Computer Engineering Commons^™

New Three-Dimensional Space Vector Pulse Width Modulation Of Pv-Af System Based On The Gh$\Gamma $ Coordinate System, Juan Zhou, Malong Liu, Chen Wei, Chaoxu Gao, Xiaojie Wu

Turkish Journal of Electrical Engineering and Computer Sciences

The photovoltaic power generation and active filter (PV-AF) system can realize photovoltaic grid-connected power regulation, and meanwhile it can also improve the power quality of power grid effectively. The four-leg grid-connected inverter has successfully been used in the three-phase four-wire system. In this paper, a three-dimensional space vector pulse width modulation (3D-SVPWM) method based on the gh$\gamma $ coordinate system for a four-leg inverter has been proposed. As the switching vectors of the four-leg inverter are in the three-dimensional space, it is difficult to realize the complex modulation process. In order to simplify the modulation process, the reference vector is …

Stability Preservation And Power Management In Autonomous Microgrids Using Adaptive Nonlinear Droop Scheme, Sara Nourollah, Abolfazl Pirayesh, Poria Astero

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes sharing active and reactive power in autonomous voltage source inverter (VSI)-based microgrids with no physical communication links. In decentralized VSI-based microgrids, when the demand or generation changes, the output voltage of distributed generation units and the frequency of the system will also change. This study presents a novel adaptive nonlinear droop (ANLD) scheme for preserving network stability, improving the system's dynamics, and controlling power sharing in multibus microgrids in a decentralized manner. Subcontrollers are modeled in a state space and combined together so that a complete dynamic model of the network can be developed. Note that controller …

Performance Analysis Of A Low-Cost Current-Source 1-Ph Grid-Connected Pv Inverter, Gürhan Ertaşgin, Wen Liang Soong, Nesimi Ertugrul

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the design and performance of a 150 W single-phase current-source grid-connected inverter topology that is based on a PV array and DC link inductor acting as a constant-current source. The inverter is implemented using a single boost switch, an H-bridge inverter, and a CL output filter. The inverter output current is simply controlled using the boost switch and open-loop or feedforward control. The dark I-V configuration is used to simulate two series PV modules. Comprehensive test results are obtained to validate the computer simulation results. Furthermore, the proposed inverter's ability to deliver a sinusoidal current to the …

Amorphous Core Transformers Efficiency Analysis In Turkish Electrical Distribution Systems, Fati̇h Işik, Yilmaz Uyaroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Transformers are an indispensable element in the transmission and distribution of electricity. While they are highly efficient, the increasing global demand for electrical energy has prompted efforts to improve their performance. No-load power losses constitute the majority of total losses within electrical energy distribution, especially when looking at load ratio. In recent years, some studies have found that no-load power losses of amorphous core transformers are less than those of laminated steel core transformers by as much as 60{\%} to 70{\%}. For this paper, we have manufactured an amorphous distribution transformer prototype rated 33 kV and 1 MVA. By quantifying …

Energy Economy In Regulated And Market-Based Power System: Case Study In Serbia, Mileta Zarkovic, Ivan Skokljev

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a possible process of simulating power plant generation planning. The process combines expected overall industry costs, associated cost uncertainty, and expected CO$_{2}$ emissions for different generations, variations of future fossil fuel costs, carbon prices, plant investment costs, and demand, including price elasticity impacts. Uncertainty in the decision stems from the elasticity of prices of fuel and electricity. The aim of this paper is to apply fuzzy numbers to power generation planning and to use a Monte Carlo simulation to check. Simulations are demonstrated through a case study of an electricity industry with coal and lignite, combined cycle …

Design, Application, And Power Performance Analyses Of A Micro Wind Turbine, Hayati̇ Mamur

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, design, implementation, and power performance analyses of a micro wind turbine (MWT) system are presented. An original permanent magnet synchronous generator (PMSG) that reduced cogging torque was employed as a generator in the MWT. A novel blade form offering better performance at low wind speeds was also utilized for the MWT blades. Power performance analyses of the MWT were carried out for different wind regimes by truck testing. Performance coefficient, cut-in, and cut-out of the MWT were determined as 27.7{\%}, 2.7 m/s, and 20 m/s at the end of the truck testing, respectively. Moreover, a new supervisory …

Common Path Pessimism Removal In Static Timing Analysis, Chunyu Wang

Masters Theses

"Static timing analysis is a key process to guarantee timing closure for modern IC designs. However, additional pessimism can significantly increase the difficulty to achieve timing closure. Common path pessimism removal (CPPR) is a prevalent step to achieve accurate timing signoff. To speed up the existing exhaustive exploration on all paths in a design, this thesis introduces a fast multi-threading timing analysis for removing common path pessimism based on block-based static timing analysis. Experimental results show that the proposed method has faster runtime in removing excess pessimism from clock paths."--Abstract, page iii.

