• Journal of Koreanology Reviews
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• v.1 no.1
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• pp.25-29
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• 2022

Economic growth is one of the significant benchmarks determining a country's sustainable growth. Before WWII, most countries perceived their priority in terms of military strength as they dedicated most of their efforts and resources to creating weapons of mass destruction. The current research aims to establish some of the significant factors that may have contributed to the sustainable and progressive economic growth of South Korea within the 60-year timeframe. Multiple prior studies have attributed the economic growth in South Korea to policy reforms that opened the country to foreign markets. The outstanding increase in the percentage of exports stands out as an indication of the improvement in the quality of goods produced in the country. Finally, in recent years, China has dedicated more resources to research and developments as a strategy to improve innovation within the country and its overall economic growth. Other issues of concern likely to undermine the prospects of the country's economic growth include the limited geographical size, aging population, and limited natural resources. As such, South Korea needs to emphasize innovation and improve the business environment as its main strategy for sustainable economic growth in the future to maintain its continuous economic miracle.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.817-828
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• 2023

Deteriorating soil physical properties and increasing soil pathogens due to the continuous cultivation of field crops are the leading causes of productivity deterioration. Crop rotation, soil heat treatment, and chemical control are used as pest control methods; however, each has limitations in wide application to domestic agriculture. In particular, chemical control requires improvement due to direct exposure to sterilizing solution, odor, and high-intensity work. To improve the overall domestic agricultural environment, the problems of time and cost, such as field maintenance and cultivation scale, must be addressed; therefore, mechanization technology for chemical control must be secured to derive improvement effects in a short period. Most related studies are focused on the control effect of the DMDS (dimethyl disulfide) sterilizer, and research on the performance of the sterilization spray device has been conducted after its introduction in Korea, but research on the corrosion suitability of the material is lacking. This study conducted a corrosion test to secure the corrosion resistance of a soil sterilizer injection pump, and a mechanical failure mode by corrosion by the material was established. The corrosion test comprised operation and neglect tests in which the sterilizing solution was circulated in the pump and remained in the pump, respectively. As a result of the corrosion test, damage occurred due to the weakening of the mechanical strength of the graphite material, and corrosion resistance to aluminum, stainless steel, fluororubber, and PPS (polyphenylene sulfide) materials was confirmed.

• The Journal of Industrial Distribution & Business
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• v.15 no.5
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• pp.29-37
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• 2024

Purpose: Numerous prior researchers have identified only that sustainable management of ESG factors promotes business value creation and shapes enhanced innovation performance. This study aims to determine the positive relationships between ESG management and economic development, focusing on the mutual benefits and risks and the various stakeholders involved in managing change. Research design, data and methodology: This study selected the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement as a key methodology. Literature search used the following databases: Web of Science, Scopus, and Google Scholar. The quality assessment criteria for selected prior studies ranged from issues like design, sample size and the representativeness of the subjects, validity of measurements, and analytical strength. Results: The findings of this study indicates that there are four critical solutions for economic development triggers using ESG strategy, such as (1) ESG and Innovation-Driven Growth, (2) ESG and Human Capital Development, (3) ESG and Operational Efficiency, (4) ESG and Market Opportunities. This study insists that public-private partnerships are critical for enhancing sustainable economic development and meeting the needs of society. Conclusions: It is, therefore, important for governments and policymakers to play a critical role in setting the proper framework that allows for the uptake of ESG and an enabling environment for sustainable economic development.

• Corrosion Science and Technology
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• v.23 no.1
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• pp.11-19
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• 2024

A Fe-Ni Bainitic steel as a weathering steel application was developed by combining its excellent mechanical properties and corrosion resistance in maritime environments. Nickel concentration (0.4-3 wt%) and inverted austempering multi-step (IAM) process were primary determinants of the microstructure of the Fe-Ni Bainitic steel. The initial austempering steel was performed at 300 ℃ for 600 seconds to obtain a partly bainitic transformation. The steel was heated again for 1800 s at 450 ℃. The microstructure was comprised of ferrite, a blocky martensite/austenite island, and a homogeneous lath-shape bainite structure with widths ranging from 4.67 to 6.89 ㎛. The maximum strength, 1480 MPa, was obtained with 3 wt% nickel. In this study, corrosion behavior was investigated utilizing potentiodynamic and electrochemical impedance spectroscopy (EIS) tests. A higher nickel content in Fe-Ni Bainitic steel refined the grain size, improved the bainite fraction, lowered the corrosion rate to 0.0257 mmpy, and increased the charge transfer of film resistance to 1369 Ω.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.98-120
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• 2007

