• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.1967-1969
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• 2001

This paper deals with the design of observer-based $H_{\infty}$ controller for linear time-delay systems. By adapting the model transformation and Lyapunov theorem, we presents a sufficient condition which meets the prescribed $H_{\infty}$ norm upper bound from the exogenous disturbances to the measured outputs. The conditions are expressed in terms of coupled two matrix inequalities, and the $H_{\infty}$ controller and the observer are obtained by checking the feasibility of two matrix inequalities. Finally, we shows the usefulness of our result by an example.

• 한국환경과학회지
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• 제28권2호
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• pp.211-217
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• 2019

A Numerical modeling approach is usually applied to reproduce the physical phenomena of a fill dam-break. The accuracy of the dam-break model depends on the physical structure that defines input variables such as the storage volume, breach formation and progress, and the parameters of the model, which are subjective as they are prescribed by users. In this study, a sensitivity analysis was performed for the nonlinear breach progression curve that was already developed, which includes four parameters. The study focuses on the two of the parameters which control the breach forming time and peak discharge. The model is coupled with a two-dimensional flood simulation model (FLO-2D) to examine flood coverage and depth. It is generally observed that the parameter ${\beta}$ controls only the breach forming time, the parameter ${\gamma}$ is particularly sensitive to the peak flow.

• Journal of Applied and Pure Mathematics
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• 제4권3_4호
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• pp.107-122
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• 2022

This manuscript aims to investigate the existence, uniqueness, and stability of non-local random impulsive neutral stochastic differential time delay equations (NRINSDEs) with Poisson jumps. First, we prove the existence of mild solutions to this equation using the Banach fixed point theorem. Next, we demonstrate the stability via continuous dependence initial value. Our study extends the work of Wang, and Wu [16] where the time delay is addressed by the prescribed phase space 𝓑 (defined in Section 3). To illustrate the theory, we also provide an example of our methods. Using our results, one could investigate the controllability of random impulsive neutral stochastic differential equations with finite/infinite states. Moreover, one could extend this study to analyze the controllability of fractional-order of NRINSDEs with Poisson jumps as well.

• 콘크리트학회논문집
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• 제18권6호
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• pp.777-783
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• 2006

본 연구에서는 상동지역 중석광 광미를 콘크리트용 혼화재료로 사용하기 위한 연구의 일환으로 자기충전 콘크리트의 분체로서 적용가능성을 검토하였다. 상동지역 중석광 광미를 혼합한 자기충전 콘크리트의 자기충전성을 평가는 일본의 토목학회 기준을 적용한 슬럼프플로우, 슬럼프플로우 500mm 도달시간, V-funnel 유하시간 및 U-box 충전높이 시험을 실시하여 검토하였다. 그 결과 슬럼프 플로우는 목표기준을 만족하였으며, 슬럼프플로우 500mm도달시간 및 V-funnel 유하시간은 상동지역 중석광 광미의 혼합률이 증가함에 따라 측정시간이 감소하였으며, U-box 충전높이는 상동지역 중석광 광미의 혼합률 30% 까지 목표기준을 만족하였다. KS 규준에 의해 평가된 역학적 특성 검토 결과는 압축강도의 경우 상동지역 중석광 광미의 혼합률이 증가함에 따라 압축강도는 감소하였고, 쪼갬인장강도 및 탄성계수는 기존의 연구 경향과 유사하였다. 건조수축률 및 탄산화 깊이는 상동지역 중석광 광미의 혼합률이 증가함에 따라 비례적으로 증가하는 경향을 나타내었다.

• 동의생리병리학회지
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• 제16권5호
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• pp.888-892
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• 2002

Nae-Kyung says the puberty is corresponded to the age of 16～24(male) and 14～21 (female). And that time they are promoted the growth. However, Kidney qi doesn't make average situation during that time. So, the function of five viscera and six entrails fails to be perfect and symptoms appear. I came to the conclusion through the survey of about 200 high school students(male and female) and the theory of oriental medicine the distinctive features (like migraine, amnesia, depression, dysphoria, inappetence, irregular menstruation) came out that time. I defined this distinctive symptoms in boys and girls at puberty ‘synthetic symptoms of puberty’. For the medical cure and prevention I prescribed ‘Sachun-Nyung’ and that has medical benefits for ‘Replenishing qi and relieving the spleen, Soothing the liver and promoting blood circulation’

