• Journal of Korea Water Resources Association
• /
• v.57 no.1
• /
• pp.1-8
• /
• 2024

Persistent droughts due to climate change will intensify water shortage problems in Korea. According to the 1st National Water Management Plan, the shortage of domestic and industrial waters is projected to be 0.07 billion m³/year under a 50-year drought event. A long-term prediction of water demand is essential for effectively responding to water shortage problems. Unlike industrial water, which has a relatively constant monthly usage, domestic water is analyzed on monthly basis due to apparent monthly usage patterns. We analyzed monthly water usage patterns using water usage data from 2017 to 2021 in Chungcheong, South Korea. The monthly water usage rate was calculated by dividing monthly water usage by annual water usage. We also calculated the water distribution rate considering correlations between water usage rate and climate variables. The division method that divided the monthly water usage rate by monthly average temperature resulted in the smallest absolute error. Using the division method with average temperature, we calculated the water distribution rates for the Chungcheong region. Then we predicted future water usage rates in the Chungcheong region by multiplying the average temperature of the SSP5-8.5 scenario and the water distribution rate. As a result, the average of the maximum water usage rate increased from 1.16 to 1.29 and the average of the minimum water usage rate decreased from 0.86 to 0.84, and the first quartile decreased from 0.95 to 0.93 and the third quartile increased from 1.04 to 1.06. Therefore, it is expected that the variability in monthly water usage rates will increase in the future.

• Journal of the Korean earth science society
• /
• v.45 no.2
• /
• pp.136-146
• /
• 2024

This paper introduces the seismic facies classification and mapping of igneous bodies found in the sedimentary sequences of the Yellow Sea shelf area of Korea. In the research area, six extrusive and three intrusive types of igneous bodies were found in the Late Cretaceous, Eocene, Early Miocene, and Quaternary sedimentary sequences of the northeastern, southwestern and southeastern sags of the Gunsan Basin. Extrusive igneous bodies include the following six facies: (1) monogenetic volcano (E.mono) showing cone-shape external geometry with height less than 200 m, which may have originated from a single monogenetic eruption; (2) complex volcano (E.comp) marked by clustered monogenetic cones with height less than 500 m; (3) stratovolcano (E.strato) referring to internally stratified lofty volcanic edifices with height greater than 1 km and diameter more than 15 km; (4) fissure volcanics (E.fissure) marked by high-amplitude and discontinuous reflectors in association with normal faults that cut the acoustic basement; (5) maar-diatreme (E.maar) referring to gentle-sloped low-profile volcanic edifices with less than 2 km-wide vent-shape zones inside; and (6) hydrothermal vents (E.vent) marked by upright pipe-shape or funnel-shape structures disturbing sedimentary sequence with diameter less than 2 km. Intrusive igneous bodies include the following three facies: (1) dike and sill (I.dike/sill) showing variable horizontal, step-wise, or saucer-shaped intrusive geometries; (2) stock (I.stock) marked by pillar- or horn-shaped bodies with a kilometer-wide intrusion diameter; and (3) batholith and laccoliths (I.batho/lac) which refer to gigantic intrusive bodies that broadly deformed the overlying sedimentary sequence.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.19 no.2
• /
• pp.215-235
• /
• 2024

