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Articles 2221 - 2250 of 2757

Full-Text Articles in Engineering

Pperfgrid: A Grid Services-Based Tool For The Exchange Of Heterogeneous Parallel Performance Data, John Jared Hoffman Jan 2004

Pperfgrid: A Grid Services-Based Tool For The Exchange Of Heterogeneous Parallel Performance Data, John Jared Hoffman

Dissertations and Theses

This thesis details the approach taken in developing PPerfGrid. Section 2 discusses other research related to this project. Section 3 provides general background on the technologies utilized in PPerfGrid, focusing on the components that make up the Grid services architecture. Section 4 provides a description of the architecture of PPerfGrid. Section 5 details the implementation of PPerfGrid. Section 6 presents tests designed to measure the overhead and scalability of the PPerfGrid application. Section 7 suggests future work, and Section 8 concludes the thesis.


Low-Frequency Surface Wave Propagation And The Viscoelastic Behavior Of Porcine Skin, Donald D. Duncan, Sean J. Kirkpatrick, Li Fang Jan 2004

Low-Frequency Surface Wave Propagation And The Viscoelastic Behavior Of Porcine Skin, Donald D. Duncan, Sean J. Kirkpatrick, Li Fang

Electrical and Computer Engineering Faculty Publications and Presentations

A physical model describing the propagation of lowfrequency surface waves in relation to the viscoelastic behavior of porcine skin is presented, along with a series of empirical studies testing the performance of the model. The model assumes that the skin behaves as a semi-infinite, locally isotropic, viscoelastic halfspace. While the assumption of a semi-infinite body is violated, this violation does not appear to have a significant impact on the performance of the model based on the empirical studies. 1-Hz surface waves in the skin propagate primarily as Rayleigh waves with a wavelength and velocity of approximately 3 m and 3.0 …


Logic Synthesis For Regular Fabric Realized In Quantum Dot Cellular Automata, Marek Perkowski, Alan Mishchenko Jan 2004

Logic Synthesis For Regular Fabric Realized In Quantum Dot Cellular Automata, Marek Perkowski, Alan Mishchenko

Electrical and Computer Engineering Faculty Publications and Presentations

Quantum Dot Cellular Automata are one of the most prospective nano-technologies to build digital circuits. Because of the requirements of only 2 layer wiring and noise avoidance, realizing the circuit in a regular fabrics is even more important for this technology than for classical technologies. In this paper, we propose a regular layout geometry called 3x3 lattice. The main difference of this geometry compared to the known 2x2 lattices is that it allows the cofactors on a level to propagate to three rather than two nodes on the lower level. This gives additional freedom to synthesize compact functional representations. We …


Synthesis Of Reversible Circuits From A Subset Of Muthukrishnan-Stroud Quantum Realizable Multi-Valued Gates, Marek Perkowski, Nicholas Denler, Bruce Yen, Pawel Kerntopf Jan 2004

Synthesis Of Reversible Circuits From A Subset Of Muthukrishnan-Stroud Quantum Realizable Multi-Valued Gates, Marek Perkowski, Nicholas Denler, Bruce Yen, Pawel Kerntopf

Electrical and Computer Engineering Faculty Publications and Presentations

We present a new type of quantum realizable reversible cascade. Next we present a new algorithm to synthesize arbitrary single-output ternary functions using these reversible cascades. The cascades use “Generalized Multi-Valued Gates” introduced here, which extend the concept of Generalized Ternary Gates introduced previously. While there were 216 GTGs, a total of 12 ternary gates of the new type are sufficient to realize arbitrary ternary functions. (The count can be further reduced to 5 gates, three 2-qubit and two 1-qubit). Such gates are realizable in quantum ion trap devices. For some functions, the algorithm requires fewer gates than results previously …


A Transformation Based Algorithm For Ternary Reversible Logic Synthesis Using Universally Controlled Ternary Gates, Marek Perkowski, Eric Curtis Jan 2004

A Transformation Based Algorithm For Ternary Reversible Logic Synthesis Using Universally Controlled Ternary Gates, Marek Perkowski, Eric Curtis

