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2022

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Hinterlands To Cities: The Archaeology Of Northwest Mexico And Its Vecinos, Matthew C. Pailes, Michael T. Searcy Jan 2022

Hinterlands To Cities: The Archaeology Of Northwest Mexico And Its Vecinos, Matthew C. Pailes, Michael T. Searcy

Faculty Publications

Tis approachable book is a comprehensive synthesis of Northwest Mexico from the US border to the Mesoamerican frontier. Filling a vital gap in the regional literature, it serves as an essential reference not only for those interested in the specific history of this area of Mexico but western North America writ large. A period-by-period review of approximately14,000 years reveals the dynamic connections that knitted together societies inhabiting the Sea of Cortez coast, the Sonoran and Chihuahuan deserts, and the Sierra Madre Occidental. Networks of interaction spanned these diverse ecological, topographical, and cultural terrains in the millennia following the demise of …

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Regolith Based Polymer Matrix Composites For In-Situ Additive Manufacturing For Long Term Extraterrestrial Missions, Christopher Matetich Jan 2022

Regolith Based Polymer Matrix Composites For In-Situ Additive Manufacturing For Long Term Extraterrestrial Missions, Christopher Matetich

Mechanical Engineering and Applied Mechanics

The completed study investigated Martian regolith simulant composites’ material properties when there was variation in the type of used Martian regolith simulant. Four types of Martian regolith simulant were mixed at varying weight percent loadings with polypropylene using twin screw extrusion. Test parts were made via injection molding with all the polymeric composites, and additive manufacturing with select polymeric composites. ASTM standard based tests and ANOVA tests were completed to investigate material characteristics. Depending on the creation process, the results suggested that Martian regolith simulant type impacted several material characteristics. During material processing, a foaming behavior was observed with all …

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Influences Of Seawater Flows On The Degradation Of Organic Coatings Applied On Offshore Wind Turbines, Amin Vedadi Jan 2022

Influences Of Seawater Flows On The Degradation Of Organic Coatings Applied On Offshore Wind Turbines, Amin Vedadi

Mechanical Engineering and Applied Mechanics

The regular protection methods of offshore wind structures consist of the application of two or three layers of epoxy-based coatings with a polyurethane topcoat. The coating systems of offshore wind turbines are mostly tested on-site, where different coated samples are exposed to the sea water at the specific locations planned for the installations of the turbines. Despite several advantages of laboratory testing, the majority of laboratory-based tests have been limited to the exposure of coated or unprotected metals to stationary electrolytic solutions, while the flow-induced corrosion measurements have not received enough attention until recently. The focus of our work is …

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Process Optimization Of 3d Printing With Continuous Fiber Reinforced Uv Curable Thermoset Resin, Md Atikur Rahman Jan 2022

Process Optimization Of 3d Printing With Continuous Fiber Reinforced Uv Curable Thermoset Resin, Md Atikur Rahman

Mechanical Engineering and Applied Mechanics

3D printed polymer components cannot be used as structural components due to the 3D printable material property limitations. To improve mechanical properties, a composite 3D printer is developed and studied. Technical aspects of 3D printing with continuous carbon fiber reinforced dual UV and thermal curable thermoset composite were experimented. To optimize the 3D printing process parameters, the effect of printing nozzle size, line spacing of the print, and resin flow rate was studied. To achieve minimum void content and maximum fiber volume fraction, print parameter configurations were studied using microscopic surface roughness analysis. The tensile and flexural properties of 3D …

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A Review Of Biomechanics Of Arterial Stent Implants, Joshua Collin Yurek Jan 2022

A Review Of Biomechanics Of Arterial Stent Implants, Joshua Collin Yurek

Mechanical Engineering and Applied Mechanics

This work looks to provide a review of modern stents by evaluating the need for them as well as providing a detailed engineering analysis of the conditions they are subjected to. It is estimated that over two million of these devices are implanted in patients annually. Of those implanted, a majority are used in the treatment of arteriosclerosis. This disease causes arterial walls to thicken and toughen leading to restricted blood flow and in extreme cases, complete loss of circulation. Arteriosclerosis and complications arising from it form a leading cause of death in the developed world. Although there are a …

