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2006

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Articles 2761 - 2790 of 3391

Full-Text Articles in Engineering

An Improved Microwave Radiative Transfer Model For Ocean Emissivity At Hurricane Force Surface Wind Speed, Salem El-Nimri Jan 2006

An Improved Microwave Radiative Transfer Model For Ocean Emissivity At Hurricane Force Surface Wind Speed, Salem El-Nimri

Electronic Theses and Dissertations

An electromagnetic model for predicting the microwave blackbody emission from the ocean surface under the forcing of strong surface winds in hurricanes is being developed. This ocean emissivity model will be incorporated into a larger radiative transfer model used to infer ocean surface wind speed and rain rate in hurricanes from remotely sensed radiometric brightness temperature. The model development is based on measurements obtained with the Stepped Frequency Microwave Radiometer (SFMR), which routinely flys on the National Oceanic and Atmospheric Administration's hurricane hunter aircraft. This thesis presents the methods used in the wind speed model development and validation results for …

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A Life Cycle Software Quality Model Using Bayesian Belief Networks, Justin Beaver Jan 2006

A Life Cycle Software Quality Model Using Bayesian Belief Networks, Justin Beaver

Electronic Theses and Dissertations

Software practitioners lack a consistent approach to assessing and predicting quality within their products. This research proposes a software quality model that accounts for the influences of development team skill/experience, process maturity, and problem complexity throughout the software engineering life cycle. The model is structured using Bayesian Belief Networks and, unlike previous efforts, uses widely-accepted software engineering standards and in-use industry techniques to quantify the indicators and measures of software quality. Data from 28 software engineering projects was acquired for this study, and was used for validation and comparison of the presented software quality models. Three Bayesian model structures are …

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Wide Viewing Angle Liquid Crystal Displays, Qi Hong Jan 2006

Wide Viewing Angle Liquid Crystal Displays, Qi Hong

Electronic Theses and Dissertations

In this dissertation, novel phase compensation technologies are applied to the designs of wide viewing angle and high transmittance liquid crystal displays. First, a design of wide viewing angle liquid crystal displays utilizing crossed linear polarizers is proposed. The designed multi-domain vertical-alignment liquid crystal display predicts superb contrast ratio over wide viewing angles. Next, to increase the bright state transmittance while maintain the high contrast. Finally, to reduce the cost and improve the applicability of the broadband and wide-view circular polarizer, the device configuration of the broadband and wide-view circular polarizer is significantly simplified by the application of biaxial compensation …

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On-Chip Spiral Inductor/Transformer Design And Modeling For Rf Applications, Ji Chen Jan 2006

On-Chip Spiral Inductor/Transformer Design And Modeling For Rf Applications, Ji Chen

Electronic Theses and Dissertations

Passive components are indispensable in the design and development of microchips for high-frequency applications. Inductors in particular are used frequently in radio frequency (RF) IC's such as low-noise amplifiers and oscillators. High performance inductor has become one of the critical components for voltage controlled oscillator (VCO) design, for its quality factor (Q) value directly affects the VCO phase noise. The optimization of inductor layout can improve its performance, but the improvement is limited by selected technology. Inductor performance is bounded by the thin routing metal and small distance from lossy substrate. On the other hand, the in-accurate inductor modeling further …

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Design, Analysis And Implementation Of Orthogonal Frequency Coding In Saw Devices Used For Spread Spectrum Tags And Sensors, Derek Puccio Jan 2006

Design, Analysis And Implementation Of Orthogonal Frequency Coding In Saw Devices Used For Spread Spectrum Tags And Sensors, Derek Puccio

Electronic Theses and Dissertations

SAW based sensors can offer wireless, passive operation in numerous environments and various device embodiments are employed for retrieval of the sensed data information. Single sensor systems can typically use a single carrier frequency and a simple device embodiment, since tagging is not required. In a multi-sensor environment, it is necessary to both identify the sensor and retrieve the sensed information. This dissertation presents the concept of orthogonal frequency coding (OFC) for applications to SAW sensor technology. OFC offers all advantages inherent to spread spectrum communications including enhanced processing gain and lower interrogation power spectral density (PSD). It is shown …

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A Real Option Strategic Scorecard Decision Framework For It Project Selection, Cesar Munoz Jan 2006

A Real Option Strategic Scorecard Decision Framework For It Project Selection, Cesar Munoz