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper a synthesis algorithm for reversible ternary logic cascades is presented. The algorithm can find a solution for any reversible ternary function with n inputs and n outputs utilizing ternary inverter gates and the new (quantum realizable) UCTG gates which are a powerful generalization of ternary Toffoli gates and Generalized Ternary Gates [4]. The algorithm is an extension of the algorithm presented by Dueck, Maslov, and Miller in [3]. A unique feature of this algorithm is that it utilizes no extra wires to generate the outputs. A basic compaction algorithm is defined to improve the results of the …


Ultra-Thin Silicon Chips For Submillimeter-Wave Applications, Robert B. Bass, J. C. Schultz, Arthur W. Lichtenberger, R. M. Weiklel, S K. Pan, E. Bryerton, C. K. Walker, Jacob Kooi Jan 2004

Ultra-Thin Silicon Chips For Submillimeter-Wave Applications, Robert B. Bass, J. C. Schultz, Arthur W. Lichtenberger, R. M. Weiklel, S K. Pan, E. Bryerton, C. K. Walker, Jacob Kooi

Electrical and Computer Engineering Faculty Publications and Presentations

We present a process for fabricating ultra-thin silicon chips for submillimeter-wave mixing applications using SOI (Silicon On Insulator) wafers. Such chips allow the profile of the mixer substrate to be minimized within the microstrip channel, thereby simplifying RF design considerations and minimizing machining constraints. The chips feature gold beam leads, RF filter structures, and hot-electron bolometers as the non-linear element. We designed a prototype receiver to demonstrate the feasibility of the ultra-thin silicon chip technology. The receiver has a center frequency of 585GHz and accommodates both diffusion-cooled and phonon-cooled hotelectron bolometer mixers fabricated atop an ultra-thin silicon chip. The chip …


Exact Synthesis Of 3-Qubit Quantum Circuits From Non-Binary Quantum Gates Using Multiple-Valued Logic And Group Theory, Guowu Yang, William N. N. Hung, Xiaoyu Song, Marek Perkowski Jan 2004

Exact Synthesis Of 3-Qubit Quantum Circuits From Non-Binary Quantum Gates Using Multiple-Valued Logic And Group Theory, Guowu Yang, William N. N. Hung, Xiaoyu Song, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We propose an approach to optimally synthesize quantum circuits from non-permutative quantum gates such as Controlled-Square-Root–of-Not (i.e. Controlled-V). Our approach reduces the synthesis problem to multiple-valued optimization and uses group theory. We devise a novel technique that transforms the quantum logic synthesis problem from a multi-valued constrained optimization problem to a permutable representation. The transformation enables us to utilize group theory to exploit the symmetric properties of the synthesis problem. Assuming a cost of one for each two-qubit gate, we found all reversible circuits with quantum costs of 4, 5, 6, etc, and give another algorithm to realize these reversible …


Technology Forecasting Using Data Envelopment Analysis, Oliver Lane Inman Jan 2004

Technology Forecasting Using Data Envelopment Analysis, Oliver Lane Inman

Dissertations and Theses

The ability to anticipate future capabilities of technology products has broad implications for organizations. Technological forecasting allows management to improve resource allocation, make better staffing decisions, and more confidently plan facilities and capital expenditures. Technology forecasting may also identify potential new markets and opportunities, such as finding ways to exploit current technology beyond its originally intended purposes.

Modern technology forecasters use an array of forecasting methods to predict the future performance of a technology, such as time-series analysis, regression, stochastic methods, and simulation. These quantitative methods rely on the assumption that past behavior will continue. Shortcomings include their lack of …


Using Dynamic Optimization For Control Of Real Rate Cpu Resource Management Applications, Varin Vahia, Ashvin Goel, David Steere, Jonathan Walpole, Molly H. Shor Dec 2003

Using Dynamic Optimization For Control Of Real Rate Cpu Resource Management Applications, Varin Vahia, Ashvin Goel, David Steere, Jonathan Walpole, Molly H. Shor

Computer Science Faculty Publications and Presentations

In this paper we design a proportional-period optimal controller for allocating CPU to real rate multimedia applications on a general-purpose computer system. We model this computer system problem in to state space form. We design a controller based on dynamic optimization LQR tracking techniques to minimize short term and long term time deviation from the current time stamp and also CPU usage. Preliminary results on an experimental set up are encouraging.


