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Search Results: 1 - 10 of 2981 matches for " Hossein Barati "
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Generation Reliability Evaluation in Deregulated Power Systems Using Game Theory and Neural Networks  [PDF]
Hossein Haroonabadi, Hassan Barati
Smart Grid and Renewable Energy (SGRE) , 2012, DOI: 10.4236/sgre.2012.32013
Abstract: Deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. In the present research, generation reliability is considered, and a method for its assessment is proposed using Game Theory (GT) and Neural Networks (NN). Also, due to the stochastic behavior of power markets and generators’ forced outages, Monte Carlo Simulation (MCS) is used for reliability evaluation. Generation reliability focuses merely on the interaction between generation complex and load. Therefore, in the research, based on the behavior of players in the market and using GT, two outcomes are considered: cooperation and non-cooperation. The proposed method is assessed on IEEE-Reliability Test System with satisfactory results. Loss of Load Expectation (LOLE) is used as the reliability index and the results show generation reliability in cooperation market is better than non-cooperation outcome.
Investigating the Construct Validity of the FCE Reading Paper in Iranian EFL Context
Elahe Tavakoli,Hossein Barati
Journal of Language Teaching and Research , 2011, DOI: 10.4304/jltr.2.1.239-247
Abstract: Validity studies on language proficiency tests have attracted many researchers in the last decades. Most of such studies try to investigate skills assessed by the items in the tests, hence the construct validity of the test. The present study took the same approach and therefore aimed to investigate the construct validity of the reading paper of the First Certificate in English (FCE) in the Iranian EFL context. The research addressed the following three questions: (1) Do the majority of the Iranian EFL expert judges agree on the skills measured by the items in the FCE reading paper? (2) Do the majority of the Iranian EFL undergraduates come to agreement on the skills measured by the items in the FCE reading paper? (3) Does exploratory factor analysis support that the FCE reading paper assesses the same reading skills claimed by its developing board, i.e. UCLES, in the context of Iranian EFL undergraduates? The present study deployed triangulated approach in collecting and analyzing the data. It attempted to use both qualitative (i.e. experts’ and test takers’ judgment) and quantitative (i.e. Factor Analysis) approaches to address the above questions. The findings revealed that there was not a substantial agreement among expert judges on the skills claimed to be assessed by the items in the FCE reading paper nor could any significant agreement be observed amongst the test takers on the skills being measured by such items in the FCE reading paper. Finally, exploratory factor analysis revealed similar findings as those in the judgmental phase of the study. The individual items in the FCE reading paper did not confirm the claims by the test developers.
Function of English Sub-tests of the INUEE for Male Candidates
Maryam Javadizad,Hossein Barati,Akbar Hesabi
Journal of Language Teaching and Research , 2011, DOI: 10.4304/jltr.2.6.1392-1404
Abstract: Iranian National University Entrance Exam (INUEE) plays a vital role in the life of Iranian students in terms of screening applicants for higher education. The present study aimed to investigate if there is any highly positive correlation between various English sub-tests of the INUEE for male candidates. The study utilized Pearson Product Moment Correlation Coefficient formula to investigate correlation coefficient for a sample of 329 students randomly selected out of a population of 90858 male candidates who sat for the INUEE. The results of the study identified a high correlation between grammar and reading comprehension, vocabulary and reading comprehension, vocabulary and grammar, and language functions and reading comprehension sub-tests for male students.
