Engineering Commons^™

A Regulated Charge Pump With Extremely Low Output Ripple, Mir Mohammad Navidi, David W. Graham

Faculty & Staff Scholarship

Abstract: In this paper, we present a regulated charge pump with extremely low output ripple (mV) that can be used for accurate programming of nonvolatile memory. We present a technique to include a low-drop-out regulator inside the charge-pump regulation loop to reduce the ripple. This charge pump was fabricated in a 0.35 µm standard CMOS process. The die area of this charge pump is 0.163 mm2 . While operating from a 2.5 V supply, this charge pump generates regulated voltages up to 10 V.

Correlated Blocking In Mmwave Cellular Networks: Macrodiversity, Outage, And Interference, Enass Hriba, Mathew C. Valenti

Faculty & Staff Scholarship

In this paper, we provide a comprehensive analysis of macrodiversity for millimeter wave (mmWave) cellular networks. The key issue with mmWave networks is that signals are prone to blocking by objects in the environment, which causes paths to go from line-of-sight (LOS) to non-LOS (NLOS). We identify macrodiversity as an important strategy for mitigating blocking, as with macrodiversity the user will attempt to connect with two or more base stations. Diversity is achieved because if the closest base station is blocked, then the next base station might still be unblocked. However, since it is possible for a single blockage to …

Improved Charge Injection And Transport Of Light-Emitting Diodes Based On Two-Dimensional Materials, Yuanming Zhou, Sijiong Mei, Dongwei Sun, Neng Liu, Fei Mei, Jinxia Xu, Xianan Cao

Faculty & Staff Scholarship

Light-emitting diodes (LEDs) are considered to be the most promising energy-saving technology for future lighting and display. Two-dimensional (2D) materials, a class of materials comprised of monolayer or few layers of atoms (or unit cells), have attracted much attention in recent years, due to their unique physical and chemical properties. Here, we summarize the recent advances on the applications of 2D materials for improving the performance of LEDs, including organic light emitting diodes (OLEDs), quantum dot light emitting diodes (QLEDs) and perovskite light emitting diodes (PeLEDs), using organic films, quantum dots and perovskite films as emission layers (EMLs), respectively. Two …

Improved Efficiency Of Perovskite Light-Emitting Diodes Using A Three-Step Spin-Coated Ch3nh3pbbr3 Emitter And A Pedot:Pss/Moo3-Ammonia Composite Hole Transport Layer, Yuanming Zhou, Sijong Mei, Dongwei Sun, Neng Liu, Wuxing Shi, Jiahuan Feng, Fei Mei, Jinxia Xu, Yan Jiang, Xianan Cao

Faculty & Staff Scholarship

High efficiency perovskite light-emitting diodes (PeLEDs) using PEDOT:PSS/MoO3-ammonia composite hole transport layers (HTLs) with different MoO3-ammonia ratios were prepared and characterized. For PeLEDs with one-step spin-coated CH3NH3PbBr3 emitter, an optimal MoO3-ammonia volume ratio (0.02) in PEDOT:PSS/MoO3-ammonia composite HTL presented a maximum luminance of 1082 cd/m2 and maximum current efficiency of 0.7 cd/A, which are 82% and 94% higher than those of the control device using pure PEDOT:PSS HTL respectively. It can be explained by that the optimized amount of MoO3-ammonia in the composite HTLs cannot only facilitate hole injection into CH3NH3PbBr3 through reducing the contact barrier, but also suppress the …

A Novel Cooperative Distributed Secondary Controller For Vsi And Pq Inverters Of Ac Microgrids, F. Doost Mohammadi, H. Keshtkar, A. Dehghan Banadaki, A. Feliachi

Faculty & Staff Scholarship

This paper proposes a novel cooperative secondary control strategy for microgrids which is fully distributed. There is a two-layered coordination, which exists between inverter based DGs of both types, i.e. Voltage Source Inverter (VSI) and Current Source Inverter (CSI), also called PQ inverter. In first layer of the proposed two-layered cooperative control strategy, VSIs will take care of the primary average voltage regulation by implementing the average consensus algorithm (ACA); then in the second layer of control, the PQ inverters will improve the voltage quality of the microgrid while maintaining the average voltage of buses at the same desired level. …

Effects Of Charge Transport Materials On Blue Fluorescent Organic Light-Emitting Diodes With A Host-Dopant System, Neng Liu, Sijong Mei, Dongwei Sun, Wuxing Shi, Jiahuan Feng, Yuanming Zhou, Fei Mei, Jinxia Xu, Yan Jiang, Xianan Cao

Faculty & Staff Scholarship

High efficiency blue fluorescent organic light-emitting diodes (OLEDs), based on 1,3-bis(carbazol-9-yl)benzene (mCP) doped with 4,4’-bis(9-ethyl-3-carbazovinylene)-1,1’-biphenyl (BCzVBi), were fabricated using four different hole transport layers (HTLs) and two different electron transport layers (ETLs). Fixing the electron transport material TPBi, four hole transport materials, including 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N,N’-Di(1-naphthyl)-N,N’-diphenyl-(1,1’-biphenyl)-4’-diamine(NPB), 4,4’-Bis(N-carbazolyl)-1,1,-biphenyl (CBP) and molybdenum trioxide (MoO3), were selected to be HTLs, and the blue OLED with TAPC HTL exhibited a maximum luminance of 2955 cd/m2 and current efficiency (CE) of 5.75 cd/A at 50 mA/cm2, which are 68% and 62% higher, respectively, than those of the minimum values found in the device with MoO3 …

