• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.257-267
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• 2014

The distributions of trace metals in the East Sea were investigated during the R/V Lavrentyev cruise (July 2009) in which four transects from Russia shore to South were conducted to collect 25 surface water samples. The total dissolved concentrations of Cu and Ni were measured using ICP-MS, DRC-e. In the coastal area, their concentrations of Russia shore (Cu, 1.51; Ni, 1.82 nM) were 1.9 times for Cu and 2.0 times for Ni lower than Korea shore (Cu, 2.87; Ni, 3.71 nM). In the subregion, their concentrations of Warm region (Cu, 3.03; Ni, 2.28 nM) were higher for Cu than Cold region (Cu, 2.04; Ni, 2.28 nM). The distributions of Cu and Ni concentrations were divided by lowest level at $10^{\circ}C$ of water temperature. In this study period, the surface water temperatures of Russia shore and Japan basin were lower than $10^{\circ}C$ and them of Ulleung basin and Sakhalin shore were higher. Below $10^{\circ}C$, Cu and Ni concentrations increased when surface water temperatures decreased. Above $10^{\circ}C$, their concentrations increased with temperature, which showed highest concentrations in the Ulleung basin, directly influenced by flux from East Korean Warm Current. By comparing with other sea areas (Western Mediterranean, Atlantic), Cu concentrations in the East Sea were a little higher and Ni concentrations were lower. Particularly as the level of Cu in the offshore in the Ulleung basin were higher than in the coastal area, We can suggest that the atmospheric flux of Cu is relatively important in this area.

• Korean Journal of Ichthyology
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• v.19 no.1
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• pp.1-7
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• 2007

The effect of water temperature (T) and body weight (W) on the oxygen consumption of the fasted black rockfish, Sebastes schlegeli was investigated to provide empirical data for the culture management and bioenergetic growth model of this species. The mean wet body weights of two fish groups used for the present experiment were $12.9{\pm}2.7g$ ($mean{\pm}SD$) and $351.1{\pm}9.2g$. The oxygen consumption rate (OCR) was measured under three water temperature regimes (15, 20 and $25^{\circ}C$) at an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. In each treatment three replicates were set up and 45 fish in small size groups and 6 fish in large size groups were used. The OCRs increased with increasing water temperature in both size groups (p<0.001). Mean OCRs at 15, 20 and $25^{\circ}C$ were 414.2, 691.5 and $843.8mg\;O_2\;kg^{-1}h^{-1}$ in small size groups, and 182.0, 250.7 and $328.2mg\;O_2\;kg^{-1}h^{-1}$ in large size groups, respectively. The OCRs decreased with increasing body weights in three water temperature groups (p<0.001). The mass effect on metabolic rate can be expressed by the power of 0.69~0.75. The data are best described by the relationship: OCR=89.12+28.79T-1.17W. $Q_{10}$ values ranged 1.90~2.79 between 15 and $20^{\circ}C$, 1.49~1.71 between 20 and $25^{\circ}C$, and 1.80~2.03 over the full temperature range, respectively. The energy loss by metabolic cost increased with increasing water temperature and decreasing body weight (p<0.001). Mean energy loss rates by oxygen consumption at 15, 20 and $25^{\circ}C$ were 282.9, 472.3 and $576.3kJ\;kg^{-1}d^{-1}$ in small size groups and 124.3, 171.3 and $224.1kJ\;kg^{-1}d^{-1}$ in large size groups, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.100-112
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• 2005

Soil temperature was measured from the surface to 40 cm depth at three stations with different heights in tidal flat of Gomso Bay, west coast of Korea, for one month in every season 2004 to examine the thermal structure and the variation. Mean temperature in surface layer was higher in summer and lower in winter than in lower layer, reflecting the seasonal variation of vertically propagating structure of temperature by heating and cooling from the tidal flat surface. Standard deviation of temperature decreased from the surface to lower layer. Periodic variations of solar radiation energy and tide mainly caused short term variation of soil temperature, which was also intermittently influenced by precipitation and wind. Time series analysis showed the power spectral energy peaks at the periods of 24, 12 and 8 hours, and the strongest peak appeared at 24 hour period. These peaks can be interpreted as temperature waves forced by variations of solar radiation, diurnal tide and interaction of both variations, respectively. EOF analysis showed that the first and the second modes resolved 96% of variation of vertical temperature structure. The first mode was interpreted as the heating antl cooling from tidal flat surface and the second mode as the effect of phase lag produced by temperature wave propagation in the soil. The phase of heat transfer by 24 hour period wave, analyzed by cross spectrum, showed that mean phase difference of the temperature wave increased almost linearly with the soil depth. The time lags by the phase difference from surface to 10, 20 and 40cm were 3.2,6.5 and 9.8 hours, respectively. Vertical thermal diffusivity of temperature wave of 24 hour period was estimated using one dimensional thermal diffusion model. Average diffusivity over the soil depths and seasons resulted in $0.70{\times}10^{-6}m^2/s$ at the middle station and $0.57{\times}10^{-6}m^2/s$ at the lowest station. The depth-averaged diffusivity was large in spring and small in summer and the seasonal mean diffusivity vertically increased from 2 cm to 10 cm and decreased from 10 cm to 40 cm. Thermal propagation speeds were estimated by $8.75{\times}10^{-4}cm/s,\;3.8{\times}10{-4}cm/s,\;and\;1.7{\times}10^{-4}cm/s$ from 2 cm to 10 cm, 20 cm and 40 cm, respectively, indicating the speed reduction with depth increasing from the surface.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.2
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• pp.64-73
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• 2015

