• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.70-77
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• 2001

This paper present a fuzzy mxlel of describing reacton features for ozon contactor in advanced water treatn-ent systems. Input and output variables are chosen by considenng the object of ozon processing and several parameters related to management of water quahty. Dissolved organic carbon concentration, $UV_{254}$ absorptIon and $KM_NO_4$ consumption are proposed as common variables in input and outp.lt variables. Furthermore own concentration, raw water's temperature and contact time are suggested as input variables, Membership hmctions for input variables have triangular type share and the grades in each lrembership function are determined by investigating process data gathered at pilot planl The decision parts of fuzzy model have linear combination form of input variables and coefficients included in such linear equations are computedd with process clata in the sense of least square error Also fuzzy trodel suggested in this paper is partitioned by 3 independent fuzzy rnxlels using the characteristics of having no interactions armng output variables. As a result, such fuzzy mxlel has rrerits in computation and comprehension. According to simulatIon results, fuzzy moIel's outputs give almost similar data to process output under same input conditions.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.78-86
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• 2000

This study identified a linear time-invariant mathematical model of each stand of a five-stand tandem cold mill. Two model identification methods are applied to construct a linear model of each stand of the tandem cold mill. For the model identification the input-output data that have interstand interference property in tandem cold rolling are obtained from a nonlinear simulator of the tandem cold mill. And a linear model of each stand is identified with N4SD(numerical algorithms for subspace state space system identification) method based on a state-space model and Least Square algorithm based on a transfer function. Furthermore a modeling error of the tandem cold mill is quantitatively analyzed from a maximum singular value plot of error function between an identified nominal model and uncertain model. In conclusion the comparison of the output signals between the existing Taylor linearized model the identified linear model and the nonlinear model of the tandem cold mill shows the accuracy and the applicability of the proposed identified model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1448-1454
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• 2018

In an optical observing system, three pairs of observations at equal time intervals are required for the orbit determination method to obtain orbital information of an unknown space objects. In this paper, we propose a method of estimating a streak for acquiring three pairs of observations using one streak image information. Satellite trajectory simulation data were generated for nine cases using the STK program in order to verify the characteristics of the orbit of space object and estimation performance. Simulation was performed by applying three approaches that can estimate the next streak position after a few seconds from one streak image information, and the estimation performance was evaluated. Linear vector method and Kalman Filter method based on the linear assumption tend to increase the estimation error in the region where the nonlinearity is large. However estimation method using the polynomial curve fitting based on the least square method showed smaller and uniform error result than the previous methods.

• Information Systems Review
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• v.25 no.2
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• pp.163-180
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• 2023

Based on the Technology-Organization-Environment (TOE) model, this study proposed a research model that explains the continuance intention of users in the with Covid-19 era considering the technical, organizational, and environmental aspects of Remote Work Solution (RWS). To verify the research model and hypothesis, an online survey was conducted on domestic RWS users. Partial least squares (PLS) were utilized to analyze the collected 411 data. As a result of the analysis, it was found that functionality and security level had positive impacts on both productivity improvement and satisfaction. However, it was also confirmed that organizational readiness had a positive effect on productivity improvement but did not affect satisfaction. Furthermore, the results revealed that government support had a positive relationship with continuance intention, but the health concerns did not. Finally, the correlations between productivity improvement, satisfaction, and continuous intention were confirmed to be significant. Therefore, 9 out of a total of 11 hypotheses were supported.

• Journal of the Korea Society of Computer and Information
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• v.29 no.9
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• pp.255-268
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• 2024

The purpose of this study was to analyze the effect of service quality and privacy risk on customer satisfaction and continuous use intention for convenience store parcel delivery service, and verify the moderating effect of contactless tendency. This study employed PLS-path modeling to test the research hypotheses. The results of the study were as follows: 1) service quality factors of convenience store parcel delivery (i.e., service price, reliability, and convenience) had significant effects on customer satisfaction. However, responsiveness had no significant effect on customer satisfaction; 2) privacy risk had a significant effect on both customer satisfaction and continuous use intention; 3) customer satisfaction had a significant effect on continuous use intention; and 4) contactless tendency moderated the relationship between responsiveness and satisfaction. The findings of the study are expected to provide valuable insights for future research and the development of practical service strategies.

• Journal of Digital Convergence
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• v.15 no.10
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• pp.233-241
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• 2017

This study has attempted to empirically analyze the mediating effects of small and medium venture firms' manufacturing capability and testing and inspection capability on the relation between their external information network heterogeneity and technology commercialization capability with a view to diversifying the research stream on the influential factors to small and medium firms' technology commercialization capability. By performing the ordinary least squares regression analysis, the Sobel test, and the Baron and Kenny test based on the 683 data of South Korean small and medium venture firms with the IBM SPSS version 23, this study provides the three empirical findings to be useful for future studies on the roles of small and medium venture firms' the manufacturing capability and testing and inspection capability. First, small and medium venture firms' manufacturing capability partially mediates the positive effect of their external information network heterogeneity on their technology commercialization capability. Second, their testing and inspection capability partially mediates this positive effect. Third, their manufacturing capability and testing and inspection capability jointly and partially mediates this positive effect.

