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  • 51.
    Campos, Alexandre Becker
    et al.
    Blekinge Institute of Technology, Faculty of Computing. Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Molin, Ricardo
    Aeronaut Inst Technol, ITA.
    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.
    Machado, Renato
    Aeronaut Inst Technol, ITA.
    UNSUPERVISED AUTOMATIC TARGET DETECTION FOR MULTITEMPORAL SAR IMAGES BASED ON ADAPTIVE K-MEANS ALGORITHM2020Conference paper (Refereed)
    Abstract [en]

    In this paper, we present an unsupervised automatic target detection algorithm for multitemporal SAR images. The proposed two-fold method is expected to reduce processing time for large scene sizes with sparse targets while still improving detection performance. Firstly, pixel blocks are extracted from an initial change map to reduce the algorithm's search space and favor target detection. Secondly, an adaptive k-means algorithm selects the number of clusters that better separates targets from false alarms, which are discarded. Preliminary results show the advantages of the proposed method in processing time and detection performance over a recently proposed supervised method for the CARABAS-II dataset.

  • 52.
    Campos, Alexandre Becker
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Aeronautics Institute of Technology (ITA), BRA.
    Pettersson, Mats
    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.
    Machado, Renato
    Aeronautics Institute of Technology (ITA), BRA.
    False Alarm Reduction in Wavelength-Resolution SAR Change Detection Schemes by Using a Convolutional Neural Network2022In: IEEE Geoscience and Remote Sensing Letters, ISSN 1545-598X, E-ISSN 1558-0571, Vol. 19, article id 4004805Article in journal (Refereed)
    Abstract [en]

    In this letter, we propose a method to reduce the number of false alarms in a wavelength-resolution synthetic aperture radar (SAR) change detection scheme by using a convolutional neural network (CNN). The detection is performed in two steps: change analysis and object classification. A simple technique for wavelength-resolution SAR change detection is implemented to extract potential targets from the image of interest. A CNN is then used for classifying the change map detections as either a target or nontarget, further reducing the false alarm rate (FAR). The scheme is tested for the CARABAS-II data set, where only three false alarms over a testing area of 96 km² are reported while still sustaining a probability of detection above 96%. We also show that the network can still reduce the FAR even when the flight heading of the SAR system measurement campaign differs by up to 100° between the images used for training and test. CCBY

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  • 53.
    Chalikonda, Nikhil
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Bonthu, Naga Viswanth
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Compact Radar System2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Context: Radar was developed in secret during world war II to detectobstacles or any incoming threat. The term radar was coined in 1940by United States Military as an acronym for "Radio Detection andRanging". Using radio waves a radar detects any incoming threat orobstacle [10]. The basic purpose of radar is for monitoring and security. In this work, the ability of an ultrasonic sensor to perform objectidentification and map reconstruction tasks is investigated.

    Objective: This project aims to design an affordable and reliable ultrasonic radar that rotates 180 degrees. Using certain predeterminedscenarios the sensor is tested for its accuracy and resolution extensively to know its potential to be used in an autonomous mobile robot. This analysis shall further be helpful to calibrate the sensor and build anautonomous mobile robot used for map reconstruction.

    Methods: Powered by Arduino Uno, the prototype is programmed viaIDE and examined to monitor a void/unknown environment. Whenthe sensor detects an obstacle in its range, the prototype is programmed to alert the user after the scan by displaying it on the plotgenerated on Matlab.

    Results: From this work the use of ultrasonic sensors for obstacle detection and ambient map reconstruction is determined. The sensorperformed well in accuracy tests for different objects having differentphysical properties. The standard deviation and correlation coefficient are calculated to determine the uncertainty in the ultrasonicscan. Overall a degree of uncertainty is being observed in the results.One possible cause might be due to the effects of variation in environmental parameters.

    Conclusions: Overall the sensor is precise and accurate in distancemeasurements. Although for the application of building a map-makingautonomous mobile robot, the sensor has failed to prove reliable aloneand further study is required to understand the cause of these uncertain results.

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    Compact Radar System
  • 54.
    chiluka, srikanthreddy
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Traffic Sign Recognition2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Smart vehicles with capabilities of autonomous driving are a big revolution in automobile industry. The vehicles can sense their environment and react based on it. It replaces the manual driver. Recognition of traffic sign is an important enabler for autonomous driving. Camera installed in the vehicle captures the traffic sign on the road and they must be recognized accurately for triggering the suitable action. In this thesis both image processing and Euclidean distance matching are used to pre-process and classify the traffic signs and thresholding and thinning are applied on image for feature extraction. In this work, a simple, efficient traffic sign recognition system with low computational time and to achieve good accuracy is proposed. Time to classify the traffic sign is achieved in milliseconds and accuracy is maintained using the proposed system.

    Keywords: Autonomous Driving, Image processing, Thresholding, Thinning, Euclidean distance matching.

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  • 55.
    Claesson, Lena
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Remote laboratories in STEM education: Strategies and methods for implementation2023Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    During a substantial part of their time young people of today live in an online world. The medial evolution has also influenced education and today much research work concerns the transfer of the physical world into the online one. One example is laboratories in science, technology, engineering, and mathematics (STEM) education that are available in online rooms. They enable students to be at home in front of a computer and on-screen watch and operate the physical equipment in the laboratory at school. 

    It is a general agreement that laboratory lessons are necessary in subjects such as physics, chemistry and biology. Physical experiments provide a great way for students to learn more about nature and its possibilities as well as limitations. Experimental work can be provided by laboratories in three different categories; 1) hands-on, 2) remote and 3) simulated.

    This thesis addresses how to implement remote laboratories as a teaching methodology. It presents examples of upper secondary school students’ experimental work and their evaluation of remote laboratories regarding usability, sense of reality and technical problems. 

    In order to gain a better understanding of the situation and needs regarding laboratory activities in an upper secondary school, eight physics teachers were interviewed at six different schools. Furthermore, 165 upper secondary school students answered a questionnaire survey regarding subject preferences, program choices, views on technology and self-ability, and their approach to technology and technology-related situations. This thesis also describes another education approach where academia, industry, and research institutes cooperate around the development and implementation of master level courses. The pedagogical approach utilized in these master level courses has been flipped classroom.

    In this thesis, the usage of remotely controlled laboratories in physics education at an upper secondary school and a university are addressed. The main objective of this project is to investigate the feasibility of using the Virtual Instruments System in Reality (VISIR) technology for remotely controlled laboratories, developed at Blekinge Institute of Technology, in upper secondary schools. The laboratory setup can be shared and utilized almost 24/7, thus reducing the associated costs and eliminating time restrictions.

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  • 56.
    Claesson, Lena
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Kans, Mirka
    Linnaeus University, SWE.
    Håkansson, Lars
    Linnaeus University, SWE.
    Nilsson, Kristian
    STEM Education on Equal Terms Through the Flipped Laboratory Approach2021In: Cross Reality and Data Science in Engineering / [ed] Auer M.E.,May D., Springer , 2021, Vol. 1231, p. 46-62Conference paper (Refereed)
    Abstract [en]

    The educational phenomena studied in this paper is remote-controlled physical laboratory environments and their applicability in upper secondary school physics education. In order to gain a better understanding of the situation and needs regarding laboratory activities in the upper secondary school, eight physics teachers were interviewed at six different schools. This revealed that the resources for laboratory activities vary between schools and may be inconsistent with the Swedish National Agency for Education curriculum. Furthermore, 165 upper secondary school students answered a questionnaire survey regarding subject preferences, program choices, views on technology and self-ability, and approach to technology and technology-related situations. The acquired knowledge provides a basis concerning the needs and conditions of teaching and learning within the subject of physics. This new knowledge motivates the development of the Flipped laboratory concept that is introduced in this paper, based on remote-controlled physical laboratories, for upper secondary school. © 2021, Springer Nature Switzerland AG.

