Experimental Comparison between Event and Global Shutter Cameras.

We compare event-cameras with fast (global shutter) frame-cameras experimentally, asking: "What is the application domain, in which an event-camera surpasses a fast frame-camera?" Surprisingly, finding the answer has been difficult. Our methodology was to test event- and frame-cameras on generic computer vision tasks where event-camera advantages should manifest. We used two methods: (1) a controlled, cheap, and easily reproducible experiment (observing a marker on a rotating disk at varying speeds); (2) selecting one challenging practical ballistic experiment (observing a flying bullet having a ground truth provided by an ultra-high-speed expensive frame-camera). The experimental results include sampling/detection rates and position estimation errors as functions of illuminance and motion speed; and the minimum pixel latency of two commercial state-of-the-art event-cameras (ATIS, DVS240). Event-cameras respond more slowly to positive than to negative large and sudden contrast changes. They outperformed a frame-camera in bandwidth efficiency in all our experiments. Both camera types provide comparable position estimation accuracy. The better event-camera was limited by pixel latency when tracking small objects, resulting in motion blur effects. Sensor bandwidth limited the event-camera in object recognition. However, future generations of event-cameras might alleviate bandwidth limitations.

The use of a CZT detector with robotic systems.

This work is focused on the use of a CZT detector for a radiation mapping with an industrial robotic arm. Measurements were carried out within the RadioRoSo experiment (Radioactive Waste Robotic Sorter), under the umbrella of EU FP7 project ECHORD++. In tests with a dual-arm robot and standard point sources of 137Cs and 60Co, a Magnox waste was mimicked. Thereafter, for relevant measurement geometries and selected shielding materials, full energy peak efficiencies were calculated using the MCNP transport code. Simulated FEP efficiency values were used for minimum detectable activity assessments for expected measurement conditions. Obtained results would be also applicable for cases of shielded lost/orphan point-like sources.

Validation of a new tool for automatic assessment of tremor frequency from video recordings.

We present a validation study for TremAn--a tool for automatic detection of tremor and measurement of its frequency from video recordings. To assess the validity of TremAn we designed a study consisting of tremor assessment from video, by accelerometry and by clinical evaluation using Fahn-Tolosa-Marin scale. 26 patients with essential tremor and 5 healthy volunteers underwent the examination in four standardized positions with focus on the hand tremor. Results showed that the frequencies of tremor measured with TremAn and with accelerometry are closely related, attaining agreement with less than 0.1 Hz difference in 80% and less than 0.5 Hz in 94% of measured samples. The reproducibility of frequency measurements using TremAn was comparable to the accelerometry, with the TremAn/accelerometry ratio of measurement error standard deviations equal to 0.99 (95% confidence interval (0.84, 1.17)).

Action tremor analysis from ordinary video sequence.

This paper focuses on tremor frequency analysis from the video sequence. In order to analyse the video data, the signal needs to be extracted from the video using the intensity change of the local area in time. Next, the power spectral density is used for the frequency estimate from the signal. Finally the results obtained from the video are compared with one of the standard measuring techniques for tremors--accelerometers.

Physiological responses of over-wintering common carp (Cyprinus carpio) to disturbance by Eurasian otter (Lutra lutra).

Using a tame animal, the impact of otter (Lutra lutra) disturbance on over-wintering carp (Cyprinus carpio) was monitored in two experiments, 133 and 140 days, respectively, over two consecutive winters (November-April). The level of stress in over-wintering carp exposed to various intensities of disturbance by otters was quantified using biological indicators of stress (cortisol, cortisone, indices of nitrogen, carbohydrate, lipid and mineral metabolism and activity of basic blood plasma enzymes) taken from blood plasma of stocked carp at the end of the winter seasons (when the photoperiod was 12 light:12 dark, respectively, 13L:10D). Moreover, condition (Fulton's coefficient of condition and fat content in muscles) and mortality rate of that carp were measured after over-wintering and also after the subsequent vegetation period. The analysis of blood and tissue samples of experimental fish showed changes in nitrogen, carbohydrate and mineral metabolism as well as levels of hormones and fat reserves. Higher response to stress in metabolism of carp with lower intensity of disturbance by otter suggests that high level of disturbance can lead to metabolic adaptation of carp to stress. The effect of stress on the mortality rate of carp during the over-wintering is not clear. Nevertheless, the negative effect of stress on survival, condition and growth rate of carp in the subsequent vegetation period was not observed.

The use of computer vision techniques to augment home based sensorised environments.

Technology within the home environment is becoming widely accepted as a means to facilitate independent living. Nevertheless, practical issues of detecting different tasks between multiple persons within the same environment along with managing instances of uncertainty associated with recorded sensor data are two key challenges yet to be fully solved. This work presents details of how computer vision techniques can be used as both alternative and complementary means in the assessment of behaviour in home based sensorised environments. Within our work we assessed the ability of vision processing techniques in conjunction with sensor based data to deal with instances of multiple occupancy. Our Results indicate that the inclusion of the video data improved the overall process of task identification by detecting and recognizing multiple people in the environment using color based tracking algorithm.

Parallel image reconstruction using B-spline approximation (PROBER).

A new reconstruction method for parallel MRI called PROBER is proposed. The method PROBER works in an image domain similar to methods based on Sensitivity Encoding (SENSE). However, unlike SENSE, which first estimates the spatial sensitivity maps, PROBER approximates the reconstruction coefficients directly by B-splines. Also, B-spline coefficients are estimated at once in order to minimize the reconstruction error instead of estimating the reconstruction in each pixel independently (as in SENSE). This makes the method robust to noise in reference images. No presmoothing of reference images is necessary. The number of estimated parameters is reduced, which speeds up the estimation process. PROBER was tested on simulated, phantom, and in vivo data. The results are compared with commercial implementations of the algorithms SENSE and GRAPPA (Generalized Autocalibrating Partially Parallel Acquisitions) in terms of elapsed time and reconstruction quality. The experiments showed that PROBER is faster than GRAPPA and SENSE for images wider than 150x150 pixels for comparable reconstruction quality. With more basis functions, PROBER outperforms both SENSE and GRAPPA in reconstruction quality at the cost of slightly increased computational time.