Articles in Press

  • Effects of Water Table Level on Slope Stability and Construction Cost of Highway Embankment (Accepted: 2019-05-26)
    Roaa Hamed Latief, University of Baghdad
    Abdul Kareem E. Zainal, University of Baghdad

    Highway embankments stability during its service period represents an important factor for the safety of highway users and vehicles. Consequently, the cost of construction of these embankments should be adequate to maintain the safety and durability during this period through proper estimation of the loading on asphalt pavement, slope stability, horizontal and vertical deformation, etc. Slope stability of the embankment mainly depends on the shear strength of the soil layers materials; this shear strength is affected by the water table level through the contribution of the capillary water. Negative pore water pressure above the water table level evolves matric suction in the unsaturated zone above water table; this matric suction increases the shear strength of the soil depending on the soil type, void ratio, etc. This paper studies the slope stability of highway embankment using finite element method analysis to show the effect of the presence of water table and the contribution of the matric suction. A trial slope is shown to have same factor of safety with reduced cross section due to increasing the shear strength hence, reducing the cross-sectional cost is determined.

  • Stabilized Oily-Emulsion Separation Using Modified Induced Air Flotation (MIAF): Factor Analysis and Mathematical Modeling (Accepted: 2019-06-25)
    Nattawin Chawaloesphonsiya, Chulalongkorn University
    Kritchart Wongwailikhit, Chulalongkorn University
    Saret Bun, Chulalongkorn University
    Pisut Painmanakul, Chulalongkorn University

    The objective of this work was to study the treatment of oily-wastewater by the combination of induced air flotation and coagulation or the modified induced air flotation (MIAF). Effects of bubble hydrodynamics and mixing were analyzed along with the treatment performance for separation different stable oily wastewaters, including cutting oil, lubricant oil, palm oil. The results suggested the necessity of coagulation for the efficient separation of these emulsions. Different alum concentrations were required for good separation due to the variation of oil concentration. The maximum efficiencies of higher than 85% can be attained under the optimal air flow rate of 0.3 L/min air flow rate for 10 minutes with appropriate alum dosage. Moreover, the result from factor analysis indicated the importance of coagulant dosage, mean droplet size, and hydrodynamic condition in term of a/G ratio on the treatment performance. Both individual and jointed impacts of these parameters on the separation efficiency can be seen. Finally, a good correspondence was obtained from the experimental data and the mathematical modeling at which identified the correlation between the treatment efficiency and these key factors with the mean absolute percentage error (MAPE) of at 14%.

  • Uncertainty and Fuzzy Decisions in Earthquake Risk Evaluation of Buildings (Accepted: 2019-06-25)
    Akkachai Ketsap, Chiang Mai University
    Chayanon Hansapinyo, Chiang Mai University
    Nopadon Kronprasert, Chiang Mai University
    Koraphon Saicheur, Chiang Mai University
    Suchart Limkatanyu, Prince of Songkla University

    The Northern region of Thailand has been considered as one of the seismic risk zones. However, most existing buildings in the area had been designed and constructed based on old building design codes without seismic consideration. Therefore, those buildings are required to upgrade based on earthquake building damage risk evaluation. With resource limitations, it is not feasible to retrofit all buildings in a short period. In addition, the results of the risk evaluation contain uncertain inputs and outputs. The objective of this study is to prioritize building retrofit based on fuzzy earthquake risk assessment. The risk assessment of a building was made considering the risk factors including (1) building vulnerability, (2) seismic intensity and (3) building values. Then, the total risk was calculated by integrating all the risk factors with their uncertainties using a fuzzy rule-based model. An example of the retrofit prioritization is shown here considering the three fuzzy factors. The ranking is a hospital, temple, school, government building, factory and house, respectively. The result helps decision makers to screen and prioritize the building retrofitting in the seismically prone area.

  • The Reuse of Waste Glass as Aggregate Replacement for Producing Concrete Bricks as an Alternative for Waste Glass Management on Sichang Island (Accepted: 2019-06-26)
    Hathaichanok Warnphen, Chulalongkorn University
    Nuta Supakata, Chulalongkorn University
    Vorapot Kanokkantapong, Chulalongkorn University

    The objective of this research is to manage waste glass in Koh Sichang, Chonburi province, used as a partial fine aggregate replacement in concrete brick production according to the Thai Industrial Standard (TIS) 57-2533. An experimental approach aimed to determine the level of waste glass replacement for the optimal compressive strength. Five samples of 0, 10, 20, 30, and 100% waste glass aggregates by weight were tested at 7, 14, and 28 days. The microstructure and mineralogical phases of the concrete bricks were investigated by scanning electron microscopy and X-ray diffractometry, respectively. The experimental results showed that the compressive strength was improved by increments in replacing waste glass up to 20%; in contrast, the compressive strength was decreased with an increase of waste glass of over 20% in concrete bricks. The optimum compressive strength of concrete brick was 20% by weight, which had the highest values (46.51, 47.41, and 48.49 MPa at 7, 14, and 28 days, respectively) and lowest water absorption. Therefore, waste glass can be used as a partial fine aggregate for producing concrete bricks, and it can be employed as an alternative material for waste glass management.

  • Influence of Bottom Ashes with Different Water Retainabilities on Properties of Expansive Mortars and Expansive Concretes (Accepted: 2019-07-03)
    Warangkana Saengsoy, Construction and Maintenance Technology Research Center (CONTEC), School of Civil Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University
    Thuy Nguyen,
    Somnuk Tangtermsirikul,

    An internal curing method has a significant effect on the properties of concrete, especially high-performance concrete with a low w/b ratio or concrete containing supplementary cementitious materials. This study investigates the influence of bottom ash with different water retainabilities as an internal curing material on the performances of mixtures containing an expansive additive and fly ash. Two series of experiments were conducted: expansive mortars with a controlled w/b ratio and expansive concretes with a controlled initial slump. By using bottom ashes, the compressive strength is decreased in expansive mortars with a controlled w/b ratio and increased in expansive concrete with a controlled initial slump. The internal curing ability of bottom ashes shows enhanced expansion of expansive mortars with sealed curing and expansive concretes with moist curing, reducing total shrinkage of expansive mortars with air curing. However, the total shrinkage of the expansive mortars increases with the use of bottom ashes that have higher water retainability with 7 days of water curing and then air curing. It was found by DTG analysis that expansive concretes with higher expansion containing bottom ash with higher water retainability had a higher amount of ettringite.

