• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1787-1788
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• 2006

In this paper, a noisy passive telemetry sensor system using Unscented Kalman Filter (UKF) is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including IC chip has, the principle of inductive coupling was applied to the modelling of a passive telemetry sensor system (PTSS) and its noisy capacitive parameter was estimated by the UKF algorithm. Specialty, to show the effective tracking performance of the UKF, we compared with the tracking performance of Recursive Least Square Estimation (RLSE) using linearization

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.495-498
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• 2004

In this paper, passive telemetry capacitive humidity sensor system using a RLSE(Recursive Least Square Estimation) technique Is proposed. To overcome the problem like power limits and complications that general passive telemetry sensor system including IC chip has, the principle of inductive coupling is applied to model the sensor system. Specially, by applying the forgetting factor, we show that the accuracy of its estimation can be improved even in the case of time varying parameter and also the convergence time can be reduced.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.515-520
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• 2004

In this paper, a passive telemetry RF capacitive humidity sensor system using a RLSE(Recursive Least Square Estimation) technique is proposed. To overcome these trouble problems such as a power limitation and a estimation complexity that the general passive telemetry sensor system including It chip has, the principle of inductive coupling was applied to the modeling of a passive telemetry RF capacitive humidity sensor system and its capacitance was estimatedd by the RLSE algorithm. Specially, by introducing the optimal forgetting factor, we showed that the accuracy of its estimation was improved even in the time varying system and also the convergence time was reduced.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.314-319
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• 2008

Near infrared (NIR) spectroscopy was used to classify normal and artificially aged nonviable corn (Zea mays L., cv. 'Suwon19') seeds. The spectra at 1100-2500nm were scanned with normal and artificially aged single seeds and analyzed by principle component analysis (PCA). To discriminate normal seeds from artificially aged seeds, a calibration modeling set was developed with a discriminant partial least square 2 (PLS 2) method. The calibration model derived from PLS 2 resulted in 100% classification accuracy of normal and artificially aged (aged) seeds from the raw, the 1st and 2nd derivative spectra. The prediction accuracy of the unknown normal seeds was 88, 100 and 97% from the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, and that of the unknown aged seeds was 100% from all the raw, the $1^{st}$ and $2^{nd}$ derivative spectra, respectively. The results showed a possibility to separate corn seeds into viable and non-viable using NIR spectroscopy.

• The KIPS Transactions:PartB
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• v.8B no.4
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• pp.389-394
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• 2001

본 논문에서는 독립 성분 해석(Independent Component Analysis, ICA) 기법과 인근 평균 및 정규화를 이용한 영상 분류 방법을 제안하였다. ICA에 잡음을 주어 영상을 분류하였을 때, 잡음에 대한 강인성을 증가시키기 위하여, 제안된 인근 평균 및 정규화를 전처리로 적용하였다. 제안된 방법은 전처리 없이 ICA에 주성분 해석(Principal Component Analysis, PCA)을 이용한 것에 비해 잡음에 대한 강인성을 증가시키는 것을 모의 실험을 통하여 확인하였다.

• Structural Engineering and Mechanics
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• v.4 no.6
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• pp.645-653
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• 1996

In order to avoid pathological mesh dependency in finite element modelling of strain localization, an isotropic elasto-plastic model with a yield function depending on the Laplacian of the equivalent plastic strain is implemented in a 4-node quadrilateral finite element with one integration point based on a mixed formulation derived from Hu-Washizu principle. The evaluation of the Laplacian is based on a least square polynomial approximation of the equivalent plastic strain around each integration point. This non local approach allows to satisfy exactly the consistency condition at each integration point. Some examples are treated to illustrate the effectiveness of the method.

• Journal of Welding and Joining
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• v.11 no.3
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• pp.22-33
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• 1993

Arc sensor is indispensable to arc welding robot systems for compensating the joint misalignment such as mismatch of the workpiece, ill-conditioned positioner and thermal deformation during welding. Furthermore, the amount of these mismatches cannot be preivously expected, and changes from time to time. There are many kinds of seam trackers for correcting the welding path of the robot, where non-contact type sensors arc prevalently used in arc welding robot systems. In this study, an arc sensor was developed for GMA and FCA welding robot system. Since the arc sensor uses the arc characteristics during welding, the operating principle of the arc sensor must be adjusted according to the welding condition. Especially in GMA welding with the $CO_{2}$ shielding gas, the welding arc is not stable because of the short circuit and non-axial globular transfer mode of the molten droplet. In this study, the 2nd order least square curve fitting algorithm was adopted and the applicability of this algorithm was investigated for robot welding systems. For easy usage of the arc sensor, the operating parameters for arc sensor were limited to eight which can be easily determined by the operator.

• Structural Engineering and Mechanics
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• v.46 no.1
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• pp.75-90
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• 2013

In order to identify damage of highway bridges rapidly, a method for damage identification using dynamic response of bridge induced by moving vehicle and static test data is proposed. To locate damage of the structure, displacement energy damage index defined from the energy of the displacement response time history is adopted as the indicator. The displacement response time histories of bridge structure are obtained from simulation of vehicle-bridge coupled vibration analysis. The vehicle model is considered as a four-degree-of-freedom system, and the vibration equations of the vehicle model are deduced based on the D'Alembert principle. Finite element method is used to discretize bridge and finite element model is set up. According to the condition of displacement and force compatibility between vehicle and bridge, the vibration equations of the vehicle and bridge models are coupled. A Newmark-${\beta}$ algorithm based professional procedure VBAP is developed in MATLAB, and used to analyze the vehicle-bridge system coupled vibration. After damage is located by employing the displacement energy damage index, the damage extent is estimated through the least-square-method based model updating using static test data. At last, taking one simply supported bridge as an illustrative example, some damage scenarios are identified using the proposed damage identification methodology. The results indicate that the proposed method is efficient for damage localization and damage extent estimation.

• Korean Journal of Optics and Photonics
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• v.13 no.3
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• pp.173-181
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• 2002

The principle of an illumination system including fly-eyes lenses for a liquid crystal display (LCD) projector with 3-panels was presented and its optical system was designed by using the OSLO (premium edition 6.1) optical system design program. Two panels of the illumination system are well aligned for so that the illumination path length is the same, and the third panel has a longer pass length than the others. The two illumination types with the same or different illumination path lengths were derived by using the paraxial ray design method. Refraction powers and positions of each lens were analytically determined by the method, and the damped least square method was utilized to obtain the optimized uniform illumination system.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1616-1623
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• 1996

In general, in order to recognize and modelling the 3-D object, it is necessary to have the method to express the shape of 3-D object. In case of 2-D like silhouette image, the extraction of vertex on the boundary of the object can be obtained by using the 2-D curvature function. But, in case of 3-D curvature function that can calculate the surface curvature values of 3-d object doesn't exist, it is difficult to express the share of 3-D object. Therefore, in this paper, a new method is presented. With this presented method, the approximated surface curvature values and vertex of 3-D object can be obtained effectively using the principle of 2-D curvature and the least square method.