• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.504-507
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• 1997

It is well known that Variable Structure Controller(VSC) is robust to parameters variation and disturbance but its performance depends on the design parameters such as switching gain and slope of sliding surface. This paper proposes a more robust VSC that is composed of local VSC's. Each local VSC considers the local system dynamics with narrow parameter variation and disturbance. First we optimize the local VSC's by use of Evolution Strategy, and next we use Artificial Neural Network to generalize the local VSC's and construct the overall VSC in order to cover the whole range of parameter variation and disturbance. Simulation on BLDC motor current control shows that the proposed VSC is superior to the conventional VSC.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1964-1965
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• 2011

본 연구에서는 패턴분류를 위해 기존의 방사형 기저 함수 신경회로망(Radial Basis Funtion Neural Network)과 다항식 신경회로망(Polynomial Neural Network)을 결합한 다중 출력 방사형 기저 함수다항식 신경회로망 (Multi Output Radial Basis Funtion Polynomial Neural Network)의 분류기를 제안한다. 제안된 모델은 PNN을 기본 구조로 하여 1층에 기존의 다항식 노드 대신 다중 출력 형태의 RBFNN을 적용 한다. RBFNN의 은닉층에는 기존의 활성함수가 아닌 fuzzy 클러스터링을 사용하여 입력 데이터의 특성을 고려한 적합도를 사용하였다. PNN은 입력변수의 수와 다항식 차수가 모델의 성능을 결정함으로 최적화가 필요하며 본 논문에서는 Differential Evolution(DE)을 사용하여 모델의 구조 및 파라미터를 최적화시켜 모델의 성능을 향상시켰다. 패턴분류기로써의 제안된 모델을 평가하기 위해 pima 데이터를 이용하였다.

• Information Systems Review
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• v.13 no.2
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• pp.43-54
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• 2011

The paper presents the technology trajectory of competitive wireless technologies in wireless industry. We attempt to trace the trajectory of wireless technologies with historical data, and then analyze its pattern. As a preliminary result, we find that there exists network effect and substitution effect in the trajectory. Our result can provide insight to wireless service providers where best to focus its efforts for maximizing overall gain in their networks as well as when to establish the transition strategy towards the next generation wireless network technologies.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.3
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• pp.157-163
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• 2000

In this paper, an Evolving Neural Network Controller(ENNC) which its structure and its connection weights are optimized simultaneously by Real Variable Elitist Genetic Algoithm(RVEGA) was presented for stabilization of an Inverter Pendulum(IP) system with nonlinearity. This proposed ENNC was described by a simple genetic chromosome. And the deletion of neuron, the determinations of input or output neuron, the deleted neuron and the activation functions types are given according to the various flag types. Therefore, the connection weights, its structure and the neuron types in the given ENNC can be optimized by the proposed evolution strategy. Through the simulations, we showed that the finally acquired optimal ENNC was successfully applied to the stabilization control of an IP system.

• International Journal of Computer Science & Network Security
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• v.23 no.7
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• pp.16-22
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• 2023

Enhanced radio access technologies (RAT) are deployed in Next Generation Convergence Networks by the service providers so as to satisfy the basic requirements of end-users for e.g. QoS. Whenever the available resources are being shared simultaneously and dynamically by multiple users or distribution of allocated channels randomly, the deficiency of spectral resources and dynamic behavior of Network traffic in real time Networking, we may have problem. In order to evaluate the performance of our proposed algorithm, computer simulation has been performed on NS-2 simulator and a comparison with the existing algorithms has been made.

