• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.8
• /
• pp.1190-1195
• /
• 2007

This study was conducted to improve efficiency of a follicle culture system without reducing developmental competence of intrafollicular oocytes. Preantral follicles (100 to $125{\mu}m$ in diameter) of F1 hybrid (B6CBAF1) mice were cultured singly for 216 h in modified ${\alpha}$-MEM-glutamax medium, to which 2.5 IU/ml hCG and epidermal growth factor was added 16 h prior to the end of culture. Medium change was either performed three times (54 h interval), twice (72 h interval), once (108 h interval), or not at all (216 h interval). Maturation (progression to the metaphase II stage) of intrafollicular oocytes was detected from 4 days after culture in the three-times change treatment, while all treatments yielded mature oocytes from day 5 of culture. Compared with the three-times change, decreasing the change frequency to once did not reduce the capacity to begin maturation (germinal vesicle breakdown of 82 to 86%), to mature (78 to 79%) and to develop into blastocysts after parthenogenetic activation (29 to 32%). Morphological parameters were similar among these treatments. Except for the no medium change treatment, similar colony-forming activity of inner cell mass cells after culturing of blastocysts in leukemia inhibitory factor-containing medium was detected, while the morphology of the colony-forming cells deteriorated in the change-once treatment compared with the change twice or three-times. In conclusion, the efficiency of the preantral follicle culture system could be improved by reducing frequency of medium change up to a 72 h interval (three times in total 216 h culture) without decreasing developmental competence of oocytes.

• The Journal of the Petrological Society of Korea
• /
• v.15 no.2 s.44
• /
• pp.81-89
• /
• 2006

Pb isotopic compositions were determined from the ore deposits of Beonam, Dongjin, Jeoksang and Bukchang mines distributed within Jeolabuk-do. As a result, individual mine shows significantly different values of Pb isotopic compositions from each other. Pb isotopic values of the Beonam, Bukchang and Dongjin mines altogether from linear variation, but it is too steep to represent their formation age. Instead, such trend suggests that these ore leads were originated from binary mixing. Precambrian basement rocks and Mesozoic granitoids are suggested for such two end-members. The relative contribution of lead from each source seems to be quite different for each ore deposit, implying that the circulation of the ore-forming fluid was very localized when they were formed. In the case of Dongjin mine it seems significant portion of the ore leads were originated from the basement rocks, which suggests that related igneous rock seems to have acted as heat source to generate circulation of the fluid rather than the source of the ore-forming elements.

• Journal of architectural history
• /
• v.6 no.3 s.13
• /
• pp.129-143
• /
• 1997

The perspective representation and its effect that appeared in the tombs and mural paintings of koguryo are summarized as follows: First, The inside structure of the tombs is likely to show the deepness effect, placing each function in the front and both sides centering around the mane pillars and creating the boundaries and the spaces that have various visibility between the inside and outside spaces of the structure just like a traditional Korean house shows. In addition, The deepness effect is emphasized by suggesting that the spaces are countinued with a storage attached behind the main house or by forming the level and deployment in a narrow space like the scene that a large array is looked out from the main house. Second, The deepness effect is expressed by making the form of ceiling turn to a vertical space of an ascending image, constructing it just as the lotus lamp ceiling of a wooden architecture or drawing it just like the imaginary heavenly world with the sun the moon and mythical fairies and animals spread in it. Thried, The perspective effect is disclosed by drawing the mural pictures in an equally set bird's-eye view without regard to the disfance proportion according to the conceptual visualization which is not a visual penetration, adopting the multiple view points and moving view points that are moving around as an important manner of seeing. Fourth, The deepness effect is emphasized through the scene of changing spaces when they are looked out far or looked into depending on a viewpoint of the daily life by forming the fromes of paintings that we made up with actual pillars, Du Gong, crossbeams or that are painted in most tombs. Fifth, The rich spatial senses are reflected by originating the characters of the three directions, level, deployment and ascending. An example which can support the conclusion of this study can be given here. that is, the construction ground plan of a dwelling house of a nobleman at the end of Koguryo as a remain which was excavated at Dongdae Ja in Jip An.

