• 한국광학회지
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• 제34권5호
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• pp.185-191
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• 2023

유연 스텔스 소재의 실용성 향상을 위해 보호층을 입힌 뒤의 경도, 유연성, 보호층과 스텔스 소재의 접착력을 평가하였다. 우선 ISO 15184 연필 시험법을 통해 경도를 측정하였으며, 보호층을 입히기 전과 비교하여 경도가 HB에서 3H로 3등급 올라가는 것을 확인할 수 있었다. 유연성은 ASTM D522 시험법에 따라 소재를 특정 직경의 원기둥에 대고 구부린 뒤 균열 생성 여부를 확인하며 평가하였고, 그 결과 균열이 생성되지 않는 최소 직경이 0.125인치임을 확인하였다. 접착력은 ASTM D3359 시험법에 따라 접착 띠를 보호층에 붙였다 떼어내면서 보호층이 박리되는 비율로 평가하였다. 이를 통해 보호층을 입혔을 시 군용 접착력 한계 조건인 4B보다 높은 결과(5B)를 얻었다.

• 제어로봇시스템학회논문지
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• 제15권6호
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• pp.563-566
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• 2009

This paper presents an LMI-based method to design a integral sliding mode controller for a class of uncertain systems. Using LMIs we derive an existence condition of a sliding surface. And we give a switching feedback control law. Our method is a generalization of the previous integral sliding mode control design methods. Since our method is based on LMIs, it gives design flexibility for combining various useful design criteria that can be captured in the LMI-based formulation.

• 복식
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• 제54권1호
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• pp.1-10
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• 2004

The purpose of this study was to compare the efficiency of four different cleaning method of silk and to fabrics, which were excavated from the sixteenth century tombs. The four cleaning methods were hand washing in water and hand washing in solvent, washing in ultrasonic cleaner, and using of ultrasonic gun after washing in ultrasonic cleaner. The following is the result of the experiment: ㆍBoth silk and jute fabrics shrank the most after hand-wash in water. This cleaning method decreased their thickness the most but changed their strength the least. However, the color of the fabric changed the most after had-wash in water. This washing method might discolor the dyed fabric, so one must check the condition of the fabric thoroughly before washing it. ㆍThe weight and the thickness of the fabric changed little after ultrasonic cleaning. This cleaning method, therefore. is less efficient than hand-water-wash. The use of ultrasonic gun after ultrasonic wash for partial cleansing enhanced the efficiency a little. Nevertheless, this method left stain around the area where the gun was used, and the injected water could damage the fabric. ㆍThe excavated fabric became softer in the cleaning process as the dirt was washed away. In both cases of silk and jute fabrics cleaning, solvent made the fabric softer than water. Washed in solvent, the fabric did not swell. But water penetrated to the fiber during the cleaning process and made the fabric swell. When the water evaporates, the swollen fiber structure collapses and the fabric become stiff. Ultrasonic wash did not cause much change in the flexibility of the fabric, for this method does not remove the dirt as effectively as the other method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.711-714
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• 1998

본 논문에서는 wide data-width DRAM을 위한 flexible column redundancy scheme을 제안하였다. 구현된 redundancy scheme은 DB line shift method를 사용하여 wide data-width를 갖는 고집적 DRAM에 적용할 때 기존 redundancy scheme보다 더 작은 redundancy cell 면적과 fuse개수를 가지면서 더 큰 flexibility를 가지게 되었다.

• 산업경영시스템학회지
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• 제18권35호
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• pp.157-164
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• 1995

FMS(Flexible Manufacturing System) is an automatic manufacturing system coincided with pursue of flexibility, productivity, and reliability. It is effective means to prove tje needs of market changes in view of production, This study is carried out to provide a economical evaluation methods of introduction for FMS in domestic corporations using PB, ARR, NPV and IRR.

• 산업기술연구
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• 제17권
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• pp.305-312
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• 1997

Shear connections in steel structures should satisfy dual criteria of shear strength and rotational flexibility and ductility. The connection should be strong enough to transfer the shear reaction of the beam, and should have sufficient rotational flexibility and ductility to rotate easily and supply the end rotation demand of the beam. This paper is concerned with the behavior of double-angle shear connections where the parameters are numbers of high strength bolts, bolt pitch, the length of angle leg, and connection method. An experimental investigation of shear connection was conducted by testing 12 beam-to-column joint specimens. Based on experimental and analytical study, the failure modes are developed and proposed design formulas.

• 한국생산제조학회지
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• 제7권6호
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• pp.28-35
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• 1998

Computer simulation technique has been applied on the various engineering fields to reduce cost and development period. On this paper, we introduce a crane analysis program. Using this program, we can predict reaction force of each part or supporting force of truck crane on a personal computer system with out exclusive knowledge of multi-body dynamics. In order to consider the effect of boom flexibility according to each working condition, flexible dynamic theory is applied to the program. Actual crane model is analyzed on special work condition using this program and the results are compared with those of rigid boom model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.471-475
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• 2007

Design equations of coupling plates, which connects floor beam of the upper modular unit and overhead beam of the lower one in order to improve serviceability in vibration, are proposed. End conditions of the coupled beams is semi-rigid and the optimal location of the coupling plates are assumed. Rotational constraints for both ends of the coupling plate modeled with beam elements are released and flexibility method is applied to obtain deflection equations of the coupled beam. Proposed equations are defined using the flexibility of the coupling plate, of which size can be determined inversely. Based on numerical analysis, coefficients of the design equations are calibrated and the revised equations are verified to be useful in the design of the coupled beam.

• 소음진동
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• 제11권1호
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• pp.68-75
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• 2001

A method for actively controlling dynamic reaction forces in flexible structures subject to persistent excitations is presented. Since reaction forces are not directly measured in flexible structures, reaction forces are estimated by using the Kalman filter. The estimated reaction force is used as an error signal in the adaptive feedforward disturbance cancellation controller. In order to compensate the static effect of the truncated modes in the reaction forces, the residual flexibility matrix is used with the Kalman filter. The paper presents the formulation of the reaction forces in conjunction with the Kalman filter estimator and the adaptive feedforward controller. The results show that the dynamic reaction forces at its supports in a flexible beam test rir are well suppressed.

• 한국실내디자인학회논문집
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• 제14권1호
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• pp.64-72
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• 2005

The purpose of this study was to analyze the flexible system in a typological way that develops and promotes the various methods of flexible system. The main method of this study was literature review and content analysis on various flexible systems and a case study of flexible housing. The flexible system in this typological analysis was classified into two categories: 'Elements of Flexibility' and 'Variation'. The category of Flexibility Elements was categorized into 'Primary Elements'(e.g., walls, floors, and ceilings),'Secondary Elements'(e.g., doors, windows, and furniture), and 'Tertiary Elements'(e.g., lighting, hues and finishing materials). Variation Effect was classified into 'Visual Variation', 'AppBicative Variation', and 'Layout Variation'. Also, Variation could be classified into 'Finish-centered', 'Application-centered', and 'Layout-centered' The flexible system developed in this study is a basis for further concrete flexible methods.