Electrical and Computer Engineering Commons^™

Machine Learning Techniques For Network Analysis, Irfan Lateef

Dissertations

The network's size and the traffic on it are both increasing exponentially, making it difficult to look at its behavior holistically and address challenges by looking at link level behavior. It is possible that there are casual relationships between links of a network that are not directly connected and which may not be obvious to observe. The goal of this dissertation is to study and characterize the behavior of the entire network by using eigensubspace based techniques and apply them to network traffic engineering applications.

A new method that uses the joint time-frequency interpretation of eigensubspace representation for network statistics …

Iii-Nitride Nanostructures: Photonics And Memory Device Applications, Barsha Jain

Dissertations

III-nitride materials are extensively studied for various applications. Particularly, III-nitride-based light-emitting diodes (LEDs) have become the major component of the current solid-state lighting (SSL) technology. Current III-nitride-based phosphor-free white color LEDs (White LEDs) require an electron blocking layer (EBL) between the device active region and p-GaN to control the electron overflow from the active region, which has been identified as one of the primary reasons to adversely affect the hole injection process. In this dissertation, the effect of electronically coupled quantum well (QW) is investigated to reduce electron overflow in the InGaN/GaN dot-in-a-wire phosphor-free white LEDs and to improve the …

On Resource-Efficiency And Performance Optimization In Big Data Computing And Networking Using Machine Learning, Wuji Liu

Dissertations

Due to the rapid transition from traditional experiment-based approaches to large-scale, computational intensive simulations, next-generation scientific applications typically involve complex numerical modeling and extreme-scale simulations. Such model-based simulations oftentimes generate colossal amounts of data, which must be transferred over high-performance network (HPN) infrastructures to remote sites and analyzed against experimental or observation data on high-performance computing (HPC) facility. Optimizing the performance of both data transfer in HPN and simulation-based model development on HPC is critical to enabling and accelerating knowledge discovery and scientific innovation. However, such processes generally involve an enormous set of attributes including domain-specific model parameters, network transport …

Experimental And Computational Studies Of Functionalized Carbon Nanotubes For Use In Energy Storage Devices And Membranes, Emine S. Karaman

Dissertations

Electrolytes with good interfacial stability are a crucial component of any electrochemical device. The development of novel gel polymer electrolytes (GEs) with good interface stability and better manufacturability is important for the development of the next generation electrochemical devices. Gel electrolytes are hybrid electrolyte materials, combining benefits of both liquid and solid systems. Compared with liquid and solid electrolytes, GEs open new design opportunities and do not require rigorous encapsulation methods. In this dissertation, studies on functionalized carbon nanotubes (fCNTs) and graphene oxide (GO) doped polyvinyl alcohol (PVA) based gel electrolytes (GEs) are reported. The ionic conductivity and mechanical strength …

Scalable Scientific Data Management On High-Performance Computing Systems, Zhenbo Qiao

Dissertations

As high-performance computing (HPC) is being scaled up to exascale to accommodate new modeling and simulation needs, I/O has continued to be a major bottleneck in the end-to-end scientific processes. To bridge the widening gap between compute and I/O, and enable data to be more efficiently stored and analyzed, simulation outputs need to be refactored, reduced, and appropriately mapped to storage tiers. Also, a major question that the community is striving to answer is how to co-design data storage and complex physics-rich analytics in a way that the time to knowledge can be minimized in post-processing. As HPC storage systems …

Design And Learning-Based Decoding Of Low-Density-Parity-Check Codes For Multiterminal Communication, Salman Habib

Dissertations

The field of information theory was initiated by Claude Shannon in 1948. According to his most notable work, data can be transmitted reliably over a noisy communication channel with high probability, as long as a suitable coding scheme is employed to protect the data from channel noise. Since then, coding theorists have made numerous attempts to design low-complexity error correcting schemes which achieve the Shannon limit.

