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Articles 1711 - 1740 of 1876
Full-Text Articles in Physical Sciences and Mathematics
Using Sound To Describe Scenes With Still And Moving Obstacles, Kawin Metsiritrakul
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 …
Developing An Area Classification System From Mobile Phone Usage Data, Naruethai Thongphasook
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 …
Automatic 3d Hair Model From Small Set Of Images, Nuttapon Vanakittistien
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 …
Random Field Optimization Using Local Label Hierarchy, Sangsan Leelhapantu
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 …
Efficient And Robust Grasp Planning Based On Independent Contact Region And Caging, Teesit Makapunyo
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 …
Mesh-Based Multi-View Normal Integration With Energy Minimization Using Surface Reflectance Properties, Wichayut Eaksarayut
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 …
Prediction Model Of Water Quality In Chaophraya River Using Artificial Neural Network, Weeris Treeratanajaru
Prediction Model Of Water Quality In Chaophraya River Using Artificial Neural Network, Weeris Treeratanajaru
Chulalongkorn University Theses and Dissertations (Chula ETD)
No abstract provided.
Enhancing Captcha Using Eye Movement, Apichai Siripitakchai
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. …
High Capacity Image Steganography Tolerating Image Compression, Eittipat Kraichingrith
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 …
Biological-Like Memory Allocation Scheme Simulation, Gasydech Lergchinnaboot
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 …
Discovery Of Relation Between Listeria And Other Bacterial Contamination Using Classification Refinement Technique, Napas Jeamchotpatanakul
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 …
Diagnosis Of Heart Disease Using Mixed Classifier, Sarawut Meesri
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 …
Energy Aware Scheduling For Heterogeneous Mobile Task Computing, Vittayasak Rujivorakul
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 …
Land Use And Land Cover Change Of Chanthaburi Watershed Following 1999, 2006 And 2013 Floods, Chuti Chatewutthiprapa
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 …
Geochemistry Of Petroleum Potential Source Rock In Tak Fa Formation, Phetchabun Province, Supawich Fuengfu
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 …
A Comparative Assessment Of Self-Consumption Support Schemes For Rooftop Pv Systems In Thailand, Kespanerai Kokchang
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 …
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 …
Drivers And Constraints Of Conversion To Organic Farming In The Kingdom Of Bhutan, Parladh Mahat
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 …
Paleo Sea-Level Change Of Laem Pho, Amphoe Chaiya, Changwat Surat Thani, Sinenard Polwichai
Paleo Sea-Level Change Of Laem Pho, Amphoe Chaiya, Changwat Surat Thani, Sinenard Polwichai
Chulalongkorn University Theses and Dissertations (Chula ETD)
The study of beach ridges plains at Laem Pho study area in Amphoe Chaiya, Changwat Surat Thani is aimed to investigate coastal geomorphology and sedimentology to analyze the history of Holocene sea level change. The methodology starts with satellite image interpretation of landform for field survey planning, then, geomorphologic map was done for locating sample collection sites. Grainsize analysis and Optically Stimulated Luminescence (OSL) dating were carried out. As a result, the study area has dominant landforms of beach ridge plains and sand spit oriented in southeast direction correspondence with southeast longshore current. Source of sediment supply to this coastal …
Ancient And Modern Fluvial Geomorphology Of Meandering System From Upstream Area Of The Mun River, Changwat Nakhon Ratchasima, Parisa Nimnate
Ancient And Modern Fluvial Geomorphology Of Meandering System From Upstream Area Of The Mun River, Changwat Nakhon Ratchasima, Parisa Nimnate
Chulalongkorn University Theses and Dissertations (Chula ETD)
At the southwestern rim of the Khorat Plateau, the upstream part of the Mun River flows through clastic sedimentary rocks leading to a massive amount of sand was transported via the Mun River to downstream. The Mun Bon Dam was constructed in 1986, and it would be effect more or less on river system. Therefore, the aim of this thesis is to analyze the geomorphological changes before and after the Mun Bon Dam construction. Moreover, the sedimentary facies from geological and shallow geophysical surveys were characterized. The geomorphic parameters was analyzed from series of aerial-photo and satellite image which were …
Apatite Fission Track Dating Of Mesozoic Siliciclastic Rocks From Khorat Group In Phu Phan Mountain Range, Northeastern Thailand, Apivut Veeravinantanakul
Apatite Fission Track Dating Of Mesozoic Siliciclastic Rocks From Khorat Group In Phu Phan Mountain Range, Northeastern Thailand, Apivut Veeravinantanakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
Field and remote-sensing investigations have been performed for mapping the Mesozoic siliciclastic rocks of the Phu Phan Ranges (PPR), northeastern Thailand. Stratigraphically, the PPR study area has been remapped and is occupied by 5 distinct successive formations, including the Phu Kradung Formation with the average thickness of 93 m, the Phra Wihan Formation with the average thickness of 64 m, the Sao Khua Formation with the average thickness of 63 m, the Phu Phan with the average thickness of 84 m, and the Khok Kruat with the average thickness of 49 m. Results on field and remote sensing analyses reveal …
Human Health Risk Assessment Of Cadmium Exposure Through Rice Consumption In Mae Tao, Mae Sot District, Tak Province, Parin Suwatvitayakorn
Human Health Risk Assessment Of Cadmium Exposure Through Rice Consumption In Mae Tao, Mae Sot District, Tak Province, Parin Suwatvitayakorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Mae Tao sub-district is located in the Mae Tao watershed, an important Cd contaminated area in Thailand. This study was conducted to i) investigate total Cd concentration in rice from households in the Mae Tao sub-district and ii) estimate health risks from Cd exposure through rice consumption. A total number of 159 rice samples were collected from households in all 6 villages of the Mae Tao sub-district. These rice samples were digested with concentrated nitric acid and analyzed by the inductively coupled plasma mass spectrometry (ICP-MS). Biodata information and rice consumption behavior were surveyed from the local residents at the …
