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2017

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Articles 5551 - 5580 of 8353

Full-Text Articles in Engineering

Simulation Of Sic Mosfet Power Converters, Mustafa Nameer Albadri Jan 2017

Simulation Of Sic Mosfet Power Converters, Mustafa Nameer Albadri

Electronic Theses and Dissertations

This thesis discusses the use of wide bandgap devices (SiC-MOSFET) in the design and implementation of various power converters (Push-pull inverter, Buck converter). Different parameters and scenarios were discussed and implemented for both silicon and silicon carbide MOSFET cases. A comparison between same circuits is done using silicon in the first case and silicon carbide MOSFET was implemented under the same conditions and parameters to investigate the silicon carbide MOSFET enhancement to the circuit. The modeling for silicon and silicon carbide MOSFET was created using the spice model provided from leading electronics companies as ROHM, CREE and INFINION. This spice …

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Explaining The Performance Of Bidirectional Dijkstra And A* On Road Networks, Sneha Sawlani Jan 2017

Explaining The Performance Of Bidirectional Dijkstra And A* On Road Networks, Sneha Sawlani

Electronic Theses and Dissertations

The heuristic search community traditionally uses A* as the baseline algorithm for their research methods. Research papers in the road networks community, however, often build upon Dijkstra's algorithm and use Bidirectional Dijkstra's algorithm as their baseline. This thesis investigates the performance of A* and Bidirectional Dijkstra in road networks to see how they compare and to see if there is a principled explanation for the different approaches. Our analysis reveals why Bidirectional Dijkstra can perform well in this domain, but also shows a simple mistake that can be made when building test problems that hurts the performance of A*.

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Effect Of Exponential Correlation Model On Spectral And Energy Efficiency For Massive Mimo Systems, Saleh Albdran Jan 2017

Effect Of Exponential Correlation Model On Spectral And Energy Efficiency For Massive Mimo Systems, Saleh Albdran

Electronic Theses and Dissertations

During the past few years, the number of wireless devices has been increasing rapidly. Wireless networks are serving and connecting billions of wireless devices where these devices are demanding higher data rate and lower latency to be able to support voice, video and gaming applications. Moreover, the consumed energy by the wireless systems will be increasing. Hence, the Fifth generation (5G) wireless networks needs to provide higher data rate, serve larger number of users simultaneously and be more energy efficient. One of the promising technologies that can meet the above requirements is Massive Multiple Input Multiple Output (MIMO). The main …

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P1: Measuring Wind Using A Hovering Drone Network: Met-Masts On The Go, Mohamad Khattab, Hassan Jaroudi Jan 2017

P1: Measuring Wind Using A Hovering Drone Network: Met-Masts On The Go, Mohamad Khattab, Hassan Jaroudi

Undergraduate Research Posters 2017

Renewable energy has grown considerably over the past years, with a projected growth of $460 billion per year by 2030. One of these renewable energies is deploying wind turbines to harvest wind energy. Knowledge of wind speed and direction is critical to determine the appropriate site to place wind turbines. The current method of collecting wind data primarily by installing stationary meteorological towers is expensive and limited, because met masts are fixed once built. This research aims at using a network of hovering drones as a platform to measure wind speed, direction, temperature and humidity at multiple elevations, which could …

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Convolutional Neural Networks For Predicting Skin Lesions Of Melanoma, Anuruddha Jayasekara Pathiranage Jan 2017

Convolutional Neural Networks For Predicting Skin Lesions Of Melanoma, Anuruddha Jayasekara Pathiranage

Regis University Student Publications (comprehensive collection)

Diagnosis of an unknown skin lesion is crucial to enable proper treatments. While curable with early diagnosis, only highly trained dermatologists are capable of accurately recognize melanoma skin lesions. Expert dermatologist classification for melanoma dermoscopic images is 65-66%. As expertise is in limited supply, systems that can automatically classify skin lesions as either benign or malignant melanoma are very useful as initial screening tools. Towards this goal, this study presents a convolutional neural network model, trained on features extracted from a highway convolutional neural network pretrained on dermoscopic images of skin lesions. This requires no lesion segmentation nor complex preprocessing. …

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Towards Deadline Guaranteed Cloud Storage Services, Guoxin Liu, Haiying Shen, Lei Yu Jan 2017

Towards Deadline Guaranteed Cloud Storage Services, Guoxin Liu, Haiying Shen, Lei Yu

