Asian Journal of Convergence in Technology
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OPTICAL FIBER
Get PDFOptical Fiber was initial created during the 1970s, the utilisation of and demand for optical fibber have boosted hugely. The uses of optical fibber these days are quite many. With the explosion of data traffic because of the net, electronic commerce, computer networks, multimedia, voice, data, and video, the necessity for a transmission medium with the information measure capabilities for handling such vast amounts of data is paramount. fiber optics, with its comparatively infinite information measure, has proved to be the answer
Flux Based Technique to Identify the Location of Inter Turn Faults in Transformer
Get PDFThe internal turn-to-turn faults (TTFs), as a common cause of the transformer failures, result in minor changes on terminal currents/voltages. They maybe undetected by the conventional protective relays. In this study, a simple, sensitive and robust linkage flux based technique is proposed to protect the power transformers against TTFs. In this approach, some separated multi-turn windings as search coils (SCs) have to be wrapped around the transformer core legs to sense the related passing flux. Since passing equal flux through a transformer core leg in normal condition induces equal voltages in the related SCs, variation of the induced voltages indicates the fault occurrence in that phase. Against the traditional differential protection schemes, current transformer error and saturation, tap changer operation, energizing inrush current, over-fluxing etc. cannot impact the proposed technique performance. Therefore, it can be introduced as a comprehensive protection technique for power transformers. It is notable that not only the internal TTFs can be detected by the proposed technique but also other types of internal faults are diagnosable by this technique. For example, the Earth faults near the star point are detectable whenever the star connected winding is grounded solidly. Such faults are similar to TTFs near the star point, and then they are detectable by the proposed technique, as well.
The presented technique can discriminate the external faults from the internal ones, too. When an external fault occurs, transformer winding is shorted entirely. Therefore, the corresponding SCs measure the equal reduced linkage fluxes overall the faulty phase, and accordingly the ΣΔΕ on the faulty phase cannot be activated, as it should be. As a brief review, the ΣΔΕ can detect any event that creates a distortion in the flux symmetricity along each core leg. It senses only the flux uniformity along the core legs and reacts whenever this regularity is distorted.
The proposed technique can be used for all power transformers with different rating voltages and powers. Moreover, type of windings connections cannot impact the performance of the proposed technique, while it is demonstrated on the basis of the flux homogeneity in the healthy transformer core
An Architecture to Secure (UAV) Cluster Communication
Get PDFUAVs are being increasingly used in military and commercial areas alike. They often carry sensitive information making them vulnerable to cybersecurity attacks. Potential security vulnerabilities may also exist in the modules used for functioning of the drone, for example, by launching a GPS spoofing attack or WIFI attack, adversaries can get hold of important information. RF signals are used to control UAVs, but this does not work for clusters. Hence, we use wireless networking for UAV clusters. We use the WIFI module for this, but this, too, has vulnerabilities. In this paper, we have attempted to strengthen the security layer for UAV communication by exploring various security threats
Computational complexity reduction in HEVC intra prediction using dual tree complex wavelet transform and holoentropy
Get PDFHigh efficiency video coding (HEVC) is the newest video codec to increases the coding efficiency of its ancestor H.264/Advance Video Coding at the cost of highly increased computational complexity. In this paper, a novel method using Dual tree Complex Wavelet Transform is proposed to reduce the computational time consumption in HEVC Encoding. DTCWT provides better directional selectivity. By using DTCWT, total intra prediction modes are reduced from 35 modes to 7 modes including DC and Planer mode. The encoding process in HEVC system is performed using clustered entropy computing, which distinguishes the video information has useful outliers. The pixel variations under varying frames are clustered based on the interestingness and the outliers are removed using an advanced entropy principle called as holoentropy. Compared to the current state of the art algorithms, the experimental results show that this scheme is computationally simple and achieves superior reconstructed video quality at less computational complexity
A systematic review on Android Malware Detection
Get PDFAndroid malware is growing at alarming rate and spreading rapidly despite on-going mitigating efforts. This brings a necessity to find more effective solutions to detect those malwares and prevent users from any malicious threats. The aim of the systematic review is to summarize the situation that existed from 2010 to 2015 with regards to various android malware analysis approaches and detection methods. A total of 58 selected papers met the inclusion criteria based on title of articles, exclusion criteria, reading abstract and content of the selected 58 papers. Different data are extracted from these articles and recorded in an excel sheet for further analysis. Most of the paper discussed about the use of dynamic analysis approach to analyze malware and signature-based method for malware detection. The systematic review carried out would provide information to all researchers and further inform the requirements for future development of enhanced malware analysis and detection methods
