• Economic and Environmental Geology
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• v.36 no.3
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• pp.225-232
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• 2003

Three piston cores. obtained from the northwestern Ulleung Basin of the East Sea, are analyzed to study the tephrostratigraphy of the late Quaternary core sediments and to reveal the comparative characteristics of the tephra layers. The cores consist mainly of the muddy sediments that are partly interbedded with lapilli tephra and ash layers. The muds are further divided into hemipelagic and turbiditic mud facies. The hemipelagic facies is dominated by bioturbated mud and crudely laminated mud, whereas the turbiditic facies includes mainly thinly laminated mud and homogeneous mud, and often alternates with non-turbiditic muds. According to microscopic observation and EDX analysis, three tephra layers of the Ulleung-Oki (U-Oki; ca. 9.3 ka), Aira-Tanzawa (AT: ca. 22~24.7 ka) and Ulleung-Yamato (U-Ym; ca. 25~33 ka) are identified in the study cores. Among these, the U-Oki and U-Ym layers, originating from the Ulleung Island, consist mainly of massive-type glass shards with alkali feldspar. Both of the tephra layers contain a lower content of SiO$_2$ (57~66.5 wt.%) and a higher content of Na$_2$O+K$_2$O (11~16 wt.%) than the AT layer (SiO$_2$=75~78.5 wt.%, Na$_2$O+K$_2$O=6.5~9 wt.%) that consists of typical plane-type and/or bubble-wall glass grains. Compared with that of the U-Ym layer, a sedimentary facies of the U-Oki layer is very thick and contains three stratigraphic units, probably due to relatively large and different supplies of pyroclastic sediments. Thus, the eruption of Ulleung Volcano (ca. 7,300 B.C.) is thought to have had a more powerful effect on depositional environment than the U-Ym eruption.

• Reproductive and Developmental Biology
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• v.38 no.4
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• pp.171-177
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• 2014

L-Carnitine is an antioxidant for the transport of fatty acids in mitochondria and breakdown of lipids for metabolic energy. Some studies have suggested that carnitine improves sperm motility in mammals. The objective of this study was to investigate the effect of L-carnitine on the characteristics in fresh semen of miniature pigs. The collected fresh semen was stored in modena B medium with L-carnitine (0, 1.0, 2.0, and 4.0 mg/ml) for 10 days at $18^{\circ}C$. The semen quality of viability, acrosome reaction and mitochondria integrity was analyzed on 0, 3, 7, and 10 day of semen storage. The percentages of live and dying sperm were not different among treatment groups with different concentrations of L-carnitine during the storage period. In acrosome reaction analysis, when the sperm stored for 7 day, the percentages of live sperm with acrosome reaction were significantly (p<0.05) lower in 1 ($9.0{\pm}0.9%$), 2 ($7.6{\pm}0.2%$) or 4 mg/ml ($7.9{\pm}0.8%$) L-carnitine-treated groups than the control group (0 mg/ml L-carnitine) ($11.12{\pm}0.2%$). However, there were no difference in percentages of live sperm with acrosome reaction for 3 and 10 days of storage with each concentrations of L-carnitine. When sperm was stored for 3 and 10 days, the percentages of live sperm with mitochondria integrity were significantly higher in 2 mg/ml of L-carnitine-treated group than control group (p<0.05). In conclusion, the L-carnitine has a positive effect on acrosome reaction and mitochondria integrity in liquid state of fresh semen in miniature pigs.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.1-6
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• 2004

This study was conducted to investigate novel genetic variations of MCIR^*3 allele. In general, white spotting or white belt on a black backgroud in pigs is determined by the E$^p$ allele at the MCIR/Extention locus. E$^p$ shares a frameshift mutation with the E$^{D2}$ allele for dominant black color. An oligonucleotide primer set was designed to amplify complete coding sequence of the porcine MCIR gene. The MCIR coding sequences obtained from five breeds those were Landrace(white). Yorkshire(white), Hampshire(belt), Berkshire(spot) and Jeju native black pigs(black), were used for this study. A multiple sequence alignment of the MCIR coding region using Clustal W was performed. The total length of the MCIR coding sequence ranged from 963 to 966 base pairs(bp) among the selected breeds. The sequence analysis of the complete coding region of MCIR was revealed that Hampshire and Jeju native black pig have 3 cytosines deletion and Birkshire has 2 cytosines deletion at codon 23(nt68) in Extention loci. Besides the finding, there were three different missense mutations and a frameshift mutation in the MCIR coding region.

