scholarly journals Estimation of Cutoff Values by Using Regression Lines Method in Mishrif Reservoir/ Missan oil Fields

2019 ◽  
Vol 25 (2) ◽  
pp. 82-95 ◽  
Author(s):  
Mohammed Salih Al Jawad ◽  
Baraa Ziad Tariq
Keyword(s):  
Water Saturation ◽  
Regression Line ◽  
Major Axis ◽  
Least Square ◽  
Oil Fields ◽  
Common Assumption ◽  
Cutoff Values ◽  
The Common ◽  
Limiting Values ◽  
Linear Regressions

Net pay is one of the most important parameters used in determining initial oil in place of a reservoir. It can be delineated through the using of limiting values of the petrophysical properties of the reservoir. Those limiting values are named as the cutoff. This paper provides an insight into the application of regression line method in estimating porosity, clay volume and water saturation cutoff values in Mishrif reservoir/ Missan oil fields. The study included 29 wells distributed in seven oilfields of Halfaya, Buzurgan, Dujaila, Noor, Fauqi, Amara and Kumait. This study is carried out by applying two types of linear regressions: Least square and Reduce Major Axis Regression. The Mishrif formation was divided into three main units. They are MA, MB, and MC. The methods were applied to each unit of Mishrif formation individually and as one unit. The division of Mishrif formation into subunits led to a great improvement in the accuracy of the porosity-permeability correlations. The Results indicated that the regression lines method of defining cutoffs gives unrealistic values with the common assumption of permeability cutoff = 0.1 md. Another assumption for permeability cutoff = 1 is made and it was chosen due to lithology and hydrocarbon type which are limestone and oil respectively. This assumption led to more realistic and higher porosity cutoff and smaller water saturation and clay volume cutoff values using the two types of regression lines.  

Student Perceptions of Community: A Different Perspective

NASPA Journal ◽  
1998 ◽  
Vol 35 (4) ◽  
Author(s):  
Jackie Clark ◽  
Joan Hirt
Keyword(s):  
Student Perceptions ◽  
Large Scale ◽  
Research University ◽  
Small Scale ◽  
Social Environments ◽  
Common Assumption ◽  
Small Communities ◽  
Public Research University ◽  
The Common ◽  
Using Data

The creation of small communities has been proposed as a way of enhancing the educational experience of students at large institutions. Using data from a survey of students living in large and small residences at a public research university, this study does not support the common assumption that small-scale social environments are more conducive to positive community life than large-scale social environments.

scholarly journals Śaivism after the Śaiva Age: Continuities in the Scriptural Corpus of the Vīramāheśvaras

Religions ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 222
Author(s):  
Elaine M. Fisher
Keyword(s):  
Thirteenth Century ◽  
Common Assumption ◽  
Academic Practice ◽  
The Common ◽  
Popular Work ◽  
First Time

This article makes the case that Vīraśaivism emerged in direct textual continuity with the tantric traditions of the Śaiva Age. In academic practice up through the present day, the study of Śaivism, through Sanskrit sources, and bhakti Hinduism, through the vernacular, are generally treated as distinct disciplines and objects of study. As a result, Vīraśaivism has yet to be systematically approached through a philological analysis of its precursors from earlier Śaiva traditions. With this aim in mind, I begin by documenting for the first time that a thirteenth-century Sanskrit work of what I have called the Vīramāheśvara textual corpus, the Somanāthabhāṣya or Vīramāheśvarācārasāroddhārabhāṣya, was most likely authored by Pālkurikĕ Somanātha, best known for his vernacular Telugu Vīraśaiva literature. Second, I outline the indebtedness of the early Sanskrit and Telugu Vīramāheśvara corpus to a popular work of early lay Śaivism, the Śivadharmaśāstra, with particular attention to the concepts of the jaṅgama and the iṣṭaliṅga. That the Vīramāheśvaras borrowed many of their formative concepts and practices directly from the Śivadharmaśāstra and other works of the Śaiva Age, I argue, belies the common assumption that Vīraśaivism originated as a social and religious revolution.

