• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.59-66
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• 2019

In this study, the effects of blast furnance slag cement and frost-resistant accelerator on shrinkage properties and shrinkage properties of mortar were examined. As a result, the addition of the frost-resistant accelerator to both OPC and BB has a small effect on the flash properties of mortar and the compressive strength increases from the early ages. In addition, when a frost-resistant accelerator is used in excess of the standard usage amount, it is necessary to examine the relationship of the expansion behavior at the early age, especially, between the compressive strength development and the expansion property. And it was confirmed that the addition of the frost-resistant accelerator tended to increase the shrinkage of mortar using the OPC and BB. With the addition of the frost-resistant accelerator, the amount of pores with a diameter of under the 30nm, especially, the amount of pores with a diameter of 20 to 30nm and the amount of pores with an ink-bottle decrease, and the shrinkage increases. And it is considered that a change in the amount this range of pores has a large effect on the shrinkage property.

• International Journal of Advanced Culture Technology
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• v.6 no.4
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• pp.152-157
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• 2018

In the late 19th century and early 20th century, Among those of the Northeast Asia three countries, school physical education and military-style gymnastics of Chosun can be regarded as having been the most nationalistic. The adoption of modern physical education in public schools was from the proclamation of 'the Order on Building the Country through Education by King Gojong in February 1895. This paper intends to examine the process of adopting military-style gymnastics education which played the central role in school physical education in the late Chosun period. But, unlike the common guess that military-style gymnastics in public schools in late Chosun would have been full of patriotism and nationalism, the textbooks and teaching contents of Chosun Military Officers' School were very similar to those of Japan, which is an unexpected fact. Therefore, Chosun decided to accept the Japanese-type military-style gymnastics and military training to improve physical strength of youngsters and military power. The fact that, with the advent of modern education, physical education was emphasized above all else has a very important meaning to the history of Korean physical education. Physical activity education emerged as a major education course which had been unthinkable in previous ages. The second characteristics is that the process of adopting military-style gymnastics and its contents were influenced by Japan Third, even if military-style gymnastics was imported from Japan as part of school physical education course in late Chosun period, its aim was to train military man powers for the independence movement against Japan, rather than to develop harmonious body.

• Computers and Concrete
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• v.24 no.2
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• pp.151-158
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• 2019

The sustainable development principle of replacing natural resources with renewable material is an important research topic. In this study, waste LCD (liquid crystal display) glass powder was used to replace cement (0%, 10%, 20% and 30%) through a volumetric method using three water-binder ratios (0.47, 0.59, and 0.71) to make cement mortar. The compressive strength was tested at the ages of 7, 28, 56 and 91 days. The test results show that the compressive strength increases with age but decreases as the water-binder ratio increases. The compressive strength slightly decreases with an increase in the replacement of LCD glass powder at a curing age of 7 days. However, at a curing age of 91 days, the compressive strength is slightly greater than that for the control group (glass powder is 0%). When the water-binder ratios are 0.47, 0.59 and 0.71, the compressive strength of the various replacements increases by 1.38-1.61 times, 1.56-1.80 times and 1.45-2.20 times, respectively, during the aging process from day 7 to day 91. Furthermore, a prediction model of the compressive strength of a cement mortar with waste LCD glass powder was deduced in this study. According to the comparison between the prediction analysis values and test results, the MAPE (mean absolute percentage error) values of the compressive strength are between 2.79% and 5.29%, and less than 10%. Thus, the analytical model established in this study has a good forecasting accuracy. Therefore, the proposed model can be used as a reliable tool for assessing the design strength of cement mortar from early age test results.

• International Journal of Computer Science & Network Security
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• v.22 no.9
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• pp.195-207
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• 2022

COVID-19 has remained one of the most serious health crises in recent history, resulting in the tragic loss of lives and significant economic impacts on the entire world. The difficulty of controlling COVID-19 poses a threat to the global health sector. Considering that Artificial Intelligence (AI) has contributed to improving research methods and solving problems facing diverse fields of study, AI algorithms have also proven effective in disease detection and early diagnosis. Specifically, acoustic features offer a promising prospect for the early detection of respiratory diseases. Motivated by these observations, this study conceptualized a speech-based diagnostic model to aid in COVID-19 diagnosis. The proposed methodology uses speech signals from confirmed positive and negative cases of COVID-19 to extract features through the pre-trained Visual Geometry Group (VGG-16) model based on Mel spectrogram images. This is used in addition to the K-means algorithm that determines effective features, followed by a Genetic Algorithm-Support Vector Machine (GA-SVM) classifier to classify cases. The experimental findings indicate the proposed methodology's capability to classify COVID-19 and NOT COVID-19 of varying ages and speaking different languages, as demonstrated in the simulations. The proposed methodology depends on deep features, followed by the dimension reduction technique for features to detect COVID-19. As a result, it produces better and more consistent performance than handcrafted features used in previous studies.