  • 57.
    Claesson, Lena
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Khan, Imran
    Blekinge Institute of Technology.
    Zackrisson, Johan
    Blekinge Institute of Technology.
    Skytt, Kristian
    Blekinge Institute of Technology, Faculty of Computing, Department of Technology and Aesthetics.
    Gustavsson, Ingvar
    Blekinge Institute of Technology.
    Håkansson, Lars
    Chapter 7 - Using a VISIR laboratory to supplement teaching and learning processes in physics courses in a Swedish Upper Secondary School2013In: IT Innovative Practices in Secondary Schools: Remote Experiment / [ed] O. Dziabenko and J. Garcia-Zubia, Bilbao: Universidad de Deusto - Dpto. de Publicaciones, 2013Chapter in book (Refereed)
  • 58.
    Claesson, Lena
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lövström, Benny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    STEM Education: A Remote Laboratory Implementation in Physics CoursesManuscript (preprint) (Other academic)
  • 59.
    Claesson, Lena
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Skytt, Kristian
    Blekinge Institute of Technology, Faculty of Computing, Department of Technology and Aesthetics.
    Zackrisson, Johan
    Gustavsson, Ingvar
    Håkansson, Lars
    Remote laboratory experiments at the Upper Secondary School Katedralskolan in LUND2010In: International Conference on Remote Engineering and Virtual Instrumentation (REV2010), 2010Conference paper (Refereed)
    Abstract [en]

    This paper is intended for people who are interested in using online remote laboratories in education. Blekinge Institute of Technology (BTH) have started a cooperation together with the Upper Secondary School, Katedralskolan, in Lund, Sweden. The purpose of the cooperation is to introduce remote laboratory environment for students at Katedralskolan. A remote laboratory (RL) in electronic is used as a complement to the traditional workbench. It is open 24/7 and the students can carry out laboratory assignments without any risks of damaging any equipment. When a student is familiar with the instruments and components in a laboratory assignment, and carried out parts of the experiments in the hands-on laboratory in school she/he may use the RL to finish the laboratory assignment. The students may also carry out additional experiments remote laboratory or use it to prepare for an exam. 

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  • 60.
    da Silva, Fabiano G.
    et al.
    Aeronautics Institute of Technology, BRA.
    Ramos, Lucas P.
    Aeronautics Institute of Technology, BRA.
    Palm, Bruna
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Alves, Dimas I.
    Aeronautics Institute of Technology, BRA.
    Pettersson, Mats
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Machado, Renato
    Aeronautics Institute of Technology, BRA.
    Hybrid Feature Extraction Based on PCA and CNN for Oil Rig Classification in C-Band SAR Imagery2022In: Proceedings of SPIE - The International Society for Optical Engineering / [ed] Dijk J., SPIE - International Society for Optical Engineering, 2022, article id 122760GConference paper (Refereed)
    Abstract [en]

    Feature extraction techniques play an essential role in classifying and recognizing targets in synthetic aperture radar (SAR) images. This article proposes a hybrid feature extraction technique based on convolutional neural networks and principal component analysis. The proposed method is used to extract features of oil rigs and ships in C-band synthetic aperture radar polarimetric images obtained with the Sentinel-1 satellite system. The extracted features are used as input in the logistic regression (LR), support vector machine (SVM), random forest (RF), naive Bayes (NB), decision tree (DT), and k-nearest-neighbors (kNN) classification algorithms. Furthermore, the statistical tests of Kruskal-Wallis and Dunn were considered to show that the proposed extraction algorithm has a significant impact on the performance of the classifiers. © 2022 SPIE.

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  • 61.
    da Silva, Fabiano G.
    et al.
    Aeronautics Institute of Technology (ITA), BRA.
    Ramos, Lucas P.
    Aeronautics Institute of Technology (ITA), BRA.
    Palm, Bruna
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Machado, Renato
    Aeronautics Institute of Technology (ITA), BRA.
    Assessment of Machine Learning Techniques for Oil Rig Classification in C-Band SAR Images2022In: Remote Sensing, E-ISSN 2072-4292, Vol. 14, no 13, article id 2966Article in journal (Refereed)
    Abstract [en]

    This article aims at performing maritime target classification in SAR images using machine learning (ML) and deep learning (DL) techniques. In particular, the targets of interest are oil platforms and ships located in the Campos Basin, Brazil. Two convolutional neural networks (CNNs), VGG-16 and VGG-19, were used for attribute extraction. The logistic regression (LR), random forest (RF), support vector machine (SVM), k-nearest neighbours (kNN), decision tree (DT), naive Bayes (NB), neural networks (NET), and AdaBoost (ADBST) schemes were considered for classification. The target classification methods were evaluated using polarimetric images obtained from the C-band synthetic aperture radar (SAR) system Sentinel-1. Classifiers are assessed by the accuracy indicator. The LR, SVM, NET, and stacking results indicate better performance, with accuracy ranging from 84.1% to 85.5%. The Kruskal–Wallis test shows a significant difference with the tested classifier, indicating that some classifiers present different accuracy results. The optimizations provide results with more significant accuracy gains, making them competitive with those shown in the literature. There is no exact combination of methods for SAR image classification that will always guarantee the best accuracy. The optimizations performed in this article were for the specific data set of the Campos Basin, and results may change depending on the data set format and the number of images. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 62.
    da Silva, Fabiano Gabriel
    et al.
    Centro de Guerra Acústica e Eletrônica da Marinha (CGAEM), Brazil.
    Ramos, Lucas P.
    Instituto Tecnológico de Aeronáutica (ITA), Brazil.
    Palm, Bruna
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Machado, Renato
    Instituto Tecnológico de Aeronáutica (ITA), Brazil.
    Hyperparameters Analysis of Machine Learning Techniques for Classification of Marine Targets in SAR Images2023In: Proceedings of the XX Brazilian Symposium on Remote Sensing: Anais do XX Simpósio Brasileiro de Sensoriamento Remoto, 2023, Vol. 20, p. 1095-1098, article id 155793Conference paper (Refereed)
    Abstract [en]

    Due to the extensive coastal area of Brazil, pattern recognition techniques based on artificial intelligence can search for targets at sea faster for surveillance, rescue, or illicit combat activities. This article presents a hyperparameter analysis of machine learning techniques to classify targets in SAR images. We considered a data set with vertical horizontal polarization SAR images from Campos Basin, Rio de Janeiro, to classify oil platforms and ships. The classification attributes are extracted through a convolutional neural network VGG-16 pre-trained with the ImageNet data set. Then, four machine learning techniques are evaluated, random forest, decision tree, k-nearest-neighbors, and logistic regression. As a metric for assessing the classifiers, accuracy (Acc) and area under the curve (AUC) are used. The grid search technique is used to identify the best combination of parameters of the classifiers with the highest Acc and AUC. Finally, the best result is the logistic regression classifier.

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  • 63.
    Dahl, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö University, SWE.
    Fredriksson, Henrik
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Laksman, Efraim
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Significant Route Identification using Daily 24-hour Traffic Flows2020In: 2020 IEEE 23rd International Conference on Intelligent Transportation Systems, ITSC 2020, Institute of Electrical and Electronics Engineers Inc. , 2020, article id 9294400Conference paper (Refereed)
    Abstract [en]

    Traffic flow estimates play a key role in traffic network management and planning of transportation networks. Commonly it is the average daily traffic (ADT) flow for different road segments that constitute the data. This paper shows how an advanced and detailed analysis based on hourly flow measurements over the day can contribute to a deeper understanding of how hourly flows together reflect the vehicles' routes. The proposed method identifies the shortest travel time paths between all possible origins and destinations in a transportation network, and thereafter it identifies the most significant routes in the network by performing statistical tests. For this purpose, the paper presents a mathematical model, a vehicle simulator based on this model, and a statistical framework that is able to find the most probable underlying routes. The paper contains a real test scenario based on 24-hour traffic flows (hour by hour) to demonstrate the applicability of the method. © 2020 IEEE.

  • 64.
    Dahl, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Javadi, Mohammad Saleh
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Analytical Modeling for a Video-Based Vehicle Speed Measurement Framework2020In: Sensors, E-ISSN 1424-8220, Vol. 20, no 1, article id 160Article in journal (Refereed)
    Abstract [en]

     Traffic analyses, particularly speed measurements, are highly valuable in terms of road safety and traffic management. In this paper, an analytical model is presented to measure the speed of a moving vehicle using an off-the-shelf video camera. The method utilizes the temporal sampling rate of the camera and several intrusion lines in order to estimate the probability density function (PDF) of a vehicle’s speed. The proposed model provides not only an accurate estimate of the speed, but also the possibility of being able to study the performance boundaries with respect to the camera framerate as well as the placement and number of intrusion lines in advance. This analytical modelis verified by comparing its PDF outputs with the results obtained via a simulation of the corresponding movements. In addition,as aproof-of-concept, the proposed model is implemented for avideo-based vehicle speed measurement system. The experimental results demonstrate the model’s capability in terms of taking accurate measurements of the speed via a consideration of the temporal sampling rate and lowering the deviation by utilizing more intrusion lines. The analytical model is highly versatile and can be used as the core of various video-based speed measurement systems in transportation and surveillance applications.

