• 한국항만경제학회:학술대회논문집
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• 한국항만경제학회 2006년도 국제학술대회
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• pp.235-250
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• 2006

When comparing the port management type between the both countries, there are some differences at some aspects. And also Korea is to move forward a hub port and logistics center in Northeast Asia while Japan is to pursue providing the port logistics service necessary for the Japanese economy. Major findings and implications are as follows. First, Port authority system should be extended to Gwangyang and Pyeongtaek port step by step. Second, any port which did not introducing a port authority system should enhance cooperating with its own local administration. Third, a port marketing strategy must be established and implemented by a port authority.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.340-345
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• 1996

Because of limited resources of time and information processing capability during abnormal situation, diagnosis is difficult tasks in nuclear power plant (NPP) operators. Moreover since minimizing of adverse consequences according to process abnormalities is vital for the safety of NPP, introducing of diagnosis support systems have particularly emphasized. However, considerable works to develop effective diagnostic support system are not sufficiently fulfilled because of the complexity of NPP is one of the major problems. To cope with this complexity, a lot of model-based diagnosis support systems have considered and implemented worldwide. In this paper, as a prior step to development of model-based diagnosis support systems, primary side of pressurized water reactor is functionally modeled by multilevel flow modeling (MFM) concept. MFM is suitable for complex system modeling and for diagnosis of abnormalities. Furthermore, knowledge-based diagnosis process, of NPP operator could be supported because this diagnosis strategy can represent operator's one.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권5호
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• pp.2319-2337
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• 2019

In this paper, we study the distributed cooperative caching for Internet content providers in a small cell of heterogeneous network (HetNet). A general framework based on bankruptcy game model is put forth for finding the optimal caching policy. In this framework, the small cell and different content providers are modeled as bankrupt company and players, respectively. By introducing strategic decisions into the bankruptcy game, we propose a caching value assessment algorithm based on analytic hierarchy process in the framework of bankruptcy game theory to optimize the caching strategy and increase cache hit ratio. Our analysis shows that resource utilization can be improved through cooperative sharing while considering content providers' satisfaction. When the cache value is measured by multiple factors, not just popularity, the cache hit rate for user access is also increased. Simulation results show that our approach can improve the cache hit rate while ensuring the fairness of the distribution.

• Structural Engineering and Mechanics
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• 제70권5호
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• pp.513-524
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• 2019

This study proposed an improved particle swarm optimization (IPSO) method ensemble with kriging model for model updating. By introducing genetic algorithm (GA) and grouping strategy together with elite selection into standard particle optimization (PSO), the IPSO is obtained. Kriging metamodel serves for predicting the structural responses to avoid complex computation via finite element model. The combination of IPSO and kriging model shall provide more accurate searching results and obtain global optimal solution for model updating compared with the PSO, Simulate Annealing PSO (SimuAPSO), BreedPSO and PSOGA. A plane truss structure and ASCE Benchmark frame structure are adopted to verify the proposed approach. The results indicated that the hybrid of kriging model and IPSO could serve for model updating effectively and efficiently. The updating results further illustrated that IPSO can provide superior convergent solutions compared with PSO, SimuAPSO, BreedPSO and PSOGA.

• 한국전기전자재료학회논문지
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• 제37권1호
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• pp.11-25
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• 2024

Lithium-ion batteries (LIBs) have attracted great attention as the common power source in energy storage fields of large-scale applications such as electrical vehicles (EVs), industries, power plants, and grid-scale energy storage systems (ESSs). Insertion, alloying, and conversion reactions are the main electrochemical energy storage mechanisms in LIBs, which determine their electrochemical properties and performances. The electrochemical reaction mechanisms are determined by several factors including crystal structure, components, and composition of electrode materials. This article reviews a new strategy to compensate for the intrinsic shortcomings of each reaction mechanism by introducing the material systems to form a single compound with different types of reaction mechanisms and to allow the simultaneous hybrid electrochemical reaction of two different mechanisms in a single solid solution phase.

• Journal of Information Processing Systems
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• 제19권5호
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• pp.563-575
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• 2023

Trajectory planning is a key technology for unmanned aerial vehicles (UAVs) to achieve complex flight missions. In this paper, a terminal constraints conversion-based Gauss pseudospectral trajectory planning optimization method is proposed. Firstly, the UAV trajectory planning mathematical model is established with considering the boundary conditions and dynamic constraints of UAV. Then, a terminal constraint handling strategy is presented to tackle terminal constraints by introducing new penalty parameters so as to improve the performance index. Combined with Gauss-Legendre collocation discretization, the improved Gauss pseudospectral method is given in detail. Finally, simulation tests are carried out on a four-quadrotor UAV model with different terminal constraints to verify the performance of the proposed method. Test studies indicate that the proposed method performances well in handling complex terminal constraints and the improvements are efficient to obtain better performance indexes when compared with the traditional Gauss pseudospectral method.

