• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.421-424
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• 2004

Model updating is a very active research field, in which significant efforts has been invested in recent years. Model updating methodologies are invariably successful when used on noise-free simulated data, but tend to be unpredictable when presented with real experimental data that are-unavoidably-corrupted with uncorrelated noise content. In this paper, Reanalysis using frequency response functions for correlating and updating dynamic systems is presented. A transformation matrix is obtained from the relationship between the complex and the normal frequency response functions of a structure. The transformation matrix is employed to calculate the modified damping matrix of the system. The modified mass and stiffness matrices are identified from the normal frequency response functions by using the least squares method. Full scale pseudo dynamic pier test is employed to illustrate the applicability of the proposed method. The result indicate that the damping matrix of correlated finite element model can be identified accurately by the proposed method. In addition, the robustness of the new approach uniformly distributed measurement noise is also addressed.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.731-742
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• 2005

A magnetic bearing even with multiple coil failure can produce the same decoupled magnetic forces as those before failure if the remaining coil currents are properly redistributed. This fault-tolerant, force invariance control can be achieved with simply replacing the distribution matrix with the appropriate one shortly after coils fail, without modifying feedback control law. The distribution gain matrix that satisfies the necessary constraint conditions of decoupling linearized magnetic forces is determined with the Lagrange Multiplier optimization method.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.963-968
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• 2002

This paper will review the driving methods and issues of driving circuitry for passive matrix organic electro-luminescent displays(PM-OELDs). And it will shows the proposed one-chip and two-chip solution for driving the PM-OELDs and also the pixel structure and driving methods of active matrix (AM-OELDs). We will discuss the proper applications of OELDs with its power consumption by comparison with that of LCD.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.83-86
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• 2009

BiNem$^{(R)}$ displays have entered volume manufacturing in 2009. Applications range from e-labels to e-readers. We have developed 6-inch $960{\times}720$ pixels passive matrix BiNem prototypes achieving 40 % brightness and fluid user interface based on partial image / dynamic pointer addressing. Active-matrix addressing is proposed to provide even faster operation.

• Nutritional Sciences
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• v.9 no.3
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• pp.145-151
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• 2006

Matrix metalloproteinases (MMP) play an important role in the extracellular matrix (ECM) degradation undetphysiological and pathological conditions. The present study examined the influence of (-)epigallocatechin gallate and quercetin on phorbol-12-myristate 13-acetate (PMA)-induced secretion of MMP-2 and MMP-9, when human umbilical vein endothelial cells (HUVEC) were treated with (-)epigallocatechin gallate and quercetin at supraphysiological concentrations of $25{\mu}mol/L$. No cytotoxicity was observed by MIT assay in response to a treatment with PMA in the presence of (-)epigallocatechin gallate and quercetin. Western blot analysis and gelatin zymography revealed that exposure of HUVEC to PMA enhanced the levels and gelatinolytic activities of pro and active forms of MMP-2 and active form of MMP-9. (-)Epigallocatechin gallate attenuated PMA-stimulated secretion of active forms of MMP-2 and MMP-9 concomitantly with a loss of activities of these enzymes, which was related to the decreased mRNA levels of MMP. Quercetin was more potent than (-)epigallocatechin gallate in alleviating MMP-9 protein secretion and activity with a decrease in MMP-9 mRNA accumulation. Taken together, the results indicated that (-)epigallocatechin gallte and quercetin exhibited inhibitory effects on MMP activity and may qualify as chemopreventive and cardiovascular protective agents.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.2
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• pp.41-50
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• 2004

Since the MPEG-4 visual standard enables content-based functionalities, it is necessary to extract video objects from video sequences. Segmentation algorithms can largely be classified into two different categories: automatic segmentation and user-assisted segmentation. In this paper, we propose a new user-assisted image segmentation method based on the active contour. If we define a shape space as a set of all possible variations from the initial curve and we assume that the shape space is linear, it can be decomposed into the column space and the left null space of the shape matrix. In the proposed method, the shape space vector in the column space describes changes from the initial curve to the imaginary feature curve, and a dynamic graph search algorithm describes the detailed shape of the object in the left null space. Since we employ the shape matrix and the SUSAN operator to outline object boundaries, the proposed algorithm can ignore unwanted feature points generated by low-level image processing operations and is, therefore, applicable to images of complex background. We can also compensate for limitations of the shape matrix with a dynamic graph search algorithm.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.207-207
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• 2012

