• Economic and Environmental Geology
• /
• v.53 no.6
• /
• pp.667-675
• /
• 2020

An Alum-sludge based adsorbent (ASBA) was synthesized by the hydrothermal treatment of alum sludge obtained from settling basin in water treatment plant. ASBA was applied to remove fluoride and arsenic in artificially-contaminated aqueous solutions and mine drainage. The mineralogical crystal structure, composition, and specific surface area of ASBA were identified. The result revealed that ASBA has irregular pores and a specific surface area of 87.25 ㎡ g-1 on its surface, which is advantageous for quick and facile adsorption. The main mineral components of the adsorbent were found to be quartz(SiO2), montmorillonite((Al,Mg)2Si4O10(OH)2·4H2O) and albite(NaAlSi3O8). The effects of pH, reaction time, initial concentration, and temperature on removal of fluoride and arsenic were examined. The results of the experiments showed that, the adsorbed amount of fluoride and arsenic gradually decreased with increasing pH. Based on the results of kinetic and isotherm experiments, the maximum adsorption capacity of fluoride and arsenic were 7.6 and 5.6 mg g-1, respectively. Developed models of fluoride and arsenic were suitable for the Langmuir and Freundlich models. Moreover, As for fluoride and arsenic, the increase rate of adsorption concentration decreased after 8 and 12 hr, respectively, after the start of the reaction. Also, the thermodynamic data showed that the amount of fluoride and arsenic adsorbed onto ASBA increased with increasing temperature from 25℃ to 35℃, indicating that the adsorption was endothermic and non-spontaneous reaction. As a result of regeneration experiments, ASBA can be regenerated by 1N of NaOH. In the actual mine drainage experiment, it was found that it has relatively high removal rates of 77% and 69%. The experimental results show ASBA is effective as an adsorbent for removal fluoride and arsenic from mine drainage, which has a small flow rate and acid/neutral pH environment.

• Journal of Korean Society of Forest Science
• /
• v.100 no.4
• /
• pp.630-638
• /
• 2011

This study aims to verify the economic validity of the REDD project in North Korea by estimating the potential carbon credits and the cost of REDD project. The REDD potential credits of North Korea are estimated based on the international statistics of forest area and population from 1990 to 2010, and the cost of REDD project is estimated indirectly by annual land opportunity cost of agriculture assuming that South Korea will aid the food production per area in North Korea. When the 25% reduction scenario was applied to the annual deforestation rate in North Korea, the potential REDD credits were estimated to be $4,232million{\sim}5,290milliontCO_2eq.$ for 20 years. It would account for 28~35% of South Korea's national medium-term greenhouse gas reduction target. On the other hand, the break-even price of REDD project was calculated as the profit of agriculture in the land available by forest conversion in North Korea. It was estimated to be 19.19$/$tCO_2eq.$ when the non-permanence risk of forest conserved through a REDD contract is assumed to be 20%. This price is higher than the price of REDD carbon credit 5$/$tCO_2eq.$ dealt in the 2010 voluntary carbon market, leading to no economic feasibility. However, REDD project provides co-benefits besides climate mitigation. As previous studies indicate, the break-even price is lower than 20$/$tCO_2eq.$, which is the social marginal cost of greenhouse gas emissions by loss of forest. Therefore REDD in North Korea can be justified against the social benefits. The economic feasibility of REDD project in North Korea can be largely influenced by the risk percentage. Thus, North Korean REDD project needs a strong guarantee and involvement by the government and people of North Korea to assure the project's economic feasibility.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.29 no.4
• /
• pp.124-136
• /
• 2011

