• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.157-166
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• 2018

Purpose: This study was aimed to compare the consistency between the custom abutment design and the output in two CAD software programs. Materials and Methods: Customized abutments were designed by using 3Shape Dental System CAD software and Delta9 CAD software on a plaster model with implants (CRM STL file). After milling of the designed abutments, the abutments were scanned with a contact method scanner (Test STL file). We overlaid the Test STL file with each CRM STL file by using inspection software, and then compared the milling reproducibility by measuring the output error of the specimens from each CAD software program. Results: The Delta9 showed better milling reproducibility than 3Shape when comparing the milling errors obtained with a full scan of all specimens (P < .05) and also when comparing the axial wall region specifically according to the axial angle. With 0.9 mm marginal radius, the Delta9 showed better consistency between the design and the output than 3Shape (P < .05). While, anti-rotation form had no significant difference in error between the two systems. When cumulative errors were compared, the Delta9 showed better milling reproducibility in almost cases (P < .05). Conclusion: Delta9 showed a significantly smaller error for most of the abutment design options. This means that it is possible to facilitate generation of printouts with reliable reproducibility and high precision with respect to the planned design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.2
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• pp.171-176
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• 2007

The tracking antenna must always point to track moving vehicle for data link. In this paper, we determine pointing angle from the geometric relationship of antenna and UAV(Unmaned Aerial Vehicle) to let an antenna be toward a moving vehicle. The pointing angle of antenna is set through GPS measurement data installed in antenna and UAV. We verify the performance of this system from the fixing a camcoder on the antenna.

• Journal of the Korean Magnetics Society
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• v.8 no.3
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• pp.144-149
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• 1998

A new method to calculate the spin reorientation angle of cone anisotropy from magnetization curves of magnetically aligned powder is suggested. The spin reorientation angle of polycrystalline $Nd_2Fe_{14}B$ determined by this method coincided with the results obtained from torque magnetometry or magnetization measurements on single crystal. The underestimation of about 9% is expected if the basal plane anisotropy is neglected in determination of the spin reorientation angle of $Nd_2Fe_{14}B$ at 4.2 K.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.186-190
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• 2006

This study was performed to investigate the characteristics of a co-axial swirl injector. Especially to predict the initial liquid sheet thickness and spray cone angle of an outer orifice a concept of effective area was introduced from hydraulic analysis. In addition, the parameters determining the characteristics of a co-axial swirl injector were re-defined around outer orifice. The calculated results-SMD, spray cone angle, and spray thickness agreed well with the test results qualitatively.

• Korean Journal of Child Studies
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• v.13 no.1
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• pp.5-15
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• 1992

아동의 언어습득 과정에서의 모방은 흔히 볼 수 있는 현상이지만 한편 인간의 독특하고 신기한 일면이기도 하다. 이 모방에 관하여 그동안 많은 연구들이 되어왔으나 그 중요성이나 역할에 대한 연구들의 결론이 모두 일치하는 것은 아니다. 본 논문에서는 이 모방현상에 대한 그 동안의 연구들을 이론별로 분류해 보고 각 이론들이 모방의 역할을 밝히기 위하여 사용해 온 연구방법, 절차들을 분석해 보았다. 행동주의와 사회학습이론에서는 언어습득에서의 모방의 역할을 특히 강조하고 있으며 이 모방의 효과를 입증하기 위하여 다른 어떤 이론보다도 훨씬 조직적인 실험연구를 해 왔다. 이와는 대조적으로, 언어 심리학적 접근에서는 언어습득에서의 생득성과 창의성을 강조하므로 모방의 역할은 중시하지 않으며, 모방의 정의를 엄격하게 규정하고 자연적인 관찰 중심의 연구를 주로 하여 언어습득에서의 모방의 역할이 미비하다는 결론을 내리고 있다. Piaget 중심의 인지발달적 접근에서는 모방을 인간의 전체 발달의 한 측면으로 보아 모방은 인지발달과 함께 점진적으로 발달되는 것으로 설명하고 있다. 특히 언어발달에서의 지연모방의 중요성을 강조하고 있으며, 대부분의 연구는 자연적인 관찰연구를 통하여 모방의 발달과정을 밝히고 있다. 언어발달에서의 모방의 역할에 대한 지금까지의 일치하지 않는 연구 결과들은 각각의 이론들이 나름대로 달리 모방을 정의하고, 언어의 다른 측면들을 다루어 왔기 때문으로 밝혀 졌다. 앞으로 언어발달이 아동의 발달 전체의 맥락 속에서 연구되어지고, 언어습득과정에서 보이는 아동들의 개인차까지도 고려되어지는 포괄적인 연구가 이루어지면 모방의 역할도 좀더 명백하고 일관성 있게 밝혀지리라 본다.

