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Developing A System Of Community-Based Agritourism For Sustainable Local Food Systems: A Multi-Case Study Of Rural Livelihood Diversification And Sustainable Urban Consumption In City-Regional Bangkok, Sofia Anna Enrica Cavalleri Jan 2021

Developing A System Of Community-Based Agritourism For Sustainable Local Food Systems: A Multi-Case Study Of Rural Livelihood Diversification And Sustainable Urban Consumption In City-Regional Bangkok, Sofia Anna Enrica Cavalleri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Current food systems fail to directly link rural producers and urban consumers. This research explores and categorizes emerging community-based agritourism practices as strategies to reconnect rural food producers with urban consumers. The main research question of this study is: how can community-based agritourism link rural food producers and urban consumers as a rural livelihood diversification strategy? Mixed methods for data collection were selected to answer this question and analyzed with a deductive and inductive approach. These include the review of secondary grey and academic literature, shadow observation in three rural provinces, content validity index calculation performed by experts (n = …

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Investigating Consumers' Perspective And Impact On Green Cosmetics And Personal Care Products In Thailand, Tawalhathai Suphasomboon Jan 2021

Investigating Consumers' Perspective And Impact On Green Cosmetics And Personal Care Products In Thailand, Tawalhathai Suphasomboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to investigate consumers’ perspectives and impact on green cosmetics and personal care products in Thailand. Specifically, it explores the sustainability movement for the cosmetics and personal care industry, analyzes Thai consumer behavioral intention toward the consumption of green cosmetics and personal care products, and evaluates the impact of related policies that may affect green business transitions and consumers’ intention to purchase green cosmetics and personal care products. The movement of industry and related policies were analyzed by means of Life Cycle Thinking approach. Hypotheses were formulated based on The Perceived Value Theory with extended factors of environmental …

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Developing A Model For The Integration Of Bajau Traditional Ecological Knowledge In The Management Of Locally Managed Marine Area: A Case Study Of Wakatobi Regency, Indonesia, Wengki Ariando Jan 2021

Developing A Model For The Integration Of Bajau Traditional Ecological Knowledge In The Management Of Locally Managed Marine Area: A Case Study Of Wakatobi Regency, Indonesia, Wengki Ariando

Chulalongkorn University Theses and Dissertations (Chula ETD)

Attaining sustainable resource management encompasses multilevel challenges and interdisciplinary approaches from grassroots efforts to international agreements. In the context of coastal and marine management, the complexities represented by the variety of local entities, regimes, and institutional supports are captured as current challenges in sustainability efforts. Such challenges, unfortunately, persist in the group of customary communities such as those of the Bajau, who live in coastal and marine areas. In an effort to address the aforementioned challenges, this research proposes a model for integrating the Traditional Ecological Knowledge (TEK) of the Bajau into Locally Managed Marine Areas (LMMA) scheme in Wakatobi, …

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The Relative Occlusal Force Of Natural Tooth Adjacent To Distal Extension Implant Support Fixed Prosthesis Using T-Scan Analysis : A Cross Sectional Study, Chin Purintarapiban Jan 2021

The Relative Occlusal Force Of Natural Tooth Adjacent To Distal Extension Implant Support Fixed Prosthesis Using T-Scan Analysis : A Cross Sectional Study, Chin Purintarapiban

Chulalongkorn University Theses and Dissertations (Chula ETD)

Objective: This cross-sectional study aimed to compare the relative occlusal force between implant in the distal end and tooth adjacent to implant in maximum intercuspation. Methodology: Patients with implant restoration replacing teeth in free end space adjacent to natural tooth were recalled. The occlusion is examined as shim stock passes through the occluded tooth in heavy or light bites. The heavy bite or a light bite with shim stock that cannot pull through is HB1 or LB1. If the shim stock can pull through it is considered HB0 or LB0. The implant is classified into 3 groups, HB1LB0, HB1LB1, and …

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Digital Literacy For Enhancing Preparedness Capacity To Climate Related Risks Among Ageing Population In Bankgok, Thailand, Chandhit Sawangnate Jan 2021

Digital Literacy For Enhancing Preparedness Capacity To Climate Related Risks Among Ageing Population In Bankgok, Thailand, Chandhit Sawangnate

Chulalongkorn University Theses and Dissertations (Chula ETD)

