207 Works

Applications of Graph Convolutional Networks and DeepGCNs in Point Cloud Part Segmentation and Upsampling

Abdulellah Abualshour
Graph convolutional networks (GCNs) showed promising results in learning from point cloud data. Applications of GCNs include point cloud classification, point cloud segmentation, point cloud upsampling, and more. Recently, the introduction of Deep Graph Convolutional Networks (DeepGCNs) allowed GCNs to go deeper, and thus resulted in better graph learning while avoiding the vanishing gradient problem in GCNs. By adapting impactful methods from convolutional neural networks (CNNs) such as residual connections, dense connections, and dilated convolutions,...

An Experimental Investigation on the Dynamics of Lean Premixed Swirl Flames

Francesco Di Sabatino
Gas turbine engines are an efficient and flexible way of power generation and aircraft propulsion. Even though different combustion systems can be implemented in these engines, more stringent regulations on pollutant emissions have been imposed throughout the years, especially in regard to nitrogen oxides (NOx). A very promising technology to reduce NOx emissions is lean premixed combustion (LPC), however, it is plagued by intense flame dynamics. Thermoacoustic instabilities, lean blow-off and lean instabilities are examples...

Distribution, diversity, and anemonefish associations of host sea anemones (Actiniaria) in the eastern Red Sea

Morgan Bennett-Smith
The relationship between clownfish and sea anemones is a beloved and iconic example of marine symbiosis. However, ecological information in the eastern Red Sea about the endemic Red Sea clownfish, Amphiprion bicinctus, and its host sea anemones remains relatively incomplete. For example, previous studies report that A. bicinctus forms mutualistic relationships with three to five host anemone species in the Red Sea. But the reported number and combination of host anemone species varies substantially among...

Evaluating the Application of Allele Frequency in the Saudi Population Variant Detection

Sakhaa Alsaedi
Human Mendelian disease in Saudi Arabia is both significant and challenging. Next-generation sequencing (NGS) has resulted in important discoveries of the genetic variants responsible for inherited disease. However, the success of clinical genomics using NGS requires accurate and consistent identification of rare genome variants. Rarity is one very important criterion for pathogenicity. Here we describe a model to detect variants by analyzing allele frequencies of a Saudi population. This work will enhance the opportunity to...

Fabrication and Characterization of GaN-Based Superluminescent Diode for Solid-State Lighting and Visible Light Communication

Abdullah Alatawi
To date, group-III-nitride has undergone continuous improvements to provide a broader range of industrial applications, such as solid-state lighting (SSL), visible light communications (VLC), and light projection. Recently, VLC has attained substantial attention in the field of wireless communication because it offers ~ 370 THz of bandwidth of unregulated visible spectrum, which makes it a critical factor in the evolution of the 5G networks and beyond. GaN-based light-emitting diode (LED) and laser diode (LD) have...

Exploring the Role of Glutamate Signaling in the Regulation of the Aiptasia-Symbiodiniaceae Symbiosis

Migle Konciute
The symbiotic relationship between cnidarians and their photosynthetic dinoflagellate symbionts underpins the success of coral reef communities in oligotrophic, tropical seas. Despite several decades of study, the cellular and molecular mechanisms that regulate the symbiotic relationship between the dinoflagellate algae and the coral hosts are still not clear. One of the hypotheses on the metabolic interactions between the host and the symbiont suggests that ammonium assimilation by the host can be the underlying mechanism of...


Jefferson Riera
I would like to express my sincerest gratitude to Professor Omar M. Knio for his guidance and support over the past two years. Thank you for providing me important feedback when developing our models and writing the thesis. Many thanks to Dr. Ricardo M. Lima for his advice and constant encouragement. His expertise in the technical and mathematical aspects of this work proved vital. Working together was truly an enriching experience. I appreciate the support...

Energy-Efficient AF Relay Assisted OFDM with Index Modulation

Jiusi Zhou
To broaden the application scenario and reduce energy consumption, we propose an energy-efficient fixed-gain (FG) amplify-and-forward (AF) relay assisted orthog- onal frequency-division multiplexing with index modulation (OFDM-IM) scheme in this thesis. The proposed system needs neither instantaneous channel state informa- tion (CSI) nor performing complicated processing at the relay node. It operates based on a new design of power allocation that minimizes the sum of transmit power at both source and relay node, given an...


