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New Edta-Based Drug Delivery Carrier, Nathapong Pangkom
New Edta-Based Drug Delivery Carrier, Nathapong Pangkom
Chulalongkorn University Theses and Dissertations (Chula ETD)
Most of the anticancer drugs are insoluble in water, unspecified to target site and degradable under acidic conditions in the stomach, resulting in decreasing their activities and increasing the side effects. To overcome these problems, drug delivery carriers were used to overcome these problems. Most of the drug delivery carriers were prepared by polymeric micelle systems. However, that of polymeric micelle systems are difficult to synthesize into the random polymers, where different units are aligned on a polymer chain in a random manner, immature drug-incorporation technology and possible chronic liver toxicity due to slow metabolic process. Therefore, the enhancement of …
Preparation Of Rigid Polyurethane Foams Catalyzed By Metal-Asparagine And Metal-Threonine Complexes, Nuttiya Jintana
Preparation Of Rigid Polyurethane Foams Catalyzed By Metal-Asparagine And Metal-Threonine Complexes, Nuttiya Jintana
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research aimed to synthesize metal-amino acid complexes in the form of aqueous solutions to serve as new catalysts for the preparation of rigid polyurethane foams. Aqueous solutions of metal-amino acid complexes were prepared from the reaction of metal acetates with amino acids and water was used as a solvent. Metal acetates employed were copper acetate and zinc acetate. Amino acids employed were asparagine (Asn) and threonine (Thr). Both amino acids are odorless and non-toxic. UV-Vis spectroscopy, FTIR spectroscopy and mass spectrometry were used to characterize metal-amino acid complexes. Metal-amino acid complexes, namely Zn(Asn)₂, Zn(Thr)₂, Cu(Asn)₂ and Cu(Thr)₂ (where Asn …
Characterization Of Aroma-Active Volatile Compounds In Tom Yum Soup By Gas Chromatography-Mass Spectrometry Combined With Sensory Evaluation Techniques, Pannipa Janta
Chulalongkorn University Theses and Dissertations (Chula ETD)
Gas chromatography-mass spectrometry/olfactometry coupled with headspace-solid phase microextraction (HS-SPME-GC-O/MS) was applied for the characterization of volatile compounds in Tom Yum soup and its individual ingredients including lemongrass, kaffir lime leaf, chili, fish sauce and lime juice. Using HS-SPME with a 50/30 µm DVB/CAR/PDMS fiber and an extraction temperature of 40 °C for 50 min, along with an HP-5MS capillary column programmed from 50 to 200 °C at 3 °C/min and an MS electron impact ionization at -70 eV, 101 peaks in the HS-SPME-GC-MS chromatogram of Tom Yum soup were detected, and 96 volatile compounds were identified including alcohols, aldehydes, esters, …
Colorimetric Detection Of Cyanide Ions Using Complex Formation And Ctab-Coated Silica, Patita Salee
Colorimetric Detection Of Cyanide Ions Using Complex Formation And Ctab-Coated Silica, Patita Salee
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research presents a new colorimetric method of cyanide detection in solution and water samples based on the extraction of dicyano-bis-(1,10-phenanthroline)-iron(II) complex onto CTAB-coated silica. The complex was formed at pH 10 by using phosphate buffer via the complex formation between tris-(1,10-phenanthroline)-Iron(II) (ferroin) with cyanide ions in CTAB media. When the complex was extracted onto CTAB-coated silica, it resulted in a color change of the material from pale yellow to purple. The changing of color corresponded to cyanide concentration which could be observed by naked-eyes and the color intensity was determined by Image J. The effects of various parameters were …
Fabrication Of Silver Nanofilament Based On Silver Sulfide Solid Electrolyte For Tip-Enhanced Raman Spectroscopy, Phichaya Fueaimi
Fabrication Of Silver Nanofilament Based On Silver Sulfide Solid Electrolyte For Tip-Enhanced Raman Spectroscopy, Phichaya Fueaimi
Chulalongkorn University Theses and Dissertations (Chula ETD)
Surface science analysis is the crucial fundamental of nanoscale study. The techniques combined morphological and compositional study on the surface are the promising technique. Tip-enhanced Raman spectroscopy (TERS) is the coupling of atomic force microscopy (AFM) and Raman spectroscopy which give the 3D- images and bonding information in ambient conditions. Furthermore, TERS tip is an ideal tool for the high enhancement and spatial resolution. Nowadays, TERS tip fabrication is still challenged. There are three main challenges that are high enhancement factor of the TERS tip, reproducibility of the tip and in-depth understanding of TERS process. We introduce the simple method …
