• Journal of Korean society of Dental Hygiene
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• v.20 no.3
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• pp.325-333
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• 2020

Objectives: The purpose of this study was to determine the factors influencing oral health education of adolescents from multi-cultural families. Methods: The subjects were 711 multi-cultural adolescents from the 15th(2019) Korean youth risk behavior web-based survey. Multi-cultural adolescents were defind as the children of marriage migrant women. The collected data was analyzed using the chi-squared test and logistic regression; SPSS versin 18.0 was used. Results: Middle-school adolescents received more oral health education than their high-school counterparts. The adolescents with once-daily and twice-daily teeth brushing behaviors were 0.475 (p<0.05) and 0.784 times less those with thrice-daily behavior, respectively. Adolescents who received oral health education also experienced dental care 1.644 times more than their counterparts(p<0.05). Conclusions: The promotion of oral health among multicultural families and further education through the establishment of school oral health education programs are required.

• Journal of Institute of Convergence Technology
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• v.6 no.1
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• pp.43-47
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• 2016

In this paper, we report a work-in-progress about development of multi-drone system for smart agriculture. The multi-drone system is controlled via a haptic teleoperation by a human operator. The purpose of the multi-drone system is that let the human operator to easily handle the multiple drones which are maintaining a fixed formation using ZigBee communication network.

• Journal of Fashion Business
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• v.22 no.5
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• pp.83-95
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• 2018

As the paradigm of fashion retail industry moves rapidly to the multi-channel, the role of shop master has changed as well. Therefore, the purpose of this study is to examine in-depth the changing role of shop masters in multi-channel retail paradigms. In-depth interviews were conducted, and all interviews were recorded with permission. Seven shop masters participated in in-depth interviews. All of them were sales specialists, with more than 10 years working experience, at department stores. Results of this study are as follow: First, the roles of a multi-channel shop master include store management, management of sales associates, customer relationship management, and management in relation to the headquarters and suppliers. Second, the most important competencies of shop masters are to forecast future demand, establish information networks, communicate well with others, and create a work environment resulting in higher productivity.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.167-178
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• 2019

In this paper, we study the multi-objectives vehicle and drone routing problem with time windows, MOVDRPTW for short, which is defined in an urban delivery network. We consider the dual modal delivery system consisting of drones and vehicles. Drones are used as a complement to the vehicle and operate in a point to point manner between the depot and the customer. Customers make various requests. They prefer to receive delivery services within the predetermined time range and some customers require fast delivery. The purpose of this paper is to investigate the effectiveness of the delivery strategy of using drones and vehicles together with a multi-objective measures. As experiment datasets, we use the instances generated based on actual courier delivery data. We propose a hybrid multi-objective evolutionary algorithm for solving MOVDRPTW. Our results confirm that the vehicle-drone mixed strategy has 30% cost advantage over vehicle only strategy.

• International Journal of Computer Science & Network Security
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• v.23 no.4
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• pp.39-47
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• 2023

This study compares various transformation techniques for multifocus image fusion. Multi-focus image fusion is a procedure of merging multiple images captured at unalike focus distances to produce a single composite image with improved sharpness and clarity. In this research, the purpose is to compare different popular frequency domain approaches for multi-focus image fusion, such as Discrete Wavelet Transforms (DWT), Stationary Wavelet Transforms (SWT), DCT-based Laplacian Pyramid (DCT-LP), Discrete Cosine Harmonic Wavelet Transform (DC-HWT), and Dual-Tree Complex Wavelet Transform (DT-CWT). The objective is to increase the understanding of these transformation techniques and how they can be utilized in conjunction with one another. The analysis will evaluate the 10 most crucial parameters and highlight the unique features of each method. The results will help determine which transformation technique is the best for multi-focus image fusion applications. Based on the visual and statistical analysis, it is suggested that the DCT-LP is the most appropriate technique, but the results also provide valuable insights into choosing the right approach.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.656-657
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• 2015

Recently, Multi-Objective Optimization of design elements is an important issue in building design. Design variables that considering the specificities of the different environments should use the appropriate algorithm on optimization process. The purpose of this study is to compare and analyze the optimal solution using three evolutionary algorithms and energy modeling simulation. This paper consists of three steps: i)Developing three evolutionary algorithm model for optimization of design elements ; ii) Conducting Multi-Objective Optimization based on the developed model ; iii) Conducting comparative analysis of the optimal solution from each of the algorithms. Including Non-dominated Sorted Genetic Algorithm (NSGA-II), Multi-Objective Particle Swarm Optimization (MOPSO) and Random Search were used for optimization. Each algorithm showed similar range of result data. However, the execution speed of the optimization using the algorithm was shown a difference. NSGA-II showed the fastest execution speed. Moreover, the most optimal solution distribution is derived from NSGA-II.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.193-200
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• 2015