The distributions of Pb and Cd concentrations in the surface seawater of the East Sea were investigated during the R/V Lavrentyev cruise (July 2009) in which four transects from Russia shore to South were conducted to collect 26 surface water samples. The total dissolved concentrations of Pb and Cd were measured using ICP-MS (Perkin Elmer, DRC-e). In the coastal area, their concentrations of Russia shore (Pb, 0.08; Cd, 0.10 nM) were comparable for Cd but on the other hand, 6 times lower for Pb than Korea shore (Pb, 0.49; Cd, 0.11 nM). In the subregion, their concentrations of Warm region (Pb, 0.22; Cd, 0.01 nM) were about 1.7 times higher for Pb but 0.4 lower for Cd than Cold region (Pb, 0.13; Cd, 0.14 nM). The distributions of Pb and Cd concentrations were divided by lowest level at $10^{\circ}C$ of water temperature. Below $10^{\circ}C$, Pb and Cd concentrations increased when surface water temperatures decreased. Above $10^{\circ}C$, their concentrations increased with temperature, which showed highest concentrations in the Ulleung basin, directly influenced by flux from East Korean Warm Current and neighboring countrys (Korea and Japan). Specially, in the case of Pb, the concentrations decrease remarkablely with temperatures decrease from D10 directly influenced by flux from East Korean Warm Current, which shows highest Pb level. By comparing with other sea areas (Western Mediterranean, East Pacific), Pb concentrations in the East Sea were a little higher. The influence of East Korean Warm Current and neighboring countrys (Korea and Japan) may be relatively important. Therefore, the distribution of Cd may primarily be influenced by mixing of different water masses while the distribution of Pb may mainly be influenced by flux from East Korean Warm Current and atmospheric inputs. River inputs and interaction with particulate materials may also some roles for the distribution of these elements.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.3
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• pp.187-197
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• 2010

Carbon dioxide Capture and Storage(CCS) is regarded as one of the most promising options to response climate change. CCS is a three-stage process consisting of the capture of carbon dioxide($CO_2$), the transport of $CO_2$ to a storage location, and the long term isolation of $CO_2$ from the atmosphere for the purpose of carbon emission mitigation. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the $CO_2$ mixture captured from the power plants and steel making plants contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_2$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification, transport and injection processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to analyze the impact of these impurities on the whole CCS process at initial design stage. The purpose of the present paper is to compare and analyse the relevant physical property models including BWRS, PR, PRBM, RKS and SRK equations of state, and NRTL-RK model which are crucial numerical process simulation tools. To evaluate the predictive accuracy of the equation of the state for $CO_2-SO_2$ mixture, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $SO_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable physical property model with optimized binary parameter in designing the $CO_2-SO_2$ mixture marine geological storage process.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.217-226
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• 2009

Marine geological storage of $CO_2$ is regarded as one of the most promising options to response climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_2O$, $SO_x$, $H_2S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. In order to design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of the present paper is to compare and analyse the relevant equations of state including PR, PRBM, RKS and SRK equation of state for $CO_2-N_2$ mixture. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. In addition, optimum binary parameter to consider the interaction of $CO_2$ and $N_2$ molecules was suggested based on the mean absolute percent error. In conclusion, we suggest the most reliable equation of state and relevant binary parameter in designing the $CO_2-N_2$ mixture marine geological storage process.

