Estimation of crowd density from UAVs images based on corner detection procedures and clustering analysis

With rapid developments in platforms and sensors technology in terms of digital cameras and video recordings, crowd monitoring has taken a considerable attentions in many disciplines such as psychology, sociology, engineering, and computer vision. This is due to the fact that, monitoring of the crowd is necessary to enhance safety and controllable movements to minimize the risk particularly in highly crowded incidents (e.g. sports). One of the platforms that have been extensively employed in crowd monitoring is unmanned aerial vehicles (UAVs), because UAVs have the capability to acquiring fast, low costs, high-resolution and real-time images over crowd areas. In addition, geo-referenced images can also be provided through integration of on-board positioning sensors (e.g. GPS/IMU) with vision sensors (digital cameras and laser scanner). In this paper, a new testing procedure based on feature from accelerated segment test (FAST) algorithms is introduced to detect the crowd features from UAV images taken from different camera orientations and positions. The proposed test started with converting a circle of 16 pixels surrounding the center pixel into a vector and sorting it in ascending/descending order. A single pixel which takes the ranking number 9 (for FAST-9) or 12 (for FAST-12) was then compared with the center pixel. Accuracy assessment in terms of completeness and correctness was used to assess the performance of the new testing procedure before and after filtering the crowd features. The results show that the proposed algorithms are able to extract crowd features from different UAV images. Overall, the values of Completeness range from 55 to 70 % whereas the range of correctness values was 91 to 94 %.     

Fisher Matrix-based Predictions for Measuring the <Emphasis Type="Italic">z</Emphasis> = 3.35 Binned 21-cm Power Spectrum using the Ooty Wide Field Array (OWFA)

We use the Fisher matrix formalism to predict the prospects of measuring the redshifted 21-cm power spectrum in different k-bins using observations with the upcoming Ooty Wide Field Array (OWFA) which will operate at 326.5 MHz. This corresponds to neutral hydrogen (HI) at z = 3.35, and a measurement of the 21-cm power spectrum provides a unique method to probe the large-scale structures at this redshift. Our analysis indicates that a 5σ detection of the binned power spectrum is possible in the k range 0.05 ≤ k ≤ 0.3 Mpc^?1 with 1000 hours of observation. We find that the signal- to-noise ratio (SNR) peaks in the k range 0.1?0.2 Mpc^?1 where a 10σ detection is possible with 2000 hours of observations. Our analysis also indicates that it is not very advantageous to observe beyond 1000 h in a single field-of-view as the SNR increases rather slowly beyond this in many of the small k-bins. The entire analysis reported here assumes that the foregrounds have been completely removed.     

On the D́ust content of nearby galaxies

By inspection of photographs of the Hubble Atlas of Galaxies the frequency distribution of the sizes of dark cloud complexes in the four nearby galaxies NGC 3031, 5128, 5194 and 5457 is derived and the total amount of dust in these systems is estimated. The frequency distribution of the clouds is nearly the same in all the considered galaxies and may be approximated by n(R) ∼ e^−kR, k ≈︂ 0.050 pc⁻¹. The total amount of dust yields to roughly 10⁶M⊙.     

The depositional environment of Mauddud limestone,Greater Burgan oil field,Kuwait

Six microfacies are defined on quantitative petrographic data in a carbonate/clastic sequence from the subsurface, oil producing Mauddud Formation of early Middle Cretaceous age. These are, in descending order of importance and abundance: (1) biomicritic wackestone-packstone, (2) argillaceous mudstone, (3) micritic mudstone, (4) glauconitic sandstone, (5)Orhitolina pelsparitic grainstone, and (6) argillaceous dolomite.Sedimentation took place during a marine transgression onto a very shallow, intertidal, restricted marine shelf lagoons. Facies variations appear to be related to depth and energy changes and proximity to areas of clastic deposition. These changes may have been controlled by slight tectonic events in the hinterland and changes in the rate of basin subsidence.

