• Journal of the Korean Geotechnical Society
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• v.32 no.8
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• pp.47-59
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• 2016

Rocking behavior of shallow foundation reduces the superstructure load during earthquake. However, because of deficiency of understanding of rocking mechanism and soil permanent deformation, it has not been applied to real construction. In this study, slow cyclic tests were conducted for embedded shallow foundations with various slenderness ratio via centrifuge tests. From the variation of earth pressure 'soil rounding surface' phenomenon which makes maximum overturning moment equal to ultimate moment capacity was observed. Rocking and sliding behavior mechanism was evaluated. Also, nonlinear behavior and energy dissipation increase as rotation angle increases. And ultimate moment capacity of embedded foundation is larger than that of surface foundation. Finally, adequate ultimate moment capacity can be suggested for seismic design through this study.

• Journal of the Korea Concrete Institute
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• v.17 no.3 s.87
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• pp.343-351
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• 2005

This study developed a shear strength prediction model of FRP strengthened reinforced concrete beams in shear. The primary design parameters were shear crack angle and shear span to depth ratio of FRP reinforcement. Of primary concern In the suggested model was the FRP debonding failure, which Is a typical fracture mode of RC beams strengthened with FRP, The proposed model used a crack sliding model based on modified plasticity theory. To address the effect of the shear span to depth ratio, the arch action was considered in the proposed model. The proposed model was applied to RC beams strengthened with FRP. The results showed that the proposed model agree with test results.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.357-364
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• 2018

This study was attempted to develop education programs through mobile apps to promote breastfeeding for high-risk mothers. The development of mobile apps was carried out in four stages, including analysis, design, implementation and evaluation, by referring to the software development life cycle. The subjects of this study were cesarean delivery mother, premature baby and twin delivery mother, and contents of education included difficulty in breastfeeding by high risk mother. Experts and users evaluated the program and found it appropriate as an educational mobile app. The education through mobile app is not limited by time and space. Therefore, it will help knowledge and continuous practice of breastfeeding by high risk mothers. It is necessary to directly test the effects of applying the breastfeeding app developed in this study.

• Journal of the Korean Society of Costume
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• v.57 no.3 s.112
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• pp.53-62
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• 2007

The purpose of this study was to investigate mechanical and comfort performances of the material for the improved working uniform for a volunteer fire brigade member, to get basic data for its evaluation and to help its material and design development. The results were as follows; The material of the newly developed working uniform was thinner and lighter than the material of the current used working uniform. It had better breathability, air permeability and heat transmission rate than the current one. It also had superior anti-flammability In all mechanical properties(tensile, bending, shearing, compression and surface properties), it showed better performances than the current one. It elongated and bended easier and more in both warp and weft directions. The elastic recovery and shape stability after elongation were also higher. The recovery and resistance to shearing and the resiliency and recovery after compression were also better than the current one. It was more flexible, softer and smoother in primary hand value, and was more suitable for the material for winter suit which needs softness and fullness in total hand value. The material of the improved working uniform showed lower thermal insulation value and higher evaporative resistance value compared to the material of the currently used working uniform from the sweating thermal manikin test. It was shown that the physical performances and the hand value of the textile material used in the newly developed working uniform for a volunteer fiber brigade member was improved compared to the one used in the currently used working uniform.

• Fashion & Textile Research Journal
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• v.17 no.6
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• pp.996-1003
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• 2015

This study aims to examine the effects of the cutting amount at the waistline on the jacket appearance evaluation and movement functionality, and to suggest a proper waistline cutting amount when designing the men's casual jacket for those in their 30's. The researchers prepared 4 kinds of experimental jackets varying the waistline cutting amount: 0.0cm, 0.5cm, 1.0cm, and 1.5cm. The results of the study are as follows: Regarding the front view appearance, the jacket with the 0.5cm cutting amount achieved the highest score (6 out of 9). On the side view and the back view, there was no meaningful difference. However, the jacket with 0.5cm cutting amount achieved the highest score (4 out of 5). On the other hand, on the movement functionality, there was small statistical difference; the 1.5cm experimental jacket received the highest score in the most areas. This is resulted because if the cutting amount was increased, equally with the V-zone area which gives room for movements. This result showed the difference from the previous research of men in their 20’s,where 0.0cm achieved the highest test score for both appearance and movement functionality. Therefore, this study suggests using the 0.5cm and 1.5cm for the waistline cutting amount; for the jacket appearance 0.5cm is the best while the 1.5cm is better for the movement.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.373-375
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• 2002