A Sentence-Based Image Search Engine, Weizhi Meng

Masters Theses

"Nowadays people are more interested in searching the relevant images directly through search engines like Google, Yahoo or Bing, these image search engines have dedicated extensive research effort to the problem of keyword-based image retrieval. However, the most widely used keyword-based image search engine Google is reported to have a precision of only 39%. And all of these systems have limitation in creating sentence-based queries for images.

This thesis studies a practical image search scenario, where many people feel annoyed by using only keywords to find images for their ideas of speech or presentation through trial and error. This thesis …

A Knowledge-Driven Distributed Architecture For Context-Aware Systems, Dennis Lupiana

Doctoral

As the number of devices increases, it becomes a challenge for the users to use them effectively. This is more challenging when the majority of these devices are mobile. The users and their devices enter and leave different environments where different settings and computing needs may be required. To effectively use these devices in such environments means to constantly be aware of their whereabouts, functionalities and desirable working conditions. This is impractical and hence it is imperative to increase seamless interactions between the users and devices,and to make these devices less intrusive. To address these problems, various responsive computing systems, …

Connecting People And Ideas From Around The World: Global Innovation Platforms For Next-Generation Ecology And Beyond, P. Søgaard Jørgensen, F. Barraquand, V. Bonhomme, T. J. Curran, E. Cieraad, T. G. Ezard, L. Gherardi, R. A. Hayes, T. Poisot, R. Salguero-Gómez, Lucía Desoto, B. Swartz, J. M. Talbot, B. Wee, Naupaka B. Zimmerman

Biology Faculty Publications

We present a case for using Global Community Innovation Platforms (GCIPs), an approach to improve innovation and knowledge exchange in international scientific communities through a common and open online infrastructure. We highlight the value of GCIPs by focusing on recent efforts targeting the ecological sciences, where GCIPs are of high relevance given the urgent need for interdisciplinary, geographical, and cross-sector collaboration to cope with growing challenges to the environment as well as the scientific community itself. Amidst the emergence of new international institutions, organizations, and meetings, GCIPs provide a stable international infrastructure for rapid and long-term coordination that can be …

E-Quality Design Of Experiments For Structural Electronics, Oscar Murga

Open Access Theses & Dissertations

Additive Manufacturing (AM) is a technology utilized for creating complex parts by adding layers of material in order to create a three dimensional functional part. This technology has been pushed to a new level of functionality where mechanical parts are combined with electronic components to create Three-Dimensional Structural Electronics (3DSE) systems. This new technology has been used to replace Printed Circuit Boards (PCB), for 3D SE are light weight and can be created in any desired shape. Computer Aided Design (CAD) software is used to design the part and a Fused Deposition Modeling (FDM) machine is used to 3D print …

Computation Offloading Decisions For Reducing Completion Time, Salvador Melendez

Open Access Theses & Dissertations

Mobile devices are being widely used in many applications such as image processing, computer vision (e.g. face detection and recognition), wearable computing, language translation, and battlefield operations. However, mobile devices are constrained in terms of their battery life, processor performance, storage capacity, and network bandwidth. To overcome these issues, there is an approach called Computation Offloading, also known as cyber-foraging and surrogate computing. Computation offloading consists of migrating computational jobs from a mobile device to more powerful remote computing resources. Upon completion of the job, the results are sent back to the mobile device. However, a decision must be made; …

Implementing Is-Is Routing And Dhcp Services In An Ipv4 Network, Laura Thompson

Williams Honors College, Honors Research Projects

This research project explores the operation of the IS-IS routing protocol, as well as DHCP and DNS services provided by a Raspberry Pi computer. IS-IS is a routing protocol that is commonly ignored in most training and certification programs, because it is most frequently used by service providers. However, IS-IS solutions are also deployed in some large enterprise networks, making experience with the protocol a valuable skill.

