• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.67-75
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• 2022

The purpose of this study is to present an appropriate management plan as a supplement to the scientific evidence of the currently operated distancing system for preventing COVID-19. The currently being used mathematical models are expressed as simultaneous ordinary differential equations, there is a problem in that it is difficult to use them for the management of entry and exit of small business owners. In order to supplement this point, in this paper, a method for quantitatively expressing the risk of infection by people who gather is presented in consideration of the allowable risk given to the gathering space, the basic infection reproduction index, and the risk reduction rate due to vaccination. A simple quantitative model was developed that manages the probability of infection in a probabilistic level according to a set of visitors by considering both the degree of infection risk according to the vaccination status (non-vaccinated, primary inoculation, and complete vaccination) and the epidemic status of the virus. In a given example using the model, the risk was reduced to 55% when 20% of non-vaccinated people were converted to full vaccination. It was suggested that management in terms of quarantine can obtain a greater effect than medical treatment. Based on this, a generalized model that can be applied to various situations in consideration of the type of vaccination and the degree of occurrence of confirmed cases was also presented. This model can be used to manage the total risk of people gathered at a certain space in a real time, by calculating individual risk according to the type of vaccine, the degree of inoculation, and the lapse of time after inoculation.

• The Mathematical Education
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• v.61 no.1
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• pp.1-28
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• 2022

The purpose of this study is to explore how students' fractional knowledge is related to their solving of proportion problems. To this end, 28 clinical interviews with four middle-grade students, each lasting about 30~50 minutes, were carried out from May 2021 to August 2021. The present study focuses on two 7th grade students who exhibited their ability to coordinate three levels of units prior to solving whole number problems. Although the students showed interiorization of three levels of units in solving whole number problems, how they coordinated three levels of units were different in solving proportion problems depending on whether the problems required reasoning with whole numbers or fractions. The students could coordinate three levels of units prior to solving the problems involving whole numbers, they coordinated three levels of units in activity for the problems involving fractions. In particular, the ways the two students employed partitioning operations and how they coordinated quantitative unit structures were different in solving proportion problems involving improper fractions. The study contributes to the field by adding empirical data corroborating the hypotheses that students' ability to transform one three levels of units structure into another one may not only be related to their interiorization of recursive partitioning operations, but it is an important foundation for their construction of splitting operations for composite units.

• Korean Journal of Child Education & Care
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• v.17 no.4
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• pp.145-161
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• 2017

The purpose of this study was to analyze the relationship among NCS basic vocational competencies, Teaching Personality Aptitude and DISC behavior type of pre-preschool teachers. The subjects were 110 pre-preschool teachers attended in D university located in Kyonggido. 'NCS basic vocational competencies scale', 'Teaching Personality and Aptitude scale', and 'DISC behavior type scale' were used in the collection of data. It used Pearson's correlation Analysis to analyze the data. The results of this study are as follows; first, there was positive correlations between dominance trait and mathematical competency. And, there was positive correlations between interaction trait and self-development competency. And there were negative correlations between support traits and NCS basic vocational competencies. Second, it was revealed that positive correlations between almost sub scale's of NCS basic vocational competencies and teacher teaching personality aptitude. Third, there was positive correlations between dominance trait and sub scale of teaching personality aptitude(e.g.: problem solving/ inquiry skills, judgment, creativity/practical ability, leadership, knowledge/information ability, planning ability, sincerity/responsibility). And there were negative correlations between support traits and sub scale of teaching personality aptitude(e.g.: problem solving/ inquiry skills, judgment, creativity/practical ability, leadership, sincerity/responsibility).

• Journal of the Korean School Mathematics Society
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• v.6 no.1
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• pp.65-85
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• 2003

The purpose of this research is to increase mathematical problem solving abilities VIa STAD evaluation after completing classes. to which ST AD group study is applied, and promoting the learning accomplishments of students by developing gradual self-leading learning materials about the research project on ' How to use an hour math class efficiently\ulcorner ' For this purpose, the items below were studied. Firstly, gradual self-leading learning materials were developed and applied which were composed of textbook abstracts, basic problems, developing problems and intensive problems rather than existing textbooks. Secondly, the ST AD group study model was selected and applied which invokes competitions among small groups of which learning goals were clear. individual responsibility was important. and successive opportunities were equal. The evaluation using STAD at each end of a chapter was announced instantly using the EXCEL scoring system. Though the results of experimental classes were limited in their size. experimental time, and class selection, there were meaningful changes in the aspect of being able to heighten the accomplishment desire of students by inducing voluntary competitions among small groups without any student omitted. As the result of applying this research to my class, the ST AD group study using gradual self-leading learning materials invoked the interests of students and increased learning accomplishments via increasing problem solving abilities in mathematics. The ST AD group study was easy to use by beginning teachers, and its process was simple. It increased interactions among students and learning motives because its compensation system was open to all students. Among various studying methods for small groups. STAD group study is expected to be widely used for mathematics classes.

