• International Journal of Oral Biology
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• v.33 no.2
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• pp.59-64
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• 2008

This study was designed to investigate the changes in the properties of the neuronal setm cells or progenitor cells associated with age-related decline in neurogenesis of the hippocampal dentate gyrus (DG). Active whole cells cycle marker Ki67 (a marker of whole cell cycle)-positive and S phase marker bromodeoxyuridine (BrdU)-positive. Neural stem cells gradually were reduced in the hippocampal subgranular zone (SGZ) in an age-dependant manner after birth (from P1 month to P1 year). The ratio of BrdUpositivecells/Ki67-positive cells was gradually enhanced in an age-dependent manner. The ratio of Ki67-positive cells/accu-mulating BrdU-positive cells at 3 hrs after BrdU injection was injected once a day for consecutive 5 days gradually decreased during ageing. TUNEL- and caspase 3 (apoptotic terminal caspase)-positive cells gradually decreased in the dentate SGZ during ageing and immunohistochemical findings of glial fibrillary acid protein (GFAP) were not changed during ageing. NeuN, a marker of mature neural cells, and BrdU-double positive cells gradually decreased in an age-dependent manner but differentiating ratio and survival rate of cells were not changed at 4 wks after BrdU injection once a day for consecutive 5 days. The number of BrdU-positive cells migrated from the hippocampal SGZ into granular layer and its migration speed was gradually declined during ageing. These results suggest that the adult neurogenesis in the mouse hippocampal DG gradually decrease through reducing proliferation of neural stem cells accompanying with cells cycle change and reduced cells migration rather than changes of differentiation.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.75-82
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• 1996

Object : The aim of this study was to evaluate the changes of positive stmtoms. negative symptoms, and depressive symptoms after fluoxetine trial in haloperidol-stabilized schizophrenic in-patients. Method : Fluoxetine(20mg/day) was added for 6weeks to stable doses of haloperidol given to 32 schizophrenic in-patients. The subjects was divided into positive and negative schizophrenics by PANSS. The authors checked PANSS. HRSD at baseline, the 2nd week. the 4th week, the 6th week of treatment. Result were as follows : 1) In all subjects, positive and depressive symptoms were significantly improved. 2) As time went on, positive and negative symptoms were not significantly improved in positive and negative schizophrenics. 3) As time went on, depressive symptoms were not significantly improved in positive and negative schizophrenics. Conclusion : We suggested that fluoxetine may be useful in the treatment of positive symptoms in schizophrenia and, It may be due to the effect on the serotonin system and the interaction between serotonin and dopamine system.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.129-134
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• 2008

The purpose of this study was to find out older adults' current uses, satisfaction level and life changes by using digital home services. The study collected data from 140 persons who were 55 years and older living in a digital home. The uses and attitude of digital home services by older adults turned out to be the important variables that led to their positive life changes. For older adults, various ideas to expand their understanding of digital home services should be developed to increase the positive life changes.

• Journal of People, Plants, and Environment
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• v.23 no.3
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• pp.321-332
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• 2020

Background and objective: The concept of 'money' in the numbers and operations domain is a fundamentally necessary domain of economic life. This study was conducted to examine the effects of a horticulture-mathematics integration program on mathematical attitude and money calculating ability of high school students with intellectual disabilities. Methods: We analyzed the changes in the mathematical attitude and money calculating ability of students with mild intellectual disabilities in S special school in the city of D, Republic of Korea, with 12 students in the control group and 12 students in the experimental group, from August 27 to October 29, 2019. Results: The results of the comparison showed no statistically significant changes in the three items of mathematical attitude for the control group, while the experimental group, which took part in the horticulture-mathematics integration program, showed statistically significant differences across all three items, such as self-concept about the subject (p = .003), attitude toward the subject (p = .004), and study habit related to the subject (p = .012). The horticulture-mathematics integration program, which was developed by integrating horticultural activities and the mathematics curriculum, used plants and horticultural activities to provide students with positive experiences in mathematics. These included the sense of closeness, curiosity, interest, attention, and enjoyment, leading to positive changes in mathematical attitude. In terms of money calculating ability, both the control group and experimental group showed statistical differences across the three items, but the experimental group showed greater degrees of increase, 15.0 or more, in the scores compared to the control group. Conclusion: These results suggest that utilizing horticultural materials as a part of purchase learning programs with elements of money calculation chapters in the mathematics curriculum could lead to the improvement of students' ability in money calculation. These positive changes are thought to be related to the high degrees of interest in horticulture among students, which led to active participation in the program and enabled the simple and repeated purchase activities in the program to generate positive changes in the money calculation ability of the students.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.992-996
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• 2008

In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.821-827
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• 2001

In this study performed to identify a degradation mechanism in macromolecular insulating material, the contact angel, surface potential decay, surface resistivity, and XPS analysis were compared after exposure of FRP laminate to plasma discharge. In the case of contact angle, the surface of specimen untreated showed weak hydrophobic property of 73。. However, the contact angle was decreased to 20。in the plasma-treated specimen. In the case of chemical changes arising form plasma treatment, carboxl radicals were generated mainly in the surface treated, which was rapidly changed to the hydrophilic one. In the corona potential decay study to determine the electrical changes of the surface, positive charges were rapidly decreased when compared with negative charges, leading to negative property in the surface of specimen not treated. However, in the case of the hydrophilic surface, lots of carboxl radicals acting as positive polarity were generated, resulting in positive surface. Owing to such positive surface, charges of negative polarity applied were rapidly decreased.

