• Journal of the Korean association of regional geographers
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• v.22 no.1
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• pp.135-150
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• 2016

This paper studied on the geographical distribution location arrangement and the social construction of Pungsu discourse and the Pungsu(Fengshui) management of royal tombs on the Joseon Dynasty from the historical, cultural geographical perspective. The Pungsu landscape of royal tombs during the Joseon dynasty was the direct result of the political dynamics among the king, his family, other royal families, and various groups of vassals. Pungsu was a important factor in deciding tomb sites or landscapes, but it was a secondary factor to politics in the Joseon Dynasty. The primary factor was politics, clearly showing Pungsu's status in social discourse. The royal tomb Pungsu is defined as the Pungsu discourse of the Joseon Dynasty period which is combined with Confucian ideology in Korean Pungsu history.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.251-257
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• 2020

The study investigates the role of commodity prices and tax purpose recognition on bitcoin prices. Since the introduction of bitcoin in 2008, emphasis has focused on economists, policy-makers and analysts drastically increasing bitcoin's accessibility and commodity values (Dumitrescu & Firică, 2014). This study employs GARCH and EGARCH from ARCH/GARCH family on daily nature data. We measure the volatile behavior of bitcoin by employing auto-regressive conditional heteroscedasticity model with the aim to explore the relationship between major commodities and bitcoin volatility. We focus on major commodities like gold, silver, platinum, and crude oil to be regressed with bitcoin. The daily prices of commodities were retrieved from www.investing.com and bitcoin prices from www.coindesk.com for the period from 29April 2013 to 16 October 2018. Results confirmed the currency's long-term volatile behavior, which is due to its composition and market dynamics, whereas the existence of asymmetric information effect is not confirmed. Tax recognition by other countries may in future help in controlling the volatility as bitcoin is not a country-specific security. But, only silver impacts on volatility in comparison to oil prices and platinum, which is due to its similar features with gold. Eventually, bitcoin can be used for risk diversification and money making.

• Structural Engineering and Mechanics
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• v.41 no.1
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• pp.113-137
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• 2012

Frame structures with viscoelastic (VE) dampers mounted on them are considered in this paper. It is the aim of this paper to compare the dynamic characteristics of frame structures with VE dampers when the dampers are modelled by means of different models. The classical rheological models, the model with the fractional order derivative, and the complex modulus model are used. A relatively large structure with VE dampers is considered in order to make the results of comparison more representative. The formulae for dissipation energy are derived. The finite element method is used to derive the equations of motion of the structure with dampers and such equations are written in terms of both physical and state-space variables. The solution to motion equations in the frequency domain is given and the dynamic properties of the structure with VE dampers are determined as a solution to the appropriately defined eigenvalue problem. Several conclusions concerning the applicability of a family of models of VE dampers are formulated on the basis of results of an extensive numerical analysis.

• Computational Structural Engineering
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• v.7 no.4
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• pp.85-101
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• 1994

A family of variational principles governing the dynamics of laminated plate has been derived using a variationally consistent shear deformable discrete laminated plate theory with particular reference to finite element procedures. The theoretical basis for the derivation is Sandhu's generalized procedure for the variational formulation of linear coupled boundary value problem. As the bilinear mapping to write the operator matrix of the field equations in self-adjoint form, convolution product was employed. Boundary conditions, initial conditions and probable internal discontinuity were explicitly included in the governing functionals. Some interesting extensions and specializations of the general variational principle were presented, which can provide many different finite element formulations for the problem.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.191-192
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• 2017

In response to the economic depression, the demand for fixed rent income has increased according to the easing construction regulations. it caused indiscriminated investment to stakeholders. This leads to oversupply in the multi-family Housing market and increases unsold housing and vacancy rates except specific area such as Gangnam-gu.In order to solve this issue, although studies on the optimization price of apartment houses has been conducted, the study is insufficient regarding on residential officetel. Therefore, the objective is to suggest a basic study on optimal price estimation model development by using probabilistic forecasting method in planning phase. To achieve the objective, first, variables are defined such as expenses, financial costs, income, etc. Second, causal loop diagram is suggested. Third, basic optimization prices estimation model is developed. In the future, this study can be used as one of decision making tools in planning phase of officetel development projects.

