• Journal of applied mathematics & informatics
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• v.5 no.3
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• pp.691-700
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• 1998

Simulation algorithms for one-sided and two-sided trun-cated gamma distributions are proposed. These algorithms suggest the optimal choice of derived functions. Some results of simulation are given. Finally an application with real data is presented.

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.70-70
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• 2006

• Communications for Statistical Applications and Methods
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• v.21 no.1
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• pp.105-114
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• 2014

In this paper we suggest an efficient method to estimate the distribution function using the Bezier curve, and compare it with existing methods by simulation studies. In addition, we suggest a robust version of cross-validation criterion to estimate the number of Bezier points, and showed that the proposed method is better than the existing methods based on simulation studies.

• Environmental and Resource Economics Review
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• v.9 no.4
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• pp.641-661
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• 2000

The study examines the relation between yield insurance and nitrogen fertilizer in Korea. Since the yield insurance has never been introduced in Korea, the simulation method developed by Babcock & Hennessy is used to see the effect. From the simulation, we obtained the following results: (1) When a farmer is assumed to have a risk-neutral utility function, the yield insurance reduces nitrogen fertilizer by 19.74% (2) When a farmer is assumed to have a risk-averse utility function, the yield insurance reduces nitrogen fertilizer by 24.53%.

• Journal of the Korea Society for Simulation
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• v.1 no.1
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• pp.77-86
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• 1992

In this paper, we study validation test methods of DEVSA(Descrete Event system Specification) models using SPN(Stochastic Petri Net) models. We discuss conventional validation test methods, by which DEVS models can be transformed to SPN models, by reviewing the features of DEVS model. Based on the model transformation method, we define a new homogeneous function for validation test and suggest a new validation test method of DEVS models using the property of SPN models and the new homogeneous function.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3521-3523
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• 2011

• Korean System Dynamics Review
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• v.15 no.3
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• pp.5-36
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• 2014

The purpose of this paper is to develop a System Dynamics model for estimating the volume of forest resources in the future and simulating the volume of function of public benefit linked to forest resources in dynamic manner. Also it is to analyze the impact when the volume of forest land conversion is controlled by policy using the SD model. The analysis was done at nation-wide for the simulation period 2000 to 2040. Estimated forest area was 6.2 million ha and estimated growing stock was $4.7\;billion\;m^3$ in 2040 from the future forecast without policies. Changing of forest resources, 13.9 billion tons of forest-ground-water storage was estimated, $1.8\;million\;m^3$ of erosion control of forest was estimated and 377 million tons of $CO_2$ absorption was estimated. As a result of simulation with two alternatives, forest area was less reduced and growing stock was bigger than do nothing policy. Also, function of public benefit reflected by changes of forest resources was enhanced. This study contributes to estimate the quantitatively measured volume of forest resources and function of public benefit over the 30 years in Korean forest land in scientific way. Using this SD model, decision maker would develop forest land policies more delicately for deserving forest resources and increasing the volume of function of public.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1533-1545
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• 1996

In this paper, the design and implementation of echo canceller with new variable step size algorithm is discussed. The method used in the new algorithm is to periodically adopt the test function which helps an optimal coefficient tracking. This algorithm outperforms LMS and VS algorithms in convergence speed and steady state error. As the period of test function is decreased, the speed of convergence is improved, but the number of calculation is increased, then the trade off between these parameters must be considered. Simulation results show new algorithm outperforms LMS and VS algorithms in convergence rate. For the design of hardware, circuit is designed with VHDL, and synthesized with Act1 withc is a FPGA library of ActelTM in use of synovation of InterGraph$^{TM}$. Verification of the synthesized circuit is carried out with simulator DLAB. The circuit based on the algorithm which is suggested in this paper calculated 7 radix places of inary number. A simulation data for the verification is based on the data of algorithm simulation. When the same input data is applied to the both simulation, output results of circuit simulation had slight difference in compare with that of algorithm simulation. The number of used gate is about 5,500 and We have 5.53MHz in maximum frequency.y.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.133-144
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• 1996

We, in this paper, propose a nonparametric estimator of bivariate mean residual life function based on Lin and Ying's (1993) bivariate survival function estimator of paired failure times under univariate censoring and prove the uniform consistency and the weak convergence result of this estimator. Through Monte Carlo simulation, the performances of the proposed estimator are tabulated and are illustrated with the skin grafts data.

• International Journal of Reliability and Applications
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• v.1 no.1
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• pp.81-87
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• 2000

One of the most important quantities in reliability theory is the expected number of renewals of a system during a given interval. This quantity, the renewal function, is used to determine the optimal preventive maintenance policy and to estimate the cost of a warranty. In this paper we study a parametric approach for a renewal function. The simulation study is presented to compare the relative performance of the introduced estimators of a renewal function. And we show that the proposed parametric estimator performs well.