• Structural Engineering and Mechanics
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• v.90 no.3
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• pp.253-261
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• 2024

This research explores a new finite element model for the free vibration analysis of bi-directional functionally graded (BDFG) beams. The model is based on an efficient higher-order shear deformation beam theory that incorporates a trigonometric warping function for both transverse shear deformation and stress to guarantee traction-free boundary conditions without the necessity of shear correction factors. The proposed two-node beam element has three degrees of freedom per node, and the inter-element continuity is retained using both C1 and C0 continuities for kinematics variables. In addition, the mechanical properties of the (BDFG) beam vary gradually and smoothly in both the in-plane and out-of-plane beam's directions according to an exponential power-law distribution. The highly elevated performance of the developed model is shown by comparing it to conceptual frameworks and solution procedures. Detailed numerical investigations are also conducted to examine the impact of boundary conditions, the bi-directional gradient indices, and the slenderness ratio on the free vibration response of BDFG beams. The suggested finite element beam model is an excellent potential tool for the design and the mechanical behavior estimation of BDFG structures.

• Journal of the Korea Furniture Society
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• v.20 no.6
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• pp.599-604
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• 2009

For the search of unified law of moisture movement in wood, moisture distribution of Korean red pine at non-steady state was investigated. We assume that the equilibrium moisture content (EMC) in wood depends on only temperature and relative humidity, it can be control in temperature and humidity chamber. If temperature is constant and humidity or vapor pressure is changed with sin curve shape at adequate cycles, EMC in chamber can be changed as well with sin-curve shape. The setup condition of a non-steady state in humidity control chambers is a constant temperature at $20^{\circ}C$ and 15+10 sin ${\omega}t$ percent EMC. It can be found that the distribution of moisture in the specimen with varying relative humidity are illustrated various types. Moisture in wood is complicated and vibrates with the moisture sorption process. Considering a unified law of moisture movement in wood, it is considered that the most important fact is to search the method of precise diffusion & transfer coefficients.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.397-405
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• 2022

NFT art is a new art formed based on NFT technology. This is attracting great attention in the existing art world and art market. Therefore, it is required to analyze whether NFT art can establish itself as a new area of art. Therefore, the formation and development process of NFT art is analyzed from the perspective of Actor-Network Theory of Science and Technology and Studies, and the case of NFT artist 'beeple' is a representative example. It also discusses the artistic value of NFT art and its relationship with traditional art networks based on the aesthetics of science and technology researcher Graham Harman. In particular, it analyzes the future and genre sustainability of NFT art through the case of NFT project "Cryptopunks" and "PUNKISM" advocating a new art genre. By analyzing NFT art with ANT, I would like to raise a technical, aesthetic, and philosophical questions and propose a positive prospect as a new art genre.

• New & Renewable Energy
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• v.20 no.1
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• pp.38-51
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• 2024

The rapid expansion of industrialization and population growth worldwide has led to a significant surge in energy demand, perpetuating heavy reliance on finite fossil fuel reserves. Although prevailing policies primarily target ground-mounted solar photovoltaics, there is a noticeable increase in the adoption of floating solar power generation systems on water surfaces. Nonetheless, adequate studies and legislative reviews on offshore solar photovoltaics in Korea are lacking. The absence of well-defined criteria for the economic analysis of floating solar photovoltaics presents hurdles to their economic feasibility. This study conducted a comprehensive cost-benefit analysis of offshore photovoltaics to evaluate their economic viability and compared four types of solar photovoltaics based on the operating area and technology: ground-mounted, floating on inland water, pontoon-based offshore, and flexible system offshore. Perspectives from both central and local government entities, emphasizing social aspects, as well as inputs from private companies with a financial focus were considered. The findings revealed variations in economic viability depending on the operating area and technology employed. This study aims to contribute to the advancement of market maturity and technology within the realm of offshore solar photovoltaics.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.2116-2124
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• 2003

