• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.99-104
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• 2023

The purpose of this study was to examine the effect of children's academic stress on school adaptation and to verify whether ego-resilience plays a mediating role in the relationship between academic stress and school adaptation. Based on the data from the 12th year of the Korean Children's Panel (2019), the general characteristics of the main subjects and the mean, standard deviation, skewness and kurtosis of the main variables were confirmed through basic statistical analysis, and correlation analysis was conducted between variables. In addition, to examine whether ego-resilience mediated the effect of academic stress on school adaptation, a three-step regression analysis was conducted following the procedure of Baron and Kenny. The results of this study were as follows. First, it was found that children's academic stress, school adaptation, and ego resilience were all significantly correlated. The higher the academic stress, the lower the ego-resilience and school adaptability. Second, it was confirmed that ego-resilience has a partial mediating effect in the relationship between children's academic stress and school adjustment. Ego resilience in the academic stress situation means that it acts as an important mediating factor to flexibly adapt to school life by objectively grasping and coping with the stress situation. Therefore, we need to recognize the need for flexible and resilient individual characteristics so that children can reduce academic stress and adapt well to school life, and seek active interest and intervention plans.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6B
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• pp.665-673
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• 2008

This study is to assess the future potential climate and land use change impact on streamflow and stream water quality of the study watershed using the established model parameters (I). The CCCma (Canadian Centre for Climate Modelling and Analysis) CGCM2 (Canadian Global Coupled Model) based on IPCC SRES (Special Report Emission Scenarios) A2 and B2 scenarios were adopted for future climate condition, and the data were downscaled by Stochastic Spatio-Temporal Random Cascade Model technique. The future land use condition was predicted by using modified CA-Markov (Cellular Automata-Markov chain) technique with the past time series of Landsat satellite images. The model was applied for the future extreme precipitation cases of around 2030, 2060 and 2090. The predicted results showed that the runoff ratio increased 8% based on the 2005 precipitation (1160.1 mm) and runoff ratio (65%). Accordingly the Sediment, T-N and T-P also increased 120%, 16% and 10% respectively for the case of 50% precipitation increase. This research has the meaning in providing the methodological procedures for the evaluation of future potential climate and land use changes on watershed hydrology and stream water quality. This model result are expected to plan in advance for healthy and sustainable watershed management and countermeasures of climate change.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.649-659
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• 2006

Recently there has been huge efforts to improve performance in construction process by applying emerging techniques such as the Lean principle and Just-in-time concept. However, little achievement as we expected has come out in reality due to the lack of strategy to set a definite goal of the execution and differences of personal viewpoints on construction productivity. Accordingly, it is the most important to promote the circumstances for the construction process improvement by quantifying the goals of respective unit activity groups. This research explores feasible solutions for the improvement of construction projects performance by combining the six-sigma principle for the generic administrative innovation based on the idea of construction process performance. For this purpose, mutual comparisons of various current approaches are performed in an attempt to establish the advantages in applying six-sigma idea and to provide its fundamental strategy. Furthermore, through a case study with the simulation of applying six-sigma to a unit activity group in construction process, this paper verifies that the overall performance improves as the degree of sigma level gets advanced.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.6
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• pp.417-427
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• 2010

In the ease that a new cross tunnel is constructed under the existing tunnel, development of a longitudinal arching would be influenced by the existing tunnel. But it is not enough to investigate. Especially, the influence of the structure loads on the ground surface on the new tunnel, which the under-passes existing tunnel has been rarely studied. This study, therefore, aimed to clarify the effect of the existing tunnel and the structure on the ground surface on the development of a longitudinal ground arching during the excavation of a cross tunnel under the existing tunnel. Two-dimensional model tests were carried out in the test box, whose dimension was 30 cm (wide) ${\times}$ 113 cm (deep) ${\times}$ 87 cm (high). The existing tunnel was made of S21 steel tube in 16 cm diameter and 1 mm thickness. The ground surface load was 4.9 kPa and was loaded on the model structure in the size with 30 cm width ${\times}$ 16 cm height. New tunnel was excavated in 250 mm height by a bench cut method. As results, the longitudinal arching would be developed but it was severely influenced by not only the existing upper tunnel but also the ground surface load. The influence of the ground surface load on the development of longitudinal ground arching around a new tunnel showed the highest value when the tunnel face located direct under the surface load.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4C
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• pp.163-174
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• 2009

Mechanical device using the load cell or strain gage sensor can be influenced by tempearute changes because temperature change can cause a shift in the load cell or straing gage output at zero loading. In this paper, micro cone penetrometers with 1~7mm in diameter, are developed by using an optical fiber sensor (FBG: Fiber Bragg Grating) to compensate the continous temperature change during cone penetration test. Note the temperature compensated method using optical fiber sensor which has hair-size in diameter, and is not affected by environmental conditions because the measured data is the wavelength shifting of the light instead of the intensity of the electric voltage. Temperature effect test shows that the output voltage of strain gage changes and increases with an increase in the temperature. A developed FBG cone penetrometer, however, achieves excellent temperature compensation during penetration, and produces continuous change of underground temperature. In addition, the temperature compensated FBG cone shows the excellent sensitivity and detects the interface of the layered soils with higher resolution. This study demonstrates that the fiber optic sensor renders the possibility of the ultra small size cone and the new fiber optic cone may produce more reliable temperature compensated tip resistance.

