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  • Westphal, Florian
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap.
    Lavesson, Niklas
    Jönköpings universitet.
    Representative Image Selection for Data Efficient Word Spotting2020Ingår i: 14th IAPR International Workshop on Document Analysis Systems (DAS), Springer, 2020Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper compares three different word image representations as base for label free sample selection for word spotting in historical handwritten documents. These representations are a temporal pyramid representation based on pixel counts, a graph based representation, and a pyramidal histogram of characters (PHOC) representation predicted by a PHOCNet trained on synthetic data. We show that the PHOC representation can help to reduce the amount of required training samples by up to 69% depending on the dataset, if it is learned iteratively in an active learning like fashion. While this works for larger datasets containing about 1 700 images, for smaller datasets with 100 images, we find that the temporal pyramid and the graph representation perform better.

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  • Josyula, Sai Prashanth
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper.
    Investigating ethical issues in research concerned with data sources involving sensitive personal data2017Rapport (Övrigt vetenskapligt)
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  • Högström, Ebba
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för fysisk planering. School of Geogrpahy and Earth Sciences, University of Glasgow, Glasgow, UK.
    Philo, Chris
    School of Geography and Earth Sciences, University of Glasgow, Glasgow, UK.
    Space out of time, spaces full of times and shaking the kaleidoscope of memory: Investigating the temporalities of an urban mental health campus2019Konferensbidrag (Refereegranskat)
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    AHRA 2019 Book of abstracts
  • Engström, Carl-Johan
    et al.
    Kungliga tekniska högskolan, Institutionen Samhällsplanering och miljö.
    Högström, Ebba
    Kungliga tekniska högskolan, Institutionen Samhällsplanering och miljö.
    Rostvik, Maja
    Kungliga tekniska högskolan, Institutionen Samhällsplanering och miljö.
    Synergier mellan investeringar.: Åtta fallstudier.2013Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Denna rapport är framtagen för att få en ökad förståelse för hur olika investeringar i Stockholmsregionen påverkar varandra och genom att för-stå det, på sikt få ett mer kraftfullt och samordnat genomförande. Frågor som ställs i studien är bland annat dessa: Vilka synergier finns det mellan olika investeringar och hur kan man utnyttja dem? Kan man stöd-ja privata investeringar genom offent-liga investeringar? Kan man påvisa att offentliga investeringar som gjorts har gett upphov till privata investe-ringar som annars inte skulle ha genomförts? Vad är det som påverkar om en investering ger följdeffekter eller inte?

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  • Högström, Ebba
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för fysisk planering.
    Jörgensen, Rasmus
    Architecture as an agent of change: The case of school 53 in St Petersburg2013Ingår i: Contemporary design in the social sector.: New ideas for school environments / [ed] Veits, Maria, St Petersburg: Design Platform, TOK Curators , 2013, s. 50-61Kapitel i bok, del av antologi (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Conducting a thorough organisational analysis is crucial for coming up with sustainable design interventions and architec- tural alteration. Architecture has the power to influence or constrain spatial practices. Therefore in order to be successful every proposal has to be based on knowledge about the organisation, their everyday activities and goals

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    Contemporary Design in the Social Sector. Yes ideas for School Environments.
  • Högström, Ebba
    Tillfälliga förbindelser.: Reflektioner på färd längs periferin1998Ingår i: Nordisk arkitekturforskning, ISSN 1102-5824, Vol. 11, nr 3, s. 95-105Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Kartan och planen. An kartlägga eller konstruera. En motsatsställning mellan det skapade och det upptäckta. Mellan det byggda och det funna. Var skapas det upptäckta och var upptäckts det skapade? Är kartläggandet en avbild eller är det en skapad och konstruerad plan? Och är då pla­nen är en sorts karta? 

