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Automated Cecum Identification In Colonoscopy Using Deep Learning Approach, Kittipoom Sutthinuntakorn
Automated Cecum Identification In Colonoscopy Using Deep Learning Approach, Kittipoom Sutthinuntakorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Colonoscopy is essential for the early detection and prevention of colorectal cancer. Identifying the cecum is a vital element of this process. However, most existing automated methods rely on still images or temporal cues alone, without incorporating camera motion awareness, and are rarely suitable for real-time use. In this paper, we present a real-time cecum detection method that integrates spatial features, temporal modeling, and camera motion cues. We deploy ConvNeXtV2 for spatial feature extraction, LTContext for temporal modeling, and Depth Anything in Robotic Endoscopic Surgery (DARES) to enhance understanding of endoscope positioning and camera motion. The dataset used in this …
Evacuation Plan Assessment Using Agent-Based Simulation: A Case Of Mix-Use Building, Peerada Tangprasert
Evacuation Plan Assessment Using Agent-Based Simulation: A Case Of Mix-Use Building, Peerada Tangprasert
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigates the effectiveness of fire evacuation plan in complex urban structures by developing an agent-based simulation (ABS) model tailored to a high-rise, mixed-use case building located in Bangkok, Thailand. As urban populations grow and multi-functional buildings become more prevalent, ensuring efficient evacuation during fire emergencies has become increasingly critical. The selected case building features a combination of commercial, retail, and public transit access points, making it representative of modern urban infrastructure with high pedestrian traffic and structural complexity. The simulation model incorporates key factors influencing evacuation performance, including walking speed, age demographics, and crowd density. Empirical data such …
Craftjai: Llm-Enhanced Generative Ai For Gamified Mood Journal, Kingrak Phairoh
Craftjai: Llm-Enhanced Generative Ai For Gamified Mood Journal, Kingrak Phairoh
Chulalongkorn University Theses and Dissertations (Chula ETD)
Mood journaling helps promote emotional self-awareness, but maintaining user motivation remains difficult. This study presents CRAFTJAI, a generative AI system that enhances journaling through emotionally aligned visual feedback. Instead of replacing diary entries, the system adds character-based imagery to support intrinsic motivation and symbolic emotional reflection. It consists of emotional feature extraction using a large language model, emotion-labeled dataset construction based on eight core moods, and LoRA fine-tuning of a diffusion-based text-to-image model to improve emotional fidelity and stylistic consistency. A web-based prototype was developed with Gradio for real-time evaluation. Drawing on gamification and self-determination theory, the system integrates emotional …
Graphene Quantum Dot Spray-Coated Indium Tin Oxide Electrode For Fe3+ Detection, Firadao Bennui
Graphene Quantum Dot Spray-Coated Indium Tin Oxide Electrode For Fe3+ Detection, Firadao Bennui
Chulalongkorn University Theses and Dissertations (Chula ETD)
Ferric ion (Fe3+) contamination in water sources poses significant risks, making reliable detection technologies essential. In this study, electrochemical sensors were developed by spray-coating Graphene quantum dots (GQDs) on indium tin oxide (ITO) electrodes to enhance Fe3+ detection in aqueous systems. The performance of Assembly GQDs and GQDs on ITO electrodes was compared, and the electrochemical sensing of Fe3+ was investigated. GC-358 exhibited a 3D structure with aggregated particles and high electroconductivity, while CLS-3 showed a broad absorption peak around 300 nm and green photoluminescence at 505 nm due to carboxyl groups. Cyclic voltammetry showed the highest current response for …
Process Optimization Of Bioactive Compound Extraction From Aloe Vera Leaf Skin Using Natural Deep Eutectic Solvents: An Integrated Computational-Experimental Approach, Sopita Chanmee
