• Structural Engineering and Mechanics
• /
• 제20권3호
• /
• pp.347-362
• /
• 2005

The input energy to a base-isolated (BI) building during an earthquake is considered and formulated in the frequency domain. The frequency-domain approach for input energy computation has some notable advantages over the conventional time-domain approach. Sensitivities of the input energy to the BI building are derived with respect to uncertain parameters in the base-isolation system. It is demonstrated that the input energy can be of a compact form via the frequency integration of the product between the input component (Fourier amplitude spectrum of acceleration) and the structural model component (so-called energy transfer function). With the help of this compact form, it is shown that the formulation of earthquake input energy in the frequency domain is essential for deriving the sensitivities of the input energy to the BI building with respect to uncertain parameters. The sensitivity expressions provide us with information on the most unfavorable combination of the uncertain parameters which leads to the maximum energy input.

• 정보처리학회논문지D
• /
• 제9D권4호
• /
• pp.659-666
• /
• 2002

Park, Seo and Kim은 소프트웨어의 시험단계와 유지보수단계에 모두 적용할 수 있는 입력 영역 기반 소프트웨어 신뢰성 성장 모델을 개발하였다. 이들의 모형은 완전디버깅의 가정 하에서 개발되어졌다. 입력 영역 기반 소프트웨어 신뢰성 성장 모델이 현실적이기 위해서는 이러한 가정은 개선되어야 한다. 본 논문에서는 불완전 디버깅 하에서 사용할 수 있는 입력 영역 기반 소프트웨어 신뢰성 성장 모델을 제안하고 그 통계적 특성을 조사한다.

• 대한기계학회논문집A
• /
• 제24권7호
• /
• pp.1854-1862
• /
• 2000

Input shaping method is to convolute input shaper, which is sequence of impulses, with reference input command not to excite the natural frequency of system. To reduce residual vibration for the ch ange of frequency, the number of impulses should be increased. Until now, amplitudes and time interval of those has been searched from the derivative of residual vibration. However, if time interval of impulses is fixed as the half of vibration period of system, input shaper H(z) in z-domain becomes (I-pz-1)n/K in which increasing n is the mean that robustness for change of parameter is improved. Also, design of many types of input shapers in z-domain is very easy because sensitivity curve is displayed with $\mid$H(z)zn$\mid$$\times$100. In the z-domain, EI(Extra-Insensitive) input shaper could be designed without solving nonlinear simultaneous equations as design in continuous time domain. In addition to, the design possibility of input shaper for a damped system was shown.

• 제어로봇시스템학회논문지
• /
• 제5권8호
• /
• pp.883-888
• /
• 1999

To obtain high positioning auccuracy for a long, flex bleman Ipulator, residual vibration must be removed from the tip motion. But it is difficult to control the vibration of low frequency. There are open-loop and closed loop methods in the elimination of the residual vibration. We inroduce input shaping technique has been used as a simple open-loop method of controlling the residual vibration of a flexible manipulator. Design of input shaper in the continuous time domain is complicated. This paper presents a new technique that designs input shaper in the z-domain and analyzes input shaping method in the z-domain. This technique is simple and easy to design input shaper.

• 한국정밀공학회지
• /
• 제17권4호
• /
• pp.181-188
• /
• 2000

Input shaping is a method fur reducing residual vibration. Vibration is eliminated by convolving an input shaper, which is a sequence of impulses, with the desired system command. It has been applied to robot with a flexible manipulator. But it can be applied to the reduction of residual vibration far overhead crane. In this paper, input shaping shows good performance for anti-sway of overhead crane. In the z-domain, we designed an input shaper and calculated the sensitivity of it. If sensitivity is calculated in the z-domain, the shapes of sensitivity curves are expected easily. Accordingly, it is easy to design an input shaper in the z-domain. We compared the response of a system with shaper to it without that. Also, we compared El shaper to ZV shaper in view of robustness.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.242-242
• /
• 2000

