• Restorative Dentistry and Endodontics
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• v.28 no.1
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• pp.80-88
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• 2003

Object The purpose of this study were to evaluate the microtensile bond strength of resin fiber reinforced post to radicular dentin using resin cement according to various dentin surface treatment and to observe the inter face between post and root dentin under SEM Material and Method A total 16 extracted human single rooted teeth were used. A lingual access was made using a #245 carbide bur in a high-speed handpiece with copious air water spray. The post space was mechanically enlarged using H-file(up to #60) and Gates Glidden bures(#3). This was followed by refining of the canal space using the calbrating drill set provided in ER Dentinpost(GEBR, BRASSELER GmbH&Co. KG). The 16 teeth were randomly distributed into 4 group of 4 teeth. Group 1 teeth had their post space prepared using 10% phosphoric acid as root canal surface treatment agent during 20s. The canal was then rinsed with saline and dried with paper point. Group 2 teeth had their post space prepared using 3% NaOCl as root canal surface treatment agent during 30min. The canal was then rinsed with saline and dried with paper point. Group 3 teeth had their post space prepared using 17% EDTA as root canal surface treatment agent during 1min. The canal was then rinsed with saline and dried with paper point. Group 4 teeth had their post space prepared using 17% EDTA as root canal surface treatment agent during 1min. After rinsing with saline, the canal was rinced 10m1 of 3% NaOCl for 30min. After drying with paper point, the post(ER Dentinpost, GEBR, BRASSELER GmbH&Co. KG) was placed in the treated canals using resin cement. Once the canal was filled with resin cement(Super bond C&B sunmedical co. Ltd.), a lentulo was inserted to the depth of the canal to ensure proper coating of the root canal wall. After 24 hours, acrylic resin blocks($10{\cdot}10{\cdot}50mm$) were made. The resin block was serially sectioned vertically into stick of $1{\cdot}1mm$. Twenty sticks were prepared from each group. After that, tensile bond strengths for each stick was measured with Microtensile Tester. Failure pattern of the specimen at the interface between post and dentin were observed under SEM. Results 1. Tensile bond strengths(meen{\pm}SD$) ) were expressed with ascending order as follows group 4, $12.52{\pm}6.60$ ; group 1, $7.63{\pm}5.83$ ; group 2, $4.13{\pm}2.31$ ; group 3, $3.31{\pm}1.44$. 2. Tensile bond strengths of Group 4 treated with 17% EDTA +3%NaOCl were significant higher than those of group 1, 2 and 3 (p<0.05). 3. Tensile bond strengths of Group 1 treated with 10% phosphoric acid were significant higher than those of group 2 (p<0.05). Tensile bond strengths of Group 4 treated with 17% EDTA +3% NaOCl was significant higher than those of other groups.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.305-312
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• 2003

This study was performed to delineate the subsurface geology, geologic structure, and distribution pattern of the Palgongsan granitic body, and to reveal the relationship between the Kyeongsang basin and Yongnam massif by gravity survey. The study area is located between the latitude of 35$^{\circ}$45'-36$^{\circ}$21'N and longitude of 128$^{\circ}$15'-129$^{\circ}$00'E. Total of 966 gravity data measured by Seoul National University, KlGAM(Korea Institute of Geology, Mining ＆ Materials), Pusan National University and Yonsei University were used. The Bouguer gravity anomaly in the study area ranges from -12.88 to 26.01 mgal with a mean value of 11.27 mgal. A very low anomaly zone is located in the Yongnam massif in west of the study area. The anomaly value increases going from west to east. A low anomaly distribution in Palgongsan granite and Yongnam massif is interpreted as the effect of their lower density than that of Kyeongsang Super Group. Power spectrum analysis is applied to evaluate the average depth of basement the Kyeongsang Basin and Conrad discontinuity from gravity anomaly. The average depths of density discontinuities are calculated 10.45 km and 4.9 km, and these are interpreted as Conrad discontinuity and depth of basement of the Kyeongsang Basin, respectively. The depth of Palgongsan granite is derived by means of 2-dimensional modeling and it decreases gradually toward the east. The gravity anomaly east of the study area decreases abruptly due to Shingryeong fault and Nogosan ring fault. Two deepest and sharp roots of Palgongsan granite are recognized by 2-dimensional modeling of each profiles. The depths of those roots are 5.3 km on a profile AA' and 7 km on a profile BB' which is the maximum depth of Palgongsan granite. Small granitic bodies are also seen to be intruded around the Palgongsan granite. The root of Palgongsan granite is shown by 3-dimensional analysis based on the interpolation of 2-dimensional modeling along each profiles to exist in the southwest vicinity of Palgongsan granite. The total volume of Palgongsan granite is approximately 31.211 $Km^3$.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.4
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• pp.791-799
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• 1996

