• Proceedings of the Korea Society of Design Studies Conference
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• 2001.10a
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• pp.49.1-49
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• 2001

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.233-236
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• 2004

The major objective of this paper is to clarify the effect of constitutive laws on bulk forming design based on the ideal flow theory. The latter theory is in general applicable for perfectly/plastic materials. However, its kinematics equations constitute a closed-form system, which are valid for any incompressible materials, therefore enabling us to extend design solutions based on the perfectly/plastic constitutive law to more realistic laws with rate sensitive hardening behavior. In the present paper, several constitutive laws commonly accepted for the modeling of cold and hot metal forming processes are considered and the effect of these laws on one particular plane-strain design is demonstrated. The closed form solution obtained describes a non-trivial nonsteady ideal process. The design solutions based on the ideal flow theory are not unique. To achieve the uniqueness, the criterion that the plastic work required to deform the initial shape of a given class of shapes into a prescribed final shape attains its minimum is adopted. Comparison with a non-ideal process is also made.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.140-151
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• 2000

Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. in the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert\`s knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program, two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.231-234
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• 2005

The ecological theory of perception provides the human living, and meaning integrating norm to overcome the crisis caused by an eastern belief in human-centered wrong rationality formed at the past process of modernization. Prior to the overall consideration of ecological perception theory, looked into the concepts, contribution extent and its limitation of the existing perception theories for the environmental design. By experimentally applying inferred concepts of design to department bridge space and forming the space, certified the applicability of it to the green amenity space. The site Is located in Nowon- Gu Sangge- Dong. The design was processed on the basis of survey, plants growth environment and plants characters. It is expected that this design would serve the commercial space- consumer as a symbolic, environmentally friendly space design

• Korean Institute of Interior Design Journal
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• no.16
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• pp.182-189
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• 1998

The existential space concept which introduced the sense of place that began emerging recently together with the change of space concept results from people's fundamental existential humane aspect as the subject of perceptive experience. The tendencies of enlargement layering and diversification which we can see in contemporary architecture imply the possibility that elements of urban image can be incorporated into interior design. This study utilizes Kevin Lynch's theory which tries to relate environment to existential space. In this study we re-analyze and apply Lynch's $\ulcorner$the Theory of Urban Image$\lrcorner$to interior space and using the conclusion from a case study examine the applicability of the theory about visual perception to interior design. This study considers a new method of analysis to perceive and grasp interior space through the understanding of the cognitive map and image concept.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.2
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• pp.484-495
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• 2014

This paper introduces the use of network theory to model and analyze disparate ship design information. This work will focus on a ship's distributed systems and their intra- and intersystem structures and interactions. The three system to be analyzed are: a passageway system, an electrical system, and a fire fighting system. These systems will be analyzed individually using common network metrics to glean information regarding their structures and attributes. The systems will also be subjected to community detection algorithms both separately and as a multiplex network to compare their similarities, differences, and interactions. Network theory will be shown to be useful in the early design stage due to its simplicity and ability to model any shipboard system.

• Proceedings of the Korean Institute of Interior Design Conference
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• 1999.04a
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• pp.61-64
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• 1999

Environmental design should be based on the positive theory, a researcher structured symbolic aesthetics on the basis of positive perception theory. Symbolic aesthetics by ecological theory of perception, human preference is related to existence and the formation of place-identity and cognitive map is dealt importantly in this study. Symbolic aesthetics is a study on environmental meaning and a researcher understood the operation of environmental meaning by regarding symbology as a methodological frame and defined architecture as a visual language system after discussing the importance of signified.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.191-199
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• 2005

Many researchers have been investigating the design of multi-mode absorption vibration absorber for multi degree-of-freedom (DOF) system. The approach taken to this problem has been to find the optimized constants of stiffness and damping for the given set of single-DOF absorbers or single multi-DOF absorber attached to a multi degree-of-freedom system. This paper presents a novel geometrical and direct design theory of a 6 DOF vibration absorber via screw theory. Theoretical development is demonstrated by a practical example in which the diagonal stiffness matrix is synthesized using rectangular configuration of springs. The performance of this absorber is simulated by modal analysis.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.530-535
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• 2004

This paper deals with the unknown input observer (UIO) design problem for a class of linear time-delay systems. A case in which the observer error can completely be decoupled from an unknown input is treated. Necessary and sufficient conditions for the existences of such observers are present. Based on Lyapunov stability theory, thedesign of the observer with internal delay is formulated in terms of linear matrix inequalities (LMI). The design of the observer without internal delay is turned into a stabilization problem in linear systems. Two design algorithms of UIO are proposed. The effect of the proposed approach is illustrated by two numerical examples.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.8
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• pp.669-681
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• 2016

Mechanical designers often make mistakes that result in unwanted over-constraints, causing difficulty in assembly operations and residual stress due to interference among parts. This study is concerned with detection and elimination of over-constraints. Screw theory is a general method that is used for constraint analysis of an assembly and motion analysis of a mechanism. Mechanical assemblies with plane-plane, pin-hole, and pin-slot constraint pairs are analyzed using screw theory to illustrate its utility. As a real-world problem, a ball valve design is analyzed using the same method, and several unwanted over-constraints are detected. Elimination measures are proposed. Nominal dimensions of some parts are adjusted, and dimensions and tolerances of the pins and holes are modified using the virtual condition boundary concept. The revised design is free of over-constraints. General procedure for applying screw theory to constraint analysis is established and demonstrated; it will contribute to improving quality of assembly designs.