• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2173-2182
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• 2020

Control valves are widely used to regulate fluid flux in nuclear power plants, and there are more than 1500 control valves in the primary circuit of one nuclear power plant. With their help, the flux can be regulated to a specific level of water or steam to guarantee the energy efficiency and safety of the nuclear power plant. The flux characteristics of the control valve mainly depend on the valve core shape. In order to analyze the effects of valve core shapes on flux characteristics of control valves, this paper focuses on the valve core shapes. To begin with, numerical models of different valve core shapes are established, and results are compared with the ideal flux characteristics curve for the purpose of validation. Meanwhile, the flow fields corresponding to different valve core shapes are investigated. Moreover, relationships between the valve core opening and the outlet flux under different valve core shapes are carried out. The flux characteristics curve and equation are proposed to predict the outlet flux under different valve core openings. This work can benefit the further research of the flux control and the optimization of the valve core for control valves in nuclear power plants.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1322-1326
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• 1997

Characteristics of viscosity and spray dried particles for several polysaccharides were studied to investigate the possibilities as wall materials for microencapsulation. Viscosities of 10% maltodextrin, 10% gum arabic, 10% dextran, 1% gum locust bean, and 1% gum karaya were 2.2 mPa.s, 9.2 mPa.s, 13.0 mPa.s, 4660.0 mPa.s, and 77.0 mPa.s, respectively. In scanning electron micrographs for spray dried polysaccharides, gum arabic had spherical shapes at 20% and 30% emulsion concentration, while trailed shapes at 40%. Maltodextrin had uniform spherical shapes at 30%, while aggregated form with various kinds of capsule sizes at 40%. Dextran had spherical shapes at 20%, while trailed fibrous shapes at over 30%. Mixed polysaccharides with gum arabic:maltodextrin (1:3, w/w) had uniform spherical shapes at 20%, 30%, and 40% with increasing diameter with increasing concentration.

• Journal of the Earthquake Engineering Society of Korea
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• v.7 no.4
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• pp.81-87
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• 2003

In this paper, the feasibility of using Shannon's sampling theorem to reconstruct exact mode shapes of a structural system from a limited number of sensor points and localizing damage in that structure with reconstructed mode shapes is investigated. Shannon's sampling theorem for the time domain is reviewed. The theorem is then extended to the spatial domain. To verify the usefulness of extended theorem, mode shapes of a simple beam are reconstructed from a limited amount of data and the reconstructed mode shapes are compared to the exact mode shapes. On the basis of the results, a simple rule is proposed for the optimal placement of accelerometers in modal parameter extraction experiments. Practicality of the proposed rule and the extended Shannon's theorem is demonstrated by detecting damage in laboratory beam structure with two-span via applying to mode shapes of pre and post damage states.

• Journal of Korea Game Society
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• v.21 no.6
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• pp.31-40
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• 2021

Go has a history of more than 2,500 years, and the life-and-death problems in Go is a fundamental problem domain that must be solved when implementing a computer Go. We attempted to determine the numbers of prototypical eye shapes with 3, 4, 5, and 6 eyes that are directly related to the life-and-death problems, and to classify the prototypical eye shapes represented in 4-tuple forms. Experiment was conducted by Monte-Carlo method and point pattern matching. According to the experimental results, the numbers of prototypical eye shapes were 2 for 3-eye, 5 for 4-eye, 12 for 5-eye, and 35 for 6-eye shapes. Further, using a 4-tuple form, we classified prototypical eye shapes into 1 for 3-eye, 3 for 4-eye, 4 for 5-eye, and 8 for 6-eye shapes.

• Earthquakes and Structures
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• v.22 no.1
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• pp.1-13
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• 2022

