Electrical and Electronics Commons^™

Towards The Integration Of Ferroelectric Negative Capacitance With Gallium Oxide Semiconductors For High Power Applications, Guillermo A. Salcedo

Theses and Dissertations

Gallium oxide is a relatively new semiconductor material with characteristics auspicious for high frequency and high-voltage applications. Although several research groups have already demonstrated radio-frequency (RF) devices on Ga₂O₃ with remarkable features, there is still room for improvement. For instance, the operating frequency of RF field-effect transistors (FET) decreases with the parasitic capacitance, which can be counteracted by higher gate capacitance. Implementing ferroelectric dielectrics with suitable parameters in Ga₂O₃ FET promises to enhance the gate capacitance and therefore increase operating frequency. This work investigated the effect of various factors (film composition, film thickness, TiN …

Utilization Of Characteristic Modal Analysis For Antenna Design Needed For An Afit Satellite, Scott C. Podlogar

Theses and Dissertations

Antenna design is a pervasive, growing field for electrical engineers. As the number of new materials and techniques increase so too does the demand and requirements pushing forth new innovative ideas. Among these ideas is a leading edge analytic technique called Characteristic Modal Analysis (CMA) originally credited to Garbacz and Turpin. CMA works to break down the current distribution along a structure in a way that can offer great insights into how that structure operates as an antenna. This technique has great merits in post design analytics but it is rarely seen to be integrated into the design process. This …

Real-Time Complex Hand Gestures Recognition Based On Multi- Dimensional Features, Isack Bulugu

Tanzania Journal of Engineering and Technology (TJET)

Gesture recognition is broadly utilized within the field of sensing. There are basically three gesture recognition methods based on computer vision, depth sensor and motion sensor. Motion sensor-based gesture recognition has few input data, fast speed, and direct access to three- dimensional information of the hand. The advantages of traditional motion sensor-based gesture recognition have gradually become a current research hotspot. The essence of traditional motion sensor-based gesture recognition is a pattern recognition problem, and its accuracy depends heavily on the feature dataset extracted from prior experience. Unlike traditional pattern recognition methods, deep learning can be used to a large …

Complete Neighbourhood Search Heuristic Algorithm For Portfolio Optimization, Collether John

Tanzania Journal of Engineering and Technology (TJET)

In portfolio optimization, the fundamental goal of an investor is to optimally allocate investments between different assets. Mean-variance optimization methods make unrealistic assumptions to solve the problem of optimal allocation. On the other hand, when realistic constraints like holding size and cardinality are introduced it leads to optimal asset allocation which differ from the mean variance optimization. The resulting optimization problem become quite complex as it exhibits multiple local extrema and discontinuities. Heuristic algorithms work well for the complex problem. Therefore, a heuristic algorithm is developed which is based on hill climbing complete (HC-C). It is utilized to solve the …

Economic Analysis Of Islanded Microgrid: A Case Study Of Kisiju Village - Coastal Region, Jackson Justo

Tanzania Journal of Engineering and Technology (TJET)

The concept of Microgrid (MG) has gained significant attention of researchers and projects on the business side of electrical power generation and utilization, particularly in electrification of islanded areas such as villages. Most of these microgrids are powered by renewable energy resources (RERs) and they distribute power in low voltage distribution networks. Hence, these systems are faced with reliability problems due to the intermittency nature of RERs which affect the technical as well as the return on Investment of specific projects. In the latter context, reliability and economic analysis of the MG systems is an inevitable choice. This paper presents …

The Surface Conditions Of Spacecraft Panels May Significantly Affect Spacecraft Survivability, Trace Taylor

Research on Capitol Hill

USU junior Trace grew up in Brigham City and studies physics and electrical engineering. The majority of spacecraft failure is caused by electron charging on the outer surfaces of the craft. Additionally, contaminants on the craft can cause a film over surface panels, increasing the problem. Trace is studying how roughness on panels can mitigate this contamination as it affects the charging that can lead to craft failure. This research will help determine what optimal panel materials should be used in future spacecraft construction. Trace started research almost as soon as he came to campus in his freshman year, and …

