• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.4
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• pp.648-656
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• 2022

As environmental regulations such as the International Maritime Organization (IMO)'s strategy to reduce greenhouse gases(GHG) are strengthened, technology development such as eco-friendly ships and alternative fuels is expanding. As part of this, ship propulsion technology using energy reduction and wind propulsion technology is emerging, especially in shipping companies and shipbuilders. By securing wind propulsion technology and introducing empirical research into shipbuilding and shipping, a high value-added market using eco-friendly technology can be created. Moreover, by reducing the fuel consumption rate of operating ships, GHG can be reduced by 6-8%. Rotor Sail (RS) technology is to generate a hydrodynamic lift in the vertical direction of the cylinder when the circular cylinder rotates at a constant speed and passes through the fluid. This is called the Magnus effect, and this study attempted to propose a plan to increase propulsion efficiency through a numerical analysis study on turbulence flow characteristics around RS, a wind power assistance propulsion system installed on a ship. Therefore, C_L and C_D values according to SR and AR changes were derived as parameters that affect the aerodynamic force of the RS, and the flow characteristics around the rotor sail were compared according to EP application.

• Animal Bioscience
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• v.35 no.2
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• pp.260-271
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• 2022

Objective: We aimed to investigate the effect of the differing amino acid (AA) release dynamics of two protein sources on the growth performance, nitrogen deposition, plasma biochemical parameters, and muscle synthesis and degradation of piglets when included in their diets at normal and low concentrations. Methods: Forty-eight piglets (Duroc×Landrace×Large White) with initial body weight of 7.45±0.58 kg were assigned to six groups and fed one of 6 diets. The 6 dietary treatments were arranged by 3×2 factorial with 3 protein sources and 2 dietary protein levels. They are NCAS (a normal protein content with casein), NBlend (a normal protein content with blend of casein and corn gluten meal), NCGM (a normal protein content with corn gluten meal), LCAS (a low protein content with casein), LBlend (a low protein content with blend of casein and corn gluten meal), LCGM (a low protein content with corn gluten meal). The release dynamics of AA in these diets were determined by in vitro digestion. The digestibility, utilization and biological value of nitrogen in piglets were determined by micro Kjeldahl method. Plasma insulin was measured by enzyme-linked immunosorbent assay kits. The protein expression of mediators of muscle synthesis and degradation was determined by western blotting. Results: Although the consumption of a low-protein diet supplemented with crystalline AA was associated with greater nitrogen digestion and utilization (p<0.05), the final body weight, growth performance, nitrogen deposition, and phosphorylation of ribosomal protein S6 kinase 1 and eIF4E binding protein 1 in the muscle of pigs in the low-protein diet-fed groups were lower than those of the normal-protein diet-fed groups (p<0.05) because of the absence of non-essential AA. Because of the more balanced release of AA, the casein (CAS) and Blend-fed groups showed superior growth performance, final body weight and nitrogen deposition, and lower expression of muscle ring finger 1 and muscle atrophy F-box than the CGM-fed groups (p<0.05). Conclusion: We conclude that the balanced release of AA from CAS containing diets and mixed diets could reduce muscle degradation, favor nitrogen retention, % intake and improve growth performance in pigs consuming either a normal- or low-protein diet.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.218-229
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• 2021

