Two-parameter differential calculus on the h-superplane

We introduce a noncommutative differential calculus on the two-parameter $h$-superplane via a contraction of the (p,q)-superplane. We manifestly show that the differential calculus is covariant under $GL_{h_1,h_2}(1| 1)$ transformations. We also give a two-parameter deformation of the (1+1)-dimensional phase space algebra.Comment: 14 page

Cartan calculi on the quantum superplane

Cartan calculi on the extended quantum superplane are given. To this end, the noncommutative differential calculus on the extended quantum superplane is extended by introducing inner derivations and Lie derivatives

Evaluation Of Voice Trunking Performance Using AA2 Over ATM Networks

The urgent market needs for an efficient transport mechanism to carry voice traffic over Broadband Integrated Service Digital Networks (B-ISDN). Asynchronous Transfer Mode (A TM) network has been developed to integrate all types of traffic (e.g. voice, data and video) over B-ISDN networks. ATM Adaptation Layer 2 (AAL2) has been designed for efficient transport of voice, fax, and voice-band data traffic over an A TM virtual circuit. AAL2 allows the VBR sources to generate different packet sizes to be packed in an A TM cell, which increases the number of voice channels and decreases the packetization delay. The growing trend of using A TM has also given great impetus to the use of AAL2 in wire-line trunking (e.g. PBX), which provides a good opportunity for multiplexing many voice channels over a single A TM virtual connection. Voice trunking over A TM using AAL2 is the main subject of this thesis. The efficiency of AAL2 for voice transport in ATM networks is evaluated using a simulation approach. Additionally, the performance and capacity of an ATM multiplexer are analysed based on AAL2 technique. The power of AAL2 trunking and multiplexing high number of voice channels over a single ATM virtual connection makes it an efficient layer to support voice traffic with low delay and high efficiency using low bit rate as a reliable compression technique. In this thesis, the comparison between AAL2 and AAL 1 is made in terms of the number of users that can be carried over Tl AThI trunk. Then the focus is shifted to the use of AAL2 to support Voice and Telephony Over ATM (VTOA) networks. The effect of Timer-Composite Unit (Timer-CD) parameter, number of voice channels and voice coding rate on the packing density and link efficiency is further discussed. The results show that ATM cell packetization delay decreases when the number of users increases. Also, the Timer-CD affects the generation of partially filled cells when it is not set properly. Finally, the use of low coding bit rates to support high number of voice channels makes AAL2 a very efficient layer to carry VTOA networks

Transfer functions of the 2-phase servomotor

One of the most common electromechanical positioning devices for low-power applications is the 2-phase servomotor, several different . constructional forms being available. When used in a control application, various transfer functions of the machine are important and these have been investigated by previous workers using analyses of varying validity. For example, in early studies, it was common to regard the speed-torque characteristics of the machine as straight lines, and also to neglect the electrical energy storage elements in comparison with those of the mechanical system. Quite sophisticated mathematical studies using, for example, symmetrical components, were based on these assumptions, but the results obtained are obviously highly suspect in view of the doubtful basis from which they are established. Experimental verification of the results of the analyses were confined to steady-state. measurements, attention being devoted to establishing an equivalent circuit to provide steady-state characteristics. Recently, with the increasing use of powerful mathematical tools in engineering situations, several workers have attempted to obtain direct solutions of the nonlinear equations characterising the -operation of the servomotor. Thus, simulation and state transition methods, involving a step-by-step numerical solution, have attracted considerable interest. Although these approaches may provide useful numerical answers, they do not help in forming any understanding of the main factors affecting the transient performance of the machine. A recent paper used the complex convolution approach to provide analytical transfer functions, but unfortunately this paper contains a fundamental error which completely invalidates the work. The same formal approach is followed in this thesis, with the complex convolution technique being used to find time-domain expressions for the variations in speed which follow step changes in either the torque or the magnitude or phase of the control-winding voltage. As in the previous work, attention is confined to the practically important range of speed much lower than synchronous speed, Results obtained from the analysis are compared with experimentally obtained results and with results provided by earlier analyses, and an assessment is made of the usefulness and limitations of the various techniques

