• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.136-141
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• 1973

DL-1-aminobutylphosphonic acid was synthesized from the pentanoic acid which was prepared from the butyl alcohol, by the modified Curtius reaction. DL-2-amino-2-carboxyethylphosphonic acid was also synthesized from the pyruvic acid was also synthesized from the pyruvic acid. Four previously unreported N-acylated derivatives were prepared according to the modified Schotten-Baumann method. They are as follows; N-acetyl-DL-1-aminobutylphosphonic acid, N-benzoyl-DL-1-aminobutylphosphonic acid, N-benzoyl-DL-2-amino-2-carboxyethylphosphonic acid, N-p-chlorobenzoyl-DL-2-amino-2-carboxyethylphosphonic acid. The products were identified by the methods of elemental analysis, infrared spectra, ninhydrin test and neutralization equivalent.

• Structural Engineering and Mechanics
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• v.58 no.4
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• pp.731-743
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• 2016

Plastic behaviors, based on the von Mises yield criterion, of circular discs containing a purely elastic, circular inclusion under uniform temperature loading are studied with the finite element analysis. Temperature-dependent mechanical properties are considered for the matrix material only. In addition to analyzing the plane stress and plane strain disc, a 3D thin disc and cylinder are also analyzed to compare the plane problems. We determined the elastic irreversible temperature and global plastic collapse temperature by the finite element calculations for the plane and 3D problem. In addition to the global plastic collapse, for the elastically hard case, the plane stress problem and 3D thin disc may exhibit a local plastic collapse, i.e. significant pile up along the thickness direction, near the inclusion-matrix interface. The pileup cannot be correctly modeled by the plane stress analysis. Furthermore, due to numerical difficulties originated from large deformation, only the lower bound of global plastic collapse temperature of the plane stress problem can be identified. Without considerations of temperature-dependent mechanical properties, the von Mises stress in the matrix would be largely overestimated.

• Journal of The Korean Association For Science Education
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• v.32 no.8
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• pp.1295-1317
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• 2012

There has been disagreement on the importance of definitions in science education. Yager (1983) believes that one crisis in science education was due to the considerable emphasis upon the learning of definitions. Hobson (2004) disagrees with physics textbooks that do not provide general definition on energy. Some textbooks explain that "there is no completely satisfactory definition of energy" or they can only "struggle to define it." In general, imprecise definitions in textbooks (Bauman, 1992) and inaccuracies in definition provided by teachers (Galili & Lehavi, 2006) may cause alternative conceptions. Besides, there are at least four challenges in defining physical concepts: precision, circularity, context and completeness in knowledge. These definitional problems that have been discussed in The Feynman Lectures, may impede the learning of physical concepts. A meta-study approach is employed to examine about five hundreds journal papers that may discuss definitions in physics, problems in defining physical concepts and how they may result in alternative conceptions. These journal papers are mainly selected from journals such as American Journal of Physics, International Journal of Science Education, Journal of Research in Science Teaching, Physics Education, The Physics Teachers, and so on. There are also comparisons of definitions with definitions from textbooks, Dictionaries of Physics, and English Dictionaries. To understand the nature of alternative conception, Lee et al. (2010) have suggested a theoretical framework to describe the learning issues by synthesizing cognitive psychology and science education approaches. Taking it a step further, this study incorporates the challenges in semantics and epistemology, proposes that there are at least four variants of alternative conceptions. We may coin the term, 'alternative definitions', to refer to the commonly available definitions, which have these four problems in defining physics concepts. Based on this study, alternative definitions may result in at least four variants of alternative conceptions. Note that these four definitional problems or challenges in definitions cannot be easily resolved. Educators should be cognizant of the four variants of alternative conceptions which can arise from alternative definitions. The concepts of alternative definitions can be useful and possibly generalized to science education and beyond.

• Cartoon and Animation Studies
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• s.19
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• pp.127-143
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• 2010

The purpose of this study is to aesthetically approach a game, which was popular at home, through microscopic analysis on World of Warcraft. World of Warcraft(hereunder called WOW), which improved a game method of MMORPG that had been popular conventionally at home, from several angles, is suggesting new paradigm of MMORPG game. This study aims to propose new vision on game analysis by approaching this new method from the perspective of player. For this, it divided WOW into shift method, instruction implementation method, and communication configuration method, and analyzed this, respectively, by introducing a concept of empty time, empty space, and non-place, which was borrowed from Zygmunt Bauman's "Liquid Modernity". WOW's shifting method rather extends empty time, that is, the waiting time, contrary to the conventional MMORPG, which used a method of removing. Instead of maximally reducing boring, which becomes disturbance of a game, it is what overwhelmingly enlarges time that needs to be waited, thereby being what induces a sense of time, which a player experiences daily life, to the inside of a game. WOW's instruction implementation method offers one of hugely single map instead of zone-system necessary for map loading in the discontinued form. This minutely implements even a greatly insignificant place in playing a game, thereby stirring up a sense of travel, which explores there in reality. Finally, WOW's community configuration method makes a hunting-targeted group clear, which added a concept of hunting called the raid to the existing gild system. The raid, which is a large party of being bound to the inside of Instant Dungeon, clearly gives a performance role to each of party members, thereby allowing the identity in character to be connected directly to the identity of player. Through this, the player filled the suggested 'space' with experience, thereby being able to change it into 'place' that is significant to an individual.