Fluoride Encapsulation In Calcium Matrix, Piyada Dissara
Fluoride Encapsulation In Calcium Matrix, Piyada Dissara
Chulalongkorn University Theses and Dissertations (Chula ETD)
Fluoride ion (F-) is an important ingredient in a toothpaste. It protects caries by reacting with hydroxyapatite [Ca10(PO)4(OH)2] in tooth enamel to form insoluble fluorapatite [Ca10(PO)4(F)2]. Unfortunately, F- also easily interacts with calcium species in a toothpaste, and then it is deactivated. In this work, we focus on the encapsulation of F- in a shellac bead by using a simple extrusion method. To construct shellac beads, an aqueous solution of F- is injected into an ethanolic solution of shellac. The shellac beads are formed due to insolubility of shellac in water. Then, the beads are transferred into DI water for …
Ferrocene-Bearing Tea Polyphenol Particles As Anticancer Drug Carriers, Punnawich Phaiyarin
Ferrocene-Bearing Tea Polyphenol Particles As Anticancer Drug Carriers, Punnawich Phaiyarin
Chulalongkorn University Theses and Dissertations (Chula ETD)
Ferrocene is a redox moiety that can be positively charged upon being oxidized. Thus, it is possible to use this moiety to make a polymer platform that is redox responsive regarding their water solubility. Here we prepared polymerized EGCG nanoparticles (pEGCG) and polymerized EGCG gum (pEGCG-gum) from tea polyphenol EGCG. Ferrocene was grafted onto the polymerized tea polyphenol and the obtained polymers were allowed to self-assemble into water-insoluble and indispersible sub-micron particles. The water-insoluble ferrocene-bearing particles became water-dispersible particles with nanometer sizes upon being oxidized by hydrogen peroxide. The oxidized particles, Fc-pEG-gum can inhibit growth of HepG2 liver cancer cells …
Colorimetric Detection Of Cysteine Using Silver-Hydroxyapatite Nanoparticles, Retno Prasetia
Colorimetric Detection Of Cysteine Using Silver-Hydroxyapatite Nanoparticles, Retno Prasetia
Chulalongkorn University Theses and Dissertations (Chula ETD)
Cysteine is a sulphur-containing amino acid that acts as an effective antioxidant in human body. An excessive amount of cysteine leads to cystine formation that causes the stone formation in kidney, bladder, and ureters. A new method was developed for detection of cysteine in urine samples based on the aggregation of silver nanoparticles (AgNPs) on Hydroxyapatite (HAp) in the presence of cysteine. Transmission Electron Microscope (TEM) was used to observe the morphology of prepared HAp and AgNPs on HAp. The presence of cysteine of different concentrations resulted in different cluster sizes of AgNPs on HAp and hence different solid color. …
Synthesis And Supramolecular Polymerization Of Peptide Nucleic Acid-Containing Monomer, Ruttiyakorn Donthongkwa
Synthesis And Supramolecular Polymerization Of Peptide Nucleic Acid-Containing Monomer, Ruttiyakorn Donthongkwa
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nucleobase-induced self-assembly interaction, have gained much attention as potential non-covalent driving force for generating interesting assembled structures. Pyrrolidinyl peptide nucleic acid (PNA), with (2′R,4′R)-prolyl/(1S,2S)-2-aminocyclopentanecarboxylic acid backbone (acpcPNA) has shown the recognition with complementary nucleic acids following Watson-Crick base rules. Another PNA system having different stereochemistry on proline ring with a backbone of (2′R,4′S)-prolyl/(1S,2S)-2-aminocyclopentanecarboxylic acid backbone (epi-acpcPNA) can undergo self-pairing. Here in this work, both acpcPNA- and epi-acpcPNA-functionalized monomers consisting of two PNA segments joined together by a flexible polyethylene glycol linker were prepared on solid support, purified by high performance liquid chromatography (HPLC) and characterized by MALDI-TOF mass spectrometry. The …
Synthesis And Cytotoxicity Evaluation Of Gold Nanoparticles/Pullulan Derivatives For Cancer Treatment, Sakchai Laksee
Synthesis And Cytotoxicity Evaluation Of Gold Nanoparticles/Pullulan Derivatives For Cancer Treatment, Sakchai Laksee
Chulalongkorn University Theses and Dissertations (Chula ETD)
