Patjawit A.,Chulachomklao Royal Military Academy |
Chinnarasri C.,King Mongkut's University of Technology Thonburi
Journal of Civil Structural Health Monitoring | Year: 2014
In order to execute dam safety planning, it is necessary to develop a method to monitor dam health, which considers and simulates the actual physical failure processes of an embankment dam. The objective of this study is to monitor the behaviour of the earthen dam during the impact of ground force through experimental modal analysis. The model of an earthen dam was constructed on a steel plate, which could be easily moved by input force. Accelerometers were installed on the model in many positions to measure respondent acceleration. The post-processing data were processed to show signs such as natural frequency and mode shape using the least-square complex exponential method. Natural frequency shifts were tracked throughout the testing period and the effects of the varying water levels were identified. During vibration, the effect of liquefaction observed in tests was found to be the first factor to deteriorate on the upstream side of the embankment model. The measurement position of the accelerometer was found to be very important for the health monitoring of the embankment dam. The proposed dam health index is the comparison of acceleration at the crest and the upstream side in both time and frequency domains which can identify damage to the embankment dam. © 2013 Springer-Verlag Berlin Heidelberg.
Devine M.T.,University of Limerick |
Devine M.T.,Irish Economic and Social Research Institute |
Devine M.T.,Trinity College Dublin |
Gabriel S.A.,University of Maryland University College |
Moryadee S.,Chulachomklao Royal Military Academy
Computers and Operations Research | Year: 2016
In this paper we present a new approach for solving energy market equilibria that is an extension of the classical Nash-Cournot approach. Specifically, besides allowing the market participants to decide on their own decision variables such as production, flows or the like, we allow them to compete in terms of adjusting the data in the problem such as scenario probabilities and costs, consistent with a dynamic, more realistic approach to these markets. Such a problem in its original form is very hard to solve given the product of terms involving decision-dependent data and the variables themselves. Moreover, in its more general form, the players can affect not only each others' objective functions but also the constraint sets of opponents making such a formulation a more complicated instance of generalized Nash problems. This new approach involves solving a sequence of stochastic mixed complementarity (MCP) problems where only partial foresight is used, i.e., a rolling horizon. Each stochastic MCP or roll, involves a look-ahead for a fixed number of time periods with learning on the part of the players to approximate the extended Nash paradigm. Such partial foresight stochastic MCPs also offer a realism advantage over more traditional perfect foresight formulations. Additionally, the rolling-horizon approach offers a computational advantage over scenario-reduction methods as is demonstrated with numerical tests on a natural gas market stochastic MCP. Lastly, we introduce a new concept, the Value of the Rolling Horizon (VoRH) to measure the closeness of different rolling horizon schemes to a perfect foresight benchmark and provide some numerical tests on it using a stylized natural gas market. © 2015 Elsevier Ltd.
Albright W.H.,Desert Research Institute |
Benson C.H.,University of Wisconsin - Madison |
Apiwantragoon P.,Chulachomklao Royal Military Academy
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2013
A study was conducted at seven sites across the United States to evaluate the field hydrology of final covers with a composite barrier (a geomembrane over a soil barrier or a geosynthetic clay liner) for final closure of landfills. The water balance of each cover was monitored with a large (10×20 m) instrumented drainage lysimeter. With one exception, the covers limited the average annual percolation to<2.8mm/year (<0.4% of precipitation). The geomembrane barrier at one site (Marina, California) was likely damaged during construction; percolation at this site averaged 30 mm/year (6.9% of precipitation). The annual percolation through the cover at the wettest site (Cedar Rapids, Iowa) ranged between 0.1 and 6.2 mm/year. The annual percolation at arid and semiarid sites was typically no more than a trace (<0.1 mm/year). Percolation from all test covers generally was coincident with high water storage in the surface soil layer and lateral flow in the drainage layer on the surface of the geomembrane barrier. Water balance predictions were made with the hydrologic evaluation of landfill performance model using sitespecific input. Surface runoff was overpredicted and evapotranspiration underpredicted when as-built soil hydraulic properties were used as input. Better agreement was obtained when in-service soil hydraulic properties were used as input. The lateral flow was consistently overpredicted regardless of the hydraulic properties, and no correspondence existed between the predicted and measured percolations. © 2013 American Society of Civil Engineers.
