• Journal of Korea Foundry Society
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• v.21 no.2
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• pp.127-134
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• 2001

Misch metal (rare earth element, Ce, La, Nd, Pr) which has large influence on high-temperature stability and toughness was added to the Al-5%Ni-5%Mg alloy, and squeeze casting was used for Al-5%Ni-5%Mg-(Mm) alloys. The effect of applied pressure and misch metal additions on mechanical properties in Al-5%Ni-5%Mg alloy by direct squeeze casting has been investigated. The applied pressure were 0 MPa(gravity casting), 25, 50 and 75 MPa. Squeeze-cast Al-5%Ni-5%Mg-(Mm) alloys had better mechanical properties than those of non-pressurized cast alloys because of the increased cooling rate by the application of pressure during solidification. By the addition of misch metal in Al-5%Ni-5%Mg alloy, better combination of strength and elongation was obtained. The addition of 0.3%Mm in Al-5%Ni-5%Mg alloy improved the heat resistant property due to the formation of fine eutectic phases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.1
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• pp.43-49
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• 2005

Temperature stabilities of resonance frequencies of the substrates are very important in piezoelectric ceramics oscillators and fitters. In this study, it was investigated thermal resisting property of the length-extensional vibration mode of PZT ceramics. The mode can be utilized in fabricating ultra-small 55 kHz IF devices. We fabricated the ceramic specimens with x = 0.51, 0.52, 0.53, 0.54, and 0.55 in the Pb(Zr$\sub$x/Ti$\sub$1-x/)O$_3$ system. And their resonance frequencies were measured before 1st thermal aging, after 1st and 2nd thermal aging. In order to investigate the influence of thermal aging on thermal resisting properties, thermally aged specimens were once mote thermally aged. Before 1st thermal aging, the specimens of the compositions with morphotropic phase, x = 0.53 and rhombohedral phase, x = 0.54 have weak thermal resisting property of resonance frequency, while tetragonal phase, x = 0.51 has robust thermal resisting property of resonance frequency. 1st thermal aging improved thermal resisting property of resonance frequency in all specimens.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05a
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• pp.30-33
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• 2003

YBCO coated conductor, also called the 2nd generation high temperature superconducting wire, consists of oxide multi-layer hetero-epitaxial thin films. Pulsed laser deposition (PLD) is one of many film deposition methods used to make coated conductor, and is the one known to be the best to make superconducting layer so far. As a part of the effort to make long length coated conductor, the optimum deposition condition of YBCO film on single crystal substrate (SrTiO3) was investigated using PLD. Substrate temperature, oxygen partial pressure, and laser fluence were varied to find the best combination to grow high quality YBCO film.

• Journal of Conservation Science
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• v.33 no.4
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• pp.225-239
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• 2017

This study aimed to investigate the chemical properties and production techniques for white wares from the Gwirae-1ri 3rd, Songok-3ri 2nd kiln sites in Kangwon Wonju regions. Further, another aim was to determine the correlation among the materials used to produce the white wares. The analysis of white wares in Kangwon Wonju regions produced the following results. The excavated white wares were analyzed using the Seger formula, and all the samples showed similar clay sources ($RO_2:4.33-5.82$, $RO+R_2O:0.32-0.43$) and glaze sources. Moreover, the white wares were made of host rocks of the same geological origin, according to the results of the rare earth elements analysis. When the crystalline phases of the white wares were investigated via the XRD analysis, quartz and mullite were found in all the samples, and their proportions were similar to each other. Although the firing temperatures for the samples were different, most were fired at a temperature below $1,200^{\circ}C$, with some being fired at temperatures as low as $1,000{\pm}20^{\circ}C$.

