• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.191-192
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• 2008

For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Ge-Se-Te and Ag/$Ge_1Se_1Te_2$ samples are fabricated and irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light. Because of Ag ions, the Ag layer inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.82-98
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• 1998

In the literatual studies on the causes and treatments of the melasma, the results were as follows. 1. Melasma is the blackish patch on the face, is belong to the cartegory of the 'Myunjin(面塵)', 'Myunganzung(면간증)', 'Jakban(雀斑)' etc. in Oriental medicine 2. Melasma is deeply associated with Yangming channel in Meridian, with the spleen, stomach, heart and kidney in Viscera. 3. The pathogenic factors of Melasma is divided five parts. One is insufficient of Yangming's energy in Neijing(內經). Two is incoordination between vital energy and blood caused by wind-evil and phlegm-retention syndrome. Three is anxiety impairing the spleen. Four is kidney-asthenia and fire-hyperactivity. Five is heat-evil. 4. In the treatments of Melasma, Sthenia-syndrome was used cooling blood and activating blood circulation, or dispelling wind-evil and promoting meridian, or expelling fire-evil and removing toxic material etc. Asthenia-syndrome was used invigorating the liver and kidney, or nourishing yin and keeping fire downwards etc. 5. Melasma is concerned with sun-light, is mostly seen in female. 6. In the prescription of Melasma, it was used Jujesamultang(酒製四物湯加減), Okyong -san(玉容散), Chunghwasungitang(沖和順氣湯), Okyongseosisan(玉容西施散), Yukmiji-hwanghwan(六味地黃丸) etc.

• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.357-366
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• 2007

This paper is a pilot study regarding an experimental and parametric study to investigate the structural behavior of slimfloor beam(ASB) in fire. The objective of this research is to obtain the rational fire resistance design method through understanding the structural behavior of composite members in fire. The flexural capacity of slimfloor section under various thermal conditions is examined on a basis of the strength retention of the materials at elevated temperatures and full bonding assumption. The effect of web thickness and ASB depth to the moment capacity in fire is also examined.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.365-372
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• 2010

Low-fat sausages were prepared with various meats to investigate the effect of the addition of oatmeal at 10% as a fat substitute. The sausages were made with beef, pork and chicken after trimming the visible fat, and the physical and sensory properties of the sausages were evaluated. Beef sausage had the lowest cooking yield and the highest hardness, while chicken sausage showed the opposite properties. The addition of oatmeal resulted in sausage products with less cooking loss and softer texture for all types of meat sausages. Such changes were more pronounced for beef low-fat sausage than for the other types of sausages. The results of moisture absorption suggested that the difference in cooking yield and hardness among sausage products was due to the water-retention properties of different meats and the substitute in response to heat treatment. Sensory evaluation indicated that the greatest overall acceptability of the sausage products were obtained from 10% oatmeal-added pork sausage and that the addition of oatmeal led to better acceptability for all types meat sausages.

• Journal of Information Processing Systems
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• v.16 no.4
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• pp.750-759
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• 2020

The wide application of various integrated location-based services (LBS social) and tourism application (app) has generated a large amount of trajectory space data. The trajectory data are used to identify popular tourist attractions with high density of tourists, and they are of great significance to smart service and emergency management of scenic spots. A hot spot analysis method is proposed, based on spatial clustering of trajectory stop points. The DBSCAN algorithm is studied with fast clustering speed, noise processing and clustering of arbitrary shapes in space. The shortage of parameters is manually selected, and an improved method is proposed to adaptively determine parameters based on statistical distribution characteristics of data. DBSCAN clustering analysis and contrast experiments are carried out for three different datasets of artificial synthetic two-dimensional dataset, four-dimensional Iris real dataset and scenic track retention point. The experiment results show that the method can automatically generate reasonable clustering division, and it is superior to traditional algorithms such as DBSCAN and k-means. Finally, based on the spatial clustering results of the trajectory stay points, the Getis-Ord Gi* hotspot analysis and mapping are conducted in ArcGIS software. The hot spots of different tourist attractions are classified according to the analysis results, and the distribution of popular scenic spots is determined with the actual heat of the scenic spots.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1845-1850
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• 2022

In-vessel corium retention (IVR) during external reactor vessel cooling (ERVC) is a key severe accident management strategy adopted in advanced nuclear power plants. The injection of nanofluids has been regarded as a means of enhancing CHF when using the IVR-ERVC strategy to safeguard high-power nuclear reactors. However, a critical practical concern is that various types of debris flowing from the contaminant sump during operation of an ERVC system might degrade CHF enhancement by nanofluids. Our objective here was to experimentally assess the viability of nanofluid use to enhance CHF in practical ERVC contexts (e.g., when fluids contain various types of debris). The types and characteristics of debris expected during IVR-ERVC were examined. We performed pool boiling CHF experiments using nanofluids containing these types of debris. Notably, we found that debris did not cause any degradation of the CHF enhancement characteristics of nanofluids. The nanoparticles are approximately 1000-fold smaller than the debris particles; the number of nanoparticles in the same volume fraction is 1 billion-fold greater. Nanofluids increase CHF via porous deposition of nanosized particles on the boiling surface; this is not hindered by extremely large debris particles.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.308-311
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• 2012