In the 1960s, Robert Gallager introduced sparse graph-based low-density-parity-check (LDPC) codes which are practically suitable for various coding applications, mainly due to their low encoding and decoding complexity compared to classical codes (e.g., Reed-Muller …

A New Two Switched-Impedance Network For High Ratio Quasi-Z-Source Inverter, Irham Fadlika, Mega Agustina, Rahmatullah Aji Prabowo, Misbahul Munir, Arif Nur Afandi

Elinvo (Electronics, Informatics, and Vocational Education)

The increasing demand and widespread of renewable energy inherently compel the development of power electronics converter as an interface between consumers and the energy source/s. This paper presents a new two switched-impedance networks qZSI converter called High Ratio Two Switched-impedance quasi-Z-Source Inverter (HR2SZ-qZSI). Compared with the previous topology, this proposed HR2SZ-qZSI topology can achieve higher voltage gain with lower shoot-through duty ratio, and a higher boost factor. This paper also discusses comparative analysis between the previous topology and the proposed HR2SZ-qZSI topology. Furthermore, the simulation and experimental data are presented to prove the theoretical analysis of the proposed HR2SZ-qZSI topology. …

Design And Implementation Of Real-Time Health Vital Sign Monitoring Device With Wireless Sensor-Based On Arduino Mega, Bekti Wulandari, Mentari Putri Jati

Elinvo (Electronics, Informatics, and Vocational Education)

This paper discusses the realization of vital sign monitoring devices and knowing their performance. This device is expected to assist medical personnel in measuring and monitoring vital signs without having to have physical contact with patients. The design phase of the patient's vital sign monitoring device with an Arduino Mega-based wireless sensor starts from the identification, needs analysis, design, manufacture, troubleshoot, and testing. Arduino Mega and ESP8266 as the main components that function for the controller and upload data to the server. Then MAX30100, DS18B20, and MPX5700AP sensors which function to detect the vital sign. Android smartphones are used to …

Flood Analysis And Hydraulic Competence Of Drainage Structures Along Addis Ababa Light Rail Transit, Moses Kiwanuka, Seleshi Yilma, Joel Webster Mbujje, John Bosco Niyomukiza

Journal of Environmental Science and Sustainable Development

The occurrence of flooding events and the associated risks are increasing in the urban areas of most developing countries. Flooding in any circumstance causes major stresses on affected area’s economic, social and environmental regimes. Therefore, the current study presents a flood analysis and hydraulic competence of existing drainage structures on some selected roads of Addis Ababa City, after integration with Addis Ababa Light Rail Transit (AALRT) Drainage Systems. The existing side drains and cross drainage structures located within the study area were inspected and assessed to ascertain different aspects relating to their performance. Different watersheds were delineated. Hydrological analysis was …

Stability Analysis Of Dc Microgrid With Constant Power Load, Sarah Ansari

Theses and Dissertations

Development towards sustainability has led to an increase in the integration of various distributed generation (DG) units like renewable sources of energy, energy storage systems (ESS). In order to counteract the challenges, caused due to integration of DG units into conventional power systems, the concept of DC microgrid (DCMG) has been introduced. DCMGs have power converters that are present on the source side and load side of the DCMGs. The power converters at the load side when tightly regulated behave as constant power loads (CPLs). There are stability issues pertaining to the inherent non-linear characteristic of the ideal CPLs because …

Optimal Design Of Hybrid Renewable Energy For Tanzania Rural Communities, Ester T Marcel, Joseph Mutale, Aviti T Mushi

Tanzania Journal of Science

Rural communities in developing countries lack access to electricity due to high costs of grid extension. This paper proposes a hybrid system of renewable energy (HRES) as solution. The HRES consists of solar, wind, and battery energy storage (BES). The village called Ngw’amkanga in Shinyanga region of Tanzania, East Africa is selected as a case study. An iterative method to determine the size of wind and solar photovoltaic (PV) generation required assuming a project life of 25 years at minimum annualised cost of the system ( ) is proposed. The project life time is fixed on the life span of …

Flexible Microfluidic Device With Nonplanar Interdigitated Microelectrodes, Saud Alssaidy

Theses

The lab-on-a-chip concept has improved significantly in recent years to meet global demand for various applications with the advent of new technologies. Much progress has been achieved, but many microfluidic devices still suffer from design limitations in terms of sensitivity and selectivity because they use rigid, fragile substrate materials and conventional electrodes, which do not provide high sensitivity or selectivity and suffer from signal-to-noise ratio issues. This work proposes a novel device architecture that uses flexible, transparent top and bottom layers integrated with (nonplanar interdigitated microelectrodes) to create a sandwich-like flexible substrate base. The top and bottom layers consist of …

Stress Classification Using Deep Learning With 1d Convolutional Neural Networks, Abdulrazak Yahya Saleh, Lau Khai Xian