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  • 65.
    Dahl, Mattias
    et al.
    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.
    Verifiering av mätmetoder, Yttäckande mätningar med SAR2017Report (Other academic)
    Abstract [sv]

    Inom ARENA, den svenska kunskapsplattformen för vägavgifter,har vi tidigare föreslagit satellitbase-rad Syntetisk Apertur Radar (SAR) för att göra effektutvärderingsmätningar av lastbilstrafik över stora områden av Sverige. Denna nya mätmetod är mycket lovande och syftet med detta delprojekt har varit att studera hur ett urval avmätområden kan ske om man avser att genomföra trafikmätningar ur ett effektutvärderingsperspektiv. Som utgångspunkt för rapporten används resultatetfrån de mätningar som inom ramen för ARENA tidigarehar genomförts och avrapporterats, det vill sägaenserie avmätning över södra Sverige där satellitsystemetTerraSAR-X användes för att mäta trafik. Motiveringen till att använda ett satellitsy-stemmed SAR är kostnadseffektivitetenoch förmåganatt mäta trafik på samma sättöver hela Sve-rige och dessutomunder allaåretsdagaroavsett väderlek. Beräkningarna för var man skall eller bör mäta baserar sig på underlag från Nationell vägdata-bas(NVDB) som ärTrafikverketsdatabas över vägnätet i Sverige. Detta underlagi form av trafikflö-denhar i sin tur fått utgöra ett underlag tillhur satellitmätningar kan skei olika landsändar det vill sägaförmågan att observeralastbilstrafiki de aktuella områdena.Avsikten med en mätning av detta slag är att den härledda informationen ska levereras till slutanvän-darevars syfte är att utvärdera effekterna av en Vägslitageskatt. Idenna rapport presenteras kartor ur vilka intressanta områden ur olika aspekter kan väljas ur och inte minst var man i sådant fall skall eller bör mäta.Rapporten avslutas med ett mer teoretiskt resonemang kring hur effektiva skatt-ningar av medeltrafikur ett satellitperspektiv skulle kunna betraktas ochi någon meninghur mät-ningar och den efterföljande statistiska databehandlingendärigenomblir så effektiv som möjligt.

  • 66.
    Dahl, Mattias
    et al.
    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.
    Sjögren, Thomas
    Yttäckande mätningar med satellit - Studie avmätmetoder och datafångst2017Report (Other academic)
    Abstract [sv]

    Avståndsbaserade vägavgiftssystem införs successivt i många länder världen över. Effekten av ett systems implementering kan i många delar vara svårt att analysera, inte minst ur ett mer övergri-pande perspektiv. Denna rapport är en studierörande en helt ny typ av satellitbaserad,yttäckande mätteknik som har genomförts inom ARENA, den svenska kunskapsplattformen för brukaravgifter i transportsektorn. Den yttäckande trafikmätningen sker med avancerad radarteknik som blivit tillgänglig under de sen-aste åren och där vi idag befinner oss i ett stort skifte på så sätt att tillgängligheten av data kommer att öka betydande de närmsta åren. Rapporten innehåller resultat från ett fältförsök över södra Sverige där det tyska satellitsystemet TerraSAR-X användes. Syftet är också att få en uppfattning över hur metodiken, som krävs vid en fullskalig satellitmätning, ser ut. Det vill säga hur man skall välja ut mätområdet, beställning av mät-ning över mätområdet, nedladdning av satellitdatauttag samt en verifiering av hur mätningarna på olika sätt kan bidra till före-och efteranalyser vid ett eventuellt införande av ett vägavgiftssystem.Rapporten har ett övergripande mål att knyta an till de inom ARENAidentifierade domäner, faktorer och nyckeltal som i sin tur ansetts vara relevanta för att utvärdera effekterna av ett införande av en vägslitageskatt för tung trafik. Rapportens huvudsakliga fokus är vad som möjligt att mäta från satel-litbaserade system men även i någon mening översiktligt uppskatta förmågan hos andra yttäckande system såsom drönare och flygburna system. Det vill säga vad systemen kan förväntas leverera uti-från en analys kring tillgänglighet, kvalitet, kostnad och användbarhet.

  • 67.
    Dalarsson, Mariana
    et al.
    KTH, SWE.
    Ivanenko, Yevhen
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Nordebo, Sven
    Linnaeus Univ, SWE.
    Wave propagation in waveguides with graded plasmonic obstacles2021In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 38, no 1, p. 104-113Article in journal (Refereed)
    Abstract [en]

    In this paper, wave propagation in a hollow waveguide with a graded dielectric layer is studied. Analytic formulas are derived for the electric field components as well as general analytical results for the reflection and transmission coefficients for propagating waves. These results are all valid for waveguides of arbitrary cross sections, and the derived reflection and transmission coefficients are in exact asymptotic agreement with those obtained for a wry thin homogeneous dielectric layer using cascading and mode-matching techniques. Furthermore, the power transmission, reflection, and absorption coefficients, as functions of frequency and layer width, are studied, showing the expected behavior of these parameters. The method proposed in this paper gives directly applicable results that do not require cascading and mode matching, while at the same time having the ability to model smooth transitions that are more realistic in several applications. (C) 2020 Optical Society of America

  • 68.
    Danielsson, Max
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Technology and Aesthetics.
    Grahn, Håkan
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Sievert, Thomas
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Rasmusson, Jim
    Sony Mobile Communications AB, SWE.
    Comparing Two Generations of Embedded GPUs Running a Feature Detection AlgorithmManuscript (preprint) (Other academic)
    Abstract [en]

    Graphics processing units (GPUs) in embedded mobile platforms are reaching performance levels where they may be useful for computer vision applications. We compare two generations of embedded GPUs for mobile devices when run- ning a state-of-the-art feature detection algorithm, i.e., Harris- Hessian/FREAK. We compare architectural differences, execu- tion time, temperature, and frequency on Sony Xperia Z3 and Sony Xperia XZ mobile devices. Our results indicate that the performance soon is sufficient for real-time feature detection, the GPUs have no temperature problems, and support for large work-groups is important.

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  • 69. Danielsson, Max
    et al.
    Sievert, Thomas
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Grahn, Håkan
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Rasmusson, Jim
    Sony Mobile Communications AB.
    Feature Detection and Description using a Harris-Hessian/FREAK Combination on an Embedded GPU2016Conference paper (Refereed)
    Abstract [en]

    GPUs in embedded platforms are reaching performance levels comparable to desktop hardware, thus it becomes interesting to apply Computer Vision techniques. We propose, implement, and evaluate a novel feature detector and descriptor combination, i.e., we combine the Harris-Hessian detector with the FREAK binary descriptor. The implementation is done in OpenCL, and we evaluate the execution time and classification performance. We compare our approach with two other methods, FAST/BRISK and ORB. Performance data is presented for the mobile device Xperia Z3 and the desktop Nvidia GTX 660. Our results indicate that the execution times on the Xperia Z3 are insufficient for real-time applications while desktop execution shows future potential. Classification performance of Harris-Hessian/FREAK indicates that the solution is sensitive to rotation, but superior in scale variant images.

  • 70.
    Dost, Shahi
    et al.
    TIB, Leibniz Information Centre for Science and Technology, DEU.
    Saud, Faryal
    National University of Computer and Emerging Sciences, PAK.
    Shabbir, Maham
    National University of Computer and Emerging Sciences, PAK.
    Khan, Muhammad Gufran
    National University of Computer and Emerging Sciences, PAK.
    Shahid, Muhammad
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lövström, Benny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Reduced reference image and video quality assessments: review of methods2022In: EURASIP Journal on Image and Video Processing, ISSN 1687-5176, E-ISSN 1687-5281, Vol. 2022, no 1, article id 1Article, review/survey (Refereed)
    Abstract [en]

    With the growing demand for image and video-based applications, the requirements of consistent quality assessment metrics of image and video have increased. Different approaches have been proposed in the literature to estimate the perceptual quality of images and videos. These approaches can be divided into three main categories; full reference (FR), reduced reference (RR) and no-reference (NR). In RR methods, instead of providing the original image or video as a reference, we need to provide certain features (i.e., texture, edges, etc.) of the original image or video for quality assessment. During the last decade, RR-based quality assessment has been a popular research area for a variety of applications such as social media, online games, and video streaming. In this paper, we present review and classification of the latest research work on RR-based image and video quality assessment. We have also summarized different databases used in the field of 2D and 3D image and video quality assessment. This paper would be helpful for specialists and researchers to stay well-informed about recent progress of RR-based image and video quality assessment. The review and classification presented in this paper will also be useful to gain understanding of multimedia quality assessment and state-of-the-art approaches used for the analysis. In addition, it will help the reader select appropriate quality assessment methods and parameters for their respective applications.

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  • 71.
    Dziak, Damian
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Detection and Classification Multi-sensor Systems: Implementation of IoT and Systematic Design Approaches2020Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The detection and classification of features or properties, which characterize people, things or even events can be done in reliable way due to the development of new technologies such as Internet of Things (IoT), and also due to advances in Artificial Intelligence (AI) and machine learning algorithms. Interconnection of users with sensors and actuators have become everyday reality and IoT, an advanced notation of a Multi-sensor System, has become an integral part of systems for assessment of people’s habits and skills as well as the evaluation of quality of things or events' performances. The assessment approach presented in this thesis could be understood as an evaluation of multidimensional fuzzy quantities, which lack standards or references.

