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1,383 results on '"Barker, Steve"'

6. An Artificial Neural Network to Estimate the Foliar and Ground Cover Input Variables of the Rangeland Hydrology and Erosion Model

Author

Saeedimoghaddam, Mahmoud, primary, Nearing, Grey, additional, Goodrich, David, additional, Hernandez, Mariano, additional, Guertin, D. Phillip, additional, Metz, Loretta, additional, Wei, Haiyan, additional, Ponce-Campos, Guillermo E., additional, Burns, Shea, additional, McCord, Sarah E., additional, Nearing, Mark, additional, Williams, C Jason, additional, Houdeshell, Carrie-Ann, additional, Rahman, Mashrekur, additional, Meles, Menberu B., additional, and Barker, Steve, additional

Published
2023
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7. A 10.5 ppm/°C Modified Sub-1 V Bandgap in 28 nm CMOS Technology with Only Two Operating Points.

Author

Nagulapalli, Rajasekhar, Yassine, Nabil, Tammam, Amr A., Barker, Steve, and Hayatleh, Khaled

Subjects
MONTE Carlo method, VOLTAGE references, BIOSENSORS, ANALOG circuits, ON-chip charge pumps, SUCCESSIVE approximation analog-to-digital converters
Abstract

Reference voltage/current generation is essential to the Analog circuit design. There have been several ways to generate quality reference voltage using bandgap reference (BGR) and there are mainly two types: current mode and voltage mode. The current-mode bandgap reference (CBGR) is widely accepted in industry due to having an output voltage which is below 1 V. However, its drawbacks include a lack of proportional to absolute temperature (PTAT) current availability, a large silicon area, multiple operating points, and a large temperature coefficient (TC). In this paper, various operating points are explained in detail with diagrams. Similar to the conventional voltage mode bandgap reference (VBGR) circuits, modifications of the existing circuits with only two operating points have also been proposed. Moreover, the proposed BGR occupies a much smaller area due to eliminating the complimentary to absolute temperature (CTAT) current-generating resistor. A new self-biased opamp was introduced to operate from a 1.05 V supply, reducing systematic offset and TC of the BGR. The proposed solution has been implemented in 28 nm CMOS TSMC technology, and extraction simulations were performed to prove the robustness of the proposed circuit. The targeted mean BGR output is 500 mV, and across the industrial temperature range (−40 to 125 °C), the simulated TC is approximately 10.5 ppm/°C. The integrated output noise within the observable frequency band is 19.6 µV (rms). A 200-point Monte Carlo simulation displays a histogram with a 2.6 mV accuracy of 1.2% (±3-sigma). The proposed BGR circuit consumes 32.8 µW of power from a 1.05 V supply in a fast process and hot (125 °C) corner. It occupies a silicon area of 81 × 42 µm (including capacitors). This design can aim for use in biomedical and sensor applications. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Dynamic Event-Based Access Control as Term Rewriting

Author

Bertolissi, Clara, Fernández, Maribel, Barker, Steve, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Barker, Steve, editor, and Ahn, Gail-Joon, editor

Published
2007
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13. Logical Approaches to Authorization Policies

Author

Barker, Steve, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Goebel, Randy, editor, Siekmann, Jörg, editor, Wahlster, Wolfgang, editor, Artikis, Alexander, editor, Craven, Robert, editor, Kesim Çiçekli, Nihan, editor, Sadighi, Babak, editor, and Stathis, Kostas, editor

Published
2012
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14. The Scientific Contribution of Marek Sergot

Author

Barker, Steve, Jones, Andrew J. I., Kakas, Antonis, Kowalski, Robert A., Lomuscio, Alessio, Miller, Rob, Muggleton, Stephen, Sartor, Giovanni, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Goebel, Randy, editor, Siekmann, Jörg, editor, Wahlster, Wolfgang, editor, Artikis, Alexander, editor, Craven, Robert, editor, Kesim Çiçekli, Nihan, editor, Sadighi, Babak, editor, and Stathis, Kostas, editor

Published
2012
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15. Socially Constructed Trust for Distributed Authorization

