Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2017

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 22861 - 22890 of 24650

Full-Text Articles in Entire DC Network

Characterization Of Non-Volatile Compounds In Tom Yum Soup Using High Performance Liquid Chromatography-Tandem Mass Spectrometry, Wanabud Wongbubpha Jan 2017

Characterization Of Non-Volatile Compounds In Tom Yum Soup Using High Performance Liquid Chromatography-Tandem Mass Spectrometry, Wanabud Wongbubpha

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, high performance liquid chromatography hyphenated with tandem mass spectrometry (HPLC-MS/MS) was developed and validated for simultaneous determination of 31 targeted non-volatile compounds, such as 2 organic acids, 20 amino acids and 9 phenolic acids, in Tom Yum ingredient, Tom Yum soup made from the fresh ingredients and commercial Tom Yum pastes, where the main Tom Yum ingredients include galangal, lemongrass, kaffir lime leaves, Bird's eye chili, lime juice and fish sauce. The following HPLC-MS/MS conditions were used: a PoroShell C18 column (4.6 x 100 mm, 2.7 µm) using a gradient elution of A:B mobile phase at a …

Go to article

Synthesis And Development Of Dipicolylamine Derivatives As New Fluorescent Chemosensors, Waroton Paisuwan Jan 2017

Synthesis And Development Of Dipicolylamine Derivatives As New Fluorescent Chemosensors, Waroton Paisuwan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Di-2-picolylamine (DPA) is a powerful chelator for many transition metal ions. In this thesis, new DPA fluorescent chemosensors consisting of a fluorophore such as either naphthalimide or quinoline are developed. The first part deals with the synthesis of 1,8-naphthalimide derivatives linked 2-, 3-, 4-((bis(pyridin-2-ylmethyl)amino)methyl)aniline, and 4-amino-2-((bis(pyridin-2-ylmethyl)amino)methyl)phenol. The metal ion sensing experiments showed N3D was selective toward Ag+ with fluorescent enhancement in aqueous emitting green fluorescence under blacklight. The complexation of [N3D+Ag+] is a 1:1 stoichiometric binding with a limit of detection (LOD) 0.67 µM. Second part is the synthesis of oxazolidinonyl DPA derivatives by using self-developed halo-induced cyclization followed by …

Go to article

Metabolic Responses Of Aspergillus Niger Es4 To Ethanol Stress, Wimonsiri Kongchai Jan 2017

Metabolic Responses Of Aspergillus Niger Es4 To Ethanol Stress, Wimonsiri Kongchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Aspergillus niger ES4 is a fungus isolated from the top wall of an ethanol tank of the PTT public company limited. Because normally, microorganism cannot tolerate high amount of ethanol, the growth of A. niger ES4 on the ethanol tank indicates the special properties of this fungal strain in response to ethanol. This research was therefore aimed at studying the effects of ethanol on the metabolites production of A. niger ES4 by using both untargeted and targeted metabolomics. When A. niger ES4 cultures were grown in minimal media containing 4% of ethanol for 3 days, A. niger ES4 responded to …

Go to article

Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira Jan 2017

Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira

Chulalongkorn University Theses and Dissertations (Chula ETD)

Multi-layered nano-scale structures have been found in a wide range of applications these days. Since the surface energy effect is presented at the nano-scale level, a novel calculation scheme is required to accurately capture the mechanical behaviors of such structures. In this study, a solution scheme for analysis of a multi-layered elastic medium with influence of surface energy effects subjected to axisymmetric loading by adopting Gurtin-Murdoch surface elasticity theory is presented. The standard Love's representation and Hankel integral transform are employed to derive the general solutions, and the obtained solutions are employed in the determination of the stiffness matrix for …

Go to article

Analysis Of Near Interface Cracks By Weakly Singular Boundary Integral Equation Method, Pisit Watanavit Jan 2017

Analysis Of Near Interface Cracks By Weakly Singular Boundary Integral Equation Method, Pisit Watanavit

