• International Journal of Aeronautical and Space Sciences
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• v.4 no.2
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• pp.88-94
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• 2003

This paper describes the design of the Ka-band Antenna/RF system, which was developed for the experiment of the high-speed satellite communications with geostationary satellite. The design issues described here are the ka-band characteristics for having an optimum performance. and the system characteristic for having a reliable and an extensional operation.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.1
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• pp.11-19
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• 2011

This study was carried out to investigate consciousness of users about management of multipurpose space introduced in open planned elementary school after the year of 1990's. Thirteen open planned elementary schools were participated through questionnaire and interviews. As the results, the positive response was maintained a superior position in the need of multipurpose space and changes of classroom management. Independence type in the arrangement of multipurpose space and the additional corridor type having extra moving line in comparison with the extensional corridor type were remarkably preferred, respectively. The consciousness of utilization about multipurpose space was comparatively low in a type having traffic line in surroundings of classroom compared to a type having entrance or a type having roundabout corridor. Finally, the group accepting changes positively showed high need to solve urgent problems about management of classroom.

• Journal of Korean Society of Steel Construction
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• v.24 no.3
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• pp.337-348
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• 2012

This study investigated the characteristics of bifurcation and the instability due to the initial imperfection of the space truss, which is sensitive to the initial conditions, and the calculated buckling load by the analysis of Eigen-values and the determinant of tangential stiffness. A two-free nodes model, a star dome, and a three-ring dome model were selected as case studies in order to examine the unstable phenomenon due to the sensitivity to Eigen mode, and the influence of the rise-span ratio and the load parameter on the buckling load were analyzed. The sensitivity to the imperfection of the two-free nodes model changed the critical path after reaching the limit point through the bifurcation mode, and the buckling load level was reduced by the increase in the amount of imperfection. The two sensitive buckling patterns for the model can be explained by investigating the displaced position of the free node, and the asymmetric Eigen mode was a major influence on the unstable behavior due to the initial imperfection. The sensitive mode was similar to the in-extensional mechanism basis of the simplified model. Since the rise-span ratio was higher, the effect of local buckling is more prominent than the global buckling in the star dome, and bifurcation on the equilibrium path occurring as the value of the load parameter was higher. Additionally, the buckling load levels of the star dome and the three-ring model were about 50-70% and 80-90% of the limit point, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.05a
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• pp.103-105
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• 2006

The revised legislation is introduced that the extension of the balcony area for the apartment houses is allowed. In the past the tenants had to install them illegally by themselves when they wanted to extend their balcony. We have reviewed the standard of the balcony's windows to be set up for them because the contractors can construct the exterior windows. At present, the detailed capacity standard for them is not established Of course some items of them are classified within five capacities among the KS standards. But the standard of the extensional balcony windows are not defined. Therefore this study is aimed at setting up the criteria of the noise, insulation and leak for the window system in expanding the balcony area and adopting it into window's works.

• KIEAE Journal
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• v.8 no.1
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• pp.11-18
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• 2008

The purpose of this study is to analyze application methods and structural characteristics of each element of environment-friendly European housing through classification of skin types. The results of the study are following. 1) The skins are classified by three types; single skin with multi layers, double skin with single layer and double skin with multi layers. 2) Most single skins with multi-layer are composed with wooden louvers, sun blinds and insulating windows. There are introduction of atrium and balcony, and variation sectional space composition according to cases. 3) There are two types of double skins; to put cavity between inner skin and outer skin and more extensional spaces such as balconies, corridors and stair halls. Solar walls and mechanical ventilators are often introduced to double skins with multi-layer. 4) The functions of the latest environment-friendly skins are vary from controllers and buffers of indoor environmental elements such as temperature, light, air and sound to equipments to perform essential functions to efficiently operate HVAC systems.

• Journal of Korean Philosophical Society
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• v.116
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• pp.1-31
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• 2010

This Article studies a meaning of geometrical-mathematical spatial idea in the source of modern theories of space. Modern theories of space elucidated a relation of human and space through the geometrical terms; point, line, plane and extension etc. Descartes and Newton identified space as a natural realty, Leibniz and Kant elucidated space as a subjective idea or form. It is the result of modern spatial theories that space is lied nearly in human. In the meaning of natural space, space is empirically unfolded with a shape of measuring in front of human's eyes. In the meaning of cognitional space, space is a method or subjective cognitional form that human understands nature and constitutes world. Modern theories of space would be divided into four patterns. In Newton's theory space is absolutely prior to things. In Leibniz' theory space is a co-existence order of Monads. In Descartes's theory space is identified with extension. In Kant's theory space is cognitional form of subject. They all are confronted with each other in the source of space. In their confrontation they reflected on the relation of human and space in their own standpoint. We classify their particularly differential concepts of space into natural space and cognitional space. And then we analyze a difference of spatial meanings, and then investigate foundations of meaning of modern theories of space. On the one hand they are become to the source of alienation of human from space. But on the other they are contributed to get space familiar with human through a wakening for the correlation of human and space. The natural space indicates that with measurable shape space is extended really in front of human's experiential eyes. But the cognitional space elucidates that space is only a subjective idea or form with which human understands nature and constructs world. In the former it is embossed that space is independent to human, and is able to be measured and to be treated according to natural raws. In the latter it is evidenced that space is not separated to human, and that space is not without human, and a correlation existed between human and space. Humanist ideal is declared in them. It was a declaration of human sovereignty to nature. But this declaration is caused to alienate human beings from space.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.10-20
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• 2003

