Computer Engineering Commons^™

Ieee Access Special Section Editorial: Security And Privacy For Cloud And Iot, Kuo-Hui Yeh, Weizhi Meng, Sk Hafizul Islam, Kuan Zhang, Ennan Zhai

Department of Electrical and Computer Engineering: Faculty Publications

No abstract provided.

Ieee Access Special Section Editorial: Energy Management In Buildings, Kun Wang, Yi Qian, Joel J.P.C. Rodrigues, Fei Richard Yu, Peng Li

Department of Electrical and Computer Engineering: Faculty Publications

No abstract provided.

Fiber-Optic Temperature And Flow Sensory System And Methods, Ming Han, Guigen Liu, Weilin Hou, Qiwen Shen

Department of Electrical and Computer Engineering: Faculty Publications

A fiber optic sensor, a process for utilizing a fiber optic sensor, and a process for fabricating a fiber optic sensor are described, where a double-side-polished silicon pillar is attacked to an optical fiber tip and forms, a Fabry-Perot cavity. In an implementation, a fiber optic sensor in accordance with an examplary embodiment includes an optical fiber configured to be coupled to a light source and a spectrometer; and a single silicon layer or multiple silicon layers disposed on an end face of the optical fiber, where each of the silicon layer(s) defines a Fabry-Perot interferometer, and where the sensor …

Aluminum/Carbon Composites Materials Fabricated By The Powder Metallurgy Process, Amélie Veillère, Hiroki Kurita, Akira Kawasaki, Yongfeng Lu, Jean-Marc Heintz, Jean-François Silvain

Department of Electrical and Computer Engineering: Faculty Publications

Aluminum matrix composites reinforced with carbon fibers or diamond particles have been fabricated by a powder metallurgy process and characterized for thermal management applications. Al/C composite is a nonreactive system (absence of chemical reaction between the metallic matrix and the ceramic reinforcement) due to the presence of an alumina layer on the surface of the aluminum powder particles. In order to achieve fully dense materials and to enhance the thermo-mechanical properties of the Al/C composite materials, a semi-liquid method has been carried out with the addition of a small amount of Al-Si alloys in the Al matrix. Thermal conductivity and …

Water Pipeline Leakage Detection Based On Machine Learning And Wireless Sensor Networks, Yang Liu, Xuehui Ma, Yong Tie, Yinghui Zhang, Jing Gao

Department of Electrical and Computer Engineering: Faculty Publications

The detection of water pipeline leakage is important to ensure that water supply networks can operate safely and conserve water resources. To address the lack of intelligent and the low efficiency of conventional leakage detection methods, this paper designs a leakage detection method based on machine learning and wireless sensor networks (WSNs). The system employs wireless sensors installed on pipelines to collect data and utilizes the 4G network to perform remote data transmission. A leakage triggered networking method is proposed to reduce the wireless sensor network’s energy consumption and prolong the system life cycle effectively. To enhance the precision and …

Machine Current Sensor Fdi Strategy In Pmsms, Haibo Li, Yi Qian, Sohrab Asgarpoor, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

This work proposes a machine current sensor fault detection and isolation (FDI) strategy in permanent magnet synchronous machines (PMSMs) resilient to multiple faults. The fault detection is performed by comparing the measured and estimated DC link currents. The fault isolation is achieved according to machine phase signal estimation and the corresponding residual examination. Single sensor fault, multiple sensor faults and non-sensor fault are covered by the proposed FDI method. The proposed sensor FDI method is not influenced by machine imbalance, feasible for FDI of both single and multiple machine current sensor faults, and capable of distinguishing between machine current sensor …

Hybrid Superhydrophilic–Superhydrophobic Micro/ Nanostructures Fabricated By Femtosecond Laserinduced Forward Transfer For Sub-Femtomolar Raman Detection, Xiaodan Ma, Lan Jiang, Xiaowei Li, Bohong Li, Ji Huang, Jiaxing Sun, Zhi Wang, Zhijie Xu, Liangti Qu, Yongfeng Lu, Tianhong Cui

Department of Electrical and Computer Engineering: Faculty Publications

Raman spectroscopy plays a crucial role in biochemical analysis. Recently, superhydrophobic surface-enhanced Raman scattering (SERS) substrates have enhanced detection limits by concentrating target molecules into small areas. However, due to the wet transition phenomenon, further reduction of the droplet contact area is prevented, and the detection limit is restricted. This paper proposes a simple method involving femtosecond laser-induced forward transfer for preparing a hybrid superhydrophilic–superhydrophobic SERS (HS-SERS) substrate by introducing a superhydrophilic pattern to promote the target molecules to concentrate on it for ultratrace detection. Furthermore, the HS-SERS substrate is heated to promote a smaller concentrated area. The water vapor …

