• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.1
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• pp.17-29
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• 1996

N-substituted acrylamide hydrogel is reported to have the feature of bing transparent and sensitive enough to response to a temperature stimulus below the temperature of phase transition. Especially at the near of 35 C it becomes shrunk and opaque very quickly. It has also the characteristic of reversing swelling and shrinking. The experiment showed that it is possible to produce a functional gel of super water absorption with the process of free radical polymerizing PVA(polyvinylalcohol) and PAA(polyacrylamide), and crosslinking. The ratio of shrinking and swelling caused by copolymerization rises 10% to 80% at the each temperature of 20 C, 30 C, 40 C, respectively. Phase transition temperature of this gel by copolymerization is50 C while that of ordinary N-substituted acrylamides is between 32~35 C. This temperature reaches the rearing limit of animals and plants so that volumetric transition polymer gel can be ulilized in varying fields such as agriculture/gardening which are water-using field, on-off switch sensing temperature and volumetric variation, processing of liquid wastes and civil engineering works, architecture and electronics. We have no doubt that this material will be the high-functional resin in the hi-tech age of the near future.

• Advances in Traditional Medicine
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• v.6 no.1
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• pp.12-20
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• 2006

Some natural products are able to inhibit radiation effects and exert an antitumor effect with fewer adverse reactions; however, their antitumor effects are less than those of widely-used synthetic drugs. Propolis is a natural material that has been attracting attention, and we extracted this material with water and investigated the effect of continuous propolis administration on radioactivity-induced reduction of hemocytes, in addition to the antioxidant and antitumor effects of propolis. Following a 1-week adjustment period, water-soluble propolis was administered intraperitoneally to male ICR mice at a dose of 100 mg/kg every other day for 2 weeks. Following administration, 2 Gy whole-body irradiation was performed and the counts of leukocytes, lymphocytes, and granulocytes and monocytes in the peripheral blood were determined 1, 3, 7, 15 and 30 days after irradiation. These cells were considered since they are closely associated with immunity to radioactivity. In a second experiment, water-soluble propolis was similarly administered to the mice for 2 weeks after a 1-week adjustment period, and 2 Gy whole-body irradiation was performed. The antioxidant effects in hemocytes were then investigated using 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH), a radical generator. In a third experiment, $1\;{\times}\;10^6$ Sarcoma-180 cells were inoculated into the right thigh of mice, which were divided into four groups: control, water-soluble propolis-treated, 6 Gy irradiated and water-soluble propolis-treated + 6 Gy irradiated groups, and changes in tumor size were measured for 20 days. Statistical analysis was conducted using ANOVA for multiple groups. In the three experiments, administration of water-soluble propolis inhibited the reduction of hemocytes caused by whole-body irradiation, showed antioxidant effects against radioactivity, and inhibited tumor growth, respectively. In conclusion, our data suggest that the antioxidant effect of watersoluble propolis inhibits hemocyte reduction caused by whole-body irradiation and enhances immunological inhibition of tumor growth.

• The Research Journal of the Costume Culture
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• v.13 no.3 s.56
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• pp.425-438
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• 2005

This study is to examine the types of expression and aesthetic characteristics of on-line game characters by analyzing those game characters' body and their costume that appear in various domestic on-line game sites. It is shown in this study that types of the human bodies and costume expressed through the game characters are grouped into five categories such as exposure and tightness, enlargement and exaggeration, curtailment and simplification, gender stereotype and unification. Furthermore, there are four typical aesthetic characteristics resulting from those types of expressions; First, 'grotesque' is expressed in the form of extreme enlargement and exaggeration, extreme exposure and concealment, combined images among human, animal or machine, or monstrous devilish images. Second, in an effort to express 'eroticism', bodies are directly exposed, see-through costumes are used in order to emphasize the body lines or very tight designs are used. Third, 'futuristic' characteristics are shown through geometrical shape and silhouette, machine-like details, strong artificial colors or glossy hi-tech material. Lastly, 'pastiche' is expressed with reconciliation of variety of costumes of game characters. Various opposite or heterogeneous styles are combined or harmonized each other to show pastiche, of which examples are male and female, superior culture and inferior one, rich and poor, oriental and western, human and machine, human and nature or past and future, etc.

• Journal of the Korea Fashion and Costume Design Association
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• v.5 no.2
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• pp.57-64
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• 2003

The rapid development of information media in the 21th century has given rise to the acceleration of fashion change and its diversification due to individual lifestyle, the personification and differentiation of consumers. This has got away from the function-centeredness of clothing and awakened people to the important task of hi-tech new materials development and design development. We immediately need to develop the measure to cope quickly and properly with changes in the dwindled fabric market. Consumers; needs are personified and diversified and the cycle of fashion materials become curtailed. From this perspective, this study attempted to manufacture the material for capable of satisfying consumers; psychology and needs with the handicraft based on the multi-item and small-quantity production system. This study attempted to present the possibility of differentiating products and developing diverse materials by applying the Woolsmok technique. It is expected that the development of these materials will not simply stay at the level of handicraft but contribute to the competitive materials of creativity and aesthetics by inducing it to be applicable to the industrial world and activate them as differentiated high-grade clothing materials for consumers at home and abroad.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.3
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• pp.165-171
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• 2023