• Journal of Educational Research in Mathematics
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• v.15 no.3
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• pp.251-272
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• 2005

Given that cognitive demands of mathematical tasks can be changed during instruction, this study attempts to provide a detailed description to explore how tasks are set up and implemented in the classroom and what are the classroom-based factors. As an exploratory and qualitative case study, 4 of six-grade classrooms where high-level tasks on ratio and proportion were used were videotaped and analyzed with regard to the patterns emerged during the task setup and implementation. With regard to 16 tasks, four kinds of Patterns emerged: (a) maintenance of high-level cognitive demands (7 tasks), (b) decline into the procedure without connection to the meaning (1 task), (c) decline into unsystematic exploration (2 tasks), and (d) decline into not-sufficient exploration (6 tasks), which means that the only partial meaning of a given task is addressed. The 4th pattern is particularly significant, mainly because previous studies have not identified. Contributing factors to this pattern include private-learning without reasonable explanation, well-performed model presented at the beginning of a lesson, and mathematical concepts which are not clear in the textbook. On the one hand, factors associated with the maintenance of high-level cognitive demands include Improvising a task based on students' for knowledge, scaffolding of students' thinking, encouraging students to justify and explain their reasoning, using group-activity appropriately, and rethinking the solution processes. On the other hand, factors associated with the decline of high-level cognitive demands include too much or too little time, inappropriateness of a task for given students, little interest in high-level thinking process, and emphasis on the correct answer in place of its meaning. These factors may urge teachers to be sensitive of what should be focused during their teaching practices to keep the high-level cognitive demands. To emphasize, cognitive demands are fixed neither by the task nor by the teacher. So, we need to study them in the process of teaching and learning.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.3
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• pp.183-190
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• 2000

The purpose of this study is to evaluate the magnetic property change of the nuclear reactor vessel steel irradiated by fast neutrons using $M{\ddot{o}}ssbauer$ spectroscopy, and the effects of the defects produced by neutron irradiation on the changes using X-ray diffraction. The specimens, fabricated with the dimension of $23mm{\times}18mm{\times}70{\mu}m$, were irradiated by neutron fluence from $10^{12}n/cm^2\;to\;10^{18}n/cm^2$ at 343K. Throughout the experiments, it is understood that (1) the X-ray diffraction measurement shows that the change of crystal nature is started at the irradiation of $10^{16}n/cm^2$ and a crystal structure has been severely damaged at the irradiation over $10^{17}n/cm^2$, (2) the analysis of the $M{\ddot{o}}ssbauer$ spectra has shown that magnetic transition phenomena occur at the irradiation over $10^{17}n/cm^2$ and (3) both methods can be utilized as nondestructive test methods for the embrittlement evaluation of materials irradiated by fast neutrons.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.307-316
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• 2003

Fish assemblage structure in a sheltered shallow water in the Southern Coast of Korea was examined monthly. Sampling was conducted in Doam Bay using a beam trawl between March 2001 and February 2001. A total of 53 fish species from 33 families were caught. Pinkgray goby (Chaeturichthys hexanema), ponyfish (Leiognathus nuchalis) and yellowfin goby (Acanthogobius favimanus) were the most frequent species, comprised 67.4％ of the total numbers captured. Snailfish (Liparis tanakai), yellowfin goby (Acanthogobius flavimanus) and pinkgray goby (Chaeturichthys hexanema) represented 50.8％ of the total biomass. While total abundance (number of individuals) and biomass were high in autumn and winter, species richness (number of species) and diversity were high in spring. Cluster analysis, based on monthly abundance data of the 14 most frequent species, showed that the species were separated into three different groups. Group A composed of pinkgray goby, yellowfin goby, robust tonguefish (Cynoglossus robustus) and scaly hairfin anchovy (Setipinna taty), which were year-round residents, and devil flathead (Onigocia spinosa), Red dragonet (Repomucenus lunatus) and ponyfish, which were abundant in autumn, group B surmullet (Upeneus japonicus), hairtail (Trichiurus lepturus) and gaff-topsail goby (Cryptocentrus filifer), which were abundant in summer, and group C grassfish (Liparis tanakai), spotted velvefish (Erisphex pottii), chameleon goby (Tridentiger trigonocephalus) and Richardson dragonet (Repomucenus richardsonii), which were abundant in winter and spring. A seasonal homogeneity of fish assemblage indicates that overall fish assemblage in Dom Bay is largely controlled by year-round residents.

