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Electrical and Computer Engineering

2014

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Articles 61 - 90 of 1673

Full-Text Articles in Engineering

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei Dec 2014

Design Of A Haptic Interface For Medical Applications Using Magneto-Rheological Fluid Based Actuators, Nima Najmaei

Electronic Thesis and Dissertation Repository

This thesis reports on the design, construction, and evaluation of a prototype two degrees-of-freedom (DOF) haptic interface, which takes advantage of Magneto-Rheological Fluid (MRF) based clutches for actuation. Haptic information provides important cues in teleoperated systems and enables the user to feel the interaction with a remote or virtual environment during teleoperation. The two main objectives in designing a haptic interface are stability and transparency. Indeed, deficiencies in these factors in haptics-enabled telerobotic systems has the introduction of haptics in medical environments where safety and reliability are prime considerations. An actuator with poor dynamics, high inertia, large size, and heavy …


Design Of Gan-Based Low-Loss Y-Branch Power Splitter, Retno Wigajatri Purnamaningsih, Irma Saraswati, Nji Raden Poespawati, Elhadj Dogheche Dec 2014

Design Of Gan-Based Low-Loss Y-Branch Power Splitter, Retno Wigajatri Purnamaningsih, Irma Saraswati, Nji Raden Poespawati, Elhadj Dogheche

Makara Journal of Technology

We present a Y-branch power splitter design with a multimode section using GaN on Sapphire at telecommunication wavelength. The GaN sample optical properties were also investigated, resulting in a refractive index for the GaN layers nTE=2.289±0.001 and nTM=2.324±0.00. Optimization of the structure parameters for this structure was conducted accurately using BPM methods. The results demonstrated the possibility of realizing a GaN-based Y-branch power splitter for various applications.


Section 3-Renewable Energy Cource, Asadollah Kazemi Dec 2014

Section 3-Renewable Energy Cource, Asadollah Kazemi

Dr. ASADOLLAH KAZEMI

No abstract provided.


Development Of The Soekarno–Hatta International Airport Rail Link Project Using The Value Engineering Method: Creating Value For Money, Mohammed Ali Berawi, Bambang Susantono, Suyono Dikun, Tommy Ilyas, Herawati Zetha Rahman, Abdur Rohim Boy Berawi, Teuku Yuri Zagloel, Perdana Miraj, Jade Sjafrecia Petroceany Dec 2014

Development Of The Soekarno–Hatta International Airport Rail Link Project Using The Value Engineering Method: Creating Value For Money, Mohammed Ali Berawi, Bambang Susantono, Suyono Dikun, Tommy Ilyas, Herawati Zetha Rahman, Abdur Rohim Boy Berawi, Teuku Yuri Zagloel, Perdana Miraj, Jade Sjafrecia Petroceany

Makara Journal of Technology

Soekarno–Hatta Airport is the main gateway for international flights to Greater Jakarta. Its accessibility depends on the inter-city and Sedyatmo toll roads, which causes congestion in peak hours, leading to uncertainty about travel times. The Soekarno–Hatta International Airport Rail Link (SHIARL) is proposed as an alternative mass transportation project, which is expected to provide accessibility and mobility for people and goods to and from the airport. Previously, the project was unattractive to private investors as it was technically and financially unfeasible. Therefore, this research aims to improve the feasibility of the Soekarno-Hatta International Airport Rail Link (SHIARL) by using a …


Endoscopic Application Of A Compact Compound-Eye Camera, Keiichiro Kagawa, Shoji Kawahito Dec 2014

Endoscopic Application Of A Compact Compound-Eye Camera, Keiichiro Kagawa, Shoji Kawahito

Makara Journal of Technology

A multi-functional compound-eye endoscope enabling multi-spectral imaging and variable field-of-view is presented, which is based on a compact compound-eye camera called TOMBO (thin observation module by bound optics). Narrow-band filters attached to some lenses provide snap-shot multi-band images. Fixed and movable mirrors are introduced to control the field of view, which realizes several observation modes such as three-dimensional shape measurement, wide field-of-view, and close-up observation.