• Journal of Educational Research in Mathematics
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• v.23 no.2
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• pp.213-235
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• 2013

The purpose of this study is to analyze how the teaching activities which used EXCEL influence the specialized high school underachieved students. They have difficulties in making use of various representations for better understanding of function. EXCEL is helpful for learning function because it enables the students to use real life materials in math learning as well as formulates Tabular, Algebraic and Graphical which represent function. Furthermore, the students in specialized high school also have the experience of using EXCEL while studying other subjects. For that reason they have no burdens and fears on using EXCEL in learning activities. Utilizing EXCEL in the classroom gives an expectation that it helps to have interests on studying function and prepare for the next learning in the end. Research classes were conducted in a group of five students who have different hopes of career and a variety of mathematical interests. Though the students couldn't transfer Algebraic to Graphical in the diagnostic evaluation, they could resolve the problem of connections between Graphical, Tabular and Algebraic in the process perspectives, and could also express graphical representation by linking object perspectives with process perspectives. Therefore, they solved the connection problem of Tabular, Algebraic and Graphical in the object perspectives. As a result, the students could make transitions between Algebraic and Graphical in object perspectives through the classes applying EXCEL. Consequently, teaching the students with underachievement utilizing EXCEL enables them to recover their interests on math and it helps them to complete their following curriculum.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.483-496
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• 2018

NCS (National Competency Standards) has emerged as an issue of great importance amongst Korean universities and corporations. Although previously used mostly for vocational education purposes at colleges, NCS is currently receiving an increasing amount of attention from 4-year universities as well. In the ever-evolving information economy, the basic workplace skills defined by NCS, which include soft skills such as communication skills, problem-solving skills, and interpersonal skills, have now become more important than specific technical skills. This study analyzes the correlation between the basic workplace skills of NCS with participation in Formula SAE activities, a common component of Capstone design courses across North America and Europe. Data are derived from site visits to Formula SAE competitions, competition-related documents drafted by student participants, and questionnaires administered to student participants at the Formula SAE Lincoln completion and at the Korea KSAE competition. From the study findings, we claim that the basic workplace skills of NCS are closely correlated to participation in Formula SAE activities. Through a survey designed to measure the degree to which Formula SAE activities can enhance an individual's NCS Basic Workplace Skills, we find that these activities overall improved NCS basic workplace skills averaging 4.0 points above in the Likert 5-point scale. For reference the mathematical skills, communication skills, and problem-solving skills displayed statistically significantly correlation with NCS but the remaining 7 skills did not show a statistically strong correlation with NCS comparatively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.805-811
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• 2012

The reliability based design optimization (RBDO) approach requires high computing cost to consider uncertainties. In order to reduce the design cost, the single loop single vector (SLSV) approach has been developed for RBDO. This method can reduce the cost in calculating deign sensitivity by elimination of the nested optimization process. However, this process causes the increment of the instability or inaccuracy of the method according to the problem characteristics. Therefore, the method may not give accurate solution or the robustness of the solution is not guaranteed. Especially, when the function is concave, the process frequently diverges. In this research, the concept of the conjugate gradient method for unconstrained optimization is utilized to develop a new single loop single vector method. The conjugate gradient is calculated with gradient directions at the most probable points (MPP) of previous cycles. Mathematical examples are solved for the verification of the proposed method. The numeri cal performances of the obtained results are compared to those of other RBDO methods. The SLSV approach using conjugate gradient is not greatly influenced by the problem characteristics and improves its convergence capability.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.159-165
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• 2018

This study was conducted to investigate the convergence effects of key vocational competency on career decision making in dental hygiene students. To this end, 196 students with an experience of clinical field training, who were enrolled in the department of dental hygiene in universities of Busan and Ulsan area. The collected data were analyzed by frequency analysis, correlation analysis and linear regression analysis using SPSS 24.0 program. The subjects' awareness level of key vocational competency was 3.38 points, while that of career decision making was 3.30 points. Among the sub-factors of key vocational competency, the awareness level of professional ethics was 3.46 points, which was the highest. As factors of key vocational competency affecting career decision making, interpersonal skills(p<0.01), skills for understanding groups(p<0.01), resource management skills(p<0.01), self-development skills(p<0.05), problem-solving skills(p<0.05), and mathematical skills(p<0.05) were found to be significant. It is necessary to make student individual, departmental, and university level convergence efforts and to develop curriculum so that dental hygiene education can help students equip with the key vocational competency as well as major competency.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.304-315
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• 2018

Harmony Search (HS) is a recently developed metaheuristic algorithm that is widely known to many researchers. However, due to the increasing complexity of optimization problems, the optimal solution cannot be efficiently found by HS. To overcome this problem, there have been many studies that have improved the performance of HS by modifying the parameter settings and incorporating other metaheuristic algorithms. In this study, Copycat HS (CcHS) is suggested, which improves the parameter setting method and the performance of searching for the optimal solution. To verify the performance of CcHS, the results were compared to those of HS variants with a set of well-known mathematical benchmark problems. The effectiveness of CcHS was proven by finding final solutions that are closer to the global optimum than other algorithms in all problems. To analyze the applicability of CcHS to engineering optimization problems, it was applied to a design problem for Water Distribution Systems (WDS), which is widely applied in previous research. As a result, CcHS proposed the minimum design cost, which was 21.91% cheaper than the cost suggested by simple HS.

• Journal of Educational Research in Mathematics
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• v.17 no.2
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• pp.163-177
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• 2007

Studies on mathematically gifted students have been conducted following Krutetskii. There still exists a necessity for a more detailed research on how these students' mathematical competence is actually displayed during the problem solving process. In this study, it was attempted to analyse the algebraic thinking process in the problem solving a peg puzzle in which 4 mathematically gifted students, who belong to the upper 0.01% group in their grade of elementary school in Korea. They solved and generalized the straight line peg puzzle. Mathematically gifted elementary school students had the tendency to find a general structure using generic examples rather than find inductive rules. They did not have difficulty in expressing their thoughts in letter expressions and in expressing their answers in written language; and though they could estimate general patterns while performing generalization of two factors, it was revealed that not all of them can solve the general formula of two factors. In addition, in the process of discovering a general pattern, it was confirmed that they prefer using diagrams to manipulating concrete objects or using tables. But as to whether or not they verify their generalization results using generalized concrete cases, individual difference was found. From this fact it was confirmed that repeated experiments, on the relationship between a child's generalization ability and his/her behavioral pattern that verifies his/her generalization result through application to a concrete case, are necessary.