Publications

729 publications

• 2013

  Amplitude Adaptive Asynchronous Sigma-Delta Modulator

  K.Ozols, M.Greitans, R.Shavelis

  Abstract

  <p>K.Ozols, M.Greitans, R.Shavelis. "Amplitude Adaptive Asynchronous Sigma-Delta Modulator", 8th International Symposium on Image and Signal Processing and Analysis (ISPA 2013), Trieste, Italy, September 4-6, 2013 Conference Proceedings pp.460-464<br /> Abstract:</p> <p>The paper presents an improved version of Asyn-chronous Sigma-Delta Modulator (ASDM) in order to reduce its power consumption for time-encoding of analog signals. The proposed method is called Amplitude Adaptive ASDM (AA-ASDM) since time-varying envelope of the signal is used in the feedback loop of ASDM to reduce the switching rate of the output trigger. Regardless of this reduction the perfect recovery of the original signal from the obtained time sequence is still possible. The proposed method is particularly advantageous for signals with wide dynamic range and is demonstrated by numerical results on the example of electroencephalography (EEG) signal.</p>
• 2013

  SEAL: a Domain-Specific Language for Novice Wireless Sensor Network Programmers

  A. Elsts, J. Judvaitis and L. Selavo

  Abstract

  <p><span lang="EN-GB">A. Elsts, <u>J. Judvaitis</u> and L. Selavo, „<i>SEAL: a Domain-Specific Language for Novice Wireless Sensor Network Programmers</i>”, 39th Euromicro Conference on Software Engineering and Advanced Applications (SEAA 2013), Proceedings, Santander, Spain, 2013.</span></p>
• 2013

  Embedded Solution for Dangerous Road Situation Warnings

  Nikolajs Agafonovs, Andrejs Skageris, Girts Strazdins, and Artis Mednis

  Abstract

  <p>Nikolajs Agafonovs, Andrejs Skageris, Girts Strazdins, and Artis Mednis. IMilePost: Embedded Solution for Dangerous Road Situation Warnings. The 1st International Conference on Artificial Intelligence, Modelling and Simulation (AIMS 2013), Proceedings of the 1st International Conference on Artificial Intelligence, Modelling and Simulation (AIMS 2013), pp. 481-486, 2013. IEEE Computer Society, 2013.</p>
• 2013

  Vehicle classification in video using virtual detection lines

  Kadiķis Roberts, Freivalds Kārlis

  Abstract

  <p><img class="wp-image-6950 aligncenter" src="/storage/wp/2019/07/extended_iovdl-300x88.png" alt="" width="507" height="149" /></p> <p>A video processing algorithm for vehicle parameter acquisition and classification is presented. The algorithm is based on a combination of several detection lines. According to passing vehicles, intervals are created on the detection lines. Intervals on different lines, belonging to the same vehicle, are combined. Further processing of vehicle intervals allows acquiring vehicle parameters and to classify vehicles. The accuracy of vehicle counting and classification is analyzed on different videos.</p> <p><a href="https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9067/90670Y/Vehicle-classification-in-video-using-virtual-detection-lines/10.1117/12.2051028.short">Kadiķis, R., &amp; Freivalds, K. (2013, December). Vehicle classification in video using virtual detection lines. In <i>Sixth International Conference on Machine Vision (ICMV 2013)</i> (Vol. 9067, p. 90670Y). International Society for Optics and Photonics.</a></p> <p><a href="https://makonis.edi.lv/s/4Wp7K6XfKfqpeCN">pdf</a></p>
• 2013

  Real-time object tracking in 3D space using mobile platform with passive stereo vision system

  Harijs Grinbergs, Artis Mednis, and Modris Greitans

  Abstract

  <p>Harijs Grinbergs, Artis Mednis, and Modris Greitans. Real-time object tracking in 3D space using mobile platform with passive stereo vision system. N. Tagoug (Ed.): Proceedings of World Congress on Multimedia and Computer Science (WCMCS 2013), pp. 60-68, 2013. Association of Computer Electronics and Electrical Engineers, 2013.<br /> searchdl.org<br /> Abstract</p> <p>Tracking of objects in 3D space performed in real-time is a significant task in different domains from autonomous robots to smart vehicles. Traditional methods for this task include the usage of specific data acquisition equipment as radars, lasers etc. The expansive development of computer technologies enables to solve this task using general purpose data acquisition equipment as stereo cameras and smart image processing for object tracking. The paper is describing a passive stereo vision based mobile system for real-time object tracking in 3D space. Selected image processing algorithm is discussed and its evaluation on real world data presented with tracking time per target as short as 0.1-0.2ms in urban environment traffic scenarios. The initial set of algorithm parameters and constraints is determined as well as some recommendations for their application is given.</p>
• 2013

