Pētniecība

Publikācijas

729 publikācijas

2011
Team “Latvia” GCDC 2011 Technical Paper

G. Strazdins, A. Gordjusins, G. Kanonirs, V. Kurmis, A. Mednis, R. Zviedris, L. Selavo

Kopsavilkums

G. Strazdins, A. Gordjusins, G. Kanonirs, V. Kurmis, A. Mednis, R. Zviedris, L. Selavo, "Team “Latvia” GCDC 2011 Technical Paper", in The Grand Cooperative Driving Challenge (GCDC 2011), associated with Automotive Week 2011, Helmond, Netherlands, May 15-16, 2011. <a href="http://www.google.lv/url?sa=t&rct=j&q=team%20%E2%80%9Clatvia%E2%80%9D%20gcdc%202011%20technical%20paper%20&source=web&cd=2&ved=0CCYQFjAB&url=http%3A%2F%2Fwww.gcdc.net%2Fmainmenu%2FHome%2Fnews%2FNews_-_current%2FGCDC_Final%253A_teams_videos_and_final_papers%2FLatvia&ei=uhILT4KuEc73sgb8sPiBDw&usg=AFQjCNEOuXiN89Zmul3KI6WAG-GxDyL5fw&sig2=qKBDPLTw1tFWubq-Sx7B8A&cad=rja" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Design problems of tree species classifiers for multispectral images

A. Lorencs, I. Mednieks, J. Sinica-Sinavskis

Kopsavilkums

A. Lorencs, I. Mednieks, J. Sinica-Sinavskis, “Design problems of tree species classifiers for multispectral images,” Automatic Control and Computer Sciences, Vol. 45, No. 2, pp. 61-69, 2011.
2011
Physical model for solving problems of cost-effective mobile robot development

A. Baums and A. Gordyushin

Kopsavilkums

A. Baums and A. Gordyushin Physical model for solving problems of cost-effective mobile robot development, Automatic Control and Computer Sciences Volume 45, Number 1, 39-46, DOI: 10.3103/S0146411611010020 Abstract A physical model including hardware and software is designed for the purpose of the development of a cost-effective mobile robot capable of moving in a heavy-going environment. The analysis of the realizable control system processes is performed and the trial of a physical model is carried out. <a href="http://www.springerlink.com/content/217370535qwm1352/" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Signal-dependent analog-to-digital conversion based on MINIMAX sampling (MWSCAS)

I.Homjakovs, M.Hashimoto, T.Hirose and T.Onoye

Kopsavilkums

I.Homjakovs, M.Hashimoto, T.Hirose and T.Onoye, „Signal-dependent analog-to-digital conversion based on MINIMAX sampling”, Proceedings of the IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS), ISSN 1548-3746, pp. 1 – 4, 2011. Abstract This paper presents an architecture of signal-dependent analog-to-digital converter (ADC) based on MINIMAX sampling scheme that allows achieving high data compression rate and power reduction. The proposed architecture consists of a conventional synchronous ADC, a timer and a peak detector, and AD conversion is carried out only when input signal peaks are detected. To improve the accuracy of signal reconstruction, MINIMAX sampling is improved so that multiple points are captured for each peak, and its effectiveness is experimentally confirmed. In addition, power reduction, which is the primary advantage of the proposed signal-dependent ADC, is analytically discussed and then validated with circuit simulations. <a href="http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6026466&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6026466" target="_blank" rel="noopener noreferrer">pdf</a>
2011
An Algorithmic Method for Increasing ADC Fault Resilience

V. Chapenko

Kopsavilkums

V. Chapenko, An Algorithmic Method for Increasing ADC Fault Resilience, Automatic Control and Computer Sciences, Allerton Press, Inc., Vol.45, No1, 2011, pp.53-59,.
2011
Processing of palm print and blood vessel images for multimodal biometrics

