Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Materials Science and Engineering (888)
- Civil and Environmental Engineering (788)
- Chemical Engineering (656)
- Engineering Science and Materials (484)
- Physical Sciences and Mathematics (462)
-
- Operations Research, Systems Engineering and Industrial Engineering (375)
- Industrial Engineering (372)
- Electrical and Computer Engineering (358)
- Operational Research (307)
- Civil Engineering (274)
- Construction Engineering and Management (274)
- Electrical and Electronics (264)
- Computer Engineering (243)
- Computer Sciences (235)
- Social and Behavioral Sciences (217)
- Environmental Sciences (216)
- Environmental Studies (216)
- Environmental Engineering (161)
- Mechanical Engineering (102)
- Applied Mechanics (101)
- Engineering Mechanics (100)
- Petroleum Engineering (88)
- Power and Energy (86)
- Biomedical Engineering and Bioengineering (40)
- Polymer Science (40)
- Geological Engineering (39)
- Metallurgy (39)
- Mining Engineering (39)
- Risk Analysis (38)
- Keyword
-
- Microstructure (9)
- Chitosan (7)
- Rice husk ash (7)
- Mechanical properties (6)
- Hardness (5)
-
- Heat treatment (5)
- Coating (4)
- Oxidation (4)
- Sintering (4)
- Stainless steel (4)
- Adhesion (3)
- Fatigue (3)
- Glass-ceramics (3)
- Hydroxyapatite (3)
- Layer-by-layer (3)
- Polypropylene (3)
- Powder metallurgy (3)
- Precipitation (3)
- Silica (3)
- Strain rate (3)
- X-ray diffraction (3)
- คลังสินค้า (3)
- AISI 4140 steel (2)
- Adsorption (2)
- And Nickel-Based Superalloy (2)
- Collagen (2)
- Corrosion (2)
- Cotton fabric (2)
- Cyclohexane (2)
- ECAP (2)
- Publication Year
- Publication
- Publication Type
Articles 2641 - 2670 of 3637
Full-Text Articles in Engineering
Lactic Acid Production From Glucose By Using Divalent Transition Metal Oxide Catalyst On Magnesium Oxide Support Without Alkaline Solution, Tanyatorn Udomcharoensab
Lactic Acid Production From Glucose By Using Divalent Transition Metal Oxide Catalyst On Magnesium Oxide Support Without Alkaline Solution, Tanyatorn Udomcharoensab
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research was studied the effects of the type of divalent metal oxide (Cu, Co, Ni, and Zn) supported on magnesium oxide catalyst using the hexadecyltrimethylammonium bromide (CTAB) as the capping agent with metal loading at 1.5, 5, and 10 mmol/gram-catalyst on lactic acid production from glucose. To achieve the lactic acid production of lower reactor corrosion rate and being environmentally friendly, the reaction was performed in an alkali additive-free environment. The catalysts were synthesized by hydrothermal method and characterized by various techniques. The XRD pattern of spent CuCTAB/MgO and CoCTAB/MgO catalyst showed the reduced metal species indicated the used …
Effect Of Tio2 Polymorphs And Crystallite Size On The Catalytic Properties Of Pt/Tio2 In The Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Thunyaporn Kaewla-Ueat
Effect Of Tio2 Polymorphs And Crystallite Size On The Catalytic Properties Of Pt/Tio2 In The Selective Hydrogenation Of Furfural To Furfuryl Alcohol, Thunyaporn Kaewla-Ueat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Furfuryl alcohol (FA) is an important intermediate for the manufacturing of many fine chemical products such as furan, resin, vitamin C, and lysine. In this research, the selective hydrogenation of furfural to FA was carried out in a batch reactor at 50ºC, 20 bar H2 and 2 h reaction time using Pt (0.5 wt. %) on TiO2 support. The Pt/TiO2 catalysts were prepared by the incipient wetness impregnation on different commercial TiO2 polymorphs and different temperatures calcined TiO2 sol-gel. Among the commercially available TiO2, it was found that Pt supported on P25 exhibited the highest furfural conversion and selectivity of …
Analysis Of Cracked Body Repaired By Adhesively Bonded Patches By Bem-Fem Coupling, Binh Viet Pham
Analysis Of Cracked Body Repaired By Adhesively Bonded Patches By Bem-Fem Coupling, Binh Viet Pham
