• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.1
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• pp.10-15
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• 2003

This paper presents the digital computer performance evaluations of the three-phase self-excited induction generator (SEIG) driven by the variable speed prime mover such as the wind turbine using the nodal admittance approach steady-state frequency domain analysis with the experimental results. The three-phase SEIG setup is implemented for small-scale rural renewable energy utilizations. The experimental performance results give a good agreement with those ones obtained from the digital computer simulation. Furthermore, a feedback closed-loop voltage regulation of the three-phase SEIG as a power conditioner which is driven by a variable speed prime mover employing the static VAR compensator (SVC) circuit composed of the thyristor phase controlled reactor (TCR) and the thyristor switched capacitor(TSC) is designed and considered herein for the wind-turbine driven the power conditioner. To validate the effectiveness of the SVC-based voltage regulator of the terminal voltage of the three-phase SEIG, an inductive load parameter disturbances in stand-alone are applied and characterized in this paper. In the stand-alone power utilization system, the terminal voltage response and thyristor triggering angle response of the TCR are plotted graphically. The simulation and the experimental results prove the effectiveness and validity of the proposed SVC which is controlled by the Pl controller in terms of fast response and high performances of the three-phase SEIG driven directly by the rural renewable energy utilization like a variable-speed prime mover.

• Korean Journal of Social Welfare
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• v.65 no.2
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• pp.53-78
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• 2013

The purpose of this study was to understand the context of happiness that low-income households have experienced. To achieve this purpose, this study used qualitative panel data collected from in-depth interviews and analysed the data through an inductive approach. Specifically, a researcher analysed the context of individual cases, and visualized the contexts comprised of phenomenon and participants' experiences. The researcher, also, comprised the integrated context by continuous individual and complicated analysis. As results, the researcher found that the level of happiness that low-income households have experienced was more directly related with subjective experiences than objective status. In addition, the participants' subjective experiences were comprised of very complicated components of experience, and the level of happiness could differ depending on how individuals perceived positive experiences and negative ones. Based on these findings, researcher proposed the guidelines for social welfare policy and practice to improve the level of low-income households' happiness.

• Journal of the Korean School Mathematics Society
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• v.10 no.1
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• pp.91-111
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• 2007

This study investigated how high school students predict the rule, the sum of sequence for the concept of sequence, for the given patterns based on inductive approach using computers that provide dynamic functions and materials that are visual. Students for themselves were able to induce the formula without using the given formula in the textbook. Furthermore, this study examined how these technology and materials affect students' understanding of the concept of actual infinity for those who have the concept of the potential infinity which is the misconception of infinity in a infinity series. This study shows that students made a progress from the concept of potential infinity to that of actual infinity with technology and materials used I this study. Students also became interested in the use of computer and the visualized materials, further there was a change in their attitude toward mathematics.

• Information Systems Review
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• v.9 no.3
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• pp.67-82
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• 2007

The myth about BPO is: since firms do not want to continue to control the business process, they outsourced it to the external provider. Therefore, there is no need for controlling the outsourced process. Based on resource dependency theory, this study explores control mechanism used in BPO context. The overall approach of this study is qualitative, inductive and exploratory. First, a generic framework on the control structure is derived from extant literature, which includes outcome/process control, IS and social control. This framework is applied to a Korean BPO case. This study has found that the hybrid control structure consisting of behavior, outcome and social control mechanisms are effective for BPO success. As outsourcing grows rapidly and IS functions become smaller, the business struggles to redefine its IS capability. This research proposes setting up proper control mechanism between user and BPO service provider as new IS capability that business should focus on; and provides guidelines for managers in development of new IS capability.

• Journal of the Korean School Mathematics Society
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• v.11 no.2
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• pp.299-314
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• 2008

The purposes of this study were to investigate what attitudes students have toward learning proofs and what difficulties they have in learning proofs, and to examine how the use of dynamic geometry software, the Geometer's Sketchpad, helps students' proof learning. The study involved 117 9th graders in 2 high schools. According to questionnaire data, over 50 percent of the total respondents(116) indicated negative attitudes toward learning proofs, on the other hand, only 16 percent of the total respondents indicated positive attitudes toward the learning. Memorizing and remembering many kinds of theorems, definitions, and postulates to use in proving statements was the most difficult part in learning proofs, which the largest proportion of the total respondents indicated. The study found that the use of the Geometer's Sketchpad played positive roles in developing students' understanding of proofs and stimulating students' interests in learning proofs.