  Efficient Video Processing Method for Traffic Monitoring Combining Motion Detection and Background Subtraction

  Roberts Kadiķis, Kārlis Freivalds

  Abstract

  <p><img class="size-medium wp-image-6947 aligncenter" src="/storage/wp/2019/07/detection_line-300x147.png" alt="" width="300" height="147" /></p> <p>A computationally efficient video processing algorithm for vehicle detection is presented. The algorithm detects vehicles that arrive on a defined detection line. Inter-frame difference is used to detect the presence of a vehicle and background subtraction is used to find the shape of the object that does not belong to an empty road. If movement is detected, intervals corresponding to the moving objects are created on the detection line. Further processing of intervals allows detecting and counting the objects. The accuracy of the proposed method is analyzed on different roads and in different weather conditions.</p> <p><a href="https://link.springer.com/chapter/10.1007/978-81-322-0997-3_12">Kadiķis, R., &amp; Freivalds, K. (2013). Efficient video processing method for traffic monitoring combining motion detection and background subtraction. In <i>Proceedings of the Fourth International Conference on Signal and Image Processing 2012 (ICSIP 2012)</i> (pp. 131-141). Springer, India.</a></p> <p><a href="https://makonis.edi.lv/s/6W23kk5EAQHDXDZ" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2013

  Development of distributed real time data aquisition system for radio telescope monitoring

  Ruibys, K., A. Andziulis, T. Eglynas, M. Jusis, D. Drungilas, and G. Gaigals.

  Abstract

  <p><span class="m_-8665640760123692966459473308-23082019"><span lang="EN-GB">Ruibys, K., A. Andziulis, T. Eglynas, M. Jusis, D. Drungilas, and G. Gaigals. Development of distributed real time data aquisition system for radio telescope monitoring. Space Research Review: 34.</span></span></p>
• 2013

  Embedded Configurable Sensor Interface Devices for Seamless Data Acquisition

  U. Grunde

  Abstract

  <p>U. Grunde. ”Embedded Configurable Sensor Interface Devices for Seamless Data Acquisition”. 21th IEEE Telecommunications Forum (TELFOR 2013), IEEE Catalog Number: CFP1398P-CDR, Belgrade, Serbia, November 2013., Proceedings of Papers, pp.526-528.<br /> Abstract</p> <p>The presented embedded configurable interface device is a feasible solution for interfacing different types of smart sensor systems and user devices. A micro-controller with dedicated I/O interface driver and a smart sensor communication driver is necessary in creating the seamless interface between end-user and smart sensors systems.</p> <p><a href="http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&amp;arnumber=6716282" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2013

  Wearable Posture Monitoring System with Biofeedback via Smartphone

  A. Hermanis, K. Nesenbergs, R. Cacurs, and M. Greitans

  Abstract

  <p>A. Hermanis, K. Nesenbergs, R. Cacurs, and M. Greitans, "Wearable Posture Monitoring System with Biofeedback via Smartphone", Journal of Medical and Bioengineering, (ISSN: 2301-3796), March 2013, Vol. 2, no. 1, pp.40-44, 2013<br /> Abstract</p> <p>In this paper a novel portable posture monitoring and feedback system is proposed. System is designed to be unobtrusively used during daily activities and provide alternative solution to traditional bracing used in treatment of scoliosis. System consists of wearable sensor network for posture data acquisition, wireless data transmission and conventional smartphone for data processing, visualization and vibrating feedback generation. Special data acquisition board is designed for data sampling from sensor network and wireless transmission to smartphone. A custom made Android application is used for real time data processing, current posture model visualization, data logging and instantaneous feedback. System was tested for posture monitoring and feedback generation on multiple test subjects. Tests demonstrated systems effectiveness on improving posture related behavior and ability to help subject to hold specific reference posture performing similar task as traditional bracing.</p> <p><a href="http://www.jomb.org/index.php?m=content&amp;c=index&amp;a=show&amp;catid=34&amp;id=38" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2013

