• Advances in Computational Design
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• v.7 no.2
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• pp.113-128
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• 2022

Water consumption is strongly affected by numerous factors, such as population, climatic, geographic, and socio-economic factors. Therefore, the implementation of a reliable predictive model of water consumption pattern is challenging task. This study investigates the performance of predictive models based on multi-layer perceptron (MLP), multiple linear regression (MLR), and support vector regression (SVR). To understand the significant factors affecting water consumption, the stepwise regression (SW) procedure is used in MLR to obtain suitable variables. Then, this study also implements three predictive models based on these significant variables (e.g., SWMLR, SWMLP, and SWSVR). Annual data of water consumption in Thailand during 2006 - 2015 were compiled and categorized by provinces and distributors. By comparing the predictive performance of models with all variables, the results demonstrate that the MLP models outperformed the MLR and SVR models. As compared to the models with selected variables, the predictive capability of SWMLP was superior to SWMLR and SWSVR. Therefore, the SWMLP still provided satisfactory results with the minimum number of explanatory variables which in turn reduced the computation time and other resources required while performing the predictive task. It can be concluded that the MLP exhibited the best result and can be utilized as a reliable water demand predictive model for both of all variables and selected variables cases. These findings support important implications and serve as a feasible water consumption predictive model and can be used for water resources management to produce sufficient tap water to meet the demand in each province of Thailand.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.292-292
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• 2014

Wide band gap semiconductors, such as III-nitrides (GaN, AlN, InN, and their alloys), SiC, and diamond are expected to play an important role in the next-generation electronic devices. Specifically, GaN-based high electron mobility transistors (HEMTs) have been targeted for high power, high frequency, and high temperature operation electronic devices for mobile communication systems, radars, and power electronics because of their high critical breakdown fields, high saturation velocities, and high thermal conductivities. For the stable operation, high power, high frequency and high breakdown voltage and high current density, the fabrication methods have to be optimized with considerable attention. In this study, low ohmic contact resistance and smooth surface morphology to AlGaN/GaN on 2 inch c-plane sapphire substrate has been obtained with stepwise annealing at three different temperatures. The metallization was performed under deposition of a composite metal layer of Ti/Al/Ni/Au with thickness. After multi-layer metal stacking, rapid thermal annealing (RTA) process was applied with stepwise annealing temperature program profile. As results, we obtained a minimum specific contact resistance of $1.6{\times}10^{-7}{\Omega}cm2$.

• Journal of Fashion Business
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• v.25 no.2
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• pp.18-33
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• 2021

This study sought to understand the clothing consumption values of male consumers and analyze the attributes of online fashion multi-brand stores. The study examined the effect of clothing consumption values of male consumers on the perceived attributes of online fashion multi-brand stores and use intention. The study also aimed to investigate whether online information search moderated the relationship between the perceived attributes of online fashion multi-brand stores and use intention. An online survey of male consumers in their 20s and 30s was conducted, and a total of 338 responses were analyzed. The SPSS 24.0 program was used to perform frequency analysis, factor analysis, reliability analysis, regression analysis, and stepwise-regression analysis. The results are as follows. First, fashionableness out of the four attributes of online fashion multi-brand stores (fashionableness, entertainment, variety, and scarcity) influenced the practical and conspicuous values of clothing consumption values. Entertainment had a significant effect on all clothing consumption values. Variety had a significant impact on practical and conspicuous values and the scarcity factor influenced epistemic and conspicuous values. Second, while entertainment, variety, and scarcity influenced sharing intention, fashion, entertainment, and variety influenced purchase intention. Third, online information search moderated the relationship between the perceived attributes of online fashion multi-brand stores and sharing intention but not purchase intention.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.11-19
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• 2017

The decision-making process is the act of finding the best solution among various alternatives through comparison between various criteria based on objectives of the project, evaluation standard, and conditions. However, in practice it is not easy to simply decide the optimum decision, especially for selecting malfunctioning reservoirs because no systematic evaluation criteria or standard assessment process are available. Therefore, this study adopted AHP method, which is a MCDM (multi-criteria decision making technique) to identify the malfunctioning reservoirs for efficient management of reservoirs. Important criteria of the selection of malfunctioning reservoirs and priority weights of each criteria were determined based on results of expert's survey under a stepwise hierarchical approach. The most important factor for the decision of malfunctioning reservoirs was obtained as Reservoir efficiency among the selected criteria including Reservoir efficiency decrease, Disaster Risk, Reservoir efficiency, Available water storage, Future water demand, Resident Needs. The AHP technique was applied on 11 reservoirs in Andong region to verify its applicability. Scoring method was applied for the comparison with the results of AHP method.