• Animal Systematics, Evolution and Diversity
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• v.19 no.2
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• pp.227-235
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• 2003

The euplotid hypotrich collected from a puddle, Jeju-do in 2002 and cultured in the laboratory was identified as Euplotes muscorum Dragesco, 1970. The species is reported for the first time from Korea. The description was based on the observation of living specimens, protargol impregnation and biometrical analysis. This species is characterized by following diagnosis: 63-78 ${\mu}m$ in length, 40-52 ${\mu}m$ in width in vivo, 9 frontoventral cirri, 5 transverse cirri,4 caudal cirri, 1 micro- and macronucleus, adoral zone of membranelles with 32-36 adoral membranelles covering approximately 2/3 of body length, 8 dorsal kineties, mid-dorsal kinety with 20-24 cilia 3nd dargyrome complex type. This species with 9 frontoventral cirrotype is very similar to E. muscicola Kahl, 1932. The differences between these two species are: E. muscorum has 8 dorsal kineties and complex dargyrome type, while E. muscicola 9 dorsal kineties and multiple dargyrome type.

• Journal of Korean Public Health Nursing
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• v.18 no.2
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• pp.286-298
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• 2004

The purpose of this study was to survey the general characteristics, lifestyle include health habits, subjective health problems include physical, psychological and overall health complaints that occurring among Korean and Japanese nursing students. Data collected with the self-administered Okayama Medical Index Health Questionnaire(devised Cornell Medical Index) from 466 Korean and 688 Japanese Nursing Students were analyzed. The subjects were 18 to 24 years old in their 1st, 2nd, 3rd and 4th year-class of nursing department. The total O.M.I. score(section A-R) ranged from 1 to 110 with an average of 22.3(SD=11.5) in Korean nursing students and 18.3(SD=10.1) in Japanese nursing students. A statistically significant inverse correlation was observed between Korean nursing student and Japanese nursing students for the overall health complaints. Korean nursing students have more health problems than Japanese nursing students in terms of physical and overall health complaints excluding psychological problems. About $4\%$ of Korean nursing students were current smokers and $64.2\%$ of Korean nursing students were drinker. Korean nursing students in the drinker's group were more likely to eat fatty foods(p<.001), and take worst lifestyle and have more subjective health problems than non drinker's group of Korean nursing students. Korean nursing students were more likely to perform bad health behaviors than Japanese nursing students. The drink habit is one of the biggest problems among the nursing student, and then we have to have the mobilizing for 'Change on Alcohol' in our universities. This conclusion should provide grounds for future studies of strategies for health promotion and of prevention measures for psychological ill-health of nursing students.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.3
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• pp.291-299
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• 1991

We retrospectively reviewed 334 inpatients who sustained a total of 518 mandibular fractures and who ewer treated in our department between l980-1990. This results were obtained as follows : 1. In respect of incidence, there were the highest frequency in July, and the lowest frequency in May. The number of patients has not been increased year after year due to competition with other department in our hospital. 2. The age frequency was the highest in the 2nd decade(38.9%) and the ratio of man to women was 4.9 : 1. 3. The most frequent cause of mandibular fracture was traffic accident(43.4%), and the next was fall down(24.3%), fist blow(71%), industrial accident(21%) and others in order. In the traffic accident, autobicycle accident was 14.1%. 4. The most common location of mandibular fracture was symphysis(38.8%), condyle(20.7% ), angle(19.9%) and body(15.1%) were next in order of frequency. The classification by location of fracture, the frequency of single fracture was 54.8%. 5. In 334 patients of mandibular fracture, the frequency of associated injuries was facial laceration(58.4%), teeth injuries(37.7%), extremity injuries(13.2%) were next in order of frequency. 6. The patients arrived in hospital immediately within 24 hours after accident wee 61.4% of all. In respect of treatment, open reduction was 68.7% of all. 7. Complications including infection were present 11.1% of patient. Other complications inclued delayed healing malocclusion, malocclusion and neurologic problem.

