• Korean Journal of Ecology and Environment
• /
• v.56 no.2
• /
• pp.161-171
• /
• 2023

The medium-large cladoceran species Simocephalus spp. predominantly occur in habitats with developed aquatic vegetation. Accordingly, due to Simocephalus' high contribution to zooplankton community biomass in the lake's littoral zone and wetland habitats, estimating their biomass is important to understand the matter cycling based on biological interactions within the aquatic food web. In this study, we reviewed the length-weight regression equations used previously to estimate Simocephalus biomass, directly measured S. serrulatus' body specification (length, width and area) and their biomass(dry weight) using instruments such as a microscopic digital camera and a microscale, and performed regression analysis between each other. When S. serrulatus biomass was estimated using the equation (Kawabata and Urabe, 1998) presented in 『Biomonitoring Survey and Assessment Manual』, Korea, errors between estimates and measures were relatively large compared to the S. serrulatus species-specific biomass estimate equation developed by Lemke and Benke (2003). In addition, both equations showed not only increasing trends in error (estimate-measure) with increasing S. serrulatus' body length, but also in error variance among similar-sized individuals. The results of regression analysis with dry weight by body specifications indicated that the most appropriate equation for estimating the biomass of S. serrulatus was derived from the width-dry weight exponential regression equation (R²=0.9555). The review and development study of such species-specific biomass estimation equations for zooplankton can be used as a tool to understand their role and function in aquatic ecosystem food webs.

• The Korean Journal of Franchise Management
• /
• v.3 no.1
• /
• pp.73-91
• /
• 2012

This study is in the purpose for the revitalization of traditional market as comparing to the relevancy between the central characteristics of a floating population going around for buying something or eating food and lots of small-sized businesses comprising of the commercial districts. The several traditional markets such as Cheonan station, Dujeong-dong, Sinbu-dong in Cheon-An city has been investigated repeatedly almost every two or three years by the Small Enterprise development Agency(SEDA) since 2001. By analyzing the raw data of those commercial districts made by SEDA, we can calculate the number of firms andthe ratio of business type of each commercial districts. In this research, the type of each business is classified into four groups such as restaurant, service, retail and the rest. Moreover, the central character of the floating population is derived from the raw data, which means the customer information about sex, age structure or the most populous time zones. From these characteristics, one commercial districts has his own specific features distinguishing from the others. The most important differences of past researches are firstly the dynamic viewpoint rather than a static one. Secondly it suggests that the relation between the central characteristics of districts and the floating population would exist. Lastly, it suggests that the interaction between both of them have a significant effect on the growth or decline of the districts and the rates of business type, other adjacent commercial districts as well. Eventually, this study provides several meaningful points for the revitalization of commercial districts to government or stakeholder such as management organization, business owners and new starter etc.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.6B
• /
• pp.689-694
• /
• 2006

The system performance of a bioactive foam reactor (BFR), that consists of a foam column using a surfactant and a biodegradation basin containing suspended bacteria, was investigated for the treatment of gaseous toluene or a mixture of four volatile organic compounds (VOCs, benzene, toluene, p-xylene, and styrene). Overall, the BFR achieved stable VOC removal efficiencies, indicating that it can be used as a potential alternative over conventional packed-bed biofilters. Furthermore, a dynamic loading test showed that relatively constant removal was maintained at the elevated loading due to a high mass transfer rate in the foam column. However, as the inlet concentration of VOCs increased, a portion of the VOCs mass-transferred to the liquid phase was stripped out from the biodegradation basin, resulting in a decrease in the overall removal efficiency. In the BFR, the removal efficiency of the individual VOC was mainly determined depending on the biodegradation rate (styrene > toluene > benzene > p-xylene), rather than the mass transfer rate. Consequently, increases in the microbial activity and the volume of the basin could improve the overall performance of the BFR system. Further investigation on microbial activity and community dynamics is required for the BFR when subjected to high loadings of VOC mixtures.