Rihards Fuksis, Modris Greitāns, Mihails Pudžs

Kopsavilkums

Rihards Fuksis, Modris Greitāns, Mihails Pudžs. “Processing of palm print and blood vessel images for multimodal biometrics”. Biometric ID Management, COST 2101 European WorkShop, BioID 2011, Branderburg, Germany, March 2011.g., Proceedings, pp. 238 – 249. Springer. Abstract This paper presents a design of PC-based multimodal biometric system, where palm blood vessels and palm prints are used as the biometric parameters. Image acquisition is based on dual spectrum illumination of the palm. By using near infrared light the image of blood vessels can be obtained and using the visible light the pattern of palm print can be captured. Images are processed using gradient filtering and complex matched filtering. After filtering, most significant features from the image are extracted as a vector set, and compared later in the recognition stage. Database of palm print and blood vessel images of 50 persons have been developed for experimental evaluation. The fusion approach of the two parameters is discussed and experimental results are presented. <a href="http://www.springerlink.com/content/f038745678127j26/" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Generalized Complex 2D Matched Filtering for Local Regular Line-Like Feature Detection

M.Pudzs, M.Greitans, R.Fuksis

Kopsavilkums

M.Pudzs, M.Greitans, R.Fuksis. "Generalized Complex 2D Matched Filtering for Local Regular Line-Like Feature Detection". 19th European Signal Processing Conference (EUSIPCO 2011), Barcelona, Spain, August 29 - September 2, 2011. Abstract In pattern recognition systems it is usually necessary to detect different image details, like edges, lines, corners, blobs, etc. For this purpose a bank of special filters, matching each individual detail can be used. As the details usually are oriented in different directions and have different scales, the image processing leads to many convolution operations. The complex 2D matched filter (CMF) is an angle invariant line detection filter, which also provides additional information about orientation of detected lines. In this paper we follow the idea of complex matched filtering, and develop generalized complex matched filtering (GCMF) approach, which is a whole bank of different angle invariant filters, where each filter is denoted by the order. These filters can be used to detect a broader range of image details: edges, lines, line intersections and corners; and, like its predecessor, the GCMF provides additional information about the detected features - the orientation angle. Each kernel from the GCMF bank is analyzed in polar coordinates and the specifics of detail detection are explained. A method of generating GCMF normalized kernels of arbitrary order is proposed. GCMF algorithm is presented and its performance is demonstrated on test images. <a href="http://www.google.lv/url?sa=t&rct=j&q=generalized%20complex%202d%20matched%20filtering%20for%20local%20regular%20line-like%20feature%20detection%20&source=web&cd=1&ved=0CCEQFjAA&url=http%3A%2F%2Fwww.eurasip.org%2FProceedings%2FEusipco%2FEusipco2011%2Fpapers%2F1569423987.pdf&ei=JhILT5vRJ4zZsgbo7eSCDw&usg=AFQjCNE0HaMNdWdzn2H7nBMPt8Sb_AqZJg&sig2=k33TITOpjSODOYt3_sa37w&cad=rja" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Research of dynamics of a gated balanced comparator

Э. Бейнер и К. Круминьш

Kopsavilkums

Э. Бейнер и К. Круминьш „Исследование динамики стробируемого балансного компаратора”, АВТОМАТИКА И ВЫЧИСЛИТЕЛЬНАЯ ТЕХНИКА, Выпуск No.6, 2011 (Vol. 45)c.21-30. E. Beiner and K. Krumin’sh “Research of dynamics of a gated balanced comparator “Automatic Control and Computer Sciences Volume 45, Number 6 (2011), pp.314-321.
2011
Virtual Ground Truth in Vehicular Sensing Experiments

G. Strazdins, A. Mednis, R. Zviedris, G. Kanonirs, and L. Selavo

Kopsavilkums

G. Strazdins, A. Mednis, R. Zviedris, G. Kanonirs, and L. Selavo, “Virtual Ground Truth in Vehicular Sensing Experiments: How to Mark it Accurately,” in The 5th International Conference on Sensor Technologies and Applications (SENSORCOMM 2011), (Nice, France), pp. 295–300, August 2011. Abstract Road surface quality monitoring is an important requirement for efficient, safe and comfortable transportation. However, the data collection is made difficult by the scope of the data source. Therefore, participatory sensing is a promising approach for road damage assessment. We are developing a vehicular participatory sensing application using Android smart-phones for pothole detection. This paper describes lessons learned from our field tests, which have exposed the deficiencies in terms of collected data quality. Nevertheless, the tests provide invaluable experience for planing future field tests and improvements to the test execution procedure for vehicular sensing researchers. Based on empirical and analytical results, we conclude, that semi-automated ground-truth reference point recording by a human observer in a moving vehicle while doing the actual data collection is imprecise as a consequence of multiple technical and human factors. We also discuss the motivation, why careful pothole position marking and categorization by walking along the test track is capable of providing highly accurate ground-truth. <a href="http://www.thinkmind.org/index.php?view=article&articleid=sensorcomm_2011_11_50_10162" target="_blank" rel="noopener noreferrer">pdf</a> (Thinkmind) <a href="http://strazdins.lv/papers/strazdins2011sensorcomm.pdf" target="_blank" rel="noopener noreferrer">pdf</a> (G. Strazdins personal page)<a href="http://www.thinkmind.org/download.php?articleid=sensorcomm_2011_11_50_10162" target="_blank" rel="noopener noreferrer"> </a>
2011
Complex 2D Matched Filtering Without Halo Artifacts

