• Journal of Power Electronics
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• v.6 no.1
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• pp.8-17
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• 2006

In this paper, we propose a fault-tolerant control system for the position control and vibration suppression of a flexible arm robot. The proposed control system has a strain gauge sensor signal observer based on a reaction force observer and detects a fault by monitoring an estimated error. In order to improve the estimation accuracy, the plant parameters included in the sensor signal observer are updated by using the strain gauge sensor signal in normal time through the adaptive law. After fault detection, the proposed control system exchanges the faulty sensor signal for the estimated one and switches to a fault mode controller so as to maintain the stability and the control performance. We confirmed the effectiveness of the proposed control system through several experiments.

• Steel and Composite Structures
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• v.7 no.3
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• pp.253-262
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• 2007

A methodology to design symmetrically laminated fibre-reinforced structures under transverse loads for minimum weight, with manufacturing uncertainty in the ply angle, is described. The ply angle and the ply thickness are the design variables, and the Tsai-Wu failure criteria is the design constraint implemented. It is assumed that the probability of any tolerance value occurring within the tolerance band, compared with any other, is equal, and thus the approach is a worst-case scenario approach. The finite element method, based on Mindlin plate and shell theory, is implemented, and thus effects like bending-twisting coupling are accounted for. The Golden Section method is used as the search algorithm, but the methodology is flexible enough to allow any appropriate finite element formulation, search algorithm and failure criterion to be substituted. In order to demonstrate the procedure, laminated plates with varying aspect ratios and boundary conditions are optimally designed and compared.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.12.1-12.1
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• 2009

For the micro conductive line, memory device fabrication process use many expensive processes such as manufactur-ing of photo mask, coating of photo resist, exposure, development, and etching. However, direct printing technology has the merits about simple and cost effective processes because nano-metal particles contained inks are directly injective without mask. And also, this technology has the advantage about fabrication of fine pattern line on various substrates such as FPCB, PCB, glass, polymer and so on. In this work, we have fabricated the fine and thick metal pattern line on flexible PCB substrate for the next generation electronic circuit using Ag nano-particles contained ink. To improve the line tolerance on flexible PCB, metal lines are fabricated by sequential prinitng method. Sequential printing method has vari-ous merits about fine, thick and high resolution pattern lines without bulge.

• Architectural research
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• v.15 no.4
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• pp.191-200
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• 2013

Since Modern Movement flexibility has been one of the most attractive words in architecture. However, "overprovision first, division later" has been the most prevailing design method for spatial flexibility, and many of buildings designed for flexible use are practically quite inflexible due to insufficient building systems or/and irresponsible planning. There have been two dominant strategies to achieve architectural flexibility: multi-functionality and polyvalence. These two approaches, which point contradictory directions, actually reflect the difficulty in providing a proper form of architectural flexibility. Multi-functionality can afford changeable environments with satisfying spatial conditions; however it lacks tolerance to accommodate other uses but intended functions by architects. Meanwhile, flexibility by a polyvalent form relies on the vague anticipation of user's various interpretations. In this study by looking up these two different standpoints and historical precedents flexibility in architecture is carefully scrutinized focused on the contradiction, and as an alternative for architectural flexibility contextual relations is proposed. Unlike both multi-functionality and polyvalence, which produce flexibility by changing its own properties, manipulating contextual relations infuses flexibility into space by changing the properties of a building, not of its individual room. By using this contextual relations method, a community-centered school in Manhattan, NY, which was in danger of being closed because of its academic failure, is represented as a flexible space.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.6
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• pp.350-360
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• 1988

As the capacity of DC motor is increased, we should recheck several encountered problems like volume increase. Particularly, when a large DC motor should be installed within the limited space, it is necessary to minimize the volume of motor for the effective utilization of the limited space. This paper describes the procedure and the method of finding optimum design of a large DC motor. The result of the optimization will decide the basic dimensions of a large DC motor. The flexible tolerance method and polyhedron searching method are used in this optimization. This result of simulation of the existing large DC motors is compared with the data of the existing large DC motors to confirm the validity of this optimum design.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10a
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• pp.882-885
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• 1987

The path of an industrial manipulator in a crowded workspace generally consists of 8 set of Cartesian straight line path connecting a set of two adjacent points. To achieve the Cartesian straight line path is, however, a nontrivial task and an alternative approach is to place enough intermediate points along a desired path and linearly interpolate between these points in the joint space. A method is developed that determines the subtravelling- and the transition-time such that the total travelling time for this path is minimized subject to the maximum joint velocities and accelerations constraint. The method is based on the application of nonlinear programming technique, i.e., FTM (Flexible Tolerance Method). These results are simulated on a digital computer using a six-joint revolute manipulator to show their applications.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1995.03a
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• pp.124-130
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• 1995

An upper-bound elemental stream function technique(UBST) is proposed for solivng forging and backward extrusion problems that are geometrically complex or need a forming simulation . And in the forging problems, this study investigates that layer of elements effects dissipation of total energy and load. The element system of UBSTuses the curve fitting property of FEM and the fluid incompressiblity of the stream function . The foumulated optimal design problems with constraints ae solved by the flixible toerance method. In the closed-die forging and backward extrusion, the result of layer of element by this study produces a lower upper-bound solution than that fo UBET and conventional layer of element . And the main advantage of UBST program is that a computer code, once written , can be used for a large variety problems by simply changing the input data.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.31-36
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• 2005

This paper describes a research work on the die design for the deep drawing & ironing(D. D. I) of high pressure gas cylinder. D. D. I die set is large-sized die used in horizontal press, which is usually composed of a drawing, and an ironing die. Design method of D. D. I die set is very different from that of conventional cold forging die set. Outer diameter of the die set is fixed because of press specification and that of the insert should be as small as possible for saving material cost. In this study, D. D. I die set has been designed to consider those characteristics, and the feasibility of the designed die has been verified by FE-analysis. In addition, the automated system of die design has been developed in AutoCAD R14 by formulating the applied methods to the regular rules.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.51-57
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• 2010

The shape of the register mark for the image processing becomes very important, because the printing quality is determined by the error correction between the register marks for the image processing. In this paper, printing marks are developed using the image process for the gravure printing method which is commonly being used in roll to roll, high resolution printing. The marks which can be cited to the flexible display print are developed The developed register marks which satisfies 10[${\mu}m$] error tolerance are tested under 70[mpm] printing conditions and confirmed through the experiments.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.255-261
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• 2008

In this study, the propagation characteristics and the fabrication tolerance of an optical wire in a flexible optical PCB were analyzed by using a ray-tracing method. It is found from the analysis that the sidewall angle of a core should be controlled within $1^{\circ}$ in order to maintain the propagation loss to less than -1 dB/mm, and that the bending radius of the optical wire should be larger than 5 mm in order to suppress the bending loss below -1 dB. In addition, it is confirmed that the lateral misalignment of ${\pm}15\;{\mu}m$, and the angular tilting of VCSEL of $6^{\circ}$ are allowable for the coupling loss of -1 dB.