• Journal of Power Electronics
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• v.19 no.5
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• pp.1289-1302
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• 2019

In this paper, an optimal allocation method of a hybrid active power filter in an active distribution network is designed based on the differential evolution algorithm to resolve the harmonic generation problem when a distributed generation system is connected to the grid. A distributed generation system model in the calculation of power flow is established. An improved back/forward sweep algorithm and a decoupling algorithm are proposed for fundamental power flow and harmonic power flow. On this basis, a multi-objective optimization allocation model of the location and capacity of a hybrid filter in an active distribution network is built, and an optimal allocation scheme of the hybrid active power filter based on the differential evolution algorithm is proposed. To verify the effect of the harmonic suppression of the designed scheme, simulation analysis in an IEEE-33 nodes model and an experimental analysis on a test platform of a microgrid are adopted.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.45-52
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• 2020

Recently, a multi facility, multi product and multi period industrial problem has been widely investigated in Supply Chain Network(SCN). One of keys issues in the current SCN research area involves minimizing both production and distribution costs. This study deals with finding an optimal solution for minimizing the total cost of production and distribution problems in supply chain network. First, we presented an integrated mathematical model that satisfies the minimum cost in the supply chain. To solve the presented mathematical model, we used a genetic algorithm with an excellent searching ability for complicated solution space. To represent the given model effectively, the matrix based real-number coding schema is used. The difference rate of the objective function value for the termination condition is applied. Computational experimental results show that the real size problems we encountered can be solved within a reasonable time.

• ETRI Journal
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• v.46 no.2
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• pp.205-217
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• 2024

We propose a bandwidth prediction approach based on deep learning. The approach is intended to accurately predict the bandwidth of various types of mobile networks. We first use a machine learning technique, namely, the gradient boosting algorithm, to recognize the connected mobile network. Second, we apply a handover detection algorithm based on network recognition to account for vertical handover that causes the bandwidth variance. Third, as the communication performance offered by 3G, 4G, and 5G networks varies, we suggest a bidirectional long short-term memory model with time distribution for bandwidth prediction per network. To increase the prediction accuracy, pretraining and fine-tuning are applied for each type of network. We use a dataset collected at University College Cork for network recognition, handover detection, and bandwidth prediction. The performance evaluation indicates that the handover detection algorithm achieves 88.5% accuracy, and the bandwidth prediction model achieves a high accuracy, with a root-mean-square error of only 2.12%.

• International Journal of Computer Science & Network Security
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• v.23 no.12
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• pp.194-198
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• 2023

The current electricity networks will undergo profound changes in the years to come to be able to meet the growing demand for electricity, while minimizing the costs of consumers and producers, etc. The electricity network of tomorrow or even the intelligent « Smart Grids » network will be the convergence of two networks: the electricity network and the telecommunications network. In this context falls our work which aims to study the impact of the integration of energy decentralization into the electricity network. In this sense, we have implemented a new smart grid model where several coexisting suppliers can exchange information with consumers in real time. In addition, a new approach to energy distribution optimization has been developed. The simulation results prove the effectiveness of this approach in improving energy exchange and minimizing consumer purchase costs and line losses.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.52-59
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• 2010

As electric power demand of customers is constantly increasing, more bulk power systems are needed to install in a network. By development of renewable energies and high-efficient facilities and deregulated electricity market, moreover, the amount of distributed resource is considerably increasing in distribution network consequently. Also, distribution network has become more and more complex as mesh network to improve the distribution system reliability and increase the flexibility and agility of network operation. These changes make fault current increase. Therefore, the fault current will exceed a circuit breaker capacity. In order to solve this problem, replacing breaker, changing operation mode of system and rectifying transformer parameters can be taken into account. The SFCL(Superconducting Fault Current Limiter) is one of the most promising power apparatus. This paper proposes a methodology for on optimal location of SFCL. This place is defined as considering the decrement of fault current by component type and the increment of reliability by customer type according to an location of SFCL in a distribution network connected with DG(Distributed Generation). With case studies on method of determining optimal location for SFCL applied to a radial network and a mesh network respectively, we proved that the proposed method is feasible.

• Journal of Distribution Science
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• v.15 no.6
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• pp.13-24
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• 2017

Purpose - The current study aims to examine the effect of social network factors on travel agency employees' occupational outcomes such as job performance and job satisfaction through innovation behavior in a comprehensive model. Research design, data, and methodology - Based on a theory of social network, the concept of social network was assessed by three factors: a) network size, b) network range, and c) tie strength. To test the proposed hypotheses, structural equation modeling (SEM) was employed based on data from 197 travel agency employees in Korea. Result - The results showed that the associational activity of network size had a positive effect on innovation behavior, while the network range of network size had a significant negative effect on innovation behavior. Subsequently, innovation behavior positively influenced on job performance and job satisfaction, respectively. Conclusions - The results offer some insights into the extended model and have important managerial implications for Korean travel agencies. More specifically, considering diverse domains of social network and organizational research, this study advances critical utility of social network factors in a high facilitating level of innovation behavior, which can help travel agency employees promote their job performance and job satisfaction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.87-90
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• 2009

Wireless Mesh Network(WMN) is wireless backbone networks technique which has ease of network configuration and cost of advantage. Recently, WNM released a new product, but most of existing research and technology analysis the performance through the simulation. This paper build the wireless mesh network testbed for actual situation. Testbed supports multi-channel multi-interface using bridge, the Wireless Distribution System and dynamic location-based routing protocol. This routing protocol strongly design against wireless interference using metric for link channel change and real distance. Then, the address of mesh clients assigned by the centralized address management server. Mesh clients is designed and implemented to manage network through Simple Network Management Protocol.

• Journal of Distribution Science
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• v.20 no.5
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• pp.97-104
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• 2022

Purpose: This study intends to analyze the effect of competitor pressure and customer pressure on social media technology use and the value of the business network and their implications for marketing performance. Research design, and methodology: A constructed questionnaire was conducted with 90 respondents of MSME's Business Actors in South Sulawesi Partial Least Square (PLS) analysis was applied to analyze and verify all the data. Results: Competitor pressure has a significant effect on social media technology, Competitor pressure has a positive and significant impact on business network accentuation. Customer pressure has a positive and significant impact on social media technology. Customer pressure has a positive and significant impact on business network accentuation. Social media technology utilization has a significant impact on Business Network Accentuation. Social media technology utilization has a significant effect on Marketing Performance. Business Network has a significant effect on Marketing Performance. Conclusions: It is an important thing for MSMEs to increase the use of social media technology to meet the demands of consumers and pressure from competitors. The use of social media technology must be implemented effectively and efficiently so that it can be utilized as an effective tool for distributing the value that own by a company to improve the company's marketing performance.

• Convergence Security Journal
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• v.24 no.2
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• pp.175-180
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• 2024

Future warfare is evolving with advanced science and technology, introducing a variety of unmanned and manned combat systems. These systems generate and exchange massive amounts of information, challenging current tactical communication systems as a foundation for future communication infrastructure. To analyze the information distribution capability of the Army TIGER corps, this paper examines four scenarios: standalone ground network operation, integrated network operation, load distribution, and error recovery. Utilizing M&S results, we highlight the potential of a multilayer integrated command and control network, incorporating ground, air, and space networks, to enhance the reliability and stability of the overall communication network.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.295-296
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• 2005