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Dahl, Mattias
Publications (10 of 76) Show all publications
Vu, V. T., Sjögren, T., Pettersson, M. & Dahl, M. (2017). Measurement of traffic flows with SAR: Field test on the swedish road network. In: International Geoscience and Remote Sensing Symposium (IGARSS): . Paper presented at 37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS,Forth Worth (pp. 3321-3324). Institute of Electrical and Electronics Engineers Inc.
Open this publication in new window or tab >>Measurement of traffic flows with SAR: Field test on the swedish road network
2017 (English)In: International Geoscience and Remote Sensing Symposium (IGARSS), Institute of Electrical and Electronics Engineers Inc. , 2017, p. 3321-3324Conference paper, Published paper (Refereed)
Abstract [en]

This paper reports the measurement campaign Blekingetraffic that was performed by Blekinge Institute of Technology with collaboration with the partners. The measurements are part of a case study to evaluate the feasibility of spaceborne SAR for measuring traffic flow change before and after toll charge introduced in Sweden. The radar measurements were conducted around Pukavik, western of Karlshamn, Sweden in the end of 2015 and in the beginning of 2016. In this paper, the results of one of the controlled measurements performed in the first week of February 2016 is presented. In the ground scene, some trucks tracked with GPS were deployed in European route E22 and local roads. The trucks have either cabinets or food tankers resulting in different radar cross sections. The data acquisition is with TanDEM-X using two satellites giving up to 6 data channels. Since the measurements were performed at 5:00 pm there were unknown traffic i.e. trucks and cars that were not controlled. Therefore, the traffic on the roads was recorded by cameras next to the road and on a drone. The initial analysis of the measured data shows the possibilities to apply available processing techniques such as ground moving target indication and change detection to obtain the knowledge of traffic flow change. © 2017 IEEE.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc., 2017
Series
IEEE International Symposium on Geoscience and Remote Sensing IGARSS, ISSN 000426954603103
Keywords
change detection, SAR, STAP, TanDEM-X, TerraSAR-X, traffic monitoring
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:bth-15924 (URN)10.1109/IGARSS.2017.8127708 (DOI)000426954603103 ()2-s2.0-85041860005 (Scopus ID)9781509049516 (ISBN)
Conference
37th Annual IEEE International Geoscience and Remote Sensing Symposium, IGARSS,Forth Worth
Available from: 2018-02-22 Created: 2018-02-22 Last updated: 2018-04-12Bibliographically approved
Javadi, M. S., Dahl, M. & Pettersson, M. (2016). Change detection in aerial images using a Kendall's TAU distance pattern correlation. In: PROCEEDINGS OF THE 2016 6TH EUROPEAN WORKSHOP ON VISUAL INFORMATION PROCESSING (EUVIP): . Paper presented at 2016 6th European Workshop on Visual Information Processing (EUVIP), Marseille. IEEE
Open this publication in new window or tab >>Change detection in aerial images using a Kendall's TAU distance pattern correlation
2016 (English)In: PROCEEDINGS OF THE 2016 6TH EUROPEAN WORKSHOP ON VISUAL INFORMATION PROCESSING (EUVIP), IEEE, 2016Conference paper, Published paper (Refereed)
Abstract [en]

Change detection in aerial images is the core of many remote sensing applications to analyze the dynamics of a wide area on the ground. In this paper, a remote sensing method is proposed based on viewpoint transformation and a modified Kendall rank correlation measure to detect changes in oblique aerial images. First, the different viewpoints of the aerial images are compromised and then, a local pattern descriptor based on Kendall rank correlation coefficient is introduced. A new distance measure referred to as Kendall's Tau-d (Tau distance) coefficient is presented to determine the changed regions. The developed system is applied on oblique aerial images with very low aspect angles that obtained using an unmanned aerial vehicle in two different days with drastic change in illumination and weather conditions. The experimental results indicate the robustness of the proposed method to variant illumination, shadows and multiple viewpoints for change detection in aerial images.