  Ļevinskis, A. Convolutional Neural Network Feature Reduction Using Wavelet Transform. Electronics and Electrical Engineering, 2013, Vol.19, No.3, pp.61-64. e-ISSN 2029-5731. ISSN 1392-1215. Available from: doi:10.5755/j01.eee.19.3.3698

  Ļevinskis, A

  Abstract

  <p>Ļevinskis, A. Convolutional Neural Network Feature Reduction Using Wavelet Transform. Electronics and Electrical Engineering, 2013, Vol.19, No.3, pp.61-64. e-ISSN 2029-5731. ISSN 1392-1215. Available from: doi:10.5755/j01.eee.19.3.3698</p>
• 2013

  Efficient Real-Time Data Acquisition of Wired Sensor Network with Line Topology

  Atis Hermanis, Ričards Cacurs, Krišjānis Nesenbergs, Modris Greitāns

  Abstract

  <p>A. Hermanis, R. Cacurs, K. Nesenbergs un M. Greitans. "Efficient Real-Time Data Acquisition of Wired Sensor Network with Line Topology", 2013 IEEE Conference on Open Systems, 2-4 dec., 6lpp.</p> <p>doi: <a href="http://10.1109/ICOS.2013.6735062">10.1109/ICOS.2013.6735062</a></p> <p>All authors:</p> <p>Atis Hermanis, Ricards Cacurs, Krisjanis Nesenbergs un Modris Greitans.</p> <p><strong>Abstract:</strong></p> <p>In this paper a method for efficient data acquisition from sensor network with large number of nodes is proposed. A specific design allows simple device connection in daisy-chain configuration, thus removing addressing problems and allowing synchronized sampling design using just 4 wires. Several limitations are considered to provide mathematical model for estimation of maximum number of sensor nodes. An experimental setup was designed which demonstrated theoretical ability to acquire data from up to 200 sensors with 50 Hz sampling rate using conventional low-cost hardware, however, more advanced setup could allow to increase maximum number of sensors several times. The wiring structure of the network as well as hardware is specifically designed for use in smart garments or similar applications that require sensor integration in compact environment and low-power, real-time performance.</p>
• 2012

  A Multimodal Approach for Determination of Vehicle Position

  Artis Mednis

  Abstract

  <p>Artis Mednis. A Multimodal Approach for Determination of Vehicle Position. L. Niedrite et al. (Eds.): BIR 2011 Workshops, LNBIP 106, pp. 223–235, 2012. Springer-Verlag Berlin Heidelberg 2012.<br /> Abstract</p> <p>One of the most important tasks during development of hardware/software systems for assisted and automatic driving is determination of vehicle position with sufficient accuracy in real time. Most of experimental systems developed yet are based on relatively expensive Real Time Kinematic technique which primary usage is land and hydrographical surveys with centimetre level accuracy.<br /> The paper is describing technique for determination of vehicle position, based on multimodal data sources with subsequent data integration. Data acquisition is performed using several GNSS receivers with SBAS capability as well as stationary reference stations. Data acquisition and integration methods are discussed as well as their performance analyzed using data from real world experiments.</p> <p><a href="http://www.springerlink.com/content/t3364388922p4987/" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2012

