• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.293-305
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• 2019

In this study we investigated the effect of a floating photovoltaic (FPV) system in Cheongpung Lake on water quality. The FPV with a tilt angle of 33° covered ca. 0.04% of surface area (97 ㎢) of Chungju Lake. The water qualities of the whole lake before and after installation of FPV were first compared. DO, BOD, TOC, and Chl-a of the whole lake were increased, while conductivity decreased after installation period at the significance level of 0.05. This change was probably due to the increased influx of nutrients by 40% resulting from increased precipitation during the same period. We also measured water quality parameters on May and Nov. 2017 at the FPV center (FPVC) and nearby control sites, and compared water quality. The result showed that the FPVC and nearby sites were not significantly different (p>0.05), demonstrating that the FPV does not cause a decline of water quality. The water temperature, light intensity, and phytoplankton community were also measured. The water temperature was not different between the sites, while the light intensity decreased to 27~50%. Despite reduced light intensity at FPVC, the phytoplankton standing crops and the number of species were not significantly different (p>0.05). However, in the early November samples, standing crops was significantly higher in FPVC than control with periphytic diatoms belonging to Aulacoseira genus being dominant. This may be due to the temporal water body behavior or local retention of current by FPV system. This study may provide a measure of future installation of a FPV system.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.201-210
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• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mats. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributons. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks dial not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the $K_{I}$ vague increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.s.

• Journal of Music and Human Behavior
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• v.14 no.2
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• pp.1-18
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• 2017

The relationships between the ability to understand changes in meaning depending on the prosody of spoken words and the ability to perceive pitch and melodic contour in cochlear implants (CI) recipients were examined. Fifteen postlingual CI recipients were measured in terms of speech prosody perception, speech perception, pitch discrimination (PD), and melody contour identification (MCI). The speech prosody perception test consists of words with positive (PW) and neutral meaning (NW). Participants were asked to identify the meaning of words depending on the conditions of positive and negative prosody. The MCI consists of subtests 1 and 2 with different chance levels to choose. Then, the relationships between speech prosody perception, speech perception, PD, and MCI performance were analyzed. There was a significant difference in identifying the meaning of words expressed in a different prosody between the PW and NW conditions. Speech prosody perception showed a significant correlation with MCI 1 while there was no significant relationship with speech perception. Although speech perception may be possible after CI, limited spoken word comprehension due to decreased sensitivity for prosodic changes may persist in CI recipients. In addition, there was a limitation in perception of melodic contour change compared to pitch discrimination, which is related to speech prosody perception.

• Journal of dental hygiene science
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• v.10 no.5
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• pp.379-385
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• 2010

The purpose of this study was to examine the oral health knowledge and oral health practice of teachers in early childhood education institutions. The subjects in this study were 169 teachers who worked in early childhood education institutions. After a survey was conducted, the collected data were analyzed with a SPSSWIN 14.0 program. The findings of the study were as follows: 1. Concerning oral health knowledge, they got a mean of 7.97(9), 2.66(3), 2.86(5), 2.42(5) and 1.04(2) respectively in knowledge on dental caries, toothbrushing, periodontitis, fluoride and diet. Overall, they got a mean of 16.98 in 24 items, and the score corresponded to approximately 70 out of 100 points. 2. As for oral health practice, tongue cleaning(4.22) was what they did the most to take care of their oral health, and they just got 2.60 in regular dental checkup. Overall, they got about 3.11 in oral health practice. 3. Regarding relationship between general characteristics and oral health knowledge, the teachers who were in their 30s got 17.47 in overall oral health knowledge, and those with a career of five to less than 10 years got 17.50. The teachers who received college or higher education got 17.27, and the principals got 18.26. Those who had ever received education on oral health got 17.01. But the gaps between them and the others were not statistically significant. 4. As to connections between general characteristics including age and oral health practice, restricted sugar intake, regular dental checkup, the use of oral hygiene supplies, tongue cleaning and overall oral health practice were more prevailing among the older teachers, and the gaps between them and the younger teachers were statistically significant. 5. In terms of relationship between oral health knowledge and oral health practice, there was no statistically significant relationship between the two on the whole, but better oral health knowledge led to better oral health practice in each part. This study shows that various oral health education programs for the kindergarten teachers should be developed and continuous education through the programs is important to improve the knowledge of oral health and to change oral health behavior.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.1
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• pp.59-73
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• 2023

