• Journal of the Korean GEO-environmental Society
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• v.13 no.11
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• pp.69-79
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• 2012

This pre-supported nail method is able to decrease ground displacements more than NATM because this method reinforces ground with grouted steels before tunnel excavation. Therefore this method has advantage of being able to increase the stability and workability. This study presents applicability of pre-supported nail method with case of site measurement for shallow tunnel composed with high groundwater level and unconsolidated soil, performs this research the mechanism of new supporting system is compared with the conventional existing supporting system in terms of soil reinforcement. NATM has characteristics that construction stage displacement of the apparent height difference is observed in the step of divided excavation processing. Otherwise it is analyzed that pre-supported nail method is not sensitive in the displacement problem of excavation processing in comparison to NATM. It is found that this method is very applicable in shallow depth tunnel such as portal area, tunnel in soil and weak zone without arching effect.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.79-88
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• 2009

In this study, it was studied on arching characteristics of a grand section tunnel with pre-steel-rib nail reinforcement. In this study, we examine the adaptation of tunnel plan and the case which is based on the strengthening method for preexistence tunnel and other pre-steel-rib nail while the upper part of cover depth is low or soil condition is bad. When the pre-steel-rib nail as new technology and method reinforces the foundation placed of grand section tunnel, it is much better in strengthening effect, safety and effectiveness than the conventional one. After investigation about the plan pre-steel-rib nail method, construction case and calibration data, it was confirmed and examined about the upper part of tunnel for strengthening the pre-steel-rib nail thereby arching characteristics of grand section tunnel using MIDAS/GTS finite element program. Moreover we present the method that could upgrade the accurate installation interval and adaptation method for strengthening effect to adapt the pre-steel-rib nail method in a foundation placed over a tunnel.

• Journal of the Korean Geotechnical Society
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• v.25 no.7
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• pp.11-21
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• 2009

This paper presents a new high-performance supporting system of the shallow tunnel. In order to perform this research the mechanism of new supporting system is suggested and compared with the conventional existing supporting system. It is found that the new supporting system as pre-support system has several advantages such as improvement of ground before tunnel excavation and increment of capacity of the tunnel support. The construction procedures of this supporting system are also reviewed. In addition, the numerical simulation is carried out to evaluate the new supporting system. It is found that the new high-performance supporting system is very applicable in shallow depth tunnel such as portal area, tunnel in soil and weak zone, and so on.

• Magazine of korean Tunnelling and Underground Space Association
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• v.18 no.4
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• pp.40-56
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• 2016

• (The)Study of the Eastern Classic
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• no.35
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• pp.275-295
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• 2009

The aim of this paper is to reject Graham's interpretation of bi (必) and xianzhi (先知) of Later Mohists' Mojing ("墨經") as logical necessity and a priori knowledge respectively. Graham's interpretations of them are based on his beliefs that Mojing distinguishes lun (論), the art of description from bian (辯), the art of inference in the Mohist disciplines and that the latter art should be seen as such a rigorous proof as Euclidean geometry even though it is not a Western formal logic. His beliefs also start from his distinguishing 'knowledge of names' from 'knowledge of conjunction of names and objects' according to the objects of knowledge. In my reading, the art of description and the art of inference, however, can't be sharply distinguished each other in Mojing and bi and xianzhi should be taken as suggesting both a normative necessity and an empirical necessity. A normative necessity is derived from 'normative theory of definition' which comes form the theory of rectification of names in China. The normative theory of definition, unlike the descriptive theory of definition, defines terms normatively rather than descriptively. For example, although such a definition of father, 'father is beneficient', has the form of being descriptive, but it actually is prescriptive and therefore means 'father should be beneficient'. Through this normative theory of definition, empirical knowledge, as long as it is a knowledge, is seen as necessary and so can't be wrong. To conclude, for Mohists an empirical knowledge is always a basis of an inferential knowledge or a priori knowledge, so Mohists' a priori knowledge is not really a fundamental knowledge and its necessity therefore is nothing but both a normative necessity and an empirical necessity.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.668-671
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• 2002

