• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.993-994
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• 2008

Electrochromic (EC) devices are capable of reversibly changing their optical properties upon charge injection and extraction induced by the external voltage. The characteristics of the EC device, such as low power consumption, high coloration efficiency, and memory effects under open circuit status, make them suitable for use in a variety of applications including smart windows and electronic papers. Coloration due to reduction or oxidation of redox chromophores can be used for EC devices (e-paper), but the switching time is slow (second level). Recently, with increasing demand for the low cost, lightweight flat panel display with paper-like readability (electronic paper), an EC display technology based on dye-modified $TiO_2$ nanoparticle electrode was developed. A well known organic dye molecule, viologen, was adsorbed on the surface of a mesoporous $TiO_2$ nanoparticle film to form the EC electrode. On the other hand, ZnO is a wide bandgap II-VI semiconductor which has been applied in many fields such as UV lasers, field effect transistors and transparent conductors. The bandgap of the bulk ZnO is about 3.37 eV, which is close to that of the $TiO_2$ (3.4 eV). As a traditional transparent conductor, ZnO has excellent electron transport properties, even in ZnO nanoparticle films. In the past few years, one-dimension (1D) nanostructures of ZnO have attracted extensive research interest. In particular, 1D ZnO nanowires renders much better electron transportation capability by providing a direct conduction path for electron transport and greatly reducing the number of grain boundaries. These unique advantages make ZnO nanowires a promising matrix electrode for EC dye molecule loading. ZnO nanowires grow vertically from the substrate and form a dense array (Fig. 1). The ZnO nanowires show regular hexagonal cross section and the average diameter of the ZnO nanowires is about 100 nm. The cross-section image of the ZnO nanowires array (Fig. 1) indicates that the length of the ZnO nanowires is about $6\;{\mu}m$. From one on/off cycle of the ZnO EC cell (Fig. 2). We can see that, the switching time of a ZnO nanowire electrode EC cell with an active area of $1\;{\times}\;1\;cm^2$ is 170 ms and 142 ms for coloration and bleaching, respectively. The coloration and bleaching time is faster compared to the $TiO_2$ mesoporous EC devices with both coloration and bleaching time of about 250 ms for a device with an active area of $2.5\;cm^2$. With further optimization, it is possible that the response time can reach ten(s) of millisecond, i.e. capable of displaying video. Fig. 3 shows a prototype with two different transmittance states. It can be seen that good contrast was obtained. The retention was at least a few hours for these prototypes. Being an oxide, ZnO is oxidation resistant, i.e. it is more durable for field emission cathode. ZnO nanotetropods were also applied to realize the first prototype triode field emission device, making use of scattered surface-conduction electrons for field emission (Fig. 4). The device has a high efficiency (field emitted electron to total electron ratio) of about 60%. With this high efficiency, we were able to fabricate some prototype displays (Fig. 5 showing some alphanumerical symbols). ZnO tetrapods have four legs, which guarantees that there is one leg always pointing upward, even using screen printing method to fabricate the cathode.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1824-1826
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• 1999

In order to develop key technologies for a kW class for polymer electrolyte fuel cell (PEFC), various membranes (Nafion(112, 115, 117), Dow, Flemion, Gore, and Hanwha), and electrocatalysts (Pt/C, PtNi/C PtNiCo/C and PtRu/C) were used in the fabrication of the MEAs by using transfer printing technique. The effects of the thickness of Nafion membranes, electrocatalysts and the operating conditions (e.g. temperature, reactant gas pressure, and composition) on the performance of the MEA were investigated in the PEFC single cell($O_2/H_2$, and Air/$H_2$ cell). The performances of the MEAs for $O_2/H_2$ and Air/$H_2$ cells has been evaluated.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.38.1-38.8
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• 2019

