• 한국IT서비스학회:학술대회논문집
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• 2005.11a
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• pp.345-355
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• 2005

As the portion of information systems(IS) budget to the total government budget becomes greater, the cost estimation of IS development and maintenance projects is recognized as one of the most important problems to be resolved for quantitative and efficient management of IS budget. The primary concern in the cost estimation of IS projects is to estimate software development cost. In this paper, we propose a new method to estimate software cost using support vector regression(SVR), which has attracted considerable attention because of its good performance and theoretical clearness. The paper is the first study which apply SVR to software cost estimation.

• Journal of the Korean Statistical Society
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• v.29 no.1
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• pp.109-122
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• 2000

An adaptive estimator of the efficient score function for censored and truncated regression models is developed by using $\beta$-splines to estimate the score function and a relatively simple cross validation method to determine the number of knots.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.703-705
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• 1999

In this paper, we introduce the direction of arrival(DOA) estimation of distributed signal based on the improved ESPRIT algorithm. Most research on the estimation of DOA has been performed based on the assumption that the signal sources are point sources. However, we consider a two-dimensional distributed signal source model using improved ESPRIT algorithm. In the distributed signal source model, a source is represented by two parameters, the azimuth angle and elevation angle. We address the estimation of the elevation and azimuth angles of distributed sources based on the parametric source modeling in the three-dimensional space with two uniform linear arrays. The array output vector is obtained by integrating a steering vector over all direction of arrival with the weighting of a distributed source density function. We also develop an efficient estimation procedures that can reduce the computational complexity. Some examples are shown to demonstrate explicity the estimation procedures under the distributed signal source model.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.10
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• pp.1183-1189
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• 1999

This paper presents the method of parameter estimation of diffusion model for monitoring Demand-Side Management program. Bass diffusion model was applied in this paper, which has different values according to the following parameters; coefficients of innovation, imitation and potential adopters. Though it is very important to estimate three parameters precisely, there has been no empirical way in practice. Thus, this paper presents the method of parameter estimation in case of few data with constraints to reduce the possibility of bad estimation. The constraints can be empirical results or expert's decision. Case studies show the diffusion curves and forecasted values of the peak for the high-efficient lighting. The feedback and nonlinear least-square parameter estimation methods used in this paper enable us to evaluate the status and to predict the effect of DSM program.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5365-5380
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• 2016

Estimation of signal-to-noise ratio (SNR) is an important problem in wireless communication systems. It has been studied for various constellation types and channels using different estimation techniques. Maximum likelihood estimation is a technique which provides efficient and in most cases unbiased estimators. In this paper, we have applied maximum likelihood estimation for systems employing square or cross QAM signals which are undergoing slow flat Rayleigh fading. The problem has been considered under various scenarios like data-aided (DA), non-data-aided (NDA) and partially data-aided (PDA) and the performance of each type of estimator has been evaluated and compared. It has been observed that the performance of DA estimator is best due to usage of pilot symbols, with the drawback of greater bandwidth consumption. However, this can be catered for by using partially data-aided estimators whose performance is better than NDA systems with some extra bandwidth requirement.

• Journal of Ship and Ocean Technology
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• v.3 no.3
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• pp.25-44
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• 1999

Estimation efficiencies according to different sea trial are investigated in connection with sensitivity analysis, and new trial method is proposed which can improve the estimation efficiency of hydrodynamic derivatives. MMG Equation with Kijima's formula is used for simulation. Extended Kalman Filter is chosen for estimation technique and hydrodynamic derivatives of interest is limited to 12 of those in sway and yaw equations. Esso Osaka is selected for the test ship. Sensitivity analysis and estimation results based on conventional trials show that a more sensitive derivative gives more efficient estimation result. Sensitivities of nonlinear derivatives become pronounced in the trial where steady condition lasts longer such as turning test, while sensitivities of linear derivatives gas a larger values in the trial where unsteady condition lasts longer such as 10deg-10deg zigzag test. Consequently, in new method , named S-type trial, steady and unsteady condition are combined appropriately to increase sensitivities. Linear derivatives are estimated better in S-type trial and the estimation of nonlinear derivatives is improved to extent.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.387-390
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• 2000

This paper proposes an efficient and accurate power estimation method for Application Specific Instruction set Processors (ASIPs). Proposed method takes advantage of the data types of variables in application program to be executed on the ASIP. According to the experimental results, the efficiency of proposed method was more than 1000 times as high as that of conventional RTL based power estimation method, and the estimation error was within 10% compared to a conventional gate-level accurate power estimation method

• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.101-108
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• 2003

Presented in this paper is the development of an product cost estimation system at the product design stage. The efficient cost estimation function at the design stage is essential for the cost reduction activities through the entire product life cycle. For this purpose, it is necessary to establish a systematic working procedure, and to develop information system for managing a great deal of production and product-related data required for the cost estimation. The developed system has the capability of estimating a cost of assembly type products as well as unit-item type products. As proposed system is based on the variant approach, it can be used easily at an early design stage without the need for detail design information. Also, this system is integrated with legacy PDM (Product Data Management) and ERP (Enterprise Resource Planning) system for fast. accurate and easy product cost estimation. The estimated cost includes material cost, overhead cost as well as labor cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11A
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• pp.1889-1896
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• 2001

This paper proposes the hierachically regularized motion estimation technique for the efficient and accurate motion estimation. To use hierachical technique increases the reliability of motion vectors. And the regularization of neighbor vectors decreases bit rate of motion vectors. Also, using fast motion estimation algorithm with a few candidate vectors, the processing time added by regularization can be decreased. In the result of the experiment, the fast motion estimation with hierachical regularization technique achieves less computations and decreases estimation and distribution of false vectors.

• Journal of the Korea Safety Management & Science
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• v.9 no.1
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• pp.175-186
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• 2007

The employment permit system for foreigners, which stresses introduction of foreign work force in a legal manner rather than in the position of being trainees, is anticipated to efficiently improve introduction and the overall management system of foreign work force and related difficulties such as illegal alien problems, absurdity on sending laborers overseas. In this paper, a prospective model of supply and demand of work force has been developed basing on various categories of industries and patterns about nationally practical foreign employees to look over efficient supply and demand of work force suiting employment of foreigner among foreign work force policies. To propose the prospective model, we have derived industry- and pattern-related matrixes of foreign laborers basing on Inter-Industry Analysis Method put forth by Professor Leontiyef in 1930, and through the derived matrix assessed repercussions concerning overall domestic industries and foreigner types and decided yearly weight; the capacity of supply and demand of foreign laborers can be compared through proposed statistical estimation and government estimation by combining the determined weight with yearly incomes of foreign laborers. This paper has thoroughly considered the particularity of our employment permit system for foreigners and applied the Weibull distribution and incorporated the dependence of foreign laborers during the limited period of 3 years to the industry relation analysis, ultimately proposing an efficient supply and demand method about domestic foreign work force.