• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.8
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• pp.86-92
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• 2021

As interest and demand for high value-added industries, including the global automobile and aerospace industries, have increased recently, demand for line centers with excellent performance that can respond to the production system for producing high value-added products is also rapidly increasing. A line center improves productivity based on the installed area using a multi-spindle compared to a conventional machining center. However, as the number of spindles increases, the weight increases and results in structural problems owing to the heat and vibration generated by each spindle. Therefore, it is necessary to improve machining precision through the structural improvement of the line center. This study presents research on the stabilization design of the line center through structural stability analysis through structural analysis to develop a compact multi-axis line center. An optimization model of the line center has been proposed to improve the processing precision and increase the rigidity by performing weight reduction based on the structural analysis results.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.7
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• pp.393-402
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• 2021

This study aims to examine whether symmetric effects or asymmetric effects of exchange rates exist in determining the money demand in Indonesia. Simple-sum money and Divisia money were included in different models for comparison due to the financial developments in Indonesia. This study uses time-series data from 1996Q1 to 2019Q4 for the estimation. The nonlinear autoregressive distributed lag (NARDL) model is utilized to verify the asymmetric effects of exchange rates on money demand. The Augmented Dickey-Fuller and Phillips-Perron unit root tests were performed to verify the order of integration of the variables. The findings of this study revealed that the exchange rate is one of the most important determinants of money demand in Indonesia and the effect is asymmetric. The findings further indicated that money demand function, which incorporates Divisia monetary aggregate is parsimonious. Monetary targets such as money supply and interest rates are critical for monetary policy conduct to achieve inflation levels set by government. As the adoption of an inflation targeting framework needs to be in keeping with the flexible exchange rate system, the asymmetric effect of exchange rate changes can be used in exchange rate policy conduct to achieve financial system and price stability.

• The Korean Journal of Food & Health Convergence
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• v.7 no.3
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• pp.41-50
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• 2021

The purpose of this study is to analyze the work value factors regarded as important by the culinary-related graduates in their 20s, and also to analyze the effects of work value factors on the life satisfaction. To achieve this purpose, this study analyzed the data of 155 graduates from departments including 'culinary arts', 'foodservice', and 'confectionery' among the college graduates in their 20s who participated in GOMS 2018. The results of analysis are as follows. First, the new generation majors in culinary arts showed the high importance of their aptitude and interest, employment stability, earned income. Second, in relation to the major field, the male graduates majored in culinary arts more highly perceived the importance than the female graduates majored in culinary arts. On the other hand, regarding the social reputation of job and work duty, the female graduates majored in culinary arts more highly perceived the importance than the male graduates majored in culinary arts. Third, the developmental value factor of work value had positive effects on the life satisfaction. Thus, the career-related staffs or professors of college should provide the career guidance by considering gender when the majors in culinary arts transit to the labor market after graduation.

• Clean Technology
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• v.26 no.4
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• pp.257-262
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• 2020

Two-dimensional (2D) metal organic framework (MOF) nanosheets (NSs) have recently gained considerable interest owing to their structural advantages, such as large surface area and exposed active sites. Two different types of 2D MOF NSs have been reported, including inherently layered MOFs and non-layered ones. Although several studies on inherently layered 2D MOFs have been reported, non-layered 2D MOFs have been rarely studied. This may be because the non-layered MOFs have a strong preference to form three-dimensionality intrinsically. Furthermore, the non-layered MOFs are typically synthesized in the presence of the surfactant or modulator, and thus developing facile and clean synthetic routes is highly pursued. In this study, a facile and clean synthetic methodology to grow non-layered 2D cobalt-based zeolitic imidazolate framework (ZIF-67) NSs is suggested, without using any surfactant and modulator at room temperature. This is achieved by directly converting ultrathin α-Co(OH)2 layered hydroxide salt (LHS) NSs into non-layered 2D ZIF-67 NSs. The comprehensive characterizations were conducted to elucidate the conversion mechanism, structural information, thermal stability, and chemical composition of the non-layered 2D ZIF-67. This facile and clean approach could produce a variety of non-layered 2D MOF NS families to extend potential applications of MOF materials.

• Journal of Information Technology Services
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• v.20 no.5
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• pp.177-187
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• 2021

The global economy has been very difficult due to the recent impact of COVID-19. Korea is also pushing for strong quarantine policies such as K- quarantine and social distancing, but the economy is hardly recovering. In particular, the economic situation began to change rapidly depending on the export and domestic market, the public's interest in the economy increased, and companies became more sensitive. In order to estimate this rapidly changing economic situation, major advanced countries have also developed models that can periodically monitor the economy at the government level. Through this, by periodically reporting the economic trends, the public and companies can be aware of the economic trends to some extent. This study analyzed the cases of weekly business trends in advanced countries and developed a model of weekly economic activity suitable for Korea. To verify this, indices closely related to the economy such as mobility, industrial activity, face-to-face consumption, and psychology were discovered and estimated. As a result of the study, the weekly economic activity index was judged to be very useful in capturing short-term real economic activity. In the future, in order to secure the robustness and stability of the index and to increase the reflection of reality, model improvement and parameter estimation should be performed regularly.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.226-236
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• 2021

