Engineering Commons^™

Long Short-Term Memory With Spin-Based Binary And Non-Binary Neurons, Meghana Reddy Vangala

Electronic Theses and Dissertations, 2020-2023

Research in the field of neural networks has shown advancement in the device technology and machine learning application platforms of use. Some of the major applications of neural network prominent in recent scenarios include image recognition, machine translation, text classification and object categorization. With these advancements, there is a need for more energy-efficient and low area overhead circuits in the hardware implementations. Previous works have concentrated primarily on CMOS technology-based implementations which can face challenges of high energy consumption, memory wall, and volatility complications for standby modes. We herein developed a low-power and area-efficient hardware implementation for Long Short-Term Memory …

Representative-Based Big Data Processing In Communications And Machine Learning, Mohsen Joneidi

Electronic Theses and Dissertations, 2020-2023

The present doctoral dissertation focuses on representative-based processing proper for a big set of high-dimensional data. Compression and subset selection are considered as two main effective methods for representing a big set of data by a much smaller set of variables. Compressive sensing, matrix singular value decomposition, and tensor decomposition are employed as powerful mathematical tools to analyze the original data in terms of their representatives. Spectrum sensing is an important application of the developed theoretical analysis. In a cognitive radio network (CRN), primary users (PUs) coexist with secondary users (SUs). However, the secondary network aims to characterize PUs in …

The Roles Of Groundwater Table In Catchment Hydrology, Lili Yao

Electronic Theses and Dissertations, 2020-2023

The main goal of this dissertation research is to investigate catchment hydrological processes including infiltration and saturation excess runoff generation with consideration of groundwater table. For the infiltration process, an infiltration Péclet number was proposed to quantify the relative effects of gravity and capillary force on the evolution of infiltration capacity in the special case of the presence of a shallow water table, and a power law functional form of Time Compression Approximation was developed whose exponent was found to vary with the Péclet number. For the saturation excess runoff process, a new probability distribution model based on the SCS …

Enhancing Preservice Teachers' Intention To Integrate Engineering Through A Multi-Disciplinary Partnership (Evaluation), Francisco Cima, Pilar Pazos, Jennifer Jill Kidd, Kristie S. Gutierrez, Stacie I. Ringleb, Orlando M. Ayala, Krishnanand Kaipa

Engineering Management & Systems Engineering Faculty Publications

Driven by the need to broaden participation and increase recruitment in STEM fields, considerable efforts are underway to promote the infusion of engineering into elementary and secondary grade levels. The benefits of engineering education and the strong support from professional and educational groups are well documented, yet the actual integration of engineering content in the K-12 setting remains a challenge. Pre-college educator programs that train future teachers are a natural target for the integration efforts. Although elementary educators recognize the importance of integrating engineering in their classrooms, they often lack the confidence to teach engineering content. The absence of effective …

New Longitudinal Error Balancing Approaches For Closed Traverses, Jose L. Manzano

College of Graduate Studies: Theses & Dissertations

This study presents two novel approaches to balance the horizontal longitudinal error of closure, E_C, in closed polygonal traverses. The standard procedure to balance E_C is the Compass Rule. This technique reduces E_C to zero by applying corrections in the lengths of all traverse sides. Those corrections are proportional to the corresponding side lengths. That is, this approach is not an error-correcting approach, but an error-balancing procedure.

The proposed new techniques are based on sensitivity analysis of E_C with respect to small variations, Δ_i, in the lengths of all sides i = 1, …

A Semi-Active Vibration Isolator For 3d Printing On Shipboard, Mohammad Z. Shahabuddin

College of Graduate Studies: Theses & Dissertations

In the recent years, additive manufacturing (AM) (aka 3D printing)-has become a viable alternative to traditional manufacturing due to its unique advantages, such as enabling the fabrication of complex geometries at reduced weight and costs as well as allowing on-site fabrication for maintenance and repair. One specific application area of the AM is the navy vessels. During extended voyages, the navy vessels likely require the convenience of on-site fabrication of the malfunctioned parts. However, the shipboard equipment suffers from a broad range of external excitations arising not only from the waves but also from the vessel’s engines, which …