    The main objective of this thesis is systematical design of multi-sensor systems for industrial and behavioral applications. The systematization is based on User Oriented Design (UOD), the methodology where stakeholders and future users are actively involved in all steps of the development process. An impact of the application environment on design principles is quantitatively and qualitatively analyzed. It shows different design approaches, which can be used for developing systems monitoring human activities or industrial processes.

    The features identification approach applied in this thesis involves the extraction of the necessary data, which could be used for behavior classification or skills assessment. The data used for these purposes are vision or radio-based localization and orientation combined with measurement data of speed, acceleration, execution time or the remaining energy level.

    Background removal, colour segmentation, Canny filtering and Hough Transform are the algorithms used in vision applications presented in the thesis. In cases of radio-based solutions the methods of angle of arrival, time difference of arrival and pedestrian dead reckoning were utilized. The applied classification and assessment methods were based on AI with algorithms such as decision trees, support vector machines and k-nearest neighborhood.

    The thesis proposes a graphical methodology for visualization and assessment of multidimensional fuzzy quantities, which facilitate assessor's conceptualization of strengths and weaknesses in a person's skills or abilities. Moreover, the proposed method can be concluded as a single number or score useful for the evaluation of skills improvement during of training.

    The thesis is divided into two parts. The first part, Prolegomena, shows the technical background, an overview of applied theories along with research and design methods related to systems for identification and classification of people’s habits and skills as well as assessing the quality of things or performances. Moreover, this part shows relationships among the papers constituting the second part titled Papers, which includes six reformatted papers published in peer reviewed journals. All the papers concern the design of IoT systems for industrial and behavioral applications.

     

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  • 72.
    Dziak, Damian
    et al.
    Bioseco S. A., POL.
    Gradolewski, Dawid
    Bioseco S. A., POL.
    Witkowski, Szymon
    Bioseco S. A., POL.
    Kaniecki, Damian
    Bioseco S. A., POL.
    Jaworski, Adam
    Bioseco S. A., POL.
    Skakuj, Michal
    Ekoaviation, POL.
    Kulesza, Wlodek
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Airport Wildlife Hazard Management System - A Sensor Fusion Approach2022In: Elektronika ir Elektrotechnika, ISSN 1392-1215, Vol. 28, no 3, p. 45-53Article in journal (Refereed)
    Abstract [en]

    Aviation reports indicate that between 1988 and 2019 there were 292 human deaths and 327 injuries that had been reported from wildlife strikes with airplanes. To minimize these numbers, a new approach to airport Wildlife Hazard Management (WHM) is presented in the following article. The proposed solution is based on the data fusion of thermal and vision streams, which are used to improve the reliability and adaptability of the real-time WHM system. The system is designed to operate under all environmental conditions and provides advance information on the fauna presence on the airport runway. The proposed sensor fusion approach was designed and developed using user-driven design methodology. Moreover, the developed system has been validated in real-case scenarios and previously installed at an airport. Performed tests proved detection capabilities during day and night of dog-sized animals up to 300 meters. Moreover, by using machine learning algorithms during daylight, the system was able to classify person-sized objects with over 90 % efficiency up to 300 meters and dog-sized objects up to 200 meters. The general accuracy of the threat level based on the three safety zones was 94 %. © 2022 Kauno Technologijos Universitetas. All rights reserved.

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  • 73.
    Eriksson, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Fe II fluorescence in main-sequence K-dwarfs2024In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 527, no 3, p. 9522-9528Article in journal (Refereed)
    Abstract [en]

    Main-sequence K-dwarfs possess strong emission in the form of the H I Ly α line. There is a close coincidence between the energy corresponding to the transitions H I 1s-2p and Fe II (5D)5s 4D5/2–(5D)5p 4D5/2. Singly ionized iron has been confirmed being pumped by photo-excitation by accidental resonance (PAR) in planetary nebulae, symbiotic stars, K-giants, and active galactic nebulae. I investigate in this work whether PAR can occur in the atmospheres of main-sequence K-dwarfs, which do not possess the large extended atmospheres of the late-type K-giants. Specifically a search for possible Fe II fluorescence lines is conducted. For the case when I can confirm PAR, I estimate the total flux leaving the stars in the form of Fe II fluorescence. I search for emission lines from the Fe II (5D)5p 4D5/2 level. Since those of these lines with the largest branching fractions correspond to lines at wavelengths covered by the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, a search for archival FUSE spectra from K-dwarfs within 20 ly from the sun is conducted. I retrieve and analyse FUSE spectra for four of these K-dwarfs. In each case I can confirm PAR, I fit the H I Ly α line in Hubble Space Telescope spectra recorded with the Space Telescope Imaging Spectrograph, in order to estimate the efficiency of the PAR mechanism. I can now confirm Fe II fluorescence in the two closest K-dwarfs, Alpha Centauri B, and Epsilon Eridani. The total power leaving as Fe II fluorescence are 4.9 × 1017 and 1.30 × 1018 W respectively. © The Author(s) 2023 Published by Oxford University Press on behalf of Royal Astronomical Society.

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  • 74.
    Eriksson, Mattias
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lennerstad, Håkan
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    A new formula for the statistical weight for a sequence of Rydberg levels in an atom or ion2017In: Journal of Physics: Conference Series / [ed] Majeed T.,Egilmez M.,Alnaser A.S.,Abdel-Naby S.,Hamdan N.,Guessoum N.,Salamin Y.,El-Khatib S.,Sakhi S.,Syed R., Institute of Physics Publishing , 2017, Vol. 869, no 1, article id UNSP 012010Conference paper (Refereed)
    Abstract [en]

    We present a new formula for the total statistical weight of all Rydberg levels Gion (nl, nh ) for which the principal quantum number n is between higher, nh , and a lower, nl , limits. This formula can be used for all atoms in the periodic table and for all corresponding ions.

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  • 75.
    Fabrin, Ana
    et al.
    Universidade Federal de Santa Maria, BRA.
    Molin, Ricardo
    Universidade Federal de Santa Maria, BRA.
    Alves, Dimas Irion
    Universidade Federal do Pampa, BRA.
    Machado, Renato
    Universidade Federal de Santa Maria, BRA.
    Bayer, Fabio
    Universidade Federal de Santa Maria, BRA.
    Pettersson, Mats
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    A CFAR optimization for low frequency UWB SAR change detection algorithms2017In: International Geoscience and Remote Sensing Symposium (IGARSS), Institute of Electrical and Electronics Engineers Inc. , 2017, p. 1071-1074Conference paper (Refereed)
    Abstract [en]

    This paper presents a study on the constant false alarm rate (CFAR) filter design for change detection algorithms (CDA). More specifically, we are interested in CFAR filters used in CDA for low frequency ultra-wideband (UWB) synthetic aperture radar (SAR) systems. The filter design performance was evaluated in terms of false alarm rate (FAR) and probability of detection (PD). For evaluation purposes, we considered a set of SAR images obtained with the CARABAS-II system. The results are compared with the ones presented in [1], where the same CDA was considered, except for the CFAR filter. The results show that relevant FAR performance improvements can be obtained by just modifying the CFAR filter parameters taking into account the image resolution and target characteristics. © 2017 IEEE.

  • 76.
    Fredriksson, Henrik
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    On the use of traffic flows for improved transportation systems: Mathematical modeling and applications2021Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concerns the mathematical modeling of transportation systems for improved decision support and analysis of transportation-related problems. The main purpose of this thesis is to develop and evaluate models and methods that exploit link flows. Link flows are straightforward to obtain by measurements or estimation methods and are commonly used to describe the traffic state. The models and methods used in this thesis apply mathematical optimization techniques, computer simulations, and probabilistic methods to gain insights into the transportation network under study and provide benefits for both traffic managers and road users. 

    First, we present an optimization model for allocating charging stations in a transportation network to serve owners of electric vehicles. The model utilizes a probabilistic route selection process to detect locations through which vehicles may pass. It also considers the limited driving range of electric vehicles. The iterative solution procedure finds the minimal number of minimal charging stations and their locations, which provides a lower bound of charging stations to cover each of the considered routes. Second, we present a case study, in which we argue that stationary and mobile measurement devices possess complementary characteristics. In that study, we investigate how speed cameras and probe vehicles can be used in conjunction with each other for the collection of detailed traffic data. The results show that the share of successfully observed and identified vehicles can be significantly improved by using both stationary and mobile measurement devices. Third, we present a simulation model with the intent of finding the most probable underlying routes based on hourly link flows. The model utilizes Dijkstra's algorithm to find the shortest paths and uses a straightforward statistical test procedure to find the most significant routes in the network based on replicated movements of trucks. Finally, we investigate the possibility to study how the traffic flow in one location reflects the flows in the surrounding area. The statistical basis of the proposed model is built upon measured link flows to study the dispersion of aggregate traffic flows in nodes. By considering the alternative ways vehicles can travel between locations, the model is able to determine the expected link flow that originates from a node in a nearby region.