In this study, the effective properties were numerically calculated for laminated plain weave textile composites with arbitrary s tacking orientation angles. A single-field macroelement with modified sub-domain integration was used in the analysis to reduce computer resource requirement while efficiently accounting for the internal microstructure. A sample calculation procedure based on the Monte Carlo method was employed to consider the random shift between the layers. Results showed that a significant deviation occurred when the orientation angles were near 0 deg for extensional modulus and Poisson's ratio and 45 deg for the shear modulus. It was also found that the average properties calculated by the 2-layer numerical specimen had large differences compared to the CLT results, which indicated that a caution must be needed when designig of thin plain weave composite structures.

• Journal of the Korea Furniture Society
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• v.21 no.6
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• pp.439-448
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• 2010

Furniture world which is closely associated with human life had been constantly developed, but traditional furniture disappeared after modernization almost. The reason lies rather in the importance of the diversity of Western-style furniture pursuing convenience and shapes, than in change of life style meanwhile. The diversity however reached the limit and it made a new advanced role of not only furniture, also design sector in general necessary, and as solution to solve this problem the immaterial value based on Eastern philosophy/mental was suggested in architecture and all around design sector overall as well. It means that the immaterial point which traditional furniture involved should be focused now and furthermore it's emotional and mental value which is more natural and has close relation with human being accordingly could be judged rightly. The reason why traditional furniture had been used since long time is the immaterial tendency which is well harmonized with the surrounding environment rather than the function. To verify this, the present study aimed to analyze not only the basic, also additional function of traditional furniture used in Hanok (traditional Koran-style house) by the inductive method for investigating the additional effects which users felt. Such immaterial role offers the user more convenience besides the original function of furniture and this made it available that furniture dominates the space. As good examples of such roles it was investigated that traditional furniture played meaningful roles like extensional serviceability, variable space, formation & movement of space, expression of grade of rank. That allowed that this study suggested the sustainable design and also the direction of development of interactive function of furniture through the expected effect having been showed in the modern space where the immaterial role of traditional furniture was applied to and the related cases.

• Korean Journal of Applied Biomechanics
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• v.14 no.3
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• pp.1-15
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• 2004

The purpose of this study was to investigate the kinematic variables of the upper part of the body for 8 elderly men during walking. For this study, kinematic data were collected using a six-camera (240Hz) Qualisys ProReflex system. The room coordinate system was right-handed and fixed in space, with righted orthogonal segment coordinate systems defined for the head, trunk, and pelvis. Based on a rigid body model, reflective marker triads were attached on the 3 segments. Three-dimensional Cartesian coordinates for each marker were determined at the time of recording using a nonlinear transformation(NLT) technique with ProReflex software (Qualisys, Inc.). Coordinate data were low-pass filtered using a fourth-order Butterworth with cutoff frequency of 6Hz. Three-dimensional angles of the head, trunk, and pelvis segment were determined using a Cardan method. On the basis of each segment angle, angle-angle plot used to estimated the movement coordinations between segments. The conclusions were as follows; (1) During the support phase of walking, the elderly people generally kept their, head the flexional and abductional posture. Particularly, the elderly displayed little internal/external rotation. (2) The elderly people showed extensional and external rotation postures in the trunk movement. Particularly, It showed the change from adduction into abduction at the heel contact event of the stance phase. (3) The elderly people showed almost same pelvis movement from the flexion into extension, from the abduction into adduction, and from internal rotation into external rotation at the mid stance and toe off of the stance phase.

• Tunnel and Underground Space
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• v.13 no.1
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• pp.44-51
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• 2003

Changes of the hydraulic conductivity resulting from the redistribution of stresses by underground excavation are examined using the strain-dependent hydraulic conductivity modification relation, where the modulus reduction ratio and induced strain are the major parameters. The modulus reduction ratio is defined in terms of RMR(Rock Mass Rating) to represent the full gamut of rock mass condition. Though shear dilation has the effect on the modification of hydraulic conductivity, the extent of it depends on RMR When the extensional strain is applied to a fracture, the hydraulic conductivity increases with the decrease of RMR Loading configuration has the effect on the modification of hydraulic conductivity, where the differential stress mode with a magnitude of the minimum principal stress $($\sigma$_x)$ fixed and a magnitude of the maximum principal stress $($\sigma$_y)$ varied is found to exert the greatest effect on the change of hydraulic conductivity.