High-Temperature Performance Of Ambient-Cured Alkali- Activated Binder Concrete, Kruthi Kiran Ramagiri, Darshan Chauhan, Shashank Gupta, Arkamitra Kar, Dibyendu Adak, Abhijit Mukherjee

Civil and Environmental Engineering Faculty Publications and Presentations

Owing to their lower carbon footprint and efficient performance compared to portland cement (PC), alkali-activated binders (AAB) show promising potential as an alternative to PC. The present paper investigates the high-temperature performance of AAB concrete through compressive and bond strength tests. Four different AAB concrete mixes with varying proportions of fly ash: slag (100:0, 70:30, 60:40, and 50:50) cured under ambient conditions are exposed to elevated temperatures. The mechanical performance of AAB concrete is corroborated with microstructural changes. The results show that AAB concrete with fly ash: slag ratio of 70:30 exhibits the best mechanical performance after exposure to elevated …

'Menthol-Plus’: A Major Category Of Cigarette Found Among ‘Concept’ Descriptor Cigarettes From Mexico, James F. Pankow, Wentai Luo, Kevin J. Mcwhirter, Samantha M. Gillette, Joanna E. Cohen

Civil and Environmental Engineering Faculty Publications and Presentations

Background Tobacco companies are offering cigarettes with ‘concept’ descriptor names that suggest sensation and/or flavour properties (eg, Marlboro ‘Velvet Fusion’). Little has been known about the identities and levels of flavour chemicals in such cigarettes.

Methods Thirty-three filter cigarette variants from 27 packs (including two sampler packs with four variations each) from Canada and Mexico were analysed (rod + filter) for 177 flavour chemicals plus triacetin, a filter plasticiser and possible flavourant. Five brands of US mentholated filter cigarettes were also analysed.

Results Twenty-seven of the 33 cigarettes (all were Mexican variants) were categorised as ‘menthol-plus’: significant menthol (3.0–11.9 mg/cigarette), …

Exploring The Impact Of Socio-Demographic Characteristics, Health Concerns, And Product Type On Home Delivery Rates And Expenditures During A Strict Covid-19 Lockdown Period: A Case Study From Portland, Or, Miguel Figliozzi, Avinash Unnikrishnan

Civil and Environmental Engineering Faculty Publications and Presentations

E-commerce volumes and home deliveries have experienced steady growth in the last two decades. Strict COVID-19 lockdowns made home delivery an essential service and a lifeline for many households that, for travel restrictions or health concerns, were not able to utilize traditional shopping methods. This research studies the impact of socio-demographic variables and e-commerce attitudes on household deliveries for seven product categories (groceries, meals, electronics, household and office goods, recreational items, and fashion, beauty and personal care products, and medicine/health-related products) during the lockdown period in the greater Portland metropolitan region. To understand these impacts, exploratory factor analysis and …

Wavefront-Selective Fano Resonant Metasurface, Adam C. Overvig, Andrea Alù

Publications and Research

Fano resonances are conventionally understood as sharp spectral features with selectivity in the momentum-frequency domain, implying that they can be excited only by plane waves with specific frequencies and incident angles. We demonstrate that Fano resonances can be made generally selective in the space-frequency domain. They can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. Although in conventional Fano systems this trivially occurs for normally incident plane waves, we show that, in general, the selected …

การจัดสรรแหล่งผลิตไฟฟ้าแบบกระจายหลายตำแหน่งในระบบจำหน่ายไฟฟ้าแบบเรเดียลโดยพิจารณาการลดการสูญเสียกำลังไฟฟ้าและการจำกัดปริมาณการรับซื้อไฟฟ้า, กฤตภาส เพียรวิบูลย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