• The Journal of Internal Korean Medicine
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• v.32 no.3
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• pp.387-396
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• 2011

Objectives : Recently a lot of research is being done for find antidiabetic medicine which has no side effects. This study aimed to investigate the antidiabetic and antiobesity effects of Supungsunki-hwan partitioned prescriptions on obese type 2 diabetes mouse. Methods : Type 2 diabetes mellitus and obesity were induced by Surwit's high fat, high sucrose diet for 8 weeks. Mice were divided into 3 groups of ND (normal diet, n=10) HFD (high fat and high sucrose diet, n=10) and SPP (high fat and high sucrose diet with Supungsunki-hwan partitioned prescriptions, n=10) groups. Body weights were measured every week. After 7 weeks, fasting blood sugar and oral glucose tolerance tests were conducted. After 8 weeks, blood samples of all mice were taken from their heart and analyzed biochemically. At the same time, epididymal fat pad and liver weights were measured. Histological size of white adipocyte were measured as well. Results : Compared with a HFD group, body weight, fructosamine, epididymal fat pad weight and white adipocyte size decreased. High-density lipoprotein cholesterol levels increased in the SPP group. Conclusions : These results suggest that SPP has antidiabetic and antiobesity effects in high fat, high sucrose diet induced obese mice.

• Communications of Mathematical Education
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• v.24 no.2
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• pp.385-413
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• 2010

The purpose of this study is to set appropriate targets for school-year levels and types of mathematical communication. First, I classify mathematical communication into four types as Discourse, Representation, Operation and Complex and refer to them collectively as the 'D.R.O.C pattern'. I have listed achievement factors based on the D.R.O.C pattern hearing opinions from specialists to set a target, then set a final target after a 2nd survey with specialists and teachers. I have set targets for mathematical communication in elementary schools suitable to its status and students' levels in our country. In NCTM(2000), standards of communication were presented only from kindergarten to 12th grade students, and, for four separate grade bands(prekindergarten through grade 2, grades 3-5, grades 6-8, grades 9-12), they presented characteristics of the same age group through analysis of classes where communication was active and the stated roles of teachers were suitable to the characteristics of each school year. In this study, in order to make the findings accessible to teachers in the field, I have classified types into Discourse, Representation, Operation and Complex (D.R.O.C Pattern) according to method of delivery, and presented achievement factors in detail for low, middle and high grades within each type. Though it may be premature to set firm targets and achievement factors for each school year group, we hope to raise the possibility of applying them in the field by presenting targets and achievement factors in detail for mathematical communication.

• Journal of Soil and Groundwater Environment
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• v.12 no.6
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• pp.107-117
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• 2007

Dispersion characteristics and envirounmental impactes of the stream sediments were investigated and geochemical disaster in the Namhae-Hwagye area was predicted. Stream sediments having no possibility of contamination effect and representing drainage basins were collected. Major and hazardous elements concentrations were determined by XRF, ICP-AES and NAA analysis methods. Acid decomposition for the ICP-AES have been used $HClO_4$ and HF with $200^{\circ}C$ heating at 1'st and after that $HClO_4$, HF and HCl with $200^{\circ}C$ heating at 2'nd stage. Hazardous elements concentrations for the stream sediments in the Namhae area were Cu $5.66{\sim}168\;ppm$, Pb $18.0{\sim}40.7\;ppm$, Cr $21.6{\sim}147\;ppm$, Co $4.86{\sim}25.3\;ppm$. Hazardous elements concentrations for the stream sediments in the Hwagye area were Cu $16.4{\sim}41.2\;ppm$, Pb $26.5{\sim}37.5\;ppm$ Cr $79.6{\sim}153\;ppm$, Co $15.7{\sim}29.5\;ppm$. Concentration of Cu and Co in the stream sediments show a negative correlation with $SiO_2$ in all study area. According to E.I.(Enrichment Index) of stream sediments was not enriched in study area. And average E.I. was 0.35 (Namhae) and 0.56 (Hwagye) respectively. The stream sediments were enriched as in order of Pb > Cr > Co > Cu. And the average of Enrichment Factor (E.F.) was 0.46 to 2.84, respectively. E.F. concentration of Cu and Co were nearly similar enrichment characteristic but E.F. concentration of Cr were higher enrichnent characteristic in Namhae than Hwagye area. Pb was highly enriched in all study area but the tolerable level that used to investigate the enrichment degree of hazardous elements, was not exposed to harmful hazardous elements.