Ability Grouping as a Way towards More Academic Success in Teaching EFL - A Case of Iranian Undergraduates
Bahareh Khazaeenezhad,Hossein Barati,Mehdi Jafarzade
English Language Teaching , 2012, DOI: 10.5539/elt.v5n7p81
Abstract: This research is an attempt to find out if grouping learners, through using a placement test will significantly help students become more successful in learning English. 320 non-English major undergraduates studying at the University of Isfahan participated in this research. The final scores of 121 freshmen who attended their general English courses in homogenised classes were compared with those of 199 freshmen who did not undergo any placement procedure. The analysis of data suggested that grouping the learners and dividing them into different ability groups had a significant impact on the participants’ academic success, in their course of general English. In addition, the results suggested that ability grouping provides sufficient ground for methodological decisions and hence sequencing of teaching materials and procedures
Problematizing Rating Scales in EFL Academic Writing Assessment: Voices from Iranian Context
Batoul Ghanbari,Hossein Barati,Ahmad Moinzadeh
English Language Teaching , 2012, DOI: 10.5539/elt.v5n8p76
Abstract: Along with a more humanitarian movement in language testing, accountability to contextual variables in the design and development of any assessment enterprise is emphasized. However, when it comes to writing assessment, it is found that multiplicity of rating scales developed to fit diverse contexts is mainly headed by well-known native testing agencies. In fact, it seems that EFL/ESL assessment contexts are receptively influenced by the symbolic authority of native assessment circles. Hence, investigating the actualities of rating practice in EFL/ESL contexts would provide a realistic view of the way assessment is conceptualized and practiced. To investigate the issue, present study launched a wide-scale survey in the Iranian EFL writing assessment context. Results of a questionnaire and subsequent interviews with Iranian EFL composition raters revealed that rating scale in its common sense does not exist. In fact, raters relied on their own internalized criteria developed through their long years of practice. Therefore, native speaker legitimacy in the design and development of scales for the EFL context is challenged and the local agency in the design and development of rating scales is emphasized.
The Effects of Pre-task, On-line, and both Pre-task and On-line Planning on Fluency, Complexity, and Accuracy – The Case of Iranian EFL Learners’ Written Production
Faramarz Piri,Hossein Barati,Saeed Ketabi
English Language Teaching , 2012, DOI: 10.5539/elt.v5n6p158
Abstract: Previous studies on the effect of planning on language production have revealed that planning does have a positive effect on language performance in terms of fluency, complexity, and accuracy. The present study was an attempt to investigate the effects of pre-task, on-line, and both pre-task and on-line planning on fluency, accuracy, and complexity of Iranian EFL learners’ written production. Forty five Iranian learners of English performed a narrative task based on a series of six pictures. The narratives, then, were coded to measure the fluency, accuracy, and complexity of the participants' production. The results of one-way ANOVA revealed that on-line planning (OLP) and pre-task plus on-line planning (PTP+OLP) had no effect on the fluency, complexity, and accuracy of the Iranian EFL learners’ written narratives. However, pre-task planning (PTP) had a significant effect on one variable of fluency (i.e. syllables per minute) but it had no effect on the complexity and accuracy of the written narratives. Findings have pedagogical implications for language teachers and syllabus designers in EFL context.
An Investigation into Ambiguity Tolerance in Iranian Senior EFL Undergraduates
Amin Marzban,Hossein Barati,Ahmad Moinzadeh
English Language Teaching , 2012, DOI: 10.5539/elt.v5n1p76
Abstract: The present study aimed to explore how tolerant of ambiguity Iranian EFL learners at university level are and if gender plays a role in this regard. To this end , upon filling in the revised SLTAS scale of ambiguity tolerance 194 male and female Iranian teacher trainees were assigned to three ambiguity tolerance groups; namely, high, moderate and low. Cluster analysis of the SLTAS scores indicated that Iranian EFL learners were mostly moderate as far as tolerance of ambiguity was concerned. Examining the gender differences through an independent sample t-test manifested that female participants were less tolerant of ambiguity than their male peers. Also, the differences between the expected and observed number of participants categorized in the three AT groups were non-significant undermining the role of gender as a moderator variable in assigning participants to AT groups and further approving of SLTAS validity. Implications for classroom practice are presented in the light of findings. The results are helpful in syllabus design and teaching methodology.