The elderly population is amongst the most vulnerable group confronting climate related risks. This research aims to assess flood hazards distribution and investigate factors influencing flood literacy and preparedness actions among the elderly in Bangkok, Thailand. The AHP-GIS technique, land-use, drainage density, and annual maximum rainfall are the most important factors that influence flood hazard in Bangkok while land subsidence, past flooding events, and slope of the city have the lowest scores. Around 50% (784.089 sq.km.) of total area, mainly situated in the economic centers, is defined as high hazard. The results of policy analysis found that lack of integration …

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A Comparison Of Implant Stability Between Two Implant Systems Using Guided Surgery In Inexperienced Surgeons, Pinmuk Supachaiyakit Jan 2021

A Comparison Of Implant Stability Between Two Implant Systems Using Guided Surgery In Inexperienced Surgeons, Pinmuk Supachaiyakit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Aim: To investigate the implant stability in relation to two different implant designs, a cylindrical shaped single threaded design (CS/ST) and a tapered shaped double threaded design (TS/DT) using RFA over the first 8 weeks. Materials and Methods: 28 implants were randomly allocated into two groups and were placed as single tooth implant in the posterior arch. CBCT scan was used to determine the bone density and the implants were placed with guided surgical template by inexperienced surgeons which were prepared with the same implant planning software. The implant stability was measured using the RFA over the first 8 weeks …

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Football As A Tactical Innovation For Mobilization: A Study Of Fc Barcelona And The Catalan Independence Movement, Phawin Seangkumchoo Jan 2021

Football As A Tactical Innovation For Mobilization: A Study Of Fc Barcelona And The Catalan Independence Movement, Phawin Seangkumchoo

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Catalan Independence Movement is the movement in the Northern region of Spain which aims to be independent from Spain cause of problems in politics and economic. The Catalan mobilization not only marches on the street but also plays their role through the Spanish political procedure. In Catalan, the referendum on independence was issued in 2009-2011, 2014, and 2017. This study focuses on the Catalan mobilization tactical innovation which uses football as a tool against Spain. In this case, football which was used mean ‘FC Barcelona,’ one of the famous football club in the world. This study aims to identify …

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Eu-Vietnam Fta: Implications For Thailand, Uthaipan Promkhatkaew Jan 2021

Eu-Vietnam Fta: Implications For Thailand, Uthaipan Promkhatkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

In 2007, the EU launched a region-to-region Free Trade Agreement (FTA) with the ASEAN; however, negotiations were suspended in 2009, and the EU subsequently decided to negotiate bilateral FTAs with individual ASEAN member states. Thailand, a parliamentary democratic country, launched the first round of trade negotiations with the EU in 2013, but they were put on hold due to the military coup in 2014. On the other hand, the EU still continued to negotiate and ultimately concluded the FTA with Vietnam in 2020 despite the fact that Vietnam is one of the world’s five remaining communist states. This has raised …

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Diversification Benefits Of Commodity Indices Versus Islamic Stock Indices, Sita Khan Jan 2021

Diversification Benefits Of Commodity Indices Versus Islamic Stock Indices, Sita Khan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this study is to investigate conditional correlations between the Dow Jones Emerging Market index and commodity indices (i.e., agriculture, energy, industrial metals, livestock, precious metals) and Islamic stock indices (i.e., JKII, KLFTEMSI, MSCI Bahrain, MSCI Kuwait, and MSCI Qatar). Additionally, this paper classifies the properties of assets whether it is a diversifier, a hedger, or a safe-haven assets to the Dow Jones Emerging Market index. The estimation method is the dynamic conditional correlation generalized autoregressive conditional heteroskedasticity (DCC-GARCH) model to estimate the conditional correlations during the period of 2007-2021 which covers the Global financial crisis (GFC) and …

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Do Issuers Affect Derivative Warrants Overpricing? Evidence Of Thailand, Sarunporn Thupthong Jan 2021

Do Issuers Affect Derivative Warrants Overpricing? Evidence Of Thailand, Sarunporn Thupthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Derivative warrants have become increasingly popular in many countries. However, numerous literatures provide the empirical evidences that derivative warrants are overpriced relative to the comparable options. Many researchers found that the derivative warrant overpricing can be explained by hedging cost, liquidity premium, market power, and asymmetric information of investors. These explanations are likely to be related to characteristics of derivative warrant issuer. Therefore, this paper comes up with the objective to reconfirm the overpricing phenomenon in Thailand and investigate the issuer identity effect on the derivative warrant overpricing as well as examine what issuer’s characteristics cause the level of overpricing …

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Effects Of Ferulic Acid And Uv Curing On Properties Of Soy Protein Film, Md Shakil Jan 2021

