• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.281-291
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• 1999

The objective of this study was to optimize the freezing/thawing method of in vitro produced Hanwoo blastocysts. Day 7 blastocysts after IVF were vitrified using EFS40 (40% ethylene glycol, 18% ficoll, 0.3 M sucrose and 10% FBS added m-DPBS) as a freezing solution and electron microscope (EM) grid (V-G) or straw (V-S) as an embryo container. In both method, freezing/thawing were treated by 2-step, treatment time was required in V-G method and V-S method, for 2 min / 3 min and 3.5 min / 10 min, respectively. Embryo survival was assessed as re-expanded and hatched rates at 24 h and 48 h after warming, respectively. The results obtained in these experiments were summarized as follows: when the effect of exposure in vitrification solution and chilling injury from freezing procedure on in vitro produced expanded blastocysts were examined, at 24 h after warming, embryo survival in exposure group (100.0%) was not different compared to that in control group (100.0%), although those results were significantly different with two vitrified groups (V-G: 87.8, V-S: 77.8%) (P＜0.001). However, at 48 h after warming, hatched rates of V-G group (67.8%) were significantly higher than those of V-S group (53.3%) (P＜0.05). In addition, this hatched rate in V-G group was not different with that in exposure group (73.3%). When the effects of embryo developmental stage (early, expanded and early hatching blastocysts) and embryo container (EM grid and straw) to the in vitro survival of vitrified-warmed day 7 Hanwoo blastocysts were simultaneously examined, fast developed embryos were indicated the better resistance to freezing than delayed developed one, irrespective of embryo containers (early; 57.1 ＆ 24.4%, expanded; 84.7 ＆ 60.6%, early hatching; 91.7 ＆ 80.0%) (P＜0.001). Especially, in expanded and early hatching blastocysts, embryo survival of V-G group (67.8, 95.0%) was significantly higher than those of V-S group (53.0, 65.0%) at 48 h post warming, respectively (P＜0.05, P＜0.001). Therefore, this study indicates that Hanwoo blastocysts can be cryopreserved more simple, efficient and successful by vitrification method using EM grid.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.123-133
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• 2011

The objective of this study was to find optimal nutrient condition of container seedling production of two tropical species for high seedling quality. This study was conducted to investigate photosynthesis, chlorophyll fluorescence, chlorophyll contents, and growth performances of container seedlings of Eucalyptus pellita and Acacia mangium growing under four different fertilization treatments (Con., $0.5\;g{\cdot}l^{-1}$, $1.0\;g{\cdot}l^{-1}$, and $2.0\;g{\cdot}l^{-1}$ fertilization). E. pellita showed outstanding photosynthetic capacity, photochemical efficiency, and chlorophyll contents at $1.0\;g{\cdot}l^{-1}$ fertilization. Meanwhile, E. pellita showed the highest photosynthetic capacity, photochemical efficiency, and chlorophyll contents at $2.0\;g{\cdot}l^{-1}$ fertilization, as fertilization rate were increased, those of A. mangium increased. Like physiological characteristics, Both E. pellita at $1.0\;g{\cdot}l^{-1}$ fertilization and A. mangium at $2.0\;g{\cdot}l^{-1}$ fertilization were higher root collar diameter, height, biomass, and seedling quality index than other treatments. These results showed that E. pellita at $1\;g{\cdot}l^{-1}$ fertilization and A. mangium at $2.0\;g{\cdot}l^{-1}$ fertilization is optimal nutrient condition, respectively. Moreover, fertilization rate controlling is very important for growth and seedling quality of container seedling.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.336-342
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• 2012