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An Experimental Study Of Fluid-Structure Interaction In Collapsible Vessels, Jennifer Schmeling Jan 2022

An Experimental Study Of Fluid-Structure Interaction In Collapsible Vessels, Jennifer Schmeling

Mechanical Engineering and Applied Mechanics

The fluid-structure interaction in collapsible thin-walled vessels is an important topic of research to better understand the physical mechanisms behind many physiological processes and diseases. In this work, we established an experimental setup to study the collapsible tube deformation and fluid-structure interaction within a thin-walled collapsible vessel. The effects of transmural pressure and flow rate were characterized experimentally using high-frequency pressure transducers and optical measurements. Various transmural pressures were also simulated through finite element analysis. Results suggest that the deformation of thin-wall vessel follows the pattern described by Shapiro’s tube law. The collapsed pattern and cross-sectional area changes with different …

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An Investigation On Residual Stress Build-Up In Cold Sprayed Metallic Samples: Effect Of Stress Relaxation Heat Treatment, Deepika Shrestha Jan 2022

An Investigation On Residual Stress Build-Up In Cold Sprayed Metallic Samples: Effect Of Stress Relaxation Heat Treatment, Deepika Shrestha

Mechanical Engineering and Applied Mechanics

Residual stress formation during cold spraying process may result in deteriorative effects on the performance of coating materials. The objective of this investigation is to characterize residual stress built-up in some of well-known metallic alloys deposited by cold spraying. Two different nickel based super alloys (Inconel 625 and Inconel 718) and the most commercially used titanium alloy (Ti-6Al-4V) were considered for investigation in this study. The average residual stress was higher in Inconel samples compared to the titanium one. Stress relaxation heat treatment helped in the reduction of porosities. However, the recovery of residual stress was highest in Ti-6Al-4V compared …

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Characterization Of A Lab-Scale Polymethylmethacrylate And Gaseous Oxygen Hybrid Rocket, Porter Dixon Jan 2022

Characterization Of A Lab-Scale Polymethylmethacrylate And Gaseous Oxygen Hybrid Rocket, Porter Dixon

Mechanical Engineering and Applied Mechanics

Hybrid rockets are a type of chemical rocket propulsion where the reactants are in different phases. Historically, hybrid rockets have been underutilized in the aerospace industry. However, due to their simple nature, they are easy to construct and test. Research on hybrid rocket propulsion was conducted using optically clear polymethylmethacrylate and gaseous oxygen with a nozzle designed to achieve Mach 2. Characterization was performed using combustion simulations available from NASA and measurements with pressure transducers, thermocouples, a load cell, and high-speed cameras. The test stand and hybrid rocket itself were designed by previous senior design groups. From the results, performance …

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Sexual Dimorphisms In The Adipose Biology Of Vasoactive Intestinal Peptide Deficient Mice, Emma Hawley Jan 2022

Sexual Dimorphisms In The Adipose Biology Of Vasoactive Intestinal Peptide Deficient Mice, Emma Hawley

Microbiological Sciences

Both VIP and PACAP deficient mice display impaired fat storage, but only the molecular adipose characteristics of PACAP KO mice are known. While mice deficient in these peptides are lean, supplementation could promote weight gain in livestock after establishing tissue distribution. We investigated both sides of this 'metabolic coin' by measuring serum metabolites, adipocyte area, and pscWAT gene expression in VIP deficient mice and screening 15 ruminant tissues for VIP, PACAP, and their receptors using RT-qPCR. We found male VIP deficient mice displayed hypertrophic adipocytes, low serum FFAs, and suppressed relative mRNA expression of TMEM26. In ruminants, VIP and PACAP …

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Finite Integration Method Using Chebyshev Expansion For Solving Heat Equation With Non-Local Boundary Conditions, Thanakorn Prasansri Jan 2022

Finite Integration Method Using Chebyshev Expansion For Solving Heat Equation With Non-Local Boundary Conditions, Thanakorn Prasansri

Chulalongkorn University Theses and Dissertations (Chula ETD)

No abstract provided.

