• Journal of Power Electronics
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• 제18권3호
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• pp.746-756
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• 2018

Harmonic resonance exists in grid-connected inverter systems. In order to determine the network components that contribute to harmonic resonance and the composition of the resonant circuit, sensitivity theory is applied to the resonance characteristic analysis. Based on the modal analysis, the theory of sensitivity is applied to derive a formula for determining the sensitivities of each network component parameter under a resonance circumstance that reflects the participation of the network component. The solving formula is derived for both parallel harmonic resonance and series harmonic resonance. This formula is adopted to a 4-node grid-connected test system. The analysis results reveal that for a certain frequency, the participation of parallel resonance and series resonance are not the same. Finally, experimental results demonstrate that the solving formula for sensitivity is feasible for grid-connected systems.

• 대한지리학회지
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• 제51권3호
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• pp.311-326
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• 2016

최근 관계적, 물질적 전환이라는 거대한 흐름 속에서 아상블라주라는 개념은 현대 사회공간이론의 가장 친숙한 어휘가 되어가고 있다. 본 논문은 아상블라주 본연의 개념을 탐색하기 위해 먼저 개념의 전체적인 틀과 사유의 방식을 제공한 들뢰즈와 가타리의 작업에 주목한다. 유사개념과의 비교를 통해서는 푸코의 장치 개념을 아상블라주의 한 유형으로 봄으로써 아상블라주가 탈영역화뿐만 아니라 (재)영역화라는 두 가지 모두의 성향에 의해 구성됨을 확인하였으며, 관계의 외재성은 아상블라주 이론이 행위자연결망 이론(Actor-Network Theory)과 같은 다른 형태의 관계적 사고와 차이점을 보이는 부분임을 강조했다. 마지막으로 아상블라주는 분석적 측면에서 형성과 과정에 주목함으로써 경험주의의 가치를 재조명할 수 있고, 정치적 측면에서 아상블라주의 다양체(multiplicity)와 중첩결정에 대한 용인이라는 특성으로 인해 다수의 정치적 프로젝트, 실천, 결과의 실질적 공존과 새로운 공간적 상상력에 개방적이라는 장점을 가진다.

• Smart Structures and Systems
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• 제12권3_4호
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• pp.345-361
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• 2013

Locating and assessing the severity of damage in large or complex structures is one of the most challenging problems in the field of civil engineering. Considering that the wavelet packet transform (WPT) has the ability to clearly reflect the damage characteristics of structural response signals and the artificial neural network (ANN) is capable of learning in an unsupervised manner and of forming new classes when the structural exhibits change, this paper investigates a multi-stage structural damage diagnosis method by using the WPT and ANN based on "energy-damage" theory, in which, the wavelet packet component energies are first extracted to be damage sensitive feature and then adopted as input into an improved back propagation (BP) neural network model for damage diagnosis in a step by step mode. To validate the efficacy of the presented approach of the damage diagnosis, the benchmark structure of the American Society of Civil Engineers (ASCE) is employed in the case study. The results of damage diagnosis indicate that the method herein is computationally efficient and is able to detect the existence of different damage patterns in the simulated experiment where minor, moderate and severe damages corresponds to involving in the loss of stiffness on braces or the removal bracing in various combinations.

• Advances in nano research
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• 제13권3호
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• pp.297-312
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• 2022

Coughing and breath shortness are common symptoms of nano (small) cell lung cancer. Smoking is main factor in causing such cancers. The cancer cells form on the soft tissues of lung. Deformation behavior and wave vibration of lung affected when cancer cells exist. Therefore, in the current work, phase velocity behavior of the small cell lung cancer as a main part of the body via an exact size-dependent theory is presented. Regarding this problem, displacement fields of small cell lung cancer are obtained using first-order shear deformation theory with five parameters. Besides, the size-dependent small cell lung cancer is modeled via nonlocal stress/strain gradient theory (NSGT). An analytical method is applied for solving the governing equations of the small cell lung cancer structure. The novelty of the current study is the consideration of the five-parameter of displacement for curved panel, and porosity as well as NSGT are employed and solved using the analytical method. For more verification, the outcomes of this reports are compared with the predictions of deep neural network (DNN) with adaptive optimization method. A thorough parametric investigation is conducted on the effect of NSGT parameters, porosity and geometry on the phase velocity behavior of the small cell lung cancer structure.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1882-1890
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• 2014

This paper proposes an augmented Lagrange Hopfield network (ALHN) based method for solving multi-objective short term fixed head hydrothermal scheduling problem. The main objective of the problem is to minimize both total power generation cost and emissions of $NO_x$, $SO_2$, and $CO_2$ over a scheduling period of one day while satisfying power balance, hydraulic, and generator operating limits constraints. The ALHN method is a combination of augmented Lagrange relaxation and continuous Hopfield neural network where the augmented Lagrange function is directly used as the energy function of the network. For implementation of the ALHN based method for solving the problem, ALHN is implemented for obtaining non-dominated solutions and fuzzy set theory is applied for obtaining the best compromise solution. The proposed method has been tested on different systems with different analyses and the obtained results have been compared to those from other methods available in the literature. The result comparisons have indicated that the proposed method is very efficient for solving the problem with good optimal solution and fast computational time. Therefore, the proposed ALHN can be a very favorable method for solving the multi-objective short term fixed head hydrothermal scheduling problems.

• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.293-298
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• 2010

유비쿼터스 센서 네트워크(Ubiquitous Sensor Network) 기술의 핵심은 저전력 무선 통신기술과 효율적 라우팅을 위한 적절한 자원할당 기술이다. 센서 네트워크에서 효율적인 자원할당을 위해서는 서비스에 따른 차별화된 자원할당 방식이 필요하다. 이를 위하여, 본 논문에서는 유선망에 사용되는 PQ와 WRR의 단점을 보완하여 USN에 적용이 가능한 스케줄러 알고리즘을 제안한다. 제안된 알고리즘은 센서 네트워크에서 각 클래스의 큐 상태를 체크하여 퍼지 이론을 적용한 제어 정책에 따라 WRR 스케쥴러의 가중치를 동적으로 할당하였다. 시뮬레이션 결과 제안된 알고리즘은 EF 클래스의 패킷 손실률에서 WRR 스케쥴러 방식보다 평균 6.5% 향상되었으며, AF4 클래스에서는 PQ 방식보다 평균 45% 향상된 결과를 보였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.1129-1134
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• 1989

In this paper, we propose a neural network for learning to control semi-linear dynamical systems. The network is a composite system of four three-layer backpropagation subnetworks, and is able to control inverted pendulums better than systems based on modern control theory at least in some ranges of parameters. Three of the four subnetworks in our network system process angles, velocities, and positions of a moving inverted pendulum, respectively. The outputs from those three subnetworks are input to the remaining subnetwork that makes control decisions. Each of the four subnetworks learns connection weights independently by backpropagation algorithms. Teaching signals are given by the human operator. Also, input signals are generated by the human operator, but they are converted by preprocessors to actual input data for the three subnetworks except for the network for control decisions. The whole system is implemented on both of 16 bit personal computers and 32 bit workstations. First, we briefly provide the research background and the inverted pendulum problem itself, followed by the description of our composite neural network model. Next, some results from the simulation are given, which are subsequently compared with the results from a control system based on modern control theory. Then, some discussions and conclusion follow.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.5116-5134
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• 2015

In this paper, due to the network security defense is mainly static defense, a dynamic classification network security defense strategy model is proposed by analyzing the security situation of complex computer network. According to the network security impact parameters, eight security elements and classification standard are obtained. At the same time, the dynamic classification algorithm based on fuzzy theory is also presented. The experimental analysis results show that the proposed model and algorithm are feasible and effective. The model is a good way to solve a safety problem that the static defense cannot cope with tactics and lack of dynamic change.

• 한국정보과학회논문지:시스템및이론
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• 제36권5호
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• pp.429-436
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• 2009

오드 연결망은 그래프이론 모델의 하나로 발표되었는데, [1]에서 고장허용 다중컴퓨터에 대한 하나의 모형으로 소개되었고, 여러 가지 유용한 성질들 - 간단한 라우팅 알고리즘, 최대고장허용도, 노드 중복 없는 경로 등 - 이 분석되었다 본 논문에서는 오드 연결망 $O_d$ 에서 에지 중복 없는 스패닝 트리를 구성하는 알고리즘을 제안한다. 그리고 제안한 알고리즘에 의해 구성된 에지 중복 없는 스패닝 트리가 에지 중복 없는 최적 스패닝 트리임을 증명한다.

• 한국정보시스템학회지:정보시스템연구
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• 제21권4호
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• pp.1-29
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• 2012

The purpose of this study was to find about personal information security of internet and social networks by focusing on end users. User competence and subjective criterion, which are the antecedents, are affecting security behaviors For these security behaviors, the study examined the relationship between security behavior intention on internet use and security behavior intention about social network that is actively achieved in many fields. Behaviors of internet and social network were classified into an action of executing security and an action of using a security technology. In addition, this study investigated a theory about motivational factors of personal intention on a certain behavior based on theory of reasoned action in order to achieve the purpose of this study. A survey was conducted on 224 general individual users through online and offline, and the collected data was analyzed with SPSS 12.0 and SmartPLS 2.0 to verify demographic characteristics of respondents, exploratory factor analysis, and suitability of a study model. Interesting results were shown that security behavior intention of social network is not significant in all security behavior execution, which is security performance behavior, and security technology use. Internet security behavior is significant to security technology use but it does not have an effect on behavior execution.