YMCA University of Science and Technology

About: YMCA University of Science and Technology is a education organization based out in Faridabad, India. It is known for research contribution in the topics: Web crawler & Web page. The organization has 299 authors who have published 568 publications receiving 4547 citations.

A framework for utilising usage trends in the crawling and indexing process of search engines

Abstract: Making search engines responsive to human needs requires understanding of user navigations through the search results in response to the submitted queries. The user behaviour characterisation provides an interesting perspective towards understanding the workload imposed on the search engine and can be used to address crucial points such as load balancing, content caching, data distribution and result optimisation. The user browsing behaviour is recorded in the query logs of search engines and usually referred to as web usage data. In this paper, a technique to utilise the users' browsing behaviour at the crawling and indexing process is being proposed so as to direct the crawler to download the important pages, which were not previously crawled. As the work attempts to index most of important pages based on user feedback, it would benefit the search engine to enhance its efficiency. To add further to the proposed work, the existing data structures maintained by the search engines has been refined so as to support the proposed user feedback mechanism and open more research directions.

Experimental Investigation and Simulation of Magnetic Flux Leakage from Metal Loss Defects

Abstract: Magnetic flux leakage (MFL) principle is widely used in detecting defects in cross-country pipelines The tools based on the MFL techniques termed as instrumented pipeline inspection gauge (IPIG) are frequently used as per statutory requirement The tool identifies the location of metal loss and also characterizes the size of metal loss defects in terms of length, width along circumference and depth in terms of percentage loss Tool velocity in terms of frequency of data acquisition is important parameter whose effect on the MFL signal and on the defect quantification has been studied Operation of linear pull through rig under various combinations of MFL tool parameters such as velocity, frequency and spatial sampling has been developed A set of experiments by varying velocity from 025 to 2 m/s keeping frequency constant at 450 Hz have been carried out MFL signals obtained from all known defects have been analyzed for its nature and quantifying the dimension of defect The effect of velocity on individual dimensions of the defect has been studied in this work Within the limitation of the experiments carried out, the present work indicates that smaller defects cannot be reported with better accuracy Also, the velocity is seen to have a significant effect in characterizing the length of the defect using IPIG especially for defects of larger area

Semantic Analysis Based Approach for Relevant Text Extraction Using Ontology

Abstract: Semantic analysis computation is done by extracting the interrelated concepts used by an author in the text/content of document. The concepts and linking i.e. relationships that are available among the concepts are most relevant as they provide the maximum information related to the event or activity as described by an author in the document. The retrieved relevant information from the text helps in the construction of the summary of a large text present in the document. This summary can further be represented in form of ontology and utilized in various application areas of information retrieval process like crawling, indexing, ranking, etc. The constructed ontologies can be compared with each other for calculation of similarity index based on semantic analysis between any texts. This paper gives a novel technique for retrieving the relevant semantic information represented in the form of ontology for true semantic analysis of given text. KEywORdS Concepts, Ontology, Parsing, Semantic, Similarity, Syntactic Analysis

Detection of Stator Winding Faults Using Finite Element Analysis (FEA) in BLDC Motors

Abstract: Detection of eccentricity faults has been feasible using physical and vibrational parameters. The Brushless DC motor is undergoes various kinds of stresses including mechanical, electrical, thermal, and environmental. These stresses increase the probability of occurrences of stator faults with various severity levels. The well maintained BLDC motor and correct operations decrease the probability of occurrences of faults. These faults are of three types as damage in laminations, damage in frame of stator and faults in stator winding. As per study of IEEE and EPRI, most frequent fault is stator fault, which is approximately 28–36 % of overall faults [1, 2]. Majority of these faults are due to a combination of above stresses. It is essential to detect and diagnose such faults at the early stage through measurement and monitoring of changes in the magnetic flux of the BLDC motor in the motor windings and stator slots. In this paper, brushless dc motor and its stator, rotor and windings are designed using FEA method .Changes in magnetic flux of each of the element in the motor are monitored in case of the change in the air gap between rotor and stator .Changes in the magnetic flux ,current are analysed using model of healthy and faulty motors with static and dynamic eccentricity faults. The results indicate detection of faults at the early stages of operation of BLDC motor. This early detection and correction of faults will be useful in avoiding wear and tear . Key Words: Brushless DC motor, Air Gap Eccentricity Faults, FEA Magnetic Flux

Enhancement of Transient Stability of Multimachine System Using TCSC, SSSC and UPFC

Abstract: This paper presents the transient stability enhancement of a multimachine system using series FACTS controllers. Series FACTS controller devices, i.e. TCSC, SSSC and UPFC, have been used in this paper for enhancing the transient stability of the system. Time-domain simulations are carried on PSAT (power system analysis tool box). The simulation results demonstrate that transient stability improves commendably of the multimachine system by using TCSC, SSSC and UPFC. Eigen value analysis also has been done during prefault condition, fault condition and with series FACTS controllers, i.e. TCSC, SSSC and UPFC. It also been observed that UPFC gives better transient stability enhancement as compared to TCSC and SSSC.