IMPACT : International Journal of Research in Engineering & Technology

1-8

Authors: Dodda Satish Reddy, Tewodros Degu Kebede, Biks Alebachew Taye & Chakrala Krishna Prasad

This paper aims to extend the knowledge about performance of different Cascade H-Bridge multilevel inverters (CHB-MLI) through harmonic analysis. Large utility applications require advanced power electronics converter to meet high power demands. As a result, multilevel power converter structure has been introduced as an alternative for high power and medium voltage situations. A multilevel converter not only achieves high power ratings, but also improves performance of the whole system in terms of harmonics, dv/dt stresses, and stresses in the bearings of a motor [1]. Multilevel inverters are becoming more popular in the power conversion systems for high power and power quality demanding applications. The MATLAB based simulation on SIMULINK platform is presented for Cascade H-Bridge multilevel inverter (CHB-MLI) topology of Single Phase cascaded H-bridge Multilevel Inverter for 13, 23, and 33-levels. A detailed comparison of Cascade H-Bridge multilevel inverters (CHB-MLI) are presented in the paper based on number of power devices used, Total Harmonic Distortion [1].

17-22

Authors: Sonali Godara, Hira Durrani & Mayank Gupta

Throughout history, there have been countless instances of people protesting against the government, in order to bring the required change. Staged sit-ins, blockades, hunger strikes, and marches are some of the tactics used to pressurize government and organizations to change a particular law, which these protestors find morally wrong. This paper highlights the relevance of Civil Disobedience, and presents exactly what it entails. The paper explains why acts of civil disobedience are justified, and how to deal with the unsolvable dilemma caused by the conflict between moral and civil law.

29-40

Authors: Ojulari H. O., Arulogun O. T. & Oke A. O

The vast majority of Automatic Teller Machines (ATMs) researches is mostly focused on security and ATM modeling, but no study has considered extracting financial information from the electronic journal (EJs). ATM Customer transactions are recorded in a semi-structured text file called EJ. This makes it difficult to run a direct search query on such format to resolve transaction disputes in banks. This research focuses on how to extract financial information from ATM EJs. An EJ Parser algorithm was developed to establish information extraction (IE) method. The IE applied a divide and conquer concept to decompose the EJ into sub-problems of unit transaction sessions, and named entity recognition (NER) was performed to identify all financial transaction tokens or entities, and the extraction task adopted a regular expression (Regex) as an entity classifier. The algorithm was tested with a collection of live EJ data from a Wincor ATM of a bank, and its performance was evaluated accordingly, using standard performance metrics such as precision, accuracy, f-secure, misclassification and recall. The algorithm indicated 99%, 99.7%, 99.7% of precision, recall and accuracy respectively. However, there were a few exceptions that happened as misclassification of which, were traced to ‘comments’ and ‘avail balance’ entities.

51-60

Authors: Jayalakshmi K, Uma K M, Veena A, & Lavanya Santhosh

In cloud computing technology, user can store large amount of data on storage provided by cloud and make use of resources as and when required, due to which, it becomes very significant. As a result, cloud computing technology has recently become a new model, by which we can host and deliver services over the internet. In cloud computing, resources are shared between different computers and other devices by means of the internet. There are so many issues, which have been observed in a cloud computing environment that need to be addressed. These issues can be categorized as: Security, Protection, Identity Management, Management of resources, Management of Power and Energy, Data Isolation, Availability of resources and Heterogeneity of resources. The first point of security, where, cryptography can facilitate cloud computing is secure storage, but the major disadvantages of secure storage is that we cannot perform processing on encrypted data. This paper presents the challenges and issues of security aspects in cloud computing method. We first look into the impacts of the distinctive characteristics of cloud computing, namely, multi-tenancy, elasticity and third party control, upon the security requirements. Then, we analyze the cloud security requirements in terms of the fundamental issues, i.e., confidentiality, integrity, availability, audit and compliance.

75-86

Authors: G. H. Rushaa & M. A. Hosany

With the advent of communication technologies, we have more and more multi-media services available. Therefore, the main focus is to transmit video at high quality, and this concept tends to continue in the years to come. In this work, a Trellis Coded Modulation (TCM) system is used in order to achieve high video quality. The aim is to reduce the effect of transmission errors on the transmitted H.264 AVC by using the concept of Unequal Error Protection (UEP). UEP gives higher priority to the most important bits and vice-versa. The performance of the TCM system is investigated by varying the Doppler shift (Hz) and the Eb/No values which will reflect on the quality of the received signal. The signal is transmitted through the Rayleigh channel, followed by the Additive White Gaussian Noise channel (AWGN). The output of this system is to prove that the relation between Energy of Bit to Noise Ratio (Eb/No) and Bit Error Rate (BER) is as expected in theory. The design, implementation and simulation are carried out using the MATLAB R2008b. The performance of the system can be illustrated using graphical and analytical representation of BER with respect to the applied Doppler shift.

95-100

Authors: Nazar A. Hussein, Omar Naji Ali, Asawir Salim Tumma & Ayat Jawdat Kadhum

Ac conductivity in the frequency range of 5 103 to 5 103 Hz of Octapheny tetrapyrazinoporphrazine Cupper (II) (OpTpPzCu) was measured, which consists of frequency independent (Dc conductivity) and frequency dependent part. This kind of conductivity results from hopping of charge carriers between localized sites around Fermi levels. The hopping sites is indication of the degree of imperfection in the crystal. The number of the hopping sites was calculated using Webb and William equation which is estimated to be 1 1020 eV-1cm-3.