  • In-situ Observation of Martensite Decomposition in HAZ of Cr-Mo Steel Weldment (Accepted: 2019-06-11)
    Isaratat Phung-on, King Mongkut's University of Technology Thonburi
    Sudarat Khetsoongnoen, Suranaree University of Technology
    Jongkol Srithorn, Suranaree University of Technology
    Chanan Euaruksakul, Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand
    Pat Photongkam, Synchrotron Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand

    In-situ observation of martensite decomposition at Heat Affected Zone (HAZ) was investigated on a dissimilar joining between 2.25Cr-0.5Mo grade T22 as base material and ER90S-B9 as filler metal using GTAW process using LEEM at a synchrotron facility. A post weld heat treatment (PWHT) cycle was simulated on a welded specimen in high vacuum chamber by heating cartridge and electron bombardment. Both effects PWHT duration and weld areas were studied for comparisons. At the simulated PWHT between 690oC -700oC in CGHAZ, martensite started to decompose by the dissolution of carbide flakes. The prior-austenite grain boundaries were also shown during the process. The same phenomena were also observed in FGHAZ with different extent. In un-affected base material, ferrite and new pearlite grains presented and grew at the expense of old pearlite. Longer PWHT duration resulted in more ferrite formed in all weld areas. Raising PWHT temperature to 730oC could push the reaction above Eutectoid temperature as the new austenite formed at grain boundaries. The proposed mechanism for martensite decomposition would be in steps as dissolution of carbide followed by formation of ferrite and growth as PWHT proceeded.

  • Carbon Dioxide Capture from Flue Gas Using a Potassium-Based Sorbent in a Circulating-Turbulent Fluidized Bed (Accepted: 2019-06-11)
    Pilaiwan Chaiwang, Chulalongkorn University
    Benjapon Chalermsinsuwan, Chulalongkorn University
    Pornpote Piumsomboon, Chulalongkorn University

    This research aimed to study the carbon dioxide (CO2) capture process using a potassium-based solid sorbent in a circulating fluidized bed riser (CFBR). The solid sorbent in this study was potassium carbonate on gamma alumina supporter (K2CO3/g-Al2O3). The hydrodynamics under a circulating-turbulent fluidized bed (C-TFB) regime occurred when the gas velocity was 1.00 m/s and could promote a solid sorbent distribution, with transition and transport velocities of 0.82 and 2.22 m/s, respectively, giving a uniform solid volume fraction distribution of 0.15 along the CFBR for the CO2 capture process. The study started with finding the operating condition in the riser so that the particle flowed in the reactor in the C-TFB regime. In addition, the kinetic of the adsorption under C-TFB flow regime in the riser was studied and the kinetic parameters corresponding to C-TFB flow regime were determined using deactivation kinetic model.

  • A New Incremental Decision Tree Learning for Cyber Security based on ILDA and Mahalanobis Distance (Accepted: 2019-06-11)
    Saichon Jaiyen, King Mongkut’s Institute of Technology Ladkrabang
    Ployphan Sornsuwit, King Mongkut’s Institute of Technology Ladkrabang

    A cyber-attack detection is currently essential for computer network protection. The fundamentals of protection are to detect cyber-attack effectively with the ability to combat it in various ways and with constant data learning such as internet traffic. With these functions, each cyber-attack can be memorized and protected effectively any time. This research will present procedures for a cyber-attack detection system Incremental Decision Tree Learning (IDTL) that use the principle through Incremental Linear Discriminant Analysis (ILDA) together with Mahalanobis distance for classification of the hierarchical tree by reducing data features that enhance classification of a variety of malicious data. The proposed model can learn a new incoming datum without involving the previous learned data and discard this datum after being learned. The results of the experiments revealed that the proposed method can improve classification accuracy as compare with other methods. They showed the highest accuracy when compared to other methods. If comparing with the effectiveness of each class, it was found that the proposed method can classify both intrusion datasets and other datasets efficiently.

  • Optimal Storage Locations for Warehouse Efficiency Improvement in a Haircare Manufacturer (Accepted: 2019-07-10)
    Naragain Phumchusri,

    This study aimed to enhance efficiency of raw materials warehouse in a case study haircare manufacturer in Thailand though identifying the optimal storage locations for materials locating at this raw materials warehouse. At the same time, it was our goal to increase capacity and improve utilization at internal raw materials warehouse in order to store some finished products at this internal warehouse instead of storing all of them at external public warehouse. As a result, the case study company can save storage cost of finished products at the external public warehouse. The key methodologies used to improve current raw materials warehouse were removing obsolete materials from warehouse, regrouping materials according to types, sizes, and turnover rate, reallocating space for each group of materials, considering beam height adjustment, and reassigning locations for each group of materials using optimization model. The results showed that capacity of raw materials warehouse was enhanced by 12.65%, picking distance was reduced by 51.9% compared to current situation, utilization was more balanced throughout warehouse and annual cost saving of 874,800 THB was obtained from locating some finished products at the internal raw materials warehouse. In addition, robustness of the proposed model was analyzed and contingency plan was developed for handling with over flow materials if over utilization occurs.