This study analyzed the linkage relations of technological innovation between Daedeok Innopolis and other seven innovative clusters in industrial complexes which have played important roles as innovative centers in Korea. To begin with, we selected major technologies of Daedeok Innopolis for which the linkage with other clusters of innovative activities was analyzed quantitatively and graphically with association matrices, network analysis and dendrogram. Based on this network analysis, we analyzed the technological linkage among clusters and found the direction and strength of technological cooperation of the Daedeok Innopolis with other innovative clusters by technology field. This study analyzed the technological network between the Daedeok Innopolis and other clusters on 6 technology fields in which Daedeok has innovative capabilities. In the analysis was measured the centrality of Daedeok compared with that of other clusters in areas where Daedeok is relatively active in innovative activities. As a result, Daedeok showed the highest centrality with the active innovative activities. Except Daedeok, Banwol-Sihwa cluster showed the highest centrality in all of the 6 technology fields. Putting all the centrality of each innovative cluster and the linkage relations of Daedeok Innopolis together, it need to consider the following policy directions to strengthen the innovative linkage with other clusters. In Daedeok's main technology areas, it needs to increase the regional linkage with the clusters with relatively high centrality and relatively low linkage with Daedeok. For Changwon, Wonju and Gunsan with which Daedeok has the relatively low innovative linkage, it need to examine a new policy to improve the linkage with technologies related with the industry other clusters are nurturing. When Daedeok formulates a plan to cooperate with other clusters, it does not only have to consider the linkage relations of technological innovation analyzed in this study and but also has to examine the cooperative strategies from the comprehensive point of view considering every aspect of their strategic industries, supportive policies, industrial base and competitiveness. This study analyzed the linkage relations between regions based on the network analysis of patents only by co-invention. Consequently, it did not examine the factors inducing the co-invention, which is a limitation of the study and is to be investigated in the future. Also, the exploratory analysis on determinants of linkage intensity and the strategies to get synergy effects through solidified linkage will be the issues of further study.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.3
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• pp.271-277
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• 2013

Inconel 718 super alloy was aging heat treated at the temperature range from $675^{\circ}C$ to $785^{\circ}C$ for 5~40 hours after solution annealing at $1025^{\circ}C$ for 1 hour. The aging treated specimens were investigated microstructure, mechanical properties and thermal expansion/contraction. Precipitates appeared for a long time aging treatment were niobium carbide and also ${\gamma}^{\prime}$ phase. For the aging treatment time of 10 hours, the changes in strength and hardness with increasing aging treatment temperature showed the maximum value at the temperature of $725^{\circ}C$. This maximum value is to be related with the precipitation of ${\gamma}^{\prime}$ and ${\gamma}^{{\prime}{\prime}}$ phases. The decrease in strength, elongation and hardness during long time aging at $725^{\circ}C$ were thought to be induced from the coarsening of the grain size and the transformation of ${\gamma}^{{\prime}{\prime}}$ phase to ${\gamma}^{\prime}$ phase. For the specimens treated for 10 hours, impact energy showed constant value of ~105 J with increasing the aging temperature, however this value continuously decreased with elapsing time at the aging temperature of $725^{\circ}C$. It was found that the decrease in impact value was induced from the coarsening of grain size and the carbide coarsening. The coefficient of thermal expansion of aging treated Inconel 718 alloy increased with raising test temperature, and the coefficient was appeared $11.57{\sim}12.09{\mu}m/m{\cdot}^{\circ}C$ and $14.28{\sim}14.39{\mu}m/m{\cdot}^{\circ}C$, respectively, after heating to $150^{\circ}C$ and $450^{\circ}C$.