• Journal of the Korean Home Economics Association
• /
• v.39 no.3
• /
• pp.107-133
• /
• 2001

This study aims to understand the Process of Communality formation among the Families of Communal Childcare Cooperative. Ethnographic, in-depth interview and participant observation at field are used as method. The families of communal childcare cooperative form their communality through investment and harmony, making relationship, and struggles and overcoming the struggles. Each family is willing to put in their money and time for an unfamiliar group to organize and manage a community. They head for the same direction accepting the diversity of expectation and thought based on the diversity of environment of each family. They have interactions upon the basis of equality among the families. Sharing their unique cloture such as communal place(teojeon), common issues, same generation, unique terms, specific modes of speaking informally or nicknaming, they accept the diversities and head for the sameness to have a harmony. In the reset of forming relationship, these families transfer successfully from the field of I and my family to that of group. They escape from a sense of priority that concerns their own family first and then others. They come to be able to consider the group first. Besides, they come to assimilate themselves to the group by identification with the group. They come to form their identity and sense of membership of the group recognizing power of group they belong in their families and local society. The process of forming community among the families of cooperative has inescapable struggles. Each family becomes a real host of the cooperative in the process of overcoming the struggles and experiences a growth of individual and group in the process of looking for the ways of overcoming the struggles. In the end, the families cooperates and reestablish their community.

• Transactions of Materials Processing
• /
• v.26 no.5
• /
• pp.271-276
• /
• 2017

A tee is the most common pipefitting used to combine or divide fluid flow. Tees can connect pipes of different diameters or change the direction of a pipe run. To manufacture tee type of stainless steel pipe, combinations of punch piercing and burr forming have been widely used in the industry. However, such method is considerably time consuming with regard to performing empirical work necessary to attain process conditions to prevent upper end tearing of the tee product and meet target tee height. Numerous experiments have shown that the piercing profile is the main cause of defects mentioned above. Furthermore, the mold design is formed through trial and error according to pipe diameters and changes in requirements. Thus, the objective of this study was to perform piercing and burring process analysis via finite element analysis using DYNAFORM to resolve problems mentioned above. An optimization design method was used to determine the piercing punch profile. Three radii of the piercing punch (i.e., large, small, and joined radii) were selected as design variables to minimize thinning of a tee pipe. Based on results of correlation and multiple regression analyses, we developed a predictive approximation model to satisfy requirements for both thickness reduction and target height. The new piercing punch profile was then applied to actual tee forming using the developed prediction equation. Model results were found to be in good agreement with experimental results.

• Geomechanics and Engineering
• /
• v.9 no.3
• /
• pp.373-395
• /
• 2015

Comprehensive results from cyclic plate loading at a diameter of 300 mm supported by layers of geocell are presented. The plate load tests were performed in a test pit measuring $2000{\times}2000mm$ in plane and 700 mm in depth. To simulate half and full traffic loadings, fifteen loading and unloading cycles were applied to the loading plate with amplitudes of 400 and 800 kPa. The optimum embedded depth of the first layer of geocell beneath the loading plate and the optimum vertical spacing of geocell layers, based on plate settlement, are both approximately 0.2 times loading plate diameter. The results show that installation of the geocell layers in the foundation bed, increase the resilient behavior in addition to reduction of accumulated plastic and total settlement of pavement system. Efficiency of geocell reinforcement was decreased by increasing the number of the geocell layers for all applied stress levels and number of cycles of applied loading. The results of the testing reveal the ability of the multiple layers of geocell reinforcement to 'shakedown' to a fully resilient behavior after a period of plastic settlement except when there is little or no reinforcement and the applied cyclic pressure are large. When shakedown response is observed, then both the accumulated plastic settlement prior to a steady-state response being obtained and the resilient settlements thereafter are reduced. The use of four layers of geocell respectively decreases the total and residual plastic settlements about 53% and 63% and increases the resilient settlement 145% compared with the unreinforced case. The inclusion of the geocell layers also reduces the vertical stress transferred down through the pavement by distributing the load over a wider area. For example, at the end of the load cycle of the applied pressure of 800 kPa, the transferred pressure at the depth of 510 mm is reduced about 21.4%, 43.9%, 56.1% for the reinforced bases with one, two, and three layers of geocell, respectively, compared to the stress in the unreinforced bed.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.1
• /
• pp.103-108
• /
• 2023

In this study, basic research was conducted to secure microbial resources applicable to autonomous crack healing concrete. To this end, in this experiment, biomineral-forming microorganisms were separated from natural sources, and the ability of survival in cement and calcium carbonate precipitation were compared to secure suitable microbial resources. Bacillus-type bacteria forming endospores were isolated from the sample, and the amount of calcium carbonate produced by the six microorganisms identified by 16S rRNA sequencing was compared. Two types of microorganisms, Bacillus velezensis and Bacillus subtilis, with the highest calcium carbonate precipitation were selected, and the survival of the microorganisms was confirmed through phase contrast microscopy after being cured after being added to the mortar. In addition, it was confirmed that the autonomous crack healing capability by the crack healing material produced by microorganisms was confirmed by artificially generating cracks in the mortar.