• Journal of the Korean School Mathematics Society
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• v.26 no.2
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• pp.87-110
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• 2023

This study aimed to proposed repeated reading aloud, which combines repetitive reading and reading aloud, as a method for teaching and learning mathematics. We investigated the effect of repeated reading aloud on students' academic achievement and cognitive load, and explored the implications of repeated reading aloud as a method for teaching and learning mathematics. To this end, we conducted a case study involving repeated reading aloud for two units: the limit of a function and the number of cases. The study targeted four 9th-grade students and four 10th-grade students, analyzing how their academic achievement and cognitive load changed. As a result, the eight students showed positive changes in academic achievement and cognitive load as the repeated reading aloud accumulated. When comparing the units, the academic achievement was lower for the limit of function than the number of cases. In terms of cognitive load, students exhibited higher cognitive load in the unit on the limit of function. When compared cognitive load by grade, there was no significant difference after 3rd repeated reading. However, in both units, the academic achievement of four 10th-grade students was higher than that of four 9th-grade students. Nonetheless, the gap narrowed as the reading aloud was repeated.

• Korean Journal of Dental Materials
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• v.46 no.1
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• pp.1-10
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• 2019

There are several causes of tooth discoloration following root canal treatment. In this study, we evaluated the effects of sealers on tooth discoloration and internal bleaching. Twenty-four teeth were divided into 4 groups: control group, AH plus, Endosequece BC, and MTA fillapex group. Root canal filling was performed using each sealer conventionally and non-vital bleaching was performed with sodium perborate. The L, a, and b values were measured using Vita easyshade. Tooth discoloration after root canal treatment occurs irrespective of the type of sealers and may cause discoloration with only gutta-percha cone. The effect of non-vital bleaching following the use of calcium silicate-based sealers such as Endosequece BC and MTA fillapex was higher than that of AH plus. Therefore, it needs careful use of sealers in endodontics and calcium silicate-based sealers have advantages of bleaching in case of discolored tooth.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.25-32
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• 2019

According to a recent KOFICE survey, K-Pop's popularity factor is divided into visual and auditory elements, and the importance of hearing elements is found. Among the various types of singers, idol groups led K-Pop and Black Pink, which topped the list of favorite K-Pop singers in 2018, was selected as the study target. In addition, Twice's music, which is similar to Black Pink's period of activity, has been set as a comparative research scope. The common features in the music of the two groups are the chorus and rhythm structure implemented around melody and Harmony rhythm, and the frequency of use of Major and Minor is greatly different. Through this method and modal interchange, K-Pop from 2016 to 2018 is analyzed. Research shows that first, more than one mode is used as a main melody. When more than one mode is used, different lines in the same line will vary depending on the functional form of the song. Second, the rhythm of the melody expressed with vocals and instruments is repeated based on a two-bar pattern. Finally, when using less chord and slowly expressing the igneous rhythms, there is a way to omit or modify the third notes that determine chord characteristics. Through this study, we can see that the usage patterns of the mode and modal interchange are divided according to the major and minor.

• Exercise Science
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• v.21 no.2
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• pp.243-254
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• 2012

This study tried to suggest the applicapability of soy protein supplementation and treadmill running exercise for the replacement theraphy on negative effects to estrogen metabolism in menopause. This study was analyzed the effects of 8 week soy protein supplementation and treadmill running exercise on the changes of body composition, blood concentrations of glucose, insulin, triglycerides, C-reactive protein (CRP) and estradiol, estrogen receptor gene expression of liver in ovariectomized rats. Ovariectomized groups showed the increasing responses of body weight, body fat percentage, and blood concentration of triglycerides, but these groups showed the decreasing responses of blood estradiol level and estrogen receptor gene expression in liver. Ovariectomized groups showed the positive responses of blood concentrations of lipid markers, insulin, estradiol, and estrogen receptor gene expression of liver except bone mineral contents after 8 week soy protein supplementation and treadmill running exercise. I could find the positive effects of 8 week soy protein supplementation and treadmill running exercise on the estrogen and lipid metabolism in ovariectomized rats, but this study could not confirmed the detailed replacement program of exercise intensity, duration, and soy protein volume for estrogen metabolism in ovariectomized rats.

• Exercise Science
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• v.21 no.3
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• pp.373-384
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• 2012

The effects of inspiratory muscle training in conjunction with aerobic exercise on inspiratory muscle strength, pulmonary function, and maximal oxygen uptake(VO₂max) were examined. Twenty four healthy collegiate men were divided into three groups; respiratory muscle training group(RTG; n=8), running exercise group(REG; n=8), and both respiratory muscle training and running group(BTG; n=8). Their pulmonary function, maximal inspiratory pressures(PImax), and VO₂max were assessed before and after intervention. RTG underwent inspiratory muscle training(IMT) with load set to 50 % of PImax, 30 times per session, twice a day, 4 days a week REG ran on a treadmill at 70-75 % of VO₂max for 30 min a day, 4 days a week. BTG participated both IMT and the running exercise. Participant's anthropometric parameters and pulmonary function were not changed. VO₂max increased by 6.1±3.3 %, 5.9±6.6 %, and 10.0±8.3 % in RTG, REG, and BTG, respectively(p< .05), and PImax also increased by 21.7±14.3 %, 19.7±12.0 %, and 27.0±12.1 % in RTG, REG, and BTG, respectively, but no group differences were found. Based on the study, although statistically insignificant, BTG showed the biggest increase of VO₂max and PImax indicating a possible synergic effect of inspiratory muscle training and aerobic exercise on respiratory responses.