• 한국해양학회지
• /
• v.28 no.2
• /
• pp.114-120
• /
• 1993

Numerical method of nonlinear regression was introduced to characterize grain-size distribution more effectively than using the traditional textural parameters. This technique proved critical particularly to multimodal size distributions, as exemplified by samples from Cheju strait continental shelf. Grain-size analysis of samples collected from the Cheju Strait continental shelf reveals that 86% of the grain-size distributions are multimodal. As multimodal grain-size distribution deviates from the statistical (log) normal distribution, the grain-size parameters traditionally used in sediment studies do not describe the distribution efficiently. Therefore, the use of grain-size curves into elementary normal component curves was used. Means and standard deviations of 387 decomposed normal components were decided by a decomposition method (nonlinear least square regression) from 167 size curves of the Cheju Strait sediments. The mean values of decomposed normal components show peaks at 1-3 phi and 8-9 phi size classes. The plot of mean values of the coarse fraction normal components on the map shows a characteristic and complex areal distribution. On the basis of the areal distribution of the mean values of the components and that of isopach of total Plenipotence sediment, the areal distribution of layers composing a transgressive sand of Late Plenipotence age were revealed.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.3
• /
• pp.386-392
• /
• 1996

A numerical method based on genetic algorithms was introduced to characterize the grain-size distribution more effectively. This technique was proved significant particularly for multimodal size distributions, as was verified for samples from Korea Strait continental shelf. Sediment samples collected from the Korea Strait continental shelf revealed that $96\%$ of the grain-size distributions were multimodal. Therefore, the use of grain-size parameters was not the ideal method. As an alternative method, the decomposition of sue curves into elementary normal component curves was used. Means and standard deviations of 593 decomposed normal components were calculated by a numerical method from 268 size curves of Korea Strait sediments. The mean values of decomposed normal components showed peaks at $1\~3\phi\;and\;7\~9\phi$ size classes. The plot of mean and standard deviation values of the coarse fraction normal components on the map showed a characteristic areal distribution. The characteristic distribution was found to derive from underlying Pleistocene sediment on the basis of sea bottom geologic distribution of the area. The method of decomposition into normal components was found to be more effective than the analysis using traditional grain-size parameters in investigation of multimodal size distribution of Korea Strait shelf sediment.

• Journal of Korean Academy of Nursing
• /
• v.45 no.2
• /
• pp.169-182
• /
• 2015

Purpose: This study was a meta-analysis designed to identify effects of Cognitive Behavioral Therapy (CBT) interventions in alleviating main symptoms of Attention Deficit Hyperactivity Disorder (ADHD) among school-aged children in Korea. Methods: Examination of several databases including Research Information Sharing Service, Korean Studies Information Service System, Data Base Periodical Information Academic and hand-searched article references, resulted in identification of 1,298 studies done between 2000 and 2013 of which 21 met the inclusion criteria. Comprehensive Meta-Analysis version 2.0 was used to analyze effect sizes, explore possible causes of heterogeneity, and check publication bias with a funnel plot and its trim-and-fill analysis. Results: Overall effect size of CBT intervention was large (g=1.08) along with each outcome of self-control (g=1.26), lack of attention (g=1.02), social skills (g=0.92), and hyperactivity (g=0.92). For heterogeneity, moderator analysis was performed, but no significant differences were found between the RCT (Randomized Controlled Trials) group and the NRCT (Non RCT) group. Also, meta-regression was performed using sample size, number of sessions, and length of session as predictors, but no statistically significant moderators were found. Finally, a funnel plot along with trim-and-fill analysis was produced to check for publication bias, but no significant bias was detected. Conclusion: Based on these findings, there is clear evidence that CBT intervention has significant positive effects on the main symptoms of school-aged children suffering ADHD. Further research is needed to target diverse age groups with ADHD along with more RCT studies to improve the effectiveness of the CBT intervention.

• Applied Chemistry for Engineering
• /
• v.4 no.4
• /
• pp.701-708
• /
• 1993

Hydrodemetallation(HDM) of VO-tetraphenylporphyrin(VO-TPP) was studied over $CoMo/{\gamma}-Al_2O_3$ catalyst at emperatures between $300^{\circ}C$ and $400^{\circ}C$, the total pressure between $15{\times}10^5$ and $30{\times}10^5$ Pa and the contact times between 0.008 and 0.020gcat. hr./ml teed. HDM of VO-TPP was inhibited by pyridine because the increase of pyridine concentration(up to 4mole%) caused the decrease of HDM conversion. The reaction rate of VO-TPP was found to be apparently 1st order over $350^{\circ}C$ and its activation energy was determined to be about 23kca1/mo1e by Arrhenius plot. Pore mouth-plugging phenomena were shown by ad/desorption isotherm and pore size distribution of fresh and aged catalysts.

• Journal of the Microelectronics and Packaging Society
• /
• v.18 no.1
• /
• pp.15-21
• /
• 2011

In this study, flexural strength and fracture behavior of silicon die from single crystalline silicon wafer were investigated as a function of thickness. Silicon wafers with various thickness of 300, 200, 180, 160, 150, and 100 ${\mu}m$ were prepared by mechanical grinding and polishing of as-saw wafers. Flexural strength of 40 silicon dies (size: 62.5 mm${\times}$4 mm) from each wafer was measured by four point bending test, respectively. For statistical analysis of flexural strength, shape factor(i.e., Weibull modulus) and scale factor were determined from Weibull plot. Flexural strength reflecting both statistical fracture probability and size (thickness) effect of brittle silicon die was obtained as a linear function of die thickness. Fracture appearance was discussed in relation with measured fracture strength.

