• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.23 no.1
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• pp.20-31
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• 2018

Marine parasitoid Amoebophrya infects and kills various bloom-forming dinoflagellates and strongly influences the harmful algal bloom dynamics. We investigated the effect of temperature on survival, infectivity, generation time of the parasite from the parasitoid Amoebophrya sp. and the harmful dinoflagellate host Akashiwo sanguinea system. Temperature had a significant effect on the parasite generation time and infectivity. While the lower temperature ($15^{\circ}C$) arrested parasite intracellular development and infectivity, resulting in the longer generation time ($115{\pm}0.1h$), the higher temperatures ($25^{\circ}C$ and $20^{\circ}C$) accelerated the parasite development, with the generation times of $58{\pm}0.1h$ and $83{\pm}0.1h$, respectively. Parasite prevalence (percent of host infected) was $71.5{\pm}0.30%$, $54.3{\pm}1.68%$, and $29.6{\pm}1.42%$ at $25^{\circ}C$, $20^{\circ}C$, and $15^{\circ}C$, respectively. These results suggest that biological control by parasitism on A. sanguinea bloom would not be highly effective during low water temperature season. Further, water temperature would be an important factor of bottom-up controls for the host-parasite population dynamics.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.125-129
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• 2020

In this study we developed a method for determining the geographic origin of soybeans by combining energy dispersive X-ray fluorescence spectrometry with statistical analysis. In 2018, 197 soybean samples (100 Korean domestic samples and 97 foreign samples) were collected for the construction of a geographic origin model. The mineral concentrations of 26 elements were measured and determined via the fundamental parameters approach. One-way analysis of variance, t-test, and canonical discriminant analysis were employed to reveal five elements (P, Ni, Br, Zn, and Mn) that could be used for the determination of geographic origins. The sensitivity, specificity, and efficiency for the above method were 91.0, 95.9, and 93.4%, respectively. Validation results from 60 samples collected in 2019 showed a predictive rate of 93.3% for Korean domestic soybeans and 100.0% for foreign soybeans. In conclusion, the combination of energy dispersive X-ray fluorescence spectrometry and chemometrics could be used to effectively determine the geographic origin of soybeans.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.329-339
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• 2016

The purpose of this study was to investigate the level of job stress and organizational commitment, as well as to identify the factors that influence patient safety management activities among the operating room nurses. Participants were 136 nurses working at 1 university hospital and 9 general hospitals located in G metropolitan city. The data were collected between July 25 and August 7, 2014 using structured questionnaires. Data were analyzed by descriptive statistics, t-test, one-way ANOVA, Pearson's correlation, and multiple regression analysis using SPSS version 21.0. The level of job stress, organizational commitment, and patient safety management activities was 3.76, 3.09, and 4.15, respectively, out of a 5-point scale. Patient safety management activities were significantly correlated with organizational commitment. The significant factors that influence patient safety management activities were organizational commitment and number of patient safety education, which explained 23% of patient safety management activities. In conclusion, organizational commitment and patient safety education have a positive effect on the improvement of patient safety management activities of operating room nurses. It is necessary to develop various intervention programs for operating room nurses to improve organizational commitment and should be reinforced via continuous, systematic patient safety education on patient safety management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.111-117
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• 2017

This study examined the material properties of Korean rice husk ash (RHA) according to the manufacturing process, and evaluated the feasibility of its use as a new admixture for high strength concrete. For this purpose, its particle size distribution, chemical composition, and microstructure were analyzed under various parameters, such as calcination temperature ($400^{\circ}C$, $650^{\circ}C$, and $900^{\circ}C$) and the inclusion of a milling process. X-ray fluorescence analysis confirmed that the silicon oxide ($SiO_2$) content of RHA was improved to more than 92% with a calcination process at $650^{\circ}C$ or higher. In addition, microstructural analysis showed that the RHA calcined at $650^{\circ}C$ has a porous structure. Because of this, the absorption capacity of the RHA was improved. On the other hand, when the milling process was applied, the porous structure was destroyed; thus, the absorption capacity tended to decrease further. Based on the analysis results, it was concluded that RHA calcined at $650^{\circ}C$ can be used as an admixture for high strength concrete, which possesses functions of both a shrinkage reducing agent and a pozzolanic activator.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.380-390
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• 2017

This study examined the relationship between social support, social participation and physical functioning among older adults in community senior centers. The subjects of this study were 194 persons aged 60 years or older who participated in the senior center in K province and D city, from June 16 to June 30, 2016. The collected data were analyzed using descriptive statistics, T-test, one way ANOVA, Pearson correlation analysis, multiple regression analysis, and structural model analysis using IBM SPSS Statistics 23.0 and IBM AMOS 21.0. The result showed that the social support and physical functioning of the elderly in the community were above normal, and social participation was somewhat low. Interestingly, an analysis of the physical functioning between social support, social participation and depression revealed significant correlations. The factors affecting the physical health were 23.4% of the respondents who had a significant influence on social support and leisure activities. In addition, the result of structural model analysis showed that social support had a significant influence on the social participation, depression and physical functioning. Therefore, the results suggests that the development of educational programs and an age-friendly environment should be actively provided to older adults in the community by strengthening the physical function through social support for active ageing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.576-584
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• 2017

