• Journal of the Korean Society of Combustion
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• v.7 no.2
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• pp.49-61
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• 2002

Numerical simulation is performed for stagnating turbulent flows of impinging and countercurrent jets by the Reynolds stress model(RSM). Results are compared with those of the ${\kappa}-{\varepsilon}$ model and available data to assess the flow characteristics and turbulence modes. Three variants of the RSM tested are those of Gibson and Launder(GL), Craft and Launder(GL-CL) and Speziale, Sarkar and Gatski(SSG). As well known, the ${\kappa}-{\varepsilon}$ model overestimates turbulent kinetic energy near the wall significantly. Although the RSM is superior to the ${\kappa}-{\varepsilon}$ model, it shows considerable difference according to how the redistributive pressure-strain term is modeled. Results of the RSM for countercurrent jets are improved with the modified coefficients for the dissipation rate, $C_{{\varepsilon}1}\;and\;C_{{\varepsilon}2}$ suggested by Champion and Libby. The performance of the three variants of the RSM model for stagnating flows are assessed.

• Genomics & Informatics
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• v.12 no.4
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• pp.136-144
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• 2014

Besides single-nucleotide variants in the human genome, large-scale genomic variants, such as copy number variations (CNVs), are being increasingly discovered as a genetic source of human diversity and the pathogenic factors of diseases. Recent experimental findings have shed light on the links between different genome architectures and CNV mutagenesis. In this review, we summarize various genomic features and discuss their contributions to CNV formation. Genomic repeats, including both low-copy and high-copy repeats, play important roles in CNV instability, which was initially known as DNA recombination events. Furthermore, it has been found that human genomic repeats can also induce DNA replication errors and consequently result in CNV mutations. Some recent studies showed that DNA replication timing, which reflects the high-order information of genomic organization, is involved in human CNV mutations. Our review highlights that genome architecture, from DNA sequence to high-order genomic organization, is an important molecular factor in CNV mutagenesis and human genomic instability.

• Journal of Communications and Networks
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• v.18 no.2
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• pp.238-245
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• 2016

A sequence number checking technique is proposed to improve the performance of TCP connections in mobile ad hoc networks. While a TCP connection is initialized, a routing protocol takes the responsibility for checking the hop count between a source and destination pair. If the hop count is greater than a predefined value, the routing protocol decides to use a proxy node. The responsibility of a proxy node is to check the correctness of data packets and inform the missing packets by sending an acknowledgement from a proxy node to the source node. By doing so, the source node is able to retransmit any missing packet in advance without waiting until an end-to-end acknowledgement is received from the destination. Simulation results show that the proposed mechanism is able to increase throughput up to 55% in static network and decrease routing overhead up to 95%in mobile network.

• Genomics & Informatics
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• v.11 no.4
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• pp.191-199
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• 2013

High-throughput next-generation sequencing (NGS) technology produces a tremendous amount of raw sequence data. The challenges for researchers are to process the raw data, to map the sequences to genome, to discover variants that are different from the reference genome, and to prioritize/rank the variants for the question of interest. The recent development of many computational algorithms and programs has vastly improved the ability to translate sequence data into valuable information for disease gene identification. However, the NGS data analysis is complex and could be overwhelming for researchers who are not familiar with the process. Here, we outline the analysis pipeline and describe some of the most commonly used principles and tools for analyzing NGS data for disease gene identification.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.634-641
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• 1998

Quasiclassical trajectory calculations were carried out for the reactions of $H+H_2$ (V=O, J=O) and its isotope variants on the Siegbahn-Liu-Truhlar-Horowitz potential energy surface for the relative energies E between 6 and 150 kcal/mol. The goal of the work was to understand the inter- and intramolecular isotope effects. We examine the relative motion of reactants during the collision using the method of analysis that monitors the intermolecular properties (internuclear distances, geometry of reactants, and final product). As in other works, we find that the heavier the incoming atom is, the greater the reaction cross section is at the same collision energy. Using the method of analysis we prove that the intermolecular isotope effect is contributed mainly by differences in reorientation due to the different reduced masses. We show that above E=30 kcal/mol recrossing also contributes to the intermolecular isotope effect. For the intramolecular isotope effect in the reactions of H+HD and T+HD, we reach the same conclusions as in the systems of $O(^3P)+HD$, F+HD, and Cl+HD. That is, the intramolecular isotope effect below E=150 kcal/mol is contributed by reorientation, recrossing, and knockout type reactions.

