\r\n\tThe LED can be lingering further into three major categories are (i) Traditional inorganic LEDs, (ii) Organic LEDs (Small Molecule OLED, Polymer LED, Passive Matrix OLED Active Matrix OLED), (iii) High brightness LEDs, (iv) Deep-UV LEDs, (v) Active Matrix Organic Light-Emitting Diodes (AMOLED).
",isbn:"978-1-83968-886-7",printIsbn:"978-1-83968-885-0",pdfIsbn:"978-1-83968-887-4",doi:null,price:0,priceEur:0,priceUsd:0,slug:null,numberOfPages:0,isOpenForSubmission:!1,hash:"97e861d1556a639f0e5cc6ee8bdb0a0f",bookSignature:"Prof. Jagannathan Thirumalai",publishedDate:null,coverURL:"https://cdn.intechopen.com/books/images_new/10559.jpg",keywords:"Aluminum Gallium Arsenide, Gallium Arsenide Phosphide, Indium Phosphide, Thin-Film-Display, Organic Rare-Earth Complexes, Colour Rendering Index, High Brightness Leds, Luminous Control, Air Purification, Skin Therapy, Organic Compounds Form the Electroluminescent Material, Specific Type of Thin-Film-Display",numberOfDownloads:4,numberOfWosCitations:0,numberOfCrossrefCitations:0,numberOfDimensionsCitations:0,numberOfTotalCitations:0,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"September 21st 2020",dateEndSecondStepPublish:"October 19th 2020",dateEndThirdStepPublish:"December 18th 2020",dateEndFourthStepPublish:"March 8th 2021",dateEndFifthStepPublish:"May 7th 2021",remainingDaysToSecondStep:"3 months",secondStepPassed:!0,currentStepOfPublishingProcess:4,editedByType:null,kuFlag:!1,biosketch:"As an expert in the optoelectronics and nanotechnology area, Dr.Thirumalai has been invited to examine several MSc and Ph.D. theses, invited to give a talk in various forums, and to review papers for international and national journals.",coeditorOneBiosketch:null,coeditorTwoBiosketch:null,coeditorThreeBiosketch:null,coeditorFourBiosketch:null,coeditorFiveBiosketch:null,editors:[{id:"99242",title:"Prof.",name:"Jagannathan",middleName:null,surname:"Thirumalai",slug:"jagannathan-thirumalai",fullName:"Jagannathan Thirumalai",profilePictureURL:"https://mts.intechopen.com/storage/users/99242/images/system/99242.png",biography:"Dr. J. Thirumalai received his Ph.D. from Alagappa University, Karaikudi in 2010. \n\nHe was awarded the Post-doctoral Fellowship from Pohang University of Science and Technology (POSTECH), Republic of Korea, in 2013.\nHe worked as an Assistant Professor of Physics, B.S. Abdur Rahman University, Chennai, India (2011 to 2016). \nCurrently, he is working as an Assistant Professor & Head of the Department of Physics, SASTRA Deemed to be University, Kumbakonam (T.N.), India. \n\nHis research interests focus on luminescence, self-assembled nanomaterials, thin-film optoelectronic devices & Supercapacitors. \n\nHe has published more than 60 SCOPUS/ISI indexed papers, 11 book chapters, and he edited 5 books. He is serving as a member in various national and international societies. Currently, he is acting as a principal investigator for a funded project towards the application of luminescence-based thin-film optoelectronic devices, funded by the Science and Engineering Research Board (SERB), India. \nAs an expert in optoelectronics and nanotechnology area, he has been invited to examine several MSc and Ph.D. theses, invited to give a talk in various forums and to review papers for international and national journals.",institutionString:"SASTRA University",position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"10",totalChapterViews:"0",totalEditedBooks:"6",institution:{name:"SASTRA University",institutionURL:null,country:{name:"India"}}}],coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"11",title:"Engineering",slug:"engineering"}],chapters:[{id:"74673",title:"Economic Applications for LED Lights in Industrial Sectors",slug:"economic-applications-for-led-lights-in-industrial-sectors",totalDownloads:5,totalCrossrefCites:0,authors:[{id:"150046",title:"Prof.",name:"Muhammad M.A.S.",surname:"Mahmoud",slug:"muhammad-m.a.s.-mahmoud",fullName:"Muhammad M.A.S. Mahmoud"}]}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"},personalPublishingAssistant:{id:"297737",firstName:"Mateo",lastName:"Pulko",middleName:null,title:"Mr.",imageUrl:"https://mts.intechopen.com/storage/users/297737/images/8492_n.png",email:"mateo.p@intechopen.com",biography:"As an Author Service Manager my responsibilities include monitoring and facilitating all publishing activities for authors and editors. From chapter submission and review, to approval and revision, copyediting and design, until final publication, I work closely with authors and editors to ensure a simple and easy publishing process. I maintain constant and effective communication with authors, editors and reviewers, which allows for a level of personal support that enables contributors to fully commit and concentrate on the chapters they are writing, editing, or reviewing. I assist authors in the preparation of their full chapter submissions and track important deadlines and ensure they are met. I help to coordinate internal processes such as linguistic review, and monitor the technical aspects of the process. As an ASM I am also involved in the acquisition of editors. 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\n\t\t\t
1. Introduction
\n\t\t\t
Student evaluation is the process of determining the performance levels of individual students in relation to educational learning objectives. A high quality evaluation system certifies, supports, and improves individual achievement and ensures that all students receive a fair evaluation in order not to constrain students\' present and future prospects. Thus, the system should regularly be reviewed and improved to ensure that it is suitable, fair, impartial and beneficial to all students. It is also desirable that the system is transparent and automation measures should be embedded in the evaluation. Fuzzy reasoning has proven beneficial to infer scores of students (e.g. Saleh & Kim, 2009). However, in order to improve the reliability and robustness of the system, Gaussian membership functions (MFs) are proposed as an alternative to the traditional triangular MFs.
\n\t\t\t
Since its introduction in 1965 by Lotfi Zadeh (1965), the fuzzy set theory has been widely used in solving problems in various fields, and recently in educational evaluation. Biswas (1995) presented two methods for evaluating students’ answer scripts using fuzzy sets and a matching function; a fuzzy evaluation method and a generalized fuzzy evaluation method. Chen and Lee (1999) presented two methods for applying fuzzy sets to overcome the problem of rewarding two different fuzzy marks the same total score which could result from Biswas’ method (1995). Echauz and Vachtsevanos (1995) proposed a fuzzy logic system for translating traditional scores into letter-grades. Law (1996) built a fuzzy structure model for an educational grading system with its algorithm aimed at aggregating different test scores in order to produce a single score for an individual student. He also proposed a method to build the MFs of several linguistic values with different weights. Wilson, Karr and Freeman (1998) presented an automatic grading system based on fuzzy rules and genetic algorithms. Ma and Zhou (2000) proposed a fuzzy set approach to assess the outcomes of Student-centered learning using the evaluation of their peers and lecturer. Wang and Chen (2008) presented a method for evaluating students’ answer scripts using fuzzy numbers associated with degrees of confidence of the evaluator. From the previous studies, it can be found that fuzzy numbers, fuzzy sets, fuzzy rules, and fuzzy logic systems are and have been used for various educational grading systems.
\n\t\t\t
Evaluation strategies based on fuzzy sets require a careful consideration of the factors included in the evaluation. Weon and Kim (2001) pointed out that the system for students’ achievement evaluation should consider three important factors of the questions which the students answer: the difficulty, the importance, and the complexity. Singleton functions were used to describe the factors of each question reflecting the effect of the three factors individually, but not collectively. Bai and Chen (2008b) stressed that the difficulty factor is a very subjective parameter and may cause an argument about fairness in the evaluation.
\n\t\t\t
The automatic construction of the grade MFs of fuzzy rules for evaluating student’s learning achievement has been attempted (Bai & Chen, 2008a). Also, Bai and Chen (2008b) proposed a method for applying fuzzy MFs and fuzzy rules for the same purpose. To solve the subjectivity of the difficulty factor embedded in the method of Weon and Kim (2001), Bai and Chen (2008b) acquired the difficulty parameter as a function of accuracy of the student’s answer script and time used for each question. However, their method still has the subjectivity problem, since the resulting scores and rankings are heavily dependent on the values of several weights which are assessed by the subjective knowledge of domain experts.
\n\t\t\t
\n\t\t\t\tSaleh and Kim (2009) proposed a three node fuzzy logic approach based on Mamdani’s fuzzy inference engine and the centre-of-gravity (COG) defuzzification technique as an alternative to Bai and Chen’s method (2008b). The transparency and objective nature of the fuzzy system makes their method easy to understand and enables teachers to explain the results of the evaluation to sceptic students. The method involved conventional triangular MFs of fixed parameters which could result in different results when changed. In this chapter, the Gaussian MFs are proposed as an alternative and a sensitivity study is conducted to get the appropriate values of their parameters for a more robust evaluation system.
