with varying temporal resolution, as well as the amount of data (number of crimes) available during analysis. A dataset of all Swedish residential burglaries reported between 2010 and 2014 is used (N = 103,029). From that dataset, a subset of burglaries with known precise offense times is used for evaluation. The accuracy of the temporal analysis methods in approximating the distribution of burglaries with known precise offense times is investigated. The aoristic and the novel aoristic_ext method perform significantly better than three of the traditional methods. Experiments show that the novel aoristic_ext method was most suitable for estimating crime frequencies in the day-of-the-year temporal resolution when reduced numbers of crimes were available during analysis. In the other configurations investigated, the aoristic method showed the best results. The results also show the potential from temporal analysis methods in approximating the temporal distributions of residential burglaries in situations when limited data are available.

  • Linde, Peter
    Blekinge Institute of Technology, The Library.
    Årsberättelse 2016 Högskolebiblioteket BTH2017Other (Other (popular science, discussion, etc.))
  • Khan, Imran
    Blekinge Institute of Technology, Faculty of Engineering, Department of Applied Signal Processing.
    Measurements, Analysis Techniques and Experiments in Sound and Vibration: Applied to Operational MRI Scanners and in Remote Laboratories.2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    High quality noise and vibration measurements outside of a laboratory environment on real life structures and applications are not trivial. True boundary and operating conditions enforce unique challenges on the measurements. Measurements in hazardous situations such as high magnetic fields, and high temperature environments, etc., where ordinary measurement equipment and methods may not be employed, require further precautions. Post measurements objectives such as analysis, design and strategic decisions, e.g., control, rely heavily on the quality and integrity of the measurements (data).

    The quality of the experimental data is highly correlated with the on-field expertise. Practical or hands-on experience with measurements can be imparted to prospective students, researchers and technicians in the form of laboratory experiments involving real equipment and practical applications. However, achieving expertise in the field of sound and vibration measurements in general and their active control in particular is a time consuming and expensive process. Consequently most institutions can only afford a single setup, resulting in the compromise of the quality of expertise.

    In this thesis, the challenges in the field of sound and vibration measurements in high magnetic field are addressed. The analysis and measurement of vibration transferred from an operational magnetic resonance imaging (MRI) scanner to adjacent floors is taken as an example. Improvised experimental measurement methods and custom-made frequency analysis techniques are proposed in order to address the challenges and study the vibration transfer. The methods may be extended to other operational industrial machinery and hazardous environments. To encourage and develop expertise in the field of acoustic/vibration measurements and active noise control on practical test beds, remotely controlled laboratory setups are introduced. The developed laboratory setup, which is accessed and controlled via the Internet, is the first of its kind in the active noise control and acoustic measurements area. The laboratory setup can be shared and utilized 24/7 globally, thus reducing the associated costs and eliminating time restrictions.

  • Imran, khan
    Blekinge Institute of Technology, Faculty of Engineering, Department of Applied Signal Processing.
    MRI Scanner’s Vibration Isolation: Experimental Measurements, Analysis Techniques and Analytical Models2017Report (Other academic)
    Abstract [en]

    Modern Magnetic Resonance Imaging (MRI) scanners employ techniques for faster switching of currentsin the gradient coils. The aim is to improve the imaging quality and/or shorter scanning time at thecost of further escalating the associated vibration and noise excited by the Lorentz forces in the gradientcoil. These developments necessitate the employment of effective vibration isolation measures, both priorand post installation, for which a comprehensive analysis of the vibration transfer paths is essential. Such ananalysis is presented in this paper for an operational MRI scanner. The vibration transfer paths are studiedboth analytically and experimentally. Based on the spectral analysis results, improvements in the existingvibration isolation mechanism are discussed.

