• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.298-307
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• 2019

The evolution of the cavity and the variation of the drag for an underwater body with control fins are investigated through a numerical analysis of the steady cavitating turbulent flow. The continuity and the steady-state RANS equations are numerically solved using a mixture fluid model for calculating the multiphase turbulent flow of air, water and vapor together with the SST $k-{\omega}$ turbulence model. The method of volume of fluid is applied by the use of the Sauer's cavitation model. Numerical solutions have been obtained for the cavity flow about an underwater body shaped like the Russian high-speed torpedo, Shkval. Results are presented for the cavity shape and the drag of the body under the influence of the gravity and the free surface. The evolution of the cavity with the body speed is discussed and the calculated cavity shapes are compared with the photographs of the cavity taken from an underwater launch experiment. Also the variation of the drag for a wide range of the body speed is investigated and analyzed in details.

• The Journal of Korean Philosophical History
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• no.38
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• pp.97-128
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• 2013

Originally confucianism is closer to communitarianism than to individualism. The ideal of confucianism is to realize ethical community. Chu Hsi's theory of the Song dynasty reestablishes the ideal of ethical community and dignitaries(士大夫) take the job to realize it as their own vocation. There are many developed 'family clans and kinsfolk societies', 'local covenants and sacred storehouses' and 'private academies' in the Chosun dynasty as in the Song dynasty. These communities are three kinds of axial confucian community, which are both natural ascriptive groups and voluntary contract groups in nature. Communities of Chosun dynasty are to strengthen the solidarity through friendship and mutual help as well as to cultivate good customs in society. Also these traditional communities are managed by democratic procedures, as these are originally voluntary contract groups. On the other hand, traditional neo-confucian self-training theories like that individual personality should be harmony with general order, or one should pursuit his private interest according to fair principles are the process of sublimation private individual into public citizen.

• Korean Journal of Social Welfare
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• v.62 no.3
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• pp.299-321
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• 2010

The purpose of this study was to analyze the development of social welfare network. The qualitative case study method was utilized from a communities of practice perspective. Depth interviews were conducted among 10 social workers of community welfare agencies who have practiced network activities. Data were analyzed with constant-comparative methods(Strauss and Corbin(1990)). The result are the followings; In incubation stage, the core theme was "collaboration for surmount overcoming difficulties from the bottom". In intergration stage, "acquirement of normative value basement" was emerged. "Reinforcement of solidarity" and "reconfirmation of identity" were drawn as core themes in muturation stage. There were core themes "construction of original image" and "shifting from private connection to public connection" in maintenance stage. Lastly stage a care theme of "qualitative transition" was emerged in transformation.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.

• The Korean Journal of Air & Space Law and Policy
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• v.24 no.2
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• pp.187-210
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• 2009

Space law(or outer space law) and the law of the sea are branches of international law dealing with activities in geographical ares which do not or do only in part come under national sovereignty. Legal rules pertaining to the outer space and sea began to develop once activities emerged in those areas: amongst others, activities dealing with transportation, research, exploration, defense and exploitation. Naturally the law of the sea developed first, followed, early in the twentieth century, by air law, and later in the century by space law. Obviously the law of the sea, of the air and of outer space influence each other. Ideas have been borrowed from one field and applied to another. This article examines some analogies and differences between the outer space law and the law of the sea, especially from the perspective of the legal status, the exploration and exploitation of the natural resources and environment. As far as the comparisons of the legal status between the outer space and high seas are concerned the two areas are res extra commercium. The latter is res extra commercium based on both the customary international law and treaty, however, the former is different respectively according to the customary law and treaty. Under international customary law, whilst outer space constitutes res extra commercium, celestial bodies are res nullius. However as among contracting States of the 1967 Outer Space Treaty, both outer space and celestial bodies are declared res extra commercium. As for the comparisons of the exploration and exploitation of natural resources between the Moon including other celestial bodies in 1979 Moon Agreement and the deep sea bed in the 1982 United Nations Convention on the Law of the Sea, the both areas are the common heritage of mankind. The latter gives us very systematic models such as International Sea-bed Authority, however, the international regime for the former will be established as the exploitation of the natural resources of the celestial bodies other than the Earth is about to become feasible. Thus Moon Agreement could not impose a moratorium, but would merely permit orderly attempts to establish that such exploitation was in fact feasible and practicable, by allowing experimental beginnings and thereafter pilot operations. As Professor Carl Christol said until the parties of the Moon Agreement were able to put into operation the legal regime for the equitable sharing of benefits, they would remain free to disregard the Common Heritage of Mankind principle. Parties to one or both of the agreements would retain jurisdiction over national space activities. In so far as the comparisons of the protection of the environment between the outer space and sea is concerned the legal instruments for the latter are more systematically developed than the former. In the case of the former there are growing tendencies of concerning the environmental threats arising from space activities these days. There is no separate legal instrument to deal with those problems.

