• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.36-41
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• 1996

Turbulent thermal mixing experiments by the injection of two parallel non-isothermal water jets have been performed. The turbulent velocities and fluctuations under the isothermal conditions have been measured using LDV system. The velocity vectors have been plotted in two dimensions from the data measured at 29$\times$16 points. The thermal mixing experiments also have been conducted, where we used 45 K-type thermocouples with a sheath diameter of 0.020" which were fixed with 5 mm distance in a line at a measured height. The measured heights were 5, 10, 20, 30, 40 cm from the upper end of rectangular nozzles. We measured the turbulent temperatures under the various flow velocity conditions with 12$^{\circ}C$ $\leq$ $\Delta$T $\leq$4$0^{\circ}C$. The sampling frequency and sampling time were about 420 Hz and 10 seconds, respectively. The measured results of equal velocity parallel jets were analyzed axially and radially to obtain the variation of temperature fluctuation.tion.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1152-1166
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• 2023

The bubbly flow of air or steam in subcooled water are investigated here in several test cases, characterized by different pipe sizes, bubble dimensions and flow rates, by means of CFD using a Eulerian-Eulerian approach. The performance of models that differ for the turbulence closure in the continuous phase, as well as for the description of the lift force on the dispersed phase, are compared in detail. When air is considered, the space of the experimental parameters leading to a reasonable performance for the selected models are identified and discussed, while the issues left in the modelling of the concurrent condensation are highlighted for the cases where steam is used.

• Educational Technology International
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• v.10 no.1
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• pp.25-40
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• 2009

The purpose of this study was to explore procedures and modalities on collaborative visualization processing of text information for developing e-Learning contents. In order to investigate, two research questions were explored: 1) what are procedures on collaborative visualization processing of text information, 2) what kinds of patterns and modalities can be found in each procedure of collaborative visualization of text information. This research method was employed a qualitative research approaches by means of grounded theory. As a result of this research, collaborative visualization processing of text information were emerged six steps: identifying text, analyzing text, exploring visual clues, creating visuals, discussing visuals, elaborating visuals, and creating visuals. Collaborative visualization processing of text information came out the characteristic of systemic and systematic system like spiral sequencing. Also, another result of this study, modalities in collaborative visualization processing of text information was divided two dimensions: individual processing by internal representation, social processing by external representation. This case study suggested that collaborative visualization strategy has full possibility of providing ideal methods for sharing cognitive system or thinking system as using human visual intelligence.

• Asia pacific journal of information systems
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• v.28 no.4
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• pp.240-257
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• 2018

In today's turbulent business landscape, a firm's ability to explore new IT capabilities and exploit current ones is essential for enabling organizational agility and achieving high organizational performance. We propose IT exploration and exploitation as two critical organizational learning processes that are essential for gaining and sustaining competitive advantages. However, it remains unclear how the emerging cloud-based IT architecture affects an organization's ability to explore and exploit its IT capabilities. We conceptualize modularity and virtuality as two critical dimensions of emerging cloud-based IT architecture and investigate how they affect IT exploration and exploitation. We test our hypotheses using data obtained from our field survey of IT managers. We find that modularity is positively associated with both exploration and exploitation whereas virtuality is positively associated with exploration, but not with exploitation. We also find that the effect of modularity on exploitation is stronger than its effect on exploration.

• Science of Emotion and Sensibility
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• v.24 no.3
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• pp.71-80
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• 2021

Previous studies using facial expressions have revealed valence and arousal as two core dimensions of affective space. However, it remains unknown if the two dimensional structure is consistent across ages. This study investigated affective dimensions using six facial expressions (angry, disgusted, fearful, happy, neutral, and sad) at three ages (young, middle-aged, and old). Several studies previously required participants to directly rate subjective similarity between facial expression pairs. In this study, we collected indirect measures by asking participants to decide if a pair of two stimuli conveyed the same emotions. Multidimensional scaling showed that "angry-disgusted" and "sad-disgusted" pairs are similar at all three ages. In addition, "angry-sad," "angry-neutral," "neutral-sad," and "disgusted-fearful" pairs were similar at old age. When two faces in a pair reflect the same emotion, "sad" was the most inaccurate in old age, suggesting that the ability to recognize "sad" decreases with old age. This study suggested that the general two-core dimension structure is robust across all age groups with the exception of specific emotions.

