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  • 51.
    Backén, Staffan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Akos, Dennis
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Nordenvaad, Magnus Lundberg
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Post-processing dynamic GNSS antenna array calibration and deterministic beamforming2008Ingår i: Proceedings of the 21th International Technical Meeting of the Satellite Division of the Institute of Navigation: ION GNSS 2008, 2008, Vol. 3, s. 1311-1319Konferensbidrag (Refereegranskat)
    Abstract [en]

    An array processing GNSS (Global Navigation Satellite System) receiver may provide increased accuracy, reliability and integrity by forming beams towards satellites and nulls towards interference or reflective surfaces. Also, software defined receivers have proven themselves versatile and provide a convenient environment to implement novel algorithms.This paper first describes the gain/phase calibration of a seven element custom array antenna and proceeds to compare the single antenna performance to that of the performance attained by forming beams towards the satellites. IF (Intermediate Frequency) data, high rate samples representing the received signal in a narrow band around the GPS L1 frequency, from an array antenna have been recorded both in an environment with open sky conditions and also in more challenging areas (central Boulder, Colorado). Simultaneously, data from a high quality GPS based INS was recorded in order to obtain accurate estimates of position/ orientation. Calibration of the system (including antennas and front-ends) was performed using data from the benign environment, and based on this information, deterministic beams were formed towards the satellites using data from the semi-urban dataset. The single antenna accuracy was then compared to the position obtained by processing after forming beams.

  • 52.
    Backén, Staffan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Akos, Dennis
    Wilson, Steve G.
    University of Boulder at Colorado.
    RF replay system for narrowband GNSS if signals2011Ingår i: IEEE Transactions on Aerospace and Electronic Systems, ISSN 0018-9251, E-ISSN 1557-9603, Vol. 47, nr 1, s. 586-595Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although GNSS RF signal simulators have long possessed the capability to generate scenarios they are, for example, not yet able to model a realistic scenario with complex multipath. Software defined receivers bridge the gap between simulated and real data to the extent that they may offer a replay capability, where a data set is first recorded to disk and later can be processed several times. Unfortunately, the recorded data generally can not be used by other GNSS receivers, making receiver to receiver comparisons difficult and time consuming.This paper describes a system capable of replaying recorded IF data into any narrow bandwidth L1 GNSS receiver, including an evaluation of the difference (position, timing and SNR) between live and replayed data using a high sensitivity, consumer grade receiver. The performance of the replayed data set was found to match that of the live data.

  • 53.
    Backén, Staffan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Nordenvaad, Magnus Lundberg
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Akos, Dennis
    A novel software defined research receiver architecture2009Ingår i: Proceedings of the 13th IAIN World Congress: Stockholm, 27-30 October 2009, Nordic Institute of Navigation , 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Software defined receivers (SDR) are an increasingly important tool within the GNSS research community as the high level of flexibility offer a significant advantage over traditional hardware implementations. Over the last decade, software receivers have been used to investigate techniques as diverse as bi-static radar (additional correlators), multipath mitigation techniques, GPS/INS integration and array processing.Mentioned above are only a few examples of features that could be required of an SDR, other include support for new signals (Galileo, GPS L5), multiple data file formats, high sensitivity and support for very long data sets. The large number of available features should ideally be coupled with program simplicity (such that other people can understand the program) and efficiency. This paper discusses these issues and proposes several solutions such asgeneralized data buffers (that is trivial to extend for new data formats) and a unified tracking structure (regardless of signal modulation). Examples are given using a Matlab implementation based on the Borre/Akos book Ä Software-Defined GPS and Galileo Receiver", however with significant modifications. Where critical, Java is used to increase performance while maintaining cross platform compatibility. Near real-time operation is available under optimal circumstances and the receiver currently supports GPS C/A- and GPS P-code signals.

  • 54.
    Barabash, Victoria
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Rymdteknik.
    Ejemalm, Johnny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Rymdteknik.
    Kuhn, Thomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Rymdteknik.
    Milz, Mathias
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Rymdteknik.
    Molin, Sven
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Westerberg, Lars-Göran
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Masters Programs in Space Science and Engineering in Northern Sweden2017Konferensbidrag (Refereegranskat)
  • 55.
    Beckman, Claes
    et al.
    Department of Communications systems, School of ICT, Royal Institute of Technology, Kista.
    Borg, Johan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Tecsor, Irina
    Department of Communications systems, School of ICT, Royal Institute of Technology, Kista.
    Design considerations for the EISCAT-3D phased array antenna2014Ingår i: 2014 8th European Conference on Antennas and Propagation: (EuCAP); The Hague; Netherlands, 6 -11 April 2014, Piscataway, NJ: IEEE Communications Society, 2014, s. 1700-1704Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper presents a background and an overview of the initial design considerations for phased array antenna being designed for the New Generation multi-static, incoherent-scatter radar station - EISCAT-3D - in Northern Scandinavia. Its anticipated electrical, mechanical and environmental design requirements are given both by the physics as well as by the extreme climate in the subarctic region of northern Scandinavia

  • 56.
    Berglund, Tomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Estimating geometric primitives using 3D range data1999Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Master's Thesis at the Department of Mathematics and at the Division of Robotics at the Department of Computer Science and Electrical Engineering, Luleå University of Technology, Sweden

  • 57.
    Berglund, Tomas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Path-planning with obstacle-avoiding minimum curvature variation B-splines2003Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    We study the general problem of computing an obstacle-avoiding path that, for a prescribed weight, minimizes the weighted sum of a smoothness measure and a safety measure of the path. We consider planar curvature-continuous paths, that are functions on an interval of a room axis, for a point-size vehicle amidst obstacles. The obstacles are two disjoint continuous functions on the same interval. A path is found as a minimizer of the weighted sum of two costs, namely 1) the integral of the square of arc- length derivative of curvature along the path (smoothness), and 2) the distance in L2 norm between the path and the point-wise arithmetic mean of the obstacles (safety). We formulate a variant of this problem in which we restrict the path to be a B-spline function and the obstacles to be piece-wise linear functions. Through implementations, we demonstrate that it is possible to compute paths, for different choices of weights, and use them in practical industrial applications, in our case for use by the ore transport vehicles operated by the Swedish mining company Luossavaara-Kiirunavaara AB (LKAB). Assuming that the constraint set is non-empty, we show that, if only safety is considered, this problem is trivially solved. We also show that properties of the problem, for an arbitrary weight, can be studied by investigating the problem when only smoothness is considered. The uniqueness of the solution is studied by the convexity properties of the problem. We prove that the convexity properties of the problem are preserved due to a scaling and translation of the knot sequence defining the B-spline. Furthermore, we prove that a convexity investigation of the problem amounts to investigating the convexity properties of an unconstrained variant of the problem. An empirical investigation of the problem indicates that it has one unique solution. When only smoothness is considered, the approximation properties of a B-spline solution are investigated. We prove that, if there exists a sequence of B-spline minimizers that converge to a path as the number of B-spline basis functions tends to infinity, then this path is a solution to the general problem. We provide an example of such a converging sequence.