Solitary Metastasis of Gastric Cancer to Fibula: A Case Report
Sepideh Hekmat,Tahereh Ghaedian,Hossein Barati,Mansour Movahed
Iranian Journal of Radiology , 2012,
Abstract: ABSTRACT: Gastric cancer is one of the most common and most fatal neoplasms in human. Its skeletal metastasis is less frequent, particularly when solitary. The objective of this article is to represent a case of solitary fibular metastasis from this cancer not reported before based on Medline search.Keywords: Gastric Cancer,Neoplasm Metastasis,Fibula
Nonlinear Behavior of Lumbar Extensor Muscle Activities Following Onset of Muscle Fatigue in Women with Nonspecific Low Back Pain
Saied Talebian,Hossein Bagheri,Gholam Reza Olyaei,Nahid Barati
Modern Rehabilitation , 2008,
Abstract: Background and aim:The role of thoraco-lumbar muscles is important in spinal column stability. Following fatigue due to constant activity, these muscles encounter with variable control pattern and variations of median and mean frequencies are little in relation to torque of force. However these parameters are useful in the literatures, but due to complexity of neuromuscular interaction and variety of motor control, signal processing can determine a wide range of changes and measurements Signal processing nonlinear techniques exploit in biologic signals. Variables of nonlinear techniques are recurrence, determinism, entropy and so on. The purpose of this study was to determine changes of entropy as nonlinear parameter in comparison with linear parameter and applicability of entropic measurements of the erector spinae muscles during fatigue. Materials and methods: Ten healthy women and 6 women with nonspecific low back pain (NSLBP) with a range of 20-30 years old patticipated in this study. Surface electromyography of isometric activities recorded from trunk (T12), lumbar (L3) and biceps femoris muscles during modified Sorenson isometric fatigue test. Median and mean frequency and also nonlinear parameters such as entropy and trend measured in one second of muscles activities before and onset of fatigue. Results: Following fatigue in healthy group, median and mean frequencies reduced at a range of 12-20% (p<0.05). This decrement in LBP group was little (4 - 20%, p<0.05). Entropy increased 120-200% and trend reduced 800-2000% in normal subjects (p<0.05), whereas subjects with LBP indicated increment of entropy 65-220% and decrement of trend 240-500% (p<0.05). Before and after fatigue there was a significance difference between two groups in entropy parameter (p<0.05), whereas median and mean frequencies differences were not significant. Conclusion:Following static positions, fatigue occurred in three levels of above muscles particularly at lumbar region. Traditional fatigue indicators showed good differences, but percentage of variability was low in comparison to nonlinear parameters. It suggests that nonlinear variables especially entropy are more sensitive than traditional indicators and can explain these stochastic behaviors.
The effect of one bout of incremental exercise on salivary immunoglobulin A (IgA) of high school students
Alireza Ramezani,Amir hossein Barati,Mohammad ali Azarbaijani,Mohammad Tohidi
Archives of Exercise in Health and Disease , 2012,
Abstract: Objective: The aim of present study is study the effect of one bout incremental exercise on salivary IgA changes in boy athlete and no athlete high school students. Design: 15 no athlete and 30 athlete (15 wrestlers, 15 endurance runners) students were selected as subject randomly among students of Neishabur city in Iran. Subject ran on the treadmill to exhaustion range using Bruce protocol. Four milliliter unstimated saliva was collected pre, immediately and 2 hour after exercise. Results: The result showed that one bout incremental exercise caused significant increase in S-IgA concentration in non-athlete and endurance runners groups, and this increase continued to 2 hours after exercise. There was significant increase in S-IgA concentration in wrestlers group after activity. S-IgA concentration decreased after 2 hours of activity, but it did not reach to initial levels of pre-activity, this different was statically significant. Conclusion: Based on these findings, it is inferred that one bout incremental exercise in young students had no suppressor effect on the mucosal immune system and there is no probability of existence of the upper respiratory tract infection following this activities.
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