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Zusammenfassung Auf der Grundlage quantitativer petrographischer Daten werden sechs Mikrofazies in einer karbonat/klastischen Folge aus der unter der ErdoberflÄche liegenden, ölliefernden Mauddud-Formation der frühen Mittelkreide definiert. In absteigender Reihenfolge der Bedeutung und HÄufigkeit sind dieses: (1) biomikritischer wackestone-packstone, (2) toniger Schlickstein, (3) unkritischer Schlickstein, (4) glaukonitischer Sandstein, (5) Orbitolina-führender pelsparitischer Grainstone und (6) toniger Dolomit.Die Sedimentation erfolgte wÄhrend einer marinen Transgression auf sehr flache, intertidale Lagunen eines begrenzten marinen Schelfs. Die Fazies-Variationen scheinen mit den Wechseln in Wassertiefe und Energie sowie der mit NÄhe von Gebieten mit klastischer Sedimentation zusammenzuhÄngen.Diese Wechsel könnten durch kleinere tektonische Ereignisse im Hinterland und durch VerÄnderungen der Absenkungsrate des Beckens ausgelöst worden sein.

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Résumé Des données pétrographiques quantitatives permettent de définir six microfacies dans une série clasto-carbonatée d'âge crétacé inférieur du sous-sol de la région pé trolifère de Mauddud. Ce sont par ordre décroissant d'importance et d'abondance: (1) des wacstones-pacstone biomicritiques; (2) des argilites; (3) des argilites micritiques; (4) des grès glauconitiques; (5) des grainstone pelsparitiques à orbitolines; (6) des dolomies argileuses.La sédimentation se produisit au cours d'une transgression marine dans des lagunes très plates, intercotidales, d'une plate-forme continentale de faible étendue. Les variations de facies semblent Être dues à des changements de profondeur et d'énergie, ainsi qu'à la proximité de régions à sédimentation clastique.Ces changements pourraient résulter de légers mouvements tectoniques dans l'arrière-pays et de variations dans le degré de subsidence du bassin de sédimentation.

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A 2-year study of soil tillage and cattle manure application effects on soil fauna populations under Zea Mays cultivation, in western Iran (Sanandaj)

The absence of environmentally sensitive soil management systems can be considered as one of the major risks to sustainability of agricultural soils in Iran. Tillage is the most critical operation in soil management designed to achieve high crop yield, but it can adversely affect the soil fauna in several ways. In the present study, assessment of soil fauna was carried out in Western Iran in 2008 and 2009 in soil subjected to conventional (CT), minimum (MT) and no (NT)-tillage systems and amended with three levels of cattle manure (CM). Earthworm, mite, springtail and nematode populations were measured as indicators of macro, meso and micro fauna groups, respectively. Soil moisture and bulk density were also determined. Generally, low populations of soil fauna were observed consistent with expectations under similar conditions for this region. Earthworm populations were low and had a patchy distribution. Tillage and CM were found to have no effects on soil mites in both years. Soil springtails were reduced by soil tillage, indicating their sensivity to soil disturbance induced by tillage. In 2008, the nematode population was greater with application of 40 ton ha^?1 CM applications (113 N.100 g soil^?1). Soil tillage-induced disturbance reduced nematode population in 2009 (214 N.100 g soil^?1 at CT). Minimum seedbed preparation besides less soil disturbance makes MT a proper tillage system for Zea mays cultivation. Cattle manure application increased Z. mays’ biomass, but according to our results its annual application is not recommended. There were no changes in BD in both years. We conclude that in short-term studies, soil nematode populations are suitable biological indices (under similar soil and climatic conditions) for the ecological comparison of agricultural management systems in Iran.     