Place, publisher, year, edition, pages
IEEE, 2016
Keywords
Aerial images, change detection, Kendall rank correlation, optical remote sensing
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-13878 (URN)10.1109/EUVIP.2016.7764604 (DOI)000391630800023 ()978-1-5090-2781-1 (ISBN)
Conference
2016 6th European Workshop on Visual Information Processing (EUVIP), Marseille
Available from: 2017-02-03 Created: 2017-02-03 Last updated: 2017-02-21Bibliographically approved
Holmgren, J., Dahl, M., Davidsson, P. & Person, J. A. (2013). Agent-based simulation of freight transport between geographical zones. In: : . Paper presented at 4th International Conference on Ambient Systems, Networks and Technologies (ANT) / 3rd International Conference on Sustainable Energy Information Technology (SEIT), Halifax, Nova Scotia (pp. 829-834). Elsevier, 19
Open this publication in new window or tab >>Agent-based simulation of freight transport between geographical zones
2013 (English)Conference paper, Published paper (Refereed)
Abstract [en]

We present TAPAS-Z, which is an agent-based freight transport analysis model for simulation of decision-making and transport activities. TAPAS-Z is a further development of a simulation model called TAPAS, and it has improved support for simulation of transport in large geographical regions. It is based on the principles that shipments are simulated for chosen supplier-consumer relations in a geographic region, and that the geographic locations of suppliers and consumers are randomly varied for each shipment. In TAPAS-Z, one supplier represents all real-world suppliers in a geographic zone, and one consumer represents all real-world consumers in a zone. In that way, TAPAS-Z is able to capture some of the diversity in freight transport that is caused by the varying geographic locations of senders and receivers, and which is important when assessing the impact of transport policy and infrastructural measures.

Place, publisher, year, edition, pages
Elsevier, 2013
Series
Procedia Computer Science, ISSN 1877-0509
Keywords
Multi-agent-based simulation, MABS, Freight transport modeling, Zone-based freight simulation
National Category
Computer Sciences
Identifiers
urn:nbn:se:bth-6843 (URN)10.1016/j.procs.2013.06.110 (DOI)000361480500100 ()
Conference
4th International Conference on Ambient Systems, Networks and Technologies (ANT) / 3rd International Conference on Sustainable Energy Information Technology (SEIT), Halifax, Nova Scotia
Available from: 2013-12-02 Created: 2013-11-28 Last updated: 2018-01-11Bibliographically approved
Mbiydzenyuy, G., Dahl, M. & Holmgren, J. (2013). Road travel time prediction: A micro-level sampling approach. In: : . Paper presented at 16th International Conference on IEEE Intelligent Transport Systems. The Hague: IEEE Intelligent Transport Systems Society
Open this publication in new window or tab >>Road travel time prediction: A micro-level sampling approach
2013 (English)Conference paper, Published paper (Refereed)
Abstract [en]

The ability to generate accurate travel time predictions for road freight transport is important when, for example, estimating the arrival times for heavy goods vehicles (HGVs) in order to plan terminal activities. We present a micro-level sampling method for road travel time prediction. The method makes use of historical GPS-data in order to determine the movement of a vehicle from an origin to a destination along a specific route. The method generates a travel time distribution, which can be used to obtain the expected travel time and probabilities for deviations. The method has been illustrated and evaluated in an experiment where the effective travel time was predicted for transport between two terminals. The experiment made use of GPS data that was recorded for two HGVs during a period of two months. An important feature of the method is that it does not need road network information, such as speed limits and number of lanes.

Place, publisher, year, edition, pages
The Hague: IEEE Intelligent Transport Systems Society, 2013
Keywords
Simulation, Statistics, GPS, travel time, freight transport
National Category
Computer Sciences
Identifiers
urn:nbn:se:bth-6362 (URN)000346481000258 ()oai:bth.se:forskinfo0434A7C290EC55D1C1257C350040DE06 (Local ID)oai:bth.se:forskinfo0434A7C290EC55D1C1257C350040DE06 (Archive number)oai:bth.se:forskinfo0434A7C290EC55D1C1257C350040DE06 (OAI)
Conference
16th International Conference on IEEE Intelligent Transport Systems
Note

The online version on IEEE Xplore is yet to be avialble.