As artificial intelligence (AI) technology is recognized as a key technology that will determine future national competitiveness, competition for AI technology and industry promotion policies in major countries is intensifying. This study aims to present implications for domestic policy making by analyzing the policies of major countries on the start-up of AI companies, which are the basis of the AI industry ecosystem. The top four countries and the EU for the number of new investment attraction companies in the 2023 AI Index announced by the HAI Research Institute at Stanford University in the United States were selected, The United States enacted the National AI Initiative Act (NAIIA) in 2021. Through this law, The US Government is promoting continued leadership in the United States in AI R&D, developing reliable AI systems in the public and private sectors, building an AI system ecosystem across society, and strengthening DB management and access to AI policies conducted by all federal agencies. In the 14th Five-Year (2021-2025) Plan and 2035 Long-term Goals held in 2021, China has specified AI as the first of the seven strategic high-tech technologies, and is developing policies aimed at becoming the No. 1 AI global powerhouse by 2030. The UK is investing in innovative R&D companies through the 'Future Fund Breakthrough' in 2021, and is expanding related investments by preparing national strategies to leap forward as AI leaders, such as the implementation plan of the national AI strategy in 2022. Israel is supporting technology investment in start-up companies centered on the Innovation Agency, and the Innovation Agency is leading mid- to long-term investments of 2 to 15 years and regulatory reforms for new technologies. The EU is strengthening its digital innovation hub network and creating the InvestEU (European Strategic Investment Fund) and AI investment fund to support the use of AI by SMEs. This study aims to contribute to analyzing the policies of major foreign countries in making AI company start-up policies and providing a basis for Korea's strategy search. The limitations of the study are the limitations of the countries to be analyzed and the failure to attempt comparative analysis of the policy environments of the countries under the same conditions.

• Journal of Food Hygiene and Safety
• /
• v.39 no.2
• /
• pp.95-101
• /
• 2024

In this study, we investigated the migration level of items specified in the Korean Standards and Specifications for Utensils, Containers, and Packages (Ministry of Food and Drug Safety Notification) for 50 utensils and hygiene products made of biodegradable resins. Our results revealed that one Polylactide (PLA) baby tableware contained 20 mg/L in consumption of potassium permanganate, exceeding the standard of 10 mg/L or less. In all other samples, formaldehyde, lead (Pb), and arsenic (As) levels could be considered very safe and remained below the standard. Moreover, we tested the PLA baby tablewares (n = 21) for migration into a food simulant (4% v/v acetic acid) upon repeated elution at 100℃ for 30 min or UV irradiation for 2 h. We detected increased formaldehyde and As amounts at the repeated 100℃ treatment for 30 min compared to those upon repeated UV irradiation. However, the migration level was markedly low under both conditions. Furthermore, the Estimated Daily Intake (EDI) calculated on an infant-to-child basis from the formaldehyde and As migration at 100℃ for 30 min in the PLA sample was at the maximum value, i.e., 6.0×10^-4 mg/kg b.w./day and 1.3×10^-1 ㎍/kg b.w./day, corresponding to 0.40% and 10.42% of the Tolerable Daily Intake (TDI, 0.15 mg/kg b.w./day) and Provisional Tolerable Weekly Intake (PTWI, 9.0 ㎍/kg b.w./week), respectively. Therefore, in this study, we confirmed that biodegradable synthetic resins are safe to use for food.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.19 no.2
• /
• pp.109-124
• /
• 2024

The value of platform companies is rapidly increasing, exerting significant influence across industries. Identifying and fostering promising platform companies is crucial for enhancing national competitiveness. Consequently, tailored evaluation standards are necessary for such companies. This study derived investment decision factors specific to platform companies and compared the importance of each factor using Analytic Hierarchy Process (AHP) analysis. Key factors included platform characteristics, finance, entrepreneur (team), market, and product/service attributes. The findings revealed that platform characteristics were deemed the most crucial factor for investors. Specifically, factors such as platform size, ease of value fixation, core participant group, and data value were identified as pertinent for evaluating platform companies. Moreover, analysis distinguished between investors with prior platform investment experience and those without. Significantly, investors with platform investment experience placed greater emphasis on the value of data secured by platform Furthermore, it was observed that investors prioritized future value and growth potential over current value when investing in platform. Notably, founder/team characteristics, typically highly regarded in previous studies, ranked lower in importance in this study, highlighting a shift in focus. The discrepancy between this study's results and prior research on investment decision factors is attributed to the specificity of the questions posed. By focusing on investment decision factors for platform startups rather than generic startup inquiries, investor responses aligned more closely with platform-focused considerations. Given the burgeoning venture investment landscape, there's a growing need for detailed research on startups within specific sectors like IT, travel, and biotech. This approach can replace extensive research covering all startup types to identify investment decision factors suited to the characteristics of each individual industry.