Sebastian Celis Sierra

Optimal Control Strategies for the Alignment Problem of Optical Communication Systems

Wenqi Cai
In this work, we propose three control strategies from different perspectives to solve the alignment problem for different optical wireless communication (OWC) systems. • Experimental modeling based strategy: we model and analyze the vibration effects on the stationary OWC system (e.g. urban free-space optical (FSO) communication system in our case). The proposed Bifurcated-Gaussian (B-G) distribution model of the receiver optical power is derived under different vibra- tion levels and link distances using the nonlinear iteration...

Crosstalk Cancellation in Structured Light Free Space Optical Communication

Dmitrii Briantcev
Free-space optics (FSO) is an unlicensed communication technology that uses the free space as a propagation medium to connect two communicating terminal wire- lessly [1]. It is an attractive solution to the last-mile connectivity problems in commu- nication networks, mainly when installing optical fibers is expensive or unavailable. A possible idea to increase the throughput of wireless optical links in free space is to use spatial multiplexing (SMM) [2]. Optical beam distortion due to propagation...

Contributions to the semi-classical signal analysis method: The arterial stiffness assessment case study

Evangelos Piliouras
Semi-classical signal analysis (SCSA) is a signal representation framework based on quantum mechanics principles and the inverse scattering transform. The signal of interest is decom- posed in a linear combination of the Schrodinger operator squared eigenfunctions, influenced by the semi-classical parameter. The framework has been utilized in several applications, in virtue of the adaptivity and localization of its components. In this thesis, we expand two direc- tions. From the theoretical perspective, up to date, the...

Rejection of Organic Micropollutants by Nanofiltration and Reverse Osmosis Membranes

Emmanuel Alonso
Abstract: The worldwide consumption of pharmaceuticals and personal care products for healthcare purposes has resulted in the occurrence of organic micropollutants (OMPs) in freshwater and wastewater resources. These pollutants are not entirely removed by conventional water and wastewater treatment plants, leading to potential human and animal health problems. Membranes are a promising technology capable of solving this problem. This study evaluated the ability of high-pressure driven membranes such as nanofiltration (NF) and reverse osmosis (RO)...

Percolation Theory-Analysis of Malware Epidemics in Large-Scale Wireless Networks

Ainur Zhaikhan
The foreseen massive deployment of the internet of things (IoT) is expected to suffer from high security risks. This mainly results from the difficulty to monitor and cure the IoT devices in such large-scale deployment. In this thesis, we propose a spatial random deployment of special nodes (firewalls) which can detect and cure infected nodes within certain radius. An important concern is to add sufficient number of firewalls to make an epidemics finite and, hence,...

Analyzing Germline-Specific Expression in Caenorhabditis elegans

Samar Alkoblan
Maintaining cells in an undifferentiated totipotent state is essential for initiating developmental programs that lead to a fully formed organism in each generation and for maintaining immortal germ cells across generations. Caenorhabditis elegans is a powerful genetic model organism to study early germ cell development due to the animal’s transparency and the ability to screen for mutant phenotypes. However, our ability to use standard techniques to study gene expression using fluorescent reporter genes has been...

Machine Learning to Predict Entropy and Heat Capacity of Hydrocarbons

Mohammed Aldosari
Chemical substances are essential to all aspects of human life, and understanding their properties is essential for effective application. The properties of chemical species are usually measured by experimentation or computational calculation using theoretical methods. In this work, machine learning models (ML) for predicting entropy, S, and heat capacity, cp, were developed for alkanes, alkenes, and alkynes at 298.15 K. The data for entropy and heat capacity were collected from various sources. Commercial software (alvaDesc)...

Contact Angle Hysteresis: Implications for Fluid Flow

Cristhian F. Andrade
Contact angle behavior controls the spreading, sticking, or movement of fluid droplets on top of solid substrates, and the immiscible displacement of mixed fluids in porous media. Therefore, it influences applications such as oil recovery, CO2 geological storage, water transport in unsaturated soils, and DNAPL soil remediation techniques. The attraction forces and geometrical-molecular arrangement at the atomic scale define the strength of the interfacial tension that changes in response to changes in temperature, pressure, or...

