• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.77-77
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• 2000

Titanium oxide (TiO2) thin films have valuable properties such as a high refractive index, excellent transmittance in the visible and near-IR frequency, and high chemical stability. Therefore it is extensively used in anti-reflection coating, sensor, and photocatalysis as electrical and optical applications. Specially, TiO2 have a high dielectric constant of 180 along the c axis and 90 along the a axis, so it is highlighted in fabricating dielectric capacitors in micro electronic devices. A variety of methods have been used to produce patterned self-assembled monolayers (SAMs), including microcontact printing ($\mu$CP), UV-photolithotgraphy, e-beam lithography, scanned-probe based micro-machining, and atom-lithography. Above all, thin film fabrication on $\mu$CP modified surface is a potentially low-cost, high-throughput method, because it does not require expensive photolithographic equipment, and it produce micrometer scale patterns in thin film materials. The patterned SAMs were used as thin resists, to transfer patterns onto thin films either by chemical etching or by selective deposition. In this study, we deposited TiO2 thin films on Si (1000 substrateds using titanium (IV) isopropoxide ([Ti(O(C3H7)4)] ; TIP as a single molecular precursor at deposition temperature in the range of 300-$700^{\circ}C$ without any carrier and bubbler gas. Crack-free, highly oriented TiO2 polycrystalline thin films with anatase phase and stoichimetric ratio of Ti and O were successfully deposited on Si(100) at temperature as low as 50$0^{\circ}C$. XRD and TED data showed that below 50$0^{\circ}C$, the TiO2 thin films were dominantly grown on Si(100) surfaces in the [211] direction, whereas with increasing the deposition temperature to $700^{\circ}C$, the main films growth direction was changed to be [200]. Two distinct growth behaviors were observed from the Arhenius plots. In addition to deposition of THe TiO2 thin films on Si(100) substrates, patterning of TiO2 thin films was also performed at grown temperature in the range of 300-50$0^{\circ}C$ by MOCVD onto the Si(100) substrates of which surface was modified by organic thin film template. The organic thin film of SAm is obtained by the $\mu$CP method. Alpha-step profile and optical microscope images showed that the boundaries between SAMs areas and selectively deposited TiO2 thin film areas are very definite and sharp. Capacitance - Voltage measurements made on TiO2 films gave a dielectric constant of 29, suggesting a possibility of electronic material applications.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.641-645
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• 2005

Using aqueous solution of 60% ethanol, the isoflavones contained in the Soybean (Chungsun, Korea), Tawon (Suwon, Korea), Jackbean (Hongsung, Korea), Soybean (Jilin, China), Black Soybean (Jilin, China), Kidneybean (Jilin, China) and Soybean (California, U.S.A.) were extracted. In this work, the pretreatment step was composed of agitation extraction, filtration, concentration, ultracentrifuge, and membrane filtration. The analysis by $C_{18}$ column was performed, and the mobile phase applied was linearly changed with A/B of 85/15-65/35 vol% for 50 min (A water/acetic acid, 99.9/0.1 vol%, B acetonitrile/acetic acid, 99.9/0.1 vol%). Among the soybeans tested, the total amounts of the four isoflavones (daidzin, genistin, daidzein, and genistein) extracted by the soybeans from Korea, China and U.S.A. were 1.37, 1.60, and 2.25 mg/g, respectively. It was also found that the total amount of aglycone of daidzein and genistein from soybean (American California) was $144{\mu}g/g$, which was the largest for the soybeans experimented.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.252-260
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• 2009