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study aimed to evaluate the efficiency of environmentally friendly natural eutectic solvents (NADESs) for the extraction of bioactive compounds from Aloe vera leaf skin (AVLS) in comparison with conventional solvents, namely water and 80% ethanol. The experiment used NADES based on choline chloride with four hydrogen bonding agents (HBDs), namely xylose, glycerol, propylene glycol and lactic acid. The results showed that ChCl:Xy gave the highest phenolic compounds content, while ChCl:La gave the highest anthraquinone content and antioxidant activity as tested by DPPH and FRAP. COSMO-RS and sigma profile analyses revealed the molecular interactions affecting the extraction efficiency, which showed …
การพยากรณ์และวิเคราะห์ปัจจัยที่เกี่ยวข้องกับสุขภาพจิตของเยาวชนในสหรัฐอเมริกา ด้วยการเรียนรู้ของเครื่อง, นิธิพล เฮงวิวัฒนชัย
การพยากรณ์และวิเคราะห์ปัจจัยที่เกี่ยวข้องกับสุขภาพจิตของเยาวชนในสหรัฐอเมริกา ด้วยการเรียนรู้ของเครื่อง, นิธิพล เฮงวิวัฒนชัย
Chulalongkorn University Theses and Dissertations (Chula ETD)
ปัญหาสุขภาพจิตโดยเฉพาะอย่างยิ่งในเยาวชนกำลังเพิ่มสูงขึ้นอย่างน่ากังวลใจ ซึ่งจะส่งผลต่อคุณภาพชีวิตและพฤติกรรมการเรียนรู้ โดยในประเทศสหรัฐอเมริกามีรายงานว่า ในเยาวชนพบผู้ที่มีปัญหาสุขภาพจิตเป็นจำนวนมาก และมีแนวโน้มที่จะเพิ่มสูงขึ้น ผู้วิจัยจึงได้ทำการพัฒนาแบบจำลองการเรียนรู้ของเครื่องสำหรับการพยากรณ์ระดับสุขภาพจิตของเยาวชน โดยอาศัยข้อมูลด้านพฤติกรรม จากข้อมูลการสำรวจพฤติกรรมเสี่ยง ปี 2023 (YRBSS2023) และประเมินประสิทธิภาพ โดยแบบจำลองที่ศึกษาจะใช้เทคนิคการจำแนกประเภทแบบหลายคลาส ได้แก่ Logistic Regression, Support Vector Classification, Decision Tree, Random Forest และ XGBoost และเทคนิคการถดถอย ได้แก่ Multiple Linear Regression, Support Vector Regression, Decision Tree, Random Forest และ XGBoost รวมถึงเปรียบเทียบความสามารถของทั้งสองเทคนิค และงานวิจัยนี้ทำการวิเคราะห์ปัจจัยที่เกี่ยวข้องกับปัญหาสุขภาพจิตด้วย SHAP Value จากการศึกษาพบว่า ในเทคนิค Classification แม้ว่าต้องจำแนกถึง 5 ระดับ แต่แบบจำลอง XGBoost ยังมีประสิทธิภาพดีที่สุด โดยมี Accuracy บนข้อมูล Test Set อยู่ที่ ร้อยละ 45.6 และค่าเฉลี่ยแบบถ่วงน้ำหนักของ F1 Score อยู่ที่ 0.449 สำหรับเทคนิค Regression แบบจำลอง XGBoost ยังคงให้ประสิทธิภาพดีสุดเช่นกัน โดยมี MAE บนข้อมูล Test Set เท่ากับ 0.730 และ MSE เท่ากับ 0.837 เมื่อทำการเปรียบเทียบความสามารถของเทคนิค Classification และเทคนิค Regression ที่อาศัยแบบจำลองคู่เทียบพบว่า เทคนิค Classification จะให้ค่า MAE ต่ำกว่าแบบจำลอง Regression แต่ในทางกลับกันเทคนิค Regression จะมีค่า MSE ต่ำกว่าเทคนิค Classification นอกจากนี้ พบว่า …
Investigation Of Mechanism And Inventory Of Greenhouse Gases Emission From Activated Sludge Wastewater Treatment Facility, Chawakorn Sanusan
Investigation Of Mechanism And Inventory Of Greenhouse Gases Emission From Activated Sludge Wastewater Treatment Facility, Chawakorn Sanusan
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aims to elucidate the mechanisms and quantify the inventory of greenhouse gas (GHG) emissions—specifically carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)—from an activated sludge (AS) wastewater treatment facility at the Pattaya Wastewater Treatment Plant (Soi Wat Nongyai), Thailand. A closed dynamic flux chamber (CDC) technique coupled with a portable Fourier-transform infrared (FTIR) gas analyzer was utilized to measure gas concentrations across three critical units: the primary sedimentation tank, aeration tank, and final sedimentation tank together with a direct-probe technique to measure across the sludge thickening tank, and sludge dewatering area. Emission rates were calculated using both …
Enhancing Mechanical Properties Of Recycled Aggregate Concrete For Sleepers Using Graphene Quantum Dots, Papassara Yamkasikorn
Enhancing Mechanical Properties Of Recycled Aggregate Concrete For Sleepers Using Graphene Quantum Dots, Papassara Yamkasikorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Concrete sleepers play a vital role in modern railway infrastructure due to their high strength and durability. This study explores the feasibility of using recycled aggregate concrete (RAC) as a sustainable alternative to natural aggregate (NA) in concrete sleeper production. Two sources of recycled aggregates were evaluated: general construction and demolition waste, and decommissioned railway sleepers. Replacement levels of 0%, 25%, 50%, 75%, and 100% by volume were investigated. Additionally, graphene quantum dots (GQDs) were incorporated into mixes to assess their potential in enhancing mechanical and durability properties. Experimental results showed that replacing natural aggregates with recycled aggregates, particularly from …
Cattle Identification By Muzzle Patterns Using Few-Shot Learning And Two-Branch Feature Extraction, Kunanon Sereewatanapong
