• Journal of the Korean Ceramic Society
• /
• v.52 no.5
• /
• pp.304-307
• /
• 2015

To reduce the lateral conduction loss of thin-film-processed cathodes, the microstructure of the thin-film cathode is engineered to contain a denser bridging layer in the middle. By doing so, the characteristic crack-like pores that separate the cathode domains in thin-film-processed cathodes and hamper lateral conduction are better connected and, as a result, the sheet resistance of the cathode is effectively reduced by a factor of 5. This induces suppression of the lateral conduction loss and expansion of the effective current collecting area; the cell performance is improved by more than 30%.

• Journal of the Korean institute of surface engineering
• /
• v.49 no.3
• /
• pp.252-259
• /
• 2016

In order to form an aluminum-doped zinc oxide (AZO) transparent electrode film on a polyethylene terephthalate (PET) substrate used for a flexible display substrate, the AZO transparent electrode was produced at low temperature without substrate heating. Even though the produced electrode showed characteristic optical transmittance of 90 % (at 550 nm) and sheet resistance within $100{\Omega}/sq$, cracks occurred 10 minutes after loading applied 2 mm radius of curvature, and the sheet resistance increased linearly. An insertion layer of ZrCu was formed between the AZO film and the PET substrate to suppress the generation of cracks on the AZO film. It was verified that the crack was not generated 30 minutes after the loading of 2 mm radius of curvature, and no increase in sheet resistance was recorded. There was also not cracks in the dynamic bending test of 4 mm radius, but surface resistance was slightly increased. As a result, the ZrCu insertion film improved the interfacial adhesion between the substrate and AZO film layer without increasing sheet resistance and decreasing transmittance.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.2 no.2
• /
• pp.209-217
• /
• 1998

Compared to normal-strength concrete, high-strength concrete has the lower lateral expansion capacity caused by the higher elastic modulus and the lower internal crack characteristic. Therefore, the effect of the lateral confining action of hoops appears slowly. Nevertheless, it has been reported that the strength and deformation capacity of high-strength concrete is improved by well-distributed hoops. Due to that argument, this investigation has been compared and analyzed by the experimental works on the deformation capacity and the confinement mechanism of high-strength concrete shear wall of the high-rise building reinforced by rectangular steel tubes and rectangular hoops at both edges. It is suggested that, using high-strength concrete($500kgf/cm^2$, $700kgf/cm^2$), hoops should be replaced with rectangular steel tubes in order to prevent closely spaced hoops at the edge of the shear wall.

• Journal of Applied Reliability
• /
• v.13 no.3
• /
• pp.207-216
• /
• 2013

This paper, we classified LED failure mechanisms that occur due to the delamination and analyzed each of the mechanism that gives the LED PKGs the effect. Usually, the LED is composed of several materials which are LED chips, gold wire, phosphor, epoxy resin, adhesive, reflector and lead frame. These different materials are usually delaminated in trouble conditions which are huge temperature difference, hot and humid or mechanical shocked. When the components are delaminated, a luminance will be lost and moisture be absorbed easily, a thermal resistance be increased attendantly. In this paper, we experimented to investigate failure mechanism of the thermal resistance and failure mechanism of the decrease of luminance that occur due to the delamination. A thermal shock test was performed to reproduce this phenomena by subjecting samples to a cold-hot cyclling process between $-30^{\circ}C$(15min) and $110^{\circ}C$(15min). The samples were inspected at 200, 600 and 1,000 cycles. We measured feature of LED using the spatial analyzer, optical microscope, thermal resistance, photometer, scanning electron microscope (SEM). As a result, the progression of the crack and the thermal resistance and decrease in luminance are proportional to number of thermal shock.