Purpose: The purpose of this study was to investigate the energy saving effects and characteristics of plant growth in a greenhouse with an aluminum multi-layer curtain compared to a greenhouse with non-woven fabric. Method: The dimensions of both greenhouses $43m{\times}3.6m{\times}8m(L{\times}H{\times}W)$, and both used hot air heater systems for maintaining a constant temperature $15^{\circ}C$. Heating characteristics such as solar intensity, inside and ambient temperatures, and fuel consumption were measured and analyzed. Results: The changes of average temperature of both greenhouses during a 15-days (December 06 - 20) showed approximately $26^{\circ}C$ at around 2 pm when the ambient temperature was highest. The greenhouses were set by the heater to keep a temperature of $15^{\circ}C$ from 4 pm to 8 am the following day. The average heat loss (for 15 days) from the greenhouse with an aluminum multi-layer curtain was $161.2-268.4kJ/m^2{\cdot}h$ during the daytime and $152.3-198.1kJ/m^2{\cdot}h$ during the nighttime. The average heat loss (for 15 days) from the greenhouse with non-woven fabric was $155.7-258.9kJ/m^2{\cdot}h$ during the daytime and $144.9-207.0kJ/m^2{\cdot}h$ during the nighttime. The total heat loss (for one day) from the non-woven fabric system was $7,960kJ/m^2$($2,876kJ/m^2$ during the daytime, $5,084kJ/m^2$ during the nighttime). The heat supply over 36 days for the non-woven fabric system was higher than the aluminum multi-layer curtain system by $616.3-65,079.4kJ/m^2$. Conclusions: These results suggest that a greenhouse with an aluminum multi-layer curtain could save energy usage by 35% over a greenhouse with non-woven fabric.

• Journal of Electrical Engineering and Technology
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• v.3 no.2
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• pp.224-234
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• 2008

Multi-phase machines can be used in variable speed drives. Their applications include electric ship propulsion, 'more-electric aircraft' and traction applications, electric vehicles, and hybrid electric vehicles. Multi-phase machines enable independent control of a few numbers of machines that are connected in series in a particular manner with their supply being fed from a single voltage source inverter(VSI). The idea was first implemented for a five-phase series-connected two-motor drive system, but is now applicable to any number of phases more than or equal to five-phase. The number of series-connected machines is a function of the phase number of VSI. Theoretical and simulation studies have already been reported for number of multi-phase multi-motor drive configurations of series-connection type. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, information concerning the rotor speed is extracted from measured stator currents and voltages at motor terminals. Open-loop estimators or closed-loop observers are used for this purpose. They differ with respect to accuracy, robustness, and sensitivity against model parameter variations. This paper analyses operation of an MRAS estimator based sensorless control of a vector controlled series-connected two-motor five-phase drive system with current control in the stationary reference frame. Results, obtained with fixed-voltage, fixed-frequency supply, and hysteresis current control are presented for various operating conditions on the basis of simulation results. The purpose of this paper is to report the first ever simulation results on a sensorless control of a five-phase two-motor series-connected drive system. The operating principle is given followed by a description of the sensorless technique.

• The Journal of the Convergence on Culture Technology
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• v.5 no.1
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• pp.45-50
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• 2019

This research analyzed that what factors affect to the change of social positioning of 'multi-cultural family(MCF)' centered on 'multi-cultural family in Jecheon City using Social Construction. The purpose of this research analyze the social positioning of MCF in Jecheon City, policy design depending on that social positioning and the effect of social perception. Therefore, this research carried out qualitative analysis method that analyzed news articles, legislations and interviews from 1990 to 2013 based on social construction theory. For the purpose, first, the time scope could be divided into four periods such as 'the quickening period in 1990s', 'quantitative growth period from 2000 to 2005', 'qualitative growth period from 2006 to 2011', 'the period of antagonism after 2012' of MCF.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.173-182
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• 2020

Since 2000, Korea has seen a big trend in the market, as the EU tightened regulations on environment due to global warming, high oil prices and aging rural population distribution, strengthening the need for multi-purpose electric moto vehicles for small farmers based on eco-friendly energy. Multi-purpose electric motor vehicles for rural small businesses will be a very innovative means of transportation, not only maintained at a low cost and to reduce greenhouse gases through the activation of eco-friendly energy, but also be a very innovative means of transportation for reducing the labor intensity of the aging farming industry and transporting night work and logistics. In this paper, with the implementation of eco-friendly energy policies, small and medium-sized rural small business owners can easily operate on unpaved roads and well-drawn farming environments, while the intensity of labor can be reduced when transporting crops also can simply replace parts at a low cost in the event of an accident. To propose rural multi-purpose modular electric vehicles, the existing literature is reviewed and 12 modular parts are presented by benchmarking electric vehicles at home and abroad. This paper is thought to be helpful for the research of the industry as well as the design industry of modular electric vehicles.