When a building suffers damages under moderate to severe loading condition, its physical properties such as damping and stiffness parameters will change. There are different practical methods besides various numerical procedures that have successfully detected a range of these changes. Almost all the previous proposed methods used to work with translational components of mode shapes, probably because extracting these components is more common in vibrational tests. This study set out to investigate the influence of using both rotational and translational components of mode shapes, in detecting damages in 3-D steel structures elements. Three different sets of measured components of mode shapes are examined: translational, rotational, and also rotational/translational components in all joints. In order to validate our assumptions two different steel frames with three damage scenarios are considered. An iterative model updating program is developed in the MATLAB software that uses the OpenSees as its finite element analysis engine. Extensive analysis shows that employing rotational components results in more precise prediction of damage location and its intensity. Since measuring rotational components of mode shapes still is not very convenient, modal dynamic expansion technique is applied to generate rotational components from measured translational ones. The findings indicated that the developed model updating program is really efficient in damage detection even with generated data and considering noise effects. Moreover, methods which use rotational components of mode shapes can predict damage's location and its intensity more precisely than the ones which only work with translational data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.809-816
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• 2006

More than effectively judging the existence of reinforcing bars under multi boundary layers and void shapes in concrete, this study aims to develop the analysis algorithm of radar response on multi boundary layers in reinforced concrete and radar capable of estimation of the shape of specific voids in plain concrete. To detect or estimate reinforcing bars and void shapes in these conditions, the simulation analysis model of transmission and reflection wave of electromagnetic radar is used. This radar simulation model is carried out with reinforced or non reinforced concrete of various boundary conditions and void shapes. And, the output signals (images) of radar simulation results are calculated and represented by convolution method. As the results, it is clarified that this simulation analysis technique can be used to analyze radar response on multi boundary layers in reinforced concrete and void shapes in concrete.

• The Journal of Advanced Prosthodontics
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• v.15 no.6
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• pp.302-314
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• 2023

PURPOSE. The aim of this study was to classify the shapes of retromolar pads and assess their morphometric differences using a 3D model. MATERIALS AND METHODS. Two hundred fully edentulous or Kennedy Class I partially edentulous patients (400 retromolar pads) were enrolled. Scan data of the definitive mandibular casts produced through functional impressions were obtained using a 3D laser scanner. Seven parameters (transverse diameter, longitudinal diameter, transverse-contour length, longitudinal-contour length, longitudinal/transverse diameter ratio, longitudinal/transverse-contour length ratio, and angle of the retromolar pad line to the residual alveolar ridge line) were measured using image analysis software. Subsequently, the pads were classified according to the shape. Statistical analyses were performed using 95% confidence intervals. RESULTS. Classifying the retromolar pads into three shapes led to high intra-examiner reliability (Cronbach's alpha = 0.933). The pear shape was the most common (56.5%), followed by oval/round (27.7%) and triangular (15.8%) shapes. There were no significant differences between the left and right sides according to the shape and no significant differences in any parameter according to age. The transverse diameter and longitudinal/transverse diameter ratio differed between sexes (P < .05). The triangular shape had a significantly different transverse diameter, transverse-contour length, longitudinal/transverse diameter ratio, and longitudinal/transverse-contour length ratio compared with the pear and oval/round shapes (P < .05). CONCLUSION. From a clinical reliability standpoint, classifying retromolar pads into three shapes (oval/round, pear-shaped, and triangular) is effective. The differences in the sizes among the shapes were attributed to the transverse measurement values.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.1
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• pp.61-76
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• 2024

The purpose of this study is the development of an experimental design that aims to implement three-dimensional fashion design by observing the human body, extracting and combining geometric shapes and forms, and focusing on attempts to decompose the geometry of the human body in art history. Considering the characteristics of fashion design, which inevitably reflect human images visually, this study considered works by deriving geometric shapes and forms of the human body and focusing on decomposition and combination to apply them to fashion design. The results obtained through the development of fashion design through decomposition and combination based on geometric human body analysis are as follows. First, geometric analysis of the human body as an object of expression continues from the history of Cubism to modern fashion design. Second, the geometric shapes of the human body that appear in contemporary fashion design maximize visual effects through three-dimensional composition, emphasizing simplicity while showing originality through various expressions. Third, when exploring the geometric shapes of a moving human body, it was possible to extract a wide variety of shapes and forms through drawing and simplifying the human body's movements. Fourth, the formative method of fashion design was introduced and used for the aesthetic combination of objects for fashion design through decomposition and combination. This study was able to show unique and diverse combinations of visually concise and ordered geometric shapes in the expression of fashion design by decomposing and combining them. The significance of these geometric forms is that they can diversify formative informativeness in the expression of fashion design with modern compositional beauty.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.315-316
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• 2009