• Bulletin of the Korean Mathematical Society
• /
• v.53 no.4
• /
• pp.971-983
• /
• 2016

A partially ordered set P is ideal-homogeneous provided that for any ideals I and J, if $$I{\sim_=}_{\sigma}J$$, then there exists an automorphism ${\sigma}^*$ such that ${\sigma}^*{\mid}_I={\sigma}$. Behrendt [1] characterizes the ideal-homogeneous partially ordered sets of height 1. In this paper, we characterize the ideal-homogeneous partially ordered sets of height 2 and nd some families of ideal-homogeneous partially ordered sets.

• Journal of Industrial Convergence
• /
• v.12 no.2
• /
• pp.40-52
• /
• 2014

I present a theoretical analysis of the charismatic leadership and the follower's role. I distinguish between two types of charismatic relationships and present general propositions about how followers' self-concepts may dertermine the type of charismatic relationship they form with the leader. I conclude by suggesting further the study.

• BMB Reports
• /
• v.51 no.9
• /
• pp.462-467
• /
• 2018

A previous study of ours indicated that Drosophila flightless-1 controls lipid metabolism, and that there is an accumulation of triglycerides in flightless-1 (fliI)-mutant flies, where this mutation triggers metabolic stress and an obesity phenotype. Here, with the aim of characterizing the function of FliI in metabolism, we analyzed the levels of gene expression and metabolites in fliI-mutant flies. The levels of enzymes related to glycolysis, lipogenesis, and the pentose phosphate pathway increased in fliI mutants; this result is consistent with the levels of metabolites corresponding to a metabolic pathway. Moreover, high-throughput RNA sequencing revealed that Drosophila FliI regulates the expression of genes related to biological processes such as chromosome organization, carbohydrate metabolism, and immune reactions. These results showed that Drosophila FliI regulates the expression of metabolic genes, and that dysregulation of the transcription controlled by FliI gives rise to metabolic stress and problems in the development and physiology of Drosophila.

• Journal of the Korean Society of Industry Convergence
• /
• v.10 no.2
• /
• pp.123-128
• /
• 2007

The demand for the precision rubber products has been rapidly increasing with the recent growth of industries. And the requirement for the productivity and the quality calls out for the injection molding machines with the precision machining ability as well as the high productivity. Especially modern automobile industry is in urgent need of developing injection molding machines for the high quality rubber products with high productivity. And the inability of the domestic companies to meet the standards causes importing foreign machines and as a result spending good amount of dollars. It is extremely important to develop competitive machines and strengthen the infrastructure of the related industries. In this paper the functions and the structure of a automatic multi-nozzle injection molding machine has been studied to set up a proper test system for the precision rate and the reliability of the machines, which can help build the machines to meet the request of the industry.

• Journal of Convergence for Information Technology
• /
• v.12 no.5
• /
• pp.290-297
• /
• 2022

This study was conducted to determine the cell cytotoxicity, astringency, nitrite oxide scavenging, iNOS protein expression level, pro-inflammatory cytokine, elastase inhibition, and type I pro-collagen synthesis as a functional cosmetics material of Salvia miltiorrhiza root. We prepared the 80% ethanol(SE) and hot-distilled water(SW), respectively. Both SE and SW showed no toxicity from 0.05 to 0.5 mg/mL concentration as a result of MTT assay in NHDF or RAW264.7 cells. In the measurement of astringent effect, SE reveled 74.6% of astringent activity in 10 mg/mL. SE showed that LPS-induced nitric oxide production, iNOS protein expression, and cytokines were inhibited in a dose-dependent manner. Furthermore, two extracts significantly inhibited elastase activity and increased the type I pro-collagen production. Therefore, it is expected that Salvia miltiorrhiza extract is used as a natural material for functional cosmetics that can effectively prevent skin-related inflammation and wrinkles, and aging.

• Bulletin of the Korean Mathematical Society
• /
• v.47 no.3
• /
• pp.645-651
• /
• 2010

In this note we study positive solutions of the mth order rational difference equation $x_n=(a_0+\sum{{m\atop{i=1}}a_ix_{n-i}/(b_0+\sum{{m\atop{i=1}}b_ix_{n-i}$, where n = m,m+1,m+2, $\ldots$ and $x_0,\ldots,x_{m-1}$ > 0. We describe a sufficient condition on nonnegative real numbers $a_0,a_1,\ldots,a_m,b_0,b_1,\ldots,b_m$ under which every solution $x_n$ of the above equation tends to the limit $(A-b_0+\sqrt{(A-b_0)^2+4_{a_0}B}$/2B as $n{\rightarrow}{\infty}$, where $A=\sum{{m\atop{i=1}}\;a_i$ and $B=\sum{{m\atop{i=1}}\;b_i$.

