dr. h. kaviani

The homogeneous charge compression ignition (HCCI) engines with ethanol fuel as a renewable fuel is a promising solution to some of the major challenges of combustion engines. Incomplete or misfiring combustion limits HCCI operation and damages the catalyst converter and exhaust systems. The experimental data of a 0.3-liter combustion engine was used for modeling and detecting misfiring combustion. Incomplete and misfiring combustion in HCCI engine was studied by fuzzy-neural network. There is a significant relationship between misfiring combustion and in-cylinder pressure variations at 0, 5, 10, 15 and 20 crankshafts. These experimental findings were used to design a fuzzy-neural network for misfiring incomplete combustion in a HCCI engine. This model has been tested on experimental data. The results showed that the fuzzy-neural network fault diagnostic model can detect incomplete and misfiring combustion in HCCI engine with ethanol fuel. In addition, the developed model was able to identify the transition success from the normal operating area and incomplete combustion.

Higher education has faced many challenges and issues during the last two decades, among which we can mention the following: inability to produce theoretical knowledge and use of basic and theoretical knowledge produced in other countries. Of the world, the inapplicability of university education, the lack of an inappropriate relationship between the university and other social sectors, neglecting research functions and services in universities, the problem of multiple decision centers and the existence of multiple trustees on the one hand, and the excalating growth of students and applicants to universities and institutions of higher education, the slight expansion of the higher education system regardless of the existing capacity and economic, social and cultural capacity of the community to accept university graduates, reduced financial resources and pressure from society For responsibility and accountability on the other hand; the higher education system needs to maintain and improve the quality of higher education to meet these challenges. To succeed in this, all the functions of higher education in general must be considered comprehensively. In this regard, one of the measures that higher education deliberates to answer its problems was technology-based education, including distance education and distance learning. Considering the contradiction in the findings of the studies conducted on the effectiveness of distance education methods, the present study was conducted to evaluate the effectiveness of distance education in higher education.

The research method is based on secondary analysis and meta-analysis. The statistical population consists of all quasi-experimental studies which have already been conducted on the effectiveness of various types of distance education in higher education in Iran. The whole census was used for sampling. According to the inclusion and exclusion criteria, 79 studies were identified as the sample size.To collect the data, a researcher-made worksheet was employed in three sections: bibliographicaldata, methodological data, and findings. To analyze the data, the effect size index and the homogeneity test were performed using CMA-Version 2.0 statistical software.

The research findings indicated that all of distance education methods in higher education of Iran were effective, but this effectiveness was moderate (ES =0.526, P <0.01); the area under the normal curve, the average implementation of distance education is 69% more effective than traditional methods. In addition, the meta-regression of the effect of year on the results of research showed that with an increase in the implementation of distance education methods, .07%was added to the effectiveness of these methods. In other words, the implementation of distance education methods in higher education will become more effective over time.

Considering that the study of moderating variables was not one of the objectives of this study, it is recommended that in future research, the impact of these components on the results of the study be examined to determine the impact of these components to explain and control the results. 

In today's classrooms, teaching is more about direct content than inspiring a sense of research and creativity in learners. Given that teaching is a factor that provides opportunities for learners to learn, it is necessary that teaching-learning processes be coordinated with these developments and move from traditional information transfer strategies to new problem-solving that develop abilities. On the other hand, over the past decades, educational standards have emphasized the potential value of learner-centered learning environments in which learners are actively involved in high-level learning activities. learner-centered learning environments require the use of active learning methods in the classroom, including presentations, problem-solving in small groups, self-assessment and peer review, and group discussion, but creating such environments is a challenge. The aim of the present study was to identify the flipped classroom educational outputs via a synthesis research method.

Therefore, the analysis unit consisted of all related scientific studies, which were based on systematic searches in internal and external databases based on the inclusion criteria of 1298 scientific studies were identified and finally, based on the inclusion criteria, 106 studies were selected for the final analysis. To collect the required data, a researcher made worksheet was employed and to ensure the used coding, two examiners were asked to reencode the findings. For analyzing the data, Roberts ’six-step synthesis model was used via open and axial coding methods in Nvivo-8 software.

Results indicated that applying flipped classroom instruction to training led to the occurrence of 119 types of educational outputs, which according to the classification of efficiencies in the overall axis of those outputs, including 7 temporal, interaction, skill, personal, group, educational, and teaching dimensions  among which the individual dimension achieved the highest educational output

The findings of this study showed that it should be acknowledged that today teaching-learning approaches have evolved, learners prefer to play an active role in the classroom and learning, and they are found to prefer a passive role in the classroom. On the other hand, learning tools and situations have also changed, so in line with these developments, one of the most important things to consider in teaching-learning approaches is to create attractive learning situations. This can be achieved through the use of audio and video technologies as well as the use of flipped class in education. Therefore, further research in this field and recognizing its advantages and obstacles in implementation seems necessary.

This study was performed aims to Identification challenges of evaluating Virtual College students' perceptions of electronics courses. Statistical population was consisted of all students of Virtual University. For samples, 140 students were selected using stratified random sampling. Research instrument, researcher made questionnaire was a valid and reliable. The obtained data were analyzed. The mean, standard deviation, variance analysis and paired t-tests to measure t. The results showed that the greatest challenges to the evaluation of students' views of electronic Respectively Technical problems with mean 3/71 , Pedagogical difficulties, with a mean 3/20, And Mental health problems with an average of 3.Also, the students' perspective. In the terms different And various disciplines. There was a difference. In the particular challenges of of evaluation. Yet from the perspective of students And in terms different academic, technical problems as the most important challenge of evaluating students' academic performance was introduced.