• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.182-192
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• 2001

During the deep drawing process an initially flat blank is clamped between the die and the blank holder after which the punch moves down to deform the clamped blank into the desired shape. In general, sheet metal forming may involve stretching, drawing, bending or various combinations of those basic modes of deformation. The deformation problems of sheet metal working involve non-linearity in geometry and material. In this work, The punch load and thickness strain of electro-galvanized sheet steel (SECD) for elliptical deep drawing are examined under the various process conditions including, punch shape radius, die shape radius. The changes of punch load and thickness strain distribution of the deformed elliptical cup are affected by the size of each die shape radius.

• Architectural research
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• v.15 no.2
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• pp.87-94
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• 2013

Throughout the history of architecture, sometimes the main focus of design was determined by a particular visual representation method, and other times a particular form of visual representation method was required by perception of a particular architectural issue or an architectural form or idea. That is why the visual representation method of architects becomes an important means of reading the flow of idea and thinking behind architecture. This study is an investigation on the relation between architectural thinking and visual representation method expressed through the conceptual drawings by avant-garde architects of the 1970s and 80s, a period of the emergence of postmodernism. Rather than proving the objective reality regarded important by traditional architectural drawing, attempts are made to express the design concept in which the project has its base. Such interpretation and explanation regarding the concept become the main interest of the drawing. It is not that the architecture itself was not expressed in the contents, but it may not be the main subject of expression in the drawing. The value of architectural drawing recovers its value as an art work in itself, as a means of communication, and as an important conceptual tool in the design process. It can be seen that the visual representation method in postmodern architectural drawings is breaking free of the traditional objective depiction of matter and is changing and developing as a design tool of the architect.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.55-64
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• 2008

This paper describes a research work of developing an automated progressive design system for manufacturing the product with multi processes such as piercing, bending, and deep drawing. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system consists of three main modules, which are shape treatment, strip layout, and die layout modules. Based on knowledge-based rules, the system is designed considering several factors, such as material and thickness of a product, piercing, bending and deep drawing sequence, and the complexities of the blank geometry and punch profiles. It generates the strip layout drawing for an automobile product. Die design for each process is carried out through the die layout module from the results of the strip layout module. Results obtained using the modules enable the designers for manufacturing products with multi processes to be more efficient in this field.

• Korean Journal of Materials Research
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• v.14 no.12
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• pp.851-856
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• 2004

The aim of this study is to investigate the optimum drawing parameter for BAS121 welded tubes. The BAS121 aluminium alloy tubes with 25 mm in external diameter and 1.3 mm in thickness for heat-exchangers were manufactured by high frequency induction welding with the V shaped convergence angle $6.5^{\circ}$ and power input 55 kW. With increasing the reduction of area ($13,\;21\%$) by drawing, tensile strength was increased and elongation was decreased. With increasing the reduction of area by drawing, hardness in weld metal increased rapidly, while that of base metal increased slowly. In the specimen with the outer diameter smaller than 22 mm, hardness of weld metal was higher than that of base metal. The optimum drawing parameter of area reduction in BAS121 alloys was estimated about $13\%$ because of the work hardening of welds.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.10a
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• pp.301-301
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• 2003

In current study, Nanocomposites are reinforced with carbon nanofiber, carbon nanotube and SiC, etc. Since the nano reinforcements have the excellent mechanical, thermal and electrical properties compared with that of existing composites, it has lately attracted considerable attention in the various areas. Cu have been widely used as signal transmission materials for electrical electronic components owing to its high electrical conductivity. However, it's size have been limited to small ones due to its poor mechanical properties. Until now, strengthening of the copper alloy was obtained either by the solid solution and precipitation hardening by adding alloy elements or the work hardening by deformation process. Adding the alloy elements lead to reduction of electrical conductivity. In this aspect, if carbon nanofiber is used as reinforcement which have outstanding mechanical strength and electric conductivity, it is possible to develope Cu matrix nanocomposite having almost no loss of electric conductivity. It is expected to be innovative in electric conducting material market. The unidirectional alignment of carbon nanofiber is the most challenging task developing the cooer matrix composites of high strength and electric conductivity. In this study, the unidirectional alignment of carbon nanofibers which is used reinforced material are controlled by drawing process and align mechanism as well as optimized drawing process parameter are verified via numerical analysis. The materials used in this study were pure copper and the nanofibers of 150nm in diameter and of 10∼20$\mu\textrm{m}$ in length. The materials have been tested and the tensile strength was 75MPa with the elongation of 44% for the copper. it is assumed that carbon nanofiber behave like porous elasto-plastic materials. Compaction test was conducted to obtain constitutive properties of carbon nanofiber Optimal parameter for drawing process was obtained by analytical and numerical analysis considering the various drawing angles, reduction areas, friction coefficient, etc. The lower drawing angles and lower reduction areas provides the less rupture of co tube is noticed during the drawing process and the better alignment of carbon nanofiber is obtained.

