Levin, David Asher 1971
Overview
Works:  16 works in 30 publications in 2 languages and 387 library holdings 

Genres:  Academic theses 
Roles:  Author 
Classifications:  QA274.7, 519.233 
Publication Timeline
.
Most widely held works by
David Asher Levin
Markov chains and mixing times by
David Asher Levin(
Book
)
13 editions published between 2008 and 2009 in English and held by 338 WorldCat member libraries worldwide
This book is an introduction to the modern approach to the theory of Markov chains. The main goal of this approach is to determine the rate of convergence of a Markov chain to the stationary distribution as a function of the size and geometry of the state space. The authors develop the key tools for estimating convergence times, including coupling, strong stationary times, and spectral methods. Whenever possible, probabilistic methods are emphasized. The book includes many examples and provides brief introductions to some central models of statistical mechanics. Also provided are accounts of random walks on networks, including hitting and cover times, and analyses of several methods of shuffling cards. As a prerequisite, the authors assume a modest understanding of probability theory and linear algebra at an undergraduate level. Markov Chains and Mixing Times is meant to bring the excitement of this active area of research to a wide audience
13 editions published between 2008 and 2009 in English and held by 338 WorldCat member libraries worldwide
This book is an introduction to the modern approach to the theory of Markov chains. The main goal of this approach is to determine the rate of convergence of a Markov chain to the stationary distribution as a function of the size and geometry of the state space. The authors develop the key tools for estimating convergence times, including coupling, strong stationary times, and spectral methods. Whenever possible, probabilistic methods are emphasized. The book includes many examples and provides brief introductions to some central models of statistical mechanics. Also provided are accounts of random walks on networks, including hitting and cover times, and analyses of several methods of shuffling cards. As a prerequisite, the authors assume a modest understanding of probability theory and linear algebra at an undergraduate level. Markov Chains and Mixing Times is meant to bring the excitement of this active area of research to a wide audience
Phase transitions in probability : percolation and hidden Markov models by
David Asher Levin(
)
3 editions published in 1999 in English and held by 8 WorldCat member libraries worldwide
We investigate combinatorial probability structures which exhibit phase transitions. The simplest and most widely studied such model is Bernoulli percolation on the lattices Zd, for d & ge; 2. We investigate the geometry of infinite percolation clusters on Zd when d & ge; 3, characterizing which flows these clusters can support. We also study a class of hidden Markov models first proposed by Harris and Keane [HK97]. We prove that in many cases, the model exhibits an unexpected phase transition. Finally, we study a generalization of the HarrisKeane model when the underlying Markov chain is random walk on Z. This model is a noisy version of the random walks on scenery studied by Benjamini and Kesten [BK96] and Howard [How96a, How96b]
3 editions published in 1999 in English and held by 8 WorldCat member libraries worldwide
We investigate combinatorial probability structures which exhibit phase transitions. The simplest and most widely studied such model is Bernoulli percolation on the lattices Zd, for d & ge; 2. We investigate the geometry of infinite percolation clusters on Zd when d & ge; 3, characterizing which flows these clusters can support. We also study a class of hidden Markov models first proposed by Harris and Keane [HK97]. We prove that in many cases, the model exhibits an unexpected phase transition. Finally, we study a generalization of the HarrisKeane model when the underlying Markov chain is random walk on Z. This model is a noisy version of the random walks on scenery studied by Benjamini and Kesten [BK96] and Howard [How96a, How96b]
The role of trichomes in plant defense by
David Asher Levin(
)
in English and held by 1 WorldCat member library worldwide
in English and held by 1 WorldCat member library worldwide
Hybridization Benchamark Papers in Genetics Vol. 11 by
David Asher Levin(
Book
)
1 edition published in 1970 in English and held by 1 WorldCat member library worldwide
1 edition published in 1970 in English and held by 1 WorldCat member library worldwide
The chemical defenses of plants to pathogens and herbivores by
David Asher Levin(