Lateral Load Resistance Of Laminated Veneer Lumber Sengonwooden Joints With Wooden Dowels, Niken Palaeowati, Ali Awaludin, Suprapto Siswosukarto Dec 2014

Lateral Load Resistance Of Laminated Veneer Lumber Sengonwooden Joints With Wooden Dowels, Niken Palaeowati, Ali Awaludin, Suprapto Siswosukarto

Makara Journal of Technology

Analytical models for wooden-doweled joints need to be developed. The objective of this research is to determine whether the strength of wooden-doweled joints can be well predicted by equations developed for steel-doweled joints. In this experiment, various connection parameters, such as dowel diameter, species of the wooden dowel, and angle of joints, are studied. The joint specimens are loaded in a quasi-static state with four replications each. A5% offset diameter method is used to determine the lateral load resistance of the tested joints, while the predictions are evaluated by equations given in Indonesian National Standard (SNI) 7973-2013 and the European …


Ultra-Wideband Notched Characteristic Fed By Coplanar Waveguide, Rastanto Hadinegoro, Yuli Kurnia Ningsih, Indra Surjati Dec 2014

Ultra-Wideband Notched Characteristic Fed By Coplanar Waveguide, Rastanto Hadinegoro, Yuli Kurnia Ningsih, Indra Surjati

Makara Journal of Technology

In this paper, a novel Ultra-Wide Band (UWB) notch patch antenna with co-planar waveguide (CPW) fed is presented. This antenna only used one layer and the patch antenna is constructed on the first layer and back to back with CPW fed and bottom part is ground plane. The width notch is used to achieve the UWB characteristic. The results shown that the impedance bandwidth is 1130 MHz (1.662–2.792 GHz) or about 50.7% for VSWR <2.


Analysis Of Vibration Generated By The Rubbing Of Flat Surfaces, Zahrul Fuadi Dec 2014

Analysis Of Vibration Generated By The Rubbing Of Flat Surfaces, Zahrul Fuadi

Makara Journal of Technology

Among the phenomena that occur as a result of contact between two surfaces is friction sound, in which surface roughness is of great importance. In this study, the parameter of contact stiffness is used to explain the frequency characteristic of vibration generated by the rubbing of flat surfaces under a small load. A 3-disk configuration rubbing method was used, which provides a unique characteristic of the system's frequency response function containing specific information about the rubbing vibrations. It is shown that the peak frequency of the rubbing vibration can be explained by using a two-degrees-of-freedom model incorporating the parameter of …


The Mechanical And Tribology Properties Of Sputtered Titanium Aluminum Nitride Coating On The Tungsten Carbide Insert Tool In The Dry Turning Of Tool Steel, Esmar Budi, Mohd. Razali Bin Muhamad, Md. Nizam Bin Abdul Rahman Dec 2014

The Mechanical And Tribology Properties Of Sputtered Titanium Aluminum Nitride Coating On The Tungsten Carbide Insert Tool In The Dry Turning Of Tool Steel, Esmar Budi, Mohd. Razali Bin Muhamad, Md. Nizam Bin Abdul Rahman

Makara Journal of Technology

The effect of the sputtering parameters on the mechanical tribology properties of Titanium Aluminum Nitride coating on the tungsten cabide insert tool in the dry turning of tool steel has been investigated. The coating was deposited using a Direct Current magnetron sputtering system with various substrate biases (-79 to -221 V) and nitrogen flow rates (30 to 72 sccm). The dry turning test was carried out on a Computer Numeric Code machine using an optimum cutting parameter setting. The results show that the lowest flank wear (~0.4 mm) was achieved using a Titanium Aluminum Nitride-coated tool that was deposited at …


Modified Design Of Pin-On-Ring Tribometer For Hip Joint Prostheses Measurement; Case Study On Salat Activity, Muhammad Khafidh, Jamari Jamari, Sulardjaka Sulardjaka, Mohamad Tauviqirrahman, Emile Van Der Heide Dec 2014

Modified Design Of Pin-On-Ring Tribometer For Hip Joint Prostheses Measurement; Case Study On Salat Activity, Muhammad Khafidh, Jamari Jamari, Sulardjaka Sulardjaka, Mohamad Tauviqirrahman, Emile Van Der Heide

Makara Journal of Technology

Total hip replacement (THR) is one of the most successful orthopedic surgical procedures for replacing a broken hip joint. In THR, wear may occur at the articulating surface of the acetabular cup and the femoral head. In Indonesia, the country with the largest Muslim population in the world, most of the inhabitants do salat (praying) every day. THR users are banned from doing salat for fear it will damage the hip joint prostheses. The previous wear calculation methods on the hip joint prostheses use the gravimetric, coordinate measuring machine (CMM), profiler, and geometric method. The disadvantages of the previous methods …