印度板块和亚洲大陆在何时何地碰撞

印度板块和亚洲大陆的初始碰撞时间是所有相关的喜马拉雅-西藏造山体系演化模式的主控条件,并严重影响到对众多与青藏高原隆升和东亚大陆挤出相关的地质过程速率的解释,以及对新生代全球气候变化的理解。尽管印度板块和亚洲大陆汇聚的速率在55Ma突然减缓被广泛地认为是初始碰撞的标志,但这次碰撞所造成的主要构造效应直到20多个百万年以后才显现出来。对印度板块和亚洲大陆相对位置的重新估算,表明它们在55Ma时并没有达到可以彼此发生碰撞的距离。基于来自西藏新的野外证据和对已有数据的重新评估,认为初始碰撞发生在始新世—渐新世之交（约34Ma）,并对55Ma时发生的地质事件提出了另一种解释     

Taxonomical and Biogeochemical Investigation of Elements in Holocene Mollusk Shells in the South and Southwestern Marmara Basin,Turkey

Concentrations of some heavy metals and trace elements such as Cr, Ga, Ni, Zn, Mo, Cu, Pb, Yb, Y, Nb, Ti, Sr, Ba, Mn, Sc, Co, V, Zr, Fe, Al, W, Se, Bi, Sb, As, Cd in recent mollusk shells and factors affecting their distribution and deposits collected from various depths in the southern and southwestern parts of the Marmara Sea are investigated. The distribution of the elements in the shells is categorized into four groups. Of these, concentrations of 12 elements （As, Bi, Cd, Co, Ga, Mo, Nb, Sb, Se, Sc, W and Yb） are below zero [（0.053-0.79）×10^-6]; concentrations of seven elements （Cr, Ni, Pb, V, Y, Zr and Cu） are （1.0-6.0）×10^-6; concentrations of four elements （Ti, Mn, Ba and Zn） are 10- 20×10^-6; and concentrations of five elements （Si, Al, Fe, Mg and Sr） are （47.44-268.11）×10^-6. The taxonomic characteristics of the 29 elements were studied separately in mollusk shells such as Chamalea gallina （Linn6）, Pitar rudis （Poli）, Nassarius reticulatus （Linn6）, Venerupis senescens （Coocconi）, Mytilus galloprovincialis （Lamarck）, Mytilaster lineatus （Gemelin in Linne） and Chlamys glabra. It was found that, in mollusk taxonomy, the elements have unique values. In other words, element concentrations in various mollusk shells depend mainly on the taxonomic characteristics of mollusks. In various bionomic environments different element distributions of the same species are attributed to the different geochemical characters of the each environment. Data obtained in this study indicate that the organisms are the most active and deterministic factors of the environment.     

Identification and evaluation of the hydrogeochemical processes of the lower part of Wadi Siham catchment area, Tihama plain, Yemen

One hundred forty-eight groundwater samples were collected from the lower part of Wadi Siham catchment area for hydrogeochemical investigations to understand the hydrogeochemical processes affecting groundwater chemistry and their relation with groundwater quality. Groundwater in the study area is abstracted from different aquifers. The study area is characterized by arid climate and extremely high relative humidity. The results indicate that groundwater in the study area is fresh to brackish in nature. The abundance of the major ions is as follows: Na⁺¹?>?Ca⁺²?>?Mg⁺²?≥?K⁺¹ and Cl^?1?>?HCO ₃ ^?1 ?>?SO ₄ ^?2 ?>?NO ₃ ^?1 . Various graphical and ionic ration plots, statistical analyses, and saturation indices calculations have been carried out using chemical data to deduce a hydrochemical evaluation of the study area. The prevailing hydrogeochemical processes operating in the study area are dissolution, mixing, evaporation, ion exchange, and weathering of silicate minerals in the eastern part (recharge areas). The reverse ion exchange and seawater intrusion control the groundwater chemistry along the Red Sea coast areas and few parts of the study area. Deterioration in groundwater quality from anthropogenic activities has resulted from saltwater intrusion along the coastal areas due to groundwater overpumping and extensive use of fertilizers and infiltration of sewage water. Salinity and nitrate contamination are the two major problems in the area, which is alarming considering the use of this water for drinking.