Traffic demand prediction result is a primary factor for decision making such as the traffic planning and operation. The existing traffic demand prediction 4-step model only covers the trip between the origin and the destination, and not the demand followed by the accessibility improvement, due to the characteristic of this model. Therefore, the purpose of this research is to improve the limitations of the existing model by developing the inter-city trip generation and trip distribution model with more accessibility. After calculating of the trip generation and trip distribution model with more accessibility, the sign of the accessibility coefficient was positive. Commuting was the most insensitive indicator, affected by external factors among the other trip purposes. The leisure trip was the most sensitive, affected by the trip fee. According to the result of comparison with each of estimated model and observational data, it was certain that the reliability and assumption of the model have been improved by discovering the reduced weighted average error rate, Root Mean Square Error (RMSE) and total error through the model with more accessibility compared with the existing one.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.80-86
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• 2012

This study is about selecting Landscape Viewpoint on Bukchon Hanok Village, Jongno-Gu, Seoul. The process on selecting photo spots was focused on visualizing elements, and it was hard to find an objective standard for selecting landscape viewpoint. Therefore, by literature review and site study, this study selects more objective and empirical Landscape View Point on Bukchon. Landscape Viewpoint Standards are Traditional Hanok Landscape, Historical Heritage Landscape, Alley Street Landscape, City Architecture Landscape, and Natural Forest Landscape. By Landscape Preference and Character of Place survey, this study finds out another Landscape Viewpoint and correlation of those variables. A coefficient of correlation is 0.846, and its correlation is considerably high. Through this result, it could provide a concrete standard for selecting Landscape View Point and a preliminary information for finding Landscape View Point on Histo-Cultural area.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.756-766
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• 2001

A phytosociological study on the community structure was carried out in the evergreen broad-leaved forests around Baegunbong area in Wando from June to August, 2000. A total of 31 plots, the size of which was $10m{\times}30m$, were set up in the study area. Cluster analysis for the total 54 tree species appearing in the 31 plots, showed that forest community cloud be classified into 5 groups, such as : Quercus acuta community, Quercus acuta-Camellia japonica community, Quercus acuta-Deciduous broad-leaved tree species community, Quercus acuta-Evergreen Deciduous broad-leaved tree species community, Quereus acuta-Carpinus tschonoskii community. The species of high appearance frequency ratio in 31 plots were Quercus acuta, Camellia japonica, Styrax japonica, Eurya japonica, Ligustrum japonicum, Cinnamomum japonicum, Sapium japonicum and Acer psuedo-sieboldianum. Dominant tree species were covered with Quercus acuta, Styrax japonica, Prunus sargentii, Carpinus laxiflora and Quercus serrata, and Quercus acuta, Camellia japonica, Eurya japonica, Ligustrum japonicum, Cinnamomum japonicum and Sapium japonicum at sub-canopy. The forest vegetation in the surveyed area except the summit of Baegunbong will be proceeding with Quercus acuta community. The species diversity of Quercus acuta community, Quercus acuta-Camellia japonica community, Quercus acuta-Deciduous broad-leaved tree species community, Quercus acuta-Evergreen Deciduous broad-leaved tree species community, and Quercus acuta-Carpinus tschonoskii community were 0.687, 0.866, 0.933, 0.966, and 1.018, respectively. The species diversity of Quercus acuta community was rather low.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.85-93
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• 2015

Previous studies have estimated crash prediction models with the fixed effect model which assumes the fixed value of coefficients without considering characteristics of each intersections. However the fixed effect model would estimate under estimation of the standard error resulted in over estimation of t-value. In order to overcome these shortcomings, the random effect model can be used with considering heterogeneity of AADT, geometric information and unobserved factors. In this study, data collections from 89 intersections in Daejeon and estimates of crash prediction models were conducted using the random and fixed effect negative binomial regression model for comparison and analysis of two models. As a result of model estimates, AADT, speed limits, number of lanes, exclusive right turn pockets and front traffic signal were found to be significant. For comparing statistical significance of two models, the random effect model could be better statistical significance with -1537.802 of log-likelihood at convergence comparing with -1691.327 for the fixed effect model. Also likelihood ration value was computed as 0.279 for the random effect model and 0.207 for the fixed effect model. This mean that the random effect model can be improved for statistical significance of models comparing with the fixed effect model.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.36-49
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• 2016

A subway system is one of the major transportation modes at a metropolitan area. When it meets the other lines, the metro station, so-called transferring station, is usually threatened by severe pedestrian congestion and safety issue of transit users including the transportation vulnerable. Although transportation planners forecast travel demand at the beginning, it is not easy to predict pedestrian flows precisely for a long term if land use plans have dramatically changed. Due to expensive costs, structural extension of metro stations is limited. Therefore, it requires efficient and technical improvements as meeting the demand of pedestrian and physical characteristics. In this study, the core mechanism of pedestrian movement-based simulation model was introduced and evacuation scenarios were analyzed with the developed model. As a result, the multiple optimal routes for unexpected events at the solid space of the multiple stories are easily searched through the simulator and in the case of Sadang Station, travel time can be reduced by 60% when the evacuation information and intuitive design are provided.