• Journal of the Korean Society of Industry Convergence
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• v.23 no.4_2
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• pp.683-691
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• 2020

In the era of super-aged societies, research and development (R&D) projects related to aging are very important agenda for establishing the direction of future R&D planning and technological competitiveness in the country. In order to respond promptly to this agenda, it is essential to establish a national-level convergence R&D policy. In this study, we utilized the global R&D funding project data from major nations (US, Europe, Japan), and then standardized them with the same fields. To analyze the current status of global R&D related to aging, we performed cluster analysis based on the co-occurrence matrix to explore convergence R&D areas in the US, Europe, and Japan related to aging. In addition, comparative analysis by country suggested that different points on the interdisciplinary area and the convergence of aging-related R&D by each country. These results provide fundamental understandings for the status of convergence in aging-related global R&D, the current technology trends, and establish the direction and strategy of R&D policy.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.151-157
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• 2011

Crosslinked SPEEK/PVDF membrane were prepared by EB radiation method with various contents of PVDF. The prepared membranes were subjected to a comparative study of proton exchange membranes for fuel cell appreciations. The crosslinked SPEEK/PVDF membranes were characterized by using DMA, DSC and SAXS. The DMA data indicate that the ionic modulus values and cluster $T_g$ decrease with increasing PVDF content. Thus, it was suggested that the number of clustering in the crosslinked membranes can be reduced with increasing PVDF content. The DSC results were shown that the degree of crystalline of the membrane increased with increasing PVDF content. The morphology of the crosslinkied membranes was shown that with increasing PVDF content, the number of crystalline domain of the SPEEK/PVDF membranes increased but ionic aggregation of the membranes decreased. The water uptake behavior, ionic exchange capacity (IEC) and proton conductivity were decreased with increasing PVDF content. The overall findings suggest that the crosslinked membranes offer the possibility for improving the performance of PEMFC, provided that the membranes have thermal and hydration stability.

• The Journal of Fisheries Business Administration
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• v.49 no.4
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• pp.53-68
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• 2018

The industrial structure of Chuja Island is mainly occupied by fisheries. Since the fisheries resources have been depleted and the marine environment has been changed, the fishery industry has been hard to survive. It is the time when residents are looking for a breakthrough in the tourism industry. Market segmentation is a valuable tool in the establishment of marketing strategies. Segmentation of tourists by the same desire and motivation is an essential factor in identifying the characteristics of tourists. The research on market segmentation of tourism sector focuses mainly on demographic subdivision, psychological subdivision, and behavioral subdivision, so it is urgent to study geographical market segmentation. The purpose of this study is to present data that can be used to establish a marketing strategy for tourism promotion in Chuja Island by analyzing the tourism activities via subdivision market according to demographic characteristics, tourism behavior characteristics, and tourism motivation after grasping the geographical segment of tourists through empirical analysis. In this study, 285 valid samples were analyzed by frequency analysis, ${\chi}^2$ test, cluster analysis and ANOVA test.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.4_2
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• pp.481-490
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• 2021

In the ultrasonic welding machine, when the load fluctuates, the L and C of the piezo element in the oscillation part change. As a result, the resonant frequency is changed, so it is necessary to match the operating frequency of the ultrasonic welding machine to the new resonant frequency. That is, in order to maximize the output of the oscillation unit of the ultrasonic welding machine, it is inevitable to follow the resonance frequency. Accordingly, many methods for following the resonant frequency are being actively studied. In addition, in order to check the effect of external inductance on the operation of the ultrasonic welding machine, The equivalent circuit of the piezo element was analyzed by including the external inductance for resonance in the equivalent circuit of the piezo element, and the method of selecting an appropriate inductance was described. In this paper, we propose a new system that allows the switching frequency of the inverter to tracking the resonance frequency even if the resonance frequency is changed due to the load of the ultrasonic welding machine.

• Journal of Korea Society of Digital Industry and Information Management
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• v.17 no.1
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• pp.75-84
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• 2021

For analyzing big data, the social network is increasingly being utilized through relational data, which means the connection characteristics between entities such as people and objects. When the relational data does not exist directly, a social network can be configured by calculating relational data such as attribute similarity from attribute data of entities and using it as links. In this paper, the composition method of the social network using the attribute similarity between entities as a connection relationship, and the clustering method using subgroups for the configured social network are suggested, and the clustering effectiveness of the clustering results is evaluated. The analysis results can vary depending on the type and characteristics of the data to be analyzed, the type of attribute similarity selected, and the criterion value. In addition, the clustering effectiveness may not be consistent depending on the its evaluation method. Therefore, selections and experiments are necessary for better analysis results. Since the analysis results may be different depending on the type and characteristics of the analysis target, options for clustering, etc., there is a limitation. In addition, for performance evaluation of clustering, a study is needed to compare the method of this paper with the conventional method such as k-means.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.4_2
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• pp.491-499
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• 2021