Cattle Identification By Muzzle Patterns Using Few-Shot Learning And Two-Branch Feature Extraction, Kunanon Sereewatanapong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Cattle identification is a critical component of modern farm management systems, particularly in ensuring traceability, disease control, and improved production efficiency. Traditional identification methods such as ear tags or microchips often face challenges related to cost, durability, and animal welfare concerns. To address these limitations, this study proposes TBPN-ACEM (Two-Branch Prototype Network with Adaptive-Color Local Binary Pattern and Enhanced Margin Prototype Loss), a lightweight and few-shot learning framework designed for cattle identification using muzzle patterns, a unique and permanent biometric trait analogous to human fingerprints. The TBPN-ACEM architecture consists of three core components: (1) a two-branch structure that jointly extracts …
Effect Of Graphene Nanoplatelets Addition During Electroless Plating Of Abs On The Quantity Of Pdcl2 Usage For Copper-Nickel-Chromium Coated Abs, Wantana Chuakamhod
Effect Of Graphene Nanoplatelets Addition During Electroless Plating Of Abs On The Quantity Of Pdcl2 Usage For Copper-Nickel-Chromium Coated Abs, Wantana Chuakamhod
Chulalongkorn University Theses and Dissertations (Chula ETD)
Acrylonitrile Butadiene Styrene (ABS) with chromium coating is widely used in applications requiring high strength, durability, and aesthetic appeal, such as automotive parts, electronics, appliances, sanitary fixtures, and decorative consumer goods. Before electroplating, nickel electroless plating is applied to ABS to create a conductive base, but this process traditionally relies on palladium (Pd), a costly material. This research explores reducing Pd usage by incorporating graphene into the plating bath, enabling a decrease in Pd concentration from the industrial standard of 16-25 ppm to just 6 ppm with the addition of 15 mg/L of graphene. The Ni-coated ABS achieved an electrical …
Simulation On Acid Gas Removal From Natural Gas Processing With Membrane And Absorption Process, Ratikorn Sornumpol
Simulation On Acid Gas Removal From Natural Gas Processing With Membrane And Absorption Process, Ratikorn Sornumpol
Chulalongkorn University Theses and Dissertations (Chula ETD)
The comparison using simulations of CO₂ removal from natural gas via membrane separation and monoethanolamine (MEA) absorption has been studied. The membrane model is applied with the single- and two-stage configurations over feed pressures 3,000–9,000 kPa, temperatures 10–59 °C, CO₂ concentrations 20–70 mol %, membrane areas 2,500–5,500 m², and flows 331,800–580,600 m³/h. At 10 °C feed temperature, CO₂ permeability is enhanced while CH₄ selectivity improves slightly, increasing CO₂ capture efficiency up to 74 % with only minor methane losses, though at the cost of higher refrigeration duty. The 10 °C operation also leads to stronger driving force across the membrane, …
An Unsupervised Pipeline For Class-Agnostic Object Detection Using Self-Supervised Vision Transformers And Kolmogorov–Arnold Networks, Yuno Otsuka
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays, object bounding boxes can help create training data for instance segmentation, which is essential for many computer vision applications. However, generating these bounding boxes still relies heavily on manual annotation, making the process costly and time-consuming. To address this, we propose a fully unsupervised four-stage pipeline that automatically generates pseudo-bounding boxes without any human-labeled data. The pipeline includes (1) Background Removal, (2) Pseudo-Bounding Box Generation, (3) Complementary Bounding Box Generation (optional), and (4) Class-Agnostic Detector Training. At the core of this pipeline is KFOUND, which builds upon FOUND, a fast and lightweight method that avoids assumptions about object count …
Evaluating Flood Hazards And Damage On Paddy Fields: A Case Study Of The Prek Thnot River Basin, Cambodia, Koem Sreang Ka
Evaluating Flood Hazards And Damage On Paddy Fields: A Case Study Of The Prek Thnot River Basin, Cambodia, Koem Sreang Ka
Chulalongkorn University Theses and Dissertations (Chula ETD)
Flooding is a pervasive natural hazard that leads to substantial damage, economic losses, and social disruption. In Cambodia, the Lower Mekong River basin is particularly prone to recurrent flooding due to seasonal monsoons. The Prek Thnot River, a Bassac and Mekong Rivers tributary, experiences heightened flood risks from heavy rainfall and fluctuating water levels. This study aims to assess flood inundation hazards during extreme events and evaluate paddy damage within the Prek Thnot River Basin (PTRB). By analyzing rainfall data from eight monitoring stations, we performed a frequency analysis. The LP3 distribution is identified as the most optimal distribution for …