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents a weakly singular boundary integral equation method for analysis of sub-interface cracks in a three-dimensional, linearly elastic, multi-material domain. The formulation is established in a general framework allowing finite bodies, general material anisotropy and loading conditions, arbitrarily shaped cracks, and curved material interface to be treated. A system of integral equations governing the unknown data on the boundary, the crack surface and the material interface are established using a pair of weakly singular, weak-form displacement and traction integral equations and the continuity along the material interface. A symmetric Galerkin boundary element method together with the standard finite …

Go to article

Contact Problems With Surface Stress Effects, Supakorn Tirapat Jan 2017

Contact Problems With Surface Stress Effects, Supakorn Tirapat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation presents a theoretical study of contact problems with consideration of surface energy effects by adopting a complete Gurtin-Murdoch theory of surface elasticity. The fundamental solution of a layered elastic half-space subjected to axisymmetric surface loading is obtained by using Love's representation and the Hankel integral transform. The analytical solutions for both displacement and stress fields are expressed in terms of semi-infinite integrals, which can be accurately evaluated by employing a numerical quadrature scheme. The obtained solutions are employed as the required influence functions in the investigation of axisymmetric indentation on a layered elastic medium with frictionless and adhesive …

Go to article

Seismic Effects Of Cornice Projection In Masonry-Infill Reinforced Concrete Buildings In Bhutan, Tek Nath Kararia Jan 2017

Seismic Effects Of Cornice Projection In Masonry-Infill Reinforced Concrete Buildings In Bhutan, Tek Nath Kararia

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bhutan is located in utmost active seismic zone in the belt of the Himalayan region. However, there is a prevailing architectural requirement of cornice projections away from the perimeter columns at each floor proportional to the floor level to increase floor area and retain Bhutanese architectural style. This irregular projection with thick solid brick walls resting at the edge of cantilever projection affects the structural response during a strong earthquake. To date, there is not adequate investigation on the effects of such cornice projection on seismic performance of buildings. In this study, Nonlinear Response History Analysis (NLRHA) using vertical ground …

Go to article

Using Sound To Describe Scenes With Still And Moving Obstacles, Kawin Metsiritrakul Jan 2017

Using Sound To Describe Scenes With Still And Moving Obstacles, Kawin Metsiritrakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The information human get from sight and hearing sense are similar. With these correlations, there are many works that take this idea to describe the spatial information with sound. The previous works only described the nearest obstacle with the direction and distance information to sound. To let the user clearly understand the spatial information in the scene, we aim to develop the describing solution from spatial information to auditory information including direction, distance, boundary and speed info with the multiple obstacle descriptions. The participants took the experiment by controlling the character and avoiding the obstacles in the different scenarios to …

Go to article

Developing An Area Classification System From Mobile Phone Usage Data, Naruethai Thongphasook Jan 2017

Developing An Area Classification System From Mobile Phone Usage Data, Naruethai Thongphasook

Chulalongkorn University Theses and Dissertations (Chula ETD)

Since human activities are vary by time and place, there have been many attempts to extract social behavior in spatial studies which included area use in the city. This information helps gaining advantages in city and facilities planning. Nowadays, many people carry mobile phone with them for communication purpose. This motivates us to analyze mobile phone usage in different area types. This thesis proposes method of an analysis for area use classification from mobile phone usage pattern. CDR data was used to define mobile phone usage pattern by hour from 1:00 to 24:00 and day of week from Monday to …

Go to article

Automatic 3d Hair Model From Small Set Of Images, Nuttapon Vanakittistien Jan 2017

Automatic 3d Hair Model From Small Set Of Images, Nuttapon Vanakittistien

Chulalongkorn University Theses and Dissertations (Chula ETD)

We present a system for creating hair model that matches a user's hairstyle from images. The model consists of guide hair strands and can be used in a real-time hair simulator. Our goal differs from most previous work which aims to create realistic high resolution hair for off-line applications or create mesh of the exterior of the hair volume for image manipulation. Our primary aim is for user to be able to put his/her hairstyle into game or other real-time applications. By taking photos in 8 views of the user's head using a smart phone camera and segmenting images with …