    The results of the thesis show that the link flows, which are basic descriptors of the road segments in a transportation network, can be used to study a broad range of problems in transportation.

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  • 77.
    Fredriksson, Henrik
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö universitet, SWE.
    Optimal Allocation of Charging Stations for Electric Vehicles Using Probabilistic Route Selection2021In: Computing and informatics, ISSN 1335-9150, Vol. 40, no 2, p. 408-427Article in journal (Refereed)
    Abstract [en]

    Electric vehicles (EVs) are environmentally friendly and are considered to be a promising approach toward a green transportation infrastructure with lower greenhouse gas emissions. However, the limited driving range of EVs demands a strategic allocation of charging facilities, hence providing recharging opportunities that help reduce EV owners' anxiety about their vehicles' range. In this paper, we study a set covering method where self-avoiding walks are utilized to find the most significant locations for charging stations. In the corresponding optimization problem, we derive a lower bound of the number of charging stations in a transportation network to obtain full coverage of the most probable routes. The proposed method is applied to a transportation network of the southern part of Sweden.

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  • 78.
    Fredriksson, Henrik
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö Högskola, SWE.
    Optimal placement of charging stations for electric vehicles in large-scale transportation networks2019In: Procedia Computer Science / [ed] Shakshuki, E; Yasar, A; Malik, H, Elsevier B.V. , 2019, Vol. 160, p. 77-84Conference paper (Refereed)
    Abstract [en]

    This paper presents a new practical approach to optimally allocate charging stations in large-scale transportation networks for electric vehicles (EVs). The problem is of particular importance to meet the charging demand of the growing fleet of alternative fuel vehicles. Considering the limited driving range of EVs, there is need to supply EV owners with accessible charging stations to reduce their range anxiety. The aim of the Route Node Coverage (RNC) problem, which is considered in the current paper, is to find the minimum number of charging stations, and their locations in order to cover the most probable routes in a transportation network. We propose an iterative approximation technique for RNC, where the associated Integer Problem (IP) is solved by exploiting a probabilistic random walk route selection, and thereby taking advantage of the numerical stability and efficiency of the standard IP software packages. Furthermore, our iterative RNC optimization procedure is both pertinent and straightforward to implement in computer coding and the design technique is therefore highly applicable. The proposed optimization technique is applied on the Sioux-Falls test transportation network, and in a large-scale case study covering the southern part of Sweden, where the focus is on reaching the maximum coverage with a minimum number of charging stations. The results are promising and show that the flexibility, smart route selection, and numerical efficiency of the proposed design technique, can pick out strategic locations for charging stations from thousands of possible locations w ithout numerical difficulties. ©2019 Hie Authors. Published by Elsevier B.V.

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    Optimal placement of Charging Stations for Electric Vehicles inlarge-scale Transportation Networks
  • 79.
    Fredriksson, Henrik
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö universitet.
    Lövström, Benny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Irvenå, Johan
    Trafikverket.
    Mårtensson, Matilda
    Trafikverket.
    Förstudie – Datadriven analys av restider2022Report (Other academic)
    Abstract [en]

    Modern vehicles are to a large extent connected today, either directly by built-in navigation systems in the vehicles or indirectly by other devices such as mobile phones and GPS units. This enables the possibility to continuously collect traffic data in a cost-effective way. The increased access to detailed data allows practitioners and researchers to analyze the transportation system from various perspectives. The travel speed is a common descriptor of the traffic state, and it can be extracted from GPS data. By analyzing how the travel speed vary over time and detect anomalies among the measured travel speeds, it is possible to detect potential deficiencies in the transportation system, e.g., insufficient road capacity which may cause bottlenecks. Often, a weakness in the infrastructure is detected in a very late stage which means that extensive investments may be required to resolve the deficiency.

    The purpose of the pilot study is to develop methods and models to detect deficiency in the transportation system and to identity travel speeds that deviates from the normal state, i.e., travel speeds that are considered as very low or very high with respect to the normal behavior. Thus, the starting point of the pilot study is to find appropriate ways to model the traffic state along the studied road segments by using measured travel speeds from a general point of view. Analysis of the traffic state allows the study of how the normal state of the road segments change of time to detect deficiency related to road capacity and road access which may occur if no changes are made, or to detect road segments where the normal state is unchanged.

    Typically, slower travel speeds may be an indicator of that a deficiency along a road segment exists. Thus, we present a method to systematically partition measured travel speeds in low, normal, and high travel speeds. The method is robust and enable the possibility to compare different road segment with different attributes, such as number of lanes and free-flow travel speed, with each other. Furthermore, we present a new measurement to describe how the low travel speeds relates to the free flow travel speed, e.g., the speed limit. Existing measurements and indicators used today utilize travel speeds which range from low to high. Our proposed measurement uses low travel speed and free flow travel speed exclusively and aims to quantify the accessibility and condition of a road segment.

    The pilot study also includes an initial attempt to apply cluster analysis to detect recurrent patterns along the studied road segments. Cluster analysis is in several contexts an effective method to group time series to detect recurrent patterns among the speed profiles. The purpose of using cluster analysis is to evaluate if speed profiles with similar behavior is related to, for instance, weekday or time of the day. Thus, cluster analysis may be used to detect road segments with recurring low travel speeds, and potentially be used to forecast when congestion or queues may occur.

    The pilot study is mainly limited to travel speed data. The proposed methods and models show that it is possibly to solely use travel speed data to detect deficiencies in the transportation system. In particular, the pilot study shows the potential to detect deficiencies in the transportation system without additional data sources such as link flow data.

  • 80.
    Fredriksson, Henrik
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lövström, Benny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö Universitet, SWE.
    Lennerstad, Håkan
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Modeling of road traffic flows in the neighboring regions2021In: Procedia Computer Science / [ed] Shakshuki E., Yasar A., Elsevier, 2021, p. 43-50Conference paper (Refereed)
    Abstract [en]

    Traffic flows play a very important role in transportation engineering. In particular, link flows are a source of information about the traffic state, which is usually available from the authorities that manage road networks. Link flows are commonly used in both short-term and long-term planning models for operation and maintenance, and to forecast the future needs of transportation infrastructure. In this paper, we propose a model to study how traffic flow in one location can be expected to reflect the traffic flow in a nearby region. The statistical basis of the model is derived from link flows to find estimates of the distribution of traffic flows in junctions. The model is evaluated in a numerical study, which uses real link flow data from a transportation network in southern Sweden. The results indicate that the model may be useful for studying how large departing flows from a node reflect the link flows in a neighboring geographic region. 

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  • 81.
    Fredriksson, Henrik
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Holmgren, Johan
    Malmö universitet.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lövström, Benny
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    A Median-Based Misery Index for Travel Time Reliability2023In: Procedia Computer Science / [ed] Elhadi Shakshuki, Elsevier, 2023, Vol. 220, p. 162-169Conference paper (Refereed)
    Abstract [en]

    Travel time reliability is vital for both road agencies and road users. Expected travel time reliability can be used by road agencies to assess the state of a transportation system, and by road users, to schedule their trips. Road network deficiencies, such as insufficient traffic flow capacity of a road segment or poor road design, have a negative impact on the reliability of travel times. Thus, to maintain robust and reliable travel times, the detection of road network deficiencies is vital. By continuously analyzing travel times and using appropriate travel time reliability measurements, it is possible to detect existing deficiencies or deficiencies that may eventually occur unless necessary actions are taken. In many cases, indices and measurements of travel time reliability are related to the distribution of the travel times, specifically the skewness and width of the distribution. The current paper introduces a median-based misery index for travel time reliability. The index is robust and handles travel times that follow a skewed distribution well. The index measures the relative difference between the slow travel speeds and the free-flow travel speed. The index is inspired by the median absolute deviation, and its primary application is to detect routes or road segments with potential road network deficiencies. To demonstrate the applicability of the index, we conducted an empirical case study using real travel speed data from the European route E4 in Sweden. The results from the empirical case study indicate that the index is capable of detecting road segments with slow travel speeds regardless of the travel speed distribution.

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  • 82. Gazizov, R. K.
    et al.
    Ibragimov, N. H.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Lukashchuk, S. Yu.
    Nonlinear self-adjointness, conservation laws and exact solutions of time-fractional Kompaneets equations2015In: Communications in nonlinear science & numerical simulation, ISSN 1007-5704, E-ISSN 1878-7274, Vol. 23, no 1-3, p. 153-163Article in journal (Refereed)
    Abstract [en]

    Four time-fractional generalizations of the Kompaneets equation are considered. Group analysis is performed for physically relevant approximations. It is shown that all approximations have nontrivial symmetries and conservation laws. The symmetries are used for constructing group invariant solutions, whereas the conservation laws allow to find non-invariant exact solutions. (C) 2014 Elsevier B.V. All rights reserved.

