• 전자공학회논문지 IE
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• v.44 no.4
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• pp.19-25
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• 2007

In this paper, we consider the input-state(I/S) transformation for the time-varying linear system with the uncertainty because of to determine the bounded range of the uncertainty. And we get the time-invarying linear system after the I/S transformation. We present the necessary sufficient condition for the I/S transformation. The transformed system represent the system with the multiple integral. We verify the proposal algorithm via the example and examine.

• Journal of Technology Innovation
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• v.30 no.1
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• pp.1-20
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• 2022

Digital transformation refers to the economic and social effects of digitisation and digitalisation. Although digital transformation acts as a useful tool for economic/social development and enhancing the convenience of life, it can have negative effects (misuse of personal information, ethical problems, deepening social gaps, etc.). The government is actively establishing policies to promote digital transformation to secure competitiveness and technological hegemony, however, understanding of digital transformation-related risk issues and implementing policies to prevent them are relatively slow. Thus, this study systematically identifies risk issues of the future society that can be caused by digital transformation based on quantitative analysis of media articles big data through the Embedded Topic Modeling method. Specifically, first, detailed issues of negative effects of digital transformation in major countries were identified. Then detailed issues of negative effects of artificial intelligence in major countries and Korea were identified. Further, by synthesizing the results, future direction of the government's digital transformation policies for responding the negative effects was proposed. The policy implications are as follows. First, since the negative effects of digital transformation does not only affect technological fields but also affect the overall society, such as national security, social issues, and fairness issues. Therefore, the government should not only promote the positive functions of digital transformation, but also prepare policies to counter the negative functions of digital transformation. Second, the detailed issues of future social risks of digital transformation appear differently depending on contexts, so the government should establish a policy to respond to the negative effects of digital transformation in consideration of the national and social context. Third, the government should set a major direction for responding negative effects of digital transformation to minimize confusion among stakeholders, and prepare effective policy measures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1812-1818
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• 2005

Even though SMA actuators have high power to volume ratio, there exist disadvantages such as hysteresis and saturation. So the model identification for SMA actuators is very difficult. For the qualitative model identification, we described the behavior of SMA actuators using a so-called diagonal model, which can readily expect the turning point of an incomplete phase transformation. For the quantitative model identification, we developed the general dynamics of SMA actuators using the modified Liang's model. Using this dynamics we can describe the hysteresis and the saturation very well. It is also very important to notice that the modified Liang's model maintains a continuous martensite fraction at the change of the phase transformation but the original model cannot.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.2
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• pp.94-101
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• 1996

The equations of motion for a basic industrial robotic system which has a rigid or a flexible arm are derived by Lagrange's equation, respectively. Especially, for the deflection of the flexible arm, the assumed mode method is employed. These equations are highly nonlinear equations with nonlinear coupling between the variables of motion. In order to design the control law for the rigid-arm robot, Hunt-Su's nonlinear transformation method and Marino's feedback equivalence condition are used with linear quadratic regulator(LQR) theory. The control law for the rigid-arm robot is employed to input the desired path and to provide the required nonlinear transformations for the flexible-arm robot to follow. By using the implicit Euler method to solve the nonlinear equations, the comparison of the motions between the flexible and the rigid robots and the effect of flexibility are examined.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.4
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• pp.118-127
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• 1998

In this paper, we propose a voice personality transformation method which makes one person's voice sound like another person's voice. In order to transform the voice personality, vocal tract transfer function is used as a transformation parameter. Comparing with previous methods, the proposed method can obtain high-quality transformed speech with low computational complexity. Conversion between the vocal tract transfer functions is implemented by a linear mapping based on soft clustering. In this process, mean LPC cepstrum coefficients and mean removed LPC cepstrum modeled by the low dimensional vector are used as transformation parameters. To evaluate the performance of the proposed method, mapping rules are generated from 61 Korean words uttered by two male and one female speakers. These rules are then applied to 9 sentences uttered by the same persons, and objective evaluation and subjective listening tests for the transformed speech are performed.

