• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.9
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• pp.1040-1049
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• 1992

When the model of control object is not described correctly, ambiguity is often expressed by unknown parameter, In a case that this ambiguity satisfies a certain condition of limit, if robust control method is used, even if model is not correctly discribed, control system can be composed. The characteristic of control based on the variable structure theory is that the influence by ambiguity of system eradicates high-gain feedback. Therefore in this paper, VSS indentifier is proposed. Transformation of control input producing control system in sliding mode actually reflects influence of ambiguity unknown parameter of control object. If useful information is out from transformation input by a few times of operation, proper identify mechanism is selected and this information is used, to decide the unknown parameter is possible. So more effective controller was composed by addition of the proposed identifier to the unknown parameter identifier of robot manipulator.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.4
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• pp.101-111
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• 2013

In this study, DEA (Data Envelopment Analysis) was carried out on the four bridges, which have the same extension (L=1,615m), in order to select the most superior, economical method of construction using the LCC concept of each bridge structure in the case of the Ulsan-Pohang double track railway which is scheduled to be constructed. DEA models were analyzed with the CCR model, which was designed for the evaluation of relative efficiency of each model. The initial construction costs, maintenance costs, indirect costs (user costs + indirect loss of social costs), and life cycle costs were used as input variables, and average duration was applied as the output variable. LCC was applied to calculate the input variables, and to get the costs of LCC, 100 years of period and 4.83% of real discount rate were applied, and the costs are classified into initial construction, maintenance, user, and indirect loss of social cost. The analysis results showed that the Method 2 and 3 were evaluated as the most efficient, and the other alternatives were evaluated as the following order; Method 1, the default, and Method 4.

• Korean Journal of Remote Sensing
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• v.26 no.1
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• pp.29-38
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• 2010

It is necessary to develop an integration model which can account for various data acquired at different measurement scales in environmental thematic mapping with high-resolution ground survey data and relatively low-resolution remote sensing data. This paper presents and applies a multi-scale geostatistical methodology for downscaling of thematic maps generated from lowresolution remote sensing data. This methodology extends a traditional ordinary kriging system to a block kriging system which can account for both ground data and remote sensing data which can be regarded as point and block data, respectively. In addition, stochastic simulation based on block kriging is also applied to describe spatial uncertainty attached to the downscaling. Two downscaling experiments including SRTM DEM and MODIS Leaf Area Index (LAI) products were carried out to illustrate the applicability of the geostatistical methodology. Through the experiments, multi-scale geostatistics based on block kriging successfully generated relatively high-resolution thematic maps with reliable accuracy. Especially, it is expected that multiple realizations generated from simulation would be effectively used as input data for investigating the effects of uncertain input data on GIS model outputs.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.412-417
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• 2013

Analytical modeling of photovoltaic power systems has been receiving significant attentions in recent years in that it is easy to apply for prediction of its dynamics and fault detection and diagnosis in advanced engineering technologies. This paper presents a novel probabilistic modeling approach for such power systems with a big data sequence. Firstly, we express input/output function of photovoltaic power systems in which solar irradiation and ambient temperature are regarded as input variable and electric power is output variable respectively. Based on this functional relationship, conditional probability for these three random variables(such as irradiation, temperature, and electric power) is mathematically defined and its estimation is accomplished from ratio of numbers of all sample data to numbers of cases related to two input variables, which is efficient in particular for a big data sequence of photovoltaic powers systems. Lastly, we predict the output values from a probabilistic model of photovoltaic power systems by using the expectation theory. Two case studies are carried out for testing reliability of the proposed modeling methodology in this paper.

• The Journal of the Acoustical Society of Korea
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• v.33 no.6
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• pp.420-426
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• 2014

In this paper, we propose a new affine projection sign algorithm (APSA) to improve the convergence speed of the conventional APSA which has been proposed to enable the affine projection algorithm (APA) to operate robustly in impulsive noise environment. The conventional APSA has two advantages; it operates robustly against impulsive noise and does not need calculation for the inverse matrix. The proposed algorithm also has the conventional algorithm's advantages and furthermore, better convergence speed than the conventional algorithm. In the conventional algorithm, each input signal is normalized by $l_2$-norm of all input signals, but the proposed algorithm uses input signals normalized by their corresponding $l_2$-norm. We carried out a performance comparison of the proposed algorithm with the conventional algorithm using a system identification model. It is shown that the proposed algorithm has the faster convergence speed than the conventional algorithm.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.317-328
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• 2011

Logistic system and methods of the transportation have been changed rapidly by the variety of the logistics environment. It is necessary to analyze the efficiency of Korean trucking companies for enhancing the competitive power and operating. This paper will describe the analysis of the efficiency of the trucking companies with DEA models. By the CCR and the BCC models, which are in parts of DEA model, the efficiency and RTS(Return To Scale) of forty two selected trucking companies were studied. It was also analyzed how the study the input-output variables were effected. And then, some of the forty two trucking companies were shown as the benchmark. As the result of analysis on the two models, seven companies won the score '1' on CCR model and seventeen companies on BCC model. Moreover, this study showed that reducing the total asset out of input variables, and raising the sales profit out of the output variables played a main role to increase the efficiency of the trucking companies highly.

