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Electrical and Computer Engineering

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West Virginia University

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2019

Articles 1 - 8 of 8

Full-Text Articles in Engineering

A Regulated Charge Pump With Extremely Low Output Ripple, Mir Mohammad Navidi, David W. Graham Jan 2019

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.

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Correlated Blocking In Mmwave Cellular Networks: Macrodiversity, Outage, And Interference, Enass Hriba, Mathew C. Valenti Jan 2019

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 …

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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 Jan 2019

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 …

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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 Jan 2019

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 …

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A Novel Cooperative Distributed Secondary Controller For Vsi And Pq Inverters Of Ac Microgrids, F. Doost Mohammadi, H. Keshtkar, A. Dehghan Banadaki, A. Feliachi Jan 2019

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. …

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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 Jan 2019

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 …

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Deep Learning Using Convolutional Lstm Estimates Biological Age From Physical Activity, Syed Ashiqur Rahman, Donald A. Adjeroh Jan 2019

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 …

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Unique Constant Phase Element Behavior Of The Electrolyte–Graphene Interface, Jianbo Sun, Yuxin Liu Jan 2019

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; …

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