• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.12-15
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• 1994

To establish the sea surface temperature estimation scheme for the upcoming advanced remote sensor, the quasi-analytical solution of the approximated radiative transfer equation which express the radiative transfer process of the radiant energy radiated from the sea surface to the satellite is approximated into the non-linear equation. To solve the simultaneous approximated radiative transfer equation which express the radiative transfer process of the radiant energy radiated from the sea surface to the satellite is approximated into the nonlinear equation. To solve the simultaneous approximated radiative transfer equation at each channel, the constrained non-linear optimization technique is adopted. To define the coefficients of the approximated radiative transfer equation and the constraints, the satellite detected radiance and the total transmittance are computed from the 1350 kinds of simulated atmosphere / surface models via radiative transfer code. The verification from the simulated data show the sufficient result.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.3
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• pp.121-132
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• 2015

The purpose of this study is to investigate the behavior characteristics of new hollow reinforced concrete (RC) bridge pier sections with triangular reinforcement details and to provide the details and reference data. Among the numerous parameters, this study concentrates on the shape of the section, the reinforcement details and the spacing of the transverse reinforcement. Additional eight column section specimens were tested under quasi-static monotonic loading. In this study, the computer program, named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), was used. A innovative confining effect model was adopted for new hollow bridge pier sections. This study documents the testing of new hollow RC bridge pier sections with triangular reinforcement details and presents conclusions based on the experimental and analytical findings.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.111-118
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• 1995

The three-dimentional effects on the breakdown voltage of non-reachthrough planar junctions which have the finite lateral radius of window curvature are analytically investigated. The critical electric fields at breakdown and the breakdown voltages are expressed successfully in a form which is normalized to the parallel plane case. The analytical results are in excellent agreement with the published results of experiment and the quasi-three-dimensional device simulation by MEDICI for non-reachthrough plane junctions having different background doping and junction depth. The results may be applicable to the estimations of breakdown voltages in many practical power devices.

• Journal of Mechanical Science and Technology
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• v.20 no.7
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• pp.929-940
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• 2006

Early detection and diagnosis of incipient induction machine faults increases machinery availability, reduces consequential damage, and improves operational efficiency. However, fault detection using analytical methods is not always possible because it requires perfect knowledge of a process model. This paper proposes a neural network based expert system for diagnosing problems with induction motors using vibration analysis. The short-time Fourier transform (STFT) is used to process the quasi-steady vibration signals, and the neural network is trained and tested using the vibration spectra. The efficiency of the developed neural network expert system is evaluated. The results show that a neural network expert system can be developed based on vibration measurements acquired on-line from the machine.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.10
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• pp.1623-1629
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• 2003

In this paper, the arc beam is considered as a moving disc heat source with a pseudo-Gaussian distribution of heat intensity. The solution for temperature distribution on welds is derived by using the image heat source method and the superposition method. It is general solution in that it can determine the temperature-rise distribution in and around the arc beam heat source, as well as the width and depth of the melt pool (MP) and the heat-affected zone (HAZ) in welding short lengths, where quasi-stationary conditions may not have been established. As a comparative study, the results of this analytical approach has been compared with that of the finite-element modeling. As a result, The theoretical analysis presented here has shown good consistency and is more time/cost-effective method compared with FEM.

• Steel and Composite Structures
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• v.26 no.5
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• pp.557-572
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• 2018

In this paper, a refined higher-order shear deformation theory including the stretching effect is developed for the analysis of bending analysis of the simply supported functionally graded (FG) sandwich plates resting on elastic foundation. This theory has only five unknowns, which is even less than the other shear and normal deformation theories. The theory presented is variationally consistent, without the shear correction factor. The present one has a new displacement field which introduces undetermined integral variables. Equations of motion are obtained by utilizing the Hamilton's principles and solved via Navier's procedure. The convergence and the validation of the proposed theoretical numerical model are performed to demonstrate the efficacy of the model.

• Structural Engineering and Mechanics
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• v.10 no.5
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• pp.505-516
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• 2000

This paper is a presentation of an experimental study about the elastic-partly plastic behavior of rectangular hollow steel pinned struts subjected to static cyclic axial loading and the evaluation of the compressive strength of retrofitted crooked struts. Retrofitting is achieved by welding stiffening plates along the webs of damaged struts. The material follows a quasi-kinematic hardening hysteresis path as observed from coupon tests. Test results are compared to those of an analytical model showing a good agreement for both standard and retrofitted struts. The comparison of different stiffener plate dimensions shows that more efficient strengthening is achieved by using long thin stiffeners rather than short thick ones.

• Bulletin of the Society of Naval Architects of Korea
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• v.13 no.1
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• pp.25-34
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• 1976

Analytical solutions for the transient temperature and quasi-static thermal stresses which arise in thin plates subjected to an instantaneous point source of heat have been investigated. And the solutions have been extended to the case of a moving source of heat with the aid of the Duhamel's superposition integral. For finite disk an experiment was conducted, the measured temperature histories show a good agreement with the theoretical temperature histories, And the histories of thermal stresses show a good qualitative agreement with the physical phenomena. And also we can find out that the maximum temperature and thermal stresses and their location can be estimated by using the solutions for infinite plates instead of the solutions for a finite plate. The solutions can be used for the problems such as a welding or line heating in a hull construction.

• Journal of Power Electronics
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• v.11 no.6
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• pp.787-792
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• 2011

In this paper, a new three phase soft switching inverter is presented. All of the semiconductor elements of this converter are soft switched. Employing only two auxiliary switches as DC-link switches and a simple control circuit are the advantages of the proposed inverter. The analytical equations and operating modes of the presented inverter are explained in details. The design considerations are presented and the experimental results verify the theoretical analysis.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.67-69
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• 1998

In order to design or predict the performance of a cylindrical electrostatic motor it is necessary to analyze the torque generated by such a structure. In this paper a simple but sufficiently accurate analytical model is developed for use in design. Conformal mapping are used to model the capacitance and torque of the motor as a function of the rotor position, using a quasi-static, two-dimension approximation, the effect of an insulating dielectric layer on the stator or rotor is also evaluated.