• Journal of Space Technology and Applications
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• v.4 no.2
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• pp.137-152
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• 2024

Currently, investigations in microgravity environments are carried out in a variety of applications, including drop towers, where experiments can be performed for short periods of time, and space stations, where time is not limited. However, producing a microgravity environment for long-term scientific research requires huge development expenditures and efforts. As a result, if the microgravity experiment is carried out on a cubesat, the variety of scientific studies will likely increase even more due to its low cost. The Korea Microgravity Science Laboratory (KMSL) cubesat, which has these features, is a satellite that has carried out microgravity science missions. On March 22, 2021, the KMSL satellite was launched by a Soyuz2.1a from Baikonur in Kazakhstan and operated normally for nearly two months. This article presents results and lessons gained for successfully completing science missions in microgravity based on the KMSL satellite's operational experience.

• Journal of Korean Elementary Science Education
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• v.33 no.2
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• pp.335-351
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• 2014

The 96 elementary school teachers' the degrees of understandings about the characteristics of the currents according to the connection methods of batteries in simple electric circuits were investigated. In this study, the concepts on the characteristics of currents according to the connection methods of batteries were divided 'the learned concepts' and 'the differentiated concepts'. The characteristics of the currents in the region of the larger resistance of load than the internal resistance of a battery were called the learned concepts, they are taught in the science curriculum. While the characteristics of the currents in the region of the smaller resistance of load than the internal resistance of a battery were called the differentiated concepts, they are not exposed clearly in the science curriculum. The results obtained in this study are as follows: The average score related to the learned concepts was relatively high, while the degree of the teachers' cognitions of the internal resistance of a battery and the resistance of wires were low. Also the average score related to the differentiated concepts was very low because it seems so new to the elementary school teachers. It strongly suggests that the elementary school teachers did not understand meaningfully the characteristics of the currents related to the connections of batteries on the ground of the cognitions of the internal resistances of batteries and the resistances of loads in simple electric circuits. Hence, they might experience difficulties due to the problems occurred in relation to the connections of batteries in the elementary school science lessons.

• Bulletin of the Korea Photovoltaic Society
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• v.6 no.1
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• pp.8-20
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• 2020

Nepal has huge potential of hydro and other renewable energy resources including solar energy. However, only 70% of the total population have access to electricity despite the long history of hydropower development in the country. Still more than 37% population in rural areas and around 73% population in Karnali Province, one of the least developed provinces, are living without access to electricity despite taking several initiatives and implementing various policies by government supporting electrification in off-grid rural areas. Government together with donors and private sector has extensively been promoting the off-grid solar photovoltaic (PV) echnology in un-electrified areas to increase electricity access. So far, more than 900,000 households in rural areas of Nepal are getting electricity from stand-alone solar PV systems. However, there are many challenges including financial, technical, institutional, and governance barriers in Nepal. This study based on extensive review of literatures and author's own long working experiences in renewable energy sector in Nepal, shares the best practices and lessons of off-grid solar PV for increasing access to electricity in rural areas of Nepal. This study suggests that flexible financial instruments, financial innovations, bundling of PV systems for concentrating energy loads, adopting standards process, local capacity building, and combination of technology, financing and institutional aspects are a key for enhancing effectiveness of solar PV technology in rural areas of Nepal.

• Agribusiness and Information Management
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• v.1 no.2
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• pp.61-80
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• 2009

Information and Communication Technology is now widely accepted by developing countries as a development tool in their efforts to alleviate poverty, enhance human development, and achieve Millennium Development Goals. Recognizing this untapped potential and development strategies incorporating ICT are being increasingly promoted and launched across the developing countries requiring a comprehensive ICT policy that plays a crucial rule, in particular, in the area of agriculture and rural development. While the potential advantages of ICT for development are enormous in developed countries, national policies of developing countries are yet to adequately reflect truly comprehensive and integrated strategies for harnessing and exploiting this potential. This paper tries to provide implication of ICT policy to the agriculture and rural development in developing countries, in particular through lessons learned from European Union (EU) IT policy. Through the examination of vital projects in the agriculture and rural development sectors and case study analysis of applied policies and strategies implemented in the European Union, this paper provides tangible examples and lessons for policy-makers and practitioners involved in the field. Hence, this study provides policy-makers the necessary tools, information and knowledge to facilitate the formulation and adoption of ICT policies and strategies in the agriculture and rural development sector.