Author

Barker, Steve, Genovese, Valerio, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Atluri, Vijay, editor, and Diaz, Claudia, editor

Published
2011
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16. Dynamics in Delegation and Revocation Schemes: A Logical Approach

Author

Aucher, Guillaume, Barker, Steve, Boella, Guido, Genovese, Valerio, van der Torre, Leendert, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, and Li, Yingjiu, editor

Published
2011
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17. Secommunity: A Framework for Distributed Access Control

Author

Barker, Steve, Genovese, Valerio, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Goebel, Randy, editor, Siekmann, Jörg, editor, Wahlster, Wolfgang, editor, Delgrande, James P., editor, and Faber, Wolfgang, editor

Published
2011
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18. A Logic of Privacy

Author

Barker, Steve, Genovese, Valerio, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Foresti, Sara, editor, and Jajodia, Sushil, editor

Published
2010
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19. Dynamic Meta-level Access Control in SQL

Author

Barker, Steve, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, and Atluri, Vijay, editor

Published
2008
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22. Term Rewriting for Access Control

Author

Barker, Steve, Fernández, Maribel, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Dough, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Damiani, Ernesto, editor, and Liu, Peng, editor

Published
2006
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32. TRBACN: A Temporal Authorization Model

Author

Barker, Steve, Goos, Gerhard, editor, Hartmanis, Juris, editor, van Leeuwen, Jan, editor, Gorodetski, Vladimir I., editor, Skormin, Victor A., editor, and Popyack, Leonard J., editor

Published
2001
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35. Data Protection by Logic Programming

Author

Barker, Steve, Goos, G., editor, Hartmanis, J., editor, van Leeuwen, J., editor, Carbonell, Jaime G., editor, Siekmann, Jörg, editor, Lloyd, John, editor, Dahl, Veronica, editor, Furbach, Ulrich, editor, Kerber, Manfred, editor, Lau, Kung-Kiu, editor, Palamidessi, Catuscia, editor, Pereira, Luís Moniz, editor, Sagiv, Yehoshua, editor, and Stuckey, Peter J., editor

Published
2000
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36. Panel Session: What Are the Key Challenges in Distributed Security?

Author

Barker, Steve, Chadwick, David, Crampton, Jason, Lupu, Emil, Thuraisingham, Bhavani, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, and Atluri, Vijay, editor

Published
2008
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45. A 0.82V supply and 23.4 ppm/0C current mirror assisted bandgap reference

Author

Nagulapalli, R., Hayatleh, Khaled, Yassine, Nabil, Barker, Steve, and Palani, R.

Subjects
Hardware_INTEGRATEDCIRCUITS
Abstract

Traditional BGR circuits require a 1.05V supply due to the VBE of the BJT. Deep submicron CMOS technologies are limiting the supply voltage to less than 940mV. Hence there is a strong motivation to design them at lower supply voltages. The supply voltage limitation in conventional BGR is described qualitatively in this paper. Further, a current mirror-assisted technique has been proposed to enable BGR operational at 0.82V supply. A prototype was developed in 65nm TSMC CMOS technology and post-layout simulation results were performed. A self-bias opamp has been exploited to minimize the systematic offset. Proposed BGR targeted at 450mV works from 0.82-1.05V supply without having any degradation in the performance while keeping the integrated noise of 15.2µV and accuracy of 23.4ppm/0C. Further, the circuit consumes 21µW of power and occupies 73*32µm2 silicon area.

Published
2021

46. Design, analysis and experimental verification of the self-resonant inverter for induction heating crucible melting furnace based on IGBTs connected in parallel

Author

Dimitrov, Borislav, Hayatleh, Khaled, Barker, Steve, Collier, Gordana, Dimitrov, Borislav, Hayatleh, Khaled, Barker, Steve, and Collier, Gordana

