• International Journal of Reliability and Applications
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• v.4 no.1
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• pp.41-50
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• 2003

This paper represents the first comprehensive comparison of the Newton-Raphson's method and Simple Iterative Procedure (SIP) in the maximum likelihood estimation of the two-parameter Weibull distribution. Computer simulation is employed to compare these two methods for multiply censored, singly censored data (Type I or Type Ⅱ censoring) and complete data. Results indicate the Newton-Raphson's with the Menon's estimated value, as an initial point remains the effective iterative procedure for estimating the parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.170-177
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• 1997

In this study, an analysis technique using simple beam model for predicting structure crashworthiness of the passenger car side impacted with an angle by another passenger car was investigated. The simple model was composed of major beam-like side structure which carry almost all side impact load. A procedure of component collapse test, calculation of load carrying capability and dynamic simulation was carryed out sequentially. Transient dynamic algorithms and a computer program to simulate deformations and motions of the impacted car was developed. The developed procedure was applied to a 3 door passenger car side impacted with an angle of 75 degree and the analysis results show good agreements with the actual test results.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.4
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• pp.485-492
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• 1998

Most forecasting models often fail to produce appropriate forecasts because we build a model based on the assumption of the data being generated from the only one stochastic process. However, in many real problems, the time series data are generated from one stochastic process for a while and then abruptly undergo certain structural changes. In this paper, we assume the basic underlying process is the simple state-space model with random level and deterministic drift but interrupted by three types of exogenous shocks: level shift, drift change, outlier. A Bayesian procedure to detect, estimate and adapt to the structural changes is developed and compared with simple, double and adaptive exponential smoothing using simulated data and the U.S. leading composite index.

• Journal of Chest Surgery
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• v.33 no.2
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• pp.179-182
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• 2000

Background: A pleural effusion is not a disease entity but a clincial sign of systemic or pleural disease. Although the diagnosis of pleural effusion can often be done by toracentesis and pleural needle biopsy the yeild of positive diagnosis is low.

• Journal of the Korean Operations Research and Management Science Society
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• v.12 no.2
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• pp.36-41
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• 1987

This paper presents a heuristic algorithm for solving the simple facility location problem. Its main procedure is essentially of 'add' type, which progressively selects facilities to open according to a certain criterion derived from the analysis of the linear programming dual. Computational experience with test problem from the literature is presented.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.2
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• pp.23-38
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• 1995

In manfacturing systems, to overcome the inherent complexities and uncertainties, due-dates are usually decided by some simple rules. This study proposes a computational procedure for estimating production lead time for computerized manufacturing systems. Based on the current system status stored in the computers, the procedure estimates production lead time for an incoming order. The result is more accurate than the ones produced by old rules, and yet the procedure is fast in computation speed enough to use in real time. Simulations are used to prove these.

• Earthquakes and Structures
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• v.12 no.5
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• pp.543-557
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• 2017

Results of an extensive study aiming to properly extend the well known pushover analysis into 3-D problems of asymmetric buildings are presented in this paper. The proposed procedure uses simple, 3 DOF, one-story models with shear-beam type elements in order to quantify the effects of inelastic torsional response of such buildings. Correction coefficients for the response quantities at the "stiff" and "flexible" sides are calculated using results from non-linear time history analyses of the simple models. Their values are then applied to the results of a simple, plane pushover analysis of the detailed building models. Results from the application of the new method for a set of three, conventionally designed, five-story buildings with high values of uniaxial eccentricities are compared with those obtained from multiple non-linear dynamic time history analyses, as well as from similar pushover methods addressing the same problem. This initial evaluation indicates that the proposed procedure is a clear improvement over the simple (conventional) pushover method and, in most cases, more accurate and reliable than the other methods considered. The accuracy, however, of all these methods is reduced substantially when they are applied to torsionally flexible buildings. Thus, for such challenging problems, use of inelastic dynamic analyses for a set of two component earthquake motions appears to be the preferable solution.

• Structural Engineering and Mechanics
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• v.38 no.2
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• pp.211-229
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• 2011

In this paper, we present a new explicit procedure using periodic cubic B-spline interpolation polynomials to solve linear and nonlinear dynamic equation of motion governing single degree of freedom (SDOF) systems. In the proposed approach, a straightforward formulation was derived from the approximation of displacement with B-spline basis in a fluent manner. In this way, there is no need to use a special pre-starting procedure to commence solving the problem. Actually, this method lies in the case of conditionally stable methods. A simple step-by-step algorithm is implemented and presented to calculate dynamic response of SDOF systems. The validity and effectiveness of the proposed method is demonstrated with four examples. The results were compared with those from the numerical methods such as Duhamel integration, Linear Acceleration and also Exact method. The comparison shows that the proposed method is a fast and simple procedure with trivial computational effort and acceptable accuracy exactly like the Linear Acceleration method. But its power point is that its time consumption is notably less than the Linear Acceleration method especially in the nonlinear analysis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.199-203
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• 2012

This paper introduces a simple new procedure approach to determine the permittivity of dielectric slabs. The method uses a parallel plate waveguide which supports a TEM mode. The presence of the dielectric slab placed at the bottom of the waveguide makes the speed of the TEM wave slower. The relationship between the change of the speed and the permittivity of the dielectric slab allows the determination of the permittivity. The relationship is analyzed electromagnetically, and the results of measurements are in good agreement with the analysis.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.5
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• pp.579-584
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• 1998

This paper presents an efficient algorithm which determines the parameters of discrete PID controller. The proposed algorithm is an algebraic method to obtain controller parameters using ROM(Reduced Order Model), which can not only make design procedure simple but also reduce the computational burden required for controller implementation. Also, by solving a set of linear equations based on least squares method, the proposed method can make the controller design procedure systematic. Simple examples are given to demonstrate the effectiveness of our method when compared with widely-used conventional method.