วิทยานิพนธ์ฉบับนี้ได้ศึกษาการหาขนาดที่เหมาะสมของแหล่งผลิตไฟฟ้าแบบกระจายหลายตัวในระบบจำหน่ายไฟฟ้าแบบเรเดียล และ ศึกษาผลกระทบของการลดการสูญเสียกำลังไฟฟ้าและการจำกัดปริมาณรับซื้อไฟฟ้าของระบบที่มีแหล่งผลิตไฟฟ้าแบบกระจายหลายตัว นอกจากนี้วิทยานิพนธ์ได้ศึกษาผลกระทบของการลดการสูญเสียกำลังไฟฟ้าและการจำกัดปริมาณรับซื้อไฟฟ้าของระบบที่มีแหล่งผลิตไฟฟ้าแบบกระจายหลายตัวร่วมกับเทคโนโลยีระบบกักเก็บพลังงาน กรณีศึกษาถูกแบ่งเป็น 3 ส่วน ดังนี้ กรณีศึกษาที่ 1 การเปรียบเทียบวิธีการจัดสรรแหล่งผลิตไฟฟ้า กรณีศึกษาที่ 2 ผลกระทบของวิธีการจัดสรรแหล่งผลิตไฟฟ้าเมื่อมีจำนวนแหล่งผลิตไฟฟ้าเพิ่มขึ้น และ กรณีศึกษาที่ 3 ผลการจำลองเวลาจริงของการหาค่าขนาดที่เหมาะสมของการจัดสรรแหล่งผลิตไฟฟ้า วิทยานิพนธ์ใช้ข้อมูลการผลิตไฟฟ้าของแหล่งผลิตไฟฟ้าแบบกระจายตัวจากการไฟฟ้าฝ่ายผลิตแห่งประเทศไทย ข้อมูลความต้องการโหลดแบบผู้อยู่อาศัยและแบบเชิงอุตสาหกรรมจากการไฟฟ้าส่วนภูมิภาค และ ระบบทดสอบ IEEE-33 บัส การจำลองหาขนาดที่เหมาะสมของแหล่งผลิตไฟฟ้า ใช้โปรแกรม Power Factory – DIgSILENT และ MATLAB ผลการศึกษาแสดงให้เห็นว่าวิธีที่นำเสนอของวิทยานิพนธ์สามารถใช้แก้ปัญหาของการจัดสรรแหล่งผลิตไฟฟ้าแบบกระจายตัวเมื่อพิจารณาดรรชนีความอ่อนไหวที่มีค่ามากที่สุดในระบบ ผลการทดลองของกรณีศึกษาที่ 2 แสดงให้เห็นว่า ระบบไฟฟ้ามีจุดอิ่มตัวของค่าการลดลงของกำลังไฟฟ้าเมื่อมีการเพิ่มจำนวนการติดตั้งแหล่งผลิตไฟฟ้า โดยค่าการลดลงของกำลังไฟฟ้าไม่มีความแตกต่างทางนัยสำคัญที่จุดอิ่มตัว ผลการทดลองสำหรับกรณีศึกษาที่ 3 แสดงให้เห็นว่าการจัดสรรขนาดแหล่งผลิตไฟฟ้าแบบกระจายตัวเมื่อมีการพิจารณาการลดการสูญเสียกำลังไฟฟ้าและการจำกัดปริมาณการรับซื้อไฟฟ้า สามารถลดปริมาณเฉลี่ยการจำกัดปริมาณรับซื้อไฟฟ้าของระบบได้อย่างมีนัยสำคัญ โดยที่มีพลังงานไฟฟ้าสูญเสียไม่แตกต่างกันระหว่างการพิจารณาการจำกัดปริมาณการรับซื้อไฟฟ้ากับไม่พิจารณาการจำกัดปริมาณการรับซื้อไฟฟ้า สำหรับการจัดสรรแหล่งผลิตไฟฟ้าแบบกระจายตัวเมี่อมีการใช้แหล่งผลิตไฟฟ้าแบบกระจายตัวและระบบกักเก็บพลังงาน ผลลัพธ์แสดงให้เห็นว่าการจัดสรรขนาดแหล่งผลิตไฟฟ้าแบบกระจายตัวเมื่อมีการพิจารณาการลดการสูญเสียกำลังไฟฟ้าและการจำกัดปริมาณการรับซื้อไฟฟ้า สามารถลดปริมาณเฉลี่ยการจำกัดปริมาณรับซื้อไฟฟ้าของระบบได้อย่างมีนัยสำคัญ อย่างไรก็ตาม วิธีนี้ไม่สามารถทำให้ระบบมีพลังงานไฟฟ้าสูญเสียต่ำกว่ากรณีการจัดสรรแหล่งผลิตไฟฟ้าแบบกระจายตัวเมื่อพิจารณาเฉพาะการลดการสูญเสียกำลังไฟฟ้าได้