M.Pudzs, M.Greitans, R.Fuksis

Kopsavilkums

M.Pudzs, M.Greitans, R.Fuksis. "Complex 2D Matched Filtering Without Halo Artifacts". 18th International Conference on Systems, Signals and Image Processing, IWSSIP 2011, Sarajevo, Bosnia and Herzegovina, June 16-18, 2011, pp. 109-112. Abstract Accurate extraction of previously defined objects from noisy images is still a challenge for most image processing systems. There is a trade-off between the unwanted and useful amount of extracted information. From quality aspect, the matched filtering approach is preferable, as it significantly reduces the amount of unwanted information; however, the segmentation of filtered images usually is difficult. Complex matched filtering does the opposite: it provides the additional information, which simplifies the segmentation procedure; however, the resulting images are filled with the unwanted artifacts. This paper introduces the improved 2D complex matched filtering approach. The approach discussed in this paper doesn't produce the unwanted artifacts and still retains the angular information about the extracted objects. This improvement is significant for the systems that are sensitive to noise and demand precise segmentation results. <a href="http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5977398&abstractAccess=no&userType=inst" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Advanced Level-Crossing Sampling Method

U. Grunde, M. Greitans

Kopsavilkums

U. Grunde, M. Greitans. ”Advanced Level-Crossing Sampling Method”. 2011 19th IEEE Telecommunications Forum (TELFOR 2011), IEEE Catalog Number: CFP1198P-CDR, Belgrade, Serbia, November 2011., Proceedings of Papers, pp.797-800. Abstract We propose an advanced signal-driven sampling method that uses the level-crossing sampling technique based on the selected signal sampling and non-uniformly distributed quantization levels. The number of the quantization levels is chosen to compress the volume of sampled data. The proposed sampling method is targeting sporadic signals. The trade between the accuracy of the recovered signals and the compression ratio is evaluated. <a href="http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6143665&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6143665" target="_blank" rel="noopener noreferrer">pdf</a>
2011
An asynchronous FIR filter architecture coupled to a level-crossing ADC

T.Beyrouthy, L.Fesquet, M.Greitans, R.Shavelis and R.Roland

Kopsavilkums

T.Beyrouthy, L.Fesquet, M.Greitans, R.Shavelis and R.Roland, "An asynchronous FIR filter architecture coupled to a level-crossing ADC", The 9th International Conference on Sampling Theory and Applications SampTA 2011, Singapore, May 2-6, 2011.g. Abstract This paper presents the architecture of an asynchronous digital signal processing chain, working with non-uniformly sampled data in time. We focus on a Finite Impulse Response filter (FIR) applied to this non-uniform sampled signal obtained from an asynchronous analog to digital converter (A-ADC). The main advantage of combining the asynchronous design with the non-uniform sampling is the drastic reduction of the power consumption, thanks to the reduction of the computational load.
2011
Amplitude–Frequency Band Control for Oscilloscopes and Signal Converters

M. Greitans, E. Hermanis, V. Aristov

Kopsavilkums

M. Greitans, E. Hermanis, V. Aristov "Amplitude–Frequency Band Control for Oscilloscopes and Signal Converters ". Automatic Control and Computer Sciences, Vol.45, Issue 4, 2011. pp.218–222.М. Грейтанс, В. Аристов и Э. Херманис “Контроль амплитудно-частотной полосы осциллографов и преобразователей сигналов, Выпуск No.4, 2011 (Vol. 45) с.49-54. Abstract The possibility of data smoothing for the amplitude-frequency band control of oscilloscopes and signal converters is studied. It is shown that data smoothing by third-order splines differs slightly in performance compared to smoothing by a series of shifted functions Erf(t − Δt). <a href="http://link.springer.com/article/10.3103%2FS0146411611040043" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Combined peak and level-crossing sampling scheme