  • Optimization of a Hybrid Carbon/Glass Composites Afterbody of the Amphibious Plane with Finite Element Analysis (Accepted: 2019-07-05)
    Mongkol Thianwiboon, Mahidol University

    Due to high stiffness, high strength-to-weight ratio and substantial corrosion resistance, the use of composite materials as a replacement for the aluminum structure in aerospace applications has been increasing. The most widely used composites in aerospace are glass-fiber reinforced polymer (GFRP) and carbon-fiber reinforced polymer (CFRP). CFRP has higher strength and lighter than GFRP but more expensive while the GFRP provide adequate strength with low cost. Then the hybrid carbon/glass fiber composites could combine the strong sides on CFRP and GFRP to balance between strength, weight and cost to achive the requirement for each design of the aircraft. In this study, a finite element analysis of hybrid carbon/glass composites are carried out using ANSYS ACP. The main objective is to find the optimized lay up for the afterbody of the amphibious plane which can carried load according to ASTM F2245 (Standard Specification for Design and Performance of a Light Sport Airplane). While the stress of the carbon and glass fiber in the structure are within the safety limit, the results show that the weight is minimum when the laminate ply pattern consists of 3.18 mm foam core  sandwiched by 3 layers of carbon woven fabrics on both side [(+45)C(0/90)C(+45)CD]S . While the laminate ply pattern with 3.18 mm foam core sandwiched by 2 layers of carbon and 1 layer of glass woven fabric [(+45)C(0/90)C(+45)GD]S on both side have a good balance between weight and cost.

  • Synthesis of Light Hydrocarbons via Oxidative Coupling of Methane over Silica-supported Na2WO4-TiO2 Catalyst (Accepted: 2019-06-10)
    Anusorn Seubsai, Kasetsart University
    Palida Tiencharoenwong, Kasetsart University
    Phattaradit Kidamorn, Kasetsart University
    Chalida Niamnuy, Kasetsart University

    Methane is of great interest for conversion into high-value hydrocarbons (C2+) and olefins, via oxidative coupling of methane (OCM) using catalysts. In this work, Na2WO4-TiO2/SiO2 catalyst, along with the single catalysts of its components (Na2WO4/SiO2 and TiO2/SiO2), was investigated for OCM reaction to C2+. We found that 5 wt% Na2WO4+ 5 wt% TiO2 on the SiO2 support was a superior catalyst for OCM reaction compared to the single catalysts. The maximum C2+ formation of the Na2WO4-TiO2/SiO2 catalyst was found under test conditions of a N2/(4CH4:1O2) feed gas ratio of 1:1, a reactor temperature of 700 ºC, and gas hourly space velocity of 9,500 h−1, exhibiting 71.7% C2+ selectivity, 6.8% CH4 conversion, and 4.9% C2+ yield. Moreover, the activity of the catalyst had good stability over 24 h of on-stream testing. The characterizations of the Na2WO4-TiO2/SiO2 catalyst using XRD, FT-IR, XPS, FE-SEM, and TEM revealed that a crystalline structure of α-cristobalite of SiO2 was present along with TiO2 crystals, substantially enhancing the activity of the catalyst for OCM reaction to C2+.

  • Acid-Pepsin Soluble Collagen from Saltwater and Freshwater Fish Scales (Accepted: 2019-06-10)
    Settakorn Upasen, Burapha University
    Kornrat Naeramitmarnsuk, Burapha University
    Christian Antonio, University of Queensland
    Susan Roces, De La Salle University
    Héctor Morillas, University of the Basque Country (UPV/EHU)
    Piyachat Wattanachai, Department of Chemical Engineering, Faulty of Engineering, Burapha University

    Extraction and characterization of acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from scales of Giant groupers (saltwater fish) and Nile tilapia (freshwater fish) were carried out in this research.  Due to a higher protein content in scales, collagen yield extracted from the Giant groupers scales was higher than that of the Nile tilapia scales.  The yield increased as extraction time increased for both ASC and PSC and pepsin extraction resulted in higher yields than acid extraction.  Even though there were differences in collagen yields, collagen characteristics were independent of the scale sources but some differences were observed for the ASC and PSC.  The peptide hydrolysis patterns of the ASC showed a wide range of molecular weights whereas all of the PSC had similar molecular weight of around 42 kDa.  FTIR spectra showed that all the collagens remained the triple helical structure though ASC might be self-aggregated.  From zeta potential analysis, net charge of zero was found at pH 3.2-4.0 and the dynamic light scattering suggested that the average particle sizes at pH 11-12 were around 100-200 nm.  The denaturation temperatures (Tds) in a range of 35-42oC indicated that the collagens were considerably thermally stable.

  • Computer Simulation Study for Functional Group Effect on Methane Adsorption in Porous Silica Glass (Accepted: 2019-06-10)
    Pongpon Teerachawanwong, Suranaree University of Technology
    Bharanabha Makkaroon, Suranaree University of Technology
    Chontira Boonfung, Suranaree University of Technology
    Chaiyot Tangsathitkulchai, Suranaree University of Technology
    Atichat Wongkoblap, Suranaree University of Technology

    In this paper, adsorption of methane on porous silica glass was investigated to see whether functional groups can affect the adsorption behavior. Adsorption isotherms for pores having widths between 7 and 40Å at 283 and 298 K were investigated using a Monte Carlo simulation (MC) method. The model of porous silica glass proposed in this study was assumed to be a finite-length slit pore which consisted of two parallel walls. The tetrahedral structure of SiO4 was used as atomic structure for the wall surface. Hydroxyl was assumed as the surface functional group which allocated either at pore mouth or random with concentration of 5 and 10%. It was found that the concentration of functional group has less significant effect on the adsorption of methane. The adsorption isotherm decreased a bit with an increase of functional group concentration. Effects of functional group position on adsorption isotherm were also investigated, the adsorption isotherm obtained for the random topology was greater than that for the pore mouth topology, due to the pore blocking effects. At the same pore width, the adsorption isotherm at 283K was greater than that at 293K, and this was due to that the adsorption of methane on porous silica glass was a physical adsorption. The initial adsorption of methane shifted to the higher pressure by increasing pore width, and the maximum adsorption capacity decreased with an increase of pore size, because of the pore packing effect.