Effects Of Ferulic Acid And Uv Curing On Properties Of Soy Protein Film, Md Shakil

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this study was to explore the effect of UV-C curing on the properties of ferulic acid-added soy protein film. The films were fabricated from soy protein isolate and added with 1.5% ferulic acid. UV-C radiation was applied at four different doses (0.32, 1.56, 4.00, 12.00 J/cm2) to either preformed film or film-forming solution. The mechanical, physicochemical, and morphological properties of the film samples were investigated. Ferulic acid addition and UV-C curing at 0.32 J/cm2 posed a significant effect on film thickness while film density was slightly affected by ferulic acid addition and/or UV-C treatment. UV-C irradiation of …

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Solid-State Modification Of Tapioca Starch Using Non-Thermal Plasma, Natchanon Srangsomjit Jan 2021

Solid-State Modification Of Tapioca Starch Using Non-Thermal Plasma, Natchanon Srangsomjit

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this research was to investigate the physical, chemical, and functional properties of tapioca starch subjected to solid-state modification by using nonthermal dielectric barrier discharge (DBD) plasma treatment using different gases (helium and argon), voltage levels (10 kV and 15 kV), and treatment times (5, 10, and 15 minutes). After treatment, an increase in L* value and a marginal decrease in pH value of all treated samples were noted. Scanning electron micrographs showed dented starch granules after the plasma treatment but showed birefringence. From XRD measurement, all samples showed a characteristic C-type diffraction pattern but a reduction in …

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Investigation Of Statistical Seismology In Thailand-Laos-Myanmar Borders, Manunchaya Neanudorn Jan 2021

Investigation Of Statistical Seismology In Thailand-Laos-Myanmar Borders, Manunchaya Neanudorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this research is to understand more about the statistical seismology of the Thailand-Laos-Myanmar border in order to monitor earthquake activity and locate potentially dangerous area. The seismicity data was collected from the Thailand Meteorological Department. Following that, the catalog's homogeneity and completeness were improved. The first step is to identify the earthquake activity by using the adaptive frequency-magnitude distribution. The results are that Nan province, Thailand, and south Luang Prabang, Laos are the highest activity areas which can generate a maximum magnitude of 5.1 ML, 5.6 ML, 6.3 ML, and 6.7 ML in 5, 10, 30, 50 …

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Analysis Of Ancient Storm Deposits Along Coastal Areas Of Andaman Sea, Thailand And Coastal Areas Of South China Sea, Vietnam, Stapana Kongsen Jan 2021

Analysis Of Ancient Storm Deposits Along Coastal Areas Of Andaman Sea, Thailand And Coastal Areas Of South China Sea, Vietnam, Stapana Kongsen

Chulalongkorn University Theses and Dissertations (Chula ETD)

The frequency of high energy storm and tsunami events is crucial for apprehending the vulnerability of coastal communities. Identifying and dating sedimentary evidence deposited by such high energy events can assist in the planning and installation of suitable protection measurements. The Andaman Sea coast of Thailand is particularly vulnerable to such events as illustrated by the 2004 Indian Ocean Tsunami (2004 IOT) and the South China Sea coast of Vietnam has been experienced from the past severe storm event. Here, the authors study the high energy sediments. The selected area of Andaman Sea coast Thailand is Laem Son National park, …

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Trace Elements And Color-Causing Role In Spinel And Tanzanite, Teerarat Pluthametwisute Jan 2021

Trace Elements And Color-Causing Role In Spinel And Tanzanite, Teerarat Pluthametwisute

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research is aimed to investigate the significant trace elements and their color-causing roles in tanzanite and spinels (7 color varieties) by focusing on their concentrations, valencies, and site occupancy since no palpable research has been reported previously either before or after heating of both gems. According to this finding, natural tanzanites usually show strongly trichroic colors of violet, blue, and brown in different directions. However, this characteristic is easily changed to violet-blue dichroism after heat treatment. As the result, the violet-blue absorption band (centered around 450–460 nm) is obviously decreased after heating, and XAS analysis indicates the higher valency …

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Stratigraphy And Paleoenvironment Of Thong Pha Phum Group In Kanchanaburi Province, Warunee Maneerat Jan 2021

