• Smart Structures and Systems
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• 제26권5호
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• pp.591-603
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• 2020

Dynamic deflection monitoring is an essential and critical part of structural health monitoring for high-speed railway bridges. Two critical problems need to be addressed when using inclinometer sensors for such applications. These include constructing a general representation model of inclination-deflection and addressing the ill-posed inverse problem to obtain the accurate dynamic deflection. This paper provides a dynamic deflection monitoring method with the placement of optimal inclinometer sensors for high-speed railway bridges. The deflection shapes are reconstructed using the inclination-deflection transformation model based on the differential relationship between the inclination and displacement mode shape matrix. The proposed optimal sensor configuration can be used to select inclination-deflection transformation models that meet the required accuracy and stability from all possible sensor locations. In this study, the condition number and information entropy are employed to measure the ill-condition of the selected mode shape matrix and evaluate the prediction performance of different sensor configurations. The particle swarm optimization algorithm, genetic algorithm, and artificial fish swarm algorithm are used to optimize the sensor position placement. Numerical simulation and experimental validation results of a 5-span high-speed railway bridge show that the reconstructed deflection shapes agree well with those of the real bridge.

• 한국군사과학기술학회지
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• 제20권3호
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• pp.328-336
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• 2017

The goal of this study is simulation of optimal search pattern of ships based on performance surface which are reflected underwater environmental. The process is as follows. First, temporal and spatial environmental database are extracted in complex environment and input hull mounted SONAR system parameters. The environmental database and SONAR system parameters are substituted to SONAR equations, and calculate signal excess, detection probability, detection range. And then, the performance surface, which can be used to provide operational insight of SONAR detection performance, are pictorialized. Finally, optimal search pattern of ships are simulated using genetic algorithm based on performance surface. And then, we certify optimal search pattern in various ways.

• Journal of Mechanical Science and Technology
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• 제20권3호
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• pp.426-434
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• 2006

The impact of leakage was incorporated into the transfer functions of the complex head and discharge. The impedance transfer functions for the various leaking pipeline systems were also derived. Hydraulic transients could be efficiently analyzed by the developed method. The simulation of normalized pressure variation using the method of characteristics and the impulse response method shows good agreement to the condition of turbulent flow. The leak calibration could be performed by incorporation of the impulse response method with Genetic Algorithm (GA) and Harmony Search (HS). The objective functions for the leakage detection can be made using the pressure-head response at the valve, or the pressure-head or the flow response at a certain point of the pipeline located upstream from the valve. The proposed method is not constrained by the Courant number to control the numerical dissipation of the method of characteristics. The limitations associated with the discreteness of the pipeline system in the inverse transient analysis can be neglected in the proposed method.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.669-676
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• 2002

유전표지인자를 이용한 선발(marker assisted selection; MAS)과 전통적인 표현형기록에 근거한 반응의 비교분석을 위하여 고정효과모델(deterministic model)을 이용하여 시뮬레이션을 하였다. 자신의 단일 기록을 이용한 경우와 자신의 기록과 자신의 표지인자 정보를 이용할 경우 유전력이 높을수록 MAS의 효율성이 38%정도 높게 나타났다. 그러나 유전력이 높은 경우(50%) MAS의 효율성은 약 1%정도로서 효율성이 대단히 낮은 것으로 나타났다. 자신의 기록과 부모의 표현형 정보에 표지인자 정보를 추가할 경우 MAS의 효율성은 27% 정도였으며 마찬가지로 유전력이 높은 경우에는 효율성이 0에 가깝게 나타났다. MAS의 효율성은 유전력이 낮을수록 그리고 이용한 표지인자의 유전적 변이가 클수록 효율성이 높아지는 것으로 나타났다.

• 한국가구학회지
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• 제27권2호
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• pp.128-136
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• 2016

Digital designs that appear in the three-dimensional virtual space by the digital type are designed as there is not an image created with an organic artificially generated (Creation) and representation (Modifying), developed by the specific environment given. The advanced digital design will produce a result with an algorithm according to a mathematical operation and the environment and has the nature of generating the real world, changes, development and affinity (Genetic Process). The digital design process is largely defined by a set of processes that are consistently designed to integrate form of creation, reproduction, proceeds in three steps, while the manufacture and assembly as a form of maintenance as possible the intended form of control data from the concept of building. By Joris Laarman 3D printer design is a simulation created by the digital process by the various algorithms and design achieved through the development of 3D printers, such as new materials and MX3D. From the mold production of a complex whole by using a robot and other digital production tool extracts a variety of forms.