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    Högström (1998) Tillfälliga förbindelser
  • Gradolewski, Dawid
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Maslowski, Dawid
    Intema Sp Zoo, POL.
    Dziak, Damian
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Jachimczyk, Bartosz
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Mundlamuri, Siva Teja
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap. Intema Sp Zoo, Siennicka 25a, POL.
    Prakash, Chandran G.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap. Intema Sp Zoo, Siennicka 25a, POL.
    Kulesza, Wlodek
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    A Distributed Computing Real-Time Safety System of Collaborative Robot2020Ingår i: ELEKTRONIKA IR ELEKTROTECHNIKA, ISSN 1392-1215, Vol. 26, nr 2, s. 4-14Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Robotization has become common in modern factories due to its efficiency and cost-effectiveness. Lots of robots and manipulators share their workspaces with humans what could lead to hazardous situations causing health damage or even death. This article presents a real-time safety system applying the distributed computing paradigm for a collaborative robot. The system consists of detection/sensing modules connected with a server working as decision-making system. Each configurable sensing module pre-processes vision information and then sends to the server the images cropped to new objects extracted from a background. After identifying persons from the images, the decision-making system sends a request to the robot to perform pre-defined action. In the proposed solution, there are indicated three safety zones defined by three different actions on a robot motion. As identification method, state-of-the-art of Machine Learning algorithms, the Histogram of Oriented Gradients (HOG), Viola-Jones, and You Only Look Once (YOLO), have been examined and presented. The industrial environment tests indicated that YOLOv3 algorithm outperformed other solutions in terms of identification capabilities, false positive rate and maximum latency.

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    A Distributed Computing Real-Time Safety System of Collaborative Robot
  • Shahmardani, Mahdieh
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Ståhle, Per
    Lund University, SWE.
    Islam, Md Shafiqul
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Kao-Walter, Sharon
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för maskinteknik.
    Numerical simulation of buckling and post-buckling behavior of a central notched thin aluminum foil with nonlinearity in consideration2020Ingår i: Metals, ISSN 2075-4701, Vol. 10, nr 5, artikel-id 582Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In thin notched sheets under tensile loading, wrinkling appears on the sheet surface, specifically around the cracked area. This is due to local buckling and compression stresses near the crack surfaces. This study aims to numerically study the buckling behavior of a thin sheet with a central crack under tension. A numerical model of a notched sheet under tensile loading is developed using the finite element method, which considers both material and geometrical nonlinearity. To overcome the convergence problem caused by the small thickness-to-length/width ratio and to stimulate the buckling, an imperfection is defined as a small perturbation in the numerical model. Both elastic and elasto-plastic behavior are applied, and the influence of them is studied on the critical buckling stress and the post-buckling behavior of the notched sheet. Numerical results for both elastic and elasto-plastic behavior reflect that very small perturbations need more energy for the activation of buckling mode, and a higher buckling mode is predominant. The influences of different parameters, including Poisson’s ratio, yield limit, crack length-to-sheet-width ratio, and the sheet aspect ratio are also evaluated with a focus on the critical buckling stress and the buckling mode shape. With increase in Poisson’s ratio. First, the critical buckling stress reduces and then remains constant. A higher yield limit results in increases in the critical buckling stress, and no change in the buckling mode shape while adopting various crack length-to-sheet-width ratios, and the sheet aspect ratio changes the buckling mode shape.

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    Numerical simulation of buckling and post-buckling behavior of a central notched thin aluminum foil with nonlinearity in consideration
  • Peixoto, Mariana
    et al.
    Universidade Federal de Pernambuco, BRA.
    Ferreira, Dayse
    Universidade Federal de Pernambuco, BRA.
    Cavalcanti, Mateus
    Universidade Federal de Pernambuco, BRA.
    Silva, Cléber Costa
    Universidade Federal de Pernambuco, BRA.
    Vilela, Jéssyka
    Universidade Federal de Pernambuco, BRA.
    Araújo, João
    Universidade Nova de Lisboa, PRT.
    Gorschek, Tony
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    On Understanding How Developers Perceive and Interpret Privacy Requirements Research Preview2020Ingår i: Lecture Notes in Computer Science / [ed] Madhavji N.,Pasquale L., Springer , 2020, Vol. 12045, s. 116-123Konferensbidrag (Refereegranskat)
    Abstract [en]

    [Context and motivation] Ensuring privacy of users’ data has become a top concern in software development, either to satisfy users’ needs or to comply with privacy laws. The problem may increase by the time a new law is in the vacancy period, and companies are working to understand how to comply with it. In addition, research has shown that many developers do not have sufficient knowledge about how to develop privacy-sensitive software. [Question/problem] Motivated by this scenario, this research investigates the personal factors affecting the developers’ understanding of privacy requirements during the vacancy period of a data protection law. [Principal ideas/results] We conducted thirteen interviews in six different private companies. As a result, we found nine personal factors affecting how software developers perceive and interpret privacy requirements. [Contribution] The identification of the personal factors contributes to the elaboration of effective methods for promoting proper privacy-sensitive software development. © 2020, Springer Nature Switzerland AG.