Go to article

Random Field Optimization Using Local Label Hierarchy, Sangsan Leelhapantu Jan 2017

Random Field Optimization Using Local Label Hierarchy, Sangsan Leelhapantu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Random field formulation has proven to be a powerful framework for solving various computer vision tasks, specifically those involving assigning labels to image pixels or superpixels subjected to spatial relationships and visual contexts, due to the ability to intuitively incorporate global and local information. Unfortunately, solving these problems can be impractical when large number of variables and possible labels are present as the computational complexity grows fast with the problem size. In this thesis, we propose a speedup scheme for random field optimization using local label hierarchy. We focus on problems in which the label space has a natural ordering …

Go to article

Efficient And Robust Grasp Planning Based On Independent Contact Region And Caging, Teesit Makapunyo Jan 2017

Efficient And Robust Grasp Planning Based On Independent Contact Region And Caging, Teesit Makapunyo

Chulalongkorn University Theses and Dissertations (Chula ETD)

A conventional way to find a proper grasp to grab and hold any object is to measure its stability which usually is based on physical constraint called force-closure. This execution works well from the theoretical point of view but often fails on an actual robot due to many reasons such as intrinsic errors in robot's system and a disparity between real and simulated physics. Several research works introduced methods to alleviate those issues and increase the success rate of grasping for a real robot. Caging and Independent Contact Region are ones of them. In this work, we investigate a method …

Go to article

Mesh-Based Multi-View Normal Integration With Energy Minimization Using Surface Reflectance Properties, Wichayut Eaksarayut Jan 2017

Mesh-Based Multi-View Normal Integration With Energy Minimization Using Surface Reflectance Properties, Wichayut Eaksarayut

Chulalongkorn University Theses and Dissertations (Chula ETD)

We propose a technique to reconstruct a general 3D object using surface reflectance information from multiple viewpoints. Our core optimization framework uses multi-view normal integration, which can recovers water-tight surface of the object iteratively in a coarse to fine manner. The integration requires normal vector field from multiple viewpoints, which we can derive from surface reflectance. We then handle the topological changes if self-intersection occurs from the optimization. We also employ the idea of multi-resolution and weighted data heuristic which helps dealing with noisy data and improves both accuracy and optimization time. Our experiment shows that the framework is able …

Go to article

Prediction Model Of Water Quality In Chaophraya River Using Artificial Neural Network, Weeris Treeratanajaru Jan 2017

Prediction Model Of Water Quality In Chaophraya River Using Artificial Neural Network, Weeris Treeratanajaru

Chulalongkorn University Theses and Dissertations (Chula ETD)

No abstract provided.

Go to article

Enhancing Captcha Using Eye Movement, Apichai Siripitakchai Jan 2017

Enhancing Captcha Using Eye Movement, Apichai Siripitakchai

Chulalongkorn University Theses and Dissertations (Chula ETD)

CAPTCHA is a method designed to prevent automatic registration and access. It can distinguish between real human and automated program (BOT). CAPTCHA connects to a server and then starts human verification process. The user must answer a question correctly or follow an instruction in order to get access to the system. However, there are some problems occurred to users. For example, the verification text is too distorted that even real humans do not understand or the effectiveness of preventing an automated computer program is doubted. From these reasons, researchers are still developing CAPTCHA to make it better and more effective. …

Go to article

High Capacity Image Steganography Tolerating Image Compression, Eittipat Kraichingrith Jan 2017

High Capacity Image Steganography Tolerating Image Compression, Eittipat Kraichingrith