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis presents an efficient numerical technique capable of handling the stress analysis of three-dimensional cracked bodies strengthened or repaired by adhesively bonded patches. The proposed technique is implemented within the framework of the coupling of the weakly singular boundary integral equation method and the standard finite element procedure. The former is applied to efficiently treat the elastic body containing cracks whereas the latter is adopted to handle both the adhesive layers and the patches. The approximation of the near-front relative crack-face displacement is enhanced by using local interpolation functions that can capture the right asymptotic behaviour. This also offers …
The Relationship Of Influential Factors On Material Management Effectiveness In Building Construction Projects: Case Study In Vietnam, Bao Van Pham
Chulalongkorn University Theses and Dissertations (Chula ETD)
The improvement of management processes in construction could be seen as one of the important keys to project success in which material management should be appropriately taken into consideration. Although many previous research studies have examined the components of construction material management, the relationship of factors influencing material management effectiveness has not been explored. This study was carried out to identify influential factors on material management effectiveness and develop a model to explain the relationships between these factors and the effectiveness of material management based on practical projects. The research method included the collection of contractors' opinions in building projects …
Sbfe Analysis Of Layered Elastic Media With Consideration Of Surface Energy Effect, Chantha Chhuon
Sbfe Analysis Of Layered Elastic Media With Consideration Of Surface Energy Effect, Chantha Chhuon
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis presents an efficient and accurate numerical technique for determining mechanical response of a two-dimensional, infinite, elastic, layered medium under arbitrary surface loading and surface stress effects. Governing equations of a generic bulk layer are formulated from the classical linear elasticity theory via a SBFE technique whereas those of the generic material surface are obtained from a full version of Gurtin-Murdoch surface elasticity theory. The formulation is established sufficiently general allowing both homogenous and functionally graded bulk materials to be treated for each layer. By enforcing the continuity at the interface of the material surface and the bulk, it …
Compression Behavior Of Fire-Damaged Concrete-Filled Steel Tubular Columns Confined With Fiber-Reinforced Polymer Sheets, Dat Thanh Vu
Compression Behavior Of Fire-Damaged Concrete-Filled Steel Tubular Columns Confined With Fiber-Reinforced Polymer Sheets, Dat Thanh Vu
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research investigates the axial compression behavior of fire-damaged circular concrete-filled steel tube (CFST) stub columns externally confined with fiber-reinforced polymer (FRP) sheets. A total of 38 CFST specimens were tested under axial compression to investigate the load capacity, ductility, stiffness and failure mode of fire-damaged CFST columns before and after strengthening with FRP sheets. The test variables include the level of fire damage (no damage and 2-hour ISO standard fire), compressive strength of infill concrete (24MPa and 55MPa), type of FRP sheets (carbon and glass), and the number of FRP layers (0, 1, and 2 layers). The test results …
A Bim-Database-Integrated System For Evaluating Building Life-Cycle Costs Using A Multi-Parametric Model, Hang Thi Thu Le
A Bim-Database-Integrated System For Evaluating Building Life-Cycle Costs Using A Multi-Parametric Model, Hang Thi Thu Le
Chulalongkorn University Theses and Dissertations (Chula ETD)
Life-cycle cost analysis (LCCA) has become an essential requirement of the sustainable procurement for many construction projects. Conventional building LCCA methods are extremely complex and time-consuming due to repetitive works, numerous required data, scattered data inputs, and various regulatory requirements, which subsequently lead to inaccurate building life-cycle costs (LCC). Building information modeling (BIM) offers a revolutionary information technology, which can overcome the asperities of the conventional building LCCA. This research develops the BIM-database-integrated system for evaluating building life-cycle costs using a multi-parametric model (BIM-BLCC). The BIM-BLCC consists of four interrelated modules. The relational database management module collects and organizes the …
