• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1545-1550
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• 2021

We propose an optimal variable step size adjustment method for the simplified subband affine projection algorithm (Simplified SAP; SSAP) in a subband structure based on a polyphase decomposition technique. The proposed method provides an optimal step size derived to minimize the mean square deviation(MSD) at the time of updating the coefficients of the subband adaptive filter. Application of the proposed optimal step size in the SSAP algorithm using colored input signals ensures fast convergence speed and small steady-state error. The results of computer simulations performed using AR(2) signals and real voices as input signals prove the validity of the proposed optimal step size for the SSAP algorithm. Also, the simulation results show that the proposed algorithm has a faster convergence rate and good steady-state error compared to the existing other adaptive algorithms.

• Fashion & Textile Research Journal
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• v.23 no.2
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• pp.226-236
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• 2021

The purpose of this study was to classify the torso shape based on abdominal protrusion caused by changes in the physical characteristics of middle-aged women. This study analyzed 3D shape data of 401 females ranging in age from 40 to 59 years who participated in the 6th Size Korea project. Based on the Size Korea 3D measurement standard, 27 additional items such as height, protrusion, and angle were measured in the 3D scan data. Nine factors were extracted from the analysis of constituent factors of the torso: "vertical size of torso," "flatness and protrusion of abdomen," "torso front extrusion," "upper body height," "bust size and flatness," "size of belly and angle of lower abdomen," "hip length," "hip flatness," and "horizontal size of bust." As a result of the cluster analysis using these nine factors, the torsos of middle-aged women were classified into three types. Type 1 has upper abdominal deposition with a small and long upper body and an advanced abdomen; type 2 has lower abdominal deposition with a small and short torso and a small belly and hip flexion; and type 3 has central abdominal deposition with a big and long torso, large breasts, and protruding abdo¬men front. The middle-aged women were mostly distributed in Type 2. The above results will be useful as basic data for the development of clothing with improved fit to accommodate the changed physical characteristics of middle-aged women.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.495-498
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• 2021

In 2021, Tokyo held the delayed 2020 Olympics in the ongoing COVID-19 pandemic. As with any Olympics, the final medal count was of particular interest. Since 2004, South Korea has consistently ranked in the top ten most successful countries for four straight Summer Olympics. However, in 2021, it fell short of a top ten finish for the first time since 2004. There may be many factors that affect the final medal count in any Olympics, and this study compares and looks for correlations between some of these factors including final medal count, GDP, population, size of Olympic contingent, and Freedom Index. The study pays particular attention to South Korea and other countries which have seen a dramatic change in Freedom Index score since 1972, when the index was first published.

• Membrane Journal
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• v.31 no.1
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• pp.52-60
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• 2021

When preparing calcium alginate microspheres using rotating membrane emulsification that rotates SPG (Shirasu porous glass) tubular membrane in the continuous phase, the optimal conditions of rotating membrane emulsification process parameters for producing monodisperse microspheres were determined. We determined the effects of process parameters of rotating membrane emulsification (the rotating speed of membrane module, the transmembrane pressure, the ratio of dispersed phase to continuous phase, the alginate concentration, the emulsifier concentration, the stabilizer concentration, the crosslinking agent concentration, and the membrane pore size) on the mean size and size distribution of alginate microspheres. As a result, the size of the microspheres decreased as the rotating speed of membrane module, the emulsifier concentration, and the crosslinking agent concentration increased among the process parameters of rotating membrane emulsification. On the contrary, as the ratio of dispersed phase to continuous phase, the transmembrane pressure, and the alginate concentration increased, the size of the microspheres increased. In the rotating membrane emulsification using an SPG membrane with a pore size of 3.2 ㎛, it was possible to finally prepare monodisperse alginate microspheres with a particle size of 4.5 ㎛ through the control of process parameters.

• Korean Journal of Materials Research
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• v.31 no.6
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• pp.313-319
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• 2021

Understanding of effects of changes in the particle size of the matrix material on the mullite whisker growth during the production of porous mullite is crucial for better design of new porous ceramics materials in different applications. Commercially, raw materials such as Al₂O₃/SiO₂ and Al(OH)₃/SiO₂ are used as starting materials, while AlF₃ is added to fabricate porous mullite through reaction sintering process. When Al₂O₃ is used as a starting material, a porous microstructure can be identified, but a more developed needle shaped microstructure is identified in the specimen using Al(OH)₃, which has excellent reactivity. The specimen using Al₂O₃/SiO₂ composite powder does not undergo mulliteization even at 1,400 ℃, but the specimen using the Al(OH)₃/SiO₂ composite powder had already formed complete mullite whiskers from the particle size specimen milled for 3 h at 1,100 ℃. As a result, the change in sintering temperature does not significantly affect formation of microstructures. As the particle size of the matrix materials, Al₂O₃ and Al(OH)₃, decreases, the porosity tends to decrease. In the case of the Al(OH)₃/SiO₂ composite powder, the highest porosity obtained is 75 % when the particle size passes through a milling time of 3 h. The smaller the particle size of Al(OH)₃ is and the more the long/short ratio of the mullite whisker phase decreases, the higher the density becomes.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4122-4129
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• 2021