Inorganic materials were commonly used as container media in domestic plant factories. Objective of this research was to secure the information in soil physical and chemical properties of inorganic materials such as vermiculites and perlites. To achieve this, 12 gold and silver vermiculites from China, Zimbabwe, and South Africa and 5 perlites from China were collected based on the marketing grades (MG) in particle sizes and analyzed for determination of their characteristics. The percentage of particles larger than $710{\mu}m$, in China perlite MG 3~5 mm, China silver vermiculites MG > 8 mm and MG 3~8 mm were 99.9%, 99.8%, and 99.7%, respectively, which were much higher than 28.4% in China gold vermiculite MG 0.3~1.0 mm, 14.0% in perlite MG < 1.0 mm, and 12.6% of Zimbabwe silver vermiculite MG < 1.0 mm. The container capacities of perlite MG < 1.0 mm and South Africa silver vermiculite MG 0.25~1.0 mm were 72.0% and 71.1%, respectively. The air space in China silver vermiculite MG 3~8 mm was 49.3% which was higher than other materials tested. However, the China gold and silver vermiculites MG 0.3~1 mm had 3.5% and 2.4% in air space indicating that possible problems could occur in soil aeration when they are used for container media. The percentage of easily available and buffering water of China gold vermiculite MG 0.3~1 mm and perlite MG < 1.0 mm were the highest among test materials. The ranges of pH and electrical conductivity were 6.36 to 10.7 and 0.032 to $0.393dS{\cdot}m^{-1}$ in vermiculites and 7.78 to 8.62 and 0.030 to $0.041dS{\cdot}m^{-1}$ in perlite, respectively. The cation exchange capacity of China silver vermiculite MG 0.3~1 mm were $14.7cmol{\cdot}kg^{-1}$ that was 10 times as high as $0.34cmol{\cdot}kg^{-1}$ in perlite MG 1~2.5 mm. The vermiculites had the higher contents of exchangeable cations such as Ca, K, and Na, than those of perlites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6047-6052
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• 2013

A cosmetic manufacturing process requires a mold that is inevitable for mass production. Cosmetic containers are one of major factors affecting the customer's purchase decision. In addition, the manufacturing cost in cosmetic container comprises a large portion of the entire product cost. Therefore, a mold satisfying the economical feasibility, aesthetics and functionality is necessary. Among the cosmetic containers, square shape containers have a tendency of having a short shot defect product. The square shaped cosmetic containers are mostly produced as a side gate shape on the two-plate molds. On the other hand, there are two disadvantages, such as gate trace and post processing requirement. The overlap-gateproposed in this study has the characteristics of intaglio gate cutting and no need for post processing. The delivery system of the overlap gate was simulated and compared with the side gate via Moldflow. The improvement in flow, frozen rate, density, and Air trap was confirmed. Based on the simulation results, the mold and performed injection molding was fabricated. In this study, the possibility of the mass production of high aesthetic and functionality cosmetic containers was verified.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.62-67
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• 2015

A very large shell-structure built in shipyards like ship hulls or offshore structures are joined by welding through full process. As the welding contains a high thermal cycle at a local area, the welded structures should be distorted unavoidably. Because a distorted ship block should be revised to the designed value before the next stage, the ability to predict and to control the weld distortion is an accuracy level of the yard itself. Despite the ship block size, several present thermal distortion methodologies can deal those sizes, but it is a different story to deal full ship size model. Even a fully constructed ship hull not remaining any welding can have an accuracy issue like outfitting installation problems. Any present thermal distortion methodology cannot accept this size for its recommended element size and the number. The ordinary welding breadth at erection stage is about 20~40 mm. It can hardly be a good choice to make finite element model of these sizes considering human effort and computational environment. The finite element model for structure analysis of a ship hull is prepared at front-end engineering design stage which is the first process of the project. The element size of the model is as fine as the longitudinal space, and it is not proper to obtain a weld distortion at the erection stage. In this study, a methodology is suggested that a weldment can be shrunk at original place instead of using structural finite element model. We cut the original shell elements at erection weld-line and put truss elements between the edges of cut elements for weld shrinkage. Additional truss elements are used to facsimile transverse weld shrinkage which cannot be from the weld-line truss element shrink. They attach to weld-line truss element like twigs from barks. The capacity of developed elements is verified through an accuracy check of erection process of a container vessel at the apt. hull. It can be a useful tool for verifying a centering accuracy after renew and for block-separating planning considering accuracy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.5
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• pp.545-553
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• 2012

This paper reports the development of an automatic system for mixing offset printing ink. The ink mixing process is important in industrial fields where paint and ink are used. In particular, there is a demand for automating the process of producing spot colors, which involves mixing a small quantity of high-viscosity ink. The authors designed, fabricated, and experimentally tested an automatic mixing system that employs the revolution and rotation of ink and the transmission by belts. The performance of the ink mixing system was verified by conducting numerous experiments to determine the effect of rotation direction, speed, ink container axis angle, and ink amount. Conditions suitable for mixing offset ink are presented for use as guidelines for producing spot colors.