Apiwantragoon P.,Chulachomklao Royal Military Academy |
Benson C.H.,University of Wisconsin - Madison |
Albright W.H.,Desert Research Institute
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2015
A study was conducted at 12 sites across the United States to evaluate field-scale hydrology of landfill final covers using water balance methods to control percolation. The sites were located in climates ranging from arid to humid, with annual precipitation varying from 119 to 1,263 mm. Fifteen test sections were constructed with large (10 × 20 m) drainage lysimeters for continuous and direct monitoring of the water balance over a period of 3-6 years. Monolithic and capillary barrier designs were used for water storage, and plant communities consisting of grasses, grasses and shrubs, or grasses and trees were used to promote evapotranspiration. Data from these test sections are analyzed along with data from 10 other sites in the literature to draw general inferences regarding the hydrology of water balance covers. Percolation ranges from 0 to 225 mm/year (0-34% of precipitation) on an average annual basis and is shown to be affected by annual precipitation, preferential flow, and storage capacity of the cover. Evapotranspiration is the largest component of the water balance ( > 60% of precipitation) and varies with water availability from precipitation, energy demand as characterized by potential evapotranspiration, and type of plant community. Surface runoff is the smallest fraction ( < 16% of precipitation) and depends on the saturated hydraulic conductivity of the surface soils, intensity of precipitation, and the occurrence of snowmelt and frozen ground. © 2014 American Society of Civil Engineers.
Bobaru F.,University of Nebraska - Lincoln |
Duangpanya M.,Chulachomklao Royal Military Academy
Journal of Computational Physics | Year: 2012
We introduce a multidimensional peridynamic formulation for transient heat-transfer. The model does not contain spatial derivatives and uses instead an integral over a region around a material point. By construction, the formulation converges to the classical heat transfer equations in the limit of the horizon (the nonlocal region around a point) going to zero. The new model, however, is suitable for modeling, for example, heat flow in bodies with evolving discontinuities such as growing insulated cracks. We introduce the peridynamic heat flux which exists even at sharp corners or when the isotherms are not smooth surfaces. The peridynamic heat flux coincides with the classical one in simple cases and, in general, it converges to it in the limit of the peridynamic horizon going to zero. We solve test problems and compare results with analytical solutions of the classical model or with other numerical solutions. Convergence to the classical solutions is seen in the limit of the horizon going to zero. We then solve the problem of transient heat flow in a plate in which insulated cracks grow and intersect thus changing the heat flow patterns. We also model heat transfer in a fiber-reinforced composite and observe transient but steep thermal gradients at the interfaces between the highly conductive fibers and the low conductivity matrix. Such thermal gradients can lead to delamination cracks in composites from thermal fatigue. The formulation may be used to, for example, evaluate effective thermal conductivities in bodies with an evolving distribution of insulating or permeable, possibly intersecting, cracks of arbitrary shapes. © 2011 Elsevier Inc.
Kaewkamnerd N.,Chulachomklao Royal Military Academy |
Rao K.R.,University of Texas at Arlington
European Signal Processing Conference | Year: 2015
This paper proposes an image adaptive watermark embedding method based on discrete wavelet transform (DWT). To increase the robustness and perceptual invisibility of watermark, the algorithm is combined with the quantization model based on human visual system (HVS). Number of factors that affect the noise sensitivity of human eye, such as background luminance, proximity to an edge, frequency band and texture masking are taken into consideration. To extract the embedded watermark, both blind (uncorrupted image is not required) and non-blind methods are introduced. Simulation results show that the proposed method is robust to the image intensity attack such as high compression. © 2000 EUSIPCO.
