• Restorative Dentistry and Endodontics
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• v.30 no.6
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• pp.461-469
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• 2005

The aim of this study was to compare the root canal systems of maxillary and mandibular premolars that had a single root using radiographs and clearing samples. 142 single rooted premolars were selected and mesio-distal and bucco-lingual views were radiographed using intra-oral dental standard films. Four equally trained examiners classify the root canal types from the developed radiographs. After opening the tooth for access, it was stored in $5\%$ NaOCl to dissolve the pulp tissue. Indian ink was then injected into the pulp cavity to stain the pulp tissue. It was cleared in methyl salicylate after being decalcified with $5\%$ nitric acid for 48 hours, and the root canal type was evaluated at a magnification of $\times$ 20 using a stereomicroscope. The results are as follows ; There were statistically significant differences between the radiographs and clearing samples of the root canal types among examiners (p < 0.05). There might be differences in the root canal types among examiners when the same radiograph is used. Therefore, considering the difficulty in estimating the root canal types, clinicians need to be careful when interpreting radiographs before root canal therapy.

• Journal of Conservation Science
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• v.34 no.6
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• pp.525-538
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• 2018

Myazedi Quadrilingual Stone Inscription of Myanmar, inscribed to the World Heritage List in 2015, is a rare historical artifact which has an exact date of inscription. It is a written record that displays the history, religion, and culture of Myanmar. Since the surface of the Stone Inscription has been rubbed with ink many times during the process of making printed copies for interpretation and academic research, it has developed a serious stain problem. Therefore, scientific analysis of the stain and research on the treatment for its removal have been conducted. In particular, an experiment was conducted on stain removal using laser cleaning and chemical treatment. The stains are mostly ink dirt, which accumulated from previous ink-rubbing processes. In order to conduct the experiment under similar conditions, a sample with similar stain has been reproduced, and a set of different conditions for treatment was applied to the sample to determine an effective solution. Laser cleaning was found to be effective in removing stains from most samples. However, chemical treatment showed different results. The physical friction method using ethanol provided the best result. In conclusion, laser cleaning is an effective universally-applicable technique but chemical treatment with laser cleaning can be considered an alternative method in certain situations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.2
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• pp.48-55
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• 2022

The color image of the brand comes first and is an important visual element that leads consumers to the consumption of the product. To express more effectively what the brand wants to convey through design, the printing market is striving to print accurate colors that match the intention. In 'offset printing' mainly used in printing, colors are often printed in CMYK (Cyan, Magenta, Yellow, Key) colors. However, it is possible to print more accurate colors by making ink of the desired color instead of dotting CMYK colors. The resulting ink is called 'spot color' ink. Spot color ink is manufactured by repeating the process of mixing the existing inks. In this repetition of trial and error, the manufacturing cost of ink increases, resulting in economic loss, and environmental pollution is caused by wasted inks. In this study, a deep learning algorithm to predict printed spot colors was designed to solve this problem. The algorithm uses a single DNN (Deep Neural Network) model to predict printed spot colors based on the information of the paper and the proportions of inks to mix. More than 8,000 spot color ink data were used for learning, and all color was quantified by dividing the visible light wavelength range into 31 sections and the reflectance for each section. The proposed algorithm predicted more than 80% of spot color inks as very similar colors. The average value of the calculated difference between the actual color and the predicted color through 'Delta E' provided by CIE is 5.29. It is known that when Delta E is less than 10, it is difficult to distinguish the difference in printed color with the naked eye. The algorithm of this study has a more accurate prediction ability than previous studies, and it can be added flexibly even when new inks are added. This can be usefully used in real industrial sites, and it will reduce the attempts of the operator by checking the color of ink in a virtual environment. This will reduce the manufacturing cost of spot color inks and lead to improved working conditions for workers. In addition, it is expected to contribute to solving the environmental pollution problem by reducing unnecessarily wasted ink.