Knowledge Engineering and Data Science

Stress has been a major problem impacting people in various ways, and it gets serious every day. Identifying whether someone is suffering from stress is crucial before it becomes a severe illness. Artificial Intelligence (AI) interprets external data, learns from such data, and uses the learning to achieve specific goals and tasks. Deep Learning (DL) has created an impact in the field of Artificial Intelligence as it can perform tasks with high accuracy. Therefore, the primary purpose of this paper is to evaluate the performance of 1D Convolutional Neural Networks (1D CNNs) for stress classification. A Psychophysiological stress (PS) dataset …

Method And Methods For Determining Shapes And Sizes Of Solar Dryer Elements, Sh M. Mirzaev, J R. Kodirov, S S. Ibragimov

Scientific-technical journal

This article presents the calculation of the drying plant, the shape of which is a parallelepiped with non-isosceles triangular bases. Concepts were selected, on the basis of which a computational computational method was developed and the geometric dimensions of the elements of a direct type dryer were determined. The formula for the ratio of the dimensions of the height to the length and, accordingly, to the width of the dryer has been established, and a method has been developed for determining the dimensions of the dampers intended for the flow of air from the environment into the chamber and for …

Influence Of Heat Treatment Time On Cathode Material Cr8O21 For Lithium Battery, Jiu-Kang Teng, Qing-Jie Wang, Liang Zhang, Hong-Mei Zhang, Xiao-Tao Chen, Peng Zhang, Jin-Bao Zhao

Journal of Electrochemistry

Chromium oxide (Cr₈O₂₁) cathode material for lithium batteries was synthesized by thermal decomposition of chromium trioxide (CrO₃) at high temperature. The electrochemical properties of chromium oxide depended on the time and temperature during the heat treatment. Pure phase chromium oxide was prepared, and the effects of heat treatment time on the structures and electrochemical properties of Cr₈O₂₁ were systematically studied. The first discharge mechanism of chromium oxide in lithium batteries was explored, and the results were similar to that in lithium-sulfur batteries. The crystal phases and electrochemical properties of the prepared …

Nitrogen-Sulfur Co-Doped Porous Carbon Preparation And Its Application In Lithium-Sulfur Batteries, Gui-Xiang Zhao, Wail Hafiz Zaki Ahmed, Fu-Liang Zhu

Journal of Electrochemistry

In recent years, lithium-sulfur (Li-S) batteries have been considered as a promising candidate for the next generation of energy storage system due to their ultrahigh theoretical capacity (1675 mAh·g^-1) and energy density (2600 Wh·kg^-1). However, the practical application of Li-S batteries is seriously limited by their insulating nature of sulfur, the shuttle effect of polysulfides (LiPSs), and volume expansion during charging and discharging. To overcome those disadvantages, one of the commonly methods is to infiltrate sulfur into porous conductive carbon framework, such as porous carbon, hollow carbon spheres, graphene, carbon nanotubes and some composites of the …

Formation And Morphological Evolution Of Nanoporous Anodized Iron Oxide Films, Jin-Wei Cao, Nan Gao, Zhao-Qing Gao, Chen Wang, Sheng-Yan Shang, Yun-Peng Wang, Hai-Tao Ma

Journal of Electrochemistry

The preparation of iron oxide films with nanoporous structure by anodization has attracted much attention for its potential applications. However, the formation mechanism of porous structure during anodization is still unclear. In this paper, the composition of anodic current during the formation of nanoporous anodized iron oxide film was analyzed in combination with the current density-potential response (I-V curve) and the derivation of Faraday’s law. The results showed that the anodic current consisted of an ionic current (leading to the migration of ions to form oxide) and an electronic current (leading to the oxygen evolution), and the …

Photoelectrochemical Sensing Based On Zr-Mofs For Homocysteine Detection, Wen-Xia Dong, Guang-Ming Wen, Bin Liu, Zhong-Ping Li

Journal of Electrochemistry

Due to the independent form of the light source and detection system, photoelectrochemical (PEC) sensor has the advantages of low background, high sensitivity and simple operation. So far, PEC systems have been widely used in the fields including the actual detection of metal ions, biological antibodies or antigens in environmental pollutants. When the photosensitive material is irradiated by a light source with an energy being equal to or greater than its band gap, electrons (e^-) transition occurs from the valence band to the conduction band, leaving a hole (h⁺), at the same time, the generated electron-hole …