• Molecules and Cells
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• v.42 no.8
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• pp.589-596
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• 2019

${\beta}Pix$ is a guanine nucleotide exchange factor for the Rho family small GTPases, Rac1 and Cdc42. It is known to regulate focal adhesion dynamics and cell migration. However, the in vivo role of ${\beta}Pix$ is currently not well understood. Here, we report the production and characterization of ${\beta}Pix$-KO mice. Loss of ${\beta}Pix$ results in embryonic lethality accompanied by abnormal developmental features, such as incomplete neural tube closure, impaired axial rotation, and failure of allantois-chorion fusion. We also generated ${\beta}Pix$-KO mouse embryonic fibroblasts (MEFs) to examine ${\beta}Pix$ function in mouse fibroblasts. ${\beta}Pix$-KO MEFs exhibit decreased Rac1 activity, and defects in cell spreading and platelet-derived growth factor (PDGF)-induced ruffle formation and chemotaxis. The average size of focal adhesions is increased in ${\beta}Pix$-KO MEFs. Interestingly, ${\beta}Pix$-KO MEFs showed increased motility in random migration and rapid wound healing with elevated levels of MLC2 phosphorylation. Taken together, our data demonstrate that ${\beta}Pix$ plays essential roles in early embryonic development, cell spreading, and cell migration in fibroblasts.

• Ocean Systems Engineering
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• v.12 no.2
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• pp.143-157
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• 2022

In this study, the nominal wake field of a semi-displacement type high-speed vessel was computed at full scale by using CFD (Computational Fluid Dynamics) and GEOSIM-based approaches. A scale effect investigation on nominal wake field of benchmark Athena vessel was performed with two models which have different model lengths. The members of the model family have the same Fr number but different Re numbers. The spatial components of nominal wake field have been analyzed by considering the axial, radial and tangential velocities for models at different scales. A linear feature has been found for radial and tangential components while a nonlinear change has been obtained for axial velocity. Taylor wake fraction formulation was also computed by using the axial wake velocities and an extrapolation technique was carried out to get the nonlinear fit of nominal wake fraction. This provides not only to observe the change of nominal wake fraction versus scale ratios but also to estimate accurately the wake fraction at full-scale. Extrapolated full-scale nominal wake fractions by GEOSIM-based approach were compared with the full-scale CFD result, and a very good agreement was achieved. It can be noted that the GEOSIM-based extrapolation method can be applied for estimation of the nominal wake fraction of semi-displacement type high-speed vessels.

• Mycobiology
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• v.50 no.5
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• pp.326-344
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• 2022

The fungal-like family Saprolegniaceae (Oomycota), also called "water mold," includes mostly aquatic saprophytes as well as notorious aquatic animal pathogens. Most studies on Saprolegniaceae have been biased toward pathogenic species that are important to aquaculture rather than saprotrophic species, despite the latter's crucial roles in carbon cycling of freshwater ecosystems. Few attempts have been made to study the diversity and ecology of Saprolegniaceae; thus, their ecological role is not well-known. During a survey of oomycetes between 2016 and 2021, we investigated the diversity and distribution of culturable Saprolegniaceae species in freshwater ecosystems of Korea. In the present study, members of Saprolegniaceae were isolated and identified at species level based on their cultural, morphological, and molecular phylogenetic analyses. Furthermore, substrate preference and seasonal dynamics for each were examined. Most of the species were previously reported as animal pathogens; however, in the present study, they were often isolated from other freshwater substrates, such as plant debris, algae, water, and soil sediment. The relative abundance of Saprolegniaceae was higher in the cold to cool season than that in the warm to hot season of Korea. This study enhances our understanding of the diversity and ecological attributes of Saprolegniaceae in freshwater ecosystems.