\n\t\t\t
The chapter will be organized as follows: In Section 2, a review of the three nodes fuzzy evaluation method based on triangular MFs is introduced. In Section 3, Gaussian MFs are proposed for a more robust evaluation system. A comparison of the two methods is presented in Section 4. Conclusions are drawn in Section 5.
\n\t\t
\n\t\t
\n\t\t\t
2. A review of the three nodes fuzzy evaluation system
\n\t\t\t
The method proposed by Bai and Chen (2008b) has several empirical weights which are determined subjectively by the domain expert. Quite different ranks can be obtained depending on these weight values. By using this method, the examiners could not easily verify how new ranks are acquired and could not persuade sceptical students. Naturally, there is no method to determine the optimum values of these weights. Also, the weighted arithmetic mean formula used to compute the outputs do not satisfy the concept of fuzzy set. To reduce the degree of subjectivity in this method and provide a method based on the theory of fuzzy set, Saleh and Kim (2009) proposed a system applying the most commonly used Mamdani’s fuzzy inference mechanism (Mamdani, 1974) and center of gravity (COG) defuzzification technique. In this way, the system is represented as a block diagram of fuzzy logic nodes as shown in Fig. 1. The model of Bai and Chen (2008b) can be considered as a simple specific case of the block diagram by replacing each node with a weighted arithmetic mean formula. The system consists of three nodes; the difficulty node, the cost node and the adjustment node. Each node of the system behaves like a fuzzy logic controller (FLC in Fig. 1) with two scalable inputs and one output, as in Fig. 2. Each FLC maps a two-to-one fuzzy relation by inference through a given rule base.
\n\t\t\t
Figure 1.
Block diagram of the three nodes fuzzy evaluation system.
\n\t\t\t
Figure 2.
Node representation as a fuzzy logic controller.
\n\t\t\t
The inputs to the system in the left hand side of Fig. 1 are given by examination results and domain experts. Assume that there are n students to answer m questions. From examination results, we get an accuracy rate matrix, A, of dimension m x n, which is the student’s scores in each question divided by the maximum score assigned to this question
\n\t\t\t
\n\t\t\t\tA = [a\n\t\t\t\t\n\t\t\t\t\tij\n\t\t\t\t], m x n,
\n\t\t\t
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\ta\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\tj\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the accuracy rate of student j on question i. We also get a time rate matrix, T, of dimension m x n, which is the time used by a student to solve a question divided by the maximum time allowed to solve this question
\n\t\t\t
\n\t\t\t\tT = [t\n\t\t\t\t\n\t\t\t\t\tij\n\t\t\t\t], m x n,
\n\t\t\t
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tt\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\tj\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the time rate of student j on question i. We are also given a grade vector, G, of dimension m x 1
\n\t\t\t
\n\t\t\t\tG = [g\n\t\t\t\t\n\t\t\t\t\ti\n\t\t\t\t], m x 1,
\n\t\t\t
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tg\n\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t100\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the assigned maximum score of question i satisfying
Based on the accuracy rate matrix, A, and the grade vector G, we obtain the total score vector of dimension n x 1,
\n\t\t\t
\n\t\t\t\tS = ATG = [s\n\t\t\t\t\n\t\t\t\t\tj\n\t\t\t\t], n x 1,
\n\t\t\t
where s\n\t\t\t\t\n\t\t\t\t\tj\n\t\t\t\t\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t100\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\tis the total score of student j. The “classical” ranks of students are then obtained by sorting the element values of S in descending order.
\n\t\t
\n\t\t
\n\t\t\t
Example. Assume that 10 students laid to an exam of 5 questions and the accuracy rate matrix, the time rate matrix, and the grade vector are given as follows (Bai & Chen, 2008b, Saleh & Kim, 2009):
where S\n\t\t\t\t\n\t\t\t\t\ta\n\t\t\t\t> S\n\t\t\t\t\n\t\t\t\t\tb\n\t\t\t\t means that the score of student a is higher than score of student b and S\n\t\t\t\t\n\t\t\t\t\ta\n\t\t\t\t = S\n\t\t\t\t\n\t\t\t\t\tb\n\t\t\t\t means that their scores are equal.
\n\t\t\t
From the domain expert, we get the importance matrix, P, of dimension m x l which describes the degree of importance of each question in the fuzzy domain.
\n\t\t\t
\n\t\t\t\tP = [p\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t], m x l,
\n\t\t\t
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tp\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\tk\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the degree of importance of question i belonging to the importance level k. Here, five levels of importance (l = 5) are represented by five fuzzy sets; k = 1 representing the linguistic term “low”, k = 2 representing “more or less low”, k = 3 representing “medium”, k = 4 representing “more or less high” and k = 5 representing “high”. The MFs are shown in Fig. 3. Once crisp values are given as a vector for the importance of questions by a domain expert, the values of fuzzy importance matrix or p\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t’s are obtained by the fuzzification.
\n\t\t\t
Figure 3.
Triangular membership functions of the five levels.
\n\t\t\t
It is noted that the same five fuzzy sets, shown in Fig. 3, are applied to represent the accuracy, the time rate, the difficulty, the complexity, and the adjustment of questions in the fuzzy domain.
\n\t\t\t
We are also given the complexity matrix of dimension m x l, which is an important factor indicating the ability of students to give correct answers of complex questions
\n\t\t\t
\n\t\t\t\tCo = [co\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t], m x 1,
\n\t\t\t
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tc\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\to\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\tk\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the degree of complexity of question i belonging to the complexity level k.
\n\t\t
\n\t\t
\n\t\t\t
Example. For the above example we get the following, in fuzzy domain, by the domain expert:
As a primary step, the inputs from the examination results are averaged and fuzzified based on the defined levels (fuzzy sets) in Fig. 3. The average accuracy rate vector of dimension m x 1 is obtained as
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\ta\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\t•\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the average accuracy rate of question i which is obtained by
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tt\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\t•\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the average time rate of question i which is obtained by
Next, by fuzzification, we obtain the fuzzy accuracy rate matrix of dimension m x l,
\n\t\t\t
\n\t\t\t\tFA = [fa\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t], m x l,
\n\t\t\t
where fa\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\tdenotes the membership value of the average accuracy rate of question i belonging to level k, and the fuzzy time rate matrix of dimension m x l,
\n\t\t\t
\n\t\t\t\tFT = [ft\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t], m x l,
\n\t\t\t
where ft\n\t\t\t\t\n\t\t\t\t\tik\n\t\t\t\t\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t∈\n\t\t\t\t\t\t\t\t[\n\t\t\t\t\t\t\t\t0\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t1\n\t\t\t\t\t\t\t\t]\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t denotes the membership value of the average time rate of question i belonging to level k, respectively.
\n\t\t
\n\t\t
\n\t\t\t
Example. For the above by formula (2) and formula (3), respectively, we get
In the first node, both inputs are given by examination results, whereas in the later nodes, one input is the output of its previous node and the other is given by a domain expert. The output of each node can be in the form of a crisp value (defuzzified) or in the form of linguistic variables (MFs). Each node has two scale factors (SFs in Fig. 1). We can adjust the effects of inputs by varying the values of scale factors. Here, we let both scaling factors have the same value of unity assuming equal influence of each input on the output. Each fuzzy node proceeds in three steps:
\n\t\t\t
\n\t\t\t\tStep 1 (Fuzzification). In this step, if given in crisp sets, inputs are converted into membership values in the fuzzy sets shown in Fig. 3. Triangular MF is the commonly used due to its simplicity and easy computation.
\n\t\t\t
\n\t\t\t\tStep 2 (Inference). Here, inference is performed based on the given rule base, in the form of IF–THEN rules. We use Mamdani’s max-min inference mechanism which is the most commonly used inference mechanism to produce fuzzy sets for defuzzification (1974). In Mamdani’s max-min mechanism, implication is modelled by means of minimum operator, and the resulting output MFs are combined using maximum operator.
\n\t\t\t
The inference mechanism can be written into the form:
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\tα\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\t\tk\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\tis the output of inference (i.e. the fire-strength) of question i in fuzzy set k. A matrix of dimension m x l is then obtained as
\n\t\t\t\tStep 3 (Defuzzification). In this step, fuzzy output values are converted into a single crisp value or final decision. Here, the COG method is applied. The crisp value of question i is obtained by
where integrals are taken over the entire range of the output where µ(x) is obtained from step 2. By using the COG method, a computable and reliable crisp value can be obtained. The proposed system has been implemented using the Fuzzy Logic Toolbox™ 2.2.7 by MathWorks (http://www.mathworks.com/products/fuzzylogic).
\n\t\t\t
In order to obtain the adjustment vector, each of the three nodes follows the above scheme. The difficulty node has two inputs comprising the accuracy rate and the time rate, and one output displaying the difficulty. The cost node has two inputs comprising difficulty and complexity, and one output displaying the cost. Likewise, the adjustment node has two inputs comprising cost and importance, and one output displaying the resulting adjustment.
\n\t\t\t
The adjustment vector, W, is then used to obtain the adjusted grade vector of dimension m x 1,
where \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\tg\n\t\t\t\t\t\t\t\t\t\t˜\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\ti\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t is the adjusted grade of question i,
New and modified ranks of students are then obtained by sorting element values of \n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\tS\n\t\t\t\t\t\t\t\t˜\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t in descending order.
