Effectiveness of an after-school English program at a community childcare center in Korea

Community childcare centers in Korea are established mainly for students from low-income family for the purpose of protecting and educating children in the community. English program is one of the most important program at the centers. This study investigated the effectiveness of an after-school English program at a community childcare center in a region of Seoul, Korea. Students registered in this English program were encouraged to participate in an online survey using a google form to fill out the questionnaire via a computer or mobile phone. Survey questions included effectiveness of the program, students’ satisfaction, and most helpful class activity for learning English. A semi-structured interview was conducted to gather students’ views on the program. Nine students among who completed online survey and volunteered for interview. Collected survey data were statistically analyzed using SAS Enterprise Guide 7.12. Final survey data set includes 11 respondents. The overall satisfaction with the after-school English program was high for both contents and effectiveness. High school students and student who participated in the program for more than six months chose the free conversation activity as the most helpful. The mean score for debates was the highest among all activities for English writing. The survey provided an opportunity for students to report their levels of satisfaction with the program. Results of this study indicate that students are satisfied with the English program at the community childcare centers overall and, that the performance of the lecturer can be categorized very well. This study provides insights into the need and direction of English education for students from low-income families. This study will serve as a basis to develop specialized and quality English programs for successful English learning of low-income students, and facilitate the continuous improvement process.

Experimental analysis of heat prosumers under low temperature thermal network

This study investigated the applicability and thermal performance of heat prosumers in a bidirectional thermal network through experimental analysis. To realize the bidirectional thermal network and heat prosumers, the existing small-scale centralized district cooling and heating system was retrofitted to form a small-scale heat network with three thermal energy prosumers. The existing small-scale centralized district cooling and heating network consists of seven buildings: high schools, management center, childcare center, baby care center, youth center, library, and public health center. Among these, high school and childcare center were retrofitted from heat consumers to heat prosumers. Control logic for the proposed heat prosumer was also demonstrated. For the case study, the operation of the specific day was selected. The amount of heat supplied from the STES in the management center was 798.7 kWh that contained 17% of the total load. The heat supply from the TES connected to the heat pump in the management center was 2,270.5 kWh, the absorption heat pump for high school. The amount of heat supply for public buildings and schools was 824.0 kWh and 513.8 kWh, respectively, and the heat supply from the childcare center through geothermal heat pump was 295.2 kWh.

Experimental Analysis of Bi-Directional Heat Trading Operation Integrated with Heat Prosumers in Thermal Networks

District cooling and heating methods that can utilize highly efficient heat pumps and various unused new and renewable types of energy are required to achieve low carbon emissions and zero energy usage in buildings and community units. The technical requirements for the implementation of decentralized thermal networks and heat trading are increasing, both for thermal networks in new buildings and for those remodeled based on existing centralized thermal networks. In this study, a conventional centralized thermal network was implemented as a decentralized thermal network and the possibility of heat prosumers feeding thermal networks was demonstrated experimentally. A real-scale plant was constructed by employing unused thermal energy facilities as prosumers in a school and childcare center based on the existing small-scale block heating and cooling thermal network. The decentralized thermal network and heat prosumer concepts were proven through operation experiments performed on the constructed system in summer and winter. An economic benefit can be achieved by increasing the peak power cost. The experimental results also showed that the proposed bi-directional heat trading reduced carbon emissions by 12.7% compared with conventional centralized thermal systems.