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, data privacy becomes more important. Most of the existing data protection schemes based on cryptography cannot hide the existence of secret data. Thus, a steganography approach plays an important role to handle this problem. Image steganography can be categorized into two methods which are baesd on spatial domain and transform domain. Methods using spatial domain have high embedding capacity but they are not robust to image compression. On the other hand, methods using transform domain usually work with image compression but have low embedding capacity. In recent image steganography research, many transform domain methods are based on JPEG format …

Go to article

Biological-Like Memory Allocation Scheme Simulation, Gasydech Lergchinnaboot Jan 2017

Biological-Like Memory Allocation Scheme Simulation, Gasydech Lergchinnaboot

Chulalongkorn University Theses and Dissertations (Chula ETD)

When Gordon Moore observed the number of transistor increasing pattern while memory bandwidth could not catch up with processing unit performance, this diverging rate kept stretching out to create what eventually transpired to be “Memory Wall.” This consequence becomes a major performance bottleneck. Many bottleneck elimination approaches have been attempted. They incorporate considerable overhead and high complexity. This research proposes a novel memory allocation scheme that employs biological behavioral principles of the living creatures. At the principal construct of their life form lives the cells having limited resources, yet passively operates with little overhead. The proposed method imitates this unicellular …

Go to article

Discovery Of Relation Between Listeria And Other Bacterial Contamination Using Classification Refinement Technique, Napas Jeamchotpatanakul Jan 2017

Discovery Of Relation Between Listeria And Other Bacterial Contamination Using Classification Refinement Technique, Napas Jeamchotpatanakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

People often use chicken to prepare their diary meal which creates a great demand for food producers and exporters in Thai food industry. Thailand is ranked fourth in chicken exporters in the world. Standards on chicken meat regulations differ from country to country. One commonality remains: controlling the bacteria that can affect human life, particularly pregnant women and the unborn. One of the important bacteria is called Listeria which receives high attention for the industry to prevent their contamination in chicken. A microbiological test is usually conducted to analyze the data from industry. However, the microbiological test is incapable of …

Go to article

Diagnosis Of Heart Disease Using Mixed Classifier, Sarawut Meesri Jan 2017

Diagnosis Of Heart Disease Using Mixed Classifier, Sarawut Meesri

Chulalongkorn University Theses and Dissertations (Chula ETD)

At present, there are many studies related to the use of medical information, in order to assist in the analysis and diagnosis of the patients. In the field of computer science, there are methods to assist in analysis and diagnosis of the various diseases using the data mining techniques. Data mining is a popular technique used for analyzing a large number of data, to find the relationship of the hidden information in those data and applied for the benefits of the organization. Classification technique based on the supervised learning is one of the data mining techniques, which divides the dataset …

Go to article

Energy Aware Scheduling For Heterogeneous Mobile Task Computing, Vittayasak Rujivorakul Jan 2017

Energy Aware Scheduling For Heterogeneous Mobile Task Computing, Vittayasak Rujivorakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The problem of scheduling a set of dependent tasks from a user mobile device to several servers in communication cells while the user is moving along these cell in various speed is studied in this thesis. The challenging issue is the execution speed of each server and the speed of user's movement are not compatible. This leads to the difficulty of assigning and finishing the subset of scheduled dependent tasks to each server within the limitation of execution time during passing a cell. Another concern involved this study is the constraints on the length of makespan in terms of minimum …

Go to article

Land Use And Land Cover Change Of Chanthaburi Watershed Following 1999, 2006 And 2013 Floods, Chuti Chatewutthiprapa Jan 2017

Land Use And Land Cover Change Of Chanthaburi Watershed Following 1999, 2006 And 2013 Floods, Chuti Chatewutthiprapa

Chulalongkorn University Theses and Dissertations (Chula ETD)

The application of remote sensing (RS) and Geographic Information System (GIS) has become an effective tool and widely used in monitoring the environment on the earth surface. In this study, Landsat imageries were used as a data to deal with the assessment of land use and land cover changes (LULC) before and after the 3-year floods in 1999, 2006 and 2013. The images were classified by supervised classification process and it can be identified as 9 classes consisting of paddy field, field crop, para rubber, orchard, aquacultural land, forest land, mangrove forest, urban and built-up area, and water bodies. The …