In landscape architecture, plants play an important role in realizing the intention of the architect and user- behavior as well as an ecology and appearance of the space for them. However, it is true that many researches have focused on ecological characteristics of plants, their cultivation environment and symbolic meanings in traditional terms, while relatively few for the analysis of the aspects of each period through plants. For this, cherry trees that we often see around are selected and their introduction, propagation, development and symbolism from the view of chronicle are studied and the results are followings; Firstly, three-year seedlings of 1,500 pieces of cherry tree from Osaka and Tokyo were planted for the first time in Oieseongdae, Namsan Park, Seoul. Since then, they had been widely planted at traditional sites, modern parks, newly-constructed roads for street trees, and for this, the Japanese Government-General of Chosun had actively supported by its direct cultivation and selling of cherry trees. The spread of cherry trees planted raised the question of whether or not Prunus yedoensis is originated from Jeju Island. Secondly, such massive and artificial planting of them had become attractions over the time and mass media at that time also had actively promoted it. And such trend made the day and night picnic under the cherry blossoms one of the most representative cultures of enjoying spring in Seoul. Thirdly, although general people enjoyed cherry blossoms, but they had dual view and attitude for cherry trees, which were well expressed in their use of them: for example, cherry blossoms, aeng and sakura were used altogether for same meaning, but night aeng or night picnic under cherry blossoms were especially used instead of yojakura when mentioning just pleasure, which meant some saw night enjoying cherry blossoms a low culture. Fourth, symbolic space of Chosun had been transformed into the space for enjoyment and consumption. Anyone who paid entrance fee could enjoy performance of revugirl, cinema and entertainment along with enjoying cherry blossoms. The still-existing strict differentiation of enjoyment culture by social status, class and ethnicity was dismantled from that trend and brought about a kind of disorder. From this, we could find that cherry blossoms had made a great contribution to the change of traditional enjoyment culture over the Japanese colonial period and become a popular spring enjoyment.

• 한국사회정책
• /
• v.24 no.1
• /
• pp.153-185
• /
• 2017

The purpose of this study is to investigate the actual conditions and causes of the problem behaviors of Korean Chinese'left-behind'children in China in order to propose a support system to prevent problem behaviors of them. For this purpose, a questionnaire survey was conducted on 399 children who attend at three Korean Chines schools in Yonbian in China. The questionnaire consisted of general characteristics, internalizing problem behavior, social support, self-esteem, and self-resilience. This paper analysed the survey data by employing one-way ANOVA and a structural equation modeling. It verified if there is significant difference in internalizing problem behaviour, self-esteem, self-resilience, and social support between left-behind children's group and non left-behind children's group. It also identified a structural causal relationship and direct or indirect effects among problematic behaviour, self-esteem, self-resilience, and social support. The results of the analysis are as follows. First, there was a statistically significant difference in the social withdrawal and depression of internalizing problem behaviors between left-behind children's group and non left-behind children's group. Second, the left-behind children's group showed no significant difference in self-resilience and social support compared to non left-behind children's group, but showed a significant difference in self-esteem. In the positive self- esteem factor, non left-behind children's group showed much higher score whereas left-behind children's group was higher in the negative self-esteem factor. Third, social support for left-behind children's group has a statistically significant direct negative effect on internalizing problem behaviors, and indirectly negative effects on problem behavior through self-resilience. These results suggest the necessity of establishing a social support system for mitigating and preventing problem behaviors and the necessity of preparing measures to improve self-resilience. Based on the results of the study, we discussed how to establish a social support system in China to mitigate internalizing problem behaviors of Korean Chinese left-behind children.

• Journal of Christian Education in Korea
• /
• v.64
• /
• pp.203-235
• /
• 2020

The purpose of this study is to identify the degree of social presence perceived by students and to explore the factors that have affected it after practicing Christian Education classes as synchronous distance course due to Covid-19. It is also to suggest effective ways in the aspects of the design and operation to improve social presence. In order to measure social presence and derive influencing factors, research related to synchronous distance class and social presence is summarized through literature review. The researchers also surveyed 58 students in three courses of Christian education major at a University in Gyeonggi-do and conducted in-depth interviews with 6 students. The main findings are as follows: First, the sense of social presence was moderate, the emotional bond was the lowest by sub-factor, the open communication, the sense of community was moderate, and the mutual support and concentration were the highest. Second, factors that had a positive impact on the sense of social reality were group activities, selfintroduction activities, active participation in classes, mutual communication such as Q & A or response to peer learners' opinions during lectures by professors, questions, feedback, etc, and having a smaller number of students. Factors that had a negative impact on the perception of social presence were lack of private conversations, poor participation in classes, lack of communication with each other, and difficulty concentrating. The causes of these negative factors were technical problems and limitations arising from zoom, inconvenience and distracting surroundings, lack of time, and psychological awkwardness. Reflecting the results of the study, orientation to effective synchronous distance course, guidance on smooth communication methods, strengthening the role of professors to promote learning, strengthening group activities and learner-centered activities, and proposing a smaller scale of students were ways that are offered to improve the sense of social presence in synchronous distance courses.