Process Simulation And Techno-Economic Evaluation Of Free Lutein Production From Marigold Flowers, Yada Meayrin
Process Simulation And Techno-Economic Evaluation Of Free Lutein Production From Marigold Flowers, Yada Meayrin
Chulalongkorn University Theses and Dissertations (Chula ETD)
Lutein is a carotenoid widely recognized for its health benefits, including improved vision, cognitive function, and prevention of age-related diseases. This study presents a comprehensive techno-economic and environmental assessment of three crude free lutein production processes using marigold flowers (Tagetes erecta L.) at a processing capacity of 74 tons/year, modeled in Asplen Plus V.11. The evaluated processes include sequential extraction and de-esterification (SQP) using hexane (HEX) or liquefied dimethyl ether (LiqDME), and a one-step simultaneous extraction and de-esterification (SMP) using LiqDME. Among these, the SMP-DME process demonstrated the best performance, with a net present value (NPV) of 146.98 million US$, …
Assessment Of Sediment Yield And Soil Erosion With The Impact Of Land Use Change In The Upper Loei River Basin Using Soil Water Assessment Tool (Swat) And Revised Universal Soil Loss Equation (Rusle), Sotheanea Khe
Chulalongkorn University Theses and Dissertations (Chula ETD)
Soil erosion and sediment yield pose significant threats to sustainable land and water resource management, particularly in regions undergoing rapid land-use transitions. The Upper Loei River Basin (ULRB) in northeastern Thailand has experienced extensive land-use changes over recent decades, primarily due to the expansion of rubber plantations. This study assesses the impacts of these changes on soil erosion and sediment yield from 2010 to 2020 using the Soil and Water Assessment Tool (SWAT) model, complemented by validation with the Revised Universal Soil Loss Equation (RUSLE). The SWAT model simulations were carried out for two distinct periods: 2007–2009 (pre-expansion) and 2010–2020 …
Arsenic Removal From Synthetic Produced Water Using Ionic Extractants And Vegetable Oils Via Hollow Fiber Supported Liquid Membrane, Natthawan Srinam
Arsenic Removal From Synthetic Produced Water Using Ionic Extractants And Vegetable Oils Via Hollow Fiber Supported Liquid Membrane, Natthawan Srinam
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis presents the separation of arsenic from water derived from synthetic petroleum production using a hollow fiber supported liquid membrane (HFSLM) system. The membrane system incorporates an ionic liquid extractant and a vegetable oil-based diluent. The study began with the selection of suitable extractants and diluents, followed by experimental design to determine optimal operating conditions using response surface methodology (RSM). Box-Behnken Design (BBD) and Central Composite Face-Centered Design (FCCD) were employed, and the data were analyzed through analysis of variance (ANOVA). Kinetic and thermodynamic studies revealed that the HFSLM system could achieve arsenic extraction and stripping efficiencies of up …
A Study Of Electric Vehicle Charging To Mitigate Impacts On A Power Distribution System, Samran Saleem
A Study Of Electric Vehicle Charging To Mitigate Impacts On A Power Distribution System, Samran Saleem
Chulalongkorn University Theses and Dissertations (Chula ETD)
Electric vehicles continue to gain rapid acceptance in the global market thus reshaping the way power distribution systems function today. The study examines how EV’s charging affects the voltage quality, voltage unbalance, overloading the system as well as performance of the distribution grids. MATLAB/Simulink simulations have been done using the modified IEEE 13 node test system on Node 634, Node 692, and Node 611 to analyze four charging cases including no charging (Case A) and evening peak (Case B) and early morning (Case C) and overnight off-peak (Case D) charging to assess EVs charging impact on domestic power grid. The …
A Hybrid Framework Based On Cnn-Lstm For Parkinson's Disease Severity Level Classification From 3-Axis Hand Gesture Signal Under The Frequency Domain, Theerawat Pinijwattananon
A Hybrid Framework Based On Cnn-Lstm For Parkinson's Disease Severity Level Classification From 3-Axis Hand Gesture Signal Under The Frequency Domain, Theerawat Pinijwattananon
