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2018

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Articles 13141 - 13170 of 13644

Full-Text Articles in Physical Sciences and Mathematics

A New Method For Detecting Jittered Pri In Histogram-Based Methods, Mostafa Bagheri, Mohammad Hossein Sedaaghi Jan 2018

A New Method For Detecting Jittered Pri In Histogram-Based Methods, Mostafa Bagheri, Mohammad Hossein Sedaaghi

Turkish Journal of Electrical Engineering and Computer Sciences

Histogram-based methods are among the best methods for deinterleaving, because of their easy implementation. However, they have a basic defect when they encounter a jittered pulse repetition interval (PRI). Jittered PRI is one of the most sophisticated patterns for electronic warfare (EW) receivers. In jittered PRI, the time among successive pulses varies in a totally random manner; thus its detection is very complicated. In this paper we present a new method for extracting jittered PRI from histogram-based methods. Simulation results demonstrate excellent performance of the proposed method in normal as well as hard circumstances where a higher missing pulse rate …


Composite Vector Quantization For Optimizing Antenna Locations, Zekeri̇ya Uykan, Riku Jantti Jan 2018

Composite Vector Quantization For Optimizing Antenna Locations, Zekeri̇ya Uykan, Riku Jantti

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we study the location optimization problem of remote antenna units (RAUs) in generalized distributed antenna systems (GDASs). We propose a composite vector quantization (CVQ) algorithm that consists of unsupervised and supervised terms for RAU location optimization. We show that the CVQ can be used i) to minimize an \textit{upper bound} to the cell-averaged SNR error for a desired/demanded location-specific SNR function, and ii) to maximize the cell-averaged \textit{effective} \textit{SNR}. The CVQ-DAS includes the standard VQ, and thus the well-known squared distance criterion (SDC) as a special case. Computer simulations confirm the findings and suggest that the proposed …


Compact Local Gabor Directional Number Pattern For Facial Expression Recognition, Zhengyan Zhang, Guanming Lu, Jingjie Yan, Haibo Li, Ning Sun, Xia Li Jan 2018

Compact Local Gabor Directional Number Pattern For Facial Expression Recognition, Zhengyan Zhang, Guanming Lu, Jingjie Yan, Haibo Li, Ning Sun, Xia Li

Turkish Journal of Electrical Engineering and Computer Sciences

This paper explores a novel method to represent face images for facial expression recognition; it is named compact local Gabor directional number pattern (CLGDNP). By convolving the face images with Gabor filters, we encode the magnitude and phase response images in each scale, and calculate the histograms in several nonoverlapping regions of each encoded image. Finally, we obtain two spatial histogram sequences by the aid of the mean pooling technology and concatenate them to form the facial descriptor. Moreover, for evaluating the performance of the proposed method, we employ a support vector machine to conduct some extensive classification experiments on …


Dynamic Simulation Of The Cad Model In Simmechanics With Multiple Uses, Jiri Zátopek, Zdenek Ú?Ední?Ek, José Machado, João Sousa Jan 2018

Dynamic Simulation Of The Cad Model In Simmechanics With Multiple Uses, Jiri Zátopek, Zdenek Ú?Ední?Ek, José Machado, João Sousa

Turkish Journal of Electrical Engineering and Computer Sciences

When designing a mechatronic system, several steps are taken into account. One of the main steps is the design of a CAD model representing the physical part of the system, and another major point is the development of the mathematical model necessary for the respective controller design. This paper combines both design steps and shows the advantages of using this approach. First, a CAD model is created considering the kinematic and dynamic behavior of the system as well as respective material properties. This CAD model is, in parallel, used for both purposes: as the main basis for developing a mathematical …


Gradient Domain Photomontage Via Interactive Object Selection, Beki̇r Di̇zdaroğlu Jan 2018

Gradient Domain Photomontage Via Interactive Object Selection, Beki̇r Di̇zdaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

One of the most critical steps in photomontage is marking an object that is to be copied from a source image to a target image efficiently. Some unexpected and unwanted effects such as bleeding usually occur on the resulting image if the object is roughly marked, copied, and then pasted to the target region, even when using the Poisson equation approach. Moreover, original color information for the pasted object cannot be preserved, and color values for the boundary pixels of the pasted object may change and/or blurriness may occur when using some methods described in the literature. The proposed methods …


Improvement Of Air Pollution Prediction In A Smart City And Its Correlation With Weather Conditions Using Metrological Big Data, Talat Zaree, Ali Reza Honarvar Jan 2018