The purpose of this study was to compare the shear bond strength of adhesion bridge by various resin cements. One hundred and foully 1st premolars were used. The teeth were cut below 2mm from CEJ and the coronal portions were used. The coronal portions were embeded with the acrylic resin and trimmed with sic paper until the flat plane with ${\phi}$ 4mm above acrylic resin sticks in height 5mm were casted with nonprecious metal and the using surfaces were treated with sic paper from #200 to #1200 and polished with alminum oxide paste. And then, the using surfaces were sandblasted and treated with the electrochemical etching. The teeth were divided into three groups of fourty two each. In group I, teeth and specimens were cemented with Panavia 21 In group II, teeth and specimens were cemented with Superbond In group I, teeth and specimens were cemented with All-Bond & composite resin cement Each group was subdivided into three subgroups according to the storage period ; one-day storage, fifteen-day storage, and thirty-day storage. The special jig was made. Then, the specimen and jig were mounted to Instron Universal Testing Machine and the failure were measured. The results were as follows. 1. There was statisfically significant difference between the failure loads of group I and group II and III after one day storage(P<0.01), 2. There was statisfically significant difference between the failure loads of group II and group I and III and between group I and group III at fifteen day storage(P<0.01). 3. There was statisfically significant difference between the failure loads of group I and II and group III after thirty day storage(P<0.01). 4. There was statisfically significant difference between the failure loads of one day storage and fifteen and thirty days storages in group III (P<0.01).

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.452-460
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• 2007

Ultra-low loss ZERODUR and fused silica mirrors were manufactured and their light scattering characteristics were investigated. For this purpose, ZERODUR and fused silica substrates were super-polished by the bowl feed method. The surface roughness were 0.292 ${\AA}$ and 0.326 ${\AA}$ in rms for ZERODUR and fused silica, respectively. To obtain the high reflectivity, 22 thin film layers of $SiO_2$ and $Ta_2O_5$ were deposited by Ion Beam Sputtering. The measured light scattering of ZERODUR and fused silica mirror were 30.9 ppm and 4.6 ppm, respectively. This shows that the substrate surface roughness is not the only parameter which determines the light scattering of the mirror. In order to investigate the mechanism for additional light scattering of the ZERODUR mirror, the surface roughness of the mirror was measured by AFM and was found to be 2.3 times higher than that of the fused silica mirror. It is believed that there is some mismatch at the interface between the substrate and the first thin film layer which leads to the increased mirror surface roughness. To clarify this, the contact angle measurements were performed by SEO 300A, based on the Giriflaco-Good-Fowkes-Young method. The fused silica substrates with 0.46 ${\AA}$ in its physical surface roughness shows lower contact angle than that of the ZERODUR substrate with 0.31 ${\AA}$. This indicates that the thin film surface roughness is determined by not only its surface roughness but also the surface energy of the substrate, which depends on the chemical composition or crystalline orientation of the materials. The surface energy of each substrate was calculated from a contact angle measurement, and it shows that the higher the surface energy of the substrate, the better the surface roughness of the thin film.

• Korean Journal of Applied Biomechanics
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• v.15 no.4
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• pp.43-53
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• 2005

This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1157-1163
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• 2005

