• Geotechnical Engineering
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• v.13 no.3
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• pp.53-62
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• 1997

Analytical studies were conducted to develop the Spectral-Analysis-of-Surface-Waves (SASW) method for underwater use. For the precise estimation of the in-situ soil stiffness profile from SASW measurements, it is essential to determine economical and reasonable theoretical dispersion curves reflecting various experimental conditions. In this paper, therefore, analytical methods are mainly discussed, which were developed to determine theoretical dispersion curves of surface waves propagated along the soil-water interface. Application of the analytical methods is then illustrated by an example involving estimation of a stiffness profile through a forward modeling process of SASW measurements. Applicabilities of the SASW method as well as the developed analytical methods are evaluated, respectively, from the example.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.221-226
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• 2002

This paper deals with the estimation of the bond stress based on experimental data that were tensed by axial force on both sides. It is certificated that the concrete stress condition clearly affects the bond-slip relationship. The proposed method utilizes the conventional bond-slip theories as well as the characteristics of deformed reinforcement and concrete cross-sectional area. An analytical equation for the estimation of the bond stress is formulated as the function of non-dimensional factors (e.g. bond stress, relative slip, etc.). The validity, accuracy and efficiency of the proposed method are established by comparing the analytical results with the experimental data of Ikki (1996, 1999) and the representative bond stress equations of Shima (1987). The analytical results presented in this paper indicate that the proposed method can be effectively estimated the bond stress-relative slip relationship.

• Earthquakes and Structures
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• v.12 no.2
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• pp.145-152
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• 2017

The analytical method is used to develop new models for an elevated tank to estimate its natural period. The equivalent mass- spring method is used to configure the developed analytical models. Also direct method is used for numerical verification. The current study shows that developed models can have a good estimation of natural period compared with concluded results of finite elements. Additional results show that, the dependency of impulsive period to soil stiffness condition is higher than convective period. Furthermore results show that considering the fluid- structure- soil interaction has remarkable effects on natural impulsive and convective periods in case of hard to very soft soil.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.129-131
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• 2005

This paper deals with an electromagnetic analysis and control parameter estimation of a moving-coil linear oscillatory actuator (MCLOA). Analytical solutions for electromagnetic characteristics of the MCLOA are obtained from transfer relations derived in terms of a magnetic vector potential and two-dimensional (2-d) rectangular coordinate systems. And then, on the basis of 2-d analytical solutions, control parameters such as the thrust constant, the back-emf constant and winding inductances are estimated. Finally, analytical results for both electromagnetic characteristics and control parameters of the MCLOA are validated extensively by finite element (FE) analyses. In particular, test results such as static thrust, resistance and inductance measurements are given to confirm the analyses.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.468-478
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• 2020

The wave interaction problem with a vertical slotted breakwater, consisting of impermeable upper, lower parts and a permeable middle part, has been studied theoretically. An analytical model was presented for the estimation of reflection and transmission of monochromatic waves by a slotted breakwater. The far-field solution of the wave scattering involving nonlinear porous boundary condition was obtained using eigenfunction expansion method. The empirical formula for drag coefficient in the near-field, representing energy dissipation across the slotted barrier, was determined by curve fitting of the numerical solutions of 2-D channel flow using CFD code StarCCM+. The theoretical model was validated with laboratory experiments for various configurations of a slotted barrier. It showed that the developed analytical model can correctly predict the energy dissipation caused by turbulent eddies due to sudden contraction and expansion of a slotted barrier. The present paper provides a synergetic approach of the analytical and numerical modelling with minimum CPU time, for better estimation of the hydrodynamic performance of slotted breakwater.

• Smart Structures and Systems
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• v.26 no.6
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• pp.735-751
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• 2020

Identification of structure parameters is crucial in Structural Health Monitoring (SHM) context for activities such as model validation, damage assessment and signal processing of structure response. In this paper, guided waves generated by piezoelectric transducers are used for in-situ and non-destructive structural parameter estimation based on Bayesian approach. As Bayesian approach needs iterative process, which is computationally expensive, this paper proposes a method in which an analytical model is selected and developed in order to decrease computational time and complexity of modeling. An experimental set-up is implemented to estimate three target elastic and geometrical parameters: Young's modulus, Poisson ratio and thickness of aluminum and steel plates. Experimental and simulated data are combined in a Bayesian framework for parameter identification. A significant accuracy is achieved regarding estimation of target parameters with maximum error of 8, 11 and 17 percent respectively. Moreover, the limitation of analytical model concerning boundary reflections is addressed and managed experimentally. Pulse excitation is selected as it can excite the structure in a wide frequency range contrary to conventional tone burst excitation. The results show that the proposed non-destructive method can be used in service for estimation of material and geometrical properties of structure in industrial applications.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.39-42
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• 2000

Motion estimation plays an important role for video coding. In this paper, we derive optimal search patterns for fast block matching motion estimation. By analyzing the block matching algorithm as a function of block shape and size, we can find an optimal search pattern for initial motion estimation. The proposed idea, which has been verified experimentally by computer simulations, can provide an analytical basis for the current MPEG-2 proposals. In order to choose a more compact search pattern for BMA, we exploit the statistical relationship between the motion and the frame difference of each block.

• Journal of Information Technology Services
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• v.11 no.1
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• pp.197-210
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• 2012

This paper presents the ways that can improve the Software Cost Estimation Guidelines in order to replace those that are expected to be abolished at February, 2012, and solve the problems that are being occurred in the current Software Cost Estimation Guidelines. By using multidimensional modeling of OLAP(On-Line Analytical Processing), this paper does three dimensional modeling that considers the product/service view, process view and skill view. Also, it presents the identification method of cost estimation data through the view of each dimension. Furthermore, it defines the software cost estimation process and adapts them into the bottom up estimation and the top down estimation. Finally, it proposes the access of cost estimation data by the multidimensional analysis of OLAP.

• Journal of Magnetics
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• v.17 no.1
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• pp.19-26
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• 2012

This paper deals with the performance analysis and estimation of the electrical parameters of a permanent magnet synchronous generator (PMSG) for hydrokinetic energy conversion applications using vortex induced vibration (VIV). The analytical solutions for the magnetic fields produced by permanent magnets (PMs) and stator winding currents are obtained using a 2D polar coordinate system and a magnetic vector potential. An analytical expression for the 2D permeance is also derived, which takes into account stator skew effects. Based on these magnetic field solutions and the 2D permeance function, electrical circuit parameters such as the backemf constant and the air-gap inductance are obtained analytically. The performances of the PMSG are investigated using the estimated electrical circuit parameters and an equivalent circuit (EC). All analytical results are validated extensively using 2D finite element (FE) analyses. Experimental measurements for parameters such as the back-emf and inductance are also presented to confirm the analyses.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04b
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• pp.447-454
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• 1998

The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation) including probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation). Finally, The established experimental data for axial force-moment relationships are compared to the analytical data(data for Linear statstical method and Monte Carlo Simulation) for axial force-moment relationships in this analytical method.