Showing papers by "YMCA University of Science and Technology published in 2012"

Optimization of multi machining characteristics in WEDM of WC-5.3%Co composite using integrated approach of Taguchi, GRA and entropy method

Abstract: Wire electrical discharge machining (WEDM) is a well known process for generating intricate and complex geometries in hard metal alloys and metal matrix composites with high precision. In present work, intricate machining of WC-5.3%Co composite on WEDM has been reported. Taguchi’s design of experiment has been utilised to investigate the process parameters for four machining characteristics namely material removal rate, surface roughness, angular error and radial overcut. In order to optimize the four machining characteristics simultaneously, grey relational analysis (GRA) coupled with entropy measurement method has been employed. Through GRA, grey relational grade has been computed as a performance index for predicting the optimal parameters setting for multi machining characteristics. Using Analysis of Variance (ANOVA) on grey relational grade, significant parameters affecting the multi-machining characteristics has been determined. Confirmatory results prove the potential of present approach.

Applying fuzzy grey relational analysis for ranking the advanced manufacturing systems

Abstract: Purpose – Advanced manufacturing system (AMS) offers opportunities for industries to improve their technology, flexibility and profitability through a highly efficient and focused approach to manufacturing effectiveness. Selecting a proper AMS is a complicated task for the managers as it involves large tangible and intangible selection attributes. Failure to take right decision in selecting proper AMS alternative may even lead industry to losses. The purpose of this paper, therefore, is to rank the AMS alternatives by using fuzzy grey relational analysis, which will help managers when choosing an appropriate AMS.Design/methodology/approach – This research proposes a multi‐attribute decision‐making (MADM) method, fuzzy grey relational analysis (FGRA), for AMS selection. The methodology is explained as follows. AMS alternatives and selection attributes will be chosen. The qualitative attributes will be converted into quantitative using fuzzy conversion scale. Then these data will be pre‐processed to normali...

Advanced manufacturing technology effectiveness: A review of literature and some issues

Abstract: Advanced manufacturing technology (AMT) provides advantages to manufacturing managers in terms of flexibility, quality, reduced delivery times, and global competitiveness. Although a large number of publications had presented the importance of this technology, only a few had delved into related literature review. Considering the importance of this technology and the recent contributions by various authors, the present paper conducts a more comprehensive review. Literature was reviewed in a way that will help researchers, academicians, and practitioners to take a closer look at the implementation, evaluation, and justification of the AMT. The authors reviewed various papers, proposed a different classification scheme, and identified certain gaps that will provide hints for further research in AMT management.

Optimal placement of FACTS devices for voltage stability using line indicators

Abstract: Optimal location of FACTS (Flexible AC Transmission System) is very important for static voltage stability. This paper presents the determination of most unstable bus of system using P-V curve and eigenvalue analysis and the critical line using the stability indices. Voltage collapse indicators indices give exact information about the stability condition of a system and also determine the most insecure bus of the system. The line indices are evaluated for IEEE 14 bus system and critical line is found where the index reaches its maximum value. PSAT (power System Analysis Toolbox) software is used for Continuation Power Flow (CPF)) and the results shows that optimal placement of Unified Power Flow Controller (UPFC) significantly increase the loadability margin and stability of system.

Evaluation of Barriers Affecting Reconfigurable Manufacturing Systems with Graph Theory and Matrix Approach

Abstract: In response to the requirement, the manufacturing processes have evolved from mass production technique, through its implementation on reconfigurable systems. The most difficult part of reconfigurable manufacturing systems (RMSs) is an understanding of the barriers related to their relative interdependencies. This article presents a conceptual framework of various barriers associated with RMSs along with their interdependencies. Using graph theory and matrix methods, the barriers of RMSs presented in the form of a single numerical index. The proposed model is quite versatile from the point of view that it provides an opportunity to integrate new barriers which could impact on manufacturing processes. In the present work, an attempt has been made to develop a mathematical model of these barriers using graph theory and matrix methods. An index of barriers in RMS is proposed which evaluates the inhibiting power of these barriers.