\n\t\t
\n\t\t
\n\t\t\t
Example. By referring to Fig. 1, the average values of A and T in the difficulty node are computed using formula (2) and formula (3) and then fuzzified, in step 1, to obtain the fuzzy matrices FA and FT, respectively. Next, as an example for step 2, the output for question 1 in level 4 (fuzzy set “more or less high”) is computed based on the rule base given in Table 1a. The computation uses the Mamdani’s fuzzy interference mechanism and is obtained by formula (7) as the following:
In Step 3, we use COG to compute the crisp value of the difficulty of question 1 by formula (8) as 0.576, as illustrated in Fig. 4. Likewise, we compute the crisp values of other questions as
In Step 2, based on the rule base given in Table 1b, we obtain the inference output (i.e. the fire-strength) of the cost matrix as a function of the fuzzy difficulty and fuzzy complexity matrices by formula (7) as:
In Step 2, based on the rule base given in Table 1c, we obtain the inference output (i.e. the fire-strength) of the adjustment matrix as a function of the fuzzy cost and fuzzy importance matrices by formula (7) as:
The surface view of the rule base in Table 1c for the adjustment is typically that of effort shown in Fig. 5. In Step 3, the crisp values of adjustment are obtained as:
3. Three nodes system based on Gaussian membership functions
\n\t\t\t
The three nodes fuzzy evaluation system described in Section 2 is based on triangular MF’s which are the simplest MF’s formed using straight lines. Triangular MFs are defined by three parameters and there is no way to acquire its optimum values. It was noted that when theses parameters are changed slightly, different ranking orders are obtained which could impair the system’s reliability. In order to avoid losing reliability and having a robust system, the system should be able to give the same ranking orders without changing students’ scores and for various values of these parameters. As an alternative approach, Gaussian MF’s are proposed. Gaussian MF’s are suitable for problems which require continuously differentiable curves and therefore smooth transitions, whereas the triangular do not posses these abilities. Gaussian MF’s are defined by two parameters which is one parameter less than that of the triangular MF’s. The tuning of a reduced number of parameters will result in a reduced Degree Of Freedom (DOF) and hence a more robust system. Gaussian MF’s is defined as
Where c\n\t\t\t\t\n\t\t\t\t\ti\n\t\t\t\t is the center (i.e., mean) of the i\n\t\t\t\tth fuzzy set and σ\n\t\t\t\t\n\t\t\t\t\ti\n\t\t\t\t is the width (i.e., standard deviation) of the i\n\t\t\t\tth fuzzy set, which have by nature, infinite support (i.e., every control point influences the whole calculations of the output) (Lohani et al., 2007). Therefore, for Gaussian MF’s with wide widths it is possible to obtain a membership degree to each fuzzy set greater than 0 and hence every rule in the rule base fires. Consequently, the relationship between input and output can be described accurate enough. Here, the centres of the five Gaussian MF’s are chosen to be the same as that of the triangular MFs shown in Fig. 3 (i.e. [0.1 0.3 0.5 0.7 0.9]). Gaussian MF’s of the five levels for = 0.1 are shown in Fig. 6. From Fig. 6, it is obvious that Gaussian MF’s provide more continuous transition from one interval to another and hence provides smoother control surface from the fuzzy rules. The surface view of the rule base in Table 1a and b for Gaussian MFs of = 0.1 are shown in Fig. 7.
\n\t\t\t
Figure 6.
Gaussian membership functions of the five levels for = 0.1.
\n\t\t
\n\t\t
Figure 7.
Surface view of rule base in Table 1a (left) and in Table 1b (right) for Gaussian MFs of = 0.1.
\n\t\t
\n\t\t\t
Example. The width of the Gaussian MF’s, , is varied between 0.05 and 12 in steps of 0.05 and the three nodes fuzzy system based on Gaussian MF’s is applied to the same example introduced in Section 2. The new total scores of the students are then obtained using formula (11) as shown in Table 2.
\n\t\t\t
The mean of the new scores of the 10 students is computed for each value of the membership width, , and is shown in Fig. 8. From the figure, it is obvious that the mean of the new scores is equal to the mean of the classical scores obtained using formula (1) for membership width of 4.0 and higher. Although the new scores, rounded to two digits, are equal, the system is still able to give the correct ranking order of the students with equal total scores.
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1"/
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2"/
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3"/
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4"/
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5"/
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6"/
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"/7
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"/8
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"/9
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10
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.05
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
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10
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4
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6
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5
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7
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8
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3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.59
\n\t\t\t\t\t\t
65.00
\n\t\t\t\t\t\t
52.58
\n\t\t\t\t\t\t
51.43
\n\t\t\t\t\t\t
50.80
\n\t\t\t\t\t\t
50.22
\n\t\t\t\t\t\t
48.31
\n\t\t\t\t\t\t
48.30
\n\t\t\t\t\t\t
48.16
\n\t\t\t\t\t\t
43.22
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.10
\n\t\t\t\t\t\t
9
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1
\n\t\t\t\t\t\t
2
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4
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6
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10
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8
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5
\n\t\t\t\t\t\t
7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.36
\n\t\t\t\t\t\t
64.27
\n\t\t\t\t\t\t
53.24
\n\t\t\t\t\t\t
52.12
\n\t\t\t\t\t\t
51.78
\n\t\t\t\t\t\t
51.43
\n\t\t\t\t\t\t
49.49
\n\t\t\t\t\t\t
48.44
\n\t\t\t\t\t\t
48.31
\n\t\t\t\t\t\t
41.77
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.15
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9
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1
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2
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4
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6
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10
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8
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5
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7
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3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.54
\n\t\t\t\t\t\t
64.55
\n\t\t\t\t\t\t
53.59
\n\t\t\t\t\t\t
51.49
\n\t\t\t\t\t\t
50.93
\n\t\t\t\t\t\t
50.89
\n\t\t\t\t\t\t
50.44
\n\t\t\t\t\t\t
48.65
\n\t\t\t\t\t\t
47.80
\n\t\t\t\t\t\t
40.91
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.20
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9
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1
\n\t\t\t\t\t\t
2
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8
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4
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10
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6
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5
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7
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3
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\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.66
\n\t\t\t\t\t\t
64.61
\n\t\t\t\t\t\t
53.78
\n\t\t\t\t\t\t
51.12
\n\t\t\t\t\t\t
50.87
\n\t\t\t\t\t\t
50.44
\n\t\t\t\t\t\t
50.13
\n\t\t\t\t\t\t
48.96
\n\t\t\t\t\t\t
47.26
\n\t\t\t\t\t\t
40.09
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.25
\n\t\t\t\t\t\t
9
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1
\n\t\t\t\t\t\t
2
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8
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4
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10
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6
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5
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7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.74
\n\t\t\t\t\t\t
64.61
\n\t\t\t\t\t\t
53.87
\n\t\t\t\t\t\t
51.52
\n\t\t\t\t\t\t
50.49
\n\t\t\t\t\t\t
50.18
\n\t\t\t\t\t\t
49.67
\n\t\t\t\t\t\t
49.17
\n\t\t\t\t\t\t
46.90
\n\t\t\t\t\t\t
39.57
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.30
\n\t\t\t\t\t\t
9
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1
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2
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8
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4
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10
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6
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5
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7
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3
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84.79
\n\t\t\t\t\t\t
64.61
\n\t\t\t\t\t\t
53.93
\n\t\t\t\t\t\t
51.74
\n\t\t\t\t\t\t
50.26
\n\t\t\t\t\t\t
50.03
\n\t\t\t\t\t\t
49.40
\n\t\t\t\t\t\t
49.31
\n\t\t\t\t\t\t
46.68
\n\t\t\t\t\t\t
39.25
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
0.35
\n\t\t\t\t\t\t
9
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1
\n\t\t\t\t\t\t
2
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8
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4
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10
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5
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6
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7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.83
\n\t\t\t\t\t\t
64.61
\n\t\t\t\t\t\t
53.96
\n\t\t\t\t\t\t
51.89
\n\t\t\t\t\t\t
50.12
\n\t\t\t\t\t\t
49.94
\n\t\t\t\t\t\t
49.41
\n\t\t\t\t\t\t
49.24
\n\t\t\t\t\t\t
46.54
\n\t\t\t\t\t\t
39.04
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
4.0~12.0
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
\n\t\t\t\t\t\t
8
\n\t\t\t\t\t\t
4
\n\t\t\t\t\t\t
10
\n\t\t\t\t\t\t
5
\n\t\t\t\t\t\t
6
\n\t\t\t\t\t\t
7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.95
\n\t\t\t\t\t\t
64.60
\n\t\t\t\t\t\t
54.05
\n\t\t\t\t\t\t
52.30
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
48.80
\n\t\t\t\t\t\t
46.10
\n\t\t\t\t\t\t
38.40
\n\t\t\t\t\t
\n\t\t\t\t
Table 2.
New total scores and new ranking orders of 10 students using the three fuzzy nodes system based on Gaussian MF’s
\n\t\t
\n\t\t
Figure 8.