)
in English and held by 1 WorldCat member library worldwide
in English and held by 1 WorldCat member library worldwide
Sot︠s︡iologicheskai︠a︡ teorii︠a︡ Rostou, novyĭ variant apologii sovremennogo monopolisticheskogo kapitalizma by
David Asher Levin(
Book
)
1 edition published in 1968 in Russian and held by 1 WorldCat member library worldwide
1 edition published in 1968 in Russian and held by 1 WorldCat member library worldwide
Hybridization : an evolutionary perspective by
David Asher Levin(
Book
)
1 edition published in 1970 in English and held by 1 WorldCat member library worldwide
1 edition published in 1970 in English and held by 1 WorldCat member library worldwide
O+HCl Cross Sections and Reaction Probabilities in DSMC (Postprint)(
Book
)
1 edition published in 2006 in English and held by 1 WorldCat member library worldwide
A chemical reaction model, suitable for use in the Direct Simulation Monte Carlo (DSMC) method, is developed to simulate hypervelocity collisions of an important reaction in atmosphericjet interactions. The model utilizes the QuasiClassical Trajectory (QCT) method with two potential energy surfaces (PES), new benchmark triple surfaces and LondonEyringPolanyiSato (LEPS) PES. The sensitivity of the flow to the fidelity of the chemical model is investigated for the new QCTderived model and the widely used Total Collision Energy (TCE) model of Bird. The adequacy of the total collision cross section is also considered, and to obtain accurate collision cross sections, the Dynamic Molecular Collision model of Tokumasu and Matsumoto is assumed and the collision cross section is obtained by using the MD/QCT method with the aforementioned potential energy surfaces. The magnitude of the inelastic cross section is small compared to the total cross section for both PESs. Therefore, MD/QCT VHSequivalent collision cross sections are obtained and along with the MD/QCT reaction cross sections are utilized in the full DSMC calculation of the flow field. It is found that chemical reaction models do not affect the general flowfield, however, the OH production rate is dependent on the chemical reaction model
1 edition published in 2006 in English and held by 1 WorldCat member library worldwide
A chemical reaction model, suitable for use in the Direct Simulation Monte Carlo (DSMC) method, is developed to simulate hypervelocity collisions of an important reaction in atmosphericjet interactions. The model utilizes the QuasiClassical Trajectory (QCT) method with two potential energy surfaces (PES), new benchmark triple surfaces and LondonEyringPolanyiSato (LEPS) PES. The sensitivity of the flow to the fidelity of the chemical model is investigated for the new QCTderived model and the widely used Total Collision Energy (TCE) model of Bird. The adequacy of the total collision cross section is also considered, and to obtain accurate collision cross sections, the Dynamic Molecular Collision model of Tokumasu and Matsumoto is assumed and the collision cross section is obtained by using the MD/QCT method with the aforementioned potential energy surfaces. The magnitude of the inelastic cross section is small compared to the total cross section for both PESs. Therefore, MD/QCT VHSequivalent collision cross sections are obtained and along with the MD/QCT reaction cross sections are utilized in the full DSMC calculation of the flow field. It is found that chemical reaction models do not affect the general flowfield, however, the OH production rate is dependent on the chemical reaction model
An inventory of natural lands held by Yale University by
David Asher Levin(
Book
)
1 edition published in 1971 in English and held by 1 WorldCat member library worldwide
1 edition published in 1971 in English and held by 1 WorldCat member library worldwide
Application of the DSMC and NS Techniques to the Modeling of a Dense, Low Reynold's Number MEMS Device(
)
1 edition published in 2005 in English and held by 0 WorldCat member libraries worldwide
The modeling of micro flows through a 3D micro nozzle was investigated by means of the DSMC and NS techniques in order to verify the influence of the computational scheme parameters on the predicted flow quantities. The investigated low Reynold's number flow has a complex structure containing subsonic and supersonic parts. Since the influence of the boundary layer on the flow characteristics is significant, a strong effort was made to predict the boundary layer structure as exactly as possible
1 edition published in 2005 in English and held by 0 WorldCat member libraries worldwide