• Education of Primary School Mathematics
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• v.13 no.2
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• pp.67-84
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• 2010

The purpose of the research is to assure the effect of learner-centered instruction driven from the constructivism. The school in participation of the research is one of them called "achievement increase intensive school". Quasi-experimental design is applied for the research. Some conclusions were drawn from the research. Experimental group' achievements of both "learned contents" and "none learned contents" were more superior than ones gained from comparative group with statistically significant difference. The results implied that learner-centered instruction is effective for students who have low achievements from standards tests.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.35 no.3
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• pp.163-168
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• 2024

Stress is a natural state that emerges due to the dynamics of an individual's life. Children must learn how to effectively manage stress as part of their growth and development. Resolution is possible when children are exposed to stress and receive adequate support from their families. However, when stress is intense, frequent, protracted, or traumatic, as in cases of childhood abuse, it can become toxic and interfere with the development of the child's brain and body. This results in vulnerability, which can have detrimental effects on the child's overall physical, mental, and emotional health. This perspective discusses the impact of childhood maltreatment and toxic stress, drawing on insights gained during the COVID-19 pandemic. We aimed to shed light on the lessons learned from this unique and challenging period and how they inform our understanding of the effects of stress on children's well-being.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.281-302
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• 2021

Railway projects have been consistently increasing in Korea. In relation to this trend, the mechanized tunneling using Tunnel Boring Machine (TBM) is preferably applied for mining urban areas and passing under rivers. The TBM tunneling under difficult grounds like mixed faces with high water pressure could require ground improvements for stable TBM advance or safe cutter head intervention (CHI). In this study, pre-grouting works for CHI in Daegok-Sosa railway project are presented in terms of the grouting zone design, the executions and the results, the lessons learned from the experience. It should be mentioned that the grouting from inside TBM was carried out several times and turned out to be inefficient in the project. Therefore, grouting experiences from the surface are highlighted in this study. Jet grouting was implemented on CHI points on land, while permeation grouting off shore in the Han River, which mostly allow to access the cutter head of TBM in free air with stable faces. The results of CHI works have been analyzed and the lesson learned are suggested.

• Smart Structures and Systems
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• v.21 no.5
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• pp.695-703
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• 2018

Based on monitoring data collected from the Nanjing Dashengguan Bridge over the last five years, this paper systematically investigates the effects of temperature field and train loadings on the structural responses of this long-span high-speed railway bridge, and establishes the early warning thresholds for various structural responses. Then, some lessons drawn from the structural health monitoring system of this bridge are summarized. The main context includes: (1) Polynomial regression models are established for monitoring temperature effects on modal frequencies of the main girder and hangers, longitudinal displacements of the bearings, and static strains of the truss members; (2) The correlation between structural vibration accelerations and train speeds is investigated, focusing on the resonance characteristics of the bridge at the specific train speeds; (3) With regard to various static and dynamic responses of the bridge, early warning thresholds are established by using mean control chart analysis and probabilistic analysis; (4) Two lessons are drawn from the experiences in the bridge operation, which involves the lacks of the health monitoring for telescopic devices on the beam-end and bolt fractures in key members of the main truss.

• Journal of Elementary Mathematics Education in Korea
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• v.20 no.2
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• pp.259-281
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• 2016

Teaching practicum plays a significant role in teacher education program because it provides pre-service teachers with an opportunity to apply what they have learned to the actual teaching contexts. As such, it needs to be conducted in terms of close collaboration between university and school. Given that, in a mathematics methods course the prospective teachers in this study had an opportunity to discuss mathematics lessons they had implemented during their teaching practicum. This paper analyzed in what ways prospective teachers' comments on elementary mathematics instruction were changed through this experience. The results of this study showed that in late comment the teachers tended to focus more on mathematical discourse, consider not only the teacher of the lesson but also students, and suggest alternative approaches on the classroom events they had noticed. It is noticeable that the results analyzed by researchers were consistent with prospective teachers' self-assessment. Building on these results, this paper provides implications of teacher preparation programs to enhance prospective teachers' ability to analyze elementary mathematics lessons.

• Spatial Information Research
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• v.21 no.6
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• pp.11-21
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• 2013

This study aims to establish a strategic NSDI (National Spatial Data Infrastructure) model for developing countries based on good practices in the Republic of Korea. The Republic of Korea is a unique country in the world, which has become a developed country from a recipient of international aid since the Korean War in 1950. The rapid economic growth can be mostly attributed to the IT technologies and the Republic of Korea's NSDI efforts as a good practice could provide useful lessons for developing countries. This study consists of theoretical reviews, interviews of Korean NSDI experts, analysis for lessons learned, a summary of the lessons in terms of Six NSDI components and finally a strategic NSDI model for developing countries. The NSDI model is structured by (1) implementation strategies suggested for geospatial data, capacity building, geospatial platform, and cost-effective management with partnership, (2) a roadmap of important NSDI tasks and activities, and finally, (3) a harmonized approach for successful NSDI implementation.