Rice is the most important cereal crop not only in supplying the basic staple food for more than half of the world's population but also as a model plant for functional genomic studies of monocotyledons. Although rice transformation method using A. tumefaciens has already been widely used to generate transgenic plants, the transformation rate is still low in most Korean elite cultivars. We made several modifications of the standard protocol especially in the co-cultivation step to improve the efficiency of the rice transformation. The co-culture medium was modified by the addition of three antioxidant compounds (10.5 mg/L L-cysteine, 1 mM sodium thiosulfate, 1 mM dithiothreitol) and of Agrobacterium growth-inhibiting agent (5 mg/L silver nitrate). Co-cultivation temperature ($23.5^{\circ}C$ for 1 day, $26.5^{\circ}C$ for 6 days) and duration (7 days) were also changed. The plasmid of pMJC-GB-GUS carrying the GUS reporter gene and the bar gene as the selectable marker was used to evaluate the efficiency of the transformation. After co-cultivation, a high level of GUS gene expression was observed in calli treated with the modified method. It is likely that those newly added compounds helped to minimize the damage due to oxidative bursts during plant cell-Agrobacterium interaction and to prevent necrosis of rice cells. And the transformation rate under the modified method was also remarkably increased approximately 8-fold in Heungnambyeo and 2-fold in Ilmibyeo as compared to the corresponding standard method. Furthermore, we could produce the transgenic plants stably from Ilpumbyeo which is a high-quality rice but its transformation rate is extremely low. Transformation and the copy number of transgenes were confirmed by PCR, bar strip and Southern blot analysis. The improved method would attribute reducing the effort and the time required to produce a large number of transgenic rice plants.

• Korean Chemical Engineering Research
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• v.57 no.2
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• pp.239-243
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• 2019

In this study, anthraquinone-2,7-disulfonic acid (2,7-AQDS) is used as negative active material and Tiron is used as positive active material for aqueous redox flow battery (RFB). In previous results that used the 2,7-AQDS and Tiron, sulfuric acid ($H_2SO_4$) was a supporting electrolyte. However, in this study, ammonium chloride ($NH_4Cl$) is suggested as the electrolyte for the first time. By changing the supporting electrolyte from $H_2SO_4$ to $NH_4Cl$, the cell voltage of RFB is improved from 0.76 V to 1.01 V. To investigate the effect of $NH_4Cl$ supporting electrolyte of the performance of RFB, the full-cell tests of RFB using 2,7-AQDS and Tiron that are dissolved in $NH_4Cl$ supporting electrolyte are carried out, while cut-off voltage range is a main parameter to determine their performance. When the cut-off voltage range is 0.2~1.6 V, the hydrogen evolution occurs during charging step. To address the side reaction effect, the cut-off voltage range is changed to 0.2~1.2 V. When the revised cut-off voltage range is used and the current density of $40mA/cm^2$ is applied, hydrogen evolution is not observed and the optimal RFB shows the charge efficiency of 99% and discharge capacity of 3.3 Ah/L at 10cycle.

• The Mathematical Education
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• v.61 no.4
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• pp.559-579
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• 2022

Research on lexicon and language provides insights into the interests, values and practices of a community where individuals use the language. The International Classroom Lexicon Project, in which ten countries participated, identified own country's mathematics teaching and learning lexicons by investigating mathematics classroom instruction from teachers' perspectives in a speaking-oriented community. This study, as an extension of the International Classroom Lexicon Project research, investigated pedagogical lexicons used in 「Mathematics and Education」 journals specialized for Korean professional mathematics teachers published by the Korean Society of Teachers of Mathematics. Using the text mining approach, we also traced how these pedegogical lexicons have changed quantitatively over the past 10 years with a diachronic perspective. As a results, several novel terms were found in the writing-oriented community, which were not identified in the speaking-oriented community. In addition, we could discover some pedagogical lexicons have increased statistically significantly and some lexicons appeared(increased) rapidly across years. This implies the teacher community's values and zeitgeist by reflecting these changes in the sociocultural, incidental and social changing (i.e., periodical change) contexts. This study has value as a first step in understanding zeitgeist for mathematics education in Korean mathematics teacher community according to changes of times over the past 10 years. Also, this study contributes to the methodological insights: the text mining technique provides a methodological contribution to researching changes in interests, values and zeitgeist according to these changes in the times.

