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1.
Aleksandar Mezga Christian A. Meyer Blanka Cvetko Te&#x;ovi&#x; Zlatan Bajraktarevi&#x; Ivan Gu&#x;i&#x; 《Cretaceous Research》2006,27(6):735-742
The first discovery of dinosaur footprints on the Dalmatian part of the Adriatic-Dinaric carbonate platform (ADCP) is reported. They constitute the geologically youngest record of footprints on the ADCP. The trackbearing layer was formed in the intertidal environment and represents the final stage of a shallowing-upward cycle. Just below it, a heavy dinoturbated limestone layer can be observed. Microfacies analysis, incorporating evidence from benthic foraminifera and algae, indicates a Late Turonian–Early Coniacian age. The overall morphology and size of the footprints points to sauropod dinosaurs; they represent the largest forms recorded so far on the ADCP. This hints at a prolonged sauropod presence on the platform and to its Late Cretaceous connection to the continent rather than isolation. 相似文献
2.
Aleksandar Milosavljević Dejan Rančić Aleksandar Dimitrijević Bratislav Predić Vladan Mihajlović 《International journal of geographical information science》2016,30(10):2089-2107
This paper discusses the integration of three-dimensional (3D) geographic information systems (GIS) and video surveillance systems using augmented reality (AR) techniques. The motivation for this integration is to overcome problems faced by conventional video surveillance systems. Explicit information concerning which camera currently monitors what area in such systems is missing; therefore, insight into the situation depends heavily on the operator’s training and experience. To ensure the complete coordination and monitoring of a situation in a system with multiple cameras, it is necessary to introduce a single reference system. GIS arises as a natural solution because it not only provides a solid ground truth but also provides semantic information that can be highly important in certain video surveillance applications. To integrate information into a GIS application, that information must be georeferenced. Based on our previous research regarding the addition of georeferencing information to surveillance video, this paper introduces models that can be applied to help integrate video and GIS. With an analogy to Milgram’s continuum between the real world and virtual reality, and analogous to the augmented reality and augmented virtuality in Milgram’s continuum, two models of integration are defined here: GIS-augmented video and video-augmented GIS. Then, we define the architecture of GIS-based video surveillance based on these proposed integration models, and finally, a prototype is implemented. The implemented prototype serves as a basis for analysing possible applications of real-world systems based on the integration of GIS and video. 相似文献
3.
Nonlinear dynamics of meteorological variables: multifractality and chaotic invariants in daily records from Pastaza, Ecuador 总被引：1，自引：0，他引：1
Humberto Millán Aleksandar Kalauzi Milena Cukic Riccardo Biondi 《Theoretical and Applied Climatology》2010,102(1-2):75-85
Weather represents the daily state of the atmosphere. It is usually considered as a chaotic nonlinear dynamical system. The objectives of the present study were (1) to investigate multifractal meteorological trends and rhythms at the Amazonian area of Ecuador and (2) to estimate some nonlinear invariants for describing the meteorological dynamics. Six meteorological variables were considered in the study. Datasets were collected on a daily basis from January 1st 2001 to January 1st 2005 (1,460 observations). Based on a new multifractal method, we found interesting fractal rhythms and trends of antipersistence patterns (Fractal Dimension >1.5). Nonlinear time series analyses rendered Lyapunov exponent spectra containing more than one positive Lyapunov exponent in some cases. This sort of hyperchaotic structures could explain, to some extent, larger fractal dimension values as the Kaplan–Yorke dimension was also in most cases larger than two. The maximum prediction time ranged from ξ?=?1.69 days (approximately 41 h) for E/P ratio to ξ?=?14.71 days for evaporation. Nonlinear dynamics analyses could be combined with multifractal studies for describing the time evolution of meteorological variables. 相似文献
4.
Dubravka Relić Dragana Đorđević Aleksandar Popović 《Environmental Earth Sciences》2011,63(6):1303-1317
We used elemental carbon, nitrogen, hydrogen and sulfur as well as ratios of hydrogen and nitrogen with total organic carbon
for investigation of source and conditions of organic matter in alluvial Danube sediments. We also determined the pseudo total
concentrations of metals presented as a sum of extracted concentration after five sequential extraction steps. The pseudo
total metal concentrations were found to be (mg kg−1) for Mn, 666; Fe, 25,852; Mg, 16,193; K, 2,063; Ni, 32.4; Zn, 72.2; Pb, 15.0; Cu, 26.0 and for Cr, 15.9. Correlation analysis
and two multivariate analysis methods (principal component and cluster analysis) were helpful in determining the associations
between the pseudo total extracted fractions of metals and with elemental carbon, hydrogen, nitrogen, sulfur, total inorganic
and organic carbon. These correlations will help us to identify substrates of trace metals in different oxic/anoxic conditions.
The correlation results of the trace metals and Fe, K, Mg and Mn suggest their adsorption, mainly onto Fe and Mn (hydro)oxides
and K alumosilicates, whereas correlations of metals with sulfur indicate that they were precipitated as Fe-sulfides. 相似文献
5.
6.