Mean scores of the 10 students ranked using classical method (dotted line) and the three nodes fuzzy system based on Gaussian MF’s (solid line).
\n\t\t
\n\t\t\t
4. Comparison of the methods
\n\t\t\t
The ranking order has been obtained when the three nodes fuzzy system based on triangular MF’s are applied to students with equal total scores. When the three nodes fuzzy system based on triangular membership functions is applied to all students, new scores and hence new rankings are obtained. When the three nodes system based on Gaussian membership of width of 4.0 is applied to all students, the resultant new total scores of students rounded to two digits are equal to that of the classical scores but with new ranking orders. Ranking orders and scores of students are shown in Table 3.
\n\t\t\t
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\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
Ranking method
\n\t\t\t\t\t\t
1"/
\n\t\t\t\t\t\t
2"/
\n\t\t\t\t\t\t
3"/
\n\t\t\t\t\t\t
4"/
\n\t\t\t\t\t\t
5"/
\n\t\t\t\t\t\t
6"/
\n\t\t\t\t\t\t
"/7
\n\t\t\t\t\t\t
"/8
\n\t\t\t\t\t\t
"/9
\n\t\t\t\t\t\t
10
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
Classical
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
\n\t\t\t\t\t\t
8
\n\t\t\t\t\t\t
4=
\n\t\t\t\t\t\t
5=
\n\t\t\t\t\t\t
10=
\n\t\t\t\t\t\t
6
\n\t\t\t\t\t\t
7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.95
\n\t\t\t\t\t\t
64.60
\n\t\t\t\t\t\t
54.05
\n\t\t\t\t\t\t
52.30
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
48.80
\n\t\t\t\t\t\t
46.10
\n\t\t\t\t\t\t
38.40
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
3 nodes based triangular (3)
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
\n\t\t\t\t\t\t
8
\n\t\t\t\t\t\t
4
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10
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5
\n\t\t\t\t\t\t
6
\n\t\t\t\t\t\t
7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.95
\n\t\t\t\t\t\t
64.60
\n\t\t\t\t\t\t
54.05
\n\t\t\t\t\t\t
52.30
\n\t\t\t\t\t\t
52.19
\n\t\t\t\t\t\t
51.49
\n\t\t\t\t\t\t
48.31
\n\t\t\t\t\t\t
48.80
\n\t\t\t\t\t\t
46.10
\n\t\t\t\t\t\t
38.40
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
3 nodes based triangular (10)
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
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4
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6
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10
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8
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7
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5
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
85.23
\n\t\t\t\t\t\t
67.15
\n\t\t\t\t\t\t
53.17
\n\t\t\t\t\t\t
52.19
\n\t\t\t\t\t\t
51.81
\n\t\t\t\t\t\t
51.49
\n\t\t\t\t\t\t
49.27
\n\t\t\t\t\t\t
48.47
\n\t\t\t\t\t\t
48.31
\n\t\t\t\t\t\t
42.10
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
3 nodes based Gaussian (10)
\n\t\t\t\t\t\t
9
\n\t\t\t\t\t\t
1
\n\t\t\t\t\t\t
2
\n\t\t\t\t\t\t
8
\n\t\t\t\t\t\t
4
\n\t\t\t\t\t\t
10
\n\t\t\t\t\t\t
5
\n\t\t\t\t\t\t
6
\n\t\t\t\t\t\t
7
\n\t\t\t\t\t\t
3
\n\t\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t\t\t
84.95
\n\t\t\t\t\t\t
64.60
\n\t\t\t\t\t\t
54.05
\n\t\t\t\t\t\t
52.30
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
49.70
\n\t\t\t\t\t\t
48.80
\n\t\t\t\t\t\t
46.10
\n\t\t\t\t\t\t
38.40
\n\t\t\t\t\t
\n\t\t\t\t
Table 3.
Ranking orders and new scores obtained by the three methods. (3): Applied to 3 students with equal score, (10): applied to 10 (i.e. all) students
\n\t\t\t\n\t\t\t
From Table 3 it is seen that the same ranking order has been obtained when the three nodes fuzzy system based on triangular MF’s is applied to only students with total scores and the three nodes fuzzy system based on Gaussian MF’s applied to all students. The varying of the parameters of the triangular MF’s results in different scores and different ranking orders while the same scores and the same ranking orders are obtained for Gaussian MF’s of various widths.
\n\t\t
\n\t\t
\n\t\t\t
5. Conclusions
\n\t\t\t
In this chapter, we proposed Gaussian MF’s to represent the fuzzy sets (i.e., levels) representing the importance, the complexity and the difficulty of the questions given to students. Results show that using Gaussian MFs with a width value (i.e., standard deviation) of 0.4 and higher provide a more reliable evaluation system which is able to provide new ranking orders without changing students’ total scores. Gaussian MFs provide smooth transition between levels and provides a way to fire the maximum number of rules in the rule base and hence a more accurate representation of the input-output relationship is achieved. Gaussian MF’s also provides a system with less degree of freedom and hence more robustness. The proposed three nodes fuzzy evaluation system based on Gaussian MF’s provides a new ranking order while keeping the scores of students unchanged. The system is implemented by using the Fuzzy Logic Toolbox™ 2.2.7 by MathWorks®.
\n\t\t
\n\t\n',keywords:null,chapterPDFUrl:"https://cdn.intechopen.com/pdfs/6928.pdf",chapterXML:"https://mts.intechopen.com/source/xml/6928.xml",downloadPdfUrl:"/chapter/pdf-download/6928",previewPdfUrl:"/chapter/pdf-preview/6928",totalDownloads:3626,totalViews:343,totalCrossrefCites:1,totalDimensionsCites:5,hasAltmetrics:0,dateSubmitted:null,dateReviewed:null,datePrePublished:null,datePublished:"February 1st 2010",dateFinished:null,readingETA:"0",abstract:null,reviewType:"peer-reviewed",bibtexUrl:"/chapter/bibtex/6928",risUrl:"/chapter/ris/6928",book:{slug:"fuzzy-systems"},signatures:"Ibrahim A. Hameed and Claus G. Sorensen",authors:null,sections:[{id:"sec_1",title:"1. Introduction",level:"1"},{id:"sec_2",title:"2. A review of the three nodes fuzzy evaluation system",level:"1"},{id:"sec_3",title:"Example. Assume that 10 students laid to an exam of 5 questions and the accuracy rate matrix, the time rate matrix, and the grade vector are given as follows (Bai & Chen, 2008b, Saleh & Kim, 2009):",level:"1"},{id:"sec_4",title:"Example. For the above example we get the following, in fuzzy domain, by the domain expert:",level:"1"},{id:"sec_5",title:"Example. For the above by formula (2) and formula (3), respectively, we get",level:"1"},{id:"sec_6",title:"Table 1.",level:"1"},{id:"sec_7",title:"3. Three nodes system based on Gaussian membership functions",level:"1"},{id:"sec_8",title:"Table 2.",level:"1"},{id:"sec_9",title:"4. Comparison of the methods",level:"1"},{id:"sec_10",title:"5. Conclusions",level:"1"}],chapterReferences:[{id:"B1",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tBai\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tChen\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2008a\n\t\t\t\t\tAutomatically constructing grade membership functions of fuzzy rules for students’ evaluation. Expert Systems with Applications, 35, 3, 1408\n\t\t\t\t\t1414 .\n\t\t\t'},{id:"B2",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tBai\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tChen\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2008b\n\t\t\t\t\tEvaluating students’ learning achievement using fuzzy membership functions and fuzzy rules. Expert Systems with Applications, 34, 399\n\t\t\t\t\t410 .\n\t\t\t'},{id:"B3",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tBiswas\n\t\t\t\t\t\t\tR.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1995\n\t\t\t\t\tAn application of fuzzy sets in students’ evaluation. Fuzzy Sets and Systems, 74, 2, 187\n\t\t\t\t\t194 .\n\t\t\t'},{id:"B4",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tChen\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tLee\n\t\t\t\t\t\t\tC. H.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1999 New methods for students’ evaluating using fuzzy sets. Fuzzy Sets and Systems, 104, 2, 209\n\t\t\t\t\t218 .\n\t\t\t'},{id:"B5",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tEchauz\n\t\t\t\t\t\t\tJ. R.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tVachtsevanos\n\t\t\t\t\t\t\tG. J.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1995\n\t\t\t\t\tFuzzy grading system. IEEE Transactions on Education, 38(2), 158 EOF\n\t\t\t\t\t165 EOF .\n\t\t\t'},{id:"B6",body:'\n\t\t\t\t\n\t\t\t\t\tFuzzy Logic Toolbox™\n\t\t\t\t\t227 from http://www.mathworks.com/products/fuzzylogic/.\n\t\t\t\t\n\t\t\t'},{id:"B7",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tLarsen\n\t\t\t\t\t\t\tP. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1980 Industrial applications of fuzzy logic control. International Journal of Man-Machine Studies, 12, 1, 3\n\t\t\t\t\t10 .\n\t\t\t'},{id:"B8",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tLaw\n\t\t\t\t\t\t\tC. K.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1996\n\t\t\t\t\tUsing fuzzy numbers in education grading system.\n\t\t\t\t\tFuzzy Sets and Systems, 83, 3, 311\n\t\t\t\t\t323 .\n\t\t\t'},{id:"B9",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tLohani\n\t\t\t\t\t\t\tA. K. .\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tGoel\n\t\t\t\t\t\t\tN. K.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tBhatia\n\t\t\t\t\t\t\tK. K. S.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2007 Reply to comments provided by Z. Şen on “Takagi-Sugeno fuzzy system for modeling stage-discharge relationship” by A.K. Lohani, N.K. Goel and K.K.S. Bhatia. Journal of Hydrology, 337, 1-2, 244\n\t\t\t\t\t247 .\n\t\t\t'},{id:"B10",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tMa\n\t\t\t\t\t\t\tJ.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tZhou\n\t\t\t\t\t\t\tD.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2000\n\t\t\t\t\tFuzzy set approach to the assessment of student-centered learning. IEEE Transactions on Education, 43, 2, 237\n\t\t\t\t\t241 .\n\t\t\t'},{id:"B11",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tMamdani\n\t\t\t\t\t\t\tE. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tAssilian\n\t\t\t\t\t\t\tS.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1975\n\t\t\t\t\tAn experiment in linguistic synthesis with a fuzzy logic controller. International Journal of Man-Machine Studies, 7, 1\n\t\t\t\t\t13 .