• Journal of Satellite, Information and Communications
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• v.8 no.1
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• pp.77-82
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• 2013

The object tracking method using particle filtering has been proved successful since it is based on the Monte Carlo simulation to estimate the posterior distribution of the state vector that is nonlinear and non-Gaussian in the real-world situation. In this paper, we present two nobel methods that can improve the performance of the object tracking algorithm based on the particle filtering. First one is the feedback method that replace the low-weighted tracking sample by the estimated state vector in the previous frame. The second one is an tracking box correction method to find an confidence interval of back projection probability on the estimated candidate object area. An sample propagation equation is also presented, which is obtained by experiments. We designed well-organized test data set which reflects various challenging circumstances, and, by using it, experimental results proved that the proposed methods improves the traditional particle filter based object tracking method.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.2
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• pp.1-15
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• 2003

This paper presents a new evolutionary algorithm to solve complex multi-level integration problems, which is called multi-level symbiotic evolutionary algorithm (MEA). The MEA uses an efficient feedback mechanism to flow evolution information between and within levels, to enhance parallel search capability, and to improve convergence speed and population diversity. To show the MEA's applicability, It is applied to the integrated planning of production and distribution in supply chain management. The encoding and decoding methods are devised for the integrated problem. A set of experiments has been carried out, and the results are reported. The superiority of the algorithm's performance is demonstrated through experiments.

• Journal of Distribution Science
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• v.17 no.11
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• pp.27-34
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• 2019

Purpose: This study explored the improvement and the direction of the smart disaster management system newly attempted in South Korea by analyzing the utilization of the existing system. This study focuses on making it easy to apply to user tasks and improving on site information. Research design, data and methodology: Problems were identified through field surveys with administrators in charge of administration and public institutions based on GIS based status board for NDMS which is widely used in Korea. Also, this study attempted to generalize to specialists in disaster management who are more likely to use the system in the future. Results: We derived improvement plans and verified the results through expert feedback. The results show that the GIS based status board for NDMS is cumbersome to use due to the vast array of unnecessary information compared to the high expected utilization. Conclusions: We found that improving the speed and accuracy of the smart disaster management information delivery system is necessary. Also, it is important to identify reasons for not improve the willingness to use this technology in disaster management and to figure out the process by which field personnel makes decisions that smart disaster information cannot be used for disaster management.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2464-2467
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• 2005

The purpose of this study was to explore the effectives of a virtual bicycle system in improving the ability of equilibrium sense of normal healthy adults. Experiments were performed to find the factors related to the training of equilibrium sense. The subjects consisted of young and elderly people and the group of young people was compared against the group of elderly people. We investigated three different running modes of virtual bicycle system with two successive sets in total. W measured the parameters related to the running time, the velocity, the weight movement, the degree of the deviation from the road, and the location of the center of pressure (COP). The results showed that the running capability of the elderly became much better after repeated training. In addition, it was found out that the ability to control postural balance and the capability of equilibrium sensory were improved with the presentation of the visual feedback information of the distribution of weight. We also found that the running time and the running velocity reduced when there was no visual feedback information. From the results, our newly developed bicycle system seems to be effective in the diagnosis of equilibrium sense as well as in the improvement of the sense of sight, and vestibular function of the elderly in the field of rehabilitation training.

• Journal of information and communication convergence engineering
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• v.9 no.2
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• pp.193-196
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• 2011

Transmit antenna selection techniques are prominent since they exploit the spatial selectivity at the transmitter side. In the literature, antenna selection techniques assume full knowledge of the channel state information (CSI). In this paper, we consider that the CSI is not perfectly known at the transmitter; however, a quantized version of the channel coefficients is fed back by the users. We employ the non-uniform Lloyd-Max quantization algorithm which takes into consideration the distribution of the channel coefficients. Simulation results show that the degradation in the BER of the system with imperfect CSI at the transmitter is tolerable, especially when the transmit diversity order is high.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.1
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• pp.35-49
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• 2010