The modeling of micro flows through a 3D micro nozzle was investigated by means of the DSMC and NS techniques in order to verify the influence of the computational scheme parameters on the predicted flow quantities. The investigated low Reynold's number flow has a complex structure containing subsonic and supersonic parts. Since the influence of the boundary layer on the flow characteristics is significant, a strong effort was made to predict the boundary layer structure as exactly as possible
Applicability of the Homogeneous Nucleation Theory to the Condensation in Free Gas Expansions(
)
1 edition published in 2005 in English and held by 0 WorldCat member libraries worldwide
The traditional application of the classical homogeneous nucleation theory (CNT) to the condensation in rapidly expanding flows involves the use of the steadystate nucleation rate. Since this rate is derived under the assumption of both steadystate and isobaric/isothermal conditions, the applicability of CNT to highly nonequilibrium environments may be questionable. In addition, the usual strategy of CNT gas dynamics coupling violates the original nucleation theory even in the isothermal/isobaric environment. In this study, we consider condensation in jets freely expanding into a vacuum. Using the isentropic solution, we approximate the timedependent pressure and temperature in a given small volume of a gas that is moving along the jet axis with the flow velocity. Several possible strategies of CNT implementation are considered within this volume. It is shown that the terminal cluster distributions are strongly affected by the steadystate assumption and that the original CNT rate equations should be integrated into a computational scheme to model the coupled condensation flow
1 edition published in 2005 in English and held by 0 WorldCat member libraries worldwide
The traditional application of the classical homogeneous nucleation theory (CNT) to the condensation in rapidly expanding flows involves the use of the steadystate nucleation rate. Since this rate is derived under the assumption of both steadystate and isobaric/isothermal conditions, the applicability of CNT to highly nonequilibrium environments may be questionable. In addition, the usual strategy of CNT gas dynamics coupling violates the original nucleation theory even in the isothermal/isobaric environment. In this study, we consider condensation in jets freely expanding into a vacuum. Using the isentropic solution, we approximate the timedependent pressure and temperature in a given small volume of a gas that is moving along the jet axis with the flow velocity. Several possible strategies of CNT implementation are considered within this volume. It is shown that the terminal cluster distributions are strongly affected by the steadystate assumption and that the original CNT rate equations should be integrated into a computational scheme to model the coupled condensation flow
O+HCl Chemistry Models for Hypervelocity Collisions in DSMC(
)
1 edition published in 2006 in English and held by 0 WorldCat member libraries worldwide
In earlier work, atmosphericjet interaction flows were simulated using direct simulation Monte Carlo (DSMC) calculations for altitudes of 80, 120 and 160 km. At high altitudes, the O+HCl yields OH+Cl reaction was found to contribute the most to OH production. However, the total collision energy (TCE) reaction probability was often found to be unphysically greater than unity. In this work, we examine in detail different reaction models such as the TCE model using the rate constants of Mahmud et al. and Xie et al. In addition to the TCE model, quasiclassical trajectory (QCT) calculations were performed to obtain the reaction probability for the O+HCl reaction with the new benchmark triplet A" and A' surfaces. Both reaction and total collision cross sections were calculated by the QCT method. The dynamic molecule collision model was used to calculate the viscosity cross section from which the VHSequivalent collision cross sections were derived. The tabulated QCT reaction probabilities were then used in the DSMC calculations to model OH production at 120 km. It is found that the QCTbased collision cross sections are greater than the Bird VHS cross sections, and the QCT reaction probabilities for O+HCl are lower than the TCE probabilities using the rate of Mahmud et al. Using the QCT reaction probability, the maximum reaction probability for the O+HCl reaction was found to be lower than 0.4 in the atmosphericjet interaction flows for an altitude of 120 km and a freestream velocity of 5 km/s
1 edition published in 2006 in English and held by 0 WorldCat member libraries worldwide