Infrastructure For Performance Tuning Mpi Applications, Kathryn Marie Mohror Nov 2003

Infrastructure For Performance Tuning Mpi Applications, Kathryn Marie Mohror

Dissertations and Theses

Clusters of workstations are becoming increasingly popular as a low-budget alternative for supercomputing power. In these systems, message-passing is often used to allow the separate nodes to act as a single computing machine. Programmers of such systems face a daunting challenge in understanding the performance bottlenecks of their applications. This is largely due to the vast amount of performance data that is collected, and the time and expertise necessary to use traditional parallel performance tools to analyze that data.

The goal of this project is to increase the level of performance tool support for message-passing application programmers on clusters of …


Use Of Hierarchical Decision Modeling For Site Selection Of A Major League Baseball Stadium In Portland, Priya Ajgaonkar, Aroonrat Auysakul, Edward Cespedes, Ryan Jefferis, Seiji Shinriki Oct 2003

Use Of Hierarchical Decision Modeling For Site Selection Of A Major League Baseball Stadium In Portland, Priya Ajgaonkar, Aroonrat Auysakul, Edward Cespedes, Ryan Jefferis, Seiji Shinriki

Engineering and Technology Management Student Projects

This paper proposes a hierarchical decision model to select a site from various potential sites for a major league baseball stadium in Portland, Oregon. A short background on MLB in Portland, with all the related factors, is provided. Next this paper describes Hierarchical Decision Modeling using pair wise comparisons and the process of using this as a decision making tool. A detailed description of the HDM developed is then provided. This model includes determination of the number of levels of the HDM and their relationship with each other. It describes all the elements of each level and the process of …


An Evaluation Of Public Construction Contracting Methods For The Public Building Sector In Oregon Using Data Envelopment Analysis, Gerald Herman Williams Jr. Sep 2003

An Evaluation Of Public Construction Contracting Methods For The Public Building Sector In Oregon Using Data Envelopment Analysis, Gerald Herman Williams Jr.

Dissertations and Theses

Since 1976 public agencies in Oregon have been allowed to select construction contractors using a "qualification" based competition instead of the more typical lowest responsible bid or Design-Bid-Build (DBB) basis. Since 1985, at least 136 such selections, commonly known as CM/GC for Construction Manager/General Contractor, have been made. The results of this policy have not previously been analyzed. This research compares these selection methods, seeking to answer the following questions:

  1. Does the CMl/GC method result in projects that differ from DBB projects regarding cost and schedule control?

  2. Are CMl/GC projects more efficient than DBB projects, where efficiency is defined as …


Impacts Of Columbia River Discharge On Salmonid Habitat: 2. Changes In Shallow-Water Habitat, David A. Jay, Tobias Kukulka Sep 2003

Impacts Of Columbia River Discharge On Salmonid Habitat: 2. Changes In Shallow-Water Habitat, David A. Jay, Tobias Kukulka

Civil and Environmental Engineering Faculty Publications and Presentations

This is the second part of an investigation that analyzes human alteration of shallow-water habitat (SWH) available to juvenile salmonids in the tidal Lower Columbia River. Part 2 develops a one-dimensional, subtidal river stage model that explains ~90% of the stage variance in the tidal river. This model and the tidal model developed in part 1 (Kukulka and Jay, 2003) uncouple the nonlinear interaction of river tides and river stage by referring both to external forcing by river discharge, ocean tides, and atmospheric pressure. Applying the two models, daily high-water levels were predicted for a reach from rkm-50 to rkm-90 …


Impacts Of Columbia River Discharge On Salmonid Habitat: 1. A Nonstationary Fluvial Tide Model, David A. Jay, Tobias Kukulka Sep 2003

Impacts Of Columbia River Discharge On Salmonid Habitat: 1. A Nonstationary Fluvial Tide Model, David A. Jay, Tobias Kukulka

