Enhancing Learner Involvement in the Academic Subject of Electromagnetic Compatibility

Petre Ogrutan1, Ana-Maria Cazan2, Lia-Elena Aciu3

1Transilvania University of Braşov, Electronics and Computers Department 2Transilvania University of Braşov, Department of Psychology and Training in Education

3Transilvania University of Braşov, Electrical Engineering Department petre.ogrutan@unitbv.ro, ana.cazan@unitbv.ro, lia_aciu@unitbv.ro

Abstract- The paper presents the way in which the teaching

activities relating with the subject of Electromagnetic Compatibility were enhanced through applying some original methods of learner involvement. A brief history on this subject taught at the Faculty of Electrical Engineering and Computer Science of Transilvania University of Braşov is presented along with the course content. The actions proposed for enhanced involvement include fieldwork and mini-projects. The mini-projects were approached through the PBL-method (Project Based Learning). Specific questionnaires were used for data collection. The students were asked to express their opinions by completing these questionnaires at both the beginning and at the end of the course period. The obtained results were evaluated by solving a common problem area using specific methods depending on the field of study pursued by the students. The obtained results opened new horizons in developing and applying teaching methods based on learning through new projects and communication, intended for increasing the students’ degree of interest and satisfaction. The results provide the possibility of evaluating the differences at the level of academic performance depending on the students’ field of study. The acquired knowledge allowed for the implementation of several solutions for improving the teaching activity, thereby offering better opportunities for the integration of the students in the labour market.

I. INTRODUCTION

Like other higher education institutions, the Faculty of Electrical Engineering and Computer Science of Transilvania University of Braşov is confronted, among other aspects, with the problem of a heterogeneous pre-university education. The university applicants come from high schools with different degrees of education quality. Since Braşov is located in the centre of the country, students of different nationalities choose to pursue careers in Engineering at Transilvania University and Electrical Engineering appears to be a particularly attractive study field for both male and female students.

The great diversity among students raises various problems, especially in terms of differences between their education level. The teachers are engaged in a continuous endeavour to enhance the quality of the education process and its outcomes. With respect to this situation the teaching techniques in the subject of Electromagnetic Compatibility were based on a new conceptual approach. It intended to ensure equal educational opportunities for all students while emphasizing students’ involvement in solving several concrete project tasks, thus encouraging individual work and

communication both among students as well as among teachers and students.

A retrospective look shows that the first courses dealing with Electromagnetic Compatibility notions were held in the 1970’s at the Uppsala University of Sweden, Politecnico di Torino, Italy and the Federal Armed Forces University of Hamburg, Germany. The first course ever is considered the one delivered in 1982 at the University of York, U.K. [1]. Within the current context Clayton Paul promotes the introduction of this subject into the engineering education and proposes a syllabus along with a set of 11 simple laboratory projects [2]. The curriculum of Electrical Engineering was already overloaded since the 1990’, therefore new arguments had to be presented in support of this new subject, e.g. that the considered subject provides an impact on all facets of Electrical and Electronics Engineering [3]. The programme of the Grant University, developed in 1997, by the Society of Electromagnetic Compatibility within the frame of the Institute of Electrical and Electronic Engineers played an important role in the spread of this subject. The programme promoted the basic principles of electromagnetic compatibility for more than 10 years with remarkable results [4].

With the increased number of electronics applications, the subject of Electromagnetic Compatibility was increasingly adopted by more and more universities. As the teaching methods are becoming more diversified, there are more and more proposals for dividing the course material into a fundamentals section and an applications section [5,6]. One initiative [7] proposes a course of Electromagnetic Compatibility and Signal Integrity at beginner’s level, which shows that the importance of this subject is considered to be increasing. The association between electromagnetic compatibility and signal integrity is also mentioned by Abhari in relation with diversified applications, higher operating frequency and miniaturization [8]. The author proposes simulation of the studied phenomena and laboratory projects based on simulation of signal integrity. The development of new learning methods leads to an upgraded education process in the field of electromagnetic compatibility. Thus, Hellany and Nagrial present the initiative to introduce such a course at the Western Sidney University, for the electrical engineering fields as well as a non-electric field, Mechatronics [9]. This literature reference mentions a first application of PBL

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(Project Based Learning) for educational purposes in the field of the electromagnetic compatibility.

