• Journal of information and communication convergence engineering
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• v.21 no.4
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• pp.351-358
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• 2023

This study designed a model-based Vehicle Control Unit (VCU) software for electric vehicles. Electric vehicles have transitioned from conventional powertrains (e.g., engines and transmissions) to electric powertrains. The primary role of the VCU is to determine the optimal torque for driving control. This decision is based on the driver's power request and current road conditions. The determined torque is then transmitted to the electric drive system, which includes motors and controllers. The VCU employs an Artificial Neural Network (ANN) and calibrated reference torque to enhance the electric vehicle's performance. The designed VCU software further refines the final reference torque by comparing the control logic with the torque calculation functions and ANN-generated reference torque. Vehicle tests confirmed the effective optimization of vehicle performance using the model-based VCU software, which includes an ANN.

• (The) Korean Journal of Educational Psychology
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• v.32 no.1
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• pp.1-27
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• 2018

The proposes of this study were to develop the learning consulting model based on creative problem solving and to verify the effects of its implementation. The model was developed based on ADDIE program developing model. In the analysis stage, literature review and needs survey were conducted for data collection on learning consulting at universities including the literature in related fields. Specific areas needed in the learning consulting model were selected from the results of this collected data. During the design and development stage, the learning consulting processes were established. These constituted the learning consulting model developed and it had been based on the Creative Problem Solving. To verify the validity of the learning consulting model based on the creative problem solving, a pilot study was implemented. The model was completed content a validity verification process performed by experts through focus group interviews. The aim this final model is to improve the self-directed learning ability and creative problem solving capacity of the university students. The study results showed that mean scores on self-directed learning ability of the experimental group increased significantly compared to the control group. Based on these findings, the learning consulting model seemed very effective in improving the university students' self-directed learning ability, as well as their creative problem solving capacity. Based on the results of this study, implications and limitations of the final model and its implementation were discussed.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.323-330
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• 2011

Globalization of market and diversification of customers' needs make enterprises to collaboration of participants in supply chain. To establish collaboration, supply chain must have the flexibility and reconfigurability, which are supported by fractal based supply chain management (FrSCM). In this paper, base on the FrSCM, formulation of trust model among the enterprises in the supply chain, and development of profit sharing strategies in the supply chain based on the trust model are investigated. To evaluate trust model, generation of enterprise's goal and its description, extraction and systematic composition of trust factors and trust evaluation are investigated. Based on the developed model, we developed the fuzzy inference engine to evaluate the trust value in terms of numerical value. And then revenue sharing strategies are developed based on the fractal concept and trust model for the collaborative SCM. The fractal concept is used to obtain the optimal production and transportation plans. In addition, the trust model will be integrated into the RS model. In such an RS model, the supply chain will obtain the maximum total profit and profit of each participant depends on its trust value.

• The Journal of Information Systems
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• v.26 no.3
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• pp.63-90
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• 2017

Purpose This study proposes a novel system trading model using case-based reasoning (CBR) based on absolute similarity threshold. The proposed model is designed to optimize the absolute similarity threshold, feature selection, and instance selection of CBR by using genetic algorithm (GA). With these mechanisms, it enables us to yield higher returns from stock market trading. Design/Methodology/Approach The proposed CBR model uses the absolute similarity threshold varying from 0 to 1, which serves as a criterion for selecting appropriate neighbors in the nearest neighbor (NN) algorithm. Since it determines the nearest neighbors on an absolute basis, it fails to select the appropriate neighbors from time to time. In system trading, it is interpreted as the signal of 'hold'. That is, the system trading model proposed in this study makes trading decisions such as 'buy' or 'sell' only if the model produces a clear signal for stock market prediction. Also, in order to improve the prediction accuracy and the rate of return, the proposed model adopts optimal feature selection and instance selection, which are known to be very effective in enhancing the performance of CBR. To validate the usefulness of the proposed model, we applied it to the index trading of KOSPI200 from 2009 to 2016. Findings Experimental results showed that the proposed model with optimal feature or instance selection could yield higher returns compared to the benchmark as well as the various comparison models (including logistic regression, multiple discriminant analysis, artificial neural network, support vector machine, and traditional CBR). In particular, the proposed model with optimal instance selection showed the best rate of return among all the models. This implies that the application of CBR with the absolute similarity threshold as well as the optimal instance selection may be effective in system trading from the perspective of returns.

