• Korean Journal of Optics and Photonics
• /
• v.8 no.1
• /
• pp.7-13
• /
• 1997

This paper describes the automation of an object generator and an image analyser in a knife scan OTF equipment to enhance the accuracy of OTF measurement. Pinholes and slits of various size in the object generator are used as an objects. A fishtail edge is mounted to the image analyzer and is translated to the direction of 45 degree angle with the horizontal to measure MTF simultaneously in the radial and tangential azimuths. The stepping motor control unit and software for the image analyzer are modified and the accuracy of this equipment is evaluated by measuring the OTF of SIRA group 50 mm standard lens.

• Journal of the Korean Society of Tobacco Science
• /
• v.27 no.1 s.53
• /
• pp.120-126
• /
• 2005

The Fishtail Chimney system mounted on 1 channel smoking machine is not appropriate for the routine analysis of sidestream smoke, because of its low repeatability and very long time required for smoke collection. To overcome this inconvenience, we developed a new sidestream smoke collecting apparatus compatible for 8 channel linear smoking machine. An electric motor driven stroke and automatic control system were adopted in this device to maximize convenience and efficiency of its operation. Also, we carried out the international collaborative study on monitoring sidestream smoke analysis to test the performance of this system. From the statistical analysis of the data obtained in our laboratory and other participating labs, it has been indicated that the newly developed sidestream smoke collection apparatus could be applicable to the routine analysis of sidestream smoke.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.5
• /
• pp.815-822
• /
• 2003

The ring rolling process involves not only three-dimensional non-steady material flow and continuous change of radius and thickness of the ring workpiece but also heat transfer among workpiece, rolls and environment. In this study, deformation and heat transfer analyses were conducted by using the three-dimensional thermo-rigid-plastic finite element method. Three cases of plain ring rolling process were, respectively, simulated for the predictions of roll forces and the highest temperature zone during the aluminum process that ductile fracture often occurs. In addition, to prevent fishtail phenomena of the ring workpiece, axial rolls were used for this study.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.7
• /
• pp.1278-1284
• /
• 1992

In plate rolling, it is desired to reduce the trimming loss by controlling the formation of defective end shapes. For this reason, edge rolling is frequently performed in the plate mill. In this paper, the effect of various process variables on the deformation of plate ends in edge rolling is examined by conducting experiments and finite element computer simulation. A focus is given to investigating the effect of edging on the width of the deformed plate trimming-free plate rolling.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.08a
• /
• pp.438-446
• /
• 1999

Crop minimization of the top and bottom ends of hot rolled plate, in a plate, in a plate mill, has been investigated. The existing model to determine the edging pattern at the finishing rolling pass was not reasonable to get high width accuracy and rolling yields. New models including width prediction have been formulated by using neural network model of back propagation learning algorithm and statistical analysis based on the actual production rolling data to give the optimal pattern for minimizing trimming loss. Using these models, at a given rolling condition of broadside pass and finishing pass and the permissible condition of width variation, it was possible to minimize crip at the top and bottom ends according to optimum procedure in plate mill. An application to improve the plan view pattern reduced width variation by 23% and crop length by 30% on average with an effective fishtail crop shape.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.04a
• /
• pp.48-51
• /
• 2000

In plate mill studies on crop decrease of the top and bottom ends of hot rolled plate have been performed. The plane view shape for the thin plate after broadside rolling was controlled by roll gap difference with AGC in broadside rolling process. New models for thin slab after broadside rolling have been formulated based on the actual production rolling data to give optimal rolling condition A new plate rolling method called by dog bone rolling has been applied making it is possible to prevent non-uniform plastic deformation at top and bottom ends. By new rolling method crop losses of rolled plate have been improved by 10% on average with an effective fishtail crop shape.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.7
• /
• pp.771-779
• /
• 2004

Unsteady behavior of the early wake in the viscous flow field past an impulsively started semicircular cylinder is studied numerically. In this paper, we propose the hybrid diffusion scheme to simulate dynamic characteristics of wake such as a fishtail-like flapping and an alternate vortex-shedding more accurately. This diffusion scheme based on particle strength exchange is mixed with the stochastic nature of random walk method. Also, the viscous splitting algorithm which calculates convective and diffusion terms successively is applied in order to handle random walk method effectively. Consequently, the early behavior of wake due to the breakdown of symmetrical vortici balance is more practically simulated with the vortex particle method.

• Journal of the Korean Society of Tobacco Science
• /
• v.21 no.2
• /
• pp.128-135
• /
• 1999

This study was conducted to determine the sidestream smoke concentration, nicotine, tar, and CO, by the characteristics of tobacco leaves and their combinations. 20 kinds of tobacco leaves and 15 types of their combinations were selected for this study. After collecting the sidestream smoke by fishtail chimney, the concentrations of nicotine, tar, and CO in sidestream smoke were analyzed. Variation in nicotine concentration of sidestream smoke among tobacco leaves and their combinations was as much as 9-times. Heavy leaves and burley leaves were higher in nicotine concentration than light leaves and flue-cured leaves, respectively, the reconstituted tobacco leaf had the minimum concentration of nicotine. Tar concentration of sidestream smoke also was changed by the characteristics of tobacco leaves and their combinations. As the american C4F had the maximum concentration of tar in sidestream smoke, the reconstituted tobacco leaf showed the minimum concentration. Blending 50 % flue-cured B1-0 plus 50% burley B1-T grade showed the highest value in the nicotine concentration. Also, in case of adding B3K and izmir tobacco leaves, the nicotine concentration was decreased. The tar concentration in the sidestream smoke increased as increasing the amount of flue-cured heavy leaf. The CO concentration was not so much Changed by the characteristics of tobacco leaves and their combinations.

• Journal of the Society of Naval Architects of Korea
• /
• v.50 no.1
• /
• pp.8-13
• /
• 2013

Excessive yaw motion of a turret moored vessel was examined in this paper. The vessel was moored by an internal turret and catenary mooring lines. The experiments were conducted in regular waves. Turret moored vessel can oscillate from side to side or move to one particular direction, and eventually exhibit large yaw motion. The results showed that the excessive yaw occured for specific condition, ratio of wave lengths and vessel length. It was found that turret moored floating vessel was unstable for regular wave period from 14 to 18 sec and excessive yaw occurred to maximum 50 deg. The time series, trajectory, phase plot and qualitative analysis are performed. The analysis showed that the results of experiments agreed with the that of analytic method and the excessive yaw could be predicted by the stability analysis.

• Journal of Fashion Business
• /
• v.27 no.4
• /
• pp.67-87
• /
• 2023

This study analyzed the fashion design features of Iris van Herpen and createdsixdigital fashion designsusing the SCAMPER technique with 3D clothing design software, incorporating a futuristic theme. The research methodology involvedcase analysis and a literature survey. First, the study summarizedthe design style and characteristics of Iris van Herpen. Second, a design concept wasestablished, and a design mood board wascreated. Third, the resulting design features were combined with the SCAMPER technique to incorporate Iris van Herpen's design elements intonew digital fashion designs. Fourth, after discussion with the professor and expert group, six designs were selected for production. They includededgy suit coats, overcoats, asymmetrical hoodies and asymmetrical skirts, irregularly shaped tops, dresses, leggings, jackets,and fishtail skirts. This study provides a reference for the future development of digital fashion designs and showcases the integration of science and technology in fashion design.