Бактерицидный эффект He-Ne лазера (632,8 нм) на колонии Staphylococcus aureus

The bactericidal effect of 632.8 nm low level laser has been studied in order to point out both the effective power and laser exposure time on Staphylococcus aureus, which is reported to be involved in several dermatology problems. Low level laser has been reported to be useful for infected wounds, tissue necrosis, nerve injury, osteoarthritis or other chronic pain syndromes. Numerous studies have been conducted to quantify the effective laser parameters, i.e. dose, power, and exposure time, which ultimately leads toward clinical implementation. Staphylococcus aureus bacteria colonies were exposed to laser doses with powers of both 1 and 3 mW at different exposure times varies between 3 to 30 minutes. The bacterial colonies were isolated from a patient with inflamed wounds. Two sets of bacterial colonies were prepared to be exposed to laser beam. Next, the bacterial colonies were compared before and after exposing them to laser doses. The results showed that laser sessions have reduced the number of the bacterial colonies for both doses; 1 and 3 mw at the different exposure times and concentrations. The results revealed significant dose dependent bactericidal effects of He-Ne laser on Staphylococcus aureus at 3 mW for 30 minutes, which was found to be more effective in reducing the amount of bacteria to the less than 2% of its initial count. The results exhibited the reduction of the number of colonies as a function of exposure time. Appropriate doses of 632.8 nm can kill Staphylococcus aureus, suggesting that a similar effect may be used in clinical cases of bacterial infection.Нами был изучен бактерицидный эффект низкочастотного лазера с длиной волны 632,8 нм с целью определения эффективной мощности и времени воздействия лазера на бактерии Staphylococcus aureus, участвующие в патогенезе ряда дерматологических заболеваний. Ранее проведены многочисленные исследования количественной оценки эффективных параметров лазера: световой дозы, плотности мощности и времени воздействия. В настоящем исследовании на колонии бактерий Staphylococcus aureus воздействовали лазерным излучением мощностью 1 и 3 мВт при разном времени воздействия (от 3 до 30 мин). Колонии бактерий были выделены у больного с воспаленными ранами. Воздействие лазером уменьшило количество бактериальных колоний во всех экспериментах. Результаты выявили значительное дозозависимое бактерицидное воздействие гелий-неонового лазера на Staphylococcus aureus. При мощности 3 мВт при воздействии в течение 30 мин количество бактерий снизилось до уровня менее 2% от его первоначального количества. Результаты показали уменьшение количества колоний в зависимости от времени воздействия. Лазерное излучение на длине волны 632,8 нм обладает бактерицидным действием в отношении Staphylococcus aureus

Study of Optical OFDM System for Wireless LAN Applications

The advantages of optical fiber make it possible to extend the data rate transmission and propagation distance. Orthogonal frequency division multiplexing (OFDM) as a multicarrier technique (MC) is used in hybrid optical-wireless system designs because it has the best spectral efficiency to radio frequency (RF) interference and lower multipath distortion. In this dissertation, a study and evaluation of optical OFDM based wireless local area network (W-LAN) systems are presented. The baseband of the OFDM signal is fully transmitted and up-converted to a radio frequency signal. Also, to reduce system costs, simple base stations (BSs) are interconnected to a central office (CO) via an optical fiber. All the required operations are achieved in the CO. The directly modulated laser (DML) and continuous wave (CW) laser are used in the system simulations as optical laser sources. Identical rectangular microstrip patch antennas have been used at the transmitter and the receiver as well. The simulations were carried out for different SMF and MMF lengths, and the variable wireless distance between the transmitting and receiving antennas was in a range of 40 dB to 80 dB. The purpose of this work is to provide a framework for integrating wireless and optical technologies in one system with the presence of OFDM technology. The required microstrip patch antenna parameters for the system are analyzed and designed. The microstrip patch antenna (S-parameters) is loaded into the Optisystem communication software tool in Touchstone format. As a result, this achievement gives a greater impetus to design an integrated optical-wireless system, and simulation results validate the proposed technique. Then, the integration of the microstrip patch antenna and optical OFDM system is achieved, and the performance is intensely studied. The entire system has been presented by developing analytical models and simulations. The system performance results are obtained regarding EIRP, SNR, signal constellations and BER. The results show that this integrated optical wireless link is very robust for carrying OFDM based wireless LAN signals over an optical fiber. Moreover, using an active patch antenna in the system helps to increase the coverage service to more than 30 meters when an SMF of 80 km length is utilized