• Proceedings of the KSAR Conference
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• 2005.06a
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• pp.47-54
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• 2005

In boars, unlike the cases in males of other species, gonadal hormones suppress voluntary feed intake. for this reason, barrows, compared with gilts or boars, eat too much feed resulting in excessive fat deposition. Two experiments were performed in the present study to investigate the effects of implantation of Revalor H[Experiment(Exp.) I: 140mg trenbolone acetate(a synthetic androgen) + 14mg estradiol-$17\beta(E_{2}\beta)$] and Compudose(Exp. II; 24mg $E_{2}\beta$) on growth efficiency, carcass characteristics and circulating concentrations of IGF-I and IGF-binding protein-3(IGFBP-3). In Exp. I, sixty-four cross-bred finishing barrows weighing approximately 60kg were randomly divided into eight pens under a 2[control vs Revalor implant] $\times$ 2(ad libitum vs $80\%$ ad libitum feeding) $\times$2[control($103\%$ NRC-recommended level) vs low-energy($87\%$ NRC recommendation) diet] arrangement of treatments. In Exp. II, effects of Compudose were studied using 80 finishing barrows(10 animals/pen). In both Exps., all the animals were slaughtered at 100- to 110-kg body weight. Both Revalor and Compudose implants caused a decrease in feed intake and backfat thickness without affecting major physicochemical characteristics of the carcass and an increase in circulating IGF-I concentration. Moreover, Revalor implant exhibited greater effects than restricted feeding, low-energy diet, or Compudose in these variables. In addition, Revalor implantation suppressed weight gain, but enhanced the feed efficiency without exhibiting any interaction with the diet or feeding. In summary, results suggest that 1) both androgen and estrogen suppress voluntary feed intake and backfat deposition and enhance IGF-I secretion and 2) these effects of the gonadal steroid hormones in growth are likely to be mediated, in part, by IGF-I in finishing barrows.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.485-496
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• 2022

Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO₂ enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

• Journal of Service Research and Studies
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• v.13 no.4
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• pp.97-112
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• 2023

Background: In modern society, the importance of Public Design has become increasingly significant in contributing to the enhancement of urban functionality and the quality of life of citizens. Smart Public Facilities have played a pivotal role in enriching user experience by improving accessibility, convenience, and safety, and in elevating the value of the city. This research recognizes the importance of Public Facilities and explores the potential of Smart Public Facilities in solving urban challenges and progressing towards sustainable and Inclusive cities. Method: The literature review comprehensively examines existing theories and research results on Smart Public Facilities. The case study analyzes actual examples of Smart Public Facilities implemented in cities both domestically and internationally, drawing out effects, user satisfaction, and areas for improvement. Through analysis and discussion, the results of the case studies are evaluated, discussing the potential development of Smart Public Facilities. Results: Smart Public Facilities have been found to bring positive changes in various aspects such as urban management, energy efficiency, safety, and information accessibility. In terms of urban management, they play a crucial role in optimization, social Inclusiveness, environmental protection, fostering citizen participation, and promoting technological innovation. These changes create a new form of urban space, combining physical space and digital technology, enhancing the quality of life in the city. Conclusion: This research explores the implications, current status, and functions of Smart Public Facilities in service and design aspects, and their impact on the urban environment and the lives of citizens. In conclusion, Smart Public Facilities have brought about positive changes in the optimization of urban management, enhancement of energy efficiency, increased information accessibility, User-Centric design, increased interaction, and social Inclusiveness. Technological innovation and the integration of Public Facilities have made cities more efficient and proactive, enabling data-based decision-making and optimized service delivery. Such developments enable the creation of new urban environments through the combination of physical space and digital technology. The advancement of Smart Public Facilities indicates the direction of urban development, where future cities can become more intelligent, proactive, and User-Centric. Therefore, they will play a central role in Public Design and greatly contribute to improving the urban environment and the quality of life of citizens.

• Restorative Dentistry and Endodontics
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• v.32 no.1
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• pp.28-36
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• 2007

The purpose of this study was to compare the effect of exponential curing method with conventional curing and soft start curing method on polymerization shrinkage of composite resins. Three brands of composite resins (Synergy Duo Shade, Z250, Filtek Supreme) and three brands of light curing units (Spectrum 800, Elipar Highlight, Elipar Trilight) were used. 40 seconds curing time was given. The shrinkage was measured using linometer for 90 seconds. The effect of time on polymerization shrinkage was analysed by one-way ANOVA and the effect of curing modes and materials on polymerization shrinkage at the time of 90s were analysed by two-way ANOVA. The shrinkage ratios at the time of 20s to 90s were taken and analysed the same way. The results were as follows : 1. All the groups except Supreme shrank almost within 20s Supreme cured by soft start and exponential curing had no further shrinkage after 30s (p < 0.05). 2. Statistical analysis revealed that polymerization shrinkage varied among materials (p = 0.000) and curing modes (p = 0.003). There was no significant interaction between material and curing mode. 3. The groups cured by exponential curing showed the statistically lower polymerization shrinkage at 90s than the groups cured by conventional curing and soft start curing (p < 0.05). 4. The initial shrinkage ratios of soft start and exponential curing were statistically lower than conventional curing (p < 0.05). From this study, the use of low initial light intensities may reduce the polymerization rate and, as a result, reduce the stress of polymerization shrinkage.