Electronic Theses and Dissertations

The problem of project selection is of significant importance in management of information systems. Almost $2 trillion is spent worldwide every year on IT projects, with over $600 billion spent in the US alone. Traditionally, managers have being using the classical net present value (NPV) method in conjunction with multicriteria scoring models for ROI analysis and selection of IT project investments The multicriteria models use ad-hoc evaluation criteria to assign priority weights and then rate the alternatives against each criterion. These models have two limitations. First, the criteria and weights are based on subjective judgments, allowing the introduction of politics …

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Safety Effects Of Traffic Signal Installations On State Road Intersections In Northeast Florida, Christopher Ledew Jan 2006

Safety Effects Of Traffic Signal Installations On State Road Intersections In Northeast Florida, Christopher Ledew

Electronic Theses and Dissertations

The purpose of this thesis is to explore how the installations of traffic signals affect crash experience at intersections, to identify those factors which help predict crashes after a signal is installed, and to develop a crash prediction model. It is the intent of this thesis to supplement the Manual on Uniform Traffic Control Devices Signal Warrant procedure and aid the traffic engineer in the signal installation decision making process. Crash data, as well as operational and geometric factors were examined for 32 state road intersections in the northeast Florida area before and after signal installation. Signal warrant studies were …

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Algorithms For Discovering Communities In Complex Networks, Hemant Balakrishnan Jan 2006

Algorithms For Discovering Communities In Complex Networks, Hemant Balakrishnan

Electronic Theses and Dissertations

It has been observed that real-world random networks like the WWW, Internet, social networks, citation networks, etc., organize themselves into closely-knit groups that are locally dense and globally sparse. These closely-knit groups are termed communities. Nodes within a community are similar in some aspect. For example in a WWW network, communities might consist of web pages that share similar contents. Mining these communities facilitates better understanding of their evolution and topology, and is of great theoretical and commercial significance. Community related research has focused on two main problems: community discovery and community identification. Community discovery is the problem of extracting …

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Wavelets In Real-Time Rendering, Weifeng Sun Jan 2006

Wavelets In Real-Time Rendering, Weifeng Sun

Electronic Theses and Dissertations

Interactively simulating visual appearance of natural objects under natural illumination is a fundamental problem in computer graphics. 3D computer games, geometry modeling, training and simulation, electronic commerce, visualization, lighting design, digital libraries, geographical information systems, economic and medical image processing are typical candidate applications. Recent advances in graphics hardware have enabled real-time rasterization of complex scenes under artificial lighting environment. Meanwhile, pre-computation based soft shadow algorithms are proven effective under low-frequency lighting environment. Under the most practical yet popular all-frequency natural lighting environment, however, real-time rendering of dynamic scenes still remains a challenging problem. In this dissertation, we propose a …

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Synthesis Of Self-Resetting Stage Logic Pipelines, Rashad Oreifej Jan 2006

Synthesis Of Self-Resetting Stage Logic Pipelines, Rashad Oreifej

Electronic Theses and Dissertations

As designers began to pack multi-million transistors onto a single chip, their reliance on a global clocking signal to orchestrate the operations of the chip has started to face almost insurmountable difficulties. As a result, designers started to explore clockless circuits to avoid the global clocking problem. Recently, self-resetting circuits implemented in dynamic logic families have been proposed as viable clockless alternatives. While these circuits can produce excellent performances, they display serious limitations in terms of area cost and power consumption. A middle-of-the-road alternative, which can provide a good performance and avoid the limitations seen in dynamic self-resetting circuits, would …

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Coupling Of Hydrodynamic And Wave Models For Storm Tide Simulations: A Case Study For Hurricane Floyd (1999), Yuji Funakoshi Jan 2006

Coupling Of Hydrodynamic And Wave Models For Storm Tide Simulations: A Case Study For Hurricane Floyd (1999), Yuji Funakoshi

Electronic Theses and Dissertations

This dissertation presents the development of a two-dimensional St. Johns River model and the coupling of hydrodynamic and wave models for the simulation of storm tides. The hydrodynamic model employed for calculating tides and surges is ADCIRC-2DDI (ADvanced CIRCulation Model for Shelves, Coasts and Estuaries, Two-Dimensional Depth Integrated) developed by Luettich et al. (1992). The finite element based model solves the fully nonlinear shallow water equations in the generalized wave continuity form. Hydrodynamic applications are operated with the following forcings: 1) astronomical tides, 2) inflows from tributaries, 3) meteorological effects (winds and pressure), and 4) waves (wind-induced waves). The wave …