• Korean Journal of Environmental Biology
• /
• v.25 no.4
• /
• pp.349-355
• /
• 2007

Phylogeny of the species mainly from the genus Amynthas in family Megascolecidae was inferred at the molecular level using ITS regions in rDNA. With 26 species of earthworms from 10 genera in 2 families, a stretch comprising the 3'-end of the 18S rRNA, ITS1, 5.8S rRNA, ITS2, and 5' end of 28S rRNA was amplified by applying the primers ITS-1, ITS-2. Phylogenetic analyses of nucleotide sequences with a help of MP, NJ, and QP yielded 5 groups similarly. Genus Amynthas was separated largely into two groups, Korean and Philippine origins. Species grouped into the 1st were Amynthas jirensis, A. agrestis, A. gucheonensis, A. sopaikensis, A. bubonis, A. multimaculatus, A. koreanus, A. dageletensis, A. heteropodus, A. odaesanensis, Pontoscolex sp., Pheretima sp. 1, and Dendropheretima banahawensis. Amynthas halconensis, A. isarogensis, A. mindrooensis, Pithemera sp. 2, Pithmera sp. 1, and Pleionogaster sp. clustered into one clade forming the 2nd group. Polypheretima sp. 1 and polypheretima. sp. 2 stayed closely together representing a separate monophyletic status, forming the 3rd group, apart from species in other genera. Archipheretima sp. falls into the 4th group. Distinct morphological characteristics from Archipheretima also coinsides with its branching away from others in the previously reported molecular analyses. Similar to Perionyx excavatus that has been selected as an outgroup, Aporrectodea tuberculata also showed a long branch in the phylogram, but it differed from other 24 species included in the analyses. Unlike others, for example, its habitat is very closely related to that of man.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.3
• /
• pp.261-269
• /
• 2003

The length of the links in an eccentrically braced frame will dictate the behavior of the frame. Link length controls the yielding mechanism and the ultimate failure mode. For short links, the links' shear forces reach the plastic shear capacity before the end moments reach the plastic moment capacity, and the links yields in the shear, forming a shear hinges. These links are termed "shear links." For long links, the end moments reach the plastic moment capacity before the links' shear forces reach the plastic shear capacity, forming moment hinges. These links are termed moment links." In long links, flexural yielding dominates the response, and very high bending strains are required at the link ends to produce large link deformations. In a shear links, the shear force is constant along the length of the links, and the inelastic shear strain are is uniformly distributed over the length of the links. This permits the development of large inelastic link deformations without the development of excessively high local strains. However, The use of eccentrically braced steel frames for the purpose of architectural cionsiderations such as openings and doors, areis dictating the use of longer links, though. Little data areis available on the behavior of long links under cyclic loading conditions. In This paper documents the results of an experimental program is that was conducted to assess the response of moment links in eccentrically braced frames. Sixteen specimens awere tested using a cyclic load.

• Journal of Science of Art and Design
• /
• v.12
• /
• pp.125-143
• /
• 2007

The politics penetrating through the contemporary art since modernism to postmodernism is to accomplish the 'Non-representation' in the artworks. This study argues that postmodernism did not put an end to the formalistic feature of modernism but intended to accomplish it. Modernist art aimed at purity, i.e. self-referential and self-definition art advocated by Clement Greenberg, and it carne to the end by accomplishing flatness and materiality. It was an 'evasion to the matter' which allocated the object from visuality of outer object to the psychic image of the subject. It failed being 'non-representational' as what it really achieved was transition of object. Jean Baudrillard's theory tried to overcome the representational quality by 'being simulacre'. In the representative artworks of the past, the meaning of artworks was reverted under the outer context or object. The meaning again failed being 'Non-representational' as it was restored to the psychic image of the subject in modernist artworks where the definite illusion was demolished Meanwhile, artwork advocating simulacre acquired Non-representational quality by liberating from both models. It did not deconstruct the self-referential tendency of modernism but maximized the Non-representational modernistic principle. After creating 'Non-representation' through simulacre, the existential status and function of an artwork is the inclination and moral of contemporary art as 'Non-representation'. The image theory of Henri Bergson sets the existential status of 'image' as it does not belong to either subject nor object. It provides significant foundation for arguing the existential status of simulacre. Moreover, though an artwork as a fragment forming a movement image in the world cannot represent the object, it can however sustain certain kind of fractal resemblance with the world by letting the two parties communicate. The theory of sense by Gilles Deleuze is of profound significance as it specifically indicated way how the stage of absorption through the unity of subject and object is realized in forms of artworks, and configured the latent and invisible energy.