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Cairo, Egypt

Saad N.H.,Ain Shams University | Sattar A.A.,Ain Shams University | Mansour A.E.A.M.,Police Academy
Renewable Energy | Year: 2015

Wind Energy Conversion System (WECS) based on Doubly Fed Induction Generator (DFIG) connected to the grid is subjected to high transient currents at rotor side and rise in DC-link voltage during voltage sag at stator/grid side. To secure power system operation wind turbines have to meet grid requirements through the Low voltage ride through (LVRT) capability and contribute to grid voltage control during severe situations. This paper presents the modeling and control designs for WECS based on a real model of DFIG taking into account the effect of stator resistance. The non-linear control technique using sliding mode control (SMC) strategy is used to alter the dynamics of 1.5MW wind turbine system connected to the grid under severe faults of grid voltage. The paper, also discusses the transient behavior and points out the performance limit for LVRT by using two protection circuits of an AC-crowbar and a DC-Chopper which follow a developed flowchart of system protection modes under fault which achieved LVRT requirements through results. The model has been implemented in MATLAB/SIMULINK for both rotor and grid side converters. © 2015 Elsevier Ltd. Source


Ping T.,Police Academy
Proceedings - 2015 7th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2015 | Year: 2015

This paper introduces the basis deep packet inspection technology, studies data filtering technology, stream filter technology and intrusion prevention system. Then it further puts forward a string matching-based deep packet inspection model, explains framework structure of model and its various parts design in detail and analyzes key parts affecting packet detection performance. We study relevant string matching algorithm. After it analyzes classical BM algorithm and standard BF algorithm, this paper proposes an improved BF string matching algorithm. Finally, based on open source IDS system Snort, this paper performs comparison analysis on BM, BF and its improved algorithm on matching speed and memory occupation. The results prove that the improved project is superior to traditional BM algorithm on matching speed or memory occupation based on certain scale of rule set. © 2015 IEEE. Source


Atac Y.,Police Academy
Turkish Journal of Agriculture and Forestry | Year: 2013

The effects of heartwood and sapwood on kraft pulp properties of Pinus nigra J.F.Arnold. and Abies bornmuelleriana Mattf. were investigated. The differences in terms of chemical composition and fiber properties between the heartwood and sapwood of these species were also examined. Heartwood had more holocellulose and extractive compared to sapwood. Moreover, heartwood fiber length was shorter than that of sapwood. Kraft cookings of heartwood and sapwood each species were separately done under fixed cooking conditions. The results indicated that heartwood pulp had lower pulp viscosity and total pulp yield than sapwood did. The tear index of sapwood unbeaten and beaten kraft pulp was higher than that of heartwood. However, the burst and tensile indices of heartwood unbeaten and beaten kraft pulp were higher than those of sapwood. © TÜBİTAK. Source


Wu R.-C.,University of Electronic Science and Technology of China | Feng-Li Z.,University of Electronic Science and Technology of China | Ben-Jun N.,Police Academy
International Journal of Multimedia and Ubiquitous Engineering | Year: 2014

The abstract is to be in fully-justified italicized text as it is here, below the author information. Use the word "Abstract" as the title, in 12-point Times New Roman, boldface type, centered relative to the column, initially capitalized. The abstract is to be in 11-point, single-spaced type, and may be up to 3 in. (18 picas or 7.62 cm) long. Leave two blank lines after the abstract, then begin the main text. All manuscripts must be in English. © 2014 SERSC. Source


Aksoy C.,Diyarbakir Police Forensic Laboratory | Bora T.,Ankara Police Forensic Laboratory | Senocak N.,Police Academy | Aydin F.,Dicle University
Forensic Science International | Year: 2015

False positives due to the presence of antimony in vehicle seat fabrics are a problem in gunshot residue (GSR) analysis, in particular, when graphite furnace atomic absorption spectrometry (GFAAS) is employed. In this study, we sought to determine the reason for the prevalence of false positive results and to propose a new approach for the analysis of GSR on vehicle seats. GFAAS was used to examine adhesive tape swabs collected from 100 seats of 50 different automobiles. Characterization of seat fabrics was carried out by using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy with energy dispersive X-ray (SEM/EDX) spectroscopy. The results of FTIR analysis indicated that all seat covers containing antimony were composed of polyester. Experimental results obtained by SEM/EDX analysis revealed that the fabrics in these seat covers contained evenly distributed antimony within the structure of polyester fibers. This study shows that the type of seat fabric should be determined by FTIR spectroscopy before elemental GSR analysis. In this way, most of the false positives caused by polyester fibers in GSR analysis can be prevented. © 2015 Elsevier Ireland Ltd. Source

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