science education
M. Kazerooni; G. Azami Rod
Abstract
During the press working process of the shearing progressive die, the position of the die's pressure center has a direct impact on whether the die can work accurately in balance. If the shearing progressive die suffers from being off-center the area close to the product edge may have a burr. This paper ...
Read More
During the press working process of the shearing progressive die, the position of the die's pressure center has a direct impact on whether the die can work accurately in balance. If the shearing progressive die suffers from being off-center the area close to the product edge may have a burr. This paper describes a system for feature recognition of sheet metal components from standard files and optimal strip working sequence for shearing progressive die. The system initially recognizes the different kinds of internal and external cutting features then genetic algorithms (GA) are applied as a solution tool in the analysis of the optimal strip working sequence possessing a smaller difference between the right and left torque in the shearing progressive die. The purpose is to reduce the time spent in adjusting the pressure center of the shearing progressive die. The system was developed using Microsoft Visual Basic .NET 2003.
science education
Z. Khoshneshin
Abstract
Background and Objectives:The world of communication in the third wave of communication approaches has brought a new way of life in the form of new tools, which has led to it being called the electronic hut. Rapid developments resulting from the application of technology, including productive technology ...
Read More
Background and Objectives:The world of communication in the third wave of communication approaches has brought a new way of life in the form of new tools, which has led to it being called the electronic hut. Rapid developments resulting from the application of technology, including productive technology and information technology in human life have caused dramatic changes in the industrial, economic, political and civil structures of societies, and these changes have had a significant impact on the life and work of people around the world. It has seriously challenged traditional methods of teaching, learning, and managing education. With the help of new educational tools, there is an opportunity to make new choices to combine the knowledge of students and students, including the use of blended teaching methods in an environment based on e-learning technology. Blended instruction is the preparation of an active environment and the introduction of dynamic training methods through which it is possible to use educational facilities with its minimum and maximum benefits. In this environment, it is possible to move from face-to-face learning to combining it with virtual classes and finally using fully online facilities. Blended learning as a new paradigm in educational context undergrounded in using ICT when learning occurs both in the classroom and online situation. The paper explains students' achievement in learning science through blended method at a secondary school in a city in Iran. Method and Materials: Research sample includes 160 students in 6 classes and in 3 grades. 60 of learners after revising of their pre - test score on the basis of scores' variances randomized as control and experimental group.30 of them considered as experimental group learned in blended method and the same sample participated as control in classic styles of learning. Data were analyzed by T test and covariance analysis. Findings: Findings showed that blended learning method could promote achievement results in experimental group on learning science conceptions. Conclusion: Learning is formed with a blended approach based on activity-based principles and the learner is required to reflect and decide on events and facts online or offline and explain the reality by reflecting group or individual processes effective in problem solving or decision-making, reviewing the solution and reviewing the effective feedback on solving the problem. Using the teaching method in a blended way and in fact combining education by using the computer as a powerful medium in the learning and teaching processes in addition to improving the teaching of science concepts, after direct teaching in the classroom and in combination with the curriculum assignments related to daily life, can be effective in improving the learning of learners.
science education
H. Meiboudi; S.M. Shobeiri; R. Arjmandi; F. Babaei Semiromi
Abstract
The attitude and values for preserving and supporting the environment shape at an early age. This paper, using the way of analyzing the visual concept has studied mural paintings of Mashhad kindergartens. Statistical universe of this research includes total kindergartens of Mashhad city which totals ...
Read More
The attitude and values for preserving and supporting the environment shape at an early age. This paper, using the way of analyzing the visual concept has studied mural paintings of Mashhad kindergartens. Statistical universe of this research includes total kindergartens of Mashhad city which totals include 322 kindergartens. The quality and quantity of most applicable environmental concept showed in this painting. In the way of analyzing visual concepts, at first a total interpretation from each mural painting is presented and then compared it with all available concepts in the table of analyzing content, one mural painting can comprise a collection of concepts. Results show that overall environmental concepts are not well covered in the mural paintings. However, the most selected subjects for mural paintings in kindergartens are the pictures of the friendly relations with nature and the least subjects about the discussion of restraining the pollution of the environment. The all related conceptions environments in these mural paintings are 2017 items that in an overall 27.2 percent of the content in Mural paintings are related to environmental concepts. This result, in addition to study the mural painting in kindergartens, will generalize also a new way in Enhancing children’s environmental awareness in kindergarten.
science education
S. Olyaee; S. Hamedi
Abstract
Surveying and identifying objectives are the first step to be taken in engineering educational programming, so that if carried out properly, a more objective basis for correlating educations with organizational needs will be achievable. In this article it is aimed to that using comparative- surveying ...