A comparison of production system life cycle models

Abstract: Companies today need to keep up with the rapidly changing market conditions to stay competitive. The main issues in this paper are related to a company’s market and its competitors. The prediction of market behavior is helpful for a manufacturing enterprise to build efficient production systems. However, these predictions are usually not reliable. A production system is required to adapt to changing markets, but such requirement entails higher cost. Hence, analyzing different life cycle models of the production system is necessary. In this paper, different life cycle models of the production system are compared to evaluate the distinctive features and the limitations of each model. Furthermore, the difference between product life cycle and production life cycle is summarized, and the effect of product life cycle on production life cycle is explained. Finally, a production system life cycle model, along with key activities to be performed in each stage, is proposed specifically for the manufacturing sector.

Modelling and experimental investigation of process parameters in WEDM of WC-5.3 % Co using response surface methodology

Abstract: . Tungsten carbide-cobalt (WC-Co) composite is a difficult-to-machine material owing to its excellent strength and hardness at elevated temperature. Wire electrical discharge machining (WEDM) is a best alternative for machining of WC-Co composite into intricate and complex shapes. Efficient machining of WC-Co composite on WEDM is a challenging task since it involves large numbers of parameters. Therefore, in present work, experimental investigation has been carried out to determine the influence of important WEDM parameters on machining performance of WC-Co composite. Response surface methodology, which is a collection of mathematical and experimental techniques, was utilised to obtain the experimental data. Using face-centered central composite design, experiments were conducted to investigate and correlate the four input parameters: pulse-on time, pulse-off time, servo voltage and wire feed for three output performance characteristics – cutting speed (CS), surface roughness (SR) and radial overcut (RoC). Using analysis of variance on experimental data, quadratic vs. two-factor interaction (2FI) models have been suggested for CS and RoC while two-factor interaction (2FI) has been proposed for SR. Using these mathematical models, optimal parameters can be determined easily for desired performance characteristics, and hence a trade-off can be made among different performance characteristics.

Coupled common fixed point results involving a ( φ , ψ )-contractive condition for mixed g-monotone operators in partially ordered metric spaces

Abstract: In the setting of partially ordered metric spaces, using the notion of compatible mappings, we establish the existence and uniqueness of coupled common fixed points involving a (ϕ, ψ )-contractive condition for mixed g-monotone operators. Our results extend and generalize the well-known results of Berinde (Nonlinear Anal. TMA 74:7347-7355, 2011; Nonlinear Anal. TMA 75:3218-3228, 2012) and weaken the contractive conditions involved in the results of Alotaibi et al. (Fixed Point Theory Appl. 2011:44, 2011), Bhaskar et al. (Nonlinear Anal. TMA 65:1379-1393, 2006), and Luong et al. (Nonlinear Anal. TMA 74:983-992, 2011). The effectiveness of the presented work is validated with the help of suitable examples. MSC: 54H10; 54H25

Empirical modeling of shot peening parameters for welded austenitic stainless steel using grey relational analysis

Abstract: The attempt of this paper is to present an effective approach for the optimization of the shot peening process of welded AISI 304 austenitic stainless steel with multi performance characteristics using Grey relational analysis (GRA) based on Taguchi orthogonal array. Twenty-seven experimental runs are performed to determine best process parameters level. An analysis of variance (ANOVA) is carried out to identify significant peening parameters. The response tables are obtained for analyzing the optimal levels of shot peening parameters and major factors that affect the quality function. The multiple performance characteristics including tensile strength, surface hardness and surface roughness are the quality functions considered for the optimization. Further mathematical models are developed using regression analysis for the tensile strength, surface hardness and surface roughness. It will be very helpful to the engineers in deciding the levels of the shot peening parameters for desired performance characteristics.

Identification of novel single nucleotide polymorphisms in the DGAT1 gene of buffaloes by PCR-SSCP.

