• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.2 s.110
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• pp.38-46
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• 2005

Experimental work was carried out in order to produce a novel grade of ink-jet paper that has both high print-out quality and price competitiveness. Usually, silica and PVOH has been used for ink-jet paper to design the coating layer that has a hydrophilic and micro-porous structure. However, poor rheological characteristics and low productivity of the silica-PVOH system make the price of the ink-jet paper high. The main focus of this study was replacing the conventional silica (coating pigment) PVOH (binder) coating system with the new PCC (coating pigment) cationic starch (binder) coating system, and optimizing thecoating technology associated with PPC-cationic starch system. In this study, ink-jet print quality of PCC-coated papers was compared with that of silica-coated paper. Two types of PCC were used: conventional type and colloid type. It turned out that PCC C, a conventional coating pigment, has not given a desirable result: it showed high dot reproduction, but it gave low optical density. In spite of low dot reproduction, the qualities of PCC A were comparable or superior to those of silica in optical density, color reproduction, and the uniformity of printing surface. It was also shown that the problems that are happened when the dosage level of cationic starch was too low were varied with ink-type used in each printer. However, in the case of low binder level, the produced image was widely spread resulting fromtoo low optical density of images, or from the lack of bonding ability to set ink into coating surface.

• Analytical Science and Technology
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• v.12 no.3
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• pp.218-223
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• 1999

A single use, screen-printed sensor for the measurement of liquid phase ethanol was developed and its electrochemical performance was investigated. Disposable type edthanol sensor was fabricated by serially screen printing the carbon paste, silverd pasted and insulator inlon a polyester substrate to pattern working and reference electrode sites and electrical contact. Alcohol dehydrogenase(ADH) or alcohol oxidase(AOD) together with appropriate electron transfer mediators was immobilized on the working electrode. To improve the sensitivity and reproducibility of carbon paste electrode, some pretreatment procedures were applied and their resultant electrochemical performance was examined. The disposable type electrochemical ethanol sensor developed in this study conveniently determines the ethanol in liquid samples such as blood and in fermentation process.

• Journal of architectural history
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• v.17 no.5
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• pp.71-94
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• 2008

This study examines the examples and changes of wooden member terms in Yeonggeon-euigwe(營建儀軌) in the era of Joseon Dynasty. As a result of examining examples, about 240 wood member terms were found on the basis of phonetic value and examples different from today's term use were also confirmed. Wood member terms were derived in variety and synonym and different style, that is, coexistence or transition of several notations as the term indicating the same member was found. Derivation of detail terms has the characteristic increasing on the basis of morpheme and formation of different notation followed Chinese notation or was caused by complex coinage features like a coined word of Korea by the meaning of a word and borrowed character notation borrowing sound and it is also related to the specificity of that time which had dual language system. The typical examples without different style for long were pillar, rafter, door and window. Examples with active generation and selection of different styles included beam, capital and bracket-system terms. Different styles were caused by the combination of several notations including borrowed character in the process of Chinese character notation borrowing sound, Korean unique character emphasizing and limiting combination of 木 (wood) with side of character and Chinese. Period showing remarkable change of example notation was the compilation of ${\ll}$the Hwa-Sung-Sung-Euk-Eui-Gue${\gg}$ 華城城役儀軌. ${\ll}$the Hwa-Sung-Sung-Euk-Eui-Gue${\gg}$ is the representative type uigwe made by printed type not by handicraft. Printing by type accompanies unification of the shape of a character necessarily and it was considered that it resulted in the unification of character of different style, the number of strokes and minute difference of strokes, and it was interpreted that common use of intentional notation with the unification of the shape of a character was achieved.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.33-40
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• 2019

FDM 3D printers have become widespread, and investment in the 3D printer industry is increasing. Therefore, many 3D printers are released and the functions of products are emphasized. However, to lower unit prices, open-type 3D printers are sold in kit form, and their performance is very low. If the 3D printer has many heat sources and is sealed, there is the possibility that the main accessories (the main board, power supply, and motor) will be damaged by trapped heat. At the same time, if the ambient temperature is low due to the properties of the material, the output quality deteriorates. In this study, we analyzed the temperature rise of the main accessories and the quality of the output by the heat bed when a chamber was added to an open-type 3D printer. We also compared the quality of the output due to the air flow with the temperature rise of the main accessories. Moreover, we found the optimal value. As a result of the quality analysis, it was finally confirmed that the case with the chamber at $95^{\circ}C$ was the best for the printing condition. In addition, in the absence of the chamber, the bending of the specimen was found to be large, and in the case of the chamber, the degree of bending was slightly decreased by 0.05 mm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.8
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• pp.461-465
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• 2016

n-type silicon shows the better tolerance towards metal impurities with a higher minority carrier lifetime compared to p-type silicon substrate. Due to better lifetime stability as compared to p-type during illumination made the photovoltaic community to switch toward n-type wafers for high efficiency silicon solar cells. We fabricated the front electrode of the n-type solar cell with AgAl paste. The electrodes characteristics of the AgAl paste depend on the contact junction depth that is closely related to the firing temperature. Metal contact depth with p+ emitter, with optimized depth is important as it influence the resistance. In this study, we optimize the firing condition for the effective formation of the metal depth by varying the firing condition. The firing was carried out at temperatures below $670^{\circ}C$ with low contact depth and high contact resistance. It was noted that the contact resistance was reduced with the increase of firing temperature. The contact resistance of $5.99m{\Omega}cm^2$ was shown for the optimum firing temperature of $865^{\circ}C$. Over $900^{\circ}C$, contact junction is bonded to the Si through the emitter, resulting the contact resistance to shunt. we obtained photovoltaic parameter such as fill factor of 76.68%, short-circuit current of $40.2mA/cm^2$, open-circuit voltage of 620 mV and convert efficiency of 19.11%.

