• Journal of The Korean Society of Grassland and Forage Science
• /
• v.43 no.1
• /
• pp.11-21
• /
• 2023

This study was conducted to estimate the damage of Whole Crop Corn (WCC; Zea Mays L.) according to abnormal climate using machine learning as the Representative Concentration Pathway (RCP) 4.5 and present the damage through mapping. The collected WCC data was 3,232. The climate data was collected from the Korea Meteorological Administration's meteorological data open portal. The machine learning model used DeepCrossing. The damage was calculated using climate data from the automated synoptic observing system (ASOS, 95 sites) by machine learning. The calculation of damage was the difference between the dry matter yield (DMY)_normal and DMY_abnormal. The normal climate was set as the 40-year of climate data according to the year of WCC data (1978-2017). The level of abnormal climate by temperature and precipitation was set as RCP 4.5 standard. The DMY_normal ranged from 13,845-19,347 kg/ha. The damage of WCC which was differed depending on the region and level of abnormal climate where abnormal temperature and precipitation occurred. The damage of abnormal temperature in 2050 and 2100 ranged from -263 to 360 and -1,023 to 92 kg/ha, respectively. The damage of abnormal precipitation in 2050 and 2100 was ranged from -17 to 2 and -12 to 2 kg/ha, respectively. The maximum damage was 360 kg/ha that the abnormal temperature in 2050. As the average monthly temperature increases, the DMY of WCC tends to increase. The damage calculated through the RCP 4.5 standard was presented as a mapping using QGIS. Although this study applied the scenario in which greenhouse gas reduction was carried out, additional research needs to be conducted applying an RCP scenario in which greenhouse gas reduction is not performed.

• Journal of The Korean Association For Science Education
• /
• v.33 no.1
• /
• pp.17-29
• /
• 2013

High school 'science' in the 2009 revised curriculum in Korea was developed for the purpose of enhancing students' scientific literacy needed for citizenship in a democratic society. For this analysis, 'science' includes a variety of scientific topics from the origin of the universe to the birth of life, and the relationship between technology and modern society. It aims to make students understand the process of scientific inquiry and foster interest and curiosity about science. On the other hand, interest has been studied as a psychological construct to affect academic achievement and career selection of students. In this study, the authors investigated students' interest in high school 'science' in view of the 2009 revised curriculum. To carry this out, a survey tool was developed according to previous research, with 997 high school students' responses analyzed with descriptive statistics and factor analysis. The result showed that the students' interest in high school 'science' in view of the 2009 revised curriculum can be interpreted into three dimensions such as motivation, activity, and topic, which has several sub-dimensions. Students' interest in motivation dimension was higher than in activity or topic dimension, while the average value was slightly higher than the middle value. They showed different distribution of interest by gender and job orientation, especially in activity and topic dimensions. From this study, the authors can infer the multi-dimensional property of students' interest in high school 'Science' and the different distribution of interest by dimensions.

• Journal of The Korean Association For Science Education
• /
• v.42 no.4
• /
• pp.429-438
• /
• 2022

In this study, we propose a way to improve science teacher expertise through infographics creation teacher training program by analyzing the infographics types focusing on the Earth Science subject of the 2015 revised curriculum, and inspecting the teachers' utilization of graphic tools. The data visualization characteristics of Earth Science textbooks were analyzed, the execution results of the infographics creation teacher training program were presented, and a survey on science teachers' change in perception and competency of infographics. As a result of the Earth Science textbook analysis, diagram-type, map-type, and comparative analysis-type infographics were frequently used, and were mainly presented as text-assisted-type infographics. The infographics creation teacher training program was conducted five times for 112 science teachers to create the complete, text-assisted, incomplete, and gradient-type infographics. Incomplete infographics for development of evaluation questions were most needed. Although many science teachers recognize the importance of infographics, they lacked the competency to create high-quality infographics because there were no training opportunities for infographics creation. After completing the training, 74.1% of teachers felt that the quality of developments of supplementary textbooks and evaluation questions had improved, and answered that it was helpful in re-educating knowledge and improving teaching-learning methods. Based on the research results, ways to improve science teacher expertise through infographics creation teacher training program were suggested.