• Journal of The Korean Association For Science Education
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• v.32 no.5
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• pp.805-822
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• 2012

The purpose of this study was to explore the patterns of group model development about blood flow in the heart and reasoning process by small group interaction. The subjects were 14, 8th graders in a Science Gifted Center. The group discussion was made possible by using triggering questions that can be answered based on experiences of hands-on activities such as a siphon pump analogy model activity and a dissection of pigs' hearts. Despite participating in same activities, the groups showed different model development patterns: unchanged, persuasive, and elaborated. Due to the critical revising, the group's explanatory model was elaborated and developed in the added and elaborated pattern. As critical revising is a core element of the developing model, it is important to promote a group interaction so that students become critical and receptive. The pedagogical analogy model and conflict situation enabled students to present elaborated reasoning. The Inquiry activity with the pedagogical analogy model promote students' spontaneous reasoning in relation to direct experience. Therefore offering a pedagogical analogy model will help students evaluate, revise and develop their models of concerned phenomena in science classroom. Conflict situation by rebuttal enable students to justify more solid and elaborate a model close to the target model. Therefore, teachers need to facilitate a group atmosphere for spontaneous conflict situation.

• Journal of the Korean Geotechnical Society
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• v.25 no.10
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• pp.17-30
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• 2009

Underground construction such as tunneling can induce damages on the surrounding rock mass, due to the stress concentration of in situ stresses and excessive energy input during construction sequence, such as blasting. The developed damage on the rock mass can have substantial influence on the mechanical and hydraulic behaviors of the rock masses around a tunnel. In this study, investigation on the generation of damage around an opening in a jointed rock model under biaxial compression condition was conducted. The joint dip angles employed are 30, 45, and 60 degrees to the horizontal, and the synthetic rock mass was made using early strength cement and water. From the biaxial compression test, initiation and propagation of tensile cracks at norm to the joint angle were found. The propagated tensile cracks eventually developed rock blocks, which were dislodged from the rock mass. Furthermore, the propagation process of the tensile cracks varies with joint angle: lower joint angle model shows more stable and progressive tensile crack propagation. The development of the tensile crack can be explained under the hypothesis that the rock segment encompassed by the joint set is subjected to the developing moment, which can be induced by the geometric irregularity around the opening in the rock model. The experiment results were simulated by using discrete element method PFC 2D. From the simulation, as has been observed from the test, a rock mass with lower joint angle produces wider damage region and rock block by tensile cracks. In addition, a rock model with lower joint angle shows progressive tensile cracks generation around the opening from the investigation of the interacted tensile cracks.

• Journal of the Korean association of regional geographers
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• v.21 no.2
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• pp.304-318
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• 2015

As the number of foreigners who stay for a long time increases, their residential concentrations have emerged and developed. This research aims at investigating how and why immigrants' residential concentration sustains and develops. In order to understand the roles of the residential concentration for the immigrants' everyday, we used the framework of grunddaseins funktionen including residence, labor, shopping, education, leisure, commuting, and community activity. Accompanied is a case study of Daelim-dong which is the largest Chinese concentrations. The result shows that combined with co-ethnic preference in residence, various amenities at the concentrations attract new immigrants and hold existing immigrants, allowing the concentrations sustain and develop. It has been pointed out that there are the difference factors that foreign immigrants concentrate residentially: 'co-ethnic residential preference' for immigrants from more developed countries and 'discrimination' for immigrants from less developed countries. However this study shows that the residential concentrations for less-developed-country-immigrants could maintain and develop with grunddaseins funktionen based on co-ethnicity.

• Journal of Christian Education in Korea
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• v.68
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• pp.279-306
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• 2021

This paper intends to say that children's worship as a liturgy for children living in modern society is an important place to support children's personal development and experience of coziness necessary for their personal development. To this end, this thesis first regards modern society as an unstable society, analyzes fluid society and individualism as the causes, and deals with changes in educational style accordingly. In a fluid society, children are not provided with a solid form and lasting environment that supports personality development, and the education style changed under the influence of individualism and pluralism requires a heavy task of determining the direction of one's life and constantly making choices and decisions. Therefore, children need rules and forms that help them live together, and they need a space that can give them comfort that helps them develop their personality. As an argument for this, second, this paper deals with the concept and function of the liturgy in order to understand the worship of children as the liturgy. The third deals with the elements necessary for the development of children's personality that can be experienced in children's worship. First, it deals with the meaning of religious, aesthetic, and communal driving forces that children can experience in children's worship, focusing on Eberhard's research. In addition, it deals with the meaning of language and expression methods provided in children's worship, and finally, it says that children's worship can be a space where you can experience stability and coziness. Through this, it is emphasized that children's worship can play an important role in supporting the personal development of children living in modern times.

• Tunnel and Underground Space
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• v.24 no.4
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• pp.255-274
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• 2014

The target of this study is large scale rock slope collapsed by around 7 pm on August, 2012, which is located at ${\bigcirc}{\bigcirc}$ limestone quarries of Gangneung city, Gangwondo. The slope prior to the collapse is formed as the height of about 200 m and the average inclination of $45^{\circ}$. The estimated amount of the collapse is about $1,500,000m^3$ with respect to the slope after the collapse. Geotechnical and field investigations such as boring, geophysical prospecting, surface geological survey, geological lineaments, borehole imaging, metric 3D imaging, experimental and field test, mining work by year, and daily rainfall were performed to find the cause of rock slope failure. Various analyzes using slope mass rating, stereonet projection, limit equilibrium method, continuum and non-continuum model were conducted to check of the stability of the slope. It is expected that the cause of slope failure from the results of various analysis and survey is due to the combined factors such as topography, rainfall, rock type and quality, discontinuities, geo-structural characteristics as the limestone cavity and fault zones, but the failure of slope in case of the analysis without the limestone cavity is not occurred. Safe factor of 0.66 was obtained from continuum analysis of the slope considering the limestone cavity, so the ultimate causes of slope failure is considered to be due to the influence of limestone cavity developed along fault zone.