A wide range of possible hazards existing in thermal batteries are mainly caused by thermal runaway, which results in overheating or explosion in extreme case. Battery separators ensure the separation between two electrodes and the retention of ion-conductive electrolytes. Thermal runaways in thermal batteries can be significantly reduced by the adoption of these separators. The high operating temperature and the violent reactivity in thermal batteries, however, have limited the introduction of conventional separators. As a substitute for separators, MgO powders have been mostly used as a binder to hold molten salt electrolyte. During recent decades the fabrication technology of ceramic fiber, which has excellent mechanical strength and chemical stability, has undergone significant improvement. In this study we adopted wet-laid nonwoven paper making method instead of the electrospinning method which is costly and troublesome to produce in volume. Polymeric precursor can readily be coated on the surface of wet-laid ceramic paper, and be formed into ceramic film after heat treatment. The mechanical strength and the thermo-chemical stability as well as the wetting behaviors of ceramic separators with various molten salts were investigated to be applicable to thermal batteries. Due to their excellent chemical, mechanical, and electrical properties, wet-laid nonwoven separators made from ceramic fibers have revealed positive possibility as new separators for thermal batteries which operate at high temperature with no conspicuous sign of a short circuit and corrosion.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.273-278
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• 2019

The multi-layer insulating curtains used in the experiment was produced in six combinations using non-woven fabric containing aerogel and compared and analyzed by measuring heat flux and heat perfusion rates due to weight, thickness and temperature changes. Using silica aerogel, which have recently been noted as new material insulation, this study tries to produce a new combination of multi-layer insulating curtains that can complement the shortcomings of the multi-layer insulating curtains currently in use and maintain and improve its warmth, and analyze the thermal properties. The heat flux means the amount of heat passing per unit time per unit area, and the higher the value, the more heat passing through the multi-layer insulating curtain, and it can be judged that the heat retention is low. The weight and thickness of multi-layer insulation curtains were found to be highly correlated with thermal insulation. In particular, insulation curtains combined with aerogel meltblown non-woven fabric had relatively higher thermal insulation than insulation curtains with the same number of insulation materials. However, the aerogel meltblown non-woven fabric is weak in light resistance and durability, and there is a problem that the production process and aerogel are scattering. In order to solve this problems, the combination of expanded aerogel non-woven fabric and hollow fiber non-woven fabric, which are relatively simple manufacturing processes and excellent warmth, are suitable for use in real farms.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.312-325
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• 2020

The heat perm is the preferred hair technique to get positive affects such as increase of work efficiency and sale in hair industry. The subjects of this study is 262 hair shop workers and it was investigated heat perm device using reason, using satisfaction and repurchase. As a result, the perm accounted for 32.1 and the use of digital perm devices was more than that of setting perm devices. The reasons for the use were that the longer the setting device was engaged, the flexible it was the hair wave. The higher the rank, the better the hair wave retention and the long hair treatment, and it also helped sales. (p<0.05) Digital perm device can be hair-wavy in the desired style while in use, and the longer the working period, the more advantageous. The repurchase intention was that the longer the period of service and the higher the rank, the more advantageous it was. (p<0.05) The reasons for the usage of setting perm and digital perm were correlated with the satisfaction of use and the repurchase intention. The reasons for the use were helpful for sales and elastic hair wave and long hair waving was possible, which affected the repurchase. In conclusion, heat perm had been found not only helped sales, made a good hair wave, and the long hair waving, but also to be preferred to the long working period of the hair shop and the rank above the designer.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.3
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• pp.287-295
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• 2002

Statement of Problem. Endodontically treated teeth frequently required posts and cores to provide retention and resistance form for crowns. In spite of excellent mechanical properties of metal post and core, its metallic color can be detected through all ceramic restorations occasionally. To solve esthetic problems of metal post and core zirconia post system has been introduced recently. Purpose. The purpose of this study was to examine the fracture strength and mode of resin root analogs restored with zirconia, gold and titanium posts with resin, ceramic and metal cores after cementation with metal crowns. Materials and methods. To avoid the morphological variations of natural teeth, 40 root analogs were fabricated with composite resin. Forty resin root analogs were randomly assigned to four groups according to post and core materials: Group A: cast gold post and core and complete cast crowns, as control. Group B: titanium posts (Parapost, Coltent/Whaledent Inc., NJ, USA) and composite resin cores. Group C: zirconia posts (Cosmopost, Ivoclar AG, Schaan/Liechtenstein) and composite resin cores Group D: zirconia posts and heat-pressed ceramic cores (IPS Empress Cosmo Ingots, Ivoclar AG) After thermocycling ($5^{\circ}C{\sim}55^{\circ}C$, 30 sec.), cyclic loading was applied at 3mm below the incisal edge on the palatal surfaces at an angle of 135 degree to the long axis (2Hz, 50N, 50000cycles). Fracture strength was measured by universal testing machine (Instron, High Wycombe, UK) and fracture pattern of restored resin root analogs was also evaluated. Results and conclusion. Within the limitations of this study following results were drawn. 1. Resin root analogs restored with zirconia posts and composite resins demonstrated lowest fracture strength among tested groups. 2. There was no significant difference in the fracture strength between zirconia posts and heat pressed glass ceramic cores and cast gold posts and cores 3. The fracture strength of resin root analogs restored with titanium posts and composite resin cores was lower than that of gold posts and cores. 4. The deep oblique fracture lines were dominantly observed in root analogs restored with cast gold post and core and zirconia post and heat-pressed ceramic core groups.