Feature Relevance Assessment Of Multispectral Airborne Lidar Data For Tree Species Classification

Abstract. The presented experiment investigates the potential of Multispectral Laser Scanning (MLS) point clouds for single tree species classification. The basic idea is to simulate a MLS sensor by combining two different Lidar sensors providing three different wavelngthes. The available data were acquired in the summer 2016 at the same date in a leaf-on condition with an average point density of 37 points/m2. For the purpose of classification, we segmented the combined 3D point clouds consisiting of three different spectral channels into 3D clusters using Normalized Cut segmentation approach. Then, we extracted four group of features from the 3D point cloud space. Once a varity of features has been extracted, we applied forward stepwise feature selection in order to reduce the number of irrelevant or redundant features. For the classification, we used multinomial logestic regression with L1 regularization. Our study is conducted using 586 ground measured single trees from 20 sample plots in the Bavarian Forest National Park, in Germany. Due to lack of reference data for some rare species, we focused on four classes of species. The results show an improvement between 4–10 pp for the tree species classification by using MLS data in comparison to a single wavelength based approach. A cross validated (15-fold) accuracy of 0.75 can be achieved when all feature sets from three different spectral channels are used. Our results cleary indicates that the use of MLS point clouds has great potential to improve detailed forest species mapping. </jats:p

THE PHYSIOLOGICAL DEMANDS OF PROFESSIONAL SOCCER REFEREEING ACROSS A SEASON

Professional soccer referees are tasked with officiating the highest profile and most watched competitive soccer matches in the world. Accurate determination of their match play demands is key to understanding how to programme their training, whilst making sure they continue to be able to successfully officiate over matches. There is little match play data from elite level officials and thus being able to prescribe training regimes and determine physiological prerequisites of successful officials is difficult. Twenty elite level soccer referees, 10 from the Premier League (45.5 yr, 180 cm, 79 kg), and 10 from the Championship (35.6 yr, 178 cm, 79 kg), had their data collected from 330 competitive matches over the course of the 2017/2018 season via the use of an integrated GPS and heart rate monitoring system. The data collected was broken down into 2 different categories; the effects of competition level and season quarter and the effects of match ranking using teams final league positions. Within these categories specific focus was applied to; internal match demands, external match demands, time spent in varying heart rate zones, player loading™, accelerations and decelerations. This thesis considered the differences between Premier League and Championship match officials over a season. Premier League matches induced a higher absolute HR response compared to Championship matches, but despite a lower absolute HR, Championship officials spent more time between 85-100% of their maximum HR (P < 0.05). In addition, Championship referees performed more accelerations and decelerations compared to that of their Premier League counterparts (P < 0.05) at the expense of less walking and more jogging (P < 0.05). Across the playing season, HR, walking (P < 0.01) and running (P < 0.01) were higher in the last quarter of the season whereas total distance covered (P < 0.02), jogging (P < 0.01) and sprinting (P < 0.01) were lowest in the last quarter of the season. There were more accelerations and decelerations in the first quarter of the season (P < 0.05). When considering the effect of the position in the league of the two teams playing particular matches, top ranked (teams that finished in the top 7) Premier League games influenced physiological load of officials via increased total distance (P < 0.01), high-speed running and sprint distance (P < 0.05). These findings provide a range of important information for referees and their coaches/trainers at the highest levels for the optimal preparation for competitive officiating across the Premiership and Championship leagues. Findings from this thesis allow us to suggest that regarding physical training of officials specific focus to those aspiring to work in the Premier League should consider these greater physiological demands. More acutely, considerations regarding training should include the level of the two teams playing each other in upcoming fixtures

A SEASON-LONG COMPARISON OF SOCCER REFEREE MATCH DEMANDS BETWEEN THE ENGLISH PREMIER LEAGUE AND CHAMPIONSHIP

Conference Poste

Spatial heterogeneity and irreversible vegetation change in semi-arid grazing systems

Recent theoretical studies have shown that spatial redistribution of surface water may explain the occurrence of patterns of alternating vegetated and degraded patches in semiarid grasslands. These results implied, however, that spatial redistribution processes cannot explain the collapse of production on coarser scales observed in these systems. We present a spatially explicit vegetation model to investigate possible mechanisms explaining irreversible vegetation collapse on coarse spatial scales. The model results indicate that the dynamics of vegetation on coarse scales are determined by the interaction of two spatial feedback processes. Loss of plant cover in a certain area results in increased availability of water in remaining vegetated patches through run-on of surface water, promoting within-patch plant production. Hence, spatial redistribution of surface water creates negative feedback between reduced plant cover and increased plant growth in remaining vegetation. Reduced plant cover, however, results in focusing of herbivore grazing in the remaining vegetation. Hence, redistribution of herbivores creates positive feedback between reduced plant cover and increased losses due to grazing in remaining vegetated patches, leading to collapse of the entire vegetation. This may explain irreversible vegetation shifts in semiarid grasslands on coarse spatial scales

Effect of 24-h severe energy restriction on appetite regulation and ad libitum energy intake in lean men and women