  • Preparation of VO2 Nanoparticles with Surface Functionalization for Thermochromic Application (Accepted: 2019-06-10)
    Lalipat Janamphansang, King Mongkut’s University of Technology Thonburi
    Jatuphorn Wootthikanokkhan, King Mongkut’s University of Technology Thonburi
    Saiwan Nawalertpanya, King Mongkut’s University of Technology Thonburi

    This recent work investigates on the modification of metal oxide particles surface by the addition of amorphous coating layer. This core-shell structure is expected to decrease particles aggregation and increase their distribution in polymer matrix. VO2 particles were firstly prepared via hydrothermal process with 87% yield and XRD analysis showed that VO2 monoclinic was obtained with 100% of purity. XPS technique also showed that the surface of VO2 particles contains -OH group which is promising to form the strong covalent bond with silane coupling agent. The addition of functional groups on the surface of VO2 particles was then performed by the grafting of (3-Aminopropyl) triethoxysilane (APTES) via the silane anchoring group with 1:10 weight ratio VO2/APTES. The effect of solvent was also studied by using 10 ml of different solvent such as distilled water, ethanol and chloroform during surface coating. The TEM image clearly shows the presence of the thick organic layer on VO2 particles and as a result, the core-shell structure was perfectly identified. The round shape of coated VO2 particles was detected with small aggregation by SEM imageries. Furthermore, the presence of characteristic absorption band of C-H, Si-O-C, Si-O-Si and NH stretching in the FTIR spectra of coated VO2 particles confirmed the existence of APTES on the surface of VO2 particles prepared in distilled water and ethanol.

  • Citronella Oil Microencapsulated in Carboxymethylated Tamarind Gum and its Controlled Release (Accepted: 2019-06-10)
    Keonakhone Khounvilay, National University of Laos
    Berta Nogueiro Estevinho, University of Porto
    Wancheng Sittikijyothin, Burapha University

    Citronella oil is one of possible natural insect’s repellents extracted from leaves of Cymbopogon winterianus. It is used extensively as a source of perfumery chemicals such as 25% citronellal, 18% citronellol and 20% geraniol. To prolong the citronella oil release, carboxymethylated tamarind gum (CTG) was used as coating material for citronella oil encapsulation and compared to crude tamarind gum (TG), using spray drying technique. Three formulas of microcapsule were prepared at different gum to oil ratios (1.25, 1.14, and 0.87). The appearance feature of CTG microcapsule from SEM images showed a smooth surface while TG microcapsule showed many holes and crack on particle surface. It was observed that increasing the gum to oil ratio increases the retention of citronella oil in microcapsules. At 1.14 gum to oil ratio, CTG microcapsules were shown longer oil retention more than one month. The citronella oil release mechanism was analyzed by different kinetic models such as Korsmeyer-Peppas, Higuchi, and Avrami’s models. The microcapsules were found to release the citronella oil

  • Input/Output Linearization for a Real-Time pH Control: Application on Basic Wastewater Neutralization by Carbon Dioxide in a Fed-Batch Bubble Column Reactor (Accepted: 2019-06-10)
    Chanin Panjapornpon, Kasetsart University
    Pawat Saksomboon, Kasetsart University
    Kittayot Juyteiy, Kasetsart University
    Jedsada Chinprasit, Kasetsart University

    A model-based application for pH regulation in a pilot unit of wastewater treatment by carbon dioxide gas is presented.  A reactor pH is an important factor to enhance the gas absorption of carbon dioxide bubbles in an alkaline wastewater, and it needs to operate within a tight pH range.  Under a fed-batch operation mode, the reactor behavior has unstable dynamics resulting in a difficulty to achieve the pH target by manipulating the basic influent feed rate.  To solve the problem, an input/output (I/O) linearization is applied because it provides excellent the setpoint trackability with a few numbers of tuning parameters required. The first principles approach is employed for reactor modeling.  The model is then used in the I/O feedback formulation.  Control performance is evaluated through a real-time implementation to track the desired pH target in comparison with a two-degree-of-freedom control scheme used as a compared case.  The developed control system proficiently forces the output to the pH target and also improves the control performances.

  • Simultaneous Parameter Tuning of PSS and Wide-Area POD in PV Plant using FPA (Accepted: 2019-08-09)
    Herlambang Setiadi, The University of Queensland

    In future power grid scenario, large-scale renewable energy based on power plant will be one of the main generations. Among renewable based power plant type, large-scale photovoltaic (PV) plant becoming more popular as they could provide zero emission and sustainable energy. However, even though PV plant could contribute positive impact to the environment, they could also contribute negatively to the power system. Large-scale PV generation came with different dynamic and zero inertia characteristic due to the application of the power electronic devices. Furthermore, PV plant has also drawback in terms of intermittent power output due to the uncertainty of the sources. Those handicaps could deteriorate the stability performance of power system especially oscillatory stability. Adding power system stabilizer (PSS) to the systems is one of the approaches for handling the oscillatory stability. However, with integration of PV plant in the systems, PSS alone is not enough to handle the oscillatory problems coming from various sources such us from PV plant dynamic. Hence, utilizing wide-area power oscillation damping (POD) as PV plant supplementary controller is inevitable. Hence, this paper proposes simultaneous parameter tuning between PSS and wide-area POD in PV plant using flower pollination algorithm (FPA) as the optimization method. The two-area power system is employed to evaluate the performance of PSS and POD using FPA. From the results, it is found that the proposed method could enhance the oscillatory stability of the systems

  • Analysis of tropospheric nitrogen dioxide using satellite and ground based data over northern Thailand (Accepted: 2019-08-05)
    Pichnaree Lalitaporn, Kasetsart University

