An edit distance model that can be used for the approximate matching of contiguous and noncontiguous timed strings is presented the paper. The model extends the concept of the weighted stringedit distance by introducing timed edit operations and by making the edit costs time dependent. Special attention is paid to the timed null symbols that are associated with the timed insertions and deletions. The proposed original algorithm can be applied to general problems involving the comparison of time series of events and thus also for evaluating intelligent surveillance systems.
COBISS.SI-ID: 6651220
Person recognition using facial features extracted, for example, from mug-shot images, represents one of the most established research fields of biometrics. However, due to the widespread use of web-cams and mobile devices embedded with a camera, it is now possible to realize facial video recognition, rather than resorting to just still images. Due to these developments, we are currently witnessing a shift in the research focus of many research groups, which direct their efforts more towards video-based face recognition and away from recognition techniques relying solely on still images. This paper presents an evaluation of person identity veri?cation using facial video data. It involves 18 systems made available by seven academic institutes such as IDIAP, the University of Surrey, the University of Ljubljana, etc. These systems provide for a diverse set of assumptions, including feature representation and preprocessing variations, allowing us to assess the effect of adverse conditions, usage of quality information, query selection, and template construction for video-to-video face authentication.
COBISS.SI-ID: 8062804
A novel 3D triangulation-based imaging method and device is proposed, which has the following the following advantages over known state-of-the-art methods: low energy consumption, enables uninterrupted usage of several devices in the same room, is robust to illumination changes and disturbancies. This patent was recognised as the most important achievement on the 2.15 Metrology field among the 2011 ARRS programs and projects.
COBISS.SI-ID: 8985172
The invention proposes a new method and equipment for monitoring suitability of a tubular object geometry, which guides a user in properly positioning said complex-shaped object before photographing it and makes it possible to simply and most appropriately illuminate it and to rapidly assess the suitability of the object geometry. The invention is adapted for a fast industrial application. A computer provides for displaying where and in which position the tubular object to be monitored must be positioned, whereby higher accuracy of the proposed method is guaranteed. Identifying spots, on which the currently monitored tubular object critically deviates from the designed object, as well as automatic calibration of the equipment without need to position a calibration pattern next to the monitored object advantageously accelerate the monitoring procedure. An international patent application has been filed for this patent, which exhibits a significant potential for commercial exploitation. The EU patent EP2950042 has been granted in December 2016.
COBISS.SI-ID: 11299156
We analyzed a month-long measurement of indoor air and environment quality parameters in one gym during sporting activities such as football, basketball, volleyball, badminton, boxing and fitness. We have determined an average single person's contribution to the increase of temperature, humidity and dust concentration in the gym air volume of 12500 m3: during 90 min exercise performed at an average heart rate of 143 ± 10 bpm, a single person evaporated 0.94 kg of water into the air by sweating, contributed 0.03 K to the air temperature rise and added 1.5 µg/m3 and 5 ng/m3 to the indoor concentration of inhalable particles (PM10) and Ca concentration, respectively. As the air exchange by breathing at the observed exercise intensity was about three times faster with respect to the resting condition and since the exercise-induced PM10 concentration was about two times larger than outdoors, a sportsman in the gym would receive about a six-fold higher dose of PM10 inside than he/she would have received at rest outside.
COBISS.SI-ID: 1538041540
In the last decade space-density of monitoring stations increased, in addition also air pollution modeling made big progress. Exploiting the diversity of big data can lead to better knowledge about air pollution at continental scale. The focus of the study was a data-driven approach using non-negative matrix factorization to provide new insights and to study the characteristic space-time particulate-matter patterns across Europe. We analyzed the PM10 concentrations obtained from 1097 monitoring stations (AirBase data) and the Monitoring Atmospheric Composition and Climate (MACC) modeled fields for a period of 3 years. We distinguished five characteristic patterns obtained from the AirBase data and five patterns from the MACC data. A comparison between the AirBase and MACC data shows a good spatial overlap for the east Europe, central Europe and the Mediterranean patterns. However, it should be noted that an analysis of the MACC data revealed two additional marine patterns: the Celtic and the North Seas. The Po Valley and Balkan patterns were very clearly identified when analyzing the AirBase data. In order to better understand the influence of the synoptic situation on the particulate-matter concentrations the synoptic meteorological situations were additionally analyzed. The cold season, low wind and very stable conditions, which can last for several days, is the most common situation linked to high concentrations of anthropogenic air pollution with particulate matter. In contrast, for the Mediterranean pattern the most common situation (high factor loadings) is observed during the summer period. This pattern also exhibits a clearer annual cycle. A closer look at the sea-salt patterns (Celtic and North Seas) shows low time-series correlations between these two factors. Nevertheless, the physical mechanism is the same: a steep gradient between the cyclone and the anti-cyclone that causes high winds and, consequently, higher sea-salt production.
COBISS.SI-ID: 1538229188
In searching for the more sensitive 14N nuclear quadrupole resonance (NQR) detecting system for illicit substances, a promising combination of a classic RF pulse NQR spectrometer and a K optically pumped magnetometer was tested. The initial results are encouraging. The principles of such a combination are described, and the detection limits in the low frequency RF region, where the 14N pulse NQR frequencies are usually positioned, are presented. Several illicit substances which are difficult to detect with a classic pulse NQR spectrometer were detected with both types of spectrometers. We noticed that with the proposed combination of classic RF excitation of 14N nuclei, using a pulse NQR spectrometer and subsequent optical detection of the sample’s response, a gain in S/N of up to a factor of 10 was possible.
COBISS.SI-ID: 11677268
Optical pumping magnetometers are emerging as an alternative to SQUID magnetometers for detection of biological magnetic fields. One of the advantages of optical pumping magnetometers is their ability to operate as a multi-channel detector while using many common elements. Here we study two configurations of such a multi-channel atomic magnetometer. We describe measurements of auditory evoked fields (AEF) from a human brain as well as localization of dipolar phantoms and auditory evoked fields.
COBISS.SI-ID: 10306644
In this article we present an efficient approach to modeling the acoustic features for the tasks of recognizing various paralinguistic phenomena. Instead of the standard scheme of adapting the Universal Background Model (UBM), represented by the Gaussian Mixture Model (GMM), normally used to model the frame-level acoustic features, we propose to represent the UBM by building a monophone-based Hidden Markov Model (HMM). We present two approaches: transforming the monophone-based segmented HMM–UBM to a GMM–UBM and proceeding with the standard adaptation scheme, or to perform the adaptation directly on the HMM–UBM. Both approaches give superior results than the standard adaptation scheme (GMM–UBM) in both the emotion recognition task and the alcohol detection task. Furthermore, with the proposed method we were able to achieve better results than the current state-of-the-art systems in both tasks.
COBISS.SI-ID: 8921940
Depth image acquisition with structured light approaches in outdoor environments is a challenging problem due to external factors, such as ambient sunlight, which commonly affect the acquisition procedure. This paper presents a novel structured light sensor designed specifically for operation in outdoor environments. The sensor exploits a modulated sequence of structured light projected onto the target scene to counteract environmental factors and estimate a spatial distortion map in a robust manner. The correspondence between the projected pattern and the estimated distortion map is then established using a probabilistic framework based on graphical models. Finally, the depth image of the target scene is reconstructed using a number of reference frames recorded during the calibration process. We evaluate the proposed sensor on experimental data in indoor and outdoor environments and present comparative experiments with other existing methods, as well as commercial sensors.
COBISS.SI-ID: 11577684