หุ่นยนต์ 3 มิติชนิดจับที่ปลายแบบรับรู้แรงเพื่อการฟื้นฟูรยางค์ส่วนบน, เกวลี อัศวะไพฑูรย์เสริฐ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อออกแบบต้นแบบหุ่นยนต์ 3 มิติชนิดจับที่ปลายแบบรับรู้แรงที่มีระบบควบคุมทางพลศาสตร์และโปรแกรมควบคุมการทำงาน เพื่อการประยุกต์ใช้ในการฟื้นฟูรยางค์ส่วนบน โดยงานวิจัยนี้ได้ออกแบบและพัฒนาต้นแบบหุ่นยนต์ที่มีชื่อว่าหุ่นยนต์ 3DEE (3D End-effector Manipulator Arm) ซึ่งเป็นหุ่นยนต์กายภาพบำบัดชนิดจับที่ปลายที่มีจุดสัมผัสอยู่ที่บริเวณข้อมือ มีลักษณะโครงสร้างเป็น 3-dimensional five-bar linkage manipulator ซึ่งสามารถเคลื่อนไหวใน 3 มิติได้และมีโครงสร้างที่ไม่ซับซ้อน อีกทั้งหุ่นยนต์ยังถูกออกแบบให้เหมาะสำหรับหุ่นยนต์กายภาพบำบัดและคำนึงถึงความปลอดภัยของผู้ใช้เป็นหลัก ระบบควบคุมที่ใช้ในงานวิจัยนี้เป็นระบบควบคุมกำแพงเสมือนแบบสปริงและตัวหน่วงสำหรับโปรแกรมอุโมงค์เสมือนที่เหมาะสำหรับให้ผู้ป่วยได้ออกแรงเคลื่อนไหวเองโดยมีหุ่นยนต์ประคองให้อยู่ในเส้นทางเท่านั้น โปรแกรมถูกออกแบบให้สามารถปรับค่าพารามิเตอร์ต่างๆ บันทึกข้อมูลและแสดงผลข้อมูลได้ การทดสอบหุ่นยนต์เริ่มจากการทดสอบความแม่นยำของส่วนชดเชยน้ำหนักของแขนหุ่นยนต์ก่อนซึ่งเป็นส่วนสำคัญส่วนหนึ่งของระบบควบคุม ซึ่งผลที่ได้นำมาสรุปได้ว่าส่วนชดเชยน้ำหนักของแขนหุ่นยนต์มีความแม่นยำที่มาก ตามด้วยการทดสอบประสิทธิภาพของระบบควบคุม ซึ่งผลที่ได้แสดงให้เห็นว่าระบบควบคุมนี้สามารถช่วยให้เคลื่อนไหวในเส้นทางที่กำหนดได้อย่างสะดวก อีกทั้งยังออกนอกเส้นทางได้ยาก

Spectral And Latent Representation Distortion For Tts Evaluation, Thananchai Kongthaworn

Chulalongkorn University Theses and Dissertations (Chula ETD)

One of the main problems in the development of text-to-speech (TTS) systems is its reliance on subjective measures, typically the Mean Opinion Score (MOS). MOS requires a large number of people to reliably rate each utterance, making the development process slow and expensive. Recent research on speech quality assessment tends to focus on training models to estimate MOS, which requires a large number of training data, something that might not be available in low-resource languages. We propose an objective assessment metric based on the DTW distance using the spectrogram and the high-level features from an Automatic Speech Recognition (ASR) model …

