• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.278-282
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• 2001

The discovery of tacit knowledge from domain experts is one of the most exciting challenges in today\`s knowledge management. The nature of decision knowledge in determining the quality a firm\`s short-term liquidity is full of abstraction, ambiguity, and incompleteness, and presents a typical tacit knowledge extraction problem. In dealing with knowledge discovery of this nature, we propose a scheme that integrates both knowledge elicitation and knowledge discovery in the knowledge engineering processes. The knowledge elicitation component applies the Verbal Protocol Analysis to establish industrial cases as the basic knowledge data set. The knowledge discovery component then applies fuzzy clustering to the data set to build a fuzzy knowledge based system, which consists of a set of fuzzy rules representing the decision knowledge, and membership functions of each decision factor for verifying linguistic expression in the rules. The experimental results confirm that the proposed scheme can effectively discover the expert\`s tacit knowledge, and works as a feedback mechanism for human experts to fine-tune the conversion processes of converting tacit knowledge into implicit knowledge.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1377-1381
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• 2014

In order to discover and develop novel signaling inhibitors from plants, a screening system was established targeting the two-component system of Cryptococcus neoformans by using the wild type and a calcineurin mutant of C. neoformans, based on the counter-regulatory action of high-osmolarity glycerol (Hog1) mitogen-activated protein kinase and the calcineurin pathways in C. neoformans. Among 10,000 plant extracts, that from Harrisonia abyssinica Oliv. exhibited the most potent inhibitory activity against C. neoformans var. grubii H99 with fludioxonil. Bioassay-guided fractionation was used to isolate two bioactive compounds from H. abyssinica, and these compounds were identified as chebulagic acid and chebulanin using spectroscopic methods. These compounds specifically inhibited the calcineurin pathway in C. neoformans. Moreover, they exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentrations ranging from 0.25 to over $64{\mu}g/ml$.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2003.11a
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• pp.279-281
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• 2003

We analysed the operating properties of resistive type superconducting fault current limiters (SFCLs) based on YBCO thin films with a single line-to-ground fault. When a single line-to-ground fault occurred, the short circuit current of a fault phase increased up to about 6 times of transport currents immediately after the fault instant and was effectively limited to the designed current level within 2 ms by the resistance development of the SFCL. The fault currents of the sound phases almost did not change because of their direct grounding system. The unsymmetrical rates of a fault phase were distributed from 6.4 to 1.4. It was found that the unsymmetrical rates of currents were noticeably improved within one cycle after the fault instant. We calculated the zero phase currents for a single line-to-ground fault using the symmetrical component analysis. The positive sequence resistance was reduced remarkably right after the fault but eventually approached the balanced positive resistance component prior to the system fault. This means that the system reaches almost the three-phase symmetrical state in about 60 ㎳ after the fault. The ground currents were almost 3 times of the zero phase mts since most of the fault currents flowed through the grounding line.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.4
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• pp.226-235
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• 2024

A method for quantifying the adaptability of ship maneuver scenarios for data-driven modeling of ship dynamics is developed based on the principal component analysis. A random maneuver scenario is suggested as a reference for ship dynamics, which can obtain the converged principal components of ship dynamics features by the Monte Carlo simulation. Principal components of conventional maneuver scenarios defined by the International Maritime Organization (IMO) are compared to that of the random maneuver. A conventional ship dynamics model for a container carrier vessel for four degrees of freedom dynamics is introduced to simulate the random and IMO maneuver scenarios. It is confirmed that the IMO tests follow the tendency of random maneuver scenario in terms of execution time and adaptability.

