• Journal of the Korean Society of Food Culture
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• v.14 no.1
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• pp.29-42
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• 1999

This study was performed with 482 subjects(278 boys and 204 girls in Seoul and Kyunggido area) to find out the attitude and eating behaviors about Kimchi on Korean young generation. General characteristics about subject and attitude and eating behavior were surveyed by self-developed questionnaires. 85.9% of the subjects were nuclear family type and 49.9% of respondent's mother had full-time job and 96.1% of subjects were middle or upper economic status. The preference for Kimchi, 60.4% of respondents answered that they liked Kimchi. According to grade, the rate of preference about Kimchi was significantly different, higher grade students were found higher preference on Kimchi : 64.4% of middle and 70.4% of high school students liked Kimchi. The eating patterns of Kimchi, up to 60% of respondents answered they ate Kimchi in every meal time, which suggested that it was still an important side dish in Korean meal among teenagers. The eating behaviors on Kimchi, $85{\sim}90%$ of respondents answered that they preferred Kimchi in meal time. Baechu Kimchi(chinese cabbage Kimchi) and Gakdugi(radish cube Kimchi) was highly preferred. And their preference of food which made from Kimchi (such as Kimchi fried rice, Kimchi stew, Kimchi pancake) was highly evaluated. 65.6% of residents pointed out that 'Kimchi is very nutritious food'. The respondent's structure of value on Kimchi were not significantly difference between sex and age. But it was significantly difference(p<0.01) between the groups with preference and familiarity on Kimchi. The group had higher preference and familiarity on Kimchi agreed to the positive values about Kimchi. These result suggested that various kinds of Kimchi should be developed for young generation to meet their taste and also continuous nutrition education about traditional food especially Kimchi should be promoted at home and school.

• Korean Journal of Materials Research
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• v.27 no.9
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• pp.495-500
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• 2017

Oxide layers were formed by an environmentally friendly plasma electrolytic oxidation (PEO) process on AZ91 Mg alloy. PEO treatment also resulted in strong adhesion between the oxide layer and the substrate. The influence of the KF electrolytic solution and the structure, composition, microstructure, and micro-hardness properties of the oxide layer were investigated. It was found that the addition of KF instead of KOH to the $Na_2SiO_3$ electrolytic solution increased the electrical conductivity. The oxide layers were mainly composed of MgO and $Mg_2SiO_4$ phases. The oxide layers exhibited solidification particles and pancake-shaped oxide melting. The pore size and surface roughness of the oxide layer decreased considerably with an increase in the concentration of KF, while densification of the oxide layers increased. It is shown that the addition of KF to the basis electrolyte resulted in fabricating of an oxide layer with higher surface hardness and smoother surface roughness on Mg alloys by the PEO process. The uniform thickness of the oxide layer formed on the Mg alloy substrates was largely determined by the electrolytic solution with KF, which suggests that the composition of the electrolytic solution is one of the key factors controlling the uniform thickness of the oxide layer.

• Progress in Superconductivity
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• v.7 no.2
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• pp.167-173
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• 2006

Coated conductors suitable for the fabrication of persistent mode high $T_c$ magnets are suggested and the fabrication method of persistent mode magnets using coated conductor are demonstrated. Persistent current was observed in a small piece of coated conductor. Closed loop of coated conductor with a diameter of around 1 em was successfully prepared and was cooled with a magnetic field of about 500 Gauss in order to induce supercurrent. Coated conductor with a $I_c$ of 100 A/cm-width was used for the preparation of closed loop of coated conductor. Persistent current was confirmed by measuring the magnetic field generated from closed loop of coated conductor by using Gauss meter. Magnetic field of 4.4 Gauss was detected from the supercurrent of closed loop of coated conductor. It shows that superconducting joint of coated conductor is not a prerequisite for the construction of persistent mode magnets. It is thought that this work opens the possibility to use coated conductor for the construction of persistent mode high $T_c$ magnets for MRI, NMR and magnetic separation applications.