  • 83.
    Glashoff, Sofia
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Systemsäkerhetsarbete för forsknings- och försöksverksamhet inom Försvarsmaktens dykeri2023Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To enable further technical development and research, developing new systems or products that are not yet available on the market is often necessary. The safety risks that arise with newly developed systems or products should be addressed before they are put into use, which is done through system safety work within the Swedish Armed Forces (FM). System safety work aims for the system or product to undergo a systematic process to achieve the organization's safety requirements and tolerable risk levels.

    This report examines how system safety work can be applied to research and test setups in diving at the Swedish Armed Forces Diving and Naval Medicine Center (FM DNC) in Karlskrona. The work aims to examine the updated process according to the new version of the System Safety Handbook, published year 2022, and to apply it to research and experimental setups. The report uses the Inert Gas Utvädringsmaskin (IGUM) system as an example to be able to develop a suitable process with the aim of getting the system approved for research purposes. The report also examines whether system safety work can be made more efficient by developing a more standardized process.

    The method consists of four parts: Literature studies, interviews, a course, and supervision. By combining information from the literature with answers gathered from the interviews, a result was found. The outcome includes three exemplified process methods, depending on the system or product's area of use, as well as how system safety work can be made more efficient. The three process methods presented are based on the handbook and a combination of Regler för Militär Sjöfart Dyk (RMS-Dyk) and Handlingsregel 05 (HR 05), as well as the answers given during the interviews.

    Currently, there is still no established knowledge of how system safety work should be done on research and test setups within the Swedish Armed Forces diving operations, which makes the report an asset for further development within this field. This not only benefits personnel within the organization but also the society, as there is an opportunity for further development and research.

  • 84.
    Gomes, Natanael Rodrigues
    et al.
    Federal University of Santa Maria, BRA.
    Dammert, Patrik
    Saab Surveillance AB, SWE.
    Pettersson, Mats
    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.
    Hellsten, Hans
    Saab Surveillance AB, SWE.
    Comparison of the Rayleigh and K-Distributions for Application in Incoherent Change Detection2019In: IEEE Geoscience and Remote Sensing Letters, ISSN 1545-598X, E-ISSN 1558-0571, Vol. 16, p. 756-760Article in journal (Refereed)
    Abstract [en]

    The aim of this letter is to compare two incoherent change-detection algorithms for target detection in low-frequency ultrawideband (UWB) synthetic aperture radar (SAR) images. The considered UWB SAR operates in the frequency range from 20 to 90 MHz. Both approaches employ a likelihood ratio test according to the Neyman–Pearson criterion. First, the bivariate Rayleigh probability distribution is used to implement the likelihood ratio test function. This distribution is well known and has been used for change-detection algorithms in low-frequency UWB SAR with good results. Aiming to minimize the false alarm rate and taking into consideration that low-frequency UWB SAR images have high resolution compared to the transmitted wavelength, the second approach implements the test by using a bivariate K-distribution. This distribution has scale and shape parameters that can be used to adjust it to the data. No filter is applied to the data set images, and the results show that with a good statistical model, it is not needed to rely on filtering the data to decrease the number of false alarms. Therefore, we can have a better tradeoff between resolution and detection performance.

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  • 85.
    Gradolewski, Dawid
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Sensors and Algorithms in Industry 4.0: Security and Health Preservation Applications2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Globalisation and technological digitisation have triggered an Industry 4.0. revolution.  The core of this revolution is autonomisation of complex processes, which require expert knowledge. The technical foundations of Industry 4.0 are IoT, Big Data and AI technologies. Nowadays, autonomous systems are widely used to increase human and environmental safety and to prevent health degradation.  Such non-industrial, life related applications demand high reliability as well as precision and accuracy, which challenge engineering science. 

    The thesis objective is to provide suitable solutions for non-invasive, automated, and autonomous systems used for life protection and health maintenance. The proposed solutions enable non-invasive measurements by means of vision and acoustic sensors. The presented methods and systems are designed based on an analytical assessment of existing technologies and algorithms. New hardware solutions, signal and data processing methods, as well as classification and decision-making algorithms are proposed. Where required, additional customisations and modifications are applied. The systems and methods presented have been modelled and rigorously validated, and subsequently implemented and verified in a real environment.  

    The scope of the thesis includes the assessment of functional requirements, precision, accuracy and reliability of life-related technological systems. It covers an analytical evaluation of proposed methods and algorithms of filtration, feature extraction, also detection, localization, identification, and classification of objects. The application fields are health monitoring, nature observation and facilitating collaborative frameworks in modern factories. 

    The thesis specifically focuses on methods and algorithms of autonomous decision making concerning the risk of heart disease, the threat of fatal collision of rare birds with man-made structures and the prevention of accidents in modern robotised factories. It also deals with the implementation of the Industry 4.0 fundamentals, which are smart sensing, IoT and AI methods optimised to improve the system performance in a broad sense. The applied distributed computing method and machine-to-machine communication are aimed at limiting the data stream at an early stage of the decision-making process, and thus ensure the system’s cost-effectiveness. From the thesis, one can understand how the Industry 4.0 paradigm can contribute to autonomisation of compound processes and to increase system performance, without compromising its affordability.

    The thesis is divided into two parts. The first, Prolegomena provides an overview of the sensors and algorithms applicable to industrial safety along with human health and nature preservation. This part also visualizes the relationships and interactions among the articles comprising the second part named Papers. In general, each of the enclosed six papers deals with the problem of autonomisation of complex processes in real-time and in a regular environment.

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  • 86.
    Gradolewski, Dawid
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Bioseco Sp. z. o. o, POL.
    Dziak, Damian
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Kaniecki, Damian
    Bioseco Sp. z. o. o, POL.
    Jaworski, Adam
    Bioseco Sp. z. o. o, POL.
    Skakuj, Michal
    Ekoaviation, POL.
    Kulesza, Wlodek
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    A runway safety system based on vertically oriented stereovision2021In: Sensors, E-ISSN 1424-8220, Vol. 21, no 4, p. 1-25, article id 1464Article in journal (Refereed)
    Abstract [en]

    In 2020, over 10,000 bird strikes were reported in the USA, with average repair costs exceeding $200 million annually, rising to $1.2 billion worldwide. These collisions of avifauna with airplanes pose a significant threat to human safety and wildlife. This article presents a system dedicated to monitoring the space over an airport and is used to localize and identify moving objects. The solution is a stereovision based real-time bird protection system, which uses IoT and distributed computing concepts together with advanced HMI to provide the setup’s flexibility and usability. To create a high degree of customization, a modified stereovision system with freely oriented optical axes is proposed. To provide a market tailored solution affordable for small and medium size airports, a user-driven design methodology is used. The mathematical model is implemented and optimized in MATLAB. The implemented system prototype is verified in a real environment. The quantitative validation of the system performance is carried out using fixed-wing drones with GPS recorders. The results obtained prove the system’s high efficiency for detection and size classification in real-time, as well as a high degree of localization certainty. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 87.
    Gradolewski, Dawid
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Bioseco Sp. z. o. o., POL.
    Dziak, Damian
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Bioseco Sp. z. o. o., POL.
    Martynow, Milosz
    Bioseco Sp. z. o. o., POL.
    Kaniecki, Damian
    Bioseco Sp. z. o. o., POL.
    Szurlej-Kielanska, Aleksandra
    University of Gdansk, POL.
    Jaworski, Adam
    Bioseco Sp. z. o. o., POL.
    Kulesza, Wlodek
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Comprehensive bird preservation at wind farms2021In: Sensors, E-ISSN 1424-8220, Vol. 21, no 1, p. 1-35, article id 267Article in journal (Refereed)
    Abstract [en]