Improvement Of Air Pollution Prediction In A Smart City And Its Correlation With Weather Conditions Using Metrological Big Data, Talat Zaree, Ali Reza Honarvar

Turkish Journal of Electrical Engineering and Computer Sciences

Smart cities are an important concept for urban development. This concept addresses many current critical urban problems including traffic and environmental pollution. As utilization of the Internet of things and technology in smart cities increases, large volumes of big data are generated and collected by sensors embedded at different places in the city, which present a real-time display of what is happening throughout the city at all times. Such data should be processed and analyzed as a response to ensure effectiveness and improvement in quality of provided services; correct use and analysis of such data is valuable. Big data mining …


Interactive Process Miner: A New Approach For Process Mining, İsmai̇l Yürek, Derya Bi̇rant, Kökten Ulaş Bi̇rant Jan 2018

Interactive Process Miner: A New Approach For Process Mining, İsmai̇l Yürek, Derya Bi̇rant, Kökten Ulaş Bi̇rant

Turkish Journal of Electrical Engineering and Computer Sciences

Process mining is a technique for extracting knowledge from event logs recorded by an information system. In the process discovery phase of process mining, a process model is constructed to represent the business processes systematically and to give a general opinion about the progressive of processes in the event log. The constructed process model can be very complex as a result of structured and unstructured processes recorded in real life. Previous studies proposed different approaches to filter or eliminate some processes from the model to simplify it by implementing some statistical or mathematical formulas rather than user interactions. The main …


Will It Pass? Predicting The Outcome Of A Source Code Review, Çağdaş Evren Gerede, Zeki̇ Mazan Jan 2018

Will It Pass? Predicting The Outcome Of A Source Code Review, Çağdaş Evren Gerede, Zeki̇ Mazan

Turkish Journal of Electrical Engineering and Computer Sciences

It has been observed that allowing source code changes to be made only after source code reviews has a positive impact on the quality and lifetime of the resulting software. In some cases, code review processes take quite a long time and this negatively affects software development costs and employee job satisfaction. Establishing mechanisms that predict what kind of feedback reviewers will provide and what revisions they will ask for can reduce the number of times this problem occurs. Thanks to such mechanisms, developers can improve the maturity of their code change requests before the review process starts. In this …


Gait Pattern Discrimination Of Als Patients Using Classification Methods, Süleyman Bi̇lgi̇n, Zahi̇de Eli̇f Akin Jan 2018

Gait Pattern Discrimination Of Als Patients Using Classification Methods, Süleyman Bi̇lgi̇n, Zahi̇de Eli̇f Akin

Turkish Journal of Electrical Engineering and Computer Sciences

Amyotrophic lateral sclerosis (ALS) is a mortal and idiopathic neurodegenerative disturbance of the human motor system. The disturbances of locomotion due to neurodegenerative diseases (NDDs) consisting of ALS, Parkinson disease (PD), and Huntington disease (HD) cause some abnormal fluctuations in gait signals. The investigation into gait patterns of NDDs provides significant information in order to develop new biomedical diagnosis devices. The main objective of this study is to evaluate the best discrimination method of ALS among control subjects (Co.), PD patients, and HD patients. The D2, D4, D5, and D6 detailed components, which were determined as critical features extracted from …


Laser Printer As A Source Of Sensitive Emissions, Ireneusz Kubiak Jan 2018

Laser Printer As A Source Of Sensitive Emissions, Ireneusz Kubiak

Turkish Journal of Electrical Engineering and Computer Sciences

Each electronic (electric) device generates electromagnetic emissions during its operation. Most often these emissions are generated unintentionally and they are radiated into the surrounding space in an uncontrolled way. In the case of significant levels of these emissions, they can disturb the operation of other devices or can be used as typical radio emissions. If the nature of their changes corresponds to the processed information occurring in a form of electric signals, the mentioned emissions can be a basis for effective realization of electromagnetic infiltration processes. Most often, these emissions are classified in laboratory conditions using anechoic chambers. Inside such …


A Modeling And Simulation Study About Co$_{2}$ Amount With Web-Based Indoor Air Quality Monitoring, Nesi̇be Yalçin, Deni̇z Balta, Ahmet Özmen Jan 2018

A Modeling And Simulation Study About Co$_{2}$ Amount With Web-Based Indoor Air Quality Monitoring, Nesi̇be Yalçin, Deni̇z Balta, Ahmet Özmen

