• Bulletin of the Korean Mathematical Society
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• v.60 no.6
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• pp.1697-1704
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• 2023

We study a multidimensional nonlinear variational sine-Gordon equation, which can be used to describe long waves on a dipole chain in the continuum limit. By using the method of characteristics, we show that a solution of a nonlinear variational sine-Gordon equation with certain initial data in a multidimensional space has a singularity in finite time.

• Macromolecular Research
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• v.17 no.2
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• pp.84-90
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• 2009

We prepared side-chain liquid crystalline polymers comprising two monomeric units, one having a mesogenic side group that could form a smectic mesophase and the other having a phenolic group attached to the polymer backbone via a thermally reversible urethane bond. The urethane linkage between the isocyanate and phenol groups was stable at room temperature, but it cleaved to generate an isocyanate group when the temperature was increased. When annealed, the copolymers in their smectic mesophases became insoluble in common organic solvents, suggesting the formation of network structures. XRD analysis showed that the annealed polymers maintained their smectic LC structures. The crosslinking process probably proceeded via the reaction of the dissociated isocyanate groups. Some of the isocyanate groups would have first reacted with moisture in the atmosphere to yield amino groups, which underwent further reaction with other isocyanate groups, resulting in the formation of urea bonds. We presume that only polymer chains in the same layer were crosslinked by the reaction of the isocyanate groups, resulting in the formation of a layered polymer network structure. Reactions between the layers did not occur because of the wide layer spacing.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.2
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• pp.22-48
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• 1995

This study was investigated to search for the effects of the structure of each component in four-component O/W microemulsion system on its formation region, droplet size and stablilty. The results was that the more number of OH site, the shorter carbon chain length of polyol, the larger formation region of microemulsion was showed. The small microemulsion droplet was obtained on condition that the polatry of oil was large and carbon chain length of hydrophobic group of surfactant was long. In using satrated hydrocarbon (such as liquid paraffin, squalane) as dispersed phase, the stability of microemulsion was better than aromatic oil phase.

• Journal of Korea Trade
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• v.27 no.5
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• pp.23-40
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• 2023

Purpose - This study aims to present the changes and directions in the automotive supply chain in the face of changes in the global supply chain caused by external factors and the integration of industries resulting from internal factors. Assuming FDI in the Korean automotive industry in the US, this study analyzed the influential factors over the long term and derived the optimal location. Design/methodology - For this analysis, the characteristics and current status of the automotive industry are presented. Additionally, the study emphasizes the necessity and direction of change. The factors influencing Korea-US FDI in the automotive industry and the electric vehicle industry were analyzed through panel analysis. The optimal location from the perspective of distribution costs was selected using linear programming under the assumption that local demand will be replaced by local production in the future. Findings - This study found that the electric vehicle supply chain will change with the characteristics of the electric and electronic industries rather than with the traditional automotive industry. Additionally, in deriving the optimal location, the study emphasized the proximity to the consumption market. Originality/value - The analysis method and conclusions of this study not only present the influential factors and direction of FDI in the automotive industry but also can be applied to other industries. Moreover, the study provides practical and policy implications for industries and governments considering FDI in the US.

• The Microorganisms and Industry
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• v.13 no.1
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• pp.4-9
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• 1987

The regulation of gene expression in procaryotes is accomplished primarily at the level of transcription. Initiation of transcription is subject to numerous promoter-specific controls which act to ensure coordinate expression of disparate genes. The kinetics of formation of a functional("open") complex at a promoter, prior to the catalytic steps of RNA chain initiation and elongation, is thought to play a major role in controlling the efficiency of transcription of that promotor, since the subsequent processes of nucleotide binding and phosphodiester bond formation are rapid and are not promoter-specific (Mangel and Chamberlin, 1974 Shimamoto et al., 1981)

• 한국기계연구소 소보
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• s.13
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• pp.15-25
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• 1984

The infrared spectra were determined to discover the characteristics and properties of poff-, PV-, and cc-samples, and studied influence on the formation of mesophase or liquid crystal. The experimental results were as follows; a) Samples with long aliphatic side chain appear cracking texture on temperature forming liquid crystal. b) The fine isotropic microstructure appears in a heterogeneous material containing sulfur, 7.18 w%. c) In the size of molecular weight the lighter than 500 form liquid crystal. d) When poff-sample was treated at $400^{\circ}C$ aliphatic hydrocabon compounds decrease, presented well-oriented bulk liquid crystal.