Advanced Mathematical And Numerical Methods In Control And Optimization For Smart Grids, Zhan Shu, Michael Z.Q. Chen, Qing Hui

Department of Electrical and Computer Engineering: Faculty Publications

While renewable energy, as a part of smart-grid technologies, brings clean energy, it also brings a series of power quality problems. An increasing number of power electronic devices and new smart-grid technologies are used to ensure a safe, reliable, and high-quality operation of the power grid. However, the effectiveness of these control devices and technologies largely depends on the accuracy of the model, the advancement of control methods, and the numerical optimization of the parameters.

This special issue focuses on recent advances in modeling, numerical analysis, control, and optimization of smart grids with some special emphasis on the mathematical problems …

Online Eeg Seizure Detection And Localization, Amirsalar Mansouri, Sanjay P. Singh, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

Epilepsy is one of the three most prevalent neurological disorders. A significant proportion of patients suffering from epilepsy can be effectively treated if their seizures are detected in a timely manner. However, detection of most seizures requires the attention of trained neurologists-- a scarce resource. Therefore, there is a need for an automatic seizure detection capability. A tunable non-patient-specific, non-seizure-specific method is proposed to detect the presence and locality of a seizure using electroencephalography (EEG) signals. This multifaceted computational approach is based on a network model of the brain and a distance metric based on the spectral profiles of EEG …

Fqstat: A Parallel Architecture For Very High-Speed Assessment Of Sequencing Quality Metrics, Sree K. Chanumolu, Mustafa Albahrani, Hasan H. Otu

Department of Electrical and Computer Engineering: Faculty Publications

Background: High throughput DNA/RNA sequencing has revolutionized biological and clinical research. Sequencing is widely used, and generates very large amounts of data, mainly due to reduced cost and advanced technologies. Quickly assessing the quality of giga-to-tera base levels of sequencing data has become a routine but important task. Identification and elimination of low-quality sequence data is crucial for reliability of downstream analysis results. There is a need for a high-speed tool that uses optimized parallel programming for batch processing and simply gauges the quality of sequencing data from multiple datasets independent of any other processing steps.

Results: FQStat is a …

Asymptotic Orthogonal Space Shift Keying In Massive Mimo Systems, Won Mee Jang

Department of Electrical and Computer Engineering: Faculty Publications

We investigate space shift keying, which is a simple form of spatial modulation. The bit error rate performance of line-of-sight (LOS) multiple-input and multiple-output (MIMO) was obtained in the literature with orthogonal subchannels for indoor millimeter-wave (mmWave) communications. It is essential to impose a rigid restriction on the distance between the transmitter and the receiver and antenna spacing to maintain orthogonal subchannels. However, in wireless communications, it is not viable to meet the strict distance requirements since user equipment is portable. We propose asymptotic orthogonal space shift keying with mobile stations. The asymptotic orthogonal space shift keying approaches orthogonal subchannels …

Absorptive/Transmissive Frequency Selective Surface With Wide Absorption Band, Qingxin Guo, Jianxun Su, Zengrui Li, Lamar Y. Yang, Jiming Song

Department of Electrical and Computer Engineering: Faculty Publications

An absorptive/transmissive frequency selective surface (ATFSS) with absorption bands at both sides of a passband is presented. Equivalent circuits of the ATFSS that consists of a lossy frequency selective surface (FSS) and a lossless FSS were modeled. To improve the rejection at an undesired band, a transmission zero was introduced and controlled by loading the lossless FSS with four-legged loaded slots. The parasitic passband was suppressed when the cross structure in the lossless FSS was loaded with resistance. In order to expand the absorption band, loaded dipoles were utilized for the lossy FSS design. An ATFSS with wide absorption bands …

Fiber Optic Bolometer, Ming Han, Matthew L. Reinke

Department of Electrical and Computer Engineering: Faculty Publications

The present disclosure is directed to a fiber optic bolometer device . In an implementation , a fiber optic bolometer device includes an optical fiber and a silicon layer that comprises a Fabry - Perot interferometer . The silicon layer includes a first surface and a second surface . The fiber optic bolometer device includes a reflective dielectric film disposed over the first surface of the silicon layer where the reflective dielec tric film is adjacent to an end face of the optical fiber . The fiber optic bolometer device also includes an absorptive coating disposed over the second surface …