An Improvement Of Data Analytics Detection Rules In The Internal Audit Of The Procurement And Inventory Processes, Penpak Rangsipunyaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Data analytics is a powerful tool to deliver value-added internal audit results as it reduces execution time and increases efficiency, effectiveness, and assurance level compared with the audit sampling approach. Because detection rules are criteria applied in the data analytics method to discover anomalies in the business transactions. Therefore, this project aims to improve the anomaly detection rules in the procure-to-pay and inbound inventory processes for an audit firm based in Thailand to provide internal audit services for clients in the manufacturing business. The sub-processes cover (1) process governance, (2) vendor selection, evaluation, and master data maintenance, (3) ordering, (4) …

Chaos Game Optimization Method For Weight Minimization Of Steel Truss Structure, Eain Kyi Thar

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research proposes the so-called chaos game optimization (CGO) method to perform the optimal sizing design of steel truss structures under applied loading regimes. The optimization problem aims at the minimization of the total weight (directly related to the cost function) of the designed structure subjected to the constraints describing the intrinsic structural responses complying with limit-state specifications. The CGO approach is based on the underlying chaos theory that establishes the primary patterns as fractals in responses to the systems representing them as self-organized dynamical systems. The fractal is generated as an initial Sierpinski triangle (i.e., search space of solution …

Total Quality And Innovation Management In Hospital, Suebsakul Tonjang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Previously, quality of care and customers' satisfaction in healthcare services is fulfilled only through total quality management (TQM) which as a core management philosophy, as adopted by many healthcare organizations. Nevertheless, TQM focuses on incremental improvement may prove insufficient to address the new technology and innovation-driven organization with a faster pace. Therefore, this research aimed to integrate quality and innovation management in healthcare affecting healthcare performance. To propose the key factor of both TQM and innovation management in healthcare, we conducted a systematic literature review. Then, TQM and innovation management factors were combined and integrated with ISO 56002 as to …

Neurovascular Catheter Measurement System Development For Process And Design Effect Evaluation, Cathal Tadhg Merz

Theses

Neurovascular guide catheters are used to treat problems affecting blood vessels within the brain through minimally invasive procedures. Catheters are inserted into the patient via their femoral or brachial arteries and manually navigated to the brain to deliver treatment. This procedure replaces the requirement to cut into the patient’s skull and brain tissue but is limited by reduction of blood vessel lumen diameter and increase in tortuosity of blood vessels deep in the brain. During these procedures, catheters can sometimes fail by kinking or fracturing into two pieces. The rate of failure by fracture of a particular neurovascular catheter device …

Adaptive Uplink Data Rate Prediction And Networkselection In A Vehicular Mobile Channel, Georgi Nikolov

Theses

The rapid acceleration into the digital age brings a worldwide interconnectedness of an unprecedented level. This interconnectedness transforms the modern transportation network by linking its infrastructure components (e.g., signaling systems, traffic control systems, maintenance systems) together. Intelligent transportation systems (ITS) can utilize this newly emerged network infrastructure, improving traffic safety, traffic control, and reducing transportation-related environmental impacts, changing the way drivers, businesses and governments deal with road transport. It is expected that in the near future self-aware vehicles (e.g., trains, cars or trucks) will constitute the majority of the transportation infrastructure. Vehicles need to be able to reliably communicate critical …

Material Handling System For An Advanced Flexible Manufacturing Environment, Con Cronin

Theses

A Flexible Manufacturing System (FMS) is a method of production that is designed to easily adapt to changes in the type and quantity of the product being manufactured. Machines and computerised systems can be configured to manufacture a variety of parts and to handle the changing levels of production that is required. The aim of this project was to investigate the current manufacturing processes of Kostal Ireland GmbH with the aim of developing a bespoke prototype material handling system to achieve flexible manufacturing. Kostal Ireland GmbH currently do not have the ability to change their manufacturing operations easily when a …

Nnbmss: A Novel And Fast Method For Model Structure Selection, Amaury Lendasse, Kallin Khan, Edward Ratner

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, We Present a New Method to Perform Model Structure Selection. This Proposed Method Can Be Used to Select the Complexity of Any Continuous Regression Method. We Also Present an Asymptotic Mathematical Proof of the Proposed Method and the New Method is Illustrated on a Benchmark. Compared to the Well-Known 10-Fold Cross-Validation, the Computational Time Associated to Our New Method is Approximately Divided by a Factor 8 as Illustrated on the Benchmark.