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Numerical Algorithm For Heat Equation With Moving Boundary Using Finite Integration Method With Chebyshev Polynomial Expansion, Warunya Wong-U-Ra Jan 2022

Numerical Algorithm For Heat Equation With Moving Boundary Using Finite Integration Method With Chebyshev Polynomial Expansion, Warunya Wong-U-Ra

Chulalongkorn University Theses and Dissertations (Chula ETD)

No abstract provided.

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Estimating Stock Price Based On Information From Financial Statement Using Machine Learning Approach, Thitikun Kunathananon Jan 2022

Estimating Stock Price Based On Information From Financial Statement Using Machine Learning Approach, Thitikun Kunathananon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study introduces a new tool for stock market investors and institutions constructed from Long Short-Term Memory (LSTM) for predicting stock prices. By effectively analyzing financial statements and stock market data, LSTM provides a fast, unbiased, low-cost solution for stock price prediction, intending to increase profits for investors and reduce losses. The study results indicate that LSTM can maintain effectively captures complex relationships in the data and predicts stock prices. This research highlights the potential of LSTM as a valuable and innovative tool for investors and institutions in the stock market.

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Real-Time Image Classification For Malignant Biliary Strictures On Cholangioscopy Images Based On Deep Learning Approach, Passakron Phuangthongkham Jan 2022

Real-Time Image Classification For Malignant Biliary Strictures On Cholangioscopy Images Based On Deep Learning Approach, Passakron Phuangthongkham

Chulalongkorn University Theses and Dissertations (Chula ETD)

It is challenging to determine if the cause of bile duct strictures is benign or malignant. Currently, endoscopists may more precisely inspect the bile duct thanks to computerized single-operator cholangioscopy. As a result, lesions in the bile duct can be seen with the naked eye. However, endoscopists continue to diagnose patients differently. Consequently, a biopsy is typically regarded as the gold standard. The necessity to repeat operations results from a biopsy sample mistake that results in a false-negative cancer diagnosis. In this study, we suggest a convolutional neural network developed particularly for real-time malignant biliary stricture classification. Our approach, which …

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Corporate Credit Rating Prediction Using Deep Learning, Napasorn Thavichaigarn Jan 2022

Corporate Credit Rating Prediction Using Deep Learning, Napasorn Thavichaigarn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Corporate credit rating has an important role in reducing asymmetric information between investors and borrowers and assisting investors as a signal of the entities’ performance and creditworthiness for making appropriate investment decisions in a company’s assets. The economic distress has negatively affected various businesses and resulted in company rating transitions. This led to a problem in adjusting investment strategy and a serious loss as there is a lack of time between officially announced credit rating transitions and real transition. This study provides alternative methods for credit rating prediction by applying machine learning models; Support Vector Machine (SVM), Linear Regression, and …

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Multi-Agent Deep Reinforcement Learning For Cryptocurrency Trading, Kittiwin Kumlungmak Jan 2022

Multi-Agent Deep Reinforcement Learning For Cryptocurrency Trading, Kittiwin Kumlungmak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Reinforcement learning has emerged as a promising approach for enhancing profitability in cryptocurrency trading. However, the inherent volatility of the market, especially during bearish periods, poses significant challenges in this domain. Existing literature addresses this issue through the adoption of single-agent techniques such as deep Q-network (DQN), advantage actor-critic (A2C), and proximal policy optimization (PPO), or their ensembles. Despite these efforts, the mechanisms employed to mitigate losses during bearish market conditions within the cryptocurrency context lack robustness. Consequently, the performance of reinforcement learning methods for cryptocurrency trading remains constrained within the current literature. To overcome this limitation, we present a …

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Real-Time Gastric Intestinal Metaplasia Semantic Segmentation With Multiple Abnormalities Using Deep Learning Approach, Passin Pornvoraphat Jan 2022