• Clean Technology
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• v.29 no.2
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• pp.95-101
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• 2023

An experiment was conducted to produce vaterite-type precipitated calcium carbonate from waste oyster shells in order to use them as recyclable resources. Calcined oyster shells containing calcium oxide as their main component were prepared at a temperature of 800℃ for 24 h. The oyster shells were dissolved in nitric acid or hydrochloric acid solution to make 0.1 M calcium nitrate or calcium chloride aqueous solution, and a carbonation reaction was performed using a 0.1 M sodium carbonate aqueous solution under various experimental conditions, which included varying the amount of aspatic acid additive, the amount of NH₄OH added, the reaction time, the reaction temperature, the stirring speed, and the type of dissolved acid. The XRD, SEM, and size distributions were analyzed and the vaterite content was calculated. Spherical precipitated calcium carbonate with a vaterite content of 95.9% was synthesized by adding 0.1 mol aspatic acid/1 mol CaO and 2 cm³ of NH₄OH, and reacting for 1 h at 25℃ while stirring at 600 rpm. The average particle diameter was found to be 12.11 ㎛. Calcium carbonate contatining high vaterite is used as high value added calcium carbonate for medical, food, inke additiver, etc.

• Textile Coloration and Finishing
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• v.35 no.4
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• pp.196-205
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• 2023

Water-dispersed pigment is on-going study for without air pollution in the textile and print industry. Primer treatment is essential for the substrate to improve the printing quality of eco-friendly water-dispersed pigment ink. Otherwise in the case of untreated primer, the water-dispersed pigment ink will dry onto the surface and cause defective images. This study was conducted on film substrate coating (primer) to fix eco-friendly water-dispersed pigment ink on film substrate. The drying, bleeding, and color strength of the pigment ink were examined depending on the composition and mixing ratio of the coating solution. The mixing ratio of silica gel in the coating film is increased to 0, 0.5, 1, 2 and 3 and results that DK-1-3 of silica gel ratio of 1 showed the lowest bleeding such as 52%, the letter thickness of 0.76mm and DK-1-5 of SG ratio of 3 showed the highest bleeding such as 304%, the letter thickness of 2.02mm. The mixing ratio of SPA in the coating film is increased to 2.5, 5, 7.5, SPA ratio of 7.5 has a bleeding ratio of 9% and letter thickness of 0.544mm. It showed the closest value to 0.5mm. According to the result, the optimal mixing ratio of binder, polymer coagulant, silica gel is 100:7.5:1.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.2
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• pp.1-12
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• 2023

In the current era of the global mobile smart device revolution, electronic devices are required in all spaces that people interact with. The establishment of the internet of things (IoT) among smart devices has been recognized as a crucial objective to advance towards creating a comfortable and sustainable future society. In-mold electronic (IME) processes have gained significant industrial significance due to their ability to utilize conventional high-volume methods, which involve printing functional inks on 2D substrates, thermoforming them into 3D shapes, and injection-molded, manufacturing low-cost, lightweight, and functional components or devices. In this article, we provide an overview of IME and its latest advances in application. We review biomimetic nanomaterials for constructing self-supporting biosensor electronic materials on the body, energy storage devices, self-powered devices, and bio-monitoring technology from the perspective of in-mold electronic devices. We anticipate that IME device technology will play a critical role in establishing a human-machine interface (HMI) by converging with the rapidly growing flexible printed electronics technology, which is an integral component of the fourth industrial revolution.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.65-71
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• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.322-326
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• 2006