Recently, as consumers' interest and importance in health care have significantly increased, they prefer natural and organic foods that do not use chemical pesticides. Since sprout vegetables effectively promote health and prevent diseases such as cancer and cardiovascular disease, the consumption of sprout vegetables, a highly functional and safe food, has been increased significantly. This study aimed to investigate the effect of light on the growth and bioactive compounds of seven different sprout vegetables. After sowing the seeds of various sprout vegetables (kale, Chinese kale, broccoli, red cabbage, alfalfa, red radish, and radish), the sprouts were cultivated under light conditions (20℃, RGB 6:1:3, 130 μmol·m^-2·s^-1, 12 hours photoperiod) and dark condition for 7 days. Sprouts samples were taken at 1-day intervals from 4 to 7 days after treatment. The fresh weight, dry weight, plant height, total phenol content, and antioxidant capacity were measured. Brassica species (kale, Chinese kale, broccoli, red cabbage) and Medicago species (alfalfa) had significantly higher fresh weight values under dark conditions, while the content of bioactive compounds was increased considerably under light conditions. In contrast, the fresh weight of Raphanus genus (red radish, radish) significantly increased under the light condition, but the antioxidant phenolic compounds were significantly higher under the dark state. A negative correlation was observed between the growth and secondary metabolites in various sprout vegetables. This study confirmed the effect of light and dark conditions on different sprout vegetables' growth and nutritional value and emphasizes the importance of harvest time in producing high-quality sprout vegetables.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.276-280
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• 2021

The oxygen transfer rate at the liquid surface of the reciprocally shaking vessel was studied. The required power of the reciprocally shaking vessel was not proportional to the shaking frequency, unlike the rotational shaking vessel, and the liquid level suddenly fluctuated greatly at a certain frequency as the flow pattern in the vessel was a left and right wave flow different from that of the rotational shaking that has a rotational flow. The effect of the shaking frequency on the required power in the reciprocally shaking vessel was very complex, such as less power required than the rotational shaking vessel when the shaking frequency is more than 3 s-1, but the required power for the range of the generated rotational flow in the reciprocally shaking vessel could be correlated with the equation that was reported for the rotational shaking vessel. The kLa (mass transfer capacity coefficient) in the reciprocally shaking vessel also increased in a complex pattern because the required power for shaking was not consumed in a simple pattern, unlike kLa in the rotational shaking vessel, which increases linearly with increasing frequency. The kLa of the reciprocally shaking vessel was larger than the kLa of the rotational shaking vessel, and as the kLa value increased, the difference between them increased sharply. As a result, the oxygen transfer rate in the reciprocal motion was greater than that of the rotational motion, and could be correlated with the required power per unit volume.

• Animal Bioscience
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• v.34 no.10
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• pp.1643-1652
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• 2021

Objective: Two experiments were conducted to provide a new approach for evaluating feed nutritional value by metabolizable glucose (MG) in piglet diets with different levels of starch and crude fiber. In Exp 1, a regression equation for MG was generated. In Exp 2, the equation was verified, and the optimal growth performance of piglets under appropriate MG levels was tested. Methods: In Exp 1, 20 weaned piglets (7.74±0.81 kg body weight [BW]) were randomly assigned to 1 of 4 treatments, including the basal diet containing different levels of MG (starch, 25.80%, 31.67%, 45.71%, 49.36%; crude fiber, 1.23%, 1.35%, 1.80%, 1.51%). The piglets were implanted with an ileal fistula, cannulation of the carotid artery, portal vein, and mesenteric artery. The chyme from the ileum fistula and blood samples were collected. In Exp 2, 30 weaned piglets (8.96±0.50 kg BW) were randomly assigned to 1 of 5 treatments, including the experimental diets with different levels of MG (37.6, 132.5, 300.0, 354.3, and 412.5 g/kg). The piglets' BW, and feed consumption were recorded to calculate growth performance during the 28-d experiment. Results: In Exp 1, the MG levels in 4 diets were 239.62, 280.68, 400.79, and 454.35 g/kg. The regression equation for the MG levels and dietary nutrients was: Y (MG) = 12.13×X₁ (starch)+23.18×X₂ (crude fiber)-196.44 (R² = 0.9989, p = 0.033). In Exp 2, treatments with 132.5 and 300.0 g/kg MG significantly (p<0.05) increased average daily gain and feed conversion efficiency of weaned piglets, increased digestibility of crude fat, and had no effect on digestibility of crude protein compared to 300.0 to 412.5 g/kg MG. Conclusion: The pig model combining the ileum fistula and cannulation of blood vessels was successfully used to determine the dietary MG levels. The recommended MG level in weaned pig diets is 132.5 to 300.0 g/kg.