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study introduces a novel multi-class classification model designed for the early-stage detection and severity assessment of Parkinson's Disease (PD). Machine learning model uses data from a 6 Degrees of Freedom (6DoF) sensor, collected during a simple keyboard-tapping test. Our research substantially analyzes finger movement patterns, since movement dysfunction like finger dexterity reduction is a primitive PD indication. First, raw data from wearable sensors are preprocessed by feature selection and normalization. Then, the data were converted into the frequency domain using Fourier transformation. Eventually, Gaussian filtering is applied to reduce noise and highlights relevant pattern. These processed spectral features are …
Aluminium-Doped And Carbon-Supported Zinc Oxide Ternary Composite Electrodes For Supercapacitor Applications, Abdulkadeem Sanni
Aluminium-Doped And Carbon-Supported Zinc Oxide Ternary Composite Electrodes For Supercapacitor Applications, Abdulkadeem Sanni
Chulalongkorn University Theses and Dissertations (Chula ETD)
Developing high-performance supercapacitor electrodes requires materials with optimized electrical conductivity, surface area, morphology, energy density, and cyclability. Herein, we report a facile hydrothermal synthesis of carbon nanotubes (CNTs)-supported Al-doped ZnO@CuO composite. Structural characterization reveals that Al doping and CuO incorporation can transform ZnO nanoflakes into nanorod/nanoflower heterostructures. The electrochemical analysis of the quaternary composite in a mixed electrolyte containing 2 M KOH, 0.2 M KFC, and 0.2 M KI exhibits a specific capacitance of 1860 F/g at 1 mV/s. The fabricated asymmetric supercapacitor (ASC) yields an energy density of 36 Wh/kg, a power density of 3502.8 W/kg at 30 mA/g, …
Integrated Socio-Economic Analysis Of Drought Impacts On Agricultural Areas In Sukhothai Province, Thailand, Thanasit Promping
Integrated Socio-Economic Analysis Of Drought Impacts On Agricultural Areas In Sukhothai Province, Thailand, Thanasit Promping
Chulalongkorn University Theses and Dissertations (Chula ETD)
Drought is a prolonged period of deficient precipitation that can result in significant water-related challenges across the globe. It may arise from multiple factors, including reduced rainfall, limited water availability, and low soil moisture content. To effectively assess and monitor drought conditions, drought indicators and indices are essential tools for determining the severity, spatial extent, and duration of drought events. This study introduces the development of the Composite Drought Hazard Index (CDHI), a comprehensive methodology that incorporates multiple drought-related parameters using appropriate weighting factors. The CDHI integrates the Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI), Standardized Groundwater Index (SGI), …
A Study Of Characteristics, Origins And Fates Of Ultrafine Particles Over Taichung City, Taiwan, Kijpat Thavorn
A Study Of Characteristics, Origins And Fates Of Ultrafine Particles Over Taichung City, Taiwan, Kijpat Thavorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Ultrafine particles (UFPs, <0.1 μm) pose health risks and are challenging to model. This study investigated UFP dynamics in Taichung City, Taiwan, using April 2021 observations and GEOS-Chem-TOMAS simulations. Observations included particle number size distributions (analyzed from 11.8 to 593.5 nm), sulfuric acid, and meteorological data. The model used 15 size bins, testing five nucleation schemes (Base, Binary, Binary ion, Ternary, Ternary ion) for new particle formation (NPF) sensitivity.Base, Ternary, and Ternary ion schemes simulated sporadic nucleation bursts; Binary schemes showed minimal activity. Despite visual coincidence with sulfuric acid peaks, simulated nucleation rates exhibited weak linear correlation (Pearson R ≈ −0.04). The model consistently and substantially underestimated observed particle number concentrations across all modes (NMBs ranging from -8.5% to -90.9%; correlation coefficients (absolute values) from 0.06 to 0.21). Crucially, no clear classical "banana-shaped" NPF events were observed in observations or model simulations. These findings underscore the need for improved nucleation/growth parameterizations, higher-resolution meteorological data, and refined local emissions for urban aerosol modeling in subtropical environments.
