• Journal of Elementary Mathematics Education in Korea
• /
• v.18 no.3
• /
• pp.459-474
• /
• 2014

The purpose of this study was to investigate the effects of mathematical instruction using GSP program on the symmetrical figures learning and self-directed learning attitude. According to the pretest result, the experiment group and the comparison group showed to be homogeneous groups. The experiment group has learned symmetrical figures for 9 hours using the GSP program and the comparison group has learned for 9 hours using the traditional method(paper and pen lesson). As the posttests, self-directed learning attitude test and symmetry figure understanding test were performed. The results obtained in this research are as follows; First, there was a significant difference in symmetry figure understanding test between the experiment group which learned through GSP program and the comparison group which learned through traditional method. Since there showed a very high achievement in the experiment group which learned using GSP, it can be inferred that GSP was very effective in the lessons of symmetrical movements. Second, there was a significant difference in self-directed learning attitude test between the experiment group and the comparison group. This seems to be because the length of the sides of the figures, size of the angles of the figures etc can be verified instantly and the students can correct by themselves and give feedbacks when they use GSP program. Students preferred drawing using the GSP over drawing using rulers and pencils, and they showed interest in the GSP program and they did not have burden in being wrong in their study and studied in various methods. And as they become familiar with the GSP program, they even studied other contents beyond the scope presented in the textbook.

• East Asian mathematical journal
• /
• v.37 no.4
• /
• pp.355-379
• /
• 2021

In this article, we investigated plane figures introduced in elementary school mathematics in the perspective of traditional classification, and also analyzed plane figures focused on the invariance of plane figures out of traditional classification. In the view of traditional classification, how to treat trapezoids was a key argument. In the current mathematics curriculum of the elementary school mathematics, the concept of sliding, flipping, and turning are introduced as part of development activities of spatial sense, but it is rare to apply them directly to figures. For example, how are squares and rectangles different in terms of symmetry? One of the main purposes of geometry learning is the classification of figures. Thus, the activity of classifying plane figures from a symmetrical point of view has sufficiently educational significance from Klein's point of view.

• Steel and Composite Structures
• /
• v.47 no.1
• /
• pp.1-17
• /
• 2023

This paper deals with the free vibration behavior of rotating composite beams reinforced with carbon nanotubes (CNTs) under uniform thermal loads. The temperature-dependent beam material is assumed to be a mixture of single-walled carbon nanotubes (SWCNTs) in an isotropic matrix and five different functionally graded (FG) distributions of CNTs are considered according to the variation along the thickness, namely the UD-uniform, FG-O, FG-V, FG-Λ and FG-X distributions where FG-V and FG-Λ are unsymmetrical patterns. Considering the Timoshenko beam theory (TBT), a new finite element formulation of functionally graded carbon nanotube reinforced composite (FGCNTRC) beam is created for the first time. And the effects of several essential parameters including rotational speed, hub radius, effective material properties, slenderness ratio, boundary conditions, thermal force and moments due to temperature variation are considered in the formulation. By implementing different boundary conditions, some new results of both symmetric and non-symmetrical distribution patterns are presented in tables and figures to be used as benchmark for further validation. In addition, as an alternative advanced composite application for rotating systems exposed to thermal load, the positive effects of CNT addition in improving the dynamic performance of the system have been observed and the results are presented in several tables and figures.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.18 no.3
• /
• pp.41-49
• /
• 2012

Most large-sized and tall-risen general hospitals of today fairly depend on in-patient wards in designing hospital styles. The core planning for the efficient movements of various people in the words should take into account the sustainable connections between/among the floors, as well as hospital structures and mechanical functions. This study sampled for the study 19 hospital in-patient wards and investigated their flat-core styles. It was found out that hospital structures are changing from symmetrical styles of triangles, quadrangles and rectangles through bending, configuring, transforming to efficient new styles. Symmetrically quadrangled flat-styles are made of multi-cores spread with main an sub-cores. In contrast, symmetrically triangled flat-styles place the open place in the middle in order to prevent from its deepening, and widened the depth line through changing the outdoor top point. Non-symmetrical rectangles minimized the depth value to maintain the recent styles used in the wards, and tended to prefer the transformed styles of quadrangles. The double-corridors easily transshaped from mono corridors reveals the triangled, W-shaped, or Y-shaped figures. The site area ratio of the cores is 11.95% in average. The number of beds which one elevator covers is 66.51 beds in average, and the size of site area which one elevator covers 216.68m. Most cores on the base floor clustered around the average value, with more than 1000 beds shoes 12.83%, does 12.93%, does 14.64%, does 14.58%, which says that the core ratio increases according to hospital beds.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.4
• /
• pp.751-757
• /
• 1997

Cherubism is an uncommon, benign fibrosseous lesion of the jaws that causes a progressive, painless, symmetrical expansion of the maxilla and mandible. It's autosomal dominance pattern of inheritance has been confirmed. A characteristic deformity is specific to this disease: hypertrophy of the mandible, swelling of cheeks and sometimes hypertrophy of maxilla with eyes tending to look up ; that looks like the Renaissance cherubs. It usually makes figures during childhood between 2-4 years of age and progresses until puberty, after which it spontaneously regresses 10 most cases. As a result of this case review, the management strategies for cherubismic children in standpoint of pediatic dentistry can be summarized as follows: 1. It can be detected early in childen through its characteristic clinical and radiographic features, which is confirmed by histopathological examination and familial history. 2. The supervision of arch space is required against its frequent sequelae, the early missing of primary teeth and eruption disorders of permanent teeth. 3. It is highly recommended to continue the periodic check-up with clinical and radiographic examination, leading to surgical intervention in cases of aggravation.

