• 한국공간구조학회논문집
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• 제13권3호
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• pp.91-98
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• 2013

A multi-input single-output (MISO) semi-active control systems were studied by many researchers. For more improved vibration control performance, a structure requires more than one control device. In this paper, multi-input multi-output (MIMO) semi-active fuzzy controller has been proposed for vibration control of seismically excited small-scale buildings. The MIMO fuzzy controller was optimized by multi-objective genetic algorithm. For numerical simulation, five-story example building structure is used and two MR dampers are employed. For comparison purpose, a clipped-optimal control strategy based on acceleration feedback is employed for controlling MR dampers to reduce structural responses due to seismic loads. Numerical simulation results show that the MIMO fuzzy control algorithm can provide superior control performance to the clipped-optimal control algorithm.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1565-1570
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• 2003

Passive Haptic Devices have more benefit than the active in Stability. But Apart from benefits, it shows poor performance in haptic display. The author proposed the passive FME(Force Manipulability Ellipsoid) which can graphically show force generating ability of a passive haptic device. In this paper, performance indexes for the force approximation and pseudo friction cone are obtained with the passive FME and an optimized planar device with the indexes is proposed. Based on the above theory, experiment is conducted.

• 한국전기전자재료학회논문지
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• 제28권4호
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• pp.222-228
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• 2015

Power MOSFETs (metal oxide semiconductor field effect transistor) operate as energy control semiconductor switches. In order to reduce energy loss of the device, it is essential to increase its conductance. However, a trade-off relationship between the breakdown voltage and conductance of the device have been the critical difficulty to improve. In this paper, theoretical analysis of electrical benefits on single floating island power MOSFET is proposed. By the method, the optimization point has set defining the doping limit under single floating island structure. The numerical multiple 2.22 was obtained which indicates the doping limit of the original device, improving its ON state voltage drop by 45%.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.436-445
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• 2013

The use of a demand response controller is necessary for electric devices to effectively respond to time varying price signals and to achieve the benefits of cost reduction. This paper describes a new formulation with the form of constrained optimization for designing an optimal demand response controller. It is demonstrated that constrained optimization is a better approach for the demand response controller, in terms of the ambiguity of device operation and the practicality of implementation of the optimal control law. This paper also proposes a design scheme to construct a demand response controller that is useful when a system controller is already adapted or optimized for the system. The design separates the demand response function from the original system control function while leaving the system control law unchanged. The proposed formulation is simulated and compared to the system with simple dynamics. The effects of the constraints, the system characteristics and the electricity price are examined further.

• 열처리공학회지
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• 제34권1호
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• pp.25-30
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• 2021

The differential gear system is a device designed to distribute the driving force of both vehicle wheels and control the rotational speed when the vehicle turns on a curve. The differential device consists of a differential gear case, a ring gear, and a pressure ring. A differential pinion gear and side gear are mounted on the differential pinion shaft inside the differential gear case. In this study, a pin press-fitting device that mounts the pinier gear and side gear to the differential pinion shaft in the differential gear case was designed, and a jig device for pin press-fitting using servo press was developed. In addition, by precisely measuring the pin press-in load and press-in distance according to the pin hole diameter of the differential gear shaft, the optimization of the pin pressin process was established.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1380-1385
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• 2004

In this paper, auto-tuning technique of the PID controller gain by particle swarm optimization algorithm is presented. PID controller is easy to implement to numerous control systems. After PID gain tuning is completed, its result could be implemented to control spacecraft vibration such as jitter that is high frequency vibration usually over 10Hz. The off-line PID controller tuning is done under system nonlinearities and uncertainties existence, then its result is applied to control experiment device to prove the PSO efficiencies.

