• Journal of Korea Water Resources Association
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• v.52 no.2
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• pp.125-132
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• 2019

In this study, we developed a heavy rainfall risk impact matrix, which can be used to evaluate the influence of heavy rainfall risk, and propose a method to evaluate the impact of heavy rainfall risk. We evaluated the heavy rainfall risk impact for each receptor (Residential, Transport, Utility) on Sadang-dong using the heavy rainfall event on July 27, 2011. For this purpose, the potential risk impact was calculated by combining the impact level and the rainfall depth based on the grid. Heavy Rainfall Risk Impact was calculated by combining with Likelihood to predict the heavy rainfall impact, and the degree of heavy rainfall in the Sadang-dong area was analyzed and presented based on grid.

• Computers and Concrete
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• v.27 no.2
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• pp.111-130
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• 2021

In the present work, an extensive study for predicting efficiency parameters (��i) of various simulated nanocomposites including Polymethyl methacrylate (PMMA) as matrix and different structures including various sizes of graphene platelets (GPLs), single, double, and multi-walled carbon nanotubes (SWCNTs-DWCNTs-MWCNTs), and single and double-walled boron nitride nanotubes (SWBNNTs-DWBNNTs) are investigated. It should be stated that GPLs, carbon and boron nitride nanotubes (CNTs, BNNT) with different chiralities (5, 0), (5, 5), (10, 0), and (10, 10) as reinforcements are considered. In this research, molecular dynamics (MDs) method with Materials studio software is applied to examine the mechanical properties (Young's modulus) of simulated nanocomposite boxes and calculate η1 of each nanocomposite boxes. Then, it is noteworthy that by changing length (6.252, 10.584, and 21.173 nm) and width (7.137, 10.515, and 19.936) of GPLs, ��1, ��2, and ��3 approximately becomes (0.101, 0.114, and 0.124), (1.15, 1.22, and 1.26), (1.04, 1.05, and 1.07) respectively. After that efficiency parameters of SWCNTs, DWCNTs, and MWCNTs are calculated and discussed separately. Finally efficiency parameters of SWBNNTs and DWBNNTs with different chiralities by PMMA as matrix are determined by MD and discussed separately. It is known that the accurate efficiency parameters helps a lot to calculate the properties of nanocomposite analytically. In particular, the obtained results from this research can be used for analytical work based on the extended rule of mixture (ERM) in bending, buckling and vibration analysis of structure in future study.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.871-876
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• 2023

In this paper, we deal with the stable conditions when two uncertainties exist simultaneously in a linear discrete time-varying interval system with time-varying delay time. The interval system is a system in which system matrices are given in the form of an interval matrix, and this paper targets the system in which the delay time of these interval system matrices and state variables is time-varying. We propose the system stability condition when there is simultaneous unstructured uncertainty that includes nonlinearity and only its magnitude and uncertainty in the system matrix of delayed state variables. The stable bounds for two types of uncertainty are derived as an analytical equation. The proposed stability condition and bounds can include previous stability condition for various linear discrete systems, and the values such as time-varying delay time variation size, uncertainty size, and range of interval matrix are all included in the conditional equation. The new bounds of stability are compared with previous results through numerical example, and its effectiveness and excellence are verified.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.4
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• pp.27-34
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• 2011

In this paper, it was presented a design on the dynamic multimedia fingerprinting code for anti-collusion code(ACC) in the protection of multimedia content. Multimedia fingerprinting code for the conventional ACC, is designed with a mathematical method to increase k to k+1 by transform from BIBD's an incidence matrix to a complement matrix. A codevector of the complement matrix is allowanced fingerprinting code to a user' authority and embedded into a content. In the proposed algorithm, the feature points were drawing from a content which user bought, with based on these to design the dynamical multimedia fingerprinting code. The candidate codes of ACC which satisfied BIBD's v and k+1 condition is registered in the codebook, and then a matrix is generated(Below that it calls "Rhee matrix") with ${\lambda}+1$ condition. In the experimental results, the codevector of Rhee matrix based on a feature point of the content is generated to exist k in the confidence interval at the significance level ($1-{\alpha}$). Euclidean distances between row and row and column and column each other of Rhee matrix is working out same k value as like the compliment matrices based on BIBD and Graph. Moreover, first row and column of Rhee matrix are an initial firing vector and to be a forensic mark of content protection. Because of the connection of the rest codevectors is reported in the codebook, when trace a colluded code, it isn't necessity to solve a correlation coefficient between original fingerprinting code and the colluded code but only search the codebook then a trace of the colluder is easy. Thus, the generated Rhee matrix in this paper has an excellent robustness and fidelity more than the mathematically generated matrix based on BIBD as ACC.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.1
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• pp.1-7
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• 2007

As fiber reinforced composite materials are widely used in aircraft, space structures and robot arms, the study on non-destructive testing methods has become an important research area for improving their reliability and safety. AE (acoustic emission) can evaluate the defects by detecting the emitting strain energy when elastic waves are generated by the initiation and growth of crack, plastic deformation, fiber breakage, matrix cleavage, or delamination. In the paper, AE signals generated under uniaxial tension were measured and analyzed using the $8{\times}8$ matrix piezo electric sensor. The electronic circuit to control the transmitting distance of AE signals was designed and constructed. The optical data storage system was also designed to store the AE signal of 64channels using LED (light emitting diode) elements. From the tests, it was shown that the source location and propagation path of AE signals in composite materials could be detected effectively by the $8{\times}8$ matrix piezo electric sensor.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.8
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• pp.27-34
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• 2012

In this paper, the implementation of high throughput two-dimensional (2-D) $8{\times}8$ forward and inverse integer DCT transform for H.264 is presented. The forward and inverse transforms are represented using simple shift and addition operations. Matrix decomposition and matrix operation such as the Kronecker product and direct sum are used to reduce the computation complexity. The proposed design uses integer computations and does not use transpose memory and hence, the resource consumption is also reduced. The maximum operating frequency of the proposed pipelined architecture is 1.184 GHz, which achieves 25.27 Gpixels/sec throughput rate with the hardware cost of 44864 gates. High throughput and low hardware makes the proposed design useful for real time H.264/AVC high definition processing.