M.Greitans, R.Shavelis, L.Fesquet and T.Beyrouthy

Kopsavilkums

M.Greitans, R.Shavelis, L.Fesquet and T.Beyrouthy, "Combined peak and level-crossing sampling scheme", The 9th International Conference on Sampling Theory and Applications SampTA 2011, Singapore, May 2-6, 2011.g. Abstract The paper proposes a modification of the traditional level-crossing sampling technique, which allows reducing the number of obtained samples, if the levels are placed too densely within the dynamic range of the input signal. The reduction is based on finding and keeping only those level-crossing samples, which are most closely located to signal peaks. All the other samples are discarded. In such a way, the obtained result is similar to peak sampling with samples being taken only at peak points (local extrema) of the signal. The recovery of the continuous signal can be based on piecewise linear interpolation, which provides good results for the speech signal. The proposed sampling technique can be used in data acquisition systems to reduce the amount of data being transferred.
2011
Experimental investigation of noise suppression using the modified up-and-down method

K. Krūmiņš, V. Pētersons and V. Plociņš

Kopsavilkums

K. Krūmiņš, V. Pētersons and V. Plociņš. Experimental investigation of noise suppression using the modified up-and-down method. Automatic Control and Computer Sciences, 2011, Vol. 45, No. 1, pp. 47-52 Abstract The noise suppression efficiency is experimentally investigated for discrete stroboscopic signal transformation providing 5–15 μV (RMS) sensitivity. A balanced comparator based on tunnel diodes is used as a clocked comparator. Ordinary and modified up-and-down methods are used to measure the instantaneous signal values. The experimental results are compared to the theoretical calculations. <a href="http://springerlink.com/content/5111ql7h16t40k24/fulltext.pdf" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Towards Vehicular Sensor Networks with Android Smartphones for Road Surface Monitoring

G. Strazdins, A. Mednis, G. Kanonirs, R. Zviedris, and L. Selavo

Kopsavilkums

G. Strazdins, A. Mednis, G. Kanonirs, R. Zviedris, and L. Selavo, “Towards Vehicular Sensor Networks with Android Smartphones for Road Surface Monitoring,” in The Second International Workshop on Networks of Cooperating Objects (CONET’11), Electronic Proceedings of CPSWeek'11, 2011. pp. 1-4. Abstract Road surface monitoring, including automated pothole and bump detection, is essential for both drivers and road maintainers. This paper presents preliminary results from an ongoing experimental study with the central question: is a smartphone with Android operating system capable of performing road surface monitoring using participatory sensing approach? The test results with 3 Android models and several tracks are presented and demonstrate feasibility of the approach. <a href="http://strazdins.lv/papers/strazdins2011androidpotholes.pdf" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Biohashing and Fusion of Palmprint and Palm Vein Biometric Data

Rihards Fuksis, Arturs Kadikis, and Modris Greitans

Kopsavilkums

Rihards Fuksis, Arturs Kadikis, and Modris Greitans "Biohashing and Fusion of Palmprint and Palm Vein Biometric Data", International Conference on Hand-based Biometrics, ICHB2011, Hong Kong, China, November 17-18, 2011, pp. 268-273 Abstract This paper combines the results of our previous experiments concerning acquisition of the images of the human palm in infrared and visible light, the extraction of features from images as well as our current results on biometric data hashing with the advanced biohashing algorithm. We first describe the properties of the complex 2D matched filtering for feature extraction from images, followed by biometric vector construction techniques and raw biometric data comparison. We address the problem of securing biometric data for multimodal biometric systems, by analyzing the biohashing algorithm and proposing our enhancements. Results of experiments that include raw biometric data comparison, biohashing and advanced biohashing biocode comparisons are presented at the end of the paper. <a href="http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6094334&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6094334" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Vehicle Position Determination Using Several SBAS Receivers and Data from Local Reference Stations

Artis Mednis

Kopsavilkums

Artis Mednis. Vehicle Position Determination Using Several SBAS Receivers and Data from Local Reference Stations. L. Niedrite et al. (Eds.): BIR 2011 Associated Workshops and Doctoral Consortium, pp. 379-386, 2011. Riga Technical University, 2011. <a href="http://www.google.com/url?q=http%3A%2F%2Fbir2011.rtu.lv%2Fsites%2Fbir2011.rtu.lv%2Ffiles%2FBIR2011_PROGRAM_webpage%25282%2529.pdf&sa=D&sntz=1&usg=AFrqEzfSAocUM8ZX9F0SbrCeSsINSHZWAg" target="_blank" rel="noopener noreferrer">pdf</a>
2011
Real Time Pothole Detection using Android Smartphones with Accelerometers