Integration Of Electrical Impedance Spectroscopy For Multichannel Cell Culture Measurement, Conard Chan

Master's Theses

ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) has been widely used to study the electrical properties of biological material due to its non-invasive nature and experimental reliability. However, most of the precision impedance analyzers used in EIS only provide single- or two-channel measurements which are inadequate for larger-scale multiplexed measurements, such as those found in modern microfluidic cell culture experiments. The Biomedical Microsystems Laboratory has developed a 16-channel cell culture platform with integrated electrode arrays for monitoring cell growth and electrical properties (i.e., the so-called “electrical phenotype”). In this paper, a system consisting of a 16-channel solid-state analog multiplexer (MUX)paired with a low-cost, …

Investigating The Variation In The Optical Properties Of Tio2 Thin-Film Utilized In Bifacial Solar Cells Using Machine Learning Algorithm, Ziad Khalifa, Sameh Abdellatif, Ahmed Fathi, Kareem Abdullah, Minatallah Hassan

Chemical Engineering

Among various solar cell architectures, dye-sensitized solar cells (DSSCs) and perovskite solar cells have demonstrated the capability of being bifacial as both can be fabricated on conducting glass electrodes. In both cells, TiO2 plays a key role in the optoelectronic properties of the cell. Various studies have reported a range of recipes and deposition techniques for TiO2 thin films. Such variety introduces some uncertainties into the optical properties of the prepared films as well as in the process repeatability. Here, we utilized machine learning methods to correlate the film porosity to the film refractive index, making it capable of studying …

A Comparison Of Sporadic-E Occurrence Rates Using Gps Radio Occultation And Ionosonde Measurements, Rodney Carmona, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons

Faculty Publications

Sporadic-E (E_s) occurrence rates from Global Position Satellite radio occultation (GPS-RO) measurements have shown to vary by a factor of five between studies, motivating the need for a comparison with ground-based measurements. In an attempt to find accurate GPS-RO techniques for detecting E_s formation, occurrence rates derived using five previously developed GPS-RO techniques are compared to ionosonde measurements over an eight-year period from 2010–2017. GPS-RO measurements within 170 km of a ionosonde site are used to calculate E_s occurrence rates and compared to the ground-truth ionosonde measurements. The techniques are compared individually for each ionosonde site …

Characterization Of Li-Ion Battery Internal Short Circuit Caused Failures Using Smart Nails, Guangsheng Zhang, Mary Long

Summer Community of Scholars (RCEU and HCR) Project Proposals

No abstract provided.

Design And Implementation Of Photovoltaic Energy Harvesting Automaton, Iskandar Askarov

Theses

Global domestic electricity consumption has been rapidly increasing in the past three decades. In fact, from 1990 to 2020, consumption has more than doubled from 10,120 TWh to 23,177 TWh [1]. Moreover, consumers have been turning more towards clean, renewable energy sources such as Photovoltaic. According to International Energy Agency, global Solar power generation alone in 2019 has reached almost 3% [4] of the electricity supply. Even though the efficiency of photovoltaic panels has been growing, presently, the highest efficiency solar panels available to an average consumer range only from 20%-22% [14]. Many research papers have been published to increase …

Single Event Transient Sensitivity Measurement And Worst-Case Test Vector Exploration For Asic Devices Exposed To Space Single Event Environment, Mohamed Wael

Theses and Dissertations

Space radiation and nuclear reactors produce single event effects (SEE) in electronic circuits and impact their performance. The SEE phenomena cause circuits and electronic devices to fail by producing faulty results. Therefore, today’s circuit’s reliability is a significant concern for all circuit designers.