The current study examined the effects of radish loaves powder on hepatic antioxidative system in rats fed high-cholesterol diet. Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to normal group (N group), normal diet with 5$\%$ radish leaves powder supplemented group (NR group) and high-cholesterol groups, which were sub-divided into radish leaves powder free diet group (HC group) and 2.5$\%$ (HRL group), 5$\%$ (HRM group), 10$\%$ (HRH group) radish leaves powder supplemented groups. Hepatic super oxide dimutase activity was no significant differences. Hepatic glutathione peroxidase activity was sig-nificantly increased in 5$\%$, 10$\%$ radish leaves powder supplemented groups. Hepatic hydrogen peroxide contents in cytosol were no significantly differences Hepatic hydrogen peroxide contents in mitochondria were sig-nificantly reduced in radish leaves powder supplemented groups. Hepatic superoxide radical contents in mi-crosome were significantly reduced in radish leaves powder supplemented groups. Hepatic superoxide radical contents in mitochondria were significantly reduced in 5$\%$, 10$\%$ radish leaves powder supplemented groups. Hepatic TBARS values were significantly reduced in 5$\%$, 10$\%$ radish leaves powder supplemented groups. Hepatic lipofuscin contents were no significant difference in high-cholesterol groups. Hepatic carbonyl values were significantly reduced in 5$\%$, 10$\%$ radish leaves powder supplemented groups among high-cholesterol groups. The results indicate that radish leaves may reduce oxidative damage by activating antioxidative de-fense system of liver in rats fed high-cholesterol diets.

• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.123-131
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• 2020

This study proposes a real-time rendering algorithm for lighting when each of more than 100,000 moving particles exists as a light source. Two 3D textures are used to dynamically determine the range of influence of each light, and the first 3D texture has light color and the second 3D texture has light direction information. Each frame goes through two steps. The first step is to update the particle information required for 3D texture initialization and rendering based on the Compute shader. Convert the particle position to the sampling coordinates of the 3D texture, and based on this coordinate, update the colour sum of the particle lights affecting the corresponding voxels for the first 3D texture and the sum of the directional vectors from the corresponding voxels to the particle lights for the second 3D texture. The second stage operates on a general rendering pipeline. Based on the polygon world position to be rendered first, the exact sampling coordinates of the 3D texture updated in the first step are calculated. Since the sample coordinates correspond 1:1 to the size of the 3D texture and the size of the game world, use the world coordinates of the pixel as the sampling coordinates. Lighting process is carried out based on the color of the sampled pixel and the direction vector of the light. The 3D texture corresponds 1:1 to the actual game world and assumes a minimum unit of 1m, but in areas smaller than 1m, problems such as stairs caused by resolution restrictions occur. Interpolation and super sampling are performed during texture sampling to improve these problems. Measurements of the time taken to render a frame showed that 146 ms was spent on the forward lighting pipeline, 46 ms on the defered lighting pipeline when the number of particles was 262144, and 214 ms on the forward lighting pipeline and 104 ms on the deferred lighting pipeline when the number of particle lights was 1,024766.

• Journal of Korean Home Economics Education Association
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• v.31 no.4
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• pp.149-161
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• 2019

At present, we are at the point of change of the 4th industrial revolution era due to the development of artificial intelligence(AI) and rapid technological innovation that no one can predict until now. This study started from the question of 'What role should home economics education play in the era of the Fourth Industrial Revolution?'. The Fourth Industrial Revolution is characterized by AI, cloud computing, Internet of Things(IoT), big data, and Online to Offline(O2O). It will drastically change the social system, science and technology and the structure of the profession. Since the dehumanization of robots and artificial intelligence may occur, the 4th Industrial Revolution Education should be sought to foster future human resources with humanity and citizenship for the future community. In addition, the implication of education in the fourth industrial revolution, which will bring about a change to a super-intelligent and hyper-connected society, is that the role of education should be emphasized so that humans internalize their values as human beings. Character education should be established as a generalized and internalized consciousness with a concept established in the integration of the curriculum, and concrete practical strategies should be prepared. In conclusion, home economics education in the 4th industrial revolution era should play a leading role in the central role of character education, and intrinsic improvement of various human lives. The fourth industrial revolution will change not only what we do, or human mental and physical activities, but also who we are, or human identity. In the information society and digital society, it is important how quickly and accurately it is possible to acquire scattered knowledge. In the information society, it is required to learn how to use knowledge for human beings in rapid change. As such, the fourth industrial revolution seeks to lead the family, organization, and community positively by influencing the systems that shape our lives. Home economics education should take the lead in this role.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.1
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• pp.78-95
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• 1999

