• Journal of Korean Academy of Nursing
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• v.3 no.3
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• pp.1-14
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• 1973

This study is designed to meet the following objectives: (1) To study attitude and behavior regarding marriage and age at marriage, (2) To learn correlates of age at marriage and to examine their relations, (3) To measure relative importance of the correlates of age at marriage, and (4) To study relations of age at marriage and family planning practice to fertility and their relative importance as correlates of fertility. The data are obtained by an independent cross-sectional survey in three study areas purposively selected to represent metropolitan. semihuman. rural population. The study population is confined to women age 17-50 as of survey. The overall response rate is 90%. Reliability of data is measured by . individual and aggregate inconsistency based upon a 15% subsample of the original interviews. The individual inconsistency (31%) is found to be high compared to the aggregate inconsistency (6%) for all 85 variables. However, the magnitude of differences between means is small, and the mean absolute shifts and proportional shifts are also small on the whole. In a word respondents did not change their answers too extremely or radically. The study populations of each study area are compared on some basic characteristics. It is found that the three study populations have more dissimilarities than similarities. The findings on seven different attitudinal positions of women toward marriage indicate that there have been tremendous changes in all study areas Iron "traditional" attitudes which have been prevalent for a long time in Korean society to "liberalized" or "modernized" attitudes. An apparent tendency is that women generally take a position of a "golden mean" attitude by not preferring either extreme of marriage attitudes. Nevertheless, the young, single, educated, and urbanite appears more "liberalized. " There has been some increase in ideal age at marriage from 1958 to 1970 for both sexes. No age group, marital status, or study area differentials in ideal age at marriage are found, the average ideal age at marriage in every sub-group being 24-25. Awareness of existing legal marriageable ages is low; only 4.4% are aware that "with parental permission: minimum age for males is 18 years and for females 16 years,"and only 3.7% are aware that "without parental permission: 27 years for males and 23 years for females." People in Korra tend to marry spouses who are in various social ways like themselves: the similarities include (a) education, occupational status of father, (c) economic status, (d) usual residence before marriage, and (e) religion. Both singulars and actual mean ages at marriage in this study confirm the trend of rising age at marriage previously established by other independent studies. The urban-rural differential in age at marriage is observed, but the differential narrows down gradually from 1935 to 1970. All socio-economic, demographic, and other variables pertaining to wife before and at first marriage, excluding (a) religion, (b) father′s of occupation, and (c) as: of menarche, are correlated with respondent's age at first marriage, whereas only three variables out of all socio-economic variables relating to husband before and at wife′s first marriage, viz., (a) education, (b) usual residence, and (c) economic level of his old home, are correlated with respondent′s age at marriage. Among socio-economic and modernity variables related to either husband or wife at the time of survey, only education and duration of residence are correlated with wife′s age at first marriage. Among the correlates of respondent′age at first marriage, education is in general the most important variable. However, it is found that wife′s education is more important than husband′s. The combined effects or the correlates studied explain no more than about 40% of variance for any of the selected groups of variables. Points which might counteract the effects of late marriage on fertility are not serious in Korea. For each of the correlates of the three fertility indices chosen for this study. namely, (a) number of living children, (b) number of live births, and (c) number of pregnancies, age at marriage is the major contributor to the variance in all age groups except the age group of 20-29 in which the index of family planning practice is the major contributor. The proportion of variability in fertility indices accounted for by the correlates is never more than 40% of the total variance in any age group. Based upon the findings from this study, it could be concluded that in the foreseeable future (a) celibate group will no! be increased to a point that would slow down population growth rate in Korea, (b) age at marriage will not increase continually, (c) although education stands out as the major contributing variable which independently explains the variation in age at marriage, it seems probable that education may not be the major variable in the near future, and (d) despite the fact found by this study that age at marriages has been the major contributor to the variance of each of the fertility indices used, family planning practice will play a more important role in the reduction of fertility in the Korean society. Therefore, factors interrupting practice of family planning must be eliminated and family planning program should be strengthened if further fertility reduction is needed.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.404-411
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• 2012