Lattice Dynamics Of Orthorhombic Ndgao3, Alyssa Mock, Rafal Korlacki, Sean Knight, Megan Stokey, A. Fritz, Vanya Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

A complete set of infrared-active and Raman-active lattice modes is obtained from density functional theory calculations for single-crystalline centrosymmetric orthorhombic neodymium gallate. The results for infraredactive modes are compared with an analysis of the anisotropic long-wavelength properties using generalized spectroscopic ellipsometry. The frequency-dependent dielectric function tensor and dielectric loss function tensor of orthorhombic neodymium gallium oxide are reported in the spectral range of 80–1200 cm⁻¹. A combined eigendielectric displacement vector summation and dielectric displacement loss vector summation approach augmented by considerations of lattice anharmonicity is utilized to describe the experimentally determined tensor elements. All infrared-active transverse and longitudinal …

Lattice Dynamics Of Orthorhombic Ndgao3, A. Mock, Rafal Korlacki, Sean Knight, Megan Stokey, A. Fritz, V. Darakchieva, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

A complete set of infrared-active and Raman-active lattice modes is obtained from density functional theory calculations for single-crystalline centrosymmetric orthorhombic neodymium gallate. The results for infraredactive modes are compared with an analysis of the anisotropic long-wavelength properties using generalized spectroscopic ellipsometry. The frequency-dependent dielectric function tensor and dielectric loss function tensor of orthorhombic neodymium gallium oxide are reported in the spectral range of 80–1200 cm⁻¹. A combined eigendielectric displacement vector summation and dielectric displacement loss vector summation approach augmented by considerations of lattice anharmonicity is utilized to describe the experimentally determined tensor elements. All infrared-active transverse and longitudinal …

Phonon Order And Reststrahlen Bands Of Polar Vibrations In Crystals With Monoclinic Symmetry, Mathias Schubert, Alyssa Mock, Rafal Korlacki, Vanya Darakchieva

Department of Electrical and Computer Engineering: Faculty Publications

In this Rapid Communication, we present the order of the phonon modes and the appearance of the reststrahlen bands for monoclinic symmetry materials with polar lattice vibrations. Phonon modes occur in associated pairs of transverse and longitudinal optical modes, and pairs either belong to inner or outer phonon modes. Inner modes are nested within outer modes. Outer modes cause polarization-dependent reststrahlen bands. Inner modes cause polarization-independent reststrahlen bands. The directional limiting frequencies within the Born-Huang approach are bound to within outer mode frequency regions not occupied by inner mode pairs. Hence, an unusual phonon mode order can occur where both …

Phonon Order And Reststrahlen Bands Of Polar Vibrations In Crystals With Monoclinic Symmetry, Mathias Schubert, Alyssa Mock, Rafał Korlacki, Vanya Darakchieva

Department of Electrical and Computer Engineering: Faculty Publications

In this Rapid Communication, we present the order of the phonon modes and the appearance of the reststrahlen bands for monoclinic symmetry materials with polar lattice vibrations. Phonon modes occur in associated pairs of transverse and longitudinal optical modes, and pairs either belong to inner or outer phonon modes. Inner modes are nested within outer modes. Outer modes cause polarization-dependent reststrahlen bands. Inner modes cause polarization-independent reststrahlen bands. The directional limiting frequencies within the Born-Huang approach are bound to within outer mode frequency regions not occupied by inner mode pairs. Hence, an unusual phonon mode order can occur where both …

Femtosecond Photon-Mediated Plasma Enhances Photosynthesis Of Plasmonic Nanostructures And Their Sers Applications, Peng Ran, Lan Jiang, Xin Li, Bo Li, Pei Zuo, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Laser ablation in liquid has proven to be a universal and green method to synthesize nanocrystals and fabricate functional nanostructures. This study demonstrates the superiority of femtosecond laser-mediated plasma in enhancing photoredox of metal cations for controllable fabrication of plasmonic nanostructures in liquid. Through employing upstream high energetic plasma during laser-induced microexplosions, single/three-electron photoreduction of metallic cations can readily occur without chemical reductants or capping agents. Experimental evidences demonstrate that this process exhibits higher photon utilization efficiency in yield of colloidal metal nanoparticles than direct irradiation of metallic precursors. Photogenerated hydrated electrons derived from strong ionization of silicon and water …

