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Title |
High Order Dual Polarization Modulation Formats for Coherent Optical Systems |
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Author |
Kamran Ali Memon, Asiya Siddiqui, Khalid Husain Mohmadani, Saleemullah Memon, Muhammad Abbas, Noor ul Ain |
| Citation |
Vol. 25 No. 7 pp. 154-158 |
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Abstract |
The present high capacity, speedy and spectral efficient optical access networks face immense challenges to deal with ever-increasing bandwidth demand, which arises from common use of high bandwidth-hungry applications, such as Video-on-demand, online gaming, and other multimedia applications. Present research trends encourage the use of higher order modulation formats for the further improvement in the spectral efficiency and overall capacity of the network. In this paper, we investigated the comparison of a single-channel coherent-optical-system (CO-OS) with dual polarization (i) Quadrature phase shift keying Modulation (DP-QPSK) and (ii) Quadrature amplitude modulation (DP-QAM) methods with the use of single mode fiber by considering digital-signal-processing (DSP) at the data rate of 112 GB/s. The evaluation metrics include fiber nonlinearities, the power of the CW-laser and the range of the distance. We displayed the relation between error-vector-magnitude in percentage (% EVM), transmitted power and transmission distance to indicate the efficiency and robustness of the modulation scheme. Results analyzed from the comparison of higher order modulation techniques conclude that modulation schemes are more vulnerable to nonlinearities, channel dispersion and thus are less spectral efficient. |
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Keywords |
Dual Polarization formats, %EVM, DSP, channel dispersion |
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Title |
Presenting a new Method of Intrusion Detection Systems based on Fuzzy Logic using Genetic Algorithms |
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Author |
Shahin Ghafori and Mansour Esmaeilpour |
| Citation |
Vol. 25 No. 7 pp. 154-160 |
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Abstract |
Nowadays, the speed of access to information as well as immediate processing are necessary. This has led to the storage of more information in computer systems and to use this information, we have to share them. Intruders may use specific patterns that their detection and identification is very difficult. In the suggested method and to optimize the obtained fuzzy rule set, heuristic method was used. This method, according to the criteria such as accuracy and interpretability, looks for a set of fuzzy rules in the space related to the rule set that indicates the best efficiency. One of the problems of intrusion detection systems is that there is little opportunity for identification. Also, it is not possible to make a good distinction between efficient features and inefficient features manually. Finally, the suggested method was implemented as software on NSL-KDD99 intrusion detection dataset that contains information about normal and intruded behaviors in computer networks. |
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Keywords |
intrusion detection system, fuzzy logic, genetic algorithms |
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