• Korean Journal of Schizophrenia Research
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• v.22 no.2
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• pp.51-55
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• 2019

Objectives: Late-onset schizophrenia (LOS, age at first onset ≥40 years) is characterized by including predominance of women, better premorbid social adjustment and lower severity of positive/negative symptoms. However, few studies have been conducted on LOS, especially in Asian countries. This study aimed to examine the clinical features of LOS in comparison with early-onset schizophrenia (EOS). Methods: By retrospectively reviewing medical records, we assessed demographic data and clinical features of 76 LOS (20 males) and 357 EOS (144 males) who admitted to the psychiatric ward of a general hospital. Results: The mean ages of onset were 47.3±5.1 (LOS) and 25.7±6.5 (EOS) years. There were significantly more women in LOS (73.7%) than EOS (59.6%). Significantly more LOS patients had a marital (88.2% vs. 25.8%) and employment history (28.9% vs. 13.1%) than EOS. Patients with LOS had fewer negative (14.3±9.0 vs. 19.9±9.3), general psychopathology score (36.9±11.1 vs. 42.3±13.9) than EOS patients. Conclusion: In line with previous studies, this study demonstrated that LOS patients have better premorbid social adjustment. Our finding also replicates previous findings that LOS patients differ from EOS in predominance of women and relative lack of negative symptoms. These results suggest that LOS may be a distinct subtype of schizophrenia.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.665-676
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• 1994

The purpose of this study is to observe the longitudinal changes in BMI (Body Mass Index) of obese and non-obese 3rd. grade high school students in Seoul for 12 years and to see the trends of overt weight gain in obese adolescents. The results are as follows; 1. The average annual increasing rates of body mass Indices in male students were $1.14kg/m^2$ in obese group and $0.59kg/m^2$ in non-obese group. In female students, the average annual increasing rates of body mass indices were $0.93kg/m^2$ in obese group and $0.53kg/m^2$ in non-obese group. 2. The change rate of BMI for 12 years was significantly higher in obese group than non-obese group. 3. Puberty had less influence on the change rate of BMI in obese group compared to non-obese group. 4. In obese group, 71.8% of the variance in BMI at 17 can be predicted by BMI at 16 years in male students. In female students 44.4% can be predicted by BMI at age 16. 5. Among the 17-year-old obese students, 58.8% of the males and 56.2% of females were found not to have been obese at 7 years of age. 6. Among the 17-year-old obese students, those who were obese at 7 years of age were found to have higher BMI at later ages than those who were in the non-obese group. Obese adolescents were more likely to be obese in their childhood than non-obese group. There was no optimal age for the significant weight gain and the increasing rate of BMI was constantly higher in obese group than in non-obese group. Due to the fact that child obesity in early age contributes to obesity in adolescence, close observation is advised. On the other hand, a large proportion of obese adolescents can be preventable by early interventions, because about 50% of obese adolescents were not obese in early elementary school age.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.426-433
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• 2009

Background: Remarkable progress has recently been made in achieving successful early repair of congenital heart disease with using cardiopulmonary bypass in the neonatal period. The aim of this study is to evaluate our short-term outcomes for performing neonatal cardiac surgery under extracorporeal circulation. Material and Method: Fifty five neonates underwent open heart surgery from February 2002 to December 2007. The mean ages and body weight was 13.5 days. and 3.2 kg, respectively. The diagnoses of the patients were transposition of the great arteries (14), total anomalous pulmonary venous connection (7), large ventricular septal defect (VSD) (7), coarotation of the aorta with VSD (6), interrupted aortic arch (5) and others (16). Result: Six patients had difficulties being weaned from extracorporeal circulation. Four patients left the operating room with an open sternum. Low cardiac output syndrome and acute renal insufficiency were observed in 3 patients each, respectively. Post-operative complications were observed in 27 patients (49.1%). The postoperative mortality was 12.7% (7 patients); 5 patients experienced early hospital death and 2 experienced late death (2). Conclusion: In our hospital, early surgical repair with extracorporeal circulation in neonates was feasible with tolerable mortality. Further follow-up required to establish the long-term survival and complications.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.349-356
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• 2016

