• The Journal of the Acoustical Society of Korea
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• v.29 no.6
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• pp.374-380
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• 2010

It is known that the problem of FIR filtering with noisy input and output data can be solved by a total least squares (TLS) estimation. It is also known that the performance of the TLS estimation is very sensitive to the ratio between the variances of the input and output noises. In this paper, we propose a convex combination algorithm between the ordinary recursive LS based TLS (RTLS) and the ordinary recursive LS (RLS). This combined algorithm is robust to the noise variance ratio and has almost the same complexity as the RTLS. Simulation results show that the proposed algorithm performs near TLS in noise variance ratio ${\gamma}{\approx}1$ and that it outperforms TLS and LS in the rage of 2 < $\gamma$ < 20. Consequently, the practical workability of the TLS method applied to noisy data has been significantly broadened.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.42-51
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• 1999

An experimental modeling of cutting and structural dynamics and the on-line detection of malfunction process is substantial not only for the investigation of the static and dynamic characteristics of cutting process but also for the analytic realization of diagnostic systems. In this regard, We have discussed on the comparative assessment of two recursive time series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision round shape machining such as turning, drilling and boring in mold and die making. In this study, simulation and experimental work were performed to show the malfunctioned behaviors. For this purpose, two new recursive approach (REIVM, RLSM) were adopted fur the on-line system identification and monitoring of a machining process, we can apply these new algorithm in real process for the detection of abnormal machining behaviors such as chipping, chatter, wear and round shape lobe waviness.

• Annual Conference of KIPS
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• 2005.11a
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• pp.1279-1282
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• 2005

본 논문은 초고속 전송을 위해 설계된 HCOC(High Capacity Orthogonal Code) 기술을 적용한 Multi-Code Spread Spectrum System에서 발생할 수 있는 PAPR(Peck to Average power Ratio) 문제해결을 위한 연구이다. H(HCOC)MC-SS 시스템의 PAPR 감소를 위해 기본적인 SLM(Selected Mapping) 기법을 적용하였으며, 또한 SLM 기법의 단점인 많은 계산량 감소를 위해 Recursive 방법을 적용한 Recursive SLM HMC-SS 시스템을 제안하였다. 컴퓨터 시뮬레이션을 통해 제안하는 시스템을 검증하였으며, 또한 초고속 전송을 위한 16 QAM-SS 시스템과 $4{\times}4$ HMC-SS 시스템의 성능을 비교 분석하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.6
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• pp.1265-1272
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• 1988

Kinematic and dynamic equations of open-loop mechanical systems are derived using the velocity transformation. The velocities of a link are defined by the velocities of the previous link and relative velocities between the links. The velocities and angular velocities are expressed with joint velocities and 6*1 velocity transformation vector. Using the velocity relations, recursive formula are derived and compared to the previous results. The derived recursive formula are modified and applied to the dynamic simulation of a vehicle. The computational efficiency of the vehicle simulation with the derived recursive formula is much enhanced.

• The Journal of the Acoustical Society of Korea
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• v.18 no.2
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• pp.61-65
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• 1999

This paper derives a sufficient condition on the stability of recursive third-order Volterra filters based on their filter coefficients. A Volterra filter is very effective in modeling nonlinear systems with memory. However, it is well-known that the nonrecursive Volterra filter requires a large number of filter coefficients to describe a nonlinear system. For this reason, recursive Volterra filters are usually considered because the recursive implementation requires a smaller number of coefficients compared to the nonrecursive one. Unfortunately, the main problem of the recursive Volterra filters is their inherent instablility. In this paper. we present a simple condition for the output of a recursive discrete-time third-order Volterra filter to be bounded whenever the input signal to the recursive Volterra filter is bounded by a finite constant.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.427-432
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• 2018

This paper uses a recursive least squares method to estimate the projectile motion trajectory of an object in real time. The equations of motion of the object are obtained considering the air resistance which occurs in the actual experiment environment. Because these equations consider air resistance, parameter estimation of nonlinear terms is required. However, nonlinear recursive least squares estimation is not suitable for estimating trajectory of projectile in that it requires a lot of computation time. Therefore, parameter estimation for real-time trajectory prediction is performed by recursive least square estimation after using Taylor series expansion to approximate nonlinear terms to polynomials. The proposed method is verified through experiments by using VICON Bonita motion capture system which can get three dimensional coordinates of projectile. The results indicate that proposed method is more accurate than linear Kalman filter method based on the equations of motion of projectile that does not consider air resistance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.19
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• pp.31-37
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• 1989

The recursive residuals are obtained by the iterative processes as descrbed in section 2. They may require more efforts and time to compute and may face difficultie in ordering of data. But we can investigate each case to be deleted and gather more informations on each case. The recursive residuals are much more effective with conjecture of cusum technique. We suggest to use the predicted residual for the construction of recursive residuals in nonlinear regression models. The assessment of influence and leverage by the connection with recursive residuals will be necessary.

• The Journal of the Acoustical Society of Korea
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• v.14 no.3
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• pp.37-48
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• 1995

This paper presents an sstimation of ARMA coefficients of noisy ARMA system using generalized total least square (GTLS) method. GTLS problem for ARMA system is defined as minimizing the errors between the noisy output vectors and estimated noisy-free output. The GTLS problem is solved in closed form by eigen-problem and the perturbation analysis of GTLS is presented. Also its recursive solution (recursive GTLS) is proposed using the power method and the covariance formula of the projected output error vector into the input vector space. The simulation results show that GTLS ARMA coefficients estimator is an unbiased estimator and that recursive GTLS achieves fast convergence.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.249-258
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• 2002

One of the jai or purposes of multiprocessor system is to get a high efficiency in performance improvement. But in most cases, it is unavoidable to use some special programming languages or tools for full use of multiprocessor system. In general, loop and recursive call statements of algorithms are considered as typical parts for parallelization. Especially, recursive call statements are easy to parallelize conceptually without support of any special languages or tools. But it is difficult to control the degree of parallelism caused by high depth of recursive call leading to execution crash. This paper proposes a device to control Parallelism in the process of POSIX thread bated parallelization of recursive algorithms. For this, we define the concept of thread and process in UNIX system, and analyze the results of experimental application of the device to quick sorting algorithm.

• International Journal of Control, Automation, and Systems
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• v.3 no.spc2
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• pp.262-269
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• 2005

In this paper, a nonlinear robust control approach is applied to design a controller for the Static Synchronous Compensator (STATCOM). A robust control dynamic model of STATCOM in a one-machine, infinite-bus system is established with consideration of the torque disturbance acting on the rotating shaft of the generator set and the disturbance to the output voltage of STATCOM. A novel recursive approach is utilized to construct the energy storage function of the system such that the solution to the disturbance attenuation control problem is acquired, which avoids the difficulty involved in solving the Hamilton-Jacobi-Issacs (HJI) inequality. Sequentially, the nonlinear disturbance attenuation control strategy of STATCOM is obtained. Simulation results demonstrate that STATCOM with the proposed controller can more effectively improve the voltage stability, damp the oscillation, and enhance the transient stability of power systems compared to the conventional PI+PSS controller.