The grafting of a kidney has been found to be the best medical treatment for patients who have renal insufficiency failure, but the patients still have experienced much trouble and apprehension. This study was done to further nursing theory developing for patients who have has a kidney graft from another person. The research method followed grounded theory methodology of Strauss and Corbin. The subjects were three female and four male patients. This study done befween Oct. 1997 and Mar. 1998. All of the subjects were interviewed by the author. Interview were done by the long interview technique and observation. In the process of data analysis, 'heart-boiling' was found to be the core phenomenon. The results were composed to 101 concepts. These concepts were grouped into nineteen categories, and then to twelve categories. There were 12 super-class categories as follows ; 'pain', 'heart-boiling', 'experience of dialysis', 'term of admission to a hospital', 'support of other person', 'dependence on God', 'direction', 'negative reaction', 'positive reaction', 'comfortable', 'lacking', 'acceptance'. In this process, 14 hypotheses were derived from the categories as follows ; (1) The more experience with dialysis that the patients have, the stronger the heart-boiling will tend to be. (2) The less experience with dialysis the patients have, the weaker the heart-boiling will tend to be. (3) The longer admission to hospital the patients have, the stronger the heart-boiling will be. (4) The shorter the admission to hospital the patients have, the weaker the heart-boiling will be. (5) The weaker the intense-grief is, the more positive the reaction to heart-boiling the patients wll have. (6) The stronger the intense-grief is, the more negative the reaction to heart-boiling the patients will have. (7) The stronger the support of other persons that the patients have, the more positive the reaction to heart-boiling the patients will have. (8) The weaker the support of other person that the patients have, the more negative the reaction to heart-boiling the patients will have. (9) The stronger the dependence on God that the patients have, the mure positive reaction to heart-boiling the patients will have. (10) The weaker the dependence on God that the patients have, the more negative reaction to heart-boiling the patients will have. (11) The more positive thoughts that the patients have, the more positive reaction to heart-boiling the patinets will have. (12) The more negative thoughts that the patients have, the more negative reaction to heart-boiling the patients will have. (13) The more positive reaction the patients have, the more free from heart-boiling the patients tend to be. (14) The more negative reaction the patients have, the less free from heart-boiling the patients tend to be. From the analysis of observed data and comparing each class, I concluded that there are four formula relation types between reaction of patients and heart-boiling. (1) If patients have the experience of dialysis, have a long term admission to hospital, are strong in heart-boiling, depend on God, have positive thoughts and another's strong support, they experience release by positive reaction to the intense-grief. (2) If patients have the experience of dialysis, have a short term admission to hospital, are weak in heart-boiling, do not depend on God, have negative thoughts, and have few supports from others, they experience attachment to heart-boiling though a negative reaction. (3) If patients have the experience of dialysis, have a long term admission to hospital, are strong in heart-boiling, do not depend on God, and have negative thoughts, they experience attachment to heart-boiling through negative reaction in spite of support from another. (4) If patients have the experience of dialysis, have a long term admission into hospital, are strong in heart-boiling and satisfaction is low, but they have positive thoughts, then they experience acceptance and harmony through the positive reaction to heart-boiling. The results of this study are expected to help the way nurses care for patients who have had a kidney graft from another.

• Food Science and Preservation
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• v.22 no.1
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• pp.63-69
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• 2015

The highly producible rice cultivars, hanareum and dasan 2, were prepared and investigated for their physicochemical properties, and the quality characteristics of frozen cookie dough with rice flour according to the thawing time were measured. The water, ash, crude protein, amylose, and damaged starch contents of rice flour, as well as its water holding capacity, particle size, and Hunter color value, were measured. The water, ash, and crude protein contents of the hanareum and dasan 2 rice flours were shown to range from 7.28 to 13.14%, from 0.35 to 0.39, and from 6.05 and 8.68%, respectively. The protein content of the control group was higher than that of hanareum and dasan 2 rice flours. The amylose contents of the hanareum and dasan 2 rice flour were 19.05 and 23.04%, respectively. The damaged starch content and water holding capacity of the control group were lower than those of the hanareum and dasan 2 rice flours. The particle sizes of the samples were $48.54{\sim}50.05{\mu}m$. The lightness values of the hanareum, and dasan 2 rice flour, and of the control were 93.72, 93.51 and 92.63, respectively. The quality characteristics of the gluten-free frozen cookie dough were investigated. The lightness of the cookie made with frozen cookie dough decreased according to the by thawing time, but the diameter of the cookie did not differ significantly. The hardness of the cookie made with rice frozen dasan 2 rice dough was lower than that of the cookie made with frozen hanareum rice dough.