• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12B
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• pp.1736-1743
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• 2011

In Network Centric Warfare (NCW) environment, having a tactical communication network which provides high data exchange rate is very important. In the process, Korean Army developed Mobile Subscriber Access Point (MSAP) which is based on the commercial Wireless BroadBand (Wibro). MSAP is a vehicle attached base station which provide high data exchange communication environment in a given area. Thus MSAP can provide high data exchange rate and mobility to accomplish missions in the battlefield more effectively. In this paper, we propose an operational strategy of using MSAP to provide tactical communication network in the battlefield. The idea is to find the optimal location point of the MSAP in the operational area where all the troops in the operational area can be supported by the MSAP with a minimum number of MSAP. Since the current Korean Army's basic idea of using MSAP is just distribute this MSAP to each troop, so by applying our strategy we can save MSAP devices for more flexible operation. We will show our strategy's benefits through the mathematical model and the algorithm of the presented problem.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.3
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• pp.36-40
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• 2002

In this paper, we proposed a digital watermarking method based on the edge-wavelet transform to protect digital contents copyrights. We find out the optimal watermark insertion region and the proper amount of watermark in order to satisfy robustness and imperceptibility against various attacks such as noise, compression, collusion, clipping, scaling. Especially through this experiment, we could find out the adequate location of watermark insertion and proper amount of watermark and it is also viewed to satisfy robustness and imperceptibility in the lower frequency region with small watermark quantity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3275-3295
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• 2012

In this paper, we analyze the performance of an amplify-and-forward (AF) two-way relaying system, where two sources exchange information via the aid of an intermediate relay that is selected among multiple relays according to max-min criterion. We consider a practical scenario, where one source-relay link undergoes Rician fading, and the other source-relay link is subject to Rayleigh fading. To be specific, we derive a tight lower bound for the outage probability. From this lower bound, the asymptotic outage probability and average symbol error rate (SER) expressions are derived to gain insight into the system performance at high signal-to-noise ratio (SNR) region. Furthermore, we investigate the optimal power allocation (PA) with fixed relay location (RL), optimal RL with fixed PA and joint optimization of PA and RL to minimize the outage probability and average SER. The analytical expressions are verified through Monte Carlo simulations, where the positive impact of Rician factor on the system performance is also illustrated. Simulation results also validate the effectiveness of the proposed PA and relay positioning schemes.

• International Commerce and Information Review
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• v.16 no.4
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• pp.171-190
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• 2014

A short consumption cycle caused by the technological development and the diversification of customer lead to both the dynamic growth of the industry and the waste recycling issue at the same time. Including Korea, the situation is particularly worrisome in some countries, such as India and China, where acute environmental hazards have resulted from a combination of a lack of recycling centers' capacity and the domination of a large backyard recycling sector. A study about to maximize the current recycling center efficiency with minimal changes is required. In this study, we suggest the optimal location selection method for the recycling center based on the well-known reverse logistics cost minimization model. An actual recycling data about a specific electronic equipment and region in Korea are used for the verification of the method suggested.

• Journal of Environmental Science International
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• v.23 no.7
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• pp.1307-1320
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• 2014

A number of problems associated with environmental noises in urban areas have significantly been considered. Specific measurement and estimation of the environmental noise became a primary issue in local governments. Environmental noise monitoring system is required in order to estimate and verify the a city noise map. However, current monitoring positions may not perfectly represent and incorporate many different view points, such as districts of a city, different utilizations of a city by the law, populations, and classifications and traffics of roads. In addition, scientific method to provide specific noise monitoring positions my not be avaliable in current literature. For this reason, the primary objective of this paper is to propose a new method for introducing a number of monitoring positions in the entire city. First, the quality function deployment (QFD) method was utilized to simultaneously represent both districts and utilizations of a city. Second, a new algorithm to find a number of monitoring positions was proposed by compromising many different view points: populations, classifications of roads and areas, and traffics of roads. Finally, the proposed monitoring positions and a sample noise map was provided for verification purposes. Based on these results, the proposed algorithm including the QFD concept may successfully provide specific noise monitoring positions by simultaneously consider may different view points and requirements of a city.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.131-140
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• 2022

The magnitude and frequency of extreme floods are increasing owing to the effects of climate change. Therefore, multipurpose flood management techniques incorporating nature-based solutions have been introduced to mitigate the limitations of flood management and river design methods relying on existing observation data. Nature-based solutions to prepare for such extreme flooding events include ways to retreat the embankment, expand the floodplain, and reduce flood damage. To apply these technologies, adopting appropriate location selection methods based on various evaluation factors, such as flood damage reduction effects, sustainable ecological environments, river connectivity, and physical channel structure enhancements, should be prioritized. Therefore, in this study, the optimal location for implementing the multipurpose floodplain construction project was determined by selecting the location of the floodplain expansion with objectivity in the river waterfront area upstream of Daecheong Dam to downstream of Yongdam Dam. Through the final location determination, the Dongdaeje and Jeogokje sections were included in the optimal location considering both flood damage reduction and water environment improvement.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2145-2157
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• 2018