• Journal of the Korean Society of Radiology
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• v.10 no.6
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• pp.403-409
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• 2016

MRI scan is a useful method in the diagnosis of musculoskeletal excellent contrast of the organization. Depending on the patient's musculoskeletal examinations state the type of aids provided the aid is used there is also challenging as well as the costs do not vary. This study was produced by the use of 3D printing technology, an MRI aids. Aids in the production process, then through 3D modeling and then convert stl files using (3D MAX.2014, Fusion360) slicing programs (Cubicreater 2.1ver., Cura 15.4ver) converted to G-code printed on the FDM scheme (Cubicon Style, output was MICRO MAKE). Output is, but in the FDM to evaluate the SNR on the MRI images were compared to the test is the case before use, and then to produce a Water Phantom case of a PLA, ABS, a TPU thickness 3mm, using aids before, It was evaluated in a clinical image after qualitatively. Obtaining an image of SNR Warter Phantom appeared to have been evaluated as T1 NON $123.778{\pm}28.492$, PLA $123.522{\pm}28.373$, ABS $124.461{\pm}25.716$, TPU $124.843{\pm}27.272$. T2 NON $127.421{\pm}26.949$, was rated as PLA $124.501{\pm}27.768$, ABS $128.663{\pm}26.549$, TPU $130.171{\pm}25.998$. The results did not show statistically significant differences. The use of assistive devices before and after images Clinical evaluation method palliative $3.20{\pm}0.88$, $3.95{\pm}0.76$ after using the aids used to aid improved the quality of the image. Production of the auxiliary mechanism using a future 3D printing is expected are thought to be used clinically, it can be an aid making safe and comfortable than the inspection of the patient is an alternative to improve the problems of the aids used in the conventional do.

• Korean Journal of Materials Research
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• v.14 no.3
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• pp.224-228
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• 2004

Respectively the powder made of ZnO added $SnO_2$ was prepared by coprecipitation method and the thick film gas sensor was fabricated by screen-printing technique, The morphology and phase of the powder and film was investigated by SEM and XRD. The specific area of the particle was linearly increased with ZnO contents. Target gas was di(propylene glycol) methylether ($CH_3$($OC_3$$H_{6}$ )$_2$OH, DPGME), which is simulant gas of blister gas. The gas sensing characteristics for DPGME were examined with flow type measurement system and the concentrations of target gas were controlled from 500 ppb to 1500 ppb. ZnO (2 wt%) added $SnO_2$ showed maximum sensitivity to DPGME at $300^{\circ}C$.

• Advances in concrete construction
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• v.9 no.1
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• pp.93-102
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• 2020

In this study, we examined the relationship among the rheological properties, workability, and extrudability in the construction of concrete structures using additive manufacturing. We altered the component materials (binder type, water-binder (W/B) ratio, sand ratio) to assess their effect on the rheological properties experimentally. The results indicated that the W/B and sand ratios had the largest effect on the rheological properties. In particular, when the sand ratio increased, it indicated that adjusting the sand ratio would facilitate control over the rheological properties. Additionally, we compared the rheological properties with the results of a traditional workability evaluation, namely the table flow test. This indicated the possibility of inferring the rheological properties by using traditional methods. Finally, we evaluated extrusion quantity according to table flow. The extrusion rate was 350 g/s for a flow of 210 mm and 170 g/s for a flow of 130 mm, indicating that extrusion rate increased as flow increased; however, we concluded that a flow standard of approximately 140-160 mm is suitable for controlling the actual extrusion quantity and rate.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.226-228
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• 2006

This paper presents the two lossless auxiliary inducors-assisted voltage source type half bridge(single ended push pull:SEPP) series resonant high frequency inverter for induction heated fixing roller in copy and printing machines. The simple high-frequency inverter treated here can completely achieve stable zero current soft switching (ZCS) commutation forwide its output power regulation ranges and load variations under constant high frequency pulse density modulation (PDM) scheme. Its transient and steady state operatprinciple is originally described and discussed for a constant high-frequency PDM control strategy under a stable ZCS operation commutation, together with its output effective power regulation charactertics-based on the high frequency PDM strategy. The experimenoperating performances of this voltage source SEPP ZCS-PDM series resonant high frequency inverter using IGBTs are illustrated as compared with computer simulation results and experimenones. Its power losses analysis and actual efficiency are evaluated and discussed on the basis of simulation and experimental results. The feasible effectiveness of this high frequency inverter appliimplemented here is proved from the practical point of view.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.75-79
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• 2001

This paper presents a novel version of an active voltage clamped ZVS-PWM high frequency inverter using IGBTs for electromagnetic induction eddy current-based rolling drum heating in new generation copy and printing machines in consumer business use. The operating principle of this inverter circuit and unique features are described herein. Its constant frequency duty cycle (asymmetrical PWM) controlled voltage source quasi-resonant soft switching high frequency inverter employing IGBTs is proposed, which is capable of achieving stable and efficient zero voltage soft switching commutation over a widely specified power regulation range from full power to low power. The operating performances in a steady state of this inverter is discussed and evaluated on basis of simulation and experimental results as an induction heated roller in new generation copy machine.