  • 58.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Brodnik, Andrej
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Jonsson, Håkan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mrozek, Kent
    Staffansson, Mats
    Luleå tekniska universitet.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Minimum curvature variation B-splines: validation of a path-planning model2004Rapport (Övrigt vetenskapligt)
  • 59.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Brodnik, Andrej
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. University of Primorska, Slovenia. .
    Jonsson, Håkan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Staffansson, Mats
    Luleå tekniska universitet.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Planning smooth and obstacle-avoiding b-spline paths for autonomous mining vehicles2010Ingår i: IEEE Transactions on Automation Science and Engineering, ISSN 1545-5955, E-ISSN 1558-3783, Vol. 7, nr 1, s. 167-172Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the problem of automatic generation of smooth and obstacle-avoiding planar paths for efficient guidance of autonomous mining vehicles. Fast traversal of a path is of special interest. We consider four-wheel four-gear articulated vehicles and assume that we have an a priori knowledge of the mine wall environment in the form of polygonal chains. Computing quartic uniform B-spline curves, minimizing curvature variation, staying at least at a proposed safety margin distance from the mine walls, we plan high speed paths.

  • 60.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Erikson, Ulf
    Luleå tekniska universitet.
    Jonsson, Håkan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Mrozek, Kent
    Navigator AB.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Automatic generation of smooth paths bounded by polygonal chains2001Ingår i: CIMCA 2001: 2001 international conference on computational intelligence for modelling, control & automation : 9-11 July 2001, Las Vegas, Nevada, USA : proceedings / [ed] M. Mohammadian, CIMCA , 2001, s. 528-535Konferensbidrag (Refereegranskat)
  • 61.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Greppe, Anders
    Thorén, Johan
    Papp, John
    Curve and surface fitting to measured data with a B-spline approach1999Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Report in the Project course in Mathematics, MAM088, 1998/1999. Department of Mathematics, Luleå University of Technology, Sweden

  • 62.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Jonsson, Håkan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    The problem of computing an obstacle-avoiding minimum variation B-spline2003Rapport (Övrigt vetenskapligt)
    Abstract [en]

    We study the problem of computing a planar curve restricted to lie between two given polygonal chains such that the integral of the square of arc- length derivative of curvature along the curve is minimized. We introduce the Minimum Variation B-spline problem which is a linearly constrained optimization problem over curves defined by B-spline functions only. An empirical investigation indicates that this problem has one unique solution among all uniform quartic B-spline functions. Furthermore, we prove that, for any B-spline function, the convexity properties of the problem are preserved subject to a scaling and translation of the knot sequence defining the B-spline.

  • 63.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Strömberg, Thomas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Jonsson, Håkan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Epi-convergence of minimum curvature variation B-splines2003Rapport (Övrigt vetenskapligt)
    Abstract [en]

    We study the curvature variation functional, i.e., the integral over the square of arc-length derivative of curvature, along a planar curve. With no other constraints than prescribed position, slope angle, and curvature at the endpoints of the curve, the minimizer of this functional is known as a cubic spiral. It remains a challenge to effectively compute minimizers or approximations to minimizers of this functional subject to additional constraints such as, for example, for the curve to avoid obstacles such as other curves. In this paper, we consider the set of smooth curves that can be written as graphs of three times continuously differentiable functions on an interval, and, in particular, we consider approximations using quartic uniform B- spline functions. We show that if quartic uniform B-spline minimizers of the curvature variation functional converge to a curve, as the number of B-spline basis functions tends to infinity, then this curve is in fact a minimizer of the curvature variation functional. In order to illustrate this result, we present an example of sequences of B-spline minimizers that converge to a cubic spiral.

  • 64.
    Berglund, Tomas
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Synnergren, Per
    Luleå tekniska universitet.
    Söderkvist, Inge
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Estimation of curl in paper: an industrial application combining shape measurement and least squares modeling2000Ingår i: Proceedings / International Conference on Trends in Optical Nondestructive Testing: Lugano, Switzerland, May 3-6, 2000 / [ed] Pramod K. Rastogi; D. Inaudi, Lugano: Ecole Polytechnique Fédérale de Lausanne , 2000, s. 23-33Konferensbidrag (Refereegranskat)
    Abstract [en]

    If a sheet of paper is subjected to humidity changes and have structural variations through its thickness such as gradients of fibre orientation, density and filler content, the sheet will curl and hence assume a cylindrical shape. Curl is a quality problem that makes the paper less suitable for printing. We propose a method to measure curl that can be used for automated analysis of the paper quality. The shape of the curled paper is measured from the perspective difference in a stereoscopic camera system, which is viewing an irregular pattern that is projected onto the specimen. The perspective difference is calculated by a correlation algorithm, a technique often referred to as digital speckle photography. The most interesting quality parameters are the magnitude of curl, which is defined as the inverse of the radius of curvature and also the orientation of the curled paper. These parameters are estimated by performing a least squares fit of a cylindrical shape to the three-dimension...