• Korean Journal of Remote Sensing
• /
• v.39 no.5_3
• /
• pp.1009-1029
• /
• 2023

Urban trees play a vital role in urban ecosystems,significantly reducing impervious surfaces and impacting carbon cycling within the city. Although previous research has demonstrated the efficacy of employing artificial intelligence in conjunction with airborne light detection and ranging (LiDAR) data to generate urban tree information, the availability and cost constraints associated with LiDAR data pose limitations. Consequently, this study employed freely accessible, high-resolution multispectral satellite imagery (i.e., Sentinel-2 data) to estimate fractional tree canopy cover (FTC) within the urban confines of Suwon, South Korea, employing machine learning techniques. This study leveraged a median composite image derived from a time series of Sentinel-2 images. In order to account for the diverse land cover found in urban areas, the model incorporated three types of input variables: average (mean) and standard deviation (std) values within a 30-meter grid from 10 m resolution of optical indices from Sentinel-2, and fractional coverage for distinct land cover classes within 30 m grids from the existing level 3 land cover map. Four schemes with different combinations of input variables were compared. Notably, when all three factors (i.e., mean, std, and fractional cover) were used to consider the variation of landcover in urban areas(Scheme 4, S4), the machine learning model exhibited improved performance compared to using only the mean of optical indices (Scheme 1). Of the various models proposed, the random forest (RF) model with S4 demonstrated the most remarkable performance, achieving R² of 0.8196, and mean absolute error (MAE) of 0.0749, and a root mean squared error (RMSE) of 0.1022. The std variable exhibited the highest impact on model outputs within the heterogeneous land covers based on the variable importance analysis. This trained RF model with S4 was then applied to the entire Suwon region, consistently delivering robust results with an R² of 0.8702, MAE of 0.0873, and RMSE of 0.1335. The FTC estimation method developed in this study is expected to offer advantages for application in various regions, providing fundamental data for a better understanding of carbon dynamics in urban ecosystems in the future.

• Journal of The Korean Association For Science Education
• /
• v.30 no.1
• /
• pp.13-26
• /
• 2010

The purpose of the study was to investigate the effect of observation knowledge generation based on a scientific observation strategy in 6th grade students. In this study, we selected the topics related to the observation in elementary science curricula and developed worksheets and guidelines such that subjects accomplished the systematic observation based on the method and strategy of the observation knowledge generation. Seventy-five 6thgraders, 38 for the experimental group and 37 for the control group, were chosen for this study. The experimental group was taught the science lessons with 14 sessions based on the generation of various scientific observation types, whereas the control group was provided with traditional lessons. Before and after the treatment, a candle-burning task was set for subjects to test the effect of the lessons of scientific observation knowledge generation. According to the results, subjects in the experimental group were more effective in the generation of various observations than subjects in the traditional one. The observation abilities of the experimental group was shown statistically to have a significantly higher performance in richness and the diversity. In addition, they showed higher scores in the scientific observation ability task than the control one. Therefore, the systematic lesson strategy in scientific observation is presumably effective to improve students' ability of scientific observation knowledge generation.

• Journal of The Korean Association For Science Education
• /
• v.41 no.6
• /
• pp.519-531
• /
• 2021

This study investigates the science teacher identity of pre-service science teachers (PSTs) in the context of a teaching practice course. Twenty-two PSTs who took the 'Biological Science Lab. for Inquiry Learning' course at the College of Education participated in this study. Artifacts created during the course were collected, and the teaching practices and reflections were recorded and transcribed. In addition, semi-structured interviews were conducted with nine PSTs, recorded, and transcribed. We found the science teacher identity was not well revealed at the beginning of the course. Authoritative discourse appeared in the early oral reflections of PSTs, indicating that the PSTs perceived oral reflection activities as 'evaluation activities for teaching practice'. This perception shows that pre-service teachers participate in teaching practice courses as students attending a university, performing tasks and receiving evaluations from instructors. After the middle of the course, discourses showing the science teacher identity of the PSTs were observed. In the oral reflection after the middle part, dialogic discourses often arose, showing that the PSTs perceive the oral reflection activities as a 'learning activity for professional development'. In addition, in the second half, discourse appeared to connect and interpret one's experience with the teacher's activity, indicating that the PSTs perceive themselves as teachers at this stage. In addition, the perception of experimental classes was expanded through the course. During the course, the practice of equalizing the authority of the participants, providing a role model for reflection, and experiencing various positions from multiple viewpoints in the class had a positive effect on the formation and continuation of the teacher identity. This study provides implications on the teacher education process for teacher identity formation in PSTs.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.42 no.2
• /
• pp.127-136
• /
• 2022