• Korean small business review
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• v.40 no.1
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• pp.25-52
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• 2018

The purpose of this study is to investigate the relationship between supply chain sustainability antecedent, supply chain competence, and supply chain sustainability. The relationship between supply chain sustainability antecedence factor and supply chain competence, supply chain competence and supply chain sustainability and to identify the differences between sustainability antecedence factors, capacity and sustainability depending on the size of the firm. To accomplish this, each research hypothesis was established and the results are as follows. First, compliance with environmental regulations, NGO response activities, CSR activities, and trade fairness were found to have a significant positive impact on manufacturing agility, environmental management, and social capital. And manufacturing agility, environmental management, and social capital has been confirmed that most of the economic, environmental and social sustainability have a significant positive influence. In addition, it has been confirmed that there are differences in the factors of supply chain sustainability, capacity, and sustainability depending on the size of the company. According to the results of the study, environmental regulation compliance, NGO response activities, CSR activities, and fairness factors selected as the leading factors of supply chain sustainability play a role as fundamental prerequisites for supply chain competence to achieve sustainability. Manufacturing agility, environmental management, and the formation of social capital have confirmed that they can raise the level of economic, environmental and social sustainability. Therefore, it was confirmed that the enhancement of supply chain sustainability precedence factors can lead to enhancement of supply chain competence, and furthermore, sustainability of supply chain. Compared with large corporations, SMEs' supply chain sustainability precedence factor, capacity and sustainability should be further improved.

• Journal of Distribution Science
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• v.11 no.4
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• pp.51-60
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• 2013

Purpose - The objective of this paper is to investigate the effect of asset specificity, the level of information sharing, the importance of information sharing, and an integrated collaborative environment on supply chain performance. Research design, data, and methodology - Data collection was implemented as follows: questionnaires were distributed to 250 companies that have business ties with Halla Climate Control Corporation. The empirical study to test our hypothesis was based on statistical analysis (using SPSS 18.0 and AMOS 18.0). The hypothesis of this paper is that the asset specificity variable has positive effects on the following variables: Level of information sharing, the importance of information sharing, and integrated collaborative environment. Moreover the variables, the level of information sharing, and the importance of information sharing are strongly influenced by the variable integrated collaborative environment, and these when combined, have an effect on the dependent variable, supply chain performance. We tested our hypothesized model utilizing path analysis with latent variables. Results - According to the results of our analysis, hypothesis H1, which tests whether there is a relationship between asset specificity and the integrated collaborative environment, is supported at the 0.01 level. Hypotheses H2 and H3 were also confirmed, and asset specificity had positive effects (+) on the level of information sharing variable. The importance of the information sharing variable was statistically significant at the 0.01 level. Hypotheses H4 and H5 posited that the integrated collaborative environment variable would have a positive effect on the level of information sharing; the importance of information sharing variable was strongly supported statistically, with a significant p-value below. Moreover, the level of information sharing (H6), and the importance of information sharing (H7) variables also had a statistically relevant influence on supply chain performance. As a result, existence of a collaborative system between companies would influence supply chain performance by strengthening real-time information access and information sharing. Thus, it is important to construct a collaborative environment where information sharing among companies and cooperation is possible. Conclusions - First, with rapid changes in the business environment, it becomes necessary for enterprises to acquire the right information in order to properly implement SCM. For successful SCM, firms should understand the importance of collaboration with supply chain partners and an internally built collaboration system, which in turn will better promote a partnership commitment with suppliers as well as collaborative integration with buyers. A collaborative system, as we suggest in this paper, facilitates the maintenance of a long-term relationship of trust, and can help reinforce information sharing. Second, it is necessary to increase information sharing over time via a collaborative system so that employees of the suppliers become aware of the system. The more proactive and positive attitudes are towards such a collaborative system by the managerial group, the higher the level of information sharing will be among the users. Successful SCM performance is achieved by information sharing through a collaborative environment rather than by investing only in setting up an information system.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.254-256
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• 2004

Polymerase chain reaction (PCR) is a powerful tool for precisely amplifying selected DNA sequences that have had a broad impact on genomic studies. When examining human $\alpha$- and $\beta$- tryptase genes which have 95% DNA homology, inconsistent PCR amplification of genomic sequences hampered our progress. This study suggests that long PCR technique on the original DNA digested with restriction enzymes improves both efficiency and sensitivity of PCR. These improved results seem to derived from the effective denaturation of the original genomic DNA template or reduction of formation of secondary structures that block either primer annealing or extension in PCR. Elimination of homo- or hetero-duplex products derived from highly homologous genes provides an additional advantage in this study. This communication describes how the use of restriction enzymes improved these efficiencies, and also facilitated studies of highly homologous genes including tryptase genes.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.27-32
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• 2012

Generally, hair treatments by complementary actions to give a sense of activity are permanent setting, dyeing, and bleaching, etc. In this study, we investigated the wave formation ability and hair damage occuring in permanent setting and bleaching process. The wave formation ability was evaluated by the differences of length and curl diameter after permanent setting. And the hair damage was also evaluated by the protein release ability and SEM of hair. The bleached hair immediately after permanent setting treatment has better wave formation ability, but much more damaged than the bleached hair after rinsing thoroughly with warm water. It was considered that the chain of hair keratin broke down easily by the bleaching action in the existence of permanent setting agents.