Available from: 2015-05-25 Created: 2013-12-02 Last updated: 2018-01-11Bibliographically approved
Westerlund, N., Grbic, N. & Dahl, M. (2006). Subband Adaptive Feedback Control in Hearing Aids with Increased User Comfort.
Open this publication in new window or tab >>Subband Adaptive Feedback Control in Hearing Aids with Increased User Comfort
2006 (English)Report (Other academic)
Abstract [en]

This report describes important physiological and anatomical aspects of human hearing, including instruments for hearing improvements, i.e. hearing aids. One common problem with hearing aids is acoustic feedback (howling). A new subband Adaptive Feedback Control (AFC) system for hearing aids is proposed. This system detects howling by calculating distances between zero crossings in the subband input signal. A stable subband zero crossing distance measure indicates that howling is present in a particular subband. This triggers an adaptation to estimate and attenuate the feedback channel. The adaptation is driven by a probe noise sequence constrained in both time and frequency. This constraint implies increased signal quality and that user discomfort due to emitted probe noise is reduced. Also, an effective and reliable adaptation is achieved. The method has proven to operate well in computer simulations, with speech as well as music as signal input. Initial simulations indicate that an increased hearing aid gain of at least 15 dB is possible.

Series
Blekinge Tekniska Högskola Forskningsrapport, ISSN 1103-1581 ; 1
Keywords
Speech Enhancement, Adaptive Feedback Control, Hearing Aids, Zero Crossing
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-00314 (URN)oai:bth.se:forskinfo45B1340BC7B0352EC12571240048B810 (Local ID)oai:bth.se:forskinfo45B1340BC7B0352EC12571240048B810 (Archive number)oai:bth.se:forskinfo45B1340BC7B0352EC12571240048B810 (OAI)
Available from: 2012-09-18 Created: 2006-03-01 Last updated: 2015-06-30Bibliographically approved
Nilsson, M., Dahl, M. & Claesson, I. (2005). A cepstrum domain HMM-based speech enhancement method applied to nonstationary noise. Paper presented at 7th International Symposium on Digital Signal Processing for Communication, Systems, DEC, 2003. Paper presented at 7th International Symposium on Digital Signal Processing for Communication, Systems, DEC, 2003. Coolangatta, AUSTRALIA: Springer
Open this publication in new window or tab >>A cepstrum domain HMM-based speech enhancement method applied to nonstationary noise
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

This paper presents a Hidden Markov Model (HMM)-based speech enhancement method, aiming at reducing non-stationary noise from speech signals. The system is based on the assumption that the speech and the noise are additive and uncorrelated. Cepstral features are used to extract statistical information from both the speech and the noise. A-priori statistical information is collected from long training sequences into ergodic hidden Markov models. Given the ergodic models for the speech and the noise, a compensated speech-noise model is created by means of parallel model combination, using a log-normal approximation. During the compensation. the mean of every mixture in the speech and noise model is stored. The stored means are then used in the enhancement process to create the most likely speech and noise power spectral distributions using the forward algorithm combined with mixture probability. The distributions are used to generate a Wiener filter for every observation. The paper includes a performance evaluation of the speech enhancer for stationary as well as non-stationary noise environment.