Sanpachai H.,Chulachomklao Royal Military Academy |
Settapong M.,National Broadcasting and Telecommunications Commission NBTC
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
Biometrics is a promising technique that is used to identify individual traits and characteristics. Iris recognition is one of the most reliable biometric methods. As iris texture and color is fully developed within a year of birth, it remains unchanged throughout a person's life. Contrary to fingerprint, which can be altered due to several aspects including accidental damage, dry or oily skin and dust. Although iris recognition has been studied for more than a decade, there are limited commercial products available due to its arduous requirement such as camera resolution, hardware size, expensive equipment and computational complexity. However, at the present time, technology has overcome these obstacles. Iris recognition can be done through several sequential steps which include pre-processing, features extractions, post-processing, and matching stage. In this paper, we adopted the directional high-low pass filter for feature extraction. A box-counting fractal dimension and Iris code have been proposed as feature representations. Our approach has been tested on CASIA Iris Image database and the results are considered successful. © 2014 Copyright SPIE.
McAleer M.,Rotterdam University |
Wiphatthanananthakul C.,Chiang Mai University |
Wiphatthanananthakul C.,Chulachomklao Royal Military Academy
Mathematics and Computers in Simulation | Year: 2010
In 2003, the Chicago Board Options Exchange (CBOE) made two key enhancements to the volatility index (VIX) methodology based on S&P options. The new VIX methodology seems to be based on a complicated formula to calculate expected volatility. In this paper, with the use of Thailand's SET50 Index Options data, we modify the VIX formula to a very simple relationship, which has a higher negative correlation between the VIX for Thailand (TVIX) and SET50 index options. We show that TVIX provides more accurate forecasts of option prices than the simple expected volatility (SEV) index, but the SEV index outperforms TVIX in forecasting expected volatility. Therefore, the SEV index would seem to be a superior tool as a hedging diversification tool because of the high negative correlation with the volatility index. Crown Copyright © 2010.
A comparative study of pelleted broiler litter biochar derived from lab-scale pyrolysis reactor with that resulted from 200-liter-oil drum kiln to ameliorate the relations between physicochemical properties of soil with lower organic matter soil and soybean yield
Sanvong C.,Chulachomklao Royal Military Academy |
Nathewet P.,Maejo University
EnvironmentAsia | Year: 2014
Biochars can be used as soil amendments for improving soil properties and crop yield. In this study, a pot experiment was conducted to compare the efficiency of pelleted broiler litter biochar (PBLB) derived from a lab-scale pyrolysis reactor (PBLBL) with that resulted from 200-liter-oil drum kiln (PBLBO). The biochar generated from each reactor was applied to the pot that contained lower organics materials, sandy soil, and grown soybeans cv.Chiangmai-60 (Glycine max [L.] Merr.) at the application rates of 5.00, 10.0, 15.0, and 20.0 t ha-1. The results showed that both types of pyrolysis reactors (PBLBL and PBLBO), at every application rate, significantly improved the physicochemical properties of soil and increased the growth and yield of soybean; their comparison with a control treatment of soybeans is p < 0.05. At the application rate of 15.0 t ha-1 the PBLBL showed the highest soybean yield. The application of PBLBL and PBLBO significantly led to increased pH, soil organic matter, C:N ration, N, P, K, Ca, Mg and CEC.
Ayuttaya S.S.N.,Chulachomklao Royal Military Academy
Kasetsart Journal - Natural Science | Year: 2015
Cost analysis for the eradication of water hyacinth was undertaken using a mechanical water hyacinth harvester. Two foreign harvester models (V 4702 and S 2800) were ordered and a prototype water hyacinth harvester was designed and built in Thailand. Based on reports, there are 4.52 million t of water hyacinth in Thailand. A budget of USD 0.27 million per year would eradicate 477,000 t using water hyacinth harvesters. The operating cost is not satisfactory and the permanent eradication of water hyacinths would involve an operating cost of USD 2.68/t. The results showed that the initial investment in the prototype water hyacinth harvester was lower than for the two foreign models. The engine used in the V 4702 model was the biggest and so its fuel price was the highest. Furthermore, the maintenance and labor costs of the prototype were the lowest. There was little difference in the payback period among the three units. All three water hyacinth harvesters were considered a worthwhile investment based on net present value analysis. Finally, the main capital investment was associated with the initial purchase. In future, the prototype water hyacinth harvester will reduce the initial capital investment required compared to purchasing foreign brands. © 2016, Canadian Science Publishing. All rights reserved.