    Wind as a clean and renewable energy source has been used by humans for centuries. However, in recent years with the increase in the number and size of wind turbines, their impact on avifauna has become worrisome. Researchers estimated that in the U.S. up to 500,000 birds die annually due to collisions with wind turbines. This article proposes a system for mitigating bird mortality around wind farms. The solution is based on a stereo-vision system embedded in distributed computing and IoT paradigms. After a bird’s detection in a defined zone, the decision-making system activates a collision avoidance routine composed of light and sound deterrents and the turbine stopping procedure. The development process applies a User-Driven Design approach along with the process of component selection and heuristic adjustment. This proposal includes a bird detection method and localization procedure. The bird identification is carried out using artificial intelligence algorithms. Validation tests with a fixed-wing drone and verifying observations by ornithologists proved the system’s desired reliability of detecting a bird with wingspan over 1.5 m from at least 300 m. Moreover, the suitability of the system to classify the size of the detected bird into one of three wingspan categories, small, medium and large, was confirmed. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 88.
    Gradolewski, Dawid
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Intema Sp. z o.o., POL.
    Maslowski, Dawid
    Intema Sp Zoo, POL.
    Dziak, Damian
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Jachimczyk, Bartosz
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Mundlamuri, Siva Teja
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Intema Sp Zoo, Siennicka 25a, POL.
    Prakash, Chandran G.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Intema Sp Zoo, Siennicka 25a, POL.
    Kulesza, Wlodek
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. University of Social Sciences, POL.
    A Distributed Computing Real-Time Safety System of Collaborative Robot2020In: Elektronika ir Elektrotechnika, ISSN 1392-1215, Vol. 26, no 2, p. 4-14Article in journal (Refereed)
    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
  • 89.
    Gradolewski, Dawid
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Redlarski, Grzegorz
    Gdansk University of Technology, POL.
    Palkowski, Aleksander
    Gdansk University of Technology, POL.
    A system for heart sounds classification2014In: PLOS ONE, E-ISSN 1932-6203, Vol. 9, no 11, p. 1-12, article id e112673Article in journal (Refereed)
    Abstract [en]

    The future of quick and efficient disease diagnosis lays in the development of reliable non-invasive methods. As for the cardiac diseases – one of the major causes of death around the globe – a concept of an electronic stethoscope equipped with an automatic heart tone identification system appears to be the best solution. Thanks to the advancement in technology, the quality of phonocardiography signals is no longer an issue. However, appropriate algorithms for auto-diagnosis systems of heart diseases that could be capable of distinguishing most of known pathological states have not been yet developed. The main issue is non-stationary character of phonocardiography signals as well as a wide range of distinguishable pathological heart sounds. In this paper a new heart sound classification technique, which might find use in medical diagnostic systems, is presented. It is shown that by combining Linear Predictive Coding coefficients, used for future extraction, with a classifier built upon combining Support Vector Machine and Modified Cuckoo Search algorithm, an improvement in performance of the diagnostic system, in terms of accuracy, complexity and range of distinguishable heart sounds, can be made. The developed system achieved accuracy above 93% for all considered cases including simultaneous identification of twelve different heart sound classes. The respective system is compared with four different major classification methods, proving its reliability.

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  • 90.
    GUDURU, TABU SRAVANI
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    THATAVARTHY, SURYA NARAYANA MURTHY
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    IoT Based Home Monitoring System2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     Home surveillance is a major concern in this day and age as with the rapid increase in the technology around us. There is a need to get updated with new possibilities to make our lives better and easy. Some cases and situations exhibit the need for home monitoring. So, we set out to discover a solution to this problem of home monitoring.

    Generally, we have issues with pets and kids alike such as approaching dangerous places like electric switches, stairs, and hot things. Not only a problem with kids and pets but also a chance of burglary and stranger's unusual activities. To overcome this problem we are designing and prototyping a system to keep an eye on kids, pets, and older people. This system is used in other applications like theft monitoring. The device can monitor the field all the time. In this way, this system helps in-home monitoring.

    The system consists of Arduino, which is the brain of the system, the PIR sensor, ESP32-CAM, and buzzer. The PIR sensor detects motion then gives input to the Arduino. Arduino gives output to the ESP32-CAM and buzzer. The ESP32-CAM can be activated and sends information to the user through the web Interface and the application. The user can see the video streaming on the PC screen or any other display. The buzzer can emit a high volume signal indicating that "there is an alert at the home".

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  • 91.
    Hallösta, Simon
    et al.
    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.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Impact of Neural Network Architecture for Fingerprint Recognition2024In: Intelligent Systems and Pattern Recognition: Third International Conference, ISPR 2023, Hammamet, Tunisia, May 11–13, 2023, Revised Selected Papers, Part I / [ed] Akram Bennour, Ahmed Bouridane, Lotfi Chaari, Springer, 2024, Vol. 1940, p. 3-14Conference paper (Refereed)
    Abstract [en]

    This work investigates the impact of the neural networks architecture when performing fingerprint recognition. Three networks are studied; a Triplet network and two Siamese networks. They are evaluated on datasets with specified amounts of relative translation between fingerprints. The results show that the Siamese model based on contrastive loss performed best in all evaluated metrics. Moreover, the results indicate that the network with a categorical scheme performed inferior to the other models, especially in recognizing images with high confidence. The Equal Error Rate (EER) of the best model ranged between 4%−11% which was on average 6.5 percentage points lower than the categorical schemed model. When increasing the translation between images, the networks were predominantly affected once the translation reached a fourth of the image. Our work concludes that architectures designed to cluster data have an advantage when designing an authentication system based on neural networks.

  • 92. Hellisten, Hans
    et al.
    Machado, Renato
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Pettersson, Mats I.
    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.
    Dammert, Patrik
    EXPERIMENTAL RESULTS ON CHANGE DETECTION BASED ON BAYES PROBABILITY THEOREM2015In: 2015 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS), IEEE Communications Society, 2015, p. 318-321Conference paper (Refereed)
    Abstract [en]

    In this paper we propose a new change detection (CD) algorithm based on the Bayes theorem and probability assignments. Differently from any kind of likelihood ratio test (LRT) algorithms, the proposed algorithm does not present target alarms, but the probability of certain image position is a target position. In other words, the proposed method leads to quantitative estimates on the probability of a target at any pixel, whereas LRT algorithms can only be used as a figure of merit for any pixel to contain a target.

  • 93.
    Heskebeck, Frida
    et al.
    Lund Univ, SWE.
    Bergeling, Carolina
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Bernhardsson, Bo
    Lund Univ, SWE.
    Multi-Armed Bandits in Brain-Computer Interfaces2022In: Frontiers in Human Neuroscience, E-ISSN 1662-5161, Vol. 16, article id 931085Article, review/survey (Refereed)
    Abstract [en]

    The multi-armed bandit (MAB) problem models a decision-maker that optimizes its actions based on current and acquired new knowledge to maximize its reward. This type of online decision is prominent in many procedures of Brain-Computer Interfaces (BCIs) and MAB has previously been used to investigate, e.g., what mental commands to use to optimize BCI performance. However, MAB optimization in the context of BCI is still relatively unexplored, even though it has the potential to improve BCI performance during both calibration and real-time implementation. Therefore, this review aims to further describe the fruitful area of MABs to the BCI community. The review includes a background on MAB problems and standard solution methods, and interpretations related to BCI systems. Moreover, it includes state-of-the-art concepts of MAB in BCI and suggestions for future research.

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  • 94.
    Hjelte, Carl
    et al.
    Lund University.
    Plogmark, Oskar
    Lund University .
    Silvanius, Mårten
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences. Swedish Armed Forces Diving and Naval Medicine Center.
    Ekström, Magnus
    Lund University.
    Frånberg, Oskar
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Risk assessment of SWEN21 a suggested new dive table for the Swedish armed forces: bubble grades by ultrasonography2023In: Diving and Hyperbaric Medicine, ISSN 1833-3516, Vol. 53, no 4, p. 299-305Article in journal (Refereed)
    Abstract [en]

    Introduction: To develop the diving capacity in the Swedish armed forces the current air decompression tables are under revision. A new decompression table named SWEN21 has been created to have a projected risk level of 1% for decompression sickness (DCS) at the no stop limits. The aim of this study was to evaluate the safety of SWEN21 through the measurement of venous gas emboli (VGE) in a dive series. Methods: A total 154 dives were conducted by 47 divers in a hyperbaric wet chamber. As a proxy for DCS risk serial VGE measurements by echocardiography were conducted and graded according to the Eftedal-Brubakk scale. Measurements were done every 15 minutes for approximately 2 hours after each dive. Peak VGE grades for the different dive profiles were used in a Bayesian approach correlating VGE grade and risk of DCS. Symptoms of DCS were continually monitored. Results: The median (interquartile range) peak VGE grade after limb flexion for a majority of the time-depth combinations, and of SWEN21 as a whole, was 3 (3-4) with the exception of two decompression profiles which resulted in a grade of 3.5 (3-4) and 4 (4-4) respectively. The estimated risk of DCS in the Bayesian model varied between 4.7-11.1%. Three dives (2%) resulted in DCS. All symptoms resolved with hyperbaric oxygen treatment. Conclusions: This evaluation of the SWEN21 decompression table, using bubble formation measured with echocardiography, suggests that the risk of DCS may be higher than the projected 1%. Copyright: This article is the copyright of the authors who grant Diving and Hyperbaric Medicine a non-exclusive licence to publish the article in electronic and other forms.