4D CT is a dynamic volume imaging system of moving organs with an image quality comparable to conventional CT, and is realized with continuous and high-speed cone-beam CT. In order to realize 4D CT, we have developed a novel 2D detector on the basis of the present CT technology, and mounted it on the gantry frame of the state-of-the-art CT-scanner. In the present report we describe the design of the first model of 4D CT-scanner as well as the early results of performance test. The x-ray detector for the 4D CT-scanner is a discrete pixel detector in which pixel data are measured by an independent detector element. The numbers of elements are 912 (channels) ${\times}$ 256 (segments) and the element size is approximately 1mm ${\times}$ 1mm. Data sampling rate is 900views(frames)/sec, and dynamic range of A/D converter is 16bits. The rotation speed of the gantry is l.0sec/rotation. Data transfer system between rotating and stationary parts in the gantry consists of laser diode and photodiode pairs, and achieves net transfer speed of 5Gbps. Volume data of 512${\times}$512${\times}$256 voxels are reconstructed with FDK algorithm by parallel use of 128 microprocessors. Normal volunteers and several phantoms were scanned with the scanner to demonstrate high image quality.

• The Journal of Korean Association of Computer Education
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• v.17 no.1
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• pp.51-63
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• 2014

Learning objectives is used to be a good guidance of a class evaluation and activity design for an effective teaching and learning activities in class. Anderson's taxonomy of Educational Objectives that was a revision of Bloom's taxonomy has presented in research field of other subject matters and used as a better guideline for analyzing learning objectives in textbook and achievement levels in test recently. This study has behaved some questionnaires for that Anderson's taxonomy is suitable for a guideline of stating learning objective in Informatics subject matter, and analyzed the learning objectives in 6 Informatics textbooks by Anderson's taxonomy. It has proposed that Anderson's taxonomy is satisfactory for expressing learning objective of Informatics subject matter in class and some dimensions, such as conceptual and procedural knowledge, understand, and apply, are much more used in learning objectives in 6 Informatics textbooks. This results will be a good case study in research about taxonomy of educational objectives and development of Informatics textbooks.

• Journal of dental hygiene science
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• v.14 no.1
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• pp.15-21
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• 2014

The purpose of this study in vitro investigation was to evaluate the dimensional stability of dental digital models made by impression scanning method. Twenty working models were produced. Twenty impressions were made from study models. The dimensional stability of models of two groups (stone and digital models) was examined using six landmark distances. Stone models were measured through digital vernier calipers. Digital models were measured by the computer program. Statistical analyses were performed with Wilcoxon rank sum test (${\alpha}=0.05$). The mean of six landmark distances were significantly larger in the stone models than in the digital models (p<0.05) but digital models showed clinically acceptable accuracy.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.1
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• pp.81-86
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• 2008

Recently, a mesh-size insensitive structural stress definition that provides a stress state at weld toe with relatively larger mesh size compared to conventional approaches has been proposed. The structural stress definition is based on the elementary structural mechanics theory and provides an effective measure of a stress state in front of weld toe. In this study, as an experimental validation of structural stress method in obtaining the fatigue strength of weldments, a series of fatigue test has carried out for longi-web connections, which are representative of ship-like structures. Based on the result from this study, it is expected to develop a more precise fatigue strength evaluation technique and to reduce time and cost associated with the fatigue design of ship and offshore structures.

• Journal of the Korea Society of Computer and Information
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• v.25 no.11
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• pp.83-88
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• 2020

This paper proposes a method of applying an advanced preamble detection technology to wireless sensor nodes and analyzes the trade-off relationship between throughput and fairness that may occur when sensor nodes equipped with the MIM function compete with the legacy IEEE 802.15.4 sensors. Sensor nodes employing the MIM capability have more chances of concurrent transmissions than the legacy IEEE 802.15.4-based sensor nodes, resulting in gains in terms of throughput, whereas the transmission opportunities of 802.15.4 sensor nodes might be limited due to the additional simultaneous transmissions of the MIM sensor nodes. The extensive evaluation results performed under a test environment built using Python program with reflecting the setting value of a commercial sensor node shows MIM sensor nodes outperform up to 40% over the legacy 802.11 sensors. Meanwhile, it was confirmed that a balance can be achieved in terms of throughput and fairness by properly adjusting the concurrent transmission threshold.