• Korean Journal of Construction Engineering and Management
• /
• v.22 no.4
• /
• pp.59-65
• /
• 2021

Since the 2016 "Housing Act Partial Amendment" and the "2018 Housing Comprehensive Amendment Plan", interest in the pre sale system and post sale system of apartment houses has been on the rise. In order to compare the advantages and disadvantages of the pre sale system and the post sale system of apartment houses, and to establish the basis for the institutional policy of the post sale system, a questionnaire survey method was used for tenants of the apartment house from the public side, and issues of time and cost. The time series analysis method is intended to suggest an appropriate time for payment of contributions. Accordingly, through a review of existing theories and literature, the post sale system of public and private institutions was organized, and through a questionnaire survey, the path to securing pre sale money, product information of the model house, and the degree of awareness of the effect of the post sale system were investigated. For the post sale fund support and payment method, it is necessary to increase the commercial line for existing financiers from the user's point of view, and it is necessary to operate in consideration of the economic power of the pre sale market by region. Both 60% post sale and 80% post sale have a price range of up to KRW 10 million, and the total interest rate is 5.0%, and the annual interest rate is about 2.8% for 60% post sale, and about 2.1% for 80% post sale, which is lower than the current 3.1%. I need an interest rate. The research is a perception survey targeting a total of 5,213 households in a sample of after sale apartments in public institutions. As the actual values are analyzed using a time series on the effects of market supply and demand and market prices, there is a limit to applying them to prospective residents of private apartments. In addition, to respond to first time tenants, a questionnaire survey was conducted on five complexes that have moved in within the last five years.

• Journal of Digital Convergence
• /
• v.19 no.7
• /
• pp.57-70
• /
• 2021

As COVID-19 spreads, people's interest in smart learning that can do non-face-to-face learning is increasing nowadays. In this study, we aim to empirically analyze how users' thoughts on COVID-19 and the information quality and system quality of smart learning systems affect users' acceptance of smart learning and examine the effect of perceived sensitivity and severity of COVID-19 on the satisfaction and use of smart learning through concerns about the risk of transmission. In addition, we examined the influence of information quality composed of content quality and interaction quality and system quality composed of system accessibility and functionality on the use of smart learning through user satisfaction. To verify the validity of the proposed model, we conducted a survey on 334 users with experience in using smart learning, and performed the analysis using Smart PLS 3.0. According to the analysis results, among information quality and system quality, only functionality has a positive (+) effect on the satisfaction of smart learning, and satisfaction has a positive (+) effect on the usage behavior. However, it is found that accessibility among system quality do not affect satisfaction, and concern about the risk of transmission has a negative effect on satisfaction. This study can provide meaningful guidelines to researchers when researching smart learning to support students' learning in a pandemic situation of a new infectious disease, such as COVID-19. It will also be able to provide useful implications for educational institutions and companies related to smart learning.

