• 한국환경보건학회지
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• 제19권2호
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• pp.46-54
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• 1993

This study was carried out on the stabilized/solidified treatment for the reducing leachability of hazardous heavy metals copper, lead, chromium and cadmium in the hazardous sludge which treated to be unleached heavy metals by sodium diethyl dithiocarbamate. Cement matrix was analyzed for the leachability of 24 hrs and dynamic leaching test, structure and the optimum condition for the stabilization and solidification of the hazardous sludge. In 28 days of curing time the unconfined compressive strength was 21.5 kg/cm$^2$ at the ratio of portland cement (0.5)+fly ash (0.25) and 23.5 kg/cmz at the ratio of portland cement (0.5)+fly ash (0.25) + cake (0.25). High concentration of Pb, Cr and Cd in the sea water and Cu in the distilled water were leached at the dynamic leaching test. The concentration of leaching heavy metals for specimens which were tested 24 hrs were found low leachability with decreasing pH of leachant. According to dynamic leaching test, the low level of copper, lead, cadmium and chromium were leached in the cement matrix with sodium diethyl dithiocarbamate. But the effective diffusion coefficient of unleached cement matrix which was treated sodium diethyl dithiocarbamate was decreased above 2 times than that of cement matrix. The relation of leachant renewal period (Y) and cumulative fraction ion leached (X) was the following regression equations. Solidification with unleached agent. Y$_{Cu}$ = 1413752X + 247, Y$_{Pb}$ = 223501IX + 214, Y$_{Cr}$ = 8310601X - 472, Y$_{Cd}$ = 168787X + 1061 The structure of' solidified matrix with X-ray diffraction analysis was composed more Ca(OH)$_2$, Si, Mg(OH)$_2$ and Al in the unleached cement matrix than those in cement matrix.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.61-72
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• 2003

In cosmetic area, retinol is prominent ingredient for anti-wrinkle but unstable against light, heat, oxygen and so on. Therefore the stabilization of retinol is required. Here, we capsulated doubly retinol in the SLM(Skin Lipid Matrix) that makes three dimensional lamellar structure similar to skin, after formation of primary liposome (retinol-nanoemulsion). First, we make primary liposome from retinol / hydrogenated lecithin / polysorbate20 / caprylic ＆ capric triglyceride / ethanol / and so on, and the mean diameter to 70 nm, using microfluidizer passed three times at 800 Bar, repeatedly. Then we produce DC-liposome (doubly capsulated-liposome) that was encapsulated primary liposome with SLM made of hydrogenated phosphatidyl choline / caprylic ＆ capric triglyceride / 1, 3-butylene glycol / ceramide3 / cholesterol /etc. We measured for color stability against light and heat with chromameter. As a result of this experiment, we observed DC-liposome was more than from 1.5 to 3 times as stable as general liposome. Livability of retinol has improved from 2 to 6 times when we analyzed it by HPLC. Also, penetration effect of DC-liposome has improved.

• 한국지능시스템학회논문지
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• 제21권5호
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• pp.630-636
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• 2011

본 논문은 매개변수 불확실성을 가지는 Takagi-Sugeno(T-S) 퍼지 시스템의 안정도 해석과 안정화 조건을 고려한다. T-S 퍼지 시스템의 안정도 해석 시 conservativeness를 줄이기 위해 퍼지 리아푸노프 함수를 이용한다. 매개변수 불확실성을 가지고 있는 시스템의 안정도를 해석하고 시스템을 안정화 시키는 퍼지 강인 제어기 설계 기법을 제시한다. 안정도조건과 안정화조건은 선형행렬부등식의 형태로 표현된다. 모의실험을 통해 제안된 접근 방법의 효용성을 보인다.

• 한국지능시스템학회논문지
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• 제19권2호
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• pp.174-179
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• 2009

본 논문은 뉴트럴 타입 시간 지연을 갖는 네트워크 제어 시스템의 안정도 분석 및 제어기 설계에 대해서 논의한다. 네트워크상에서 발생하는 뉴트럴 타입 시간 지연을 모델링하며, 전체 네트워크 제어 시스템은 뉴트럴 타입 시간 지연을 가지는 비선형 시스템이 된다. 네트워크 제어 시스템을 TS(Takagi-Sugeno) 퍼지 시스템으로 모델링한다. 제안하는 퍼지 제어기를 모델링하는 네트워크 제어 시스템과 같은 멤버쉽 함수를 가지게 설계한다. 전체 폐루프 시스템의 안정도를 시간 지연 간격에 종속적이게 분석하고, 네트워크 제어 시스템을 안정화 시키는 퍼지 제어기 설계를 위한 충분조건을 유도한다. 제안된 필요 중분조건을 선형 행렬 부등식의 형태로 나타내고, 해를 통하여 퍼지 제어기의 이득 값을 설계한다. 예제를 통하여 제안된 이론의 타당성을 확인한다.