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    On Understanding How Developers Perceive and Interpret Privacy Requirements Research Preview
  • Romare, Charlotte
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa. Region Blekinge, SWE.
    Skär, Lisa
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Smart glasses for caring situations in complex care environments: Scoping review2020Ingår i: JMIR mhealth and uhealth, E-ISSN 2291-5222, Vol. 8, nr 4, artikel-id e16055Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Background: Anesthesia departments and intensive care units represent two advanced, high-tech, and complex care environments. Health care in those environments involves different types of technology to provide safe, high-quality care. Smart glasses have previously been used in different health care settings and have been suggested to assist health care professionals in numerous areas. However, smart glasses in the complex contexts of anesthesia care and intensive care are new and innovative. An overview of existing research related to these contexts is needed before implementing smart glasses into complex care environments. Objective: The aim of this study was to highlight potential benefits and limitations with health care professionals' use of smart glasses in situations occurring in complex care environments. Methods: A scoping review with six steps was conducted to fulfill the objective. Database searches were conducted in PubMed and Scopus; original articles about health care professionals’ use of smart glasses in complex care environments and/or situations occurring in those environments were included. The searches yielded a total of 20 articles that were included in the review. Results: Three categories were created during the qualitative content analysis: (1) smart glasses as a versatile tool that offers opportunities and challenges, (2) smart glasses entail positive and negative impacts on health care professionals, and (3) smart glasses' quality of use provides facilities and leaves room for improvement. Smart glasses were found to be both a helpful tool and a hindrance in caring situations that might occur in complex care environments. This review provides an increased understanding about different situations where smart glasses might be used by health care professionals in clinical practice in anesthesia care and intensive care; however, research about smart glasses in clinical complex care environments is limited. Conclusions: Thoughtful implementation and improved hardware are needed to meet health care professionals’ needs. New technology brings challenges; more research is required to elucidate how smart glasses affect patient safety, health care professionals, and quality of care in complex care environments. ©Charlotte Romare, Lisa Skär.

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    Smart Glasses for Caring Situations in Complex Care Environments: Scoping Review
  • Christiansen, Line
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Lindberg, Catharina
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Sanmartin Berglund, Johan
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Anderberg, Peter
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Skär, Lisa
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för hälsa.
    Using Mobile Health and the Impact on Health-Related Quality of Life: Perceptions of Older Adults with Cognitive Impairment2020Ingår i: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 17, nr 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Digital health technologies such as mobile health (mHealth) are considered to have the potential to support the needs of older adults with cognitive impairment. However, the evidence for improving health with the use of mHealth applications is of limited quality. Few studies have reported on the consequences of technology use concerning the older adults' quality of life. The purpose of this study was to describe perceptions of mHealth and its impact on health-related quality of life (HRQoL) among older adults with cognitive impairment. The study was conducted using a qualitative design with a phenomenographic approach. A total of 18 older participants with cognitive impairment were interviewed. The interviews were analyzed in order to apply phenomenography in a home-care context. The results showed variations in the older adults' perceptions that were comprised within three categories of description; Require technology literacy, Maintain social interaction, and Facilitate independent living. In conclusion, the development and design of mHealth technologies need to be tailored based on older adults´ needs in order to be understood and perceived as useful in a home-care context. For mHealth to support HRQoL, healthcare should be provided in a way that encourages various forms of communication and interaction.

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    Using Mobile Health and the Impact on Health-Related Quality of Life: Perceptions of Older Adults with Cognitive Impairment
  • Javadi, Mohammad Saleh
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Dahl, Mattias
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Pettersson, Mats
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Change Detection in Aerial Images Using Three-Dimensional Feature Maps2020Ingår i: Remote Sensing, ISSN 2072-4292, E-ISSN 2072-4292, Vol. 12, nr 9, artikel-id 1404Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Interest in aerial image analysis has increased owing to recent developments in and availabilityofaerialimagingtechnologies,likeunmannedaerialvehicles(UAVs),aswellasagrowing need for autonomous surveillance systems. Variant illumination, intensity noise, and different viewpointsareamongthemainchallengestoovercomeinordertodeterminechangesinaerialimages. In this paper, we present a robust method for change detection in aerial images. To accomplish this, the method extracts three-dimensional (3D) features for segmentation of objects above a defined reference surface at each instant. The acquired 3D feature maps, with two measurements, are then used to determine changes in a scene over time. In addition, the important parameters that affect measurement, such as the camera’s sampling rate, image resolution, the height of the drone, and the pixel’sheightinformation,areinvestigatedthroughamathematicalmodel. Toexhibititsapplicability, the proposed method has been evaluated on aerial images of various real-world locations and the results are promising. The performance indicates the robustness of the method in addressing the problems of conventional change detection methods, such as intensity differences and shadows.