The reliability of solid oxide fuel cells (SOFCs) particularly depends on the high quality of solid oxide electrolytes. The application of thinner electrolytes and multi electrolyte layers requires a more reliable characterization method. Most of the investigations on thin film solid electrolytes have been made for the parallel transport along the interface, which is not however directly related to the fuel cell performance of those electrolytes. In this work an array of ion-blocking metallic Ti/Au microelectrodes with about a $160{\mu}m$ diameter was applied on top of an ultrathin ($1{\mu}m$) yttria-stabilized-zirconia/gadolinium-doped-ceria (YSZ/GDC) heterolayer solid electrolyte in a micro-SOFC prepared by PLD as well as an 8-${\mu}m$ thick YSZ layer by screen printing, to study the transport characteristics in the perpendicular direction relevant for fuel cell operation. While the capacitance variation in the electrode area supported the working principle of the measurement technique, other local variations could be related to the quality of the electrolyte layers and deposited electrode points. While the small electrode size and low temperature measurements increaseed the electrolyte resistances enough for the reliable estimation, the impedance spectra appeared to consist of only a large electrode polarization. Modulus representation distinguished two high frequency responses with resistance magnitude differing by orders of magnitude, which can be ascribed to the gadolinium-doped ceria buffer electrolyte layer with a 200 nm thickness and yttria-stabilized zirconia layer of about $1{\mu}m$. The major impedance response was attributed to the resistance due to electron hole conduction in GDC due to the ion-blocking top electrodes with activation energy of 0.7 eV. The respective conductivity values were obtained by model analysis using empirical Havriliak-Negami elements and by temperature adjustments with respect to the conductivity of the YSZ layers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.2
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• pp.177-184
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• 2013

This study was conducted to determinate the optimum times of transplanting and harvest for enhancing the fresh leaf yield and colorant level of an indigo crop, Persicaria tinctoria H. Gross, containing the blue dye indigo. Two cultivars, Naju Local and a new cultivar, NaramBlue, were transplanted 5 times from May 30 to July 10 at an interval of 10 days, and all of experiment plots harvested on Aug. 23 in Muan, the south area of Korea. As transplanting time was delayed, fresh leaf yield were maximum at earliest transplanting (May 30) and then decreased, while Niram (blue dye extract) and indigo content of fresh leaf remained almost constant though showed a small variation. Also, two cultivars transplanted on May 23 were harvested 5 times from Jul. 20 to Sept. 20 at an interval of 15 days. As harvest time was delayed, plant height, No. of first branches, and fresh leaf yield changed increasingly, while Niram content was increased to Aug. 20 and then decreased slightly. Indigo level increased largely to Aug. 5, and then continuously decreased with more delayed harvest. These tendencies of changes in fresh leaf yield and colorant level with different transplanting and harvest times were shown similarly in both cultivars. The results indicate that early transplanting before May 30 and harvest in early August will be appropriate for improving fresh leaf yield and colorant level.

• Journal of Environmental Science International
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• v.18 no.7
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• pp.721-733
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• 2009

To examine the fluctuations of aerosol number concentration with different size in the boundary layer of marine area during summer season, aerosol particles were assayed in the Ieodo Ocean Research Station, which is located 419 km southwest of Marado, the southernmost island of Korea, from 24 June to 4 July, 2008. The Laser Particle Counter (LPC) was used to measure the size of aerosol particles and NCEP/NCAR reanalysis data and sounding data were used to analyze the synoptic condition. The distribution of aerosol number concentration had a large variation from bigger particles more than 3 ${\mu}m$ in diameter to smaller particles more than 1 ${\mu}m$ in diameter with wind direction during precipitation. The aerosol number concentration decreased with increasing temperature. An increase (decrease) of small size of aerosol (0.3${\sim}$0.5 ${\mu}m$ in diameter) number concentration was induced by convergence (divergence) of the wind fields. The aerosol number concentration of bigger size more than 3 ${\mu}m$ in diameter after precipitation was removed as much as 89${\sim}$94% compared with aerosol number concentration before precipitation. It is considered that the larger aerosol particles would be more efficient for scavenging at marine boundary layer. In addition, the aerosol number concentration with divergence and convergence could be related with the occurrence and mechanism of aerosol in marine boundary layer.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.343-352
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• 2013

