• Journal of the Korean Wood Science and Technology
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• v.51 no.6
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• pp.542-554
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• 2023

This study is a continuation of our previous work, which focused on the resistance of jabon wood to termites after impregnation with wood vinegar (WV) and animal-based adhesive (kak). This paper presents the physicomechanical properties of fast-growing jabon wood impregnated with kak at two concentrations (8% and 10%) in wood vinegar or water as a solvent with and without 4% borax. The physical properties of the impregnation solution, that is, viscosity, density, pH, and solid content, were evaluated according to SNI 06-4567-1998. Some physical parameters, such as weight percent gain (WPG), density, water uptake, anti-swelling efficiency (ASE), crystallinity, and mechanical properties, i.e., modulus of elasticity (MOE), modulus of rupture (MOR), and compression strength parallel to the grain (CS), of the impregnated wood were determined. Based on these results, wood impregnated using a mixture of kak in WV presented better physical (increased WPG, density, dimensional stability, and crystallinity) and mechanical (increased MOE/MOR and compression strength) properties than wood impregnated with a water solvent or untreated wood. The wood impregnated using WV and water solvent improved the physical and mechanical properties. The density of the wood increased by 44%-58% and 32%-47%, ASE radial-tangential increased by 38%-45%; 15%-28% after 24 h of water immersion, crystallinity increased by 59%-74%; 36%, MOE increased by 46%-57%; 28%-31%, MOR increased by 29%-34%; 14%-27%, and compression strength increased by 40%-76%; 38%-72% values to untreated wood.

• Journal of KIBIM
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• v.13 no.3
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• pp.1-11
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• 2023

In order to use BIM as a tool for improving the productivity and quality of products in the construction industry, a BIM model must be created from the design stage first. Infrastructure structures such as bridges and tunnels are mainly created based on three-dimensional alignment in the generation of BIM models. Especially, generation of BIM models based on three-dimensional linearity has high task difficulty and algorithms for automating BIM modeling for railway infra structures have been suggested in previous studies. This study improved the BIM modeling automation algorithm of railway infrastructures and developed a system based on the algorithm so that it can be easily used by ordinary users. The system was built as an add-in system of Autodesk's Revit. As an improvement first, it is possible to arrange different libraries for each pattern, enabling various uses. In addition, it can be created models of several members with a single process and the system can automatically places structures that are added periodically, such as Rock Bolt and Fore Polling. Finally, 3D length information and volume for each pattern are automatically calculated for more accurate 3D-based volume calculation. This study contributes to increasing user accessibility by building a BIM modeling automation algorithm into a system. The system is expected to improve the efficiency of BIM modeling creation of linear-based infra structures, including railway infrastructure.

• Journal of the Korean GEO-environmental Society
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• v.25 no.5
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• pp.15-19
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• 2024

This study aimed to develop high-efficiency grouting techniques under deep-depth conditions by experimentally verifying the applicability of various injection materials. Particle size analysis and injection model experiments were conducted with Ordinary Portland Cement (OPC) and Micro Cement (MC) to evaluate the injection performance of each material. Using Barton's Cubic Network theory, the rock fracture spacing was calculated for domestic deep-depth standards, specifically below 40 meters underground. The analysis of particle size passability under selected conditions showed that MC could pass through the rock fracture gaps, while OPC could not. According to the results of the injection model experiments using experimental devices and area calculation software, OPC failed in injection due to its larger particle size, whereas MC was capable of injection even under high-viscosity conditions. Based on these findings, the study quantitatively and visually derived the applicability of grouting materials under deep-depth conditions, and high-viscosity MC material is expected to be effective for waterproofing enhancement in deep-depth rock fracture surfaces.