  • 65. Bernhart, Martin
    et al.
    Bonvicino, Valentino
    Boschan, Eva
    Brotzenberger, Heinz
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Dewert, Francis
    Futukawa, Michio
    Rosmalen, Renée Janssen van
    Kapor, Slobodan
    Mounce, Richard
    Serracanta, Francisco
    Vercamer, Pascal
    Approach to the management of contaminated gas sites1997Ingår i: Proceedings World Gas Conference 1997, World Gas Union , 1997Konferensbidrag (Refereegranskat)
  • 66.
    Berrebi, Jonathan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Improved techniques for self-diagnosis of an ultrasonic flow meter2002Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    For both economical and environmental raisons, accurate measurements of energy consumptions are important. The District Heating Industry supplies buildings and private houses of a whole city in hot water through a network. The energy supplied to a customer is measured by thermometers and by a flow meter inside the district-heating substation present at the customer’s place. The annual cost of the total metering error is approximately estimated at 170 Millions of Swedish Crowns for the Swedish District Industry. Accurate measurements of the flow rate turn out to be essential to a correct estimation of the energy consumption. Ultrasonic flow meters are of particular interest because of their good accuracy for a low cost. The main features of ultrasonic flow meters are studied. The estimation of the mean flow velocity and the calibration of the meter are described. Once installed, any kind of meter provides larger errors than in the facility where it has been calibrated. It is particularly true for ultrasonic flow meters that are very sensitive to installations effects. Installations effects can either be static or dynamic. Special attention is paid to errors generated by velocity profile variations. A diagnosis of the sensitivity of the meter to installations effects would allow for compensations for the errors. It is outlined that the notion of diagnosis comes within the theory of detection. A self-diagnosis is performed by the meter itself. The decision rule has to be modelled and inserted into the meter. Signal analysis allows detection of specific noise characteristic of a particular type of installation effect. An example of self-diagnosis showing the detection of pulsations in a flow is described in details.

  • 67.
    Berrebi, Jonathan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Self-diagnosis techniques and their applications to error reduction for ultrasonic flow measurement2004Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Flow metering plays a major role in modern life. In the process industry, flow metering is critical in industries ranging from food processing to cosmetics. It is also essential in custody transfer or billing, as flow meters are present in gas pumps and district heating substations. In the district heating industry, the ultrasonic flow meter has become the desired meter in many of its applications because it has a low cost while being accurate. This accuracy is however sensitive to installation effects and other sources of errors. This thesis stems from research that addresses the recognition of these installation effects, informs when they are unacceptable and considers reducing the measurement errors. To present these concepts, the thesis details the estimation of the mean flow velocity, the calibration of the meter and the measurement noise properties. Once installed, any kind of meter provides larger errors than in the facility where it has been calibrated and compensated. It is particularly true for ultrasonic flow meters as they are very sensitive to installation effects. Installation effects can either be static or dynamic. Special attention is paid to errors generated by temperature and velocity profile variations. Velocity profile variations can be due to pipe bends or flow pulsations. Such disturbances often induce a bias error and change the properties of the measurement noise. It is therefore with help of the change in noise that velocity profile disturbances can be detected. The detection of such abnormal behaviour of the measurement process constitutes a diagnosis. A diagnosis of the sensitivity of the meter to installations effects would allow for compensations for the errors. Signal analysis allows detection of specific noise properties, characteristic of installation effects. An example of self-diagnosis showing the detection of real pulsations in a flow is described in details. The detection of the flow pulsations and the estimation of their frequency allow to reduce the error of estimation on the flow rate. This technique is confirmed by the simulations of a pulsating flow. To empower one with the decision whether a flowmeter performance is normal or abnormal, a study of the relative error as a function of flow rate and temperature has been conducted.

  • 68.
    Berrebi, Jonathan
    et al.
    Luleå tekniska universitet.
    Martinsson, Pär-Erik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Willatzen, M.
    University of Southern Denmark.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ultrasonic flow metering errors due to pulsating flow2004Ingår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, Vol. 15, nr 3, s. 179-185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transit-time ultrasonic flow meters present some advantages over other flow meters for district heating industries. They are both accurate and non-intrusive. It is well-known that ultrasonic flow meters are sensitive to installation effects. Installation effects could be static or dynamic. Among the possible dynamic installation effects is pulsating flow. The influence of pulsating flow on the prediction and the zero-crossing operations is investigated. Expressions are found for the prediction error and the zero-crossing error. The relative errors due to the prediction and the zero-crossing are plotted. The prediction error can reach dramatic values while the zero-crossing operation is hardly influenced by flow pulsations.

  • 69.
    Berrebi, Jonathan
    et al.
    Luleå tekniska universitet.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Detection of dynamic installation effects by an ultrasound flow meter in non-stationary flow2004Ingår i: Proceedings of the 12th International Conference on Flow Measurement: FLOMEKO, 2004, s. 277-279Konferensbidrag (Refereegranskat)
  • 70. Berrebi, Jonathan
    et al.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Delsing, Jerker
    Detection of pulsating flows in an ultrasonic flow meter2002Ingår i: Proceedings of ISA Emerging Technologies Conference, 2002Konferensbidrag (Refereegranskat)
  • 71. Berrebi, Jonathan
    et al.
    van Deventer, Jan
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Detection of pulsating flows in an ultrasonic flow meter2002Ingår i: Proceedings of the 8th International Symposium on District Heating and Cooling, 2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    Transit-time ultrasonic flowmeters present advantages for district heating applications, since they are accurate, non-intrusive, and cheap. However, such flowmeters are sensitive to velocity profile variations since the flow rate is measured in the volume area between two ultrasonic transducers. Ultrasonic flowmeters are therefore sensitive to installation effects. Installation effects could be either static or dynamic. A pulsating flow is a dynamic installation effect. In the field, the diagnostic can only be performed with the measured flow rate. Flow measurements with and without pulsating flow have been recorded in a flow meter calibration facility. The detection of a pulsating flow can be made by using Hinich's harmogram. It is possible to detect harmonics that emerge from the noise by using the harmogram.

  • 72.
    Berrebi, Jonathan
    et al.
    Luleå tekniska universitet.
    van Deventer, Jan
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Detection of the error generated by a single elbow on an ultrasonic flow meter2002Ingår i: ISA TECH/EXPO Technology Update Conference Proceedings: ETCON 2002, ISA - Instrumentation, Systems, and Automation Society , 2002, Vol. v 426 II, s. 1268-1279Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ultrasonic flow meters are accurate and non-intrusive. However, one of their drawbacks is their sensitivity to installation effects especially when elbows or pulsating flows are found in front of the meter's inlet. Depending on the flow rate, such installations can create perturbations on the flow measurement. These perturbations cause an increase of the noise level as well as a possible error on the flow estimation. A technique using the noise level as a criterion for making a diagnostic of the error is presented. The perturbations are examined and compared to gaussian distributed signals. A basic method for detecting gaussian perturbations with equal means is described. The likelihood ratio is first computed in the general case. It is also computed making the assumption of uncorrelated signals. Receiver Operating Characteristics (R.O.C.) are plotted. The assumption of gaussian perturbations is then investigated. Optimal thresholds are proposed for both methods and for a large interval of flow rates (from 0.4 ml/s to 0,75 1/s). Probabilities of detection and of false alarm are evaluated for both methods. It is concluded that correct detection can be performed. The optimal threshold is to be chosen by the operator.