Place, publisher, year, edition, pages
Coolangatta, AUSTRALIA: Springer, 2005
Keywords
HMM, PMC, speech enhancement, log-normal
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-8377 (URN)000226081100001 ()oai:bth.se:forskinfo39C65686A7F30199C12574FA00468720 (Local ID)0-387-22847-0 (ISBN)oai:bth.se:forskinfo39C65686A7F30199C12574FA00468720 (Archive number)oai:bth.se:forskinfo39C65686A7F30199C12574FA00468720 (OAI)
Conference
7th International Symposium on Digital Signal Processing for Communication, Systems, DEC, 2003
Note
SIGNAL PROCESSING FOR TELECOMMUNICATIONS AND MULTIMEDIA Book Series: MULTIMEDIA SYSTEMS AND APPLICATIONS (SERIES) Vol. 27Available from: 2012-09-18 Created: 2008-11-07 Last updated: 2015-06-30Bibliographically approved
Sällberg, B., Åkesson, H., Dahl, M. & Claesson, I. (2005). A Mixed Analog: Digital Hybrid for Speech Enhancement Purposes. Paper presented at IEEE International Symposium on Circuits and Systems (ISCAS). Paper presented at IEEE International Symposium on Circuits and Systems (ISCAS). Kobe, Japan
Open this publication in new window or tab >>A Mixed Analog: Digital Hybrid for Speech Enhancement Purposes
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

This paper presents and evaluates a hybrid implementation of a low complexity algorithm for speech enhancement, the Adaptive Gain Equalizer (AGE). The AGE is a subband based time domain method for instantaneous boosting of speech. By combination of digital analysis and analog synthesis, main advantages of the digital domain and the analog domain are utilized. The hybrid solution is implemented on a printed circuit board and evaluated in real-time. The development time of the proposed solution was very short, the solution is flexible, robust, has high signal bandwidth in the signal chain and does not require a Voice Activity Detector (VAD). Furthermore, the solution is not restricted by quantization errors in the signal chain and does not require a high speed Digital Signal Processor (DSP) for analysis. Informal listening tests and Signal-to-Noise Ratio (SNR) measures verify excellent speech enhancement performance and quality.

Place, publisher, year, edition, pages
Kobe, Japan: , 2005
Keywords
adaptive equalisers, analogue processing circuits, computational complexity, digital circuits, network analysis, network synthesis, speech enhancement
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-9516 (URN)000232002401002 ()oai:bth.se:forskinfoD1847F4BF2508AEEC1256FE10033ADF8 (Local ID)0-7803-8834-8 (ISBN)oai:bth.se:forskinfoD1847F4BF2508AEEC1256FE10033ADF8 (Archive number)oai:bth.se:forskinfoD1847F4BF2508AEEC1256FE10033ADF8 (OAI)
Conference
IEEE International Symposium on Circuits and Systems (ISCAS)
Available from: 2012-09-18 Created: 2005-04-12 Last updated: 2015-06-30Bibliographically approved
Dahl, M., Tran, T., Claesson, I. & Nordebo, S. (2005). Design of antenna array using dual nested complex approximation. Paper presented at 7th International Symposium on Digital Signal Processing for Communication Systems. Paper presented at 7th International Symposium on Digital Signal Processing for Communication Systems. Coolangatta, AUSTRALIA: SPRINGER
Open this publication in new window or tab >>Design of antenna array using dual nested complex approximation
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

This paper presents a new practical approach to complex Chebyshev approximation by semi-infinite linear programming. By the new front-end technique, the associated semi-infinite linear programming problem is solved exploiting the finiteness of the related Lagrange multipliers by adapting finite-dimensional linear programming to the dual semi-infinite problem, and thereby taking advantage of the numerical siability and efficiency of conventional linear programming software packages. Furthermore, the optimization procedure is simple to describe theoretically and straightforward to implement in computer coding. The new design technique is therefore. highly accessible. The algorithm is formally introduced as the linear Dual Nested Complex Approximation (DNCA) algorithm. The DNCA algorithm is versatile and can be applied to a variety of applications such as narrow-band as well as broad-band beamformers with any geometry, conventional Finite Impulse Response (FIR) filters, analog and digital Laguerre networks. and digital FIR equalizers. The proposed optimization technique is applied to several numerical examples dealing with the design of a narrow-band base-station antenna array for mobile communication.

