• 한국통신학회논문지
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• 제5권1호
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• pp.60-69
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• 1980

크고 複雜한 線形回路方程式을 갖는 큰 계통의 回路를 解析하기 위해서는 매우 많은 記憶容量과 時間이 必要하다. 이러한 記憶容量과 계산 時間을 줄이기 위해서 본 論文에서는 Sparse 行列을 利用하여 增幅回路의 最適 設計를 하였다.

• Structural Engineering and Mechanics
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• 제82권4호
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• pp.503-515
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• 2022

The multi-rigid-body matrix method (MRBMM) is a generalized modeling method for obtaining the displacements, forces, and dynamic characteristics of a compliant mechanism without performing inner-force analysis. The method discretizes a compliant mechanism of any type into flexure hinges and rigid bodies by implementing a multi-body mass-spring model using coordinate transformations in a matrix form. However, in this method, the deformations of bodies that are assumed to be rigid are inherently omitted. Consequently, it may yield erroneous results in certain mechanisms. In this paper, we present a multi-compliant-body matrix-method (MCBMM) that considers a rigid body as a compliant element, while retaining the generalized framework of the MRBMM. In the MCBMM, a rigid body in the MRBMM is segmented into a certain number of body nodes and flexure hinges. The proposed method was verified using two examples: the first (an XY positioning stage) demonstrated that the MCBMM outperforms the MRBMM in estimating the static deformation and dynamic mode. In the second example (a bridge-type displacement amplification mechanism), the MCBMM estimated the displacement amplification ratio more accurately than several previously proposed modeling methods.

• Journal of information and communication convergence engineering
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• 제8권1호
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• pp.23-28
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• 2010

According to increasing projection order, the AP algorithm bas noise amplification problem in large background noise. This phenomenon degrades the performances of the AP algorithm. In this paper, we analyze convergence characteristic of the AP algorithm and then suggest a noise robust modified AP algorithm for reducing this problem. The proposed algorithm normalizes the update equation to reduce noise amplification of AP algorithm, by adding the multiplication of error power and projection order to auto-covariance matrix of input signal. By computer simulation, we show the improved performance than conventional AP algorithm.

• 한국정밀공학회지
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• 제20권2호
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• pp.168-175
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• 2003

In this research, a bridge-type flexure hinge mechanism is developed and optimized to amplify the displacement of a multilayer piezostack. Developed hinge mechanism has three-dimensional structure to reduce link size, so it have high amplification ratio with respect to small size. A flexure hinge is assumed to be 6 degree-of-freedom spring elements and matrix methods are used to model a hinge mechanism. To verify derived matrix model, a displacement and frequency experiments are performed. The analysis result shows that the displacemental error between matrix model and experiments is below 10 percents and the deformation of hinge in parasitic direction should be considered In hinge modeling. Using developed matrix model, an optimal design is performed to maximize the performance of hinge mechanism.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1279-1282
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• 2008

Organic field effect transistors are excellent candidates for addressing and local amplification elements for large area electronics because they can easily be processed at low temperatures on essentially arbitrary substrates. We present the use of these devices in an active matrix photodetector and as a buffer for a strain sensor.

• Journal of Korean Neurosurgical Society
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• 제40권5호
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• pp.363-368
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• 2006

Objective : Little is known about the comprehensive molecular and biological mechanism on the development of the degeneration of the intervertebral disc. Many kinds of matrix metalloproteinase[MMP] initiate the degradation of the extracellular matrix including several kinds of collagens and proteoglycans. We compared molecular and immunohistochemical features of degenerated intervertebral disc and normal counterparts in order to investigate the role of MMP-1, 2, 3, 9. Methods : We have evaluated MMP-1, 2, 3, 9 expression in 30 surgically resected lumbar disc from degenerative disc disease patients and 5 normal control cases. RT-PCR[reverse transcriptase-polymerase chain reaction] and immunohistochemistry were performed. Results : By RT-PCR, normal tissue samples showed merely scant expression of MMP-1, 2, 3, 9 mRNA, but degenerated disc samples revealed more pronounced expression. mRNA amplifications were detected in 60%, 63.3%, 70%, 53.3% cases By immunohistochemistry, normal tissue samples showed minimal protein expression of MMP-1, 2, 3, 9, but degenerated disc samples revealed more pronounced expression. Protein expressions were detected in 73.3%, 63.3%, 76.7%, 63.3% cases. Both the mRNA amplification and protein overexpression rates were significantly higher in degenerated disc than in the normal tissue. Concordance between both the mRNA amplification and protein expressions of MMP-1, 3, 9 were not observed, but there is well correlation in MMP-2 expression. Conclusion : We concluded that the over-expressions of the MMP-1, 2, 3, 9 may contribute to the development of degeneration of the intervertebral disc.

• Journal of Microbiology
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• 제40권1호
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• pp.70-76
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• 2002

Proviral DNAs from HIV-1-infected CD4+ T cells (Molt/LAV cells) were amplified and detected in infected individual cells using polymerase chain reaction and in rifu hybridization. In this in situ PCR, three parameters were considered to achieve effective amplification and retention of amplificants inside the cells by making high molecular weight PCR products intracellularly, forming agarose matrix against the cells, and maintaining the appropriate PCR temperature profile. Over the cycles of ampliHcationl tailed primers with complementary overhanging sequences at their 5' sides manufactured high molecular weight products by using short primary products as a repeating unit. Agarose matrix could prevent the diffusion of the amplificants from the cells. Use of Thermanox coverslip inside the PCR tube offered target cells a similar temperature profile to that of conventional PCR in solution.

• 제어로봇시스템학회논문지
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• 제22권6호
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• pp.411-416
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• 2016

This paper presents the design methodology of an unknown input observer for Lipschitz nonlinear systems with unknown inputs in the framework of convex optimization. We use an unknown input observer (UIO) to consider both nonlinearity and disturbance. By deriving a sufficient condition for exponential stability in the linear matrix inequality (LMI) form, existence of a stabilizing observer gain matrix of UIO will be assured by checking whether the quadratic stability margin of the error dynamics is greater than the Lipschitz constant or not. If quadratic stability margin is less than a Lipschitz constant, the coordinate transformation may be used to reduce the Lipschitz constant in the new coordinates. Furthermore, to reduce the maximum singular value of the observer gain matrix elements, an object function to minimize it will be optimally designed by modifying its magnitude so that amplification of sensor measurement noise is minimized via multi-objective optimization algorithm. The performance of UIO is compared to a nonlinear observer (Luenberger-like) with an application to a flexible joint robot system considering a change of load and disturbance. Finally, it is validated via simulations that the estimated angular position and velocity provide true values even in the presence of unknown inputs.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.155-161
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• 1999

Many direct integration methods have been developed for dynamic analysis of structures, In order to compare each other methods and give guideline for selecting a time increment the amplification matrix is constructed according to algorithm of each method and stability and accuracy analysis is done. Four story shear building under external excitations is analyzed by each method and the RMS errors of displacements of top floor and compared with each other.

• Journal of the Optical Society of Korea
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• 제10권1호
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• pp.11-15
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• 2006

We have proposed and theoretically verified an optical regenerator using a single semi-reflective semiconductor optical amplifier (SR-SOA). To explain the operation characteristics and the operation condition of the proposed opticalregenerator, the simplified gain model for the SR-SOA is introduced and confirmed by comparing the result of the SOA simulation based on the transfer matrix method (TMM). The simulation results show that both extinction ratio (ER) enhancement and signal amplification can be achieved in the proposed regenerator.