• Journal of the Korean Solar Energy Society
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• v.36 no.5
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• pp.73-89
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• 2016

To assure maximum economic benefits and the energy performance of solar water heating systems, the proper sizing of components and operating conditions need to be optimized. In recent years, a number of studies to design optimally solar water heating systems have been tried. This paper presents a design method for optimizing the various capacity-related and installation-related design variables based on life cycle cost using a genetic algorithm. The design variables considered in this study included the types and numbers of solar collector and auxiliary heaters; the types of storage tanks and heat exchangers; the solar collector slope; mass flow rates of the fluid on the hot and cold sides. The suggested method was applied for optimizing a solar water heating system for an elementary school in Seoul, South Korea. In addition, the effectiveness of the proposed optimization method was assessed by analyzing the obtained optimal solutions of six case studies, each of which was simulated with different solar fractions. It is observed that a trade-off between the equipment cost and the energy cost results in an optimal design that yields the lowest life cycle cost. Therefore, it could be helpful to apply the optimal solar water heating system by comparing the various design solutions obtained by using the optimization method instead of the engineer's experience and intuition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.210-211
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• 2009

The container has the inherent number which for distinguish among containers. When containers were handled, the container No. identify work must be precede. The work goes by fond in Most of the ports. It has not only inefficient time and cost but also error as worker's condition. The measure is operated that to use the camera on the spreader of quay crone to solve that problem. This measure, however, showed up the difference q recognition rates at weather, camera's condition, etc The ways could be considered both improvement of hardware and conversion of error number to solve the measure. This paper defines the problem and study an efficient solution.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.6
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• pp.961-973
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• 2023

With the changes in the modern computing landscape, securing containerized workloads and addressing the complexities of container networking have become critical issues. In particular, the complexity of network policy settings and the lack of cloud security architecture cause various security issues. This paper focuses on the importance of network security and efficiency in containerized environments, and analyzes the security features and performance of various container network interface plugins. In particular, the features and functions of Cilium, Calico, Weave Net, and Kube-router were compared and evaluated, and the Layer 3/4 and Layer 7 network policies and performance features provided by each plugin were analyzed. We found that Cilium and Calico provide a wide range of security features, including Layer 7 protocols, while Weave Net and Kube-router focus on Layer 3/4. We also found a decrease in throughput when applying Layer 3/4 policies and an increase in latency due to complex processing when applying Layer 7 policies. Through this analysis, we expect to improve our understanding of network policy and security configuration and contribute to building a safer and more efficient container networking environment in the future.