Comparing to the conventional adaptive filters using LMS algorithm, the proposed adaptive filters can reduce the amounts of computation and have robustness to variance of characteristics of input signals. LMS algorithm is performed in the domain of Hadamard transform after a reference signal and input signal are transformed by fast Hadamard transformation. As a transformation from time domain to Hadamard transformed domain, the proposed filter not only maintains the performance of estimating an input signal but also greatly reduces the number of multiplication. Moreover, the effect of characteristic changes of input signal is decreased. Computer simulation shows the stability and robustness of the proposed filter.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.269-273
• /
• 2000

This paper describes Active Noise Control (ANC) using Discrete Wavelet Transform (DWT) Domain Least Mean Square (LMS) Method. DWT-LMS is one of the transform domain input decorrelation LMS and improves the convergence speed of adaptive filter especially when the input signal is highly correlated. Conventional transform domain LMS's use Discrete Cosine Transform (DCT) because it offers linear band signal decomposition and fast transform algorithm. Wavelet transform can project the input signal into the several octave band subspace and offers more efficient sliding fast transform algorithm. In this paper, we propose Wavelet transform domain LMS algorithm and shows its performance is similar to DCT LMS in some cases using ANC simulation.

• 전자공학회논문지CI
• /
• 제46권3호
• /
• pp.64-76
• /
• 2009

적응적 랜덤 테스팅 (Adaptive Random Testing, ART) 기법 중 입력 도메인 반복 분할을 이용한 기법(ART through Iterative Partitioning, IP-ART)은 초기 ART 기법이 가지는 단점인 많은 거리 연산량을 입력 도메인 반복 분할 기법을 이용해 효율적으로 개선하였다. 또한 입력 도메인 확장을 이용한 IP-ART 기법(IP-ART with Enlarged Input Domain, EIP-ART)은 IP-ART가 가지는 특징을 효과적으로 이용해 IP-ART에서 보이는 테스트 케이스 분포 불균일 현상을 완화시켰으며, 다양한 환경에서 좋은 성능을 보인다. 하지만 EIP-ART는 입력 도메인 확장에 의해 발생되는 부수적인 부하로 인해 테스트 케이스 선택이 지연된다는 단점을 가진다. 이에 따라 본 논문에서는 입력 도메인의 확장 없이, IP-ART의 변화를 통한 성능 개선가능성 확인을 위해 테스트 케이스 분포에 영향을 줄 수 있는 세 가지 조건을 정의하고 이들 각각이 기법에 미치는 영향을 평가하였으며, 실험을 통해 정의된 세 가지 조건 중 제한 영역 관리 조건이 기법의 성능에 가장 긍정적인 영향을 주는 것을 확인하였다.

• 품질경영학회지
• /
• 제30권3호
• /
• pp.186-194
• /
• 2002

In this paper we introduce formulae for estimating the failure rate of a large scaled software by using the Bayesian rule when a black-box random testing which selects an element(test case) at random with equally likely probability, is performed. A program or software can be treated as a mathematical function with a well-defined (input)domain and range. For a large scaled software, their input domains can be partitioned into multiple subdomains and exhaustive testing is not generally practical. Testing is proceeding with selecting a subdomain, and then picking a test case from within the selected subdomain. Whether or not the proportion of selecting one of the subdomains is assumed probability, we developed the formulae either case by using Bayesian rule with gamma distribution as a prior distribution.

• 한국정밀공학회지
• /
• 제16권4호통권97호
• /
• pp.155-162
• /
• 1999

Input shaping technique has been used as a simple method of controlling the residual vibration of a flexible manipulator. With the conventional methods previously proposed by several authors, the frequency range that shows a good performance is restricted. When the designed frequency being different from the natural frequency of a system, the performance of control degrades remarkably. This paper introduced a new technique that designs input shaping with robustness in the z-domain.