A spatiotemporal algebra in Hadoop for moving objects     

Mohamed S. Bakli  Mahmoud A. Sakr  Taysir Hassan A. Soliman 《地球空间信息科学学报》2018,21(2):102-114

Spatiotemporal data represent the real-world objects that move in geographic space over time. The enormous numbers of mobile sensors and location tracking devices continuously produce massive amounts of such data. This leads to the need for scalable spatiotemporal data management systems. Such systems shall be capable of representing spatiotemporal data in persistent storage and in memory. They shall also provide a range of query processing operators that may scale out in a cloud setting. Currently, very few researches have been conducted to meet this requirement. This paper proposes a Hadoop extension with a spatiotemporal algebra. The algebra consists of moving object types added as Hadoop native types, and operators on top of them. The Hadoop file system has been extended to support parameter passing for files that contain spatiotemporal data, and for operators that can be unary or binary. Both the types and operators are accessible for the MapReduce jobs. Such an extension allows users to write Hadoop programs that can perform spatiotemporal analysis. Certain queries may call more than one operator for different jobs and keep these operators running in parallel. This paper describes the design and implementation of this algebra, and evaluates it using a benchmark that is specific to moving object databases.  相似文献   

Quantitative Interpretation of Self-Potential Anomalies of Some Simple Geometric Bodies     

E. M. Abdelrahman  K. S. Soliman  E. R. Abo-Ezz  K. S. Essa  T. M. El-Araby 《Pure and Applied Geophysics》2009,166(12):2021-2035

We have developed a new numerical method to determine the shape (shape factor), depth, polarization angle, and electric dipole moment of a buried structure from residual self-potential (SP) anomalies. The method is based on defining the anomaly value at the origin and four characteristic points and their corresponding distances on the anomaly profile. The problem of shape determination from residual SP anomaly has been transformed into the problem of finding a solution to a nonlinear equation of the form q = f (q). Knowing the shape, the depth, polarization angle and the electric dipole moment are determined individually using three linear equations. Formulas have been derived for spheres and cylinders. By using all possible combinations of the four characteristic points and their corresponding distances, a procedure is developed for automated determination of the best-fit-model parameters of the buried structure from SP anomalies. The method was applied to synthetic data with 5% random errors and tested on a field example from Colorado. In both cases, the model parameters obtained by the present method, particularly the shape and depth of the buried structures are found in good agreement with the actual ones. The present method has the capability of avoiding highly noisy data points and enforcing the incorporation of points of the least random errors to enhance the interpretation results.  相似文献   

A New Algorithm for Depth Determination from Total Magnetic Anomalies due to Spheres     

E. M. Abdelrahman  T. M. El-Araby  E. R. Abo-Ezz  K. S. Soliman  K. S. Essa 《Pure and Applied Geophysics》2008,165(5):967-979

We have developed an automatic method to determine the depth of a buried sphere from numerical second horizontal derivative anomalies obtained from total field magnetic data. The method is based on using a relationship between the depth and a combination of observations at symmetric points with respect to the coordinate of the projection of the center of the source in the plane of the measurement points with a free parameter (graticule spacing). The problem of depth determination has been transformed into the problem of finding a solution of a nonlinear equation of f(z) = 0. Procedures are also formulated to determine the magnetic moment and the effective angle of magnetization. The method is applied to synthetic examples with and without random errors and tested on a field example from Senegal. In all cases, the depth solutions are in good agreement with the actual ones.  相似文献   

Heavy metal concentrations in surficial sediments from Wadi El Natrun saline lakes, Egypt     

Amany G. Taher  Ahmed A. Soliman 《International Journal of Salt Lake Research》1999,8(1):75-92

