• Journal of Electrical Engineering and Technology
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2016

It is well known that the behavior of PV curves is similar to a quadratic function. This is used in some papers to approximate PV curves and calculate the maximum-loading point by minimum number of power flow runs. This paper also based on quadratic approximation of the PV curves is aimed at completing previous works so that the computational efforts are reduced and the accuracy is maintained. To do this, an iterative method based on a quadratic function with two constant coefficients, instead of the three ones, is used. This simplifies the calculation of the quadratic function. In each iteration, to prevent the calculations from diverging, the equations are solved on the assumption that voltage magnitude at a selected load bus is known and the loading factor is unknown instead. The voltage magnitude except in the first iteration is selected equal to the one at the nose point of the latest approximated PV curve. A method is presented to put the mentioned voltage in the first iteration as close as possible to the collapse point voltage. This reduces the number of iterations needed to determine the maximum-loading point. This method is tested on four IEEE test systems.

• Korean Journal of Child Studies
• /
• v.19 no.2
• /
• pp.77-96
• /
• 1998

The purpose of this study was the development of a scale to assess the daily hassles of school age children. The subjects were 398 third and sixth grade children selected from elementary schools in Seoul, Inchon, Taejon, Kwangju and Pusan. Instruments included a questionnaire composed of a 96-item Daily Hassles Coping Scale, demographic questions, a 27-item Children's Depression Inventory, the 42-item Han & Yoo Daily Hassles Scale for Children, and a 30-item Children's Behavior Check List for mothers. Mean, %, ${\chi}^2$, Cramer's V, Cronbach's ${\alpha}$, factor analysis and Pearson's r were used for data analysis. 82 items from the 96-item Daily Hassles Coping Scale were selected through the item discriminant method. (Cramer's V discriminant coefficients ranged from .36 to .79). Five factors were extracted from the lst and 2nd factor analyses. Subscales were "parent-related," "friend-related I," "study-related," "friend-related II," and "teacher-related" stress. Criterion validity of the 82-item scale was confirmed through significant correlations with the Children's Depression Inventory (r=.55) and the Han & Yoo Daily Hassles Scale for Children (r=.22). Internal consistency of this scale was high, including internal reliability of subscales. These results confirm this scale as a valid and reliable measure of daily hassles of school age children.

• The Journal of Korean Institute for Practical Engineering Education
• /
• v.2 no.1
• /
• pp.126-134
• /
• 2010

Material Testing Method subject of Metal Materials, which is one of curriculum of engineering major high school, is not properly updated even though both science and technology are advancing rapidly. Especially, the need of fractographic technique, which can analyze the fracture surface with the advanced testing equipment and technique, is increasing. The importance and the analyzing method of Fractography are proved by the characteristic analysis of pressure tube fracture surface of HWPR. In the future, in order to increase the professional knowledge and their pride of engineering major high school student, these advanced subject should be included in the new crriculum of engineering major high school. This activity to involve the advanced subject should be carried out voluntary by the first line teacher before the responsible body.

• Journal of Korean Elementary Science Education
• /
• v.39 no.2
• /
• pp.168-182
• /
• 2020

This study investigated how elementary students' science-related affective characteristics and their perception of measurement changed following participation in citizen science activities through a GLOBE program. Before and after the activities, test of positive experiences about science (PES) and perception of measurement were conducted with twelve fourth grade students. In addition, the teacher who participated in the GLOBE program with students observed and recorded the students' involvement, conversation and behavior to qualitatively analyze the value of the program and the students' perceptions of measurement. After the end of the program, an open questionnaire was conducted to fill any gaps in these observations. The results showed that citizen science activities had a positive impact on elementary students' science-related affective characteristics. In all areas of PES test, the post-test scores were higher than the pre-test results, and a statistically significant difference was seen in the 'science learning motivation' area. Furthermore, students' perception of the value and meaning of measurements was seen to deepen through ongoing global environmental data measurement activities. And their understanding of various units of measurement and numerous situations in which they might need to make measurements was also elaborated.

• Child Health Nursing Research
• /
• v.21 no.2
• /
• pp.141-150
• /
• 2015

Purpose: The purpose of this study was to develop and evaluate a school adaptation program (SAP) for school-age children with emotional and behavioral problems who attended public elementary schools. Methods: SAP, developed by the authors, addresses school adaptation and academic efficacy and consists of 10 sessions based on five categories (i.e., school life, classroom activity, relationship with friends, relationship with teacher, and school environment). Sixteen children with emotional and behavior problems answered questionnaires before and after participation in the program. Results: The results showed that there was a significant difference between pre and post-test on school adaptation (t=-2.78, p=.015) and academic efficacy (t=-4.62, p<.001) after the 10 sessions of SAP. Conclusion: The results indicate that SAP can could serve as a practical program for school nurses and teachers. Further studies based on SAP in various school settings are recommended.