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  • Abualhaija, Sallam
    et al.
    University of Luxembourg, LUX.
    Fucci, Davide
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Dalpiaz, Fabiano
    Utrecht University, NLD.
    Franch, Xavier
    Universitat Politècnica de Catalunya, ESP.
    3rd workshop on natural language processing for requirements engineering (NLP4RE'20)2020Ingår i: CEUR Workshop Proceedings / [ed] Sabetzadeh M.,Vogelsang A.,Abualhaija S.,Borg M.,Dalpiaz F.,Daneva M.,Fernandez N.C.,Franch X.,Fucci D.,Gervasi V.,Groen E.,Guizzardi R.,Herrmann A.,Horkoff J.,Mich L.,Perini A.,Susi A., CEUR-WS , 2020, Vol. 2584Konferensbidrag (Refereegranskat)
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    3rd workshop on natural language processing for requirements engineering (NLP4RE'20)
  • Lenarduzzi, Valentina
    et al.
    Lut University, FIN.
    Fucci, Davide
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Mendez, Daniel
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    On the perceived harmfulness of requirement smells: An empirical study2020Ingår i: CEUR Workshop Proceedings / [ed] Sabetzadeh M.,Vogelsang A.,Abualhaija S.,Borg M.,Dalpiaz F.,Daneva M.,Fernandez N.C.,Franch X.,Fucci D.,Gervasi V.,Groen E.,Guizzardi R.,Herrmann A.,Horkoff J.,Mich L.,Perini A.,Susi A., CEUR-WS , 2020, Vol. 2584Konferensbidrag (Refereegranskat)
    Abstract [en]

    Technical debt is considered to have negative effects to the long term success of software projects. However, how the debt metaphor applies to requirements engineering is yet not significantly explored. Previ- ously, we proposed a framework to identify Requirements Debt (ReD) in three stages of the software development lifecycle. One of these stages is the formalization of stakeholder needs into natural language requirement specifications. In this work, we propose a live study aiming at surveying requirements engineering experts to gain further insights on the issues taking place at this stage and how they fit in our definition of ReD. Copyright © 2020 for this paper by its authors.

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    On the perceived harmfulness of requirement smells: An empirical study
  • Fotrousi, Farnaz
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Combining User Feedback and Monitoring Data to Support Evidence-based Software Evolution2020Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
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  • Javadi, Mohammad Saleh
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Dahl, Mattias
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Pettersson, Mats
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Adjustable Contrast Enhancement Using Fast Piecewise Linear Histogram Equalization2020Ingår i: ACM International Conference Proceeding Series, Association for Computing Machinery , 2020, s. 57-61Konferensbidrag (Refereegranskat)
    Abstract [en]

    Histogram equalization is a technique to enhance the contrast of the image by redistributing the histogram. In this paper, a fast piecewise linear histogram equalization method is introduced based on an adjustable degree of enhancement and piecewise continuous transformation functions using frequencies of different grey-levels. This method aims to address and maximize the contrast enhancement of the image by stretching the entire spectrum. For this purpose, particular nodes (bins) on the histogram are simultaneously detected that in comparison with recursive methods, it requires less computational time. Then, the particular nodes are stretched using transformation functions to align with the reference nodes. The experimental results indicate that the performance of the proposed method is promising in terms of contrast enhancement. Moreover, this method preserves the texture of various regions in the image very well through the equalization process by using the degree of enhancement. © 2020 Owner/Author.

