• Journal of Navigation and Port Research
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• v.32 no.1
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• pp.65-72
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• 2008

This study is aimed to contribute in establishing new port policy by research and analysis in design of global port logistics network in the East Asia region. In order to build such port logistics network, 21 ports located in East Asia among the world's 50th largest ports were selected in this study. Furthermore, the amount of container cargo and the ports of call were analyzed to categorize the subject ports in East Asia. Finally, this study tries to find economic network between the base port in East Asia, EU or North America and feeder ports in terms of logistics cost. As a result, Singapore, Hong Kong, Shanghai, and Busan ports were found as the representative ports in the East Asia that may connect North America and Europe with the minimum logistics expenses. Therefore, to maintain the stable cargo volume in ports, Korea should promote not only the overseas terminal operation which links to the Singapore, Hong Kong, and Shanghai ports, but also establish the global port logistic network connecting the Busan port.

• Electronics and Telecommunications Trends
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• v.35 no.5
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• pp.83-91
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• 2020

In this paper, the contemporary deployment of broadband and Internet-of-Things (IoT) services based on the Low Earth Orbit (LEO) satellite communication network is presented. First, the global service and key technologies of small and nanosatellites are briefly addressed, and then, the progress of relevant standard technologies is explained. Finally, the overall potential for the future development of the LEO satellite communication network is highlighted.

• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.157-164
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• 2022

The proposed privacy preserving scheme has identified the drawbacks of existing schemes in Vehicular Networks. This prototype enhances the number of nodes by decreasing the cluster size. This algorithm is integrated with the whale optimization algorithm and Block Chain Technology. A set of results are done through the NS-2 simulator in the direction to check the effectiveness of proposed algorithm. The proposed method shows better results than with the existing techniques in terms of Delay, Drop, Delivery ratio, Overhead, throughout under the denial of attack.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.123-131
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• 2015

Training neural networks is a complex task with great importance in the field of supervised learning. In the training process, a set of input-output patterns is repeated to an artificial neural network (ANN). From those patterns weights of all the interconnections between neurons are adjusted until the specified input yields the desired output. In this paper, a new hybrid algorithm is proposed for global optimization of connection weights in an ANN. Dynamic swarms are shown to converge rapidly during the initial stages of a global search, but around the global optimum, the search process becomes very slow. In contrast, the gradient descent method can achieve faster convergence speed around the global optimum, and at the same time, the convergence accuracy can be relatively high. Therefore, the proposed hybrid algorithm combines the dynamic particle swarm optimization (DPSO) algorithm with the backpropagation (BP) algorithm, also referred to as the DPSO-BP algorithm, to train the weights of an ANN. In this paper, we intend to show the superiority (time performance and quality of solution) of the proposed hybrid algorithm (DPSO-BP) over other more standard algorithms in neural network training. The algorithms are compared using two different datasets, and the results are simulated.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.2
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• pp.137-143
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• 2005

Autonomous mobile robot has an ability to navigate using both map in known environment and sensors for detecting obstacles in unknown environment. In general, autonomous mobile robot navigates by global path planning on the basis of already made map and local path planning on the basis of various kinds of sensors to avoid abrupt obstacles. This paper provides a global path planning method using self-organizing feature map which is a method among a number of neural network. The self-organizing feature map uses a randomized small valued initial weight vectors, selects the neuron whose weight vector best matches input as the winning neuron, and trains the weight vectors such that neurons within the activity bubble are move toward the input vector. On the other hand, the modified method in this research uses a predetermined initial weight vectors, gives the systematic input vector whose position best matches obstacles, and trains the weight vectors such that neurons within the activity bubble are move toward the input vector. According to simulation results one can conclude that the modified neural network is useful tool for the global path planning problem of a mobile robot.