• Journal of the Korean Home Economics Association
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• v.49 no.3
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• pp.55-66
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• 2011

The purpose of this study was to examine the effects of We Start home visiting intervention program on the positive changes of infants and their low-income families. The subjects were 171 18~36-month olds and their mothers living in We Start and non We Start areas. The instruments used were Developmental Profile, Cleminshaw-Guidubaldi Parent Satisfaction Scale(CGPSS) and Home Observation for Measurement of the Environment(HOME). The results were as follows: First, the result of Developmental Profile showed positive changes in all domains(physical development, self-help skills, social development, cognitive development, and communication ability). Second, the result of CGPSS showed positive effects on parent-child relationships. Third, the result of HOME showed positive effects on mothers' emotional and language responses. In conclusion, We Start home visiting program for infants from low-income families is an effective early intervention program to end intergenerational transition of poverty in Korea.

• Carbon letters
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• v.12 no.2
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• pp.107-111
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• 2011

Polyacrylonitrile (PAN) fibers were pre-oxidized in a temperature range of 180-275$^{\circ}C$. The effects of positive and negative stretching on the structure and morphology of PAN fiber in the pre-oxidation process were studied by FTIR spectroscopy, XRD, and SEM. Mechanical property changes were also investigated. No changes in the movement and intensity of functional groups of PAN fibers were caused by positive stretching of up to 10% and negative stretching down to -8%. The crystal structure can be affected by the positive stretching and negative stretching. The maximum strength is 479.81 MPa when the stretching is positive, and the maximum strength is 420.55 MPa when the stretching is negative.

• Human Ecology Research
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• v.61 no.1
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• pp.29-38
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• 2023

This study examined changes in dietary life and dietary life satisfaction in one-person households during the COVID-19 pandemic. Using a sample of 916 one-person households from the Food Consumption Behavior Survey, we applied ANOVA and a system of equations model for our analysis which produced four main results. Firstly, during the COVID-19 pandemic, eating homemade and delivered meals increased, whereas eating restaurant, group, and HMR meals decreased. Eating breakfast and regular eating habits also increased during the pandemic. Secondly, approximately 30% of the sample reported increased expenditure on fresh food and HMR meals. The proportion of positive changes in dietary life was also greater than negative changes, and dietary life satisfaction was about three times higher than it had been before the pandemic. Thirdly, having breakfast and regular eating fully mediated the relationship between spending on fresh food and dietary life satisfaction, as well as the relationship between HMR purchases and dietary life satisfaction. Changes in expenditure on fresh food and HMR meals positively affected dietary life satisfaction through eating breakfast and regular eating. Fourthly, increased consumption of delivered food had a positive direct effect on dietary life satisfaction. Among sociodemographic variables, gender, education, occupation, and age were also significantly related to changes in dietary life satisfaction.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.163-163
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• 2023

Flooding has become an increasing event which is one of the major natural disasters responsible for direct economic damage in South Korea. Driven by climate change, precipitation extremes play significant role on the flood damage and its further increase is expected to exacerbate the socioeconomic impact in the country. However, the empirical evidence associating changes in precipitation extremes to the historical flood damage is limited. Thus, there is a need to assess the causal relationship between changes in precipitation extremes and flood damage, especially in agricultural region like Chungcheong region in South Korea. The spatial and temporal changes of precipitation extremes from 10 synoptic stations based on daily precipitation data were analyzed using the ClimPACT2 tool and Mann-Kendall test. The four precipitation extreme indices consisting of consecutive wet days (CWD), number of very heavy precipitation wet days (R30 mm), maximum 1-day precipitation amount (Rx1day), and simple daily precipitation intensity (SDII), which represent changes in intensity, frequency, and duration, respectively, and the time series data on flooded area and flood damage from 1985 to 2020 were used to investigate the causal relationship in the ARDL-ECM framework and pairwise Granger causality analysis. The trend results showed that majority of the precipitation indices indicated positive trends, however, CWD showed no significant changes. ARDL-ECM framework showed that there was a long-run relationship among the variables. Further analysis on the empirical results showed that flooded area and Rx1day have significant positive impacts on the flood damage in both short and long-runs while R30 mm only indicated significant positive impact in the short-run, both in the current period, which implies that an increase in flooded area, Rx1day, and R30 mm will cause an increase in the flood damage. The pairwise Granger analysis showed unidirectional causality from the flooded area, R30 mm, Rx1day, and SDII to flood damage. Thus, these precipitation indices could be useful as indicators of pluvial flood damage in Chungcheong region of South Korea.