\n\t\t\t'},{id:"B12",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tMamdani\n\t\t\t\t\t\t\tE. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1974 Applications of fuzzy algorithms for simple dynamic plants. Proceedings of the IEEE, 21, 2, 1585\n\t\t\t\t\t1588 .\n\t\t\t'},{id:"B13",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tSaleh\n\t\t\t\t\t\t\tI. .\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tKim\n\t\t\t\t\t\t\tS. I.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2009\n\t\t\t\t\tA fuzzy system for evaluating students’ learning achievement. Expert Systems with Applications, 36, 3, 6236\n\t\t\t\t\t6243 .\n\t\t\t'},{id:"B14",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tWang\n\t\t\t\t\t\t\tH. Y.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tChen\n\t\t\t\t\t\t\tS. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2008\n\t\t\t\t\tEvaluating students’ answerscripts using fuzzy numbers associated with degrees of confidence. IEEE Transactions on Fuzzy Systems, 16, 2, 403\n\t\t\t\t\t415 .\n\t\t\t'},{id:"B15",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tWeon\n\t\t\t\t\t\t\tS.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tKim\n\t\t\t\t\t\t\tJ.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t2001\n\t\t\t\t\tLearning achievement evaluation strategy using fuzzy membership function, Proceedings of the 31st ASEE/IEEE Frontiers in Education Conference, Reno: NV.\n\t\t\t'},{id:"B16",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tWilson\n\t\t\t\t\t\t\tE. .\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tKarr\n\t\t\t\t\t\t\tC. L.\n\t\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tFreeman\n\t\t\t\t\t\t\tL. M.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1998 Flexible, adaptive, automatic fuzzy-based grade assigning system, Proceedings of the North American Fuzzy Information Processing Society Conference, 334\n\t\t\t\t\t338 .\n\t\t\t'},{id:"B17",body:'\n\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t\t\n\t\t\t\t\t\t\tZadeh\n\t\t\t\t\t\t\tL. A.\n\t\t\t\t\t\t\n\t\t\t\t\t\n\t\t\t\t\t1965 Fuzzy sets. Information and Control, 8, 338\n\t\t\t\t\t333\n\t\t\t\t\n\t\t\t'}],footnotes:[],contributors:[{corresp:"yes",contributorFullName:"Ibrahim A. Hameed",address:"",affiliation:'
Aarhus University, Research Centre FoulumBlichers Allé 20, Denmark
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\n
1. Introduction
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Electromyography (EMG) is an electrodiagnostic technique for assessing the contractile activity produced by skeletal muscles. Through electrodes placed on top of the skin’s surface, surface EMG signals can detect neuromuscular states and abnormalities, muscle contraction levels, muscle recruitment order, and disorders of motor control and can estimate muscle forces and human movement.
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By understanding the muscle state via EMG, the impacts of modern lifestyles and work conditions on the human musculoskeletal system that could lead to potential injuries and illnesses, such as low back pain (LBP), may be identified. LBP is one of the most common societal health problems, causing day away from works, high health services cost, and considerable disability. LBP is one of the leading factors that cause injuries and disability among those under 43 years old [1]. More than 38% of work-related musculoskeletal disorders can be linked to back disorders each year, with a total of 134,550 cases reported in the United States in 2016 [1].
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As a new trend in both modern living and contemporary work, sedentary behaviors have become more and more prevalent. Prolonged sitting as a form of sedentary behavior presents emerging health risks in both occupational and non-occupational settings [2]. Sitting is commonly considered a critical ergonomic exposure related to LBP [3, 4]. Recent research has found that muscle activation levels around the lumbar area increase over time during sitting [5, 6] and cause higher levels of muscle co-contractions [7], which have been shown to positively correlate to the development of low back pain [6, 7].
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During the sitting, postural muscles, such as trunk extensors, are required to stabilize the sitting posture via sustained contractions, which, however, usually require very low levels of muscle contractions (<10% of maximal muscle capacity) [8, 9]. However, after a long exposure duration, seated posture could block muscle oxygenation and blood flow [10], cause lumbar muscle fatigue, increase intradiscal loads, and further contribute to the development of LBP [11, 12]. Therefore, even though the muscle contraction level during sitting is low, the sustained contractions may cause above mentioned issues even after a continuous duration only greater than 20 minutes [13, 14]. After a long period of sitting (i.e., >90 min), EMG median power frequency has also been observed to shift to the lower frequencies [15, 16]. Even though there is evidence that EMG can measure muscle fatigue caused by sitting, it is generally believed that 15% of muscle contraction level (compared to maximum muscle contraction capacity) is required to detect and distinguish fatigue-induced EMG changes from noises [21]. Both lowered EMG median frequency and increased EMG amplitudes under consistent workloads are generally considered a sign of muscle fatigue [15]. However, such methods may lead to conflicting results when detecting muscle fatigue under low-level contractions.
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Therefore, EMG-related measurements provide potential paths to reveal the underneath mechanisms that link prolonged sitting with LBP. At the same time, some potential challenges may affect measurement performance. Therefore, in this chapter, using a prolonged sitting experiment as an example, a series of EMG-based muscle fatigue measurement methods are discussed with respect to their capabilities and limitations in quantifying the negative impacts of prolonged sitting.
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2. Determining the effects of prolonged sitting using EMG-based muscle fatigue measurement methods
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2.1 Study design
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Six participants [gender balanced, mean age (SD) = 25.1 (3.3) yrs] were recruited from the local community to complete a one-hour prolonged seated task. As shown in \nFigure 1\n, participants were required to sit in a relaxed posture without significant in-chair body movements, such as trunk rotation or bending that could cause significant off-sagittal plane movement. No use of backrest was allowed to minimize potential confounding effects caused by the backrest support on muscle activation pattern during the experiment.
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Figure 1.
Illustration of seating device and seated tasks.
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During the experiments, participants were asked to conduct a relaxed internet browsing task to minimize the potential impacts of high mental workloads on muscle activities. The browsing tasks were self-selected with a similar level of mental/physical workloads, e.g., participants can choose to browse websites or stream videos but cannot play intense games or other high demanding tasks. All participants read and signed an informed consent with IRB approval prior to participation.
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2.2 EMG data collection and analysis
\n
To understand how muscles support the trunk against the continuous sitting, the major muscles around the lumbar spine should be studied. In detail, sixteen muscles around the lower lumbar region were studied, which can usually be categorized into the trunk flexors group and the trunk extensors group based on the different function of each muscle. Trunk flexors are those dominant muscles that drive trunk flexion movement, while trunk extensors are those dominant muscles that lead the trunk extension movement. Trunk sideways bending and rotation usually are the results of the combined muscle activities from trunk flexors and extensors.
\n
The tested trunk flexors group includes internal oblique (IO), external oblique (EO), and rectus abdominis (RA). The tested trunk extensors group includes iliocostalis lumborum pars lumborum (ILL), iliocostalis lumborum pars thoracis (ILT), multifidus (MF), longissimus thoracis pars lumborum (LTL), and longissimus thoracis pars thoracis (LTT). Both trunk flexors and extensors can be further divided bilaterally into the left side (L) and the right side (R). The deeper trunk muscles (e.g., psoas, quadratus lumborum, and transverse abdominis) are not included in the analysis due to the fact that such deeper muscles cannot be measured through surface EMG and do not significantly contribute to lumbar kinetics [17]. Each muscle is composed of a group of functional fascicles, each of which has distinct insertion, via, and origin points attached to the bone, which represent the diverse anatomy within each muscle. The initial insertion, via, and origin points are defined as the attach or wrap points where the muscles connect to the bone [18]. For these sixteen trunk muscles, there are a total of ninety-two fascicles (EO = 4, IO = 12, RA = 4, MF = 24, ILL = 8, ILT = 16, LTL = 10, LTT = 14). Equal contraction level is usually assumed among all the fascicles from the same muscle [19]. During trunk movement, each fascicle moves differently due to the different insertion, via, and origin points positions on the bone. Measured trunk kinematics can be used to estimate the line of action and length of each fascicle at each sample instant. So, the EMG activity measured from surface EMG devices can be used to describe the muscle contraction levels.