After 2010, education in the field of electromagnetic compatibility has reached the stage of maturity. Reference papers describe the experience of teaching this subject at Hong Kong City University [10]. Another valuable experience in this field was presented by Medrano, Arcega, Lopez, Plaza and Pollan [11]. However, the problems related with electromagnetic compatibility become increasingly complex and diversified and therefore impossible to be completely covered by the course material. Therefore, the authors propose a selection of fundamental aspects, in association with applications, with a special stress on the practical applications than on the mathematical aspects.

II. THE TEACHING METHODOLOGY OF ELECTROMAGNETIC COMPATIBILITY AT THE FACULTY OF ELECTRICAL

ENGINEERING AND COMPUTER SCIENCE

A. Brief history This subject was taught for the first time in the context of

Electrical Engineering in 1996. Since 2007 the subject was taught to the students from Applied Electronics and Telecommunications, by using the information from the previously acquired experience [12]. In 2007 as well, the Romanian Agency for Quality Assurance in Higher Education defines Electromagnetic Compatibility as a domain subject for both fields of Electrical Engineering and Applied Electronics and Telecommunications [13]. In 1999, the work group that initiated the introduction of this subject in the field of Applied Electronics, published a book to be used as course support for the students involved in the study of this subject [14]. The students were already expressing their interest in some specific problems of electromagnetic compatibility, while some of them observed the occurrence of electromagnetic interference phenomena in the devices they were building.

The course material was structured in order to provide enhanced practical knowledge about Electromagnetic Compatibility (EMC), while reducing the mathematical aspects to a minimum. Before delivering the course to the students, the author made short presentations for electronics specialists from the local industry. These lectures constituted the initial framework used to develop the course intended for the students. The course elaborated by Donald D. White [15] represents a landmark among the reference documents attempting to develop a harmonized syllabus for this subject.

B. Course content The subject of Electromagnetic Compatibility (EMC) is

taught to Electrical Engineering students in the fourth year of study and to the students in Applied Electronics in the third year of study. The course consists of lecture classes and laboratory sessions. The lecture material is structured in two sections:

• Fundamental notions; • Equipment examples and current aspects.

Choosing such a structure was determined by the need to familiarize the students with the fundamental principles of Electromagnetic Compatibility. However, the only possibility to maintain their interest in this subject was to provide concrete examples based on the daily applications of various electronic equipment.

The fundamental principles are presented in a similar manner by both syllabi. The common aspects for the two fields of study are:

• The importance of EMC. Brief history. Basic definitions: compatibility, interference, immunity, susceptibility. Specific units

• Norms and standards used in EMC, types of standards. Standardizing organizations.

• Inductive, capacitive and radiative couplings. Electromagnetic pulse. Lightning ElectroMagnetic Pulse (LEMP) and Nuclear ElectroMagnetic Pulse (NEMP).

• Shielding. Classification, shielding rules, special shielding, shielding calculation.

• EMC measurements. Measurement places, measuring equipment, measurement methods, compliance with standards.

• Interactions between electromagnetic fields and living matter. Standards for limiting values. Exposure to electromagnetic fields.

These fundamental aspects are supplemented with some specific elements. Thus, in Applied Electronics the teaching activities include specifically:

• Specific EMC aspects in analog circuits; • Specific EMC aspects in digital circuits. Reflections,

crosstalk, current surges, radiative perturbations. Digital signal integrity;

• EMC and the power grid. Filters and limiting elements; The Electrical Engineering study programme is

supplemented with: • The transient mode and the perturbations introduced in

low voltage power grids; • Electrical apparatus and equipment – sources of

perturbations to the operation of digital circuits; • Calculation of perturbing voltages using the electrical

circuit theory. A special remark should be made with respect to the

section describing the interactions between electromagnetic fields and living matter. People’s apprehensions regarding electromagnetic radiation exposure, particularly radiations generated by high voltage lines and mobile phones, were emphasized by mediatization of these phenomena, yet without reaching any clear conclusion. Approaching this problem area within the context of the course of Electromagnetic Compatibility should increase the students’ interest with respect to this subject. The lecture sessions become more dynamic engendering vivid debates among students and even plans for the future. In this context, a student developed a remotely controlled vehicle to measure the electrical field strength in transformer stations at the electrical power

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distribution company, where electrical and magnetic fields may reach levels that can be harmful to humans.

C. Laboratory activity For the laboratory activity the authors’ choice was the

Project Based Learning (PBL) method. The activities were conducted according to the same schedule like the traditional laboratory activity. At the first session, the students are given an assignment for individual or group work, which they must solve during laboratory sessions and by individual study.

