• Architectural research
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• v.13 no.3
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• pp.19-29
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• 2011

Visibility of a space have been defined in several different ways: such as the axial line covering a convex space, a convex space defining the fattest shape in a space and an Isovist field formed by a field of vision at a given vantage point. Isovist fields are referred to as a descriptive medium to describe a movement by reviewing and analyzing geometric properties in them. Many descriptive methods for analysis of three-dimensional isovist are applied to analyzing the morphological properties in a 3D space more realistically. Although these models are regarded as a more advanced method for describing spatial properties, they have pros and cons such as complex mathematical calculations and somewhat arbitrary calibration in addition to huge consumption of memory space. These difficulties lead to the development of a three-dimensional visual accessibility model that explores the implication of building shape on the calculation of isovist fields drawn on a 2D plane. We propose a conceptual framework of how to measure the isovist field not as a 3D volume but as a combination of 2D plane on the ground with the 3D building shape of it's facade.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.2
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• pp.69-79
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• 1994

The conventional machine vision system which has uniform rectangular grid requires tremendous amount of computation for processing and analysing an image especially in 2-D image transfermations such as scaling, rotation and 3-D reconvery problem typical in robot application environment. In this study, the imaging system with nonuiformly distributed image sensors simulating human visual system, referred to as Ploar Exponential Grid(PEG), is compared with the existing conventional uniform rectangular grid system in terms of image resolution and computational complexity. By mimicking the geometric structure of the PEG sensor cell, we obtained PEG-like images using computer simulation. With the images obtained from the simulation, image resolution of the two systems are compared and some basic image processing tasks such as image scaling and rotation are implemented based on the PEG sensor system to examine its performance. Furthermore Fourier transform of PEG image is described and implemented in image analysis point of view. Also, the range and heading-angle measurement errors usually encountered in 3-D coordinates recovery with stereo camera system are claculated based on the PEG sensor system and compared with those obtained from the uniform rectangular grid system. In fact, the PEC imaging system not only reduces the computational requirements but also has scale and rotational invariance property in Fourier spectrum. Hence the PEG system has more suitable image coordinate system for image scaling, rotation, and image recognition problem. The range and heading-angle measurement errors with PEG system are less than those of uniform rectangular rectangular grid system in practical measurement range.

• Journal of Korean Association for Spatial Structures
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• v.17 no.4
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• pp.133-140
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• 2017

Recently, the interest in the smart buildings is increasing in the architecture field. Among them, a research of facade design using a transformable system that can adjust the effect of the external environment is in progress. One of a typical example of the deployable system is a Scissors system that can change shape by using the geometric conditions of a unit member. Scissors system is a high-tech structural system which can construct the deployable plan and curved space by using the SLE (Scissors-Like Element) consisted of two Bar and Pivot. If the facade is designed by applying Scissors system, it is possible to maximize the performance and aesthetic effect of the structure by using a shape change of the line member. This paper presents a study of deployable facade design applying hybrid-typed Scissors system. A new deployable pattern of facade design is developed by combining Angulated Scissors system and tessellation pattern. Applying the deployable pattern a double skin construction method which is to add an outer wall for design, it raises three dimensional effects and can maximize the artistic essence of the change in shape upon deployment.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2797-2804
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• 1994

This paper analyzes the behaviors of corrugated membrane under the cryogenic liquid pressure and thermal loading using the FEM analysis program MARC. The FEM calculations were carried out on the basis of measured data of Technigaz membrane. It is very important to know the concentration levels and distributions of stress in the corrugated membrane. A quarter of the membrane sheet in place of the whole membrane was simulated because of its geometric symmetricity. The calculated results of the concentrated stress showed that the maximum stress occurs at the knot parts and at the root corner radius of the corrugations. The FEM calculated results indicated that the ring knot membrane which was developed in this study showed uniformly distributed stress and the lowest stress levels in the cross knot area in comparison with other two membranes. These results are very important to optimize the shape and improve the safety of membrane structure.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.13-19
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• 2008

A Wire-woven Bulk Kagome (WBK) is the new truss type cellular metal fabricated by assembling the helical wires in six directions. The WBK seems to be promising with respect to morphology, fabrication cost, and raw materials. In this paper, first, the geometric and material properties are defined as the main design parameters of the WBK considering the fact that the failure of WBK is caused by buckling of truss elements. Taguchi approach was used as statistical design of experiment(DOE) technique for optimizing the design parameters in terms of maximizing the compressive strength. Normalized specific strength is constant regardless of slenderness ratio even if material properties changed, while it increases gradually as the strainhardening coefficient decreases. Compressive strength of WBK dominantly depends on the slenderness ratio rather than one of the wire diameter, the strut length. Specifically the failure of WBK under compression by elastic buckling of struts mainly depended on the slenderness ratio and elastic modulus. However the failure of WBK by plastic failed marginally depended on the slenderness ratio, yield stress, hardening and filler metal area.