Dynamics of heterotrophic bacterioplankton in costal ecosystems of the central Red Sea

Luis Silva
Heterotrophic bacterioplankton dynamics have seldom been assessed in the Red Sea, an exceptionally warm oligotrophic basin, which could be used as a model for the future ocean. To understand the function of heterotrophic bacteria in biogeochemical cycles and the flows of matter and energy to higher trophic levels, it is peremptory to understand how bacterial growth is controlled. Bottom-up (resources availability), top-down (mortality by predators and viruses) and temperature are the main hypotheses of control...

The Rootstock-Scion Combination Drives Microorganisms’ Selection and Recruitment in Grapevine Rhizosphere

Hend Alturkey
In the last decade, several studies demonstrated that plants have developed a tight partnership with the edaphic microbial communities, mainly bacteria, fungi, and archaea. Such microbiome accomplishes essential functions and ecological services complementary to the functions encoded by the host plant, conferring adaptive advantages to the plant, particularly during stressful conditions. The interaction between microbial communities and their host plants in the natural ecosystem are complex and the mechanisms regulating these mutualistic associations are not...

A Comparative DNA Binding Study of the Human MAPK ERK2 and the Plant MAPK MPK4

Siba I. Alharbi
Mitogen-activated protein kinases (MAPKs) are an important subfamily of protein kinases that are well conserved in all eukaryotes. MAPKs are the final component of a three-tiered signaling module that regulates the activation of various essential cellular responses. They activate most of their substrates through catalyzing their phosphorylation. However, emerging evidence reveals that some MAPKs also possess non-catalytic functions. In particular, the human MAPK ERK2 can bind to DNA directly and mediate gene expression. The mechanism...

Machine Learning Models for Biomedical Ontology Integration and Analysis

Fatima Z. Smaili
Biological knowledge is widely represented in the form of ontologies and ontology-based annotations. Biomedical ontologies describe known phenomena in biology using formal axioms, and the annotations associate an entity (e.g. genes, diseases, chemicals, etc.) with a set of biological concepts. In addition to formally structured axioms, ontologies contain meta-data in the form of annotation properties expressed mostly in natural language which provide valuable pieces of information that characterize ontology concepts. The structure and information contained...

The Umklapp Scattering and Spin Mixing Conductance in Collinear Antiferromagnets

Nisreen Alshehri
Antiferromagnetic spintronics is a new promising field in applied magnetism. Antiferromagnetic materials display a staggered arrangement of magnetic moments so that they exhibit no overall magnetization while possessing a local magnetic order. Unlike ferromagnets that possess a homogeneous magnetic order, the spin-dependent phenomena occur locally upon the interaction between the itinerant electron and the localized magnetic moments. In fact, unique spin transport properties such as anisotropic magnetoresistance, anomalous Hall effect, magnetooptical Kerr effect, spin transfer...

Photophysical Processes in Lead Halide Perovskite Solar Cells Revealed by Ultrafast Spectroscopy

Esma Ugur
Metal halide perovskites have emerged as photoactive materials in solution-processed devices thanks to their unique properties such as high absorption coefficient, sharp absorption edge, long carrier diffusion lengths, and tunable bandgap, together with ease of fabrication. The single-junction perovskite solar cells have reached power conversion efficiencies of more than 25%. Although the efficiency of perovskite devices has increased tremendously in a very short time, the efficiency is still limited by carrier recombination at defects and...

Halide Perovskites: Materials Properties and Emerging Applications

Mohammed Haque
Semiconducting materials have emerged as the cornerstone of modern electronics owing to their extensive device applications. There is a continuous quest to find cost-effective and low-temperature compatible materials for future electronics. The recent reemergence of solution processable halide perovskites have taken the optoelectronics research to new paradigms. Apart from photovoltaics, the versatile characteristics of halide perovskites have resulted in a multitude of applications. This dissertation focuses on various properties and emerging applications particularly, photodetection and...

Learning from Scholarly Attributed Graphs for Scientific Discovery

Uchenna Thankgod Akujuobi
Research and experimentation in various scientific fields are based on the knowledge and ideas from scholarly literature. The advancement of research and development has, thus, strengthened the importance of literary analysis and understanding. However, in recent years, researchers have been facing massive scholarly documents published at an exponentially increasing rate. Analyzing this vast number of publications is far beyond the capability of individual researchers. This dissertation is motivated by the need for large scale analyses...

Registration Year

  • 2020

Resource Types

  • Dissertation


  • King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia