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An Experimental Study Analysis of Security Attacks at IEEE 802.11 Wireless Local Area Network
Md Waliullah,A B M Moniruzzaman,Md. Sadekur Rahman,Member, IEEE 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.1
IEEE802.11 wireless networks have become one of the most widely used networks. Due to open nature of wireless medium, hackers and intruders can make utilization of the loopholes of the wireless communication; as a result, there are many security threats associated with Wireless Local Area Network (WLAN). In this paper, we have worked an experimental analysis to study some of the well known attacks pertaining to IEEE 802.11 WLAN. At first, some of the open issues related to this fragile technology have been discussed. Based on this vulnerabilities and threats categories some of the major attack has been performed in a live environment by using open source software tools i.e Aircrak-nj, kismet. etc. The analysis and finding from this paper’s proved that the complexity of attacks had increased by time and the Wifi technology are becoming more dangerous to the end users and business environment.
A. K. M. Mahbubul Hossen,A. B. M. Moniruzzaman,Member, IEEE,Syed Akhter Hossain,Member, IEEE, ACM 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.5
Hadoop–a popular open-source implementation of MapReduce is widely used for the analysis of large datasets. The current Hadoop implementation assumes that computing nodes in a cluster are homogeneous in nature. In this paper we evaluate performance of Hadoop Platform and Oracle for Distributed Parallel Processing in large datasets. For evaluation, we implement a prototype of a virtual datacenter using distributed and parallel computing technology. The purpose of this paper is to reduce datacenter implementation cost using commodity hardware and provide high performance. Hadoop is installed on a commodity Linux cluster the distributed processing of large data sets across clusters of computers using distributed and parallel computing architecture. This paper also helps to explain about some new technology and framework which are open source; that can easily utilize those technologies for our complex data analysis which resembling structured, semi structured and non-structured data. Here we tried to demonstrate a performance comparison by executing some queries between distributed parallel computing system and traditional single computing system. For the simulation of the infrastructure Hadoop cluster has been used for distributed parallel processing and Oracle 11g is used for traditional single processing system. We prepare three virtual host for Hadoop cluster and a high-end hardware for Oracle 11g.
An Efficient and Simple Load Flow Approach for Radial and Meshed Distribution Networks
B. Ravi Teja,V.V.S.N. Murty,Ashwani Kumar,member IEEE 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.2
The main contribution of this paper is: (i) proposing a new efficient and simple load flow method for balanced radial and meshed distribution systems, (ii) impact of load models, different X/R ratios, load growth and tolerance levels to check robustness of proposed load flow method, (iii) impact of number of loops on meshed distribution systems, (iv) Comparison of radial and mesh distribution for voltage profile, total power losses, and number of iterations. The convergence ability of the proposed load flow method is evaluated under these conditions. Computer program has been developed to implement the power flow solution scheme in MATLAB and successfully applied to several practical distribution networks with radial and mesh structure. The convergence ability is quantitatively evaluated for different loading conditions, load growth, R/X ratios, and tolerance levels. Moreover, the effects of static load modeling on the convergence characteristics of the proposed algorithm are also investigated. Effectiveness of the proposed load flow method has been tested on IEEE 33 bus and IEEE 69 bus radial and meshed distribution networks. The proposed load flow method is compared with existing load flow methods, Ghosh et al. [6], Aravindhababu et al. [7], and J.H.Teng [16] to demonstrate its effectiveness.
PSPICE Modeling and Simulation of IGBT Based Resonant Commutation Converter
M.Akherraz,IEEE Senior Member 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10
This paper presents a PSPICE simulation of an, experimentally tested, IGBT based 24-Khz-DC-DC resonant commutation converter. The DC-AC conversion is done via an IGBT bridge and the AC-DC conversion is accomplished by a high frequency ac link followed by a fast diode bridge. The ac link consists of snubbing capacitors and a variable air-gap transformer, which are designed to fulfill Zero Voltage Commutation requirement. The proposed converter is simulated using PSPICE and the obtained results are compared to experimental results with discussion and comments.
Analysis of Carrier PWM Algorithms For Three Phase Four Wire Multi-level Inverter
Nguyen Van Nho,Myung Joong Youn,IEEE Senior Member 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-
This paper presents a simple PWM method to control three phase four leg multilevel inverters, which have been developed for supplying electrical power to three phase unbalanced load and for related power active filters. The method is derived from a general correlation between space vector PWM (SVPWM) method and carrier based PWM (CPWM) method. As an advantage, the simplicity and flexibility of the proposed CPWM control can be obtained and the complicated calculations of the 3-D SVPWM concepts can be avoided. The method has been mathematical formulated and demonstrated by simulation results.
Multi-modulating Pattern - A Unified Carrier based PWM method In Multi-level Inverter - Part 2
Nguyen Van Nho,Myung Joong Youn,IEEE Senior Member 전력전자학회 2004 전력전자학술대회 논문집 Vol.- No.-
This paper presents a systematical approach to study carrier based PWM techniques (CPWM) in diode-clamped and cascade multilevel inverters by using a proposed named multi-modulating pattern method. This method is based on the vector correlation between CPWM and the space vector PWM (SVPWM) and applicable to both multilevel inverter topologies. A CPWM technique can be described in a general mathematical equation, and obtain the same outputs similarly as of the corresponding SVPWM. Control of the fundamental voltage, vector redundancies and phase redundancies in multilevel inverter can be formulated separately in the CPWM equation. The deduced CPWM can obtain the full vector redundancy control, and fully utilize phase redundancy in a cascade inverter. In this continued part, it will be deduced correlation between CPWM equations in multi-carrier system and single carrier system, present the mathematical model of voltage source inverter related to the common mode voltage and propose a general algorithm for multi-modulating modulator. The obtained theory will be demonstrated by simulation results..
Analysis and Control of an MMC-HVDC System Under an Unbalanced Grid Condition
Kim Tuan Luu,Minxiao HAN,Senior Member, IEEE,Xiaojun Tang 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6
Modular multilevel converter (MMC)-based high voltage direct current (HVDC) systems have been increasingly researched and installed in recent years. During operation, systems may be subjected to various unbalanced conditions, the single-line to ground (SLG) fault is one of the most common unbalanced faults. When a SLG fault occurs in a three-phase alternating current (AC) system, the double-line frequency positive- and zero-sequence harmonic components will be produced besides the double-line frequency negative-sequence harmonic component. And if the control system cannot suppress these harmonic components, they can propagate into the direct current (DC) side of the HVDC system and cause ripples in DC-line voltage and current as well as other unwanted consequences. Among the proposed controllers in the published papers on this topic, rarely controllers can both eff ectively suppress the circulating current and completely eliminate ripples in the DC-line voltage and current while still keeping the AC-side current balanced under unbalanced grid conditions. Therefore, this paper fi rst analyses the propagation of harmonic components in a two-terminal MMC-HVDC system under a SLG fault. Then, based on the mathematical analysis, a proposed controller including an inner current controller for controlling the negativeand positive-sequence components and a controller for suppressing the zero-sequence component is designed to eliminate harmonic propagation from the faulty three-phase AC system to the DC side of the HVDC system, resulting in suppressing ripples in DC-line voltage and current. The theoretical analysis and proposed controller are verifi ed by a simulation model in PSCAD platform.