• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.315-317
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• 2006

In this paper, we design a terminal sliding mode controller based on neural network for nonlinear systems with uncertainties. Terminal sliding mode control (TSMC) method can drive the tracking errors to zero within finite time. Also, TSMC has the advantages such as improved performance, robustness, reliability and precision by contrast with classical sliding mode control. For the control of nonlinear system with uncertainties, we employ the self-recurrent wavelet neural network(SRWNN) which is used for the prediction of uncertainties. The weights of SRWNN are trained by adaptive laws based on Lyapunov stability theorem. Finally, we carry out simulations to illustrate the effectiveness of the proposed control.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.793-796
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• 2003

This study dealt with the manufacturing process of self-healing microcapsules for damage repair in polymeric composites. The microcapsule was consisted with a DCPD (dicyclopentadiene) as the healing agent and a urea-formaldehyde resin as the wall section. The size distribution of microcapsules were measured by a particle size analyzer using a laser diffraction technique. Thermal stability of microcapsules was investigated by using a TGA under continuous and isothermal heating conditions. According to the results, these microcapsules were verified to be to thermally stable and have a great potential to be applicable for damage repair in polymeric composites.

• Computers and Concrete
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• 제30권5호
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• pp.357-367
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• 2022

In this paper, we propose an efficient control method that can be transformed into a general building control problem for building structure control using these reliability criteria. To facilitate the calculation of controller H∞, an efficient solution method based on Linear Matrix Inequality (LMI) is introduced, namely H∞-based LMI control. In addition, a self-tuning predictive grey fuzzy controller is proposed to solve the problem caused by wrong parameter selection to eliminates the effect of dynamic coupling between degrees of freedom (DOF) in Self-Tuning Fuzzy Controllers. We prove stability using Lyapunov's stability theorem. To check the applicability of the proposed method, the proposed controller is applied and the control characteristics are determined. The simulation assumes system uncertainty in the controller design and emphasizes the use of acceleration feedback as a practical consideration. Simulation results show that the performance of the proposed controller is impressive, stable, and consistent with the performance of LMI-based methods. Therefore, an effective control method is suitable for seismic reinforcement of civil buildings.

• Wind and Structures
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• 제21권4호
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• pp.407-424
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• 2015

To explore the favorable structural system of cable-stayed bridges with ultra-kilometer main span, based on a fully self-anchored cable-stayed bridge with 1400 m main span, a partially earth-anchored cable-stayed bridge scheme with the same main span is designed. Numerical investigation on the dynamic characteristics, aerostatic and aerodynamic stability of both two bridge schemes is conducted, and the results are compared to those of a suspension bridge with similar main span, and considering from the aspect of wind stability, the feasibility of using partially earth-anchored cable-stayed bridge in super long-span bridges with ultra-kilometer main span is discussed. Moreover, the effects of structural design parameters including the length of earth-anchored girder, the number of auxiliary piers in side span, the height and width of girder, the tower height etc on the dynamic characteristics, aerostatic and aerodynamic stability of a partially earth-anchored cable-stayed bridge are analyzed, and their reasonable values are proposed. The results show that as compared to fully self-anchored cable-stayed bridge and suspension bridge with similar main span, the partially earth-anchored cable-stayed bridge has greater structural stiffness and better aerostatic and aerodynamic stability, and consequently becomes a favorable structural system for super long-span bridges with ultra-kilometer main span. The partially earth-anchored cable-stayed bridge can achieve greater stiffness and better wind stability under the cases of increasing the earth-anchored girder length, increasing the height and width of girder, setting several auxiliary piers in side span and increasing the tower height.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1030-1032
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• 2011

• 한국콘텐츠학회논문지
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• 제21권3호
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• pp.653-663
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• 2021

본 연구는 중년여성을 대상으로 양가적 성차별주의와 포커싱적 태도가 자기개념에 미치는 영향을 살펴보았다. 자기개념 척도, 포커싱적 태도 척도, 양가적 성차별주의 척도를 사용하여 만35세이상 만55세이하 중년여성을 대상으로 온라인 커뮤니티를 통해 실시하였다. SPSS 21.0을 사용하여 분석한 결과 적대적 성차별주의와 온정적 성차별주의와 유의한 정적 상관이 있으며 양가적 성차별주의가 자기개념에 유의한 부적영향을 나타났다. 양가적 성차별주의의 적대적 성차별주의가 높을수록 중년여성의 자기개념의 모든 요인이 낮아지는 경향을 보였으며 포커싱적 태도는 자기개념에 유의한 정적영향이 나타났으나 하위요인별로 달랐다. 포커싱적 태도의 표현하기와 받아들이기, 여유갖기가 자기개념에 유의한 정적영향을, 알아차리기는 부적영향이 있는 것으로 나타났으며, 되새겨보기는 유의한 영향이 나타나지 않았다. 마지막으로 본 연구의 한계점에 대해 논의하였다.

• 한국산학기술학회논문지
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• 제8권5호
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• pp.1042-1046
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• 2007

본 연구에서는 제 3의 화학 원소 첨가에 의한 코발트 실리사이드와 니켈 실리사이드의 열적 안정성 향상 메카니즘을 조사하였다. 즉, Co-Si 시스템에 텅스텐을 첨가하는 경우 CoSi의 heat of formation이 증가하는 것으로 관찰되었다. 이러한 증가는 시스템 에너지 감속 속도의 최대화로 대변되는 실리사이드 형성 kinetics가 선호하는 glass의 형성을 억제하는 것으로 밝혀졌다. 이 경우 CoSi와 실리콘 기판 사이의 계면에 형성되는 다결정 구조는 glass의 self-diffusion보다 확산계수가 훨씬 작아 상 변이를 위해서는 보다 높은 열에너지를 요구하게 되어 궁극적으로 CoSi의 열적 안정성이 향상되는 것을 알 수 있었다.

• Korean Journal of Mathematics
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• 제15권2호
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• pp.135-148
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• 2007

We prove the stability of generalized Jensen's equations in a Hilbert module over a unital $C^*$-algebra. This is applied to show the stability of a projection, a unitary operator, a self-adjoint operator, a normal operator, and an invertible operator in a Hilbert module over a unital $C^*$-algebra.

• Korea-Australia Rheology Journal
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• 제20권3호
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• pp.97-107
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• 2008

This article presents an overview of current research activities that center on colloidal crystals resulting from self-assembly of surface-charged nanoparticles. It is organized into three parts: the first part discusses characterization of colloidal structures, the second part describes colloidal stability from the rheological aspects of colloidal crystals suspended in medium, and the third part highlights polymerized colloidal crystals as a promising application. Finally, we briefly discuss the directions of future research in this area.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.129-132
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• 2014

A study on laminar coflow jet flames diluted with helium and nitrogen has been conducted to investigate self-excitations. The stability map was provided with a function of nozzle exit velocity and fuel mole fractions of propane or methane. The results show that there exist three types of self-excitations; (1) buoyancy-driven self-excitation (BDSE), (2) Lewis number induced self-excitation coupled with buoyancy (LCB) and (3) Lewis number induced self-excitation (LISE).