• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.4
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• pp.399-406
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• 2020

In this paper, we propose a time-varying proportional navigation guidance law that determines the proportional navigation gain in real-time according to the operating situation. When intercepting a target, an unidentified evasion strategy causes a loss of optimality. To compensate for this problem, proper proportional navigation gain is derived at every time step by solving an optimal control problem with the inferred evader's strategy. Recently, deep reinforcement learning algorithms are introduced to deal with complex optimal control problem efficiently. We adapt the actor-critic method to build a proportional navigation gain network and the network is trained by the Proximal Policy Optimization(PPO) algorithm to learn an evasion strategy of the target. Numerical experiments show the effectiveness and optimality of the proposed method.

• Journal of Technology Innovation
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• v.24 no.1
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• pp.113-142
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• 2016

T-50 exportation to Indonesia embodied an objective of governmental policy and became a catalyst accelerating the exportation of domestic defense industries. Defense industry exportation is recognized as a new growth engine creating economic interests and it became an important policy of the government. This study will suggest an effective direction for the support policy of the defense industry exportation through analysis on factors behind the success of the T-50 exportation to indonesia in the view of policy network. Policy network theory has its efficacy and workability in analyzing what kind of results are yielded from each policy actor's attributes and their interaction during the execution and establishment of the support policy for the defense exportation. The type of policy network of the T-50 exportation to Indonesia was a policy community. Many governmental ministries, defense industry which is the group of interest, and experts from the research institutes have established the Korea Defense Trade Support Center(KODITS) for accomplishing common policy goal with mutually shared sentiment, and sought for a strategy for the success of the defense industry exportation having official and unofficial meeting centering around the KODITS. Although there were oppositions and conflicts among major actors, though forming a cooperative relationship among majority of the actors, policy-wise decision making for the exportation of the T-50 to Indonesia was efficiently carried out. The cooperative relationship was the key in the success of the T-50 exportation. Considering that the policy community from cooperative mutual interaction is efficient in reaching the goal of the defense industry exportation support policy, this study suggests operating government-wise temporary Task Force(TF) to succeed in big exportation projects such as the T-X exportation to the U.S. In addition, institutional and procedural supplementation such as regular meetings among the head of related governmental ministries and etc. are required in order to enhance the mutually cooperative relationship withing the TF.

• Health Policy and Management
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• v.21 no.3
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• pp.457-492
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• 2011

The primary goal of our study was to investigate the vast transformations of the healthcare sector in Korea during the past half century. Official data reported in the Korean statistical yearbooks and secondary data suggested by previous studies were used for institutional analysis of healthcare environment. Information on hospital released by the Korean Hospital Association was also used for ecological analysis. Institutional analysis: We identified three distinctive eras based primarily on changes in institutional logics, institutional actors, and governance structures : 'professional dominance (1952-1976)', 'government involvement (1977-1999)', and 'coexistence of competing institutional logics (2000-present)'. During the first era, physician association supported by Korean government comprised the primary governance regime. During the second era, the government became a major actor as a regulator and purchaser in health care sector, introducing of the 'mandatory national health insurance'. During the third era, making healthcare system sustainable and providing health care efficiently was overarching goals although it was hard to find a single central logic dominating this period. Ecological analysis: Evidence from the analysis of hospital population suggested that the expansion of the bed capacity was made from different processes, shifting from the ecological process in 1980s to the adaptive process in 1990s. And Korean hospitals had changed following both 'directional process' and 'stabilizing process' over time. Based on our results, we concluded that more studies to compare more organizational populations other than hospitals and to empirically test the effects of institutional changes on organizational changes and vice-versa, need to be conducted.

• Health Policy and Management
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• v.26 no.1
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• pp.51-62
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• 2016

Background: The publicness concept in healthcare has been built to its social consensus relying on historical context, with the result that the meaning of publicness has a great diversity and heterogeneous nature in Korea. Thus it needs to be addressed to clarify the meaning and boundary of the publicness concept in healthcare, so as to discuss its social implication. Methods: In order to investigate whether or how the publicness concept is used in healthcare, we conducted a text network analysis in 779 news articles from 8 Korean daily newspapers over a recent 5-year period. Results: The publicness concept was closely related to medicine and medical institution, and formed a conceptual network with public health, medicine, welfare, patient, government, Jin-ju city, and health. Keywords relating publicness tended to be similar between four major newspapers; however, the association with Jin-ju city, government, and society was noticeable in Kyunghyang Shinmun and Hankyoreh, and so was patient and service in Dong-A Ilbo. Conclusion: Publicness and medicine was closely associated, and government seemed to remain as a main actor for public interest. Publicness was related with a variety of actors and values, with its expanded boundary. The different contexts of publicness by newspapers might reflect each ideological inclination. The textual importance of publicness was relatively low in part, which suggests that publicness was used in a loose sense or as a routine.