Navigation of the main root canal and dealing with a dens invaginatus (DI) is a challenging task in clinical practice. Recently, the guided endodontics technique has become an alternative method for accessing root canals, surgical cavities, and calcified root canals without causing iatrogenic damage to tissue. In this case report, the use of the guided endodontics technique for two maxillary lateral incisors with multiple DIs is described. A 16-year-old female patient was referred with the chief complaint of pain and discoloured upper front teeth. Based on clinical and radiographic findings, a diagnosis of pulp necrosis and chronic periapical abscess associated with double DI (Oehler's type II) was established for the upper left lateral maxillary incisor (tooth #22). Root canal treatment and the sealing of double DI with mineral trioxide aggregate was planned for tooth #22. For tooth #12 (Oehler's type II), preventive sealing of the DI was planned. Minimally invasive access to the double DI and the main root canal of tooth #22, and to the DI of tooth #12, was achieved using the guided endodontics technique. This technique can be a valuable tool because it reduces chair-time and, more importantly, the risk of iatrogenic damage to the tooth structure.

• Journal of the Korean Society of Costume
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• v.61 no.5
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• pp.48-63
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• 2011

Digital makeup(DM), depending upon computer graphic softwares, is applied to various fields, e.g. character works in movie and game industries and visual printouts in printing works. Focused on makeup field, DM is extremely conducive to developing, scientizing and informationalizing makeup patterns. Despite of unlimited potential of DM of which market size has been growing day by day, its practical use by domestic makeup experts and educators is much less active than expected as far, due to the lack of knowledge accumulation. The purpose of this study is to suggest some theoretical frameworks to generalize DM techniques and analyze two cases using the frames therefore support academicians' recent efforts to theorize DM techniques. The study 1) defines and categorizes the concepts of DM and DFX(digital special effect); 2) reviews the literature relevant to DM and generalizes the types and methods of DM techniques; 3) applies general frames to analyzing two movie cases, famous for their DM effects; 4) then suggests, based upon analytical results, some efficient ways for makeup experts to use DM techniques in practice. This study contributes to providing the theoretical grounds to conceptualize DM thus broadening makeup artists' interests in DM and awakening the scholarly concerns in cultural technology including DM.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.5
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• pp.355-358
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• 2011

As a II-IV compound semiconductor, ZnO has a wide band gap of 3.37 eV with transparent properties. Due to this transparent properties, ZnO materials can be also employed as the transparent conducting electrode materials. Recently, rapid progress has been made in the field of DSSC (dye sensitized solar cell)area. Therefore, strong demands have been required for the transparent electrodes with low temperature processing and cheap cost. In this paper, we will prepare ZnO thick films on the PET substrates for the electrode applications. We will investigate the structural and microstructure properties through the XRD, and SEM analysis, respectively. Also, we will study the electrical of specimens to apply the conducting electrode.

• Journal of the Korean Society of Costume
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• v.60 no.8
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• pp.1-14
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• 2010

This study is a discussion of the expressive characteristics of contemporary fashion design with floral images. It aims to help understand the overall trends of contemporary fashion design and textile motif design and expand the potential expression fields of originative design to natural objects such as flowers. Methodologically the study analyzed 976 pieces of data gathered from Haute Couture and Pr$\hat{e}$t-$\grave{a}$-Porter collections of 2005S/S-2009F/W, according to their types of expression. The study results show a share of 42.7% for plane type expressions by printing or weaving and a share of 51.5% for relief type expressions, compared with 5.7% for solid type expressions. However, those expressions represented elegant femininity with emphasis on formative beauty and were applied to fashion accessories or hair adornments. The expressive characteristics found from the analysis were represented by natural images, feminine elegance, and decorative aesthetics of handicrafts. Flowers in the contemporary fashion purify the internal emotions of humankind stand for personality and beauty in many different ways of expression and serve as a means of expressing more artistic values breaking out of stereotype.