• Journal of Digital Convergence
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• v.14 no.6
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• pp.119-132
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• 2016

This study examined the concept and usage moderated mediating model in structural equation modeling. The theoretical model and hypothesis were developed based on the Location-Based application's Expectancy disconfirmation, Location-Based application's satisfaction, Location-Based application's continuous usage intention, service trust. The statistical results of the two model were compared: one was free model(positive/negative) and the other was the Moderated Mediating Model(positive/negative). A structure equation model analysis was carried out to test the research model. Further studies are necessary to Ssupport the research hypotheses.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.395-400
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• 2006

Among the various error sources in positioning and navigation, the paper focuses on the modeling and prediction of receiver clock bias and then tries to achieve positioning based on simulated and predicted clock bias. With the SA off, it is possible to model receiver clock bias more accurately. We selected several types of GNSS receivers for test using ARMA model. To facilitate prediction with short and limited sample pseudorange observations, AR and ARMA are compared, and the improved AR model is presented to model and predict receiver clock bias based on previous solutions. Our work extends to clock bias prediction and positioning based on predicted clock bias using only 3 satellites that is usually the case under urban canyon situation. In contrast to previous experiences, we find that a receiver clock bias can be well modeled using adopted ARMA model. Test has been done on various types of GNSS receivers to show the validation of developed model. To further develop this work, we compare solution conditions in terms of DOP values when point positioning is conducted using 3 satellites to simulate urban positioning environment. When condition allows, height component is derived from other ways and can be set as known values. Given this condition, location is possible using less than 2 GNSS satellites with fixed height. Solution condition is also discussed for this background using mode of constrained positioning. We finally suggest an effective predictive time span based on our test exploration under varied conditions.

• Journal of Korea Water Resources Association
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• v.56 no.7
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• pp.431-438
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• 2023

Many shorelines are facing the beach erosion. Considering the climate change and the increment of coastal population, the erosion problem could be accelerated. To address this issue, developing a sediment transport model for rapidly predicting terrain change is crucial. In this study, a sediment transport model based on GPU parallel arithmetic was introduced, and it was supposed to simulate the terrain change well with a higher computing speed compared to the CPU based model. We also aim to investigate the model performance and the GPU computational efficiency. We applied several dam break cases to verified model, and we found that the simulated results were close to the observed results. The computational efficiency of GPU was defined by comparing operation time of CPU based model, and it showed that the GPU based model were more efficient than the CPU based model.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.123-136
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• 2012

Web applications are widely used by the development of the Internet, but there are no separate audit model for a web-based information systems. Information business has a wide variety of characteristics. So, web-based information system audit model is needed. Therefore, a web-based information system audit model was proposed to enhance the effectiveness of audit and to increase the quality. Audit check lists were applied based on three sets of existing information audit check framework. An audit point of time was defined as analysis, design, and implementation. An audit domain was defined as contents, design, and process. Moreover, audit viewpoint and inspection standards were defined by setting standards of process, product, and performance. Moreover, this paper proposes differences between an existing model of information system development methodology and web-based information system. It also deduced audit checklists according to audit domains for web-based information system audit. The deduced audit checklists were verified for its suitability by conducting surveys, and the modified audit inspection model, in which the deduced audit checklists were applied, was proposed.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.165-168
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• 1996

In this paper, we propose a design method of PID adaptive controller based on frequency domain analysis. The method is based on the estimation of a nonparametric process model in the frequency domain and the determination of the PID controller parameters by achieving partial model matching so as to minimize a performance function concerning to relative model error between the loop transfer function of the control system and the desired system. In the design method the process is represented only by a discrete set of points on the Nyquist curve of the process. Therefore it is not necessary to estimate a full order parameterized process model.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.11a
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• pp.419-422
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• 2005

In this note, the Takagi-Sugeno (T-S) fuzzy-model-based state estimator using standard Kalman filter theory is investigated. In that case, the dynamic system model is represented the T-S fuzzy model with the fuzzy state estimation. The steady state solutions can be found for proposed modeling method and dynamic system for maneuvering targets can be approximated as locally linear system. And then, modeled filter is corrected by the fuzzy gain which is a fuzzy system using the relation between the filter residual and its variation. This paper studies the T-S fuzzy model-based state estimator which the dynamic system can be approximated as linear system.