• 펄프종이기술
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• 제43권3호
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• pp.1-10
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• 2011

Proportional.Integral.Derivative control schemes continue to provide the simplest and effective solutions to most of the control engineering applications today. However PID controller is poorly tuned in practice with most of the tuning done manually which is difficult and time consuming. This research comes up with a soft computing approach involving Genetic Algorithm, Evolutionary Programming, and Particle Swarm Optimization and Ant colony optimization. The proposed algorithm is used to tune the PID parameters and its performance has been compared with the conventional methods like Ziegler Nichols and Lambda method. The results obtained reflect that use of heuristic algorithm based controller improves the performance of process in terms of time domain specifications, set point tracking, and regulatory changes and also provides an optimum stability. This research addresses comparison of tuning of the PID controller using soft computing techniques on Machine Direction of basics weight control in pulp and paper industry. Compared to other conventional PID tuning methods, the result shows that better performance can be achieved with the soft computing based tuning method. The ability of the designed controller, in terms of tracking set point, is also compared and simulation results are shown.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권9호
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• pp.4197-4219
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• 2017

Cloud computing is a new service to provide dynamic, scalable virtual resource services via the Internet. Cloud market is available to multiple cloud computing resource providers and users communicate with each other and participate in market transactions. However, since cloud computing is facing with more and more security issues, how to complete the allocation process effectively and securely become a problem urgently to be solved. In this paper, we firstly analyze the cloud resource allocation problem and propose a mathematic model based on combinatorial double auction. Secondly, we introduce a trust evaluation mechanism into our model and combine genetic algorithm with simulated annealing algorithm to increase the efficiency and security of cloud service. Finally, by doing the overall simulation, we prove that our model is highly effective in the allocation of cloud resources.

• 한국항해항만학회지
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• 제34권2호
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• pp.117-122
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• 2010

Since fuzzy controllers are nonlinear, it is more difficult to set the controller gains and to analyse the stability compared to conventional PID controllers. This paper proposes a fuzzy PD+I controller for tracking control which uses a linear fuzzy inference(product-sum-gravity) method based on a conventional linear PID controller. In this scheme the fuzzy PD+I controller works similar to the control performance as the linear PD plus I(PD+I) controller. Thus it is possible to analyse and design an fuzzy PD+I controller for given systems based on a linear fuzzy PD controller. The scaling factors tuning scheme, another topic of fuzzy controller design procedure, is also introduced in order to fine performance of the fuzzy PD+I controller. The scaling factors are adjusted by a real-coded genetic algorithm(RCGA) in off-line. The simulation results show the effectiveness of the proposed fuzzy PD+I controller for tracking control problems by comparing with the conventional PID controllers.

• 한국지능시스템학회논문지
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• 제6권2호
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• pp.43-51
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• 1996

퍼지제어에서 퍼지규칙은 퍼지제어기의 제어결정을 내리는데 중요한 역할을 한다. 그래서, 제어성능은 주로 퍼지규칙의 질에 의해서 결정된다. 본 논문에서 우리는 교차와 돌연번이의 확률이 적응적으로 변화되는 유전자 알고리즘을 사용하여 퍼지규칙을 최적화 하는 방법을 기술한다. 또한 본 논문에서 우리는 플랜트의 응답을 듀개의 부분으로 나누어 제어 목적을 만족하게 하는 적합도 측정 방식을 제안한다. 좀더 빠른 해답을 얻기 위해 우리는 초기의 퍼지규칙으로 무작위적인 규칙을 사용하지 않고 자동으로 퍼지규칙을 생성하는 방법을 사용하여 초기 퍼지규칙으로 사용했다. 이렇게 얻어진 퍼지규칙이 좋은 것인지를 보여주기 위해 비선형 플랜트를 이용하여 시뮬레이션 해보았다. 시뮬레이션 결과 우리의 방법이 합리적이고 유용한 것임이 밝혀졌다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.314-317
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• 2002

본 논문에서는 디지털 가버너를 개발후 유효성 검증을 위해 성능평가를 위한 방법들을 제시하고, 현장 적용시에 발생할 수 있는 시행착오를 줄이는 방법의 일환으로 시뮬레이션을 통한 검증방법에 대해 다룬다. 유전알고리즘과 모델 조정기법에 의해 대상 모델을 동정하였고 완성된 모델과 실제시스템의 출력 데이터를 비교하여 유효성을 검증하였다. 한강수력발전소 섬진강수력발전소 2호기에 설치되어있는 기존 기계식 조속기를 개발된 디지털 조속기로 대체하여 현장에 적용하고, 제어기 파라 미터의 성능평가를 위해 테스트를 수행하였다.