• Journal of The Korean Association For Science Education
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• v.30 no.8
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• pp.953-970
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• 2010

The purpose of this study was to investigate the change of teacher-student interaction in a beginner secondary science teachers' class through collaborative mentoring program. Three experienced science teachers as mentors and three beginner science teachers as mentees were participated in this study. Mentors have been teaching science secondary school for more than 13 years with specialty in science education, and mentees have been teaching less than three years in secondary schools. They were matched one-toone on grounded characteristics that were revealed from pre-interview. Data collection consisted of lesson plans of mentees' classes, videotaped lessons of mentees, consultation meetings between mentors and mentees, and interviews with mentees as well as mentors. The consultation meetings and interviews were audiotaped and then transcribed with the videotaped lessons. To examine the change in teacher-student interactions, the lesson observed after four sessions of mentoring was compared to the lesson before mentoring on the basis of the analytical framework that was developed based on the interpretative approach. The analytical framework addresses the four aspects of teacher-student interaction, which include beginner of interaction (initiation), the types of the question, the student response and the feedback. After four sessions of collaborative mentoring, the beginner science teacher's classroom interactions were initiated by students more often. Teachers' questions increasingly turned into thought-provoking queries that required higherorder thinking. The students responded in the form of statements instead of asking question more frequently. Also, teachers provided more delayed feedback than immediate feedback. These changes of interaction patterns showed that students took a leading role in classroom interaction and they were encouraged to think. From this result, we argue that the beginner science teachers developed the ability to make students think and to support them in coming to an understanding of knowledge through a collaborative mentoring program.

• Journal of the Korean earth science society
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• v.22 no.5
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• pp.350-359
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• 2001

The purpose of this study is to develop theme-based integrated science unit by the interdisciplinary approach and to analyze it's effects on the science achievement and the attitude towards science learning. 'Interaction' and 'Stability' were selected as the integrated themes, and the main concept and subconcept in relation to the themes were extracted from the four areas of science, and the learning contents were constructed in the integrated ways. While the main concept have relevance to subconcept in the interaction, the main concept have little relevance to subconcept in the stability. Therefore, the stability was to fit with middle school integrated science theme, but the interaction was not. The theme-based integrated science units developed was implemented in middle school, and the results are follows. First, the science achievement of group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Second, the scores of the test of attitude toward science learning of the group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Third, the students' perception of theme-based integrated science teaching was positive. The students have participation, interest, motivation in theme-based integrated science teaching, and students have difficulty in learning theme-based integrated science teaching.

• Analytical Science and Technology
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• v.33 no.1
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• pp.33-41
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• 2020

Wet precipitation samples were collected in Jeju City and Mt. Halla-1100 site (a site at an altitude of 1100 m on Mt. Halla) during 2011-2013, and their major ionic species were analyzed to examine the chemical composition and characteristics. A comparison of ion balance, electric conductivity, and acid fraction of precipitation revealed correlation coefficients in the range of r = 0.950~0.991, thereby implying the high quality of analytical data. Volume-weighted mean pH and electric conductivity corresponded to 4.86 and 25.5 µS/cm for Jeju City, and 4.98 and 15.1 µS/cm for Mt. Halla-1100 site, respectively. Ionic strengths of the wet precipitation in Jeju City and Mt. Halla-1100 site corresponded 0.3 ± 0.5 and 0.2 ± 0.2 mM, respectively, thereby indicating that more than 30 % of total precipitation was within a pure precipitation criteria. The precipitation with a pH range of 4.5 - 5.0 corresponded to 40.8 % in Jeju City, while the precipitation with a pH range of 5.0 - 5.5 corresponded to 56.9 % in Mt. Halla-1100 site, thereby indicating slightly more weak acidity than that in Jeju city. The volume-weighted mean concentration (µeq/L) of ionic species was in the order of Na⁺ > Cl^- > nss-SO₄^2- > NO₃^- > Mg²⁺ > NH₄⁺ > H⁺ > nss-Ca²⁺ > PO₄^3- > K⁺ > CH₃COO^- > HCOO^- > NO₂^- > F^- > HCO₃^- > CH₃SO₃^- at Jeju City area, while it corresponded to Na⁺ > Cl^- > nss-SO₄^2- > NO₃^- > NH₄⁺ > H⁺ > Mg²⁺ > nss-Ca²⁺ > PO₄^3- > CH₃COO^- > K⁺ > HCOO^- > NO₂^- > F^- > HCO₃^- > CH₃SO₃^- at Mt. Halla-1100 site. The compositions of sea salts (Na⁺, Cl^-, Mg²⁺) and secondary pollutants (NH₄⁺, nss-SO₄^2-, NO₃^-) corresponded to 66.1 % and 21.8 %, respectively, in Jeju City and, 49.9 % and 31.5 %, respectively, in Mt. Halla-1100 site. The acidity contributions in Jeju City and Mt. Halla-1100 site by inorganic acids, i.e., sulfuric acid and nitric acid, corresponded to 93.9 % and 91.4 %, respectively, and the acidity contributions by organic acids corresponded to 6.1 % and 8.6 %, respectively. The neutralization factors in Jeju City and Mt. Halla1100 site by ammonia corresponded to 29.8 % and 30.1 %, respectively, whereas the neutralization factors by calcium carbonate corresponded to 20.5 % and 25.2 %, respectively. From the clustered back trajectory analysis, the concentrations of most ionic components were higher when the airflow pathways were moved from the continent to Jeju area.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.391-398
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• 2002

