• Proceedings of the KSME Conference
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• 2000.04a
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• pp.351-356
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• 2000

Various transition elements are generally used for the effective analysis of a complicated mechanical structure. In this paper, a solid-to-beam transition finite element which connects a continuum element and a $c^1-continuity$ beam element each other is proposed. The shape functions of the transition finite elements, which a 8-noded hexahedral solid element fur 3D analysis and a 4-noded quadrilateral plane element fur 2D analysis are connected to a Euler's beam element, are explicitely formulated. In order to show the effectiveness and convergence characteristics of the proposed transition elements. numerical tests are performed for various examples and their results are compared with those obtained by other methods. As the result of this study. following conclusions are obtained: (1)The proposed transition finite elements show the monotonic convergence characteristics because of having used the compatible displacement folds. (2)As being used the transition element in the finite element analysis, the finite element modelings are more convenient and the analysis results are more accurate because of the formulation characteristies of the Euler's beam element.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.10
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• pp.1034-1039
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• 2002

In this paper, the design of a dual-polarization rectangular microstrip patch antenna with high isolation between two feeding ports excited by using both an aperture-coupled feed (port 1) and a 3-dimensional microstrip feed (port 2) is presented. From the simulation using the commercial program IE3D, the optimum values of the antenna parameters are investigated at both two feed structures and the optimum antenna is designed and fabricated. Experimental results confirmed that an bandwidth of the antenna is about 17 % and the isolation of two ports is great than 30 dB over all frequency bands.

• Interaction and multiscale mechanics
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• v.7 no.1
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• pp.543-561
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• 2014

We present a full energy and force formulation of the quasicontinuum method with non-local and local transition elements. Non-local transition elements are developed to transmit inhomogeneity from the atomistic to the continuum regions. Local transition elements are developed to resolve the mathematical mismatch between non-local atoms and the local continuum. The rationale behind these transition elements is provided by analyzing the energy and force transitions between atoms and continuum under the Cauchy-Born rule. We show that breakdown of the Cauchy-Born rule occurs for slaved atoms of local elements within the cutoff of non-local atoms. The inadequacy of the Cauchy-Born rule at the transition region naturally leads to the need of atomistic treatment of transition slaved and transition representative atoms. Such an atomistic treatment together with a full or cutoff sampling allows non-local transition elements containing these transition entities to transmit inhomogeneity. Different force formulations for transition representative atoms and pure local representative atoms allow the local transition elements to resolve non-local and local mismatches. The method presented herein is validated by force calculations in an unstressed perfect crystal as well as an unrelaxed grain boundary model. A nanoindentation simulation in 3D is conducted to demonstrate the accuracy and efficiency of the proposed method.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.15-24
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• 2020

With the development of the chemical industry, the chemical accident is increasing every year, thereby increasing the risk of accidents caused by chemicals. The Ministry of Environment provides the criteria for determining shelter-in-place or outdoor evacuation by material, duration of accident, and distance from the toxic substance leak. However, it is hard to say that the criteria for determining the transition point are not clear. Transition point mean the time that evacuation method is switched from shelter-in-place to outdoor evacuation. So, the purpose of this study was to calculate appropriate transition point by comparing the cumulative toxic load. Namdong-gu in Incheon Metropolitan City was finally selected as the target area, considering the current status of the population of Incheon Metropolitan City in 2016 and the statistical survey of chemicals in 2016. The target materials were HCl, HF, and NH₃. Modeling was simulated by ALOHA and performed assuming that the entire amount would be leaked for 10 min. Residents' evacuation scenarios were assumed to be shelter-in-place, immediate outdoor evacuation, and outdoor evacuation at an appropriate time after shelter-in-place. Based on the above method, the appropriate transition point from residents located in A(800 m away), B(1,200 m away), C(1,400 m away) and D(2,200 m away) was identified. In HCl, appropriate transition point was after 15 min, after 16 min, after 17 min, after 20 min in order by A, B, C and D. In HF, appropriate transition point was before 1 min or after 16 min, before 4 min or after 19 min, before 5 min or after 20 min, before 14 min or after 26 min in order by A, B, C and D. In NH₃, appropriate transition point at A was before 4 min or after 16. Others are not in chemical cloud. This study confirmed the transition point to minimize the cumulative toxic load can be obtained by quantitative method. Through this, it might be possible to select evacuation method quantitatively that cumulative toxic load are minimal. In addition, if the shelter-in-place is maintained without transition to outdoor evacuation, the cumulative toxic load will increase more than outdoor evacuation. Therefore, it was confirmed that actions to reduce the concentration of chemicals in the room were necessary, such as conducting ventilation after the chemical cloud passed through the site.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.391-398
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• 1995

This study was carried to investigate the usefulness of the radiopaque material as the GI transition and disintegration test of enteric coated capsules radiologically. The obtained results were as follows; 1. The GI transition times that the enteric coated capsules pass through the pylorus were that the time of the first capsule was 210 minutes and the time of the last capsules was more than 300 minutes. Therefore, the GI transition times largely differ from each animal and each enteric coated capsule. 2. The disintegration times of enteric coated capsules were similar in vitro test and in vivo test. 3. The GI transition and disintegration test of enteric coated capsules using barium sulfate, radiopaque material for the gastrointestinal track, was useful to investigate the times that the capsules passed through the pylorus and disintegrated in intestinal track.

• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.339-360
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• 2011

In the h-type adaptive analysis, when an element is refined or subdivided, new nodes are added. Among them are the transition nodes which are the corner nodes of the new elements formed by subdivision and, simultaneously, the mid-side nodes of the adjacent non-subdivided elements. To secure displacement compatibility, the slave-node approach in which the DOFs of a transition node are constrained by those of the adjacent nodes had been used. Alternatively, transition elements which possess the transition nodes as active mid-side/-face nodes can be used. For C0 plate analyses, the conventional slave-node constraints and the previously derived ANS transition elements are implemented. In both implementations, the four-node element is the ANS element. With reference to the predictions of the transition elements, the slave-node approach not only delivers erroneous results but also fails the patch test. In this paper, the patch test failure is resolved by developing a set of new constraints with which the slave-node approach surpasses the transition-element approach. The accuracy of the slave-node approach is further improved by developing a hybrid four-node element in which the assumed moment and shear force modes are in strict equilibrium.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.502-507
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• 2016

Vanadium dioxide, $VO_2$, is a thermochromic material that exhibits a reversible metal-insulator phase transition at $68^{\circ}C$, which accompanies rapid changes in the optical and electronic properties. To decrease the transition temperature around room temperature, a number of studies have been performed. The phase transition temperature of 1D nanowire $VO_2$ with a 100 nm diameter was reported to be approximately $29^{\circ}C$. In this study, 1D or 2D nanostructured $VO_2$ was grown using the vapor transport method. Vanadium dioxide has a different morphology with the same growth conditions for different substrates. The 1D nanowires $VO_2$ were grown on a Si substrate ($Si{\setminus}SiO_2$(300 nm), whereas the 2D & 3D nanostructured $VO_2$ were grown on an exfoliated graphene nanosheet. The crystallographic properties of the 1D or 2D & 3D nanostructured $VO_2$, which were grown by thermal CVD, and exfoliated-transferred graphene nanosheets on a Si wafer which was used as substrate for the vanadium oxide nanostructures, were analyzed by Raman spectroscopy. The as-grown vanadium oxide nanostructures have a $VO_2$ phase, which are confirmed by Raman spectroscopy.

• Journal of the Korean Magnetics Society
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• v.20 no.3
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• pp.83-88
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• 2010

We investigated the electronic structure and magnetism of the (3d, 4d)-Pd alloyed c($2{\times}2$) monolayer systems, by use of the FLAPW band method. For comparison, pure 3d- and 4d-transition metal monolayers are also considered. We found that the antiferromagnetic configuration of pure V monolayers is sustained in the V-Pd alloy system, while the Ti-Pd alloy system is changed to antiferromagnetic configuration from the ferromagnetic state in pure Ti monolayer. The 4d TM (Mo, Ru, Rh)-Pd monolayers are found to be stable in ferromagnetic configurations. The magnetic moments of Ru and Rh atoms in Ru-Pd and Rh-Pd systems are almost same with those of pure Ru and Rh monolayers, while the magnetic moment of Mo atom is increased to $2.98\;{\mu}_B$ in Mo-Pd alloyed system from the value of Mo monolayer, $0.02\;{\mu}_B$.

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.218-224
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• 2014

In order to explore new coordination frameworks with novel designed 3-nitrophthalic acid and the same N-donor ancillary ligand, a series of novel coordination complexes, namely, $[Cd_2(3-NPA)_2(TBZ)_2(H_2O)_2]{\cdot}2H_2O$(1), $[Zn_2(3-NPA)_2(TBZ)_2]$(2), $[Zn_2O(3-NPA)(TBZ)(H_2O)]_n$(3), $[Co(3-NPA)(TBZ)(H_2O)]_n$(4) (3-$NPAH_2$ = 3-nitrophthalic acid), have been hydrothermally synthesized through the reaction of 3-nitrophthalic acid with divalent transition-metal salts in the presence of N-donor ancillary coligand (TBZ = thiabendazole). As a result of various coordination modes of the versatile 3-$NPAH_2$ and the coligand TBZ, these complexes exhibit structural diversity. X-ray structure analysis reveals that 1 and 2 are 0D molecular rings, while 3 and 4 are one-dimensional (1D) infinite chain polymers. And the weak O-H${\cdots}$O hydrogen bonds and C-H${\cdots}$O nonclassical hydrogen bonds as well as ${\pi}-{\pi}$ stacking also play important roles in affecting the final structure where complexes 1, 3 and 4 have 3D supramolecular architectures, while complex 2 has a 2D supramolecular network. Also, IR spectra, fluorescence properties and thermal decomposition process of complexes 1-4 were investigated.

• International Journal of Oral Biology
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• v.45 no.4
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• pp.152-161
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• 2020

D-pinitol is an analog of 3-methoxy-D-chiro-inositol found in beans and plants. D-pinitol has anti-inflammatory, antidiabetic, and anticancer effects. Additionally, D-pinitol induces apoptosis and inhibits metastasis in breast and prostate cancers. However, to date, no study has investigated the anticancer effects of D-pinitol in oral cancer. Therefore, in this study, whether the anticancer effects of D-pinitol induce apoptosis, inhibit the epithelial-to-mesenchymal transition (EMT), and arrest cell cycle was investigated in squamous epithelial cells. D-pinitol decreased the survival and cell proliferation rates of CAL-27 and Ca9-22 oral squamous carcinoma cells in a concentration- and time-dependent manner. Evidence of apoptosis, including nuclear condensation, poly (ADP-ribose) polymerase, and caspase-3 fragmentation, was also observed. D-pinitol inhibited the migration and invasion of both cell lines. In terms of EMT-related proteins, E-cadherin was increased, whereas N-cadherin, Snail, and Slug were decreased. D-pinitol also decreased the expression of cyclin D1, a protein involved in the cell cycle, but increased the expression of p21, a cyclin-dependent kinase inhibitor. Hence, D-pinitol induces apoptosis and cell cycle arrest in CAL-27 and Ca9-22 cells, demonstrating an anticancer effect by decreasing the EMT.