• Tunnel and Underground Space
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• v.29 no.5
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• pp.292-304
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• 2019

Limestone joint surfaces with smooth roughness were experimented by means of both the individual direct shear tests based on the KSRM standard test method and the multi-stage direct shear test to apply the stepwise vertical stresses. Changes in the roughness of the joint surfaces before and after the shear tests were examined and the difference between the two kinds of tests mentioned above was analyzed. In both tests, the shear resistance increased as the joint roughness increased and the maximum shear stress required for shearing the joint surface increased as the vertical stress increased. The peak friction angle obtained by the multi-stage direct shear tests was only 63% of that obtained by the individual direct shear tests. In the multi-stage direct shear test, the initial engagement of the concave-convex parts changes frequently during stepwise shearing process, which deforms the original roughness of a joint surface. Accordingly, the individual direct shear test is thought to be more effective when obtaining the friction angle of the rock joint surfaces. Limestone joint surfaces with smooth roughness of JRC value 4~8 were found to have peak friction angle of $47^{\circ}$, residual friction angle of $38^{\circ}$ and cohesion of 37 kPa.

• Tunnel and Underground Space
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• v.23 no.3
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• pp.203-211
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• 2013

Shear behavior of joint plane has been investigated considering the magnitude of normal stresses and initial surface roughness. Shear strength of joint plane has been measured by performing the multi-stage shear test in which applied normal stress level has been increased stepwise. Multi-stage shear test within the specified normal stress range has been repeated and two types of strength parameter variation have been observed: type 1 - both cohesion and friction angle decrease, type 2 - cohesion decrease and friction angle increase. Trends of strength parameter variation for the three rock types, gneiss, granite and shale, have been investigated and the influence of initial roughness of joint plane on the sequential shear strength change for the repeated multi-stage shear tests also has been analyzed.

• Korean Journal of Remote Sensing
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• v.30 no.3
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• pp.375-381
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• 2014

Soil moisture is an essential satellite-driven variable for understanding hydrologic, pedologic and geomorphic processes. The European Space Agency (ESA) has endorsed soil moisture as one of Climate Change Initiates (CCI) and had merged multi-satellites over 30 years. The $0.25^{\circ}$ coarse resolution soil moisture satellite data showed correlations with variables of a water stress index, Temperature-Vegetation Dryness Index (TVDI), from a stepwise regression analysis. The ancillary data from TVDI, Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) from MODIS were inputted to a multi-regression analysis for estimating the surface soil moisture. The estimated soil moisture was validated with in-situ soil moisture data from April, 2012 to March, 2013 at Andong observation sites in South Korea. The soil moisture estimated using satellite-based LST and NDVI showed a good agreement with the observed ground data that this approach is plausible to define spatial distribution of surface soil moisture.

• Computational Structural Engineering
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• v.8 no.1
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• pp.161-172
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• 1995

An Integrated processing system for finite element structural analysis has been studied. It is designed to control integratedly the preprocessing, the execution and the postprocessing of a finite element structural analysis program on Windows. It becomes a better graphic user interface(GUI) for the concurrent representation of various inputs and outputs through the dialog-type on multi-windows by the multi-tasking and the object linking and embedding(OLE). Data input can be done easily through menus, dialog boxes and automatic stepwise inputs on the multiple windows, and then output results can be seen with input data on the same screen. Efficiency and validity of the system were examined by solving several numerical examples.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.04a
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• pp.25-32
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• 1994

The pre-processor for finite to element structural analysis considering the user-friendly device is developed by using GUI. This can be used on WINDOWS' environment which is realized the multi-tasking and the concurrency by object-oriented paradigm. Data input can be done easily through menu, dialog box, automatic stepwise input and concurrent representation with the structural geometry on multiple windows. It in designed to control integratedly the pre-processing, execution and the post-processing of the finite element structural analysis program on multiple windows, and input data can be seen with result outputs at the same time. In addition, the object-oriented programming environment makes convenient revision and addition of the program components for expanding the scope of analysis and making better user environment.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.219-223
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• 2001

Within a mechanical system such as an automotive the number of standard machine parts is increasing, so that the parts selection becomes more important than ever before. Selection of appropriate bearings in the preliminary design phase of a machine is also important. In this paper, three decision-making approaches are compared to find out a model that is appropriate to bearing selection problem. An artificial neural network, which is trained with real design cases, is used to select a bearing mechanism at the first step. Then, the subtype of the bearing is selected by the weighting factor method. Finally, types of peripherals such as lubrication methods are determined by a rule-based expert system.