Heavy metal concentrations of Wadi El Natrun saline lakes were investigated. Pb, Zn, Mn, Cu, Cd, Ni, Fe and Al were measured in surficial sediments. The heavy metal concentrations largely indicate the influence of weathering of terrigenous sources on land. In comparison with the average in sedimentary rocks, the concentrations of the heavy metals studied are higher than the global average sandstone. This is also reflected in the high enrichment factors. The heavy metal concentration in lakes II and III decrease in the order Pb > Zn > Cu, while in lake I the decreasing order is Cu > Zn > Pb. Sediments with microbial mats were found to concentrate heavy metals above background sediment values.  相似文献   

The construction of a seventh-order Jupiter-Saturn analytical theory     

Osman M. Kamel  Adel S. Soliman 《Earth, Moon, and Planets》1993,60(2):141-175

We extend the construction of the Jupiter-Saturn theory to include all the terms up to the seventh order in the masses. The Hori-Lie transformation technique is employed. The Jacobian coordinates are adopted and the theory is expressed in terms of the canonical non-singular variables of H. Poincaré.  相似文献   

The expansion of negative powers of mutual distance between two planets     

Osman M. Kamel  Adel S. Soliman 《Earth, Moon, and Planets》1990,49(1):25-56

In this part we obtain the expression for ^–s by the application of Smart's method, which involves Taylor's theorem for functions of several variables. We neglected terms of power higher than the fourth with respect to eccentricities and tangents of inclinations.  相似文献   

Heterologous expression of thermostable esterase gene from Geobacillus thermoleovorans YN under different expression promoters     

N. A. Soliman  Y. R. Abdel-Fattah  H. E. Mostafa  A. Gaballa 《International Journal of Environmental Science and Technology》2014,11(1):119-126

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Nickel removal from electroplating waste water using stand-alone and electrically assisted ion exchange processes     

I. Ismail  A. Soliman  N. Abdel-Monem  H. Salah Ahmed  M. H. Sorour 《International Journal of Environmental Science and Technology》2014,11(1):199-206

Wastewater discharged from metal-finishing processes usually contains nickel, a hazardous substance that is used extensively in the surface finishing industry. In the present study, an acidic solution containing nickel was treated using strong acid cation exchange resin. A continuous lab-scale cation exchange arrangement permitting the assessment of electric current as an enhancement mechanism was designed and utilized at different flow rates successfully. Applying the electrical potential enhanced the nickel removal by 12.7 % at flow rate 240 ml/h, and 2.5 % at flow rate 500 ml/h. Nickel recovery has been also investigated using hydrochloric acid as an eluent with and without electric current enhancement.  相似文献   

Side-scan sonar image matching     

Daniel  S. Le Leannec  F. Roux  C. Soliman  B. Maillard  E.P. 《Oceanic Engineering, IEEE Journal of》1998,23(3):245-259

This paper presents a method for the matching of underwater images acquired with acoustic sensors. As a final objective, the system aims at matching data from two-dimensional scenes. The proposed approach carries out a hypothetical reasoning based on objects, represented by shadows and echoes in the sonar images, and their available features. The problem of determining measures which are invariant to changes in sonar settings and noise characteristics is addressed by mapping robust features for sonar images to a qualitative representation. To cope with the viewpoint charging appearance, the method is based on the conservation of objects' relative position from one image to another. We attempt to match geometrical structures formed by the association of three objects. The hypothetical reasoning is conducted in a decision tree framework. A tree node is generated by two objects' association, each one belonging to a respective image. Hypotheses propagation consists of creating new nodes from neighboring associations. The matching solution is determined by the selection of the decision tree's longest branch. Thus, the association mechanism is a depth-first procedure. The proposed method has been applied to real high-resolution side-scan sonar images. The matching process has shown successful and promising results which have been further improved. In particular, the parceled shadows (during the segmentation procedure) problem has been tackled  相似文献   

Expansion of the first-order planetary disturbing function by Smart's method     

Osman M. Kamel  Adel S. Soliman 《Earth, Moon, and Planets》1989,47(3):241-263

We expand the principal part of the planetary disturbing function, by Smart's method, using Taylor's theorem. In our expansion we neglect terms of degree higher than the fourth in the eccentricities and tangents of the inclinations.Now at the JPL Pasadena, California.  相似文献