Continuous Production Of Nanotubes And Carbon Clusters By Use Of The Revolver-Injection-Type Arc Jet Producer, Tetsu Mieno, Naoki Matsumoto, Takahashi Tomie, H. Inoue Dec 2014

Continuous Production Of Nanotubes And Carbon Clusters By Use Of The Revolver-Injection-Type Arc Jet Producer, Tetsu Mieno, Naoki Matsumoto, Takahashi Tomie, H. Inoue

Makara Journal of Technology

Efficient and continuous production of fullerenes, single-walled carbon nanotubes (SWNTs), and carbon nano-particles has been developed by the JxB arc jet method, where the Lorentz force of magnetic field jets out gaseous carbon particles to the JxB direction. In order to realize continuous mass production of these carbon clusters, the revolverinjection- type arc jet producer (RIT-AJP) has been developed. Production of fullerenes, endohedral metallo-fullerenes, SWNTs, metal-encapsulated carbon nano particles has been examined.


Generalized Framework For Similarity Measure Of Time Series, Hongsheng Yin, Honggang Qi, Jingwen Xu, William N. N. Hung, Xiaoyu Song Dec 2014

Generalized Framework For Similarity Measure Of Time Series, Hongsheng Yin, Honggang Qi, Jingwen Xu, William N. N. Hung, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Currently, there is no definitive and uniform description for the similarity of time series, which results in difficulties for relevant research on this topic. In this paper, we propose a generalized framework to measure the similarity of time series. In this generalized framework, whether the time series is univariable or multivariable, and linear transformed or nonlinear transformed, the similarity of time series is uniformly defined using norms of vectors or matrices.The definitions of the similarity of time series in the original space and the transformed space are proved to be equivalent. Furthermore, we also extend the theory on similarity of …


Media Usage In Post-Secondary Education And Implications For Teaching And Learning, Gerd Gidion, Luiz Fernando Capretz, Ken Mead Dr., Michael Grosch Dr. Dec 2014

Media Usage In Post-Secondary Education And Implications For Teaching And Learning, Gerd Gidion, Luiz Fernando Capretz, Ken Mead Dr., Michael Grosch Dr.

Electrical and Computer Engineering Publications

The Web 2.0 has permeated academic life. The use of online information services in post-secondary education has led to dramatic changes in faculty teaching methods as well as in the learning and study behavior of students. At the same time, traditional information media, such as textbooks and printed handouts, still form the basic pillars of teaching and learning. This paper reports the results of a survey about media usage in teaching and learning conducted with Western University students and instructors, highlighting trends in the usage of new and traditional media in higher education by instructors and students. In addition, the …


Vehicle Base Station, Emad William Saad, John L. Vian, Matthew A. Vavrina, Jared A. Nisbett, Donald C. Wunsch Dec 2014

Vehicle Base Station, Emad William Saad, John L. Vian, Matthew A. Vavrina, Jared A. Nisbett, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

A system to load and unload material from a vehicle comprises a vehicle base station and an assembly to autonomously load and unload material from the vehicle.


Numerical Modeling Of Deformation, Oscillation, Spreading And Collision Characteristics Of Droplets In An Electric Field, Osameh Ghazian Dec 2014

Numerical Modeling Of Deformation, Oscillation, Spreading And Collision Characteristics Of Droplets In An Electric Field, Osameh Ghazian

Electronic Thesis and Dissertation Repository

Electric field induced flows, or electrohydrodynamics (EHD), have been promising in many fast-growing technologies, where droplet movement and deformation can be controlled to enhance heat transfer and mass transport. Several complex EHD problems existing in many applications were investigated in this thesis.