• Korean Journal of Cleft Lip And Palate
• /
• v.10 no.1
• /
• pp.39-56
• /
• 2007

The bilateral cleft lip, a more severe form of clefting than unilateral cleft lip, involves separation of the lip along philtral lines, isolating the central segment (prolabium). Bilateral cleft lip may be either symmetrical or asymmetrical, in which case the cleft lip is split more on one side than on the other. The cleft affects the obvious facial form as an anatomic deformity and has functional consequences, affecting the child's ability to eat, speak, hear, and breathe. Although there would seem to be quite a variance in reported figures, ratios of cleft lip with or without cleft palate have gone as high as 1:500 and as low as 1:1000. It is known that less than 10% of cleft lips are bilateral. Although bilateral cleft lip is less common than unilateral cleft lip, the deformity is more severe, and the reconstructive technique is more complex. Surgery is the only treatment necessary for patients with bilateral cleft lip. Accompanying the evolution of surgical repair is the increasingly important role of orthodontic support with early presurgical alveolar and nasal molding. Repositioning the maxillary and alveolar segments into a more anatomic position allows the surgeon to repair the lip and associated nasal deformity under more optimal conditions. The purpose of this article is to review the related anatomy, presurgical management, and surgical management of bilateral cleft lip.

• Journal of The Korean Association of Information Education
• /
• v.12 no.2
• /
• pp.141-149
• /
• 2008

Congruence of figure is a basic to learn a symmetrical figure and helps to understand the characteristics of figure and know the way of drawing figures. The knowledge of congruence provides us art attainments to understand design and fine pieces of art. However, it is difficult to expect the interaction between students or between teachers and students, because of spending too much time for cutting papers and making the shapes of figure during the class for establishing the concepts. This study utilized a question-based interaction model which would foster elementary school student's learning effectiveness and make them understood the concept of congruence, also developed a congruence learning system which could communicate in both synchronous and asynchronous situation.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.45 no.1
• /
• pp.71-82
• /
• 2022

Most of the predictions using machine learning are neutral predictions considering the symmetrical situation where the predicted value is not smaller or larger than the actual value. However, in some situations, asymmetric prediction such as over-prediction or under-prediction may be better than neutral prediction, and it can induce better judgment by providing various predictions to decision makers. A method called Asymmetric Twin Support Vector Regression (ATSVR) using TSVR(Twin Support Vector Regression), which has a fast calculation time, was proposed by controlling the asymmetry of the upper and lower widths of the ε-tube and the asymmetry of the penalty with two parameters. In addition, by applying the existing GSVQR and the proposed ATSVR, prediction using the prediction propensities of over-prediction, under-prediction, and neutral prediction was performed. When two parameters were used for both GSVQR and ATSVR, it was possible to predict according to the prediction propensity, and ATSVR was found to be more than twice as fast in terms of calculation time. On the other hand, in terms of accuracy, there was no significant difference between ATSVR and GSVQR, but it was found that GSVQR reflected the prediction propensity better than ATSVR when checking the figures. The accuracy of under-prediction or over-prediction was lower than that of neutral prediction. It seems that using both parameters rather than using one of the two parameters (p_1,p_2) increases the change in the prediction tendency. However, depending on the situation, it may be better to use only one of the two parameters.

• Communications of Mathematical Education
• /
• v.37 no.2
• /
• pp.299-327
• /
• 2023

In this study, we tried to find out the level of inductive reasoning ability and the aspects of visualization components shown in students in the class using exploratory software for the 'congruence and symmetry' unit in the second semester of the 5th grade of elementary school. To this end, classes using GeoGebra, one of the exploratory software, were conducted for a total of 19 students in one class of fifth graders in elementary school, and the results of the students' activities were analyzed. As a result of this study, the level of inductive reasoning ability of students remained at a similar level or developed, and it was shown that students inferred new properties of shapes using various functions of software inductively. In addition, in terms of visualization, students were able to quickly and easily draw shapes that met the conditions, and unlike the paper-and-pencil environment, using the 'measurement' and 'symmetry' functions, they transformed and manipulated complex yet precisely congruent and symmetrical external representations. Based on these analysis results, implications for the use of exploratory software in the area of figures were derived.

• School Mathematics
• /
• v.17 no.1
• /
• pp.35-46
• /
• 2015

In this paper, the teaching contents for angle and measure of an angle in elementary mathematics textbook between Korea and Japan were compared. From this comparison, the following five suggestions were presented as implications to improve the teaching contents for angle and measure of an angle in elementary mathematics textbook in Korea. First, it is necessary to reconsider the way of the definition of angle. There is no use of half line in elementary mathematics, except when to define angle, and the way to define angle and the way to define right angle are not consistent. Second, considering to associate the turning of plane geometrical figures to the $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, $360^{\circ}$ is necessary, and associating them is connected to dealing with point-symmetrical shapes in the fifth grade. Third, there is a need to deal with "the measures of angles are same." in comparing angles. This is possible by superimposing two angles in comparing the measures of them. Fourthly, it is necessary to consider the introduction of the rotational angle. Dealing with the $360^{\circ}$ as the rotational angle is related to explaining that the sum of measures of interior angles in quadrangle is $360^{\circ}$. Fifth, it is necessary to be connected with middle school mathematics curriculum. The term 'straight angle' is used in middle school, and to obtain the sum of the measures of the interior angles of a regular polygon is the contents to be dealt with in middle school.