Manipulation Of Lipss Orientation On Silicon Surfaces Using Orthogonally Polarized Femtosecond Laser Double-Pulse Trains, Wei Liu, Lan Jiang, Weina Han, Jie Hu, Xiaowei Li, Ji Huang, Shenghua Zhan, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Laser-induced periodic surface structures (LIPSS) provide an easy and costeffective means of fabricating gratings and have been widely studied in recent decades. To overcome the challenge of orientation controllability, we developed a feasible and efficient method for manipulating the orientation of LIPSS in real time. Specifically, we used orthogonally polarized and equal-energy femtosecond laser (50 fs, 800 nm) double-pulse trains with time delay about 1ps, total peak laser fluence about 1.0 J/cm², laser repetition frequency at 100 Hz and scanning speed at 150 μm/s to manipulate the LIPSS orientation on silicon surfaces perpendicular to the scanning direction, regardless …

Growth Of Nitride Films, Yongfeng Lu, Hossein Rabiee Golgir, Yunshen Zhou

Department of Electrical and Computer Engineering: Faculty Publications

A gallium nitride thin film can be formed on a substrate at a low temperature (e.g., not higher than 600°C .) by applying a laser to resonantly excite molecules of a first precursor that contains nitrogen, in which the laser has a wavelength that is selected to match a vibration mode and/or a vibrational rotational mode of the molecules of the first precursor. A second precursor is provided in which the excited first precursor and the second precursor react to form a nitride that is deposited on the substrate. For example, the second precursor may include gallium, and the nitride …

Fabrication Of Highly Homogeneous And Controllable Nanogratings On Silicon Via Chemical Etching-Assisted Femtosecond Laser Modification, Ji Huang, Lan Jiang, Xiaowei Li, Andong Wang, Zhi Wang, Qingsong Wang, Jie Hu, Liangti Qu, Tianhong Cui, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Femtosecond laser direct writing is widely exploited in surface periodic structures processing. However, this technique still faces challenges in obtaining high surface homogeneity and flexible morphology controllability. In this study, a flexible and efficient approach has been proposed to fabricate highly homogeneous and controllable nanogratings on silicon via chemical etching-assisted femtosecond laser modification. By precisely manipulating the laser-material interaction process, alternating amorphous-crystalline nanofringes are generated when employing femtosecond laser scanning over a Si sample, with almost no material removal. Following auxiliary chemical etching, highly homogeneous nanograting structures are obtained, and the morphology of the nanogratings can be flexibly managed through …

Overview Of Extreme Manufacturing, Dongming Guo, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

Today we live in a new era of economic globalization and rapid technological growth. The advancement of both our society and standard of living require us to delve into this new world and unleash the possibilities our future. We need to broaden the horizons of our universe to discover a new realm where the future of humanity can flourish. We need to be unafraid to unveil the mysteries hidden within the depths of our oceans to unearth treasures that will benefit not only us, but the generations to come.

Effect Of Titanium And Zirconium Carbide Interphases On The Thermal Conductivity And Interfacial Heat Transfers In Copper/ Diamond Composite Materials, Clio Azina, Inaki Cornu, Jean-Francois Silvain, Yongfeng Lu, Jean-Luc Battaglia

Department of Electrical and Computer Engineering: Faculty Publications

Thermal properties of metal matrix composite materials are becoming ever more relevant with the increasing demand for thermally efficient materials. In this work, the thermal conductivity and heat transfers at the interfaces of copper matrix composite materials reinforced with diamond particles (Cu/D) are discussed. The composite materials contain either ZrC or TiC interphases and exhibit, respectively, higher and lower thermal conductivities with respect to their pure Cu/D counterparts. These thermal conductivities are accounted to the presence of strong covalent bonds and increased relative densities. The role of these interphases is also discussed regarding the phonon transmission at the interfaces.

A Novel Method Of Near-Miss Event Detection With Software Defined Radar In Improving Railyard Safety, Subharthi Banerjee, Jose Santos, Michael Hempel, Pejman Ghasemzadeh, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

Railyards are one of the most challenging and complex workplace environments in any industry. Railyard workers are constantly surrounded by dangerous moving objects, in a noisy environment where distractions can easily result in accidents or casualties. Throughout the years, yards have been contributing 20–30% of the total accidents that happen in railroads. Monitoring the railyard workspace to keep personnel safe from falls, slips, being struck by large object, etc. and preventing fatal accidents can be particularly challenging due to the sheer number of factors involved, such as the need to protect a large geographical space, the inherent dynamicity of the …

Self-Organized Twist-Heterostructures Via Aligned Van Der Waals Epitaxy And Solid-State Transformations, Peter Sutter, Rina Ibragimova, Hannu-Pekka Kosma, Bruce A. Parkinson, Eli A. Sutter

