• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.1089-1095
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• 2014

In this study, we compared and analyzed the displacement of final excavation with measured value through an inverse analysis method used in urban excavation construction. We maximized the effectiveness of the inverse analysis method, and plan to achieve cost-effective and practical construction management in the field with identical conditions. As the first stage, we suggest an example of a field which has the inverse analysis method. We applied the inverse analysis method to three different fields on which construction and measuring were finished. Of these three fields, two fields showed a very satisfactory result. However, in one field, there were significant differences between the analysis and measured value. The result of our analysis indicated that, we should unite the conditions of the inverse analysis method and field construction. We need to thoughtfully reconsider the RANKINE earth pressure application in a triangle type. This is because the uniformity of earth pressure is made by its arching effect, in the condition of the displacement of lower underground occurring widely, which is differentiated with the earth pressure conditions of RANKINE, even if the slurry wall has stiffness. Also, when recalculating the soil parameter, we should emphasize the adhesion of the weathering zone, and give experimental consideration to ground water level.

• Journal of Korea Multimedia Society
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• v.18 no.7
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• pp.886-894
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• 2015

In this paper, we conduct sensitivity analysis of parameters used for inverse modeling in order to estimate the PM₁₀ emissions from the 16 areas in East Asia accurately. Parameters used in sensitivity analysis are R, the observational error covariance matrix, and B, a priori (background) error covariance matrix. In previous studies, it was used with the predetermined parameter empirically. Such a method, however, has difficulties in estimating an accurate emissions. Therefore, an automatically determining method for the most suitable value of R and B with an error measurement criteria and posteriori emissions accuracy is required. We determined the parameters through a sensitivity analysis, and improved the accuracy of posteriori emissions estimation. Inverse modeling methods used in the emissions estimation are pseudo inverse, NNLS (Nonnegative Least Square), and BA(Bayesian Approach). Pseudo inverse has a small error, but has negative values of emissions. In order to resolve the problem, NNLS is used. It has a unrealistic emissions, too. The problems are resolved with BA(Bayesian Approach). We showed the effectiveness and the accuracy of three methods through case studies.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.125-128
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• 2002

The automotive industry have made an effort to reduce the weight of vehicle structures with increased safety, while initial model of the final product does not contain any prehistoric effects in a design stave. It takes lots of time to calculate forming effects that have great influences on the energy absorption of structures. In this paper, finite element inverse analysis is adopted to calculate forming effects, such as thickness variation and effective plastic strain as well as an initial blank shape with small amount of computation time. Crash analysis can be directly performed after inverse analysis of the forming process without remeshing scheme. The direct mesh mapping method is used to calculate an initial guess from the sliding constraint surface that is extracted from the die and punch set. Analysis results show that energy absorption of structures is increased with consideration of forming effects and finite element inverse analysis is usefully applicable to calculate forming erects of vehicle structures for the crash analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.62.1-62
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• 2001

This paper suggests an inverse optimal PID control design method for the trajectory tracking case of mechanical systems. Also, simple coarse/fine performance tuning laws are suggested based on the analysis for performance limitation of inverse optimal PID controller. Experimental results for a robot manipulator show the validity of our analysis for the performance tuning methods.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.549-556
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• 1997

The inverse heat conduction problems is the calculation of surface heat transfer coefficients by utilizing measured temperature. The numerical technique of finite element analysis and optimizition is introduced to calculate temperatures and heat transfer coefficients. The calculated heat transfer coefficients and temperature distribution are good agreement with the results of direct analysis. The inverse method has been applied to the control valve of nuclear power plant.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.2043-2050
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• 1993

This paper presents a three dimensional modeling and dynamic analysis of a hydraulic excavator. An excavator composed of a boom, a bucket, two boom cylinders, an arm cylinder, and a bucket cylinder is used for the analysis. Each cylinder is modeled to two separate bodies linked by a translational joint. Judging from the actual degrees of freedom of the excavator, proper kinematic joints are selected to exclude redundant constraints in the modeling. In order to find the reaction forces at kinematic joints during operations, inverse dynamic analysis is carried out. Dynamic analysis is also carried out to verify the results from inverse dynamic analysis. The DADS program is used for analysis, with proper modification of the DADS user routine according to various motions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.1
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• pp.104-111
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• 1998

This study solves the inverse kinematics problem of industrial FANUC robot. Because every joint angle of FANUC robot is dependent on the position of end-effector and the direction of approach vector, arm metrix T6 is very complicated and each joint angle is a function of other joint angles. Therefore, the inverse kinematics problem can not be solved by conventional methods. Noticing the fact that if one joint angle is known, the other joint angles are calculated by the algebraic methods. $ heta$1 is calculated using neumerical analysis method, and solves inverse kinematics problem. This proposed method, in this study, is more simpler and faster than conventional methods and is very useful in the real-time control of the manipulator.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.3
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• pp.364-373
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• 1999

A combination of conjugate gradient and Levenberg-Marquardt method is used to estimate the spatially varying scattering coefficient, ${\sigma}(r)$, in the solid and hollow spheres by utilizing the measured transmitted beams from the solution of an inverse analysis. The direct radiation problem associated with the inverse problem is solved by using the $S_{12}-approximation$ of the discrete ordinates method. The accuracy of the computations increased when the results from the conjugate gradient method are used as an initial guess for the Levenberg-Marquardt method of minimization. Optical thickness up to ${\tau}_0=3$ is used for the computations. Three different values of standard deviation are considered to examine the accuracy of the solution from the inverse analysis.

• Journal of electromagnetic engineering and science
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• v.2 no.1
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• pp.5-10
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• 2002

We have analized the inverse class-F and class-F amplifiers using their waveforms. From the analytic equations derived from the analysis, we have calculated tole efficiencies, output powers, DC power dissipations, and optimum fundamental load impedances of the inverse class-F and class-F amplifiers. We also have compared them for various operation conditions, which include the same peak current, saute DC power dissipation, same fundamental RF output power, and same fundamental load impedance with different Ron(on-resistance). These analyses have clearly shown the performance limitations, advantages, and guide to the optimized design of the inverse class-F amplifiers.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.12
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• pp.3856-3870
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• 1996

The objective of this study is to evaluate heat transfer coefficient distribution during heat treatment by inverse analysis. As a first procedure, the inverse heat transfer formulation by using two dimensional finite element method has been developed. The formulation can handlematerial nonlinearity and allow arbitrary placement and number of sensors. The formulation was verified through application to simulated exact and inexact measurements.