  • Renato, Machado
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Vu, Viet Thuy
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Pettersson, Mats
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dammert, Patrik
    Saab Electronic Defense Systems, SWE.
    Hellsten, Hans
    Saab Electronic Defense Systems, SWE.
    The stability of UWB low-frequency SAR images2016In: IEEE Geoscience and Remote Sensing Letters, ISSN 1545-598X, E-ISSN 1558-0571, Vol. 13, no 8, 1114-1118 p.Article in journal (Refereed)
    Abstract [en]

    This letter presents an analysis of prefiltered clutter ultrawideband (UWB) very high frequency synthetic aperture radar (SAR) images. The image data are reorganized into subvectors based on the observation of the image-pair magnitude samples. Based on this approach, we present a statistical description of the SAR clutter obtained by the subtraction between two real SAR images. The statistical analysis based on bivariate distribution data organized into different intervals of magnitude can be an important tool to further understand the properties of the backscattered signal for low-frequency SAR images. In this letter, it is found that, for “good” image pairs, the subtracted image has Gaussian distributed clutter backscattering and that the noise mainly consists of the thermal noise and, therefore, speckle noise does not have to be considered. This is a consequence of the stable backscattering for a UWB low-frequency SAR system.

  • Khan, Imran
    et al.
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Muhammad, Moazzam
    Rabbani, Muhammad Shoaib
    BTH.
    Johansson, Sven
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Håkansson, Lars
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Performance evaluation of control algorithms implemented on a remotely controlled active noise control laboratory2013In: Active Noise and Vibration Control in Practical System Implementations, 2013, 731Conference paper (Other academic)
    Abstract [en]

    The remotely controlled laboratory setup for Active Noise Control (ANC) developed by Blekin-ge Institute of Technology, Sweden provides an efficient learning platform for the students to implement and learn ANC algorithms with real world physical system, hardware and signals. The initial laboratory prototype based on a Digital Signal Processor (DSP) TMS320C6713 from Texas Instruments (TI) was successfully tested with Filtered-x Least Mean Square (F-XLMS) algorithm applied to control noise in a ventilation duct. The resources of the DSP platform used in the remote laboratory setup enable testing and investigating substantially more challenging and computationally demanding algorithms. In this paper, we expand the horizon of the laboratory setup by testing more advanced and complicated single channel feed forward ANC algorithms. Filtered-x versions of algorithms such as the normalized least mean square (N-LMS), leaky least mean square (L-LMS), Filtered-U recursive least mean square (FURLMS) and recursive least square (RLS) algorithm etc. have been implemented utilizing the remote web based client provided in the remote laboratory. A comprehensive performance comparison of the aforementioned algorithms for the remote laboratory setup is presented to demonstrate the viability of the remote laboratory.

  • Khan, Imran
    et al.
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Gertsovich, Irina
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Claesson, Ingvar
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Håkansson, Lars
    Blekinge Institute of Technology, School of Engineering, Department of Electrical Engineering.
    Johansson, Per-Erik
    Wirenstedt, Maria
    Borja, Oscar
    Petersson, Stefan
    MRI SCANNER VIBRATION PATH ANALYSIS2013In: Machinery Noise and Vibration, 2013, 725Conference paper (Other academic)
    Abstract [en]

    Magnetic Resonance Imaging (MRI) scanner is one of the most important tools in clinical diagnostics. MRI scanners are associated by strong vibration which results in unpleasant and disturbing acoustic noise. The primary source of this vibration is the Lorentz force produced by fast switching of the currents inside the gradient coils of MRI scanners under a strong static magnetic field. During an MR-imaging scan the switching is controlled in order to spatially code the hydrogen nuclei that will generate the signal, which is reconstructed into anatomical images. Faster switching of the currents allows for shorter scan times and/or higher image resolutions. Consequently, the clinical quality has motivated the drive for shorter switching time and higher currents. This development, however, has also caused an undesired increase of MRI vibrations. The overall vibration phenomenon of an installed fully functional MRI scanner system becomes unique because of the installed location and ambiance. This vibration can potentially degrade the image quality and hence the diagnosis. Apart from the vibration produced, the associated annoying acoustic noise may not only affect the patients under examination and the clinical staff, but may also be transmitted to other parts of the building and causing discomfort for the personnel working there. In order to devise an effective isolation plan or improve an existing one both for vibration and acoustic noise it is important to study the noise and vibration transfer paths. This paper concerns an investigation of vibration transfer paths for vibration excited by an installed functional MRI scanner at a medical facility. The vibration transfer paths have been investigated experimentally. The obtained results are presented and discussed.