Stratigraphy And Paleoenvironment Of Thong Pha Phum Group In Kanchanaburi Province, Warunee Maneerat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purposes of this study are to establish the detail lithology, stratigraphy, lithofacies and systematic paleontology of marine Silurian-Devonian sedimentary rocks of the Thong Pha Phum Group in Ban Tha Kraden, Si Sawat District, Kanchanaburi Province, and to interpret and reconstruct its depositional environment. The Thong Pha Phum Group is well exposed in the study area. It consists mainly of shale, siltstone, sandstone, limestone, argillaceous limestone, calcareous shale, calcareous mudstone, and laminated mudstone with the many fossils such as graptolites, tentaculites, ostracods, brachiopods, nautiloids and trilobites. These strata are conformably underlain by the Thung Song Group (Ordovician age) and are …

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Downhole Water Drainage From A Gas Reservoir For Water Dumpflood In An Underlying Oil Reservoir, Htet Myet Zin Naing Jan 2021

Downhole Water Drainage From A Gas Reservoir For Water Dumpflood In An Underlying Oil Reservoir, Htet Myet Zin Naing

Chulalongkorn University Theses and Dissertations (Chula ETD)

For wells drilled in a bottom water-drive gas reservoir, water coning may lead to a considerable amount of water production which diminishes the gas recovery. If the gas reservoir has an oil reservoir underneath, a method called “Downhole Water Drain for Water Dumpflood” (DWDDF) can be performed to drain water from the aquifer underneath the gas reservoir and dump it into the oil reservoir to perform waterflooding. DWDDF technique can help increase gas production from the upper gas reservoir and oil production from the lower reservoir at the same time. In this study, a simple reservoir model having common rock …

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Quality Control Of Chemical Grade Calcium Carbonate From Lopburi Limestone Deposit In Thailand, Pimpichcha Teawpanich Jan 2021

Quality Control Of Chemical Grade Calcium Carbonate From Lopburi Limestone Deposit In Thailand, Pimpichcha Teawpanich

Chulalongkorn University Theses and Dissertations (Chula ETD)

Calcium carbonate (CaCO3) is naturally produced from calcite, limestone, chalk, and marble. It is being used as raw material in various industries (e.g., cement, plastic, paint, paper, and pharmaceutical industries). The low-grade CaCO3 samples obtained from a calcite plant at Khoktum Sub-district, Muang Lopburi District, Lopburi Province, Thailand were used in this study. These samples contain more than 98% of CaCO3 while Fe2O3 contents are higher than 0.1% and increased after finished the process. Because of this problem, the products could not be sold since lower Fe2O3 contents are required (e.g., ≤0.05% for filler grade and ≤ 0.1% for animal …

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Effects Of Clay Minerals On Oil Recovery Mechanism In Low Salinity Waterflooding In Shaly-Sandstone Formation, Tri Yudha Putra Jan 2021

Effects Of Clay Minerals On Oil Recovery Mechanism In Low Salinity Waterflooding In Shaly-Sandstone Formation, Tri Yudha Putra

Chulalongkorn University Theses and Dissertations (Chula ETD)

Low Salinity Waterflooding (LSWF) is one of Enhanced Oil Recovery (EOR) techniques that are often mentioned nowadays. Several studies showed that injecting low salinity water leads to Multi-component Ion Exchange (MIE) which is one of oil recovery mechanisms provided by this technique. This study was performed to investigate the effects of specific clay mineral in rock and ion in injected water. First, representative clays were analytically tested to ensure their mineral compositions and the selected representative clays were tested by filtration with different water formulations to identify ionic capacities in MIE for each clay. Results obtained from filtration test and …

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The Effectiveness Of Asiaticoside On Osteogenic Differentiation Ability In Aging Human Periodontal Ligament Cells In Vitro, Adisa Suthirathikul Jan 2021

The Effectiveness Of Asiaticoside On Osteogenic Differentiation Ability In Aging Human Periodontal Ligament Cells In Vitro, Adisa Suthirathikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Retaining teeth is essential for the quality of life of the aging population. However, aging has biological effects in periodontal ligament cells with significant changes in their proliferative rate and regenerative function. Asiaticoside, extracted from Centella asiatica, was found to have potential in osteogenic differentiation and mineralization in human periodontal ligament cells (HPDLCs). The aim of this study is to investigate the effect of asiaticoside on the aging HPDLCs osteogenic differentiation and mineralization. Aging HPDLCs, retrieved from patients age 60 and above, were confirmed aging status using Senescence-Associated ß -Galactosidase assay. The cells were incubated with various concentrations of asiaticoside …

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Utilization Of Rain Tree (Samanea Saman) Residue As Modified Adsorbent To Treat Oil And Grease In Canteen Wastewater, Elga Riesta Puteri Jan 2021

