• Journal of Animal Science and Technology
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• 제65권1호
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• pp.16-31
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• 2023

Cultured meat is a potential sustainable food generated by the in vitro myogenesis of muscle satellite (stem) cells (MSCs). The self-renewal and differentiation properties of MSCs are of primary interest for cultured meat production. MSC proliferation and differentiation are influenced by a variety of growth factors such as insulin-like growth factors (IGF-1 and IGF-2), transforming growth factor beta (TGF-β), fibroblast growth factors (FGF-2 and FGF-21), platelet-derived growth factor (PDGF) and hepatocyte growth factor (HGF) and by hormones like insulin, testosterone, glucocorticoids, and thyroid hormones. In this review, we investigated the roles of growth factors and hormones during cultured meat production because these factors provide signals for MSC growth and structural stability. The aim of this article is to provide the important idea about different growth factors such as FGF (enhance the cell proliferation and differentiation), IGF-1 (increase the number of myoblasts), PDGF (myoblast proliferation), TGF-β1 (muscle repair) and hormones such as insulin (cell survival and growth), testosterone (muscle fiber size), dexamethasone (myoblast proliferation and differentiation), and thyroid hormones (amount and diameter of muscle fibers and determine the usual pattern of fiber distributions) as media components during myogenesis for cultured meat production.

• Progress in Superconductivity
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• 제4권1호
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• pp.1-9
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• 2002

Transferring single flux quanta across a Josephson junction at an exactly determined rate has made highly precise voltage measurements possible. Making use of self-shunted Nb-based SINIS junctions, programmable fast-switching DC voltage standards with output voltages of up to 10 V were produced. This development is now extended from fundamental DC measurements to the precise determination of AC voltages with arbitrary waveforms. Integrated RSFQ circuits will help to replace expensive semiconductor devices for frequency control and signal coding. Easy-to-handle AC and inexpensive quantum voltmeters of fundamental accuracy would be of interest to industry. In analogy to the development in the flux regime, metallic nanocircuits comprising small-area tunnel junctions and providing the coherent transport of single electrons might play an important role in quantum current metrology. By precise counting of single charges these circuits allow prototypes of quantum standards for electric current and capacitance to be realised. Replacing single electron devices by single Cooper pair circuits, the charge transfer rates and thus the quantum currents could be significantly increased. Recently, the principles of the gate-controlled transfer of individual Cooper pairs in superconducting A1 devices in different electromagnetic environments were demonstrated. The characteristics of these quantum coherent circuits can be improved by replacing the small aluminum tunnel Junctions by niobium junctions. Due to the higher value of the superconducting energy gap ($\Delta_{Nb}$ ＝ $7\Delta_{Al}$), the characteristic energy and the frequency scales for Nb devices are substantially extended as compared to A1 devices. Although the fabrication of small Nb junctions presents a real challenge, the Nb-based metrological devices will be faster and more accurate in operation. Moreover, the Nb-based Cooper pair electrometer could be coupled to an Nb single Cooper pair qubit which can be beneficial for both, the stability of the qubit and its readout with a large signal-to-noise ratio..

• 대한한방부인과학회지
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• 제22권1호
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• pp.243-262
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• 2009

Purpose: In recent, there have been a lot of studies exploring effective methods to relieve pains and sufferings of women delivered of child. The ultimate purpose of the study is to investigate the developmental trends of the complementary alternative medicine(CAM, hereafter), which has increasingly obtained the approval of the women and therefore established the academic foundations in effect. Methods: Systematic analysis with diverse written materials concerning the complementary alternative medicine was carried out. For the analysis, materials related with the issue of the study were searched at the Pubmed, the Korea Education & Research Information Service. Results: 1. One of the results of interest is the verification of the fact in that diverse complementary therapies are nowadays substantially applied to the many situations of delivery and childbirth. 2. The results showed clearly that CAM has several prominent influences on the whole process of the delivery: from the reduce of the pains and the time for delivery, to increasement of the satisfactional level of the mother. 3. According to the results, the emphasis of CAM is mainly placed not just on the relieving of pains and sufferings of the mothers, but on empowering them to face them with self-confidence. 4. The results of the study suggest strongly that the professionals should provide mothers with useful information and methods to help them to get through the pains during the delivery period. Conclusion: The result of the study is to suggest persuasively that more systematic attention should be paid to the researches exploring effectiveness and stability and safety of CAM.