\n
To monitor and collect muscle EMG data over a long period, a high-fidelity multimodal EMG system is required to collect reliable data continuously with flexible measurement options. A wireless EMG system (Trigno™, Delsys, MA) is included in this chapter. The Trigno wireless EMG system supports up to 16 wireless sensors, which can be used to monitor all 16 muscles simultaneously. To maximize the quality of the collected data, skin near the central position over the muscle belly (but not directly over motor points) of each target muscle was shaved, abrased, and cleaned with a mild alcohol solution to ensure that the impedance was lower than 10 KΩ. Electrodes were placed bilaterally over the surface of each muscle, as suggested in [20]. Raw EMG single amplitude usually ranges from −5000 to 5000 microvolts with frequency ranges between 10 and 500 Hz, in which most frequency power lies between 20 and 400 Hz. Using the Trigno system, raw EMG signals were collected at 2000 Hz, pre-amplified at 500 gain, and band-pass filtered between 20 and 400 Hz. To further smooth the signal, the root-mean-square (RMS) of EMG was calculated using a 200-milliseconds sliding window for the relatively static task, i.e., sitting. Then RMS EMG of the same muscle collected bilaterally were averaged since no significant off-sagittal plane in-chair movements were allowed during the experiment. Collected EMG data were furthered analyzed to answer the following questions for a better understanding of the impact of the prolonged sitting:
\n
The first question is how much effort the related muscles have to contribute continuously to maintaining a seated posture for a prolonged duration. By answering this question, the neuromuscular demands required during prolonged seated tasks could be determined, and a corresponding ergonomics intervention can be developed to lower the stress and strain on workers.
\n
To answer this question, the muscles’ contraction levels relative to their maximum capacity need to be determined. Muscle EMG collected from a maximum voluntary contraction (MVC) test can be used as a reference of 100% muscle capacity, and muscle EMG measured during a task can be normalized to this reference to generate the percentage of effort needed to complete the task. The MVC values of all sixteen muscles were measured from suggested MVC tests [20, 21]. Once the MVC value for each muscle is determined, the muscle EMG during prolonged sitting can be converted into the percentage of the MVC value to estimate the level of neuromuscular effort needed for the prolonged sitting [22].
\n
As shown in \nFigure 2\n, the average muscle activation levels over the entire one hour sitting are generally less than 10% MVC. However, unlike other physically demanding tasks, the exposure duration in such low load seated tasks is long, necessitating a significant amount of time for the muscles to recover from previous fatigue [11].
\n
Figure 2.
Average muscle contraction level (%MVC) over the prolonged seated task.
\n
The second question is whether there is any muscle fatigue developed during prolonged sitting. Muscle fatigue is one of the leading indicators that directly link to the development of LBP. Traditionally, both EMG amplitude and EMG median frequency show time-domain changes due to muscular fatigue. Therefore, monitoring EMG amplitude changes over time during prolonged sitting can estimate the level of muscle fatigue development. Using EMG amplitude, muscle fatigue is defined as an amplitude increase over time without an increase in the level of physical demands.
\n
In this study, EMG amplitudes were continuously collected for one minute, and this procedure was repeated every ten minutes. The collected EMG over one minute was then averaged to present the general trend at each data collection period during prolonged sitting. As shown in \nFigure 3\n, EMG amplitude collected from both muscle groups, in general, increased toward the end of the sitting period. Both LMF and LLTT have a significant increase in measured EMG amplitude. Such an upward change trend, however, was not consistent and fluctuated up and down, which could further indicate that many moderating factors, such as body movement and external forces, could have affected the amplitudes of the collected muscle EMG.
\n
Figure 3.
An example of EMG amplitude (LMF and LLTT) changes over the one-hour prolonged seated task.
\n
The second indicator is the median power frequency (MPF) of raw EMG obtained from the prolonged sitting. Such MPF was calculated over 3-second windows. As described above, EMG data were continuously collected for one minute every ten minutes, and the mean EMG MPF from each one-minute period was calculated and compared. Changes between these mean values were used as a predictor of fatigue development in these muscles. Multivariate analysis of variance (MANOVA, using Wilks’ Lambda) was used to determine the effects of prolonged sitting on all EMG MPFs as a whole. In the event of a significant MANOVA effect, univariate ANOVAs were performed to determine which muscle was mostly impacted by the prolonged seated task, which was considered significant when p < 0.05.
\n
MANOVA results indicated that prolonged sitting (p < 0.01) had significant effects on the tested EMG MPFs. As shown in \nTable 1\n, subsequent univariate ANOVAs indicated that prolonged sitting significantly affected MPFs from some of the muscles, which manifested as a declining percentage of EMG MPF: left side LILL (16%) and LLTT (18%) muscles and right side RMF (14%) and RIO (8%) muscles.
\n
\n
\n
\n
\n
\n\n
\n
\n
Prolonged Sitting
\n
\n\n\n
\n
\n
\n\nF\n\n(1,320)\n
\n
\n\np\n\n
\n
\n
\n
EMG Median Frequency
\n
LMF
\n
2.16
\n
0.15
\n
\n
\n
LILL
\n
7.65
\n
\n<0.01\n
\n
\n
\n
LILT
\n
3.36
\n
0.06
\n
\n
\n
LLTL
\n
3.37
\n
0.88
\n
\n
\n
LLTT
\n
9.16
\n
\n<0.01\n
\n
\n
\n
LEO
\n
3.46
\n
0.06
\n
\n
\n
LIO
\n
4.51
\n
0.05
\n
\n
\n
LRA
\n
2.71
\n
0.12
\n
\n
\n
RMF
\n
5.58
\n
\n0.02\n
\n
\n
\n
RILL
\n
4.25
\n
0.06
\n
\n
\n
RILT
\n
4.34
\n
0.06
\n
\n
\n
RLTL
\n
3.17
\n
0.08
\n
\n
\n
RLTT
\n
4.02
\n
0.06
\n
\n
\n
REO
\n
0.03
\n
0.86
\n
\n
\n
RIO
\n
4.98
\n
\n0.04\n
\n
\n
\n
RRA
\n
4.10
\n
0.06
\n
\n\n
Table 1.
Summary of ANOVA results for effects of prolonged sitting (p<0.05).
\n
As mentioned above, muscle contraction at 15% MVC or higher is usually considered to be the minimal muscle contraction level to detect fatigue-related changes in the EMG signal during different working levels [23]. During low-level sustained muscle contractions, inconsistent evidence of fatigue development was observed between different muscle groups and across individuals [10]. Therefore, the analysis of EMG amplitude and median frequency as a measurement of muscle fatigue could lead to unreliable or conflicting results under low-level contractions. Existing evidence [11, 24], on the other hand, also illustrates the possibility of using traditional EMG methods to quantify muscle fatigue during low-level contractions as low as 2% MVC. However, these results were achieved from a relatively short duration with large inter-subject variations. Therefore, a sensitive method is needed to obtain reliable muscle fatigue measurements under these conditions of low-level sustained muscle contractions, i.e., prolonged sitting.
\n
An alternative method to identify muscle fatigue is to combine muscle EMG with muscle stimulation technology. In this approach, an electrical stimulation pulse is sent to the target muscle to evoke an artificial muscle contraction, and the corresponding muscle stimulation response from these artificial contractions can be captured through surface EMG and other quantitative methods. In this method, muscle fatigue is defined as a significant change of observed muscle stimulation responses from the initial pre-fatigue status [25, 26]. Muscle fatigue has been identified using a single stimulation frequency [27, 28] or calculated as a decrement ratio of stimulation response results from high-frequency (50–100 Hz) and low-frequency (1–20 Hz) stimulation [26, 29]. While various stimulation frequencies have been used, low-frequency stimulation (LFS) usually creates stable stimulation responses and fatigue-induced changes [27]. Another benefit of using LFS is that it is less likely to cause muscle fatigue, and the level of discomfort is also low [28].
\n
Therefore, in this chapter, a muscle stimulation method was further applied to determine the muscle fatigue results from prolonged sitting. All six participants completed a muscle stimulation trial after the initial MVC test and then repeated after the prolonged seated task, and the stimulation responses collected through both stimulation trials were compared to identify the potential muscle fatigue caused by the prolonged sitting.