• The Transactions of the Korea Information Processing Society
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• v.13 no.2
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• pp.60-75
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• 2024

The demand of users, who want to focus on the core functionality of their applications without having to manage complex virtual environments in the cloud environment, has created a new computing model called serverless computing. Within the serverless paradigm, resource provisioning and server administration tasks are delegated to cloud services, facilitating application development exclusively focused on program logic. Serverless computing has upgraded the utilization of cloud computing by reducing the burden on cloud service users, and it is expected to become the basic model of cloud computing in the future. A serverless platform is responsible for managing the cloud virtual environment on behalf of users, and it is also responsible for executing serverless functions that compose applications in the cloud environment. Considering the characteristics of serverless computing in which users are billed in proportion to the resources used, the efficiency of the serverless platform is a very important factor for both users and service providers. This paper aims to identify various factors that affect the performance of serverless computing and analyze the latest research trends related to it. Drawing upon the analysis, the future directions for serverless computing that address key challenges and opportunities in serverless computing are proposed.

• The Journal of the Acoustical Society of Korea
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• v.27 no.1
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• pp.18-25
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• 2008

In this paper, new lossless coding method of spectral coefficients for audio codec is proposed. Conventional lossless coder uses Huffman coding utilizing the statistical characteristics of spectral coefficients, but does not provide the high coding efficiency due to its simple structure. To solve this limitation, new lossless coding scheme with better performance is proposed that consists of bit-plane transform and run-length coding. In the proposed scheme, the spectral coefficients are first transformed by bit-plane into 1-D bit-stream with better correlative properties, which is then coded intorun-length and is finally Huffman coded. In addition, the coding performance is further increased by applying the proposed bit-plane coding selectively to each group, after the entire frequency is divided into 3 groups. The performance of proposed coding scheme is measured in terms of theoretical number of bits based on the entropy, and shows at most 6% enhancement compared to that of conventional lossless coder used in AAC audio codec.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.3
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• pp.92-97
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• 2024

To improve the efficiency of water splitting systems for hydrogen production, the high overvoltages of electrochemical reactions caused by catalysts in the oxygen evolution reaction (OER, Oxygen Evolution Reaction) must be reduced. Among them, LDH (Layered Double Hydroxide) compounds containing transition metal such as Ni, are attracting attention as catalyst materials that can replace precious metals such as platinum that are currently used. In this study, nickel foam, an inexpensive metallic porous material, was used as a support, and NiCo LDH (Layered Double Hydroxide) nanocrystals were synthesized through a hydrothermal synthesis process. In addition, changes in the shape, crystal structure, and water decomposition characteristics of the Mo-doped NiCo LDH nanocrystal samples synthesized by doping Mo to improve OER properties were observed.

• Journal of Korean Society for Quality Management
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• v.52 no.1
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• pp.23-42
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• 2024

Purpose: This study aims to investigate the impact of two types of information quality, which are platform-oriented information quality and customer-oriented information quality, on customers' decision-making processes in the Online to offline (O2O) platform environment. Grounded in the product brokering efficiency model, which encompasses screening cost, evaluation cost, and decision quality, a model framework was developed. Furthermore, this study explores how these decision-making processes affect customer loyalty. Methods: Given that food delivery apps are the most widely used O2O service in Korea, this study targeted users of these apps for data analysis. We conducted hypothesis testing through a purposive sampling methodology focusing on food delivery app users. A Partial Least Squares Structural Equation Modeling analysis was conducted to analyze the data. The data collection occurred via an online survey from October to December 2021, with a total of 212 respondents participating. Results: The results of this study revealed the significant role of information quality in helping customers' decision processes while using food delivery apps. Specifically, it was found that platform-oriented information positively influences decision quality, while customer-oriented information significantly affects both the reduction of evaluation cost and the enhancement of decision quality. Additionally, the study indicated that lower evaluation costs and higher decision quality lead to increased platform loyalty. However, a reduction in screening cost did not have a significant impact on platform loyalty. Conclusion: While previous studies have overlooked the existence of two sides, service provider and user, in a platform, this research holds significance in its analysis of how information quality impacts loyalty by utilizing the two kinds of information quality. Practitioners can enhance customer loyalty to the platform by enriching customer-oriented information, thereby reducing customers' evaluation costs and encouraging more loyal usage of the platform.