Read More
Surveying and identifying objectives are the first step to be taken in engineering educational programming, so that if carried out properly, a more objective basis for correlating educations with organizational needs will be achievable. In this article it is aimed to that using comparative- surveying methods find out training needs of engineers in Iran electronic industries company regarding technical, human and perceptional skills. Statistic society in this research is comprised of all engineers under training course between 2005 to 2009. Since, it is not feasible to focus on all individuals, 150 people were adopted randomly and asked to fill out a questionnaire. One hundred and ten questionnaires were returned. The questionnaire includes 30 questions, which are at 92% level of validity based on Chronbach’s Alpha, that is the questionnaire has good stability. An information analysis was performed through comparative and deductive methods. Findings of the study illustrates that majority of engineers need more technical and perceptional training. In addition, our analyses showed that there is no meaningful relation between type degree, work experiences and authorities of engineers and required skills.
science education
M. Nadjafikhah; N. Yaftian; S. Bakhshalizadeh
Abstract
Mathematical creativity is often considered as a mysterious phenomenon. Most mathematicians seem to be not interested in analyzing their own thinking processes and do not describe how they work or conceive their theories. One of the goals of this paper, which is based on research findings from contemporary ...
Read More
Mathematical creativity is often considered as a mysterious phenomenon. Most mathematicians seem to be not interested in analyzing their own thinking processes and do not describe how they work or conceive their theories. One of the goals of this paper, which is based on research findings from contemporary literature, presents some definitions and characteristics of mathematical creativity and also describes and analyzes mathematicians’ thinking processes during creating mathematics. For this purpose, a four-stage model is considered consisting of: preparation, incubation, illumination and verification. Referring to literature, it is evident that there is not a specific conventional definition of mathematical creativity. According to some of definitions, a creative act in mathematics could consist of: creating a new fruitful mathematical concept; discovering an unknown relation; and reorganizing the structure of a mathematical theory. The challenges in the identification and development of mathematical creativity are due to the large variety in definitions and characteristics of mathematical creativity. Understanding, intuition, insight and generalization are some of moving powers of mathematical creativity. Fallibility is one of the characteristics of creative mathematical activities which should be appreciated since this existing chance of fallibility could lead to major success achievements of human. Hence, considering all above mentioned, learning-teaching mathematics should be so that it provides environment that fosters ability to make connections among concepts and processes and also provides opportunities to generalize.
science education
A.A. Motiebirjandi; J. Hatami; V.A. Fekri
Abstract
The purpose of this research is to examine the effectiveness of using analogies as a teaching methodology in the learning of complicated concepts for high school courses of electrical circuits. For this purpose, using random clustering method of sampling, a population of 44 people was selected from the ...
Read More
The purpose of this research is to examine the effectiveness of using analogies as a teaching methodology in the learning of complicated concepts for high school courses of electrical circuits. For this purpose, using random clustering method of sampling, a population of 44 people was selected from the third year students of martyr Rajaie high school of Azarshahr city and then was divided into two classes which were called "experimental group" and "control group". In order to examine the effect of using analogies in the educational progress of students a pretest-post test randomized group design was used. The selected groups were examined using pretest. Students in "experimental group" were taught using analogical pattern in 8 sessions with 90 minutes duration. But students in "control group" were taught using conventional methods. In posttest stage, learning rates of students in the both groups were measured using verified test. Results showed that below the 0.05 level, there was not a significant difference between averages of educational progress grades of the both "experimental group" and "control group". This difference was more considerable in high levels of Blooms taxonomy below the 0.05 level. Therefore it can be concluded that using analogies have brought about educational progress for students especially in complicated levels of learning.
science education
M. Kaboudvand; A. Esmaeelpour; A. Badriyan; M. Shams
Abstract
The focus of this study was to clarify the degree of relationship between field Transfer of Learning by means of application in the modern physics (laser) and common field. To achieve this goal an intact group of 85 students in introductory level college in Shahreray zone in Tehran in Iran participated ...
Read More
The focus of this study was to clarify the degree of relationship between field Transfer of Learning by means of application in the modern physics (laser) and common field. To achieve this goal an intact group of 85 students in introductory level college in Shahreray zone in Tehran in Iran participated in test. The major objectives of the test were to investigate students’ transfer of physics learning from their experiences of watching laser applications to the provided physical models, from one model to the other and from the models to the modern physics (laser) problems. To find the degree of relationship between tow variables point- biserial correlation coefficient was used. To compare the mean scores of the tow variables the independent T-test technique was used. The result of the statistical analyses revealed that in the knowledge domain that was significant difference between the control and the experimental groups.
science education
S. Shamsaee; M.A. Shams
Abstract
The aim of this research is to investigate the relationship between English for Specific Purposes (ESP) teachers and students’ attitude toward learning needs and teaching activities. Mismatch between teachers and students’ expectations from ESP courses can result in undesired outcomes. In ...