This study was conducted to estimate the damage of Whole Crop Maize (WCM) according to abnormal climate using machine learning and present the damage through mapping. The collected WCM data was 3,232. The climate data was collected from the Korea Meteorological Administration's meteorological data open portal. Deep Crossing is used for the machine learning model. The damage was calculated using climate data from the Automated Synoptic Observing System (95 sites) by machine learning. The damage was calculated by difference between the Dry matter yield (DMY)_normal and DMY_abnormal. The normal climate was set as the 40-year of climate data according to the year of WCM data (1978~2017). The level of abnormal climate was set as a multiple of the standard deviation applying the World Meteorological Organization(WMO) standard. The DMY_normal was ranged from 13,845~19,347 kg/ha. The damage of WCM was differed according to region and level of abnormal climate and ranged from -305 to 310, -54 to 89, and -610 to 813 kg/ha bnormal temperature, precipitation, and wind speed, respectively. The maximum damage was 310 kg/ha when the abnormal temperature was +2 level (+1.42 ℃), 89 kg/ha when the abnormal precipitation was -2 level (-0.12 mm) and 813 kg/ha when the abnormal wind speed was -2 level (-1.60 m/s). The damage calculated through the WMO method was presented as an mapping using QGIS. When calculating the damage of WCM due to abnormal climate, there was some blank area because there was no data. In order to calculate the damage of blank area, it would be possible to use the automatic weather system (AWS), which provides data from more sites than the automated synoptic observing system (ASOS).

• Journal of Science Education
• /
• v.35 no.2
• /
• pp.173-192
• /
• 2011

The purpose of this study was to develop inquiry modules for learning straight propagation of light, to verify their efficiency, and to acquire implications. this study proposes teaching modules for improvements of light experiments, which were developed in this work. Inquiry modules were applied to 75 school teachers(8 elementary school teachers, 67 middle school and high school teachers) for examining that the modules make teachers have the scientific concepts. Then, conception changes were analyzed except 5 teachers who responded poorly. The pre-test result shows that most teachers have alternative conceptions, which is that they thought the bright shape on apparatus's bottom panel itself shown in the textbook as evidence for the path of light's straight propagation. The post-test result shows this alternative conception was changed into scientific conception. Unlikely pretest, most teachers' conception was changed into the scientific conception that the light come from a light source. Teachers are able to express that the light beam comes from a miniature electric bulb. Further more, most teachers can draw light's path correctly; from the miniature electric bulb, through vertical panel having a hole, to the apparatus bottom.

• Journal of dental hygiene science
• /
• v.4 no.3
• /
• pp.97-102
• /
• 2004

In order to find out the rate of error according to intraoral standard radiographic techniques, this study analyzed 3,251 standard films, and conducted a questionnaire with 120 Daegu Health College students who have used the bisecting angle technique and the paralleling technique. Followed are the results of the study: 1. The rate of error was the highest in canine from both maxilla and mandible when used by the bisecting angle technique. 2. The rate of error was the highest in premolar from both maxilla and mandible when used by the paralleling technique. 3. The technical error was occurred most frequently in elongation. 4. The rate of error and distortion was higher in the bisecting angle technique than in the paralleling technique. 5. The processing error was occurred most frequently in light film. 6. In applying radiographic techniques, the subjects indicated that the vertical angulation of central radiation in the bisecting angle technique and the oral fixation of film holder in the paralleling technique were the most difficult.

• Journal of the Korean earth science society
• /
• v.32 no.7
• /
• pp.860-870
• /
• 2011

This study is to explore the Pedagogical Content Knowledge of beginning earth science teachers about the porphyritic texture of igneous rocks, and to suggest the teaching device that can prevent a trial and error of students in earth science instruction. We developed an interview guideline concerned with basic perception on the porphyritic texture, formation condition and formation process of porphyritic rocks, teaching and learning on porphyritic rocks for it. And data was collected from 5 beginning earth science teachers (3 high schools, 2 middle schools) through a group discussion method. In result, despite the porphyritic texture can be found at hypabyssal rocks as well as volcano rocks and plutonic rocks, most beginning earth science teachers cognized that it could be found at hypabyssal rocks only by focusing the formation depth of hypabyssal rocks. Also, the formation of porphyritic texture should be considered the factors such as cooling rate, nucleation density, growth rate, growth time, etc. However they mainly reflected the formation temperature and growth rate as it's parameter. Participants have wrongly perceived that a phenocryst necessarily differs from a groundmass on chemical composition. And they are inclined to discriminate phenocryst from groundmass through their chemical differences, instead of grain size.