This study was conducted to determine the polymorphism of transferrin exons 13, 15 and 16 by Single-Strand Conformation Polymorphism(SSCP) analysis and to compare their genotypes of Cheju horse Group I (Cheju Institute), Cheju horse Group II (farms), and Thoroughbred (KRA). SSCP of transferrin exon 13, 15, and 16 showed two (A, B), three (A, B, C) and three (A, B, C) codominant alleles, respectively. The Group I and Thoroughbred showed the similar frequencies of allele A and B in transferrin exon 13, but only allele A was observed in Group Ⅱ. In transferrin exons 15 and 16, the frequencies of each allele were different in each Groups. The multiple allele frequencies in exons 15 and 16 suggested that the genotyping of this locus could be used to identify an individual and to test the parentage of offspring. The probability for parentage exclusion were 0.46 and 0.374 for exons 15 and 16 for Cheju horse Group I. Among the 13 combined genotypes of exons 13, 15 and 16, the genotype AA-AB-AB (0.372) is the most common in Cheju horse Group I, but genotype AA-AA-AA is common in the Cheju horse Group II (0.366) and Thoroughbred (0.767). The present study showed two new SNP, which was at the cDNA position 1626 (A/G) in B allele of the exon 13 and 2075 (C/T) in C allele of the exon 16 resulting in amino acid change (Threonine $\longrightarrow$ Methionine). Result showed that polymorphism of exons 13, 15 and 16 in Cheju horses was as high as in Thoroughbred and there was a differences of transferrin allele frequencies in Cheju horses.

• Journal of the Korean Geographical Society
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• v.36 no.4
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• pp.474-482
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• 2001

The purpose of this study is to investigate the formation and development processes of beach resort by fabric construction in a island environment. The results are as follows. (1) The research area(Tong-ri beach, Bokil-myon, Chollanam-do)has been transformed to belch by sedimentary environmental change since latter half of 1800's. (2) The mean slope of beach face is 0.96°, and the difference of attitude between beach and mud flat face is 75cm. (3) The mean particle size of beach surface sediment is 3.53$\Phi$. This value is very finer than that of any other beach in Korea peninsula. But its value is coarser than that of mud flat surface sediment. (4) The particle size distribution of core sediment is become changed to fine particle in 70cm depth. This value is corresponded to difference of altitude between beach face and mud flat face. (5) The analysis of aerial photographs after 1970 indicates that sedimentation process was not brisked since 1970's. Consequently, the research ares has been developed by sedimentary environmental change for sea-level rise effect and wave height energy rise effect.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.88-94
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• 2014

This study was carried out to survey the early growth characteristics of Ligularia fischeri, plants of half-shaded grounds, primarily used as functional wild edible greens and examine its shading treatment to transplant seedling. The shading treatment was regulated with the shading level(full sunlight, 35%, 50%, 75%, and 95% of full sunlight). According to the experiment, the height was the highest under 75% of shading (17.3 cm), and root diameter was the highest under full sunlight (2.13 mm). It was found that fresh weight (leaf, shoot, root and whole) was the highest (1.784 g, 1.330 g, 0.791 g, 3.905 g respectively ) under 50% of shading. In case of dry weight, leaf, shoot and whole dry weight were surveyed the highest under 35% of shading, and root dry weight was the highest under full sunlight. It was found that S/R ratio and moisture contents (leaf, shoot, root and whole) were the highest under 95% of shading. Leaf area was the highest under 50% of shading ($39.3cm^2$) and the higher shading level, the higher SLA and LAR. It was surveyed that the higher shading level, the thinner leaf thickness. In case of root characteristics, it was showed that the relatively high height growth under 35%~75% of shading, excepting 95% of shading. As a result of surveying the whole experiment, it is concluded that the early growth of L. fischeri is more effective in producing it under 50% of shading.