  • 73.
    Berrebi, Jonathan
    et al.
    Luleå tekniska universitet.
    van Deventer, Jan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Delsing, Jerker
    Reducing the flow measurement error caused by pulsations in flows2004Ingår i: Flow Measurement and Instrumentation, ISSN 0955-5986, E-ISSN 1873-6998, nr 5-6, s. 311-315Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Different types of errors are generated by pulsations in flows. Among these errors is the sampling error due to a unadapted time-averaging of the flow rate. An improved model for pulsations in flows including harmonics is derived. The localization of the harmonics is performed by a detector. The period of the pulsations is estimated. It is then possible to reduce the sampling error by performing a correct averaging. The reduction of the sampling error is confirmed by simulations.

  • 74.
    Bhoi, Bandan Kumar
    et al.
    Department of Electronics and Telecommunication, Veer Surendra Sai, University of Technology, Burla, India.
    Misa, Neeraj Kumar
    Department of Electronics and Communication Engineering, Bharat Institute of Engineering and Technology, Hyderabad, India.
    Chouhan, Shailesh Singh
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Acharya, Sarthak
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Analyzing Design Parameters of Nano-Magnetic Technology Based Converter Circuit2019Ingår i: VLSI Design and Test: 23rd International Symposium, VDAT 2019, Indore, India, July 4–6, 2019, Revised Selected Papers / [ed] Dr. Anirban Sengupta, Dr. Sudeb Dasgupta, Virendra Singh, Rohit Sharma, Santosh Kumar Vishvakarma, Springer, 2019, s. 34-46Konferensbidrag (Refereegranskat)
    Abstract [en]

    Digital circuits need improvement in computation speed, reducing circuit complexity and power consumption. Emerging Technology NML can be such an architecture at nano-scale and thus emerges as a viable alternative for the digital CMOS VLSI. This technology has the capability to compute the logic as well as storage into the same device, which points out that it great potential for emerging technology. Since Nano-magnetic, technology fast approaches its minimal feature size, high device density and operate at room temperature. NML based circuits synthesis has to opt for novel half subtraction and Binary-to-Gray architecture for achieving minimal complexity and high-speed performance. This manuscript pro-poses area efficient binary half-subtraction and Binary-to-Gray converter architecture. Circuits’ synthesize are performed by MagCAD tool and simulate by Modelsim simulator. The circuit’s performance are estimated over other existing designs. The proposed converter consume 73.73%, and 94.49% less area than the converter designed using QCA and CMOS technique respectively. This is a significant contribution to this paper. Simulation results of converter show that the critical path delay falls within 0.15 µs.

  • 75.
    Bicaku, Ani
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. University of Applied Sciences Burgenland, Eisenstadt.
    Maksuti, Silia
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. University of Applied Sciences Burgenland.
    Hegedűs, Csaba
    AITIA International Inc., Budapest.
    Tauber, Markus G.
    University of Applied Sciences Burgenland, Eisenstad.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Interacting with the arrowhead local cloud: On-boarding procedure2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Industrial automation systems are advancing rapidly and a wide range of standards, communication protocols and platforms supporting the integration of devices are introduced. It is therefore necessary to design and build appropriate tools and frameworks that allow the integration of devices with multiple systems and services. In this work we present the Arrow-head Framework, used to enable collaborative IoT automation and introduce two support core systems, SystemRegistry and DeviceRegistry, which are needed to create a chain of trust from a hardware device to a software system and its associated services. Furthermore, we propose an on-boarding procedure of a new device interacting with the Arrowhead local cloud. This ensures that only valid and authorized devices can host software systems within an Arrowhead local cloud.

  • 76.
    Bicaku, Ani
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. University of Applied Sciences Burgenland.
    Maksuti, Silia
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. University of Applied Sciences Burgenland.
    Palkovits-Rauter, Silke
    University of Applied Sciences Burgenland.
    Tauber, Markus
    University of Applied Sciences Burgenland.
    Matischek, Rainer
    Infineon Technologies Austria.
    Schmittner, Christoph
    Austrian Institute of Technology.
    Mantas, Georgios
    Instituto de Telecomunicacoes.
    Thron, Mario
    Insitut for Automation und Kommunikation.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Towards Trustworthy End-to-End Communication in Industry 4.02017Ingår i: Proceedings: 2017 IEEE 15th International Conference on Industrial Informatics, INDIN 2017, Piscataway, NJ: Institute of Electrical and Electronics Engineers (IEEE), 2017, s. 889-896, artikel-id 8104889Konferensbidrag (Refereegranskat)
    Abstract [en]

    Industry 4.0 considers integration of IT and control systems with physical objects, software, sensors and connectivity in order to optimize manufacturing processes. It provides advanced functionalities in control and communication for an infrastructure that handles multiple tasks in various locations automatically. Automatic actions require information from trustworthy sources. Thus, this work is focused on how to ensure trustworthy communication from the edge devices to the backend infrastructure. We derive a meta-model based on RAMI 4.0, which is used to describe an end-to-end communication use case for an Industry 4.0 application scenario and to identify dependabilities in case of security challenges. Furthermore, we evaluate secure messaging protocols and the integration of Trusted Platform Module (TPM) as a root of trust for dataexchange. We define a set of representative measurable indicator points based on existing standards and use them for automated dependability detection within the whole system.