Go to article

Geochemistry Of Petroleum Potential Source Rock In Tak Fa Formation, Phetchabun Province, Supawich Fuengfu Jan 2017

Geochemistry Of Petroleum Potential Source Rock In Tak Fa Formation, Phetchabun Province, Supawich Fuengfu

Chulalongkorn University Theses and Dissertations (Chula ETD)

Since 1962, petroleum exploration was begun in Khorat Plateau until now (2018). Nam Phong and Sin Phu Horm are two onshore petroleum commercial fields. Gas and condensate have been accumulated in Permian carbonate Pha Nok Khao Formation. Upper Carboniferous - Upper Permian in Saraburi Group was predicted to a petroleum source rock beneath the Khorat Plateau. This study analyses potential source rock in Khao Khwang Platform of Tak Fa Formation as Middle Permian sedimentary rock by nine outcrop samples from Bueng Sam Phan, Chon Daen and Nong Phai areas, Phetchabun province. Petroleum geochemistry methods are used to determine petroleum potential …

Go to article

Regional Development Models With Clean Coal Power Plants, Christoph Casimir Odermatt Jan 2017

Regional Development Models With Clean Coal Power Plants, Christoph Casimir Odermatt

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis examines clean coal technology to be used in Thailand in three studies. The economic impacts on the economic structure of southern Thailand are forecasted with the input-output method. Further, the relative levelized costs of clean coal energy relative to its amount of carbon equivalent emissions are compared to other technologies and their carbon equivalent emissions in order to compute a carbon certificate price. Lastly, the costs of the solar subsidy on the end consumer is calculated in different scenarios. The results suggest that there may be slight changes in the economic structure in southern Thailand with increases in …

Go to article

Asset Pricing And Network Topology, Harnchai Eng-Uthaiwat Jan 2017

Asset Pricing And Network Topology, Harnchai Eng-Uthaiwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation provides new empirical evidence for the relationship between network structure and asset returns in US, international markets, and Thailand. Previous studies find that a network of return correlations provides the meaningful economic taxonomy of the equity market. This finding makes the network structure a suitable channel through which an idiosyncratic shock propagates. This network feature can eliminate or amplify the idiosyncratic shock on the system-wide level. Therefore, the diversifying argument of the capital asset pricing models is not always true as the idiosyncratic shock becomes more significant when interacting with the network measures. Based on this idiosyncratic shock …

Go to article

Economic Policy Uncertainty And Carry Trade Strategy, Tiranan Sanguanjeen Jan 2017

Economic Policy Uncertainty And Carry Trade Strategy, Tiranan Sanguanjeen

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study provides a comprehensive analysis of the impact of economic policy uncertainty on carry trade. Based on 24 countries (both emerging and developed markets) during the past 17 years, the paper considers five strategies of carry trade investment (i.e. positive carry, carry to risk, yield slope, policy change and valuation), three methods of portfolio constructions (equal weight, risk parity and mean variance optimization), and four types of economic policy uncertainties (US, Japan, EU and Global). Based on vector autoregressive model, it is found that US and Japan economic policy uncertainties have most impact on carry trade return. However, direction …

Go to article

Multiple Face Detection And Recognition On Embedded Computer Vision System, Savath Saypadith Jan 2017

Multiple Face Detection And Recognition On Embedded Computer Vision System, Savath Saypadith

Chulalongkorn University Theses and Dissertations (Chula ETD)

Face recognition is widely used in many applications such as biometric for authentication, surveillance system, user-identification, and personalized technology. The state-of-the-art algorithm based on Convolutional Neural Network (CNN) can achieve up to 99% of recognition accuracy. However, there is a limitation to implement the CNN based technique into embedded system to recognize multiple face in real-time as it requires extensive computation. In this thesis, we propose a framework for multiple face recognition which consists of face detection algorithm, face recognition, and tracking. Our face recognition algorithm based on state of the art deep CNN with small computational parameters. The tracking …