scholarly journals Adverse Selection, Heterogeneous Beliefs, and Evolutionary Learning

2021 ◽  
Author(s):  
Clemens Buchen ◽  
Alberto Palermo
Keyword(s):  
Adverse Selection ◽  
Relative Size ◽  
Nonlinear Dynamic System ◽  
Heterogeneous Beliefs ◽  
Evolutionary Learning ◽  
Common Assumption ◽  
Cobweb Model ◽  
The Common ◽  
Learning Set ◽  
Set Up

AbstractWe relax the common assumption of homogeneous beliefs in principal-agent relationships with adverse selection. Principals are competitors in the product market and write contracts also on the base of an expected aggregate. The model is a version of a cobweb model. In an evolutionary learning set-up, which is imitative, principals can have different beliefs about the distribution of agents’ types in the population. The resulting nonlinear dynamic system is studied. Convergence to a uniform belief depends on the relative size of the bias in beliefs.

Reform, corruption, and growth: Why corruption is more devastating in Russia than in China

2006 ◽  
Vol 39 (2) ◽  
pp. 265-281 ◽  
Author(s):  
Tomas Larsson
Keyword(s):  
Economic Growth ◽  
Comparative Advantage ◽  
Economic Performance ◽  
Political Corruption ◽  
Common Assumption ◽  
Rapid Economic Growth ◽  
The Common ◽  
The Impact ◽  
Intervening Factors

This article explains why massive political corruption appears to be incompatible with economic growth in Russia but compatible with very rapid economic growth in China. The common assumption is that corruption is bad for economic performance. So how can we explain the puzzling contrast between Russia and China? Is Russia being more severely “punished” for its corruption than China? If so, why? This article demonstrates that three intervening factors—comparative advantage, the organization of corruption, and the nature of rents—determines the impact of corruption on economic performance, and that these factors can explain the divergent outcomes. The article thereby offers an alternative to statist explanations of the Russia-China paradox.

Utilization of heterologous siderophores and rhizosphere competence of fluorescent Pseudomonas spp.

1995 ◽  
Vol 41 (2) ◽  
pp. 126-135 ◽  
Author(s):  
Jos M. Raaijmakers ◽  
Lentse van der Sluis ◽  
Peter A. H. M. Bakker ◽  
Bob Schippers ◽  
Margot Koster ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Population Densities ◽  
Common Assumption ◽  
Fluorescent Pseudomonas ◽  
Siderophore Receptors ◽  
Rhizosphere Interactions ◽  
Rhizosphere Population ◽  
Rhizosphere Competence ◽  
The Common ◽  
Derivative Strain

In this study, the potential of different Pseudomonas strains to utilize heterologous siderophores was compared with their competitiveness in the rhizosphere of radish. This issue was investigated in interactions between Pseudomonas putida WCS358 and Pseudomonas fluoresceins WCS374 and in interactions between strain WCS358 and eight indigenous Pseudomonas strains capable of utilizing pseudobactin 358. During four successive plant growth cycles of radish, strain WCS358 significantly reduced rhizosphere population densities of the wild-type strain WCS374 by up to 30 times, whereas derivative strain WCS374(pMR), harboring the siderophore receptor PupA for ferric pseudobactin 358, maintained its population density. Studies involving interactions between strain WCS358 and eight different indigenous Pseudomonas strains demonstrated that despite the ability of these indigenous isolates to utilize pseudobactin 358, their rhizosphere population densities were significantly reduced by strain WCS358 by up to 20 times. Moreover, rhizosphere colonization by WCS358 was not affected by any of these indigenous strains, even though siderophore-mediated growth inhibition of WCS358 by a majority of these strains was demonstrated in a plate bioassay. In conclusion, it can be stated that siderophore-mediated competition for iron is a major determinant in interactions between WCS358 and WCS374 in the rhizosphere. Moreover, our findings support the common assumption that cloning of siderophore receptor genes from one Pseudomonas strain into another can confer a competitive advantage in interactions in the rhizosphere. Interactions between WCS358 and the selected indigenous rhizosphere isolates, however, indicate that other traits also contribute to the rhizosphere competence of fluorescent Pseudomonas spp.Key words: siderophore, siderophore receptors, root colonization, fluorescent Pseudomonas.

