• 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.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.969-973
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• 1990

This paper presents a method of suboptimal control for nonlinear systems via block pulse transformation. The adaptive optimal control scheme proposed by J.P. Matuszewski is introduced to minimize the performance index. Nonlinear systems are controlled using the obtained optimal control via block pulse transformation. The proposed method is simple and computationally advantageous. Viablity of the this method is established with simulation results for the van der Pol equation for comparision with other methods.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.5
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• pp.765-776
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• 1995

This paper describes a speaker adaptation method to improve the recognition performance of MLP(multiLayer Perceptron) based HMM(Hidden Markov Model) speech recognizer. In this method, we use lst-order linear transformation network to fit data of a new speaker to the MLP. Transformation parameters are adjusted by back-propagating classification error to the transformation network while leaving the MLP classifier fixed. The recognition system is based on semicontinuous HMM's which use the MLP as a fuzzy vector quantizer. The experimental results show that rapid speaker adaptation resulting in high recognition performance can be accomplished by this method. Namely, for supervised adaptation, the error rate is signifecantly reduced from 9.2% for the baseline system to 5.6% after speaker adaptation. And for unsupervised adaptation, the error rate is reduced to 5.1%, without any information from new speakers.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.2
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• pp.91-107
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• 2009

In order to compute linear wave transformation over a single step bottom, both variational approximation and eigenfunction expansion method are used. Both numerical results are in good agreement for reflection and transmission coefficients, surface displacement respectively. However x velocity profiles at the boundary of step are seen to be different to each other even though x velocity matching condition is used.

• Proceedings of the Korean Society for Language and Information Conference
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• 2007.11a
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• pp.241-248
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• 2007

In this paper, we propose a Transformation-Based Learning (TBL) method on generating the Korean standard pronunciation. Previous studies on the phonological processing have been focused on the phonological rule applications and the finite state automata (Johnson 1984; Kaplan and Kay 1994; Koskenniemi 1983; Bird 1995). In case of Korean computational phonology, some former researches have approached the phonological rule based pronunciation generation system (Lee et al. 2005; Lee 1998). This study suggests a corpus-based and data-oriented rule learning method on generating Korean standard pronunciation. In order to substituting rule-based generation with corpus-based one, an aligned corpus between an input and its pronunciation counterpart has been devised. We conducted an experiment on generating the standard pronunciation with the TBL algorithm, based on this aligned corpus.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.231-236
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• 2007

This paper presents the effect of the center of the series on convergence in solving vibration problems by Differential Transformation Method(DTM) to the transverse vibration of the Euler-Bernoulli beam under varying axial force. The governing differential equation of the transverse vibration of the Euler-Bernoulli beam under varying axial force is derived. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previously published results. The effect of the center of the series on convergence in solving the problem by DTM is discussed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.11 s.104
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• pp.1318-1323
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• 2005

In this paper, the vibration analysis for the Euler-Bernoulli complete and truncate wedge beams by differential Transformation method(DTM) was investigated. The governing differential equation of the Euler-Bernoulli complete and truncate wedge beams with regular singularity is derived and verified. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previous published results. The usefulness and the application of DTM are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.507-512
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• 2005

This paper investigated the vibration analysis fer the Euler-Bernoulli complete and truncate wedge beams by Differential Transformation Method(DTM). The governing differential equation of the Euler-Bernoulli complete and truncate wedge beams with regular singularity is derived and verified. The concepts of DTM were briefly introduced. Numerical calculations are carried out and compared with previous published results. The usefulness and the application of DTM are discussed.

• Applied Biological Chemistry
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• v.40 no.3
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• pp.173-177
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• 1997

Bacillus licheniformis 9945a releases a natural ${\gamma}-poly(glutamic\;acid)({\gamma}-PGA)$ into fermentation broth and shows a mucoid phenotype on the solid agar medium. Transformation of mucoid cells of Bacillus species has not been simple and straightforward. The transpositional activity of Tn10 in B. licheniformis also has not been own either. Thus, a spontaneous non-mucoid derivative of the B. licheniformis was obtained first. Shuttle vector pHV1248 containing mini-Tn10 was introduced into the non-mucoid derivative by the method of protoplast transformation. The resulting transformant was reverted to the wild mucoid phenotype, and then mutated randomly with the mini-transposon by heat induction. Auxotrophs requiring arginine, lysine, or tryptophan were isolated by replica plating method. Southern blotting and DNA-DNA hybridzation analysis showed that these auxotrophs were generated by mini-Tn10 insertion into the chromosomal DNA. This method of transformation and mutation using pHV1248 would be useful for the generation of diverse mutants of B. licheniformis 9945a.(Received January 24,1997; accepted March 10, 1997)