Firstly, this thesis presents the results of numerical simulations of the deformation, oscillation and breakup of a weakly conducting droplet suspended in an ambient medium with higher conductivity. It is the first time that the deformation of such a droplet was investigated numerically in a 3D configuration. We have determined three types of behavior for the droplets, which …


Flatness-Based Control Methodologies To Improve Frequency Regulation In Power Systems With High Penetration Of Wind, Maryam Hassani Variani Dec 2014

Flatness-Based Control Methodologies To Improve Frequency Regulation In Power Systems With High Penetration Of Wind, Maryam Hassani Variani

Doctoral Dissertations

To allow for high penetration of distributed generation and alternative energy units, it is critical to minimize the complexity of generator controls and to minimize the need for close coordination across regions. We propose that existing controls be replaced by a two-tier structure of local control operating within a global context of situational awareness. Flatness as an extension of controllability for non-linear systems is a key to enabling planning and optimization at various levels of the grid in this structure. In this study, flatness-based control for: one, Automatic Generation Control (AGC) of a multi-machine system including conventional generators; and two, …


Development And Modeling Of A Biosensor Platform Using Algan/Gan Hemt Devices, Fahmida Shaheen Tulip Dec 2014

Development And Modeling Of A Biosensor Platform Using Algan/Gan Hemt Devices, Fahmida Shaheen Tulip

Doctoral Dissertations

The history of biosensors began in 1962 with the invention of enzyme electrodes by Leland C. Clark. Since then, biosensors have come a long way with simultaneous contributions in various fields such as biology, chemistry, material science, electronics, physics and VLSI. With the advancement in science and technology, smaller, more sensitive and dependable biosensors have become a reality. Still the need for cost-effective, sophisticated, reliable, robust biosensors that can be used to detect multiple types of biomolecules remains a technological challenge to be resolved.

The proposed AlGaN/GaN High Electron Mobility Transistors (HEMTs) have excellent prospect to become the biosensor platform …


Lifetime Estimation Of Igbts In A Grid-Connected Statcom, Lakshmi Reddy Gopi Reddy Dec 2014

Lifetime Estimation Of Igbts In A Grid-Connected Statcom, Lakshmi Reddy Gopi Reddy

Doctoral Dissertations

Lifetime estimation of power semiconductor devices, and IGBT devices in particular, used in the power electronics integrated with power systems has gained technical importance in recent times with increased scope of distributed generation, renewable energy systems and FACTS. Since most of the common failures (wire bond and solder fatigue) are caused by thermo-mechanical stresses, the methodology of lifetime estimation starts with temperature estimation, cycle counting based on rainflow algorithm, and finally degradation calculation based on linear accumulation model.

Different number of RC cells for each packaging layer in the module for the thermal model, including the influence of encapsulant is …


Elucidating Fundamental Mechanisms In Focused Electron- And Ion-Beam Induced Synthesis, Carlos M. Gonzalez Dec 2014

Elucidating Fundamental Mechanisms In Focused Electron- And Ion-Beam Induced Synthesis, Carlos M. Gonzalez

Doctoral Dissertations

A focused electron beam deposition process (FEBID) coupled with in-situ infrared pulsed laser assist (LA-EBID) has been implemented for higher purity tungsten nanowires using W(CO)6 [tungsten hexacarbonyl] as parent precursor gas. Nanowires made of Co from Co2(CO)8 [dicobalt octacarbonyl] and Pt from MeCpPtIVMe3 [trimethyl methylcyclopentadienyl platinum] have also been realized by using inert focused ion beams of helium and helium and neon, respectively. In all cases, higher electrical conductivities, higher purities and larger grain sizes have been obtained when compared with preceding traditional additive edit techniques. These new approaches will make possible successful nanoscale direct-write …


Computing Approximate Solutions To The Art Gallery Problem And Watchman Route Problem By Means Of Photon Mapping, Bruce Andrew Johnson Dec 2014

Computing Approximate Solutions To The Art Gallery Problem And Watchman Route Problem By Means Of Photon Mapping, Bruce Andrew Johnson

Doctoral Dissertations

Wireless sensor networks (WSNs) can be partitioned component sensor nodes (SNs) who are meant to operate and sense information arriving from multiple spectra in their environment. Determining where to place a single SN or multiple SNs such that the amount of information gained is maximized while the number of SNs used to gain that information is minimized is an instance of solving the art gallery problem (AGP). In order to solve the AGP, we present the Sensor Placement Optimization via Queries (SPOQ) algorithm that uses level sets populated by queries to a photon map in order to find observation points …


Uwb Precise Indoor Localization System Performance, Limitations And Its Integration, Essam Abdelkadir Elkhouly Dec 2014

Uwb Precise Indoor Localization System Performance, Limitations And Its Integration, Essam Abdelkadir Elkhouly

Doctoral Dissertations

An indoor localization system that was built at University of Tennessee is extensively studied and improved. The goal of the system is to achieve mm down to sub-mm accuracy/precision.

