• ETRI Journal
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• 제28권4호
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• pp.509-512
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• 2006

In a real environment, sound recordings are commonly distorted by channel and background noise, and the performance of audio identification is mainly degraded by them. Recently, Philips introduced a robust and efficient audio fingerprinting scheme applying a differential (high-pass filtering) to the frequency-time sequence of the perceptual filter-bank energies. In practice, however, the robustness of the audio fingerprinting scheme is still important in a real environment. In this letter, we introduce alternatives to the frequency-temporal filtering combination for an extension method of Philips' audio fingerprinting scheme to achieve robustness to channel and background noise under the conditions of a real situation. Our experimental results show that the proposed filtering combination improves noise robustness in audio identification.

• International Journal of Control, Automation, and Systems
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• 제3권spc2호
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• pp.288-295
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• 2005

In this paper a new adaptive, decentralized excitation control scheme proposed to enhance the transient stability of multimachine power systems is extensively analyzed with respect to its robustness and disturbance attenuation. As shown in the paper, both robustness and disturbance attenuation can be effectively improved by suitably selecting the design parameters of the proposed controller. Particularly, some simple rules for the selection of the control gains and the adaptation parameters are extracted which, as it is proven, may be essential for the system performance. Simulation tests on a two generator infinite bus power system absolutely confirm the theoretical results.

• 전자공학회논문지SC
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• 제39권4호
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• pp.1-5
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• 2002

본 논문에서는 2차 시스템의 안정도-강인성과 성능-강인성을 동시에 만족시키기 위해 루프형성절차기법을 사용하여 가중치 요소 Q와 R을 선정하는 최적 강인 LQ-PID 레귤레이터 동조 방법을 제안한다.

• 제어로봇시스템학회논문지
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• 제1권2호
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• pp.99-104
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• 1995

For the robust control, sliding mode control has gained a great attention. Sliding mode control has the good robustness, because it makes the state of system reach the origin of the state space, by a varying the structure of system on the sliding surface. The slope of sliding surface affects to the control performance. If it is small, robustness is increased at the expense of reaching time. On the contrary, if it is large, reaching time is decreased at the expense of robustness and overshoot. In this paper, to design the optimal sliding surface, optimal control theory is introduced. To confirm the validity of the proposed method, the position control of step motor is implemented.

• 전기학회논문지
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• 제66권1호
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• pp.66-71
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• 2017

In this paper, we study the robustness of disturbance observer based controller for DC motor in the presence of unmodeled dynamics. It is well known that the robustness property usually becomes weaker as the control gain becomes larger. On the contrary to this expectation, it is shown that the phase margin of DOB controller remains quite a large value even though the time constant of Q-filter becomes smaller. The computer simulation results show that DOB controller is able to stabilize the motor system even in the presence of unmodeled dynamics. On the contrary, the unity-feedback system fails to maintain stability when a high gain feedback is employed for the purpose of achieving better disturbance attenuation performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2142-2161
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• 2018

Distance dynamics model is an excellent model for uncovering the community structure of a complex network. However, the model has poor robustness. To improve the robustness, we design an enhanced distance dynamics model based on Ego-Leader and propose a corresponding community detection algorithm, called E-Attractor. The main contributions of E-Attractor are as follows. First, to get rid of sensitive parameter ${\lambda}$, Ego-Leader is introduced into the distance dynamics model to determine the influence of an exclusive neighbor on the distance. Second, based on top-k Ego-Leader, we design an enhanced distance dynamics model. In contrast to the traditional model, enhanced model has better robustness for all networks. Extensive experiments show that E-Attractor has good performance relative to several state-of-the-art algorithms.

• 한국건축시공학회지
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• 제17권5호
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• pp.429-435
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• 2017

본 연구의 목적은 일반강도 콘크리트 배합에 있어서 다양한 감수제에 따른 유동성과 품질 안정성을 평가하는 데에 있다. 감수제의 사용은 골재 품질이 저하되는 최근의 상황에서 피할 수 없지만 적절한 성능의 감수제 사용이 중요하다. 이에 본 연구에서는 일반강도 수준의 모르타르에 대하여 세 가지 종류의 감수제에 대하여 유동성 증진성능과 더불어 품질안정성을 레올로지적으로 평가하였다. 또한 콘크리트 배합에 있어서 단위수량 변화에 따른 유동성 변화를 측정하였으며 단위수량 저감효과와 그에 따른 제조원가를 산정하고 비교하였다. 본 연구를 통해 실제 현장에서 적절한 성능의 감수제를 선택할 수 있는 사례를 제공하고 이를 통해 경제적이고 효과적으로 유동성을 발휘하며 안정적인 품질을 확보할 수 있는 환경 마련에 기여하고자 한다.

• 대한기계학회논문집A
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• 제24권8호
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• pp.1899-1909
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• 2000

This paper proposes a new $H_{\infty}$ yaw moment control scheme using brake torque switching for improving vehicle performance and stability especially in high speed driving. In the scheme, one wheel is selected, depending on the vehicle states, at which a brake torque for control is applied. Steering angles are modeled as a disturbance to the system and the $H_{\infty}$ controller is designed to minimize the difference between the performance of the vehicle and that of the desired model. Its performance robustness as well as stability robustness to system parameter variations is assured through ${\mu}$-analysis. Various simulations with a nonlinear 8-DOF vehicle model show that proposed controller enhances the vehicle performance and stability under disturbances and parameter variations as well as under the normal driving condition.

• Smart Structures and Systems
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• 제26권1호
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• pp.49-61
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• 2020

This paper proposes a novel high performance vibration control device, multiple tuned mass dampers-inerters (MTMDI), to suppress the oscillatory motions of structures. The MTMDI, similar to the MTMD, involves multiple tuned mass damper-inerter (TMDI) units. In order to reveal the basic performance of the MTMDI, it is installed on a single degree-of-freedom (SDOF) structure excited by the ground acceleration, and the dynamic magnification factors (DMF) of the structure-MTMDI system are formulated. The optimization criterion is determined as the minimization of maximum values of the relative displacement's DMF for the controlled structure. Based on the particle swarm optimization (PSO) algorithm to tune the optimum parameters of the MTMDI, its performance has been investigated and evaluated in terms of control effectiveness, strokes, stiffness and damping coefficient, inerter element force, and robustness in frequency domain. Meanwhile, further comparison between the MTMDI with MTMD has been conducted. Numerical results clearly demonstrate the MTMDI outperforms the MTMD in control effectiveness and strokes of mass blocks. Additionally, in the aspects of frequency perturbations on both earthquake excitations and structures, the robustness of the MTMDI is also better than the MTMD.

• 전기학회논문지
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• 제60권10호
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• pp.1924-1934
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• 2011

This paper is concerned with the robustness evaluations of the guidance controller for a bimodal tram which is being developed by the Korea Railroad Research Institute (KRRI). The bimodal tram is an all-wheel steered multiple-articulated vehicle as a new kind of transportation vehicle. This vehicle has to be equipped with an automatic guidance system. In [1], such a controller has been recently proposed. However, since the performance is affected by weight change of the vehicle due to number of the passenger, model parameter uncertainties depending on the state of friction and the elasticity of the tire, and a typhoon, the controller designed must be examined with these conditions. As expected, because the vehicle dynamics is highly nonlinear, for the sake of investigating the robustness of the controller we compose two simulation ways based on the vehicle models which are implemented by the ADAMS and the MATLAB/LabVIEW toolboxes. Different uncertainties and a typhoon disturbance have been considered for the simulation conditions. Simulation results are shown.