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1

Marine palynology and environmental interpretation of the Lower Cretaceous (Barremian?–Aptian) rock units in the Koppeh-Dagh Basin, NE Iran

Sharifi M., Ghasemi-Nejad E., Sarfi M., Yazdi-Moghadam M., Tarjani-Salehani M., Akhtari M.

Geological Quarterly

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2018

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Vol. 62, No. 1

90--99

EN

The Sarcheshmeh and Sanganeh formations are the Lower Cretaceous deep marine sequences of the Koppeh-Dagh sedimentary basin, which revealed a diverse assemblage of dinoflagellates. The paper discusses palynostratigraphy, palynofacies and palaeoenvironment of these rock units in a borehole drilled in the eastern part of this basin. Ninety-five ditch-cutting samples were prepared and studied palynologically, which resulted in recognition of 76 species of dinoflagellate cysts belonging to 29 genera. The recorded assemblages are in accordance with the Odontochitina operculata Zone suggesting a Barremian?–Aptian age for the formations. Palynological data extracted led to identification of five palynofacies types based on the categories of Tyson (1995). These indicate a marginal, proximal and distal shelf environment of deposition. The obtained data from calculated palaeoecological factors revealed a gradual sea level rise during the deposition of these rock units, resulting in replacement of the oxic/dysoxic Sarcheshmeh Formation by the dysoxic/anoxic Sanganeh Formation.

2

Real-Time Object Tracking using Gradient Vector Flow

Azadi S., Pourjam E., Nikkerdar A., Sharifi M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1a

280--283

EN

In this paper an object tracking system with utilizing optical flow technique, and Gradient Vector Flow (GVF) active contours is presented. Optical flow technique is less sensitive to background structure and does not need to build a model for the background of image so it would need less time to process the image. GVF active snakes have good precision for image segmentation. However, due to the high computational cost, they are not usually applicable. Since precision is one of the important factors in the image segmentation, several methods have been developed to overcome the computational speed. In this paper, we, first, recognize the moving object. Then, the object fame with some pixels surrounding to it, was created. Then, this new frame is sent to the GVF filed calculation procedure. Contour initialization is obtained based on the selected pixels. This approach increases the calculation speed, and therefore makes it possible to use the contour for the tracking. The system was built, and tested with a microcomputer. The results show a speed of 10 to 12 frames per second which is considerably suitable for object tracking approaches.

PL

W artykule przedstawiono system śledzenia obiektu z wykorzystaniem techniki Optic Flow oraz Gradiend Vector Flow. Wykrywanie ruchomego obiektu stanowi pierwszy etap działania, następnie ramka zawierająca obiekt przesyłana jest do algorytmu GVF, gdzie określany jest zarys obiektu. Dzięki temu podejściu możliwe jest wykorzystanie, wymagającego obliczeniowo GVF w śledzeniu obiektów. Przedstawiono wyniki eksperymentalne.

3

A Graph-Based Image Segmentation Approach for Image Classification and Its Application on SAR Images

Sharifi M., Kiani K., Kheirkhahan M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 4

202-205

EN

In this paper, we propose a novel approach for image classification based on Graph-based image segmentation method and apply it on SAR images with satisfactory clustering performance and low computational cost. In this method first, the image pre-processes by mean shift algorithm to cluster into disjoint region, then the segmented regions are represented as a graph structure with all connected neighbourhood, and after that normalized cut method is applied to classify image into defined classes.

XX

W artykule przedstawiono metodę klasyfikacji obrazów, z wykorzystaniem segmentacji metodą grafową. Proponowana rozwiązanie wykorzystano w analizie obrazów SAR.

4

A comparison of the estimated effective elastic thickness of the lithosphere using terrestrial and satellite-derived data in Iran

Abbaszadeh M., Sharifi M., Nikkhoo M.

Acta Geophysica

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2013

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Vol. 61, no. 3

638--648

EN

The effective elastic thickness of the lithosphere has an important role in constraining compositional structure, geothermal gradient and tectonic forces within the lithosphere and the thickness of this layer can be used to evaluate the earthquakes’ focal depth. Hence, assessment of the elastic thickness of the lithosphere by gravitational admittance method in Iran is the main objective of this paper. Although the global geopotential models estimated from the satellite missions and surface data can portray the Earth’s gravity field in high precision and resolution, there are some debates about using them for lithosphere investigations. We used both the terrestrial data which have been provided by NCC (National Cartographic Center of Iran) and BGI (Bureau Gravimetrique International), and the satellite-derived gravity and topography which are generated by EIGEN-GL04C and ETOPO5, respectively. Finally, it is concluded that signal content of the satellite-derived data is as rich as the terrestrial one and it can be used for the determination of the lithosphere bending.

5

The effects of copper and zinc on biomass and taxonomic composition of algal periphyton communities from the River Gharasou, Western Iran

Atazadeh I., Kelly M., Sharifi M., Beardall J.

Oceanological and Hydrobiological Studies

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2009

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Vol. 38, No.3

3-14

EN

Indoor artificial streams were used to evaluate the short-term (24 day) influence of copper and zinc, individually and in combination, on the biomass and taxonomic composition of algal periphyton communities. The effects of Cu (50 μg 1^-1) and Zn (1 mg 1^-1) were assessed using measurements of biomass, ash-free dry mass (AFDM), chlorophyll-a concentration, taxonomic composition and biovolume. In artificial streams with Cu, Zn and Cu+Zn, there were significant (p < 0.05) reductions of chlorophyll-a concentrations, dry mass and AFDM, and also changes in the species diversity and relative abundances of periphyton species. In artificial streams containing both Cu and Zn the taxonomic composition shifted from a Cyanophyceaen dominated community to one consisting mainly of Chlorophyceae, whilst the relative contribution of Bacillariophyceae was not significantly altered.

6

Blasius flow of viscoelastic fluids: a numerical approach

Sadeghy K., Sharifi M.

International Journal of Applied Mechanics and Engineering

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2004

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Vol. 9, no. 2

399-411

EN

The effects of a fluid elasticity on the characteristics of a boundary layer in a Blasius flow are investigated for a second-grade fluid, and also for a Maxwell fluid. Boundary layer approximations are used to simplify the equations of motion which are finally reduced to a single ODE using the concept of similarity solution. For the second-grade fluid, it is found that the number of boundary conditions should be augmented to match the order of the governing equation. A combination of finite difference and shooting methods are used to solve the governing equations. Results are presented for velocity profiles, boundary layer thickness, and skin friction coefficient in terms of the local Deborah number. An overshoot in velocity profiles is predicted for a second-grade fluid but not for a Maxwell fluid. The boundary layer is predicted to become thinner for the second-grade fluid but thicker for the Maxwell fluid, the higher the Deborah number. By an increase in the level of fluid elasticity, a drop in wall skin friction is predicted for the second-order fluid but not for the Maxwell fluid.