• Tunnel and Underground Space
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• v.19 no.3
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• pp.248-260
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• 2009

With regard to oversea mineral resources development, recent trend has been changed from a simple capital investment to a direct development of the resources. In relation to the stability of a slope in large open-pit coal mine, groundwater system was investigated and the validity of horizontal drainage hole was evaluated in Pasir coal mine, Indonesia. In this work, various field tests were carried out for a characterization of groundwater system, which included in-situ permeability measurement, tracer test and monitoring of groundwater levels. Especially, the influence of SM river on the characteristics of the groundwater flow system was mainly inspected. For the permeability measurement, Guelph permeameter was employed, and was found that sandstone was more permeable than mudstone and coal seam. From a comparison of lithological structure and the results of groundwater level monitoring, sandstone and thin coal seam with fractures were found to be a main channel for groundwater flow. In the results of tracer tests, the effect of SM river on the groundwater system depends on the geological structure of its base. To identify the effect of horizontal drainage holes, 2-D groundwater modeling was performed. Four different cases were tested, which are different from the length of drainage hole and the existence of pond on top of the slope. To enhance the drainage effect and slope stability, the drainage hole should be drilled to the depth of coal seam layer, which provides a main pathway of groundwater flow and embedded by sandstone. For this purpose, correct identification of surrounding geology should be preceded.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.169-176
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• 1985

Six analytial methods for determing the available nitrogen in soils were tested to predict the optimum fertilizer rate for the flue-cured tobacco and to test the fertility level of soils for tobacco. All methods, nitrifiable $NO_3-N$ value for 2 and 4 weeks incubation, UV absorption value at 260nm and N-value in acid digestion of 0.01 M-$NaHCO_3$ extracts, N-value extracted in boiling with $CaCl_2$ solution, and autoclave-extractable $NH_4-N$ value in 0.01 M-$CaCl_2$, were closely correlated with total nitrogen uptake as well as yield. Therefore available nitrogen indices determined from above 6 analysis method could be used for the predicting of tobacco yield without fertilizer, criteria for fertility class, and recommendable range of optimum fertilization.

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.27-42
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• 2016

Forest accounts for almost 64 percents of total land cover in South Korea. For inventorying, monitoring, and managing such large area of forest, application of remote sensing and geographic information system (RS/GIS) technology is essential. On the basis of spectral characteristics of satellite imagery, forest cover and tree species can be classified, and forest cover map can be prepared. Using three dimensional data of LiDAR(Light Detection and Ranging), tree location and tree height can be measured, and biomass and carbon stocks can be also estimated. In addition, many indices can be extracted using reflection characteristics of land cover. For example, the level of vegetation vitality and forest degradation can be analyzed with VI (vegetation Index) and TGSI (Top Grain Soil Index), respectively. Also, pine wilt disease and o ak w ilt d isease c an b e e arly detected and controled through understanding of change in vegetation indices. RS and GIS take an important role in assessing carbon storage in climate change related projects such as A/R CDM, REDD+ as well. In the field of climate change adaptation, impact and vulnerability can be spatio-temporally assessed for national and local level with the help of spatio-temporal data of GIS. Forest growth, tree mortality, land slide, forest fire can be spatio-temporally estimated using the models in which spatio-temporal data of GIS are added as influence variables.

• CRM연구
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• v.1 no.1
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• pp.23-48
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• 2006

Internet B2C marketplace such as 'Auction', 'G Market', 'Daum onket' etc.(called open market) has grown sharply in sales about yearly 100% rate increase in recent 1-2 years in Korea. Although Open marketplace has much reputation and the customer loyalty, almost of merchants participated in open market, which size in sales are medium/small, has poor reputation and trust. Consumers, who have to get in touch with untrustworthy merchants for trade in openmarket, perceive high trade risk which undergo the monetary damages such as 'merchandise never received'. This examines what factors consumer trust develop in online marketplace. This study explores several perceived risk factors in an open market by factor analysis and multi-regression to prove the relationships between the degree of trust for the merchants and the perceived trade risk. 133 data collected from the open market user data in this survey. In this study, the consumer's trade satisfaction in open market is low by 4.2 point degree of 7 point likert scale. and perceives 4 trade risk factors such as (1) 'failure to honor warranty or guarantee' (2) 'defective/poor goods in quality' (3) 'merchandise never received or received late' (4) 'poor information'. the degree of merchant's trust has significant relationship with the degree of perceived risk(sig. = 0.0000, $R^2=.327$) We find that the open market has to enhance the relationship marketing of trust by developing the strategies.