Civil and Environmental Engineering Faculty Publications and Presentations

This is the first part of a two-part investigation that applies nonstationary time series analysis methods and the St. Venant equations to the problem of understanding juvenile salmonid access to favorable shallow-water habitat in a tidal river. Habitat access is a function of river stage, tidal range, and the distribution of bed elevation. Part 1 models nonstationary tidal properties: species amplitudes and phases and tidal range. Part 2 models low-frequency river stage in the Lower Columbia River and reconstructs historical water levels, using the tidal model from part 1. To incorporate the nonstationary frictional effects of variable river discharge into …


Adaptive Reflex Control For An Artificial Hand, Michele Flogheraiter, Giuseppina Gini, Marek Perkowski, Mikhail Pivtoraiko Sep 2003

Adaptive Reflex Control For An Artificial Hand, Michele Flogheraiter, Giuseppina Gini, Marek Perkowski, Mikhail Pivtoraiko

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper we illustrate the properties and the morphology of a human like neural reflex controller, used to set the stiffness and joint positions of an anthropomorphic artificial hand. In particular we explain, by simulations results, its ability to emulate the myotatic human reflex, and its capacity to learn in real time the best control strategy. We also present the dynamic model of the joints and of the artificial muscles used in Blackfingers, our artificial hand.


Spontaneous Coherent Pulsations In 3.39-M He–Ne Standing-Wave Laser Oscillators, Pitak Chenkosol, Lee W. Casperson Aug 2003

Spontaneous Coherent Pulsations In 3.39-M He–Ne Standing-Wave Laser Oscillators, Pitak Chenkosol, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Spontaneous pulsations similar to the type discovered in 3.51-μm Xe laser oscillators were reported several years ago in 3.39-μm He–Ne lasers, but no numerical interpretation of the He–Ne data has been given. The model for the Xe laser instability is adapted here to the He–Ne system, and the results include direct comparisons between theoretical calculations and published experimental data. Good agreement is obtained for the instability threshold, the pulsation frequencies, and many other features; and unmeasured but potentially useful pulsation characteristics are also readily obtained from the model.


Modeling Carrier Behavior In Sequential Auction Transportation Markets, Miguel Andres Figliozzi, Hani S. Mahmassani, Patrick Jaillet Aug 2003

Modeling Carrier Behavior In Sequential Auction Transportation Markets, Miguel Andres Figliozzi, Hani S. Mahmassani, Patrick Jaillet

Civil and Environmental Engineering Faculty Publications and Presentations

Online markets for transportation services, in the form of Internet sites that dynamically match shipments (shippers? demand) and transportation capacity (carriers? offer) through auction mechanisms are changing the traditional structure of transportation markets. A general framework for the study of carriers? behavior in a sequential auction transportation marketplace is provided. The unique characteristics of these marketplaces and the sources of difficulty in analyzing the behavior of these marketplaces are discussed. Learning and behavior in a sequential Vickrey auction marketplace is analyzed and simulated. Some results and the overall behavioral framework are also discussed.


Adaptive Live Video Streaming By Priority Drop, Jie Huang, Charles Krasic, Jonathan Walpole Jul 2003

Adaptive Live Video Streaming By Priority Drop, Jie Huang, Charles Krasic, Jonathan Walpole

Computer Science Faculty Publications and Presentations

In this paper we explore the use of Priority-progress streaming (PPS) for video surveillance applications. PPS is an adaptive streaming technique for the delivery of continuous media over variable bit-rate channels. It is based on the simple idea of reordering media components within a time window into priority order before transmission. The main concern when using PPS for live video streaming is the time delay introduced by reordering. In this paper we describe how PPS can be extended to support live streaming and show that the delay inherent in the approach can be tuned to satisfy a wide range of …


Technology Management For Reshaping The World, Dundar F. Kocaoglu, Timothy R. Anderson Jul 2003

Technology Management For Reshaping The World, Dundar F. Kocaoglu, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

The world is changing rapidly, and technology is playing the central role in making the changes happen. The events since PICMET '01 have made it clear that every society everywhere in the world is affected not only by the changes, but also by the technology behind them. There are few events in the world today that are not dominated, or at least influenced, by technology. This observation can be explained by recognizing the current period in the history of the world as the "technology era." When technology is properly used and managed, it leads to the reshaping of the world …


A System Dynamics Model Of The Pacific Coast Rockfish Fishery, Wayne Wakeland, Olgay Cangur, Guillermo Rueda, Astrid Scholz Jul 2003