• Advances in aircraft and spacecraft science
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• 제10권5호
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• pp.393-418
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• 2023

Drones are increasingly used in logistics delivery due to their low cost, high-speed and straight-line flight. Considering the small cargo capacity, limited endurance and other factors, this paper optimized the pickup and delivery vehicle routing problem with time windows in the mode of "truck+drone". A mixed integer programming model with the objective of minimizing transportation cost was proposed and an improved adaptive large neighborhood search algorithm is designed to solve the problem. In this algorithm, the performance of the algorithm is improved by designing various efficient destroy operators and repair operators based on the characteristics of the model and introducing a simulated annealing strategy to avoid falling into local optimum solutions. The effectiveness of the model and the algorithm is verified through the numerical experiments, and the impact of the "truck+drone" on the route cost is analyzed, the result of this study provides a decision basis for the route planning of "truck+drone" mode delivery.

• Journal of Information Technology Applications and Management
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• 제30권5호
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• pp.107-120
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• 2023

In this study, we investigate the changes and realities of the content production process focusing on Image generation AI revolutions such as Stable Diffusion, Midjourney, and DELL-E, and examine the current status of related department operations at universities and Find out the status of the current curriculum. Through this, we suggest the need to produce AI-adaptive content talent through re-establishing the capabilities of content-related departments in art universities and quickly introducing curriculum. This is because it can be input into the efficient AI content development system currently being applied in industrial fields, and it is necessary to cultivate talent who can perform managerial and technical roles using various AI systems in the future. In conclusion, we will prepare cornerstone research to establish the university's status as a source of talent that can lead the content industry beyond the AI content production era, and focus on convergence capabilities and experience with the goal of producing convergence talent to cultivate AI adaptive content talent, suggests the direction of curriculum application for value creation.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.16-24
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• 2024

With an increase in the relevance of next-generation integrated networking environments, the need to effectively utilize advanced networking techniques also increases. Specifically, integrating Software-Defined Networking (SDN) with Multi-access Edge Computing (MEC) is critical for enhancing network flexibility and addressing challenges such as security vulnerabilities and complex network management. SDN enhances operational flexibility by separating the control and data planes, introducing management complexities. This paper proposes a reinforcement learning-based network path optimization strategy within SDN environments to maximize performance, minimize latency, and optimize resource usage in MEC settings. The proposed Enhanced Proximal Policy Optimization (PPO)-based scheme effectively selects optimal routing paths in dynamic conditions, reducing average delay times to about 60 ms and lowering energy consumption. As the proposed method outperforms conventional schemes, it poses significant practical applications.

• Strategy21
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• 통권30호
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• pp.143-176
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• 2012

We are witnessing the growing maritime tension on the East Asian sea these days. Each naval powers in the region are competing each other to acquire more advanced naval capabilities. Based upon the rapid economic development, China is actively beefing up its naval capabilities and expand its boundary of naval activities all over the East Asian region. Chinese Navy already unveiled its expansive naval strategy replacing the traditional concept of 'Near-Sea Defense' with the new concept of 'Far-Sea Defense' strategy. In response to potential rival's naval build up, the U.S. is redeploying its naval forces focusing on the Asia-Pacific region. The U.S. enhances its joint naval exercises with the countries in the region, such as Japan, India, Australia and so on. In addition, Washington is devising new naval strategy under the concept of 'Air-Sea Battle' to deter Peking's so-called 'Anti-Access/ Area Denial(A2AD)' strategy. As a close ally of the U.S., Japan also disclosed its clear intention to strengthen the Maritime Self Defense Force(MSDF)'s capabilities by introducing the new concept of 'Dynamic Defense Force' in 2011. Under the new concept, JMSDF is pursuing the additional acquisition of submarines, quasi-aircraft carriers, Aegis-equipped destroyers, etc. Under the new president's strong leadership, Russia is also invigorating the naval build-up. Especially, Russia is fortifying the Pacific Fleet's naval assets by deploying new-type of naval ships such as the Mistral which was imported from France. In the midst of competitive naval build-up among the major naval powers in the region, we are observing the growing maritime conflicts on the East China Sea as well as South China Sea. Those naval conflicts can pose severe threats to our national interests. Maritime conflicts on the East or South China Sea can imperil our sea lanes which will be indispensible for national economic development. Neighboring countries' maritime conflicts also will cast an uncertainty on the path to mobilize international cooperation to resolve the North Korean issues. We should contribute to ease the maritime tension in the region by various ways. First, we should actively galvanize the bilateral maritime dialogue among the major naval powers in the region. Second, we also should take the lead to form a multilateral maritime cooperation mechanism in the region. Above all, we should set the aim to be a peaceful maritime power who can contribute to a building of stable maritime order in the region with a considerable naval power.