• Journal of the Korean association of regional geographers
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• v.19 no.1
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• pp.162-180
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• 2013

This paper is to explore the relationship between global citizenship education needed to be taught recently and geography. First, the paper examines the concept, as well as the reason why it became important concept in dimension of education in terms of progress of globalization. Second, the paper examines justification of global citizenship education through geography subject through discussion of place, space, scale and interdependence as geographical key concepts. Then, it establishes the category of sub-area of global citizenship education to grasp structurally. This is to reestablish in terms of knowledge and understanding, skill, value and attitude through the inductive examination of existing system of classification. Third, for geography instruction as practical dimension for fostering global citizenship, the paper discusses things to consider previously to design it in terms of aims, contents and methods, and examined instruction strategies in terms of issues-based approach and geographies of resistance. The last, the paper should things to pay attention to be cautious in global citizenship education through geography.

• Journal of Educational Research in Mathematics
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• v.18 no.2
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• pp.223-237
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• 2008

In this paper, We focus on grasping De Morgan's perspectives on mathematics education systematically. His perspectives can be summarized as followings. First, historico-genesis of mathematics must be considered in the teaching and learning of mathematics. Second, mathematical conception of students must be formulated progressively. Third, it is important to use errors which come out continually in the process of passing from inductive stage to deductive stage. Fourth, personal knowledge of students is important in the teaching and learning of mathematics. These De Morgan's four perspectives are the way of approach for experiencing moral certainty first of all to get to mathematical certainty. Moral certainty which he presented is a combination of rationality and humanity to fill up gaps between Platonism and general public education.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.435-451
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• 2021

The purpose of the study is to explore the experience of participants who have provided a chidlcare service, and to suggest implications for childcare service for adolescent parents. The author used a purposive sampling method to select 3 cases with experiences related to childcare service, collecting data via direct interview and by obtaining a written text describing their case management. An inductive (open) coding approach was utilized to draw themes and categories from the data. The 6 categories describing service providing experiences of the study participants include "motives for participate a childcare service", "contents of service provided by participants", "tries to establish relationship with adolescent parents", "deepening of understand about adolescent parents", "limits of providing services". Implications and future directions were discussed for childcare services on adolescent parents having crisis related to childbirth and child rearing.

• 한국노년학
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• v.40 no.2
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• pp.311-323
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• 2020

Older adults are at a high risk of falling, causing severe injuries and increased hospital stays and treatment costs. This can be a burden not only on the family but also on the national economy. Thus, fall prevention is very important in nurses' and nursing assistants' work. This study intended to grasp the real situation faced by nurses and nursing-assistants working at geriatric hospitals in J province, Korea. The researcher interviewed thirty-six nurses and nursing-assistants in four geriatric hospitals and performed four focus group interviews. Data were analyzed through an inductive content analysis based on Elo & Kyngäs's approach. Three categories and five subcategories were identified. Categories were patients, environmental, and personal factors. Patient factors included patients' impaired cognitive function. Environmental factors included lack of personnel support and assignment of inpatients without regard to fall risk. Personal factors included hopelessness regarding improvement and fear of being blamed. Promotion of fall prevention practice needs a gradual increase in nursing staff at geriatric hospitals, a system for assigning hospital room according to fall risk, and education and support system to reduce nursing burden.

• Journal of the Korean School Mathematics Society
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• v.25 no.4
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• pp.423-446
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• 2022

This study explores and compares Korean and U.S. elementary preservice teachers' analytic approaches of students' addition and subtraction computational strategies. Twenty-six Korean and twenty U.S. elementary preservice teachers participated in the study. Participants were asked to analyze mathematical approaches and errors from students' addition and subtraction operations. Preservice teachers' written documents were analyzed by applying open coding and inductive coding based on the grounded theory. As a result, the pattern of error analysis and interpretation of students' addition computations were similar for both Korean and U.S. preservice teachers whereas there were some differences in the analysis of students' subtraction computations. Both Korean and U.S. preservice teachers had difficulties identifying students' strategies and errors for a complicated and unconventional computational approach. Results also indicated that preservice teachers' noticing and interpretation of students' strategies and errors were influenced by their K-12 mathematics curriculum and teacher education program. This study suggests implications and future directions for teacher education, more contextualized teacher preparation programs and balanced connection to the K-12 curriculum.