• Food Science and Preservation
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• v.19 no.1
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• pp.95-103
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• 2012

The objective of this study was to develop models for the predict of the milk properties (fat, protein, SNF, lactose, MUN) of unhomogenized milk using the visible and near-infrared (NIR) spectroscopic technique. A total of 180 milk samples were collected from dairy farms. To determine optimal measurement temperature, the temperatures of the milk samples were kept at three levels ($5^{\circ}C$, $20^{\circ}C$, and $40^{\circ}C$). A spectrophotometer was used to measure the reflectance spectra of the milk samples. Multilinear-regression (MLR) models with stepwise method were developed for the selection of the optimal wavelength. The preprocessing methods were used to minimize the spectroscopic noise, and the partial-least-square (PLS) models were developed to prediction of the milk properties of the unhomogenized milk. The PLS results showed that there was a good correlation between the predicted and measured milk properties of the samples at $40^{\circ}C$ and at 400~2,500 nm. The optimal-wavelength range of fat and protein were 1,600~1,800 nm, and normalization improved the prediction performance. The SNF and lactose were optimized at 1,600~1,900 nm, and the MUN at 600~800 nm. The best preprocessing method for SNF, lactose, and MUN turned out to be smoothing, MSC, and second derivative. The Correlation coefficients between the predicted and measured fat, protein, SNF, lactose, and MUN were 0.98, 0.90, 0.82, 0.75, and 0.61, respectively. The study results indicate that the models can be used to assess milk quality.

• Polymer(Korea)
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• v.28 no.1
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• pp.24-34
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• 2004

Transient sorption experiments were conducted among several combinations of fluoropolymers and various organic solvents. Fully fluorinated polymer tended to exhibit ideal sorption behavior, while partially fluorinated polymers showed anomalous sorption behaviors with a drastic acceleration at the final stage of uptake. Minimization of least-squares of the measured and predicted fractional uptake, which indicated the increasing degree of deviation from Fickian diffusion, gave values of 3.0${\times}$10$\^$-4/, 1.75${\times}$10$\^$-3/, 8.68${\times}$10/sup-3/, 1.75${\times}$10$\^$-2/, respectively, for perfluoroalkoxy copolymer, poly(ethylene-co-tetrafluoroethylene), poly(vinylidene fluoride), poly(ethylene-co-chlorotrifluoroethylene). From stress-strain tests, it was confirmed that non-Fickian diffusion is closely related to the significant variation of mechanical properties (such as modulus and tensile strength) of swollen polymer. Anomalous sorption behavior stemmed from non-Fickian diffusion caused by nonlinear disruption of polar inter-segmental bonds due to solvent-induced plasticization. Thus, it is imperative to investigate the diffusion behavior of swelling solvents in partially fluorinated polymers, especially for the application to barrier materials or perm-selective membranes.

• Information Systems Review
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• v.16 no.2
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• pp.97-124
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• 2014

This study applies the concepts of sociotechnical theory and role theory in order to verify the effects of stress (that is, technostress) created from information and computer technology (ICT) concerning role stress and performance. We suggest diverse perspectives concerning the elements leading to technostress along with the stress-creating process of ICT among organizational members. The following four major hypotheses are proposed: (1) Technostress is positively related to role stress (e.g., conflict and overload of roles), adverse psychological outcomes, and adverse IS use related outcomes, (2) Role conflict is positively related to adverse psychological outcomes and adverse IS use related outcomes, (3) Role overload is positively related to adverse psychological outcomes and adverse IS use related outcomes, and (4) Innovation support will play as a moderator between technostress, roles tress, adverse psychological outcomes and adverse IS use related outcomes. A partial least square (PLS) with data gathered data from ICT users of organizations was used to verify the proposed hypotheses. The results supported our claims excluding the hypothesis associated to the relationship between technostress and role stress. We suggest a theoretical implication based on the verification of technostress related to the current concept of stress experienced by individuals within organizations. We also propose that a practical implication concerning the opposite effect of technostress, can be utilized as a method of reducing role stress, and suggests a diagnostic tool for assessing the degree of technostress within organizations.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.2
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• pp.125-130
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• 2015

The objective of this study was to investigate the feasibility of using near infrared spectroscopy (NIRS) to discriminate between grass spices. A combination of NIRS and chemometrics was used to discriminate between Italian ryegrass, perennial ryegrass, and tall fescue seeds. A total of 240 samples were used to develop the best discriminant equation, whereby three spectra range (visible, NIR, and full range) were applied within a 680 nm to 2500 nm wavelength. The calibration equation for the discriminant analysis was developed using partial least square (PLS) regression and discrimination equation (DE) analysis. A PLS discriminant analysis model for the three spectra range that was developed with the mathematic pretreatment "1,8,8,1" successfully discriminated between Italian ryegrass, perennial ryegrass, and tall fescue. An external validation indicated that all of the samples were discriminated correctly. The discriminant accuracy was shown as 68%, 78%, and 73% for Italian ryegrass, perennial ryegrass, and tall fescue, respectively, with the NIR full-range spectra. The results demonstrate the usefulness of the NIRS-chemometrics combination as a rapid method for the discrimination of grass species by seed.