Sub-sampling is used to alleviate the high sampling rate required for UWB signals. Current commercial direct sampling systems are still too slow or prohibitively expensive for UWB applications. We developed two different sub-sampling techniques, but the two systems suffer numerous shortcomings: low throughput, non-robustness, non-linearity. A third system is introduced that achieve both high accuracy and high through-put. Changes in the detection algorithm and the frame synchronization are developed to accommodate …


High-Efficiency Three-Phase Current Source Rectifier Using Sic Devices And Delta-Type Topology, Ben Guo Dec 2014

High-Efficiency Three-Phase Current Source Rectifier Using Sic Devices And Delta-Type Topology, Ben Guo

Doctoral Dissertations

In this dissertation, the benefits of the three-phase current source rectifier (CSR) in high power rectifier, data center power supply and dc fast charger for electric vehicles (EV) will be evaluated, and new techniques will be proposed to increase the power efficiency of CSRs.

A new topology, referred as Delta-type Current Source Rectifier (DCSR), is proposed and implemented to reduce the conduction loss by up to 20%. By connecting the three legs in a delta type on ac input side, the dc-link current in DCSR can be shared by two legs at the same time.

To increase the switching speed …


A Low-Power, Reconfigurable, Pipelined Adc With Automatic Adaptation For Implantable Bioimpedance Applications, Terence Cordell Randall Dec 2014

A Low-Power, Reconfigurable, Pipelined Adc With Automatic Adaptation For Implantable Bioimpedance Applications, Terence Cordell Randall

Doctoral Dissertations

Biomedical monitoring systems that observe various physiological parameters or electrochemical reactions typically cannot expect signals with fixed amplitude or frequency as signal properties can vary greatly even among similar biosignals. Furthermore, advancements in biomedical research have resulted in more elaborate biosignal monitoring schemes which allow the continuous acquisition of important patient information. Conventional ADCs with a fixed resolution and sampling rate are not able to adapt to signals with a wide range of variation. As a result, reconfigurable analog-to-digital converters (ADC) have become increasingly more attractive for implantable biosensor systems. These converters are able to change their operable resolution, sampling …


Adaptive Control For Power System Voltage And Frequency Regulation, Yao Xu Dec 2014

Adaptive Control For Power System Voltage And Frequency Regulation, Yao Xu

Doctoral Dissertations

Variable and uncertain wind power output introduces new challenges to power system voltage and frequency stability. To guarantee the safe and stable operation of power systems, the control for voltage and frequency regulation is studied in this work.

Static Synchronous Compensator (STATCOM) can provide fast and efficient reactive power support to regulate system voltage. In the literature, various STATCOM control methods have been discussed, including many applications of proportional–integral (PI) controllers. However, these previous works obtain the PI gains via a trial and error approach or extensive studies with a tradeoff of performance and applicability. Hence, control parameters for the …


Security Issues In Data Warehouse, Saiqa Aleem, Luiz Fernando Capretz, Faheem Ahmed Dr. Dec 2014

Security Issues In Data Warehouse, Saiqa Aleem, Luiz Fernando Capretz, Faheem Ahmed Dr.

Electrical and Computer Engineering Publications

Data Warehouse (DWH) provides storage for huge amounts of historical data from heterogeneous operational sources in the form of multidimensional views, thus supplying sensitive and useful information which help decision-makers to improve the organization’s business processes. A data warehouse environment must ensure that data collected and stored in one big repository are not vulnerable. A review of security approaches specifically for data warehouse environment and issues concerning each type of security approach have been provided in this paper.


A Practical Guideline For Intracranial Volume Estimation In Patients With Alzheimer’S Disease, Saman Sargolzaei, Arman Sargolzaei, Mercedes Cabrerizo, Gang Chen, Mohammed Goryawala, Shirin Noei, Qi Zhou, Ranjan Duara, Warren Barker, Malek Adjouadi Dec 2014

A Practical Guideline For Intracranial Volume Estimation In Patients With Alzheimer’S Disease, Saman Sargolzaei, Arman Sargolzaei, Mercedes Cabrerizo, Gang Chen, Mohammed Goryawala, Shirin Noei, Qi Zhou, Ranjan Duara, Warren Barker, Malek Adjouadi

Electrical and Computer Engineering Faculty Publications

Background

Intracranial volume (ICV) is an important normalization measure used in morphometric analyses to correct for head size in studies of Alzheimer Disease (AD). Inaccurate ICV estimation could introduce bias in the outcome. The current study provides a decision aid in defining protocols for ICV estimation in patients with Alzheimer disease in terms of sampling frequencies that can be optimally used on the volumetric MRI data, and the type of software most suitable for use in estimating the ICV measure.

