• ETRI Journal
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• v.30 no.5
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• pp.735-737
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• 2008

We propose a novel spatial multi-band-stop filter using modified multiple loop array elements to block electromagnetic waves or signals of mobile phones in public facilities. It operates at the following frequency bands: Korean cellular (824 MHz to 894 MHz), Personal Communication Service (PCS) (1.75 GHz to 1.87 GHz), and IMT-2000 (1.92 GHz to 2.17 GHz). Two frequency selective surfaces with modified multiple-loop elements are printed on the top and bottom of a pair-glass pane, which is a pair of glass panes with an air gap between them. A modified multiple-loop element with a meander line is used to make the size of the filter compact. The simulated and measured results show good agreement, which confirms the usefulness of the proposed tri-band spatial filter.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1996.03a
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• pp.101-109
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• 1996

Mini-mill process which is one of the new steel -marking technologies to be able to produce the hot rolled coils by thin slab caster of ISP(In-Line Strip Production) type, will be completed in the Kwangyang Steel Works of POSCO in August, 1996, SEt-Up Model of finishing mill which consists of 5 stands is the most basic and essential in mini-mill plant. Therefore, the simulation program of Finishing-mill Set-Up model were developed in this research , using new temeprature prediction model, roll gap model and rolling physical model. Using the developed FSU program , pass schedules to produce the strips with target strip thickness of 1.8mm, 2.0mm, 2.3mm, 2.7mm an d3.0mm were also determined respectively.

• Transactions of Materials Processing
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• v.19 no.3
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• pp.145-151
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• 2010

In case of thin-wall two-color injection molding, flashing often occurs when molten polymer flows into small gap at the parting line in mold with high pressure or under the unbalanced clamping force condition. In this study, flashing was examined in the production of thin-wall notebook case with large area when the rapid heat cycle molding (RHCM) technology was applied to the two-color injection molding. The effects of the RHCM technology on the part properties and weld-lines were compared with conventional injection molding. The flashing caused by the clamping device of the two-color injection molding machine was examined and compared by experiments and CAE analyses.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.3
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• pp.501-514
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• 1997

Manufacturing is fast entering a new age of industrial excellence that is being called "Agile Manufacturing." The goal of Agile Manufacturing is to link customers, suppliers, and the manufacturing system into a super-efficient confederation to produce a variety of products quickly and at a low cost. In order to improve the quality of the study of production input control(PIC) in a job shop manufacturing system by reducing the significant gap between research models and models of actual manufacturing systems, the previous line of research on PICs in a job shop manufacturing system is extended by integrating customers and suppliers with the manufacturing system. Then, a set of measures is developed to evaluate PICs, measures that reflect concerns of customers and suppliers as well as concerns of the manufacturer. Also, a weighted overall measure (with various cases to represent different possible weights of manufacturer's emphasis on the performance measures) is used to synthesize all the performance measures. Then, for each case, various existing PICs are evaluated in combination with various priority dispatching rules(PDRs).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.350-354
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• 1995

The Tension Leveller of Cold Rolling Mill In POSCO performs levelling the strip in high speed line. But minor variations in operating condition of driving machines such as motor, gear box, and support bearings, a small gap-variation of supporter and strip slip by poor roll revolutions can cause serious problems in the quality of strip. In this study, firstly, A condition monitoring standard for each sensor is made through with the detail analysis of vibration and strip slip. Secondly, An automatic monitoring and diagnosing system was developed to monitor the condition of Tension Leveller, and diagnose the cause of abnormal condition. Finally, A diagnosing algorithm for abnormal condition and man-machine interface (MMI) for easy operation are developed.

• Journal of Technology Innovation
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• v.15 no.1
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• pp.65-86
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• 2007

The purpose of the current study is to suggest a reliable starting point for roadmapping to overcome two common shortcomings of previous literatures that they do not demonstrate a robust methodology for roadmap and they describe the roadmapping process in the abstract. The proposed methodology for roadmapping considers four important business- and market-related factors: consumer requirements, engineering characteristics, the gap between the roadmapped technology and competing technologies, and future changes in consumer preferences. We capture consumer preferences using conjoint analysis and interconnect the above four factors using QFD (Quality Function Deployment). The model is applied to power line communications (PLC). The results show that there is a significant difference between priorities assigned to the engineering characteristics by expert alone and priorities determined by the roadmapping model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.9
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• pp.1180-1185
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• 2014

This paper describes the effects on SUS tube of power optical fiber composite cable on underground transmission lines. The effects on grounding, air gap between SUS tube and metal sheath, contact resistance between outer semi-conducting layer and metal sheath and grounding of SUS tube application or not are variously analysed using EMTP in normal operating condition as well as single line to ground fault. From these results, in this paper, the scheme for protecting the electrically abnormal phenomena will be established on power-optical fiber composite cable of underground transmission lines. This paper can contribute to specification of grounding reference of SUS tube of optical fiber composite power cable system.

• 연구논문집
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• s.23
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• pp.155-164
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• 1993

A drawing technique which use only fine curves and dashed lines is widely adopted in banknotes and post stamps printing. Engraving of the curves and lines are traditionally performed by hand skill which provides low productivity in printing. As an effort for higher productivity and quality, a drawing automation method which can easily produce NC codes and drawings for a mechanical or chemical engraving is proposed. An initial work shows that it is possible to draw a portrait by contolling the width and length of predetermined fine lines according to the gray scale at the end points of each line. User interface functions of a commercial CAD system are heavily employed to exploit the presented method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.12
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• pp.1039-1044
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• 2000

Breakdown voltage model and expertiments are compared for discharge cells of AC plasma display panel. In the model, discharge paths are assumed to be initial electric field lines and the one-dimensional continuity equation is applied to the charged particle transport at each field line. The comparisons are performed in the wide range of gas pressure (50-600torr), Xe partial pressure over total pressure (1-6%), sustain electrode gap(100-1000$\mu\textrm{m}$), wall height(130, 300$\mu\textrm{m}$), and voltage pulse width(2-6${\mu}$s). The presented breakdown voltage model well agree with experiments in the above wide range. The increase of breakdown voltage with the decrease of the width(L) of protruding electrode is also described by the model.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.231-231
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• 2006

We fabricated a polymer sub-microstructure for optical device application by two-photon-induced laser lithography technique. Polymer pattern could be minimized as small as ${\sim}100\;nm$. The photopolymerization resin contains laser-dye, thus promising a high level of the optical gain. We utilized the lithography technique to the photonic crystal application, where the template of the two-dimensional photonic crystal was modified by polymer gain medium as defect-shape and line-shape orientations. Photonic band gap effect from polymer-doped photonic crystals is expected to exploit the application such as organic solid-state laser device.