Background: Intermittent severe energy restriction (SER) can induce substantial weight loss, but the appetite regulatory responses to SER are unknown and may dictate long-term dietary adherence. Objective: We determined the effect of 24-h SER on appetite regulation, metabolism, and energy intake. Design: Eighteen lean men and women completed two 3-d trials in randomized, counterbalanced order. On day 1 subjects consumed standardized diets containing 100% (mean 6 SD: 9.3 6 1.3 MJ; energy balance) or 25% [2.3 6 0.3 MJ; energy restriction (ER)] of energy requirements. On day 2, a standardized breakfast was consumed, with plasma concentrations of acylated ghrelin, glucagon-like peptide 1, insulin, glucose, and nonesterified fatty acids determined for 4 h. Ad libitum energy intake was assessed at lunch and dinner with subjective appetite and resting metabolism assessed throughout. On day 3, ad libitum energy intake was assessed at breakfast and by weighed food records. Results: Energy intake was 7% greater on day 2 (P<0.05) during ER but not significantly different on day 3 (P=0.557). Subjective appetite was greater during ER on the morning of day 2 (P<0.05) but was not significantly different thereafter (P<0.145). During ER, postprandial concentrations of acylated ghrelin were lower (P<0.05), whereas glucose (P<0.05) and nonesterified fatty acids (P<0.0001) were higher. Postprandial glucagon-like peptide 17–36 (P=0.784) and insulin (P=0.06) concentrations were not significantly different between trials. Energy expenditure was lower during ER in the morning (P<0.01). Conclusions: In lean young adults, 24-h SER transiently elevated subjective appetite and marginally increased energy intake, but hormonal appetite markers did not respond in a manner indicative of hyperphagia. These results suggest that intermittent SER might be useful to attenuate energy intake and control body weight in this population. This trial was registered at www.clinicaltrials.gov.uk as NCT02696772

Gamma ray production in inelastic scattering of neutrons produced by cosmic muons in 56^{56}Fe

We report on the study of the intensities of several gamma lines emitted after the inelastic scattering of neutrons in $^{56}$Fe. Neutrons were produced by cosmic muons passing the 20t massive iron cube placed at the Earth's surface and used as a passive shield for the HPGe detector. Relative intensities of detected gamma lines are compared with the results collected in the same iron shield by the use of $^{252}$Cf neutrons. Assessment against the published data from neutron scattering experiments at energies up to 14 MeV is also provided

A Large Outbreak of Hepatitis E Among a Displaced Population in Darfur, Sudan, 2004: The Role of Water Treatment Methods.

BACKGROUND: The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur. METHODS: To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples). RESULTS: In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested. CONCLUSIONS: Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies

On the mass transfer in AE Aquarii

The observed properties of the close binary AE Aqr indicate that the mass transfer in this system operates via the Roche lobe overflow mechanism, but the material transferred from the normal companion is neither accreted onto the surface of the white dwarf nor stored in a disk around its magnetosphere. As previously shown, such a situation can be realized if the white dwarf operates as a propeller. At the same time, the efficiency of the propeller action by the white dwarf is insufficient to explain the rapid braking of the white dwarf, which implies that the spin-down power is in excess of the bolometric luminosity of the system. To avoid this problem we have simulated the mass-transfer process in AE Aqr assuming that the observed braking of the white dwarf is governed by a pulsar-like spin-down mechanism. We show that the expected H_alpha Doppler tomogram in this case resembles the tomogram observed from the system. We find that the agreement between the simulated and the observed tomograms is rather good provided the mean value of the mass-transfer rate ~5x10^16 g/s. Three spatially separated sources of H_alpha emission can be distinguished within this approach. The structure of the tomogram depends on the relative contributions of these sources to the H_alpha emission and is expected to vary from night to night.Comment: 12 pages, 3 figures (6 eps files). Published in A&A. The paper with high resolution images can be downloaded from http://urania.it.nuigalway.ie/papers/ae_aqr.ps.g

First results of site testing program at Mt. Shatdzhatmaz in 2007 - 2009

We present the first results of the site testing performed at Mt.~Shatdzhatmaz at Northern Caucasus, where the new Sternberg astronomical institute 2.5-m telescope will be installed. An automatic site monitor instrumentation and functionality are described together with the methods of measurement of the basic astroclimate and weather parameters. The clear night sky time derived on the basis of 2006 -- 2009 data amounts to 1340 hours per year. Principle attention is given to the measurement of the optical turbulence altitude distribution which is the most important characteristic affecting optical telescopes performance. For the period from November 2007 to October 2009 more than 85\,000 turbulence profiles were collected using the combined MASS/DIMM instrument. The statistical properties of turbulent atmosphere above the summit are derived and the median values for seeing $\beta_0 = 0.93$~arcsec and free-atmosphere seeing $\beta_{free} = 0.51$~arcsec are determined. Together with the estimations of isoplanatic angle $\theta_0 = 2.07$~arcsec and time constant \tau_0 = 2.58 \mbox{ ms}, these are the first representative results obtained for Russian sites which are necessary for development of modern astronomical observation techniques like adaptive optics.Comment: Accepted for publication in MNRAS, 17 pages, 15 figure

Analytical Modelling of Thirty Meter Telescope Optics Polarization

The polarization introduced due to Thirty Meter Telescope (TMT) optics is calculated using an analytical model. Mueller matrices are also generated for each optical element using Zemax, based on which the instrumental polarization due to the entire system at the focal plane is estimated and compared with the analytical model. This study is significant in the estimation of the telescope sensitivity and also has great implications for future instruments