Improved Response Spectrum Analysis Procedure For Design Of Reinforced Concrete Tall Buildings, Kimleng Khy
Improved Response Spectrum Analysis Procedure For Design Of Reinforced Concrete Tall Buildings, Kimleng Khy
Chulalongkorn University Theses and Dissertations (Chula ETD)
Response spectrum analysis (RSA) procedure commonly used in design practice has been found to underestimate design forces in tall buildings. Failure and damage of reinforced concrete (RC) shear walls in mid-rise and high-rise buildings have been observed in recent earthquakes. In this dissertation, a modified RSA (MRSA) procedure to compute shear forces and strains in RC walls and columns to identify locations requiring ductile detailing was proposed. Six tall RC shear-wall buildings of 15 to 39 stories and four RC moment-frame buildings of 3 to 15 stories subjected to earthquake ground motions expected in Bangkok and Chiang Mai were first …
Development Of Causal Relationship Model Of Knowledge Sharing In Construction Projects, Lambada Roeun
Development Of Causal Relationship Model Of Knowledge Sharing In Construction Projects, Lambada Roeun
Chulalongkorn University Theses and Dissertations (Chula ETD)
Knowledge sharing among construction project members is very crucial for improving project success and project performance. It can also reduce mistakes in the construction process. Project management has been growing more complicated, and project members need to learn best practice from others. Currently, knowledge sharing is not well performed yet; especially, few research studies have been focused on the relationship evaluation of supporting factors that affect knowledge sharing from different contexts in construction projects. Therefore, this study aims to develop the causal relationship model of supporting factors from psychological, individual, organizational, and technological factors that affect mediators - knowledge sharing …
The Influences Of Granite Particle As A Mixing Material Of High-Strength Concrete, May Thazin Khine
The Influences Of Granite Particle As A Mixing Material Of High-Strength Concrete, May Thazin Khine
Chulalongkorn University Theses and Dissertations (Chula ETD)
The aim of this study is to investigate the effect of granite particle on the properties of high strength concrete by the partial substitution as fine aggregate. By grouping two categories as concrete with and without admixture is also performed in this experiment. The granite particle substitution percentage for concrete with admixture is set with 0%, 20%, 30%, 40% and 50% by weight of fine aggregate and 0%, 10%, 15% and 20% by weight of fine aggregate for concrete without admixture. The testing of concrete strength is conducted with compressive, split tensile, flexural, water permeability, and microstructure. The result shows …
Geophysical Site Investigation And Ground Response Analysis Of Bangkok Subsoil Due To Earthquake, Muhammad Fatih Qodri
Geophysical Site Investigation And Ground Response Analysis Of Bangkok Subsoil Due To Earthquake, Muhammad Fatih Qodri
Chulalongkorn University Theses and Dissertations (Chula ETD)
The potential damages on building and infrastructure could be affected by long-distance earthquakes since the vibrations can appear ground motion amplification during the wave propagation. Bangkok urban area is located a hundred kilometers away from the potential area of the earthquake epicenter. However, some people in Bangkok could feel the shaking during the earthquake. It indicates that the long-period shaking could happen during the earthquake. In line with this phenomenon, this study aims to interpret the amplification effect and spectral acceleration in the local site of Bangkok due to remoted earthquakes. The microtremor measurement was conducted at four locations in …
Nonlinear Finite Element Analysis Of Steel Pipe With Stiffener Plate, Rut Su
Nonlinear Finite Element Analysis Of Steel Pipe With Stiffener Plate, Rut Su