The counting efficiencies obtained using anthropomorphic physical phantoms are generally used in whole-body counting measurements to determine the level of internal contamination in the body. Geometrical discrepancies between phantoms and measured individuals affect the counting efficiency, and thus, considering individual physical characteristics is crucial to improve the accuracy of activity estimates. In the present study, the counting efficiencies of whole-body counting measurements were calculated considering individual physical characteristics by employing Monte Carlo simulation for calibration. The NaI(Tl)-based stand-up and HPGe-based bed type commercial whole-body counters were used for calculating the counting efficiencies. The counting efficiencies were obtained from 19 computational phantoms representing various shapes and sizes of the measured individuals. The discrepancies in the counting efficiencies obtained using the computational and physical phantoms range from 2% to 33%, and the results indicate that the counting efficiency depends on the size of the measured individual. Taking into account the body size, the equations for estimating the counting efficiencies were derived from the relationship between the counting efficiencies and the body-build index of the subject. These equations can aid in minimizing the size dependency of the counting efficiency and provide more accurate measurements of internal contamination in whole-body counting measurements.

• Elastomers and Composites
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• v.56 no.3
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• pp.113-116
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• 2021

In this study, we report a facile fabrication of multi-walled carbon nanotubes (MWCNTs)-CuO composites synthesized by a microwave method using MWCNTs and copper oxide (CuO). The number of copper hydrate precursors affect the size and number of CuO domains formed along the MWCNTs in the composites. The domain size is controllable from 239 nm to 348 nm. The composites are characterized by transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction (XRD), Raman spectroscopy, and UV-Vis spectroscopy. The CuO produced in the composites is confirmed to be tenorite with a monoclinic crystal structure through the XRD patterns of (-111), (111) and (-202).

• Current Optics and Photonics
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• v.5 no.2
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• pp.93-100
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• 2021

Three factors that degrade the accuracy of modal decomposition are extensively studied using simulated and measured beams. These include a beam size mismatch, beam center mismatch, and signal-to-noise ratio of the images. The beam size and beam center are scanned using simulated noisy beams, and the result of the modal decomposition is compared with that of real beams. Based on the suggested procedure, error functions of approximately 1-4 × 10-3 can be acquired for real beams. This study provides important information regarding the impact of the three factors on the practical modal decomposition and tolerances of a mismatch, helping estimate the achievable values of the error function in a real beam modal decomposition.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.891-899
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• 2021

The United Nations' Millennium Development Goals (MDG) has become a goal to create a sustainable life. The MDGs' target was to be achieved in 2015, but it missed that date. The MDGs' target has turned into a Sustainable Development Goals (SDGs) to be achieved by 2030 The SDGs require financial support from companies. Funds are one of the resources to implement the SDGs. Government and private companies need to cooperate in achieving the SDGs target. The company has a responsibility to implement corporate social responsibility. The company's corporate social responsibility is part of the implementation of sustainable development in the SDGs. One of the essential industries that have responsibility for SDGs is the financial industry. This study aims to examine the determinant of corporate social responsibility funds in financial institutions in ASEAN countries. This study uses panel data to test the determinant variables on CSF provision. This study uses 45 sustainable development reports from 2015-2019. The total number of banks in the sample came from three countries, namely, Indonesia, Malaysia, and Thailand. This study concludes that firm size, profitability, efficiency, and the age of the CEO are variables that influence the size of corporate social responsibility funds.

• Journal of Information Technology Services
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• v.20 no.3
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• pp.13-25
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• 2021

The article presents the results of how employee's hierarchical job roles differently recognize a SM(smart manufacturing) and evaluate comprehensively on the SM employees training. The research was focus on small and medium size manufacturing corporation in Banwol·Siwha industrial complex, where is carried out Smart Complex National Policy. The Results from 205 participants working for a manufacturing firms in the Banwol·Siwha industrial complex. The results of study show that managers (vs workers) group is higher recognition of smart manufacturing and more intention to participate a SM employee training and utilize a SM equipments for test a manufacturing process. and these variables were mediated by SM cognition. These results will help SM manpower training center strategically design their training programs to maximize the training effectiveness.