Turkish Journal of Electrical Engineering and Computer Sciences

Human breath causes indoor air quality (IAQ) to get worse in overcrowded places such as schools, hospitals, and offices where people spend most of their time, and it is rarely felt. For a healthy and comfortable living environment, pollutant gases must also be monitored in addition to temperature and humidity control. In this respect, carbon dioxide (CO$_{2})$ is considered as one of the main indoor air pollutants to determine ventilation requirements. In this study, a mathematical model and simulator software have been developed to predict CO$_{2}$ concentrations under different indoor conditions and to visualize the predicted results that come from …


High-Speed Data Deduplication Using Parallelized Cuckoo Hashing, Jane Rubel Angelina Jeyaraj, Sundarakantham Kambaraj, Velmurugan Dharmarajan Jan 2018

High-Speed Data Deduplication Using Parallelized Cuckoo Hashing, Jane Rubel Angelina Jeyaraj, Sundarakantham Kambaraj, Velmurugan Dharmarajan

Turkish Journal of Electrical Engineering and Computer Sciences

Data deduplication is a capacity optimization technology used in backup systems for identifying and storing the nonredundant data blocks. The CPU intensive tasks involved in a hash-based deduplication system remain as challenges in improving the performance of the system. In this paper, we propose a parallel variant of the standard cuckoo hashing that enables the hashing technique to be performed in parallel. The CPU intensive tasks of fingerprint insertion and lookup operations are performed in parallel and distributed among the nodes of the deduplication cluster. Furthermore, the uniform handling of the blocks by the cluster nodes involved in the process …


Hardware Trojan Detection And Localization Based On Local Detectors, Amin Bazzazi, Mohammad Taghi Manzuri Shalmani, Ali Mohammad Afshin Hemmatyar Jan 2018

Hardware Trojan Detection And Localization Based On Local Detectors, Amin Bazzazi, Mohammad Taghi Manzuri Shalmani, Ali Mohammad Afshin Hemmatyar

Turkish Journal of Electrical Engineering and Computer Sciences

Hardware Trojans are one of the serious threats with detrimental, irreparable effects on the functionality, security, and performance of digital integrated circuits. It is difficult to detect Trojans because of their diversity in size and performance. While the majority of current methods focus on Trojan detection during chip testing, run-time techniques can be employed to gain unique advantages. This paper proposes a method based on the online scalable detection technique, which eliminates the need for a reference chip. Involving local detectors, this technique assesses the variations in the logical values of each node to find out whether there are Trojans. …


Analyzing Methods Of Network Topologies Based On Chordal Rings, Damian Ledzinski, Sandra Smigiel, Lukasz Zabludowski Jan 2018

Analyzing Methods Of Network Topologies Based On Chordal Rings, Damian Ledzinski, Sandra Smigiel, Lukasz Zabludowski

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a methodology for the transmission properties research of networks patterned according to the third-degree chordal graphs. When designing and analyzing ICT systems, it is vital to consider the topology of network components. The telecommunication network structure can be described by a graph. Computing modes or specialized computers are the vertexes and the edges are bidirectional, independent transmission channels that represent the connected nodes. The algorithm is potentially useful for the determination of the impact of diameter and an average path length of the chordal rings on the properties of the transmission network. It is also useful for …


Virtual Force-Based Intelligent Clustering For Energy-Efficient Routing In Mobile Wireless Sensor Networks, Selvi Munuswamy, Jothi Muneeswari Saravanakumar, Ganapathy Sannasi, Khanna Nehemiah Harichandran, Kannan Arputharaj Jan 2018

Virtual Force-Based Intelligent Clustering For Energy-Efficient Routing In Mobile Wireless Sensor Networks, Selvi Munuswamy, Jothi Muneeswari Saravanakumar, Ganapathy Sannasi, Khanna Nehemiah Harichandran, Kannan Arputharaj

Turkish Journal of Electrical Engineering and Computer Sciences

A mobile wireless sensor network (MWSN) consists of many sensor nodes, which can move from one position to another and gather data from the environment, and such nodes are coordinated with the support of a sink node. In recent years, the mobility behavior of sensor nodes present in wireless sensor networks is used to form effective clustering and to perform cluster-based routing. Virtual force is an important phenomenon in sensor nodes, which is used to model the mobility behavior. Production rules that use spatiotemporal constraints are able to make more accurate decisions on mobility speed, mobility area, and the required …


