• Journal of Power Electronics
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• v.7 no.3
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• pp.181-190
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• 2007

This paper presents a novel circuit topology of a DC bus line series switch and parallel snubbing capacitor-assisted soft-switching PWM full-bridge inverter type DC-DC power converter with a high frequency planar transformer link, which is newly developed for high performance arc welding machines in industry. The proposed DC-DC power converter circuit is based upon a voltage source-fed H type full-bridge soft-switching PWM inverter with a high frequency transformer. This DC-DC power converter has a single power semiconductor switching device in series with an input DC low side rail and loss less snubbing capacitor in parallel with the inverter bridge legs. All the active power switches in the full-bridge arms and DC bus line can achieve ZCS turn-on and ZVS turn-off transition commutation. Consequently, the total switching power losses occurred at turn-off switching transition of these power semiconductor devices; IGBTs can be reduced even in higher switching frequency bands ranging from 20 kHz to 100 kHz. The switching frequency of this DC-DC power converter using IGBT power modules can be realized at 60 kHz. It is proved experimentally by power loss analysis that the more the switching frequency increases, the more the proposed DC-DC power converter can achieve a higher control response performance and size miniaturization. The practical and inherent effectiveness of the new DC-DC converter topology proposed here is actually confirmed for low voltage and large current DC-DC power supplies (32V, 300A) for TIG arc welding applications in industry.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.304-306
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• 1993

In this paper, the authors show a link between a heuristic controller used in industry and a theoretical generalized controller. First, we clarify the internal structure of the generalized two-degree-of-freedom controller which yields a link between the theoretical researches and the practical applications. Secondly, we indicate how to blend identification and control together without any modification of the controller. This is in fact the problem of closed-loop identification. Thirdly, we propose a design technique of a free parameter taking into account a robust stability based on the information obtained from the identification. Finally, we apply the proposed algorithm to trajectory control of DD robot.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.761-766
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• 2005

This paper presents a dynamic precedence queue mechanism to resolve unexpected transmission delay of a lower priority transaction in a CAN based system which keeps a fixed priority in data transactions. The mechanism is implemented in the upper sub-layer of the data link layer (DLL), which is fully compatible with the original medium access control layer protocol of CAN. Thus the mechanism can be implemented dynamically while the data transactions are going on without any hardware modification. The CAN protocol was originally developed to be used in the automotive industry and it was recently applied for a broader class of automated factories. Even though CAN is able to satisfy most of real-time requirements found in automated environments, it is not to enforce either a fair subdivision of the network bandwidth among the stations or a satisfactory distribution of the access delays in message transmissions. The proposed solution provides a superset of the CAN logical link layer control, which can coexist with the older CAN applications. Through the real experiments, effectiveness of the proposed mechanism is verified.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.125-132
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• 2015

The primary purpose of present study, to take appropriate measures to prevent occupational accidents in the food service industry, was to evaluate characteristics of working condition and occupational safety and health. In order to fulfill our objective, profession and working environment, safety recognition and education, safety activities, physical conditions and accident experience were surveyed. To collect information and opinion in the field, face-to-face interviews were, using a structured questionnaire, carried out. Also, food service industry's accidents reported by Korean Occupational Safety and Health Agency at 2014 were statistically analyzed. In the resulting of analyzing data from a questionnaire survey of food service industry employees, safety/health train and management were increased.

• The Research Journal of the Costume Culture
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• v.27 no.2
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• pp.181-192
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• 2019

The growth of cheap, industrial, mass-production-so-called "fast fashion"-has led to dramatic increases in levels of consumption. Inexpensive products tend to foster unsustainable consumption behaviors, which negatively impact the environment and increase pressure to obtain goods at lower and lower prices; this, in turn, has the competitive effect of decreasing wages. This study focused on the concept of socially responsible consciousness in relation to fashion products. Environmental and labor issue concerns were employed as major variables. Empirical data were collected from males and females, between the ages of 10 and 50. Demographic differences were found in SR consciousness. For example, participants in their 10s, 40s, and 50s had higher levels of SR consciousness than those in their 20s and 30s. In addition, consumers' levels of environmental and labor issue concerns had varying effects on the criteria they used to select clothing. Product category type was also an influential factor. Moreover, the analysis showed that SR consciousness was less important in the apparel industry than in the food sector. The study also found an attitude-behavior link in relation to the concept of SR consciousness. The link was stronger for environmental concerns than for labor issue concerns. This study aimed to develop a better understanding of current customers' characteristics and levels of SR consciousness.