Functional Sulfate Electrolytes Enable The Enhanced Cycling Stability Of Nati2(Po4)3/C Anode Material For Aqueous Sodium-Ion Batteries, Shu-Jin Li, Zhi-Kang Cao, Wen-Kai Wang, Xiao-Han Zhang, Xing-De Xiang

Journal of Electrochemistry

Aqueous sodium-ion batteries show promising application in fields of large-scale storage of intermittent renewable energies owing to the earth-abundant sodium resources and incombustible aqueous electrolytes. Primary factors determining whether they can be commercially utilized are low cost and long lifetime. Among current electrode materials, NASICON-type NaTi₂(PO₄)₃ arouses wide interests as an anode material for aqueous sodium-ion batteries as it offers a high specific capacity, fast Na-transport ability and reasonable working potential, however, suffering from insufficient cycling performance caused by severe dissolution of active materials in traditional aqueous electrolytes. In this work, a functional sulfate electrolyte …

Effect Of Glycol Based Coolant Pollution On Pem Fuel Cells Stack And Recovery Measures, Cong-Yi Zhu, Xiao-Hui Li, Quan-Quan Gan

Journal of Electrochemistry

As the heat conduction medium of fuel cell cooling system, coolant is very important for the thermal management of fuel cell stack. In practical application, coolant leakage into the stack often occurs. Due to the randomness of fault location of components, the location of coolant leakage is uncertain, which may occur on the cathode side or anode side of some or all single cells. The main effects of coolant pollution on fuel cell stack are as follows: the output of open circuit voltage decreases sharply, the consistency of single cells voltage decreases and so on, which seriously affects the normal …

Structure Analysis Of Pemfc Cathode Catalyst Layer, Rui-Qing Wang, Sheng Sui

Journal of Electrochemistry

The sluggish oxygen reduction reaction (ORR) on the cathode of the proton exchange membrane fuel cell (PEMFC) has always been one of the key factors limiting its commercialization. The optimization of the cathode catalytic layer structure plays an important role in improving fuel cell performance and reducing production costs. In this paper, two different catalysts (platinum nanoparticles (Pt-NPs) and platinum nanowires (Pt-NWs)) were prepared by using catalyst coated substrate (CCS) method. By constructing a double-layer catalytic layer structure, we analyzed the effect of different catalytic layer structures by performing a single cell test. The results showed that the dense platinum …

Copper Nanoparticles In-Situ Anchored On Nitrogen-Doped Carbon For High-Efficiency Oxygen Reduction Reaction Electrocatalyst, Hui-Fang Yuan, Yue Zhang, Xing-Wu Zhai, Li-Bing Hu, Gui-Xian Ge, Gang Wang, Feng Yu, Bin Dai

Journal of Electrochemistry

Compared with noble metal platinum (Pt)-based catalysts, inexpensive non-noble metal electrocatalysts have attracted extensive attention for oxygen reduction reaction (ORR). Herein, chitosan as a kind of biomass resource rich in nitrogen and carbon was used to prepare nitrogen-doped carbon (N-C) and N-C in-situ anchored by copper nanoparticles (Cu/N-C). The as-obtained N-C and Cu/N-C nanoparticles were successfully used as non-noble eletrocatalysts tested for ORR. Compared with the N-C, the Cu/N-C showed the high surface area of 607.3 m ²·g^-1 with the mean pore size of 2.5 nm and the pore volume of 0.40 cm³·g^{-1 …}

Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun

Journal of Electrochemistry

Lithium-ion batteries (LIBs) are among the most widely used energy storage devices. Whole-cell modeling and simulations of LIBs can optimize the design of batteries with lower costs and higher speeds. The Pseudo-Two-Dimensional (P2D) electrochemical model is among the most famous whole-cell models and widely applied in LIB simulations. P2D model consists of a series of kinetic equations to model Li⁺/Li diffusion in working/counter electrodes and electrolytes, which are filled in the porous electrodes and separator, and reactions at the interface of electrolyte and active particles. The traditional applications of P2D model, however, are limited to the cases where …

Imitation Models Of The Railway Organization For Railway Transport Flows, J Usmonov, T Djuraev

Technical science and innovation

Considered the questions of solving the problem of optimization of cargo traffic management in the railway transport throughout the logistics chain, organizing the formation and implementation of cargo loading plans that do not allow exceeding the maximum and reduce the minimum levels of availability of a particular cargo on the destination road. And also the article justifies the solution of the problem of finding the maximum flow in the railway network, it is noted that in any transport network the maximum flow is equal to the minimum capacity. If the flow is maximal, then there is a section whose transmission …