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis presents the numerical studies of steel hollow section columns connected to corbels under industry crane loads, and the stiffening design using steel plates to enhance the maximum loading capacity against premature local buckling failures. The influences of inelastic material properties and geometry nonlinearity on the overall load carrying capacity of the columns were considered. Square hollow section columns were modelled in 3D using standard eight-node solid finite elements using an ANSYS software. The plate stiffener design algorithm involving variation of plate thicknesses was coded in MATLAB with a direct application programming interface to ANSYS. The full history of …
Mechanical Performances Of Concrete Beams With Hybrid Usage Of Steel And Frp Reinforcement, Linh Van Hong Bui
Mechanical Performances Of Concrete Beams With Hybrid Usage Of Steel And Frp Reinforcement, Linh Van Hong Bui
Chulalongkorn University Theses and Dissertations (Chula ETD)
Fiber-reinforced polymer (FRP) bars have been recently employed to reinforce concrete members due to their high tensile strength and especially in corrosive environments to improve the durability of concrete structures. However, FRP composites have a low modulus of elasticity and a linear elastic behavior up to rupture, thus reinforced concrete (RC) components with such materials would express a lack of ductility. In order to increase the mechanical performances of RC beams, the hybrid usage (also called combined usage) of FRP and steel reinforcements in shear and flexure is proposed. At first, an experimental investigation of concrete beams strengthened in shear …
Strengthening Of Shear Critical Reinforced Concrete Columns By Steel-Rod Collars, Phawe Suit Theint
Strengthening Of Shear Critical Reinforced Concrete Columns By Steel-Rod Collars, Phawe Suit Theint
Chulalongkorn University Theses and Dissertations (Chula ETD)
The inadequate shear strength of the existing old reinforced concrete columns located in the seismically active areas can lead the catastrophic shear failure. In this study, strengthening of shear-critical reinforced concrete columns by the steel-rod collar method is investigated. This proposed method is less intrusive to the existing building components. The steel-rod collar comprises the four sets of welded steel angles connected by steel-rods threaded at the ends. The three specimens were divided into one unstrengthened column, and the two strengthened columns. All the specimens were tested under the constant axial load and the reversed cyclic loadings. In addition, the …
Habal-Habal: Characteristics Of Motorcycle Taxi Users In Metropolitan Manila, Sebastian Mapili Cano
Habal-Habal: Characteristics Of Motorcycle Taxi Users In Metropolitan Manila, Sebastian Mapili Cano
Chulalongkorn University Theses and Dissertations (Chula ETD)
Motorcycle taxi services in the Philippines (locally referred to as habal-habal) has been deemed to be operating only in rural areas wherein public transportation is inadequate or is utterly absent. It is also perceived as illegal and unsafe for urban operations, especially in a conurbation like Metro Manila wherein more than 30% of recorded fatal road accidents come from motorcycles. However, the worsening traffic congestion in the metropolis has spurred its growing urban presence and has led the attention of commuters to alternative modes of transport that are fast, reliable, and affordable. Inadequate understanding of habal-habal's role in the urban …
Risk Management Of Public-Private Partnership (Ppp) Infrastructure Projects In Laos, Siamphone Maneevong
Risk Management Of Public-Private Partnership (Ppp) Infrastructure Projects In Laos, Siamphone Maneevong
Chulalongkorn University Theses and Dissertations (Chula ETD)
Public-private partnership (PPP) is a popular option of project delivery and contractual scheme between the public and private sectors public infrastructure projects. Many factors contribute to the success of PPP projects, most of which are country-specific. Since Laos has recently adopted PPP for several infrastructure projects, all stakeholders must understand the critical risks that influence the performance of PPP projects. In this research, we identify, evaluate and rank the critical risk factors and risk categories that affect the PPP project development of in Laos. The questionnaire survey and In-depth interviews were used to gather information from nine respondents, who represent …