    Tropospheric NO2 columns over northern Thailand were analyzed using satellite products of the SCIMACHY, OMI, GOME-2A, and GOME-2B sensors for the 14-year period 2003–2016. The comparative results of the four pairs of different satellite datasets within overlapped years showed that they were well correlated with correlation coefficients (r) ranging from 0.82 to 0.88. The r-values improved to 0.85–0.90 when the analysis was considered only during the dry period (October to April). Ground in situ measurements of NO2 concentrations were also obtained for comparative analysis with the satellite NO2 columns. The results revealed relatively good agreement between these two parameters for a seasonal pattern. High levels of NO2 were detected by both satellite and ground monitoring during January–April with the maximum levels in March. Moreover, during this period, most satellite and ground datasets recorded greater levels of NO2 in the afternoon corresponding with the number of fire hotspots collected from the MODIS-Terra and -Aqua satellites. Satellite and ground measurements show slightly increasing annual trends of NO2 levels for 2010–2016 with values of 8.40 and 1.18 %, respectively, over the 6-year period.

  • Hybrid Motor System for High Precision Position Control of a Heavy Load Plant (Accepted: 2019-08-09)
    Gridsada Phanomchoeng, Mechanical Engineering Department, Chulalongkorn University, Bangkok 10330, Thailand
    Ratchatin Chancharoen, Department of Mechanical Engineering, Chulalongkorn University

    The lift up or press process with high precision position control is an important application in industries. An example of the process lift up and press is the process of a machine tool for drilling, milling, or injection. It is difficult to design the mechanism and controller to control the position of the base table accuracy because it needs to control the base position of the system with the weight varying in a large range. Also, the friction in the system would vary in a large range. This lead to low performance of the system in some range of load. Therefore, the new design system utilizes a DC motor and ball screw and pneumatic actuator to create the hybrid motor system for applying to the lift up and press system. The pneumatic actuator is designed to support the heavy load and the DC motor and ball screw is designed to control the position. Then, the developed hybrid motor can be used to improve the performance of the system. The simulation and experiment results show that the developed system can improve the rise time, setting time, and steady state error. Then, the time response of the system with heavy load look similar to the time response of the system with light load. Moreover, the developed hybrid motor technique can apply to the applications such as to control the 3D powder painter tank base position, and the silicon injection system, the 3D print head, which is a challenge system due to the high friction in tube.

  • Perceived Service Quality and Commuter Segmentation of Informal Public Transport Service in Bangkok, Thailand (Accepted: 2019-07-13)
    Chutaporn Amrapala, Chulalongkorn University

    One informal public transport service in Bangkok is Silor (SR), given the meaning in Thai as four-wheeler. SR facilitates urban mobility both in terms of major travel mode and feeder to bus and mass transit lines in the city. This research aims to explore user subgroups characterized by attitudes through an Exploratory Factor Analysis followed by commuter segmentation through Cluster Analysis based on the obtained latent variables in order to propose future implications for SR service improvement in Bangkok. Interviews are conducted through questionnaire survey to collect users’ socioeconomic and trip profiles and attitudes towards SR service. The result reveals dimensions of service quality, which explain user perception and priorities regarding the service. Four segments of SR users are identified by four attitudinal factors, including reliability, invehicle environment, comfort and convenience, and environmental impact. Personal profiles, trip characteristics, and attitudes of each segment are analyzed and compared. Research findings would contribute to new knowledge on quality factors and area of SR service improvement as well as provide better understanding on diverse perception among SR user segments. Policy implications that best suit for each user segments are discussed.

  • Quantification of different sources of over-strength in seismic design of a reinforced concrete tall building (Accepted: 2019-09-11)
    Kimleng Khy, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
    Chatpan Chintanapakdee, Center of Excellence in Earthquake Engineering and Vibration, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand

    An over-strength factor in seismic design plays an important role in computing actual forces in a structural member designed to remain elastic. However, sources contributing to this over-strength have not yet been systematically quantified for tall buildings. This paper aims to investigate the contribution from different sources of the over-strength factor in a reinforced concrete (RC) tall building. The contribution of slab-column gravity load framing to the lateral load capacity of the building is also investigated. A 39-story RC tall building subjected to earthquake ground motions in Bangkok was first designed according to the current building codes. Then, pushover analysis was conducted to compute the capacity curves of the building with three different specified strengths: design strength (with f factor), nominal strength (without f factor), and actual strength (with material over-strength). It was found that slab-column framing action contributes about 60% of the total lateral load capacity of the building.  The building has an overall lateral over-strength factor of 3.36 to 3.71. The over-strength factor arising from the design is 2.12 to 2.42 in which the contributions from strength reduction factor, material over-strength, and other sources involving the design requirements are about 1.10, 1.17, and 1.77, respectively. The over-strength factor arising from the redundancy due to the redistribution of internal forces is about 1.55 and the contribution from the steel strain hardening to the over-strength factor is relatively small.

  • Material Cost Prediction for Jewelry Production using Deep Learning Technique (Accepted: 2019-07-24)
    chanida phitthayanon, 0829565991
    Vichai Rungreunganun, King Mongkut's University of Technology North Bangkok

    Production cost management is a key factor to increase industrial competitiveness. The precious metal and the gemstone comprise 65% of the jewelry production cost. Managing raw material cost is a challenging task especially when the price highly fluctuates. In this article, deep learning models were developed to predict the prices of main raw materials of jewelry which are silver, gold, and diamond. These models are designed for Thai jewelry manufactures which are mostly small businesses. Therefore, our models only consider historical price data. This is because small businesses usually do not have access to other relevant data, i.e. oil prices and other economic data. The machine learning based models include in this work are a naive method, linear models, decision tree models, and deep learning models. The proposed precious metal price model can provide prediction RMSE of 0.765% which is comparable to other models in literature while requires less data and offers a simpler model. In addition, the proposed diamond price model can provide RMSE of 1.81% which is 53.2% more accurate than a naive method that normally used by jewelry manufacturers.