In this study, a smooth flat surface, low fin, Turbo-B, and Thermoexcel-E surfaces are used to examine the effect of the flow velocity on the pool boiling heat transfer coefficients (HTCs) and critical heat fluxes (CHFs). HTCs and CHFs are measured on a smooth square heater of $9.53{\times}9.53mm^2$ at $60^{\circ}C$ in a pool of pure water at various fluid velocities of 0, 0.1, 0.15, and 0.2 m/s. Test results show that for all surfaces, CHFs obtained with flow are higher than those obtained without flow. CHFs of the low fin surface are higher than those of the Turbo-B and Thermoexcel-E surfaces due largely to the increase in surface area and sufficient fin spaces for the easy removal of bubbles. CHFs of the low fin surface show even 5 times higher CHFs as compared to the plain surface. On the other hand, both Turbo-B and Thermoexcel-E surfaces do not show satisfactory results because their pore sizes are too small and water bubbles easily cover them. At low heat fluxes of less than $50kW/m^2$, HTCs increase as the flow velocity increases for all surfaces. In conclusion, a low fin geometry is good for application to steam generators in nuclear power plants.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.40-48
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• 1994

The weathering of the Namsan granite was studied in terms of sorption process. The Namsan granite consists mainly of quartz, alkali feldspar, plagioclase (${Ab_{85}An_{15}}-Ab_{100}$ and biotite with small amounts of sericite, magnetite and ilmenite. The kinetic factors for altering the granite body are the proton and hydroxyl ions derived from the reaction of water and mineral. There are two different types of pH variation curves for rocks of different mineral assemblages. when powdered granite was dispersed in distilled water under ambient condition. The sorption-process proceeds by three steps for fresh granite; (1) the initial rapid pH-rise to 10 by the uptake of proton by negatively charged mineral surfaces, (2) the gradual pH-down, and (3) the stable pH tail between 7.1-7.5. For somewhat weathered granites, the sorption proceeds; (1) the initial rapid pH-down to 4.8, (2) the slight pH-rise and slow ph-down, and (3) the stable pH tail between 5.0-5.3. The reaction rate is controlled by the density of adsorbable sites, the solubility of the mineral, pH of the system and formation of amorphous gel and gibbsite. Amorphous gel floates on the surface of the solution while stirring the powdered granite and then is transformed into gibbsite in an hour or so. The pH saturation values for -325 mesh fresh granite from 5 m depth is about pH 10 when rock/water ratio is over 10g/200 ml.

• Ocean and Polar Research
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• v.41 no.4
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• pp.275-288
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• 2019

We investigated flux, grain size distribution, Nd-Sr isotope composition, mineral composition, and trace metal composition (REEs and Sc) of inorganic silicate fraction (ISF, mainly Asian dust with an unrestricted amount of volcanic materials) deposited during 600~1000 ka across the Mid-Pleistocene Transition at core NPGP 1401-2A (32°01'N, 178°59'E, 5205m) taken from the central part of the North Pacific. Our results reveal about a 2-fold increase in ISF flux after 800 ka, which is associated with an increase in La/Sc and a decrease in mean grain size. Asian dusts are finer than volcanic materials and La/Sc increases with the enhanced contribution of Asian dusts. Thus, increased flux after 800 ka can be explained by the increased contribution of Asian dusts relative to volcanic materials, likely due to an intensified Westerly Jet (WJ) and the drying of the Asian continent after the MPT. Mean grain size of ISF varies systematically in relation to glacial-interglacial cycles with a decrease during glacial stages, which is consistent with the previous results in the study area. Such a cyclical pattern is also attributed to the increase in the relative contribution of Asian dusts over volcanic components in glacial stages due to intensified WJ and drying of the Asian continent. Thus, it can be concluded that climate changes that had occurred across the MPT were similar to those of interglacial to glacial transitions at least in terms of the dust budget. Different from the Shatsky Rise, however, compositional changes associated with glacial-interglacial mean grain size fluctuations are not observed in Nd-Sr isotope ratios and trace element composition in our study of the Hess Rise. This may be attributed to the location of the study site far (> 4,000 km) from the volcanic sources. The volcanic component at the study site comprises less than 10% and varies within 3% over glacial-interglacial cycles. Such a small variation was not enough to imprint geochemical signals.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.73-82
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• 1990