This study focused on the development of multifunctional gold nanoparticles (AuNPs) using pullulan derivatives as a trifunctional reducing, stabilizing and capping agent for targeted delivery of camptothecin (CPT) or doxorubicin (DOX) in order to enhance their efficacy and reduce side effects. The surface of AuNPs was functionalized to contain 3 beneficial components on pullulan as followed: (i) quat188 as a positive charge to increase cellular uptake and activities, (ii) para-aminobenzoic acid (PABA) as a hydrophobic molecule to enhance biocompatibility, and (iii) folic acid (FA) as a targeting ligand to bind with folate receptor on cancerous cell membranes and enhance intracellular …
Functionalization Of Chemical Vapor Deposition-Grown Graphene, Shobnibhit Chatmaneerungcharoen
Functionalization Of Chemical Vapor Deposition-Grown Graphene, Shobnibhit Chatmaneerungcharoen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Graphene has been a wonder material since its discovery in 2004. Due to its interesting properties such as excellent thermal and electrical conductivities, flexibility and high strength, many researchers around the globe have turned their attention to this carbon allotrope. To synthesize graphene with high quality, chemical vapor deposition (CVD) is an industrially feasible method. Generally, methane is the most widely used carbon precursor. However, high purity grade is expensive in Thailand. Instead, acetylene should be a possible replacement. Moreover, operating CVD at atmospheric pressure would also dramatically reduce the cost. Still, growth conditions need to be optimized for new …
Bioactive Compounds From Lichens And Mycobionts In Trypetheliaceae Family, Suekanya Jarupinthusophon
Bioactive Compounds From Lichens And Mycobionts In Trypetheliaceae Family, Suekanya Jarupinthusophon
Chulalongkorn University Theses and Dissertations (Chula ETD)
Chemical constituents of two lichens Marcelaria cumingii and Trypethelium subeluteriae, and four cultured mycobionts from M. cumingii, T. platystomum, T. eluteriae and Trypethelium sp. (Trypetheliaceae) were explored. Their secondary metabolites were structurally elucidated by spectroscopic methods as xanthones, anthraquinones, naphthoquinones and phenalenones. Lichexanthone, parietin, xanthorin and emodin were disclosed as constituents of lichens M. cumingii. Whereas, two anthraquinones: parietin and emodin could be isolated from T. subeluteriae together with another anthraquinone, haematommone. The chemical compositions of four cultured mycobionts were found to totally differ from those from lichen. The phenalenone bipolaride C was derived from T. platystomum while two 1,2-naphthoquinones, …
Colorimetric Determination Of Thiocyanate Ion Using Modified Polymer Resins, Sujinda Khaosaard
Colorimetric Determination Of Thiocyanate Ion Using Modified Polymer Resins, Sujinda Khaosaard
Chulalongkorn University Theses and Dissertations (Chula ETD)
A new method for thiocyanate determination in milk samples based on the formation of dithiocyanato dipyridine copper(II) [Cu(SCN)2(Py)2] complex on polymer resin surface is proposed. Amberlite XAD-7 resin on was modified with copper-pyridine complex and used as the material for detection. The color of resin changed from blue to green with the increase of thiocyanate concentration. It could be observed by naked-eye and the color intensity used as quantitative data was measured via Image-J software. The effect of various parameters was investigated including Cu2+ concentration, time for resin modification with reagents, sample volume, detection time and pyridine volume. Under the …
Composite Fiber Of Poly(3,4-Ethylenedioxythiophene) And Derivative For Electrochemical Applications, Thanarath Pisuchpen
Composite Fiber Of Poly(3,4-Ethylenedioxythiophene) And Derivative For Electrochemical Applications, Thanarath Pisuchpen
Chulalongkorn University Theses and Dissertations (Chula ETD)
Poly(3,4-ethylenedioxythiophene) (PEDOT) is a conducting polymer that has many advantages including high conductivity, high transparency, and good stability. Despite its advantages, its insolubility and lack of active groups for further functionalization remain the major obstacles for its applications. In this work, polymer/PEDOT composite fibers were fabricated using solid state polymerization of 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) and its derivative containing carboxylic acid (DBEDOT-C4-COOH) in combination with electrospinning technique to ensure good dispersion of PEDOT in polymer matrix. The well-dispersed electrospun PEDOT/polymer composite the fiber mats were used to modify the screen-printed carbon electrode as testing models. The PEDOT/poly(vinyl alcohol) (PVA) composite fiber fabricated …