  • A new landscape classification approach for quantifying spatial pattern of Bac Kan province, Vietnam (Accepted: 2019-08-08)
    Dai Trong Ly, Suranaree University of Technology
    Suwit Ongsomwang,

    Landscape theory and its application have played an important role in natural resources exploitation and environmental protection. Various classification approaches had been employed worldwide in landscape ecology studies. This paper had developed a new hierarchical landscape classification framework for quantifying spatial pattern of Bac Kan province. A landscape formation equation was applied with three natural factors (geology, topography, and soil) and cultural factor (land use). A multi-level segmentation technique with multiresolution segmentation algorithm was chosen to segment landscape units (patches) and to categorize landscape types at different levels. The results revealed that the landscape classification of Bac Kan province has 4 hierarchical levels. Level 4, which provided full details of spatial pattern based on geologic period, elevation, soil depth, and land use, had 315 landscape types. At this level, there are 8,427 landscape units mapped with a minimum and maximum areas of 0.02 km2 and 116.63 km2, respectively. A new Bac Kan landscape map at a scale of 1:100,000 along with 16 different attributes for each landscape unit was also produced. In conclusion, the framework of research methodology presented in this paper can be used as a guideline for landscape classification at provincial and national levels.

  • Pre-project Planning Process Study of Green Building Construction Projects in Thailand (Accepted: 2019-08-26)
    Kritsada - Khun-anod, Dept. of Civil Engineering, Kasetsart University, Kamphaeng Saen, Nakorn Pathom, Thailand

    Project effectiveness is a challenge in sustainable building construction projects. Lack of experience, knowledge, and skills in sustainable projects have been highlighted as the main barriers to using sophisticated and innovative techniques. Based on the literature, the pre-project planning effort directly influences a project’s success. Nevertheless, the differences in planning efforts for green projects have not been fully determined, especially in Thailand where sustainability just has been only recently considered in this context. This study investigated the status of pre-project planning for green building construction projects located in Thailand to promote sustainable construction. The analyses were performed based on two main objectives: (1) to compare the overall planning effort and (2) to address dissimilar planning factors between green and conventional projects. The concept of a project definition rating index (PDRI) was applied to evaluate the level of pre-project planning effort in 40 sample projects. An independent t-test was used for data analysis. The findings from this study indicated the importance of pre-project planning for green building construction that contributes all stakeholders to understand which aspects were differently implemented during the planning process in green compared to conventional programs.

  • Hotspot Location Identification Using Accident Data, Traffic and Geometric Characteristics (Accepted: 2019-08-26)
    Gholamali Shafabakhsh, Professor, Faculty of Civil Engineering, Semnan University, Semnan, I.R. of Iran
    yousef sajed, Ph.D. condidate, 1Faculty of Civil Engineering, Semnan University, University, Semnan, Iran
    yousef sajed, Ph.D. condidate, 1Faculty of Civil Engineering, Semnan University, University, Semnan, Iran
    morteza bagheri, Asistant Professor, Faculty of Railway Engineering, Iran University of Science and Technology (IUST).

    Determining the criterion for critical limits is always one of the essential challenges for traffic safety authorities. The purpose of identifying accident hotspots is to achieve high-priority locations in order to effectively allocate the safety budgets as well as to promote more efficient and faster safety at the road network level. In recent years, human, vehicle, road and environment have been recognized as the three main effective elements of the road transportation in the occurrence of accidents. In the present study, with combining the parameters related to accidents, geometric parameters of the accident location and traffic parameters, hotspots were identified by using the superior methods of Poisson regression and negative binomial distribution and based on the combined criteria of frequency and severity of accidents and equivalent damage factors. Then using Time Series Models in ANN, result were compared and validated. The results of ANN models demonstrate that the frequency method of accidents tends toward places with high traffic volume. MATLAB and STATA software were used. Non-native plumbing, curvature, slope, section length and residential area had more significance, and their coefficients indicated the significant effect of these parameters on the occurrence of the frequency and severity of accidents in hotspot locations.

  • Seismic Shear Strengthening of Reinforced Concrete Short Columns using Ferrocement with Expanded Metal (Accepted: 2019-08-22)
    Dr. Phaiboon Panyakapo, Sripatum University, Thailand

    Typical reinforced concrete short column is brittle in shear rather than flexure under lateral cyclic loading due to its shear deficiency.  This paper presents the improvement of seismic behaviour of the reinforced concrete short columns which were strengthened by using ferrocement with expanded metal.  Full scale experiments were conducted for two strengthened concrete columns with different volume fractions of expanded metal and the control specimen under lateral cyclic loading.  It was found that the seismic behaviour in terms of the shear strength, stiffness, displacement ductility, and energy dissipation were significantly improved.  The expanded metal mesh with the high specific surface provided the better performance for controlling the crack propagation.  The brittle shear failure mode of the stirrup was reduced and the ductile flexure mode of the longitudinal reinforcement was dominant.  The reduced shear force of the stirrup was compensated by the shear force of the expanded metal reinforcement which experienced relatively large strain.  The technique of steel angle installation at the corners of column can successfully prevent the effect of sharpened corner wrapping of the mesh.  A model to predict the shear strength of the strengthened column is presented in term of the global efficiency factor for expanded mental.     