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A Multi-View Framework For Defining The Services Supply Chain Using Object Oriented Methodology, James Barnard Jan 2006

A Multi-View Framework For Defining The Services Supply Chain Using Object Oriented Methodology, James Barnard

Electronic Theses and Dissertations

Supply-chain management is the practice combining theory from logistics, operations management, production management and inventory control. Therefore, it is often associated exclusively with manufacturing or materials management industries. Application of supply-chain management to other industries often results in implementations that do not satisfy the needs of the involved enterprises. To improve the implementation of supply-chain solutions outside of the materials management and manufacturing industries there is a need for industry specific standards. One industry sector in need of a standard is the services industry. The current problem facing the services sector is the inability to adapt current frameworks to the …

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Digital Controller Implementation For Disturbance Rejection In The Optical Coupling Of A Mobile Experimental Laser Tracking Systems, Matthew Rhodes Jan 2006

Digital Controller Implementation For Disturbance Rejection In The Optical Coupling Of A Mobile Experimental Laser Tracking Systems, Matthew Rhodes

Electronic Theses and Dissertations

Laser tracking systems are an important aspect of the NASA space program, in particular for conducting research in relation to satellites and space port launch vehicles. Often, launches are conducted at remote sites which require all of the test equipment, including the laser tracking systems, to be portable. Portable systems are more susceptible to environmental disturbances which affect the overall tracking resolution, and consequently, the resolution of any other experimental data being collected at any given time. This research characterizes the optical coupling between two systems in a Mobile Experimental Laser Tracking system and evaluates several control solutions to minimize …

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Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin Jan 2006

Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin

Electronic Theses and Dissertations

Simulation modeling is the most cost-effective way of studying real life transportation problems, either existing or anticipated, without disturbing the balance of the transportation system. There is a vast suite of simulation models available in market, ready to choose from macroscopic, mesoscopic, or microscopic in nature, to study different transportation system elements like freeways, highways, signalized and un-signalized intersections. However, most of these network simulation models, like PARAMICS, VISSIM, CORSIM … etc, do not come readily available with built in toll plaza models. On the other hand, many researchers have independently developed toll plaza models, which can only model an isolated …

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Bench Scale Analysis Of Experimental Fouling-Resistent Low Pressure Reverse Osmosis Membranes Using High Organic Surface Water And Synthetic Colloidal Water, Matthew Doan Jan 2006

Bench Scale Analysis Of Experimental Fouling-Resistent Low Pressure Reverse Osmosis Membranes Using High Organic Surface Water And Synthetic Colloidal Water, Matthew Doan

Electronic Theses and Dissertations

The utilization of membrane treatment for the production of potable water has become more prevalent in today's industry. As drinking water regulations become more stringent this trend is expected to continue. Widespread use is also a result of membrane treatment being the best available treatment in many cases. While membrane treatment is a proven technology that can produce a consistently superior product to conventional treatment methods, membrane fouling and concentrate disposal are issues that drive up the cost of membrane treatment and can effectively eliminate it from consideration as a treatment alternative. This research focused on membrane fouling. A series …

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Alumina-Aluminum Titanate-Titania Nanocomposite: Synthesis, Sintering Studies, Assessment Of Bioactivity And Its Mechanical And Electrical Properties, Vikas Somani Jan 2006

Alumina-Aluminum Titanate-Titania Nanocomposite: Synthesis, Sintering Studies, Assessment Of Bioactivity And Its Mechanical And Electrical Properties, Vikas Somani

Electronic Theses and Dissertations

This thesis reports the development, synthesis and characterization of a ceramic-ceramic nanocomposite system for its possible application as structural and electronic biomaterial in the biomedical industry. The study selected and synthesized alumina-aluminum titanate-titania (Al2O3-Al2TiO5-TiO2) nanoceramic composite using a simple Sol-Gel technique, which can be easily reproduced. Aluminum propoxide and titanium propoxide were used as precursor chemicals. Propanol and 2- methoxy ethanol were used as solvent and stabilizer, respectively. Thermal analyses were performed for a systematic understanding of phase evolution from the synthesized gel. X-Ray diffraction technique was used to confirm the phase evolution, phase purity, crystallite size and crystal structure(s) …

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Algorithms For Haplotype Inference And Block Partitioning, Satya Ravi Vijaya Jan 2006