  • 77.
    Bicaku, Ani
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. University of Applied Sciences Burgenland, Eisenstadt.
    Schmittner, Christoph
    Austrian Institute of Technology, Vienna.
    Tauber, Markus G.
    University of Applied Sciences Burgenland, Eisenstad.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Monitoring Industry 4.0 applications for security and safety standard compliance2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    In Industry 4.0 independent entities shall inter-operate to allow flexible and customized production. To assure the parties that individual components are secured to inter-operate, we investigate automated standard compliance. The standard compliance is defined based on given sets of security and safety requirements from which are derived measurable indicator points. Those reflect configurations of systems recommended by security, safety or legally relevant standards and guidelines, which help to demonstrate the state of compliance. We propose in this paper an initial approach to automate such assessment when components are inter-operating with each other by using a monitoring and standard compliance verification framework. This will assure the parties that services or devices within their organizations operate in a secure and standard compliant way, without compromising the underlying infrastructure.

  • 78.
    Biello, Elia
    et al.
    Dipartimento di Ingegneria Industriale e dell'Informazione e di Economi, Università degli Studi dell'Aquila.
    Antonini, Giulio
    Dipartimento di Ingegneria Industriale e dell'Informazione e di Economi, Università degli Studi dell'Aquila.
    De Lauretis, Maria
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ekman, Jonas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    A delay‐rational model of electromagnetic interference on multiconductor transmission lines2018Ingår i: International journal of numerical modelling, ISSN 0894-3370, E-ISSN 1099-1204, Vol. 31, nr 4, artikel-id 2342Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multiconductor transmission lines have found a wide range of applications, as power lines, as high‐speed interconnects, and as on‐chip interconnects. Electromagnetic interference (EMI) can be described in terms of plane waves that couple to these lines, leading to unwanted disturbance. This paper presents a delayed spectral formulation for the analysis of plane‐wave coupling to multiconductor transmission lines in both the frequency and time domains, called the DeRaG‐EMI model (short for “delay‐rational model based on Green's functions for electromagnetic interference”). The model is based on Green's functions and is described in terms of delayed differential equations in the time domain. The model is suitable for studying the EMI on multiconductor transmission lines in the case of incident fields. The coupling of a plane wave to a line is described in terms of equivalent sources that account for both the delay of the line and the delays of the incoming plane wave. The delay is explicitly extracted and incorporated into the model with hyperbolic functions. The DeRaG‐EMI model does not require any segmentation of the line. Numerical results confirm its accuracy and its improved performance compared with the previous spectral model and with the inverse fast Fourier transform technique.

  • 79.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Lindgren, Per
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Riliskis, Laurynas
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Road surface networks technology enablers for enhanced ITS2010Ingår i: 2010 IEEE Vehicular Networking Conference, VNC 2010: Jersey City, NJ ; 13-15 Dec 2010, Piscataway, NJ: IEEE Communications Society, 2010, s. 152-159Konferensbidrag (Refereegranskat)
    Abstract [en]

    The increased need for mobility has led to transportation problems like congestion, accidents and pollution. In order to provide safe and efficient transport systems great efforts are currently being put into developing Intelligent Transport Systems (ITS) and cooperative systems. In this paper we extend proposed solutions with autonomous on-road sensors and actuators forming a wireless Road Surface Network (RSN). We present the RSN architecture and design methodology and demonstrate its applicability to queue-end detection. For the use case we discuss the requirements and technological solutions to sensor technology, data processing and communication. In particular the MAC protocol is detailed and its performance assessed through theoretical verification. The RSN architecture is shown to offer a scalable solution, where increased node density offers more precise sensing as well as increased redundancy for safety critical applications. The use-case demonstrates that RSN solutions may be deployed as standalone systems potentially integrated into current and future ITS. RSN may provide both easily deployable and cost effective alternatives to traditional ITS (with a direct impact independent of penetration rate of other ITS infrastructures - i.e., smart vehicles, safe spots etc.) as well as provide fine grain sensory information directly from the road surface to back-end and cooperative systems, thus enabling a wide range of ITS applications beyond current state of the art.

  • 80.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Hostettler, Roland
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Lundberg Nordenvaad, Magnus
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Gylling, Arne
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, CDT.
    Delsing, Jerker
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Mäkitaavola, Henrik
    Project: iRoad2011Övrigt (Övrig (populärvetenskap, debatt, mm))
  • 81.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Marklund, Olov
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Medvedev, Alexander
    Video monitoring of pulverized coal injection in the blast furnace2001Ingår i: Conference record of the 2001 IEEE Industry Applications Conference: thirty-sixth IAS annual meeting ; 30 September - 4 October 2001, Hyatt Regency Hotel, Chicago, Illinois, USA, Piscataway, NJ: IEEE Communications Society, 2001, Vol. 2, s. 1354-1358Konferensbidrag (Refereegranskat)
    Abstract [en]

    A novel approach for monitoring and control of the coal powder injection in a blast furnace is presented and discussed. Image analysis of video recordings is used as a means to estimate the instantaneous coal flow. Initial experiments at the blast furnace no 3 of SSAB Tunnplat AB Lulea, Sweden, have been performed and first hand results on modelling and control of a single injection line are given

  • 82.
    Birk, Wolfgang
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Signaler och system.
    Osipov, Evgeny
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    iRoad - cooperative road infrastructure systems for driver support2009Ingår i: 16th World Congress and Exhibition on Intelligent Transport Systems 2009: 16th ITS World Congress ; Stockholm, Sweden, 21 - 25 September 2009, Red Hook: Curran Associates, Inc., 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper discusses the design and implementation of a cooperative road infrastructure systems, which uses an intelligent road surface. Using an overtaking assist feature as an example it is shown how such a feature can be designed and implemented on a road infrastructure and integrated with drivers and passengers using IMS. The feasibility of this feature is assessed from a functional and communication perspective. Moreover, first results from real-life tests on the Swedish highway E4 are presented which motivate the next research and development steps.

  • 83.
    Blaschke, D.
    et al.
    University of Wroclaw.
    Klähn, T.
    University of Wroclaw.
    Łastowiecki, R.
    University of Wroclaw.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    How strange are compact star interiors?2010Ingår i: Journal of Physics G: Nuclear and Particle Physics, ISSN 0954-3899, E-ISSN 1361-6471, Vol. 37, nr 9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We discuss a Nambu-Jona-Lasinio (NJL)-type quantum field theoretical approach to the quark matter equation of state with color superconductivity and construct hybrid star models on this basis. It has recently been demonstrated that with increasing baryon density, the different quark flavors may occur sequentially, starting with down-quarks only, before the second light quark flavor and at highest densities the strange quark flavor also appears. We find that color superconducting phases are favorable over non-superconducting ones, which entails consequences for thermodynamic and transport properties of hybrid star matter. In particular, for NJL-type models no strange quark matter phases can occur in compact star interiors due to mechanical instability against gravitational collapse, unless a sufficiently strong flavor mixing as provided by the Kobayashi-Maskawa-'t Hooft determinant interaction is present in the model. We discuss observational data on mass-radius relationships of compact stars which can put constraints on the properties of the dense matter equation of state.