The experiment was carried out to study the influence of planting space and fertilizer application levels on some agronomic characters and yield in newly released semi-dwarf soybeans, Paldalbong and Dankyungkong. The number of branches per plant was not reduced by planting space from 60${\times}$10cm 30${\times}$15cm. These Semi-dwarf soybeans had good adaptability on high planting density. The number of pods per node on the main stem was different according to the planting space in Dankyungkong, but it was similar in Paldalkong except planting space 20${\times}$10cm. Regardless of planting densities and varieties, the number of grains per pod on upper node of the main stem was large. Coefficient of variation of pods and grains per node in the middle part of the main stem was small. The number of grains per plant was decreased in high planting density compared to low planting density, but the number of harvested plant per unit area was increased. Optimum planting space was 25${\times}$10cm in both varieties. The ability of nodulation was bigger in Dankyungkong than in Paldalkong.

• Economic and Environmental Geology
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• v.40 no.2 s.183
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• pp.171-189
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• 2007

A study of anisotropy of magnetic susceptibility (AMS) was undertaken on Cretaceous granitic, volcanic and sedimentary rocks in the eastern region of the Yangsan fault, southeast Korea. A total of 542 independently oriented core samples collected form 77 sites were studied. The main magnetic mineral in granitic rocks is magnetite according to the magnitude of bulk susceptibility, high-temperature susceptibility variation and isothermal remanent magnetization. Both of magnetic lineation and foliation with NE-SW trends are revealed in the granitic rocks, while volcanic rocks show scattered directions and sedimentary rocks show only load foliation parallel to the bedding planes. The following evidences read to the conclusion that both magnetic fabrics in the granitic rocks have been obtained by a tectonic stress before full solidification of the magma: (i) A fully hardened granitic rocks would get hardly any fabric, (ii) Difference of the magnetic fabric trends with those of the geological structures in the granitic rocks themselves formed by brittle deformation after solidification (e.g. patterns of small-faults and joints), (iii) Kinking of biotite and undulose extinction in quartz observed under the polarizing microscope, (iv) Discordance of magnetic fabrics in the granitic rocks with those in the surrounding rocks. The NE-SW trend of the magnetic foliations suggests a NW-SE compressive stress of nearly contemporaneous with the emplacement of the granitic rocks. The compression should have caused a sinistral strike-slip movement of the Yangsan Fault considering the trend of the latter. As the age of the granitic rocks in the study area is reported to be around $60\sim70$ Ma, it is concluded that the Yangsan fault did the sinistral strike-slip movement during this time (L. Cretaceous Maastrichtian - Cenozoic Paleocene).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.177-183
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• 1987

The catch by the set net fishery from 1971 to 1985 were analyzed in order to reveal its fluctuation characteristics. Generally, the catch increased from 16,787M/T in 1971 to 84,103M/T in 1985 and showed maximum in 1979 with 99,475M/T of catch. This trend was mainly related to the higher production of file fish which accounts for 64% of the total catch in 1979, and the change of catch statistical classification according to the revising of fishery law in 1976. It was also closely related to the variation of the sea water temperature in coastal area. The main fishing period of the set net fishery appeared from October to November. Catch of the set net fishery was led by that in the southern coast before 1976 and by that in the eastern coast from 1977 to 1980, the tendency changed irregular from 1981. Three groups of fishes could be distinguished by principal component analysis of the annual catch. A group showing steady decreasing tendency was composed of the fishes such as whiting, sand fish, hair tail and anchovy. The another group composed of small alaska pollack, round herring, goby, gizzard shad, sand lance and file fish revaled an increasing tendency. The other fishes did not show any annual tendency.