• Research in Mathematical Education
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• v.25 no.2
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• pp.99-115
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• 2022

This study examined difficulties middle school students have in learning mathematics and proposed a flipped classroom consisting of Khan Academy activities, small-group problem solving, and mathematical modeling to help improve their learning. A mixed-method approach was used to identify difficulties students have in learning mathematics, explore how the flipped classroom helped them reduce the learning difficulties identified, and examine if there were differences in students' mathematics achievement and their affective characteristics after participating in the flipped classroom. Qualitative analyses showed that students had difficulties in understanding mathematical concepts and finding effective ways to learn as well as negative views towards learning mathematics. This study also found that each activity of the flipped classroom had a different impact on student learning. Before class, the Khan Academy activities were most likely to help students understand mathematical concepts. In class, small-group problem solving activities were most helpful for students who had trouble finding effective learning methods and environments. Mathematical modeling activities were most likely effective in changing students' negative views towards mathematics. A quantitative analysis showed that the flipped classroom not only significantly improved the students' mathematics achievement, but also positively affected their confidence and motivation and how much they valued learning mathematics.

• Archives of design research
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• v.9
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• pp.801-810
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• 1994

Design Problems are often both multidimensional and highly interactive. Very rarely does any part of a designed thing serve only one purpose. The activity of designing is thus a goal-directed activity and normally a goal-directed problem-solving activity. This means, problem solving is finding a way to get from some initial situation to a desired goal. Designers are transforming agents within a society whose goals are to improve the human condition through physical metamorphosis. Many theorist have agreed that designing involves problem solving or decision making. Accordingly evaluation plays an essential role in design activity. The evaluation factors include all attributes that have levels specified by quantitative and qualitative objectives Alternatives in multi-objective decision prOblems generally possess numerous attributes by which they can be described and compared. The evaluation factors include all attributes that have levels specified by quantitative and qualitative objectives. However since qualitative factors are difficult to quantify as numeral estimates, these factors have tended to be ignored without regard for their importance to human content. We adapted the Accumulative Evaluation Model as an evaluation algorithm for IDES. Industrial Design Evaluation System (IDES) consists of 3 major modules ( 1 Design Element, 2.Matrix, 3.Evaluation). It is intended to be an aid for design evaluation. The luther thinks IDES is a new design evaluation approach which could provide effective rating of design values to make value judgements. It is an attempt to provide industrial designers with access to design evaluation. The author's aim is to produce an Object-Oriented Evaluation System which can guide the designers and decision makers under complex design projects. It uses\ulcorner an Object-Oriented Programming for this prototype, Because of managing complexity (Flexibility and Reusability) and improving productivity(Extensibility & Maintainability and Programming by User) in software development process. The author has chose the C++ because it is a hybrid, rather than pure Object-Oriented Language.

• Journal of the Korean earth science society
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• v.24 no.7
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• pp.604-613
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• 2003

The purpose of this study was to investigate the effect of a metastrategic activity on the development of student variable controlling abilities. Three groups of seventh graders at a middle-school in the City of Daegu participated in this study: a metastrategy activity group (ME), a problem-solving activity group (PR), and a control group (CO). The ME group was given metastrategy activity worksheets, which required students to monitor, control, and evaluate variable control strategies in a specified situation. The PR group was given problem-solving activity worksheets, which were needed to solve problems in various situations. The results were seen as follows. First, the metastrategy activity group showed better achievement (p<.05) and a longer standing effect (p<.01) than the other groups in the development of variable control ability. The problem-solving activity group was more effective than the control group (p<.05) in the development of variable controlled ability, but there was no lasting effect of the acquired ability. Second, the metastrategic activity group was more effective than the problem-solving activity group in finding fixed variables (p<.01), but not as effective in uncovering independent variables. What is not transferred to the development of the ability to find dependent variables.

• International Journal of Contents
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• v.16 no.4
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• pp.26-38
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• 2020

Determining the optimal levels of the technical attributes (TAs) of a product to achieve a high level of customer satisfaction is the main activity in the planning process for quality function deployment (QFD). In real applications, the number of customer requirements for developing a single product is quite large, and the number of converted TAs is also high so the size of the house of quality (HoQ) becomes huge. Furthermore, the TA levels are often discrete instead of continuous and the product market can be divided into several market segments corresponding to the number of HoQ, which also unacceptably increases the size of the QFD optimization problem and the time spent on making decisions. This paper proposed a genetic algorithm (GA) solution approach to finding the optimum set of TAs in QFD in the above situation. A numerical example is provided for illustrating the proposed approach. To assess the computational performance of the GA, tests were performed on problems of various sizes using a fractional factorial design.

• Atmosphere
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• v.20 no.4
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• pp.495-503
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• 2010

Satellite data have an intrinsic problem due to a number of various physical parameters, which can have a similar effect on measured radiance. Most evaluations of satellite performance have relied on comparisons with limited spatial and temporal resolution of ground-based measurements such as soundings and in-situ measurements. In order to overcome this problem, a new way of satellite data evaluation is suggested with statistical tools such as empirical orthogonal function(EOF), and singular value decomposition(SVD). The EOF analyses with OMI and OMI HCHO over northeast Asia show that the spatial pattern show high correlation with population density. This suggests that human activity is a major source of as well as HCHO over this region. However, this analysis is contradictory to the previous finding with GOME HCHO that biogenic activity is the main driving mechanism(Fu et al., 2007). To verify the source of HCHO over this region, we performed the EOF analyses with vegetation and HCHO distribution. The results showed no coherence in the spatial and temporal pattern between two factors. Rather, the additional SVD analysis between $NO_2$ and HCHO shows consistency in spatial and temporal coherence. This outcome suggests that the anthropogenic emission is the main source of HCHO over the region. We speculate that the previous study appears to be due to low temporal and spatial resolution of GOME measurements or uncertainty in model input data.