• Korea Trade Review
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• v.44 no.2
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• pp.269-282
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• 2019

This study analyzes the effects of participation in the global production network on the income inequality using panel data from 2005 to 2016 for 63 countries. In this study were used fixed effects model with autocorrelation, random effect model with autocorrelation and the GLS method. Results are as follows: First, the economic development level supports the Kuznets hypothesis. And then, the forward participation in global value chains increased income inequality, and the backward participation decreased income inequality. In order to derive more detailed estimation results, we analyzed OECD countries and non-OECD countries. First, OECD countries featured decreased, but increased beyond a certain level as a U-shaped curve, that did not support the Kuznets hypothesis. In contrast, non-OECD countries followed the Kuznets U-curve. Second, participation in the global production network showed that both OECD and non-OECD countries featured increased income inequality. In contrast, backward participation appears to mitigate income inequality both in OECD and non-OECD countries. Finally, the ratio of labor and capital is significant in mitigating income inequality in non-OECD countries in which they feature backward participation in production networks. This can be interpreted as developing economies participate in the global production network due to increased capital accumulation and increased the labor productivity.

• Smart Structures and Systems
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• v.32 no.4
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• pp.235-251
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• 2023

A method that can estimate global deformation and internal forces using a limited amount of displacement data and based on the shape superposition technique and a neural network has been recently developed. However, it is difficult to directly measure sufficient displacement data owing to the limitations of conventional displacement meters and the high cost of global navigation satellite systems (GNSS). Therefore, in this study, the previously developed estimation method was extended by combining displacement, slope, and strain to improve the estimation accuracy while reducing the need for high-cost GNSS. To validate the proposed model, the global deformation and internal forces of a cable-stayed bridge were estimated using limited multi-response data. The effect of multi-response data was analyzed, and the estimation performance of the extended method was verified by comparing its results with those of previous methods using a numerical model. The comparison results reveal that the extended method has better performance when estimating global responses than previous methods.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.3
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• pp.491-511
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• 2016

This paper attempts to understand the nature and dynamics of global value chains in the auto industry using the OECD TiVA 2015 edition on the bilateral foreign value added in exports over the period 1995-2011 and employing the techniques of social network analysis such as the computation of network measures and visualization of value added trade flows. It is shown that there has been a tendency towards increasing production fragmentation both within and across regions. The automotive value-added network is found to have small-world properties with a hierarchical, clustered and dense structure. The differences among the US, Germany and China as major suppliers of foreign value added in global automotive value chains are remarkably revealed. Although the fragmentation of production has been developed on a global scale, a dichotomous tension between center and periphery and domestic and foreign capital lies behind it.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.963-968
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• 2003

A feedback control implementation for a high speed train pressurization system is proposed based on CAN (Controller Area Network). Firstly, system model including network latencies by CAN arbitration mechanisms is proposed, and an analytical compensation method of control parameters based on the system model is proposed for the network latencies. For the practical implementation of the control, global synchronization is adopted for controller to measure network latencies and to utilize them for the compensation of the control parameters. Simulation results are shown with practical tunnel data response. The proposed method is evaluated to be the most effective for the system through the control performances comparing among a controller not considering network latencies, other two off-line compensation methods, and the proposed method.

• International Commerce and Information Review
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• v.10 no.1
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• pp.97-115
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• 2008

This paper is to review how Korean trading companies perform and promote the digital transformation through the e-networking with global market, and how much they extend the volume of export, and make the company grow inward or outward in order to enhance the effects of economic growth in Korea. It is suggested that global agreement on e-Trade(or u-Trade) should be made in order to expand the global e-networking practices and to ensure transferring of transport documents(or business documents). Moreover, it also suggested that networking on the global trading partners such as government authorities, diplomatic offices abroad, overseas Koreans, students studying abroad, Korean merchants abroad, etc. should be made in single window for improving and upgrading the image of Korean trading companies. By making of global e-network platform between overseas business partners, trading companies are able to expect various synergy effects such as improving the satisfaction of their customers, promoting the global transactions, reducing the operation and transaction cost, helping fording overseas buyers, and extending export volume and sales profit, etc. Customers can also obtain the information about trading goods easily and rapidly, and cut down the transaction stage using information exchange with partners. All of the trading partners in the world can maintain their business partnership as long as they use the global e-network.