Machine Learning For Measuring And Analyzing Online Social Communications, Chris Bronk, Amaury Lendasse, Peggy Lindner, Dan S. Wallach, Barbara Hammer

Engineering Management and Systems Engineering Faculty Research & Creative Works

In This Paper, We Propose a Framework for Application of a Novel Machine Learning-Based System for Analyzing Online Social Communications. as an Example, We Are Targeting Anti-Semitic Graphical Memes Posted to Social Media. We Presented Very Promising Preliminary Results on a Facebook Dataset that Consists of a Total of 10000 Labeled Memes. We Can Conclude that Machine Learning Will Soon Be Able to Successfully Analyze and Monitor Complex Social Communications.

First Ever Polymer Flood Field Pilot To Enhance The Recovery Of Heavy Oils On Alaska's North Slope Pushing Ahead One Year Later, Abhijit Dandekar, Baojun Bai, John Barnes, Dave Cercone, Jared Ciferno, Reid Edwards, Samson Ning, Walbert Schulpen, Randy Seright, Brent Sheets, Dongmei Wang, Yin Zhang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In June 2018 the team embarked on an ambitious project to address the slow development pace of Alaska's 20+ billion barrels heavy oil resource via the first ever polymer flood pilot. Following the successful commencement of the pilot in August 2018, the field demonstration, supporting laboratory experiments and numerical simulation have steadily progressed. A significant amount of valuable data and lessons learned have been collected and are reported in this paper. The ongoing pilot and the research activities is making headway toward the primary objective of validating the use of polymer flooding for extracting heavy oil in Alaska's challenging environment. …

Impact Of Rheology Models On Horizontal Well Polymer Flooding In A Heavy Oil Reservoir On Alaska North Slope: A Simulation Study, Jianqiao Leng, Mingzhen Wei, Baojun Bai, Randall S. Seright, Yin Zhang, David Cercone, Samson Ning

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polymer rheology can have either a positive or a negative effect on polymer flooding performance under varied circumstances. Many researchers have studied the effect of polymer rheology in a vertical well, but no field scale studies have been conducted to investigate whether polymer rheology is beneficial to polymer flooding in heavy oil reservoirs developed by horizontal wells. In this paper, we conducted a numerical simulation study to examine the effect of HPAM polymer rheology on a polymer flooding pilot, which is the first-ever project conducted on a heavy oil reservoir from Alaska North Slope (ANS) developed by horizontal wells. Three …

A Phewas Model Of Autism Spectrum Disorder, John Matta, Daniel Dobrino, Swade Howard, Dacosta Yeboah, Jonathan Kopel, Yasser El-Manzalawy, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

Children with Autism Spectrum Disorder (ASD) exhibit a wide diversity in type, number, and severity of social deficits as well as communicative and cognitive difficulties. It is a challenge to categorize the phenotypes of a particular ASD patient with their unique genetic variants. There is a need for a better understanding of the connections between genotype information and the phenotypes to sort out the heterogeneity of ASD. In this study, single nucleotide polymorphism (SNP) and phenotype data obtained from a simplex ASD sample are combined using a PheWAS-inspired approach to construct a phenotype-phenotype network. The network is clustered, yielding groups …

Modeling And Simulation Of Resistive Superconducting Fault Current Limiter In Pscad/Emtdc™, Fahd Hariri, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Energy networks are facing significant challenges as the result of increasing electrical loads. To meet this rapid increase in demand for electricity, new generating units are being added to support the stability and reliability of the network. This change in network structure requires a comprehensive analysis of the effect of that increase on the protection system. Limiting the fault current to safe levels prevents replacing the high-cost network components that may be subjected to damage due to exceeding the rated short-circuit current values for which they were designed. A fault analysis often requires extensive modeling and simulation of the system, …