  • 84.
    Blaschke, David
    et al.
    University of Wroclaw.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Klähn, Thomas
    University of Wroclaw.
    Berdermann, Jens
    Deutsches Elektronen-Synchrotron.
    Sequential deconfinement of quark flavors in neutron stars2009Ingår i: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 80, nr 6, s. 65807-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A scenario is suggested in which the three light quark flavors are sequentially deconfined under increasing pressure in cold asymmetric nuclear matter as found, for example, in neutron stars. The basis for this analysis is a chiral quark matter model of Nambu–Jona-Lasinio (NJL) type with diquark pairing in the spin-1 single-flavor, spin-0 two-flavor, and three-flavor channels. Nucleon dissociation sets in at about the saturation density, n0, when the down-quark Fermi sea is populated (d-quark drip line) because of the flavor asymmetry induced by β equilibrium and charge neutrality. At about 3n0, u-quarks appear and a two-flavor color superconducting (2SC) phase is formed. The s-quark Fermi sea is populated only at still higher baryon density, when the quark chemical potential is of the order of the dynamically generated strange quark mass. Two different hybrid equations of state (EOSs) are constructed using the Dirac-Brueckner Hartree-Fock (DBHF) approach and the EOS of Shen et al. [H. Shen, H. Toki, K. Oyamatsu, and K. Sumiyoshi, Nucl. Phys. A637, 435 (1998)] in the nuclear matter sector. The corresponding hybrid star sequences have maximum masses of 2.1 and 2.0 M respectively. Two- and three-flavor quark-matter phases exist only in gravitationally unstable hybrid star solutions in the DBHF case, whereas the Shen-based EOSs produce stable configurations with a 2SC phase component in the core of massive stars. Nucleon dissociation via d-quark drip could act as a deep crustal heating process, which apparently is required to explain superbursts and cooling of x-ray transients.

  • 85.
    Blaschke, David
    et al.
    University of Wroclaw.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Skokov, Vladimir
    Joint Institute for Nuclear Physics.
    Accessibility of dense QCD phases in heavy-ion collisions2010Ingår i: "White book" of the future nuclotron-based ion collider facility (NICA) in Dubna, Russia, 2010Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 86. Blaschke, David
    et al.
    Sandin, Fredrik
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Skokov, Vladimir
    Typel, Stefan
    Accessibility of color superconducting quark matter phases in heavy-ion collisions2010Ingår i: Vol. 3, nr 3, s. 741-745Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We discuss a hybrid equation of state (EoS) that fulfills constraints for mass-radius relationships and cooling of compact stars. The quark matter EoS is obtained from a Polyakov-loop Nambu-Jona-Lasinio (PNJL) model with color superconductivity, and the hadronic one from a relativistic mean-field (RMF) model with density-dependent couplings (DD-RMF). For the construction of the phase transition regions we employ here for simplicity a Maxwell construction. We present the phase diagram for symmetric matter which exhibits two remarkable features: (1) a "nose"-like structure of the hadronic-to-quark matter phase border with an increase of the critical density at temperatures below T \sim 150 MeV and (2) a high critical temperature for the border of the two-flavor color superconducting (2SC) phase, Tc >160 MeV. We show the trajectories of heavy-ion collisions in the plane of excitation energy versus baryon density calculated using the UrQMD code and conjecture that for incident energies of 4 . . . 8 A GeV as provided,  e.g., by the Nuclotron-M at JINR Dubna or by lowest energies at the future heavy-ion collision experiments CBM at FAIR and NICA at JINR, the color superconducting quark matter phase becomes accessible.

  • 87.
    Blech, Jan Olaf
    et al.
    RMIT University, Melbourne.
    Lindgren, Per
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Pereira, David
    ISEP, Instituto Superior de Engenharia do Porto.
    Vyatkin, Valeriy
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Zoitl, Alois
    fortiss GmbH, Munich.
    A Comparison of Formal Verification Approaches for IEC 614992016Ingår i: 2016 IEEE 21st International Conference on Emerging Technologies and Factory Automation (ETFA): Berlin, 6-9 Sept. 2016, Piscataway, NJ: IEEE conference proceedings, 2016, artikel-id 7733636Konferensbidrag (Refereegranskat)
    Abstract [en]

    Engineering and computer science have come up with a variety of techniques to increase the confidence in systems, increase reliability, facilitate certification, improve reuse and maintainability, improve interoperability and portability. Among them are various techniques based on formal models to enhance testing, validation and verification. In this paper, we are concentrating on formal verification both at runtime and design time of a system. Formal verification of a system property at design time is the process of mathematically proving that the property indeed holds. At runtime, one can check the validity of the property and report deviations by monitoring the system execution. Formal verification relies on semantic models, descriptions of the system and its properties. We report on ongoing verification work and present two different approaches for formal verification of IEC 61499-based programs. We provide two examples of ongoing work to exemplify the design and the runtime verification approaches

  • 88.
    Blomquist, Mats
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Non-contact measurement systems in robotics and telerobotics1999Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    In robotics, and particularly in telerobotics, non-contact measurement methods are widely used. In this thesis, systems are investigated with the range camera as the main sensor component. It is desirable that remotely controlled robot systems have a high degree of autonomy. Two systems are described where a range camera is used to increase the autonomy of the system. The first is a system where a laser pointer tracks an edge of an object or a cable. In the second system a range camera is used to control the movement of a robot arm perpendicularly towards an object, in the intention of aligning a sensor probe to the surface of the object. A problem with range camera measurements is the occurrence of occlusion, i.e. the phenomenon when objects in the foreground hide the measured object. One example of such a system is when the range camera is used to measure irregular objects, as for example objects on a conveyor belt. In the thesis, we investigate a system where we use the range camera to estimate the size distribution of iron ore pellets on a conveyor belt while systematic errors in the measurements arise due to occlusion.

