Showing posts with label top rated journal. Show all posts
Showing posts with label top rated journal. Show all posts

Friday, November 27, 2015

#IJIRST Journal: Evaluation of Response Reduction Factor using Nonlinear Analysis


Author Name:- Tia Toby

Department of Civil Engineering

Abstract:- The main objective of the study is to evaluate the response reduction factor of RC frames. We know that the actual earthquake force is considerably higher than what the structures are designed for. The structures can't be designed for the actual value of earthquake intensity as the cost of construction will be too high. The actual intensity of earthquake is reduced by a factor called response reduction factor R. The value of R depends on ductility factor, strength factor, structural redundancy and damping. The concept of R factor is based on the observations that well detailed seismic framing systems can sustain large inelastic deformation without collapse and have excess of lateral strength over design strength. Here the nonlinear static analysis is conducted on regular and irregular RC frames considering OMRF and SMRF to calculate the response reduction factor and the codal provisions for the same is critically evaluated. 

Keywords: Response Reduction Factor, Ductility Factor, Strength Factor, Nonlinear Analysis, Regular and Irregular Frames, OMRF, SMRF

I.    Introduction

The devastating potential of an earthquake can have major consequences on infrastructures and lifelines. In the past few years, the earthquake engineering community has been reassessing its procedures, in the wake of devastating earthquakes which have caused extensive damage, loss of life and property. These procedures involve assessment of seismic force demands on the structure and then developing design procedures for the structure to withstand the applied actions Seismic design follows the same procedure, except for the fact that inelastic deformations may be utilized to absorb certain levels of energy leading to reduction in the forces for which structures are designed. This leads to the creation of the Response Modification Factor (R factor); the all-important parameter that accounts for over-strength, energy absorption and dissipation as well as structural capacity to redistribute forces from inelastic highly stressed regions to other less stressed locations in the structure. This factor is unique and different for different type of structures and materials used. The objective of this paper is to evaluate the response reduction factor of a RC frame designed and detailed as per Indian standards IS 456, IS 1893 and IS 13920.The codal provisions for the same will be critically evaluated. Moreover parametric studies will be done on both regular and irregular buildings and finally a comparison of R value between OMRF and SMRF is also done.

II.  Definition of r factor and its components

During an earthquake, the structures may experience certain inelasticity, the R factor defines the levels of inelasticity. The R factor is allowed to reflect a structures capability of dissipating energy via inelastic behavior. The statically determinate structures response to stress will be linear until yielding takes place. But the behavioral change in structure from elastic to inelastic occurs as the yielding prevails and linear elastic structural analysis can no longer be applied. The seismic energy exerted by the structure is too high which makes the cost of designing a structure based on elastic spectrum too high. To reduce the seismic loads, IS 1893 introduces a “response reduction factor” R. So in order to obtain the exact response, it is recommended to perform Nonlinear analysis. In actual speaking R factor is a measure of over strength and redundancy. It may be defined as a function of various parameters of the structural system, such as strength, ductility, damping and redundancy.

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Friday, November 20, 2015

Performance Assessment for Students using Different Defuzzification Techniques


Author Name:- Anjana Pradeep, Jeena Thomas

Department of Computer Science & Engineering

Abstract:- The aim of this study is to evaluate the performance of students using a fuzzy expert system. The fuzzy process is based solely on the principle of taking non-precise inputs on the factors affecting the performance of students and subjecting them to fuzzy arithmetic to obtain a crisp value of the performance. The system classifies each student's performance by considering various factors using fuzzy logic. Aimed at improving the performance of fuzzy system, several defuzzification methods other than the built methods in MATLAB have been devised in this system for producing more accurate and quantifiable result.  This study provides comparison and in depth examination of various defuzzification techniques like Weighted Average Formula (WAF), WAF-max method and Quality Method (QM). A new defuzzification method named as Max-QM which is extended from Quality method that falls within the general framework is also given and commented upon in this study.      