Batteries are widely used for energy storage, such as ESS(Energy Storage System), electric vehicles, electric aircraft, and electric powered ships. Among them, a submarine uses a high power battery for an energy storage. When the battery of a submarine is discharged, a diesel generator generates AC power, and then AC/DC power converter change AC power to DC power for charging the battery. Therefore, in order to lower the current capacity of the diesel generator, it is necessary to use an AC/DC converter with a high input power factor. And, a power converter with a large power capacity must have high stability because it can lead to a major accident when a failure occurs. However, the control algorithm using the traditional PI controller is difficult to satisfy stability and dynamic characteristics. In this paper, we design the high power AC/DC converter with high input power factor for battery charging systems. And, we propose a stable control algorithm. The validity of the proposed method is verified through simulation and experiments.

• Journal of Korea Trade
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• v.24 no.5
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• pp.55-70
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• 2020

Purpose - This paper aims to examines the various factors influencing the purchase decisions of Malaysian consumers for halal food and based on this analysis, to present some measures by which Korea's food industry could expand exports to the Malaysian market. Design/methodology - This research used SPSS 12.0 for descriptive analysis, ANOVA, t-tests, factor analysis, cluster analysis, and reliability analysis based on a total of 571 responses were included as the final data in the 600 surveys administered. Findings - Malaysian consumers had high trust and confidence in products that had obtained halal certifications. This reflects the cultural situation where 61% of the Malaysian population consist of Muslims. In terms of the consumption of Korean foods, items such as ramyeon, confectionery, and kimchi were found to enjoy high awareness and strong preference among local consumers, thus suggesting their competitiveness. Originality/value - This paper attempts to examine consumer characteristics - an aspect that had received insufficient treatment in previous studies on halal certifications in Muslim countries. This study found the purchase practices and influencing factors behind Malaysian consumers' purchases of imported foods and Korean foods. Therefore, it is expected that this result can give Korean food industry an insights and strategies for exporting Korean food to Malaysia.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.327-331
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• 2023

This paper proposes a tourist destination recommendation application that combines a chatbot and a recommendation system. The data to be entered into the chatbot was through big data on social media. Through TEXTOM, a total of 22,701 data were collected over a one-year period from January 2022 to January 2023. Non-terms that interfere with analysis were removed through the data purification process. Using refined data, network visualization and CONCOR analysis were used to identify the information users want to obtain about travel to Jeju Island, and categories for each cluster were organized. The content was intuitively organized so that even those who approached it for the first time could easily use it, reducing the difficulty of operating the application. In this paper, users can select their own preferences and receive information. In addition, a tool called a chatbot allows users to focus more on the process of acquiring information by gaining a sense of reality while operating the application. This suggests an application that can reach the purpose of the curator by affecting the user's desire to visit tourist attractions.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.4
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• pp.672-686
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• 2022

The study classifies and analyzes the lower-body-shape types of female adolescents aged 14 to 16 years to provide meaningful information for making ready-to-wear patterns that are suitable for various female adolescent body types. The body-size data of 830 females aged 14 to 16 years were analyzed from 6th Size Korea anthropometric study. A factor analysis of 27 measurement items related to the lower body extracted 3 factors: waist/upper legs, height of the lower body, and hip area. A cluster analysis classified the female adolescent lower-body types into four clusters: the skinny body type with the shortest lower-body length, the most obese body type with the largest girth, the normal body type with the longest hip length, and the slender body type with the longest lower-body length. The discriminant analysis determined that nine measurement items had the most influence on classifying lower-body-shape types, and discriminant functions were derived. These results are meaningful because they provide more precise information about lower-body-shape types.

• Journal of Korean Society of Rural Planning
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• v.30 no.2
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• pp.79-96
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• 2024

The purpose of this study is to analyze the factors affecting residential mobility between urban and rural. After classifying urban and rural region based on discriminatory attributes of the regions, we applied a multinomial logistic model, using the sample data of 2020 Korea Population and Housing Census. The major findings are as follows. The young highly educated in cities avoided rural. The young less educated in rural engaged in 2, 3th industries as well as agricultural industry, but remained in low-paying and unstable jobs. In addition, various classes moved to rural and rising house prices in cities pushed people to rural. Therefore, it is necessary to develop diversified regional industry models and provide opportunities for high quality and stable jobs in rural by linking industrial demand, education and jobs. Also, preserving the rural environment, settlement conditions and residential environment are needed for satisfying various needs of urban residents who migrate to rural areas. While regional policies so far have focused on maintaining the population size and promoting a population influx, rural development and population policies should be established in a way that responds to diverse population classes in an era of population decline.