Deep Learning Using Convolutional Lstm Estimates Biological Age From Physical Activity, Syed Ashiqur Rahman, Donald A. Adjeroh

Faculty & Staff Scholarship

Human age estimation is an important and difcult challenge. Diferent biomarkers and numerous approaches have been studied for biological age estimation, each with its advantages and limitations. In this work, we investigate whether physical activity can be exploited for biological age estimation for adult humans. We introduce an approach based on deep convolutional long short term memory (ConvLSTM) to predict biological age, using human physical activity as recorded by a wearable device. We also demonstrate fve deep biological age estimation models including the proposed approach and compare their performance on the NHANES physical activity dataset. Results on mortality hazard analysis …

Unique Constant Phase Element Behavior Of The Electrolyte–Graphene Interface, Jianbo Sun, Yuxin Liu

Faculty & Staff Scholarship

We report a unique constant phase element (CPE) behavior ( 1Z=Q0(jω)α" role="presentation" style="box-sizing: border-box; max-height: none; display: inline; line-height: normal; font-size: 14.3px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">1Z=Q0(jω)α ) of the electrolyte–graphene interface with both Q0" role="presentation" style="box-sizing: border-box; max-height: none; display: inline; line-height: normal; font-size: 14.3px; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Q0 and α" role="presentation" style="box-sizing: border-box; max-height: none; display: inline; …

Low-Power Reconfigurable Sensing Circuitry For The Internet-Of-Things Paradigm, Alexander Dilello

Graduate Theses, Dissertations, and Problem Reports

With ubiquitous wireless communication via Wi-Fi and nascent 5th Generation mobile communications, more devices -- both smart and traditionally "dumb" -- will be interconnected than ever before. This burgeoning trend is referred to as the Internet-of-Things. These new sensing opportunities place a larger burden on the underlying circuitry that must operate on finite battery power and/or within energy-constrained environments. New developments of low-power reconfigurable analog sensing platforms like field-programmable analog arrays (FPAAs) present an attractive sensing solution by processing data in the analog domain while staying flexible in design. This work addresses some of the contemporary challenges of low-power wireless …

Low Power Voltage Reference Cells For Sensing Applications, Kody Ray Tucker

Graduate Theses, Dissertations, and Problem Reports

Two low-power voltage reference cells for a system on-chip design are presented in this report. Both cells utilize a combination of standard transistors to produce an output voltage near 1 volt. Choosing the appropriate design procedures can aid in minimizing the temperature coefficient (TC) of the output reference voltage coming out of the cell. One circuit, covered first, is currently being fabricated on a standard 0.5 µm chip complementary metal oxide semiconductor (CMOS) process, while the other is still in the designing stage. The first one has a TC of 86 ppm/◦C with a reference voltage of 1.10 V while …

Energy Efficiency Evaluation Of Blower Heater Non-Purge Compressed Air Dryers, Alexandra M. Botts

Graduate Theses, Dissertations, and Problem Reports

There are several compressed air dryers available for industrial use including, refrigerant, desiccant, and membrane. This research focuses on twin tower regenerative closed loop desiccant dryers, specifically: blower heater non-purge (BHNP) with and without cooling water pumps, Compressed-air Heater Purge (CHP), Blower Heater Purge (BHP), and Pressure Swing Heaterless (PSH). These styles of dryers are used mainly in industries that require extremely dry air such as, food manufacturing, medical air, or sensitive technology manufacturers. The research was conducted by collecting and analyzing real time current draw data on air compressors and associated dryers at eight different facilities (13 compressor systems) …

Immunity-Based Framework For Autonomous Flight In Gps-Challenged Environment, Mohanad Al Nuaimi

Graduate Theses, Dissertations, and Problem Reports

In this research, the artificial immune system (AIS) paradigm is used for the development of a conceptual framework for autonomous flight when vehicle position and velocity are not available from direct sources such as the global navigation satellite systems or external landmarks and systems. The AIS is expected to provide corrections of velocity and position estimations that are only based on the outputs of onboard inertial measurement units (IMU). The AIS comprises sets of artificial memory cells that simulate the function of memory T- and B-cells in the biological immune system of vertebrates. The innate immune system uses information about …

Optimal Compression Of Point Clouds, Benjamin Robert Smith

Graduate Theses, Dissertations, and Problem Reports

Image-based localization is a crucial step in many 3D computer vision applications, e.g., self-driving cars, robotics, and augmented reality among others. Unfortunately, many image-based-localization applications require the storage of large scenes, and many camera pose estimators struggle to scale when the scene representation is large. To alleviate the aforementioned problems, many applications compress a scene representation by reducing the number of 3D points of a point cloud. The state-of-the-art compresses a scene representation by using a K-cover-based algorithm. While the state-of-the-art selects a subset of 3D points that maximizes the probability of accurately estimating the camera pose of a new …

