• The Mathematical Education
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• v.49 no.3
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• pp.375-387
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• 2010

The focus of this article is the strategies young children use to solve rectangular covering tasks before they have been taught area measurement. seventy nine children from Grade 1 to 4 were observed while they solved various array-based tasks, and their drawing and explanation were collected and analyzed. Children's solution strategies were classified into incomplete covering, inadequate array, array constructed from moveable unit, measurement of one dimension, measurement of two dimension, and calculation. Implications for the learning of area measurement are addressed.

• The Mathematical Education
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• v.58 no.2
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• pp.283-298
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• 2019

Among the measurement attributes included in the elementary school mathematics curriculum, perimeter, area, volume and surface area are intensively covered in fifth and sixth graders. However, not much is known about the level of student performance and difficulties in this area. The purpose of this study is to examine the understanding and performance of sixth-grade elementary school students on some ideas of measurement and ultimately to give some suggestions for teaching measurement and the development of mathematics textbooks. For this, diagnosis questions were developed in relation to the following parts: measurement of perimeter and area of plane figure, measurement of surface area and volume of solid figure, and the relationships between perimeter and area, and the relationships between surface area and volume. The performances of 95 sixth graders were analyzed for this study. The results showed children's low performance in the measurement area, especially measurement of perimeter and surface area, and relationship of the measurement concepts. Finally, we proposed the introduction order of the measurement concepts and what should be put more emphasis on teaching measurement. Specifically, it suggested that we consider placing a less demanding concept first, such as the area and volume, and dealing more heavily with burdensome tasks such as the perimeter and surface area.

• Education of Primary School Mathematics
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• v.25 no.4
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• pp.313-328
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• 2022

The purpose of this study is to understand the characteristics of the questions presented in shapes area and Measurement area of elementary mathematics textbooks. For this purpose, the types of questions presented in shapes area and measurement area of elementary mathematics textbooks and their working functions were comparatively analyzed by area and by grade cluster. As a result of the analysis, the number of questions per lesson increased sharply in the 3rd and 4th grade cluster compared to the 1st and 2nd grade cluster in both shapes area and measurement area. In these two areas, the most common reasoning questions are presented. It is presented relatively more in measurement area than in shapes area. There was a clear difference between the types of questions presented in shapes area and measurement area. In common with the two areas, questions mainly were acted as a function to help students learn to reason mathematically, a function to help students to determine whether something is mathematically correct, and a function to help students learn to conjecture, invent, and solve problem. The characteristics of the questions identified in this study can provide teaching/learning implications for the design and application of the questions suitable for the guidance of shapes area and measurement area, and can be used as a reference material when writing mathematics textbooks.

• Korean Journal of Child Studies
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• v.25 no.1
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• pp.13-29
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• 2004

In this study of strategies used by young children in solving rectangular covering tasks before they have been taught area measurement, 75 5-, 6-, and 7-year-old children were asked to solve 3 rectangular covering tasks with a moveable unit. Three different sized units (4 cm., 2 cm., and 1 cm. cardboard squares) were provided and the children were asked to work out how many would be needed to cover a drawn rectangle. The resulting 5 developmental levels include incomplete covering, incomplete arrangement, complete covering, estimating, and measuring. Children using more advanced strategies were able to find correct number of units. While the tendency among older children was to use more advanced strategies, even 5-year-olds had an intuitive understanding of rectangular area measurement.

• Journal of the Korean Home Economics Association
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• v.35 no.1
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• pp.191-204
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• 1997

Reserarch on marital satisfaction adjustment or quality has been one of the most frequently studies area of the investigation in the family field. Yet there has been many problems with the theory and empirical work in this area especially in the area of definitional ambiguity problems of dimensionality level of analysis and problems of measurement. This article is a critical review of this work including both theoretical and empirical problems that typically have occured with the previous research Also a section on suggested modifications for future research in this area and a section of suggestion of new marital satisfaction measurement are included.