  • 89.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB. Luleå tekniska universitet.
    Burman, Per
    Index Braille, Gammelstad.
    The WinBraille approach to producing Braille wuickly and effectively2002Ingår i: Computer Helping People with Special Needs: 8th International Conference, ICCHP 2002, Linz, Austria, July 15-20, 2002. Proceedings, Berlin: Encyclopedia of Global Archaeology/Springer Verlag, 2002, s. 618-619Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    With WinBraille it is possible to emboss directly from a word processor like Microsoft Word on any of Index Braille's embossers, and on-the-fly contract the document into grade 2 Braille. The benefit of WinBraille is that it has a simple interface for the novice, but is still powerful for the advanced user. WinBraille contains Windows drivers for Index Braille's embossers, the WinBraille application, contraction rules for more than 20 languages, a contraction rule editor, predefined profiles and templates for immediate access, and macros to directly emboss from Microsoft Word. The combination of Word macros, drivers, predefined contraction rules, profiles and templates makes the system suitable for the user with no or limited knowledge of Braille and Braille printing. We describe how the WinBraille's approach can facilitate the daily work for people who normally do not print Braille, but occasionally have to produce materials to be read by blind or visually impaired people. We also explore some of WinBraile's less advanced features, like Braille formatting and how to select different profiles and templates.

  • 90.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Burman, Per
    Index Braille, Gammelstad.
    Blenkhorn, Paul
    Department of Computation, UMIST, Manchester.
    Emboss contracted Braille directly from your word-processor using WinBraille2002Ingår i: 2002 Conference Proceedings - Technology and Persons with Disabilities Conference, California State University, Northridge , 2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    With WinBraille, a free program from Index Braille, Sweden, it is possible to emboss directly from a word-processor like Microsoft Word on any of Index Braille's embossers, and on-the-fly contract the document into grade 2 Braille. WinBraille contains: Windows drivers for Index Braille embossers; emboss-direct macros for well known Windows programs like Microsoft Word; a built-in editor for viewing and editing the text in prior to embossing; and a translation engine for Braille contraction translations.

  • 91.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Ericsson, Hans-Ola
    Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, Musik och dans.
    Next generation stop combination systems2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    A new system concept is described for storing and retrieving stop combinations in mechanically controlled pipe organs. The system combines many features found in currently used systems, but have, so far, not been combined in one single system. Characterized features are: Both "generals" and "divisionals", as found in many anglican organs, as well as a list of consecutive com-bination steps, common in continental systems; Micro-tonal registrations with precision better than 2% of the stop piston range, if the mechanical system can compete; Time-dependent activation of specified combinations; Individual PIN-code and password for a personal set of combination lists; An aesthetically appealing design which fits both in new and in historical organs. We also describe a novel method to easily insert practically an unlimited number of extra combination steps between two already defined steps.

  • 92.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet.
    Wernersson, Åke
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Range camera on conveyor belts: estimating size distribution and systematic errors due to occlusion1999Ingår i: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 118, s. 118-126Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    When range cameras are used for analyzing irregular material on a conveyor belt there will be complications such as missing segments caused by occlusion. Also, a number of range discontinuities will be present. In the framework towards stochastic geometry, conditions are found for the cases when range discontinuities take place. The test objects are pellets for the steel industry. An illuminating laser plane will give range discontinuities at the edges of each individual object. These discontinuities are used to detect and measure the chord created by the intersection of the laser plane and the object. From the measured chords we derive the average diameter and its variance. An improved method is to use a pair of parallel illuminating light planes to extract two chords. The estimation error for this method is not larger than the natural shape fluctuations (the difference in diameter) for the pellets. The laser-camera optronics is sensitive enough both for material on a conveyor belt and free falling material leaving the conveyor.

  • 93.
    Blomquist, Mats
    et al.
    Luleå tekniska universitet.
    Wernersson, Åke
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Tracking range discontinuities in dynamic scenes: a smart range camera1994Ingår i: Intelligent robots and computer vision XIII: algorithms and computer vision: 31 October - 2 November 1994, Boston, Massachusetts, SPIE - International Society for Optical Engineering, 1994, s. 249-260Konferensbidrag (Refereegranskat)
    Abstract [en]

    The problem studied in this paper is algorithms for fast and reliable extraction of range discontinuities in dynamic scenes. The application is to control the motion of a robot using a range scanning sensor. When estimating the pose of the objects in a scene, it is obvious that range discontinuities and flat surfaces have the largest information content. The concept studied consists of a smart camera chip together with a scanning illuminating laser. Feedback loops are closed between the chip and the scanning laser so as to follow along different types of range discontinuities in the scene. More explicitly: two types of feedback laws are outlined so as to track along range discontinuities both with and without occlusion; the laser can also track along a `generalized cylinder', say, a cable free in space or laying on an uneven surface; the tracking accuracy is estimated as the laser follows along the `curve of discontinuity'. The results are too preliminary and are not in this paper. In an earlier study, the Hough transform was found to be very robust in extracting the coordinates of planar surfaces. The edge parameters in this study are thus complementary to these surface parameters. Compared with complete range scanning of the entire scene, it seems possible to gain at least one order of magnitude in speed. This is important since these extracted range features are inside the feedback loop of the robot

  • 94.
    Blomstedt, Fredrik
    et al.
    BnearIT.
    Ferreira, Luis Lino
    Klisics, Markus
    BnearIT.
    Christos, Chrysoulas
    University of Porto.
    Soria, Iker Martinez de
    Tecnalia.
    Morin, Brice
    SINTEF.
    Zabasta, Anatolijs
    Riga Technical University, Latvia.
    Eliasson, Jens
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Mats
    LTU.
    Varga, Pal
    Budapest University of Technology and Economics.
    The Arrowhead Approach for SOA Application Development and Documentation2015Ingår i: IECON 2014: 40th Annual Conference of the IEEE Industrial Electronics Society, Dallas, TX, USA , Oct. 29 2014 - Nov. 1 2014, Piscataway, NJ: IEEE Communications Society, 2015, s. 2631-2637Konferensbidrag (Refereegranskat)
    Abstract [en]

    The Arrowhead project aims to address the technical and applicative issues associated with cooperative automation based on Service Oriented Architectures. The problems of developing such kind of systems are mainly due to the lack of adequate development and service documentation methodologies, which would ease the burden of reusing services on different applications. The Arrowhead project proposes a technical framework to efficiently support the development of such systems, which includes several tools for documentation of services and to support the development of SOA-based installations. The work presented in this paper describes the approach which has been developed for the first generation pilots to support the documentation of their structural services. Each service, system and system- of-systems within the Arrowhead Framework must be documented and described in such way that it can be implemented, tested and deployed in an interoperable way. This paper presents the first steps of realizing the Arrowheadvision for interoperable services, systems and systems-of-systems.