Assessment Of Cadmium Migration Into Groundwater In Mae Sot District, Tak Province Using Monte Carlo Technique, Pongsathorn Thunyawatcharakul
Assessment Of Cadmium Migration Into Groundwater In Mae Sot District, Tak Province Using Monte Carlo Technique, Pongsathorn Thunyawatcharakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
Mae Sot is a district in Tak province that confronts Cd contamination within the area. The target organs for Cd exposure was kidneys and skeletal system which could lead to severe health effects such as renal dysfunction, osteoporosis, bone softening, Itai-Itai disease, and lung cancer. The intention of this study was to examine the sorption behavior of nine soil samples in the study area and applied Monte Carlo technique that would increase model efficiency for Cd migration in to the soil profile. Batch adsorption experiments were performed and fitted with the adsorption isotherms as follows: Linear, Langmuir, and Freundlich isotherms. …
The Effect Of Edta-Application To Heavy Metals Phytoremediation By Vetiver, Ramida Wasino
The Effect Of Edta-Application To Heavy Metals Phytoremediation By Vetiver, Ramida Wasino
Chulalongkorn University Theses and Dissertations (Chula ETD)
Contaminated soil with heavy metals includes Pb, Zn, and Cd were remediated by phytoremediation with vetiver to solved the problem in Thailand. This study compared the ability of two species of vetiver (i.e., Songkhla 3 and Prachuap Khiri Khan) in absorbing Pb, Zn, and Cd in contaminated soils and study the effect of EDTA application. After the experiment, Toxicity Characteristic Leaching Procedure (TCLP) test, Allium test, and seed germination were used to determined the toxicity of remediated soil. In this study, 5 mmol of ethylenediaminetetraacetic acid (EDTA) was used to improve the solubility of heavy metals in soil which leads …
Global Well-Posedness Of Reaction-Diffusion Equations With Non-Radial Kernel Function, Apassara Suechoei
Global Well-Posedness Of Reaction-Diffusion Equations With Non-Radial Kernel Function, Apassara Suechoei
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this thesis, we study the following reaction-diffusion equation:[Equation] where f is a continuously differentiable function on R , α > 0 is a constant, [sumbol] is a continuous function and is non-radial kernel function. We establish the corresponding comparison principle. Then, we prove the local existence and uniqueness result based on the monotone iteration sequence technique. Finally, certain sufficient conditions on the local nonlinear term that guarantee the existence and uniqueness of global solution are specified.
Boundedness Of Green Operators For Nonlocal Equations On Weighted Lebesgue Spaces, Itthinat Nuntajittanond
Boundedness Of Green Operators For Nonlocal Equations On Weighted Lebesgue Spaces, Itthinat Nuntajittanond
Chulalongkorn University Theses and Dissertations (Chula ETD)
In this research. we establish the local existence and uniqueness of solutions for the Cauchy problem of the nonlocal equation of the form ∂ₜU(x.t) = ∫R n J(x.Y)U(Y,t)dY – U (x.t) + (In(e + I x I2)) U p (x,t) where p > 1 and ∂ > 0 are constants. In this research, the kernel / of the nonlocal term may not radially symmetric. We investigate the Cauchy problem on weighted Lebesgue spaces with a logarithmic weight. One of the most important results in this thesis is the boundedness of the corresponding Green operator on the weight Lebesgue spaces. We also establish …
F-Cs-Rickart Modules, Julalak Kaewwangsakoon
F-Cs-Rickart Modules, Julalak Kaewwangsakoon
Chulalongkorn University Theses and Dissertations (Chula ETD)
No abstract provided.
Quotients Induced From Exponents Of Finite Commutative Rings, Kantapong Wannatong
Quotients Induced From Exponents Of Finite Commutative Rings, Kantapong Wannatong
Chulalongkorn University Theses and Dissertations (Chula ETD)
We use the concept of exponent of finite commutative rings to define the Carmichael quotients and the Carmichael quotients of degree d over polynomial rings over finite local rings, and then we give some congruence relations of these quotients. Moreover, we define the Carmichael quotients and the Wilson quotients over the ring of integers of number fields and study some congruence relations between them.
Non-Uniform Bounds On Normal Approximation Via Stein's Method And Exchangeable Pair, Kantapong Wannatong
Non-Uniform Bounds On Normal Approximation Via Stein's Method And Exchangeable Pair, Kantapong Wannatong
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation consists of two parts. In the first, we improve the technique of Chuntee and Neammanee (2017) to obtain an exponential non-uniform bound on normal approximation for any random variables whose exchangeable pair can be constructed. Moreover, we give applications of the theorem to obtain non-uniform exponential bounds of normal approximations for sums of bounded independent random variables, the numbers of descents and inversions of permutation and combinatorial central limit theorem for real numbers. In the second part, we construct a new version of the Rosenthal inequality and improve the technique of Simcharoen and Neammanee (2016) to obtain a …
Anomalous Assemblage Detection Using Nearest Neighbor Distance, Kayyasit Singkarn
Anomalous Assemblage Detection Using Nearest Neighbor Distance, Kayyasit Singkarn
Chulalongkorn University Theses and Dissertations (Chula ETD)
The outlierness of an instance in this thesis is defined based on the distance between two instances. For some datasets, outliers may not be isolated and formed small clusters. C-anomalous assemblage is a group of associated outliers having the number of instances less than or equal to C percent of the total instances. This thesis presents the anomalous assemblage detection algorithm called CND using a nearest neighbor distance for an anomalous score. The algorithm computes the index k equal to floor function of C percent times the total number of instances and uses the k-nearest neighbor distance for representing an …