• Genomics & Informatics
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• v.17 no.1
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• pp.4.1-4.7
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• 2019

In this paper, we propose a window-based mechanism visualization approach as an alternative way to measure the seriousness of the difference among data-insights extracted from a composite biodata point. The approach is based on two components: undirected graph and Mosaab-metric space. The significant application of this approach is to visualize the segmented genome of a virus. We use Influenza and Ebola viruses as examples to demonstrate the robustness of this approach and to conduct comparisons. This approach can provide researchers with deep insights about information structures extracted from a segmented genome as a composite biodata point, and consequently, to capture the segmented genetic variations and diversity (variants) in composite data points.

• Bulletin of the Korean Mathematical Society
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• v.56 no.3
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• pp.757-777
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• 2019

In this paper, we study the convergence analysis of the sequences generated by the proximal point method for an infinite family of pseudo-monotone equilibrium problems in Banach spaces. We first prove the weak convergence of the generated sequence to a common solution of the infinite family of equilibrium problems with summable errors. Then, we show the strong convergence of the generated sequence to a common equilibrium point by some various additional assumptions. We also consider two variants for which we establish the strong convergence without any additional assumption. For both of them, each iteration consists of a proximal step followed by a computationally inexpensive step which ensures the strong convergence of the generated sequence. Also, for this two variants we are able to characterize the strong limit of the sequence: for the first variant it is the solution lying closest to an arbitrarily selected point, and for the second one it is the solution of the problem which lies closest to the initial iterate. Finally, we give a concrete example where the main results can be applied.

• Journal of Genetic Medicine
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• v.17 no.2
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• pp.97-101
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• 2020

The combination of central nervous system abnormalities and renal impairment is a notable characteristic of Galloway-Mowat syndrome (GAMOS), a disease which often accompanies microcephaly, developmental delay, and nephrotic syndrome. Many subtypes exist having various phenotypes and genotypes, and many genetic causes are still being identified. An 18-month-old boy first visited our clinic for seizure, delayed development, and microcephaly. During follow-up visits he developed proteinuria and nephrotic syndrome at the age of 6. Nephrotic syndrome became refractory to treatment. These phenotypes were suggestive of GAMOS. Next generation sequencing was performed for genetic analysis and revealed novel compound heterozygous variants in the WDR4 gene: c.494G>A (p.Arg165Gln) and c.540C>G (p.Ile180Met). This is the first case in Korea of GAMOS involving the WDR4 gene.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.230.3-231
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• 2003

The therapeutic use of protein pharmaceuticals produced by recombinant DNA technology is increasing in recent decades. In order to investigate the quality of recombinant proteins, it is important to identify and assign the impurities produced in the process of recombination or in storage conditions. Capillary Electrophoresis is emerging technology exhibiting high sensitivity, selectivity and speed and may be most powerful tools for this application. In this study, human growth hormone (hGH) has been analyzed by various mode of capillary electrophoresis such as capillary zone electrophoresis (CZE), capillary gel electrophoresis (CGE), and capillary isoelectric focusing (cIEF) to indicate the chemically or biologically oriented variants and the degraded fragments. (omitted)

• Molecules and Cells
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• v.44 no.6
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• pp.392-400
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• 2021

It has been more than a year since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first emerged. Many studies have provided insights into the various aspects of the immune response in coronavirus disease 2019 (COVID-19). Especially for antibody treatment and vaccine development, humoral immunity to SARS-CoV-2 has been studied extensively, though there is still much that is unknown and controversial. Here, we introduce key discoveries on the humoral immune responses in COVID-19, including the immune dynamics of antibody responses and correlations with disease severity, neutralizing antibodies and their cross-reactivity, how long the antibody and memory B-cell responses last, aberrant autoreactive antibodies generated in COVID-19 patients, and the efficacy of currently available therapeutic antibodies and vaccines against circulating SARS-CoV-2 variants, and highlight gaps in the current knowledge.