• The Korean Journal of Woman Psychology
• /
• v.13 no.3
• /
• pp.263-282
• /
• 2008

This study examined the mediating role of collective self-esteem in the relationship between personal self-esteem and career aspiration, and the mediating effects of personal self-esteem and collective self-esteem on the link between social support and career aspiration. Also, This study explored whether the development of career aspiration differs by gender. A total of 316 undergraduate students(155 male and 161 female) completed measures of social support, personal self-esteem, collective self-esteem and career aspiration. Structural equation modeling results provided support for the mediating effects of personal self-esteem and collective self-esteem, In addition, the relationship model differed by gender. The results showed that the full mediation model fit of collective self-esteem in the relationship between individual self-esteem and career aspiration was better than the partial mediation model fit. Next, in the relation of social support and career aspiration, the partial mediating effect of individual self-esteem and collective self esteem was significant. Lastly, when the model of social support, individual self-esteem, and collective self-esteem, and career aspiration was tested to examine gender differences, the relations among these variables were found to be different according to gender-difference. These results suggest that evaluations and perceptions on the individual's social group as well as the individual influedced to career aspiration, interacting with the environmental factors. Also, the gender-difference of relationship model indicates that it might be different from men and women in psychological mechanism in the career aspiration formation.

• Korean Journal of Culture and Social Issue
• /
• v.19 no.2
• /
• pp.109-131
• /
• 2013

It is expected that expanded use of smartphone and enhanced information technology will enable smartwork to change individuals and organizations. Smartwork is expected to allow people to perform their roles without barriers of time and space. However, people tend not to accept and actively utilize smartwork. The present study is to examine how important flexibility-willingness is for performance outcome in the context of smartwork. It was hypothesized that flexibility-willingness mediates between perceived smartwork usefulness and work-family conflict. It was also hypothesized based on technology acceptance model that task interdependence and process control moderates the relationship between flexibility-willingness and work-family conflict because the relationship is not consistent. The results show that the mediation effect of the flexibility-willingness is statistically significant. The moderator effects of task interdependence was marginal proved but process control wasn't. From these results, we discussed the theoretical implications of findings, limitations, suggestions for future research in discussion.

• Korean Journal of Culture and Social Issue
• /
• v.13 no.1
• /
• pp.1-41
• /
• 2007

This study examines factors that influence delinquent behavior among Korean adolescents using longitudinal analysis. A total of 1,012 students completed a questionnaire when they were Grade 6 and 739 students completed a follow-up questionnaire when they became Grade 9. Results of multiple regression analysis indicate that the following variables predicted delinquent behavior of Grade 9 students: Bullying, previous delinquency, experience of punishment, victimization, social efficacy, and moral disengagement. The above six variables have direct and mediating influence of delinquent behavior. Relational factors also influenced delinquent behavior. Social exclusion from friends reduce social efficacy, which increases victimization and which in turn increases bullying, leading to greater delinquency. Parental rejection, social exclusion from friends and hostility from teachers increase moral disengagement, which increases bullying, leading to delinquency. Low academic achievement increases the likelihood of being punished, which increases bullying, leading to delinquency. The results indicate that moral disengagement and social efficacy are mediating factors of delinquency and negative life-events (i.e., social exclusion from friends, rejection from teachers, hostility from parents and low academic achievement) increase the likelihood that Korean adolescents will engage in delinquent behavior. Implications of the results for future research are discussed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.5
• /
• pp.265-278
• /
• 2022

R&D projects for product development are crucial for ventures' growth and success. Current study summarizes existing studies that identify the relationship between startup ventures' R&D department, R&D investment, and R&D cooperation on product development performance, and highlights the effects of business model as well as the roles of R&D activities for product development project that have been traditionally emphasized. In order to consider the effects of business models that were not previously available, the effects of these factors on product development performance were comprehensively analyzed. The research results with 180 venture cases surveyed on venture companies in the growth stage in Korea, showed that the effect of product development project activities measured by R&D department, R&D investment and R&D cooperation on product development performance is not evident. However, the effect of business model on product development time and product development performance measured by product innovation was confirmed. In particular, it was found that the clarity and uniqueness of the business model interacted with the R&D investment to shorten the product development time and directly increase the innovativeness of the developed product. Based on these analysis results, the implications of this study, limitations of the study, and the future research directions were described.