Publications

More and more organizations move their data and workload to commercial cloud storage systems. However, the multiplexing and sharing of the resources in a cloud storage system present unpredictable data access latency to tenants, which may make online data-intensive applications unable to satisfy their deadline requirements. Thus, it is important for cloud storage systems to provide deadline guaranteed services. In this paper, to meet a current form of service level objective (SLO) that constrains the percentage of each tenant's data access requests failing to meet its required deadline below a given threshold, we build a mathematical model to derive the …

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Demisting Using An Ultrasonic Standing Wave Field, T. M. Merrell, John Saylor Jan 2017

Demisting Using An Ultrasonic Standing Wave Field, T. M. Merrell, John Saylor

Publications

Removing drops from an air flow can be challenging, particularly, for small drops. Herein a method for demisting is presented that employs ultrasonics to force small drops to combine. Specifically, a cylindrical ultrasonic standing wave field is established in a tube, forming pressure nodes that take the form of cylinders located within the tube and having the same axis as the tube. Droplets are driven toward these pressure nodes by the acoustic radiation force, forcing smaller drops to combine to form larger drops, which eventually fall due to gravity, thereby demisting the flow. Experiments presented herein show that, for the …

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Exercise - Choose A Manager To Learn Multi-Criteria Decision Analysis - University Of Colorado Boulder, Joseph Kasprzyk Jan 2017

Exercise - Choose A Manager To Learn Multi-Criteria Decision Analysis - University Of Colorado Boulder, Joseph Kasprzyk

All ECSTATIC Materials

A prompt for an in-class exercise, so that students can learn basic principles of multi-criteria decision analysis. The ideal place for this exercise is to have it before the formal lecture of multi-criteria decision analysis. The students will start to gain an intuitive understanding of how to transform preferences to scores, how to weight the metrics, and how to make a final decision.

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Water Resource Systems And Management (Spring 2017) - University Of Colorado Boulder, Joseph Kasprzyk Jan 2017

Water Resource Systems And Management (Spring 2017) - University Of Colorado Boulder, Joseph Kasprzyk

All ECSTATIC Materials

No abstract provided.

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Introduction To Reservoir Analysis - University Of Colorado Boulder, Joseph Kasprzyk Jan 2017

Introduction To Reservoir Analysis - University Of Colorado Boulder, Joseph Kasprzyk

All ECSTATIC Materials

Introduction to reservoirs, lecture from Water Resource Systems and Management (Spring 2017), University of Colorado Boulder. By Joseph Kasprzyk. Learning goals include (i) introducing what a reservoir is, (ii) apply control volume and conservation of mass principles to analyze storage in natural lakes and reservoirs (iii) calculate required storage size for reservoirs using basic techniques (iv) define reservoir terms including safe yield and critical period (v) discuss dam building trends in the US and globally.

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Introduction To Water Resources Systems - University Of Colorado Boulder, Joseph Kasprzyk Jan 2017

Introduction To Water Resources Systems - University Of Colorado Boulder, Joseph Kasprzyk

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This is the introductory lecture to a Water Resource Systems and Management class from Spring 2017 at the University of Colorado Boulder, by Joseph Kasprzyk. Learning goals include (i) defining integrated water resources management, (ii) identifying Colorado water management issues (ii) identifying how RiverWare simulation and optimization can be used to develop water plans (iii) use the HyMod model to perform rainfall-runoff modeling (iv) generating random parameter samples and understanding how parameter uncertainty affects model results.

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Stochastic Hydrology, Meghna Babbar-Sebens Jan 2017

Stochastic Hydrology, Meghna Babbar-Sebens

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Syllabus for graduate class in Stochastic Hydrology

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Case Study For Guided Project In Stochastic Hydrology, Meghna Babbar-Sebens Jan 2017

Case Study For Guided Project In Stochastic Hydrology, Meghna Babbar-Sebens

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Attached are two guided project activities for hydrology and climate data of Eagle Creek Watershed, Indiana, USA. The zip files have flow and precipitation datasets at daily, monthly, and annual time scales.

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Optimization In Water Resources Engineering, Meghna Babbar-Sebens Jan 2017

Optimization In Water Resources Engineering, Meghna Babbar-Sebens

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No abstract provided.

