Andrew Frigyik | University of Washington (original) (raw)

Papers by Andrew Frigyik

Research paper thumbnail of Orders of chaoticity of unitaries

Physica Scripta

We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of tw... more We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of two-level quantum systems. This property is relevant in a certain quantum random number generation scheme. We show that no unitaries exist with an arbitrary order of chaoticity.

Research paper thumbnail of Quantum Cryptography: Quantum Key Distribution, a Non-technical Approach

Cornell University - arXiv, Nov 9, 2022

With the rapid development of quantum computers the currently secure cryptographic protocols may ... more With the rapid development of quantum computers the currently secure cryptographic protocols may not stay that way. Quantum mechanics provides means to create an inherently secure communication channel that is protected by the laws of physics and not by the computational hardness of certain mathematical problems. This paper is a non-technical overview of quantum key distribution, one of the most well-known application of quantum cryptography, a type of cryptography poised to exploit the laws of quantum mechanics directly.

Research paper thumbnail of Orders of chaoticity of unitaries

Cornell University - arXiv, Nov 8, 2022

We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of tw... more We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of two-level quantum systems. This property is relevant in a certain quantum random number generation scheme. We show that no unitaries exist with an arbitrary order of chaoticity.

Research paper thumbnail of Low Power Conservative Circuits in CMOS

Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instab... more Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instability caused by parasitic capacitors and leakage current is overcome by connecting each wire to the ground through the inverse of the logic function which connects it to the quasi-adiabatic clock. A canonical retractile PLA (Programmable Logic Array) and an autonomous FSM (Finite State Machine) is presented. 1 Introduction Power dissipation in CMOS circuits [1] primarily occurs during device switching. If we abruptly charge or discharge a gate capacitance C to voltage V through a slightly resistive device with resistance R, energy (1=2)CV 2 is dissipated. Note that the dissipation does not depend on the value of the resistance, and it is not due to the charging and discharging in itself, but rather to the small time allocated to perform it. If a time-varying charging voltage increases very slowly, and the rise time T AE 2RC, then the energy dissipated in R decreases by a factor of ...

Research paper thumbnail of Revisiting Stein's Paradox: Multi-Task Averaging

Research paper thumbnail of Multi-Task Output Space Regularization

Research paper thumbnail of Shadow Dirichlet for Restricted Probability Modeling

Although the Dirichlet distribution is widely used, the independence structure of its components ... more Although the Dirichlet distribution is widely used, the independence structure of its components limits its accuracy as a model. The proposed shadow Dirichlet distribution manipulates the support in order to model probability mass functions (pmfs) with dependencies or constraints that often arise in real world problems, such as regularized pmfs, monotonic pmfs, and pmfs with bounded variation. We describe some properties of this new class of distributions, provide maximum entropy constructions, give an expectation-maximization method for estimating the mean parameter, and illustrate with real data.

Research paper thumbnail of Functional Bregman Divergence and Bayesian Estimation of Distributions

IEEE Transactions on Information Theory, 2008

A class of distortions termed functional Bregman divergences is defined, which includes squared e... more A class of distortions termed functional Bregman divergences is defined, which includes squared error and relative entropy. A functional Bregman divergence acts on functions or distributions, and generalizes the standard Bregman divergence for vectors and a previous pointwise Bregman divergence that was defined for functions. A recently published result showed that the mean minimizes the expected Bregman divergence. The new functional definition enables the extension of this result to the continuous case to show that the mean minimizes the expected functional Bregman divergence over a set of functions or distributions. It is shown how this theorem applies to the Bayesian estimation of distributions. Estimation of the uniform distribution from independent and identically drawn samples is used as a case study.

Research paper thumbnail of Dynamics and stability of Bose-Einstein condensates: the nonlinear Schrodinger equation with periodic potential

The cubic nonlinear Schrödinger equation with a lattice potential is used to model a periodic dil... more The cubic nonlinear Schrödinger equation with a lattice potential is used to model a periodic dilute gas Bose-Einstein condensate. Both two-and three-dimensional condensates are considered, for atomic species with either repulsive or attractive interactions. A family of exact solutions and corresponding potential is presented in terms of elliptic functions. The dynamical stability of these exact solutions is examined using both analytical and numerical methods. For condensates with repulsive atomic interactions, all stable, trivial-phase solutions are offset from the zero level. For condensates with attractive atomic interactions, no stable solutions are found, in contrast to the one-dimensional case [8].