KEPCO(Korean Electric Power Corporation) is now operating an incorporated system for designing and maintenance of electric power facilities called NDIS (New Distribution Information System). Given the structure of the nation which exclusively permits establishment of new electric facilities and maintenance, expertise (skilled knowledge) about the related system on the part of electric engineers is very important. But in the view of education and training, it is a reality that current offline ways of education based on application for educational courses at the KEPCO Academy, an education organization under KEPCO, are unsatisfactory in efficiency and availability to related engineers. Therefore, We realize that a simulation design education system which guarantees an easy access is required to make the best of the existing system NDIS. For this purpose the present work is a study on the development of a simulation education system to make local based NDIS real on the web, which enables related engineers to practice designing and get feedback of the result.

• Journal of Communications and Networks
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• v.18 no.2
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• pp.246-260
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• 2016

A major challenge achieving scalable access control for a large number of subscribers in a public broadcast is to distribute key update messages reliably to all stateless receivers. However, in a public broadcast, the rekeying messages can be dropped or compromised during transmission over an insecure broadcast channel, or transmitted to receivers while they were off-line. In this study, we propose a novel group key management scheme. It features a mechanism to allow legitimate receivers to recover the current group key, even if they lose key update messages for long-term sessions. The scheme uses short hint messages and member computation. Performance analysis shows that the proposed scheme has the advantages of scalability and efficient rekeying compared to previous reliable group key distribution schemes. The proposed key management scheme targets a conditional access system in a media broadcast in which there is no feedback channel from receivers to the broadcasting station.

• Journal of Distribution Science
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• v.19 no.2
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• pp.37-44
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• 2021

Purpose: O2O (Online to Offline) is an internet-based platform. The purpose of this study is to confirm the effect of service quality of O2O food delivery service on service satisfaction, and whether customer orientation mediates the relationship between service quality and service satisfaction. Research design, data and methodology: This paper surveyed Chinese consumers using the O2O food delivery platform through a questionnaire technique. Smart PLS 3.0 was used to verify the hypothesis of this study. PLS is characterized by the advantage of minimizing measurement errors and maximizing the influence of each factor. Results: It was confirmed that O2O food delivery companies need to increase service quality (information quality, product quality, and social quality, system quality) in order to obtain customer satisfaction. Additionally, the perceived customer orientation was found to completely mediate the relationship between perceived service quality (information quality, product quality) and perceived service satisfaction. Conclusions: The service level of the O2O delivery company to the customer's request when a problem occurs in the customer's order must be raised to increase the customer's satisfaction. For example, timely response to customer inquiries and timely feedback of delivery information to customers during the delivery process should improve the quality of after-sales service.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.225-230
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• 1996

We propose a statistical test for the nonlinear combiner logics which are usually combined with two maximal Linear Feedback Shift Registers and generate pseudorandom bit sequences. This test uses the mutual information between the output and set of inputs which will be a random variable and its distribution is obeyed to an approximate $\{chi}^2$ -distribution. We adopt this statistic to a $\{chi}^2$ -test of independence by using contingency table. We also apply a proposed test to some non-linear crptosystems and show that this useful to evaluate the strength of the cryptosystems.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.456-462
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• 2011

This paper investigates the outage behavior of peak interference power limited cognitive radio (CR) networks with multiple transmit antennas. In CR-multi-input single-output (MISO) channel, the total transmit power is distributed over the transmitantennas. First, we use the orthogonal space-time codes (STC) to achieve the transmit diversity at CR-receiver (rx) and investigate the effect of the power distribution on the interference power received at the primary-receiver (P-rx). Then, we investigate the transmit antenna selection (TAS) scheme in which the CR system selects the best transmit antenna and allocates all the power to the selected best antenna. Two transmit antenna selection strategies are proposed depending on if feedback channel is available or not. We derive the closed form expressions of outage probability and outage capacity of all schemes with arbitrary number of transmit-antennas. We show that the proposed schemes significantly improve the outage capacity over the single antenna systems in Rayleigh fading environment. We also show that TAS based scheme outperforms the STC based scheme when peak interference power constraint is imposed on the P-rx only if a feedback channel from CR-rx to CR-transmitter is available.