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Six Degree Of Freedom Dynamic Modeling Of A High Altitude Airship And Its Trajectory Optimization Using Direct Collocation Method, Pradens Pierre-Louis Jan 2017

Six Degree Of Freedom Dynamic Modeling Of A High Altitude Airship And Its Trajectory Optimization Using Direct Collocation Method, Pradens Pierre-Louis

Electronic Theses and Dissertations

The long duration airborne feature of airships makes them an attractive solution for many military and civil applications such as long-endurance surveillance, reconnaissance, environment monitoring, communication utilities, and energy harvesting. To achieve a minimum energy periodic motion in the air, an optimal trajectory problem is solved using basic direct collocation methods. In the direct approach, the optimal control problem is converted into a nonlinear programming (NLP). Pseudo-inverse and several discretization methods such as Trapezoidal and Hermite-Simpson are used to obtain a numerical approximated solution by discretizing the states and controls into a set of equal nodes. These nodes are approximated …

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Electrode Integration Of Nanostructured Metal And Metal Oxide Materials Based On In-Situ Growth Methods For Environmental Sensors, Xiaochen Wang Jan 2017

Electrode Integration Of Nanostructured Metal And Metal Oxide Materials Based On In-Situ Growth Methods For Environmental Sensors, Xiaochen Wang

Electronic Theses and Dissertations

In the past decades, increased human population and activities have introduced a large amount of pollutants into the environment. Various types of conventional analytical instruments were used for monitoring the emitted chemicals with low detection limit, high accuracy, and discrimination power. However, many of these methods are laboratory-based owing to sample collection, transportation, extraction, and purification steps. To make real-time on-site monitoring possible, miniaturized sensors with various integrated elements were developed. One of the most well-known strategies is to utilize nanostructured materials with enhanced sensing properties for those devices. For a majority of the current state of art devices, the …

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Groundwater Modeling For Assessing The Impacts Of Natural Hazards In East-Central Florida, Han Xiao Jan 2017

Groundwater Modeling For Assessing The Impacts Of Natural Hazards In East-Central Florida, Han Xiao

Electronic Theses and Dissertations

In coastal east-central Florida (ECF) , the low-lying coastal alluvial plains and barrier islands have a high risk of being inundated by seawater due to climate change effects such as sea-level rise, changing rainfall patterns, and intensified storm surge from hurricanes., This will produce saltwater intrusion into the coastal aquifer from infiltration of overtopping saltwater. In the inland ECF region, sinkhole occurrence is recognized as the primary geologic hazard causing massive financial losses to society in the past several decades. The objectives of this dissertation are to: (1) evaluate the impacts of sea-level rise and intensified storm surge on the …

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Load-Balancing In Local And Metro-Area Networks With Mptcp And Openflow, Austin Jerome Jan 2017

Load-Balancing In Local And Metro-Area Networks With Mptcp And Openflow, Austin Jerome

Electronic Theses and Dissertations

In this thesis, a novel load-balancing technique for local or metro-area traffic is proposed in mesh-style topologies. The technique uses Software Defined Networking (SDN) architecture with virtual local area network (VLAN) setups typically seen in a campus or small-to-medium enterprise environment. This was done to provide a possible solution or at least a platform to expand on for the load-balancing dilemma that network administrators face today. The transport layer protocol Multi-Path TCP (MPTCP) coupled with IP aliasing is also used. The trait of MPTCP of forming multiple subflows from sender to receiver depending on the availability of IP addresses at …

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Context-Dependence Of Physiological Systems: Environment-Physiology Interactions In The Respiratory Control System, Joseph M. Santin Jan 2017

Context-Dependence Of Physiological Systems: Environment-Physiology Interactions In The Respiratory Control System, Joseph M. Santin

Browse all Theses and Dissertations

We know that animals are tuned to survive different environmental conditions or else life would not exist. Unfortunately, this is often forgotten or ignored when designing experiments. As Marsh Tenney articulated, "The physiologist keeps the whole always in mind. He accepts the tactical necessity of reductionism to understand parts, but, once done, for him it is only the beginning, never the end” (from Remmers, 2005). In an era when it is all too common to take environmental complexity out of the organism to understand physiology, my work puts some of that complexity back in the study of organisms. I take …

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Visualization Of Carbon Monoxide Particles Released From Firearms, Sadan Suneesh Menon Jan 2017

Visualization Of Carbon Monoxide Particles Released From Firearms, Sadan Suneesh Menon

Browse all Theses and Dissertations

A number of soldiers have come forward to report discomfort, irritation and respiratory problems after taking part in a live firing session. These problems are caused due to the fumes and particulates emitted from the gun upon firing. There exists substantial research work focused on lead and other harmful metallic particulates expelled from a firearm, since they are the most harmful among the other emissions. However, our research focuses on visualizing the carbon monoxide (CO) particles released from a firearm in order to help understand adverse effects they may have on the human body. We use data provided by researchers …