This thesis suggests a new automated flow to measure the single-event-transient (SET) effects in combinational circuits in application-specific integrated circuits (ASIC) while reaching full fault coverage. The developed flow characterizes the whole circuit nodes by identifying the most sensitive paths to the propagated SET pulses from the node under test to an observable primary output, causing single …

A Deep Neural Network For Early Detection And Prediction Of Chronic Kidney Disease, Vijendra Singh, Vijayan K. Asari, Rajkumar Rajasekaran

Electrical and Computer Engineering Faculty Publications

Diabetes and high blood pressure are the primary causes of Chronic Kidney Disease (CKD). Glomerular Filtration Rate (GFR) and kidney damage markers are used by researchers around the world to identify CKD as a condition that leads to reduced renal function over time. A person with CKD has a higher chance of dying young. Doctors face a difficult task in diagnosing the different diseases linked to CKD at an early stage in order to prevent the disease. This research presents a novel deep learning model for the early detection and prediction of CKD. This research objectives to create a deep …

Reconstructing The Radio, Daniel Burzek, Otilia Popescu

OUR Journal: ODU Undergraduate Research Journal

The goal of the research presented in this paper is to examine the techniques used for the construction of early radios, specifically crystal radios. The paper begins with a brief summary of the history that led to the transition from wired to wireless communication. Next, the paper examines the components used in building a crystal radio including basic antenna design and the resonant circuit, and it also takes a close look at the point-contact rectifier, which was a catalyst in the use of radio waves for communications and allowed for even the most inexperienced person to construct their own home …

A Progressive Learning Strategy For Large-Scale Glacier Mapping, Zhiyuan Xie, Umesh K. Haritashya, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

In recent years, the worldwide temperature increase has resulted in rapid deglaciation and a higher risk of glacier-related natural hazards such as flooding and debris flow. Due to the severity of these hazards, continuous observation and detailed analysis of glacier fluctuations are crucial. Many such analyses require an accurately delineated glacier boundary. However, the complexity and heterogeneity of glaciers, particularly debris-covered glaciers (DCGs), poses a challenge for glacier mapping when using conventional remote sensing or machine-learning techniques. Some examples exist about small-scale automated glacier mapping, but large or regional-scale mapping is challenging. Previously, a deep-learning-based approach named GlacierNet2 had been …

Flexible Battery-Less Wireless Glucose Monitoring System, Saikat Banerjee, Gymama Slaughter

Bioelectrics Publications

In this work, a low power microcontroller-based near field communication (NFC) interfaced with a flexible abiotic glucose hybrid fuel cell is designed to function as a battery-less glucose sensor. The abiotic glucose fuel cell is fabricated by depositing colloidal platinum (co–Pt) on the anodic region and silver oxide nanoparticles-multiwalled carbon nanotubes (Ag₂O-MWCNTs) composite on the cathodic region. The electrochemical behavior is characterized using cyclic voltammetry and chronoamperometry. This glucose hybrid fuel cell generated an open circuit voltage of 0.46 V, short circuit current density of 0.444 mA/cm2, and maximum power density of 0.062 mW/cm² at 0.26 V …

การวางแผนขยายกําลังผลิตไฟฟ้าร่วมกับระบบกักเก็บพลังงานโดยคํานึงถึงรูปแบบการผลิตไฟฟ้าของพลังงานหมุนเวียน การสมดุลกําลังไฟฟ้ารายชั่วโมงตลอดทั้งปี เงื่อนไขบังคับเชิงพื้นที่ และการตอบสนองของโรงไฟฟ้าต่อการเปลี่ยนแปลงโหลด, รฐนนท์ เดี่ยววิไล

Chulalongkorn University Theses and Dissertations (Chula ETD)