A System Dynamics Model Of The Pacific Coast Rockfish Fishery, Wayne Wakeland, Olgay Cangur, Guillermo Rueda, Astrid Scholz

Complex Systems Faculty Publications and Presentations

This paper presents a model of the dynamic behavior of the yellowtail rockfish of the Pacific Coast of the United States. The purpose of the model is to generate endogenously the historical data for fish population, fishing vessels, regulatory parameters, and fish harvest. The model was subjected to a variety of tests to determine its sensitivity to changes in key parameters and initial values, including extreme conditions. Model results indicate that acceptable biological catch and fleet capacity must be adjusted quickly in response to changing conditions, in order to improve fishery sustainability. Additional analysis reinforces the policy of setting the …


Mining Picmet: 1997-2003 Papers Help You Track Management Of Technology Developments, Alan L. Porter, Robert J. Watts, Timothy R. Anderson Jul 2003

Mining Picmet: 1997-2003 Papers Help You Track Management Of Technology Developments, Alan L. Porter, Robert J. Watts, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

PICMET is providing the abstracts from 1997, 1999, 2001, and 2003 to enable you to "text mine" the contents of these four conferences. Using VantagePoint reader software (available to PICMET attendees at no charge) allows you to locate specific research abstracts of interest. Text mining helps ascertain "who's doing what, when?" The software also enables you to see larger patterns in management of technology (MOT) research.


Assigning Projects To Project Managers In A Multiple-Project Management Environment: A Pilot Study Of A Decision Support Model, Peerasit Patanakul, Dragan Milošević, Timothy R. Anderson Jul 2003

Assigning Projects To Project Managers In A Multiple-Project Management Environment: A Pilot Study Of A Decision Support Model, Peerasit Patanakul, Dragan Milošević, Timothy R. Anderson

Engineering and Technology Management Faculty Publications and Presentations

Project assignment is considered one of the most critical project decisions since it influences the performance of projects, and eventually the performance of the organization. Despite its importance, the literature reveals two major gaps on project assignment criteria and methodology. To close these gaps, this study proposes an additional set of project assignment criteria and a systematic methodology for project assignments (DSM). By using the concepts of these case study research combined with a literature review, the important potential criteria for project assignments are identified. These criteria are used in conjunction with the concepts of the analytic hierarchy process (AHP) …


Evolved Reversible Cascades Realized On The Cam-Brain Machine (Cbm), Andrzej Buller, Marek Perkowski Jul 2003

Evolved Reversible Cascades Realized On The Cam-Brain Machine (Cbm), Andrzej Buller, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a new approach to reversible cascade evolution based on a 3D cellular automaton. As a research platform we used the ATR's CAMBrain Machine (CBM). Reversible circuits are investigated because they are expected to dissipate much less energy than their irreversible counterparts. One day they will be implemented as nano-scale 3-dimensional chips. A circuit is reversible if the number of its inputs equals the number of its outputs and there is a one-to-one mapping between spaces of input vectors and output vectors. This paper provides: (1) a brief introduction to reversible logic concentrating on definitions and properties of …


Evolutionary Algorithms For Beginners, Marek Perkowski May 2003

Evolutionary Algorithms For Beginners, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This presentation offers a detailed introduction into the concepts and applications of evolutionary ideas in computing, adapted from genetics and evolution.


Cellular Automata Realization Of Regular Logic, Andrzej Buller, Marek Perkowski May 2003

Cellular Automata Realization Of Regular Logic, Andrzej Buller, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents a cellular-automatic model of a reversible regular structure called Davio lattice. Regular circuits are investigated because of the requirement of future (nano-) technologies where long wires should be avoided. Reversibility is a valuable feature because it means much lower energy dissipation. A circuit is reversible if the number of its inputs equals the number of its outputs and there is a one-to-one mapping between spaces of input vectors and output vectors. It is believed that one day regular reversible structures will be implemented as nanoscale 3-dimensional chips. This paper introduces the notion of the Toffoli gate and …


Function-Driven Linearly Independent Expansions Of Boolean Functions And Their Application To Synthesis Of Reversible Circuits, Pawel Kerntopf, Marek Perkowski May 2003