Abstract: Diacylglycerol O-acyltransferase 1 (DGAT1) is a microsomal enzyme that catalyzes the final step of triglyceride synthesis. The DGAT1 gene is a strong functional candidate for determining milk fat content in cattle. In this work, we used PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) and DNA sequencing to examine polymorphism in the region spanning exon 7 to exon 9 of the DGAT1 gene in Murrah and Pandharpuri buffaloes. Three alleles (A, B and C) and four novel single-nucleotide polymorphisms were identified in the buffalo DGAT1 gene. The frequencies of the alleles differed between the two buffalo breeds, with allele C being present in Murrah but not in Pandharpuri buffalo. The allele variation detected in this work may influence DGAT1 expression and function. The results described here could be useful in examining the association between the DGAT1 gene and milk traits in buffalo.

Comparative Analysis of Ontology Ranking Algorithms

Abstract: Ontologies are the backbone of knowledge representation on Semantic web. Challenges involved in building ontologies are in terms of time, efforts, skill, and domain specific knowledge. In order to minimize these challenges, one of the major advantages of ontologies is its potential of “reuse,†currently supported by various search engines like Swoogle, Ontokhoj. As the number of ontologies that such search engines like Swoogle, OntoKhoj Falcon can find increases, so will the need increase for a proper ranking method to order the returned lists of ontologies in terms of their relevancy to the query which can save a lot of time and effort. This paper deals with analysis of various ontology ranking algorithms. Based on the analysis of different ontology ranking algorithms, a comparative study is done to find out their relative strengths and limitations based on various parameters which provide a significant research direction in ranking of ontologies in semantic web.

Management of Transaction Exposure: A Comparative Analysis of MNCs in India

Abstract: In an era of globalization, thousands of transactions of international trade take place among companies of different countries. But the profitability of these transactions can be completely wiped out by adverse movements in the exchange rate during this time gap. Transaction exposure is a measure of effect of exchange rate fluctuations on these transactions. Unmanaged transaction exposure can paralyze not only financial position but also competitive position of companies in market. The present study portrays transaction exposure management as practiced by various multinational companies in India. And compares management of transaction exposure by banking and non-banking and foreign and Indian MNCs. The effect of various factors on their management policy is also investigated. The results of the study evidence that the majority of firms make efforts to measure their transaction exposure. There is no significant effect of level of transaction exposure on estimation policy and decision to develop separate management system for management of transaction exposure of companies. Significant difference exists between management policies of companies of different sectors toward management of their transaction exposure. Companies are actively using various hedging strategies for managing their transaction exposure.

An AHP-based approach for the selection of HFMS: an Indian perspective

Abstract: To meet the challenges imposed by today’s dynamic market conditions, it is the right time for the manufacturing companies to transit from traditional manufacturing system to advance manufacturing system such as computer numerical control (CNC), flexible manufacturing system (FMS) and computer integrated manufacturing (CIM) systems. CNC, FMS and CIM are very well-known terms in the manufacturing world. Developed countries have adopted and used all these manufacturing systems in their industries. Developing countries like India have used CNC technology in their plants but are reluctant to opt for the next phase of advance manufacturing system, i.e. FMS or CIM due to their high cost and heavy risk associated with them. Hence, a new manufacturing system, i.e. humanised FMS suitable to Indian industrial and social environment has been proposed in this paper. Analytic hierarchy process methodology has been utilised for the justification of this new manufacturing concept.

Fast tracking algorithm using modified potential function

Abstract: This study introduces a new potential function-based modelling approach for real-time object tracking with single camera. Real-time tracking requires the least complex techniques for processing and classification and still provide accurate results. Particle filter-based algorithms allow accurate estimations of the displacement and scaling of the object for tracking, but at the cost of high computational complexity and complicated modelling. Also, the existing single-camera tracking systems lack the ability to predict the direction of motion of the object and their performance is significantly affected by occlusions. This study proposes a new method to address these four key issues. The method is principally based upon the potential function, which has been modified for motion image sequences. Potential function uses the current estimates of non-linear scaling and drift vector with a priori knowledge of the object to compute the tracking parameters in the form of diffusion matrices. The concept of attractors and repellers inside a potential field has been used in analogy to classify different directions of motion in the image plane, such that the object tends to drift towards the attractors and away from repellers. Attractor for every consecutive pair of frames is estimated using the set of transformations (displacement and scaling) occurred due to the motion in a particular direction. The proposed technique works well with minimal tracking errors and a computational complexity of O(1).