• Korean Association of Arts Management
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• no.58
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• pp.179-204
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• 2021

Not only the consumption trend after the COVID-19 pandemic but also low financial interest rates have stimulated people to invest artworks. With the recent noticeable growth, art investments that mainly conducted by younger generation through online platform can be characterized by a fractional ownership in art market which means several people share one piece of artwork. This study explores 4 fractional ownership platforms in the domestic art market including Art Together, Art & Guide, Tessa, and Pica projects, using a business model canvas that describes nine key elements: Customer Segments, Value Proposition, Channels, Customer Relationships, Revenue Streams, Key Resources, Key Activities, Key Partners and Cost Structure. The four cases have similar business models, but the details of revenue streams are different. The key sources of revenue are the profit and commission of the work. Thus, maximizing the profit margin of artworks is the core of revenue streams, so selecting and purchasing highly profitable artworks are significant. Based on the analysis, there are 3 suggestions to continue fractional ownership platform businesses in art market successfully. First, it is required to have a long-term perspective on art investments, as a way to diverse asset portfolio. Second, business confidence should be increased to maintain customer loyalty. Third, the role of platforms as competent experts is important.

• Animal Bioscience
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• v.36 no.1
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• pp.75-83
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• 2023

Objective: The objective of this study was to describe a methodological procedure to quantify the heat production (HP) partitioning in basal metabolism or fasting heat production (FHP), heat production due to physical activity (HPA), and the thermic effect of feeding (TEF) in roosters. Methods: Eighteen 54-wk-old Hy Line Brown roosters (2.916±0.15 kg) were allocated in an open-circuit chamber of respirometry for O₂ consumption (VO₂), CO₂ production (VCO₂), and physical activity (PA) measurements, under environmental comfort conditions, following the protocol: adaptation (3 d), ad libitum feeding (1 d), and fasting conditions (1 d). The Brouwer equation was used to calculate the HP from VO₂ and VCO₂. The plateau-FHP (parameter L) was estimated through the broken line model: HP = U×(R-t)×I+L; I = 1 if t<R or I = 0 if t>R; Where the broken-point (R) was assigned as the time (t) that defined the difference between a short and long fasting period, I is conditional, and U is the decreasing rate after the feed was withdrawn. The HP components description was characterized by three events: ad libitum feeding and short and long fasting periods. Linear regression was adjusted between physical activity (PA) and HP to determine the HPA and to estimate the standardized FHP (st-FHP) as the intercept of PA = 0. Results: The time when plateau-FHP was reached at 11.7 h after withdrawal feed, with a mean value of 386 kJ/kg^0.75/d, differing in 32 kJ from st-FHP (354 kJ/kg^0.75/d). The slope of HP per unit of PA was 4.52 kJ/mV. The total HP in roosters partitioned into the st-FHP, termal effect of feeding (TEF), and HPA was 56.6%, 25.7%, and 17.7%, respectively. Conclusion: The FHP represents the largest fraction of energy expenditure in roosters, followed by the TEF. Furthermore, the PA increased the variation of HP measurements.

• 지역과문화
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• v.7 no.2
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• pp.155-172
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• 2020

This study analyzed the factors to customer attitude on the goods and service introduced in UGC(User Generated Contents) and explored the difference between Korean and Chinese customers. For the first research question, the hypothetical factors were selected through literature review, the area of which are media consumption, social media and effect of advertising. In this study examined 4 independent variables: information, reliability, BJ attractiveness and customer innovation. Methodologies are confirmatory factor analysis, correlation analysis and multi regression. Result showed that reliability, BJ attractiveness and customer innovation are statistically significant. According to the β value, the biggest one is customer innovation, the second one is BJ attractiveness and the third one is reliability. The influence of information on customer attitude is not statistically significant. The result is well-aligned with the prior studies. The information factor's influence, however, is disputable because some prior studies shows that it is not significant when the research samples are recently developed channel such as mobile or social media commerce platforms. It is necessary to identify the root causes why the information factor is not significant in some research cases. For the second research question, this study used independent t-test between Korean and Chinese customers. The result shows that the difference in reliability, BJ attractiveness and attitude are stastically significant, and the ratings of Chinese customers are higher. This result caused by the difference of media commerce environment between Korea and China. Information and customer innovation didn't show significant difference.