\n
Muscle stimulation responses were evoked using a dual-channel current-controlled muscle stimulator (Grass S88, AstroMed, RI) connected with a stimulus isolation unit (SIU5, AstroMed, RI) and a constant current unit (CCU1, AstroMed, RI). In this study, the MF muscle was selected to evaluate prolonged sitting induced muscle fatigue. The participant’s skin around the MF muscle was appropriately prepared following the procedure described by [30]. After bilaterally placing the positive and negative stimulation electrodes (PALS, Axelgaard Manufacturing, CA) at the level of the rib cage bottom and the iliac crest, respectively, the most effective site for electrical stimulation was determined as suggested in [31] to determine appropriate stimulus intensity and electrode location for each participant. During the stimulation trial, participants were asked to sit in a customized fixture (\nFigure 4\n), with their upper body locked in a comfortable and relaxed upright sitting posture using a metal bar connected to their chest harness around the T8 level. A load cell (SM2000, Interface, AZ) was connected to the other end of the metal bar to collect the stimulation response (i.e., stimulation generated forces) generated by the artificial muscle contraction evoked by the stimulation. Muscle voluntary contractions were minimized by asking participants to relax their muscles and let the fixture hold their sitting postures. The muscle EMG were also monitored bilaterally to ensure minimal voluntary muscle contraction involved during the stimulation procedure. The stimulation train was repeated if the voluntary muscle contraction level monitored by surface EMG were greater than 5% of MVC. The fixture also has a height-adjustable seat pan to align the participant’s trunk rotation center at the level of the L5/S1 joint in the sagittal plane. The participant’s knee and ankle were also required to maintain a 90-degree using an adjustable footrest. While maintain such sitting posture, participants were also instructed to try to relax their muscles and eliminate potential movement during the data collection.
\n
Figure 4.
Illustration of experimental fixture setup with a participant in an upright sitting posture.
\n
The overall experimental procedure was illustrated in \nFigure 5\n. Each participant completed one stimulation trial, starting with one conditioning train and three sampling trains, before and after the prolonged seat task. A conditioning train included stimulating muscles continuously at 2 Hz until a plateau and steady phases of measured muscle stimulation responses were observed. The duration of conditioning, i.e., the time-to-potentiation (tp), is determined as the time at which the increasing rate of muscle stimulation response becomes zero. Immediately after the conditioning train, the same 2 Hz stimulation was applied again, and muscle stimulation responses were collected during three 9-second trains with a 10-second rest in between.
\n
Figure 5.
Illustration of the overall experimental procedure. Conditioning: tp minutes continuous stimulation at 2 Hz; train: 9-second stimulation at 2 Hz with a 10-second rest in between.
\n
A repeated-measures analysis of variance (ANOVA) method was used to identify any significant changes in muscle stimulation response before and after the one hour of prolonged sitting.
\n
Descriptive summaries of the stimulation response (i.e., stimulation generated forces) from two test trials are presented in \nFigure 6\n. Signs of muscle fatigue were clearly found in the measured stimulation response. Prolonged sitting resulted in a significant (p = 0.03) decrease in stimulation responses from the measured muscles.
\n
Figure 6.
Stimulation generated forces (mean and SD) collected among three trains before and after the prolonged seated task.
\n
As a comparison shown in \nFigure 7\n, the average EMG MPF of bilateral MF showed some signs of fatigue with a shifted MPF value, but the development of muscle fatigue was inconsistent over time, and the level of the observed shift was small.
\n
Figure 7.
Average EMG MPF of MF during the prolonged seated task.
\n
\n
\n
\n
3. Discussion and conclusions
\n
Muscle fatigue was measured using EMG MPF, EMG amplitude, and muscle stimulation methods. In general, all three methods successfully captured the sign of muscle fatigue development through prolonged sitting. Consistency among these three measures supports that muscle fatigue indeed developed during the prolonged seated task.
\n
EMG amplitude collected from 16 muscle groups showed a sign of increased amplitude toward the end of the sitting period. Two out of 16 muscles (i.e., LMF and LLTT) have significant increases in measured EMG amplitude, which in the absence of interference from external forces or movement may have been caused by muscle fatigue development over time. However, the EMG amplitude method did not detect any significant development of muscle fatigue over the rest of the 14 muscles, which may indicate the limited sensitivity of such methods in measuring muscle fatigue under prolonged sitting conditions. Furthermore, existing evidence also indicated that such EMG amplitude changes over a fatiguing task is also associated with the level of contraction, e.g., a task, which requires below 40% MVC, may show sign of EMG amplitude decrease [32], while other studies show increase of EMG amplitude during 40–50% MVC sustained contraction tasks [33, 34]. Therefore, using EMG amplitude alone may not be able to provide reliable estimation on muscle fatigue development.
\n
EMG MPFs collected from four out of 16 muscles also showed signs of fatigue, but no general consistency was observed across all measured muscles. Some of the inconsistencies among various muscles in the measured MPFs may have been the result of the insensitivity of EMG in measuring low-load muscle fatigue. As shown in \nFigure 2\n, the average contraction level of most flexors and some extensors are between 2% and 5%. Since only a deficient level of muscle contractions are needed during the prolonged seated task, collected EMG signals may fall close to or even below the noise threshold, which may significantly affect the fatigue detection results derived from noisy EMG MPF. As a result, EMG amplitude and EMG MPF may only have limited capacity in measuring fatigue related muscle changes under such task conditions.
\n
Another potential explanation could be linked to the functional differences between the trunk flexors and extensors. During the prolonged sitting, trunk extensors usually work as postural muscles that continuously contract to stabilize the sitting posture [5, 6]. Therefore, the observed decline of EMG MPF among three trunk extensors (ILL, LTT, and MF) was more substantial and could be used as a reasonable measurement of muscle fatigue caused by prolonged sitting. The decline of EMG MPF in the IO suggests that this muscle may also play an essential role in stabilizing the trunk posture during sitting, which is consistent with existing evidence [35]. All other muscles may have received only limited impacts from the prolonged seated task, or the actual fatigue could not be accurately measured using surface EMG during prolonged sitting.
\n
Muscle fatigue measured by muscle stimulation, on the other hand, was more announced with a significant drop in measured stimulation responses across all three sampling trains. The same sign of fatigue was also observed in measured EMG amplitude and EMG MPF, but the magnitude of changes was small and inconsistent. Such results could indicate that muscle stimulation methods, compared to traditional EMG-based fatigue measurement methods, could provide more stable and visible results as a more sensitive method.
\n
In summary, several EMG-based methods have been discussed in terms of their capabilities and limitations when used as ergonomic assessment methods to measure the effects of prolonged sitting. These outcomes were evident after one hour of continuous sitting. The effects of prolonged sitting have been successfully quantified by monitoring participants’ muscle fatigue development. Current findings suggest that individuals who sit for prolonged periods can be at increased risk of cumulative disorder and injury, and various EMG-based methods can be used together to provide more reliable estimation and evaluation.
\n
\n
Conflict of interest
The author declares no sources of support or conflict of interest.