Design and performance analysis of ultra low power 6t sram using adiabatic technique

Abstract: Power consumption has become a critical concern in both high performance and portable applications. Methods for power reduction based on the application of adiabatic techniques to CMOS circuits have recently come under renewed investigation. In thermodynamics, an adiabatic energy transfer through a dissipative medium is one in which losses are made arbitrarily small by causing the transfer to occur sufficiently slowly. In this work adiabatic technique is used for reduction of average power dissipation. Simulation of 6T SRAM cell has been done for 180nm CMOS technology. It shows that average power dissipation is reduced up to 75% using adiabatic technique and also shows the effect on static noise margin.

Battery operated closed loop speed control of DC Separately Excited Motor by Boost-Buck Converter

Abstract: The Boost-Buck converter, also known as Cuk converter is an alternative power conversion topology which can be used for buck and boost the battery input voltage. Hence a wide range of speed control is possible for a dc separately excited motor using such converter. In this paper, the dynamic modeling of Boost-Buck converter with motor load has been formulated using state-space averaged analysis method. Small-signal model has been derived from the state-space averaged dynamic method for linearization. The input side phenomenon, associated with passive parameters is studied using small-signal analysis to show the right-half-plane (RHP) zero in the control-to-output transfer function. Based on small-signal linearization model, the control law for speed control is derived. Speed is controlled by direct measurement of the speed and input current. The compensators for the speed loop and the current loop are designed based on the frequency responses and root locus technique. The passive parameters such as capacitor and inductors are estimated to limit the capacitor ripple voltage and inductor ripple current. Hysteresis band modulator is used for finding out the switching function of switch. Performance of control method of the compensated Boost-Buck converter is verified by simulation.

Development and comparison of quality award: based on existing quality awards

Abstract: The quality award programmes are applied worldwide. The various quality awards are the criteria for measuring performance excellence. They represent the framework for high-performance management system. In this paper the authors intend to (i) develop a quality award model based on commonalities among criteria of existing quality awards, (ii) develop interdependencies at system/sub system level and (iii) use inheritance and interdependencies to evaluate a numerical index for the developed model using graph theoretic approach. The framework incorporates the critical factors of quality evolution, which further implied for TQM implementation.

Quantitative analyses and evaluation of MANET routing protocols in effect of varying mobility model using Qual-Net simulator

Abstract: Mobile Ad hoc Network (MANET) is the collection of the mobile nodes without the aid of fixed infrastructure. The communication in MANET is therefore completely dependent on the nodes of the network. For the efficient working of the network various routing protocols have been developed. These protocols improve the efficiency of MANET by providing the path between distant nodes through multi-hop links. The performance of the protocols is affected by the various factors. One such factor is the mobility of the nodes. This paper provides the comparative analysis of various routing protocols used in day to day scenario under the effect of various mobility models: viz File, Group and Random Way Point Mobility Model. The results show significant impact of mobility models on performance of routing protocols.

Neuro-fuzzy Control of an Intelligent Mobile Robot

Abstract: This paper describes the reactive controlling of a mobile robotic system using a hybrid approach by adopting both neural network and fuzzy logic, so that, an autonomous robot should move in a crowded unknown environment to reach at a decided goal A fuzzy logic controller with a set of certain rules is used to obtain a goal reaching task While a neural network is conceived to control robot actuator system by adopting feed forward back-propagation supervised learning strategy A MATLAB simulation model is designed to show the behavior of robotic system according to binary or bipolar input as environmental input condition

A system's approach towards domain identification of web pages

Abstract: With the proliferation of the document corpora (commonly called as HTML documents or web pages) on the WWW, efficient ways of exploring relevant documents are of increasing importance [4, 8]. The key challenge lies in tackling the sheer volume of documents on the Web and evaluating relevancy for such a huge number. Efficient exploration needs a web crawler that can semantically understand and predict the domain of the web page through analytical processing. This will not only facilitate efficient exploration but also help in the better organization of the web content. As a search engine classifies the Search results by keyword matches, link analysis and other such mechanisms, the paper proposes a solution to the domain identification problem by finding keywords or key terms that are representative of the page's content through the elements like <META> and <TITLE> in the HTML structure of the webpage [11]. This paper proposes a two-step framework that automatically first identifies the domain of the specified web page and with the thus obtained domain information, classifies the web content according to the different pre- specified categories. The former uses the various HTML elements present in the web page while the latter is achieved using Artificial Neural Networks (ANN).

