• The Journal of the Acoustical Society of Korea
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• v.20 no.1E
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• pp.7-13
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• 2001

In this paper we propose a new subspace tracking algorithm based on the PASTd (Projection Approximation Subspace Tracking with deflation). The algorithm is obtained via introducing the variable forgetting factor which adapts itself to the time-varying subspace environments. The tracking capability of the proposed algorithm is demonstrated by computer simulations in an abruptly changing DOA scenario. The estimation results of the variable forgetting factor PASTd(VFF-PASTd) outperform those of the PASTd in the nonstationary case as well as in the stationary case.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.11a
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• pp.95-98
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• 2002

The purpose of this study was to Estimation the Risk of construction method to protect and reduce the risk of construction period. For this study we are using the pre and during construction period Inspection list. The inspection list was used by construction company for check a flaw of construction field. So we rearrange the individual item of inspection list to match the Risk factor, The results of this study were as follows: The inspection list was rearranged at Risk checklist for Risk estimation. So that we estimate the Risk of individual construction method.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.23-25
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• 2007

In this paper an estimation method is proposed to find reasonable load factor of the power system based on the conventional generation mix concept. To find the factor investment costs and operation costs are considered in the estimation. To use feasible results both supply side and demand side of views should be considered. But as a first step of this study only the generation mix is considered in this study.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.118-121
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• 1988

Load forecasting is an important issue as for the economic dispatch and there have been many researches which are classfied into two classes, time series method and factor analysis method. But the former is not adaptive for a sudden change of a correlated factor and the latter is not inefficient as the factor estimation is not easy. To make matters worse, both of them are not good for the estimation of special days. It is because the load forecasting is not a problem modeled precisely in mathematics, but a problem requires experience and knowledge those can solve it case by case. In this viewpoint, an expert system is proposed which can use complicated experience of an expert by use of fuzzy decision.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.2
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• pp.1-10
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• 2012

In this study, software products developed in the course of testing, software managers in the process of testing software test and test tools for effective learning effects perspective has been studied using the NHPP software. The finite failure nonhomogeneous Poisson process models presented and the life distribution applied exponential and log shaped type hazard function. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than autonomous errors-detected factor that is generally efficient model could be confirmed. This paper, a failure data analysis of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error and coefficient of determination.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.365-367
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• 2001

We are explaining shapes factor of ground electrode in a rectangular parallelepiped which is based on analysis of a hemisphere electrode. Actually, a hemisphere electrode is hardly used in a plan and construction, because it is difficult for somebody to use one. This thesis describes the method of grounding resistance estimation which is used the water tank model and electrode shopes factor.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.151-160
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• 1999

The relationship between the product design and product image can be defined using human sensibility. If there is a way to grasp the product value or product design that people want most, it could be possible to make and sell user-oriented products. In human sensibility ergonomics, the categories of design factor can be broken into shape and color of the design. Although, the color is the major factor of the design, however, texture were is also an important factor for the shape. In this study, wall-papers that have various shapes of texture were used for the experiment. The purpose of this study was to conduct a sensibility estimation experiment for the product image, and to estimate the parameters of various textures for creating new textures that could be more suitable for human sensibility.

• Journal of Climate Change Research
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• v.10 no.3
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• pp.237-242
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• 2019

Ammonia is main precursor gas of secondary particulate matter and contributes almost 78% of total ammonia emission from the agricultural sector in Korea. The current method of estimating ammonia emission from fertilizer application, which contributes 7% of the total emission, has high uncertainty and needs to be improved to better predict PM2.5 concentration. In this study, we suggest an improvement method for ammonia emission quantification from fertilizer application. The first improvement was in the emission factor of NPK fertilizer by conducting a field study to verify the currently used factor. The improved NPK emission factor of 52.2 kg NH ton-1N was confirmed by comparing with the value from the EEA (European Environment Agency) and adjusting the value for the Korean climate and soil conditions. We also improved the amount of fertilizer usage by including the sales amount to the fertilizer supply amount of the Korean Farmers Association, increasing total fertilizer usage by 39.8%. As the statistical data on fertilizer supply and sales are compiled yearly, we estimated monthly emission of ammonia by considering cultivated areas and timing of fertilization for each crop. In summary, we suggest a novel and practical method to improve estimation methodology of ammonia emission from the field of fertilizer application: 1) emission factor of NPK fertilizer was reconfirmed; 2) total amount of fertilizer use was revised considering fertilizer sales; and 3) monthly emission of ammonia was realized by considering different crop practices. A bottom-up approach to compile activity data is needed to increase the estimation accuracy of monthly emission of ammonia, which is very helpful for predicting PM2.5 concentration.

• Spatial Information Research
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• v.18 no.3
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• pp.13-22
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• 2010

Due to the frequent gales and typhoons by anomaly climates and its subsequent loss of life and property, the importance of the research estimating wind load is being emphasized when structure is designed. It is necessary to measure geographical information exactly to estimate topographic factor of wind speed because the increase of topographic factor of wind speed means the increase of wind velocity and the increase of wind velocity has an influence on wind load proportionate to a square. Therefore, the accurate and reasonable estimation method of topographic factor of wind speed is presented in this study using ArchiCAD, an architectural BIM(Building Information Modeling) software. When the structure subjected to wind load is designed, reasonability and economic performance of design will be more improved by using the proposed method.

• Environmental Engineering Research
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• v.25 no.3
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• pp.439-445
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• 2020

In the estimation of the aerosol single fiber efficiency using fibrous filters, there is a size range, where the particles penetrate most effectively through the fibrous collectors, and corresponding minimum single fiber efficiency. For small particles in which the diffusion mechanism is dominant, the Cunningham slip correction factor (C_c) affects the single fiber efficiency and the most penetrating particle size (MPPS). Therefore, for accurate estimation, C_c is essential to be considered. However, many previous studies have neglected this factor because of its complexity and the associated difficulty in deriving the appropriate parameterization particularly for the MPPS. In this study, the expression for the MPPS, and the corresponding expression for the minimum single fiber efficiency are analytically derived, and the effects of C_c are determined. In order to accommodate the slip factor for all particle-size ranges, C_c is simplified and modified. Overall, the obtained analytical expression for the MPPS is in a good agreement with the exact solution.