Research paper thumbnail of Design equations and baseband model for double-sampling phase-locked loop

ICECS'99. Proceedings of ICECS '99. 6th IEEE International Conference on Electronics, Circuits and Systems (Cat. No.99EX357), 1999

Research paper thumbnail of Frequency domain analysis of double sampling phase-locked loop

2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000

Research paper thumbnail of Phenomenological model of false lock in the sampling phase-locked loop

2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000

Research paper thumbnail of Design equations and baseband model for double-sampling phase-locked loop

ICECS'99. Proceedings of ICECS '99. 6th IEEE International Conference on Electronics, Circuits and Systems (Cat. No.99EX357), 1999

Research paper thumbnail of Low Power Conservative Circuits in CMOS

Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instab... more Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instability caused by parasitic capacitors and leakage current is overcome by connecting each wire to the ground through the inverse of the logic function which connects it to the quasi-adiabatic clock. A canonical retractile PLA (Programmable Logic Array) and an autonomous FSM (Finite State Machine) is presented. 1 Introduction Power dissipation in CMOS circuits [1] primarily occurs during device switching. If we abruptly charge or discharge a gate capacitance C to voltage V through a slightly resistive device with resistance R, energy (1=2)CV 2 is dissipated. Note that the dissipation does not depend on the value of the resistance, and it is not due to the charging and discharging in itself, but rather to the small time allocated to perform it. If a time-varying charging voltage increases very slowly, and the rise time T AE 2RC, then the energy dissipated in R decreases by a factor of ...

Research paper thumbnail of An improvement of the acoustic fetal heart rate monitoring using statistical evaluation of the abdominal signal

Biomedical sciences instrumentation, 1997

An improved acoustical method for fetal heart rate (FHR) measurement is presented. The beat ident... more An improved acoustical method for fetal heart rate (FHR) measurement is presented. The beat identification is based on the selection of the power peaks measured on two frequency channels. The identification of the valid peaks will be accomplished by rules, considering the timing and the amplitudes of the detected peaks with preferred search for pairs of the first and second sound. The introduced certainty factor as a function of the statistical probabilities that are related to the expected peaks, provides the reliability of the determined repetition time. Under a given certainty the result will be ignored and the FHR curve will be extended or left blank. The simplifications in the algorithms of the process reduce the required power consumption that enables its implementation in a low-power microcircuit and in this way to produce a battery-operated portable CTG instrument for long-term FHR monitoring on a passive.

Research paper thumbnail of Behavioral modeling of charge pump phase locked loops

ISCAS'99. Proceedings of the 1999 IEEE International Symposium on Circuits and Systems VLSI (Cat. No.99CH36349), 1999

Research paper thumbnail of Accurate baseband model for sampling phase-locked loop

IEE Colloquium on Phase Lock Loops: Theory and Practice, 1999

Research paper thumbnail of Multi-Task Averaging

We present a multi-task learning approach to jointly estimate the means of multiple independent d... more We present a multi-task learning approach to jointly estimate the means of multiple independent data sets. The proposed multi-task averaging (MTA) algorithm results in a convex combination of the single-task maximum likelihood estimates. We derive the optimal minimum risk estimator and the minimax estimator, and show that these estimators can be efficiently estimated. Simulations and real data experiments demonstrate that MTA estimators often outperform both single-task and James-Stein estimators.

Research paper thumbnail of Functional Bregman divergence

2008 IEEE International Symposium on Information Theory, 2008

Research paper thumbnail of Stability of exact solutions of the defocusing nonlinear Schrödinger equation with periodic potential in two dimensions

Research paper thumbnail of Orders of chaoticity of unitaries

Physica Scripta

We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of tw... more We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of two-level quantum systems. This property is relevant in a certain quantum random number generation scheme. We show that no unitaries exist with an arbitrary order of chaoticity.

