• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.137-138
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• 2006

This paper proposes a controller design analysis for three-axis CNC systems considering both contouring and tracking performance. The proposed analysis inclusively combines axial controllers for each individual feed drive system together with cross-coupling controller at the beginning design stage as an integrated manner. These two controllers used to be separately designed and analyzed since they have different control objectives. The proposed scheme includes a stability analysis for the overall control system and a performance analysis in terms of contouring and tracking accuracy. Computer simulation is performed and the results show the validity of the proposed methodology.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.8-13
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• 2000

In this paper, a new adaptive cross-coupling control (CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. In addition, a real-time federate adaptation scheme is included in the proposed CCC to regulate cutting force. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy and regulates cutting force more effectively than the existing method.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3749-3754
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• 2010

Various terphenyl and quaterphenyl derivatives were prepared by the Ni-NHC catalyzed cross coupling of the corresponding biphenyl- and terphenyl-sulfonates with arylmagnesium bromides. The reactions proceeded rapidly via a nucleophilic aromatic substitution of the alkoxysulfonyl moieties by the aryl nucleophiles to afford high yields within just 1.5 h at room temperature in spite of the low reactivity of the sulfur electrophiles.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.138.2-138.2
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• 2013

Copper oxide is a multi-functional material being used in various research areas including catalysis, electrochemical materials, oxidizing agents etc. Among these areas, we have synthesized and utilized graphene based copper oxide nanocomposites (CuOx/Graphene) for the catalytic applications (C-N cross coupling reaction). Briefly, Cu precursors were anchored on the graphite oxide(GO) sheets being exfoliated and oxidized from graphite powder. Two different crystalline structures of Cu2O and CuO on graphene and GO were prepared by annealing them in Ar and O2 environments, respectively. The morphological and electronic structures were systemically investigated using FT-IR, XRD, XPS, XAFS, and TEM. Here, we demonstrate that the catalytic performance was found to depend on oxidative states and morphological structures of CuOx graphene nanocomposites. The relationship between the structure of copper oxides and catalytic efficiency toward C-N cross coupling reaction will be discussed.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.108-114
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• 2000

In this paper, a new adaptive cross-coupling control(CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy more effectively than the existing method.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.151-157
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• 2014

We have reported the reaction probability, integral reaction cross section, and rate constant for the title system calculated with the aid of a time-dependent wave packet approach. The ab initio potential energy surface (PES) of Prudente et al. (Chem. Phys. Lett. 2009, 474, 18) is employed for the purpose. The calculations are carried out over the collision energy range of 0.05-1.4 eV for the two reaction channels of H + LiH ${\rightarrow}$ Li + $H_2$ and $H_b$ + $LiH_a$ ${\rightarrow}$ $LiH_b$ + $H_a$. The Coriolis coupling (CC) effect are taken into account. The importance of including the Coriolis coupling quantum scattering calculations are revealed by the comparison between the Coriolis coupling and the centrifugal sudden (CS) approximation calculations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.17-24
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• 2004

This paper describes a novel bit line structure to minimize coupling noise induced by coupling capacitance between bit lines. In DRAMs coupling capacitance is inherently present bit lines. As in submicron process the bit line space gets narrower. bit line coupling capacitance increases and this increased coupling capacitance sharply raises cross-talk noise. In this paper using different layers of metal for adjacent bit lines has been tested to reduces cross-talk noise and a novel bit line structure capable of reducing capacitance is introduced and verified.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3E
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• pp.31-37
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• 2001

Finite element model of a cMUT is constructed using the commercial code ANSYS to analyze the cross talk mechanism. Calculation results of the complex load impedance seen by single capacitor cells are presented, and then followed by a calculation of the plane wave real load impedance seen by a parallel combination of many cells that are used to make a transducer. Cross talk between 1-D array elements is found to be due to two main sources: coupling through a Stoneley wave propagating at the transducer-water interface and coupling through Lamb waves propagating in the substrate. To reduce the cross talk level, the effect of various structural variations of the substrate are investigated, which include a change of its thickness and etched trenches or polymer walls between array elements.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.983-985
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• 2013

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.25-26
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• 2010