An experimental study providing additional knowledge of quasi-conical symmetry in swept shock wave/turbulent boundary-layer interactions is described. When a turbulent boundary layer on the flat plate is subjected to interact with a swept planar shock wave, the interaction flowfield far from fin leading edge has a nature of conical symmetry, which topological features of the interaction flow appear to emanate from a virtual conical origin. Surface streakline patterns obtained from the kerosene-lampblack tracings have been utilized to obtain representative surface features of the flow, including the location of the virtual conical origin. The scaling law for the sharp-fin interactions suggested by previous investigators has been reexamined for different freestream Mach numbers. It is noticed that the scaling law reasonably agrees with the present experimental data, however, that the law is not appropriate to estimate the location of the virtual conical origin. Further knowledge of the correlation for the virtual conical origin has thus been proposed.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.

• Bulletin of the Korean Chemical Society
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• v.30 no.8
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• pp.1749-1754
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• 2009

Solubilities of carbon dioxide (C$O_2$) in a series of fluorine-free room temperature ionic liquids (RTILs), dialkylimidazolium dialkylphosphates and dialkylimidazolium alkylphosphites, were measured at 313∼333 K and pressures up to 5 MPa. Henry’s law coefficients as the solubility parameter of C$O_2$ in RTILs were derived from the isotherm of fugacity versus C$O_2$ mole fraction. The C$O_2$ solubility in a phosphorus-containing RTIL was found to increase with the increasing molar volume of the RTIL. In general, dialkylimidazolium dialkylphosphate exhibited higher absorption capacity than dialkylimidazolium alkylphosphite as long as the RTILs possess an identical cation. Among RTILs tested, 1-butyl-3-methylimidazolium dibutylphosphate [BMIM][B$u_2PO_4$] and 1-butyl-3-methylimidazolium butylphosphite [BMIM][BuHP$O_3$] exhibited similar Henry’s law coefficients to 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl)imide ([BMIM][T$f_2$N]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][B$F_4$]), respectively. The Krichevsky-Kasarnovsky equation was employed to derive the C$O_2$ solubility parameter (Henry’s law coefficient) from the solubility data measured at elevated pressures.

• Proceedings of the KSEEG Conference
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• 2005.04a
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• pp.7-10
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• 2005

• International Journal of Knowledge Content Development & Technology
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• v.12 no.2
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• pp.41-56
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• 2022

This research paper presents the use of different forms of literature by the PhD researchers of the Department of Political Science and the Department of Public Administration, Punjabi University, Patiala. It is assessed by analyzing the resources cited in the PhD theses awarded by Punjabi University, Patiala during 2015-2019. The different bibliographic forms of the references have been analyzed in order to find out the year-wise submission, average citations per thesis, authorship pattern, chronology, use of electronic resources, and format of citations in both the subjects under study. It has been found in this study that average citations per thesis in Political Science is more (200.53) than Public Administration (160.6). Books are most preferred form in both the subjects. Majority of the citations in both the subjects are from the period 2000-2009. Ranked list of journals for both the subjects have been prepared to identify core journals. The core journals in both the subjects are 9. Bradford Multipliers have been calculated and application of Bradford Law of Scattering has also been tested for both the subjects. It is expected that the present study will help librarians in selecting, retaining and cancelling the existing journals in Political Science and Public Administration.

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.129-136
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• 2016

Crucial aspects to successfully realizing the re-emergence of a contemporary and sustainable supercomputing community in South Korea will involve the devoted efforts and support from key government and R&D organizations. We suggest various supplementation plans regarding the roles of support for the statutory plan. This includes the committee and the plans which are often missing necessary support systems that help competent ministries to plan properly according to the missions of the research center. This dissertation suggests that adjustment in the HPC trends will depend upon exposing and correcting problems in the law as well as overall improvement of the law. Also, the total development of a super computing market is necessary. The results of these guidelines will create a spread of demand for supercomputing for national IT resource sharing, and will foster the development of supercomputer specialists worldwide. Other major end results include significant increases in research productivity and increased rates of product development.