• Journal of People, Plants, and Environment
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• v.24 no.1
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• pp.17-27
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• 2021

Background and objective: This study was conducted as part of research to promote garden diversity and seek sustainable garden management plans, as well as to determine the trends in understanding and use of companion plants as an eco-friendly farming method and provide the results as the basic data for sustainable urban agriculture. Methods: To determine the trends in garden activities, eco-friendly pest control, and use of companion plants, a survey was conducted on 230 urban residents participating in the Urban Agriculture Expert course. 223 copies of the questionnaire were collected excluding missing values, and IBM SPSS statistics Ver. 25 Program was used for frequency analysis, descriptive statistics, and regression analysis. Results: Most of the respondents were female (71.3%), homemakers (26.5%), were in their 50s (29.1%), and had 2 members in the family (27.8%). 164 respondents (73.5%) had experience in gardening, most of them once a week (31.7%) and for self-consumption (55.5%). Both men and women raised crops for safe food production (32.3%), and they most preferred the city garden type (39.9%). For the preparation of nourishment for eco-friendly garden management, most respondents (60.1%) purchased fertilizers from the market. For the reason why eco-friendly pest control is necessary, all respondents except 4 of them (98.2%) responded that it is necessary 'because it affects my health as I eat it (73.5%)', indicating that they still had a high level of interest in health. Only 43.9% of the respondents said that they had heard of companion plants, 89.2% responded that companion plants were effective in eco-friendly management, and 87.4% showed the will to participate in gardening using companion plants in the future. Finally, the regression analysis confirmed that the awareness of companion plants and satisfaction with gardening activities are key variables that increase the intention to participate in gardening activities in the future. Conclusion: Since plants require special care depending on the period and various diseases and insect pests occur, there must be continuous research on companion plants as an eco-friendly farming method. Moreover, by actively using companion plants in urban gardens with the utility value in not only eco-friendly pest control but also in helping plant growth, urban agriculture is expected to be continuously activated and promoted by increasing satisfaction in gardening activities with aesthetic landscaping and pest control.

• Clean Technology
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• v.28 no.3
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• pp.258-266
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• 2022

Resource productivity (GDP/DMC) is defined as GDP divided by DMC. However, it has shortcomings when estimating the value-added generated from material processing. In this paper, an energy coefficient is applied to GDP to develop a sub-indicator (referred to as GDPe/DMC). Consequently, South Korea, which is a secondary industry-oriented country, created 1,094.60 USD/ton from input materials and was ranked 4th on the OECD list, which is 10 levels higher than the level estimated by GDP/DMC. However, Luxembourg, which is a tertiary industry-oriented country, is ranked 16th on the OECD list, which is 12 levels lower than the level estimated by GDP/DMC. The resource productivity estimated by the sub-indicator (GDPe/DMC) developed in this study indicates that secondary industry-oriented countries are undervalued in the existing main GDP/DMC calculation. On the other hand, tertiary industry-oriented countries are downgraded due to the industrial features of the GDPe/DMC calculation. As a result of this paper, GDPe/DMC could be considered a more reasonable indicator to directly reflect the material input effect compared to the existing main indicator, GDP/DMC. This means that GDPe/DMC-induced resource productivities could be estimated to be slightly higher than the GDP/DMC-induced resource productivities for secondary industry-oriented countries. It is expected that the sub-indicator, GDPe/DMC, proposed in this study could be useful especially for comparing and analyzing the resource productivities between countries that have different industry structures. This study intended to consider a structurally energy/resource-intensive industry in estimating and analyzing national-level resource productivity. Thus, the sub-indicator, GDPe/DMC, may help minimize the distortion of interpreting national resource productivities in various situations, and be utilized as a more efficient tool when used together with GDP/DMC.