• ETRI Journal
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• v.42 no.4
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• pp.562-574
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• 2020

Quadrature spatial modulation (QSM) utilizes the in-phase and quadrature spatial dimensions to transmit the real and imaginary parts of a single signal symbol, respectively. The improved QSM (IQSM) transmits two signal symbols per channel use through a combination of two antennas for each of the real and imaginary parts. The main contributions of this study can be summarized as follows. First, we derive an upper bound for the error performance of the IQSM. We then design constellation sets that minimize the error performance of the IQSM for several system configurations. Second, we propose a double QSM (DQSM) that transmits the real and imaginary parts of two signal symbols through any available transmit antennas. Finally, we propose a parallel IQSM (PIQSM) that splits the antenna set into equal subsets and performs IQSM within each subset using the same two signal symbols. Simulation results demonstrate that the proposed constellations significantly outperform conventional constellations. Additionally, DQSM and PIQSM provide a performance similar to that of IQSM while requiring a smaller number of transmit antennas and outperform IQSM with the same number of transmit antennas.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.11
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• pp.444-449
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• 2016

The main objective of this work is to experimentally investigate the effect of angle variation and intrusion depth of channels on the distribution of two-phase flow at header-channel junctions. The dimensions of the header and the channels in cross-section were fixed at $16mm{\times}16mm$ and $12mm{\times}1.8mm$, respectively. Air and water were used as the test fluids. Two different header-channel positions were tested : a vertical header with horizontal channels (case VM-HC) and a horizontal header with horizontal channels (case HM-HC). In all cases, the intrusion depths of the channels are 0 mm, 2 mm, and 4 mm. For the case of the intrusion depth of VM-HC, the flow distribution became more uniform. However, the intrusion depth negatively affected the flow distribution for the case of HM-HC because liquid separation delay occurred.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.171-181
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• 2012

This paper introduces the double-density discrete wavelet transform(DWT) using quincunx sampling, which is a DWT that combines the double-density DWT and quincunx sampling method, each of which has its own characteristics and advantages. The double-density DWT is an improvement upon the critically sampled DWT with important additional properties: Firstly, It employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. Secondly, the double-density DWT is overcomplete by a factor of two, and Finally, it is nearly shift-invariant. In two dimensions, this transform outperforms the standard DWT in terms of denoising; however, there is room for improvement because not all of the wavelets are directional. That is, although the double-density DWT utilizes more wavelets, some lack a dominant spatial orientation, which prevents them from being able to isolate those directions. A solution to this problem is a quincunx sampling method. The quincunx lattice is a sampling method in image processing. It treats the different directions more homogeneously than the separable two dimensional schemes. Proposed wavelet transformation can generate sub-images of multiple degrees rotated versions. Therefore, This method services good performance in image processing fields.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.7
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• pp.1004-1014
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• 2000

The purpose of this study was to develop a well-fitting bodice basic pattern for high school irk. Two bodice patterns were first made based on the most recent existing drafting methods and sensory evaluation was done on the patterns by the present researchers Two high school girls possessing standard physical condition tried and evaluated the functionality of the garments made by the two bodice patterns. Based on the results of the evaluation, a new bodice basic pattern was developed. The new bodice basic pattern was drafted by long measurement method. The dimensions of new bodice basic pattern were as follows. Bust circumference=B/2+4cm, Arms hole depth=C.B/2+1.5cm, Back width=B/6+4cm, Front width=B/6+3cm, Back neck width=B/12+0.5cm, Back neck depth=Back neck width/3cm, Front neck width=B/12cm, Front neck depth=B/12+0.5cm. The sensory and functional evaluations were also conducted for the new bodice basic pattern and the two patterns drafted by the existing methods. The new bodice basic pattern showed better fit both visually and functionally than the existing patterns. SPSS package including means, standard deviation and one-sample T-test were used for data analysis.

• Journal of Environmental Impact Assessment
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• v.10 no.3
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• pp.175-194
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• 2001

The environment is composed of at least two components, the natural and the human-made one. Nonetheless, the environment is being used to connote the natural environment. Moreover, even though the components of environment exist in a mutual relationship as a mechanism, it is rare to study the components of environment and their system as a mechanism. With such an implication, this paper aims to identify the components of environment and their system. The components of environment can be categorized by two criteria. One is the subject of creating environment, and the other is the visuality of environment. The former categorizes the environment into the natural and the human-made one, and the latter into physical and nonphysical one. Integrating the two criteria into a framework, the environment can be categorized into the natural, the human-made physical, and the human-made nonphysical environment. The three categories of environment exist interrelatedly in a mechanism being characterized as a mutual impact. The mechanism may be called the environmental system. The environmental system can be analyzed in terms of two dimensions. One is a human-inclusive system. The other is a human-centered system. The former is a framework that includes humans as a component of environment. The latter is a framework that humans are the subject of the environment, and the others surrounding human life are the object of the environment. The former is defined as a circular system of material and energy, while the latter is defined as a mutual subjective-objective system.