• Journal of computational fluids engineering
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• v.14 no.1
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• pp.78-85
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• 2009

A combined theoretical and numerical study is conducted to design a slit nozzle for large-area liquid coating. The objectives are to guarantee the uniformity in the injected flow and to provide the capability of explicit control of flow rate. The woking fluid is a dilute aqueous solution containing single-walled carbon nanotubes and its low viscosity and the presence of dispersed materials pose technical hurdles. A theoretical analysis leads to a guideline for the geometric design of a slit nozzle. The CFD-based numerical experiment is employed as a verification tool. A new flow passage unit, connected to the nozzle chamber, is proposed to permit the control of flow rate by using the commodity pressurizer. The numerical results confirm the feasibility of this idea. The optimal geometry of internal structure of the nozzle has been searched for numerically and the related issues are discussed.

• KIEAE Journal
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• v.11 no.6
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• pp.95-100
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• 2011

Although Space Syntax is a well-known technique for spatial analysis, debates have taken place among some researchers because the Space Syntax discards geometric information as both shapes and sizes of spaces, and hence may cause some inconsistencies. Therefore, this study aims at developing methods to recognize and manage spatial shapes for more precise space syntax analysis. To reach this goal, this study employed both a graph theory and binary spatial partitioning (BSP) tree to recognize and manage spatial information. As a result, spatial shapes and sizes could be recognized by checking loops in graph converted from spatial shapes of built environment. Each spatial shape could be managed sequentially by BSP tree with hierarchical structure. Through such recognition and management processes, convex maps composed of the fattest and fewest convex spaces could be drawn. In conclusion, we hope that the methods developed here will be useful for urban planning to find appropriate purposes of spaces to satisfy the sustainability of built environment on the basis of the spatial and social relationships in urban spaces.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.3
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• pp.5-13
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• 1996

This study is about to prove one factor among many ones that contribute to the formation of the Japanese Garden's pattren. It is believed by this study that distinguished Japanese Garden's pattren are made possible by an organized ability of the japaneses traditional landscape artists who had ability to develope a diversified forms of applications within the organized framework. To verify this assumption, the study has chosen Ryu Gen In, temple garden that is considered to determine the pattren of Japanese Garden best with a new concept ; Organization. The results of this analysis show as follows : 1. Ryu Gen In, consists of a series of building and five-small gardens, is largely organized by the union of two geometric formations : concave and convex. Each garden as a sub-organization is further organixed with a series of tree-branch typed structure. 2. The five-small gardens are formed jinto a whole system by connecting each one with floor. This connection makes a timely organization. 3. Each small garden is further organized alloted roles, namely, depends upon whether they play a major or minor role. 4. It is believed that sands and moss play a cotrolling role to conbine the elements into one within each unit of small garden. 5. It is found that figured sands, moss, sands and moss, or shrubs are used as means of organization to connect the small group elements within each small gardens. 6. It is considered that buildings and mud-walls are used as means of separation between Ryu Gen In and an outer world, and betwen small gardens.

• Composites Research
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• v.16 no.5
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• pp.1-6
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• 2003

As the use of composites has become popular in recent years, the design of the composite joints has become a very important research area because the structural efficiency of the composite structure is determined by its joints, not by its basic structures. In this paper, presented comparisons of numerical results by the FAI(Failure area index) method[9] and measured data for a various geometric shapes and stacking sequence justify the validity of the FAI method. The FAI method is shown to produce very favorable comparisons with measured failure loads of mechanically fastened composite joints with the difference well within 9.96% for all II cases investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.83-88
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• 2006

One of the most important works in the development of military aircraft is to construct and utilize the various technical data and information needed in the design, analysis and evaluation under integrated system structure. A vast and various data in oder to optimize cockpit design is needed in geometric & arrangement design, vision analysis and escape system design. In addition, the application of ergonomics cockpit design concept based on the sorts of human elements and anthropometric data as design consideration for pilots is required. To accomplish above these activities, the data gathered and formed through the aircraft development program was become database and developed by tool to be able to support ergonomics cockpit design work.