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.203-206
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• 2003

In this paper we discuss an algorithm for a real time transmission of moving color images on the TCP/IP network using wavelet transform and neural network. The image frames received from the camera are two-level wavelet-transformed in the server, and are transmitted to the client on the network. Then, the client performs the inverse wavelet-fransform using only the received pieces of each image frame within the prescribed time limit to display the moving images. When the TCP/IP network is busy, only a fraction of each image frame will be delivered. When the line is free, the whole frame of each image will be transferred to the client. The receiver warns the sender of the condition of traffic congestion in the network by sending a special short frame for this specific purpose. The sender can respond to this condition of warning by simply reducing the data rate which is adjusted by a back-propagation neural network. In this way we can send a stream of moving images adaptively adjusting to the network traffic condition.

• Earthquakes and Structures
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• 제12권5호
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• pp.479-487
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• 2017

Frictional dampers are used in structural engineering as means of passive control. Meanwhile, frictional damper shave a disadvantage compared to viscous rivals since the slippage force must be exceeded to activate the device, and cannot be ideal full range of possible events. The concept of semi-active control is utilized to overcome this shortcoming. In this paper, a new semi-active frictional damper called Smart Adjustable Frictional (SAF) damper is introduced. SAF damper consists of hydraulic, electronic units and sensors which are all linked with an active control discipline. SAF acts as a smart damper which can adapt its slippage threshold during a dynamic excitation by measuring and controlling the structural response. The novelty of this damper is, while it controls the response of the structure in real time with acceptable time delay. The paper also reports on the results of a series of experiments which have been performed on SAF dampers to obtain their prescribed hysteretic behavior for various control algorithms. The results show that SAF can produce the desired slippage load of various algorithms in real time. Numerical models incorporating control simulations are also made to obtain the hysteretic response of the system which agrees closely with test results.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.1077-1081
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• 2004

In this Paper we discuss an algorithm for a real-time transmission of moving color image on the TCP/IP network using wavelet transform and neural network. The Image frames received from the camera are two-level wavelet-transformed in the server, and are transmitted to the client on the network. Then, the client performs the inverse wavelet-transform using only the received pieces of each image frame within the prescribed time limit to display the moving images. When the TCP/IP network is busy, only a fraction of each image frame will be delivered. When the line is free, the whole frame of each image will be transferred to the client. The receiver warns the sender of the condition of traffic congestion in the network by sending a special short frame for this specific purpose. The sender can respond to this information of warning by simply reducing the data rate which is adjusted with a neural network or fuzzy logic. In this way we can send a stream of moving images adaptively adjusting to the network traffic condition.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.713-716
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• 2008

본 연구는 도로터널 내 화재시 콘크리트 구조체의 내화성능을 평가하기 위한 기준을 제시하고자 실시하였다. 현재 국내에서는 지형특성 및 환경친화적인 도로건설로 도로 터널의 수가 빠른 속도로 증가하며, 터널연장이 길어짐에 따라 터널 내 화재사고가 갈수록 높아지고 있는 상황이다. 하지만 우리나라에서는 터널 화재에 대한 적합한 시간-온도 곡선을 규정하지 못하고 있는 실정이다. 따라서 본 연구에서는 국내 도로의 통행량, 차량 종류등을 고려한 열방출율을 기초로 외국에서 제시된 시간-온도 곡선을 검토해 보았으며 설계화재 모델을 제시하였다.

• 한국항공우주학회지
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• 제37권6호
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• pp.602-608
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• 2009

IEEE(Institute of Electrical and Electronics Engineers)1516 에 규정된 HLA(High Level Architecture) 기반 기술은 상이한 목적으로 개발된 다수의 개별 시뮬레이션들이 결합된 복합 시뮬레이션 네트워크 시스템을 구성하는데 있어서 필수적 요소이다. 본 논문에서는 상용 비행 시뮬레이션을 HLA를 기반으로 구현하는 과정과 구현된 시스템의 동작 과정을 보여줌으로써 확장성 및 상호 운용성을 갖춘 비행 시뮬레이션 모델 구조를 제시하였다. 또한 HLA를 기반으로 구현된 실시간 시뮬레이션 시스템과 상용 비행 시뮬레이션을 비교하여 얻어진 비행 정보 데이터 분석을 통해 완벽한 실시간성을 보장할 수 있는 지에 대한 여부를 판단하였다.