A Study Of Applying Para Rubber Sheets In Railway Track By Using Ballast Box Test, Somkith Dethvongsone
A Study Of Applying Para Rubber Sheets In Railway Track By Using Ballast Box Test, Somkith Dethvongsone
Chulalongkorn University Theses and Dissertations (Chula ETD)
Recently, attempts to reduce ballast degradation have been a major topic for many railways and researchers. Nowadays, a successfully proven alternative is applied elastic under-sleeper pads in between sleeper and ballast particles, and also as the ballast mat placed under the ballast layer. The using of synthetic material as the elastic element is able to decrease the deterioration of ballast and vibrations. Para rubber is a natural elastic material and it is abundant in South East Asia countries. Therefore, this study is aimed to investigate using para rubber as an alternative element of reducing ballast breakage in ballasted track. Experiments …
Poroelastodynamic Solutions Of Transversely Isotropic Multi-Layered Media, Suraparb Keawsawasvong
Poroelastodynamic Solutions Of Transversely Isotropic Multi-Layered Media, Suraparb Keawsawasvong
Chulalongkorn University Theses and Dissertations (Chula ETD)
This dissertation presents poroelastodynamic fundamental solutions of transversely isotropic poroelastic materials. Analytical general solutions for transversely isotropic poroelastic media under time-harmonic loading are derived for plane strain and axisymmetric problems by applying Fourier and Hankel integral transforms respectively. The fundamental solutions for a homogeneous half-space are then explicitly obtained by solving relevant boundary value-problems based on the derived general solutions. An exact stiffness matrix method is also employed based on the present general solutions to determine the fundamental solutions corresponding to multi-layered transversely isotropic poroelastic media. The obtained fundamental solutions are then employed in the analysis of dynamic interaction problems …
Analysis And Optimum Design Of Cold-Formed Steel Arch Structures, Thu Huynh Van
Analysis And Optimum Design Of Cold-Formed Steel Arch Structures, Thu Huynh Van
Chulalongkorn University Theses and Dissertations (Chula ETD)
This research presents the development of a unified framework for cold-formed steel warehouse design at variations of clear roof spans. The work involves the advanced finite element analyses of nonlinear arch-shape warehouse structures, namely one that considers 2nd-order nonlinear geometry effects-sufficiently accurate approximation of large deformation responses. An optimum design procedure of 3D arch steel warehouse structures is conducted with the help of a novel algorithm, called mixed ESO-PSO approach. The generic idea is based on the implementation of a well-known evolutionary structural optimization algorithm (ESO), and further integrates a mapping, underpinning particle swarm optimization (PSO), technique of design variables …
A Deep Relation Extraction From Biomedical Texts With Attention Mechanisms And Domain-Specific Contextual Representations, Amarin Jettakul
A Deep Relation Extraction From Biomedical Texts With Attention Mechanisms And Domain-Specific Contextual Representations, Amarin Jettakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
The biomedical relation extraction (RE) tasks aim to study the interaction between pre-defined entities from biomedical literature: Bacteria Biotope (BB) and Drug-Drug interactions (DDI) tasks. Some previous investigations have used feature-based models; others have presented deep-learning-based models such as convolutional and recurrent neural networks used with the shortest dependency paths (SDPs). Although SDPs contain valuable and concise information, sections of significant information necessary to define bacterial location relationships are often neglected. In addition, the traditional word embedding used in previous studies may suffer from word ambiguation across linguistic contexts. Here, we present a deep learning model for biomedical RE. The …