Keywords: Fuzzy logic, Fuzzy Expert System, Defuzzification, Weighted Average Formula, Quality Method 

I.   Introduction

An expert system is a software program that can be used to solve complex reasoning tasks that usually require a (human) expert. In other words, an expert system should help a novice, or partly experienced, problem solver, to match acknowledged experts in the particular domain of problem solving that the system is designed to assist. To be more specific, expert systems are generally conceptualized as shown in Fig 1. The user makes an interaction through the interface system and the system questions the user through the same interface in order to obtain the vital information upon which a decision is to be made. Behind this interface, there are two other sub-systems viz. the knowledge base, which is made up of all the domain-specific knowledge that human experts use when solving that category of problems and the inference engine, a system that performs the necessary reasoning and uses knowledge from the knowledge base in order to come to a judgment with respect to the problem modelled [1].
     Expert system has been playing a major role in many disciplines such as in medicines, assist physician in diagnosis of diseases, in agriculture for crop management, insect control, in space technology and  in power systems for fault diagnosis[5]. Some expert systems have been developed to replace human experts and to aid humans. The use of an expert system is increasing day by day in today’s world [40]. Expert systems are becoming an integral part of engineering education and even other courses like accounting and management are also accepting them as a better way of teaching[4].Another feature that makes expert system more demanding for students is its ability to adaptively adjust the training for each particular student on the bases of individual students learning pace. This feature can be used more effectively in teaching engineering students. It should be able to monitor student’s progress and make a decision about the next step in training.

Fig. 1: Expert system structure
        The few expert systems available in the market present a lot of opportunities for the students who desire more spotlight and time to learn the subjects. Some expert systems present an interactive and friendly environment for students which encourage them to study and adopt a more practical approach towards learning. The expert systems can also act as an assistor or substitute for the teacher. Expert systems focus on each student individually and also keep track of their learning pace. This behavior of an expert system provides autonomous learning procedure for both student and teacher, where teachers act as mentor and students can judge their own performance. Expert system is not only beneficial for the students but also for the teachers which help them guiding students in a better way.
        The integration of fuzzy logic with an expert system enhances its capability and is called a fuzzy expert system, as it is useful for solving real world problems which do not require a precise solution. So, there is a need to develop a fuzzy expert system as it can handle imprecise data efficiently and reduces the manual working while enhancing the use of expert system[40].

      There are various factors inside and outside college that results in poor quality of academic performance of students[2,3]. To determine all the influencing factors in a single effort is a complex and difficult task. It necessitates a lot of resources and time for an educator to identify all these factors first and then plan the classroom activities and approaches of teaching and learning. It also requires appropriate training, organizational planning and skills to conduct such studies for determining the contributing factors inside and outside college. This process of identification of determinants must be given full attention and priority so that the teachers may be able to develop instructional strategies for making sure that all the students be provided with the opportunities to attain at their fullest potential in learning and performance.  By using suitable statistical package it was found that communication, learning facilities, proper guidance and family stress were the factors that affect the student performance. Communication, learning facilities and proper guidance showed a positive impact on student performance and family stress showed a negative impact on student performance. It is indicated that communication is more important factor that affect the student performance than learning facilities and proper guidance [3].

      In this research article seven most important factors are included which affect the students’ performance. These are personal factors, college environment, family factors, and university factors, teaching factors, attendance and marks obtained by students. All these factors are scaled and ranked based on the various sub-factors that are further divided from the base factors. In this study the students’ marks have been focused and not solely on social, economic, and cultural features.  To evaluate students’ performance, fuzzy expert system has been developed by considering all the seven factors as inputs to the system. This system has been developed by taking the data of students collected from St. Josephs College of Engineering and Technology, Palai affiliated to M.G University.

II.   Literature review

In recent years, many researchers worked on the applications of fuzzy logic and fuzzy sets in educational assessments and grading systems. Biswas[25] presented two methods for evaluating  students’ answer scripts using fuzzy sets and a matching function: a fuzzy evaluation method (FEM) and a generalized fuzzy evaluation method. He used fuzzy set theory in student evaluation and found that it is potentially finer than awarding grades or numbers when evaluating answer scripts. He also highlighted that the importance of education system should be to provide students with the evaluation reports regarding their test/examination as sufficient as possible with unavoidable error as small as possible so as to make evaluation system more transparent and fairer to students.

          Chen and Lee [26] presented two methods for applying fuzzy sets to overcome the problem of giving two different fuzzy marks to students with the same total score which could arise from Biswas’ method. Their methods perform calculations much faster and complicated matching operations were not required. Echauz and Vachtsevanos [27] proposed a fuzzy logic system for translating traditional scores into letter-grades. Law [28] built a fuzzy structure model with its algorithm to aggregate different test scores in order to produce a single score for individual students in an educational grading system. A method to build the membership functions (MFs) of several linguistic values with different weights was also proposed in this paper. 

