• Journal of electromagnetic engineering and science
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• v.19 no.1
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• pp.6-12
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• 2019

An IE-FFT algorithm is implemented and applied to the electromagnetic (EM) solution of perfect electric conducting (PEC) scattering problems. The solution of the method of moments (MoM), based on the magnetic field integral equation (MFIE), is obtained for PEC objects with closed surfaces. The IE-FFT algorithm uses a uniform Cartesian grid to apply a global fast Fourier transform (FFT), which leads to significantly reduce memory requirement and speed up CPU with an iterative solver. The IE-FFT algorithm utilizes two discretizations, one for the unknown induced surface current on the planar triangular patches of 3D arbitrary geometries and the other on a uniform Cartesian grid for interpolating the free-space Green's function. The uniform interpolation of the Green's functions allows for a global FFT for far-field interaction terms, and the near-field interaction terms should be adequately corrected. A 3D block-Toeplitz structure for the Lagrangian interpolation of the Green's function is proposed. The MFIE formulation with the IE-FFT algorithm, without the help of a preconditioner, is converged in certain iterations with a generalized minimal residual (GMRES) method. The complexity of the IE-FFT is found to be approximately $O(N^{1.5})$and $O(N^{1.5}logN)$ for memory requirements and CPU time, respectively.

• Structural Engineering and Mechanics
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• v.68 no.6
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• pp.735-745
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• 2018

The Big Bang-Big Crunch (BB-BC) algorithm is an effective global optimization technique of swarm intelligence with drawbacks of being easily trapped in local optimal results and of converging slowly. To overcome these shortages, an improved BB-BC algorithm (IBB-BC) is proposed in this paper with taking some measures, such as altering the reduced form of exploding radius and generating multiple mass centers. The accuracy and efficiency of IBB-BC is examined by different types of benchmark test functions. The IBB-BC is utilized for damage detection of a simply supported beam and the European Space Agency structure with an objective function established by structural frequency and modal data. Two damage scenarios are considered: damage only existed in stiffness and damage existed in both stiffness and mass. IBB-BC is also validated by an existing experimental study. Results demonstrated that IBB-BC is not trapped into local optimal results and is able to detect structural damages precisely even under measurement noise.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.39-43
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• 2019

Recently, interest in literary therapy has been increasing. However, sometimes reading therapy is called literary therapy. But if you want to be a literary therapist, you need to know about the feelings that literary texts convey. To this end, Park Inkwa has long studied the relationship between sentences and emotions that the human body ignites. This study was also done in the view that the human body is so inspired and cured by literary text. It was conducted on the Lee Hangbok's Sijo "High Peak of Chullyoung", as it is suitable to discuss the feelings of literary therapy. In this study, Emotions were causing a transference to the reader with grief, which told the effect of literary therapy. We hope that such research will continue and further develop the technique of literary therapy.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.91-99
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• 2021

In Korea, some pharmaceutical companies and agricultural machine manufacturers associate the length of the credit period with the retailer's order size. This kind of commercial practice is based on the principle of economy of scale from the supplier's point of view and tends to make retailer's order size large enough to qualify a certain credit period break. Also, the credit period allowed by the supplier makes it possible to reduce the retail price expecting that the retailer can earn more profits by the stimulating the customer's demand. Since the retailer's order size is affected by the end customer's demand, it is reasonable to determine the retail price and the order size simultaneously. In this regard, this paper analyzes the retailer's problem who has to decide his sales price and order quantity from a supplier who offers different credit periods depending on his order size. And we show that the retailer's order size large enough to qualify a certain credit period break. Also, it is assumed that the end customer's demand rate is represented by a linear decreasing function of the retail price.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.1
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• pp.179-185
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• 2021

The aim of this study is to examine the impact of board of directors' activity on the audit committee's effectiveness score among manufactured listed companies on Saudi Stock Exchange (Tadawul) for the period 2015-2017. The final sample of this study consists of 195 firm-year observations that represent manufactured companies listed on Saudi Stock Exchange (Tadawul) for the years 2015-2017. The data of this study in terms of board of directors' meetings, audit committee size and meetings, firm leverage, firm performance, and firm age were hand-collected from the annual reports of the considered companies. The Pooled OLS regression's result indicate that audit committee's effectiveness score is influenced by the board of directors' activity. This result gives support to the agency theory prediction. This result is also consistent with the complementary function of corporate governance mechanisms in which board of directors' activity complements the function of audit committee's effectiveness score. The result of this study should be useful for manufacturing companies, Saudi Stock Exchange, auditors, and regulators which relates to the association between board of directors' activity and audit committee's effectiveness score. This study provides a new empirical evidence on the impact of board activity on the audit committee's effectiveness score in an interesting context which is Saudi Arabia.