• Journal of Industrial Convergence
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• v.19 no.1
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• pp.17-26
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• 2021

This study was conducted to do in-depth exploration of coroperate employees' learning experiences for workplace under COVID-19. We collected data through depth interviews from August 10th to November 30th, 2020 with five employees of S Energy company, and a qualitative case study was conducted using Ricci's 3-step analysis procedure. As a result, In the process of adapting from the landing of COVID-19, "The Story of a Distant Country," "No More Safe Zones," "Exploring effective responses created by a Sense of Crisis," and "Learning the changed way of work for adaptation." appeared. In addition, It has been found that the experience of learning in the work environment of the With Corona era includes "learning experience for survival from a sense of crisis", "learning experience for adapting to Untact culture", "learning experience through SNS communication", and "competitive learning experience for performance creation". In conclusion, employees have adapted to changes in the workplace environment through various learning experiences, which can enhance workers' ability to cope with crisis situations and can be used as basic data for an effective learning. In the future, we suggested follow-up researches of corporate employees in various fields.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.2
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• pp.97-115
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• 2022

The study aims to explore a new direction for research on buttons by understanding the functions and artistic features of buttons on Western clothing in the 18th and 19th centuries, and to use the findings to develop a textile design. In terms of the research method, the period was set in the 18th and 19th centuries, when decorative features and artistic values of buttons on Western clothing reached theirpeak, while theoretical analysis was made based on literature and previous research papers on Western clothing, websites of the Metropolitan Museum and French Museum of Decorative Arts and other website materials, as well as special exhibition materials of the National Museum of Modern and Contemporary Art. Textile designs were developed using computer programs, including Clip Studio Paint and Adobe Photoshop, by integrating the reinterpreted motif of buttons in the 18th and 19th centuries and the styles that prevailed at that time. The results are as follows. First, buttons on Western clothing had the following three functions: a practical function, a symbolic function representing the wearer's status, and a decorative function expressing individuality and beauty. Second, buttons in the 18th century were works of art made with various handicraft techniques and were an important medium that expressed the wearer's fashion sense. In addition, buttons in the 19th century were mass-produced as a result of industrialization and took a major step forward with the development of materials and dyeing. Buttons reflected themes of poetry, drama, biblical stories, music and art, lifestyle,, along with the political and social atmosphere that rapidly changed after the revolution and fashion trends. Third, the artistic features and shapes of buttons were reinterpreted to create a design motif, and the design was developed reflecting the characteristic elements of the rococo style of the 18th century and the art nouveau style of the 19th century that can conform to modern fashion, thereby rediscovering the artistic meaning and value implied in buttons. In the future, the research on creative buttons of 20th century artists is expected to be conducted from various perspectives.

• Journal of Ginseng Research
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• v.46 no.6
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• pp.780-789
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• 2022

Background: Incretin impairment, characterized by insufficient secretion of L-cell-derived glucagon-like peptide-1 (GLP-1), is a defining step of type 2 diabetes mellitus (T2DM). Ginsenoside compound K (CK) can stimulate GLP-1 secretion; however, the potential mechanism underlying this effect has not been established. Methods: CK (40 mg/kg) was administered orally to male db/db mice for 4 weeks. The body weight, oral glucose tolerance, GLP-1 secretion, gut microbiota sequencing, bile acid (BA) profiles, and BA synthesis markers of each subject were then analyzed. Moreover, TGR5 expression was evaluated by immunoblotting and immunofluorescence, and L-cell lineage markers involved in L-cell abundance were analyzed. Results: CK ameliorated obesity and impaired glucose tolerance in db/db mice by altering the gut microbiota, especially Ruminococcaceae family, and this changed microbe was positively correlated with secondary BA synthesis. Additionally, CK treatment resulted in the up-regulation of CYP7B1 and CYP27A1 and the down-regulation of CYP8B1, thereby shifting BA biosynthesis from the classical pathway to the alternative pathway. CK altered the BA pool by mainly increasing LCA and DCA. Furthermore, CK induced L-cell number expansion leading to enhanced GLP-1 release through TGR5 activation. These increases were supported by the upregulation of genes governing GLP-1 secretion and L-cell differentiation. Conclusions: The results indicate that CK improves glucose homeostasis by increasing L-cell numbers, which enhances GLP-1 release through a mechanism partially mediated by the gut microbiota-BA-TGR5 pathway. Therefore, that therapeutic attempts with CK might be useful for patients with T2DM.