         Wilson, Karr, and Freeman [29] presented an automatic grading system based on fuzzy rules and genetic algorithms. To assess the outcomes of student-centered learning using the evaluation of their peers and lecturer, a new fuzzy set approach was proposed by Ma and Zhou[30] .Wang and Chen [31] proposed a method for evaluating students answer scripts using fuzzy numbers associated with degree of confidence. They have considered degree of confidence of evaluator when awarding satisfaction level to questions of student answer scripts. Weon and Kim [32] developed an evaluation strategy based on fuzzy MFs. They pointed out that the system for students’ achievement evaluation should consider the three important factors of the questions: the difficulty, the importance, and the complexity. They used singleton functions to describe the factors of each question reflecting only the individual effect of the three factors and not the collective effect.
            Bai and Chen [34] pointed out that the difficulty factor is a very subjective parameter and may cause an argument concerning fairness in evaluation. Bai and Chen [33] proposed a method for automatically constructing grade membership functions of fuzzy rules for students’ evaluation. Bai and Chen [34] proposed a method for applying fuzzy MFs and fuzzy rules for the same purpose. To solve the subjectivity of the difficulty factor in Weon and Kim’s method [32], they obtained the level of difficulty as a function of the accuracy of the student’s answer script and the time consumed to answer the questions. However, their method still has the subjectivity problem, since the results in scores and ranks are heavily dependent on the values of several weights which are determined by the subjective knowledge of domain experts.

             In paper[35], a fuzzy logic evaluation system considering the importance, the difficulty, and the complexity of questions based on Mamdani’s[36] fuzzy inference and center of gravity (COG) defuzzification is proposed as an alternative to Bai and Chen’s method [34]. The transparency and objective nature of the fuzzy logic system makes it easy to understand and explain the results of evaluation, and thus to persuade students who are skeptical or not satisfied with the evaluation results. Li and Chen [37] proposed a method for automatically generating the weights for several attributes with fuzzy reasoning capability. Chiang and Lin [38] presented a method for applying the fuzzy set theory to teaching assessment. Chang and Sun [39] presented a method for fuzzy assessment of learning performance of junior high school students. From the previous studies, it can be found that fuzzy numbers, fuzzy sets, fuzzy rules, and fuzzy logic systems have been used for various educational grading systems. 

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Wednesday, September 9, 2015

Validation of Failure of Beater Shaft of Double Roller Ginning Machine using Mathematical Failure Analysis Approach

Abstract:- A cotton gin is a machine that quickly and easily separates cotton fibers from their seeds, allowing for much greater productivity than manual cotton separation. The fibers are processed into clothing or other cotton goods, and any undamaged seeds may be used to grow more cotton or to produce cottonseed oil and meal. The cotton gin is a machine used to separate cotton fibers from the seed. The double roller ginning machine consists of various parts such as beater shaft, leather roller, moving knife, fixed knife, feeder, etc.         During the ginning operation the shaft fails at certain location. The actual failure position of shaft shown in fig no A was studied and the failure analysis using theories of failure was used to identify and validate the place or point of failure.

Keywords: Ginning machine, beater shaft, theories of failure, SFD, BMD, failure analysis

I.       Introduction

Ginning, in its strictest sense, refers to the process of separating cotton fibers from the seeds. The cotton gin has as its principal function the conversion of a field crop into a salable commodity. Thus, it is the bridge between cotton production and cotton manufacturing.  Ginning is the first and most important mechanical process by which seed cotton is separated into lint (fiber) and seed and machine used for this separation is called as gin. It consists of two spirally grooved leather roller pressed against a fixed knife, are made to rotate at about 90-120 rpm. Two moving blades combined with seed grids constitutes a central assembly known as beater which oscillates by means of a crank or eccentric shaft, close to the fixed knife. When the seed cotton is fed to the machine in action, fibers adhere to the rough surface of the roller are carried in between the fixed knife and roller in such a way that the fibers are partially gripped between them. The oscillating knife beats the seed and separates the fibers. This process is repeated for number of times and due to push-pull-hit action the fibers are separated from the seed, carried forward on the roller and dropped out of machine. The ginned seeds drop down through the grid which is oscillating along with beater.