On The Effect Of Design Parameters On Fringing Fields Of A Loop-Based Fss, Swathi Muthyala Ramesh, Mahboobeh Mahmoodi, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency selective surfaces (FSSs) are periodic arrays of conductive elements that act as spatial filters of electromagnetic energy. FSSs have found recent application as sensors, filters, reflectors and radomes, amongst others. Often miniaturization techniques are used to improve the stability of the FSS to incident angle (of the excitation). However, due to the type of coupling (internal/self-vs. external/mutual with adjacent elements), some designs are more responsive to miniaturization techniques than others. Hence, this paper quantifies the effect of the ratios of inter-element spacing-to-substrate thickness (S/h) and side length-to-substrate thickness (SL/h) on fringing fields (and hence coupling and potential for miniaturization) …

An Interleaved Quadratic High Step-Up Dc-Dc Converter With Coupled Inductor, Ramin Rahimi, Saeed Habibi, Mehdi Ferdowsi, Pourya Shamsi

Electrical and Computer Engineering Faculty Research & Creative Works

A new high step-up DC-DC converter for renewable energy applications is proposed in this paper. Employing an interleaved quadratic structure, two two-winding coupled inductors (CIs), and voltage multiplier cells (VMCs), the proposed converter can provide high-voltage gains, continuous input current with low ripple, reduced voltage stresses on semiconductors, common ground between input and output sides, and low numbers of components. In addition, diode-capacitor lossless clamp circuits are utilized to limit the voltage stresses of the power switches and further extend the voltage gain. The operating and steady-state analyses, design considerations, and a comparison with other previously published high step-up converters …

Artificial Neural Networks For Asymmetric Selective Harmonic Current Mitigation-Pwm In Active Power Filters To Meet Power Quality Standards, Amirhossein Moeini, Morteza Dabbaghjamanesh, Jonathan W. Kimball, Jie Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

The main objective of an active power filter (APF) is to control the harmonics of nonlinear loads in power systems. In addition, the reactive power (fundamental component of the AC power) at the point of common coupling (PCC) can be compensated by using an APF. This paper investigates a technique for the modulation technique of the active power filters. Using the artificial neural network (ANN) technique, real-time fundamental and harmonic compensations can be achieved for the low-frequency modulation techniques such as asymmetric selective harmonic elimination/mitigation-pulse width modulation (ASHE/ASHM-PWM) and asymmetric selective harmonic current mitigation-PWM (ASHCM-PWM). This means that different phases …

Using Gated Recurrent Units For Selective Harmonic Current Mitigation-Pwm In Grid-Tied Cascaded H-Bridge Converters, Morteza Dabbaghjamanesh, Amirhossein Moeini, Jonathan Kimball, Jie Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

Grid-tied converters become more popular for electric vehicle, renewable energy, and energy storage systems applications. Different modulation techniques such as low-frequency (e.g., selective harmonic elimination-PWM, selective harmonic mitigation-PWM, and selective harmonic current mitigation-PWM (SHCM-PWM)) and high-frequency modulation techniques (e.g., phase shift-PWM and space vector modulation) are used in the literature for grid-tied converters. Low-frequency modulation techniques have a high-efficiency due to the low-switching power losses. One of the main challenges of low-frequency modulation techniques such as SHCM-PWM is how to implement the proposed technique in real-time, due to the transcendental Fourier equations of SHCM-PWM. In this paper, a deep learning …

Sizing Energy Storage System For Energy Arbitrage In Extreme Fast Charging Station, Waqas Ur Rehman, Rui Bo, Hossein Mehdipourpicha, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a non-linear programming (NLP) model to optimally size the energy storage system (ESS) and obtain an optimal energy management for energy arbitrage of an extreme fast charging station (XFCS) for electric vehicles (EVs), with minimized total cost of XFCS operation and ESS investment. Different from most reported work on sizing the ESS for EV charging stations, this paper proposes a pragmatic approach to model the ESS life degradation and accurately count the ESS cycles. Moreover, this work incorporates the peak demand charges in the operational cost of the charging station which are often overlooked in the literature. …