• International Journal of Contents
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• v.6 no.3
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• pp.89-96
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• 2010

The International air transportation industry provides a vital communication link which brings prosperity to many states in our modern age. This invaluable link has been threatened by terrorism. Airlines have been one of the most attractive targets in the eyes of terrorists for several reasons, including particularly the international and symbolic nature of aviation, and the potential of multigovernmental involvement which can inevitably generate wide publicity. Terrorist attacks against civil aviation have been committed since the earliest days of civil aviation history. The first attack against civil aircraft dates back to the early 1930s. Since then, aircraft hijacking and other forms of attack against air transport operations have become one of the most serious challenges to the safety of flying. In recent years, a new form of threats against civil aviation has appeared. Man-portable air defense systems (MANPADS) in the hands of criminals, terrorists, and other non-state actors pose a serious potential threat to passenger air travel, the commercial aviation industry, and military aircraft around the world. The purpose of this study is to provide some countermeasures against such attacks. In order to foster a better understanding of the problem, an introduction of MANPADS and a brief history of attacks using MANPADS are presented. It also examines the level of threats, trends of attacks using MANPADS and the possible countermeasures to be taken by the international community.

• International Journal of Contents
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• v.5 no.3
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• pp.57-64
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• 2009

Korea has relied on top down development method, in which companies, research and education institutions move into the industrial complexes established by the government. However, to improve local competitiveness, the paradigm is shifting from the government initiated industrial complex to the clusters based on the cooperative network of the region. Representative case is 'Samcheok-si Fire & Emergency industry cluster construction project' that begun in 2007. AHP technique analysis results on first-stage showed that priority was on policy and network elements, and the results of second-stage analysis show that priority was on Policy incentives to internationalize the cluster and strengthen link,. Cluster branding, Sharing of organizational culture to cope with changes in environment, Creation of group learning culture. The subject of this research is limited to Samcheok-si's the Fire and Emergency Industry cluster formation project. Therefore, the research area and standard should be expanded to increase generality in further researches.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.2
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• pp.105-115
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• 2017

Innovative cluster theory promotes cluster growth as the tacit knowledge and know-how approach becomes easier through industry-academia cooperation. Industry-academia cooperation is an innovation network policy that supports joint research between industry and academia. In this respect, The Flow of recent government policy is activating I-U support office in university & research institute for enable I-U Cooperation ecosystem. Then SMB Administration was first performed "research village support program", to support SMEs in industry-university cooperative research capabilities by integrating the research, development and commercializatin of the university or research institution with excellent research base in 2013. However, I-U Cooperation R&D must be based the link strategy of Localization in order to be better composition at research village. In the case of research villages where specialized discovery strategies are well reflected, integration of similar companies in specialized fields will naturally create clusters and create synergy of research. This study searching and summarizing through a recent Hanbat National University research village. Finally, we propose the implications of government policy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.1
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• pp.115-123
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• 2010

The purpose of this study was to examine the effect of Busan Ocean Industry Expo on ocean related industries and Busan regional economy. The study analyzed the effects of the various projects related to Busan Ocean Industry Expo and answered the question of how to link the effects to development of ocean related industries as well as the economic activation of Busan area. To attain this goal, first of all, this study attempted to analyze status of ocean related industries, characteristics of existing exposition and opinion of enterprises. To maximize the above positive effects of Busan Ocean Industry Expo, several strategic alternatives were suggested.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.3
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• pp.471-481
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• 2023

Digital twin is considered as a key technology of industry 4.0, thus being essential for the future of industrial production. Despite the significance, a systematic analysis of its technological landscape is lacking. This study aims to investigate the technological development trends and newly emerging technological convergence opportunities in the domain of digital twin by exploiting patent information derived from U SPTO. For this purpose, this study visualized and predicted the convergence dynamics among patent classification codes by adopting patent co-classification analysis and link prediction approach. The findings show that the number of digital twin-related patent applications has increased significantly since 2018. The CPC code G06F showed the highest eigenvector centrality, while G05B was characterized by highest betweenness centrality. According to the predictive model, 41 novel links were revealed, acting as potential technology convergence opportunities. These links were then categorized into 11 different domains. The most dominant category was "digital data processing and artificial intelligence", which could play a foundational role in the diffusion of digital twin technology. The presence of digital twin technology is dominant in manufacturing, but its applications are expected to expand, including "climate change", "healthcare" and "aerospace engineering". The derived insights can support R&D managers and policy makers in formulating R&D strategies and directing future R&D investment decisions.