Place, publisher, year, edition, pages
Coolangatta, AUSTRALIA: SPRINGER, 2005
Keywords
antenna array design, Dual Nested Complex Approximation, DNCA, optimization, semi-infinite linear program, real rotation theorem, Chebyshev approximation
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-8188 (URN)000226081100015 ()oai:bth.se:forskinfo869DAE13AAC5AE96C12575B00020DAA3 (Local ID)0-387-22847-0 (ISBN)oai:bth.se:forskinfo869DAE13AAC5AE96C12575B00020DAA3 (Archive number)oai:bth.se:forskinfo869DAE13AAC5AE96C12575B00020DAA3 (OAI)
Conference
7th International Symposium on Digital Signal Processing for Communication Systems
Available from: 2012-09-18 Created: 2009-05-08 Last updated: 2015-06-30Bibliographically approved
Westerlund, N., Dahl, M. & Grbic, N. (2005). Detection And Attenuation of Feedback Induced Howling in Hearing Aids Using Subband Zero-Crossing Measures. Paper presented at Proceedings of the Eighth International Symposium on Signal Processing and Its Applications. Paper presented at Proceedings of the Eighth International Symposium on Signal Processing and Its Applications. Sydney
Open this publication in new window or tab >>Detection And Attenuation of Feedback Induced Howling in Hearing Aids Using Subband Zero-Crossing Measures
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

A modern hearing aid should be aesthetically appealing as well as offer sufficient and adequate signal amplification. Due to the small physical size of these devices, acoustical feedback (howling) is a major problem. Apart from the annoyance and potential hearing damaging effects that howling implies, it also reduces the supplied maximum Real Ear Aided Gain (REAG). This paper proposes a novel method for subband feedback detection and cancellation, based on the zero-crossing rate measure. After splitting the hearing aid input signal into subbands, the distances between subband zero-crossings are measured. A low distance variance in a particular subband indicates that howling has arisen. The variance measure is then used to adaptively and continuously steer subband gain functions which attenuate tonal infested subbands. The method has proven to be robust and simulation indicates that it offers additional REAG of about 15 dB.

Place, publisher, year, edition, pages
Sydney: , 2005
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-9935 (URN)oai:bth.se:forskinfo6A3C84D32BF5BEEFC125709100547643 (Local ID)0-7803-9243-4 (ISBN)oai:bth.se:forskinfo6A3C84D32BF5BEEFC125709100547643 (Archive number)oai:bth.se:forskinfo6A3C84D32BF5BEEFC125709100547643 (OAI)
Conference
Proceedings of the Eighth International Symposium on Signal Processing and Its Applications
Available from: 2012-09-18 Created: 2005-10-05 Last updated: 2015-06-30Bibliographically approved
Nilsson, M., Dahl, M. & Claesson, I. (2005). Gray-Scale Image Enhancement using the SMQT. Paper presented at IEEE International Conference on Image Processing (ICIP). Paper presented at IEEE International Conference on Image Processing (ICIP). Genoa
Open this publication in new window or tab >>Gray-Scale Image Enhancement using the SMQT
2005 (English)Conference paper, Published paper (Refereed) Published
Abstract [en]

This paper explores the Successive Mean Quantization Transform (SMQT) for automatic enhancement of gray-scale images. The transform is in the paper presented using set theory. The image enhancement capabilities and properties of the transform are analyzed. The transform is capable to perform both a nonlinear and a shape preserving stretch of the image histogram. Experiments and comparisons to histogram equalization are conducted.

Place, publisher, year, edition, pages
Genoa: , 2005
National Category
Signal Processing
Identifiers
urn:nbn:se:bth-9270 (URN)000235773300149 ()oai:bth.se:forskinfoDA2EF158A19E2B67C12572CF002E0869 (Local ID)oai:bth.se:forskinfoDA2EF158A19E2B67C12572CF002E0869 (Archive number)oai:bth.se:forskinfoDA2EF158A19E2B67C12572CF002E0869 (OAI)
Conference
IEEE International Conference on Image Processing (ICIP)
Available from: 2012-09-18 Created: 2007-05-02 Last updated: 2015-06-30Bibliographically approved
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