The students were offered the possibility to freely choose their assignment, if they are interested in any particular aspect. During the last laboratory session the students provide a free Power Point presentation of the results obtained by the group. The advantages of this approach are:

1. increased responsibility for all students; 2. mixed group research training, by accessing several

online references or studying library-specific literature; 3. increased interest for team work regardless of

education level, opinions, ethnicity; 4. periodical, dynamic, free debates among students with

the teacher as moderator, to increase self-confidence in their future activity;

5. uniform training for preparing the students for any form of oral presentation of their achievements. Stimulating their relation-building ability by providing the adequate answers to questions addressed by fellow students with respect to the theme approached in the project.

The students from Applied Electronics and Telecommunications were advised to use the previously studied simulation programmes in order to evaluate the effects of electromagnetic interferences on their free-chosen assignment. Thus, they will be able to perform Spice and Simulink simulations at the moment of the final laboratory presentation.

Additionally, a laboratory session is dedicated to the measurement of electromagnetic field strength underneath high voltage power transmission lines and in the vicinity of GSM antennas. This activity was introduced as a consequence of the students’ increased interest for the interaction between electromagnetic fields and living matter. Measurements are performed by using portable spectrum analyzers connected to a notebook. Finally, the obtained results are interpreted and checked against the maximum allowed values.

A picture taken during one of the students’ practical activities including participants from both fields of study is presented in Fig.1.

Multiple examples of similar actions with the common participation of students and staff were published in various Conference Proceedings and Journals [16].

Fig. 1. Field strength measurement underneath high voltage power lines

III. DESCRIPTION OF THE PILOT STUDY INCLUDING STUDENTS FROM BOTH FIELDS OF STUDY

A. Objectives and participants The pilot study was conducted with Electrical Engineering

students, fourth study year and Applied Electronics students, third study year, in order to:

• identify the students’ attitude toward the subject of Electromagnetic Compatibility;

• establish associations between the students’ attitude with respect to the subject and to their own academic performance. Academic performance was measured by considering the marks obtained in this subject;

• evaluate the measure to which the achieved academic performance was influenced by the working method devised to create a constant framework for highlighting student capacities.

In order to determine the changes produced over time in the students’ attitude and to highlight the effects of the student-to-student interaction and of the interaction between students and teachers, the questionnaires were administered to the students at two distinctive times, after completing 5 lecture classes and a second time after the final semester examination. The study was based on a pre-test/post-test questionnaire. The lecture period comprised 14 weeks, 2 hours of class/week.

A number of 50 students were included in the pilot study, of which 17 students from Applied Electronics and 33 students from Electrical Engineering. Two students were of Hungarian nationality, the rest of Romanian nationality, 7 were female students and 43 male students.

B. Instruments A questionnaire consisting of 22 items, measured on a five

point Likert scale, was built. The questionnaire is structured on multiple dimensions: task difficulty perception (4 items), intrinsic motivation (2 items) versus extrinsic motivation (2 items), value assigned to the learning tasks at the mentioned subject (5 items), perceived utility of the task (4 items) and academic self-efficacy in terms of task-solving in Electromagnetic Compatibility (4 items). The construction of

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the questionnaire is based on a socio-cognitive approach of learning, placing learning in a specific context, by relating it to a taught subject, in accordance with the expectancy –learning value motivation theory [17]

After performing a scale analysis, the item 21 that determines the decrease of the Alfa Cronbach coefficient was eliminated. The final form includes 21 items with the 6 dimensions featuring good psychometric properties. The Alfa Cronbach coefficients take values between 0.51 and 0.83. The factorial analysis, based on the Varimax method confirms the existence of a 6-factor structure covering 69.9% of the common variance. The best represented factors are task value (factor 1, with a coefficient Alfa Cronbach of 0.83), self-efficacy (factor 2, Alfa Cronbach = 0.81), task usefulness (factor 3, Alfa Cronbach = 0.70), perception of difficulty (factor 4, Alfa Cronbach = 0.74), extrinsic motivation (factor 5, Alfa Cronbach = 0.53). With respect to intrinsic motivation (Factor 6, Alfa Cronbach = 0.51) the structure is uncertain, with item 12 grouped under factor 3.

