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Zekry A.,Ain Shams University | Ibrahim A.,University of Alberta | Atallah A.,ITT Technical Institute | Abouelatta M.,Ain Shams University | Shaker A.,Ain Shams University
Mapan - Journal of Metrology Society of India | Year: 2016

In this paper, a digital vector impedance half-bridge meter based on virtual instruments is designed, implemented and tested. Here, not only the accuracy of the magnitude of the impedance is considered but, more importantly, its phase measurement accuracy. The meter utilizes a four-voltmeter method which is a basic modification of the well-known three-voltmeter method. The half-bridge is constructed with commercially available data acquisition (DAQ) board in the form of peripheral control interconnect cards incorporated in personal computers. The DAQ board is used only to acquire the voltages instead of using four separate voltmeters, while the excitation signal is produced by an integrated circuit signal generator. The main error in this method arises from the error in measuring the voltage values. Since the resolution of the DAQ board used here is 16 bits; expect that absolute errors due to A/D conversion will be around 0.305 mV for ±10 V range. Detailed error analysis of the method is included in the context of the paper. It is found that the errors in the impedance magnitude is fairly small and relatively less sensitive on the resolution of the voltmeters because of the relative measurements in the half bridge with a precise reference resistance. The original three voltmeter vector impedance meter has relatively large error in the phase especially in the small phase angles. To decrease the phase error to an acceptable range, one has to increase the resolution of the voltmeter appreciably, which makes them expensive. The other solution to reduce the error in the phase angle with less cost is to add a fourth voltmeter which acquires directly the small phase angles. In this case, it is found that, a much lower resolution voltmeter can be utilized while achieving an acceptable measurement accuracy of the impedance. © 2016 Metrology Society of India

McLay C.L.,University of Canterbury | Hinnendael F.,ITT Technical Institute | Lavery S.,University of Auckland | Riquelme-Bugueno R.B.,University of Concepcion
Journal of Crustacean Biology | Year: 2011

The estuarine crab Hemigrapsus crenulatus (H. Milne Edwards, 1837) is a native of New Zealand, but it is also known from the coast of Chile some 8900 km eastwards across the Pacific. Mary Rathbun (1898) was the first person to call crabs from the Chilean coast, H. crenulatus, saying that they were conspecific with crabs described by Milne Edwards (1837). However, Bennett (1964) took the advice of H. Balss that the Chilean species should be known as Hemigrapsus granarius (Nicolet, 1849). No type specimens are available for either of these species. We have used mitochondrial 16S rRNA and COI sequences derived from fresh specimens to find out who was correct. There are few if any consistent morphological differences between populations from either side of the South Pacific and very few molecular differences (only 3 fixed nucleotide differences out of 1190 bp total sequenced 0.25%). None of these differences exceed variation within either population, so we must declare Miss Rathbun the winner! The molecular data suggest that there is only one species, Hemigrapsus crenulatus, and that the two populations have been separated only recently in the last few thousand years, perhaps during the last glacial epoch. How this species colonized the coast of South America remains an open question. It does not even occur on off-shore islands near the New Zealand mainland so it probably needed assistance to cross the Pacific. © The Crustacean Society.

Sackey E.,Concordia University College of Alberta | Sackey E.,ITT Technical Institute | Lindskog D.,Concordia University College of Alberta | Ruhl R.,Concordia University College of Alberta | Zavarsky P.,Concordia University College of Alberta
Proceedings - SocialCom 2010: 2nd IEEE International Conference on Social Computing, PASSAT 2010: 2nd IEEE International Conference on Privacy, Security, Risk and Trust | Year: 2010

There are several weaknesses that make home wireless networks prone to unauthorized access. The weaknesses include misconfiguration, use of default settings, and many others as a result of general lack of user education. This paper proposes a framework for educating home wireless users. It examines the nature of education frameworks and suggests a structural guide for effective education that could be used by information technology trainers and consultants. © 2010 IEEE.

Norte D.,InfoPrint Solutions Company | Norte D.,ITT Technical Institute
IEEE International Symposium on Electromagnetic Compatibility | Year: 2011

This paper discusses the benefits of scrambling high-speed data signals for reducing the electromagnetic radiation from the electrical interconnects that propagate these signals. It is shown how maximum length sequences, generated through the use of tapped shift register scrambling structures, can significantly mitigate the electromagnetic interference from data signals that are inherently periodic in the time-domain. Specifically, it is shown how a 7-bit scrambler enabled the EMC margin of a system to be increased from 3.5dB without the scrambler, to +5.5dB with the scrambler, resulting in a +9dB improvement in the EMC performance of the system. © 2011 IEEE.

Bodnar M.,Czech Technical University | Prokop J.,Czech Technical University | Dovgalenko G.,ITT Technical Institute | Wu Y.,Shanghai Jing Na Luo Decor Design Engineering Co.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The vital demand for contemporary industry of real time NDE sensors is in field operation, which often surrounded by harsh electromagnetic environment such as high level EMI fields or high level of X-Ray or nuclear radiation. Contemporary CCD image sensors are highly vulnerable even for 0.5 volt EMI fields and highly vulnerable for x-ray and gamma radiation. The high lever radiation such as 50keV, 100kev, 150keV, 200keV, 300keV, 420keV, is extremely dangerous for human body. CCD image sensors are vulnerable to that radiation level. We proposed doped single crystal 3D image sensor for the real time NDE measurement. Proposed sensor was not vulnerable to electromagnetic field produced by High Voltage Tesla generator and to the high level X-ray radiation: 50keV, 100kev, 150keV 200keV, 300keV, 420keV. Vulnerability and degradation of CCD image sensor to 40keV and 50keV X-Ray radiation was demonstrated and documented. Opportunity to use that sensor for real time NDE of protective coating layers, under high level radiation and EMI fields is discussed. © 2010 Copyright SPIE - The International Society for Optical Engineering.

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