• Journal of Sensor Science and Technology
• /
• v.32 no.5
• /
• pp.295-299
• /
• 2023

Herein, we propose a simple fabrication method for MXene-coated V-groove sensors for applications. To enhance the sensitivity of this sensor, we applied MXene particles, instead of conventional metal layers, as a sensing material on the sensor's surface. This allows for an easier fabrication, as well as higher sensitivity of the sensor compared to those of our previously demonstrated metal-based V-groove sensor. Additionally, polyurethane-acrylate, a UV-curable liquid polymer, can be easily applied using micro-electromechanical systems-based surface-texture micromachining. The sensor sensitivity is approximately 0.08 /mm, and it can be improved by increasing the number of V-grooves. We believe that the proposed MXene-based wearable sensor offers a great potential in detecting various types of motions characteristic of human activities.

• Journal of the Korean Society of Radiology
• /
• v.15 no.6
• /
• pp.781-788
• /
• 2021

Due to the high sensitivity to radiation, excessive exposure needs to be prevented by accurately measuring the dose irradiated to the skin during radiation therapy. Although clinical trials use dosimeters such as film, OSLD, TLD, glass dosimeter, etc. to measure skin dose, these dosimeters have difficulty in accurate dosimetry on skin curves. In this study, to solve these problems, we developed a skin dosimeter that can be attached according to human flexion and evaluated its response characteristics. For the manufacture of the dosimeter, lead oxide (PbO) with high atomic number (Z_Pb: 82, Z_O: 8) and density (9.53 g/cm³) and silicon binders that can bend according to human flexion were used. In the case of a dosimeter made of PbO material, the performance degradation has been prevented by using parylene and others due to the presence of degradation due to oxidation, but the previously used parylene is affected by bending, so a new form of passive layer was produced and applied to the skin dosimeter. The characteristic evaluation of the skin dosimeter was evaluated by analyzing SEM, reproducibility, and linearity. Through SEM analysis, bending was evaluated, reproducibility and linearity at 6 MeV energy were evaluated, and applicability was assessed with a skin dosimeter. As a result of observing the dosimeter surface through SEM analysis, the parylene passive layer PbO dosimeter with the positive layer raised to the parylene produced cracks on the surface when bent. On the other hand, no crack was observed in the silicon passive layer PbO dosimeter, which was raised to silicon passive layer. In the reproducibility measurement results, the RSD of the silicon passive layer PbO dosimeter was 1.47% which satisfied the evaluation criteria RSD 1.5% and the linearity evaluation results showed the R² value of 0.9990, which satisfied the evaluation criteria R² 9990. The silicon passive layer PbO dosimeter was evaluated to be applicable to skin dosimeters by demonstrating high signal stability, precision, and accuracy in reproducibility and linearity, without cracking due to bending.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.38 no.3
• /
• pp.138-149
• /
• 2022

The clinical applicability of ceramics can be increased by analyzing the causes of fractures after fracture testing of dental ceramics. Fractography to analyze the cause of fracture of dental ceramics is being widely applied with the development of imaging technologies such as scanning electron microscopy. Setting the experimental conditions is important for accurate interpretation. The fractured specimens should be stored and cleaned to avoid contamination, and metal pretreatment is required for better observation. Depending on the type of fracture, there are dimple rupture, cleavage, and decohesive rupture mainly observed in metals, and fatigue fractures and conchoidal fractures observed in ceramics. In order to reproduce fatigue fracture in the laboratory, which is the main cause of fracture of ceramics, a dynamic loading for observing slow crack growth is essential, and the load conditions and number of loads must be appropriately set. A typical characteristic of a fracture surface of ceramic is a hackle, and the causes of fracture vary depending on the shape of hackle. Fractography is a useful method for in-depth understanding of fractures of dental ceramics, so it is necessary to follow the exact experimental procedure and interpret the results with caution.

