نتایج جستجو برای: causality

تعداد نتایج: 51794  

Journal: :international journal of management and business research 2015
h. a. al-zeaud

the main purpose of the study is to examine the causal relationship between government revenues and expenditures of the jordan government over the period from 1990 to 2011 using granger causality and vecm tests methodology. which provides channels of causation between government revenues (gr) and government expenditures (ge).the empirical results show that bidirectional causality running betwee...

2008
E. Minguzzi

A unifying framework for the study of causal relations is presented. The causal relations are regarded as subset of M × M and the role of the corresponding antisymmetry conditions in the construction of the causal ladder is stressed. The causal hierarchy of spacetime is built from chronology up to K-causality and new characterizations of the distinction and strong causality properties are obtai...

2010
Sanqing Hu Yu Cao Jianhai Zhang Wanzeng Kong Kun Yang Yanbin Zhang Xun Li

Granger causality (GC) is one of the most popular measures to reveal causality influence of time series and has been widely applied in economics and neuroscience due to its simplicity and easy implementation. In this paper, we show that GC in time domain cannot correctly determine how strongly one time series influences the other when there is directional causality between two time series, that...

2013
Helmut Kiene Harald J. Hamre Gunver S. Kienle

The usefulness of clinical research depends on an assessment of causality. This assessment determines what constitutes clinical evidence. Case reports are an example of evidence that is frequently overlooked because it is believed they cannot address causal links between treatment and outcomes. This may be a mistake. Clarity on the topic of causality and its assessment will be of benefit for re...

2011
Kateřina Hlaváčková-Schindler

Barnett et al. in 2009 proved that Granger causality and transfer entropy causality measure are equivalent for time series which have a Gaussian distribution. Granger causality test is linear, while transfer entropy a non-linear test. Many biological and physical mechanisms show to have non-Gaussian distributions. In this paper we investigate under which conditions on probability density distri...

2009
Chen Chen Wenguang Chen Vugranam Sreedhar Rajkishore Barik Vivek Sarkar Guang Gao

It has been observed in previous work that it is desirable to avoid causal violations in any execution or transformation of a parallel program. In this paper, we formalize the notion of causality in memory consistency models and code transformations. For memory models, we introduce a framework of causality graph that can be used to analyze if a particular memory model violates causality. We sho...

Journal: :iranian journal of neurology 0
rouhollah dehghani social determinants of health (sdh) research center and department of environmental health, school of health, kashan university of medical sciences, kashan, iran mohammad sahebkar sabzevar university of medical sciences, sabzevar, iran mohammad ali sahraian ms research center, neuroscience institute, tehran university of medical sciences, tehran, iran milad derakhshanjazari department of occupational health, tehran university of medical sciences, tehran, iran vahid kazami moghaddam center of student research committee, hormozgan university of medical sciences, bandar abbas, iran ebrahim kouchaki associate professor, department of neurology , kashan university of medical sciences,kashan,iran

background: there has been a global rising trend in recent years in the incidence of multiple sclerosis (ms). despite being an ms low-risk region, this disease has also been recently on the rise in the middle east. as part of the middle east, iran has not been spared either; however, the cause of this dramatic increase remains to be discovered. the present study reviews possible reasons for thi...

2013
Amir Reza Alizad-Rahvar Masoud Ardakani Ivor Cribben

Identifying dynamic causal relationships between financial time series may help explain market dynamics. The Granger causality (G-causality) test is a method to detect linear causal relationships between time series. However, there exists significant evidence for nonlinear causality between financial time series. Hence, several nonlinear extensions of G-causality (NLG-causality) were proposed. ...

Journal: :nephro-urology monthly 0
nematollah jonaidi jafari health research center, baqiyatallah university of medical sciences, ir iran morteza izadi health research center, baqiyatallah university of medical sciences, ir iran farhad sarrafzadeh department of internal medicine, infectious ward, afzalipour educational medical center, kerman university of medical sciences, ir iran amir heidari nephrology and urology research center, baqiyatallah university of medical sciences, ir iran reza ranjbar molecular biology research center, baqiyatallah university of medical sciences, ir iran amin saburi chemical injuries research center, baqiyatallah university of medical sciences, mollasadra st, vanak sq, ir iran +98-9127376851, [email protected]; chemical injuries research center, baqiyatallah university of medical sciences, mollasadra st, vanak sq, ir iran +98-9127376851, [email protected]

background pulmonary tuberculosis (ptb) is one of the common diseases with high prevalence of mortality and morbidity in developing countries. various complications have been reported along with ptb. the subclinical electrolyte imbalances are customary in cases with ptb. objectives the aim of this study was the evaluation of patients with ptb and hyponatremia. patients and methods we evaluated ...

2011
Nevio Dubbini

This paper indicates causality as the tool that unifies the analysis of both activations and connectivity of brain areas, obtained with fMRI data. Causality analysis is commonly applied to study connectivity, so this work focuses on demonstrating that also the detection of activations can be handled with a causality analysis. We test our method on finger tapping data, in which GLM and Granger C...

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