• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.937-944
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• 2013

This paper describes an improved model that can be used for configuring a non-contact pneumatic head to handle a large sheet of glass. The cylindrical head model is of a large size (70 mm). It operates on vortex flow, which can simultaneously generate suction and repulsion over the flat object's surface. The head allows for the minimal non-contact lifting of objects weighing over 3N by using reference conditions (working pressure and head dimensions). Additionally, a functional flow-guide is applied for inducing a developing tangential vortex flow to increase suction and repulsion to the reference head. The cylindrical flow-guide is associated with relatively low tangential velocity. The improved model generates greater lifting force than the reference model, as verified experimentally.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.5
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• pp.435-442
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• 2014

This paper describes an improved design model that can be used to configure a non-contact pneumatic device to turn a large sheet at the in-line system. For rotational moving in the conveyor system, the conventional method is to turn the system itself. The improved non-contact pick-up system mainly uses 8 pairs of L-shaped latches and 12 swirl type heads. It is positioned above the upward air flow table. This system performs the non-contact gripping and side-edge contact support in the vertical and rotational directions to hold the self-weight of a large flat sheet. A non-contact air head can exert a sufficient gripping ability at 4N lower than the standard working pressure. The side latches support 60% of the lifting force required. Through structural and flow analysis, the working conditions were simultaneously considered in accordance with the deflection and flatness of the glass.

• Korean Journal of Mathematics
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• v.4 no.1
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• pp.45-49
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• 1996

Let $F_0$ be the maximal real subfield of $\mathbb{Q}({\zeta}_q+{\zeta}_q^{-1})$ and $F_{\infty}={\cup}_{n{\geq}0}F_n$ be its basic $\mathbb{Z}_p$-extension. Let $A_n$ be the Sylow $p$-subgroup of the ideal class group of $F_n$. The aim of this paper is to examine the injectivity of the natural $mapA_n{\rightarrow}A_m$ induced by the inclusion $F_n{\rightarrow}F_m$ when $m>n{\geq}0$. By using cyclotomic units of $F_n$ and by applying cohomology theory, one gets the following result: If $p$ does not divide the order of $A_1$, then $A_n{\rightarrow}A_m$ is injective for all $m>n{\geq}0$.