The rotary joint connecting the upper and lower structures of construction machinery and special vehicles transmits hydraulic pressure as the shaft and housing rotate, and multiple seals are assembled to prevent oil leakage into the oil flow channel. Because the seal material is rigid and difficult to assemble, we sought a method to assemble it after cutting. The shapes of the cutting surface are L-shaped and / shaped, and the leakage standard when hydraulic pressure is applied is the contact pressure generated on the cutting surface. The structure and material of the seal are composed of a double elastomer, and nonlinear contact structural analysis is performed when only the high-rigidity PE material is cut. Studies have shown that the shorter the cutting length, the better the leakage prevention and the higher the possibility of leakage to the bottom surface where NBR and PE come into contact rather than the top surface where the PE and the housing come into contact.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.80-85
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• 2023

New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.9
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• pp.1308-1319
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• 2002

The purpose of this is to analyze the aesthetics characteristics of our modern sports fashion, and thereby, discuss them in the light of the overall mentality or the 20th century, and thus, present the conditions or sports fashion design meeting modem people's divers aesthetics values and desired. Modern sports fashion sues can be categorized into futurist sports style, erotic sports style and American sheet sports style. And the 20th century mentality characterized by changes of lifestyle, identity and aspiration has influenced the aesthetic features of such sports fashion sues, which can be summed up as follows; first, the futurist sports style applies the functional items and details of active sportswear to design, while heralding a positive and hopeful message of technology and future by using the material of hi-tech functions and senses. This sports style was affected much by shift from social status, attraction and wealth to demonstration of state-of-the-art science, pursuit of functionality in terms of shapes and materials, convenience through See combinations of sportswear items or design elements. Second, the erotic sports style based on minimalism attempted to express the erotic body beauty indirectly by exposing some parts of body or using the material pressed against the body. This sports style was closely related with the changes of sexual identity such as neutral sexualism, bi-sexualism and homo-sexualism. Lastly, the American street sports style was born from black Americarns' sports and dances. This spors style pursues “youth” beyond TPO concept As mass media and commercial sports developed, the young generation copied sports stars' uniforms or fashions to share honor, wealth and youth with them. In sort, the American sheet sports style was affected much by the so-called “heroism”. Such a changed object of aspiration influenced the aesthetic characteristics of American shot sports style directly.

• Journal of the Korean Electrochemical Society
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• v.1 no.1
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• pp.14-17
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• 1998

Mesophase pitch-based carbon fibers(MPCF) have been investigated as an anode active material for lithium ion secondary battery. Graphitized MPCF gives high discharge capacity and good Ah efficiency. MPCF/Li cell shows an initial discharge capacity of 300 mAh/g and Ah efficiency above $90\%$ at a current density of 25 mA/g at $0\~1$ V. Cylindrical lithium ion secondary battery was fabricated using mixed carbon anode and $LiCoO_2$, cathode. In order to improve the cyclability of lithiun ion secondary battery, other carbons were added to the MPCF up to $10wt\%$. The cycle performance of lithium ion secondary battery using mixed carbons was superior to those using graphitized MPCF.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.415-418
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• 1999

The characteristics of VRLA (valve regulated Iead-acid) battery with the tubular positive plate and gel type electrolyte were examined as a function of active material filling density. The filling density of positive plate was 3.2 g/mL, 3.4 g/mL, and 3.6 g/mL, respectively. These VRLA batteries were cycled with 100% DOD (depth of discharge) at the $C_5/5$ rate, followed by IU-type recharge with $I_{max}=0.2C_{10}/10$ and a final voltage V=2.40 V/cell. The test was performed in a thermostatic room at $25{\pm}1^{\circ}C$. The result indicated that the initial capacity was independent of active material filling density, i.e., the highest initial capacity was 3.4 g/mL of filling density and the lowest was 3.6 g/mL. On aspect of the cycle-life performance of the VRLA battery, the filling density of 3.6 g/mL was similar to that of 3.4 g/mL in the positive plate, and both were higher than that of 3.2 g/mL. Water-loss and degradation of the VRLA battery were decreased according to an increase of the filling density in the positive plate. The optimum filling density of the active material was 3.4~3.6 g/mL.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.52-60
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• 2015

Static electricity is an imbalance of electric charges within or on the surface of a material. All packed items that are particularly sensitive to static discharge must be protected by antistatic treatment. Otherwise, static electricity generated by an electrical insulator may cause serious damages to some sensitive electronics. In order to remove or prevent a buildup of static electricity, packed items must be treated with the application of an antistatic agent, which helps any excess charge to be evenly distributed. Functional pulp tray used for packing of electronic goods was developed with application of an antistatic agent. As the concentration of the antistatic agent increased, charging voltage and surface resistance of molded pulps decreased. The increase of humidity in surrounding atmosphere around molded pulps led to the decrease of accumulation of static charges. In conclusion, the surface treatment of the antistatic agent not only reduced or eliminated buildup of static electricity in the surface, but also prevented generation of tiny dirts from molded tray.