• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.2
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• pp.131-138
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• 2015

In this paper, the modified live-load and designed formula are studied according to the fact the highway bridge design specifications are recently revised. The two examples for composite steel plates and PSC girder bridges are studied. The envelope is analyzed with the finite element models and lateral load distribution method applying the existing highway bridge specification(2010), the newly revised highway bridge specification(2015) and AASHTO LRFD. In case of composite steel plates, length changes between spans are studied, and in case of PSC girder. changes of the number of cross-beams and spans, and span-lengths, are analyzed.

• Journal of Broadcast Engineering
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• v.4 no.1
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• pp.44-58
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• 1999

In this paper, a rate-distortion based image segmentation algorithm is presented using a recursive merging with region adjacency graph (RAG). In the method, the dissimilarity between a pair of adjacent regions is represented as a Lagrangian cost function considered in rate-distortion sense. Lagrangian multiplier is estimated in each merging step, a pair of adjacent regions whose cost is minimal is searched and then the pair of regions are merged into a new region. The merging step is recursively performed until some termination criterion is reached. The proposed method thus is suitable for region-based coding or segmented-based coding. Experiment results for 256x256 Lena show that segmented-based coding using the proposed method yields PSNR improvement of about 2.5 - 3.5 dB. 0.8 -1.0 dB. 0.3 -0.6 dB over mean-difference-based method. distortion-based method, and JPEG, respectively.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.208-213
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• 2011

We calculated the EPR (electron paramagnetic resonance) line-shape function. The line-widths of a -doped single crystal was studied as a function of the temperature with 0.5 and 2 at. at a frequency of (X-band). The line-width decreases with increasing temperature, such temperature behavior of the line-width can indicate a motional narrowing of the spectrum, when impurity ions substitute for host ions in an off-center position, and thus there can be fast jumping of dipoles between several symmetrically equivalent configurations. Therefore, the present technique is considered to be more convenient to explain the resonant system as in the case of other optical transition problems.

• Nuclear Engineering and Technology
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• v.18 no.2
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• pp.107-116
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• 1986

The steady and unsteady state models were established for the performance analysis and design of heavy water distillation columns packed with corrugated wire mesh. After the steady state model was derived with pressure drops, separated D$_2$O concentration and temperature profiles and pressure gradients in the column were obtained by solving MESH equations with equation tearing method. For the analysis of unsteady state behavior, the equilibrium stage transient model deduced from modifying the Cohen's ideal cascade equation was used to predict the concentration change of heavy water with time. These models were in good agreement with the experimental results of heavy water distillation at total reflux. And the newly developed packing material turned out to be very efficient separation device for very small HETP, pressure drop and holdup.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.178-186
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• 2021

COVID-19 occurred in China in December 2019 and spread to the world. Untact culture becoming commonplace due to the spread of COVID-19, is accelerating digital transformation across society. The government is increasing government fund to overcome national crisis situations such as COVID-19. In order to efficiently execute these government funds, the government and policy financial institutions need to come up with two measures. One is to establish a transparent government fund execution process, and the other is to secure the objectivity of the review process. In this paper, to solve this problem, we designed the execution process of government funds from the government to end users with Consortium Blockchain, and designed a machine learning algorithm for internal review of policy financial institutions. The research data proposed in this paper will be helpful in setting the future government policy direction for government fund execution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.1-7
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• 2017

The RAR (Reinforced Abutment for Railways) is an economical abutment to reduce the settlement of a transitional zone and horizontal displacement of an abutment by constructing backfill before the abutment. In this paper, the performance of the RAR depending on the pile installation was evaluated using 2D (Dimensional) finite element analysis and compared with the existing abutment (with 5 rows pile). Numerical analysis showed that increasing pile installation is more effective in reducing horizontal displacement and earth pressure than settlement of the transitional zone. The horizontal displacement and earth pressure of the RAR was approximately 26~37% and 59~83% compared to the existing abutment by changing the pile installation. More pile installation led to a greater reduction of the horizontal displacement and earth pressure of the RAR. In addition, the horizontal earth pressure of RAR is influenced considerably by the reinforcement, pile, foundation, and stiffness of the ground.

• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.126-129
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• 2010

(1-X) $(Na_{0.5}K_{0.5})NbO_3-X$ $K_4CuNb_8O_{23}$ (NKN-X KCN) ceramics were produced using the conventional solid state sintering method, and their sinterability and electric properties were investigated. The density, dielectric constant (${\varepsilon}_r$), piezoelectric constant $d_{33}$, electromechanical coupling factor $k_p$ and mechanical quality factor $Q_m$ value of the NKN ceramics depended upon the KCN content and the sintering temperature. In particular, the KCN addition to the NKN greatly improved the mechanical quality factor $Q_m$ value. The ceramic with X = 2.0 mol% sintered at $1,150^{\circ}C$ possesses the optimum properties (${\varepsilon}_r=241$, $d_{33}=78$, $k_p=0.34$ and $Q_m=1,121$). These results indicate that the ceramic is a promising candidate material for applications in lead free piezoelectric transformer and filter materials.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.99-107
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• 2015

A natural hybrid of a probable intergeneric mating between the striped shiner Pungtungia herzi and the stone morocco Pseudorasbora parva (Cypriniformes: Cyprinidae) was captured in the Geumho River, a tributary of the Nakdong River basin in Korea. Morphological characters and DNA sequences were analyzed to verify its hybrid state and identify the parentage of its parent species. The hybrid exhibited a phenotypic intermediacy between the two parent species in the number of vertebrae and the mouth shape. Out of 1,488 base pair (bp) positions of the nuclear recombination activating gene 1 gene (rag1), which has a biparental mode of inheritance, 41-bp substitutions were detected between the two parent species, whereas an electropherogram of the hybrid displayed polymorphic double peaks at all of the base positions, along with one additional one, strongly indicating its hybrid state. Meanwhile, sequence comparison of the mitochondrial cytochrome b gene (mt-cyb) (1,140 bp), which has a maternal mode of inheritance, showed only 5-22-bp differences (97.6-99.5% identities) between the hybrid and Pu. herzi, but as many as 158-168-bp differences (85.2-86.1% identities) between the hybrid and Ps. parva, clearly indicating Pu. herzi as the maternal species. Thus, combined analyses of independent data sets (i.e., morphology and nuclear and mitochondrial DNA sequences) offered convincing evidence for the hybrid state of a naturally occurring hybrid resulting from intergeneric mating between a female Pu. herzi and a male Ps. parva.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.991-998
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• 2016

The propose of this study is to demonstrate how efficiently and accurately the construction stages of cable-stayed bridges are analyzed using the unstrained length method (ULM) in which all unstrained element lengths are determined from a simplified analytical method (Jung et al., 2015). A forward analysis of cable-stayed bridges using the commercial FEA program, MIDAS is sequentially carried out considering the lack of fit force but the ULM is able to analyze a intermediate construction stage directly by taking the corresponding unstrained lengths of the construction stage model simply. The closing load step analysis is achieved by loading the pavement and counter weight forces in reverse. An Incheon bridge model is analyzed using the present ULM and the commercial program, respectively, and the two analysis results are compared.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.947-954
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• 2016

A simplified analysis method is first proposed in order to determine an optimized initial shape of cable-stayed bridges including all unstrained element lengths without using complicated nonlinear FE analysis. The unstrained-length based FE method is then presented using the unstrained lengths by the simplified analysis. To demonstrate validity and accuracy of the proposed method, Incheon bridge model having the fabrication camber is constructed and initial shaping analysis is performed using the presented method and commercial finite element analysis program, MIDAS. Resultantly it is shown that the initial solutions by the proposed algorithm are well optimized and in good agreement with those by MIDAS except for axial displacements of the main member.