Engineering Commons^™

Anytime Planning For Decentralized Pomdps Using Expectation Maximization, Akshat Kumar, Shlomo Zilberstein

Research Collection School Of Computing and Information Systems

Decentralized POMDPs provide an expressive framework for multi-agent sequential decision making. While finite-horizon DECPOMDPs have enjoyed signifcant success, progress remains slow for the infinite-horizon case mainly due to the inherent complexity of optimizing stochastic controllers representing agent policies. We present a promising new class of algorithms for the infinite-horizon case, which recasts the optimization problem as inference in a mixture of DBNs. An attractive feature of this approach is the straightforward adoption of existing inference techniques in DBNs for solving DEC-POMDPs and supporting richer representations such as factored or continuous states and actions. We also derive the Expectation Maximization (EM) …

Impact Of Preferential Flow Paths On Alluvial Groundwater Flow Patterns And Phosphorus Transport, Derek M. Heeren, Ronald B. Miller, Garey A. Fox, Daniel E. Storm, Aaron R. Mittelstet, Chad J. Penn

Biological Systems Engineering: Papers and Publications

While surface runoff is considered to be the primary transport mechanism for phosphorus (P), subsurface transport through coarse subsoil to gravel bed streams may be significant and represent a source of P not alleviated by current conservation practices (e.g., riparian buffers). Previous research has documented P transport in a preferential flow path (PFP) identified as a buried gravel bar. It is hypothesized that PFPs, if connected to the soil surface, provide a rapid and efficient method of transporting P, and that these alluvial features are transient storage zones for nutrients, acting as a sink during high flow and a source …

Analysis And Transformation Of Pipe-Like Web Mashups For End User Programmers, Kathryn T. Stolee

Computer Science and Engineering: Theses, Dissertations, and Student Research

Mashups are becoming increasingly popular as end users are able to easily access, manipulate, and compose data from several web sources. To support end users, communities are forming around mashup development environments that facilitate sharing code and knowledge. We have observed, however, that end user mashups tend to suffer from several deficiencies, such as inoperable components or references to invalid data sources, and that those deficiencies are often propagated through the rampant reuse in these end user communities.

In this work, we identify and specify ten code smells indicative of deficiencies we observed in a sample of 8,051 pipe-like web …

The Surface Expression Of Semidiurnal Internal Tides Near A Strong Source At Hawaii. Part I: Observations And Numerical Predictions, Cedric Chavanne, P. Flament, Glenn S. Carter, M. Merrifield, D. Luther, Edward D. Zaron, K. W. Gurgel

Civil and Environmental Engineering Faculty Publications and Presentations

Observations of semidiurnal currents fromhigh-frequency radioDoppler currentmeters andmoored acoustic Doppler current profilers (ADCPs) in the Kauai Channel, Hawaii, are described and compared with two primitive equation numerical models of the tides. The Kauai Channel, separating the islands of Oahu and Kauai, is a site of strong internal tide generation by the barotropic tides flowing over Kaena Ridge, the subsurface extension of Oahu. The nature and impacts of internal tide generation in the Kauai Channel were intensively studied during the 2002–03 near-field component of the Hawaii Ocean Mixing Experiment. Comparisons of observed coherent (i.e., phase locked to the astronomical forcing)M_{2 …}

Geophysical Mapping Of Preferential Flow Paths Across Multiple Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Todd Halihan, Aaron R. Mittelstet

Biological Systems Engineering: Papers and Publications

In the Ozark ecoregion of Oklahoma, Arkansas and Missouri, the erosion of carbonate bedrock (primarily limestone) by slightly acidic water has left a residuum of chert gravel, producing gravel-bed streams and floodplains generally consisting of coarse chert gravel overlain by a mantle (1 to 300 cm) of gravelly loam or silt loam. Previous research has documented the occurrence of preferential flow paths (PFP) in an alluvial floodplain hypothesized to be a buried gravel bar. Field experiments have shown that the PFP affected alluvial groundwater flow in the floodplain and that water flow in the PFP was transmitted at rates that …