• Geomechanics and Engineering
• /
• v.19 no.6
• /
• pp.473-484
• /
• 2019

In this paper, the geotechnical report of the Northern Fereshteh area in Tabriz is used and the characteristics of shallow foundation of a single pile and compared pile group and geogrid in terms of the settlement of a building foundation on clayey soil. Additionally, impacts of existing variables such as the number of geogrid layers, the length of the pile, and the depth of groundwater level affected by the dynamic load caused by the Taiwan Jiji earthquake via numerical analysis using PLAXIS software are examined. The results of fifty-four models indicated that the construction of a pile group with a diameter of 1 meter and a length of 14 meters significantly diminished the consolidation settlement of the soil in the Northern Fereshteh area, where the settlement value has been triggered by the load inflicted by earthquake. Moreover, the construction of four layers of geogrid at intervals of one meter led to a significant decrease in the settlement. Finally, after reaching a maximum depth, it had no reducing effects on the foundation settlement.

• Hwankyungkyoyuk
• /
• v.25 no.2
• /
• pp.224-241
• /
• 2012

The purpose of this study was to review the research trends in school environmental education. We analyzed 383 research papers that specifically focused on the school context which were 66% of the total number (N=577) published in this journal between 1990~2011. We defined the characteristics of review and developed a review method by examining previous review studies in this area. The review framework for school environmental education research was devised in terms of seven research areas: 1) Theories and objectives of school environmental education, 2) Environmental awareness, attitude and behavior, 3) Current issues in environmental education in the school context, 4) Instructions and programs, 5) National Curriculum, 6) Environmental education contents, and 7) Teacher professionalism. In this paper, we present dominant features within each category with focus on the overall trends of research methods and themes. Finally, we discuss research issues emerging out of the empirical analysis for considering the value of research for enhancing the quality of environmental education in schools.

• Journal of the Korean earth science society
• /
• v.30 no.3
• /
• pp.366-380
• /
• 2009

The purpose of this study was to investigate the differences of reflective inquiry according to students' characteristics and interaction modes of small group in three contexts of the classroom and to obtain educational implications about using small group and teacher's intervention for an effective reflective inquiry. We transcribed and analyzed the students' conversation in inquiry activities of small group with frameworks of linguistic behavior and three contexts of the classroom. The result of the study indicated that individual and group reflective inquiry could be affected by the relationship with peers more than their own characteristics.

• The Journal of Asian Finance, Economics and Business
• /
• v.7 no.9
• /
• pp.707-717
• /
• 2020

Global warming affects climate change and has an overall impact on all aspects of life. On the other hand, community behavior and disaster aspects also have an important role in people's lives. This will also have an impact on regional development. This study aims to find the effect of climate, disaster, and social community on rural development. This study uses data on the potential of rural development from PODES 2014, and 2018 data collection on climate conditions and regional status is sourced from relevant ministries. This research uses Ordinary Least Square (OLS) Regression Analysis method, then continued with CHAID analysis to find the segmentation of the role of climate, disaster, and social factors on rural development. The results of this study found that all research regressor variables significantly influence the Rural Development Index (IPD2018), with an R-squared value of 32.9 percent. Efforts need to be taken in order to implement policies that are targeted, effective, and efficient. The results of this study can be a reference for the government in determining policies by focusing on rural development that have high duration of sunshine, cultivating natural disaster warnings, especially in areas prone to natural disasters, and need to focus on underdeveloped areas.

• Journal of Korean Academy of Nursing
• /
• v.49 no.6
• /
• pp.771-782
• /
• 2019

Purpose: To determine the effects of a child and parent program on developing social skills for preventing violent behaviors in children aged 60~72 months through a specially developed pre and posttest, control group, quasi-experimental study. Methods: A social skills development program based on Gardner's Multiple Intelligence Theory was used. The data were collected using the Social Skills Assessment Scale (SSAS), a Chart to Monitor Verbal and Behavioral Violence in Children, the Parental Attitude Scale and the Parent Interview Form. This quasi-experimental study that included a pretest, posttest, and control group had a sample comprising 67 children and parents, with 36 in the experimental group, and 31 in the control group. Results: Over a six-month period, while the social skill scores of the children in the experimental and control groups increased, their violent behaviors decreased (p<.050). Increase in social skill scores and decrease in violent behaviors were higher in the experimental than in the control group children (p<.050). The parents in the experimental group stated that they had started to empathize with their children, using "I" language, and applied rules more consistently after the program. Conclusion: This program was successful in preventing violent behaviors in children through the development of social skills. Hence, it can be effectively implemented through a teacher/nurse collaboration.