Research paper thumbnail of Quantum Cryptography: Quantum Key Distribution, a Non-technical Approach

Cornell University - arXiv, Nov 9, 2022

With the rapid development of quantum computers the currently secure cryptographic protocols may ... more With the rapid development of quantum computers the currently secure cryptographic protocols may not stay that way. Quantum mechanics provides means to create an inherently secure communication channel that is protected by the laws of physics and not by the computational hardness of certain mathematical problems. This paper is a non-technical overview of quantum key distribution, one of the most well-known application of quantum cryptography, a type of cryptography poised to exploit the laws of quantum mechanics directly.

Research paper thumbnail of Orders of chaoticity of unitaries

Cornell University - arXiv, Nov 8, 2022

We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of tw... more We introduce the concept of K-th order chaoticity of unitaries, and analyze it for the case of two-level quantum systems. This property is relevant in a certain quantum random number generation scheme. We show that no unitaries exist with an arbitrary order of chaoticity.

Research paper thumbnail of Low Power Conservative Circuits in CMOS

Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instab... more Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instability caused by parasitic capacitors and leakage current is overcome by connecting each wire to the ground through the inverse of the logic function which connects it to the quasi-adiabatic clock. A canonical retractile PLA (Programmable Logic Array) and an autonomous FSM (Finite State Machine) is presented. 1 Introduction Power dissipation in CMOS circuits [1] primarily occurs during device switching. If we abruptly charge or discharge a gate capacitance C to voltage V through a slightly resistive device with resistance R, energy (1=2)CV 2 is dissipated. Note that the dissipation does not depend on the value of the resistance, and it is not due to the charging and discharging in itself, but rather to the small time allocated to perform it. If a time-varying charging voltage increases very slowly, and the rise time T AE 2RC, then the energy dissipated in R decreases by a factor of ...

Research paper thumbnail of Revisiting Stein's Paradox: Multi-Task Averaging

Research paper thumbnail of Multi-Task Output Space Regularization

Research paper thumbnail of Shadow Dirichlet for Restricted Probability Modeling

Although the Dirichlet distribution is widely used, the independence structure of its components ... more Although the Dirichlet distribution is widely used, the independence structure of its components limits its accuracy as a model. The proposed shadow Dirichlet distribution manipulates the support in order to model probability mass functions (pmfs) with dependencies or constraints that often arise in real world problems, such as regularized pmfs, monotonic pmfs, and pmfs with bounded variation. We describe some properties of this new class of distributions, provide maximum entropy constructions, give an expectation-maximization method for estimating the mean parameter, and illustrate with real data.

Research paper thumbnail of Functional Bregman Divergence and Bayesian Estimation of Distributions

IEEE Transactions on Information Theory, 2008

A class of distortions termed functional Bregman divergences is defined, which includes squared e... more A class of distortions termed functional Bregman divergences is defined, which includes squared error and relative entropy. A functional Bregman divergence acts on functions or distributions, and generalizes the standard Bregman divergence for vectors and a previous pointwise Bregman divergence that was defined for functions. A recently published result showed that the mean minimizes the expected Bregman divergence. The new functional definition enables the extension of this result to the continuous case to show that the mean minimizes the expected functional Bregman divergence over a set of functions or distributions. It is shown how this theorem applies to the Bayesian estimation of distributions. Estimation of the uniform distribution from independent and identically drawn samples is used as a case study.

Research paper thumbnail of Dynamics and stability of Bose-Einstein condensates: the nonlinear Schrodinger equation with periodic potential

The cubic nonlinear Schrödinger equation with a lattice potential is used to model a periodic dil... more The cubic nonlinear Schrödinger equation with a lattice potential is used to model a periodic dilute gas Bose-Einstein condensate. Both two-and three-dimensional condensates are considered, for atomic species with either repulsive or attractive interactions. A family of exact solutions and corresponding potential is presented in terms of elliptic functions. The dynamical stability of these exact solutions is examined using both analytical and numerical methods. For condensates with repulsive atomic interactions, all stable, trivial-phase solutions are offset from the zero level. For condensates with attractive atomic interactions, no stable solutions are found, in contrast to the one-dimensional case [8].

