• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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• pp.163-173
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• 1996

Stereolithography is a process used to rapidly produce polymer components directly form a computer representation of the part. There are several considerations to be made for the efficient use of the process. Especially, the build-up orientation of part critically affects the part accuracy, total build time and the volume of support structures. The purpose of tis study is to determine the optimal build-up part orientation for the SLA process with improving part accuracy, and minimizing total build time and the volume of support structures. The forst factor is related to the area of surfaces whioch have staircase protrusions after solidification, the second factor is related to the total number of layers, and the third factor is related to the area of the surfaces which need to be supported with support structures. An algorithm is developed to calculate the staircase area, quantifying the process errors by the volume of materials supposed to be removed or added to the part, and the optimal layer thickness for the SLA system which can handle the variable layer thickness. So the optima l part orientation is determined based on the user's selections of primary criter- ion and the optimal thickness of layers is calculated at any part orientations.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.154-161
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• 1998

Prototypes of a design are always needed for the purpose of visualization and evaluation in the aspect of manufacturability functionality, and aesthetic appearance. Since the prototyping process requires a significant amount of cost and time, various rapid prototyping processes are recently being introduced in the process. However, it is usually necessary for a part built up by a rapid prototyping system to be refined by a post-processing process, in which the stair steps on the surfaces, the support structures (if they exist), and the unprocessed material are eliminated. This post-processing is usually done manually and is a time-consuming task. Especially, eliminating the trapped volumes, the volume of the unprocessed material entrapped by the solidified portion, is sometimes impossible in some processes. This study provides a designer with a tool to detect the existence and to calculate the quantity of the trapped volumes at the given build-up direction, so that the proper build-up direction is chosen or the part is built by pieces to avoid the problems caused by the trapped volumes in advance. Since the proposed algorithm can efficiently calculate the amount of the trapped volumes at any build-up direction, it has the potential of such application as optimizing the build-up direction to minimize the trapped volumes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.10a
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• pp.161-161
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• 2003

• (The)Study of the Eastern Classic
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• no.36
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• pp.31-56
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• 2009

The core thought of Confucius("論語") is 'Ren(仁)'. Then, how ought we to interpret this 'Ren(仁)'? In this study, the researcher has interpreted 'Ren(仁)' from the perspective of Xiujizhiren(修己治人), which is the doctrine of Confucianism and its ideal. At first, the researcher closely reviewed Ren(仁) on the viewpoint of Xiuyang (修養). Ren(仁) is the most fundamental virtue that enables general populace to equip with their qualification as a human being. Specifically, to live like a human being, Ren(仁) is a must. That is to say, it will suffice if we only can expose well what was already cherished inside us, rather than exerting efforts to attain Ren(仁), in some contexts, that must achieve in order to live like a human being. The reason that we exert our efforts for self-cultivation is to bring this Ren(仁), which is foundation of human life, before the public. Even in relationship-building, Ren(仁) is necessary. Human being is not an existence that can live alone, but at all times, humans are required to build a relationship with others. To make this relationship-building lead into right direction, we need to think of that the standpoint of oneself and the other are identical. That is, when I myself and the other person are in the most optimal situation, then a right relationship-building can take place. This most optimal status is Ren(仁). The ideal of Confucianism is to establish a society where all people can enjoy their comfortable life. To accomplish such a society, each individual and society ought to be benevolent and to cherish humanity at the first place. That is to say, people should attain Ren(仁) from both aspects of Xiuji(修己) and Zhiren (治人). If Ren(仁) has not been attained from any of either side, then it is hard to say that the ideal of Confucianism is completely realized. However, Zhiren(治人) must be backed up by Xiuji(修己). For this reason, Kongzi(孔子) presented three steps in connection with this cultivation process, to wit, 'Cultivation of himself in reverential carefulness'(修己以敬) ${\rightarrow}$ 'Cultivation of himself so as to give rest to others'(修己以安人) ${\rightarrow}$ 'Cultivation of himself so as to give rest to all the people'(修己以安百姓). It is noticeable that Xiuji(修己) is included in all three phases. The society that Kongzi(孔子) longed for is still valid in this modern world. Therefore, Ren(仁) which was edified by Kongzi(孔子) is necessary for today's society. If we don't interpret Ren(仁) as with a fixed term lying stagnant in one place, then its definition shall be interpreted newly so as to suit the times and the situation of civil society, thus this Ren(仁) shall be the foundation for building a desirable society for humans.