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Design Of A Programmable Four-Preset Guitar Pedal, Michael Trombley Jan 2017

Design Of A Programmable Four-Preset Guitar Pedal, Michael Trombley

Browse all Theses and Dissertations

Many companies in the music industry offer programmable preset guitar pedals. Presets allow musicians to save time and focus on their act by recalling predetermined settings during a performance. A majority of the companies in the music industry offer up to hundreds of presets, but realistically the substantial amount of presets may have a negative effect on the musician’s performance due to time constraints. The main contribution of this thesis is to address the musician by reducing the amount of presets offered in a guitar pedal design. Combining two systems, a digital control and audio processing circuit, will produce a …

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Fire Performance Of Reinforced Concrete Frames Using Sectional Analysis, Salah El-Din F. El-Fitiany, Maged Youssef Jan 2017

Fire Performance Of Reinforced Concrete Frames Using Sectional Analysis, Salah El-Din F. El-Fitiany, Maged Youssef

Civil and Environmental Engineering Publications

Global behavior of RC structures during fire events can be predicted using complex nonlinear thermal-structural numerical simulations. However, such simulations are computationally expensive, which limit their use by design engineers. A practical approach to track the performance of RC frames during fire exposure is proposed and validated in this paper. A previously developed simple heat transfer technique is used to calculate an average 1D temperature distribution for heated RC sections. Consequently, the flexural and axial stiffnesses as well as the unrestrained thermal deformations are evaluated using sectional analysis. Based on rational assumptions, simplified expressions are also driven to evaluate those …

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Analysis Of Reinforced Concrete Beams Strengthened Using Concrete Jackets, M. Monir A. Alhadid, Maged Youssef Jan 2017

Analysis Of Reinforced Concrete Beams Strengthened Using Concrete Jackets, M. Monir A. Alhadid, Maged Youssef

Civil and Environmental Engineering Publications

Analysis of jacketed Reinforced Concrete (RC) beams considering the interfacial slip effect is a complicated problem. In the current practice, slip is neglected in the analysis and monolithic behavior is assumed in the jacketed section resulting in higher estimates of stiffness and/or capacity. Engineers need simplified yet robust tools to predict the actual behavior of jacketed RC beams. This paper provides a simplified method to analyze jacketed RC beams taking into account the interfacial slip distribution and the actual nonlinear behavior of both concrete and steel. An iterative calculation algorithm is developed to determine the moment-curvature and load-deflection curves of …

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Shape Memory Alloy Reinforced Concrete Frames Vulnerable To Strong Vertical Excitations, M A. Elfeki, Maged A. Youssef Jan 2017

Shape Memory Alloy Reinforced Concrete Frames Vulnerable To Strong Vertical Excitations, M A. Elfeki, Maged A. Youssef

Civil and Environmental Engineering Publications

Reinforced concrete (RC) framed buildings dissipate the seismic energy through yielding of the reinforcing bars. This yielding jeopardizes the serviceability of these buildings as it results in residual lateral deformations. Superelastic shape memory alloys (SMAs) can recover inelastic strains by stress removal. This paper extends previous research by the authors that optimized the use of SMA bars in RC frames considering the horizontal seismic excitation by addressing the effect of the vertical seismic excitation. A steel RC six-storey building designed according to current seismic standards is considered as case study. Five different earthquake records with strong vertical components are …

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Ductile Corrosion-Free Gfrp-Stainless Steel Reinforced Concrete Elements, Maged A. Youssef, Mohamed E. Meshaly, Ahmed Elansary Jan 2017

Ductile Corrosion-Free Gfrp-Stainless Steel Reinforced Concrete Elements, Maged A. Youssef, Mohamed E. Meshaly, Ahmed Elansary

Civil and Environmental Engineering Publications

Corrosion of steel rebars is known to cause deterioration of concrete structures that can lead to catastrophic failures. To mitigate this problem, steel rebars can be replaced with Glass Fiber-Reinforced Polymer (GFRP) rebars. However, the lack of ductility of GFRP-reinforced elements has prevented their use in many structural applications, especially in seismic areas. Stainless Steel (SS) rebars are corrosion resistant and have adequate energy absorption and ductility. However, they are much more expensive than steel rebars. This paper proposes the combined use of SS and GFRP rebars to achieve ductile and corrosion-free elements. The first challenge for such a proposal …

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Dynamic Coupling Of Phase-Heat And Mass Transfer In Porous Media And Conjugate Fluid/Porous Domains, Mahmoud Mohamed Mostafa Elhalwagy, Anthony G. Straatman Jan 2017

Dynamic Coupling Of Phase-Heat And Mass Transfer In Porous Media And Conjugate Fluid/Porous Domains, Mahmoud Mohamed Mostafa Elhalwagy, Anthony G. Straatman

Mechanical and Materials Engineering Publications

No abstract provided.