Evaluation Of The Thickness Of Vacuum Metal And Semiconductor Coatings Using Computer Programs, Bahrom Igamov, Ilkhom Bekpulatov, Aleksey Kamardin, Tulkun Kamilov, Ilhom Turapov, D Igamova

Technical science and innovation

Comparative studies of the thickness of coatings of such metals as Cu, Ag, Cr, Co, and also Mn4 Si7 on polished substrates made of Si, Si O2 / Si structure, ST - 50 glass ceramic, mica were carried out. The coatings were deposited in vacuum using thermal evaporation and magnetron sputtering. The thickness and uniformity of deposited coatings on rotating substrates are estimated by optical measurements and computer simulation. Mathematical models for the formation of coatings on flat substrates have been developed. The possibility of the optimal position of the substrate for the formation of functional coatings uniform in thickness …

Machine Learning Based Critical Resource Allocation In Mixed-Traffic Cellular Networks, Mohamed Nomeir

Theses and Dissertations

The proliferation of cellular networks over the past two decades has encouraged the expansion of their use in many modern applications. These applications involve the use of data traffic of different quality of service (QoS) requirements. Some of these requirements are quite stringent such as in the case of critical Internet of Things (IoT) health care, military and homeland security applications. This situation resulted in imposing a variety of resource allocation requirements on the cellular network operation in a simultaneous manner.

In this thesis, we consider the challenging problem of mixed-traffic resource allocation, or scheduling, in cellular networks. We focus …

Predictive Analysis And Synthesis, Modeling And Control Of Complex Technological Processes And Systems, Zhahongir Sherboyevich Bekqulov

Chemical Technology, Control and Management

Consider the theoretical underpinnings of practically predictive analysis and synthesis, modeling and automatic control of complex chemical technological processes and systems, and the evolution of advanced (or advanced) APC (Advanced Process Control) control of technological processes and industries. The current state of industrial automation systems and the characteristics of their deployment are highlighted. The features of each stage of the analysis and synthesis of APC - advanced process control for complex dynamic objects are disclosed. The real situation and features of the implementation of industrial automation systems of industrial enterprises are reflected.

Virtual Analyzers For Increasing The Intelligence Of Industrial Process Control Systems, Umidjon Abdimajotovich Ruziev Phd, Marufjon Kobuljanovich Shodiev

Chemical Technology, Control and Management

It is shown that the development and implementation of virtual analyzers of the quality of the final industrial products is an effective tool for increasing the efficiency of industrial production. The methodology and stages of development of virtual analyzers for predicting the quality of products, monitoring non-measurable or difficult-to-measure parameters of continuous and periodic technological processes are considered, and issues of supporting and adapting a virtual analyzer during its operation without restructuring are also considered.

Algorithm For Calculating The Parameters Of A Multi-Position Electromagnetic Linear Mechatronic Module, Nazarov Khayriddin Nuritdinovich, Matyokubov Nurbek Rustamovich, Temurbek Omonboyevich Rakhimov

Chemical Technology, Control and Management

Currently, in the world in the field of science, engineering and technology, including in mechatronics and robotics, the creation of multi-coordinate mechatronic systems that perform power and control functions is becoming of paramount importance, this is due to a number of important positive qualities of the systems, such as simplicity and compactness of the design, the possibility of obtaining significant efforts, high accuracy and stability of the establishment of fixed positions, ease of control and high reliability. This article presents the calculation of the parameters of multi-position mechatronic modules based on linear execution elements. In the construction of this model, …

New Transformer Changer Static Characteristics Measuring Angle Silences Difference, Sultan Faizullayevich Аmirov, Nurulla Raxmatullayevich Yuldashev

Chemical Technology, Control and Management

Presented the specific features of the new transformer converter, which measures the difference in angular displacement, and examines the nonlinearity levels of static characteristics, sensitivity and static characteristics. Studies have shown that in a new measuring device, where one of the two moving parts consists of a magnetic conductor made in the form of an Archimedean spiral made of ferromagnetic material, the balance of the magnetic bridge changes not only depending on the angle of rotation of it’s shoulder resistances. the current is disturbed by the change in the magnitude of the combined air gap depending on the angle of …