From the perspective of the expectancy-value model, the value assigned to the task refers to the measure to which the task responds to the learner’s individual needs and it has a major impact on the individual’s choices. Those who consider themselves as competent in a particular field might not involve in tasks which they consider unimportant. Task value refers to the individual’s estimation of the degree of interest regarding the importance or the usefulness of the task. Academic self-efficacy refers to the individual’s beliefs about his own abilities to perform a task, which represents the expectancy component of the above-mentioned model. If individuals believe to be in control of both their own abilities and of the task, and if they are confident in their task-solving abilities it is more likely that they will involve themselves in that particular task and will perform well [18]. Task usefulness is the measure to which the task is included in the individual’s future plans. Orientation toward intrinsic goals refers to the measure to which the student involves in learning tasks for reasons of challenge and perfection, the involvement in the task being an end in itself rather than a means to an end. Orientation toward extrinsic goals refers to the measure to which an individual perceives himself as participating in a task for reasons of achieving marks, bonuses, performance recognition or competition. Perception of difficulty refers to the effort anticipated by the learner for achieving the proposed task.

C. Findings The main analysis criterion used in data processing was

considered the field of study. In order to highlight the efficiency of the applied teaching method and the evaluation of the motivational and attitude components regarding the learning process in the EMC subject, the differences between the two test phases were also analyzed.

The differences between pre-test and post-test phases for the entire sample are presented below. The t-test for paired samples demonstrates the existence of statistically significant

differences in the intrinsic motivation and self-efficacy dimensions. Thus, in the post-test phase, at the end of the semester, the students’ level of intrinsic motivation is definitely lower whereas the level of self-efficacy is significantly higher (Table 1).

As the students progress through the course material, they become increasingly confident in their capability to successfully solve the assigned exam tasks, given the same training framework. Demotivation can be explained through the high difficulty of the course material and the poor awareness of its usefulness. Task usefulness is a positive predictor of task persistence. The perception of the costs involved by a task and its perceived usefulness would direct the learner toward the use of certain types of strategies, involving different degrees of commitment, depending on the perceived difficulty [19]. A high score on each subscale indicates a high level for each dimension.

The results are also consistent with the values of Pearson’s correlation coefficients. The values of the post-test correlation coefficients between different questionnaire dimensions resulted lower in comparison to their pre-test counterparts. During the pre-test phase, moderate, yet statistically meaningful correlations were obtained between intrinsic motivation and the remaining components, as well as between academic self-efficacy and the remaining components. A significant difference can be ascertained with respect to the association between intrinsic motivation and perception of task difficulty: r(37) = 0.48, p<0.001. The significant correlations between task utility and the remaining components, between academic self-efficacy and extrinsic motivation (r =0.37, p < 0.001), but also between efficacy and task usefulness (r =0.46, p < 0.001) remain unchanged, however the associations between intrinsic motivation and other components become irrelevant.

TABLE 1

PRE-TEST/POST-TEST DIFFERENCES OVER THE WHOLE SAMPLE

Mean Std. Deviation

t df p

Task difficulty 1

Pre-test Post-test

2.57 2.54

0.68 0.60 0.15 19 0.87

Intrinsic motivation

Pre-test Post-test

3.85 3.15

0.89 0.54 3.39 19 0.003

Extrinsic motivation

Pre-test Post-test

3.17 3.55

1.10 1.09 -1.80 19 0.08

Task value Pre-test Post-test

3.72 3.88

0.59 0.72 -0.79 19 0.437

Task usefulness

Pre-test Post-test

3.37 3.68

0.71 0.72 -1.90 19 0.072

Self-efficacy

Pre-test Post-test

3.36 3.71

0.68 0.66 -3.11 19 0.006

The obtained results are consistent with the outcomes of the

applied t-test. The results show that the expectancies of success are playing an important role in the learning process, due to their association with intrinsic motivation and high

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value assigned to the learning task. These results are also consistent with other studies [20].

A comparison between attitudes of the students from the two fields of study shows that although the two fields of study use different teaching methods the results obtained in terms of students’ instruction are relatively similar (Table 2).

Due to the small number of students in a group, a nonparametric test, the Wilcoxon test was chosen. The results obtained for each of the two analyzed groups are similar with the results obtained for the whole sample. The intrinsic motivation for learning is higher in the pre-test phase than in the post-test phase, which shows a slight demotivation at the end of the semester, regardless of the applied teaching method. With regard to the academic self-efficacy it could be ascertained that the students from Applied Electronics have a significantly higher level of self-efficacy during the post-test phase compared to pre-test phase. With regard to the second group, the differences are statistically irrelevant, which could be explained through the use of a different work method in the case of the first group (Table 3).

Another goal of this research was to identify the associations between the students’ attitude toward the subject of Electromagnetic Compatibility and the academic performance obtained in this subject in terms of equal access to the education method and by simulating the capacities of each individual, in order to maximize the outcomes.

Two statistically significant correlations were obtained between task value and the final average mark for the considered subject and between self-efficacy and performance (Table 4).