  Heterogeneous Tool Kit for Real-Time Edutainment

  Reinholds Zviedris, Artis Mednis, and Gatis Mednis

  Abstract

  <p>Reinholds Zviedris, Artis Mednis, and Gatis Mednis. Heterogeneous Tool Kit for Real-Time Edutainment. The 5th International Scientific Conference on Applied Information and Communication Technologies (AICT 2012), Proceedings of the 5th International Scientific Conference on Applied Information and Communication Technologies (AICT 2012), pp. 201-208, 2012. Latvia University of Agriculture, 2012.<br /> Abstract</p> <p>In today’s world, digital technology is taking over our lives more and more including education and<br /> entertainment. In both fields situations occurs when someone needs to control or coordinate tasks in different locations to be performed just in time. There exists certain amount of modus operandi characterized by various levels of complexity that tries to solve this issue. During state-of-the-art research authors found a lack of simple solutions that could be easily adapted for specific user requirements while still suitable for wide area of needs. In this paper we describe our experience taken from developing of hardware and software tool kit suitable for education or entertainment event staging and management where real time user-assigned task control or task reassignment is required. Hardware part includes embedded device that performs SRD interface control and configured information output. Development of this part was done with energy economy in mind to ensure the utmost possible autonomous operation of device. Software part is lightweight web based application that can be accessed by event organizers and participants using HTML-enabled Internet browser from PC or smartphone. Mobile phone's built-in camera and matrix bar code interface can be used as an option for access to the system or execution of specific tasks. Over the course of last 5 years tool kit has been progressively implemented in hardware and software prototypes that found multiple applications in various “Autoliste” and “CDT” organized events.</p> <p><a href="http://www.google.com/url?q=http%3A%2F%2Faict.itf.llu.lv%2Ffiles%2Frakstkraj%2Fproceedings_aict2012.pdf&amp;sa=D&amp;sntz=1&amp;usg=AFrqEzcBn3i_ytDH4-sDz7HQuvyNQ6Sxug" target="_blank" rel="noopener noreferrer">Pdf</a></p>
• 2012

  The Adaptive „Up-and-Down” Method with a Variable Step

  V. Karklinsh

  Abstract

  <p>V. Karklinsh, “The Adaptive „Up-and-Down” Method with a Variable Step”, “Automatic Control and Computer Sciences” – AC&amp;CS, Vol.46, Number 5, 2012, , Allerton Press, Inc., pp.232-237.В. Карклиньш, “Адаптивный метод “up-and-down” с переменным шагом, ”Автоматика и вычислительная техника” - АВТ. Выпуск No. 5, 2012 (Vol. 46) с.70-78.</p>
• 2012

  Tree species identification in mixed Baltic forest using LiDAR and multispectral data

  R. Dinuls, G. Erins, A. Lorencs, I. Mednieks, and J. Sinica-Sinavskis

  Abstract

  <p>R. Dinuls, G. Erins, A. Lorencs, I. Mednieks, and J. Sinica-Sinavskis, “Tree species identification in mixed Baltic forest using LiDAR and multispectral data,” IEEE J. Sel. Topics Appl. Earth Observ. Remote Sens.,<br /> vol. 5, no. 2, pp. 594–603, 2012.<br /> Abstract</p> <p>This work describes the task of inventorying Baltic mixed forests at an individual tree level. The development of a practicable methodology for semi-automated identification of tree species was targeted. Data acquisition equipment and preprocessing software, explored forest area, processing approaches, obtained classification results as well as newly developed software are described. To resolve the core problem – tree species identification – a classification approach is proposed for processing multi-spectral imagery data from the vicinity of tree tops. A multi-class classifier is designed from multi-spectral data of interactively selected trees included in initial design (training) sets for two conifer and three deciduous species of interest. An approach for the stabilization of the classification results is proposed, based on improving the representativeness of the design sets by selection of trees from different locations, dismissing trees with overlapping crowns and anomalies, followed by the calculation of a spectral dissimilarity parameter of the design sets and dismissing the sets of trees of any species which are too similar. The best classification results were obtained using a two-stage procedure. In the first stage, species clusters were created by adding randomly selected trees from the whole analyzed forest area. Final classification of all trees was done by using a Bayes classifier designed on the basis of cluster properties. A procedure for increasing robustness of the clustering stage is proposed, based on performing multiple clustering attempts, each using a randomly sampled subset of a chosen design set for the classifier design, and making a decision about the class of each tree by the majority vote from the results of these attempts. This classification algorithm was tested against the set of trees, for which information was available from field work. It is shown that a mean classification error below 3% can be achieved and the m- ximum error rate was decreased substantially by applying the proposed approach for selection of representative design sets.</p> <p><a href="http://ieeexplore.ieee.org/Xplore/defdeny.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D6204116%26userType%3Dinst&amp;denyReason=-134&amp;arnumber=6204116&amp;productsMatched=null&amp;userType=inst" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2012