  • Public defence: 2017-03-31 00:00 Karlskrona
    Björklund, Svante
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Swedish Defence Research Agency (FOI ).
    Signal Processing for Radar with Array Antennas and for Radar with Micro-Doppler Measurements2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Radar (RAdio Detection And Ranging) uses radio waves to detect the presence of a target and measure its position and other properties. This sensor has found many civilian and military applications due to advantages such as possible large surveillance areas and operation day and night and in all weather. The contributions of this thesis are within applied signal processing for radar in two somewhat separate research areas: 1) radar with array antennas and 2) radar with micro-Doppler measurements.

    Radar with array antennas: An array antenna consists of several small antennas in the same space as a single large antenna. Compared to a traditional single-antenna radar, an array antenna radar gives higher flexibility, higher capacity, several radar functions simultaneously and increased reliability, and makes new types of signal processing possible which give new functions and higher performance.

    The contributions on array antenna radar in this thesis are in three different problem areas. The first is High Resolution DOA (Direction Of Arrival) Estimation (HRDE) as applied to radar and using real measurement data. HRDE is useful in several applications, including radar applications, to give new functions and improve the performance. The second problem area is suppression of interference (clutter, direct path jamming and scattered jamming) which often is necessary in order to detect and localize the target. The thesis presents various results on interference signal properties, antenna geometry and subarray design, and on interference suppression methods. The third problem area is measurement techniques for which the thesis suggests two measurement designs, one for radar-like measurements and one for scattered signal measurements.

    Radar with micro-Doppler measurements: There is an increasing interest and need for safety, security and military surveillance at short distances. Tasks include detecting targets, such as humans, animals, cars, boats, small aircraft and consumer drones; classifying the target type and target activity; distinguishing between target individuals; and also predicting target intention. An approach is to employ micro-Doppler radar to perform these tasks. Micro-Doppler is created by the movement of internal parts of the target, like arms and legs of humans and animals, wheels of cars and rotors of drones.

    Using micro-Doppler, this thesis presents results on feature extraction for classification; on classification of targets types (humans, animals and man-made objects) and human gaits; and on information in micro-Doppler signatures for re-identification of the same human individual. It also demonstrates the ability to use different kinds of radars for micro-Doppler measurements. The main conclusion about micro-Doppler radar is that it should be possible to use for safety, security and military surveillance applications.

  • Hu, Yan
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Bai, Guohua
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Lundberg, Jenny
    Linnaeus University, SWE.
    Eriksén, Sara
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    A Virtual Community Design for Home-Based Chronic Disease Healthcare2016In: Lecture Notes in Computer Science / [ed] Seyff N.,Ebert A.,Humayoun S.R.,Perini A.,Barbosa S.D.J.,Seyff N., Springer Publishing Company, 2016Conference paper (Refereed)
    Abstract [en]

    The internet based social network has been applied to serve many social functions, such as democratic decision making, knowledge sharing, educa‐ tion, and healthcare. In this paper, we provide a prototype of virtual community designed for home-based chronic diseases healthcare. We studied the concept “community” from the activity theory model in order to design the prototype with a solid theoretical base. Then we conducted a questionnaire from healthcare recipients and interviewed healthcare providers to gather the requirements for the design of the community. With some user stories we described the requirements as use cases for our design and a conceptual prototype is built based on the requirements. This virtual community servers as a shared platform for all the stakeholders who are engaged in the healthcare activity. With this shared community platform, the interoperability problems of current healthcare systems can be moderated

  • Munir, Hussan
    et al.
    Lund University, SWE.
    Wnuk, Krzysztof
    Lund University, SWE.
    Runeson, Per
    Lund University, SWE.
    Open innovation in software engineering: a systematic mapping study2015In: Empirical Software Engineering, Vol. 21, no 2, 684-723 p.Article in journal (Refereed)
    Abstract [en]