Objective : To examine changes in participation patterns of children with Autism Spectrum Disorder (ASD) in play activities during COVID-19 by reviewing relevant literature. Methods : This scoping review was conducted via five steps. we created a research question and searched for relevant literature published in English through CINAHL, PubMed, ERIC, MEDLINE, Google Scholar and Google search engine. After selecting the literature based on inclusion criteria, data were charted based on 10 items (i.e., author name, journal name, publication year, nation, authors' majors, research method, participant' age and gender as well as quantitative and qualitative results of study). The results were analyzed using descriptive numerical and thematic analyses. Results : After reviewing 437 articles and 152 websites, six articles were included. Theses articles were conducted by experts from various fields and countries. Five themes were highlighted in selected articles: COVID-19 resulted in (1) decreased time of outdoor play, (2) increased play time on screen, (3) increased time spent with family, (4) increased sensory difficulties, and (5) recommendations for services for children with disabilities and during COVID-19. Conclusion : This study suggests telerehabilitation programs about parental behavior strategies in order to solve difficulties in which children with ASD may experience when participating in play activities during disasters. Study results can be used as fundamental evidence to emphasize importance of play activities and to systematize role of occupational therapists and service guidelines for supporting play activities of children with disabilities in disasters.

• Journal of Venture Innovation
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• v.3 no.2
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• pp.1-21
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• 2020

Recently, the emergence of new technologies caused by the Fourth Industrial Revolution caused a great change not only in the overall society but also in the retail industry. In the retail industry, unmanned stores based on new technologies have emerged, changing the consumption behavior of consumers. In particular, the global pandemic caused by COVID-19, which appeared in December 2019, raised social risks, and as a result of this, the beginning of the non-face-to-face era, interest in unmanned stores is increasing. In this study, the effects of benefits factors (perceived usefulness, perceived economics, perceived enjoyment, relative advantages) and sacrifice factors (perceived risk, technicality) perceived by unmanned store users on continuous use intention through perceived value. In addition, it is a study to test through empirical analysis what role the social risk from COVID-19 plays in the process of consumption through unmanned stores. The purpose of this study is to provide strategic implications for the activation of unmanned stores in the non-face-to-face era. In this study, a total of 293 copies of data were collected for users of unmanned stores for hypothesis testing. In addition, the collected data was analyzed using SPSS 21.0 and AMOS 21.0 statistical programs. The results of the study are summarized as follows. First, it was found that the perceived benefits (perceived usefulness, perceived economics, perceived playfulness, and relative advantages) of unmanned stores all had a significant positive effect on perceived value. Second, it was found that all perceived sacrifices (perceived risk, technicality) of unmanned stores had a significant negative effect on perceived value. Third, it was found that the perceived value of unmanned stores had a significant positive effect on the intention to continue use. Finally, the social risk from COVID-19 has been shown to play a moderating role when the perceived sacrifice of unmanned stores affects the perceived value.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.403-411
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• 2012