Experimental Realization Of A Multi-Input Buck--Boost Dc--Dc Converter, Kushal Kanhav, Madhuri Chaudhari Jan 2018

Experimental Realization Of A Multi-Input Buck--Boost Dc--Dc Converter, Kushal Kanhav, Madhuri Chaudhari

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, steady and dynamic performance of a multi-input buck--boost DC--DC converter is presented. The converter has the ability to supply energy from storage and renewable energy sources individually to the load. It maintains a constant output voltage under various transient conditions of load as well as source. It has the capability to operate in buck, boost, and buck--boost modes of operation. The mathematical model of the converter is developed, which is further used to design controllers for the converter. A laboratory prototype is developed for experimental realization of the converter. The analysis, design, simulation, and experimental results of …


New Approach In Two-Area Interconnected Agc Including Various Renewable Energy Sources Using Pso, Prasun Sanki, Mousumi Basu Jan 2018

New Approach In Two-Area Interconnected Agc Including Various Renewable Energy Sources Using Pso, Prasun Sanki, Mousumi Basu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel approach for automatic generation control (AGC) as an integrated two-area thermal-hybrid power generation system (THPGS) where thermal generators are interconnected with various renewable power generators (RPGs) like a solar power generator (SPG), wind power generator (WPG), fuel cell, and aqua electrolyzer. A comparison is carried out between the THPGS and a normal thermal power system considering proportional integral and derivative controllers. Particle swarm optimization (PSO) is used for optimizing the gain parameters of the controller. Investigation of dynamic responses is carried out considering step load perturbation as well as random load perturbation (RLP). Problems are …


Higher Order Sliding Mode Controller For Urea-Scr System, Palanikumar Gurusamy, Uma Gandhi, Umapathy Mangalanathan, Arunshankar Jayabalan Jan 2018

Higher Order Sliding Mode Controller For Urea-Scr System, Palanikumar Gurusamy, Uma Gandhi, Umapathy Mangalanathan, Arunshankar Jayabalan

Turkish Journal of Electrical Engineering and Computer Sciences

The urea-selective catalytic reduction (SCR) system is one of the effective after-treatment emission reduction methods for diesel engines that comply with the emission standards. This paper presents the development of a linear parameter-varying (LPV) model for the urea-SCR system from the identified linear models. To reduce the NO$_{X}$ emissions from diesel engines, a LPV model-based supertwisting sliding mode controller with lemniscate sliding surface is designed. The closed-loop performance of the designed controller is evaluated through simulations for step change in input and disturbance in output. The controller performance is compared against the multimodel PI controller and LPV model-based supertwisting sliding …


The Application Of Analytical Mechanics In A Multimachine Power System, Zhijie Wang, Zhiyuan Liu, Jie Wang, Xiuchen Jiang, Sanming Liu, Yifang Liu, Gehao Sheng, Tianyu Liu Jan 2018

The Application Of Analytical Mechanics In A Multimachine Power System, Zhijie Wang, Zhiyuan Liu, Jie Wang, Xiuchen Jiang, Sanming Liu, Yifang Liu, Gehao Sheng, Tianyu Liu

Turkish Journal of Electrical Engineering and Computer Sciences

Analytical mechanics methods play an important role in determining the energy function and Hamilton realization of a system. In this paper, the Hamilton function of the system is obtained directly from the system differential equation by means of analytical mechanics. In addition, the system Hamiltonization process requires that the system must be even order, and the commonly used generator model is a single-axis third-order model. For this reason, the odd-order power system model is extended to an even-order system. The Hamilton function of the system is deduced with coordinate transformation and the generalized force. Then the standard form of Hamilton …


An Integrated Approach For The Development Of An Electric Vehicle Powertrain: Design, Analysis, And Implementation, Özgür Üstün, Ramazan Nejat Tuncay, Mert Safa Mökükcü, Ömer Ci̇han Kivanç, Gürkan Tosun, Can Gökce, Murat Çakan Jan 2018

An Integrated Approach For The Development Of An Electric Vehicle Powertrain: Design, Analysis, And Implementation, Özgür Üstün, Ramazan Nejat Tuncay, Mert Safa Mökükcü, Ömer Ci̇han Kivanç, Gürkan Tosun, Can Gökce, Murat Çakan