The purpose of this study is to analyze the type of latent profile for general high school students' subject selection criteria and to identify the characteristics of the latent class. The survey data of 1072 general high school students (male; 648, female; 424) in G city, Jeollabuk-do and the scale composed of 8 sub-factors: 'SAT orientation', 'academic achievement', 'ability orientation', 'pursuit of interest', 'teacher orientation', 'career development', 'others' recommendation', and 'subject availability' were used for latent profile analysis and cross-analysis between potential layers. As a result of the analysis, high school students' perceptions of subject selection were classified into four latent profiles. The four groups were named 'High Perception Type', 'Low Perception Type', 'Self-Directed Type', and 'Stability-Oriented Type' according to their types. It was found that there was a difference between the latent classes in the importance and performance level of the subject selection criteria. These results can help identify the subject selection tendencies of latent groups in the operation of the 2015 revised curriculum and the 2025 high school credit system that emphasizes the student-centered course selection curriculum and they can also provide customized course selection guidance considering individual differences.

• Corrosion Science and Technology
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• v.21 no.4
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• pp.300-313
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• 2022

Interest in polymer electrolyte fuel cell is growing to replace fossil fuels. In particular, in order to reduce the cost and volume of the fuel cell, research on a metallic bipolar plate is being actively conducted. In this research, investigated the effects of temperature and chloride concentration on the electrochemical characteristics and damage behavior of 316L stainless steel in an accelerated solution simulating the cathodic operating condition of PEMFC(Polymer electrolyte membrane fuel cell). As a result of the experiments, the corrosion current density, damage size, and surface roughness increased as the temperature and chloride concentration increased. In particular, the temperature had a significant effect on the stability of the oxide film of 316L stainless steel. In addition, it was described that the growth of the pit was affected by the chloride concentration rather than the temperature. As a result of calculating the corrosion tendency to compare the pitting corrosion rate and the uniform corrosion rate, the uniform corrosion tendency became larger as the temperature increased. And the effects of chloride concentration on corrosion tendency was different according to temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.s01
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• pp.64-85
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• 1988

Peanut seeds are characterized by high oils and proteins with good quality, and are utilized as an edible oil source and a protein-rich food products. The end products, being peanut butter, salted seed, confections, roasting stock and other by-products are favored in world-wide because of their unique roasted peanut flavor. As with many other foods, interest in the composition and chemistry of peanut is largely a result of thier use as human food. Thus, a more complete knowledge of thier chemical and food quality and flavor properties is desired. Literatures are reviewed mainly focucing on the physicochemical properties and nutritional quality of oil, protein and flavor in peanuts. Chemical properties of protein and oil, and volatile flavor component in peanut seeds are studied extensively in view point of chemical and food nutritional value. But in crop base, the synthesis and genetic studies of the chemicals could not provide valuable informations on the breeding for quality improvement. Some essential amino acids are limiting in peanut seeds and the tocopherols are very important in oil stability and for dietary adequacy ratio in high linoleic acid peanut oil, but it is thought to be quite difficult to improve by breeding technique as their lack information of gene actions. However, the selections of high protein and oil, and some essential amino acids and linoleic acid rich genotypes could be helpful for the quality improving. Research studies are also needed to elucidate the relationships between flavor components and consumer perception of peanut flavor.

• Journal of Powder Materials
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• v.30 no.4
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• pp.310-317
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• 2023

Small-film-type ion sensors are garnering considerable interest in the fields of wearable healthcare and home-based monitoring systems. The performance of these sensors primarily relies on electrode capacitance, often employing nanocomposite materials composed of nano- and sub-micrometer particles. Traditional techniques for enhancing capacitance involve the creation of nanoparticles on film electrodes, which require cost-intensive and complex chemical synthesis processes, followed by additional coating optimization. In this study, we introduce a simple one-step electrochemical method for fabricating gold nanoparticles on a carbon nanotube (Au NP-CNT) electrode surface through cyclic voltammetry deposition. Furthermore, we assess the improvement in capacitance by distinguishing between the electrical double-layer capacitance and diffusion-controlled capacitance, thereby clarifying the principles underpinning the material design. The Au NP-CNT electrode maintains its stability and sensitivity for up to 50 d, signifying its potential for advanced ion sensing. Additionally, integration with a mobile wireless data system highlights the versatility of the sensor for health applications.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.197-209
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• 2022

Extracellular vesicles (EVs) are nanosized vesicles secreted from cells into the extracellular environment and are composed of a lipid bilayer that contains cargos with biological activity, such as lipids, proteins, mRNAs, and noncoding microRNAs (miRNAs). Due to their biological activity and their role in cell-to-cell communication, interest in EVs is rapidly increasing. Bovine milk is a food consumed by people of all ages around the world that contains not only a significant amount of nutrients but also EVs. Milk-derived EVs also exhibit biological activity similar to other source-derived EVs, and studies on bovine milk EVs have been conducted in various research fields regarding sufficient milk production. In particular, not only are the effects of milk EVs themselves being studied, but the possibility of using them as drug carriers or biomarkers is also being studied. In this review, the characteristics and cargo of milk EVs are summarized, as well as their uptake and stability, efficacy and biological effects as carriers, and future research directions are presented.