• Structural Engineering and Mechanics
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• 제63권6호
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• pp.743-750
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• 2017

Modal parameter identification plays a key role in the structural health monitoring (SHM) for civil engineering. Eigensystem realization algorithm (ERA) is one of the most popular identification methods. However, the complex environment around civil structures can introduce the noises into the measurement from SHM system. The spurious modes would be generated due to the noises during ERA process, which are usually ignored and be recognized as physical modes. This paper proposes an improved stabilization diagram method in ERA to distinguish the spurious modes. First, it is proved that the ERA can be performed by any two Hankel matrices with one time step shift. The effect of noises on the eigenvalues of structure is illustrated when the choice of two Hankel matrices with one time step shift is different. Then, a moving data diagram is proposed to combine the traditional stabilization diagram to form the improved stabilization diagram method. The moving data diagram shows the mode variation along the different choice of Hankel matrices, which indicates whether the mode is spurious or not. The traditional stabilization diagram helps to determine the concerned truncated order before moving data diagram is implemented. Finally, the proposed method is proved through a numerical example. The results show that the proposed method can distinguish the spurious modes.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.153-156
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• 2001

This paper discusses a stochastic stabilization of Takagi-Sugeno (75) fuzzy system with Markovian input delay. The finite Markovian process is adopted to model the input delay of the overall control system. It is assumed that the zero and hold devices are used for control input. The continuous-time 75 fuzzy system with the Markovian input delay is discretized for easy handling delay, accordingly, the discretized 75 fuzzy system is represented by a discrete-time 75 fuzzy system with jumping parameters. The stochastic stabilizibility of the jump 75 fuzzy system is derived and formulated in terms of linear matrix inequalities (LMls).

• 한국군사과학기술학회지
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• 제14권5호
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• pp.941-947
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• 2011

This paper deals with the consensus problem for multi-agent linear dynamic systems with directed communication topology. All the agents are identical high-order linear systems and their state information is exchanged through a communication network with directed graph. It is shown that a consensus is achieved if there exists a feasible solution to a set of linear matrix inequalities obtained for a simultaneous stabilization problem for multiple systems. Examples are presented to show the effectiveness of the proposed method.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권11호
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• pp.747-752
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• 2004

This paper presents an iterative linear matrix inequality (LMI) approach to the design of a static output feedback (SOF) stabilization controller. A linear penalty function is incorporated into the objective function for the non-convex rank constraint so that minimizing the penalized objective function subject to LMIs amounts to a convex optimization problem. Hence, the overall procedure results in solving a series of semidefinite programs (SDPs). With an increasing sequence of the penalty parameter, the solution of the penalized optimization problem moves towards the feasible region of the original non-convex problem. The proposed algorithm is, therefore, convergent. Extensive numerical experiments are Deformed to illustrate the proposed algorithm.

• 제어로봇시스템학회논문지
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• 제13권4호
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• pp.365-370
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• 2007

This paper studies an automation problem of a heating, a ventilating, and an air conditioning (HVAC) for the development of smart space. The HVAC system is described by the fuzzy system for the stability analysis and the controller design. The linear matrix inequalities (LMIs) conditions are derived for the stabilization problem of the closed-loop system under the analog control. Also, it is required to digitally redesign the pre-designed the analog HVAC control system in order to accomplish the remote control via web. It is shown the this digital redesign problem can be converted to the convex optimization problem with the LMI constraints. An example is provided to show the effectiveness of the proposed method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.67-69
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• 2009

This paper deals with the consensus problem for multi-agent linear dynamic systems with parameter uncertainties. All the agents are identical high-order linear systems with parameter uncertainties and their state information is exchanged through a communication network. It is shown that a consensus is achieved if there exists a feasible solution to a set of linear matrix inequalities obtained for a simultaneous stabilization problem for multiple systems. A numerical example is presented to show the effectiveness of the proposed method.