Fuzzy clustering of web documents using equivalence relations and fuzzy hierarchical clustering

Abstract: The conventional clustering algorithms have difficulties in handling the challenges posed by the collection of natural data which is often vague and uncertain. Fuzzy clustering methods have the potential to manage such situations efficiently. Fuzzy clustering method is offered to construct clusters with uncertain boundaries and allows that one object belongs to one or more clusters with some membership degree. In this paper, an algorithm and experimental results are presented for fuzzy clustering of web documents using equivalence relations and fuzzy hierarchical clustering.

Comparative analysis of harmonic reduction in multilevel inverter

Abstract: In this paper, different multilevel inverter topologies and their comparison has been presented. Multilevel inverter topologies (MLIs) are increasingly being used in medium and high power applications due to their many advantages such as low power dissipation on power switches, low harmonic contents and low electromagnetic interference (EMI) outputs. The distortion of the output voltage decreases as the number of level increases and it is further improved by applying pulse width modulation (PWM) techniques. In this work, an attempt has been made to reduce the harmonic content in the output voltage by incorporating different multi level inverter topologies using sinusoidal PWM technique. The gating signals for the switches are generated with the help of the switching table and the power circuit is simulated in MATLAB/Simulink.

Towards realistic performance evaluation of Mobile Ad Hoc Network

Abstract: Mobile Ad-Hoc Network (MANET) is a self-configuring network of mobile nodes connected by wireless links to form an arbitrary topology without the use of existing infrastructure. In order to facilitate communication between a pair of nodes, routing protocols are used. The performance of routing protocols is evaluated using simulation tools such as QUALNET, NS-2 and MATLAB etc. Simulation tool provides researchers with a number of significant benefits, including repeatable scenarios, isolation of parameters, and exploration of a variety of metrics. We wish to make these simulations more realistic for ad hoc network. To do the same different shapes such as square, elliptical, circular and rectangular of the simulation region were taken. In addition to different shapes, we used the concept of obstacle. These obstacles restrict node movement as well as obstruct the communication path between nodes. Simulation results show that for same number of nodes deployed having equal areas and with different shapes the throughput will have inverse relationship with perimeter. The result can be very useful while designing a routing protocol.

OWL-based ontology indexing and retrieving algorithms for Semantic Search Engine

Abstract: Various researchers have recognized that ontology based retrieval is one of the best in terms of precision and recall for semantic search engine. However, they did not specify explicitly any scheme/ algorithm for ontology based indexing and retrieval. This motivates us to conceive a proposal that includes (a) suggesting indexing algorithm to effectively maintain ontologies, (b) suggesting retrieving algorithm to process user query and produce results with better precision and recall. The proposed indexing algorithm has been tested manually considering a sample of ten OWL ontologies of mammal domain but presented only a result of two ontologies due to space constraint. Finally, the proposed retrieval algorithms have also been validated against three user queries.

Reachability Analysis of Mobility Models under Idealistic and Realistic Environments

Abstract: The mobility models are used to represent the unpredictable movement pattern of the nodes in Mobile Ad-hoc Network (MANET) and give us an idea regarding their location, velocity and acceleration change over time. These models are used for simulation purpose in standard software tools such as QualNet, ns-2 etc. This paper evaluates the performance of routing protocols for mobility models such as Random Way Point (RWP), Random Walk (RW) and Random Direction (RD) under idealistic and realistic conditions based on a parameter termed as Probability of Reachability (POR). The POR is defined as the fraction of reachable routes to all possible routes between all pairs of sources and destinations. For this purpose a simulator is designed in MATLAB. We observe a marked difference in value of POR under idealistic and realistic conditions.