Research paper thumbnail of Design equations and baseband model for double-sampling phase-locked loop

ICECS'99. Proceedings of ICECS '99. 6th IEEE International Conference on Electronics, Circuits and Systems (Cat. No.99EX357), 1999

Research paper thumbnail of Frequency domain analysis of double sampling phase-locked loop

2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000

Research paper thumbnail of Phenomenological model of false lock in the sampling phase-locked loop

2000 IEEE International Symposium on Circuits and Systems. Emerging Technologies for the 21st Century. Proceedings (IEEE Cat No.00CH36353), 2000

Research paper thumbnail of Design equations and baseband model for double-sampling phase-locked loop

ICECS'99. Proceedings of ICECS '99. 6th IEEE International Conference on Electronics, Circuits and Systems (Cat. No.99EX357), 1999

Research paper thumbnail of Low Power Conservative Circuits in CMOS

Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instab... more Low-loss circuits composed of CMOS transmission gates as switches are proposed. Functional instability caused by parasitic capacitors and leakage current is overcome by connecting each wire to the ground through the inverse of the logic function which connects it to the quasi-adiabatic clock. A canonical retractile PLA (Programmable Logic Array) and an autonomous FSM (Finite State Machine) is presented. 1 Introduction Power dissipation in CMOS circuits [1] primarily occurs during device switching. If we abruptly charge or discharge a gate capacitance C to voltage V through a slightly resistive device with resistance R, energy (1=2)CV 2 is dissipated. Note that the dissipation does not depend on the value of the resistance, and it is not due to the charging and discharging in itself, but rather to the small time allocated to perform it. If a time-varying charging voltage increases very slowly, and the rise time T AE 2RC, then the energy dissipated in R decreases by a factor of ...

Research paper thumbnail of An improvement of the acoustic fetal heart rate monitoring using statistical evaluation of the abdominal signal

Biomedical sciences instrumentation, 1997

An improved acoustical method for fetal heart rate (FHR) measurement is presented. The beat ident... more An improved acoustical method for fetal heart rate (FHR) measurement is presented. The beat identification is based on the selection of the power peaks measured on two frequency channels. The identification of the valid peaks will be accomplished by rules, considering the timing and the amplitudes of the detected peaks with preferred search for pairs of the first and second sound. The introduced certainty factor as a function of the statistical probabilities that are related to the expected peaks, provides the reliability of the determined repetition time. Under a given certainty the result will be ignored and the FHR curve will be extended or left blank. The simplifications in the algorithms of the process reduce the required power consumption that enables its implementation in a low-power microcircuit and in this way to produce a battery-operated portable CTG instrument for long-term FHR monitoring on a passive.

Research paper thumbnail of Behavioral modeling of charge pump phase locked loops

ISCAS'99. Proceedings of the 1999 IEEE International Symposium on Circuits and Systems VLSI (Cat. No.99CH36349), 1999

Research paper thumbnail of Accurate baseband model for sampling phase-locked loop

IEE Colloquium on Phase Lock Loops: Theory and Practice, 1999

Research paper thumbnail of Multi-Task Averaging

We present a multi-task learning approach to jointly estimate the means of multiple independent d... more We present a multi-task learning approach to jointly estimate the means of multiple independent data sets. The proposed multi-task averaging (MTA) algorithm results in a convex combination of the single-task maximum likelihood estimates. We derive the optimal minimum risk estimator and the minimax estimator, and show that these estimators can be efficiently estimated. Simulations and real data experiments demonstrate that MTA estimators often outperform both single-task and James-Stein estimators.

Research paper thumbnail of Functional Bregman divergence

2008 IEEE International Symposium on Information Theory, 2008

Research paper thumbnail of Stability of exact solutions of the defocusing nonlinear Schrödinger equation with periodic potential in two dimensions