• Journal of Environmental Impact Assessment
• /
• v.30 no.2
• /
• pp.105-116
• /
• 2021

In the city of high population density crowded with buildings, Urban Heat Island (UHI) is intensified, and the city is vulnerable to thermal comfort. The maintenance of vacant land in downtown is treated as a factor that undermines the residential environment, spoils the urban landscape, and decreases the economic vitality of the whole region. Therefore, this study compared the effects on microclimate in the surrounding area according to the development scenarios targeting the vacant land in Songhyeon-dong, Jongno-gu, Seoul. The status quo, green oriented, building oriented and green-building mediation scenarios were established and ENVI-met was used to compare and analyze the impact of changes in wind speed, air temperature and mean radiant temperature (MRT) within 1 km of the target and the target site. The result of inside and 1 km radius the targeted area showed that the seasonal average temperature decreased and the wind speed increased when the green oriented scenario was compared with the current state one. It was expected that the temperature lowered to -0.73 ℃ or increased to 1.5 ℃ in summer, and the wind speed was affected up to 210 meters depending on the scenario. And it was revealed that green area inside the site generally affects inside area, but the layout and size of the buildings affect either internal and external area. This study is expected to help as a decision-making support tool for developing Songhyeon-dong area and to be used to reflect the part related to microclimate on the future environmental effects evaluation system.

• Journal of Korea Entertainment Industry Association
• /
• v.14 no.3
• /
• pp.51-62
• /
• 2020

The purpose of this study was to verify whether the quality of service provided by culture and arts education has a bearing on the service value of dance education, and to verify the role of the intention of reuse of culture and arts education participants in this relationship. The survey was conducted from October 1, 2019 to December 30, 2019, and a sample was collected from stratified sampling methods for the general public participating in culture and arts education. In order to verify the relationship between the independent variable and the dependent variable, multiple regression analysis was performed, and the role of the parameter in the relationship between the independent variable and the dependent variable was examined using the three-step intermediary regression analysis. The research results are as follows. First, as a result of analyzing the relationship between the sub-factors of service quality and emotional value, it was found that facilities and environmental services had the greatest impact. Second, the results of analyzing the relationship between the sub-factors of service quality and functional value showed that the most significant impact was on facilities and environmental services. Third, as a result of analyzing the relationship between the sub-factors of service quality and social values, it was found that facilities and environmental services had the greatest impact. Fourth, In the relationship between contents and instructor service and service value, the intention to reuse was found to have a full mediating effect. In addition, in the relationship between facility and environmental services and service value, the intention to reuse was found to have a partial mediating effect. Based on the quality of service of culture and arts education, this study suggested a way for dance education to work with the region.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.343-355
• /
• 2022

This study investigated the consumption tendency and awareness of paprika in order to expand and promote the consumption of Capsicum annuum L. The research investigated the relationship of preference and loyalty based on emotional response of paprika according to the semantic differential scale. The survey was conducted from January to February 2022 using a random sampling method targeting 155 general people, and a total of 142 questionnaires were analyzed excluding 13 wrong answers. The nine items on the awareness of paprika showed to be consisted of three factors such as 'Food taste', 'Usability', and 'Economics' by factor analysis. Regarding to the awareness of paprika the positive answer that 'I think paprika is good for health' among the nine questions was the highest at 92.3%. In the preference aspect of shape, blocky type had the highest preference for the shape of paprika, followed by mini and conical types in order of preference (p < 0.001). As for color preference, yellow paprika was the most preferred, followed by orange, red, and green, showing statistical significance. The emotional response of paprika by paprika image showed a statistically significant difference in the four colors. The words such as 'bright', 'clean', and 'spirited' appeared as representative emotional vocabulary for paprika. Multiple regression analysis was performed to examine the effect of paprika on the three factors of awareness, preference, and loyalty due to the quality of life. As a result, the higher the paprika preference and quality of life, and the higher the taste and availability factors, the higher the paprika awareness and loyalty. As the variable that has the most influence on the loyalty of the survey respondents, preference was found to have the highest explanatory power at 43%. From these results, it was judged as a very important factor in the survey on the shape and color preference of paprika. Therefore, the recent increase in awareness that paprika is good for health is thought to act as a positive factor in revitalizing the domestic market and increasing consumption of paprika in the future. Also, among the three types of paprika, the yellow blunt type showed the highest preference. Therefore, in order to produce and promote this type of paprika, it is also important to increase the cultivation to suit the purchasing propensity of consumers.