• Journal of the Korean association of regional geographers
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• v.19 no.1
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• pp.60-74
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• 2013

The discourses of creative city have been developed as a development and rehabilitation policy or plan in the contexts of globalization or deindustrialization society mainly progressed by Western capitalist nations, and there are a variety of effects due to the implementation of creative city in different national and local conditions. Many nations or cities have adapted and practiced the idea of creative city as a policy of development or rehabilitation without its critical examination. The purpose of this study is to make a conceptual framework of newly interpreting creative city, particularly focused on creative industry and class. The framework of creative city as a becoming locality consists of culture and art, creative actor and place continuously interacting, and it will take an active role to solve a variety of problems in the cities or regions due to globalization or deindustrialization. Creative city as a becoming locality should be developed in a close relation with the real situations in the future.

• Journal of Korea Technology Innovation Society
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• v.12 no.1
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• pp.265-289
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• 2009

This research analyzed regional innovation capabilities and technological activities of firms in Chungnam province of South Korea on the basis of a questionnaire survey of 64 regional manufacturing firms. The existence and level of regional innovation capabilities were measured by the perceptions of firms, a core actor in the regional innovation system. The analysis result revealed that research capabilities of academia, capabilities of R&D institutes, technological capabilities of industry, and governmental policy support were recognized as major capabilities of the regional innovation system. Regional proximity was also found to have significant influence on firms‘ sources of technological innovation and selection of collaboration partners. Practical as well as theoretical implications of the findings and future research directions were discussed at the last part.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.112-118
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• 2023

As technology advances, the need for enhanced preparedness against cyber-attacks becomes an increasingly critical problem. Therefore, it is imperative to consider various circumstances and to prepare for cyber-attack strategic technology. This paper proposes a method to solve network security problems by applying reinforcement learning to cyber-security. In general, traditional static cyber-security methods have difficulty effectively responding to modern dynamic attack patterns. To address this, we implement cyber-attack scenarios such as 'Tiny Alpha' and 'Small Alpha' and evaluate the performance of various reinforcement learning methods using Network Attack Simulator, which is a cyber-attack simulation environment based on the gymnasium (formerly Open AI gym) interface. In addition, we experimented with different RL algorithms such as value-based methods (Q-Learning, Deep-Q-Network, and Double Deep-Q-Network) and policy-based methods (Actor-Critic). As a result, we observed that value-based methods with discrete action spaces consistently outperformed policy-based methods with continuous action spaces, demonstrating a performance difference ranging from a minimum of 20.9% to a maximum of 53.2%. This result shows that the scheme not only suggests opportunities for enhancing cybersecurity strategies, but also indicates potential applications in cyber-security education and system validation across a large number of domains such as military, government, and corporate sectors.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.1
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• pp.17-28
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• 2019

In the financial investment management strategy, the distributed investment selecting and combining various financial assets is called portfolio management theory. In recent years, the blockchain based financial assets, such as cryptocurrencies, have been traded on several well-known exchanges, and an efficient portfolio management approach is required in order for investors to steadily raise their return on investment in cryptocurrencies. On the other hand, deep learning has shown remarkable results in various fields, and research on application of deep reinforcement learning algorithm to portfolio management has begun. In this paper, we propose an efficient financial portfolio investment management method based on Asynchronous Advantage Actor-Critic (A3C), which is a representative asynchronous reinforcement learning algorithm. In addition, since the conventional cross-entropy function can not be applied to portfolio management, we propose a proper method where the existing cross-entropy is modified to fit the portfolio investment method. Finally, we compare the proposed A3C model with the existing reinforcement learning based cryptography portfolio investment algorithm, and prove that the performance of the proposed A3C model is better than the existing one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.201-211
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• 2020

Green/climate technology has been emphasized as a growth engine that can boost the global economy via environmentally friendly products. Recently, SMEs in Korea have been recognized as a critical actor in the globalization of green/climate technologies. However, there has been no survey and few studies on the satisfaction level of the support for the overseas expansion of SMEs in the green/climate technology field. Therefore, this study aims to support a policy for the establishment of SMEs' green/climate technology by investigating and analyzing expert opinions on SMEs. Through a literature survey, support policies were classified into four types, and then according to the types, satisfaction factors and obstacle factors for overseas expansion were derived and analyzed. In the results, the SMEs overall showed low levels of awareness and satisfaction and were found to be struggling due to all obstructive factors. In addition, the most important success factor for overseas expansion was found to be the policy related to funding support. Thus, it is necessary to improve the accessibility, advertisement, and support strategies of support policies, and in particular, appropriate budget allocation should be made available by considering the characteristics of companies.

• Journal of Korea Technology Innovation Society
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• v.14 no.2
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• pp.343-372
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• 2011

Since the introduction of motion picture in the early 20th century, Korean motion picture industry has gradually evolved as one of the world leaders. However, due to the rapid technological change as exemplified by the emergence of the new digital and 3D cinema technologies, there is a need to re-consider the existing technology policy and strategy designed for the adoption and effective use of new technologies. In this paper, the authors address this issue by emphasizing the technological development side rather than the use/adoption side. In order to provide policy makers with critical information on the current status of the sector, we analyzed the sectoral innovation system of the Korean motion picture industry. In order to conduct this analysis, we re-visited previous literature and interviewed experts in the motion picture sector. Then, the authors attempted to identify the characteristics and problems of the current Korean motion picture industry. Based on the insights gained from this research, we draw policy implications for technological innovation in this sector. However, the implications from this paper are not limited to the motion picture industry. As the motion picture industry is a new case for innovation studies, our paper may provide new research opportunities to the academia.