Detection And Replacement Of States With Spikes And Noise By Long Short-Term Memory Models Or Neural Networks, Ittikorn Yutto
Detection And Replacement Of States With Spikes And Noise By Long Short-Term Memory Models Or Neural Networks, Ittikorn Yutto
Chulalongkorn University Theses and Dissertations (Chula ETD)
Spike signals are impulsive disturbances with high amplitude occurring over a very short duration. They are typically caused by external factors such as temperature fluctuations, vibrations, or sensor inaccuracies, leading to erroneous measurements and potential degradation of control system performance. This study aims to develop a Long Short-Term Memory (LSTM) model for detecting and replacing spike signals in a second-order system. The model was trained and validated using datasets contaminated with spike signals of varying amplitudes. Experimental results demonstrated that the proposed model could suppress spike amplitudes by up to 99.79%, with a minimum reduction of 92.42% and an average …
Development Of Quaternized Poly(Vinyl Alcohol)/Chitosan/Two-Dimensional Molybdenum Disulfide Anion Exchange Membrane As A Separator For Electrochemical Processes, Nuttapon Suppanucroa
Development Of Quaternized Poly(Vinyl Alcohol)/Chitosan/Two-Dimensional Molybdenum Disulfide Anion Exchange Membrane As A Separator For Electrochemical Processes, Nuttapon Suppanucroa
Chulalongkorn University Theses and Dissertations (Chula ETD)
In response to the global shift toward the expansion of large-scale energy storage systems (ESSs), secondary zinc-air batteries (ZABs) have attracted significant attention as promising candidates for next-generation batteries due to their high energy density, cost-effectiveness, and safety. However, their long-term practical application is hindered by several challenges associated with the membrane separator, including the formation of resistive zinc oxide layers and low hydroxide-ion conductivity. These limitations are attributed to poor ion-selectivity, which impedes electrochemical reactions and degrades battery performance. To address these issues, this study developed a series of innovative membrane separators featuring quaternary ammonium (QA)-functionalized polyvinyl alcohol (PVA), …
Deep Learning Approaches For Robust Heart And Respiratory Rate Estimation From Photoplethysmography, Pongpanut Osathitporn
Deep Learning Approaches For Robust Heart And Respiratory Rate Estimation From Photoplethysmography, Pongpanut Osathitporn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Respiratory rate (RR) is a vital sign widely used to assess patient health. However, estimating RR using photoplethysmography (PPG) signals remains challenging due to noise and signal variability. This paper proposes RRWaveNet, an end-to-end model based on multi-scale convolutional networks with residual connections for robust RR estimation from PPG signals. The model is evaluated on four public datasets BIDMC, CapnoBase, WESAD, and SensAI with optimal performance observed at a 32-second window. RRWaveNet achieves mean absolute errors of 1.66±1.01, 1.59±1.08, 1.92±0.96, and 1.23±0.61 breaths per minute, respectively, outperforming state-of-the-art methods across all datasets and the transfer learning using ICU datasets, which …
Optimal Centralized Operations Of Local Energy Market Considering Electric Vehicle Charging Activity For Local Grid Services, Arnon Teawnarong
Optimal Centralized Operations Of Local Energy Market Considering Electric Vehicle Charging Activity For Local Grid Services, Arnon Teawnarong
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation investigates the optimal operation of local energy markets (LEM) within Thailand’s low-voltage distribution system (LVDS) to integrate renewable energy sources and electric vehicles (EVs). Despite extensive research, uncertainties persist in selecting optimal transaction partners and negotiating prices to maximize social welfare. Additionally, LEM operations should consider self-managing energy consumption and utilizing EVs to mitigate distribution network constraint (DNC) violations and leverage local resources to alleviate power imbalances during real-time electricity delivery. Local grid service programs, which offer incentives, face challenges in ensuring equitable participation and allocating fair incentives. Additionally, implementing a penalty scheme presents issues in fairness, mitigating …
Hydrogen Production From Glycerol Using Sorption Enhanced Chemical Looping Steam Reforming With Multifunctional Pellet Catalyst, Talita Nimmas
Hydrogen Production From Glycerol Using Sorption Enhanced Chemical Looping Steam Reforming With Multifunctional Pellet Catalyst, Talita Nimmas