Real-Time Gastric Intestinal Metaplasia Semantic Segmentation With Multiple Abnormalities Using Deep Learning Approach, Passin Pornvoraphat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis declares the segmentation of gastric intestinal metaplasia (GIM) in real-time. Recently, GIM segmentation of endoscopic images has been conducted to distinguish GIM from a healthy stomach. However, achieving real-time detection is difficult. Challenging conditions include multiple color modes (white light endoscopy and narrow-band imaging), other abnormal lesions (erosion and ulcer), noisy labels, etc. Herein, our model is based on BiSeNet and can overcome the many issues regarding GIM. Applying auxiliary head and loss boosts the performance on multiple color modes. In addition, pre-processing techniques, including location-wise negative sampling, jigsaw augmentation, and label smoothing, are utilized to improve detection …

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Nft-Based Authentic Product Verification And Trading Platform, Natchapol Thongruang Jan 2022

Nft-Based Authentic Product Verification And Trading Platform, Natchapol Thongruang

Chulalongkorn University Theses and Dissertations (Chula ETD)

Counterfeit product has been a major problem to the economy for a while. The effect seems to be larger when it comes to the luxury product segment. When the consumers were unsure if the product that they are buying is genuine or not and its cost is very high, then the severity will become even greater. Among the countless number of attempts to fix this solution, utilizing blockchain technology is one of the most popular approaches for present days. In anti-counterfeit domain, associating an NFT token to a physical product is the most common approach. It allows us to unlock …

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Combining Technical Analysis And Deep Learning Models For Stock Market Trading, Phurinut Pholsri Jan 2022

Combining Technical Analysis And Deep Learning Models For Stock Market Trading, Phurinut Pholsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

The issuance of stocks constitutes a means by which ownership in a company is represented, and its distribution may vary depending on whether the company is limited or public. The stock market offers the potential for high returns, thereby serving as an attractive avenue for investment. Against this backdrop, the objective of this study is to develop a predictive model for stock prices that can facilitate profitable trading outcomes. To achieve this aim, the study focuses on intraday and hourly trading and utilizes a hybrid model that integrates Bidirectional Long Short-Term Memory (BiLSTM) and Convolutional Neural Network (CNN) architectures, along …

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Xgboost For Prediction Of Ethereum Short-Term Returns Based On Technical Factor, Wipawee Nayam Jan 2022

Xgboost For Prediction Of Ethereum Short-Term Returns Based On Technical Factor, Wipawee Nayam

Chulalongkorn University Theses and Dissertations (Chula ETD)

Unlike traditional currencies that rely on centralized such as banks or governments, cryptocurrencies today have become popular due to its decentralized transactions. Decentralization takes advantage of no requirement for intermediaries, thus reducing transaction fees and processing time. However, investing in cryptocurrencies incurs risks and uncertainties due to price volatility and rapid changes. The fact that prediction of asset prices is complex due to the influence of multiple factors on price movements. This paper studied the technical factor to analyze the short-term returns of Ethereum in the periods of 1-10 days. The historical data containing Ethereum closing price are collected from …

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Y-X-Y Encoding For Identifying Types Of Sentence Similarity, Thanaporn Jinnovart Jan 2022

Y-X-Y Encoding For Identifying Types Of Sentence Similarity, Thanaporn Jinnovart

Chulalongkorn University Theses and Dissertations (Chula ETD)

The task of finding semantic similarity of any two arbitrary sentences consists of two main steps, which are encoding sentences to produce feature vectors of equal length and measuring the similarity, respectively. The quality of an encoding technique can determine the degree of success a model can achieve in measuring the similarity. This is because a good representation is subjected to how finely established the spectrum of similarities is. The clearer the definition of similarity is, the better the representations can be constructed. This, in turn, helps distinguish between types of sentences. Generally, all existing methods for measuring similarity were …

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Real-Time Object Detection For Screening Cannabis Seed Gender, Prachya Boonsri Jan 2022