• The Journal of the Acoustical Society of Korea
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• v.24 no.3
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• pp.150-159
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• 2005

This paper addresses a voice personality transformation algorithm which makes one person's voices sound as if another person's voices. In the proposed method, one person's voices are represented by LPC cepstrum, pitch period and speaking rate, the appropriate transformation rules for each Parameter are constructed. The Gaussian Mixture Model (GMM) is used to model one speaker's LPC cepstrums and conditional probability is used to model the relationship between two speaker's LPC cepstrums. To obtain the parameters representing each probabilistic model. a Maximum Likelihood (ML) estimation method is employed. The transformed LPC cepstrums are obtained by using a Minimum Mean Square Error (MMSE) criterion. Pitch period and speaking rate are used as the parameters for prosody transformation, which is implemented by using the ratio of the average values. The proposed method reveals the superior performance to the previous VQ-based method in subjective measures including average cepstrum distance reduction ratio and likelihood increasing ratio. In subjective test. we obtained almost the same correct identification ratio as the previous method and we also confirmed that high qualify transformed speech is obtained, which is due to the smoothly evolving spectral contours over time.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.371-375
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• 1995

The antagonistic rhizobacteria Pseudomonas(P.) fluorescens against F. oxysporum and R. solani were isolated and selected, and then, their biological and physiological characteristics were investigated. The posibility and optimum condition of the electroporation of antagonistic rhizobacteria with Ps70, one of the selected one, and plasmid pSV2-neo was studied. Its optimum condition was found with HGEB which contains 1 mM (pH 7.0) hepes and 10% glycerol at setting of 200 resistance, 25 ${\mu}F$ capacitance, and 2.5 kV applied voltage. In addition, the transformation efficiency obtained with pSV2-neo was compared to other plasmids with different sizes. The applied voltage, the buffer composition and the parallel resistor (time constant) were shown to have the greatest effect on transformation efficiency in electroporation. And the rest of the selected rhizobacteria were also successfully transformed with pSV2-neo by electroporation.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.87-91
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• 2009

Welding is one of the most important joining processes and the effect of welding residual stresses in the structure has a great deal of influence on its quality. In this paper, recent development in computational welding mechanics, particularly calculation of welding residual stresses, is introduced. The hypoelastic formulation of finite element analysis for thermoelastic-plastic deformation is applied to welding processes to find residual deformations and stresses. Leblond's phase evolution equation coupled with the energy equation is employed to calculate the phase volume fraction; this plays an important role as a kinetics parameter affecting phase fraction effects in the mechanical constitutive equation of welded materials. Furthermore, transformation plasticity is taken into account for an accurate evaluation of stress. The influence of the phase transformation and the transformation plasticity on residual stress is investigated by means of numerical analyses using metallurgical parameters in Leblond's phase evolution equation that are adjusted with respect to various cooling rates in a CCT-diagram. Coding implementation is conducted by way of the ABAQUS user subroutines, UMAT.

• Journal of Information Science Theory and Practice
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• v.10 no.spc
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• pp.96-111
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• 2022

With the rapid development of the Fourth Industrial Revolution and digital transformation, scientific and technological innovation measures are being devised to overcome Korea's low-growth, high-cost structure. Accordingly, by examining the R&D investment evaluation system of R&D PIE (R&D Platform for Investment and Evaluation), which has been promoted by the Korean government in response to the Fourth Industrial Revolution, from the perspective of R&D transformation, this study aims to explore a new path for a sustainable national science and technology innovation system following digital transformation. In particular, from the perspective of R&D PIE, a MLP (Multi-level Perspective), which had been conducted as an abstract theoretical study, was attempted with specific cases and analysis for each of the three layers: niche, landscape, and regime. In conclusion, R&D PIE was intended to elevate the abstract R&D investment evaluation system to a platform that leads innovation in the digital space of the Fourth Industrial Revolution. In addition, it was confirmed that the R&D PIE could be replaced or enhanced as a platform for innovation in response to the Fourth Industrial Revolution, thereby providing an alternative to job creation and an escape from economic crisis.

• Membrane and Water Treatment
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• v.4 no.1
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• pp.1-9
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• 2013

The process of electromembrane transformation of L-lysine monohydrochlorides into their zwitterionic form in four- and two-chamber electrodialysis apparatus was investigated. The process of transformation at various concentrations of lysine monohydrochloride (0.1-0.6 mol.L-1) was studied and it was established that at the optimum density of current optimal concentrations of lysine hydrochloride during electrodyalisis was in the range of 0.2-0.4 mol.L-1. It was determined that the process of total transformation was accomplished when pH of the lysine solution achieved 10. Changes of concentrations of $Cl^-$ ions and lysine diffused into the neighboring chamber were determined depending on the time. The method developed by us allows adjusting the removal coefficient of $Cl^-$ ions during transformation to a maximal value, the losses of lysine diffused into the next chamber after its return to the technological cycle being less than 1.0 %. The specific energy consumption during the process of transformation in two- and four-chamber electrodialyzers was 0.19 and 0.205 A.h.kg-1 and the current efficiency was 75.9 and 73.1 %, correspondingly. Study of the process of electromembrane transformation allowed obtaining zwitterionic form of L-lysine from L-lysine monohydrochloride with minimal reagent and energy consumption.