• Korean Journal of Social Welfare Studies
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• v.41 no.1
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• pp.5-37
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• 2010

The purpose of this study is to see the motive, processes and strategies of change in poor single mother self-help group and analyze meaning in the self help group, agencies and themselves by change. As to this discussion, We seek to grope practical ways for self-help group. By using Participatory Action Research, We intended to an alternative plan in collaborating between practitioners and all concerned. Following four-step-process in this methodology, we explored processes of changing and considered social work practical meaning. On results, first, The motive have come from critical minds that motivate them to choose their way subjectively. We concluded that they have a necessity of change as a groping activity within their capability. Second, On process trying to be changed, They have made initiative decisions about how extensive and deep their changes should be, by discussion being themselves. So they have agreed to aim at purposeful activities beyond just emotional support. Third, they suggested and planned meaningful action as a specific strategy for changing and all these were done by local community volunteering and lecturing for supporting single mother. In conclusion, The 'Change' single mother group activity aim at is, based on subjective decision, to change a practice of a social worker into a practice of participant, and to develop social empowerment more improved to control social condition, which is forming their life, by their own choice. Furthermore, It needs to be considered approach to Community for overcome limits of self help group activities. Based on these consequences, We presented social work practical meaning.

• Journal of Intelligence and Information Systems
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• v.23 no.4
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• pp.57-76
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• 2017

Recently, consumer needs are diversifying as information technologies are evolving rapidly. A lot of IT devices such as smart phones and tablet PCs are launching following the trend of information technology. While IT devices focused on the technical advance and improvement a few years ago, the situation is changed now. There is no difference in functional aspects, so companies are trying to differentiate IT devices in terms of appearance design. Consumers also consider design as being a more important factor in the decision-making of smart phones. Smart phones have become a fashion items, revealing consumers' own characteristics and personality. As the design and appearance of the smartphone become important things, it is necessary to examine consumer values from the design and appearance of IT devices. Furthermore, it is crucial to clarify the mechanisms of consumers' design evaluation and develop the design evaluation model based on the mechanism. Since the influence of design gets continuously strong, various and many studies related to design were carried out. These studies can classify three main streams. The first stream focuses on the role of design from the perspective of marketing and communication. The second one is the studies to find out an effective and appealing design from the perspective of industrial design. The last one is to examine the consumer values created by a product design, which means consumers' perception or feeling when they look and feel it. These numerous studies somewhat have dealt with consumer values, but they do not include product attributes, or do not cover the whole process and mechanism from product attributes to consumer values. In this study, we try to develop the holistic design evaluation model based on consumer values based on three-step approach from product attributes, perceived attributes, to consumer values. Product attributes means the real and physical characteristics each smart phone has. They consist of bezel, length, width, thickness, weight and curvature. Perceived attributes are derived from consumers' perception on product attributes. We consider perceived size of device, perceived size of display, perceived thickness, perceived weight, perceived bezel (top - bottom / left - right side), perceived curvature of edge, perceived curvature of back side, gap of each part, perceived gloss and perceived screen ratio. They are factorized into six clusters named as 'Size,' 'Slimness,' 'No-Frame,' 'Roundness,' 'Screen Ratio,' and 'Looseness.' We conducted qualitative research to find out consumer values, which are categorized into two: look and feel values. We identified the values named as 'Silhouette,' 'Neatness,' 'Attractiveness,' 'Polishing,' 'Innovativeness,' 'Professionalism,' 'Intellectualness,' 'Individuality,' and 'Distinctiveness' in terms of look values. Also, we identifies 'Stability,' 'Comfortableness,' 'Grip,' 'Solidity,' 'Non-fragility,' and 'Smoothness' in terms of feel values. They are factorized into five key values: 'Sleek Value,' 'Professional Value,' 'Unique Value,' 'Comfortable Value,' and 'Solid Value.' Finally, we developed the holistic design evaluation model by analyzing each relationship from product attributes, perceived attributes, to consumer values. This study has several theoretical and practical contributions. First, we found consumer values in terms of design evaluation and implicit chain relationship from the objective and physical characteristics to the subjective and mental evaluation. That is, the model explains the mechanism of design evaluation in consumer minds. Second, we suggest a general design evaluation process from product attributes, perceived attributes to consumer values. It is an adaptable methodology not only smart phone but also other IT products. Practically, this model can support the decision-making when companies initiative new product development. It can help product designers focus on their capacities with limited resources. Moreover, if its model combined with machine learning collecting consumers' purchasing data, most preferred values, sales data, etc., it will be able to evolve intelligent design decision support system.