• 소성∙가공
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• 제23권3호
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• pp.139-144
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• 2014

In the current study, we present a new model for predicting width spread of a slab with a dog-bone shaped cross section during rolling in the roughing train of a hot strip mill. The approach is based on the extremum principle for a rigid plastic material and a three dimensional admissible velocity field. The upper bound theorem is used for calculating the width spread of the slab. The prediction accuracy of the proposed model is examined through comparison with the predictions from 3-D finite element (FE) process simulations.

• 태양에너지
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• 제20권4호
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• pp.9-16
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• 2000

This paper represents the heat storage performance of the flat plate solar collector. This research aims to application for fishing ship on the sea, and the solar collector has among of motions with pitching and rolling thus, this collector has to be a forced type circulation. In this research, we investigated the solar collector performance for the various collector tilt angle. As the experimental results with three types, we found that the S-type collector was excellent.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.57.1-57
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• 2002

$\textbullet$ This system executes the algorithm that makes the various types of shape to the flat shape. $\textbullet$ In old system, we could not develop and test the new shape control algorithms $\textbullet$ We developed the PC based cold mill shape control system. $\textbullet$ It can be added on the new shape control algorithm and is cost-effective and maintained easily. $\textbullet$ The shape control system consists of the shape controller, the MMI system and the Shape data sewer.

• 한국정밀공학회지
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• 제12권3호
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• pp.101-109
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• 1995

Axisymmetric and quasi-static finite element analysis of an inflated tire rotating with constant angular velocity and contact to road has been performed. Centrifugal force effect was added to load stiffness matrix and equation of effective material properties were calculated by the Halpin-Tsai formulation. In this report, radial truck/bus tire was analyzed. It was inflated and rotated at speeds up to 140 km/h. Then, contact problem was performed to calculate stress-strain field of tire wiht flat rigid road under the load due to the self-weight of a vehicle. Significant changes of stress-strain field of tire were observed in the finite element analysis. Shear stress, strain and strain energy density were rapidly increased at the dege of #2 belt at freely rotating state. This concentrated stress and strain made belt edge sparation. Under the condition of flat riged road contact, strain energy density of #2 belt, carcass turn-up part were concentrated and bigger values than only freely rotation state. Therefore, dynamic behaivor of tire has to considered as design factors which are affected to belt edge separation and bead breakage.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.448-457
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• 1996

Chemical application is one of the most important field operation in rice production . Rolling of a boom due to local unevenness and softness in fields causes a local under/over-application of spray. This study was conducted to develop a control system for balancing a boom. A boom mounting mechanism was modfied and a control algorithm was developed in the study. The results for testing the performance of the control system showed that the system could balance the boom in flat and inclined fields. This research can contribute to improve spraying uniformity in applying agricultural chemicals with a boom sprayers.

• Journal of Biosystems Engineering
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• 제22권2호
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• pp.151-162
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• 1997

Chemical application is one of the most important field operation in rice production. Rolling of a boom due to local unevenness and softness in fields causes a local under/over-application of spray. In this study, the vertical movement of boom tips due to unevenness of ground in paddy fields was investigated, and an active pendulum suspension control system was designed and tested for compensating the movement and balancing the boom to the ground. The results for testing the performance of the control system showed that the system could balance the boom both in flat and inclined fields. The active pendulum control system developed in this study could be properly used for improving spraying performance of a boom sprayer.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.139-143
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• 2001

Ring-stiffened cylinders are widely used as the pressure hull of submarines and underwater vehicles. For large ring-stiffened cylinders cylindrical shells are fbricated by cold rolling of flat plates and then welding of curved shells. After forming cylinders ring-stiffeners are welded on th the cylinders. Due to these cold roiling and welding initial shape imperfections and residual stresses exists in fabricated ring-stiffened cylinders. It is well known that the initial shape and material imperfections affect the ultimate strength of ring-stiffened cylinders significantly. In this paper previous researches on the effects of initial shape imperfections and residual stresses are briefly reviewed Recently a numerical analysis computer program was developed to predict the ultimate strength of ring-stiffened cylinders subjected to hydrostatic pressure, which is based on the Dynamic Relaxation technique. This program was employed to numerically investigate those effects. The numerical predictions were substantiated with relevant experimental results.

• 전기학회논문지
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• 제59권7호
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• pp.1340-1345
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• 2010

FRC(Frame Rate Control) has been applied to the monitor and TV product as part of cost-saving in many flat panel display manufacturers. As FRC can represent the same number of gray scale level with bits of a smaller amount than bits of the input image data, it is widely used. However, FRC causes visual artifacts by using repeatedly pre-designed the FRC unit size of block pattern in display devices. Therefore, this paper analyzes the cause of the visual artifacts. And in order to improve them, it proposed the pattern arrangement of FRC unit blocks through frame rolling method as analytic solution for the first time. So, we could embody causes of FRC noise. Using the proposed structure, more robust pattern to FRC noise will be designed.

• 한국의상디자인학회지
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• 제8권3호
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• pp.27-34
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• 2006

Flexibility, love of symbols, small size-these are all qualites that accompany the proclivity towards compactness in Japanese culture. They developed and have been refined to an unusual level in Japan partly out of the necessity to use limited space economically, but these qualities also characterize the aesthetic preferences of the people. Because space is so precious, it receives a great deal of attention in every aspect of life. Over the centuries Japanese have devised innumerable ways to use space that are ingenious in their successful combination of pragmatism, harmony, and beauty. Folding, stacking, rolling, nesting, carrying, consolidating, miniaturizing and transforming are some of the techniques for living that have created the compact culture. Folding allows a one-dimensional object to be placed in prescribed small space. Stacking objects of the same shape makes use of vertical space, saving valuable horizontal space. Rolling an object reduces it to a tidy cylinder without creasing it, creating yet another form of repose for functionally flat things. Nesting several identically shaped objects of graduated sizes is known as ireko. Carrying things by hand makes them available for any occasion, by plan or on impulse. Consolidating is to bring together the multifarious systems of living into an integrated whole. Miniaturizing things is a way to bring even the universe down to the scale of a human hand. Transforming the face of things is another notable propensity in the Japanese life style. Each one is put to use in countless ways, suggesting principles and conceptions that encapsulate the wisdom of tradition. In this study I wishes to investigate the principals of Japanese traditional design and the applied case in fashion goods.

• 소성∙가공
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• 제4권2호
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• pp.151-158
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• 1995

In this study, the width spreads of spring steel including Mn-Cr steel(SUP 9A), Mn-Cr-V steel(SUP 11A), and Si-Cr steel(SAE 9254) and were investigated under different reduction ratios and thickness-width ratios friction coefficients. The experimental results were compared with the theoretical prediction by the Ekelund equation, Geuze equations, etc. The width spreads of the three spring steels were found to be 10-15% larger than mild steel, and the optimal reduction ratio for the spring steel was found in a range from 20 to30%. Among the spring steels, the width spread of Mn-Cr-V steel was measured to be the largest followed by those of Si-Cr steel and Mn-Cr steel. It was found that the width spread increased with friction coefficient, width-thickness ratio and reduction ratio as predicted. However, the theoretical predictions revealed smaller width spread than the experimental results. This finding indicates that the coefficients of the width spread of the theoretical models need to be modified in order to predict the actual behavior of the width spreading of the spring steels. In this study, the coefficients of width spread of the Geuze equation were determined from the experimental results.