• The Journal of the Convergence on Culture Technology
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• v.7 no.3
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• pp.481-486
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• 2021

Machine learning algorithms adopt criterion function as a key component to measure the quality of their model derived from data. Cluster analysis also uses this function to rate the clustering result. All the criterion functions have in general certain types of favoritism in producing high quality clusters. These clusters are then described by attributes and their values. Category utility and partition utility play an important role in cluster analysis. These are fully analyzed in this research particularly in terms of how they are related to the favoritism in the final results. In this research, several data sets are selected and analyzed to show how different results are induced from these criterion functions.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.531-536
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• 2022

This paper compared the performance of the parametric method and the nonparametric method when estimating the distribution for the tail of the distribution with heavy tails. For the parametric method, the generalized extreme value distribution and the generalized Pareto distribution were used, and for the nonparametric method, the kernel density estimation method was applied. For comparison of the two approaches, the results of function estimation by applying the block maximum value model and the threshold excess model using daily fine dust public data for each observatory in Seoul from 2014 to 2018 are shown together. In addition, the area where high concentrations of fine dust will occur was predicted through the return level.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3506-3513
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• 2023

In this paper, we demonstrate the neutron attenuation of dry cask shielding materials using the S670e helium-4 detector manufactured by Arktis Radiation Ltd. In particular, two materials expected to be applied to the TN-32 dry cask manufactured by ORANO Korea and KORAD-21 by the Korea Radioactive Waste Agency (KORAD) were utilized. The measured neutron attenuation was compared with our Monte Carlo N-Particle Transport simulation results, and the difference is given as the root mean square (RMS). For the fast neutron case, a rapid decline in neutron counts was observed as a function of increasing material thickness, exhibiting an exponential relationship. The discrepancy between the experimentally acquired data and simulation results for the fast neutron was maintained within a 2.3% RMS. In contrast, the observed thermal neutron count demonstrated an initial rise, attained a maximum value, and exhibited an exponential decline as a function of increasing thickness. In particular, the discrepancy between the measured and simulated peak locations for thermal neutrons displayed an RMS deviation of approximately 17.3-22.4%. Finally, the results suggest that a minimum thickness of 5 cm for Li-6 is necessary to achieve a sufficiently significant cross-section, effectively capturing incoming thermal neutrons within the dry cask.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.249-255
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• 2023

This study aims to empirically confirm the effect and impact of community care design research centered on domestic space and environment on health promotion, diagnosis treatment, disease management, rehabilitation, and mitigation through the year of publication and perspective. To this end, based on 1,227 space and environment design studies from 2,144 community care design research data conducted for about 20 years from 2002 to 2022, when care services began in earnest through the long-term care system for the elderly, SPSS 26.0 was used to create a 'Multi-layer Perceptron' artificial neural network structure model was predicted and neural network analysis was performed. Research Results First, as a result of checking studies in each field of health care by year, there is a significant difference with the number of studies related to health promotion being the highest. Second, the five perspectives are region, time, dimension, function, and content perspective. As a result of inputting these variables as independent variables and analyzing their importance in the artificial neural network, the function perspective had the most influence, followed by the region > content > dimension > time perspective.

• Journal of Korean Society for Quality Management
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• v.52 no.3
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• pp.495-508
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• 2024

Purpose: The purpose of this study was to propose a framework for quality level diagnosis of military supplies, which consists of 7 steps for developing questionnaires and suggesting improvement guidelines. Methods: We analyze the required functions of the equipment under investigation, classify the main components, review quality characteristics, develop a quality level checklist through the first and second stages of quality function deployment, and evaluate and analyze the results of the quality level survey applied to this checklist. Results: We first compared and analyzed case studies of domestic and international military and civilian quality level surveys and proposed a framework for diagnosing the quality levels of military supplies. Additionally, we applied the proposed quality level diagnosis framework to a specific weapon system to analyze its quality characteristics and identify improvement directions, thereby verifying the applicability of the proposed frame- work for diagnosing the quality levels of military supplies. Conclusion: The results of this study, which include the application of the proposed diagnostic framework for quality investigation and analysis, can be used to understand the satisfaction with the military supplies currently in operation. This will enable the continuous assurance of quality related to the functions and performance required by the military weapon systems.