Artificially Ventilated Cavities: Evaluating the Constant-Pressure Approximation

2017 ◽  
Author(s):  
Melissa A. Fronzeo ◽  
Michael Kinzel ◽  
Jules Lindau
Keyword(s):  
Constant Pressure ◽  
Flow Behavior ◽  
Internal Cavity ◽  
Common Assumption ◽  
Ventilated Cavity ◽  
Physical Insight ◽  
Circulatory Flow ◽  
Computational Fluid Dynamics Cfd ◽  
The Common ◽  
Semi Empirical

Computational Fluid Dynamics (CFD) is employed to study the fundamental aspects of the internal pressure within artificially ventilated, gaseous cavities in both twin- and toroidal-vortex closure modes. The results show that several pressure regions develop within the cavities, indicating that the common assumption that the cavity has a constant pressure breaks down when evaluated in high detail. The internal cavity pressure is evaluated using a probability density function (PDF). The resulting PDF plots show a clusters with multiple peaks. A mixture-of-Gaussians (MOG) method is employed to better understand the distributions of these peaks. These peaks are then mapped to the simulation results, where it is observed that these peaks correlate to distinct cavity regions (which vary depending on cavity type). Moreover, these varying pressure regions appear to align with cavity-radius growth and reduction and appear to be the driving force of the internal, circulatory flow. Lastly, the importance of these pressure regions are investigated with respect to predictions from semi-empirical theory of the cavity shape, showing a moderate impact depending on where the cavity is probed. Overall, these results provide physical insight into ventilated cavity flow behavior that is often ignored.

Islamic calendar and stock market behaviour in India

2018 ◽  
Vol 45 (11) ◽  
pp. 1550-1566
Author(s):  
Dharani Munusamy
Keyword(s):  
Stock Market ◽  
Least Square Method ◽  
Least Square ◽  
Stock Market Returns ◽  
Content Type ◽  
Ordinary Least Square ◽  
Average Return ◽  
Year Effect ◽  
The Common ◽  
The Impact

Purpose The purpose of this paper is to examine the behavior of the stock market returns in the different days of the week and different months of the year in accordance with the Islamic calendar. Further, the study estimates the risk-adjusted returns to test the performance of the indices during the Ramadan and non-Ramadan days. Finally, the study investigates the impact of Ramadan on the returns and the volatility of the stock market indices in India. Design/methodology/approach Initially, the study applies the Ordinary Least Square method to test the day-of-the-week and the month-of-the-year effect of the common and Shariah indices. Next, the study employs the risk-adjusted measurement to examine the underperformance and over-performance of the indices for both the periods. Finally, the study estimates the GARCH (1,1) and GJR-GARCH (1,1) models to observe the impact of Ramadan on the returns and the volatility of the Shariah indices in India. Findings The study finds that an average return of the indices during the Ramadan days are higher than non-Ramadan days. Further, the average returns of the Shariah indices are significantly higher on Wednesday than other days of the week. In addition, the highest and significant mean returns and mean risk-adjusted returns of the indices during the Ramadan days are observed. Finally, the study finds an evidence of the Ramadan effect on the returns and volatility of the indices in India. Originality/value The study observes evidence that the Ramadan effect influences the Shariah indices, but not the common indices in the stock market of the non-Muslim countries. It indicates that the Ramadan creates the positive mood and emotions in the investors buying and selling activities. The study suggests that investors can buy the shares before Ramadan period and sell them during the Ramadan days to get an abnormal return in the emerging markets.