• Information Systems Review
• /
• v.23 no.1
• /
• pp.45-68
• /
• 2021

As the influence of online reviews on consumer decision-making increases, concerns about review manipulation are also increasing. Fake reviews or review manipulations are emerging as an important problem by posting untrue reviews in order to increase sales volume, causing the consumer's reverse choice, and acting at a high cost to the society as a whole. Most of the related prior studies have focused on predicting review manipulation through data mining methods, and research from a consumer perspective is insufficient. However, since the possibility of manipulation of reviews perceived by consumers can affect the usefulness of reviews, it can provide important implications for online word-of-mouth management regardless of whether it is false or not. Therefore, in this study, we analyzed whether there is a difference between the review evaluated by the consumer as being manipulated and the general review, and verified whether the manipulated review negatively affects the review usefulness. For empirical analysis, 34,711 online book reviews on the LibraryThing website were analyzed using multilevel logistic regression analysis and Poisson regression analysis. As a result of the analysis, it was found that there were differences in product level, reviewer level, and review level factors between reviews that consumers perceived as being manipulated and reviews that were not. In addition, manipulated reviews have been shown to negatively affect review usefulness.

• Journal of the Daesoon Academy of Sciences
• /
• v.48
• /
• pp.157-198
• /
• 2024

Aside from enriching spirituality, religiously-themed museums play a crucial role in resolving conflicts among the nations peripherally or various cultural groups in a broad sense. Relatively speaking, Korea has achieved a peaceful multi-religious society, yet the 2019 pandemic caused certain religious conflicts to surface or perhaps resurface. Since the 2000, due to the increasing number of migrants, there has been increasing awareness of the need to accommodating even greater levels of religious diversity. Accordingly, this study aims to apprehend various educational programs and exhibitions that have been developed by St. Mungo's Museum of Religious Life and Art, the State Museum of the History of Religion, and the Museum of World Religions in multi-ethnic societies such as the UK, Russia, and Taiwan. Therein, it will be determined how these museums contribute to mutual understanding and interaction and this research will suggest the development of a religiously-themed museum capable of resolving a number of social conflicts and enriching the diversity of its nation.

• Journal of Navigation and Port Research
• /
• v.48 no.3
• /
• pp.192-199
• /
• 2024

Wave overtopping is a significant natural hazard that occurs in coastal areas, primarily driven by high waves, particularly those generated during typhoons, which can cause coastal flooding. The development of residential and commercial areas along the coast, driven by increasing social and economic demands, has led to a concentration of people and assets in these vulnerable areas. This, coupled with long-term sea level rise and an increase in typhoon frequency, has heightened the risk of coastal hazards. Traditionally, the evaluation of wave overtopping volumes has relied on directly measuring the collected volume of water that exceeds the crest height of structures through hydraulic model experiments. These experiments are averaged over a specific measurement period. However, in this study, we propose a new method for estimating individual wave overtopping volumes. We utilize the temporal variation of wave overtopping heights to develop an observation system that can quantitatively assess wave overtopping volumes in actual coastal areas. To test our method, we conducted hydraulic model experiments on rubble mound breakwaters, which are commonly installed along the Korean coast. We introduce wave overtopping discharge coefficients, assuming that the inundation velocity from the structure's crest is the long-wave velocity. We then predict overtopping volumes based on wave overtopping heights and compare and review the results with experimental data. The findings of our study confirm the feasibility of estimating wave overtopping volumes by applying the overtopping discharge coefficients derived in this study to wave overtopping heights.