A. Mednis, G. Strazdins, R. Zviedris, G. Kanonirs, and L. Selavo

Kopsavilkums

A. Mednis, G. Strazdins, R. Zviedris, G. Kanonirs, and L. Selavo. Real Time Pothole Detection using Android Smartphones with Accelerometers. Proc. of the 2nd International Workshop on Mobility in Wireless Sensor Networks (MobiSensor 2011), Barcelona, Spain, pp.1-6, June, 2011. Abstract The importance of the road infrastructure for the society could be compared with importance of blood vessels for humans. To ensure road surface quality it should be monitored continuously and repaired as necessary. The optimal distribution of resources for road repairs is possible providing the availability of comprehensive and objective real time data about the state of the roads. Participatory sensing is a promising approach for such data collection. The paper is describing a mobile sensing system for road irregularity detection using Android OS based smart-phones. Selected data processing algorithms are discussed and their evaluation presented with true positive rate as high as 90% using real world data. The optimal parameters for the algorithms are determined as well as recommendations for their application. <a href="http://ieeexplore.ieee.org/search/freesrchabstract.jsp?tp=&arnumber=5982206" target="_blank" rel="noopener noreferrer">pdf</a> (IEEE Xplore) <a href="http://strazdins.lv/papers/mednis2011androidpotholes.pdf" target="_blank" rel="noopener noreferrer">pdf</a> (G. Strazdins personal page)<a href="http://strazdins.lv/papers/mednis2011androidpotholes.pdf" target="_blank" rel="noopener noreferrer"> </a>
2011
Mini-Max Method for Optimization of Energy Consumption in Real-Time Systems with a Lot of Processing Elements

A. Baums

Kopsavilkums

A. Baums “Mini-Max Method for Optimization of Energy Consumption in Real-Time Systems with a Lot of Processing Elements”, Automatic Control and Computer Sciences, Vol. 45, No. 6, 2011,. pp. 322-337. Abstract The mini-max method is designed for the analysis and optimization of energy consumption in single-processor real-time systems and offers several advantages over alternative methods when used in single-task and multitask systems. There has been no research, however, dedicated to its use in real-time systems with several processing elements. This work deals with the use of the mini-max method in subsystems with two executive elements. Two methods for the organization of systems processing sequential task threads are proposed. The first method is a synchronous one with an allotted time period for each task, and the second method involves an asynchronous task stream. The analysis and comparison of these methods are performed, and their efficiency in solving the problem of energy consumption is shown. <a href="http://www.springerlink.com/content/b87862368xq06p41/" target="_blank" rel="noopener noreferrer">pdf</a>

Team “Latvia” GCDC 2011 Technical Paper

Design problems of tree species classifiers for multispectral images

Physical model for solving problems of cost-effective mobile robot development

Signal-dependent analog-to-digital conversion based on MINIMAX sampling (MWSCAS)

An Algorithmic Method for Increasing ADC Fault Resilience

Processing of palm print and blood vessel images for multimodal biometrics

Generalized Complex 2D Matched Filtering for Local Regular Line-Like Feature Detection

Research of dynamics of a gated balanced comparator

Virtual Ground Truth in Vehicular Sensing Experiments

Complex 2D Matched Filtering Without Halo Artifacts

Advanced Level-Crossing Sampling Method

An asynchronous FIR filter architecture coupled to a level-crossing ADC

Amplitude–Frequency Band Control for Oscilloscopes and Signal Converters

Combined peak and level-crossing sampling scheme

Experimental investigation of noise suppression using the modified up-and-down method

Towards Vehicular Sensor Networks with Android Smartphones for Road Surface Monitoring

Biohashing and Fusion of Palmprint and Palm Vein Biometric Data

Vehicle Position Determination Using Several SBAS Receivers and Data from Local Reference Stations

Real Time Pothole Detection using Android Smartphones with Accelerometers

Mini-Max Method for Optimization of Energy Consumption in Real-Time Systems with a Lot of Processing Elements