• Journal of Popular Narrative
• /
• v.25 no.3
• /
• pp.143-180
• /
• 2019

This article aims to examine the manner in which the 'Byeongmat' discourse was constructed, and the mechanism of the 'Byeongmat' discourse. I claim that the constructed discourse excludes disabled persons and women. When the 'Byeongmat' first appeared in the mainstream, it was understood as being presented only by webtoons. Furthermore 'Byeongmat' and webtoons were understood as almost synonymous. In this sense, it is no exaggeration to say that the way in which the 'Byeongmat' discourse was constructed is the way in which 'Byeongmat webtoons' were interpreted. In this article, to find out how the 'Byeongmat' discourse was constructed, I examine two things. First, the reception of media of 'Byeongmat'. 'Byeongmat' was at first understood as 'kitsch' by the media, but soon after generational meaning was added. Second, the interpretation of 'Byeongmat' in academia. In academia, the 'Byeongmat' discourse is advanced as a refined generationalism. Regardless of the 'Byeongmat webtoon' itself, 'Byeongmat webtoon' is interpreted as a text which is destructing narrative and filled with parodies. Furthermore this characteristic of the 'Byeongmat webtoon' is interpreted as a resistance culture of the younger generation. However, this interpretation serves as a mechanism which excludes the disabled and women. Currently, Korean society faces the popularization of the 'Byeongmat' code, the decline of the 'Byeongmat webtoons' and the crack of the younger generation discourse. The current situation allows the 'Byeongmat' discourse to be criticized without losing its social context while securing a distance of critcism. I expect that this article can contribute to further diversifying interpretations of 'Byeongmat' and 'Byeongmat webtoons', and accelerating the crack on the younger generation discourse.

• Journal of Popular Narrative
• /
• v.25 no.4
• /
• pp.9-43
• /
• 2019

Web novels are one of the most actively adapted genre novels under a new medium called the Internet. Research on cultural content implemented on top of digital media is naturally closely related to environmental changes in digital media. The same goes for Web novels sparked by the identity of Web platforms. Especially in the case of web novels, the platform itself that provides them has triggered direct changes in genre code and reading patterns. From this perspective, this thesis wanted to examine the formation process and strategic features of web novels, which became content and products on the web platform environment. First of all, through the formation process ranging from communication novels to Internet novels and web novels, I arranged the transition to digital media and the change of genre novel market. This was an attempt to extract that Web novels not only have continuity as genre novels, but also have a turning point as digital content. Web novels are digital content that internalizes the values of the Web 2.0 era. It should also be a core product that grows the pie in the market in its own right. This paper noted that web novels are content that embodies these consumption values. So this thesis considered about what is the visualization and commercialization strategy of the web-based novels that is currently formed, and what is the current status of the web-based romance novels as the content and the product that is driving OSMU most actively in the process of commercialization. Through this process, I found that the greatest characteristic of web novels as genre novels that have evolved into digital content is their division and crack of genre.

• Journal of Conservation Science
• /
• v.27 no.2
• /
• pp.223-229
• /
• 2011

Buddha painting cultural properties couldn't avoid the change of colors and the exfoliation phenomenon by the characteristic of material and environmental factors. Especially, because in the beginning of the fine crack and the decoloration phenomenon on the surface of pigment would be significantly decrease stability of the whole object, it is necessary to take particular measure. Therefore, this is a study on conservation of Avalokitesvara in Potalaka in Hyeondeungsa in Gapyeong. It treated damaged parts of the object, carried out backing papers and matching colors. And then, it examined scientific analysis of pigments. Also, it performed nondestructive testing like XRF, FT-IR, and image microscope to investigate the quality of the material of hanji using the object and the component and characteristic of pigments. As a result, FT-IR spectrum matching Korean traditional paper(hanji) was detected in hanji of Avalokitesvara in Potalaka in Hyeondeungsa. The black pigment making a thin layer over the white pigment would estimate carbon compounds of unconfirmed ink stick or soot as XRF and FT-IR. Also, the white pigment was lead white($PbCO_3{\cdot}Pb(OH)_2$) involving Pb(Lead) and a carbonate. It was observed that the crystal of blue pigment had the different sizes of the particles from the microscope. In the case of this blue pigment, it showed cobalt blue and lead white was mixed when it used because both Cu and Pb were highly detected in XRF data.