• Archives of design research
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• v.15 no.4
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• pp.347-358
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• 2002

Architectural drawing has been changing from the general notion, in which it is to predict what it may be like for purely practical purpose. Particularly amongst the Deconstructivists' work, graphic elements make a great contribution to the realization of their self expressive style. Whereas these are often chosen for solely aesthetic reasons, there are some cases in which the act of drawing itself is a crucial, investigative process. This is true of Daniel Libeskind's architectural drawing. For him, Typography seems to be characteristic of his drawing. He Harness typographic elements as metaphors for hid abstract symbolism through his architectural drawings, which retain the possibility to relate to the more radical typographic approaches. Within this context, this thesis will argue how the typographic elements in Daniel Libeskind's architectural drawings can be interpreted. What interconnection can be made between the two practices\ulcorner How can these elements be incorporated into architecture\ulcorner Can they be involved in it as a main constituent\ulcorner This thesis explores diverse possibilities of interpretation of his architectural drawing through typological approaches to the cases where type itself meets the different media and signific ation is given to the other typographic elements.

• Korean Institute of Interior Design Journal
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• no.8
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• pp.44-57
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• 1996

Now interior designers have to meet this challenge by rising to the occasion and taking advantage of opportunities while strengthening their skills which have not kept pace with the increasing emphasis on design. furthermore, they are hampered by the lack of a general working design methodology. Interior designers in Korea have been slow to recognize the need for developing a specification methodology manual which could be adapted to meet varying requirements and modified to reflect designers experiences. The design process in Korean interior design often involves utilizing drawing document methods based on architectural prototypes rather than upon drawing methods developed by design firms as a result of work experience s and unique needs. However, these unique nees are nearly always limited by traditional working drawing methods. This has led to confusion and inaccuracies due to the lack of a single starndardized and universally acceptable working drawing methodology which is capable of reflecting the needs of all parties involved , partiality those of interior designers. This thesis is an attmepted to establish the necessity for developing a better working drawing methodogoy or technical mans of satisfying the information sorting and processing need s of interior design professionals, a five step suggestion for developing such a methodology follows. First, arrange pertinent design research information by means of a process which can be employed throughout the design process, from inception through to working drawing stage. The end result should be an interior architectural design process culminating in a pattern skillfully blending architecture, vision and product with environment . The design process should be manifested into a series of definable steps and yet sufficiently flexible and variable in order to provide the most apropos design solution. Secondly , motify the design methodology systematically according to site conditions and prevailing construction technology and manifest the design process in a booklet form so that it reflects a desired pattern. Thirdly, this methodology should incorporate a stand-ardized and functional process capable of being utilized to impact clear design concepts and objectives with preci-sion and efficiency in a manual form.

• Journal of the Korea Institute of Building Construction
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• v.3 no.3
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• pp.113-120
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• 2003

The purpose of this thesis is to provide an appropriate trade-off information for the conflicting interests caused by the various factors between building owner and contractor during selecting the contractor and performing the construction work, in which the construction was contracted by open bidding from the government or private organizations. In order to propose the legitimate evidence, the differences between the domestic contract sheet of drawing change and the process of drawing change and those of the foreign countries were compared and analysed. The number of construction ordered in Youngdong area in 2001 whose construction expenses are more than 100,000,000 won is 218 items and 147,005,000,000 won in total cost. Among them, the number of 218 items whose total cost amounts to 16,705,000,000 (11.36%) is in case of increase of construction expenses due to the drawing changes, and the number of 48 items whose total cost amounts to 2,009,000,000 won (1.37%) is the case of decrease. In conclusions, the contractor could have more benefits than the building owner in case they submit the detailed estimate sheet without eliminating the increasing expenses of construction. It is shown that the building owner's loss is increasing whenever the labor cost is higher than material cost. Therefore, this thesis proposes a proper standards for the harmonious compromise between the contractor and the building owner for the problems caused by the drawing changes when the contract agreement is occurred.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.403-407
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• 2009

In this work, finite element investigations were carried out to manufacture a seamless aluminum liner without crack generation using four-stage deep drawing followed by two-stage ironing process. In order to predict the crack generation during the liner manufacturing process, the Normalize Cockroft-Latham(NCL) which is one of ductile fracture criteria was adopted. In addition, the tensile tests were carried out to obtain the critical value of NCL by comparing the experimental and FE simulation results. From this, various case studies based on FE simulation were carried to obtain the optimum die designs which can prevent the crack generation during ironing processes. Finally, the aluminum liner was successfully made using obtained die designs so that requirements were met in terms of thickness and height of the liner.

• Transactions of Materials Processing
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• v.14 no.4 s.76
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• pp.392-398
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• 2005

The deterioration of dimensional accuracy, caused by springback, is one of problems to always occur In sheet metal forming processes. As the demand for lighter and stronger metals increases, the development of improved forming processes settling the springback problem becomes more important. In this work, asymmetric springback phenomena are investigated, which occur in the shallow-drawing process with the anisotropic sheet metal and axisymmetric tools. The improvement possibility of dimensional accuracies, mainly, flatness, was examined by applying segmented blank holding forces as a method for springback control.