Fig. 1: Double Roller Gin machine

The beater assembly is the innermost and major part of the double roller gin and is sandwiched symmetrically between the stationary knives as shown in fig.  It is composite unit consisting of moving knives and seed grids situated on the either side of the beater shaft. It has anchor shaped cross section and its axle is situated 100cm above ground and 15cm from each roller. Beater trough with perforations having concave edge with radius of 565cm and angle of 144 degree between two arms is provided to stop unginned cotton to fall down into seed chute.

http://ijirst.org/Article.php?manuscript=IJIRSTV2I3052
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This paper is published in our journal for more information go on above link.

Monday, August 24, 2015

Automatic Vs. Selective Criteria based Policy Network Extraction over Routers Data

Abstract:- Policy networks are generally utilized by political scientists and economists to clarify different financial and social phenomena, for example, the advancement of associations between political elements or foundations from diverse levels of administration. The examination of policy networks requires a prolonged manual steps including meetings and polls. In this paper, we proposed an automatic procedure for evaluating the relations between on-screen characters in policy networks utilizing web documents of other digitally documented information gathered from the web. The proposed technique incorporate website page information extraction, out-links. The proposed methodology is programmed and does not require any outside information source, other than the documents that relate to the political performers. The proposal assesses both engagement and disengagement for both positive and negative (opposing) performer relations. The proposed algorithm is tested on the political science writing from routers document database collections. Execution is measured regarding connection and mean square error between the human appraised and the naturally extricated relations.
Keywords: Policy Networks, Social Networks, Relatedness Metrics, Similarity Metrics, Web Search, Policy Actors, Link Analysis

I.       Introduction

The expression "network" is much of the time used to depict groups of various types of actor who are connected together in political, social or economic concerns. Networks may be loosely organized but must be capable for spreading data or participating in aggregate activity. The structure of these networks are frequently unclear or dynamic, or both. In any case developing such networks are required because it reflects how present day society, society and economy are related. Linkages between different organizations, have turned into the important aspect for some social scientists. The term policy network implies “a  cluster  of  actors,  each  of  which  has  an  interest,  or “stake” in a given…policy sector and the capacity to help determine policy success or failure” [1] on other words definition of a policy network, “as a set of relatively stable relationships which are of non-hierarchical and interdependent nature linking a variety of actors, who share common interests with regard to apolicy and who exchange resources to pursue these shared interests acknowledging that co-operations the best way to achieve common goals” [3]. Examiners of governance are often try to clarify policy results by examining that how networks, which relates between stakeholders over policy plan and point of interest, are organized in a specific segment. The policy networks are also acknowledged as to be an important analytical tool to analyze the relations amongst the actors who are interacting with each other in a selected policy area. Furthermore it can also be used as a technique of social structure analysis. Overall it can be said that policy networks provide a useful toolbox for analyzing public policy-making[2]. Although the policy networks are required for analysis of different relations however it is difficult to extract it because of the fact that policymaking involves a large number and wide variety of actors, which makes this taskvery time consuming and complex task.Considering the importance of policy networks and knowing that there is not any computational technique available for efficiently and automatically extracting the policy network in this paper we are presenting an efficient approach for it.

II.    Related work on policy network

The application of computational analysis for large sized datasetasgaining popularity in the recent past. Because of most of the relation documents are available in digital format and also it makes the process automated and fast. Since the policy networks is a kind of structure which presents the relations amongst the actors which are presented in documents as “name” or known words and the sentence in the text describes the relations between them hence the extraction technique in the basic form contains text data mining techniques, or it can be said that it is an extension of text and web mining, like Michael Laver et al [14] presented a new technique for extracting policy relations from political texts that treats texts not as sentences to be analyzed but rather, as data in the form of individual words. Kenneth Benoit et al [13] presented the computer word scoring for the same task. Their experiment on Irish Election shows that a statistical analysis of the words in related texts in terms of relations are well able to describe the relations amongst the parties on key policy considerations. They also evaluated that for such estimations the knowledge of the language in which the text were written is not required, because it calculates the mutual relations not the meaning of words. The WORDFISH scaling algorithm to estimate policy positions using the word counts in the related texts. This method allows investigators to detect position of parties in one or multiple elections. Their analysis on German political parties from 1990 to 2005 using this technique in party manifestos shows that the extracted positions reflectchanges in the party system very precisely. In addition, the method allows investigators to inspect which words are significant for placing parties on the opposite positions finally the words with strong political associations are the best for differentiate between parties. As already discussed that Semantic difference of documents are important for characterizing their dierences and is also useful in policy network extraction. Krishnamurthy KoduvayurViswanathanet al [7] describe several text-based similarity metrics to estimate the relation between Semantic Web documents and evaluate these metrics for specific cases of similarity.Elias Iosif et al [6] presented web-based metrics for semantic similarity calculation between words which are appeared on the web documents. The context-based metrics use a web documents and then exploit the retrieved related information for the words of interest. The algorithms can be applied to other languages and do not require any pre-annotated knowledge resources.