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this study, the synthesis of a pellet-scale material for hydrogen (H₂) production from glycerol via the Sorption Enhanced Chemical Looping Steam Reforming (SE-CL-SGR) process was investigated. The research focuses on material synthesis, performance enhancement, and the economic and environmental advantages of the developed material. Among the synthesis methods compared, the Stepwise Calcination process demonstrated the best performance, producing structurally stable and mechanically robust pellets. The optimal CaO/support mass ratio for the Ni-supported material (15Ni(70Ca.30Support)) was found to achieve 90% v/v H₂ purity with a pre-breakthrough time of approximately 75 minutes. Rare-earth metal oxides (CeO₂, La₂O₃) addition also improved mechanical …
Exploring Utilization Patterns Of Thailand's Three Main Public Health Insurance Scheme Beneficiaries, Pakhun Angsupan
Exploring Utilization Patterns Of Thailand's Three Main Public Health Insurance Scheme Beneficiaries, Pakhun Angsupan
Chulalongkorn University Theses and Dissertations (Chula ETD)
The three main public health insurance schemes in Thailand include the Universal Coverage Scheme (UCS), the Social Security Scheme (SSS), and the Civil Servant Medical Benefit Scheme (CSMBS), which the schemes cover approximately 97% of the population. However, a number of individuals reported not having utilized the schemes during their last visit to a medical facility. Non-utilization of free healthcare raises a question regarding the ability to access and utilize public health insurance schemes and whether or not they are able to appropriately provide horizontal equity. The aim of this study is to examine the influence of demographic and health-related …
The Influence Of Hospital Service Quality On National Health Insurance Patients’ Perceived Value, Satisfaction, And Revisit Intention Across Gender And Age Group In Outpatient Setting In Indonesia: A Mixed Method Study, Alvera Noviyani
Chulalongkorn University Theses and Dissertations (Chula ETD)
Background: Recent literature on healthcare quality shows the important of patient-centred design, hence more contextualized and patient-perspective research is needed to assess service quality. Hence, this study aimed to analyse and explain the relationship between patient satisfaction, perceive value, and revisit intention of Indonesian National Health Insurance patients via service quality in outpatient department in national central public hospital setting. Methods: A mixed-methods approach was employed, combining quantitative analysis through Structural Equation Modelling (SEM) and qualitative data obtained from patient interviews. The SEM results assessed the direct and indirect effects of service quality on perceived value, satisfaction, and revisit intention. …
Environmental Ethics And Democratic Citizenship In Mary Austin's The Basket Woman And The Ford, Sarunyu Thirayunthikul
Environmental Ethics And Democratic Citizenship In Mary Austin's The Basket Woman And The Ford, Sarunyu Thirayunthikul
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis examines the intertwined concepts of environmental ethics and democratic citizenship in two literary works by late nineteenth-century American writer Mary Austin (1868–1934), The Basket Woman: A Book of Indian Tales for Children (1904) and The Ford (1917). It argues that Austin attempts to employ Native American tales to promote a spiritual relationship between humans and nonhumans, a perspective rooted in Indigenous belief systems. When read alongside her political writing The Young Woman Citizen (1918), The Basket Woman can also be interpreted as an effort to cultivate certain civic values—particularly social responsibility and public-spiritedness—essential to democratic citizenship. The thesis …
Perception Of The Tiktok's Content About Dieting And Workout Towards Body Image Among Thai Teenagers, Arnond Iamsudha
Perception Of The Tiktok's Content About Dieting And Workout Towards Body Image Among Thai Teenagers, Arnond Iamsudha
Chulalongkorn University Theses and Dissertations (Chula ETD)
Short content about idealized body images, such as dieting and workouts on TikTok, has influenced teenagers' perceptions of body image due to frequent comparisons. This research examined a relationship between Thai teenagers' perception of TikTok's dieting and workout content concerning their body image and overall appreciation of their bodies. A sample of 516 Thai teenagers indicated their level of agreement with statements about the perception of their body image after watching these videos. The Body Appreciation Scale was used to measure teenagers' overall perceptions of their body image. The research findings revealed that the majority of respondents agreed that watching …