• Journal of Plant Biology
• /
• v.15 no.1
• /
• pp.33-41
• /
• 1972

Nine shrub layer communities under two relatively well conserved natural summer green forests in the central region of Korean Peninsula were studied for the pattern of stem distribution in terms of Greig-Smith's multiple split-plot experiment and for the association between the population of the two main species in terms of Kershaw's covariance analysis respectively. Four contiguous belt transects, $4{\times}64m size with 1{\times}1m$ basic unit, were set in each shrub layer communities. Significant primary clumps with $1{\times}1m or 1{\times}2m$ dimension wer observed consistently throughout the nine study sites. The primary clumps themselves were significantly distributed either regularly or at random. The association between the two principal species of each shrub layer is highly significantly either positive or negative in $1{\times}1m or 1{\times}2m$ dimension. As the plot size increases from $1{\times}1m to 8{\times}8m$ the associational trends were changed from negative to positive direction in one forests. But the change from positive to negative direction and the consistent negative association were also observed from the other forest. All of the association trends were observed only from $1{\times}1m to 4{\times}4m$ dimension. These results are suggestive that the distributional pattern of the shrub layer species under the summer green forest is simple mosaic fashioned with $1{\times}1m or 1{\times}2m$ dimension. The rest of the principal species are located in that matrix. The simple mosaic pattern of two principal species are located in that matrix. The simple mosaic pattern of two principal species seems to be controlled by change in micro-environmental pattern. Differences between the primary random group and clumped group among sites also suggest that competition exists for light or/and soil between primary clumped groups.

• Journal of the Korea Convergence Society
• /
• v.12 no.3
• /
• pp.381-388
• /
• 2021

The purpose of this study is to analyze the effects of simulation program using virtual reality (VR). Examination of databases resulted in identification of 1,415 studies of which 3 satisfied the inclusion data. Data analysis was performed using R version 4.0.2 to calculate the effect sizes, explore possible causes of heterogeneity, and check for publication bias, using a funnel plot. The mean effect size of the simulation program was medium (g=0.35), along with the skill performance (g=0.59), satisfaction (g=0.38), knowledge (g=0.21). Finally a funnel plot was produced to check for publication bias, but no significant bias was detected. Based on these findings, the simulation program using VR affects nursing education.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.49-49
• /
• 2022

One of the major problems with sweetpotato (Ipomoea batats Lam.) is the tough thread tissue that occurs in the storage root, which has a negative impact on the sales of sweet potato because it impairs the texture during cooking and the processing quality. The fiber contents in storage roots of sweetpotato is affected by cultivation conditions and environment. To investigate the effect of fiber generation at different levels of irrigation, the sweetpoatoto "Hogammi" was transplanted in greenhouse. Sweetpotato was grown in styrofoam beds(W1605*D330*H300mm) to block moisture flowing from the outside. The irrigation was carried out as 3 levels (5,10, and 20 mm through drip irrigation facilities) at 20-day intervals. Five plants were harvested per plot at 90, 100 and 120 days after transplanting (DAT). The size of the storage root was large in the order of irrigation conditions 10mm>20mm>5mm treatment. And the longer cultivation period, the larger size of the storage root was observed. As a result of the analysis of the fiber content, it showed a tendency to decrease as the cultivation period increased (90days→120days). In addition, the fiber contents of sweetpotato harvested at 90, 100 and 120 DAT in the level of 5 mm irrigation plot were 351, 324 and 207 mg/100g, respectively, which were higher than those of other irrigation level plots. During all cultivation periods, the 10mm treatment group showed the lowest fiber content of 280, 228 and 127 mg/100g. At 20 mm irrigation level, the fiber content was less than that of 5mm irrigation level, but showed a tendency to increase compared to that of 10 mm irrigation level. These results suggested that drought stress or excessive-irrigation increases the fiber content of sweetpotato, which reduces their commercial value.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1715-1720
• /
• 2011

Nanoporous structured tin dioxide ($SnO_2$) is characterized and its application in the photocatalytic destruction of endocrine, Bisphenol A, is examined. Transmission electron microscopy (TEM) reveals irregularly shaped nanopores of size 2.0-4.5 nm. This corresponds to the result of an average nanopore distribution of 4.5 nm, as determined by Barret-Joyner-Halenda (BJH) plot from the isotherm curve. The photoluminescence (PL) curve, corresponding to the recombination between electron and hole, largely decreases in the $TiO_2$/nanoporous $SnO_2$ composite. Finally, a synergy effect between $TiO_2$ and porous $SnO_2$ is exhibited in photocatalysis: the photocatalytic destruction of Bisphenol A is improved by combining the nanoporous structured $SnO_2$ with $TiO_2$, and 75% decomposition of 10.0 ppm of Bisphenol A is achieved after 24 h.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.6
• /
• pp.634-639
• /
• 1996

This experiment was conducted to evaluate the variability of hypocotyl elongation of mungbean varieties. With four mungbean cultivars, which were classified as 4234-697 and Keumsungnogdu(long), Nampyungnogdu(Medium), and Seonhwanogdu(short), hypocotyl elong-ation was measured 4 to 6 days after seeding in paper towel at different temperatures (15, 20, 25, 30, and 35$^{\circ}C$). Hypocotyl elongation of mungbean seed stored at 5$\pm$1$^{\circ}C$ for 6 months was compared with of seed stored at room temperature. As the temperature rises, the hypocotyl is longer. The hypocotyl elongation started immediately at high temperature, and longest at the range of 30 to 35$^{\circ}C$. The hypocotyl elongation became longer at the 5$^{\circ}C$ storage plot than at the room temperature plot. Correlation coefficient (r) between 100 seed weight and hypocotyllength are not significant.