• Journal of Microbiology and Biotechnology
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• v.33 no.1
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• pp.114-122
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• 2023

A family of signal transduction pathways known as wingless type (Wnt) signaling pathways is essential to developmental processes like cell division and proliferation. Mutation in Wnt signaling results in a variety of diseases, including cancers of the breast, colon, and skin, metabolic disease, and neurodegenerative disease; thus, the Wnt signaling pathways have been attractive targets for disease treatment. However, the complicatedness and large involveness of the pathway often hampers pinpointing the specific targets of the metabolic process. In our current study, we investigated the differential metabolic regulation by the overexpression of the Wnt signaling pathway in a timely-resolved manner by applying high-throughput and un-targeted metabolite profiling. We have detected and annotated 321 metabolite peaks from a total of 36 human embryonic kidney (HEK) 293 cells using GC-TOF MS and LC-Orbitrap MS. The un-targeted metabolomic analysis identified the radical reprogramming of a range of central carbon/nitrogen metabolism pathways, including glycolysis, TCA cycle, and glutaminolysis, and fatty acid pathways. The investigation, combined with targeted mRNA profiles, elucidated an explicit understanding of activated fatty acid metabolism (β-oxidation and biosynthesis). The findings proposed detailed mechanistic biochemical dynamics in response to Wnt-driven metabolic changes, which may help design precise therapeutic targets for Wnt-related diseases.

• Journal of Families and Better Life
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• v.8 no.1
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• pp.83-100
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• 1990

The purposes of the study are to understand of rural family life cycle(FLC) and to get a FLC model for the twentieth in rural area. Data for the study were collected from 603 farm households in rural area. The major findings are as follows; 1) The age of first marriage was 21.5 years old(urban : 22.4), the first bearing 23.2(24.2), the last bearing 31.7(32.6), the first child marriage 47.2(46.5), and the last child marriage 59.7(52.7). The number of child and interval were 3.9 persons and 2.9 years respectively. From the survey results, the rural family life cycle was established. Establishment stage(from the marriage to the 1st child birth) : 21-23 yrs. Extension stage(from the 1st child birth to the last child birth) : 23-32 yrs. Complete extension stage(from the last child birth to the 1st child's marriage) : 32-47 yrs. Shrinking stage(from the 1st child's marriage to the last child's marriage) : 47-60 yrs. Complete shrinking stage(from the last child's marri ge to the death of husband) : 60-63 yrs. Dissolution stage(from the death of husband to the death of wife) : 53-75 yrs. 2) In general, the older the age, the younger the first marriage age, the greater the number of child, and the longer the interval of child bearing. The last child's marriage was too last to have the period of recovery stage. In terms of FLC by marital chorts, the later the year of marriage, the older the age of the first marriage and first baby bearing, the smaller the number of child, and the faster the launching stage. The higher the educational level, the older age of the first marriage and the first baby bering, the smaller the number of child, and the shorter the interval of child bearing. 3) Two types of rural FLC model for the twentieth were formulated. Type A was formulated based on the survey results and type B was formulated based on 『'88 population dynamics survey』 of Economic Planning Board(EPB). 「TYPE A」*Establishment stage(from the marriag to the 1st child birth) : 22.5-23.5 yrs. one child : the 1st child's marriage(49.5yrs), the death of husband(64.2yrs), the death of wife(71.7yrs) two children : the last child's birth(25.7yrs), the last child's marriage(51.7 yrs) three children : the last child's birth(27.9yrs) the last child's marriage(53.9yrs) 「TYPE B」*Establishment stage(from the marriage to the 1st child birth) : 25.3-26.3 yrs. one child : the lst child's marriage(52.3yrs), the death of husband(67.0yrs), the death of wife(74.5yrs) two children : the last child's birth(27.8yrs), the last child's marriage(53.8 yrs.) three children : the last child's birth(29.3yrs), the last child's marriage(55.3yrs).