Utilization Of Rain Tree (Samanea Saman) Residue As Modified Adsorbent To Treat Oil And Grease In Canteen Wastewater, Elga Riesta Puteri

Chulalongkorn University Theses and Dissertations (Chula ETD)

The utilization of waste materials as adsorbent precursors is gaining intention to treat fats, oils, and greases (FOG), especially in wastewater treatment. Tree residue, an abundant waste, provides a potential feedstock to be converted into valuable materials. This research aimed to develop modified adsorbent prepared from rain tree (Samanea saman) residue for FOG treatment. The synthesis process of modified adsorbent was conducted by chemical pretreatment using different chemical agents (i.e., NaOH, ZnCl2, and H3PO4­). The pre-treated twigs and leaves (1:4 ratio) were continued by pyrolysis process at different temperatures (i.e., 350, 550, and 750oC) using a heating rate of 10oC …

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Surface Activation Of Rice Husk-Derived Hydrochar As An Adsorbent For Atrazine And Ammonium, Kim Anh Phan Jan 2021

Surface Activation Of Rice Husk-Derived Hydrochar As An Adsorbent For Atrazine And Ammonium, Kim Anh Phan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Due to the agricultural intensity, studies of sustainable solutions for atrazine and nitrogen contamination have attracted more attention. This study is aimed to develop rice husk hydrochar as an adsorbent for atrazine and ammonium adsorption. Effects of microwave-assisted hydrothermal carbonization (MHTC) conditions including temperature (150 – 200°C), residence time (20 – 60 min), and liquid to solid ratio (5:1 – 15:1 mL/g) on the atrazine and ammonium adsorption capacity were investigated. Surface activation of rice husk hydrochar samples was synthesized using potassium hydroxide (KOH) and hydrogen peroxide (H2O2) with various concentrations. The results showed that higher MHTC temperature with higher …

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Changes In Surface Water And Sediment Quality At A Complex Tidal-Influenced River: A Case Study Of Ganh Hao River, Mekong Delta, Vietnam, Muoi Le Van Jan 2021

Changes In Surface Water And Sediment Quality At A Complex Tidal-Influenced River: A Case Study Of Ganh Hao River, Mekong Delta, Vietnam, Muoi Le Van

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research was carried out to determine the extent of surface water and sediment pollution using the physicochemical parameters and heavy metal concentrations. The surface water and sediment samples were obtained from 25 sites along the river on March 22 and September 5, 2019 at the main river influenced by the complex tidal regime and aquaculture practices in Ca Mau peninsular in the Vietnamese Mekong Delta. The water quality was compared with international and national standards, while the sediment quality was compared with Vietnamese standards and pollution indices (geo-accumulation index, contamination factor, and pollution load index). Principal component analysis (PCA) …

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Health Risk Assessment Of Toxic Metals In Commonly Consumed Salad Leafy Vegetables In Bangkok, Zin Htoo Hlyan Jan 2021

Health Risk Assessment Of Toxic Metals In Commonly Consumed Salad Leafy Vegetables In Bangkok, Zin Htoo Hlyan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objectives of this study were 1) to investigate concentrations of toxic metals including As, Cd, and Pb in the commonly consumed salad leafy vegetables which were sold in Bangkok, and 2) to assess potential human health risks of As, Cd, and Pb exposure via salad leafy vegetables consumption. A total of 120 samples were randomly collected from local fresh markets in Bangkok. The total concentrations of toxic metals were determined by an inductively coupled plasma mass spectroscopy (ICP-MS). Total concentrations of As, Cd and Pb in coral lettuce (CL), red coral (RC) and green oak (GO) for soil cultivation …

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The Application Of Machine Learning In Clustering Borderline Mild Cognitive Impairment Among Aging Thai People Living With Hiv, Akarin Hiransuthikul Jan 2021

The Application Of Machine Learning In Clustering Borderline Mild Cognitive Impairment Among Aging Thai People Living With Hiv, Akarin Hiransuthikul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Many people living with HIV (PLWH) have cognitive impairment. Details of cognitive impairment subtypes are lacking. Unsupervised machine learning (ML) can reveal hidden subgroups within heterogeneous data. The study aimed to determine clusters of aging Thai PLWH with borderline cognitive impairment using unsupervised ML. HIV-NAT 207 study enrolled Thai PLWH aged ≥50 years. Cognitive performance was evaluated by the Thai-validated Montreal Cognitive Assessment (MoCA). This study included participants who scored between 23 and 27. The score of each cognitive domain served as cluster variables for the K-means algorithm. Among 340 PLWH, 177 (52.1%) scored between 23 and 27. Median age …