• 연구논문집
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• s.34
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• pp.113-119
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• 2004

Recently, the conventional concept of a machine-tool in manufacturing systems is changing from the target of integration to the autonomous manufacturing device based on a knowledge evolution. Subsequently, a machine-tool has been the subject of a cooperation through an advanced environment where an open architecture controller, high speed network and internet technology are contained In the future, a machine-tool will be more improved in the form of a knowledge evolution based device. In order to develop the knowledge evolution based machine-tool, this paper proposes the structure of knowledge evolution and the scheme of a dialogue agent among agent-based modules such as a sensory module, a dialogue module, and an expert system. The dialogue agent has a role of interfacing with another machine for cooperation. To design of the dialogue agent module in M2M(Machine To Machine)environment, FIPA-OS and ping agent based on FIPA-OS are analyzed in this study. Through this, it is expected that the dialogue agent module can be more efficiently designed and the knowledge evolution based machine-tool can be hereafter more easily implemented.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.8
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• pp.2805-2826
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• 2021

In most cases, the routing policy of networks shows a preference for a static one-to-one mapping of communication pairs to routing paths, which offers adversaries a great advantage to conduct thorough reconnaissance and organize an effective attack in a stress-free manner. With the evolution of network intelligence, some flexible and adaptive routing policies have already proposed to intensify the network defender to turn the situation. Routing mutation is an effective strategy that can invalidate the unvarying nature of routing information that attackers have collected from exploiting the static configuration of the network. However, three constraints execute press on routing mutation deployment in practical: insufficient route mutation space, expensive control costs, and incompatibility. To enhance the availability of route mutation, we propose an OpenFlow-based route mutation technique called Polymorphic Path Transferring (PPT), which adopts a physical and virtual path segment mixed construction technique to enlarge the routing path space for elevating the security of communication. Based on the Markov Decision Process, with considering flows distribution in the network, the PPT adopts an evolution routing path scheduling algorithm with a segment path update strategy, which relieves the press on the overhead of control and incompatibility. Our analysis demonstrates that PPT can secure data delivery in the worst network environment while countering sophisticated attacks in an evasion-free manner (e.g., advanced persistent threat). Case study and experiment results show its effectiveness in proactively defending against targeted attacks and its advantage compared with previous route mutation methods.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.6
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• pp.600-607
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• 2006

For the effective operation of manufacturing system, FMS(Flexible Manufacturing System) and CIM(Computer Integrated Manufacturing) system are developed. In these systems, a machine tool is the target of integration in last 3 decades. In nowadays, the conventional concept of machine tools is changing to the autonomous manufacturing device based on knowledge-evolution through applying advanced information technology in which open architecture controller, high speed network and internet technology are contained. In this environment, a machine tool is not the target of integration but the subject of cooperation. In the future, a machine tool will be more improved in the form of a knowledge-evolution based device. In order to develop the knowledge-evolution based machine tools, this paper proposes the structure of knowledge evolution in M2M(Machine To Machine) and the scheme of a dialogue agent among agent-based modules such as a sensory module, a dialogue module, and an expert system. The dialogue agent has a role of interfacing with another machine for cooperation. To design the dialogue agent module in M2M environment, FIPA-OS and ping agent based on FIPA-OS are analyzed in this study. Through this, it is expected that the dialogue agent module can be more efficiently designed and the knowledge-evolution based machine tools can be hereafter more easily implemented.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.2
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• pp.109-121
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• 2007

This paper focuses on algorithms based on the evolution, which is applied to various optimization problems. Especially, among these algorithms based on the evolution, we investigate the simple genetic algorithm based on Darwin's evolution, the Lamarckian algorithm based on Lamark's evolution and the Baldwin algorithm based on the Baldwin effect and also Investigate the difference among them in the biological and engineering aspects. Finally, through this comparison, we suggest a new algorithm to find more various solutions changing the genotype or phenotype search space and show the performance of the proposed method. Conclusively, the proposed method showed superior performance to the previous method which was applied to the constrained minimum spanning tree problem and known as the best algorithm.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1301-1305
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• 2009

The evolution of living organisms occurs via a combination of highly complicated processes that involve modification of various features such as appearance, metabolism and sensing systems. To understand the evolution of life, it is necessary to understand how each biological feature has been optimized in response to new environmental conditions and interrelated with other features through evolution. To accomplish this, we constructed contents-based trees for a two-component system (TCS) and metabolic network to determine how the environmental communication mechanism and the intracellular metabolism have evolved, respectively. We then conducted a comparative analysis of the two trees using ARACNE to evaluate the evolutionary and functional relationship between TCS and metabolism. The results showed that such integrated analysis can give new insight into the study of bacterial evolution.