Semantic Web Engineering: Boon or Bane
Get PDFSemantic is the study of meaning of words in a sentence. Semantics help us find words which will fit better in sentence without changing the actual meaning of the sentence. Semantic is very important because, it is necessary to understand the different meanings of words and solves the problem of data overloading while retrieving information from Web. But semantics in ontological world has some shortcomings also. All the advantages and disadvantages related with semantics are collected and explicitly listed out clearly in this paper after a lot of research. Further, graphs have been used to depict the aim of the paper in a coherent manner and visualize the information written focusing on every aspect and need. The study of ontology and semantics in today’s world is considered necessity and ontological axioms have found their use in many fields like medicine, laboratories, mathematical calculation etc. Through this paper, we propose to find if semantic web engineering is a boon or a bane in the field of technology
State of Art Survey Signature Verification Techniques 2019
Get PDFCurrently a lot of time is needed for the verification of signature manually. The need of developing an automated checking system is felt because of signature forgery in various transactions. The dynamic signature is a biometric trait which is used in identification. The aim of the model is identifying correct signature for reducing fraudulent transactions. The idea is to duplicate a given signature a number of times and train the verifier with each of the resulting signatures. Automatic signature verification is an application of image processing. Signature Verification can be 1) Online (Dynamic) 2) Offline (Static). For duplication of signature one approach is using the Cognitive Inspired Model. The approach for creating human like signatures can be done by introducing Intra-Component and Inter-Component variability. This system, with a single reference signature, is capable of achieving a similar performance to standard verifiers trained with up to five signature specimens. For classification classifiers like SVM, CNN can be used
A Survey On: Sentiment Analysis framework of Twitter data Using Classification
Get PDF Sentiment means classify the opinions which are in the form of text. As we are classifying the text it must having different unstructured contains with information of particular subject. There are various social media sites which gives us information with their thoughts but twitter is biggest among them where anyone who having account on twitter can tweet their opinions of any subject in any certain or uncertain way. Hence, we get extra scope in mining of such data. The analysis is done with the help of machine learning algorithms on the dataset. Classification is done by the classifier algorithms. The reviews data is used for performing sentimental analysis. This paper gives idea about how the analysis is done on twitter data by using various algorithms and machine learning concepts. It is a survey of different papers for analyzing the sentiments of text. 
Positive and Negative Sequence Voltage Compensation Using Statcom at Wind Farm
Get PDFThe study of shunt connected FACTS devices is a connected field with the problem of positive and negative voltage compensation and better mitigation of instability problems in today’s world. In this project, the shunt operation of FACTS controller is studied, the STATCOM, and how it helps in the better utilization of a network operating under normal conditions. First literature review of many papers related to FACTS and STATCOM is carried out, along with positive and negative voltage compensation. The study of STATCOM and its principles of operation and control, including phase angle control and PWM techniques, are carried out. The study of shunt connected devices is a shunt connected field positive and negative sequence voltage compensation and better mitigation of transmission related world. Statcom is a FACTS device whose capacitive or inductive current can be controlled independent of system ac voltage. Whenever an asymmetrical fault occurs in a system, power loss and voltage instability can occur in that system. So to increase the life time of generator drives and to reduce that voltage instability, Statcom can be used. Statcom can compensate positive sequence voltage for improving voltage stability and for reducing torque ripples negative sequence voltage has to be compensated. Statcom can perform co-ordinated action regarding positive and negative voltage compensation. In this thesis, review of positive and negative voltage compensation and results for positive sequence voltage compensation and negative voltage compensation using MATLAB simulation is shown
Design of Zero Index Metamaterial Lens for Gain Enhancement of the Antenna array
Get PDFA zero index metamterial layer used for the gain enhancement of the patch antenna array operating in the L band. The slotted double circular ring resonator structure acts as the metamterial for the gain enhancement of the Microstrip patch antenna array. An improved gain, compact size with Near Zero Index (NZI) patch antenna array is designed with enhanced radiation properties. Slotted Double Circular Ring Resonator structure layer is placed above the microstrip patch antenna array. Moreover, it acts as Meta Surface lens. The proposed NZI lens is designed to increase the measured gain in E- and H-plane in operating frequency band (L-band)