Knowledge Sharing In Cooperative Compact Genetic Algorithm, Orakanya Gateratanakul
Knowledge Sharing In Cooperative Compact Genetic Algorithm, Orakanya Gateratanakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
The compact genetic algorithm is derived from the genetic algorithm in which the population is represented by the probabilistic vector. To improve the search capability and avoiding local minima, parallelization has been employed where many search processes are deployed concurrently. In order to coordinate the work of multiple processes, knowledge sharing is necessary. Multiple processes share their probabilistic vectors partially. To escape from local minima the restart step is introduced. The experiment compares the proposed algorithm with two other competitive algorithms using Traveling Salesman problem, Bin Packing problem, Subset Sum problem, and Knapsack problem. The results show that the proposed …
Explicit Energy-Minimal Short-Term Path Planning For Collision Avoidance In Bidirectional Crowd Simulation, Saran Sillapaphiromsuk
Explicit Energy-Minimal Short-Term Path Planning For Collision Avoidance In Bidirectional Crowd Simulation, Saran Sillapaphiromsuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
การหาเส้นทางการเดินในระยะยาวรวมกับการหลบหลีกสิ่งกีดขวางรอบๆ เป็นวิธีทั่วไปที่ถูกนำมาใช้ในการจำลองการเคลื่อนไหวของตัวตนจำลองจากตำแหน่งหนึ่งไปยังอีกตำแหน่งหนึ่ง โดยไม่ให้เกิดการชนกันระหว่างตัวตนจำลองกับวัตถุในฉากและระหว่างตัวตนจำลองด้วยกันเอง วิธีนี้สามารถให้ผลการจำลองที่ดีในสถานการณ์ที่ผู้คนสามารถเดินได้หลายทิศทาง แต่ในสถานการณ์ที่ผู้คนถูกจำกัดทิศทางการเดินให้เหลือเพียงหนึ่งหรือสองทิศทางนั้น ปรากฏว่าตัวตนจำลองมีลักษณะการเดินที่ผิดธรรมชาติ เช่น เดินเข้าไปติดและอยู่นิ่งระหว่างตัวตนจำลองสองตัวที่เดินสวนมาหรือเดินเข้าไปในพื้นที่ที่แออัดหรือมีกลุ่มคนเยอะๆ ทั้งๆที่ยังมีเส้นทางเดินที่ทำให้ตัวตนจำลองสามารถเดินหลบหลีกไปได้ ลักษณะเช่นนี้เกิดขึ้นบ่อยและเห็นได้ชัดในสถานการณ์แบบสองทิศทาง งานวิจัยนี้จึงได้เสนอขั้นตอนในการหาเส้นทางในระยะสั้นเพื่อขจัดความบกพร่องของพฤติกรรมการเดินของตัวตนจำลองในสถานการณ์แบบสองทิศทางนี้ขึ้น โดยใช้สมการพลังงานทางชีวกลศาสตร์ของการเดินเข้ามาเป็นตัวแปรที่บังคับให้ตัวตนจำลองมีความฉลาดในการเลือกเส้นทางในระยะสั้นได้ ผลลัพธ์ของการวิเคราะห์สมการพลังงานนั้น ช่วยบ่งบอกลักษณะของการเลือกเส้นทางการเดินที่ดีที่สุด โดยคำนึงถึงความเร็วที่ใช้เพื่อให้ประหยัดพลังงานที่สุด พร้อมๆ กับถึงจุดหมายปลายทางให้เร็วที่สุดด้วย นอกจากนี้ยังพบว่าการนำวิธีที่เสนอนี้ไปใช้ในสถานการณ์แบบหลายทิศทางนั้น ตัวตนจำลองสามารถหาเส้นทางที่เหมาะสมกว่าเมื่อเทียบกับวิธีก่อนอีกด้วย ยกตัวอย่าง เช่น ตัวตนจำลองสามารถเดินแทรกเข้าไปในช่องแคบๆ ของขบวนพาเหรดได้ เป็นต้น
Development Of Eeg-Based Emotion Classification Using Deep Learning Networks, Suwicha Jirayucharoensak
Development Of Eeg-Based Emotion Classification Using Deep Learning Networks, Suwicha Jirayucharoensak
Chulalongkorn University Theses and Dissertations (Chula ETD)
Emotion classification is one of essential tasks for Human Computer Interaction (HCI) to make computers more efficiently interact with their users. Electroencephalogram (EEG) signals, associated with cognitive states of emotions, propagate though a complex hierarchy of neuron cells. Therefore, EEG-based emotion classification requires sophisticated learning algorithms that can represent high-level abstraction of a complicated task. This dissertation focuses on applying deep learning networks (DLNs) to enhance accuracy performance of the EEG-based emotion classification system. The DLN provides hierarchical feature learning methodology which is suitable for EEG-related feature learning algorithms. Furthermore, this research investigates the effects of temporal neural dynamics of …
Multi-Paths Quest Generation For Structural Analysis, Thongtham Chongmesuk
Multi-Paths Quest Generation For Structural Analysis, Thongtham Chongmesuk
Chulalongkorn University Theses and Dissertations (Chula ETD)
Existing quest generation systems that used quest structures had an important limitation. They were not compatible with dynamic environment games, where player actions may have unforeseen repercussion from chain-reaction, such as locking the quest or preventing it from being completed. In addition, quests generated by such systems were not guaranteed to have multiple completion paths.