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An Ensemble Learning Framework For Anomaly Detection In Building Energy Consumption, Daniel B. Araya, Katarina Grolinger, Hany F. Elyamany, Miriam Am Capretz, Girma T. Bitsuamlak Jan 2017

An Ensemble Learning Framework For Anomaly Detection In Building Energy Consumption, Daniel B. Araya, Katarina Grolinger, Hany F. Elyamany, Miriam Am Capretz, Girma T. Bitsuamlak

Electrical and Computer Engineering Publications

During building operation, a significant amount of energy is wasted due to equipment and human-related faults. To reduce waste, today's smart buildings monitor energy usage with the aim of identifying abnormal consumption behaviour and notifying the building manager to implement appropriate energy-saving procedures. To this end, this research proposes a new pattern-based anomaly classifier, the collective contextual anomaly detection using sliding window (CCAD-SW) framework. The CCAD-SW framework identifies anomalous consumption patterns using overlapping sliding windows. To enhance the anomaly detection capacity of the CCAD-SW, this research also proposes the ensemble anomaly detection (EAD) framework. The EAD is a generic framework …

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A Gamification Framework For Sensor Data Analytics, Alexandra L'Heureux, Katarina Grolinger, Wilson A. Higashino, Miriam A. M. Capretz Jan 2017

A Gamification Framework For Sensor Data Analytics, Alexandra L'Heureux, Katarina Grolinger, Wilson A. Higashino, Miriam A. M. Capretz

Electrical and Computer Engineering Publications

The Internet of Things (IoT) enables connected objects to capture, communicate, and collect information over the network through a multitude of sensors, setting the foundation for applications such as smart grids, smart cars, and smart cities. In this context, large scale analytics is needed to extract knowledge and value from the data produced by these sensors. The ability to perform analytics on these data, however, is highly limited by the difficulties of collecting labels. Indeed, the machine learning techniques used to perform analytics rely upon data labels to learn and to validate results. Historically, crowdsourcing platforms have been used to …

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Deep Neural Networks With Confidence Sampling For Electrical Anomaly Detection, Norman L. Tasfi, Wilson A. Higashino, Katarina Grolinger, Miriam A. M. Capretz Jan 2017

Deep Neural Networks With Confidence Sampling For Electrical Anomaly Detection, Norman L. Tasfi, Wilson A. Higashino, Katarina Grolinger, Miriam A. M. Capretz

Electrical and Computer Engineering Publications

The increase in electrical metering has created tremendous quantities of data and, as a result, possibilities for deep insights into energy usage, better energy management, and new ways of energy conservation. As buildings are responsible for a significant portion of overall energy consumption, conservation efforts targeting buildings can provide tremendous effect on energy savings. Building energy monitoring enables identification of anomalous or unexpected behaviors which, when corrected, can lead to energy savings. Although the available data is large, the limited availability of labels makes anomaly detection difficult. This research proposes a deep semi-supervised convolutional neural network with confidence sampling for …

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Study Of The Influence Of The Agarose Hydrogel Layer Thickness On Sensitivity Of The Coated Silica Microsphere, Arun Mallik, Gerald Farrell, Qiang Wu, Yuliya Semenova Jan 2017

Study Of The Influence Of The Agarose Hydrogel Layer Thickness On Sensitivity Of The Coated Silica Microsphere, Arun Mallik, Gerald Farrell, Qiang Wu, Yuliya Semenova

Articles

In this paper, we investigate both theoretically and experimentally the influence of the agarose hydrogel layer thickness on the sensitivity of a proposed relative humidity (RH) sensor based on a silica microsphere resonator coated with agarose hydrogel. The operating principle of the sensor relies on excitation of whispering gallery modes (WGMs) in the coated silica microsphere using the evanescent field of a tapered fiber. A change in the ambient relative humidity is detected by measuring the wavelength shift of the WGMs in the transmission spectrum of the tapered fiber. Using perturbation theory, we analyze the influence of the agarose coating …

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