• Journal of the Korea Convergence Society
• /
• v.9 no.6
• /
• pp.347-355
• /
• 2018

A convergence study was conducted to identify effect size, intervention characteristics, and tendency of laughter therapies on depression for Korean older adults. Of the 486 studies searched in 10 databases, 20 studies in the inclusion criteria were selected. The risk of bias was assessed by SIGN's tool, and the data were analyzed using CMA 3.0 software. Overall effect size of laughter therapy on depression of older adults was medium (standardized mean difference [SMD]=-0.57, 95% CI: -0.70~-0.44, p<.001), and heterogeneity was small ($I^2=18%$). Subgroup analysis showed that the effect sizes of institutionalized group, mixed group, 4-6 weeks of duration, and group intervention were higher than the compared groups. Findings of this convergent meta-analysis would be helpful for health professionals to provide more effective laugher therapy sessions. Further replicative studies in long-term care facilities and more randomized controlled trials of laughter therapy are needed.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.2
• /
• pp.613-619
• /
• 2011

Colloidal silver nanoparticles (AgNPs) have been commercialized as the typically stabilized form via the addition of a variety of surfactants or polymers. Herein, to examine the effects of stabilizing AgNPs in suspension, we modified the surface of bare AgNPs with four type of surfactants (NaDDBS, SDS, TW80, CTAB) and polymers (PVP, PAA, PAH, CMC). The modified AgNPs was applied to compare suspension stability and nanotoxicity test using Escherichia coli (E. coli) as a model organism. Modification of AgNPs surface using chemical stabilizer may be not related with molecular weight, but chemical structure such as ionic state and functional group of stabilizer. In this study, it is noteworthy that AgNPs modified with a cationic stabilizer (CTAB, PAH) were importantly toxic to E. coli, rather than anionic stabilizers (NaDDBS, SDS). Comparing similar anionic stabilizer, i.e., NaDDBS and SDS, the result showed that lipophilicity of chemical structure can affect on E. coli, because NaDDBS, which contains a lipophilic benzene ring, accelerated the cytotoxicity of AgNPs. Interestingly, none of the stabilizers tested, including biocompatible nonionic stabilizers (i.e., TW80 and cellulose) caused a reduction in AgNP toxicity. This showed that toxicity of AgNPs cannot be reduced using stabilizers.

• The Journal of the Korea Contents Association
• /
• v.10 no.12
• /
• pp.146-154
• /
• 2010

Recently 'convergence' and 'communication' have been keywords in many areas. Artists and engineers have begun to communicate each other through collaboration based on new technologies. One of the exemplary technologies of this era of convergence is a technology of fusing five senses used by both Internet Art and industrial technologies such as car navigation systems and the iPhone. Sommerer and Mignonneau's Internet Art $\ll$Riding the Net$\gg$,$\ll$The Living Room$\gg$, and $\ll$The Living Web$\gg$ implement the Internet and the five-sense fusion technology to translate not only sound into visual images but also tactile senses into tempo-spatial representations. Likewise, industrial technologies such as car navigation systems and the iPhone employ the five-sense fusion technology of speech recognition, which leads to the expansion of the realm of senses in technology as seen in Internet Art. As examined in this study, the development of art and technology through their convergence will open up a new dimension of digital art and culture technology industry.

• Journal of radiological science and technology
• /
• v.42 no.4
• /
• pp.291-299
• /
• 2019

The International Electrotechnical Commission (IEC) has regulated the definition and requirements of the exposure index (EI). In this study, we calculated the EI of several image receptors in digital radiography system of two different manufacturers according to the method as per IEC, and evaluated the relationship with incident air kerma. To calculate the EI, w e obtained the characteristics curve of each image receptor by increasing the incident air kerma at RQA 3, 5, 7 and 9, respectively. As a result, there was no significant difference in the EI values between different image receptors of the same manufacturer, but EI values of different manufacturer was different despite the same air kerma was incident. Therefore, understanding the characteristics of the digital radiography systems is important in order to use EI as a tool for measuring and managing the radiation dose.