Browsing by Subject "Logic circuits"

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Open Access
Design and determination of stator geometry for axial flux permanent magnet free rod rotor synchronous motor
(2011) Kalender O.; Ege, Y.; Nazlibilek, S.
During designing a new axial flux permanent magnet free rod rotor synchronous motor, it is important to know before hand in which phase the largest angular velocity can occur, what is the ways to reduce the power consumption, how to achieve to increase or decrease the rotation speed by changing the core geometry. Therefore, presenting these preliminary information that are necessary for the design of a free rod rotor synchronous motor to the researchers is the aim of this work. In this respect, this study presents the design and geometrical dimensions of the stator for a new synchronous motor which is an axial flux permanent magnet free rod machine with three, four, five and six phases. This type of motors are an innovative approach especially for the applications used in industrial stirrers. Each type of stator is designed such that it has an appropriate number of phases. The rotating magnetic field over the stator is established by a PIC based microcontroller feeding the interface circuit to the stator wounds. The maximum angular speeds of bar magnet rotors with four different lengths and masses are calculated theoretically and determined experimentally. In addition, the effects of the distance between the rotor and stator, the angular speed of the rotor within the limits of the operation, and the volume of the liquid to be stirred to the power applied are investigated. Furthermore, the effects of the lengths and angular speeds of the bar magnet rotors to the distance between the rotor and stator are determined. In the light of the information obtained and taking into account the power used, the most appropriate parameters and variables such as the stator geometry changing with the phase used, the length of rotor, the distance between the rotor and stator and the angular speeds of rotor are determined. © 2011 Elsevier Ltd. All rights reserved.
Open Access
A hand gesture recognition technique for human-computer interaction
(Academic Press, 2015) Kılıboz, N. Ç.; Güdükbay, Uğur
We propose an approach to recognize trajectory-based dynamic hand gestures in real time for human-computer interaction (HCI). We also introduce a fast learning mechanism that does not require extensive training data to teach gestures to the system. We use a six-degrees-of-freedom position tracker to collect trajectory data and represent gestures as an ordered sequence of directional movements in 2D. In the learning phase, sample gesture data is filtered and processed to create gesture recognizers, which are basically finite-state machine sequence recognizers. We achieve online gesture recognition by these recognizers without needing to specify gesture start and end positions. The results of the conducted user study show that the proposed method is very promising in terms of gesture detection and recognition performance (73% accuracy) in a stream of motion. Additionally, the assessment of the user attitude survey denotes that the gestural interface is very useful and satisfactory. One of the novel parts of the proposed approach is that it gives users the freedom to create gesture commands according to their preferences for selected tasks. Thus, the presented gesture recognition approach makes the HCI process more intuitive and user specific.
Open Access
A Wired-AND Current-Mode Logic Circuit Technique in CMOS for Low-Voltage, High-Speed and Mixed-Signal VLSIC
(1997) Ungan I.E.; Aşkar, M.
A wired-AND current-mode logic (WCML) circuit technique in CMOS technology for low-voltage and high-speed VLSI circuits is proposed, and a WCML cell library is developed using standard 0.8 micron CMOS process. The proposed WCML technique applies the analog circuit design methodologies to the digital circuit design. The input and output logic signals are represented by current quantities. The supply current of the logic circuit is adjustable for the required logic speed and the switching noise level. The noise is reduced on the power supply lines and in the substrate by the current-steering technique and by the smooth swing of the reduced node potentials. Precise analog circuits and fast digital circuits can be integrated on the same silicon substrate by using the low noise property of the WCML. It is shown by the simulations that at low supply voltages, the WCML is faster and generates less switching noise when compared to the static-CMOS logic. At high speeds, the power dissipation of the WCML is less than that of the static-CMOS logic.