Methods

Two groups of 22 subjects are considered, including adult controls (AC) and patients with Alzheimer Disease (AD). Reference measurements …


A Probabilistic Approach For Pediatric Epilepsy Diagnosis Using Brain Functional Connectivity Networks, Saman Sargolzaei, Mercedes Cabrerizo, Arman Sargolzaei, Shirin Noei, Anas Salah Eddin, Hoda Rajaei, Alberto Pinzon-Ardila, Sergio M. Gonzalez-Arias, Prasanna Jayakar, Malek Adjouadi Dec 2014

A Probabilistic Approach For Pediatric Epilepsy Diagnosis Using Brain Functional Connectivity Networks, Saman Sargolzaei, Mercedes Cabrerizo, Arman Sargolzaei, Shirin Noei, Anas Salah Eddin, Hoda Rajaei, Alberto Pinzon-Ardila, Sergio M. Gonzalez-Arias, Prasanna Jayakar, Malek Adjouadi

Electrical and Computer Engineering Faculty Publications

Background

The lives of half a million children in the United States are severely affected due to the alterations in their functional and mental abilities which epilepsy causes. This study aims to introduce a novel decision support system for the diagnosis of pediatric epilepsy based on scalp EEG data in a clinical environment.

Methods

A new time varying approach for constructing functional connectivity networks (FCNs) of 18 subjects (7 subjects from pediatric control (PC) group and 11 subjects from pediatric epilepsy (PE) group) is implemented by moving a window with overlap to split the EEG signals into a total of …


Mega: An Energy Aware Algorithm For Self-Powered Wireless Sensor Networks In Sustainable Smart Infrastructure, Dong Qi, Yu Chen, Shahrzad Towfighian Dec 2014

Mega: An Energy Aware Algorithm For Self-Powered Wireless Sensor Networks In Sustainable Smart Infrastructure, Dong Qi, Yu Chen, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

Smart infrastructure is attractive for possessing many desirable features, such as uninterrupted monitoring of health conditions, timely response to damages, and human-infrastructure interactions. Embedded sensors that collectinformation are critical for decision making. However, the lifetime of electronic sensors is a constraint to infrastructure lifetime if sensors are physically embedded in the infrastructure at construction time. In this paper, we studied a self-powered wireless sensor network that harvests energy from mechan-ical vibration in the environment. A dynamic, hierarchical algorithm called MEGA is proposed that constructs clusters and elects the cluster head based on residue energy and energy harvest rate. Taking a …


An Optogenetic Brain-Machine Interface For Spatiotemporal Neuromodulation, Ryan Andrew Baumgartner Dec 2014

An Optogenetic Brain-Machine Interface For Spatiotemporal Neuromodulation, Ryan Andrew Baumgartner

Theses and Dissertations

Direct neural stimulation has recently become a standard therapy for neurological disorders such as Parkinson's Disease, Essential Tremors, and Dystonia. Currently, deep brain electro-stimulation and neuro-pharmaceutical treatments are the dominant therapeutic options available to the public. As our understanding of brain function and neurological diseases improves, we are able to develop more advanced neuromodulation techniques. These methods could become viable treatment solutions for treating brain dysfunction. Optogenetics, first introduced by a research team led by Karl Deisseroth at Stanford University, has proved to be a versatile technique with remarkable potential to be used in treatments for brain disorders, dysfunction, and …


Improving Mri Surface Coil Decoupling To Reduce B1 Distortion, Christian K. Larson Dec 2014

Improving Mri Surface Coil Decoupling To Reduce B1 Distortion, Christian K. Larson

Theses and Dissertations

As clinical MRI systems continue to advance, larger focus is being given to image

uniformity. Good image uniformity begins with generating uniform magnetic fields, which

are easily distorted by induced currents on receive-only surface coils. It has become an

industry standard to combat these induced currents by placing RF blocking networks on

surface coils. This paper explores the effect of blocking network impedance of phased array surface coils on B1 distortion. It has been found and verified, that traditional approaches for blocking network design in complex phased arrays can leave undesirable B1 distortions at 3 Tesla. The traditional approach of …