Turkish Journal of Electrical Engineering and Computer Sciences

Electric motor and power electronic systems are essential elements for the performance and efficiency of electric vehicles (EVs) and hybrid electric vehicles. The inadequacy of the range due to battery limitations is compensated by powertrain solutions and innovative control algorithms. Future targets of electric powertrains are mostly based on weight, space, and efficiency issues. Highly efficient low-volume and light-weight propulsion systems increase the performance of EVs and also enhance their importance as an alternative to internal combustion engine vehicles. In this paper, a detailed propulsion system design study is presented by considering all of the important constraints of the electric …


High-Power Density Switched Reluctance Machine Development For High-Speed Spindle Applications, Yusuf Yasa, Yilmaz Sözer, Muhammet Gari̇p Jan 2018

High-Power Density Switched Reluctance Machine Development For High-Speed Spindle Applications, Yusuf Yasa, Yilmaz Sözer, Muhammet Gari̇p

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a high-speed switched reluctance machine (HS-SRM) with cobalt-iron lamination material is proposed for spindle motors, which are used in computer numerical control machines. Wide torque-speed range, high power density, high efficiency, and low cost are the crucial issues in spindle applications. Three types of electric machine candidates, the permanent magnet synchronous machine (PMSM), induction machine (IM), and switched reluctance machine (SRM), are compared with their outstanding features. The SRM spindle motor will offer a more robust, reliable, compact, and cost-effective solution compared to the IM or PMSM spindle applications. Moreover, advancement on cobalt-iron laminations gives a chance …


A Novel Dtc-Svm Approach For Two Parallel-Connected Induction Motors Fed By Matrix Converter, Mahdi Jafari, Karim Abbaszadeh, Mustafa Mohamadian Jan 2018

A Novel Dtc-Svm Approach For Two Parallel-Connected Induction Motors Fed By Matrix Converter, Mahdi Jafari, Karim Abbaszadeh, Mustafa Mohamadian

Turkish Journal of Electrical Engineering and Computer Sciences

AC machines fed by a single inverter are widely used in industries such as railroad electrification systems where speed synchronization does not have to be exact. The low cost and volume and the small number of power electronic components are attractive aspects of single-inverter multi-motor systems. This paper proposes a novel approach to controlling the speed and torque of two induction motors connected in parallel and fed by a matrix converter under unbalanced load condition. This single-inverter dual-motor (SIDM) drive uses average and differential values of speed and torque together with stator and rotor flux parameters based on the flux …


Post-Translational Modification Of Hypoxia-Inducible Factor Proteins By O-Linked -N-Acetylglucosamine In Breast Cancer Cells, Sean Williamson Jan 2018

Post-Translational Modification Of Hypoxia-Inducible Factor Proteins By O-Linked -N-Acetylglucosamine In Breast Cancer Cells, Sean Williamson

Honors Theses

One of the hallmarks of cancer is its ability to adapt its metabolism to survive and thrive despite needing to overcome significant energy barriers and low oxygen settings in order to do so. The hypoxia-inducible factor proteins (HIFs) play important roles in the processes in which cancer fulfills these requirements. The O-linked -N-acetylglucoseamine (O-GlcNAc) can be attached to cellular proteins through O-glycosylation, and is thus considered a potential target for anticancer mechanisms. HIFs are composed of (HIF-1 and HIF-2, respectively) and subunits. This research found that O-GlcNAc is able to attach to and modify the HIF proteins. This was accomplished …


Energetics And Vibrational Signatures Of Nucleobase Argyrophilic Interactions, Suhwan Paul Lee Jan 2018

Energetics And Vibrational Signatures Of Nucleobase Argyrophilic Interactions, Suhwan Paul Lee

Honors Theses

This study investigates the interactions of both purine (adenine and guanine) and pyrimidine (cytosine, thymine, and uracil) nucleobases with a pair of silver atoms (Ag2). Full geometry optimizations were performed on several structures of each nucleobase/Ag2 complex and the corresponding isolated monomers using the M06-2X density functional theory (DFT) method with a correlation consistent triple-ζ basis set augmented with diffuse functions on all atoms and a relativistic pseudopotential on Ag (aug-cc-pVTZ for H, C, N, and O and aug-cc-pVTZ-PP for Ag; denoted aVTZ). Harmonic vibrational frequency computations indicate that each optimized structure corresponds to a minimum on the M06-2X/aVTZ potential …


Handwritten Bangla Character Recognition Using The State-Of-The-Art Deep Convolutional Neural Networks, Md Zahangir Alom, Paheding Sidike, Mahmudul Hasan, Tarek M. Taha, Vijayan K. Asari Jan 2018

