• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.697-703
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• 2007

In this paper, we focuses on the development of Takagi-Sugeno (T-S) fuzzy modeling in a nonlinear container crane system. A T-S fuzzy model is characterized by fuzzy "if-then" rules which represent the locally input-output relationship whose consequence part is described by a state space equation as subsystem. The T-S fuzzy model in container cranes first obtains a few number of linear models according to operation conditions and blends these conditions using fuzzy membership functions. Parameters of the membership functions are adjusted by a RCGA to have same dynamic characteristics with nonlinear system of a container crane. Simulations are given to illustrate the performance of T-S fuzzy model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2514-2520
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• 2010

The objective of this paper is to propose the methodology for automated generation of the optimal security defense strategies using evolutionary techniques. As damages by penetration exploiting vulnerability in computer systems and networks are increasing, security techniques have been researched actively. However it is difficult to generate optimal defense strategies because it needs to consider various situations on network environment according to countermeasures. Thus we have adopted a genetic algorithm in order to generate an optimal defense strategy as combination of countermeasures. We have represented gene information with countermeasures. And by using simulation technique, we have evaluated fitness through evaluating the vulnerability of system having applied various countermeasures. Finally, we have examined the feasibility by experiments on the system implemented by proposed method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1368-1373
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• 2015

Recently, There is increasing interest in the IoT(Internet of Thing) as intelligent information service that enables communication between people and things based on internet. In particular the demand for indoor location-based services with the development of smart devices is rapidly increasing. Using the RSSI signal that is provide to the BLE(Bluetooth Low Energy) for Indoor location information measurement calculates distance information between beacon and mobile terminal. However, simply using the RSSI signal to the distance measurement has a difficult to get the indoor location information due to the influence of the signal interference and the weather. In this paper, by performing an operation for obtaining a reliable distance information from the signal information of iBeacon we propose a system for providing reliable indoor location.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.715-719
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• 2009

Incorrect deployment of RFID readers occurs reader-to-reader interferences in many applications using RFID technologies. Reader-to-reader interference occurs when a reader transmits a signal that interferes with the operation of another reader, thus preventing the second reader from communicating with tags in its interrogation zone. Interference detected by one reader and caused by another reader is referred to as a reader collision. In RFID systems, the reader collision problem is considered to be the bottleneck for the system throughput and reading efficiency. In this paper, we propose a novel RFID reader anti-collision algorithm based on evolutionary algorithm(EA). First, we analyze characteristics of RFID antennas and build database. Also, we propose EA encoding algorithm, fitness algorithm and genetic operators to deploy antennas efficiently. To show superiority of our proposed algorithm, we simulated our proposed algorithm. In the result, our proposed algorithm obtains 95.45% coverage rate and 10.29% interference rate after about 100 generations.

• Journal of the Korea Society for Simulation
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• v.21 no.4
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• pp.65-73
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• 2012

Due to the development of technology related to a weapon system and the info-communication, the battle system of a warship has to manage many kinds of human intervention tactics according to the complicated battlefield environment. Therefore, many kinds of studies about M&S(Modeling & Simulation) have been carried out recently. The previous M&S system based on an agent, however, has simply used non-flexible(or fixed) tactics. In this paper, we propose an agent modeling methodology which has reinforcement learning function for spontaneous(active) reaction and generation evolution learning Function using Genetic Algorithm for more proper reaction for warship battle. We experiment with virtual 1:1 warship combat simulation on the west sea so as to test validity of our proposed methodology. We consequently show the possibility of both reinforcement and evolution learning in a warship battle.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.2
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• pp.131-136
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• 2003

The problem of maneuvering target tracking has been studied in the field of the state estimation over decades. The Kalman filter has been widely used to estimate the states of the target, but in the presence of a maneuver, its performance may be seriously degraded. In this paper, to solve this problem and track a maneuvering target effectively, DNA coding-based intelligent Kalman filter (DNA coding-based IKF) is proposed. The proposed method can overcome the mathematical limits of conventional methods and can effectively track a maneuvering target with only one filter by using the fuzzy logic based on DNA coding method. The tracking performance of the proposed method is compared with those of the adaptive interacting multiple model (AIMM) method and the GA-based IKF in computer simulations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.88-102
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• 2016

This paper considers the allocation and engagement scheduling problem of interceptor missiles, and the problem was formulated by using MIP (mixed integer programming) in the previous research. The objective of the model is the maximization of total intercept altitude instead of the more conventional objective such as the minimization of surviving target value. The concept of the time window was used to model the engagement situation and a continuous time is assumed for flying times of the both missiles. The MIP formulation of the problem is very complex due to the complexity of the real problem itself. Hence, the finding of an efficient optimal solution procedure seems to be difficult. In this paper, an efficient genetic algorithm is developed by improving a general genetic algorithm. The improvement is achieved by carefully analyzing the structure of the formulation. Specifically, the new algorithm includes an enhanced repair process and a crossover operation which utilizes the idea of the PSO (particle swarm optimization). Then, the algorithm is throughly tested on 50 randomly generated engagement scenarios, and its performance is compared with that of a commercial package and a more general genetic algorithm, respectively. The results indicate that the new algorithm consistently performs better than a general genetic algorithm. Also, the new algorithm generates much better results than those by the commercial package on several test cases when the execution time of the commercial package is limited to 8,000 seconds, which is about two hours and 13 minutes. Moreover, it obtains a solution within 0.13~33.34 seconds depending on the size of scenarios.

• Journal of Navigation and Port Research
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• v.33 no.6
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• pp.437-442
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• 2009

The PID controller type autopilot is applied to support shipmaneuvering for course-keeping and heading control. A control constants of autopilot system should be evaluated by promoting energy loss (fuel consumption) from the view point of economic efficiency of the ship. This paper is obtained control constants of autopilot system from the RCGA pursued the minimum energy loss. In addition, the controller which is designed involves a constrained optimization problem. The performance of the proposed method is demonstrated through a set of simulation.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.712-716
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• 2010

In this paper, we propose a novel shape-based approach to detect CNV regions (CNVR) by analyzing the coverage graph obtained by aligning the giga-sequencing data onto the human reference sequence. The proposed algorithm proceeds in two steps: a filtering step and a post-processing step. In the filtering step, it takes several shape parameters as input and extracts candidate CNVRs having various depth and width. In the post-processing step, it revises the candidate regions to make up for errors potentially included in the reference sequence and giga-sequencing data, and filters out regions with high ratio of GC-contents, and returns the final result set from those candidate CNVRs. To verify the superiority of our approach, we performed extensive experiments using giga-sequencing data publicly opened by "1000 genome project" and verified the accuracy by comparing our results with those registered in DGV database. The result revealed that our approach successfully finds the CNVR having various shapes (gains or losses) in HLA (Human Leukocyte Antigen) region.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.787-798
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• 2015

The emergence of mid-to-small satellites has created a need for rapid development with a relatively low cost. However, the development of mid-to-small satellites requires considerable time and cost in early phase, in particular, during the development of mission and system requirements through iterations of conceptual design and mission design. In this research, Spacecraft Conceptual Design Tool(SCDT) which is based on Graphical User Interface(GUI) was developed to reduce the time and cost for early phase development. Furthermore, GUI-based software can make the input values to be editable easily and show users design results in various way. In this paper, the development results of MATLAB GUI-based SCDT are introduced.