Si quantum dot (QD) imbedded in a $SiO_2$ matrix is a promising material for the next generation optoelectronic devices, such as solar cells and light emission diodes (LEDs). However, low conductivity of the Si quantum dot layer is a great hindrance for the performance of the Si QD-based optoelectronic devices. The effective doping of the Si QDs by semiconducting elements is one of the most important factors for the improvement of conductivity. High dielectric constant of the matrix material $SiO_2$ is an additional source of the low conductivity. Active doping of B was observed in nanometer silicon layers confined in $SiO_2$ layers by secondary ion mass spectrometry (SIMS) depth profiling analysis and confirmed by Hall effect measurements. The uniformly distributed boron atoms in the B-doped silicon layers of $[SiO_2(8nm)/B-doped\;Si(10nm)]_5$ films turned out to be segregated into the $Si/SiO_2$ interfaces and the Si bulk, forming a distinct bimodal distribution by annealing at high temperature. B atoms in the Si layers were found to preferentially substitute inactive three-fold Si atoms in the grain boundaries and then substitute the four-fold Si atoms to achieve electrically active doping. As a result, active doping of B is initiated at high doping concentrations above $1.1{\times}10^{20}atoms/cm^3$ and high active doping of $3{\times}10^{20}atoms/cm^3$ could be achieved. The active doping in ultra-thin Si layers were implemented to silicon quantum dots (QDs) to realize a Si QD solar cell. A high energy conversion efficiency of 13.4% was realized from a p-type Si QD solar cell with B concentration of $4{\times}1^{20}atoms/cm^3$. We will present the diffusion behaviors of the various dopants in silicon nanostructures and the performance of the Si quantum dot solar cell with the optimized structures.

• Journal of Pharmaceutical Investigation
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• v.31 no.1
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• pp.37-41
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• 2001

Various characteristics of polyethylene oxide (PEO) are useful for drug delivery systems. In this study, PEO was used as a sustained release matrix system containing cefatrizine propyleneglycol (Cefa-PG) which is a new semi-synthetic broad-spectrum and orally active cephalosporin. Five kinds of sustained release matrix tablets were formulated with various content of PEO and other ingredients. And three types of matrix tablets were formulated of which compositions were the same but the hardness was different. It was found that PEO content influenced drug release rate. Increasing PEO content, the drug release rate from matrix tablets was decreased. In addition, Avicel, one of the ingredients of matrix components, changed the drug release from the sustained release PEO matrix tablets. With increasing Avicel content, the rate of drug release was increased. For the effect of hardness of matrix tablets, the rate of drug release is decreased with increasing hardness. In comparison of bioavailability parameters after oral administration of Cefa-PG PEO matrix tablets and general Cefa-PG capsule in beagle dog, the sustained release PEO matrix tablets is more useful than a general dosage form. $AUC^{0-12}$ of the sustained release PEO matrix tablet and the general dosage form was 1.16 and 0.644 respectively.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1258-1266
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• 2005

The present study was carried out in order to assess the protective effects of calycosin-7-O-$\beta$-D-glucopyranoside, isolated from Astragali radix (AR), on hyaluronidase (HAase) and the recombinant human interleukin-$1\beta$ (IL-$1\beta$)-induced matrix degradation in human articular cartilage and chondrocytes. We isolated the active component from the n-butanol soluble fraction of AR (ARBu) as the HAase inhibitor and structurally identified as calycosin-7-O-$\beta$-D-glucopyranoside by LC-MS, IR, ${1}^H$ NMR, and ${13}^C$ NMR analyses. The $IC_{50}$ of this component on HAase was found to be 3.7 mg/ml by in vitro agarose plate assay. The protective effect of ARBu on the matrix gene expression of immortalized chondrocyte cell line C28/I2 treated with HAase was investigated using a reverse transcription polymerase chain reaction (RT-PCR), and its effect on HAase and IL-$1\beta$-induced matrix degradation in human articular cartilage was determined by a staining method and calculating the amount of degraded glycosaminoglycan (GAG) from the cultured media. Pretreatment with calycosin-7-O-$\beta$-D-glucopyranoside effectively protected human chondrocytes and articular cartilage from matrix degradation. Therefore, calycosin-7-O-$\beta$-D-glucopyranoside from AR appears to be a potential natural ant-inflammatory or antii-osteoarthritis agent and can be effectively used to protect from proteoglycan (PG) degradation.

• Journal of Korea Multimedia Society
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• v.20 no.1
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• pp.43-50
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• 2017

According to living environment, the number of deaths due to thyroid diseases increased. In this paper, we proposed an algorithm for recognizing a thyroid detection using texture analysis based on shape, gray level co-occurrence matrix and gray level run length matrix. First of all, we segmented the region of interest (ROI) using active contour model algorithm. Then, we applied a total of 18 features (5 first order descriptors, 10 Gray level co-occurrence matrix features(GLCM), 2 Gray level run length matrix features and shape feature) to each thyroid region of interest. The extracted features are used as statistical analysis. Our results show that first order statistics (Skewness, Entropy, Energy, Smoothness), GLCM (Correlation, Contrast, Energy, Entropy, Difference variance, Difference Entropy, Homogeneity, Maximum Probability, Sum average, Sum entropy), GLRLM features and shape feature helped to distinguish thyroid benign and malignant. This algorithm will be helpful to diagnose of thyroid nodule on ultrasound images.