Function-Driven Linearly Independent Expansions Of Boolean Functions And Their Application To Synthesis Of Reversible Circuits, Pawel Kerntopf, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

The paper presents a family of new expansions of Boolean functions called Function-driven Linearly Independent (fLI) expansions. On the basis of this expansion a new kind of a canonical representation of Boolean functions is constructed: Function-driven Linearly Independent Binary Decision Diagrams (fLIBDDs). They generalize both Function-driven Shannon Binary Decision Diagrams (fShBDDs) and Linearly Independent Binary Decision Diagram (LIBDDs). The diagrams introduced in the paper, can provide significantly smaller representations of Boolean functions than standard Ordered Binary Decision Diagrams (OBDDs), Ordered Functional Decision Diagrams (OFDDs) and Ordered (Pseudo-) Kronecker Functional Decision Diagrams (OKFDDs) and can be applied to synthesis of reversible …


Extending Productivity Research Frontiers: Dea Resource Of Datasets And Errata, Timothy R. Anderson, Paul Rouse, Rafael Borja, Ivan Patricio Hernandez, Fabricio Tobar, Liono Setiowijoso Apr 2003

Extending Productivity Research Frontiers: Dea Resource Of Datasets And Errata, Timothy R. Anderson, Paul Rouse, Rafael Borja, Ivan Patricio Hernandez, Fabricio Tobar, Liono Setiowijoso

Engineering and Technology Management Faculty Publications and Presentations

Website databases provide the opportunity to fundamentally change the way research and knowledge are advanced and disseminated. This paper describes a website, http://www.etm.pdx.edu/dea/dataset/, focused on Data Envelopment Analysis and DEA researchers.


Blackfingers A Sophisticated Hand Prothesis, Michele Folgheraiter, Giuseppina Gini, Marek Perkowski, Mikhail Pivtoraiko Apr 2003

Blackfingers A Sophisticated Hand Prothesis, Michele Folgheraiter, Giuseppina Gini, Marek Perkowski, Mikhail Pivtoraiko

Electrical and Computer Engineering Faculty Publications and Presentations

Our goal is to develop the low level control system for an artificial hand ”Blackfingers”. Blackfingers was thought to have two main applications: as humanoid robot’s hand or as a human hand prothesis. In this last application our intent is to realize a device more sophisticated respect the actual commerce prothesis. Also in our intention is to use some biological paradigms to create a human like reflex control easy to be interfaced also with the human nervous system. In this paper we illustrate the properties and the morphology of a human like neural reflex controller, used to set the stiffness …


Upper Spokane River Model In Idaho: Boundary Conditions And Model Setup For 2001, Scott A. Wells, Robert Leslie Annear, Chris Berger Apr 2003

Upper Spokane River Model In Idaho: Boundary Conditions And Model Setup For 2001, Scott A. Wells, Robert Leslie Annear, Chris Berger

Civil and Environmental Engineering Faculty Publications and Presentations

The Spokane River in Idaho originates in Coeur d’Alene Lake (Figure 1 and Figure 2). The section of the Spokane River from Coeur d’Alene Lake to the Washington state line is the subject of a water quality study for the US Environmental Protection Agency. The objective of this study is to create a water quality and hydrodynamic model of the Spokane River in Idaho using CE-QUAL-W2 Version 3.1 (Cole and Wells, 2002).

Since the Spokane River is water quality limited, a hydrodynamic and water quality model for the Spokane River in Washington was developed by Portland State University for the …


Interfacial Mixing In A Highly Stratified Estuary: 1. Characteristics Of Mixing, David J. Kay, David A. Jay Mar 2003

Interfacial Mixing In A Highly Stratified Estuary: 1. Characteristics Of Mixing, David J. Kay, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This article is Part I of a set of papers addressing mixing in a highly stratified estuary. Measurements of interfacial turbulence were made in Columbia River estuary under conditions of moderate river flow and neap tides. A flux correlation method was used to determine buoyancy fluxes, and fits to theoretical velocity and temperature variance spectra were used to measure turbulent kinetic and potential energy dissipation rates. At the measurement site in the interior of the estuary, mixing along the top of the salt wedge is found to occur only on ebb, during periods when the internal Froude number is supercritical. …