• 디지털융복합연구
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• 제20권1호
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• pp.41-46
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• 2022

선진국의 자본시장과 비교해 중국 자본시장의 주요한 문제점으로 주가급락 사태를 꼽을 수 있다. 따라서 주가급락 위험을 줄일 수 있는 요인에 관한 연구는 상당히 중요한 의미가 있다. 본 연구는 최대주주의 보유주식 비율에 초점을 두고, 지분율이 증가함에 따라 기업의 경영자를 감독할 유인이 더 높아지는 지와 이를 통해 경영자의 기회주의적 행동이 감소 되는지 검토해보고자 한다. 이를 위해 2009년부터 2019년까지의 중국 상장기업 자료를 수집하고, 실증분석을 통해 최대주주 지분율과 상장기업의 주가급락 위험 간의 관계를 분석하였다. 연구결과에 따르면 국유기업의 최대주주 지분율이 높을수록 기업의 주가급락 위험이 유의하게 낮아진 것으로 나타났다. 이는 국유기업의 최대주주는 정부 기관으로서 경영자에 대한 정부의 감독이 비국유기업의 최대주주보다 더 엄격하기 때문으로 보인다. 본 연구는 최대주주의 지분율이 높을수록 경영자의 기회주의 행위가 감소하며, 기업과 주주 간의 정보비대칭이 완화될 수 있음을 시사한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.148-149
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• 2020

Currently, the most commonly used EPS insulation material has been mainly used because its ease of adhesion with concrete. However, due to poor adhesion with wallpaper, separate adhesion needs to be strengthened and there are cases of breakage or grooves in the process of dismantling the mold. The biggest problem is that when a fire breaks out, various harmful substances are present and highly flammable. Cork used in this study is a truly eco-friendly building material that is taken from between the outer and inner bark of cork trees and does not damage the wood. Also, it is a porous material that is made up of countless cells and contains an air gap between the cells. It is very light in weight between 0.06 and 0.07 and has excellent insulation with a heat conductivity of 0.04W/mK. In addition, it has high stability in the topic of conversation because it does not produce harmful gas when burned and has self-sustaining properties. However, research on cork, an eco-friendly building material with excellent performance to date, is scarce Therefore, we encourage existing scholars to raise interest in new eco-friendly building materials through this study. It also aims to manufacture insulation boards with new inorganic properties using the low weight and heat conductivity held by the cork.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.131-131
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• 2021

Deep learning models, especially those based on long short-term memory (LSTM), have presented their superiority in addressing time series data issues recently. This study aims to comprehensively evaluate the performance of deep learning models that belong to the supervised learning category in streamflow prediction. Therefore, six deep learning models-standard LSTM, standard gated recurrent unit (GRU), stacked LSTM, bidirectional LSTM (BiLSTM), feed-forward neural network (FFNN), and convolutional neural network (CNN) models-were of interest in this study. The Red River system, one of the largest river basins in Vietnam, was adopted as a case study. In addition, deep learning models were designed to forecast flowrate for one- and two-day ahead at Son Tay hydrological station on the Red River using a series of observed flowrate data at seven hydrological stations on three major river branches of the Red River system-Thao River, Da River, and Lo River-as the input data for training, validation, and testing. The comparison results have indicated that the four LSTM-based models exhibit significantly better performance and maintain stability than the FFNN and CNN models. Moreover, LSTM-based models may reach impressive predictions even in the presence of upstream reservoirs and dams. In the case of the stacked LSTM and BiLSTM models, the complexity of these models is not accompanied by performance improvement because their respective performance is not higher than the two standard models (LSTM and GRU). As a result, we realized that in the context of hydrological forecasting problems, simple architectural models such as LSTM and GRU (with one hidden layer) are sufficient to produce highly reliable forecasts while minimizing computation time because of the sequential data nature.

• 품질경영학회지
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• 제51권2호
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• pp.171-184
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• 2023