    Open innovation (OI) means that innovation is fostered by using both external and internal influences in the innovation process. In software engineering (SE), OI has existed for decades, while we currently see a faster and broader move towards OI in SE. We therefore survey research on how OI takes place and contributes to innovation in SE. This study aims to synthesize the research knowledge on OI in the SE domain. We launched a systematic mapping study and conducted a thematic analysis of the results. Moreover, we analyzed the strength of the evidence in the light of a rigor and relevance assessment of the research. We identified 33 publications, divided into 9 themes related to OI. 17/33 studies fall in the high–rigor/high–relevance category, suggesting the results are highly industry relevant. The research indicates that start-ups have higher tendency to opt for OI compared to incumbents. The evidence also suggests that firms assimilating knowledge into their internal R&D activities, have higher likelihood of gaining financial advantages. We concluded that OI should be adopted as a complementary approach to facilitate internal innovation and not to substitute it. Further research is advised on situated OI strategies and the interplay between OI and agile practices.

  • Asklund, Ulf
    et al.
    Lund University, SWE.
    Höst, Martin
    Lund University, SWE.
    Wnuk, Krzysztof
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Experiences from Monitoring Effect of Architectural Changes2016In: Software Quality.: The Future of Systems- and Software Development / [ed] Winkler, Dietmar, Biffl, Stefan, Bergsmann, Johannes, 2016, 97-108 p.Conference paper (Refereed)
    Abstract [en]

    A common situation is that an initial architecture has been sufficient in the initial phases of a project, but when the size and complexity of the product increases the architecture must be changed. In this paper experiences are presented from changing an architecture into independent units, providing basic reuse of main functionality although giving higher priority to independence than reuse. An objective was also to introduce metrics in order to monitor the architectural changes. The change was studied in a case-study through weekly meetings with the team, collected metrics, and questionnaires. The new architecture was well received by the development team, who found it to be less fragile. Concerning the metrics for monitoring it was concluded that a high abstraction level was useful for the purpose.

  • França, César Levy
    Blekinge Institute of Technology, Faculty of Engineering, Department of Strategic Sustainable Development.
    Business Model Design for Strategic Sustainable Development2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Humanity confronts an existential threat without historic precedent. Environmental pressures have reached such intensity and pace of change that the earth system may be irreversibly tipped into a new and unpredictable state. The emerging global reality is, in turn, redefining overall conditions for business success. Addressing these challenges both demands and brings great opportunities for innovation. An important and sometimes neglected aspect of innovation is the design or redesign of business models, which has been identified as a greater source of lasting competitive advantage than new products and services per se. The business model has also been suggested as a new unit of analysis when discussing sustainability. However, this is still a relatively underexplored area. The aim of this work was therefore to develop an approach to business model design that supports strategic sustainable development, i.e., supports organizations to contribute to society’s transition towards sustainability in a way that strengthens the organization.    

     

    To be able to design a business model that supports strategic sustainable development, it is necessary to know what sustainability is and how to develop sustainability-promoting, economically viable strategies. Therefore, the Framework for Strategic Sustainable Development, which includes, e.g., an operational definition of sustainability and strategic guidelines for how to approach it, was used as an overarching framework. Specific research methods and techniques included, e.g., literature reviews, questionnaires, interviews, work with focus groups, participatory action research with partner organizations, creative problem solving techniques, modeling, and simulation.

     

    The literature reviews revealed potential sustainability benefits of developing business models in conjunction with product-service systems (PSS). However, a knowledge gap exists regarding how to effectively connect these fields. Arguably, PSS strategies can best contribute to sustainability when business models support their implementation and when both the business models and the PSS strategies are guided by an understanding of strategic sustainable development. Therefore, an integrated approach to Business Model Design for Strategic Sustainable Development was co-developed and tested in PSS innovation work with partners, e.g., companies within the energy and lighting sectors. The tests indicated that the new approach helped to clarify strengths and weaknesses of current business models from a strategic sustainability perspective; to transform an organization’s vision and strategy into a sustainability-framed vision and a sustainability-promoting strategy; and to communicate the new vision and strategy to the value network as a basis for engaging important stakeholders in the change. For example, the approach supported one of the partner companies in its transformation towards providing sustainable PSS solutions in the form of light as a service.

    Examples of business benefits of the new approach include improved scalability and risk avoidance, which provide a foundation for better investment strategies. Benefits also include improved differentiability and a broadened view on, and a more solid foundation for, collaboration with stakeholders that are increasingly important to sustainable business success.