• Earthquakes and Structures
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• 제11권2호
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• pp.347-369
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• 2016

The main objective of this paper is the robust multi-objective optimization design of semi-active tuned mass damper (STMD) system using genetic algorithms and fuzzy logic. For optimal design of this system, it is required that the uncertainties which may exist in the system be taken into account. This consideration is performed through the robust design optimization (RDO) procedure. To evaluate the optimal values of the design parameters, three non-commensurable objective functions namely: normalized values of the maximum displacement, velocity, and acceleration of each story level are considered to minimize simultaneously. For this purpose, a fast and elitist non-dominated sorting genetic algorithm (NSGA-II) approach is used to find a set of Pareto-optimal solutions. The torsional effects due to irregularities of the building and/or unsymmetrical placements of the dampers are taken into account through the 3-D modeling of the building. Finally, the comparison of the results shows that the probabilistic robust STMD system is capable of providing a reduction of about 52%, 42.5%, and 37.24% on the maximum displacement, velocity, and acceleration of the building top story, respectively.

• KIEAE Journal
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• 제16권5호
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• pp.21-28
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• 2016

Purpose: The Objective of this study is to explore the capabilities of an integrated modelling and simulation workflow when applied to an experiment-based research process, aimed at deriving daylight optimization strategies specific to tall buildings. Methods: Two methods were devised to apply this workflow with the help of DIVA and Rhino/Grasshopper. The first method is a multiple variant analysis by setting up an appropriate base case and analysing its daylight and energy performance, forming the basis of comparison for subsequent cases for design variants. The second method involved setting up the base case within a site context and conducting a solar irradiation study. An architectural variables such as overhang and shading device, were then defined as inputs in the parametric definition in Grasshopper to control the selected variable. Results: While the first method took advantage of the speed and efficiency of the integrated workflow, the second method was derived based on the ability to directly process simulation data within the integrated, single-software platform of the proposed workflow. Through these methods, different architectural strategies were explored, both to increase daylight penetration and to reduce radiant heat gain. The focus is on methods by which this workflow can be applied to facilitate the experimental derivation of daylight optimization strategies that are specific to tall building design.

• 국제강구조저널
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• 제18권5호
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• pp.1598-1606
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• 2018

An integrated optimal structural design method for a diagrid structure and control device was developed. A multi-objective genetic algorithm was used and a 60-story diagrid building structure was developed as an example structure. Artificial wind and earthquake loads were generated to assess the wind-induced and seismic responses. A smart tuned mass damper (TMD) was used as a structural control system and an MR (magnetorheological) damper was employed to develop a smart TMD (STMD). The multi-objective genetic algorithm used five objectives including a reduction of the dynamic responses, additional stiffness and damping, mass of STMD, capacity of the MR damper for the integrated optimization of a diagrid structure and a STMD. From the proposed method, integrated optimal designs for the diagrid structure and STMD were obtained. The numerical simulation also showed that the STMD provided good control performance for reducing the wind-induced and seismic responses of a tall diagrid building structure.

• 한국산학기술학회논문지
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• 제17권1호
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• pp.219-224
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• 2016

본 연구에서는 지진하중을 받는 인접한 건물의 진동제어를 위한 준능동 제어장치의 제어성능을 검토하였다. 준능동 제어장치로는 MR 감쇠기를 사용하였다. MR 감쇠기로 연결된 인접한 건물을 효과적으로 제어하기 위하여 퍼지제어알고리즘을 사용하였다. MR 감쇠기로 연결된 인접한 건물의 제어시 한쪽 건물의 응답을 저감시키는 것은 다른 한 쪽 건물의 응답을 증가시키는 효과를 가져온다. 따라서 연결된 건물의 제어는 서로 상충되는 특성이 있기 때문에 다목적 최적화문제로 귀결된다. 따라서 본 연구에서는 다목적 유전자알고리즘을 사용하여 MR 감쇠기를 제어하는 퍼지제어알고리즘을 최적화하였다. 수치해석을 통하여 준능동 MR 감쇠기를 이용한 인접건물의 연결제어효과를 검토하였고 매우 우수한 성능을 나타내는 것을 확인하였다.