• Journal of the Korean Dietetic Association
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• v.17 no.3
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• pp.276-286
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• 2011

This study aimed to examine consumers' interest, preference, and consumption frequency of Kimchi in elementary school students in the fifth grade and their mothers living in Changwon city. In a comparison of eating habits, students exhibited better eating habits than their mothers (P<0.01). Though the mothers' levels, were higher than those of the students in the category of 'eat foods with a bit of salt usually', the students' levels were higher in the rest of the eating habit categories. The categories of 'like Kimchi', 'spicy taste', and 'appropriately spicy taste' got high levels. Among several kinds of Kimchi, both students and mothers preferred 'cabbage Kimchi' the most. Among various Kimchi foods, preferences for 'Kimchi pancake', 'fried rice with Kimchi', and 'tuna Kimchi soup', were highest in that order. The preferences differed between students and mothers in each category; mothers' preferences were significantly higher than those of students. However, in the rest of categories, except 'boiled kimchi and fish' and 'Kimchi and stir-fried spicy pork', students' preferences were higher than mothers' ones. Compared to their preferences, students' consumption frequencies were significantly higher than mothers' ones (P<0.01). There were positive correlations among students' eating habits, awareness of Kimchi, consumption frequency, and preference. For mothers, there were positive correlations not only between eating habits and awareness, but also between awareness and preference.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.869-874
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• 2014

It was discovered in a Korean PWR that an extensive number of very short and shallow cracks in the SG tubes were undetectable by eddy current in-service-inspection because of the masking effect of sludge deposits. Axial stress corrosion cracks at the outside diameter of the steam generator tubes near the line contacts with the tube support plates are the major concern among the six identical Korean nuclear power plants having CE-type steam generators with Alloy 600 high temperature mill annealed tubes, HU3&4 and HB3~6. The tubes in HB3&4 have a less susceptible microstructure so that the onset of ODSCC was substantially delayed compared to HU3&4 whose tubes are most susceptible to ODSCC among the six units. The numbers of cracks detected by the eddy current inspection jumped drastically after the steam generators of HB4 were chemically cleaned. The purpose of the chemical cleaning was to mitigate stress corrosion cracking by removing the heavy sludge deposit, since a corrosive environment is formed in the occluded region under the sludge deposit. SGCC also enhances the detection capability of the eddy current inspection at the same time. Measurement of the size of each crack using the motorized rotating pancake coil probe indicated that the cracks in HB4 were shorter and substantially shallower than the cracks in HU3&4. It is believed that the cracks were shorter and shallower because the microstructure of the tubes in HB4 is less susceptible to ODSCC. It was readily understood from the size distribution of the cracks and the quantitative information available on the probability of detection that most cracks in HB4 had been undetected until the steam generators were chemically cleaned.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.61-66
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• 2011

The integrity of the SG(Steam Generator) tubes has been challenged by numerous factors such as flaws, operation, atmosphere, inherently degraded materials, loose parts and even human errors. Of the factors, loose parts(or foreign materials) on the secondary side of the tubes can bring about volumetric defects and even leakage from the primary to the secondary side in a short period of time. More serious concerns about the loose parts are their unknown influx path and rapid growth rate of the defects affected by the loose parts. Therefore it is imperative to detect and characterize the foreign materials and the defects. As a part of the measures for loose part detection, TTS(Top of Tubesheet) MRPC(Motorized Rotating Pancake Coils) ECT has been carried out especially to the restricted high probability area of the loose part. However, in the presence of loose parts in the other areas, wide range loose part detection techniques are required. In this study, loose part standard tube was presented as a way to accurately detect and characterize loose part signals. And the SG tube ECT bobbin coil and MRPC ISI(In-service Inspection) data of domestic OPR-1000 and Westinghouse Model F(W_F) were reviewed and consequently, comprehensive loose part detection technique is derived especially by applying bobbin coil signals

• Journal of the Korean Dietetic Association
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• v.2 no.1
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• pp.69-80
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• 1996