Real-Time Object Detection For Screening Cannabis Seed Gender, Prachya Boonsri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Perception and understanding of cannabis are more expansive than they formerly were. Almost all growers are primarily interested in getting harvests of big flower buds from cannabis female plants since THC, CBD and other cannabinoids are found in female flowers and valuable for medical and industrial market segments. Selecting only female seeds to cultivate is thus an important step to produce THC, CBD profitably. Unfortunately, outdoor cultivation in Thailand traditionally grows regular cannabis seeds that grow up of mixed male and female plants. The male plants will be later spot and eliminated during the pre-flowering stage. This incurs the higher …

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Formation Control Of Mobile Robot Swarm In Search Operation, Chanun Asavasirikulkij Jan 2022

Formation Control Of Mobile Robot Swarm In Search Operation, Chanun Asavasirikulkij

Chulalongkorn University Theses and Dissertations (Chula ETD)

The use of swarm mobile robots has emerged as a promising approach to enhance search efficiency in various applications. This thesis focuses on proposing an effective design and fabrication methodology for a swarm mobile robot system based on the Robot Operating System (ROS) framework. Additionally, a novel network architecture is presented to improve communication efficiency among the robots. The primary objective of this research is to investigate the formation control of swarm mobile robots and their superior ability in search operations. Through extensive experiments and quantitative analysis, the performance of the proposed formation control strategy is evaluated in terms of …

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An Analysis On Trends Of Research Topics In Civic Education Using Dynamic Topic Model, Poon Thongsai Jan 2022

An Analysis On Trends Of Research Topics In Civic Education Using Dynamic Topic Model, Poon Thongsai

Chulalongkorn University Theses and Dissertations (Chula ETD)

The aim of this thesis is to study the trend of civic and citizenship education research from 2000 to 2020 and the influence the regional background of researches has on the research discussion. Relevant data is collected from ERIC and SCOPUS database. This includes abstracts, published year, regional background of researchers, and author h-index. The keywords used are “civic education” or “citizenship education” or “civics”. There are 4917 papers extracted in total. Upon doing further preparation, 4854 articles are prepared for analysis. We apply Structural Topic model (STM) technique to the abstracts with covariates including the published year and the …

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An Improvement In Protection Coordination And Criteria Settings For Bhutanese Power System, Cheten Tshering Jan 2022

An Improvement In Protection Coordination And Criteria Settings For Bhutanese Power System, Cheten Tshering

Chulalongkorn University Theses and Dissertations (Chula ETD)

Overcurrent and ground fault relay coordination have been studied for a pilot 132/33/11 kV Substation in Bhutan. The calculated settings as well as the existing settings have been simulated and the critical findings and recommendations are made. The methodology of overcurrent and ground fault relay coordination are also proposed. Similarly, the criteria settings for differential relay have been discussed along with the compensation in respect of CT ratio, vector correction, magnetic inrush and zero sequence filtering. The pickup setting followed by 1st and 2nd slope biasing has been discussed. Further, the distance relay setting has been analysed whereby the parameters …

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Classification Of Cardiac Arrhythmias Based On Overlapped Ecg Image With Lightweight Neural Network, Khaing Su Thway Jan 2022

Classification Of Cardiac Arrhythmias Based On Overlapped Ecg Image With Lightweight Neural Network, Khaing Su Thway

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation presents the classification of different types of cardiac arrhythmias, including Atrial Fibrillation (AF), Normal Sinus Rhythm (NSR), Premature Atrial Contraction (PAC), and Premature Ventricular Contraction (PVC), using a lightweight neural network. A novel ECG data transformation method, referred to as transforming into overlapped ECG images, has been developed and utilized as input images for our neural network. During the transformation process, individual heartbeats within a 30-second time frame are cropped based on heart rate calculations. These resulting beats are then overlapped with respect to the x and y axis limits, generating distinctive images representing different arrhythmia types examined …

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Genetic Algorithm Based Deep Multi-Route Self-Attention For Single Image Super-Resolution, Nisawan Ngambenjavichaikul Jan 2022