• Journal of KIISE
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• v.43 no.9
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• pp.1015-1025
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• 2016

Currently, software testing is becoming increasingly important in the industrial field and a large body of research supports the improvement of efficient software testing. Model-based testing is generally used to formalize user requirement data for test design. Complex system that includes loop and concurrency has a high probability of path explosion problem. Specially, as threads are added to concurrency, test scenarios have also increased exponentially. However, it is difficult to solve this problem using existing techniques. In this paper, we propose novel path-search technique that focuses on behavioral features of concurrency path in order to avoid path explosion problem. A system that contains concurrent paths is represented by activity diagram in case study section. Efficiency of our study is shown through comparison with several generated test scenarios of other studies. The result indicate that our approach is efficient for finding faults in loop and concurrency with fewer test scenario.

• Education of Primary School Mathematics
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• v.6 no.2
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• pp.75-84
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• 2002

After entering an elementary school, in fact, a number of children regard mathematics as one of very difficult subjects because of its abstractiveness. This is caused by the fact that their basic thinking power is not yet formed or they can not understand the special quality of mathematics. So this article emphasizes the need to build up the higher logical thought and a basic mathematical concept at the lower grade elementary school stage in which the loaming activity on mathematics begins in earnest, that is, at the stage before having an experience on the calculating activity using numbers. But at present the lower grade elementary school students in our country do not understand the special quality of mathematics composed of a various symbolic system and lay stress upon mathematics learning attached to the calculative activity. In order to make the right mathematical concept of the lower grade elementary school, the basic knowledge and ability as follows is sure to be formed. 1) the foundational logical manipulation activity and knowledge 2) the using ability of the sign and symbolic system At the stage on which mathematics learning activity begins, it is a very important task to make the right concept of the abstractive math and nurse the capability for finding mathematical relations covered under the sign system through the continuos loaming activity on . Through the basic logical manipulation activity and the game activity of sign for lower grade elementary school students mentioned in this article, they can not only foster the higher level logical thinking power and the foundational calculative ability but also bring up the interest on the activity of establishing a new problem solving strategy.

• School Mathematics
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• v.11 no.3
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• pp.527-546
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• 2009

This study was designed to gain insights into instrumental genesis process of CAS in Korean high school students and to explore its practical potentials in secondary mathematics education. Two activities, such as Concept-Centered Mathematics Activity based on CAS and Problem Solving Activities, were constructed and executed to 10th Grade seven students for twelve class hours. The finding on the students' activities are as follows : it is meaningful in mathematics education, especially in algebra education, in that the CAS based concept centered mathematics activity offers great opportunities to deal with high-qualified application problems. The problem solving activities based on the instrumented CAS may have an influence on the sequence of mathematics curriculum, e.g. the optimization problems may precede the calculus problems such as derivatives in high school. The results of this study to investigate the instrumental genesis of CAS in mathematical activities will give insights into the secondary mathematics curriculum to prepare the CAS in Korea.

• Korean Journal of Social Welfare
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• v.58 no.1
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• pp.347-372
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• 2006

Drinking Problems among college students have been increasing and being severe social problems. When it is compared with other areas, the research about drinking problems of college students are rare. This study was to examine psychosocial factors influencing on problem drinking among college students. The sample size of this study was 414, which made it possible to do statistical inference. AUDIT was applicated to measure the drinking problems in college student. As statistical method, $X^2$-test, t-test, hierarchial multiple regression analysis were used. The main finding provided that drinking problem of college students was more severe than adult one. Especially binge drinking pattern was remarkable. Male student had many alcohol problems than female students. This study also revealed gender, religious activity, first drinking age, sensation -seeking, drinking motivation, parents' drinking problem, schoolwork record, peer influence had significant direct impact in problem drinking of college students. Based on the results of this study, the author suggested some practical implication and preventive program based on the results and added further study tasks.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.3 s.39
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• pp.263-270
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• 1991

The main purpose of this study was to give a right and proper direction in high school girls' uniforms through the comparison of the attitude toward school uniforms and free choice of wearing clothings. The samples were consisted of 319 high school girls' students in Gwanju and Mokpo. The data were analyzed using frequency, percentage and chi-square test. The finding of this study can be summarized as follows: 1. Students prefered to take uniforms than self·control clothes. The greatest reason for the agreement on uniforms is th,It uniforms make sure the identity of the students. The problem in uniform was the disconvenience for activity. 2. Preference for uniform style was semi-fitted double jacket, flat collar blouse, vest and pleated skirt. 3. They make choice of prefering color were green, bluepurple and white, free-choice clothing color were green, light yellow and light blue and uniform color were bluepurple, darkblue and black.