Congestion Management (CM) is an attractive research area in the electrical power transmission with the power compensation abilities. Reconfiguration and the Flexible Alternating Current Transmission Systems (FACTS) devices utilization relieve the congestion in transmission lines. The lack of optimal power (real and reactive) usage with the better transfer capability and minimum cost is still challenging issue in the CM. The prediction of suitable place for the energy resources to control the power flow is the major requirement for power handling scenario. This paper proposes the novel optimization principle to select the best location for the energy resources to achieve the real-reactive power compensation. The parameters estimation and the selection of values with the best fitness through the Symmetrical Distance Travelling Optimization (SDTO) algorithm establishes the proper controlling of optimal power flow in the transmission lines. The modified fitness function formulation based on the bus parameters, index estimation correspond to the optimal reactive power usage enhances the power transfer capability with the minimum cost. The comparative analysis between the proposed method with the existing power management techniques regarding the parameters of power loss, cost value, load power and energy loss confirms the effectiveness of proposed work in the distributed renewable energy systems.

• Smart Structures and Systems
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• v.26 no.6
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• pp.721-733
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• 2020

The present study investigates the employing of piezoelectric patches in active control of a sandwich plate. Indeed, the active control and optimal patch distribution on this structure are presented together. A sandwich plate with honeycomb core and composite reinforced by carbon nanotubes in facesheet layers is considered so that the optimum position of actuator/sensor patches pair is guaranteed to suppress the vibration of sandwich structures. The sandwich panel consists of a search space which is a square of 200 × 200 mm with a numerous number of candidates for the optimum position. Also, different dimension of square and rectangular plates to obtain the optimal placement of piezoelectric actuator/senor patches pair is considered. Based on genetic algorithm and LQR, the optimum position of patches and fitness function is determined, respectively. The present study reveals that the efficiency and performance of LQR control is affected by the optimal placement of the actuator/sensor patches pair to a large extent. It is also shown that an intelligent selection of the parent, repeated genes filtering, and 80% crossover and 20% mutation would increase the convergence of the algorithm. It is noted that a fitness function is achieved by collection actuator/sensor patches pair cost functions in the same position (controllability). It is worth mentioning that the study of the optimal location of actuator/sensor patches pair is carried out for different boundary conditions of a sandwich plate such as simply supported and clamped boundary conditions.

• Journal of Korea Port Economic Association
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• v.27 no.2
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• pp.1-26
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• 2011

This study was conducted to select the location of the logistics center for environment-friendly agricultural products in the Gwangyang Bay Area. AHP(Analytic Hierarchy Process) technique was used to examine location selection factors and factor hierarchy was made through a questionnaire survey and an expert interview for objective and quantitative decision. The hierarchy process of location factors of logistics center for environment-friendly agricultural products in the Gwangyang Bay Area were categorized into five factors such as natural factors, economic factors, social factors, distribution efficiency, and land use plan. Then, those factors were sub-categorized into three factors each. As a result of pair-wise comparison analysis of five categories, the weight of economic factors was the highest, and easy cargo transportation, fitness to higher-order plan, climate, land price, and limitation regulations of sub-categorized factors appeared as comparative evaluation criteria. The priority of the final candidate was decided through this process. While the weight of the Yulchon II Industrial Complex was the highest in natural and economic factors were the highest, the weight of the Gwangyang Hwanggeum Industrial Complex was the highest in social factors, distribution efficiency, and land use plan. The result of the final analysis showed that the Gwangyang Hwanggeum Industrial Complex was the most optimal location candidate for the logistics center for environment-friendly agricultural products.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.573-580
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• 2018

Various studies have been conducted to analyze the location appropriateness and capacity of shelters. However, research on how to select new shelters is relatively insufficient. Since the shelter is designated in case of emergency, it is also necessary to efficiently select the location of the shelter. Therefore, this study presented a method for selecting the location of the shelter using network analysis that has been used to analyze the location appropriateness of shelters and genetic algorithm which is a representative heuristic algorithm. First, the network analysis using the existing civil defense evacuation facility data was performed and the result showed that the vulnerability of evacuation has a high deviation by region in the study area. In order to minimize the evacuation vulnerable area, the genetic algorithm was designed then the location of new shelters was determined. The initial solution consisting of candidate locations of new shelters was randomly generated and the optimal solution was found through the process of selection, crossover, and mutation. As a result of the experiment, the area with a high percentage of the evacuation vulnerable areas was prioritized and the effectiveness of the proposed method could be confirmed. The results of this study is expected to contribute to the positioning of new shelters and the establishment of an efficient evacuation plan in the future.