Algorithms For Haplotype Inference And Block Partitioning, Satya Ravi Vijaya

Electronic Theses and Dissertations

The completion of the human genome project in 2003 paved the way for studies to better understand and catalog variation in the human genome. The International HapMap Project was started in 2002 with the aim of identifying genetic variation in the human genome and studying the distribution of genetic variation across populations of individuals. The information collected by the HapMap project will enable researchers in associating genetic variations with phenotypic variations. Single Nucleotide Polymorphisms (SNPs) are loci in the genome where two individuals differ in a single base. It is estimated that there are approximately ten million SNPs in the …

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Influence Map Methodology For Evaluating Systemic Safety Issues, Timothy Barth Jan 2006

Influence Map Methodology For Evaluating Systemic Safety Issues, Timothy Barth

Electronic Theses and Dissertations

Raising the bar in safety performance is a critical challenge for many organizations. Contributing factor taxonomies organize information on why accidents occur. Therefore, they are essential elements of accident investigations and safety reporting systems. Organizations must balance efforts to identify causes of specific accidents with efforts to evaluate systemic safety issues in order to become more proactive about improving safety. This research successfully addressed two problems: (1) limited methods and metrics exist to support the design of effective taxonomies, and (2) influence relationships between contributing factors are not explicitly modeled within a taxonomy. The primary result of the taxonomic relationship …

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Transmission Lines For Ir Signal Routing, Tasneem Mandviwala Jan 2006

Transmission Lines For Ir Signal Routing, Tasneem Mandviwala

Electronic Theses and Dissertations

In this dissertation, the design, fabrication, and characterization of coplanar striplines, vias, and microstrip lines is investigated, from the point of view of developing interconnections for antenna-coupled infrared detectors operating in the 8- to 12-micron wavelength range. To our knowledge, no previous efforts have been made to study the performance of metallic-wire transmission lines at infrared frequencies. Both the design and fabrication of these structures present unique challenges. Because of attenuation and dispersion issues, the analytical formulas for transmission-line parameters that are valid below a few hundred GHz are not applicable in the infrared. Therefore, numerical modeling was performed to …

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The Effectiveness Of A Specifically Designed Green Roof Stormwater Treatment System Irrigated With Recycled Stormwater Runoff To Achieve Pollutant Removal And Stormwater Volume Reduction, Michael Hardin Jan 2006

The Effectiveness Of A Specifically Designed Green Roof Stormwater Treatment System Irrigated With Recycled Stormwater Runoff To Achieve Pollutant Removal And Stormwater Volume Reduction, Michael Hardin

Electronic Theses and Dissertations

One of our greatest threats to surface-water quality is polluted stormwater runoff. In this research, investigated is the use of a green roof irrigated with recycled stormwater runoff to remove pollutants from stormwater runoff and reduce the volume of stormwater runoff leaving developed areas. The green roof properties of interest are the filtration and biological processes as well as the roof's ability to hold water and increase evapotranspiration, reducing the volume of stormwater runoff from the source. Because of the above mentioned reasons the experiment consists of a water quality analysis and a water budget done on several experimental chambers …

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The Effect Of Hot Carrier Stress On Low Noise Amplifier Radio Frequency Performance Under Weak And Strong Inversion, Lin Shen Jan 2006

The Effect Of Hot Carrier Stress On Low Noise Amplifier Radio Frequency Performance Under Weak And Strong Inversion, Lin Shen

Electronic Theses and Dissertations

This thesis work is mainly focused on studying RF performance degradation of a low noise amplifier (LNA) circuit due to hot carrier effect (HCE) in both the weak and strong inversion regions. Since the figures of merit for the RF circuit characterization are gain, noise figure, input, and output matching, the LNA RF performance drift is evaluated in a Cadence SpectreRF simulator subject to these features. This thesis presents hot carrier induced degradation results of an LNA to show that the HCE phenomenon is one of the serious reliability issues in the aggressively scaled RF CMOS design, especially for long-term …

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Heuristic 3d Reconstruction Of Irregular Spaced Lidar, Nicholas Shorter Jan 2006