• Animal Bioscience
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• v.37 no.2
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• pp.184-192
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• 2024

Objective: This study aims to investigate the genetic structure and characteristics of the Angus cattle population in Hungary. The survey was performed with the assistance of the Hungarian Hereford, Angus, Galloway Association (HHAGA). Methods: Genetic parameters of 1,369 animals from 16 Angus herds were analyzed using the genotyping results of 12 microsatellite markers with the aid of PowerMarker, Genalex, GDA-NT2021, and STRUCTURE software. Genotyping of DNA was performed using an automated genetic analyzer. Based on pairwise identity by state values of animals, the Python networkx 2.3 library was used for network analysis of the breed and to identify the central animals. Results: The observed numbers of alleles on the 12 loci under investigation ranged from 11 to 18. The average effective number of alleles was 3.201. The overall expected heterozygosity was 0.659 and the observed heterozygosity was 0.710. Four groups were detected among the 16 Angus herds. The breeders' information validated the grouping results and facilitated the comparison of birth weight, age at first calving, number of calves born and productive lifespan data between the four groups, revealing significant differences. We identified the central animals/herd of the Angus population in Hungary. The match of our group descriptions with the phenotypic data provided by the breeders further underscores the value of cooperation between breeders and researchers. Conclusion: The observation that significant differences in the measured traits occurred among the identified groups paves the way to further enhancement of breeding efficiency. Our findings have the potential to aid the development of new breeding strategies and help breeders keep the Angus populations in Hungary under genetic supervision. Based on our results the efficient use of an upcoming genomic selection can, in some cases, significantly improve birth weight, age at first calving, number of calves born and the productive lifespan of animals.

• Resources Recycling
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• v.33 no.2
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• pp.24-36
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• 2024

The lithium-ion battery recycling process has been classified into direct recycling, hydrometallurgical process, and pyrometallurgical process. The commercial process based on the hydrometallurgical process produces black mass through pretreatment processes consisting of dismantling, crushing and grinding, heat treatment, and beneficiation, and then each metal is recovered by hydrometallurgical processes. Since all lithium-ion battery recycling processes under development conducts hydrometallurgical processes such as leaching, after the pretreatment process, to produce precursor raw materials, this article suggests a classification method according to the pretreatment method of the recycling process. The processes contain sulfation roasting, carbothermic reduction roasting, and alloy manufacturing, and the economic feasibility of the lithium-ion battery recycling process can be enhanced using unused by-products in the pretreatment process.

• Earthquakes and Structures
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• v.26 no.4
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• pp.261-267
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• 2024

With the increase in the exploitation depth of offshore oil and gas, it is possible to control the global buckling of deep-sea pipelines by the snake lay method. Previous studies mainly focused on the analysis of critical buckling force and critical temperature of pipelines under the snake-like laying method, and pipelines often suffer structural failure due to seismic disasters during operation. Therefore, seismic action is a necessary factor in the design and analysis of submarine pipelines. In this paper, the seismic action of steel pipes in the operation stage after global buckling has occurred under the active control method is analyzed. Firstly, we have established a simplified finite element model for the entire process cycle and found that this modeling method is accurate and efficient, solving the problem of difficult convergence of seismic wave and soil coupling in previous solid analysis, and improving the efficiency of calculations. Secondly, through parameter analysis, it was found that under seismic action, the pipe diameter mainly affects the stress amplitude of the pipeline. When the pipe wall thickness increases from 0.05 m to 0.09 m, the critical buckling force increases by 150%, and the maximum axial stress decreases by 56%. In the pipe soil interaction, the greater the soil viscosity, the greater the pipe soil interaction force, the greater the soil constraint on the pipeline, and the safer the pipeline. Finally, the pipeline failure determination formula was obtained through dimensionless analysis and verified, and it was found that the formula was accurate.