  • Geographically Weighted Regression Analysis Applied to the Establishment of Paddy Field Flooding Loss Functions (Accepted: 2019-06-10)
    Ling-Fang Chang, Agricultural Engineering Research Center Taoyuan, Taiwan
    Ming-Daw Su, National Taiwan University
    Wen-Tsun Fang, Agricultural Engineering Research Center Taoyuan, Taiwan
    Hsueh-Yen Shih, Agricultural Engineering Research Center Taoyuan, Taiwan

    Disasters due to typhoons and heavy rainfall occur frequently in Taiwan. With the increase of social and economic development density, flood damages are becoming more and more serious. Flood risk management has thus turned into a very important task. Flood damage assessment is the basis of flood risk management. The disaster damage estimation model is often divided into residential areas, industrial and commercial areas, agricultural areas and public facilities. Previous studies have mostly focused on residential, industrial and commercial areas. Agricultural losses are due to a large number of impact factors, and the relevant literature is insufficient. The most common methods are the loss curves for unit area and the flood depth loss curves method. Although the loss curves for unit area method is relatively simple, the differences in loss caused by various flooding depths are not considered. The flooding depth loss curve method often needs to be established through questionnaires. However, questionnaire surveys have to consume lots of manpower and material resources. Both the two methods above do not take the growth period of crops into consideration. When disasters occur in different growth periods of crops, the losses caused by the same flooding depth are different due to the various flooding tolerances of crops in each growth period. Due to the hydrological and geographical factors, such as climate, the growth period of rice transplanting is different due to dissimilar climatic conditions. The complexity of establishing a flooding loss curve for paddy field is thus obvious. In addition, in case the analysis of the flooding loss data is based on the traditional global regression analysis approach, there usually exists a spatial autocorrelation of the residual term with no consideration of spatial variation. This result violates the assumption of linear regression. In view of this, this study is expected to use paddy field as the research object. At first, paddy field loss factors considered in each literature are reviewed and studied. Relevant domestic factors are also collected and it then to establish a paddy field flooding loss estimation model, and then use the geographically weighted regression model for spatial analysis and spatial grouping comparison. The selection of the research site is to consider large-scale historical disaster events. The event is selected for analysis and assessment of the disaster area o of Typhoon Morakot in Kaohsiung City in 2008.

  • Flooding in Oda River Basin during Torrential Rainfall Event in July 2018 (Accepted: 2019-06-10)
    Shakti P. C., National Research Institute for Earth Science and Disaster Resilience (NIED), Tsukuba, Japan
    Hideyuki Kamimera, National Research Institute for Earth Science and Disaster Resilience (NIED), Tsukuba, Japan

    Extreme rainfall events cause severe flooding and/or landslides almost every summer in Japan. It seems that the frequency of such events and induced human/economic losses has increased in recent years. A torrential rainfall event in early July 2018 caused severe flooding in many river basins over Hiroshima and Okayama Prefectures of western Japan and resulted a number of fatalities and serious damage to property. One of them is the Oda river basin (about 498 km2), which was severely affected by the flood during the event. Different types of observation systems were used to measure or estimate rainfall for this event. Comparison of radar and satellite-based rainfall shows a good agreement with the rain gauge observations of the entire period. Basin-mean total rainfall from Japan Meteorological Agency’s analyzed radar rainfall (RADJ), Water and Disaster Management Bureau’s radar rainfall (RADW), Automated Meteorological Data Acquisition System (AMeDAS), and satellite-based rainfall data (GSMaP) were about 314, 322, 357 and 304 mm during July 5–7 2018. In this study, we applied Rainfall–Runoff–Inundation (RRI) to acquire a detailed understanding of flood processes in the Oda river basin. All the available rainfall data including different spatial resolution of hydrographic features were considered as the main input data in the model separately. Gridded flow and map of the possible maximum flood depth across the basins were generated and validated. Simulated results based on high resolution topographic data are more closely aligned with observed data. It is also found that the maximum flood inundation areas estimated by the RRI model using radar rainfall data appeared somewhat closer with the extent of flood-affected areas from the model with data of the Japanese Geospatial Information Authority (GSI) over the Mabi city. It is believed that modelled results can be used an important reference in the disaster mitigation and that they may be useful for further studies.

  • Estimation of Groundwater Use Pattern and Distribution in the Coastal Mekong Delta, Vietnam via Socio-Economical Survey and Groundwater Modelling (Accepted: 2019-06-10)
    Tuan Pham Van, Chulalongkorn University
    Sucharit Koontanakulvong, Chulalongkorn University

    In many provinces of Mekong delta, excessive groundwater extraction has resulted in many serious groundwater-related problems. To solve problems relevant to increasing water demand as well as other negative influence of groundwater depletion, an exigent question was raised whether at what time in future is the limits to local groundwater use reached? Hence, there is a need to know groundwater use (GWU) pattern and distribution in the study area for future groundwater management. In this study, firstly, the study used socio-economic data of Tra Vinh Province to classify groups of revenue, potential of water resources and population distributed in each district in order to design and conduct the socio-economic survey and to explore information relevant to GWU for each purpose. Secondly, the data set of 419 survey questionnaires per 9 surveyed communes were analysed by SPSS tool to estimate ratio of household using groundwater (RHHUG) for each purpose as well as average pumping rate (APR) per household for domestic use and per ha for agriculture use, respectively. Thirdly, the APRs were extended to propose the total GWU pattern and distribution during 2007-2016 by using socio-economic data of the province and expand to spatial distribution by using correlation with land surface temperature (LST) which was estimated from Landsat 8 images. Besides, the groundwater flow model of the study area was developed to verify the estimated amount of groundwater pumping (pattern and distribution) in the period. The study found that the annual GWU of Tra Vinh Province in 2016 was 347,793 m3/d in which two coastal districts occupied more than 50 percentages, i.e., about 188,551 m3/d. RHHUG increased from 2 to 3 times during the period of 2007 to 2016 in this area. LST distribution performed a good correlation (adj-R2 = 0.646) with GWU distribution in Tra Cu district. Results of groundwater modelling also showed that the discharge from aquifer (mainly pumping) was always higher than the recharge to aquifer.