Anomalous origin of the coronary artery in children is a rare disease. Especially anomalous origin of the left coronary artery from pulmonary artery(ALCAPA) is a fatal condition in neonates with myocardial failure. Among the ALCAPA, origin of the circumflex coronary artery from the pulmonary artery is an extremely rare congenital coronary anomaly. We report a case of reimplantation of the left circumflex coronary artery from the left pulmonary artery to the ascending aorta in a 4-year-old girl.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.1
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• pp.95-103
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• 2010

In this paper, a new soft ground tunneling technique termed the PNT method(Pre-Nailed Tunneling Method) is studied. Mechanism of the method is investigated in terms of theoretical and numerical approaches. The pre-nailing effects are validated by performing two dimensional numerical analyses. It is identified that the method is successful in soft grounds, and greatly efficient in reducing the ground deformation by nailing the ground. To develop the design guidelines of the method, numerical parametric analyses on the installation range and angle were also carried out.

• Journal of the Korean GEO-environmental Society
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• v.17 no.11
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• pp.45-53
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• 2016

A precast panel wall system resists against the horizontal earth pressure by increasing the shear strength of ground by reinforcement connected to the panel. The application of precast panel wall system is growing to lately minimize the earth work and environmental damage caused by large cut slope and to use the limited land effectively. The ground adhered panel wall system is the construction method that has the panel engraved with natural rock shape to improve the landscape. This system is developed to complete Top-Down method, and it is possible to have vertical cut, and to adhere to in-situ ground, improve construction ability by minimizing the ground relaxation and exclusion the trench and backfill process. In this study the field tests were performed to verify the construction ability about the vertical cut and complete Top-Down process and the construction behavior of ground adhered panel wall system was analyzed by large scale loading test and measurement results during loading test.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.7 no.4
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• pp.19-25
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• 1993

The purpose of this study was to investigate the scope of color perception for Korean standard color. 99 male and 126 female university students were selected as the random sample. Color perception was made with the naked eyes. Minolta Chroma Meter CR 300 was used for physical measurement of the color. The results were as follows, 1) Color perception was classified into four large groups: simple group includes Red, Yellow Red, Pale Red Yellow, Yellow, X( -axis)group includes Pale Yellow Red, Pale Green Yellow, Green Yellow, Purple, Pale Red Purple, Y( -axis)group includes Pale Blue Green, Blue Green, Pale Green Blue, Blue, Pale Ptuple Blue, complex group includes Pale Yellow Green, Green, Purple Blue, Pale Blue Purple, Red Purple, Pale Purple Red. 2) There is little difference between the values of standard color and mean percept color for Blue, Yellow, Pale Green Yellow, Green Yellow, Pale Yellow Green, Green, Pale Blue Green, Blue Green, Purple, while big difference for Blue, Pale Green Blue, Pale Red Purple, Pale Purple Red. 3) As for as sex was concerned, female is more accurate than male in color perception.

• Journal of The Korean Association For Science Education
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• v.40 no.3
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• pp.307-320
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• 2020

This study explores how the positioning of two pre-service science teachers (PSTs) is reflected in their different epistemic understandings of inquiry-based lessons. We collected the PSTs' products during their design and enactment of an inquiry-based lesson and recorded their practices in the enacted lesson. Interviews were recorded and transcribed for analysis. The results indicate that one PST, Dohyung was positioned as a subject of evaluation throughout the course and the other, Jinwoo, was positioned as a preservice teacher and a subject of evaluation. Their positions were reflected in their epistemic understandings of inquiry-based lessons, which were developed when designing these lessons. During lesson design, both PSTs showed a shared understanding; they explained inquiry-based lessons as students setting and evaluating hypotheses under teachers' guidance. However, as they faced unexpected situations during lesson enactment, they developed different epistemic understandings. To receive a good grade, Dohyung showed a strong preference for anticipating situations that could occur in class and planning responses to them. He understood inquiry-based lessons as ones in which students conduct experiments to produce results expected by the teacher. On the other hand, Jinwoo emphasized the reasoning process based on students' prior knowledge and explained inquiry-based lessons as ones in which students construct new knowledge through a scientific reasoning process based on their knowledge. The findings of this study will contribute to developing strategies to support PSTs' development of their epistemic understandings of knowledge construction in inquiry-based lessons.