III.  Similarity computation techniques in documents

Metrics that live linguistics similarity between words or terms will be classified into four main classes relying if information resources area unit used or not[5]:
-        Supervised resource based mostly metrics, consulting solely human-built data resources, like ontologies.
-        Supervised knowledge-rich text-mining metrics, i.e., metrics that perform text mining relying conjointly on data resources,
-        Unsupervised co-occurrence metrics, i.e., unsupervised metrics that assume that the linguistics similarity among words or terms will be expressed by associate association quantitative relation that could be a measure of their co-occurrence.
-        Unsupervised text-based metrics, i.e., metrics that square measure absolutely text-based and exploit the context or proximity of words or terms to cipher linguistics similarity.
The last 2 classes of metrics don't use any language resources or skilled data, each rely solely on mutual relations, hence in this sense, the metrics are brought up as “unsupervised”; no linguistically labeled human-annotated information is needed to calculate the semantic distance between words or terms.
Resource-based and knowledge-rich text mining metrics, however, use such knowledge, and square measure henceforward stated as “supervised” metrics. Many resource-based strategies are planned within the literature that use, e.g., Word-Net, for linguistics similarity computation.

This paper is published in our journal for more information about this paper go on to below link

http://ijirst.org/Article.php?manuscript=IJIRSTV2I2001

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Saturday, August 22, 2015

Modeling of Student’s Performance Evaluation


Abstract:- We proposed a Fuzzy Model System (FMS) for student performance evaluation. A suitable fuzzy inference mechanism has been discussed in the paper. We mentioned how fuzzy principal can be applying in student performance prediction. This model can be useful for educational organization, educators, teachers, and students also. We proposed this model especially for first year students who need some extraordinary monitoring to their performance. Modeling based on the past academic result and on some information they earlier submitted for admission purposes.

Keywords: Fuzzy Logic, Membership Functions, Academic Evaluation

I.       Introduction

Success rate of any Educational Institute or Organization may depend upon the prior evaluation of student’s performance. They use different method for student’s performance evaluation usually any educational organization use grading system on the basis of academic performance especially higher education. We can involve other key points to evaluating student performance such as communication skill, marketing skill, leadership skill etc.
Performance evaluation can provide information. Information generated by evaluation can be helpful for students, teachers, educators etc. to take decisions.[6] In corporate field employers highly concern about all mentioned skill. If an educational institute involve other than academic performance for evaluation then it will be beneficial for students as well as organization also.

A.      Traditional Evaluation Method

Traditionally student’s performance evaluate done by academic performance like class assignment, model exams, Yearly etc. This Primary technique involves either numerical value like 6.0 to 8.0 which may call grade point average or 60% to 80% i.e average percentage. Some organization also using linguistic terms like pass, fail, supply for performance evaluation. Such kind of evaluation scheme depends upon criteria which are decided by experienced evaluators. So that evaluation may be approximate.
The objective of this paper is to present a model .which may be very useful for teachers, organization and students also. It helps to better understanding weak points which acts as a barrier in student’s progress.

B.      Method Used

Fuzzy logic can be described by fuzzy set. It provide reasonable method / technique through input and output process fig[1].Fuzzy set can be defined by class of object, there is no strident margins for object[1].A fuzzy set formed by combination of linguistic variable using linguistic modifier.
Linguistic Modifier is link to numerical value and linguistic variable [2]. In our work linguistic variable is performance and linguistic modifiers are good, very good, excellent, and outstanding.

For more information go to below link.

http://ijirst.org/Article.php?manuscript=IJIRSTV2I3022

http://ijirst.org/index.php?p=SubmitArticle

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