PhD Thesis

Ph.D. Thesis

Serkan Özdemir, Development of a Decision-Support Tool for Managing Drinking Water Reservoir by Using Machine Learning and Deep Learning Methods

Global climate change induces lake level fluctuations, impacted by evolving meteorological factors and water use. Input or output changes swiftly affect the water balance equation. This study explores predictive models for climatic and hydrologic variables, assessing their correlations with lake water level and water quality. Using diverse algorithms—Naive Method, ANN, and RNN—LSTM excels in accuracy by RMSE. Comparisons with the Naïve Method confirm ANN and RNN predictive prowess, especially with extended horizons. Correlations with temperature and evaporation highlight lake water quality impacts. Models and metrics construct a decision support tool for water managers.

Date: 19.12.2023 / 13:30 Place: A-212

English

Burak Demiralay, Efficient Primer Design for Genotype and Subtype Detection of Highly Divergent Viruses in Large Scale Genome Datasets

We developed an efficient and scalable method for identification of signature sequences that can handle thousands of whole genomes for organisms with high mutation rates and genetic diversity. Thermodynamics is the main driving force in our method, which is tested on three highly divergent viruses. The oligonucleotides found can identify 99.9% of 1657 HCV genomes, 99.7% of 11838 HIV genomes, and 95.4% of 4016 Dengue genomes. We also show subspecies identification on genotypes 1-6 of HCV and genotypes 1-4 of the Dengue virus with >99.5% true positive and <0.05% false positive rate. None of the state-of-the-art methods achieve this performance.

Date: 11.09.2023 / 17:00 Place: A-212

English

Mine Yoldaş Orhon, MutEXP: A Tool to Identify SNPs That Affect Gene Expression

Most of the variants in the genome are at the non-coding region. While variations in the coding region effect the protein, variations in non-coding region effect the regulatory mechanism. Therefore, observation of non-coding variations may ensure to identify variations that effect gene expression. eQTL is a popular method used for the purpose to determine the SNPs that effect the gene expression. We have implemented a python based, easy-to-use tool to understand the relationship between the somatic SNPs and gene expression based on eQTL analysis.

Date: 11.09.2023 / 14:00 Place: A-212

English

Kerem Alp Usal, Neural Mechanisms Underlying Joint Action

In this study, changes in neural activation during joint action were investigated with hyperscanning, using functional near infrared spectroscopy (fNIRS) and electroencephalography (EEG) as participants performed the same task individually and then collaborated as a dyad. 62 participants were tested in dyads with a dual n-back task. Results are in support of the social facilitation model, and neural measures including hyperscanning were successful to differentiate between individual and social task settings. Overall, this study is one of the first studies to conduct EEG and fNIRS-hyperscanning during a complex collaboration task that brought together temporal constraints and elements of visuospatial reasoning.

Date: 05.09.2023 / 11:00 Place: A-212

English

Murat Koçak, Bibliometric Analysis of Functional Near-Infrared Spectroscopy (Fnirs) in Neuroimaging

This study aims to provide a bibliometric map of Functional Near Infrared Spectroscopy (fNIRS), a growing research area worldwide, in terms of interdisciplinary and institutional collaboration. Interdisciplinary and institutional collaborations are increasingly encouraged by universities as they have a high academic citation impact. In this study, the number of articles, number of citations, CNCI and IREW percentage in the field of fNIRS from 1980 to 2020 were analysed. Interdisciplinary and university & country collaborations that can increase these academic indicators are analysed from a bibliometric perspective.

Date: 11.09.2023 / 10:30 Place: -

English

Serap Yağmur, Investigating The Impact of Selective Directional Auditory Attention on Eye Movements, Pupil Responses, and Auditory Perception in The Presence of Competing Speech

This PhD thesis delves into the impact of selective directional auditory attention on eye movements and pupil responses. Concentrating on single-ear stimuli is shown to enhance attentiveness and task performance. The research explores effects of multi-talker speech interference, age, gender, and audio direction on eye movements and pupil dilation. Notably, interference influences pupils, prompting gaze shifts toward sound sources and larger pupils during competing speakers. This underscores the study's significance. These findings highlight the value of eye movement patterns and pupillometry in understanding auditory attention nuances. The implications are profound, benefiting hearing aid technology, communication for autism spectrum disorder and hearing-impaired individuals. The study also uncovers links between speech quality, word familiarity, and emotional connotations on pupil responses, contributing to a comprehensive comprehension of auditory processes.

Date: 06.09.2023 / 10:00 Place: A-212

English

Murat Yılmaz, Implementation of An Onboard Acoustic Gunshot Detection & Localization System on Unmanned Air Vehicles: Realization, Measurements and Performance Enhancement

This study aims for detection and DOA estimation of gunshot sound onboard a drone, despite the excessive ego-noise. Array Correlation Map concept is introduced for improved detection through unanimity among sensors of an array. Also, adaptive auto-tuning to advantegous CWT scales brings adaptive denoising for transient events of varying frequency. Although studied specifically for the processing of gunshot sounds on drones, the novelties this study offers is expected to generalize to other array processing applications. Results reveal signal-to-noise-ratio enhancement, successful muzzle and shock wave signal detection, and DOA estimation performance improvement.

Date: 04.09.2023 / 10:00 Place: A-212

English

Melike Çağlayan, Allosteric Regulation in Proteins Through Residue-Residue Contact Networks

A new method has been developed to study allosteric protein regulation, which is important for understanding how proteins function. The method represents proteins as networks and identifies allosteric pathways, or sites where molecules bind and regulate protein activity, in order to predict the presence and location of allosteric regions. This could potentially aid in the development of targeted therapies.

Date: 28.07.2023 / 10:00 Place: A-212

English

Ayhan Serkan Şık, A Conceptual Design for Genetic Information Exchange Coding Standards in Türkiye

In Türkiye, Social Security Institution is the primary healthcare insurer. Turkish citizens are registered under General Medicare Insurance coverage. In 2003, Ministry of Health (MoH) has initiated the “Health Transformation Program”, and implemented the interoperable health data exchange standards. The MoH is focusing on collecting medical data in a coded, structured, and electronic format, generated at all healthcare providers. Contrarily, genetic test results are exchanged in narrative, unstructured form among governmental and private health care providers. In this dissertation, we lay out the bottlenecks and put forward a conceptual model for meaningful genomic data exchange for Turkish Electronic Health Records.

Date: 24.07.2023 / 17:00 Place: A-108

English

Utku Can Kunter, A Bayesian Model of Turkish Derivational Morphology

Building on an extensive review of the psycholinguistics literature and Turkish Derivational Morphology (DM), we propose a novel structure for representing DM in three hierarchical layers: segmentation, lexical selection and derivation. This proposal involves laying a conventionalized structure over the traditional morphological structure of DM. We develop a computational model of morphology processing based on this structure using Bayesian Belief Networks (BBN). We present an algorithmic implementation for this model that learns and accurately represents new lexical items, recognizes affixes and tracks the salience of each item probabilistically. We carry out trials on this model with realistic observation lists and observe that model predictions are in line with the findings in studies in psycholinguistics.

Date: 21.07.2023 / 11:30 Place: A-212

English

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