การวางแผนขยายกำลังผลิตไฟฟ้านั้นมีวัตถุประสงค์เพื่อให้ได้ระบบผลิตไฟฟ้าที่มีความพร้อมจ่าย มีเสถียรภาพและความเชื่อถือได้เพียงพอที่จะรองรับความต้องการใช้ไฟฟ้าในอนาคตได้ เพื่อให้ได้ระบบไฟฟ้าที่สามารถทำได้จริง ผู้วางแผนขยายกำลังผลิตไฟฟ้าจึงต้องมีเครื่องมือช่วยในการวางแผนที่สามารถพิจารณาถึงเงื่อนไขต่างๆ ทั้งทางเศรษฐศาสตร์ ทางเทคนิค ทางสิ่งแวดล้อม และเงื่อนไขที่สนใจอื่นๆ เช่น เงื่อนไขบังคับเชิงพื้นที่ เป็นต้น นอกจากนี้ในปัจจุบันมีแนวโน้มที่ระบบผลิตไฟฟ้าจะพึ่งพาการผลิตไฟฟ้าจากแหล่งพลังงานหมุนเวียนมากขึ้นเพื่อลดผลกระทบที่อาจจะเกิดขึ้นจากการเปลี่ยนแปลงสภาพภูมิอากาศ ทำให้เครื่องมือดังกล่าวต้องสามารถวางแผนขยายกำลังผลิตไฟฟ้าที่มีความยืดหยุ่นเพียงพอที่จะรองรับความไม่แน่นอนและความผันผวนจากแหล่งพลังงานหมุนเวียน ซึ่งการใช้ระบบกักเก็บพลังงานก็เป็นแนวทางหนึ่งที่ใช้เพื่อเพิ่มความยืดหยุ่นดังกล่าว วิทยานิพนธ์ฉบับนี้จึงนำเสนอวิธีการวางแผนขยายกำลังผลิตไฟฟ้าร่วมกับระบบกักเก็บพลังงานโดยคำนึงถึงรูปแบบการผลิตไฟฟ้าของพลังงานหมุนเวียน การสมดุลกำลังไฟฟ้ารายชั่วโมง เงื่อนไขบังคับเชิงพื้นที่ และการตอบสนองของโรงไฟฟ้าต่อการเปลี่ยนแปลงโหลด โดยจะนำเสนอวิธีสร้างแบบจำลองการผลิตไฟฟ้าจากแหล่งพลังงานหมุนเวียนที่เสมือนจริง มีการนำเสนอวิธีการแบ่งระดับความต้องการใช้ไฟฟ้า และเงื่อนไขสมดุลกำลังไฟฟ้าของกำลังผลิตไฟฟ้าและความต้องการใช้ไฟฟ้าในแต่ระดับตามความสามารถในการตอบสนองต่อการเปลี่ยนแปลงโหลดของโรงไฟฟ้า นอกจากนี้ยังมีการพิจารณาเงื่อนไขจำเพาะเชิงพื้นที่ในการตัดสินใจเพิ่มโรงไฟฟ้าเพื่อให้มั่นใจว่าโรงไฟฟ้าใหม่จะสามารถสร้างได้จริงตามแผน และท้ายที่สุด วิทยานิพนธ์ฉบับนี้ยังนำเสนอวิธีวางแผนขยายกำลังผลิตไฟฟ้าร่วมกับระบบกักเก็บพลังงาน ซึ่งประกอบไปด้วยแบบจำลองการสั่งการเดินเครื่องโรงไฟฟ้าร่วมกับระบบกักเก็บพลังงาน การคำนวณดัชนีความเชื่อถือได้ร่วมกับระบบกักเก็บพลังงาน และการตัดสินใจขยายขนาดระบบกักเก็บพลังงาน วิธีการที่นำเสนอนี้ถูกทดสอบกับฐานข้อมูลสำหรับจัดทำแผนพัฒนากำลังผลิตไฟฟ้าของประเทศ พ.ศ. 2566-2580 เพื่อจัดทำแผนขยายกำลังผลิตไฟฟ้าสำหรับประเทศไทย

การศึกษาการเบรกดาวน์ทางไฟฟ้าของเม็ดเลือดแดงสําหรับการตรวจจับมาลาเรีย, วีรดา หมัดสี

Chulalongkorn University Theses and Dissertations (Chula ETD)

มาลาเรียยังคงเป็นปัญหาสาธารณสุขสำคัญของโลก ถึงแม้ว่าจำนวนผู้ป่วยจะลดลงทุกปี. การดื้อยาของเชื้อมาลาเรียส่งผลกระทบต่อการควบคุมโรคเป็นอย่างมาก. ดังนั้น การวินิจฉัยของมาลาเรียจำเป็นต้องมีความรวดเร็วและแม่นยำ. ปัจจุบันการตรวจหามาลาเรียมีหลายวิธี เช่น การตรวจหาด้วยกล้องจุลทรรศน์, การตรวจโดยใช้ชุดตรวจ RDTs, การตรวจด้วยวิธีการพีซีอาร์. ขีดจำกัดและความสามารถในการตรวจแต่ละวิธีนั้นมีความแตกต่างกัน. วิทยานิพนธ์นี้ศึกษาการคัดแยกเซลล์เลือดเพาะปกติและเซลล์เลือดเพาะเชื้อมาลาเรีย และการตรวจหาดีเอ็นเอของมาลาเรีย โดยใช้แรงไดอิเล็กโตรโฟเรติก. การสลายเซลล์เลือดเพาะเชื้อมาลาเรียด้วยหลักการอิเล็กโตรพอเร-ชัน. ตัวอย่างที่ใช้สำหรับการทดลอง คือ เซลล์เม็ดเลือดแดงปกติ และเซลล์เลือดเพาะเชื้อมาลาเรีย. การทดลองคัดแยกเซลล์เลือดปกติออกจากเซลล์เลือดเพาะเชื้อมาลาเรียถูกทำที่อัตราส่วนจำนวนเซลล์ 1:10,000. เซลล์เลือดเพาะเชื้อมาลาเรียหลังผ่านกระบวนการคัดแยกจะถูกสลายที่แรงดัน 9 Vp, 100 kHz เพื่อสกัดสารพันธุกรรม. ตัวอย่างที่ได้จากการสลายเซลล์ถูกนำไปขยายปริมาณดีเอ็น-เอด้วยวิธีการพีซีอาร์. ผลิตผลที่ได้จากการทำพีซีอาร์จะถูกนำมาตรวจหาดีเอ็นของมาลาเรียด้วยวิธีการวัดอิมพีแดนซ์เชิงไดอิเล็กโตรโฟเรติก.

Removing Physical Presence Requirements For A Remote And Automated World - Api Controlled Patch Panel For Conformance Testing, Hunter George Wells

Honors Theses and Capstones

Quality assurance test engineers at the UNH-InterOperability Lab must run tests that require driving and monitoring a selection of DC signals. While the number of signals is numerous, there are limited ports on the test equipment, and only a few signals need patching for any given test. The selection of signals may vary between the 209 different tests and must be re-routed frequently. Currently, testers must leave their desk to manually modify the test setup in another room. This posed a considerable issue at the onset of the COVID-19 Pandemic when physical access was not possible. In order to enable …

Development Of A Fluxgate Magnetometer Model, Eleonora Olsmats

Honors Theses and Capstones

As a part of the UNH SWFO-L1 mission to monitor space weather and the sun’s behavior, the fluxgate magnetometer is an important component to measure external magnetic fields. The basic principle of a fluxgate magnetometer is to detect changes in the ambient magnetic field by inducing a magnetic field in a ferromagnetic material via a drive winding. Each magnetometer is unique due to the ferromagnetic properties of the core material which can be seen in the hysteresis loop which is a relationship between the magnetic field strength (H) and the induced magnetic field (B). Measuring the hysteresis of a fluxgate …

Optimal Design Of Photovoltaic, Biomass, Fuel Cell, Hydrogen Tank Units And Electrolyzer Hybrid System For A Remote Area In Egypt, Abd El-Sattar Abd El-Sattar, Salah Kamel, Hamdy M. Sultan, Hossam Zawbaa, Francisco Jurado

Articles

In this paper, a new isolated hybrid system is simulated and analyzed to obtain the optimal sizing and meet the electricity demand with cost improvement for servicing a small remote area with a peak load of 420 kW. The major configuration of this hybrid system is Photovoltaic (PV) modules, Biomass gasifier (BG), Electrolyzer units, Hydrogen Tank units (HT), and Fuel Cell (FC) system. A recent optimization algorithm, namely Mayfly Optimization Algorithm (MOA) is utilized to ensure that all load demand is met at the lowest energy cost (EC) and minimize the greenhouse gas (GHG) emissions of the proposed system. The …

Optimization Based On Movable Damped Wave Algorithm For Design Of Photovoltaic/ Wind/ Diesel/ Biomass/ Battery Hybrid Energy Systems, Mohammed Kharrich, Salah Kamel, Mamdouh Abdel-Akher, Ahmad Eid, Hossam Zawbaa, Jonghoon Kim

Articles

The actual energetic situation has several challenges such as pollution, the rarefaction of fossil fuel and the dangers of nuclear. Renewable sources are proposed as a solution and suggested, such as a cost-effectiveness system. The paper deals with the problem of feeding a domestic load with electricity which should respect the ecologies factors, so this work is a design problem of the hybrid renewable energy systems; PV/biomass, PV/diesel/battery, PV/wind/diesel/battery, and wind/diesel/battery to choose the best one of them which feed the load with the lowest cost. The study’s goal is to design a microgrid system by the minimization of the …

Reverse Engineering And Enhancement Of Automobile Infotainment System, Cole Brinsfield

Electrical Engineering

In 2011, luxury cars were released with displays built into the center. With modern computing power and technology such as Android Auto or Apple CarPlay, these older infotainment systems degrade the value of cars that are otherwise comparable to 2021 models. This project upgrades the infotainment system of one such car, a 2011 Infiniti G37. Through use of an additional microcomputer in the car, an infotainment upgrade can be achieved. This upgraded infotainment adds navigation, wireless audio, and data display capabilities to the car, while maintaining the functionality of the stock infotainment. While customized for the 2011 Infiniti G37, the …

Detecting The Presence Of Electronic Devices In Smart Homes Using Harmonic Radar, Beatrice Perez, Gregory Mazzaro, Timothy J. Pierson, David Kotz

Dartmouth Scholarship

Data about users is collected constantly by phones, cameras, Internet websites, and others. The advent of so-called ‘Smart Things' now enable ever-more sensitive data to be collected inside that most private of spaces: the home. The first step in helping users regain control of their information (inside their home) is to alert them to the presence of potentially unwanted electronics. In this paper, we present a system that could help homeowners (or home dwellers) find electronic devices in their living space. Specifically, we demonstrate the use of harmonic radars (sometimes called nonlinear junction detectors), which have also been used in …

A Soft-Switched Three-Port Dc-Dc Converter For A Pv/ Battery System, Mohamedelfatih Dosa

All Graduate Theses, Dissertations, and Other Capstone Projects

This thesis proposed a soft-switched three-port bidirectional DC-DC converter for managing the power flow of a photovoltaic (PV) and battery system. The proposed converter consists of three ports connected to a PV panel, battery, and load. These three ports are interfaced through the high-frequency transformer and use phase-shift control to achieve soft-switching for all converter switches. Compared with the traditional multiport converters, the proposed three-port converter uses the least number of power switches, and zero-voltage switching (ZVS). Simulation and experimental results validate the design and effectiveness of soft switching and power flow control. The converter can work in different scenarios …

Efficient Flatness Based Energy Management Strategy For Hybrid Supercapacitor/Lithium-Ion Battery Power System, Salam J. Yaqoob, Seydali Ferahtia, Adel Obed, Hegazy Rezk, Naseer Tawfeeq Alwan, Hossam Zawbaa, Salah Kamel

Articles

This article offers a flatness theory-based energy management strategy (FEMS) for a hybrid power system consisting of a supercapacitor (SC) and lithium-ion battery. The proposed FEMS intends to allocate the power reference for the DC/DC converters of both the battery and SC while attaining higher effciency and stable DC bus voltage. First, the entire system model is analyzed theoretically under the differential flatness approach to reduce the model order as a at system. Second, the proposed FEMS is validated under different load conditions using MATLAB/Simulink. Thus, this FEMS provides high-quality energy to the load and reduces the fluctuations in the …

Enhanced Chaotic Manta Ray Foraging Algorithm For Function Optimization And Optimal Wind Farm Layout Problem, Fatima Dadqaq, Rachid Ellaia, Mohammed Ouassaid, Hossam Zawbaa, Salah Kamel

Articles

Manta ray foraging optimization (MRFO) algorithm is relatively a novel bio-inspired optimization technique directed to given real-world engineering problems. In this present work, wind turbines layout (WTs) inside a wind farm is considered a real nonlinear optimization problem. In spite of the better convergence of MRFO, it gets stuck into local optima for large problems. The chaotic sequences are among the performed techniques used to tackle this shortcoming and improve the global search ability. Therefore, ten chaotic maps have been embedded into MRFO. To affirm the performance of the suggested chaotic approach CMRFO, it was First assessed using the IEEE …

Hosting A Community-Based Local Electricity Market In A Residential Network, Aziz Saif, Shafi K. Khadem, Michael Conlon, Brian Norton

Articles

This paper presents the potential of building a local electricity market (LEM) to boost the deployment of the local energy communities, centred around active customers with distributed energy resources (DERs). To conduct a comprehensive and detailed study on different cases with reduced computational burdens, this paper adopts a simplified modelling approach where the market and network model simulations are performed in a cascaded, decoupled fashion. This allows achieving the optimal LEM output for the energy community with different DER assets that are not bounded by the network constraints. The investigation involves quantifying the benefits brought by LEM to energy communities …

The Environmental Aspects Of Renewable Energy Consumption And Structural Change In Sweden: A New Perspective From Wavelet-Based Granger Causality Approach, Tomiwa Sunday Adebayo, Ridwan Lanre Ibrahim, Ephraim Bonah Agyekum, Hossam Zawbaa, Salah Kamel

Articles

The current paper assessed the time-frequency analysis interrelationship between CO2 emissions and financial development, economic growth, renewable energy use, structural change, and non-renewable energy use in Sweden. We utilized a quarterly dataset stretching from 1980-2019. In order to unlock these interrelationships, we leverage wavelet tools (wavelet-based Granger causality and wavelet coherence). The wavelet-based Granger causality (WGC) test accounts for the issue of multiple time scales in a time series analysis. Another uniqueness of the WGC lies in its resistance to distribution assumption and misspecification in a time series model. Additionally, the wavelet coherence estimator instantaneously evaluates correlation and causality among …

Modeling And Control Of Direct-Conversion Hybrid Switched-Capacitor Dc-Dc Converters, Ziyu Xia

Dartmouth College Ph.D Dissertations

Efficient power delivery is increasingly important in modern computing, communications, consumer and other electronic systems, due to the high power demand and thermal concerns accompanied by performance advancements and tight packaging. In pursuit of high efficiency, small physical volume, and flexible regulation, hybrid switched-capacitor topologies have emerged as promising candidates for such applications. By incorporating both capacitors and inductors as energy storage elements, hybrid topologies achieve high power density while still maintaining soft charging and efficient regulation characteristics. However, challenges exist in the hybrid approach. In terms of reliability, each flying capacitor should be maintained at a nominal `balanced' voltage …