Abstract

The object of this research was a self-resonated inverter, based on paralleled Insulated-Gate Bipolar Transistors (IGBTs), for high-frequency induction heating equipment, operating in a wide range of output powers, applicable for research and industrial purposes. For the nominal installed capacity for these types of invertors to be improved, the presented inverter with a modified circuit comprising IGBT transistors connected in parallel was explored. The suggested topology required several engineering problems to be solved: minimisation of the current mismatch amongst the paralleled transistors; a precise analysis of the dynamic and static transistors’ parameters; determination of the derating and mismatch factors necessary for a reliable design; experimental verification confirming the applicability of the suggested topology in the investigated inverter. This paper presents the design and analysis of IGBT transistors based on datasheet parameters and mathematical apparatus application. The expected current mismatch and the necessary derating factor, based on the expected mismatch in transistor parameters in a production lot, were determined. The suggested design was experimentally tested and investigated using a self-resonant inverter model in a melting crucible induction laboratory furnace.

Published
2021

48. A Single BJT 10.2 ppm/0C Bandgap Reference in 45nm CMOS Technology

Author

Nagulapalli, Rajasekhar, Hayatleh, Khaled, and Barker, Steve

Abstract

Bandgap reference using 2 BJT devices are well explored in the literature. Usually, less number of BJT's would reduce the cost of the chip in modern CMOS technologies. A single BJT based reference was discussed here. V BE of the BJT has been used as CTAT voltage and a CMOS differential pair offset voltage based PTAT generation circuit used to generate zero temp coefficient reference. A prototype was developed in 45nm TSMC CMOS technology and post-layout simulationswere performed. Designed for a nominal voltage of 525mV with 10.2ppm/°C temperature coefficient. Its supply sensitivity is 0.4% and works with 1V power supply. The proposed solution consumes 51.8μW power from 1V power supply and occupies 2478 μm2 silicon area.

Published
2020

49. Development of an Obstacle Avoidance Robot

Author

MacDonald, John, MacDonald, John, Barker, Steve, MacDonald, John, MacDonald, John, and Barker, Steve

Abstract

In the absence of university facilities to physically construct and manufacture a prototype mini robot for testing due to Covid 19 restrictions, alternative methods have been introduced and adopted to replace the original aims and objectives that was initially proposed. This dissertation is predominately theory based due to the prevailing conditions. Autonomous automation, driverless cars is the next best opportunity on the horizon, certainly the next big thing for the future. Safety is the number 1 priority in this field, and it is imperative that machines, robots, driverless cars have the full complement of safety features to prevent injury and death. This paper explores various possibilities in the search for the best sensors for obstacle avoidance in robots. A strong literature review looks at what has been done in the recent past and what is currently being done now. Methodology sets out all the hardware and software alternatives by introducing a selection matrix to determine the best product for the prototype robot. It was found that a four-wheel driving platform is better than two wheeled platform as it was deemed more manoeuvrable; more room to add extra bits and pieces or sensors if need be. From the sensor selection matrix, 3 alternative but useful sensors were selected for trails on the robot. Ultrasonic, Camera and IR sensor (Infrared) respectively, then they were individually researched for further suitability, plus how they would work on the robot. Software and hardware platforms were selected for the job to support these sensors (some having their own selection matrix), to achieve optimum performance. The Raspberry Pi was chosen to be the microcontroller along with Python language software. MATLAB was introduced quite late on as an alternative to the physical build and python language as it was not envisaged at the time to run a simulation software package. MATLAB did not produce the results as expected due to the limited time frame, but an example fo

Published
2020

50. A two-stage opamp frequency compensation technique by splitting the 2nd stage

Author

Nagulapalli, Rajasekhar, Hayatleh, Khaled, Barker, Steve, Nagulapalli, Rajasekhar, Hayatleh, Khaled, and Barker, Steve

Abstract

In this paper miller compensation of opamp has been explained intuitively and discussed the problems existing with this traditional way. Proposed an area/power efficient technique by splitting the second stage has been proposed. The splitting introduces an extra zero in the transfer function such that it will improve the stability. This tech was implemented in 45nm CMOS technology and simulated with Spectre. Simulation results show that the proposed circuit saves 50% of the capacitance area compared to the miller technique. The circuit draws320uA current from 1.5V supply and occupying 0.003108mm2 silicon area.

Published
2020

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