Properties and general use of the X-ray elastic factors

2007 ◽  
Vol 22 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Balder Ortner
Keyword(s):  
Plastic Deformation ◽  
Stress Measurement ◽  
Measured Data ◽  
Least Square ◽  
Data Evaluation ◽  
X Ray ◽  
Rank Tensor ◽  
The Matrix ◽  
Hooke's Law ◽  
Linear Regressions

The equation ε(φ, ψ, hkl)=Fij(φ, ψ, hkl)σij can be directly deduced from Hooke’s law. It is shown that the matrix Fij(φ, ψ, hkl) which is usually called X-ray elastic factors, behaves as a second rank tensor. Since this behaviour is the only criterion for the question of whether or not it is a tensor, the F-matrix must be regarded as a second rank tensor. This allows us to make some statements about the structure of the F-matrix on the basis of Neumann’s principle, to find relationships among F-matrices in different measurement directions, and to apply the methods and strategies for the measurement of a second rank tensor. All this is shown in a few examples. It is further shown that a consistent use of the F-matrix can replace all methods for data evaluation which makes use of linear regressions and, in addition, avoids all difficulties and disadvantages of these methods. One of these disadvantages is that the sin2 ψ-method, as well as its derivatives, is generally not correct least square fits of the measured data. This is also shown in an example. The more complicated cases with stress or constitution gradients in the range of the probed volume or stress measurement after plastic deformation are not discussed.

Recognition of jet engines via sparse decomposition of ISAR images using a waveguide scattering model

2017 ◽  
Vol 9 (6) ◽  
pp. 1339-1343 ◽  
Author(s):  
Simon Wagner ◽  
Joachim Ender
Keyword(s):  
Electromagnetic Waves ◽  
Radar System ◽  
Synthetic Aperture ◽  
Jet Engines ◽  
Signal Model ◽  
Common Assumption ◽  
Sparse Decomposition ◽  
Imaging Radar ◽  
Scattering Centers ◽  
The Common

Air target recognition is a critical step in the radar processing chain and reliable features are necessary to make a decision. The number and position of jet engines are useful features to perform a pre-classification and give a list of possible targets. To extract these features, a sparse decomposition framework for inverse synthetic aperture radar (ISAR) images is presented. With this framework different components of the target can be detected, if signal models for these parts are available. To use it for the detection of jet engines, a review of a signal model for air intakes, which was developed by Borden, is given. This model is based on the common assumption that the propagation of electromagnetic waves inside jet engines has the same dispersive behavior as inside waveguides. With this model a decomposition of a real ISAR image, measured with the tracking and imaging radar system of Fraunhofer FHR, into point-like scattering centers and jet engines is presented.

scholarly journals Apical length governs computational diversity of L5 pyramidal neurons

2019 ◽  
Author(s):  
Alessandro R. Galloni ◽  
Aeron Laffere ◽  
Ede Rancz
Keyword(s):  
Action Potentials ◽  
Pyramidal Neurons ◽  
Apical Dendrite ◽  
Common Assumption ◽  
Dendritic Excitability ◽  
Visual Cortices ◽  
The Common ◽  
Channel Dependent ◽  
Apical Dendrites ◽  
The Brain

AbstractAnatomical similarity across the neocortex has led to the common assumption that the circuitry is modular and performs stereotyped computations. Layer 5 pyramidal neurons (L5PNs) in particular are thought to be central to cortical computation because of their extensive arborisation and nonlinear dendritic operations. Here, we demonstrate that computations associated with dendritic Ca2+ plateaus in L5PNs vary substantially between the primary and secondary visual cortices. L5PNs in the secondary visual cortex show reduced dendritic excitability and smaller propensity for burst firing. This reduced excitability is correlated with shorter apical dendrites. Using numerical modelling, we uncover a universal principle underlying the influence of apical length on dendritic backpropagation and excitability, based on a Na+ channel-dependent broadening of backpropagating action potentials. In summary, we provide new insights into the modulation of dendritic excitability by apical dendrite length and show that the operational repertoire of L5 neurons is not universal throughout the brain.

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