In this thesis, action-based-objective quests were replaced with game state-based-objective quests, while retaining the previous grammar rule. Each quest's contents and objectives were filled using Token system and Full Condition State system to ensure the connectivity within the quest's contents and to prevent players from …
Reactive Power Management In A Distribution System By Photovoltaic Inverter, Akasinh Luangduangsitthideth
Reactive Power Management In A Distribution System By Photovoltaic Inverter, Akasinh Luangduangsitthideth
Chulalongkorn University Theses and Dissertations (Chula ETD)
Nowadays the electrical generation from the solar photovoltaic resource is extensively promoted because of the concern about greenhouse gas emission. A distribution system can be powered by a variety of solar photovoltaic resources, and can be used for various objectives, it can improve voltage profile problems and can reduce real power losses of the upgrading process of transmission and distribution system. However, presence much of the PV system may have detrimental impacts on the operation of the distribution system because of the variation of solar photovoltaic increases. This thesis proposed the optimal reactive power control modes by PV inverters when …
Coordination Between Central And Local Control Of Photovoltaic Generation System For Controlling Voltage Violation And Unbalance In Distribution Systems, Anuwat Chanhome
Coordination Between Central And Local Control Of Photovoltaic Generation System For Controlling Voltage Violation And Unbalance In Distribution Systems, Anuwat Chanhome
Chulalongkorn University Theses and Dissertations (Chula ETD)
Solar energy is a clean and pollution-free energy. Economic growth has led to increased demand for electricity in many countries, which has encouraged the installation of solar power generation systems, especially in LV distribution system. Households have the potential to install solar power generation systems because the costs of installation and maintenance have been continuously decreased. However, when there are many connected solar power generation systems in LV distribution system, the following problems may occur: (1) Loss of real power generation due to the operation of overvoltage protection of solar power generation systems, especially the ones on downstream nodes and …
Application Of Model Predictive Control To Traffic Systems With Hierarchical Distributed Control Framework, Jeerapat Jitnaunt
Application Of Model Predictive Control To Traffic Systems With Hierarchical Distributed Control Framework, Jeerapat Jitnaunt
Chulalongkorn University Theses and Dissertations (Chula ETD)
Traffic congestion is one of the chronic problems that degrades an urban traffic sustainable development especially the transport system. It seriously affects the quality of life of many people and becomes a catalyst of an increment of air pollution. If we can improve public infrastructure, logistics, and public transport system, they will reduce traffic congestion problem. This thesis aims to apply model predictive control (MPC) to traffic systems in a framework on hierarchical distributed control. The control structure composes of three layers which are network layer, area layer, and intersection layer. On the network layer and area layer, the control …
Flexible Optical Fiber Access Networks Using Wavelength Selective Switches, Maung Maung Htwe
Flexible Optical Fiber Access Networks Using Wavelength Selective Switches, Maung Maung Htwe
Chulalongkorn University Theses and Dissertations (Chula ETD)
The optical switching crosstalk is the important considerable issue in the optical fiber communication system, it tends to the signal distortion and decreasing of the system performance. This dissertation research is proposed a guideline to design a flexible fiber to the x (FTTx) system based on wavelength division multiplexing passive optical network (WDM-PON) combining with wavelength selective switches (WSSs). For the system configuration, the 4 wavelengths-10 ONUs system with the data bit rate of 10-Gbps/λ and 40-Gbps/ λ are studied in this dissertation. Moreover, to be active switching, the dynamic wavelength bandwidth allocation (DWBA) controller is used to control WSSs. …
Design And Implementation Of Medium-Range Outdoor Wireless Mesh Network With Openflow In Raspberry Pie, Soe Ye Htet
Design And Implementation Of Medium-Range Outdoor Wireless Mesh Network With Openflow In Raspberry Pie, Soe Ye Htet
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis has designed and implemented the prototype of software-defined wireless mesh network (SDWMN) testbed with in-band control approach for road traffic monitoring system on Phaya Thai road between Rama 1 and Rama 4 roads. Wireless mesh nodes for this outdoor SDWMN testbed are composed of 6 waterproof boxes, 6 Raspberry Pi's, 6 cameras, and 6 power banks and 2 Intel NUC computers. Ad-hoc based IEEE 802.11 WiFi standard is used to send the captured image from Raspberry. Two gateways are installed at the traffic police boxes and two wireless mesh nodes are installed at each crossover bridge on Phaya …
An Improvement Of Photovoltaic Power Forecasting From Numerical Weather Prediction, Supachai Suksamosorn
An Improvement Of Photovoltaic Power Forecasting From Numerical Weather Prediction, Supachai Suksamosorn
Chulalongkorn University Theses and Dissertations (Chula ETD)
This thesis presents forecasting models for improving the hourly predicted solar power from Numerical Weather Prediction (NWP) in one day horizon. A practical constraint is that the models must provide the predicted solar power before 14.00 hrs daily so that the Short-term Operation Planning Section, Generation Operation Planning Department, Power System Control and Operation Division, Electricity Generating Authority of Thailand can use the prediction to plan dispatching of the next day. Available data used in this research are from two sources: local weather measurements and power meter installed at the top of Electrical Engineering Building, Faculty of Engineering, Chulalongkorn University …