Multi-Robot System Control Architecture (Mrsca) For Agricultural Production, Santosh Pitla, Joe D. Luck, Scott A. Shearer

Conference Presentations and White Papers: Biological Systems Engineering

Coordinating multiple autonomous robots for achieving an assigned collective task presents a complex engineering challenge. In this paper multi robot system control architecture (MRSCA) for the coordination of multiple agricultural robots is developed. The two important aspects of MRSCA; coordination strategy and inter-robot communication were discussed with typical agricultural tasks as examples. Classification of MRS into homogeneous and heterogeneous robots was done to identify appropriate form of cooperative behavior and inter-robot communication. The framework developed, proposes that inter-robot communication is not always required for a MRS. Three types of cooperative behaviors; No-cooperation, modest cooperation and absolute cooperation for a MRS …

Offset Right-Turn Lanes For Improved Intersection Sight Distance, Karen Schurr, Timothy J. Foss Jr.

Nebraska Department of Transportation Research Reports

No abstract provided.

Boron Carbide Based Solid State Neutron Detectors: The Effects Of Bias And Time Constant On Detection Efficiency, Nina Hong, John Mullins, Keith Foreman, Shireen Adenwalla

Shireen Adenwalla Papers

Neutron detection in thick boron carbide(BC)/n-type Si heterojunction diodes shows a threefold increase in efficiency with applied bias and longer time constants. The improved efficiencies resulting from long time constants have been conclusively linked to the much longer charge collection times in the BC layer. Neutron detection signals from both the p-type BC layer and the n-type Si side of the heterojunction diode are observed, with comparable efficiencies. Collectively, these provide strong evidence that the semiconducting BC layer plays an active role in neutron detection, both in neutron capture and in charge generation and collection.

Hydrogen Permeation Dynamics Across A Palladium Membrane In A Varying Pressure Environment, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.

Hysteresis Loopsofmethanecatalyticpartialoxidationfor Hydrogen Productionundertheeffectsofvariedreynolds Number Anddamko¨Hlernumber, Wei-Hsin Chen

Wei-Hsin Chen

No abstract provided.

A Study On Torrefaction Of Various Biomass Materials And Its Impact On Lignocellulosic Structure Simulated By A Thermogravimetry, Wei-Hsin Chen

Wei-Hsin Chen

Enhanced Biodegradation Of Used Engine Oil In Soil Amended With Organic Wastes, Abdul Aziz Abdul Raman

Abdul Aziz Abdul Raman

Three organic wastes (banana skin (BS), brewery spent grain (BSG), and spent mushroom compost (SMC)) were used for bioremediation of soil spiked with used engine oil to determine the potential of these organic wastes in enhancing biodegradation of used oil in soil. The rates of biodegradation of the oil were studied for a period of 84 days under laboratory conditions. Hydrocarbon-utilizing bacterial counts were high in all the organic waste-amended soil ranging between 10.2 x 10(6) and 80.5 x 10(6) CFU/g compared to unamended control soil throughout the 84 days of study. Oil-contaminated soil amended with BSG showed the highest …

Report On Laboratory Testing Of Anchor Bolts Connecting Cold-Formed Steel Track To Concrete With Minimum Edge Distances, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Properties And Device Applications Of Silicon And Silicon-Germanium Nanostructures With Different Dimensions, Han-Yun Chang

Dissertations

Defect-free crystalline Si/SiGe(Ge) nanostructures are demonstrated despite the 4% lattice mismatch between Si and Ge. The lattice mismatch-induced strain is sufficiently relaxed through the designed, cluster morphology, or nanowire (NW) structures. Future device applications of these nano structures require complete understanding of their structural, optical, electrical and thermal properties. This study explores these properties in two-dimensional (2D) Si/Si:B delta-doped multilayers, 2D Si/Si_1-xGe_x planar multilayers, three-dimensional (3D) Si/Si_1-xGe_{x cluster multilayers, one-dimensional (1D) Si NWs and 1D Si/Ge NW heterojunctions (HJs).}

Raman scattering and photoluminescence measurements show that by alternating heavily boron-doped layers with layers of …