Data Driven Intelligent Grid Stability Monitoring And Adaptive Emergency Response, Hasan Ul Banna

Graduate Theses, Dissertations, and Problem Reports

Power grids are large cyber-physical systems with physical operation controlled and integrated through communications. The technological breakthroughs made by the availability of low-cost, high speed communications, larger storage spaces, greater internet bandwidths have led to increased attentions towards advantages of these systems. The use of Phasor Measurement Unit (PMU) in complex interconnected power system for monitoring and control has increased significantly. This has resulted in huge amounts of data and growing databases, thus gearing towards an era where utilities might encounter an enormous amount of data daily from their measurement units including sensitive information useful for daily operations. With increasing …

Resilient Stochastic Control Strategies In Cyber-Physical Microgrids, Mohammad Reza Khalghani

Graduate Theses, Dissertations, and Problem Reports

Microgrids are the integration of a large number of distributed energy resources in a decentralized way such that the energy supply reliability and resiliency are enhanced against natural disasters, physical and cyber disruptions. This dissertation addresses three main challenges for microgrid operation and management:

1) According to fast growing number of Electric Vehicles (EV) deployment, their impacts on microgrids resulted from their uncertain behaviors are new concerns for the microgrid operators. These concerns can be EV charging and discharging schedule and locations of EV parking-lots in the system which are considered and solved using stochastic modeling and optimization algorithms based …

Aptamer Functionalized Zinc Oxide Field Effect Transistors For Odor Detection, Michael D. Aldridge

Graduate Theses, Dissertations, and Problem Reports

Odor detection and identification are complex processes, and tasks that currently only animals do well. There is a pressing need for an electronic nose, or eNose, with good sensitivity, selectivity, and speed that mimics that ability. Food quality control operations, environmental sensing, occupational safety, and the defense sectors all require systems that can rapidly and reliably detect trace levels of volatile organic compounds. The goal of this work is to create a biologically inspired device which can accurately detect and identify odors at concentrations consistent with the most sensitive biological systems.

In order to mimic a natural olfactory system, we …

Intelligent Transportation Systems, Hybrid Electric Vehicles, Powertrain Control, Cooperative Adaptive Cruise Control, Model Predictive Control, Hadi Kazemi

Graduate Theses, Dissertations, and Problem Reports

Information obtainable from Intelligent Transportation Systems (ITS) provides the possibility of improving the safety and efficiency of vehicles at different levels. In particular, such information has the potential to be utilized for prediction of driving conditions and traffic flow, which allows us to improve the performance of the control systems in different vehicular applications, such as Hybrid Electric Vehicles (HEVs) powertrain control and Cooperative Adaptive Cruise Control (CACC). In the first part of this work, we study the design of an MPC controller for a Cooperative Adaptive Cruise Control (CACC) system, which is an automated application that provides the drivers …

Design And Implementation Of Overcurrent Protection Relays Test Bench, Khalid Daud Khattak

Graduate Theses, Dissertations, and Problem Reports

The electrical power simulator in Engineering Sciences Building (ESB) at WVU was dismantled in July 2018. The simulator was used as a teaching tool for EE students to conduct lab experiments. The power simulator employed electromechanical and microprocessor protection relays, manual isolation and industrial circuit breakers, switches, variable autotransformer (VARIAC), voltmeters and ammeters. During the dismantling, a lot of equipment was retrieved for future possible use. This led to the idea of designing and implementing a simple circuit on a test bench that can be used as a lab equipment to demonstrate the operation of overcurrent protection relays. It was …

Engineering Plasmonic Nanostructures For Light Management And Sensing, Sujan Phani Kumar Kasani

Graduate Theses, Dissertations, and Problem Reports

The two major global problems are to provide health safety and to meet energy demands for ever growing population on a large scale. The study of light interaction with nanostructures has shown a promising solution in improving the fields of bio-sensor and solar energy devices which addresses above mentioned two major global problems. Nanostructures have tunable physicochemical properties such as light absorption, electrical and thermal properties unlike bulk materials, which gives an advantage in applications like bio-sensing and energy harvesting devices. The development of nanofabrication techniques along with the discovery of Surface Enhanced Raman Scattering (SERS) and Plasmon Enhanced Fluorescence …

Scheduling For Cooperative Energy Harvesting Sensor Networks, Ahmed Ammar

Graduate Theses, Dissertations, and Problem Reports

In cooperative communication networks, the source node transmits its data to the destination either directly or cooperatively with a cooperating node. When using energy harvesting technology, where nodes collect their energy from the environment, the energy availability at the nodes becomes unpredictable due to the stochastic nature of energy harvesting processes. As a result, when the source has a transmission, it cannot immediately transmit its data cooperatively with the cooperating node. It first needs to determine whether the cooperating node has sufficient energy to forward its transmission or not. Otherwise, its transmitted data may get lost. Therefore, when using energy …