Go to article

Determination Of Waste Treatment Fee Pricing Mechanism For Municipal Solid Waste By Mechanical Biological Treatment Method Utilising The Public Private Partnership Model In Thailand, Adrian Paul Raj Jan 2017

Determination Of Waste Treatment Fee Pricing Mechanism For Municipal Solid Waste By Mechanical Biological Treatment Method Utilising The Public Private Partnership Model In Thailand, Adrian Paul Raj

Chulalongkorn University Theses and Dissertations (Chula ETD)

Private participation in the development of municipal solid waste treatment projects through public-private partnership models accelerate the implementation of sustainable treatment technologies such as Mechanical Biological Treatment (MBT) facilities within developing countries without creating excessive burden to government infrastructure investment. The introduction of preset pricing mechanism to regulate potential waste treatment fee structure based on pre-determined project internal rate-of-return mitigates multi-party risks, such as the potential developer project losses or the opportunity to profiteer. Research encompasses technical assessment of project requirements for implementation of required technologies, commercial analysis of project capital expenditure (CAPEX), operational expenditure (OPEX) and assessment of revenue …

Go to article

A Comparative Assessment Of Self-Consumption Support Schemes For Rooftop Pv Systems In Thailand, Kespanerai Kokchang Jan 2017

A Comparative Assessment Of Self-Consumption Support Schemes For Rooftop Pv Systems In Thailand, Kespanerai Kokchang

Chulalongkorn University Theses and Dissertations (Chula ETD)

The growth in the adoption of solar photovoltaic (PV) power generation systems has been accelerating around the world, contributing to the debate about the future of policy and regulation in a high distributed energy resources future. Thailand is one of the leaders in solar investment in Southeast Asia. It has recently shifted its policy framework from subsidizing power export through feed-in tariffs toward a policy that is focused on supporting self-consumption of PV electricity. There are three possible forms of self-consumption support scheme: net metering, net billing, and self-consumption only. Net metering and net billing are electricity policies to assign …

Go to article

The Socio-Economic Impact Of Iuu-Fishing And Its Countermeasures On Small Scale Fishermen In Thailand : A Case Study Of Baan Khan Kradai, Ao Noi, Prachuap Kiri Khan, Roman Zwoelfer Jan 2017

The Socio-Economic Impact Of Iuu-Fishing And Its Countermeasures On Small Scale Fishermen In Thailand : A Case Study Of Baan Khan Kradai, Ao Noi, Prachuap Kiri Khan, Roman Zwoelfer

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigates the socio-economic effects of Illegal, Unreported and Unregulated fishing (IUU-fishing) on households of small scale fishermen, whose income derives almost entirely from fishing. The research question is "What are the socio-economic impacts of IUU-fishing and government's countermeasures on Thai fishing communities, in particular small scale fishermen's households, before and after 2015?". A mixed quantitative and qualitative approach was chosen to better grasp the complexity of fishing-related changes to household income and by the case study of a small scale fishing community in Ao Noi Subdistrict of Prachuap Kiri Khan Province. This resulted to a general understanding of …

Go to article

Drivers And Constraints Of Conversion To Organic Farming In The Kingdom Of Bhutan, Parladh Mahat Jan 2017

Drivers And Constraints Of Conversion To Organic Farming In The Kingdom Of Bhutan, Parladh Mahat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Organic farming is one of the several approaches towards environmental conservation and aims to increase agricultural production and household income for small-scale farmers to enable them to come out of poverty and improve livelihood. The objective is to investigate the key drivers and constraints in conversion to organic farming for domestic organic certified and non-certified but organic farmers and provide policy recommendation to government and relevant agency. The survey data of 146 respondents comprising of certified organic (n=47) and non-certified (n=99) were collected from Gasa district of Bhutan during the month of October 2017. The data analysis includes the use …

Go to article

First Prev Next Last