  A two-stage method for building classifiers

  A. Lorencs, Yu. Sinitsa-Sinyavskis

  Abstract

  <p>A. Lorencs, Yu. Sinitsa-Sinyavskis. "A two-stage method for building classifiers," Automatic Control and Computer Sciences, September 2012, Volume 46, Issue 5, pp. 214-222.<br /> Abstract</p> <p>A specific method for the evaluation of unknown parameters of a specified pair of normally distributed populations called the two-stage method for building classifiers is discussed. The determined parameter estimates are used to generate Bayesian data classifiers obtained by sampling from specified populations. The statistical simulation method is used to study the effect of the second evaluation stage on the mean classification error probability.</p> <p><a href="http://link.springer.com/article/10.3103%2FS0146411612050045?LI=true" target="_blank" rel="noopener noreferrer">pdf</a></p>
• 2012

  An Instability Estimation of Precision Time Intervals

  V. Bespal'ko, E. Boole, and J. Savarovskiy.

  Abstract

  <p>V. Bespal'ko, E. Boole, and J. Savarovskiy. An Instability Estimation of Precision Time Intervals. Instruments and Experimental Techniques, 2012, Vol. 55, No. 3, pp. 377-382.</p>
• 2012

  RFID Communication: How Well Protected Against Reverse Engineering?

  Artis Mednis, and Reinholds Zviedris

  Abstract

  <p>Artis Mednis, and Reinholds Zviedris. RFID Communication: How Well Protected Against Reverse Engineering? The 2nd International Conference on Digital Information Processing and Communications (ICDIPC12), Proceedings of the 2nd International Conference on Digital Information Processing and Communications (ICDIPC12), pp. 56-61, 2012. Klaipeda University, 2012<br /> Abstract</p> <p>The most important advantages of RFID technology are transmitting and receiving of information wirelessly as well as low implementation and maintenance costs. Such attractive features are reason for widespread usage of RFID systems - from tracking of assets to measurement of the timing during sporting events. To ensure secure operation of such systems they should have appropriate protection against reverse engineering. The contribution of this paper is a method for reverse engineering of speci?c RFID system used for time measurements during sporting events. Selected communication protocol aspects are discussed and their replication with off-the-shelf hardware and software with the aim to simulate a non-existing RFID tag with certain self selected ID number are presented.</p> <p><a href="http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&amp;arnumber=6257290" target="_blank" rel="noopener noreferrer">pdf</a> (IEEE Xplore)<a href="http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&amp;arnumber=6257290" target="_blank" rel="noopener noreferrer"><br /> </a><br /> <a href="http://www.google.com/url?q=http%3A%2F%2Fwww.sdiwc.net%2Fkla%2Fproceedings.rar&amp;sa=D&amp;sntz=1&amp;usg=AFrqEzcwi6Xo9vHY7vTer36cDe-m2TPeOw" target="_blank" rel="noopener noreferrer">pdf</a> (ICDIPC 2012\PAPERS\214.pdf)</p>
• 2012

  Signal distortions in comparator pulse gate transformation using the statistical method for a low number of samples

  K. Kruminsh and V. Plotsinsh

  Abstract

  <p>K. Kruminsh and V. Plotsinsh. “Signal distortions in comparator pulse gate transformation using the statistical method for a low number of samples”. Automatic Control and Computer Sciences. Volume 46, Number 3 / May 2012, pp.139-145.</p>
• 2012

  Method for Wideband Signal Digitizing and their Real-time Reconstruction in Enlarged Dynamic Range

  I.Bilinskis, K. Sudars, M. Min

  Abstract

  <p>I.Bilinskis, K. Sudars, M. Min, “Method for Wideband Signal Digitizing and their Real-time Reconstruction in Enlarged Dynamic Range”, International conference “Electronics 2012”, Palanga, Lithuania, 18-20 June 2012.</p> <p><a href="http://www.google.lv/url?sa=t&amp;rct=j&amp;q=&amp;esrc=s&amp;source=web&amp;cd=3&amp;cad=rja&amp;ved=0CDcQFjAC&amp;url=http%3A%2F%2Fwww.ee.ktu.lt%2Felectronics%2Ffiles%2FE2012_program.pdf&amp;ei=zfSkUenOE6Kn4ASlq4DIDw&amp;usg=AFQjCNEdxHdqPWI1mYT5KuDXszWU2xy7gw&amp;sig2=IdyoIgRIax3xLagr8ogBbw&amp;bvm=bv.47008514,d.bGE" target="_blank" rel="noopener noreferrer">pdf</a></p>