• Journal of The Korean Association of Information Education
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• v.23 no.4
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• pp.343-353
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• 2019

The purpose of this study is to analyze the elementary pre-service teachers' preferred strategies while they solve problems which require number sense and to study a way to improve their number sense ability based on computational thinking. In a survey with 57 elementary pre-service teachers using the instrument consisting of two different number sense components, they preferred much more the rule-based strategies to the number sense-based strategies, which was consistent with the prior studies[13][14][20]. To change this situation, we present a way to improve their number sense ability by utilizing the analyzed results and the nine computational thinking components which were suggested by CSTA and ISTE(2011).

• Journal of Digital Convergence
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• v.14 no.6
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• pp.535-546
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• 2016

This study examined the relation among orthographic knowledge, phonological awareness, and visual word decoding and encoding abilities. Children aged 5 to 8 years took letter knowledge test, phoneme-grapheme correspondence test, orthographic representation test(regular word and irregular word representation), phonological awareness test(word, syllable and phoneme awareness), word decoding test(regular word and irregular word reading) and word encoding test(regular word and irregular word dictation). The performances of all tasks were significantly different among groups, and there were positive correlations among the tasks. In the word decoding and encoding tests, the variables with the most predictive power were the letter knowledge ability and the orthographic representation ability. It was found that orthographic knowledge more influenced visual word decoding and encoding skills than phonological awareness at these ages.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.107-116
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• 2003

This study investigated how appropriate the classification methods based on conventional spectral characteristics are for high resolution imagery. A supervised classification mixing parametric and non-parametric rules, a method in which fuzzy theory is applied to such classification, and an unsupervised method were performed and compared to each other for accuracy. In addition, comparing the result screen-digitized through interpretation to the classification result using spectral characteristics, this study analyzed the conformity of both methods. Although the supervised classification to which fuzzy theory was applied showed the best performance, the application of conventional classification techniques to high resolution imagery had some limitations due to there being too much information unnecessary to classification, shadows, and a lack of spectral information. Consequently, more advanced techniques including integration with other advanced remote sensing technologies, such as lidar, and application of filtering or template techniques, are required to classify land cover/use or to extract useful information from high resolution imagery.

• The Transactions of the Korea Information Processing Society
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• v.3 no.6
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• pp.1646-1657
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• 1996

This paper presents a color transformation method based on a uniform color image model. Firstly, color variation factors are grouped into identical (multiplicative) factor and independent(additive) one for the color model, and they are modelled by the Gaussian function. The shape of a color cluster in (R, G, B) feature space is an ellipsoid whose elongated major axis correspond to the direction of mean vector. Secondly, the transformation of a color cluster using the model is studied. A transformation method for three dimensional coordinated is described. The proposed method is applied to artificial and natural color images. By the result of experiments, the elongated major axis of each cluster making up the transformed color image aggress with the direction of its mean vector.

• Journal of Software Assessment and Valuation
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• v.17 no.1
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• pp.11-16
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• 2021

The importance of software is increasing due to the development of information and communication, and software copyright disputes are also increasing. In this paper, the source of the submitted programs and the files necessary for the execution of the program were taken as the scope of analysis. The large-capacity file transfer solution program to be analyzed provides additional functions such as confidentiality, integrity, user authentication, and non-repudiation functions through digital signature and encryption of data.In this paper, we analyze the program A, program B, and the program C. In order to calculate the program similarity rate, the following contents are analyzed. Analyze the similarity of the package structure, package name, source file name in each package, variable name in source file, function name, function implementation source code, and product environment variable information. It also calculates the overall similarity rate of the program. In order to check the degree of agreement between the package structure and the package name, the similarity was determined by comparing the folder structure. It also analyzes the extent to which the package structure and package name match and the extent to which the source file (class) name within each package matches.