\n',keywords:"muscle fatigue, prolonged sitting, low Back pain, EMG, muscle stimulation",chapterPDFUrl:"https://cdn.intechopen.com/pdfs/74397.pdf",chapterXML:"https://mts.intechopen.com/source/xml/74397.xml",downloadPdfUrl:"/chapter/pdf-download/74397",previewPdfUrl:"/chapter/pdf-preview/74397",totalDownloads:36,totalViews:0,totalCrossrefCites:0,dateSubmitted:"September 4th 2020",dateReviewed:"November 27th 2020",datePrePublished:"December 27th 2020",datePublished:null,dateFinished:"December 11th 2020",readingETA:"0",abstract:"This chapter demonstrates a practical application of electromyography (EMG) technology in assessing the potential negative impacts of new trends (i.e., prolonged sitting) in life and work on people’s health. With the development of advanced technologies, prolonged sitting, have become more frequent at work and in everyday life. The potential risks associated with prolonged sitting can be assessed by evaluating localized muscle states using various EMG-based methods. However, due to the unique characteristics of prolonged sitting (i.e., sustained low-load condition), there are several challenges in applying traditional EMG methods to estimate the prolonged sitting related risks. Therefore, from the following aspects, this chapter discusses the potential applications and challenges of using surface EMG-based methods in identifying the effects of prolonged sitting: (1) what are the unique characteristics of the task conditions involved in prolonged sitting; (2) what are the available EMG-based methods; and (3) the advantage and disadvantage of each method in evaluating the impacts of prolonged sitting on people’s health;",reviewType:"peer-reviewed",bibtexUrl:"/chapter/bibtex/74397",risUrl:"/chapter/ris/74397",signatures:"Bochen Jia",book:{id:"10233",title:"Sedentary Behaviour - A Contemporary View",subtitle:null,fullTitle:"Sedentary Behaviour - A Contemporary View",slug:null,publishedDate:null,bookSignature:"Prof. Adilson Marques and Dr. Élvio Rúbio Gouveia",coverURL:"https://cdn.intechopen.com/books/images_new/10233.jpg",licenceType:"CC BY 3.0",editedByType:null,editors:[{id:"210561",title:"Prof.",name:"Adilson",middleName:null,surname:"Marques",slug:"adilson-marques",fullName:"Adilson Marques"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:null,sections:[{id:"sec_1",title:"1. Introduction",level:"1"},{id:"sec_2",title:"2. Determining the effects of prolonged sitting using EMG-based muscle fatigue measurement methods",level:"1"},{id:"sec_2_2",title:"2.1 Study design",level:"2"},{id:"sec_3_2",title:"2.2 EMG data collection and analysis",level:"2"},{id:"sec_5",title:"3. Discussion and conclusions",level:"1"},{id:"sec_9",title:"Conflict of interest",level:"1"}],chapterReferences:[{id:"B1",body:'\nBureau of Labor Statistics, U.S. Department of Labor. Nonfatal Occupational Injuries and Illnesses Requiring Days Away from Work. 2018\n'},{id:"B2",body:'\nOwen, N., Salmon, J., Koohsari, M. J., Turrell, G., & Giles-Corti, B. Sedentary behaviour and health: mapping environmental and social contexts to underpin chronic disease prevention. British Journal of Sports Medicine. 2014; 48(3), 174-177\n'},{id:"B3",body:'\nChaffin, D. B., G. Andersson, et al. Occupational Biomechanics. New York, Wiley-Interscience Publication.1999\n'},{id:"B4",body:'\nPope, M. H., K. L. Goh, et al. Spine ergonomics. Annual Review of Biomedical Engineering. 2002; 4: 49-68\n'},{id:"B5",body:'\nO\'Sullivan, P. B., Mitchell, T., Bulich, P., Waller, R., & Holte, J. The relationship between posture and back muscle endurance in industrial workers with flexion-related low back pain. Manual Therapy, 2006; 11(4), 264-271\n'},{id:"B6",body:'\nNairn, B. C., Azar, N. R., & Drake, J. D. Transient pain developers show increased abdominal muscle activity during prolonged sitting. Journal of Electromyography and Kinesiology. 2013; 23(6):1421-7\n'},{id:"B7",body:'\nSchinkel-Ivy, A., Nairn, B. C., & Drake, J. D. Investigation of trunk muscle co-contraction and its association with low back pain development during prolonged sitting. Journal of Electromyography and Kinesiology. 2013;23(4):778-86\n'},{id:"B8",body:'\nMork, P. J., & Westgaard, R. H., Back posture and low back muscle activity in female computer workers: a field study. Clinical Biomechanics. 2009; 24(2):169-75\n'},{id:"B9",body:'\nVan Dieën, J. H., De Looze, M. P., & Hermans, V. Effects of dynamic office chairs on trunk kinematics, trunk extensor EMG and spinal shrinkage. Ergonomics. 2001; 44(7):739-50\n'},{id:"B10",body:'\nVøllestad, N. K. Measurement of human muscle fatigue. Journal of Neuroscience Methods. 1997; 74(2):219-27\n'},{id:"B11",body:'\nBernard, B. P., ed., Putz-Anderson, V., et al. Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiologic Evidence for Work-Related Musculoskeletal Disorders of the Neck, Upper Extremity, and Low Back. U.S. Department of Health and Human Services. 1997\n'},{id:"B12",body:'\nWomersley, L., & May, S. Sitting posture of subjects with postural backache. Journal of Manipulative and Physiological tTherapeutics. 2006;29(3):213-8\n'},{id:"B13",body:'\nMcLean, L., & Goudy, N. Neuromuscular response to sustained low-level muscle activation: within-and between-synergist substitution in the triceps surae muscles. European Journal of Applied Physiology. 2004;91(2-3):204-16\n'},{id:"B14",body:'\nvan Dieën, J. H., Westebring-van der Putten, E. P., Kingma, I., & de Looze M. P. Low-level activity of the trunk extensor muscles causes electromyographic manifestations of fatigue in absence of decreased oxygenation. Journal of Electromyography and Kinesiology. 2009;19(3):398-406\n'},{id:"B15",body:'\nMcLean, L., Scott, R. N., et al. Measurement of muscle fatigue in the cervical and lumbar regions during prolonged sitting. Engineering in Medicine and Biology Society, 1997. Proceedings of the 19th Annual International Conference of the IEEE\n'},{id:"B16",body:'\nYoshizawa, N., Michida, N., Iname, C., & Furugori, S. Evaluation of muscular fatigue after long-term sitting in automotive seat. JSAE Review. 2002;1(23):136-8\n'},{id:"B17",body:'\nMcGill, S. M. A myoelectrically based dynamic three-dimensional model to predict loads on lumbar spine tissues during lateral bending. Journal of Biomechanics. 1992;25(4):395-414\n'},{id:"B18",body:'\nDe Zee, M., Hansen, L., Wong, C., Rasmussen, J., & Simonsen, E. B. A generic detailed rigid-body lumbar spine model. Journal of Biomechanics. 2007;40(6):1219-27\n'},{id:"B19",body:'\nCholewicki, J., McGill, S. M., & Norman, R. W. Comparison of muscle forces and joint load from an optimization and EMG assisted lumbar spine model: towards development of a hybrid approach. Journal of Biomechanics. 1995; 28(3):321-31\n'},{id:"B20",body:'\nCholewicki J, van Dieën J, Lee AS, Reeves NP. A comparison of a maximum exertion method and a model-based, sub-maximum exertion method for normalizing trunk EMG. Journal of Electromyography and Kinesiology. 2011;21(5):767-73\n'},{id:"B21",body:'\nNg JK, Kippers V, Parnianpour M, Richardson CA. EMG activity normalization for trunk muscles in subjects with and without back pain. Medicine and Science in Sports and Exercise. 2002;34(7):1082\n'},{id:"B22",body:'\nPotvin, J. R., Norman, R. W., & McGill, S. M. Mechanically corrected EMG for the continuous estimation of erector spinae muscle loading during repetitive lifting. European Journal of Applied Physiology and Occupational Physiology. 1996;74(1-2):119-32\n'},{id:"B23",body:'\nÖberg. T., Sandsjö, L., Kadefors. R., & Larsson, S. E. Electromyographic changes in work-related myalgia of the trapezius muscle. European Journal of Applied Physiology and Occupational Physiology. 1992;65(3):251-7\n'},{id:"B24",body:'\nSøgaard, K., Blangsted, A. K., Jørgensen, L. V., Madeleine, P., & Sjøgaard, G. Evidence of long term muscle fatigue following prolonged intermittent contractions based on mechano-and electromyograms. Journal of Electromyography and Kinesiology. 2003;13(5):441-50\n'},{id:"B25",body:'\nBinder-Macleod S. A., & Snyder-Mackler, L. Muscle fatigue: clinical implications for fatigue assessment and neuromuscular electrical stimulation. Physical Therapy. 1993;73(12):902-10\n'},{id:"B26",body:'\nEdwards, R. H., Hill, D. K., Jones D.A., & Merton, P. A. Fatigue of long duration in human skeletal muscle after exercise. The Journal of Physiology. 1977;272(3):769-78\n'},{id:"B27",body:'\nCooper, R. G., Edwards, R. H., Gibson, H., & Stokes, M. J. Human muscle fatigue: frequency dependence of excitation and force generation. The Journal of Physiology. 1988;397(1):585-99\n'},{id:"B28",body:'\nJohnson, P. W., Lehman, S. L., & Rempel, D. M. Measuring low frequency fatigue with 2 Hertz stimulation. I. Stimulus-related potentiation effects. In Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society 1995; (Vol. 2, pp. 1207-1208). IEEE\n'},{id:"B29",body:'\nJia B, Nussbaum MA, Agnew MJ. A Stimulation Method to Assess the Contractile Status of the Lumbar Extensors in a Seated Posture. Human Factors and Ergonomics in Manufacturing & Service Industries. 2015; 25(6):674-84\n'},{id:"B30",body:'\nCram J. R., & Rommen, D. Effects of skin preparation on data collected using an EMG muscle-scanning procedure. Biofeedback and Self-regulation. 1989;14(1):75-82\n'},{id:"B31",body:'\nKarnes, J. L., Ed. Neuromuscular Electrical Stimulation: A Practical Guide. The Free Library. 2008\n'},{id:"B32",body:'\nSeidel H, Beyer H, Bräuer D. Electromyographic evaluation of back muscle fatigue with repeated sustained contractions of different strengths. European journal of applied physiology and occupational physiology. 1987;56(5):592-602\n'},{id:"B33",body:'\nNg JK, Richardson CA, Jull GA. Electromyographic amplitude and frequency changes in the iliocostalis lumborum and multifidus muscles during a trunk holding test. Physical therapy. 1997;77(9):954-61\n'},{id:"B34",body:'\nHolmström E, Moritz U, Andersson M. Trunk muscle strength and back muscle endurance in construction workers with and without low back disorders. Scandinavian journal of rehabilitation medicine. 1992;24(1):3-10\n'},{id:"B35",body:'\nSnijders, C. J., Bakker, M. P., Vleeming, A., Stoeckart, R., & Stam, H. J. Oblique abdominal muscle activity in standing and in sitting on hard and soft seats. Clinical Biomechanics. 1995;10(2):73-8\n'}],footnotes:[],contributors:[{corresp:"yes",contributorFullName:"Bochen Jia",address:"bochenj@umich.edu",affiliation:'
University of Michigan-Dearborn, Dearborn, Michigan, USA
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