• Journal of Korea Water Resources Association
• /
• v.54 no.12
• /
• pp.1255-1263
• /
• 2021

While it could become an alternative water resource, fog could undermine traffic safety and operational performance of infrastructures. To reduce such adverse impacts, it is necessary to have spatially continuous fog risk information. In this work, tree-based machine-learning models were developed in order to quantify fog risks with routine meteorological observations alone. The Extreme Gradient Boosting (XGB), Light Gradient Boosting (LGB), and Random Forests (RF) were chosen for the regional fog models using operational weather and visibility observations within the Jeollabuk-do province. Results showed that RF seemed to show the most robust performance to categorize between fog and non-fog situations during the training and evaluation period of 2017-2019. While the LGB performed better than in predicting fog occurrences than the others, its false alarm ratio was the highest (0.695) among the three models. The predictability of the three models considerably declined when applying them for an independent period of 2020, potentially due to the distinctively enhanced air quality in the year under the global lockdown. Nonetheless, even in 2020, the three models were all able to produce fog risk information consistent with the spatial variation of observed fog occurrences. This work suggests that the tree-based machine learning models could be used as tools to find locations with relatively high fog risks.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.1
• /
• pp.441-452
• /
• 2022

Training using metacognition in a learning environment is one of the topics that have been continuously studied since the 1990s. Metacognition can be broadly divided into declarative metacognitive knowledge and procedural metacognitive knowledge (metacognitive skills). Accordingly, metacognitive training has also been studied focusing on one of the two metacognitive knowledge. The purpose of this study was to examine the role of metacognitive skills training in the context of mathematical problem solving. Specifically, the learner performed the prediction of problem difficulty, estimation of problem solving time, and prediction of accuracy in the context of a test in which problems of various difficulty levels were mixed within a set, and this was repeated 5 times over a total of 5 weeks. As a result of the analysis, we found that there was a significant difference in all three predictive indicators after training than before training, and we revealed that training can help learners in problem-solving strategies. In addition, we analyzed whether there was a difference between the experiment group and control group in the degree of test anxiety and math achievement. As a result, we found that learners in the experiment group showed less emotional and relationship anxiety at 5 weeks. This effect through metacognitive skill training is expected to help learners improve learning strategies needed for test situations.

• The Mathematical Education
• /
• v.61 no.3
• /
• pp.477-497
• /
• 2022

The rapidly changing world calls for reform in mathematics education from lifelong learning perspectives. This study examines adults' perception of mathematics by reflecting on their experiences of mathematics in and out of school in order to understand what the current needs of adults are. With the two questions: "what experiences do participants have during their learning of mathematics in schools?" and "how do they perceive mathematics in their current life?", we analyzed the semi-structured interviews with 10 adults who have different sociocultural backgrounds using narrative inquiry methodology. As a result, participants tended to accept school mathematics as simply a technique for solving computational problems, and when they had not known the usefulness of mathematical knowledge, they experienced frustration with mathematics in the process of learning mathematics. After formal education, participants recognized mathematics as the basic computation skill inherent in everyday life, the furniture of their mind, and the ability to efficiently express, think, and judge various situations and solve problems. Results show that adults internalized school education to clearly understand the role of mathematics in their lives, and they were using mathematics efficiently in their lives. Accordingly, there was a need to see school education and adult education on a continuum, and the need to conceptualize the mathematical abilities required for adults as mathematical literacy.

• Journal of Korean Physical Therapy Science
• /
• v.15 no.4
• /
• pp.11-17
• /
• 2008

Background: Human body is formed of symmetric bilateral structures that are comprised of eye, upper arm, lower arm and etc. but, we are used only dominant components. The purpose of this study was to analysis length cognition ability in dominant eye. Methods: Total 88 persons (male 18, female 70) were participated in this study. They were tested with ‘hole in the card’ test for identification of dominant eye's side, then the length cognition ability was measured in right & left axillary level by describing 10cm line. Results: The results by independent t-test were as follows. In difference of length cognition ability in right axillary level between right dominant eyed group & left dominant eyed group, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). In left axillary level, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). Conclusion: These result can be applied to the learning of palpation & observation skill in physical therapy, although this study was not identify a relation between dominant eye & dominant hand.