• The Journal of Korean Obstetrics and Gynecology
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• v.27 no.3
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• pp.12-27
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• 2014

Objectives: This study was performed to evaluate the effect of Guibi-tang water extract (GB) on osteoporosis. Methods: We examined the effect of GB on osteoclast differentiation using murine pre-osteoclastic RAW 264.7 cells treated with receptor activator of nuclear factor kappa-B ligand (RANKL). The effect of GB on osteoclast was measured by counting TRAP (+) multinucleated cells and measuring TRAP activity. The mRNA expressions of osteoclastogenesis-related genes (Cathepsin K, MMP-9, TRAP, NFATc1, MITF, TNF-${\alpha}$, IL-6, COX-2) were measured by real-time PCR. We examined the effect of GB on osteoblast proliferation, ALP activity, bone matrix protein synthesis and collagen synthesis using murine calvarial cell. Results: GB decreased the number of TRAP (+) multinucleated cells and inhibited TRAP activity in RANKL-stimulated RAW 264.7 cell. GB decreased the expression of genes related osteoclastogenesis such as Cathepsin K, MMP-9, TRAP, NFATc1, MITF, COX-2 in RANKL-stimulated RAW 264.7 cell. But GB did not decrease the expression of iNOS and increased the expression of TNF-${\alpha}$, IL-6 in RANKL-stimulated RAW 264.7 cell. These genes (iNOS, TNF-${\alpha}$, IL-6) are thought to be related with the inflammatory bone destruction. GB increased cell proliferation of rat calvarial cell and also increased ALP activity in rat calvarial cell. GB did not increase bone matrix protein synthesis but increased collagen synthesis in rat calvarial cell. Conclusions: This study suggests that GB may be effective in treating osteoporosis by inhibiting osteoclast differentiation and its related gene expression and by increasing osteoblast proliferation.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1526-1531
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• 2014

Matrix metalloproteinases (MMP) are key enzymes involved in cell and tissue remodeling during ovarian follicle development and ovulation. The control of MMP9 transcription in ovarian follicles occurs through a core promoter region (-2,400 to -1,700 bp). The aim of this study was to screen genetic variations in the core promoter region and examine MMP9 transcription regulation and reproduction performance. A single cytosine deletion/insertion polymorphism was found at -1954 $C^+/C^-$. Genetic association analysis indicated significant correlation between the deletion genotype ($C^-$) with total egg numbers at 28 weeks (p = 0.031). Furthermore, luciferase-reporter assay showed the deletion genotype ($C^-$) had significantly lower promoter activity than the insertion genotype ($C^+$) in primary granulosa cells (p<0.01). Therefore, the identified polymorphism could be used for marker-assisted selection to improve chicken laying performance.

• Journal of Advanced Marine Engineering and Technology
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• v.5 no.1
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• pp.20-27
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• 1981

The alignment of propulsion shaft systems by the fair curve method has been developed over the past twenty years and in recent years its basic problems have been almost solved. At the present time, studies on introducing actual conditions are being undertaken. In a fair curve alignment, its aim is to achieve a stable shaft system which will be relatively insensitive to misalignment or the influence of external factors such as thermal variations due to the sunshine, speed change, etc. The key point of fair curve alignment is the calculations of reactions in the straight support and reaction influence numbers. The present authors have developed those calculating method by the matrix method of the three-moment theorem. The fair curve alignment is based on the analysis of propulsion shaft system which is assumed as a continous beam on multiple support points. The propeller shaft is divided into several elements. For each element, the nodal point equation is derived by the three-moment theorem. Reaction of supporting points of straight shaft and reaction influence numbers are calculated by the matrix calculation of each nodal point equation. It has been found that results of calculation for the model shaft agree well with those of experiment which had been measured by the strain gauge method. Results of calculation for the actual propulsion shafting of the steam turbine had been compared also with those of Det norske Vertas.

• Journal of applied mathematics & informatics
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• v.27 no.1_2
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• pp.97-103
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• 2009

Suppose F is a field of characteristic not 2 and $F\;{\neq}\;Z_3$. Let $M_n(F)$ be the linear space of all $n{\times}n$ matrices over F, and let ${\Gamma}_n(F)$ be the subset of $M_n(F)$ consisting of all $n{\times}n$ involutory matrices. We denote by ${\Phi}_n(F)$ the set of all maps from $M_n(F)$ to itself satisfying A - ${\lambda}B{\in}{\Gamma}_n(F)$ if and only if ${\phi}(A)$ - ${\lambda}{\phi}(B){\in}{\Gamma}_n(F)$ for every A, $B{\in}M_n(F)$ and ${\lambda}{\in}F$. It was showed that ${\phi}{\in}{\Phi}_n(F)$ if and only if there exist an invertible matrix $P{\in}M_n(F)$ and an involutory element ${\varepsilon}$ such that either ${\phi}(A)={\varepsilon}PAP^{-1}$ for every $A{\in}M_n(F)$ or ${\phi}(A)={\varepsilon}PA^{T}P^{-1}$ for every $A{\in}M_n(F)$. As an application, the maps preserving inverses of matrces also are characterized.