• Structural Engineering and Mechanics
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• v.75 no.4
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• pp.519-527
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• 2020

Dynamic analysis of a vehicle-track coupling system is important to structural design, damage detection and condition assessment of the structural system. Deterministic analysis of the vehicle-track coupling system has been extensively studied in the past, however, the structural parameters of the coupling system have uncertainties in engineering practices. It is essential to treat the parameters of the vehicle-track coupling system with consideration of uncertainties. In this paper, a method for predicting the bounds of the vehicle-track coupling system responses with uncertain parameters is presented. The uncertain system parameters are modeled as fuzzy variables instead of conventional random variables with known probability distributions. Then, the dynamic response functions of the coupling system are transformed into a component function based on the high dimensional representation approximation. The Lagrange interpolation method is used to approximate the component function. Finally, the bounds of the system's dynamic responses can be predicted by using Monte Carlo method for the interpolation polynomials of the Lagrange interpolation function. A numerical example is introduced to illustrate the ability of the proposed method to predict the bounds of the system's dynamic responses, and the results are compared with the direct Monte Carlo method. The results show that the proposed method is effective and efficient to predict the bounds of the system's dynamic responses with fuzzy variables.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.6
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• pp.47-53
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• 2004

This paper proposes an algerian for determining robot location using appearance-based paradigm. First, this algorithm compresses the image set using Principal Component Analysis(PCA) to obtain a low-dimensional subspace, called the eigenspace, and it makes a manifold that represent a continuous-appearance function. Neural network is employed to estimate the location of the mobile robot from the coefficients of the eigenspace. Then, Kalman filtering scheme is used for the fine estimation of the robot location. The algorithm has been implemented and tested on a mobile robot system. It is shown that the robot location is estimated accurately in several trials.

• The KIPS Transactions:PartD
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• v.14D no.4 s.114
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• pp.389-394
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• 2007

This study suggests that it dynamically generates semantic Web services from Java and C++ components in order to supporting semantic Web service by using ontology. And the semantic Web should enable greater access not only to content but also to services on the Web. It needs semantic service discovery for components. So, we add ontology-based framework to Web service generation system from components. Especially, components and ontologies are transformed UML model so that it makes WSDL documents to support a generation of dynamic Web service using object modeling. The main contribution of this study is to generate web service dynamically from components and to support semantic Web environment by using ontology. In other words, this study integrates semantic Web service based on ontology and CBD method.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.703-712
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• 2002

Since component-based development technologies support reusability and enhance productivity of application development, they are adopted for rapid and efficient software development, and among them, EJB component is a Jana-based software development technology widely used in industry. In this paper, we designed and implemented bulletin board and shopping mall which are major constituents of mobile e-commerce system using EJB components, and suggest construction guideline supporting reusability and interoperability.

• Journal of Power Electronics
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• v.17 no.6
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• pp.1500-1511
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• 2017

The purpose of this paper is to study a high-performance control scheme for neutral-point-clamping three-level (NPC-3L) inverter fed dual three-phase permanent magnet synchronous motor (PMSM) drives by considering some asymmetric factors such as the non-identical parameters in phase windings. To implement this, the system model is analyzed for dual three-phase PMSM drives with asymmetric factors based on the vector space decomposition (VSD) principle. Based on the equivalent circuits, PI controllers with feedforward compensation are used in the d-q subspace for regulating torque, where the cut-off frequency of the PI controllers are set at the twice the fundamental frequency for compensating both the additional DC component and the second order component caused by asymmetry. Meanwhile, proportional resonant (PR) controllers are proposed in the x-y subspace for suppressing the possible unbalanced currents in the phase windings. A dual three-phase space vector modulation (DT-SVM) is designed for the drive, and the balancing factor is designed based on the numerical fitting surface for balancing the DC link capacitor voltages. Experimental results are given to demonstrate the validity of the theoretical analysis and the proposed control scheme.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.17-21
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• 2010

As the compact and easily accessible handheld devices, such as cellular phones and MP3 players equipped with image acquisition functionality, are becoming widely available among common users, various applications of images are rapidly increasing. Image related services and software such as web-based image presentation and image manipulation for personal or commercial purpose enable users to view contents of remote image archive and to manipulate enormous amount of images in local or network based storage as well. It is necessary for users to identify the images efficiently so that the same images are perceived as one physical entity instead of recognizing them as different images as the trends are getting stronger. In order to support this environment, we propose a method that generates image identifiers or indexing for images within a solid and efficient manner. The proposed image identifier utilizes multiple index values. The integration of component index values creates a unique composite value that can be used as a file name, file system identifier, or database index. Our experimental results on generation of constituent index values have shown favorable results.