• Journal of Fashion Business
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• v.22 no.4
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• pp.47-58
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• 2018

The Belgian textile wallcovering has the following background. The unique oceanic climate is optimized for flax. Beginning in the thirteenth century, British wool was produced for export to Britain or neighboring countries. Since the 15th century, Flemish paintings were influenced by color implementations, and these colors have influenced the developments of tapestry and art. Since that time, tapestry and paintings combined with paper technologies and Oriental civilizations, such as silk, that had been developed through trade ports, have been transformed into the form of current wallcoverings. Belgium produces the highest quality textile wallcovering using natural materials i.e., a combination of irregular and modern materials, and the implementation of different colors. The Belgian textile wallcovering is also a good representation of nature at the Heimtextil 2018, It provides a wide range of colors while retaining the best styles for wallcoverings in Belgium. The characteristics of Belgian wall coverings are: First, the high proportion of achromatic colors, especially the white ones, are analyzed for current trends. Second, it expresses the characteristics of materials by using only one material. This not only shows a high level of understanding of natural materials, but also shows a high level of development in terms of processing technology. Thirdly, linen was made into a formative expression using wrinkle processing and by printing geometric patterns, the rough texture of natural materials was expressed in harmony with modern patterns.

• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.59-71
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• 2018

Purpose: Cellulose nanocrystals (CNCs) are natural polymers that have been promoted as a next generation of new, sustainable materials. CNCs are invaluable as reinforcing materials for composites because they can impart improved mechanical, chemical, and thermal properties and they are biodegradable. The purpose of this review is to provide researchers with information that can assist in the application of CNCs extracted from waste agricultural byproducts (e.g. rice husks, corncobs, pineapple leaves). Methods & Results: This paper presents the unique characteristics of CNCs based on agricultural byproducts, and lists processing methods for manufacturing CNCs from agricultural byproducts. Various mechanical treatments (microfluidization and homogenization) and chemical treatments (alkali treatment, bleaching and hydrolysis) can be performed in order to generate nanocellulose. CNC-based composite properties and various applications are also discussed. Conclusions: CNC-based composites from agricultural byproducts can be combined to meet end-use applications such as sensors, batteries, films, food packaging, and 3D printing by utilizing their properties. The review discusses applications in food engineering, biological engineering, and cellulose-based hydrogels.

• Architectural research
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• v.15 no.1
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• pp.17-23
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• 2013

The purpose of this paper is to reconsider and revaluate Ste. Genevieve Library designed by Henri Labrouste as a criticism of Classicism. Considered as the epitome of the early structural Rationalism the modern historian tried to focus only on the iron structure of the library. Arguably, the structural concern was one of the ideas that the architect wanted to manifest in the library. As a rebel against a view of the Acad$\acute{e}$mie des Beaux-Art the notions of H. Labrouste were radical. He criticized an autistic Classicism with an echoing Claude Perrault's doubt about the myth of classical beauty. These radical ideas firstly showed in his report of the Grand Prix de Rome and must have been developed through several discussions for a novel: Notre-Dame de Paris by V. Hugo. 'Ceci tuera cela', one of the chapter of the novel, was generally known as the death of architecture due to the invention of the printing press around Renaissance period. We, however, consider that even though the historical background of the novel is the Gothic period the ideas, which was discussed with Labrouste, related to the death of architecture was not the architecture itself but classical architecture recomposed during Renaissance period. As the first design work the library must be reflected his ideas, which were developed, and manifested his criticism of the Classicism indirectly.

• International Journal of Human Ecology
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• v.12 no.1
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• pp.101-113
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• 2011

This research aims to enrich the field of decorative designs for the T-shirts of youth clothes. Youth T-shirts have been chosen because they are essential apparel and one of the most important casualwear. T-shirts are probably the number one item sold across the world. Every tourist shop has many of them, worldwide. The decorative ideas have been inspired from some symbols of Coptic arts. This incorporates the cultural power of Coptic art as a vital starting point for new design ideas and development of products. However, the purpose of this research is to make our youth know something about the Coptic arts of Egypt, as a part of their history, and on the other hand for tourists as well. Youth are very suitable tools for spreading our new ideas where they are energetic and full of life. In this work, twenty-one designs are presented inspired from ten Coptic symbols. Five designs have been implemented in three different ways of printing and embroidery, i.e. there are fifteen models have been formed. An opinion poll has been occurred for two groups of youth, one is younger and the other is older, hence T-test has been applied. It is clarified that our designs are approved by the younger group than the older one. The results of this work can offer some good reasons for further investigations on the fashionable decorated designs for youth and tourists as well; in addition to the decoration education development.