Though human being has ability to percept a full colored vision, the technology of early photography only can produce black and white images. For cinema filming imagery also captured mono tone with black and white, until developed a color film technology. The desire for presenting color imagery and the technique for producing film and color ink, photography and print utilize color on it with noticeable color impact to viewers. It, however, abusing fun colors image each and every printed and filmed imagery, the freshness of eye catching power diminished now. On contrast, color becomes black and white or partially used for making discrepancy among full colored images. This image detected commercial and music video, and it spread to film. To use those bleached color images is for evoking a nostalgia and a visual differentiation. Especially, it can be provocative images brought to audience with that. such as "Anycall", "Dimchae" for CF, and "Schindler's list," and "Sin city" for movie. It is hard to investigate on the color studies for partially used images. Therefore, this study is to research that through CF and film, base on it, to investigate the application for this image. To collect data from survey, it will be established a basic concept for understanding the partial color applying.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.116-126
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• 2013

Glycol ethers are a group of solvents based on alkyl ethers of ethylene glycol commonly used in paints. These solvents typically have a higher boiling point, together with the favorable solvent properties of lower-molecular weight ethers and alcohols. The word "Glycol ethers" was registered as a United States trademark by Union Carbide Corp. Typically, glycol ethers are found in pharmaceuticals, sunscreens, cosmetics, inks, dyes and water based paints. On the other hand, glycol ethers are used in degreasers, cleaners, aerosol paints and adhesives. Most glycol ethers are relatively water soluble, biodegradable and only a few are considered toxic. Therefore, they are unlikely to pose an adverse risk to the environment. Recent study suggests that occupational exposure to glycol ethers is related to low motile sperm count in men, but the finding has been disputed by others. In this study, skin permeation of 3 types glycol ethers were studied in vitro using matrix such as solvent and detergent. The absorption of glycol ethers[methyl glycol ethers(MC), ethyl glycol ethers(EC) and butyl glycol ethers(BC)] has been measured in vitro through rat skin. Epidermal membranes were set up in Franz diffusion cells and their permeability to PBS measured to establish the integrity of the skin before the glycol ethers were applied to the epidermal surface. Absorption rates for each glycol ethers were determined and permeability assessment made to quantify any irreversible alterations in barrier function due to contact with the esters. Types of glycol ethers in vitro experimental results on MC> EC> BC quickly appeared in the following order: skin permeation was beneficial to the skin permeation small molecular weight, the difference in chemical structure, such as hydrophilic, because with the partition coefficient and solubility mechanisms and passive diffusion to increase the speed at which transmission is considered.

• The Journal of Engineering Geology
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• v.22 no.2
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• pp.145-155
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• 2012

The matric suction and volumetric water content of Jumunin standard sand with a relative density of 60% were measured using an Automated Soil-Water Characteristic Curve (SWCC) apparatus during both drying and wetting processes. The test time for the drying process was longer than that for the wetting process, because the flow of water is likely to be protected by air trapped in voids within the soils during the drying process. Based on the matric suction and volumetric water content, the SWCC was estimated using the model proposed by van Genuchten (1980). For the drying process, the unsaturated fitting parameters ${\alpha}$, n, and m were 0.399, 8.586, and 0.884, respectively; for the wetting process, the values were 0.548, 5.625, and 8.220, respectively. The hysteresis phenomenon occurred in the SWCCs, which means the SWCC of the drying process is not matched with the SWCC of the wetting process. Using these unsaturated parameters, we estimated the Suction Stress Characteristic Curve (SSCC), based on the relationship between suction stress and the effective degree of saturation. The suction stress showed a rapid decrease when the matric suction exceeds the Air Entry Value (AEV). Therefore, the effective stress of unsaturated soils is different from that of saturated soils when the matric suction exceeds the AEV. The suction stress of the drying process exceeds that of the wetting process for a given effective degree of saturation. The hysteresis phenomenon was also recognized in SSCCs. The hysteresis phenomenon of SSCCs arises from that of SWCCs, which is induced by the ink bottle effect and the contact angle effect. In the case of a sandy slope, the suction stress is positive and acts to enhance the slope stability as the water infiltrates the ground, but is negative when the suction stress exceeds the AEV. The results obtained for the wetting process should be applied in analyses of slope stability, because the process of water infiltration into ground is similar to the wetting process.