In earlier work, atmosphericjet interaction flows were simulated using direct simulation Monte Carlo (DSMC) calculations for altitudes of 80, 120 and 160 km. At high altitudes, the O+HCl yields OH+Cl reaction was found to contribute the most to OH production. However, the total collision energy (TCE) reaction probability was often found to be unphysically greater than unity. In this work, we examine in detail different reaction models such as the TCE model using the rate constants of Mahmud et al. and Xie et al. In addition to the TCE model, quasiclassical trajectory (QCT) calculations were performed to obtain the reaction probability for the O+HCl reaction with the new benchmark triplet A" and A' surfaces. Both reaction and total collision cross sections were calculated by the QCT method. The dynamic molecule collision model was used to calculate the viscosity cross section from which the VHSequivalent collision cross sections were derived. The tabulated QCT reaction probabilities were then used in the DSMC calculations to model OH production at 120 km. It is found that the QCTbased collision cross sections are greater than the Bird VHS cross sections, and the QCT reaction probabilities for O+HCl are lower than the TCE probabilities using the rate of Mahmud et al. Using the QCT reaction probability, the maximum reaction probability for the O+HCl reaction was found to be lower than 0.4 in the atmosphericjet interaction flows for an altitude of 120 km and a freestream velocity of 5 km/s
Analysis of Different Approaches to Modeling of Nozzle Flows in the Near Continuum Regime (Preprint)(
)
1 edition published in 2008 in English and held by 0 WorldCat member libraries worldwide
Conical nozzle flows are studied for Reynolds numbers of 1,230 and 12,300 using different numerical techniques: DSMC Method, NavierStokes/CFD accounting for velocity slip and temperature jump boundary conditions, and statistical and deterministic approaches to the solution of BGK equation. Detailed comparisons of the stability accuracy, and convergence of the employed numerical techniques provide better understanding of their benefits and deficiencies and assists in selecting the most appropriate technique for a particular nozzle and flow application. The deterministic and statistical solutions of the BGK equation were found to be in good agreement with the benchmark DSMC results. The NavierStokes solution differs from the DSMC in the boundary layer
1 edition published in 2008 in English and held by 0 WorldCat member libraries worldwide
Conical nozzle flows are studied for Reynolds numbers of 1,230 and 12,300 using different numerical techniques: DSMC Method, NavierStokes/CFD accounting for velocity slip and temperature jump boundary conditions, and statistical and deterministic approaches to the solution of BGK equation. Detailed comparisons of the stability accuracy, and convergence of the employed numerical techniques provide better understanding of their benefits and deficiencies and assists in selecting the most appropriate technique for a particular nozzle and flow application. The deterministic and statistical solutions of the BGK equation were found to be in good agreement with the benchmark DSMC results. The NavierStokes solution differs from the DSMC in the boundary layer
Chemical Reaction Modeling for Hypervelocity Collisions between O and HCl(
)
1 edition published in 2007 in English and held by 0 WorldCat member libraries worldwide
Treatment of chemical reactions in rarefied, nonequilibrium flows has been the subject of significant research. In some cases, proper treatment of reactions is needed to accurately predict overall shock thickness, standoff, and heat transfer. In other cases, such as when reactants are minor species, the overall flowfield is not affected by details of the reaction model, but a particular radiation signature may be strongly affected. A case of the latter situation is the subject of the present study, and allows for a detailed examination of several issues important to chemical reaction models for rarefied, highspeed flows
1 edition published in 2007 in English and held by 0 WorldCat member libraries worldwide
Treatment of chemical reactions in rarefied, nonequilibrium flows has been the subject of significant research. In some cases, proper treatment of reactions is needed to accurately predict overall shock thickness, standoff, and heat transfer. In other cases, such as when reactants are minor species, the overall flowfield is not affected by details of the reaction model, but a particular radiation signature may be strongly affected. A case of the latter situation is the subject of the present study, and allows for a detailed examination of several issues important to chemical reaction models for rarefied, highspeed flows