Handwritten Bangla Character Recognition Using The State-Of-The-Art Deep Convolutional Neural Networks, Md Zahangir Alom, Paheding Sidike, Mahmudul Hasan, Tarek M. Taha, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

In spite of advances in object recognition technology, handwritten Bangla character recognition (HBCR) remains largely unsolved due to the presence of many ambiguous handwritten characters and excessively cursive Bangla handwritings. Even many advanced existing methods do not lead to satisfactory performance in practice that related to HBCR. In this paper, a set of the state-of-the-art deep convolutional neural networks (DCNNs) is discussed and their performance on the application of HBCR is systematically evaluated. The main advantage of DCNN approaches is that they can extract discriminative features from raw data and represent them with a high degree of invariance to object …


A Survey Of Archival Replay Banners, Sawood Alam, Mat Kelly, Michele C. Weigle, Michael L. Nelson Jan 2018

A Survey Of Archival Replay Banners, Sawood Alam, Mat Kelly, Michele C. Weigle, Michael L. Nelson

Computer Science Faculty Publications

We surveyed various archival systems to compare and contrast different techniques used to implement an archival replay banner. We found that inline plain HTML injection is the most common approach, but prone to style conflicts. Iframe-based banners are also very common and while they do not have style conflicts, they suffer from screen real estate wastage and limited design choices. Custom Elements-based banners are promising, but due to being a new web standard, these are not yet widely deployed.


205.3 The Many Shapes Of Archive-It, Shawn Jones, Michael L. Nelson, Alexander Nwala, Michele C. Weigle Jan 2018

205.3 The Many Shapes Of Archive-It, Shawn Jones, Michael L. Nelson, Alexander Nwala, Michele C. Weigle

Computer Science Faculty Publications

Web archives, a key area of digital preservation, meet the needs of journalists, social scientists, historians, and government organizations. The use cases for these groups often require that they guide the archiving process themselves, selecting their own original resources, or seeds, and creating their own web archive collections. We focus on the collections within Archive-It, a subscription service started by the Internet Archive in 2005 for the purpose of allowing organizations to create their own collections of archived web pages, or mementos. Understanding these collections could be done via their user-supplied metadata or via text analysis, but the metadata is …


Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth Jan 2018

Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth

All Master's Theses

Many of the lava flows comprising the Steens Basalt in SE Oregon, the oldest and most mafic formation of the Columbia River Basalt Group (CRBG), contain exceptionally large (up to 5 cm) and abundant (up to 40 modal %) plagioclase crystals. This thesis presents a model for giant plagioclase formation in a complex system that integrates petrographic and in situ plagioclase compositional analyses with whole-rock data and computational modeling to explain systematic textural and chemical differences between plagioclase of the lower and upper Steens Basalt sub-sections. Lower Steens plagioclase are typically more chemically homogenous than upper Steens plagioclase and exhibit …


Multiscale Approaches Toward Advanced Lithium-Ion Battery: From Nano To Meso Scale, Susmita Sarkar Jan 2018

Multiscale Approaches Toward Advanced Lithium-Ion Battery: From Nano To Meso Scale, Susmita Sarkar

Masters Theses

“Battery performance and its degradation are determined by various aspects such as the transport of ions and electrons through heterogeneous internal structures composed of constituent particles, kinetic reactions at the interfaces, and a corresponding interplay between mechanical, chemical, and thermal responses. Further, modern battery materials require a variety of engineering processes such as coating, doping and mixing. As a result, in order to fully understand the behavior of the battery material and improve battery performance, it is necessary to understand and control the individual particle behavior and then connect it to the electrode. This study elucidated the physical phenomena associated …


Solidification Rate Detection Through Solid-Liquid Interface Tracking, Wei Luo Jan 2018

Solidification Rate Detection Through Solid-Liquid Interface Tracking, Wei Luo

Masters Theses

”Studying the melt pool dynamics in laser powder bed fusion (LPBF) additive manufacturing is vital to predict the microstructure of the built part. High-speed synchrotron hard X-ray imaging is an advanced technique to monitor the LPBF process in situ and in real time. However, it is very challenging to track the solid-liquid interface due to the low image contrast, high image noise and unstable intensity of the image sequences.

In this paper, we propose an solid-liquid interface detector with human interaction to track the interface to compute the solidification rate of the melt pool. The proposed method includes six independent …