• Journal of Mushroom
• /
• v.22 no.2
• /
• pp.60-66
• /
• 2024

This study was conducted to selection and investigate appropriate conditions for mass production of antagonistic microbes to control cobweb disease caused by Cladobotryum mycophilum. A grampositive bacterium was isolated from spent substrate of Agaricus bisporus and showed significant antagonistic activity against Cladobotryum mycophilum. The bacterium was identified as Bacillus altitudinis. based on the cultural, biochemical and physiological characteristics, and 16S rRNA sequence. The isolate is saprophytic, but not parasitic nor pathogenic to cultivated mushroom whereas it showed strong inhibitory effects against C. mycophilum cells in vitro. The control efficacy of B. altitudinis HC7 against cobweb disease of C. mycophilum was up to 78.2% on Agaricus bisporus. The suppressive bacterium may be useful for the development of biocontrol system. To define the appropriate conditions for the mass production of the Bacillus altitudinis HC7, we have investigated appropriate culture conditions and effects of various nutrient source on the bacterial growth. The appropriate initial pH and temperature were determined as pH 6.0 and 30℃, respectively. The appropriate concentration of medium elements for the growth of pathogen inhibitor bacterium(Bacillus altitudinis HC7) was determined as follows: 3.0% soluble startch, 10% soytone, 1.0% (NH₄)₂HPO₄, 1.0 mmol KCl, and 0.5% L-asparagine.

• Bangmulgwan gwa yeongu (The National Museum of Korea Journal)
• /
• v.1
• /
• pp.174-197
• /
• 2024

Personal ornaments made from precious metals that have been excavated from tombs dating to the Maripgan period (4th-6th century) of the Silla Kingdom are a major subject of analysis in the study of gender and hierarchy among the tomb occupants. Nonetheless, bracelets had been neglected until Ha Daeryong's recent research on determining gender through bracelets attracted attention. Accordingly, an examination and organization of the fundamental elements of Silla bracelets was needed. In response, this paper examines their physical characteristics, appearance, changes over time, and related wearing practices. The data for this study is derived from 176 bracelets, mostly made from silver or gold. Copper and glass bracelets are also included. Many of them were cast in a single-use earthen mold. Even the notched and protruding designs were created by casting rather than carving. Glass bracelets and bracelets with dragon designs were made using molds with round cavities. Excluding those produced using metal sheets, the rest of the bracelets are thought to have been cast in a mold with a long-string-shaped cavity and then bent round. After being bent, the two ends were either soldered together (closed type) or left open (open type). As demonstrated in the study by Lee Hansang, Silla bracelets evolved from plain rounded rod-shaped bracelets, such as the one excavated from the Northern Mound of Hwangnamdaechong Tomb, to versions with notched designs, and eventually to those with protruding designs, which gained popularity by the sixth century. The precedents of plain rounded rod-shaped bracelets are presumed to have been thin rod-shaped bracelets from the Proto-Three Kingdoms period. Bracelets need to be fit to the wrists so that they do not slip off easily when worn. The open type design was the preferable way to achieve this. Moreover, given the ductility of gold, silver, and copper, it seems that it would have been possible to stretch or deform them. In the end, I concluded that even if a bracelet is too small to pass man's hand, the open type could have been worn. Furthermore, if a closed-type bracelet were pressed into an oval shape, it would not be impossible for a man to put it on. When bracelets are divided according to their degree of deformability into type A (the open type) through type D, which is almost impossible to deform, type A is commonly found with wearers of thin hollow earrings, and types C and D (which are difficult to deform) are not found with wearers of thin hollow earrings, but only with wearers of thick hollow earrings. Therefore, it can be seen that men were allowed to wear bracelets, and the existing studies that differentiate between men and women based on the wearing of thin hollow earrings, thick hollow earrings, and swords remain valid.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.78-87
• /
• 2023

