• Journal for History of Mathematics
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• v.19 no.4
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• pp.97-106
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• 2006

The lattice originated from logic, not mathematics. Around 1880, Peirce thought that all the lattices were distributives, however $Schr{\"{o}}der$ corrected the error around 1890. In 1993, Birkhoff used the term lattice for the first time that had a different meaning from today's lattice. This paper introduces Peirce, and studies correlation among atomic lattices, atomistic lattices, J-lattices, strong lattices and distributive lattices.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.46-46
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• 1999

• Communications of the Korean Mathematical Society
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• v.12 no.3
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• pp.513-519
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• 1997

We show that each orthomodular lattice containing only atomic nonpath-connected blocks is a full subalgebra of an irreducible path-connected orthomodular lattice and there is a path-connected orthomodualr lattice L containing a weakly path-connected full subalgebra C(x) for some element x in L.

• Current Applied Physics
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• v.18 no.11
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• pp.1294-1299
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• 2018

In this paper, we demonstrate the feasibility of constructing DNA nanostructures (i.e. DNA rings and double-crossover (DX) DNA lattices) with appropriate doxorubicin hydrochloride (DOX) concentration and reveal significant characteristics for specific applications, especially in the fields of biophysics, biochemistry and medicine. DOX-intercalated DNA rings and DX DNA lattices are fabricated on a given substrate using the substrateassisted growth method. For both DNA rings and DX DNA lattices, phase transitions from crystalline to amorphous, observed using atomic force microscopy (AFM) occurred above a certain concentration of DOX (at a critical concentration of DOX, $30{\mu}M$ of $[DOX]_C$) at a fixed DNA concentration. Additionally, the coverage percentage of DNA nanostructures on a given substrate is discussed in order to understand the crystal growth mechanism during the course of annealing. Lastly, we address the significance of optical absorption and photoluminescence characteristics for determining the appropriate DOX binding to DNA molecules and the energy transfer between DOX and DNA, respectively. Both measurements provide evidence of DOX doping and $[DOX]_C$ in DNA nanostructures.

• Journal of Powder Materials
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• v.5 no.4
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• pp.324-328
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• 1998

This paper is aimed to study the computer simulation of sintering process for ceramics by Monte Carlo and molecular dynamics methods. Plural mechanisms of mass transfer were designed in the MC simulation of sintering process for micron size particles; the transfer of pore lattices for shrinkage and the transfer of solid lattices for grain growth ran in the calculation arrays. The MD simulation was performed in the case of nano size particles of ionic ceramics and showed the characteristic features in sintering process at atomic levels. The MC and MD simulations for sintering process are useful for microstructural design for ceramics.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.22-22
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• 1999

The HELlOS-MASTER code system is verified through the benchmark of the critical experiments that were performed by RRC "Kurchatov Institute" with water-moderated hexagonally pitched lattices of highly enriched Uranium fuel rods (8Ow/o). We also used the same input by using the MCNP code that was described in the evaluation report, and compared our results with those of the evaluation report. HELlOS, developed by Scandpower A/S, is a two-dimensional transport program for the generation of group cross-sections, and MASTER, developed by KAERI, is a three-dimensional nuclear design and analysis code based on the two-group diffusion theory. It solves neutronics model with the AFEN (Analytic Function Expansion Nodal) method for hexagonal geometry. The results show that the HELIOSMASTER code system is fast and accurate enough to be used as nuclear core analysis tool for hexagonal geometry.ometry.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.58-63
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• 1996

This paper is devoted to evaluating the accuracy of general 2D geometric transport code, HELIOS, and determining the order of merit in modeling for some important HELIOS input parameters. Benchmark test for 12 critical lattices show that HELIOS predicts criticality accurately within experimental uncertainties, showing only 250 pcm overestimation with a standard deviation of 450 pcm. The sensitivity test suggest that current coupling order, neutron group library, geometrical modeling, and resonance options must be considered carefully to obtain accurate results. Especially, current coupling order and sub-rings in fuel regions turn out to be most critical in HELIOS modeling. For MOX loaded cores, it is additionally necessary to pay attention to the resonance option and the validity of small group neutron library.

• Journal of Powder Materials
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• v.19 no.2
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• pp.146-150
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• 2012

The effects of nano $Fe_xC$ addition to superconducting properties of $in$ $situ$ processed $MgB_2$ superconductors was examined. 0.1 wt.% and 1 wt.% nano $Fe_xC$ powders were mixed with boron and magnesium powders by ball milling. The powder mixtures were made into pellets by uniaxial pressing. The pellets were heat-treated at $700^{\circ}C-900^{\circ}C$ in argon atmosphere for $MgB_2$ formation. It was found by powder X-ray diffraction that the raw powders were completely converted into $MgB_2$ after the heat treatment. The superconducting transition temperature ($T_c$) and critical current density ($J_c$), estimated from susceptibility-temperature and $M-H$ curves, were decreased by nano $Fe_xC$ addition. The $T_c$ and $J_c$ decrease by nano $Fe_xC$ addition are attributed to the incorporation of iron and carbon with $MgB_2$ lattices (Fe substitution for Mg and C substitution for B) due to the high reactivity of the nano $Fe_xC$ powder.

• Journal of computational fluids engineering
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• v.19 no.3
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• pp.77-84
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• 2014

The lattice Boltzmann (LB) method has been used to simulate rarefied gas flows in a micro-system as an alternative tool. However, previous results were mainly focused on a simple geometry with flat walls because the LB method is modeled on uniform Cartesian lattices. When previous boundary conditions for the microflows are applied to curved walls, the use of them requires approximation of the curved boundary by a series of stair steps, and introduces additional errors. For macroflows, no-slip curved wall boundary treatments have been developed remarkably in order to overcome these limits. However, the investigations for the slip curved wall boundary have rarely been performed for microflows. In this work, a curved boundary treatment of the LB method for a slip flow has been introduced. The results of the LB method for 2D microchannel and 3D microtube flows are in excellent agreement with the analytical solutions.

• Proceedings of the Korean Vacuum Society Conference
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• 1998.02a
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• pp.129-129
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• 1998

Most of the surface/interface analysis tools have limited depth profiling c capability in terms of the profiling range and the depth resolution. However, M MEIS can profile the surface and subsurface composition and structure q quantitatively and non-destructively with atomic layer depth resolution. I In this presentation, the MEIS system developed at KRISS will be briefly d described with an introduction on the principle of MEIS. Recent MEIS r results on the surface and interface composition and structural change due to i ion bombardment will be presented for preferential sputtering of T:없Os and d damage depth profiles of SHooD, Pt(l11), and Cu(l1D due to Ar+ ion b bombardment. Direct observation of strained Si lattices and its distribution i in the SHool)-SiCh interface and the initial stage of Co growth on Pt(l11) w will be reported. H surfactant effects on epitaxial growth of Ge on Si(ooD w will be discussed with STM results from SND.