• Journal of Biomedical Engineering Research
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• v.16 no.3
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• pp.359-366
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• 1995

The parameter, B/A, quantifies nonlinearity of the pressure-density relationship of propagation medium. This study investigated quantitative evaluation technique for healing fractured bones using this ultrasonic nonlinear parameter, B/A, obtained by the second harmonic amplitude method. A series of fundamental experiments were performed on cylinder phantoms made of aluminium, which demonstrated potential capability of nonlinear parameter B/A in the diagnosis of healing fractured bones using ultrasound.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.303-308
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• 2002

Genetic markers engendered by genome projects drew enormous interest in quantitative genetics, but knowledge on genetic architecture of complex traits is limited. Complexities in genetics will not allow us to easily clarify relationship between genotypes and phenotypes for quantitative traits. Quantitative genetics guides an important way in facing such challenges. It is our exciting task to find genes that affect complex traits. In this paper, landmark research and future prospects are discussed on genetic parameter estimation and quantitative trait locus (QTL) mapping as major subjects of interest.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.57-64
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• 2001

This paper propose a robust control method to achieve a desired system performance in spite of system uncertainty and disturbance uncertainty. The procedures of the robust controller based on QFT(Quantitative Feedback Theory) make template, bound and loop shaping which are considered by system parameter variations and performance specifications. To prove the efficiency, the designed controller is applied for an inverted pendulum which is so sensitive to the parameter variation and has a highly nonlinear and unstable characteristics. It is shown that the simulation and experimental results from the proposed controller are efficient in robustness of parameter variation and disturbance.

• Proceedings of the Safety Management and Science Conference
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• 2003.11a
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• pp.407-412
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• 2003

Railroad line capacity is influenced by Quantitative and Qualitative factors which is applied by parameter to calculate it. But these parameters have been used experiential value without analyzing its reasonability or appropriate level. In this paper, we introduce the concept of robustness to Quantify parameter and evaluate robustness of it. For this purpose, we develop parameter evaluation simulator and present it. If this simulator is utilized, we can find the parameter having appropriate robustness and it will be applied to calculate more reasonable and systematic railroad line capacity.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1472-1476
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• 2007

Artificial neural networks (ANNs) are successfully developed for the modeling and prediction of normalized polarity parameter (ETN) of 216 various solvents with diverse chemical structures using a quantitative-structure property relationship. ANN with architecture 5-9-1 is generated using five molecular descriptors appearing in the multi-parameter linear regression (MLR) model. The most positive charge of a hydrogen atom (q+), total charge in molecule (qt), molecular volume of solvent (Vm), dipole moment (μ) and polarizability term (πI) are input descriptors and its output is ETN. It is found that properly selected and trained neural network with 192 solvents could fairly represent the dependence of normalized polarity parameter on molecular descriptors. For evaluation of the predictive power of the generated ANN, an optimized network is applied for prediction of the ETN values of 24 solvents in the prediction set, which are not used in the optimization procedure. Correlation coefficient (R) and root mean square error (RMSE) of 0.903 and 0.0887 for prediction set by MLR model should be compared with the values of 0.985 and 0.0375 by ANN model. These improvements are due to the fact that the ETN of solvents shows non-linear correlations with the molecular descriptors.

• Journal of the Korean Society of Safety
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• v.11 no.2
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• pp.3-8
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• 1996

Fatigue fracture is the cyclic fracture phenomena at a very small local area near a crack tip. Therefore, the detailed quantitative experimental analysis about local cyclic strain distribution near a crack tip is prerequisite In order to make an effective parameter able to account for fatigue fracture problems. However, there are few reports on detailed quantitative experimental analysis of a local cyclic strain distribution near a crack tip, because of experimental difficulties. In this study, the distribution of local fatigue strains near a fatigue crack tip was in detail studied using by fine dot grid strain measurement method. From these results, a single parameter, which characterizes local fatigue strain field, was proposed. In addition, this parameter was applied to evaluate the fatigue crack propagation rate.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.268-273
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• 2000

Velocity-dependent increase in tonic stretch reflexes is one of the prominent characteristics of spasticity. It is very important to evaluate spasticity objectively and quantitatively before and after treatment for physicians. An accurate quantitative biomechanical evaluation for the spasticity which is caused by the disorder of central nervous system is made in this study. A sudden leg dropper which is designed to generate objective testing environment at every trial gives very effective environment for the test. Kinematic data are archived by the 3-dimensional motion analysis system($Elite^{(R)}$, B.T.S., Italy). Kinematic data are angle and angular velocity of lower limb joints, and length and lengthening velocity of lower limb muscle. A program is also developed to analyze the kinematic data of lower limb, contraction and relaxation length of muscles, and dynamic EMG data at the same tim. To evaluate spasticity quantitatively, total 31 parameters extracted from goniogram, EMG and muscle model are analyzed. Statistical analysis are made for bilateral correlations for all parameters. The described instrumentation and parameters to make quantitative and objective evaluation of spasticity shows good results.

• Journal of Mechanical Science and Technology
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• v.17 no.4
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• pp.484-491
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• 2003

For most of linear time-varying (LTV) systems, it is difficult to design time-varying controllers in analytic way. Accordingly, by approximating LTV systems as uncertain linear time-invariant, control design approaches such as robust control have been applied to the resulting uncertain LTI systems. In particular, a robust control method such as quantitative feedback theory (QFT) has an advantage of guaranteeing the frozen-time stability and the performance specification against plant parameter uncertainties. However, if these methods are applied to the approximated linear. time-invariant (LTI) plants with large uncertainty, the resulting control law becomes complicated and also may not become ineffective with faster dynamic behavior. In this paper, as a method to enhance the fast dynamic performance of LTV systems with bounded time-varying parameters, the approximated uncertainty of time-varying parameters are reduced by the proposed QFT parameter-scheduling control design based on radial basis function (RBF) networks.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.56-64
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• 2015

This study presents a model-based gain scheduling strategy for PI-based EGR controllers. The air-to-fuel ratio is used as an indirect measurement of the EGR rate. In order to cope with the nonlinearity and parameter varying characteristics of the EGR system, we proposed a static gain model of the EGR system using a new scheduling parameter. With the 810 steady-state measurements, the static gain model achieved 0.94 of R-squared value. Based on the static gain of the EGR system, the PI gains were robustly designed using quantitative feedback theory. Consequently, the gains of the PI controller are scheduled according to the static gain parameter of the EGR path in runtime. The proposed model-based gain scheduling strategy was validated through various operating conditions of engine experiments such as setpoint step responses and disturbance rejections.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.637-637
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• 2004