Acoustic telemetry is used to obtain a relatively continuous record of fish movement. This method has several advantages for studying migrating fish populations that are moving from large rivers. The Nakdong River is the longest river in South Korea and the main stream has faced a change, which consists of the installation of the large weirs. In this study, we applied acoustic telemetry to monitor the movement pattern of Erythroculter erythropterus (family Cyprinidae) and identified home range and movement distance in the Nakdong River. A total of fourteen individuals were released at three different locations and around 80 km section from the estuary barrage was investigated. Eight individuals were tagged and released at estuary barrage (N02) utilized up to 15.9 km (home range) upstream from the release site as home range. Four individuals were tagged and released at Samrangjin (N07), most fish moved and stayed within 9.7 km (home range) downstream area, except E12, which did not show any movement. Two individuals were tagged and released at Changnyeong-Haman weir (N10), and all individuals migrated downstream from the release site. Especially, E14 recorded the longest accumulated detected distance, 36.7 km downstream during 32 days after release. There was no correlation identified between movement (accumulated detected distance and home range) and standard length (Spearman rank correlation, p>0.05). Although, this technique could be an available method to monitor behavior and ecology of freshwater fish effectively, increment of number of receivers and tags are required for more detailed results of fish migration.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.447-456
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• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mass. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributions. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks did not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the K$_1$ value increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1366-1374
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• 2016

Most elderly have difficulties in managing food safety and nutrition by themselves. Various nutrition educations for the elderly have been developed, but food safety and nutrition education program and educational tools for the elderly are very limited. The aim of the study was to evaluate a food safety and nutrition education program based on the Health Belief Model (HBM) for the elderly. Education program was implemented for 220 seniors (137 educated group and 83 control group) aged over 65 years at senior welfare community centers. The intervention study was carried out on a weekly basis during each of 5 weeks, and each session lasted about 35 or 40 minutes. The effectiveness of the program was assessed with a questionnaire before and after education. Education program consisted of a 5 week program, and topics were 'Dietary changes for the elderly's healthy life', 'Prevention of food poisoning in everyday life', 'Safe food handling for my health', 'Healthy dietary life to prevent chronic disease', and 'Safety! nutrition! healthy dietary life'. Education program materials such as slides, handouts, videos, leaflet, and booklets were developed. As a result, there were score improvements in knowledge, dietary behaviors, and health belief after intervention in the intervention group, which were higher than those of the control group. In particular, there was a meaningful interrelation between dietary behavior and health belief (r=0.520, P<0.001). This finding suggests that changing beliefs is very important to make desirable dietary behavioral changes. For this reason, we can conclude HBM theory is an effective model to educate nutrition and food safety for the elderly. Furthermore, food safety and nutrition education programs are implemented and delivered continuously at various settings such as a health center or community welfare center, and those will contribute significantly to enhance perception and change their desirable dietary behaviors for the elderly.

• Journal of the Korean Geographical Society
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• v.43 no.5
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• pp.681-700
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• 2008

In this study, the spatial and temporal patterns of changes in means and extreme events of temperature and precipitation across the Republic of Korea over the last 35 years (1973-2007) are examined. Over the study period, meteorological winter (December-February) mean minimum (maximum) temperature has increased by $+0.54^{\circ}C$/decade ($+0.6^{\circ}C$/decade), while there have been no significant changes in meteorological summer (June-August) mean temperatures. According to analyses of upper or lower $10^{th}$ percentile-based extreme temperature indices, the annual frequency of cool nights (days) has decreased by -9.2 days/decade (-3.3 days/decade), while the annual frequency of warm nights (days) has increased by +4.9 days/decade (+6.8 days/decade). In contrast, the increase rates of summer warm nights (+8.0 days/$^{\circ}C$) and days (+6.6 days/$^{\circ}C$) relative to changes in summer means minimum and maximum temperatures means are greater than the decreasing rates of winter nights (-5.2 days/$^{\circ}C$) and days (-4.3 days/$^{\circ}C$) relative to changes in winter temperatures. These results demonstrate that seasonal and diurnal asymmetric changes in extreme temperature events have occurred. Moreover, annual total precipitation has increased by 85.5 mm/decade particularly in July and August, which led to the shift of a bimodal behavior of summer precipitation into a multi-modal structure. These changes have resulted from the intensification of heavy rainfall events above 40mm in recent decades, and spatially the statistically-significant increases in these heavy rainfall events are observed around the Taebaek mountain region.