Read More
The aim of this research is to investigate the relationship between English for Specific Purposes (ESP) teachers and students’ attitude toward learning needs and teaching activities. Mismatch between teachers and students’ expectations from ESP courses can result in undesired outcomes. In this study, the attitudes of 6 teachers and 60 students of Software Engineering toward ESP learning needs were surveyed by a questionnaire. The relationship between the ideas of these two groups was investigated through t-test analysis. The results show that ESP teachers and students think more alike about textbooks, and the incorporation of information processed through discourse and genre analysis, while recognizable differences can be observed in their view toward teaching activities, the place of language skills and components, and critical thinking. It is discussed that pedagogical mechanisms for applying the relevant principles of ‘rights analysis’ and ‘strategic planning’ in English classrooms need to be devised and appropriately applied in ESP programs.
science education
M.J. Maghrebi; M. Feyzabadi Farahani; A. Zarghami
Abstract
Theories of linear stability, reinforcement, or degradation of small disturbances examine the velocity applied to the average velocity of the flow. When the boundary layer flow expands linearly in the early stages of its development, the input boundary conditions of the computational domain are determined ...
Read More
Theories of linear stability, reinforcement, or degradation of small disturbances examine the velocity applied to the average velocity of the flow. When the boundary layer flow expands linearly in the early stages of its development, the input boundary conditions of the computational domain are determined using the results of the linear stability solution. In order to better adapt to laboratory results, spatial stability analysis is used. Using an algebraic mapping, the physical domain is converted to a computational domain. To solve the Or-Samerfeld equation, a spectral method has been used that has led to the solution of a special value problem. Comparing laboratory results and results of spatial and temporal perturbation stability analysis, it can be stated that spatial perturbation growth analysis more accurately describes the instability characteristics of the perturbation boundary flow. Small frequencies are much more accurate.
science education
Z. Nasiri Gheydari; H, Lesani; A. Darabi; F. Totonchian
Abstract
The use of a hysteresis motor in precision systems, such as inertial navigation and video recorders, requires rapid dynamics and precise control of the motor. The control system is a closed loop control system that speeds up the system's response speed, and in fact using it, alternating current motors ...
Read More
The use of a hysteresis motor in precision systems, such as inertial navigation and video recorders, requires rapid dynamics and precise control of the motor. The control system is a closed loop control system that speeds up the system's response speed, and in fact using it, alternating current motors are considered as a permanent current motor. Permanent flow motors are used in many applications that require precise control and rapid dynamic response. However, due to the many disadvantages of DC motors, such as high maintenance costs; The use of AC motors has been considered in drive systems. Therefore, the vector control method has also been used to improve the performance of AC motors. In this paper, the dynamic behavior of conventional hysteresis motor based on the two-axis model of d-q is examined and then its vector control system is simulated. In addition, the variables d and q are well separated and independently controlled using the feedback method. The results of the paper show that the use of this control method has had a significant effect on the dynamic increase of the system.
science education
S. Shirvani Moghadam; M. Jalali; H. Aminollahi
Abstract
In this paper, we first simulate ML, MUSIC, Root-MUSIC algorithms and space smoothing in noisy and fiddling environments, and then these algorithms are compared in terms of estimating the accuracy of the angles received from the two sources. By presenting the simulation results of four algorithms in ...
Read More
In this paper, we first simulate ML, MUSIC, Root-MUSIC algorithms and space smoothing in noisy and fiddling environments, and then these algorithms are compared in terms of estimating the accuracy of the angles received from the two sources. By presenting the simulation results of four algorithms in the form of tables that are based on mean, deviation from mean, variance of estimated angles and the percentage of successful experiments, it is observed that Root-MUSIC and MUSIC algorithms in terms of estimation and Detecting close angles is more accurate. In these two methods, the angles close to each other, up to about one degree, can be detected and separated. In addition, simulation results show that spatial smoothing algorithm is the most effective way to identify coherent resources.
science education
E. Reyhani
Abstract
Euclidean geometry has been taught to students in schools for many years. Topological structures are among the topics that have not received much attention in school geometry. The knot is one of the most suitable topics for teaching in school, which has a topological structure. In addition to being rooted ...
Read More
Euclidean geometry has been taught to students in schools for many years. Topological structures are among the topics that have not received much attention in school geometry. The knot is one of the most suitable topics for teaching in school, which has a topological structure. In addition to being rooted in human culture and experience, knots are a theoretical and practical field in mathematics, physics, biology, and chemistry. In this article, after a brief acquaintance with the nodes, an explanation for the title "Geometry of nodes" is given. In the first part of the article, in the first part, the reasons and analyzes for the selection of nodes and the importance of teaching it in school are explained, and in the second part, a proposed plan for teaching knot geometry to students is briefly presented. Experimental implementation of this project, in which one group of elementary school students and the other group including students from the third year of middle school and the first year of high school participated, has had satisfactory initial results.
science education
S. Olyaee; S. Mohammad Nejad
Abstract
Since 1970s the use of laser based range-finders has become a necessary part of many military and domestic systems. According to the needs and the circumstances, many different types of such systems have been developed and their technologies are adapted to the local needs. Distance or displacement measurement ...
Read More
Since 1970s the use of laser based range-finders has become a necessary part of many military and domestic systems. According to the needs and the circumstances, many different types of such systems have been developed and their technologies are adapted to the local needs. Distance or displacement measurement in the medium range is mainly divided to three groups; time of flight, frequency modulation continuous wave, and phase-shift laser range finder. In this paper we present the design, implementation and/or simulation of three such systems and compare their characteristics.