• Transactions of Materials Processing
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• v.24 no.1
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• pp.37-43
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• 2015

The purpose of the current study is to improve the clinching joint strength of aluminum and fiber metal laminates (FMLs) comprised of three layers. The joining of FML and Al 5052 by a conventional clinching joint has some disadvantages such as necking of the upper sheet, lack of interlocking, defects caused by the vertical load, and especially loss of strength of the composite material due to the low ductility. In the current study, a tapered-hole clinching method is proposed as an alternative for the joining of Al 5052 and FMLs. A hole with a tapered shape is formed before the joining process. The design parameters were evaluated using the Taguchi method for the geometry of the tapered hole in order to determine the maximum separation load. The diameter of the punch corner, clearance, punch stroke and the tapered length were used as the main variables in the Taguchi method. In conclusion, the contribution ratio for each of the fours variable examined was 35.07%, 22.44%, 21.32% and 14.11%, respectively. In addition, the appropriate combination of the design parameters can make a 5% improvement in the vertical direction joint strength.

• Structural Engineering and Mechanics
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• v.39 no.2
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• pp.241-266
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• 2011

The Self Compacting Concrete, SCC is the new generation type of concrete which is not needed to be compacted by vibrator and it will be compacted by its own weight. Since SCC is a new innovation and also the high strength self compacting concrete, HSSCC behavior is like a brittle material, therefore, understanding the strength effect on the serviceability performance of reinforced self compacting concretes is critical. For this aim, first the normal and high strength self compacting concrete, NSSCC and HSSCC was designed. Then, the serviceability performance of reinforced connections consisting of NSSCC and HSSCC were investigated. Twelve reinforced concrete connections (L = 3 m, b = 0.15 m, h = 0.3 m) were simulated, by this concretes, the maximum and minimum reinforcement ratios ${\rho}$ and ${\rho}^{\prime}$ (percentage of tensile and compressive steel reinforcement) are in accordance with the provision of the ACI-05 for conventional RC structures. This study was limited to the case of bending without axial load, utilizing simple connections loaded at mid span through a stub (b = 0.15 m, h = 0.3 m, L = 0.3 m) to simulate a beam-column connection. During the test, concrete and steel strains, deflections and crack widths were measured at different locations along each member. Based on the experimental readings and observations, the cracked moment of inertia ($I_{cr}$) of members was determined and the results were compared with some selective theoretical methods. Also, the flexural crack widths of the members were measured and the applicability for conventional vibrated concrete, as for ACI, BS and CSA code, was verified for SCCs members tested. A comparison between two Codes (ACI and CSA) for the theoretical values cracking moment is indicate that, irrespective of the concrete strength, for the specimens reported, the prediction values of two codes are almost equale. The experimental cracked moment of inertia $(I_{cr})_{\exp}$ is lower than its theoretical $(I_{cr})_{th}$ values, and therefore theoretically it is overestimated. Also, a general conclusion is that, by increasing the percentage of ${\rho}$, the value of $I_{cr}$ is increased.

• Transactions on Electrical and Electronic Materials
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• v.16 no.2
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• pp.82-85
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• 2015

Mechanical and electrical properties of epoxy/silica microcomposites were investigated. The cycloaliphatic- type epoxy resin was diglycidyl 1,2-cyclohexanedicarboxylate and the curing agent was of an anhydride type. To measure the glass transition temperature (Tg), dynamic differential scanning calorimetry (DSC) analysis was carried out, and tensile and flexural tests were performed using a universal testing machine (UTM). Electrical breakdown strength, the most important property for electrical insulation materials, and insulation breakdown strength were also tested. The microcomposite with 60 wt% microsilica showed maximum values in mechanical and electrical properties.

• Transactions of Materials Processing
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• v.22 no.2
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• pp.86-92
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• 2013

When stamping ultra-high-strength steel (UHSS), the phenomenon of galling, which corresponds to a transfer of material from the sheet to the tool surface, occurs because of the high contact pressure between tool and workpiece. Galling leads to increased friction, unstable interface conditions, scratches on the sheet and the tool surfaces and, eventually, premature tool surface failures. Therefore, a simple and accurate evaluation method for tool scratching is necessary for the selection of tool material and coating, as well as for a better optimization of process conditions such as blank holder force and die radius. In this study, the pin-on-disc (PODT) and pin-on-flat surface (POFST) tests are conducted to quantitatively evaluate scratch-related tool life for stamping of UHSS. The variation of the friction coefficient is used as an indicator of scratch resulted from galling. The U-channel ironing test (UCIT) is performed in order to validate the results of the friction tests. This study shows that the POFST test provides a good quantitative estimation of tool life based on the occurrence of scratch.