  • A Study on Local Knowledge in Adaptation to Landslide Disasters in Sri Lanka (Accepted: 2019-06-10)
    Uditha Akalanka Dasanayaka, Nagaoka University of Technology
    Yoko Matsuda, Nagaoka University of Technology

    Natural disasters are unforeseen events which occur at hydrologic, geologic, and atmospheric origins. The Policy-makers still rely on mitigation strategies based on scientific approaches. However, many scholars had emphasized the importance of incorporating local knowledge and related practices for disaster risk management. In that context, this study investigates the local knowledge in adaptation to mitigate the landslides disaster situations by studying a village in Sri Lanka which is located at the central region of Sri Lanka which is vulnerable for landslide disasters. Landslides is one of the severe types of disasters in hilly terrains and which cause to loss of lives and property damages especially in Asia region. This study employed the field surveys, questionnaire surveys and semi structured interviews for data collection. The findings of the research indicate how the local knowledge-based practices in settlement layout & planning, landscaping had enhanced disaster adaptation level of the community. Further the local knowledge-based value systems act as a strong mechanism in identifying early signs of landslide disasters. Finally, the paper discusses the possibilities of upscaling such local practices for mainstream disaster management practices.

  • Transformation Optical User-Friendly Interface for Designing Metamaterials (Accepted: 2019-09-12)
    Wanchai Pijitrojana,
    Pasit Jarutatsanangkoon, Thammasat University

    Transformation optics offers a procedure to design the structures of metamaterials to find the material parameters needed in various applications. However, a methodology of a transformation optics is too complicated. To help users who are beginning to study metamaterials and transformation optics, a transformation optical user-friendly interface is developed. The interface is implemented based on the free-form touch transformation. By combining various transformation templates, a fully arbitrary transformation can be realized. Transformation templates are created by basic functions. The interface provides both the input method as well as the real-time visualization of the space. The program uses model-view-controller architecture. Three examples from the touch interface are verified by the FDFD simulation.

  • Evaluation of Economic Damages on Rice Production under Extreme Climate and Agricultural Insurance for Adaptation Measures in Northeast Thailand (Accepted: 2019-07-25)
    Koshi Yoshida, Ibaraki University
    Mallika Srisutham, Khon Kaen University
    Supranee Sritumboon, Land Development Department, Thailand
    Desell Suanburi, Kasetsart University
    Naruekamon Janjirauttikul, Land Development Department, Thailand
    Weerakaset Suanpaga, Kasetsart University

    In northeast Thailand, the irrigated agricultural land was only 7.6% (in 2012) of total and others were classified as rain-fed so that climate change makes agricultural production unstable and also makes negative impact to the societies and economics in rural area. To mitigate these issues, it is desirable to develop enhanced adaptation measures. In this study, we focused on weather induced economic damages and effectiveness of index-based insurance system in Northeast Thailand. Firstly, we evaluated how affect the seasonal rainfall amount and patterns on rice yield and production through regression analysis by using the meteorological and agricultural statistic data. 8 province had positive correlation R>0.3 with Jul-Sep accumulated rainfall. And then, probability analysis was applied to monthly rainfall which was employed for insurance index value. As a result, setting amount and periods of insurance index was suitable. Secondly, household survey was conducted to investigate farmer’s conditions of water use, cultivation, income balance. In recent year, agricultural damage on farmer’s income was not so large (less than 3%), because 65% of farmers income relied on non-agricultural sector. That might be the one reason of constraints of insurance sales.

  • Characteristics of Gridded Rainfall Data for Thailand from 1981–2017 (Accepted: 2019-07-25)
    Shojun Arai, Toyama Prefectural University
    Kazuya Urayama, Toyama Prefectural University
    Taichi Tebakari, Toyama Prefectural University
    Boonlert Archvarahuprok, Thai Meteorological Department, Thailand

    We used a spatially interpolated gridded dataset produced by the Thai Meteorological Department (TMD) to explore long-term rainfall trends. We placed data from 1981–2017 into a 0.5° grid using the Kriging method. Long-term trends in maximum daily and monthly rainfall, and total annual rainfall, were analyzed using the nonparametric Mann–Kendall trend test. Chumphon, Lamphun, Nakhon, Sawan, and Buriram provinces exhibited significant positive trends in the annual maximum daily rainfall (p<0.05, p<0.01). The coastal area of Chachoengsao Province exhibited a significant negative trend (p<0.05). January rainfall showed a negative trend throughout Thailand. Annual rainfall showed a positive trend in many regions, especially in northern, northeastern, and southern areas. The eastern region exhibited a negative trend but statistical significance was not attained. The 10-, 30-, 50-, and 100-year daily rainfall probabilities were estimated using the Generalized Extreme Value method. The eastern side of the southern region exhibited remarkably high rainfall.

  • Prospect of Discharge at Daecheong and Yongdam Dam Watershed under Future Greenhouse Gas Scenarios using SWAT Model (Accepted: 2019-07-25)
    Seonhui Noh, Chungnam National University
    Mikyoung Choi, Chungnam National University
    Kwansue Jung, Chungnam National University
    Jinhyeog Park, K-water Institute of Water and Environment, Korea

    In this study, the future expected discharges is analyzed at Daecheong and Yongdam Dam Watershed under Future Greenhouse Gas Scenarios based on RCM with 1 km spatial resolutions from Korea Meteorological Agency(KMA). HadGEM2-AO, which is the climate change prediction model that KMA recently introduced is used for this study. Geum river watershed area is 9,914.013 km2 and there are two dams, one of dam is Daecheong Dam completed in 1980, the other dam is Yongdam Dam completed in 2001. The runoff is simulated using the ArcSWAT model from 1988 to 2010. The simulation is in good agreement with measured data at the Yongdam Dam and Daecheong Dam showing R2 of 92.25% and 95.40% respectively. Using the average discharge from 2001 to 2010 as a baseline, the simulated annual average discharge increased by approximately 47.76% and 36.52% under the RCP4.5 scenario and RCP8.5 scenario respectively for the from 2011 to 2100.