Hardware Support For Real-Time Network Security And Packet Classification Using Field Programmable Gate Arrays, Nitesh Bhicu Guinde

Dissertations

Deep packet inspection and packet classification are the most computationally expensive operations in a Network Intrusion Detection (NID) system. Deep packet inspection involves content matching where the payload of the incoming packets is matched against a set of signatures in the database. Packet classification involves inspection of the packet header fields and is basically a multi-dimensional matching problem. Any matching in software is very slow in comparison to current network speeds. Also, both of these problems need a solution which is scalable and can work at high speeds. Due to the high complexity of these matching problems, only Field-Programmable Gate …

The Floating Contract Between Risk-Averse Supply Chain Partners In A Volatile Commodity Price Environment, Mojisola Kike Otegbeye

Dissertations

In this dissertation, two separate but closely related decision making problems in environments of volatile commodity prices are addressed. In the first problem, a risk-averse commodity user's purchasing policy and his risk-neutral supplier's pricing decision, where the user can purchase his needs through contract with his supplier as well as directly from the spot market, are analyzed. The commodity user is assumed to be the supplier's sole client, and the supplier can always expand capacity, at a cost to the user, to accommodate the user's demand in excess of initially reserved capacity.

In the more generalized second problem, both parties …

Formation Of Screen-Printed Contacts On Multicrystalline Silicon (Mc-Si) Solar Cells, Vishal R. Mehta

Dissertations

Commercial multicrystalline silicon (me-Si) solar cells use screen-printing process for depositing both the Ag paste based gridded front and Al based back (whole area) metal contacts.. This thesis relates to experimental and theoretical studies of contact formation mechanisms in silicon solar cells. Temperature distribution studies during optical processing by. attached thermocouples to cells indicates that the maximum temperature reached under the front silver metal is less. than 800°C; this is lower than the eutectic point of Ag-Si (≈835°C). An analysis of the interaction of Ag particles and Si via the constituents of glass is given. This mechanism leaches metallic ions …

Novel Micron- And Nano-Scale Energetic Materials For Advanced Gun Propulsion, Their Material Properties, And Their Effects On Ballistic Performance, Thelma Gatuz Manning

Dissertations

This dissertation focused on the investigation of novel materials that are both energetic and inert in their micron- and nano-scale crystalline form. The characterization of the materials properties and its effects on the ballistic performance when incorporated into a composite material were evaluated as a gun propellant for application in a future weapon system for the US Army. Some of these materials may find dual use in civilian applications. Applications in small and medium arms, artillery, tank, aircraft, and shipboard gun systems will all benefit from these advancements. Not only will gun system performance be improved for greater stand-off range …

Optimizing Integrated Service For A Transit Route With Heterogeneous Demand, Yavuz Yusuf Ulusoy

Dissertations

The methodology developed in this dissertation attempts to optimize integrated service that minimizes the total cost, including user and supplier costs, of a transit route with heterogeneous demand. While minimizing total cost, a set of practical constraints, such as capacity, operable fleet size and frequency conservation, are considered.

The research problem is presented in three scenarios, consisting of various service patterns (e.g., all-stop, short-turn and express) under heterogeneous demand. A logit-based model was used to estimate passenger transfer demand. An exhaustive search method was developed to find the optimal solutions for a simplified transit route with six stops, and a …

Multi-Component Boron Coatings On Low Carbon Steel Aisi 1018, Naruemon Suwattananont

Dissertations

Boronizing and metalizing are thermo-chemical surface hardening treatments in which boron and metal atoms diffuse into the metal substrate forming metallic boride layers, providing complex properties of B-Me-Fe system.

To study multi-component boron coatings on low carbon steel AISI 1018, the simultaneous powder pack method of boronizing and metalizing was selected to perform the coatings. One B-Fe system and eight boron-metal (B-Me-Fe) systems from transition metals group IVB (Ti, Zr, Hf), group VB (Nb, Ta), and group VIB (Cr, Mo, W) were studied. The system specimens were thermo-chemically treated at 950°C for 4 hours in a crucible containing powder mixture …