This report presents the results of an investigation on the early strength development of pastes high volume slag cement (HVSC) activated with different concentration of sodium carbonate ($Na_2CO_3$). The ordinary Portland cement (OPC) was replaced by ground granulated blast furnace slag (GGBFS) from 50% to 90% by mass, the dry powders were blended before the paste mixing. The $Na_2CO_3$ was added at 0, 2, 4, 6, 8 and 10% by total binder (OPC+GGBFS) weight. A constant water-to-binder ratio (w/b)=0.45 was used for all mixtures. The research carried out the compressive strength, ultrasonic pulse velocity (UPV), water absorption and X-ray diffraction (XRD) analysis at early ages(1 and 3 days). The incase of mixtures, V5 (50% OPC + 50% GGBFS), V6 (40% OPC + 60% GGBFS) and V7 (30% OPC + 70% GGBFS) specimens with 6% $Na_2CO_3$, V8 (20% OPC + 80% GGBFS) and V9 (10% OPC + 90% GGBFS) specimens with 10% $Na_2CO_3$ showed the maximum strength development. The results of UPV and water absorption showed a similar tendency to the strength properties. The XRD analysis of specimens indicated that the hydration products formed in samples were CSH and calcite phases.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.279-279
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• 2017

In Korea, the single span unheated plastic house cultivated crops from autumn to spring of the following year, removed the plastic film and frame, cultivated rice, set up a plastic house again and cultivated crops. The crops in the greenhouse are utilized mainly for the production of leaf vegetables such as lettuce, leek, and fruit vegetables such as strawberry, watermelon, oriental melon, etc. and raising high income. Because, the production of these crops has characteristics requiring a lot of labor and it is difficult to produce horticultural crops at unheated plastic houses as the rural population ages. Therefore, we conducted a test to develop a crop planting system to cultivate crops in single span unheated plastic houses, although the utilization of labor is less than that of horticultural crops. The prior cropping cultivated three cultivars of sweet potatoes early, the second produced cultivated sweet potatoes, corn and soybeans. In the cultivation of the previous cropping, the sweet potatoes were harvested on the 113th day after planting on March 30th, the yield was 822 kg/10a for Pungwonmi, 1,377 kg/10a for Jinhongmi, 1,483 kg/10a for the Dahomi. Because of differences, the yield of Pungwonmi cultivar was less than that other cultivars and the yield of open field cultivations, we will expect further research. In the cultivation of the succeeding crops sweet potatoes were planted on July 27 and harvested 110 days later and investigated. The product yield of Pungwonmi cultivar was 1,024 kg/10a, and the Jinhongmi, Dahomi cultivars were not at economic level for sale and were necessary to review. In succeeding-crops, corn tested the Ilmichal cultivar, seeded on 27th July, harvested on October 11th. The day of silking was 45 days after sowing, the yield was 1,156 kg/10a, the goods rate was 100% level. The beans in the succeeding cultivation crop were sowed on 27th July, the early maturing of the varieties coming to Hwangeumol and Saeol cultivar, on 17th October, the late maturing soybean Daewonkong cultivar were harvested on October 21st. The yield of early maturing two cultivars was 214 kg/10a, Daewonkong was 257 kg/10a, and 100 seeds weight which were more than the early maturing beans were also heavy. When calculating these incomes price-wise according to the harvest time, we were able to consider the income in the order of corn, sweet potato and soybean from the second term crop. Various studies such as varieties, mulching method, moisture management, control environment management, etc. are considered necessary to develop cropping systems with sweet potato and field crops in future unheated plastic house.

• Journal of Music and Human Behavior
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• v.2 no.1
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• pp.47-65
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• 2005

One of important goals for early childhood music learning program is to build a positive attitude toward music. Positive attitude toward music is a basic condition on effective music education for all ages of children including early childhood. Although scholars realize such importance of positive music attitude, much research for creating educational environment to foster a positive music attitude has not been performed. Edwin E. Gordon who found a music learning theory for early childhood emphasized the importance of enriched musical environment. Very young children should be provided best quality of music in an interactive way. Audie's important method of education is to provide young children with a variety of musical activities containing the materials in the ordinary life. Through this method, children accept music as close as friends who are always beside themselves, which naturally builds a solid foundation for audiation for children.