• The korean journal of orthodontics
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• v.39 no.5
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• pp.300-309
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• 2009

Objective: The purpose of this study was to evaluate the correlation between menton deviation and dental compensation in facial asymmetry. Methods: Tooth axis and distance of first molar and canine to the reference plane were investigated by cone-beam computerized tomography. The subjects consisted of 50 patients with asymmetric mandibles (male 21, female 29, mean age 24.3 years). Control groups were also assessed (male 11, female 9, mean age 25.6 years). Nine measurements (5 linear measurements and 4 angular measurements) were measured in order to evaluate the correlation between menton deviation and the linear and angular difference of first molar and canine in the deviated and none-deviated sides using the defined MPR images. The differences between deviated and non-deviated side, according to menton deviation, were statistically analyzed using stepwise multiple regression analysis. Results: From the result, Menton deviation was negatively correlated with mandibular first molar's angular measurement (${\Delta\angle}LM6$-Mn plane (dev.-ndev.)) and positively with maxillary fist molar's angular measurement (${\Delta\angle}UM6$-FH plane (dev.-ndev.)) (p < 0.01). Two angular measurements (${\Delta\angle}LM6$-Mn plane (dev.-ndev.), ${\Delta\angle}UM6$-FH plane (dev.-ndev.)) explained the variability in menton deviation with a significant $r^2$ value of 0.589. Conclusions: This study suggests that the tooth axis of upper and lower first molars leans towards the deviated side of Menton when there is mandibular asymmetry with Menton deviation.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2000.04a
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• pp.9-10
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• 2000

An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.2
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• pp.163-170
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• 2009

Purpose: Intussusception is the most common cause of intestinal obstruction in young children. Although intussusceptions are easily treated, some intussusceptions with or without a pathologic lead point (PLP) often recur. In this study, we analyzed the clinical characteristics and prognosis of recurrent intussusceptions (RI), the frequency of the PLP, and correlation between RI with PLP. Methods: The medical records of 144 patients, among 590 patients with intussusceptions who had been admitted to the Department of Pediatrics and Pediatric Surgery of Dankook University Hospital between May 1994 and June 2009 were reviewed retrospectively. Results: The overall recurrence rate of intussusceptions in this study was 9.2%. The mean interval between the initial occurrence and the first recurrent attack was 130${\pm}$175 days (range, 12 hours to 3 years). There was no statistically significant difference in the recurrence rate among patients who underwent air, barium, and manual reduction (p=0.131). Eighty-seven cases (92.6%) of RI had a successful reduction by the use of non-operative techniques. A PLP was present in 18 patients (3.0%). The most common PLP was intestinal lymphoid hyperplasia, followed by Meckel's diverticulum, duplication cyst, intestinal polyp, and adenomyoma. The mean number of intussusceptions was 4.7${\pm}$1.9 in 7 patients with PLP, which was significantly higher than (2.4${\pm}$0.9) patients without a PLP (p=0.023). The mean duration of recurrences was 17.4${\pm}$19.8 months (range, 2 days to 72 months). Conclusion: A careful search for a PLP should be performed to prevent recurrence of intussusception, especially when intussusception has recurred more than three times.

• Journal of Life Science
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• v.23 no.1
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• pp.15-23
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• 2013

AprE51 from Bacillus amyloliquefaciens CH51 is a 27 kDa subtilisin-like protease with fibrinolytic activity. AprE51-6 showing increased catalytic activity was produced previously. To enhance the thermostability of AprE51-6, 2 residues, Gly-166 and Asn-218 based on B. subtilis subtilisin E were mutated by site-directed mutagenesis. The results of the mutational analysis showed that substitution of arginine for Gly-166 (AprE51-7) increased the fibrinolytic activity 1.8-fold. An N218S mutant (AprE51-8) also increased the fibrinolytic activity up to 4.5-fold in a fibrin plate assay. Purified AprE51-7 and AprE51-8 mutants had a 1.9- and a 2.5-fold higher $k_{cat}$, respectively, and a 2.1-1.9-fold lower $K_m$, respectively. This resulted in a 3.8- and a 4.7-fold increase in catalytic efficiency ($k_{cat}/K_m$), respectively, relative to that of wild-type AprE51. AprE51-8 had a broader pH range than AprE51-6 and nattokinase, especially at an alkaline pH value. In addition, AprE51-8 showed higher thermostability than AprE51-6 at $60^{\circ}C$. The half-lives of AprE51-7 and AprE51-8 at $50^{\circ}C$ were 21.5 and 27.3 min, respectively, which are 2.0 and 2.6 times longer, respectively, than that of the wild-type AprE51.