This study was conducted to evaluate the effect of different 1-methylcyclopropene (1-MCP) concentrations on fruit quality of small-sized RubyS apples during cold storage. After harvesting, the fruits were treated with 1-MCP at 0.5 or 1 µL/L concentrations and, subsequently, stored at 0℃ for 6 months. After 6 months, the flesh firmness of untreated fruits, which was 85.4 N at harvest, had gradually decreased to 46.5 N; however, that of 1-MCP-treated fruits was maintained at 59.1 and 59.5 N. Titratable acidity (TA) of untreated fruits had also decreased from 0.42 to 0.24%, whereas that of 1-MCP-treated fruits was maintained at 0.26 and 0.27%. Soluble solids content (SSC) did not differ in all fruits. However, the 1-MCP-treated fruits had lower levels of SSC/TA ratio than untreated fruits. Moreover, after 6 months, the ethylene production had increased to 47.0 µL/kg/h in the untreated fruits, whereas 1-MCP blocked the ethylene production at 1.4 and 1.7 µL/kg/h. The weight loss and peel color variables remained unaffected by 1-MCP treatments. Thus, these results indicated that, for RubyS apples, the storability was only 2 months at 0℃ without treatment, which can be extended to 6 months with 1-MCP treatments. The application of 1-MCP at 0.5 µL/L concentration is effectively and economically sufficient to maintain the quality of RubyS apples.

• Food Science and Preservation
• /
• v.31 no.1
• /
• pp.173-182
• /
• 2024

This study was designed to compare the effects on antioxidant, whitening, and anti-wrinkle improvement of 60% ethanol extracts from Trigonotis radicans var. sericea (TR) and Lactobacillus brevis-fermented T. radicans var. sericea (FTR). The total phenolics contents of TR was 18.6 mg/g, and FTR was 18.2 mg/g. The HPLC analysis confirmed more phenolic compounds were produced in FTR by bioconversion than in TR. The FTR showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than TR. The results of the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation decolorization assay, FTR and TR showed higher activity than BHT (positive control). The FTR (1.21-1.29 PF) showed higher antioxidant protection factor (PF) activity than the TR (1.15-1.22 PF) and showed higher tyrosinase, collagenase and elastase inhibitory activities. This results showed L. brevis -fermentation of Trigonotis radicans var. sericea changed the composition profile and has effects on antioxidant, whitening and anti-wrinkle improvement.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.109-121
• /
• 2023

This study was conducted to evaluate vitamin D intake of Koreans in a total diet study (TDS) and to determine the effect of irradiation on vitamin D synthesis in mushrooms. For analysis, sample were saponified and extracted with hexane, and vitamin D was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on the validation results, the recovery of the National Institute of Standards and Technology (NIST) standard reference sample (SRM) 1849a was 96.7% and the z-score of -1.6 was obtained by the Food Analysis Performance Assessment Scheme (FAPAS) proficiency test (PT) 21115. Vitamin D₂ was not detected in any samples, and the highest level of vitamin D₃ was detected in mackerel and anchovies ranging from 24.2 to 120.2 ㎍/kg. The mean daily intake of vitamin D was 0.99 ㎍/day, as estimated from the vitamin D contents of the analyzed foods and their corresponding intake. The adequate intake (AI) of vitamin D based on the Dietary reference intakes for Koreans provided by the Ministry of Health and Welfare is 5-15 ㎍/day for Koreans aged 6 to 75 years. Compared with this AI, vitamin D intake of Koreans estimated in this study was inadequate. For that, the increased vitamin D content in ultraviolet (UV)/sun light irradiated mushrooms warrants further research to increase vitamin D intake of Koreans through diet.