Department of Electrical and Computer Engineering: Faculty Publications

Vertical van der Waals (vdW) heterostructures of 2D crystals with defined interlayer twist are of interest for band-structure engineering via twist moiré superlattice potentials. To date, twist-heterostructures have been realized by micromechanical stacking. Direct synthesis is hindered by the tendency toward equilibrium stacking without interlayer twist. Here, we demonstrate that growing a 2D crystal with fixed azimuthal alignment to the substrate followed by transformation of this intermediate enables a potentially scalable synthesis of twisted heterostructures. Microscopy during growth of ultrathin orthorhombic SnS on trigonal SnS2 shows that vdW epitaxy yields azimuthal order even for non-isotypic 2D crystals. Excess sulfur drives …

The Next-Generation Retail Electricity Market In The Context Of Distributed Energy Resources: Vision And Integrating Framework, Josue Campos Do Prado, Wei Qiao, Liyan Qu, Julio Romero Aguero

Department of Electrical and Computer Engineering: Faculty Publications

The increasing adoption of distributed energy resources (DERs) and smart grid technologies (SGTs) by end-user retail customers is changing significantly both technical and economic operations in the distribution grid. The next-generation retail electricity market will promote decentralization, efficiency, and competitiveness by accommodating existing and new agents through new business models and transactive approaches in an advanced metering infrastructure (AMI). However, these changes will bring several technical challenges to be addressed in transmission and distribution systems. Considerable activities have been carried out worldwide to study the impacts of integrating DERs into the grid and in the wholesale electricity market. However, the …

The Temporal-Spatial Evolution Of Electron Dynamics Induced By Femtosecond Double Pulses, Changji Pan, Lan Jiang, Jingya Sun, Qingsong Wang, Feifei Wang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

The temporal and spatial electron dynamics were investigated under irradiation of temporally shaped femtosecond double pulses. Filament split was observed upon arrival of the second pulse, which was attributed to the emergence of transient high-reflective surface induced by the first pulse. The electron density analysis showed that the total deposition energy of double pulses case was generally higher than that of single pulse case. Particularly, the maximum deposition energy was obtained at 350 fs separation time of double pulses. The results of our experiment demonstrated optimization of energy deposition efficiency by temporally shaping laser pulses, which will benefit the fabrication …

Neutrophil Activation In Systemic Capillary Leak Syndrome (Clarkson Disease), Zhihui Xie, Douglas B. Kuhns, Xuesong Gu, Hasan H. Otu, Towia A. Libermann, John I. Gallin, Samir M. Parikh, Kirk M. Druey

Department of Electrical and Computer Engineering: Faculty Publications

Systemic capillary leak syndrome (SCLS; Clarkson disease) is a rare orphan disorder characterized by transient yet recurrent episodes of hypotension and peripheral oedema due to diffuse vascular leakage of fluids and proteins into soft tissues. Humoral mediators, cellular responses and genetic features accounting for the clinical phenotype of SCLS are virtually unknown. Here, we searched for factors altered in acute SCLS plasma relative to matched convalescent samples using multiplexed aptamer‐based proteomic screening. Relative amounts of 612 proteins were changed greater than twofold and 81 proteins were changed at least threefold. Among the most enriched proteins in acute SCLS plasma were …

Direct Observation Of Structure-Assisted Filament Splitting During Ultrafast Multiplepulse Laser Ablation, Feifei Wang, Changji Pan, Jingya Sun, Qingsong Wang, Yongfeng Lu, Lan Jiang

Department of Electrical and Computer Engineering: Faculty Publications

Laser-induced plasma evolution in fused silica through multipulse laser ablation was studied using pump-probe technology. Filament splitting was observed in the early stage of plasma evolution (before ~300 fs). This phenomenon can be attributed to competition between laser divergent propagation induced by a pre-pulse-induced crater and the nonlinear self-focusing effect. This effect was validated through simulation results. With the increasing pulse number, the appearance of filament peak electron density was postponed. Furthermore, a second peak in the filament and peak position separation were observed because of an optical path difference between the lasers propagating from the crater center and edge. …

Monitoring Aging Of Power Semiconductor Devices Based On Case Temperature, Wei Qiao, Ze Wang, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The aging of an electronic component in an electronic power converter can be monitored based on two or more case temperature measurements. A power electronic device is enclosed in a package having a baseplate, in which the power electronic device generates heat during operation and the baseplate transfers heat to a heat dissipating device or a cooling device. Sensors measure temperatures at first and second locations on a surface of the baseplate. A data processor calculates a value for a first parameter based on the temperatures at the first and second locations, in which the first parameter is indicative of …