TABLE 2

DIFFERENCES BETWEEN THE AVERAGE MARKS OBTAINED DURING THE TWO TEST PHASES BY THE STUDENTS FROM THE

TWO FIELDS OF STUDY Dimension Phase Applied

Electronics N=9

Electrical Engineering

N=9 Perception of task difficulty 1

Pre-test Post-test

2.77 2.73

2.40 2.38

Intrinsic motivation

Pre-test Post-test

3.88 3.22

3.81 3.09

Extrinsic motivation

Pre-test Posttest

2.77 3.00

3.50 4.00

Task value Pre-test Post-test

3.82 4.08

3.63 3.70

Task usefulness Pre-test Post-test

3.50 3.72

3.27 3.65

Self-efficacy Pre-test Post-test

3.08 3.44

3.59 3.93

The obtained results are consistent with the research work

conducted in this field which shows that expectancy and task value are performance predictors. The value assigned to the task predicts the intentions as well as the actual decision of involvement in the learning activities. The correlations between motivation and performance are statistically

irrelevant. This situation was also observed by other studies in this field [21, 22]. This can be explained through the occurrence of averaging effects in the relationship between motivation and performance, produced by variables such as intelligence, learning strategies, level of previous academic results. As the individuals obtain increasingly better results, they improve their self-efficacy and, vice versa, a high self-efficacy will foster the individuals’ efforts to face new challenges, to acquire new learning experiences, to optimize their learning and problem-solving strategies [23]. A high self-efficacy is associated with the use of self-regulatory learning strategies and high performance achievement [24, 25, 26].

TABLE 3

STATISTICAL SIGNIFICANCE OF THE DIFFERENCES BETWEEN AVERAGE MARKS DURING THE TWO PHASES

Field of study

Applied Electronics

Electrical Engineering

Posttest - Pretest

Z Sig.(2-tailed)

Z Sig.(2-tailed)

Perception difficulty -0.179a 0.858 -0.178a 0.859

Intrinsic motivation -1.997a 0.046 -2.005a 0.045

Extrinsic motivation -0.857b 0.391 -1.377b 0.169

Task value -1.127b 0.260 -0.461b 0.645 Task

usefulness -0.938b 0.348 -1.431b 0.152

Self-efficacy -2.070b 0.038 -1.655b 0.098 a. Based on positive ranks. b. Based on negative ranks.

TABLE 4

CORRELATION COEFFICIENTS BETWEEN ACADEMIC PERFORMANCE AND THE COMPONENTS OF LEARNING ATTITUDE

IN THE EMC SUBJECT (N=38) r p

Perception difficulty -0.152 0.362

Intrinsic motivation 0.075 0.654

Extrinsic motivation 0.029 0.863

Task value 0.455 0.004

Task usefulness 0.282 0.087

Self-efficacy 0.566 0.000

IV. CONCLUSIONS

The obtained results confirm the current research in this field, according to which, academic self-efficacy along with the motivational components, such as intrinsic motivation or task value are predictors of academic performance. Also, the results confirm that the expectancy – value model is adequate for explaining the factors that underlie the academic learning activity of the groups of students from different fields of study.

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The future research directions envisage the implementation of an experimental programme devised to highlight the effects produced on academic performance by applying the teaching-learning methods in an equitable and creative way. Moreover, the questionnaire should be improved in order to be administered to a larger group of subjects. Future research may include other variables into the study, such as the learning strategies used by the students, in order to highlight the mediation effects that these variables might have relative to the connection between motivational beliefs and academic performance.

Subsequently to the anonymous analysis performed by the University regarding the students’ feedback, independently of the present study, the degree of satisfaction of the students from Applied Electronics with respect to the subject was 4.36, while the teachers’ performance scored 4.50 points from a total of maximum 5 points. The students from Electrical Engineering assigned the subject with 4.80 pts, while the performance of the other teacher scored 4.57 pts. These results confirm the fact that the way in which the authors have approached the considered subject was successfully and has offered educational satisfaction to all students.

The two fields of study feature structural differences in terms of student nationality and percentage of female students of the total number of students. Thus, in comparison with Electrical Engineering, the number of female students in Electronics increases every year since Electronics is perceived as a more subtle and therefore more adequate specialization for women.

The conclusions obtained after analyzing the questionnaires indicate a great similarity between the students’ opinions and their academic performance in both fields of study. This confirms that the teaching and assessment methods applied during lecture classes, laboratory sessions as well as the examination period ensure equal educational conditions regardless of gender, nationality or fields of study.

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