• Communications for Statistical Applications and Methods
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• v.29 no.5
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• pp.533-545
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• 2022

Collection of data on several variables, especially in the field of medicine, results in the problem of measurement errors. The presence of such measurement errors may influence the outcomes or estimates of the parameter in the model. In classification scenario, the presence of measurement errors will affect the intrinsic cum summary measures of Receiver Operating Characteristic (ROC) curve. In the context of ROC curve, only a few researchers have attempted to study the problem of measurement errors in estimating the area under their respective ROC curves in the framework of univariate setup. In this paper, we work on the estimation of area under the multivariate ROC curve in the presence of measurement errors. The proposed work is supported with a real dataset and simulation studies. Results show that the proposed bias-corrected estimator helps in correcting the AUC with minimum bias and minimum mean square error.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.175-182
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• 2013

The digitalization of sea level measurement recording which is recorded as analog type is useful for many related oceanology. In this paper, we propose a method which separates the graph area from a sea level measurement recording image. At first, a pixel that is regarded as the pixel which is included in the graph area is selected. Then, many background pixels are separated using the color of the selected pixel. In each vertical line, a pixel is determined as the pixel within the graph area and the graph area is separated from the image using that pixels. Experimental results show that the proposed method in this paper overcome drawbacks of the previous research and can separate the graph area which similar to the graph area of the original image.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.465-472
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• 2019

To investigate the effects of iterative reconstruction algorithms on fat measurements using computed tomography (CT), we comparatively and quantitatively analyzed the ratios of visceral, subcutaneous, and visceral-subcutaneous fat areas as well as the variations of HU and noise of visceral and subcutaneous fat using ADMIRE strength and attempted to identify any difference between them. Experimental results showed that no statistically significant difference existed among the visceral, subcutaneous, and visceral-subcutaneous fat area ratios HU of visceral fat area and HU of subcutaneous fat area when applying ADMIRE as compared with existing conventional filtered back projection algorithms. However, as the ADMIRE strength increases, the noise of visceral and subcutaneous fat decreases by up to 12.1% and 19.2%, respectively. In conclusion, iterative reconstruction algorithms have no effect on the visceral, subcutaneous, and visceral-subcutaneous fat area ratios, which are indicators of fat measurement using CT.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.85-94
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• 2013

This paper presents a novel mobile measurement system with multi antennas which enable mobile measurement as well as fixed measurement with telescope mast. Proposed system installed 4 omni directional antennas for the space diversity process and one directional log periodic antenna for the simultaneous conventional fixed measurement. Whole antenna systems are connected to the custom DTV channel analyzers with Ethernet networks respectively and processed by the main controller to calculate real time average receive levels. To prove the performance of proposed system, the typical receive models are categorized as 3 area types - open area, building area and house area, and then intensive field tests were performed through mobile and fixed measurement phases. With these measurement data, the relationships between mobile and fixed measurement are analyzed, and the concept of compensation factor is proposed to assume the average receive level of signal. The field test is fulfilled as a co-work with public broadcasters and the proposed system is applied to the intensive coverage measurement projects for metropolitan areas by the korean government agencies.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.2
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• pp.270-276
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• 2003

Methodology was suggested to analyze breast volume, base area of breast bulk. and surface area of breast using the 3D measurement system. Thirty-seven middle-aged (30s-40s) women wearing 80A brassiere were participated in this study. Image of the upper body was captured by Phase-shifting moire. The posture of the subject was adjusted to get the full image of the right breast. Rapidform 2001 was used for the analysis of the images. The mean breast volume was 547.0㎤ and mean base area of breast bulk was 235. I$\textrm{cm}^2$ It was also found that the volume(r=0.169) and surface area of breast(r=10.242) were loosely correlated with the circumference difference between top and under breast. Therefore, it is noted that current selection criterion of cup size based on the difference in the two kinds of breast circumference is inadequate. The result of this study is expected to contribute to the design of ergonomic brassiere as well as surgical operations in the medical field.