Aleksandar Sekuli&#; Milan Kilibarda Dragutin Proti&#; Melita Per&#;ec Tadi&#; Branislav Bajat 《Theoretical and Applied Climatology》2020,140(1):101-114
High resolution gridded mean daily temperature datasets are valuable for research and applications in agronomy, meteorology, hydrology, ecology, and many other disciplines depending on weather or climate. The gridded datasets and the models used for their estimation are being constantly improved as there is always a need for more accurate datasets as well as for datasets with a higher spatial and temporal resolution. We developed a spatio-temporal regression kriging model for Croatia at 1 km spatial resolution by adapting the spatio-temporal regression kriging model developed for global land areas. A geometrical temperature trend, digital elevation model, and topographic wetness index were used as covariates together with measurements from the Croatian national meteorological network for the year 2008. This model performed better than the global model and previously developed models for Croatia, based on MODIS land surface temperature images. The R2 was 97.8% and RMSE was 1.2 °C for leave-one-out and 5-fold cross-validation. The proposed national model still has a high level of uncertainty at higher altitudes leaving it suitable for agricultural areas that are dominant in lower and medium altitudes. 相似文献
7.
Jelena Pantić Vladimir Urbanovich Vesna Poharc-Logar Bojan Jokić Marija Stojmenović Aleksandar Kremenović Branko Matović 《Physics and Chemistry of Minerals》2014,41(10):775-782
Sphene (CaTiSiO5), a calcium titanosilicate ceramic has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization and activation of precursors. During the high-pressure and high-temperature synthesis (HPS) process at 4 GPa and 1,200 °C, sphene undergoes into phase transition, from room-temperature phase P21 /a to high-temperature phase A2/a. Evidence of that structural phase transition is given in this paper using infrared, Raman spectroscopy and X-ray powder diffraction. Rietveld refinement was employed to get the structural information of the synthesized powder. The most important structural change due to phase transition, the disappearance of the characteristic out-of-center distortion of the Ti atom and moving to the center of octahedra, was confirmed. HPS is an effective method for producing full-dense ceramics without any additives. Reduction of particle size occurred during high-pressure compaction. Microstructure and particle size of both phases were analyzed by scanning electron microscopy. 相似文献
8.
Cold and warm air temperature spells during the winter and summer seasons and their impact on energy consumption in urban areas 总被引：1，自引：1，他引：0
The main objective of this study is to determine and analyze cold and warm air temperature spells in the last 6 years (2007–2012) and reveal their impact on electrical energy consumption in a small-sized city such as Sombor (Serbia) with less than 50,000 inhabitants. Hourly air temperature values and electrical energy consumption data have been used as database for all methods. Warm and cold temperature spells (during heat and cold waves) have had the increasing tendencies in the last 6 years and they reflect on additional electrical energy consumption. Detailed analysis showed that higher energy demands occur during workdays and daytime period. Monitoring of the amount of consumed energy showed a clear relationship during the winter cold temperature spells, when electrical energy demand was higher than 0.3 MW. In summer period, the relationship was weaker and consumption was higher than 0.15 MW only when temperature exceeded 30 °C. A small number of air condition devices in houses and companies and mainly one-store buildings with thick walls, which make a good insulation from the outside air temperatures, are probably the main reasons for the above-mentioned results in summer. This paper introduces a new method to resolve the problem of short-term load forecasting, based on the support vector machines (SVM) technology and particle swarm optimization that has been used to optimize the SVM parameters. Similar-day-based forecast has shown that similar days for training should be filtered also using classifier of temperature period (cooling degree-days or heating degree-days in a row). Forecasting error is smaller compared to solutions where similar days are found only on season and temperature. 相似文献
9.
Veljko?Perovi? Ljubomir??ivoti?Email author Ratko?Kadovi? Aleksandar??or?evi? Darko?Jaramaz Vesna?Mrvi? Mladen?Todorovi? 《Environmental Earth Sciences》2013,70(1):115-129
This study employed genetic adaptive neural networks in the classification of high-resolution satellite images from which data related to surface conditions in mountainous areas of Taiwan were derived. Principal component analysis was then used to extract factors associated with the threat of natural disaster, and logistic regression was used to compute the probability of disaster occurrence. Through field surveys, interviews with district officials and a review of relevant literature, the probability of a sediment disaster was estimated as well as the vulnerability of the villages concerned and the degree to which these villages were prepared, to construct a risk evaluation model. A geographic information system was used to plot regional risk maps as a means to enhance the safety of residents in the study area. The risk assessment model can be used by authorities to make provisions for high-risk areas, to reduce the number of casualties and social costs of sediment disasters. 相似文献
10.
The ore body “T” is the newly discovered massive-pyrite type one which is located in the central part of the Bor copper mine. The main copper minerals are chalcocite-digenite, covellite and enargite. Small amounts of colusite are frequently present in the ore-body. It mostly occurs as the distinct exsolutions in digenite and, associating with enargite and covellite. Composition of the studied colusite shows enriched Sn content, giving an empirical formula from Cu24.7V1.8Fe0.2As5.1Sb0.2Sn0.8S32 to Cu26.7V2.0Fe0.3As3.0Sb0.3Sn3.5S32. This colusite represents a solid solution between colusite and nekrasovite within a range of 14–54 mol % nekrasovite. Most of the analyses show content of <50 mol % nekrasovite corresponding to the Sn-bearing colusite variety, while one analysis shows content of 54 mol % nekrasovite corresponding to the As-bearing nekrasovite. 相似文献