Heuristic 3d Reconstruction Of Irregular Spaced Lidar, Nicholas Shorter

Electronic Theses and Dissertations

As more data sources have become abundantly available, an increased interest in 3D reconstruction has emerged in the image processing academic community. Applications for 3D reconstruction of urban and residential buildings consist of urban planning, network planning for mobile communication, tourism information systems, spatial analysis of air pollution and noise nuisance, microclimate investigations, and Geographical Information Systems (GISs). Previous, classical, 3D reconstruction algorithms solely utilized aerial photography. With the advent of LIDAR systems, current algorithms explore using captured LIDAR data as an additional feasible source of information for 3D reconstruction. Preprocessing techniques are proposed for the development of an autonomous …

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Syntax-Based Concept Extraction For Question Answering, Demetrios Glinos Jan 2006

Syntax-Based Concept Extraction For Question Answering, Demetrios Glinos

Electronic Theses and Dissertations

Question answering (QA) stands squarely along the path from document retrieval to text understanding. As an area of research interest, it serves as a proving ground where strategies for document processing, knowledge representation, question analysis, and answer extraction may be evaluated in real world information extraction contexts. The task is to go beyond the representation of text documents as "bags of words" or data blobs that can be scanned for keyword combinations and word collocations in the manner of internet search engines. Instead, the goal is to recognize and extract the semantic content of the text, and to organize it …

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Iterchanging Discrete Event Simulationprocess Interaction Modelsusing The Web Ontology Language - Owl, Lee Lacy Jan 2006

Iterchanging Discrete Event Simulationprocess Interaction Modelsusing The Web Ontology Language - Owl, Lee Lacy

Electronic Theses and Dissertations

Discrete event simulation development requires significant investments in time and resources. Descriptions of discrete event simulation models are associated with world views, including the process interaction orientation. Historically, these models have been encoded using high-level programming languages or special purpose, typically vendor-specific, simulation languages. These approaches complicate simulation model reuse and interchange. The current document-centric World Wide Web is evolving into a Semantic Web that communicates information using ontologies. The Web Ontology Language – OWL, was used to encode a Process Interaction Modeling Ontology for Discrete Event Simulations (PIMODES). The PIMODES ontology was developed using ontology engineering processes. Software was …

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A Hybrid Simulation Methodology To Evaluate Network Centricdecision Making Under Extreme Events, Sergio Quijada Jan 2006

A Hybrid Simulation Methodology To Evaluate Network Centricdecision Making Under Extreme Events, Sergio Quijada

Electronic Theses and Dissertations

Currently the network centric operation and network centric warfare have generated a new area of research focused on determining how hierarchical organizations composed by human beings and machines make decisions over collaborative environments. One of the most stressful scenarios for these kinds of organizations is the so-called extreme events. This dissertation provides a hybrid simulation methodology based on classical simulation paradigms combined with social network analysis for evaluating and improving the organizational structures and procedures, mainly the incident command systems and plans for facing those extreme events. According to this, we provide a methodology for generating hypotheses and afterwards testing …

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Fault-Tolerant Control For Sssc Using Neural Networks And Pso, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2006

Fault-Tolerant Control For Sssc Using Neural Networks And Pso, Wei Qiao, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Adaptive Distributed Fair Scheduling And Its Implementation In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda Jan 2006

Adaptive Distributed Fair Scheduling And Its Implementation In Wireless Sensor Networks, Maciej Jan Zawodniok, Jagannathan Sarangapani, Steve Eugene Watkins, James W. Fonda

Electrical and Computer Engineering Faculty Research & Creative Works

A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks is shown through hardware implementation. In contrast to simulation, hardware evaluation provides valuable feedback to protocol and hardware development process. The proposed protocol focuses on quality-of-service (QoS) issues to address flow prioritization. Thus, when nodes access a shared channel, the proposed ADFS allocates the channel bandwidth proportionally to the weight, or priority, of the packet flows. Moreover, ADFS allows for dynamic allocation of network resources with little added overhead. Weights are initially assigned using user specified QoS criteria. These weights are subsequently updated as a function of …

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Test 1882: Mccormick Xtx 215 Diesel, Nebraska Tractor Test Lab Jan 2006

Test 1882: Mccormick Xtx 215 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Test 1876: Challenger Mt 645b Diesel, Nebraska Tractor Test Lab Jan 2006

Test 1876: Challenger Mt 645b Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

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Test 1890: John Deere 8530 Ivt, Nebraska Tractor Test Lab, John Deere Jan 2006

Test 1890: John Deere 8530 Ivt, Nebraska Tractor Test Lab, John Deere

Nebraska Tractor Tests

No abstract provided.

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