• Physical Therapy Korea
• /
• v.12 no.4
• /
• pp.7-11
• /
• 2005

The purposes of this study were to investigate the effects of variability of training on the acquisition of motor skill of closed loop type tracking task using Rotary Pursuit, and to determine if there was a bilateral transfer effect to the non-dominant hand following practice with the dominant hand. Twelve healthy volunteer students (5 males and 7 females, aged 25 to 37) were randomly divided into a constant practice group and a variable practice group. A photoelectric rotary pursuit apparatus with stop clock and repeat cycle timer by Lafayette Instrumentation Co. was used for this study. Rotary pursuit is a closed loop task in which a subject attempts to keep a photoelectric stylus on a lighted target in motion. Subjects performed the clockwise circular pursuit task while standing. Experimental procedure was divided into three sessions, namely, pre-test, training, and post-test. The constant group practiced all 60 trials at 30 rpm. Variable practice group did a varied practice session with 15 trials at speeds of 20 rpm, 26 rpm, 34 rpm, and 46 rpm. No one in either group practiced with their non-dominant arm. A Mann-Whitney test and a Wilcoxon Signed Ranks test were used for statistical analyses. The results of this study showed no different training effect between groups on the post-test with the dominant hand. However, bilateral transfer effect of rotary pursuit task between hands was demonstrated. Possible mechanisms are discussed.

• International Journal of Advanced Culture Technology
• /
• v.4 no.1
• /
• pp.19-27
• /
• 2016

Technology in the animation industry has evolved significantly over the past decade. The tools to create animation are becoming more intuitive to use. Animators now spend more time on the artistic quality of their work than wasting time figuring out how to use the software that they rely on. However, one particular tool that is still unintuitive for animators is the motion graph editor. A motion graph editor is a tool to manipulate the interpolation of the movements generated by the software. Although the motion graph editor contains a lot of options to control the outcome of the animation, the emotional rhythm of the movements desired by the animator still depends on the animator's skill, which requires a very steep learning curve. More often than not, animators had to resort to trial and error methods to achieve good results. This inevitably leads to slow productivity, susceptible to mistakes, and waste of resources. This research will study the connection between the motion graph profile and the emotions they portray in movements. The findings will hopefully be able to provide animators reference materials to achieve the emotional animation they need with less effort.

• East Asian mathematical journal
• /
• v.32 no.4
• /
• pp.519-543
• /
• 2016

Today the high school mathematics lesson has an effect on the scholastic achievement internationally, but fails to lead to the interest in the mathematics which stimulates the intellectual curiosity. Due to this, 2015 revised curriculum includes the effort to improve the emotional aspect of mathematics positively. It is needed that the teaching method through discussion and debate must be introduced to accomplish the objective of the mathematics in 2015 revised curriculum focused on the improvement of the ability and attitude to solve the problems creatively by increasing the mathematical communication skill of the students. The purpose of this study is to investigate the effect of mathematical essay-typed lesson focused on discussion and debate on the mathematical disposition and attitude of high school student. The findings from this study provided that the essay-typed lessons focused on discussion and debate improved the subject students' mathematical achievement and disposition and attitude, but it is not significant change.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1995.10a
• /
• pp.124-140
• /
• 1995

The merit of fuzzy rule based systems stems from their capability of encoding qualitative knowledge of experts into quantitative rules. Recent advancement in automatic tuning or self-organization of fuzzy rules from experimental data further enhances their power, allowing the integration of the top-down encoding of knowledge with the bottom-up learning of rules. In this paper, methods of self-organizing fuzzy rules and of performing defuzzification and inference is presented based on a multi-resolution radial basis function network. The network learns an arbitrary input-output mapping from sample distribution as the union of hyper-ellipsoidal clusters of various locations, sizes and shapes. The hyper-ellipsoidal clusters, representing fuzzy rules, are self-organized based of global competition in such a way as to ensute uniform mapping errors. The cooperative interpolation among the multiple clusters associated with a mapping allows the network to perform a bidirectional many-to-many mapping, representing a particular from of defuzzification. Finally, an inference engine is constructed for the network to search for an optimal chain of rules or situation transitions under the constraint of transition feasibilities imposed by the learned mapping. Applications of the proposed network to skill acquisition are shown.

• The Mathematical Education
• /
• v.45 no.4 s.115
• /
• pp.439-457
• /
• 2006

This research was to understand the features of mathematization and didactical phenomenology, in a way that was not a routine calculation of equation, rather a complete comprehension by the reinventing historical principles of the equation. To achieve the purpose of this study, one-mate middle school student participated in the study. Interview and observation were used for collecting data during the student's performance. The results of research were: First, the student understood the mathematical concepts from a real life and developed the abstract concepts from it, which were very intimately related with his life. Second, the skill and formula definition were accomplished with the accompanying predicted and consequently derived mathematical concepts. Third, through the approach of using the history of mathematics, he became more interested in what he was doing and took lessons with confidence. Forth, the student performed his learning based on the historical reinventing principle under the proper guidance of a teacher.

• Journal of Educational Research in Mathematics
• /
• v.20 no.3
• /
• pp.241-254
• /
• 2010

Under the consideration of Chinese math education tradition and new educational orientation, we compared and analyzed Korea and China's lower-grade elementary school textbooks. The result was that Chinese textbook puts much emphases on practice, skill and repetition, presents condensed contents, provides various learning contents simultaneously, rich humorous expressions, and a lot of implicit representations. From these results, we presented some implications for our mathematics education, future textbook writing, and the follow-up studies.