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    Adjustable Contrast Enhancement Using Fast Piecewise Linear Histogram Equalization
  • G Palm, Bruna
    et al.
    Universidade Federal de Pernambuco, BRA.
    Alves, Dimas
    Universidade Federal do Pampa, BRA; .
    Pettersson, Mats
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Vu, Viet Thuy
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Machado, Renato
    Aeronautics Institute of Technology (ITA), BRA.
    J Cintra, Renato
    University of Calgary, CAN.
    M Bayer, Fabio
    Universidade Federal de Santa Maria, BRA.
    Dämmert, Patrik B. G.
    Saab Electronic Defence Systems, SWE.
    Hellsten, Hans
    Saab Electronic Defence Systems, SWE.
    Wavelength-Resolution SAR Ground Scene Prediction Based on Image Stack2020Ingår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 20, nr 7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents five different statistical methods for ground scene prediction (GSP) in wavelength-resolution synthetic aperture radar (SAR) images. The GSP image can be used as a reference image in a change detection algorithm yielding a high probability of detection and low false alarm rate. The predictions are based on image stacks, which are composed of images from the same scene acquired at different instants with the same flight geometry. The considered methods for obtaining the ground scene prediction include (i) autoregressive models; (ii) trimmed mean; (iii) median; (iv) intensity mean; and (v) mean. It is expected that the predicted image presents the true ground scene without change and preserves the ground backscattering pattern. The study indicates that the the median method provided the most accurate representation of the true ground. To show the applicability of the GSP, a change detection algorithm was considered using the median ground scene as a reference image. As a result, the median method displayed the probability of detection of 97 % and a false alarm rate of 0 . 11 / km 2 , when considering military vehicles concealed in a forest.

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    Wavelength-Resolution SAR Ground Scene Prediction Based on Image Stack
  • Andersson, Martin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för industriell ekonomi.
    Larsson, Johan P
    Geography and Entrepreneurship2020Ingår i: Handbook of Regional Science: Live, Springer , 2020Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    We take selective stock of the literature on the geography of entrepreneurship. This literature has been focused on rates of new firm formation, whereas studies of the geography of “high-impact” entrepreneurship are still scant. Entrepreneurship may be described as a “regional event” by the fact that entrepreneurs derive necessary resources from local markets, but also from regional spillovers, social networks, and engrained factors of the local industrial geography. We point to a few fields of analysis where causal or more detailed analyses are warranted.

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  • Rameez, Muhammad
    Blekinge Tekniska Högskola, Fakulteten för teknikvetenskaper, Institutionen för matematik och naturvetenskap.
    Interference Mitigation Techniques in FMCW Automotive Radars2020Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Radar has emerged as an important sensor for scenario perception in automated driving and surveillance systems. The exponential increase of radar units in traffic and their operating frequency limitations have given rise to the problem of mutual interference. Radar's performance degrades in the presence of interference, which can result in false alarms and missed detections. In the case of safety-oriented systems (such as automatic emergency braking, blind-spot detection and obstacle detection at level crossings), radar's degraded performance can result in accidents. Therefore, it is important to mitigate the effect of mutual interference to make modern radar applications safe and reliable. The goal of this work is to develop signal processing techniques for interference mitigation in frequency modulated continuous wave (FMCW) radars operating at 77-81 GHz.

    The thesis investigates radar interference suppression in the spatial domain, using antenna arrays. The interference is suppressed by placing notches in the antenna radiation pattern in the direction of the interference source by employing digital beamforming.

    The array aperture (size) determines the beam-width and notch resolution of the receiving antenna. Narrow notches are desirable since they lead to a smaller suppressed region in the radar's field of view. It is demonstrated that an extended virtual aperture in a multiple-input-multiple-output (MIMO) FMCW radar does not offer an improved notch resolution for interference suppression due to a non-coherent interference signal in the virtual aperture. Moreover, it is shown that the calibration mismatches of the receiving array completely change the final antenna beam-pattern compared to the theoretical one.

    Additionally, an adaptive beamforming approach of interference suppression based on the least mean squares (LMS) algorithm is presented, which is evaluated using outdoor measurements from a 77GHz FMCW radar. The results demonstrate that the proposed technique suppresses interference successfully, resulting in a signal to interference plus noise ratio (SINR) improvement. It is also shown that complex-baseband (IQ) receivers achieve better interference suppression compared to real-baseband receivers when spatial domain methods are employed.

    The final research publication deals with interference mitigation in the time-domain intermediate frequency signal. The disturbed samples in the received signal are detected, removed, and reconstructed based on an estimated autoregressive (AR) signal model. The baseband signal coherence in both fast- and slow-time makes it possible to perform signal reconstruction in both dimensions. With the help of outdoor measurements covering selected scenarios, it is demonstrated that by carefully selecting the signal reconstruction dimension, a better SINR and side-lobe suppression can be achieved.

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