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Analysis Of Inventory In A Food Repackaging Company, Chutipapha Thiantravan Jan 2021

Analysis Of Inventory In A Food Repackaging Company, Chutipapha Thiantravan

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to evaluate the nature of business and apply a suitable inventory policy to a case study food-repackaging company. The company adopted bulk-purchasing to packaging inventory to realize the economy of scales. Because of the lacks of purchasing standard and monitoring, this inventory policy led to the overstock, deadstock, and obsolete packaging inventories as well as the fluctuation of inventory turnover rate. The further category analysis of the packaging inventories using ABC analysis reveals that special customized bags and packaging items have a long lead time due to international sourcing and high minimum order quantity (MOQ). As a …

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Effective Traffic Signal Timing For Intersections In Bangkok, Kasidech Tantipanichaphan Jan 2021

Effective Traffic Signal Timing For Intersections In Bangkok, Kasidech Tantipanichaphan

Chulalongkorn University Theses and Dissertations (Chula ETD)

The increasing number of on-road vehicles in Bangkok, as well as the traffic flow conditions, are causing many problems for the citizens. To alleviate the problem, effective traffic signal management by optimizing traffic signal timing can be used. As a result, the goal of this research is to improve Bangkok's traffic signal system and management by establishing an effective green light time at intersections in order to increase the vehicle flow rate. The mathematical model is designed to maximize the number of vehicles leaving intersections. Six Bangkok intersections are selected for the experiments. According to the experimental results, the optimization …

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Analyzing Nypd Stop, Question, And Frisk With Machine Learning Techniques, Passiri Bodhidatta Jan 2021

Analyzing Nypd Stop, Question, And Frisk With Machine Learning Techniques, Passiri Bodhidatta

Chulalongkorn University Theses and Dissertations (Chula ETD)

Although stops from “Stop, Question, and Frisk” program have decreased dramatically after the New York Police Department (NYPD) reform in 2013, the unnecessary stops and weapon use against innocent citizens remain critical problems. This study analyzes the stops during 2014 – 2019, using three tree-based machine learning approaches: Decision Tree, Random Forest, and XGBoost. Models for predicting stops that resulted in a conviction and police’s level of force used are developed and driving factors are identified. Results show that XGBoost outperformed other models in both predictions. The performance of Guilty Prediction was at 65.9% F1 score and 84.0% accuracy. For …

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Assessments Of Chromium Pollution In Surface Sediment Of The Inner Gulf Of Thailand, Patcha Leelakun Jan 2021

Assessments Of Chromium Pollution In Surface Sediment Of The Inner Gulf Of Thailand, Patcha Leelakun

Chulalongkorn University Theses and Dissertations (Chula ETD)

The inner Gulf of Thailand is an important marine resource for economic and social developments of Thailand. Moreover, the inner Gulf of Thailand is a diverse of biological coastal ecosystem, which is make an equilibrium marine environment. On the other hand, this area is due mainly to a variety of pollutant sources from the surface runoff, particularly major large rivers including the Mae Klong, the Tha Chin, the Chao Phraya and the Bangpakong Rivers. As a result, chromium contamination can occur in the inner Gulf of Thailand and ultimately become a serious environmental issue in Thailand. Therefore, the surface sediments …

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Influence Of Seasonal Variations On Contamination Level And Ecological Risk Of Heavy Metals In The Surface Sediments Of The Inner Gulf Of Thailand, Phuttiphat Lapat-Atiwat Jan 2021

Influence Of Seasonal Variations On Contamination Level And Ecological Risk Of Heavy Metals In The Surface Sediments Of The Inner Gulf Of Thailand, Phuttiphat Lapat-Atiwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

The Inner Gulf of Thailand is a marine resource that provides ecological and economic value. Meanwhile, its can be acted like pollutions sink, especially heavy metals. After that, the extensions of industrialization, agriculturalization, and urbanization can degenerate to the inner Gulf environment quality. Therefore, this thesis was aimed to study the spatial distribution and seasonal variation of heavy metal concentration (Cd, Pb, Cu, Co, Ni, Mn and Zn) in surface sediment including the Mae Klong, the Tha Chin, the Chao Phraya and the Bangpakong River estuaries. Moreover, the contamination status and ecological risk were also evaluated. The results shown the …

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