  • 95.
    Bodin, Ulf
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap.
    Andersson, Ulf
    Dadhich, Siddharth
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Uhlin, Erik
    Volvo Construction Equipment.
    Marklund, Ulf
    Boliden AB.
    Häggström, Derny
    Oryx Simulations AB.
    Remote Controlled Short-Cycle Loading of Bulk Material in Mining Applications2015Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-capacity wireless IP networks with limited delays are nowadays being deployed in both underground and open-pit mines. This allows for advanced remote control of mining machinery with improved feedback to operators and extensive monitoring of machine status, wear and fatigue. Wireless connectivity varies however depending on channel impairments caused by obstacles, multi-path fading and other radio issues. Therefore remote control and monitoring should be capable of adapting their sending rates to handle variations in communications quality. This paper presents key challenges in advanced remote control and monitoring of working machines via high-capacity wireless IP networks in mining environments. We reason about these challenges in context of underground short-cycle load, haul and dump operation with large-volume built wheel-loaders and present a generic communication solution for an operator assistance concept capable of adapting to varying communication properties

  • 96.
    Bodén, Ida
    et al.
    Umeå universitet.
    Norén, L
    Luleå tekniska universitet.
    Wisten, Åke
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Geladi, Paul
    Umeå universitet.
    Nyström, J
    Umeå universitet.
    Lindholm-Sethsom, B
    Umeå universitet.
    Development and optimization of a novel skin impedance instrument2005Ingår i: Proceedings of the 13th Nordic-Baltic Conference of BioMedical Engineering and Medical Physics: NBC'05 / [ed] R Lundström; B Andersson; H Grip, Swedish Society for Medical Engineering and Medical Physics , 2005, s. 162-163Konferensbidrag (Refereegranskat)
    Abstract [en]

    A novel skin impedance instrument is presented. The reproducibility and stability of the measurements where evaluated with multivariate techniques and a tendency to separate different skin types with skin impedance measurements is seen.

  • 97.
    Borg, Johan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    On electronics for measurement systems2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis collects the work performed by the author on electronics for measurement systems. The first part is the work performed on the EISCAT 3D ionospheric research radar, including two papers on the investigations on required performance, electronics design, and proof of concept signal processing. The thesis also contains work on a calibration system for mitigating signal path variations in large antenna arrays with distributed front-end electronics, enabling accurate beamforming of the received signal. Although the proposed system could in theory be entirely free from systematic errors, very large receiver dynamic range would be required in systems with many channels. Thus, in this work the measurement accuracy degradation arising when trying to reduce the dynamic range requirements has been investigated. A second part is on electronics for ultrasonic measurement systems. As one part of this part of the work, the systematic errors that arise in ultrasonic transit-time flow-meters when not utilizing the reciprocity of the flow-meter have been investigated experimentally. Based on this an integrated circuit for driving ultrasonic transducers using an arbitrary excitation waveform while maintaining constant interface impedance was designed and evaluated. By driving the ultrasonic transducer directly from a DAC the clock to output delay uncertainty was minimized. This, combined with matched on-chip receiver isolation switches enable on-line calibration against an on-chip reference DAC. These two and a work on a low-noise CMOS amplifier for ultrasonic applications are covered in three papers attached to this thesis. The third and final part is on evaluation of charge coupled devices, presented in the last paper of the thesis. It proposes a method for separating measured charge transfer inefficiency of a CCD into incomplete transfer of free charge and charge trapping in the substrate. We derive a generic model for the combined effects of charge trapping and incomplete transfer. This model further allows the charge transfer defects of a single gate to be calculated from the combined transfer inefficiency of a larger CCD. As proof of concept the method is applied to measurement data from a CCD manufactured using a 0.18 μm PINNED photo diode CMOS process.

  • 98.
    Borg, Johan
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Performance and spatial sensitivity variations of single photon avalanche diodes manufactured in an image sensor CMOS process2015Ingår i: IEEE Electron Device Letters, ISSN 0741-3106, E-ISSN 1558-0563, Vol. 36, nr 11, s. 1118-1120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this letter we present the results from a series of single-photon avalanche diode (SPAD) structures implemented in a commercial 0.18 μm CMOS process intended for CMOS image sensors. Variations without effect on the performance and variations that produced non-functional devices are described. Devices based on the P+/NWELL and deep-NWELL/P-EPI SPADs junctions were found to work well in this process. When biased for 10% QE the best 10 μm diameter P+/NWELL SPADs exhibited a DCR of about 1 kHz, whereas the DCR of the deep-NWELL/P-EPI SPADs was only 10 Hz under the same conditions. We also show that the former type exhibited local sensitivity variations within the SPADs ranging from a factor 4 at low excess voltage to 1.2 at an excess voltage of about 0.5 V. No significant sensitivity variations were found for the deep- NWELL/P-EPI SPADs, but they were found to exhibit significant sensitivity outside the central junction, contributing from 8.3 % at low excess voltage to approximately 70% at high excess voltage

  • 99. Borg, Johan
    et al.
    Hyyppä, Kalevi
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Lindgren, Per
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Projekt: ESIS2010Övrigt (Övrig (populärvetenskap, debatt, mm))
    Abstract [sv]

    Samlingsprojekt för alla ESIS-projekt

  • 100.
    Borg, Johan
    et al.
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    Johansson, Jonny
    An ultrasonic transducer interface IC with integrated push-pull 40 Vpp, 400 mA current output, 8-bit DAC and integrated HV multiplexer2011Ingår i: IEEE Journal of Solid-State Circuits, ISSN 0018-9200, E-ISSN 1558-173X, Vol. 46, nr 2, s. 475-484Artikel i tidskrift (Refereegranskat)
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