• Journal of People, Plants, and Environment
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• v.23 no.6
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• pp.667-681
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• 2020

Background and objective: Recently, there has been an increasing need for relaxation and familiarity with nature in residential and living spaces faced daily by urban residents, leading to a growing social interest in urban gardens. The aim of this study was to determine how gardens in a city provide physical and social benefits, comparing cases in Korea and overseas. Methods: We used the keywords "garden" and "city" for Korea, and "urban," "garden," and "green" for overseas. We then determined the Korean and overseas research trends in urban gardens by analyzing 63 Korean and 90 overseas articles deemed suitable for this study. Results: As to the types of urban gardens, the most significant type was community gardens, both in Korea and overseas (30.2% and 48.6%, respectively), followed by rooftop gardens in Korea (22.2%) and kitchen gardens overseas (22.2%). Due to the narrow and complex urban structure in Korea, people focus on using rooftop, wall, and alley spaces, and tend to arrange container-type flexible gardens. Overseas there has been a focus on promoting health and reducing food inequality through allotment and kitchen gardens, and a tendency to use a larger area as a fixed form than Korea. In addition, it was found that gardens in urban areas had a positive effect on urban biodiversity. Conclusion: To sum up, gardens in Korea are close to living spaces, and gardens overseas influence the ecosystem with an emphasis on food production. Therefore, creating urban gardens is a method of urban regeneration with a high utility that goes beyond mere food production, both in Korea and overseas, providing comprehensive benefits for the environment (37.73%) and society (62.27%). As such, continuous research on this area of study is needed to create policy guidelines for Korea.

• Journal of Navigation and Port Research
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• v.37 no.1
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• pp.63-69
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• 2013

Since most merchant vessels are mainly influenced by the added resistance in an actual sea, they could be navigated more efficiently if this added resistance could be precisely predicted and then effectively reduced. In this paper, we have computed the effective horsepower based on the resistance performance in still water and then calculated the added resistance in regular wave in order to estimate a ship's propulsion performance on a voyage. Firstly, we have performed experiments using a model of KCS in a circulating water channel to estimate the flow characteristics around a container ship and the ship's resistance in still water. Then we have calculated the motion response function in regular wave as well as the values for the increase in resistance, and evaluated the ship's motion performance in waves according to the calculated response function. It was found that the resistance in waves increased because the ship's motion response value became larger as the ship's speed increased in the case of head sea. The effect of the added resistance could be reduced by maneuvering the ship to the encounter angle of $120^{\circ}$ in areas of long wavelengths and to head sea in areas of short wavelengths.

• Journal of the Korean Geographical Society
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• v.47 no.5
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• pp.775-790
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• 2012

This paper considers chronologically the discourse of space as one of key concepts in geography, and then argues that geography education ought to be the critical pedagogy of space. Recent social science including geography and education has more empathized the sociality and spatiality of space than the physicality of space, and argues that space is constructed socially. Thus, it has been considered that space is no longer empty container to be filled with social relationships, but is concerned with the production and reproduction of social relationships through political struggles with diverse meanings. Now, geography education has to examine the different ways which space has been conceptualized, and develop geography education as critical pedagogy of space that focuses on reading the multiple and contested nature of space.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.149-154
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• 2012

This paper aims to design and realize android smartphone mobile webapp office JPetStore order system based Seam framework. Currently in production until the lightweight container architecture, known commonly architecture is Seam framework. However, there is no design and implementation research of mobile webapp office with the Seam framework environment. In this study, the Seam environment based on the android mobile webapp office JPetStore order system implementation after analyzing the mobile webapp office development productivity with the objective is to provide guidance.