Analysis of critical success factors for implementation of humanised flexible manufacturing system in industries

Abstract: The paper focuses to identify various critical success factors that could influence the implementation of newly proposed manufacturing system i.e., humanised flexible manufacturing system (HFMS), and develop a framework to manage them. Interpretive structural modelling (ISM) is used to depict the relationship and priority among the various critical success factors (CSFs). This research provides a framework for managers and indicates the dominant CSFs on the basis of higher driving power to enable the successful implementation of HFMS. The dependent, independent, autonomous and linkage CSFs have been found using MIMAC analysis. The drive power and dependence power for CSFs has been evaluated. The proposed hierarchal model would help the manufacturing industries to effectively implement newly proposed manufacturing system, i.e., HFMS and develop suitable strategies according to the CSFs driving power and dependence power. This would encourage more number of firms to transit from traditional manufacturing sy...

Transient modeling of Z-source chopper used for adjustable speed control of DC motor drive

Abstract: The newly proposed Z-source chopper using LC impedance network with switching converter circuit coupled between power source and load can be used in modern energy conversion system because of both voltage buck and boost capabilities. This paper presents transient modeling of Z-source chopper and complete speed feed back control of separately excited dc motor. In the process of designing the control scheme for controlling the speed of separately excited dc motor, knowledge of transfer function representing the unique dc impedance network is essential. The presence of right-half-plane zero in developed average control-to-output model reveal that the output decreases initially before rising toward its new steady-state value, when a step increase in control input is applied. The nonminimum-phase transient response can be reduced by proper feedback control technique. The speed is controlled using direct measurement of speed and inductor current. Compensator for both speed loop and current loop are designed using classical control technique through small-signal analysis. Hysteresis band modulator is used for finding out the switching function of switches. Performance of control method of the compensated Z-source chopper is verified by simulation.

Exploring `hidden' parts of the web: the hidden web

Abstract: A wealth of information is hidden within databases behind search interfaces that is unreachable to the traditional Web crawlers. One of the core challenges faced by a search engine is crawling this portion of the Web that is typically known as the Hidden Web. As the WWW continues to grow at an exponential rate, the problem of accurately retrieving information from the Hidden Web continues to exacerbate. This paper focuses on the approaches this content can be made visible to search engines and the various issues the crawlers come up with. The paper also articulates the tasks that need to be carried out by the crawler to overcome and patch up the issues.

Application of Mobile Agent in Distributed Network Management

Abstract: Current management models based on client/server suffer from scalability and flexibility problems. Furthermore, the staleness of gathered data (due to network latency involved) and probable error in the selection of management task being carried over (owing to the staleness of data) reduces the reliability of the management applications. In this sense, use of mobile agents offer many possibilities for designing the next generation of distributed network management systems by reducing the management traffic around the management station and distribute processing load.. This paper discusses various mobile agent based network management models, the key advantages of mobile agents in the distributed network management systems and presents a mathematical model for the purpose of comparing client/server vs. mobile agent paradigms in terms of responsiveness and traffic generated around management station.

Design of an Automatic Ontology Construction Mechanism Using Semantic Analysis of the Documents

Abstract: Ontologies play a major role in supporting information exchange processes in various areas. At present, ontologies are applied to the World Wide Web for creation of semantic web. The main application area of ontology technology is Knowledge Management. In the present scenario, it is difficult to acquire knowledge and then to maintain knowledge in a given domain. Manual ontology population is labor intensive and time consuming. Hence there is need to devise a method to provide fully automatic feeding of Web-based knowledge to the ontology. Moreover, for constructing ontology automatically, there is a need to discover a way to find, structure, and display the relationships between attributes and objects of a sentence. In this paper, a technique of Automatic Semantic Domain-ontology Populator (ASDP) towards construction of given domain modeled by the database is being proposed. ASDP is a way to find, structure, and display relationships between concepts, which consist of attributes and objects. This method helps in understanding a given domain and in building a domain model for it.