In order to gain a deeper understanding of the routing domains, route propagation, and general operation of IS-IS, additional services were implemented in this project. A Raspberry Pi computer was used as an …

Generalized Mapping And Object Removal, Duncan Campbell

Williams Honors College, Honors Research Projects

Simultaneous localization and mapping (SLAM) is a problem that has been explored for the past few decades. SLAM deals with the concept of a robot being introduced into an environment in which it has no prior knowledge. Then, through the use of sensors, the robot is able to map its environment while simultaneously determining its position within the given area. While there has been extensive research into the development of methods by which this problem can be solved, not much has been done on what to do with the resulting maps once they are produced. The research conducted deals with …

Automated Beverage Dispenser, Sonya Istocka

Williams Honors College, Honors Research Projects

The intention of this project is to define a new way of distributing liquor. The project will consist of a device which will measure and track liquor being poured and associate it with a person, either a bartender or a bar patron. The challenges will be controlling the flow of liquor and recording it in an extremely accurate manner as well as processing data quickly so that a pour can be initiated very soon after a person is identified. The liquor dispenser will open up the possibility of a person being able to dispense their own liquor in a controlled …

Disc Golf Locator, Noah M. Sanor

Williams Honors College, Honors Research Projects

Noah Sanor

Major: Computer Engineering

Project Sponsor: The Department of Electrical and Computer Engineering

Number of Credits: 6

Disc Golf Locator

The purpose of this project was to develop a device that could help a player locate a disc used in disc golf. The device could attach to the disc and track the location and movement of the disc. In addition, the device could transfer this data to a smartphone application and emit a loud noise to aid in locating the disc. On this project, I developed the smartphone application to communicate with the device. The application transferred the saved …

Rogue Signal Threat On Trust-Based Cooperative Spectrum Sensing In Cognitive Radio Networks, David S. Jackson

Theses and Dissertations

Cognitive Radio Networks (CRNs) are a next generation network that is expected to solve the wireless spectrum shortage problem, which is the shrinking of available wireless spectrum resources needed to facilitate future wireless applications. The first CRN standard, the IEEE 802.22, addresses this particular problem by allowing CRNs to share geographically unused TV spectrum to mitigate the spectrum shortage. Equipped with reasoning and learning engines, cognitive radios operate autonomously to locate unused channels to maximize its own bandwidth and Quality-of-Service (QoS). However, their increased capabilities over traditional radios introduce a new dimension of security threats.

In an NSF 2009 workshop, …

Qcm-D Monitoring Of Binding-Induced Conformational Change Of Calmodulin, Hyun J. Kwon, Brian Dodge

Faculty Publications

Understanding conformational changes are important when studying a protein such as calmodulin (CaM), which activates various target enzymes and regulates numerous physiological functions. CaM is a highly flexible protein that can transitorily adopt various conformations. A quartz crystal microbalance with dissipation (QCM-D) sensor was used to study binding-induced conformational changes of surface-immobilized CaM. Structural changes of CaM were evaluated using the Voigt’s viscoelastic model with frequency (ΔF) and dissipation change (ΔD). When Apo-CaM layer was incubated in 0.1 mM Ca2+ solution, the layer decreased by approximately 0.56 nm, due to the release of coupled water molecules and conformational change. The …

Modular Timing Constraints For Delay-Insensitive Systems, Hoon Park, Anping He, Marly Roncken, Xiaoyu Song, Ivan Sutherland

Electrical and Computer Engineering Faculty Publications and Presentations

This paper introduces ARCtimer, a framework for modeling, generating, verifying, and enforcing timing constraints for individual self-timed handshake components. The constraints guarantee that the component’s gate-level circuit implementation obeys the component’s handshake protocol specification. Because the handshake protocols are delayinsensitive, self-timed systems built using ARCtimer-verified components are also delay-insensitive. By carefully considering time locally, we can ignore time globally. ARCtimer comes early in the design process as part of building a library of verified components for later system use. The library also stores static timing analysis (STA) code to validate and enforce the component’s constraints in any self-timed system built …

Engineering Analytics: Research Into The Governance Structure Needed To Integrate The Dominant Design Methodologies, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2014, Cotter (2014) explored the current state of engineering design, identified the dominate approaches to engineering design, discussed potential contributions from the new field of data analytics to engineering design, and proposed an Engineering Analytics framework that integrates the dominate engineering design approaches and data analytics within a human-intelligence/machine-intelligence (HI-MI) design architecture. This paper reports research applying ontological engineering to integrate the dominate engineering design methodologies into a systemic engineering design decision governance architecture.