Purpose: First, this paper suggests an alternative approach to find optimal portfolio (stocks, bonds and ESG stocks) under the maximizing utility of investors. Second, we include ESG stocks in our optimal portfolio, and compare improvement of welfares in the case with and without ESG stocks in portfolio. Methods: Our main method of analysis follows Brennan et al(2002), designed under the continuous time framework. We assume that the dynamics of stock price follow the Geometric Brownian Motion (GBM) while the short rate have the Vasicek model. For the utility function of investors, we use the Power Utility Function, which commonly used in financial studies. The optimal portfolio and welfares are derived in the partial equilibrium. The parameters are estimated by using Kalman filter and ordinary least square method. Results: During the overall analysis period, the portfolio including ESG, did not show clear welfare improvement. In 2017, it has slightly exceeded this benchmark 1, showing the possibility of improvement, but the ESG stocks we selected have not strongly shown statistically significant welfare improvement results. This paper showed that the factors affecting optimal asset allocation and welfare improvement were different each other. We also found that the proportion of optimal asset allocation was affected by factors such as asset return, volatility, and inverse correlation between stocks and bonds, similar to traditional financial theory. Conclusion: The portfolio with ESG investment did not show significant results in welfare improvement is due to that 1) the KRX ESG Leaders 150 selected in our study is an index based on ESG integrated scores, which are designed to affect stability rather than profitability. And 2) Korea has a short history of ESG investment. During the limited analysis period, the performance of stock-related assets was inferior to bond assets at the time of the interest rate drop.

• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.581-586
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• 2023

As the development of alternative energy is required due to the depletion of fossil fuels, interest in the use of hydrogen energy is increasing. Hydrogen is a promising clean energy source with high energy density and can lead to the application of environmentally friendly technologies. However, due to difficulties in production, storage, and transportation that prevent the application of hydrogen-based eco-friendly technology, research on reforming reactions using dimethyl ether (DME) is being conducted. Unlike other hydrocarbons, DME is attracting attention as a hydrogen carrier because it has excellent storage stability and transportability, and there is no C-C bond in the molecule. The reaction between DME and steam is one of the reforming processes with the highest hydrogen yield in theory at a temperature lower than that of other hydrocarbons. In this study, a hydrogen reforming device using DME was developed and a catalyst prepared by supporting Cu in alumina was put into a reactor to find optimal hydrogen production conditions for supplying hydrogen to fuel cells while changing reaction temperature (300-500℃), pressure (5-10 bar), and steam/carbon ratio (3:1 to 5:1).

• Journal of Information Technology Applications and Management
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• 제30권1호
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• pp.1-9
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• 2023

Interest in the future of the battery market is growing as Tesla announces plans to increase production of electric vehicles and to produce batteries. Tesla announced an action plan to reduce battery prices by 56% through 'Battery Day', which included expansion of factories to internalize batteries and improvement of materials and production technology. In the trend of automobile electrification, the expansion of the battery market, which accounts for 40% of the cost of electric vehicles, is inevitable, and the size of the electric vehicle battery market in 2026 is expected to increase more than five times compared to 2016. With the development of materials and process technology, the energy density of electric vehicle batteries is increasing while the price is decreasing. Soon, electric vehicles and internal combustion locomotives are expected to compete on the same line. Recently, the mileage of electric vehicles is approaching that of an internal combustion locomotive due to the installation of high-capacity batteries. In the EV battery market, Korean, Chinese and Japanese companies are fiercely competing. Based on market share in the first half of 2020, LG Chem, CATL, and Panasonic are leading the EV battery supply, and the top 10 companies included 3 Korean companies, 5 Chinese companies, and 2 Japanese companies. All-solid, lithium-sulfur, sodium-ion, and lithium air batteries are being discussed as the next-generation batteries after lithium-ion, among which all-solid-state batteries are the most active. All-solid-state batteries can dramatically improve stability and charging speed by using a solid electrolyte, and are excellent in terms of technology readiness level (TRL) among various technology alternatives. In order to increase the competitiveness of the battery industry in the future, efforts to increase the productivity and economy of electric vehicle batteries are also required along with the development of next-generation battery technology.

• Steel and Composite Structures
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• 제52권3호
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• pp.327-341
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• 2024

This paper is the first in a series of articles dealing with the study and analysis of imperfections in thin-walled, cold-formed steel sections with modified cross-sectional shapes. A study was conducted, using 3D scanning techniques, to determine the most vulnerable geometric imperfections in the profiles. Based on a review of the literature, it has been determined that few researchers are studying thin-walled sections with modified cross-sectional shapes. Each additional bend in the section potentially generates geometric imperfections. Geometric imperfections significantly affect the resistance to loss of stability, which is crucial when analyzing thin-walled structures. In addition, the most critical locations along the length where these imperfections occur were determined. Based on the study, it was found that geometric imperfections cause a reduction in critical load. It should be noted that the tests performed are preliminary studies, based on which a program of further research will be developed. In addition, the article presents the current state of knowledge in the authors' field of interest. The future objective is to ascertain if these imperfections could potentially contribute positively to structural integrity. This enhanced understanding may pave the way for novel methodologies in structural engineering, wherein imperfections are viewed not solely as flaws but also as elements that could enhance the end product.