Genetic Algorithm Based Deep Multi-Route Self-Attention For Single Image Super-Resolution, Nisawan Ngambenjavichaikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Image restoration, such as single image super-resolution (SISR), is a long-established low-level vision issue that intends to regenerate high-resolution (HR) images from low-resolution (LR) input counterparts. While state-of-the-art image super-resolution models are based on the well-known convolutional neural network (CNN), many self-attention-based or transformer-based experiment attempts have been conducted. They have shown promising performance on vision problems. A powerful baseline model based on the swin transformer adopts the shifted window approach. It enhances the capability by restricting the model to compute the self-attention function only on non-superimpose local windows while enabling cross-window relations. However, the architecture design is manually fixed. …

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A Linear Matrix Inequality Approach To Design State Feedback Control For Non-Polynomial Nonlinear Systems, Phing Lim Jan 2022

A Linear Matrix Inequality Approach To Design State Feedback Control For Non-Polynomial Nonlinear Systems, Phing Lim

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis aims to design a state feedback controller for non-polynomial systems with bounded control inputs. The problem formulation begins by transforming the non-polynomial systems into polynomial systems. This can be done by defining non-polynomial terms as new state variables with algebraic constraints satisfying the non-polynomial properties. This method avoids the approximation of the recast polynomial systems. Then we design the state feedback control based on the extended Lyapunov stability theorem and the quadratic performance criterion. Two state feedback control laws are proposed: Theorem 1 for static Lyapunov matrix variables and Theorem 2 for polynomial ones. For Theorem 1, the …

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Effect Of Drop-Out Layers Inside Recurrent Neural Networks In Household Load Forecast Application, Sanaullah Soomro Jan 2022

Effect Of Drop-Out Layers Inside Recurrent Neural Networks In Household Load Forecast Application, Sanaullah Soomro

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ensuring precise power load forecasting is highly important in planning the secure, steady, and cost-effective functioning of the power system. Grid planning and decision-making can be based on accurate long- and short-term power load forecasting. Recently, machine learning techniques have gained widespread adoption for both long- and short-term power load forecasting. Specifically, the Long Short-Term Memory (LSTM) is customized for time series data analysis. This research proposes an LSTM model for forecasting the power load of a single house containing electrical appliances over the next 20 days. We conducted a comparative analysis of the impact of dropout layers in load …

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Performance Analysis Of Jpeg Xr With Deep Learning-Based Image Super-Resolution, Taingliv Min Jan 2022

Performance Analysis Of Jpeg Xr With Deep Learning-Based Image Super-Resolution, Taingliv Min

Chulalongkorn University Theses and Dissertations (Chula ETD)

The demand for efficient high-level image and video codec compression has widely increased. Conventional image compression methods such as JPEG XR use a high quantization parameter (QP) to produce a highly compressed file for any given image. However, higher QP has unpleasing artifacts that lead to perceptual quality degradation. A feasible solution to tackle this limitation is to reduce the high-resolution image size by downsampling it before encoding it with JPEG XR. Then, the super-resolution algorithm is applied to the resultant low-resolution image to reconstruct the high-resolution result. In this research, we downsample the input image before JPEG XR. Then, …

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Deep Consecutive Attention Network For Video Super-Resolution, Talha Saleem Jan 2022

Deep Consecutive Attention Network For Video Super-Resolution, Talha Saleem

Chulalongkorn University Theses and Dissertations (Chula ETD)

In the video application, slow motion is visually attractive and gets more attention in video super resolution. To generate the high-resolution (HR) slow motion video frames from the low-resolution (LR) frames, two sub-tasks are required, including video super-resolution (VSR) and video frame interpolation (VFI). However, the interpolation approach is not successful to extract low level feature attention to get the maximum advantage from the property of space-time relation. To this extent, we propose a deep consecutive attention network-based method. The multi-head attention and an attentive temporal feature module are designed to achieve better prediction of interpolation feature frame. Bi-directional deformable …

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