  • 95. Hjälmdahl, Magnus
    et al.
    Clemedthson, Per-Olof
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Fastén, Gunnar
    Mbiydzenyuy, Gideon
    Pettersson, Mats
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Sundberg, Jonas
    Effektutvärdering av kilometerskatt: Slutrapport. Slutsats och rekommendation2017Report (Other academic)
    Abstract [sv]

    Urinsikten om behovet av brukaravgifter inom transportsektornföddes idén att skapa en arena för den samlade kompetenseni Sverige. Detta blev ARENA-projektet, vars första fas,2006-2008,hade som mål attutveckla ett koncept för ett vägavgiftssystem för lastbilar.Den andra fasen avslutades2011 med syftet att verifiera det utvecklade vägavgiftskonceptet genom praktiska demonstrationer. Projektet lade även grunden för en innovationsmiljö inom ITS, som är knuten till NetPort Science Park och Blekinge Tekniska Högskola.I den tredje fasen breddades anslaget till att stödja utveckl-ingen av samverkan och interoperabilitet mellan olika system för exempelvis trängselskatt, infra-strukturavgifter eller kilometerskatt, såväl i Sverige som internationellt.Från 2015 har ARENA övergått till att vara en långsiktig nationell kunskapsplattform för brukaravgif-ter inom transportsektorn. Inom ARENA drivs olika projekt beroende på de problemställningar som är aktuella i samhället. Ett av dessa handlar om att utveckla metodik för effektutvärdering av kilome-terskatt för tunga fordonDetta projekt har löpt parallellt med Vägslitageskattekommitténarbete och som ARENAsamverkat medoch stöttat.Arbetet inom ARENA fokuserarpå attutreda vilka effekterav en kilometerskatt som är troliga/möj-liga och vilka av dessa som i sin tur är möjliga att observeraoch hur de kan observeras. Detta har gjorts genom bl.a. inventeringar av andra liknande initiativ och hur de har utvärderats, litteraturge-nomgångar och workshops. Rapporter från detta arbete återfinns på projektets hemsida (http://www.arena-ruc.se/). Denna avslutande rapport fokuserar framförallt på övergripande slutsat-ser baserat på arbetet inom ARENA,samt de rekommendationer om datainsamling och utvärdering som projekt-och styrgruppen för ARENA anser är relevanta att nu gå vidare med, baserat på att ett beslut om införande av kilometerskatt inte har tagits och det är oklart huruvida beslut kommer att tas inom de närmaste åren. ARENA anser, med utgångspunkt i ovanstående, att en systematisk föremätning(ex-ante)bör ge-nomföras först när beslut om att införa skatten har tagits och det finns detaljerad information om hur skatten är utformad.ARENA anser dock att kunskapsnivån om godstransporter på väg generellt sett är bristfällig varför det är motiverat att inleda datafångst inom vissa utpekade områden för att stärka kunskapen. Den data som bör samlas in är värdefull också i samband med utvärdering av ef-fekterna av t.ex. förändrade cabotageregler, ändrade gränser för lastbilars mått och vikt, ändrad energi-och koldioxidbeskattning etc.Det pågår idag flera nationella initiativ kring förbättrat kunskapsunderlag om yrkestrafiken och gods-transporter på väg. ARENAs rekommendationer ligger i linje med dessa och arbetet kring att öka kun-skapsnivån bör fortgå.

  • 96.
    Holmgren, Johan
    et al.
    Malmö Universitet, SWE.
    Fredriksson, Henrik
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    On the use of active mobile and stationary devices for detailed traffic data collection: A simulation-based evaluation2021In: International Journal of Traffic and Transportation Management, ISSN 2371-5782, Vol. 3, no 1, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The process of collecting traffic data is a key component to evaluate the current state of a transportation network and to analyze movements of vehicles. In this paper, we argue that both active stationary and mobile measurement devices should be taken into account for high-quality traffic data with sufficient geographic coverage. Stationary devices are able to collect data over time at certain locations in the network and mobile devices are able to gather data over large geographic regions. Hence, the two types of measurement devices have complementary properties and should be used in conjunction with each other in the data collection process. To evaluate the complementary characteristics of stationary and mobile devices for traffic data collection, we present a traffic simulation model, which we use to study the share of successfully identified vehicles when using both types of devices with varying identification rate. The results from our simulation study, using freight transport in southern Sweden, shows that the share of successfully identified vehicles can be significantly improved by using both stationary and mobile measurement devices.

  • 97.
    Holmgren, Johan
    et al.
    Malmö Universitet, SWE.
    Fredriksson, Henrik
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Dahl, Mattias
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Traffic data collection using active mobile and stationary devices2020In: Procedia Computer Science / [ed] Elhadi M. Shakshuki, Ansar Yasar, Elsevier, 2020, Vol. 177, p. 49-56Conference paper (Refereed)
    Abstract [en]

    In this paper, we study the complementary characteristics of stationary and mobile devices for traffic data collection. Since stationary devices continuously collect traffic data at fixed locations in a network, they can give insight of the traffic at particular locations over a longer period of time. Mobile devices have wider range and are able to collect traffic data over a larger geographic region.Thus, we argue that both types of technology should be considered to obtain high-quality information about vehicle movements .We present a traffic simulation model, which we use to study the share of successfully identified vehicles when considering both stationary and mobile technologies with varying identification rate. The results of our study, where we focus on freight transport insouthern Sweden, confirms that it is possible to identify the majority of vehicles, even when the identification rate is low, and thatthe share of identified vehicles can be increased by using both stationary and mobile measurement devices

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  • 98.
    Hultgren, Anders
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Rashid, Ahmed
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Laborationer i hemmiljö2021Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Närvaro av laborationer i våra civilingenjörsprogram är av vikt för att uppfylla följande:

    • Ge erfarenhet av hur förmedlade teorier kan användas i
    • praktiskt ingenjörsarbete.
    • Ge erfarenhet av hur väl förmedlade teorier kan beskriva
    • verkligheten.
    • Ge möjlighet att förstå förmedlade teorier från en praktisk
    • infallsvinkel.
    • Ge erfarenhet att hantera fysisk utrustning och hands on
    • lösa praktiska problem.
    • Ge erfarenheter av att använda industriella komponenter
    • och industriella utvecklingssystem.
    • Ge erfarenhet av att dokumentera praktiskt utvecklingsarbete.
    • Ge erfarenhet av ingenjörsarbete inkluderande Conceive,
    • Design, Implement and Operate.
    • När praktiska laborationer inte kan utföras på skolan
    • rekommenderar vi att försöka genomföra praktiska laborationer
    • i hemmiljö.
    • Flera av en laborationens viktiga uppgifter kan då realiseras,
    • dock inte alla.
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  • 99.
    Ibragimov, Nail
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Conservation laws and non-invariant solutions of anisotropic wave equations with a source2018In: Nonlinear Analysis: Real World Applications, ISSN 1468-1218, Vol. 40, p. 82-94Article in journal (Refereed)
    Abstract [en]

    Linear and nonlinear waves in anisotropic media are used in various fields, e.g. in biomechanics, biomedical acoustics, etc. The present paper is devoted to discussion of nonlinear anisotropic wave equations with a source from point of view of their conservation laws and exact solutions associated with conservation laws. Nonlinearly self-adjoint wave equations with special source terms are singled out. The conservation laws associated with symmetries of the nonlinearly self-adjoint wave equations are computed and used for constructing exact solutions. The obtained solutions are different from group invariants solutions, in particular, from steady state and traveling wave solutions. The paper is designed for the application oriented readers. Its main goal is to introduce readers, interested in solutions of mathematical models having real world applications, to the recent method of conservation laws for constructing exact solutions of partial differential equations using conservation laws. © 2017 Elsevier Ltd

  • 100.
    Ibragimov, Nail
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    Integration of dynamical systems admitting nonlinear superposition2016In: JOURNAL OF COUPLED SYSTEMS AND MULTISCALE DYNAMICS, ISSN 2330-152X, Vol. 4, no 2, p. 91-106Article, review/survey (Refereed)
    Abstract [en]

    A method of integration of non-stationary dynamical systems admitting nonlinear superpositions is presented. The method does not require knowledge of symmetries of the differential equations under consideration. The integration procedure is based on classification of Vessiot-Guldberg-Lie algebras associated with nonlinear superpositions. It is shown that the systems associated with one-and two-dimensional Lie algebras can be integrated by quadrature upon introducing Lie's canonical variables. It is not necessary to know symmetries of a system in question in this approach. Two-dimensional non-stationary dynamical systems with three-dimensional Vessiot-Guldberg-Lie algebras are classified into thirteen standard forms. Ten of them are integrable by quadrature. The remaining three standard forms lead to the Riccati equations. Integration of perturbed dynamical systems possessing approximate nonlinear superposition is discussed.

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