Design And Synthesis Of Selenium Nanoparticles To Overcome Multiple Drug Resistance Of Cancer Cells, Urarika Luesakul
Design And Synthesis Of Selenium Nanoparticles To Overcome Multiple Drug Resistance Of Cancer Cells, Urarika Luesakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
The objective of this research is to synthesize selenium nanoparticles (SeNPs) stabilized by chitosan as a drug carrier for delivery doxorubicin to overcome drug-resistant in cancer cells. One important mechanism of multidrug resistance (MDR) includes decreased drug influx and increased drug efflux, leading to insufficient drug concentration to kill cancer cells. Therefore, to overcome MDR by increasing cellular uptake, the surface of SeNP was functionalized to provide 3 structural features: (i) a positive charge to improve their solubility, (ii) gallic acid, a hydrophobic molecule to enhance biocompatibility and (iii) folic acid, a targeting molecule to target cancer cells and enhance …
Synthesis Of Alternating Conjugated Copolymers From Direct C-H Arylation, Vasin Thummasorn
Synthesis Of Alternating Conjugated Copolymers From Direct C-H Arylation, Vasin Thummasorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
Synthesis of conjugated polymers via Direct Hetero Arylation Polycondensations (DHAPs) through palladium catalyzed cross-coupling polymerization was investigated. This synthetic method has advantages over traditional method by omitting the preactivation of one of the coupling partner, minimizing production of toxic wastes, side products, and cost. We obtained the donor-acceptor copolymer 4 from DHAPs of 2,5-dichloro-3,4-dinitrothiophene (DCDNT) and 3,4-ethylenedioxythiophene (EDOT) as orange solid in 31.7% yield. Copolymer 5 was also obtained using the same methodology from EDOT and 1,4-dibromo-2,5-bis(octyloxy)benzene (DBOB) as the precursors, in which the best result was 86% yield. The optimized DHAP condition was used to prepare copolymers 6 (from …
Synthesis Of Thiofuranosides By Dehydrative Glycosylation In Micellar Media, Trichada Ratthachag
Synthesis Of Thiofuranosides By Dehydrative Glycosylation In Micellar Media, Trichada Ratthachag
Chulalongkorn University Theses and Dissertations (Chula ETD)
Green and aqueous-based dehydrative glycosylation of thiofuranosides in micellar media was developed. The thiofuranosides are useful as precursors for carbohydrate synthesis, biological active molecules, and bio-surfactants. Dodecylbenzenesulfonic acid (DBSA), a commercially available Brønsted acid-surfactant, was employed to increase solubility of substrates and enhance rate of the glycosylation. Herein, we report the dehydrative glycosylation of furanosides and pyranosides with aliphatic, aromatic, and heterocyclic thiols in aqueous media to afford the thiofuranosides. Microwave irradiation led to improved yields and shorter reaction times. Other reaction parameters such as temperature and the amount of acid used were also optimized. Aliphatic and aromatic thiofuranosides were …
Characterization Of Non-Volatile Compounds In Tom Yum Soup Using High Performance Liquid Chromatography-Tandem Mass Spectrometry, Wanabud Wongbubpha
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 …
Synthesis And Development Of Dipicolylamine Derivatives As New Fluorescent Chemosensors, Waroton Paisuwan
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 …
Metabolic Responses Of Aspergillus Niger Es4 To Ethanol Stress, Wimonsiri Kongchai
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 …
Multi-Layered Elastic Medium Under Axisymmetric Loading And Surface Energy Effects, Kanin Tarntira
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 …
Analysis Of Near Interface Cracks By Weakly Singular Boundary Integral Equation Method, Pisit Watanavit
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 …
Contact Problems With Surface Stress Effects, Supakorn Tirapat
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 …
Seismic Effects Of Cornice Projection In Masonry-Infill Reinforced Concrete Buildings In Bhutan, Tek Nath Kararia
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 …
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 …