Assessment of BGK Approaches to Modeling of Nozzle Flows (PREPRINT)(
)
1 edition published in 2009 in English and held by 0 WorldCat member libraries worldwide
Accurate and numerically efficient modeling of low to moderate Reynolds number nozzle flow expansions to vacuum can be difficult due to the presence of multiple flow length scales. Such simulations are important for the prediction of propulsive thrust as well as spacecraft contamination, both of which can be difficult to measure in ground based facilities. To that end, conical nozzle flows were studied for Reynolds numbers of 1,230 and 12,300 using the direct simulation Monte Carlo method (DSMC), NavierStokes with velocity slip and temperature jump boundary conditions, and statistical and deterministic approaches to the solution of the BGK and ESBGK equations. The deterministic and statistical solutions of the BGK equation were found to be in good agreement with the benchmark DSMC results. Statistical BGK and ESBGK methods were also found to be more efficient methods than DSMC in the continuum and nearcontinuum regime, and more accurate than the NavierStokes equations in the portions of the flow with rarefaction, such as the boundary layer and the flow around the nozzle lip
1 edition published in 2009 in English and held by 0 WorldCat member libraries worldwide
Accurate and numerically efficient modeling of low to moderate Reynolds number nozzle flow expansions to vacuum can be difficult due to the presence of multiple flow length scales. Such simulations are important for the prediction of propulsive thrust as well as spacecraft contamination, both of which can be difficult to measure in ground based facilities. To that end, conical nozzle flows were studied for Reynolds numbers of 1,230 and 12,300 using the direct simulation Monte Carlo method (DSMC), NavierStokes with velocity slip and temperature jump boundary conditions, and statistical and deterministic approaches to the solution of the BGK and ESBGK equations. The deterministic and statistical solutions of the BGK equation were found to be in good agreement with the benchmark DSMC results. Statistical BGK and ESBGK methods were also found to be more efficient methods than DSMC in the continuum and nearcontinuum regime, and more accurate than the NavierStokes equations in the portions of the flow with rarefaction, such as the boundary layer and the flow around the nozzle lip
Analysis of Different Approaches to Modeling of the Nozzle Flows in the Near Continuum Regime(
)
1 edition published in 2007 in English and held by 0 WorldCat member libraries worldwide
A conical nozzle flow is studied for Reynolds numbers 1,230 and 12,300 using different numerical techniques: the direct simulation Monte Carlo method, the solution of NavierStokes equations that accounts for wall temperature jump and velocity slip, and statistical and deterministic approaches for the BGK equation. Detailed comparison of the efficiency, stability, accuracy, and convergence of the employed numerical techniques provides better understanding of their benefits and deficiencies, and assists in selecting the most appropriate technique for a particular nozzle and flow application. The deterministic solution of the BGK equation was found to be in good agreement with the benchmark DSMC results, while there were some differences observed between the statistical BGK and DSMC. The NavierStokes solution differs from DSMC in the boundary layer. The DSMC was shown to be the more computationally efficient than the solution of the BGK equation, both statistical and deterministic
1 edition published in 2007 in English and held by 0 WorldCat member libraries worldwide
A conical nozzle flow is studied for Reynolds numbers 1,230 and 12,300 using different numerical techniques: the direct simulation Monte Carlo method, the solution of NavierStokes equations that accounts for wall temperature jump and velocity slip, and statistical and deterministic approaches for the BGK equation. Detailed comparison of the efficiency, stability, accuracy, and convergence of the employed numerical techniques provides better understanding of their benefits and deficiencies, and assists in selecting the most appropriate technique for a particular nozzle and flow application. The deterministic solution of the BGK equation was found to be in good agreement with the benchmark DSMC results, while there were some differences observed between the statistical BGK and DSMC. The NavierStokes solution differs from DSMC in the boundary layer. The DSMC was shown to be the more computationally efficient than the solution of the BGK equation, both statistical and deterministic
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