• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.12-15
• /
• 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 Korean Institute of Telematics and Electronics B
• /
• v.32B no.3
• /
• pp.48-56
• /
• 1995

This paper presents a method of implementing efficient optical flow estimation for dynamic scene analysis using the hierarchical Hopfield neural networks. Given the two consequent inages, Zhou and Chellappa suggested the Hopfield neural network for computing the optical flow. The major problem of this algorithm is that Zhou and Chellappa's network accompanies self-feedback term, which forces them to check the energy change every iteration and only to accept the case where the lower the energy level is guaranteed. This is not only undesirable but also inefficient in implementing the Hopfield network. The another problem is that this model cannot allow the exact computation of optical flow in the case that the disparities of the moving objects are large. This paper improves the Zhou and Chellapa's problems by modifying the structure of the network to satisfy the convergence condition of the Hopfield model and suggesting the hierarchical algorithm, which enables the computation of the optical flow using the hierarchical structure even in the presence of large disparities.

• Nuclear Engineering and Technology
• /
• v.38 no.6
• /
• pp.561-574
• /
• 2006

This study presents the results of an economic analysis for a comparison of the single layer and double layer alternatives with respect to a HLW-repository. According to a cost analysis undertaken in the Korean case, the single layer option was the most economical alternative. The disposal unit cost was estimated to be 222 EUR/kgU. In order to estimate such a disposal cost, an estimation process was sought after the cost objects, cost drivers and economic indicators were taken into consideration. The disposal cost of spent fuel differs greatly from general product costs in the cost structure. Product costs consist of direct material costs and direct labor and manufacturing overhead costs, whereas the disposal cost is comprised of construction costs, operating costs and closure costs. In addition, the closure cost is required after a certain period of time elapses following the building of a repository.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.9
• /
• pp.2833-2842
• /
• 1996

This paper is to practice optimal rigidity design by the strain energy density estimation method for static buckling and sizing design sensitivity analysis for dynamic buckling of a nonlinear vehicle frame structure from those results. Using these sizing design sensitivity resutls, an optimization of a nonlinear vehicle frame structure with dynamic buckling constraint is carrried out with the graient projection method.

• New & Renewable Energy
• /
• v.3 no.2 s.10
• /
• pp.17-23
• /
• 2007

대두유로부터 생산된 바이오디젤과 바이오디젤 혼합 연료유를 대상으로 지방산메틸에스터 함량과 화학적 분석을 통해 산화 특성과 오일의 수명 예측 연구를 수행하였다. 바이오디젤, 경유, BD5, BD20은 산화가 진행될수록 산가(Acid number), 동점도(Kinematic Viscosity) 및 밀도(Density)는 증가하였다. 산가 측정결과의 활용에 의해 임의의 온도조건에서 정확한 사용수명을 예측하기 위하여 화학속도론에 의거하여 각각의 연료에 대한 사용수명식을 도출하였다. 도출된 사용수명식으로부터 바이오디젤이 가장 빠르게 산화가 진행되었고 바이오디젤 혼합량이 증가할수록 사용수명이 단축되는 것을 확인할 수 있었다.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.2
• /
• pp.828-834
• /
• 2019

Researchers have previously proven that the flapping motion of the hydrofoil can convert wave energy into propulsive energy. However, the estimation of thrust forces generated by the flapping foil placed in waves remains a challenging task for ocean engineers owing to the complex dynamics and uncertainties involved. In this study, the flapping foil system consists of a rigid NACA0015 section undergoing harmonic flapping motion and a passively actuated elastic flat plate attached to the leading edge of the rigid foil. We have experimentally measured the thrust force generated due to the flapping motion of a rigid foil attached to an elastic plate in a wave flume, and the effects of the elastic plates have been discussed in detail. Furthermore, an empirical formula was introduced to predict the thrust force of a flapping foil based on our experimental results using multiple regression analysis.

• Proceedings of the SAREK Conference
• /
• 2005.11a
• /
• pp.205-210
• /
• 2005

Ice storage system stores cold energy using ice, which is used for cooling on next day. Ice storage system is the effective cooling system that uses cheep electric energy during a night, and also suppresses the peak load of electricity. In this study, the normalized temperature, relative humidity and specific humidity are analyzed using the weather data for past five years in order to estimate the cooling load for the control of ice storage system. The calculated cooling loads show fairly good agreement with the measured data of model hospital, especially at the outdoor design temperature of $25^{\circ}C$.

• International Journal of Ocean System Engineering
• /
• v.1 no.3
• /
• pp.165-170
• /
• 2011

In this paper, for the accurate estimation of the position and orientation of the UUV (unmanned underwater vehicle), an AHRS (Attitude Heading Reference System) was developed using the IMU (inertial measurement unit) sensor which provides information on acceleration and orientation in the object coordinate and the initial alignment algorithm and the E-KF (extended Kalman Filter). The initial position and orientation of the UUV are estimated using the initial alignment algorithm with 3-axis acceleration and geomagnetic information of the IMU sensor. The position and orientation of the UUV are estimated using the AHRS composed of 3-axis acceleration, velocity, and geomagnetic information and the E-KF. For the performance test of the orientation estimation of the AHRS, a testbed using IMU sensor(ADIS16405) and DSP28335 coded with an E-KF algorithm was developed and its performance was verified through tests.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.4
• /
• pp.344-350
• /
• 2015

A battery management system requires accurate information on the battery state of charge (SOC) to achieve efficient energy management of electric vehicle and renewable energy systems. Although correct SOC estimation is difficult because of the changes in the electrical characteristics of the battery attributed to ambient temperature, service life, and operating point, various methods for accurate SOC estimation have been reported. On the basis of piecewise linear (PWL) modeling technique, this paper proposes a simple SOC observer for lithium-polymer batteries. For performance evaluation, the SOC estimated by the PWL SOC observer, the SOC measured by the battery-discharging experiment and the SOC estimated by the extended Kalman filter (EKF) estimator were compared through a PSIM simulation study.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.5
• /
• pp.1020-1025
• /
• 2007

EMS(energy management system) and SCADA(supervisory control and data acquisition) systems are used for reliable and efficient operation of electrical power systems. Various functions in EMS such as power flow, contingency analysis, security analysis essentially need accurate data set for reliable operation. State estimation can be a tool for providing these data. In this paper, programs for observability analysis and bad data processing are developed. Fundamental algorithms are introduced and validity of the proposed techniques is inspected with test cases.