This study was performed to investigate the food preference trends of the children according to age increase and change of the times. The subjects were 1,450 children who are fifth grade of primary school and 2,000 juveniles who are senior high school in 1993. This survey data were compared with the Food preference study of the primary school aged children in 1987.' The results of this study can be summarized as follows 1. State of the general taste The subject had a high preferences to bulgogi(roast beef), panbroiled cuttlefish, steamed egg, fried sausage and donuts among the all sorts of 165 principal and subsidiary foods. But, fried beef liver, pancake, sweet potato with syrup, spinach soup and boiled rice with red bean didn't suit for their taste. Compared with survey data done in 1987, in present study significantly increased preferences to steamed food, pan frying and parboiled vegetables were shown. Particularly, food preference was changed with the cooking methods rather than materials. 2. Differences of the preference according to change of the times In present study, except the rice cakes preferences to all sorts of foods were improved and markedly increased preferences to steamed food, parboiled vegetables and mixed with seasonings were observed. Compared with 87's study deviation of the preference to cooking materials was decreased considerably. Preferences to salty tasted foods as like as stew and salted food were low no better than before. 3. Changes of preference according to age increase Among the principal foods, increased preferences to boiled rice and cereals were shown but to one-dish meal, bread and rice cake were decreased. Among the subsidiary foods, significantly decreased preference to frying was observed. Irrespectively of the cooking methods, preferences to fish and vegetables were improved. And in the frying and panbroiled foods, deviation of preferences to cooking materials were considerable, which means the fixation of food behavior.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.2
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• pp.88-93
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• 2005

To develop a 100 hp high temperature superconducting(HTS) motor with high efficiency first in Korea, we fabricated a HTS field winding and test. HTS field winding is composed of sixteen HTS race track shaped coils wound with stainless steel-reinforced Bi-2223 tape conductor by react and wind fabrication method. Nomex paper was used for electrical insulation. Each of four magnet pole assemblies was constructed with four double pancake sub-coils, mechanically stacked and electrically in series. Four magnet assemblies were fixed on an aluminum support structure to make effective heat transfer. The Critical current (Ic) was 41.5A at 77K and self field. However the lowest Ic value of sub-coils was 35A. Joule heat generated by each joints between sub-coils was lower than 1mW at 77K and 34A. And Joule heat generated by the joints between field coils was lower than 10mW at 77K and 34A. Joule heat of the whole field winding was 1W at 77K and 32A. And so, the lowest Ic value of sub-coils was more important than Joule heats generated by all joints. The operating current must be lower than the lowest Ic of all the sub-coils. In this paper, design, construction and testing of HTS field winding, Joule heat generated by the joints, and operating current were discussed.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1003-1005
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• 2003

In this paper, 3-D nonlinear electromagnetic analysis of a single phase 1MVA 22.9 kV/6.6 kV high temperature superconducting(HTS) transformer with double pancake windings was accomplished. The characteristics of 1MVA HTS transformer such as The efficiency, voltage regulation and % impedance voltage drop were obtained by the 3-D non-linear electromagnetic analysis. And in order to verify the 3-D non-linear electromagnetic analysis of a single phase 1MVA HTS transformer, a 1MVA test transformer with windings made of copper tapes with the same size as BSCCO-2223 HTS tape was manufactured. The energy conservation method to perform the analysis of leakage impedances of both a 1MVA HTS transformer and test transformer was used. The characteristic analysis such as efficiency, voltage regulation and % impedance voltage drop of transformer was performed. And the obtained values of both 1MVA HTS transformer and test transformer were compared.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1166-1172
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• 2018

Degradation due to delamination occurs frequently in the high temperature superconductors (HTS) coil of rotating machines made with 2nd generation (2G) HTS wire, and the authors have observed other similar cases. Since an HTS field coil for a rotating machine is required to have stable current control and maintain a steady state, co-winding techniques for insulation material and epoxy resin for shape retention and heat transfer improvement are applied during coil fabrication. However, the most important limiting factor of this technique is delamination, which is known to be caused by the difference in thermal expansion between the epoxy resin and 2G HTS wire. Therefore, in this study, the experimental results of mixing the ratio of epoxy resin and alumina ($Al_2O3$) filler were applied to the fabrication of small and large test coils to solve the problem of degradation. For the verification of this scheme, eight prototypes of single pancake coils with different shapes were fabricated. They showed good results. The energization and operation maintenance tests of the stacked coils were carried out under liquid neon conditions similar to the operation temperature of an MW-class rotating machine. In conclusion, it was confirmed that the alumina powder mixed with epoxy resin in an appropriate ratio is an effective solution of de-lamination problem of 2G HTS coil.