• Journal of Advanced Navigation Technology
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• v.4 no.1
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• pp.50-66
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• 2000

For a long time target maneuvers in tracking problem have been a difficult task to handle. Once a maneuvering such as abrupt change in target accelerations occur, the tracking fiter no longer yields a reasonable estimate of the target position. In order to resolve this cumbersome maneuvering problem. Advanced methods have here proposed : Colored noise, IE(Input Estimation), VD(Variable Dimension), IMM(Interaction Multiple Model), Jump-type processes and jerk model, etc. In this paper, tracking performance of the jerk model is analyzed. Jerk model in which the derivative of target acceleration is included as a state recently attracted considerable attraction. Firstly 3-dimensional Kalman filter is described on the basis of jerk model. Then using this filter, Monte-Carlo simulations are carried out and the filter formance with respect to the variation of jerk time-constant is analyzed. Especially, since jerk model's transient performance is expected to be poor, the performance of analysis of transient response of the model is included too.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.56.1-56.1
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• 2011

The solar and meteorological resources map is calculated using by one-layer solar radiation model (GWNU model), satellites data and numerical model output on the Korean peninsula. The Meteorological input data to perform the GWNU model are retrieved aerosol optical thickness from MODIS (TERA/AQUA), total ozone amount from OMI (AURA), cloud fraction from geostationary satellites (MTSAT-1R) and temperature, pressure and total precipitable water from output of RDAPS (Regional Data Assimilation and Prediction System) and KLAPS (Korea Local Analysis and Prediction System) model operated by KMA (Korea Meteorological Administration). The model is carried out every hour using by the meteorological data (total ozone amount, aerosol optical thickness, temperature, pressure and cloud amount) and the basic data (surface albedo and DEM). And the result is analyzed the distribution in time and space and validated with 22 meteorological solar observations. The solar resources map is used to the solar energy-related industries and assessment of the potential resources for solar plant. The National Institute of Meteorological Research in KMA released $4km{\times}4km$ solar map in 2008 and updated solar map with $1km{\times}1km$ resolution and topological effect in 2010. The meteorological resources map homepage (http://www.greenmap.go.kr) is provided the various information and result for the meteorological-solar resources map.

• Journal of Digital Convergence
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• v.10 no.8
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• pp.73-80
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• 2012

Consulting industry is a knowledge intensive business service industry to lead to knowledge creation as well as support high value creation of other industries. While the consulting industry has a great ripple effect on whole industries, there is a lack of interest in the consulting industry. Thus, this study investigates a ripple effect of the consulting service on the national economy using an Input-Output analysis. We summarize some of our findings as follows. First, A production of 1.0 won in the business consulting industry induces production of 0.6933 won in 2005 and 0.7851 in 2009; value-added of 0.2881 won in 2005 and 0.3039 won in 2009. A production of 1.0 billion won in the business consulting industry Industry produces employment for 0.1124 persons in 2005 and 0.1207 persons in 2009. Second, the supply shortage of 1.0 won in the business consulting industry prevents other industries from producing 2.6759 won in 2005 and 3.0145 won in 2009. Third, a 10% increase in the price level of the business consulting industry raises the overall price level from 0.1691% in 2005 to 0.2161% in 2009. The research results show that consulting industry has been increasing a effect on Korea national economy.

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.77-95
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• 2023

The regional infrastructure industries of Gwangyang City, the subject of this study, are Gwangyang Port and Gwangyang Steel Mill. Therefore, it is necessary to analyze the regional economic ripple effects of the port logistics industry in Gwangyang City. In this study, a multi-stage approach using the RW and the LQ methodology using the national input-output tables in 2015 and 2019 is used to prepare the regional interindustry analysis chart in Gwangyang City, and an exogenous demand induction model that reclassified the port logistics industry was applied. Through this, the purpose of this study was to provide policy implications by figuring out the regional economic ripple effects of the port logistics industry quantitatively in Gwangyang City. As a result of the analysis, the industries with high production inducement effect and forward/backward linkage effect of the port logistics industry in Gwangyang City were analyzed as manufacturing, transportation, land and air logistics sectors. And the industries in which the added value inducement effect and the employment inducement effect were analyzed as an industry related to the service industry. Therefore, it is necessary to prepare support measures to foster the port logistics industry as a way to promote these industries and revitalize the local economy of Gwangyang City. To this end, it is desirable to improve policies and systems for the vitalization of the Gwangyang port maritime cluster and provide various policy support for the port logistics industry in Gwangyang City. This study is meaningful in suggesting policy implications for the regional economy of Gwangyang City based on the results of exogenous analysis of the port logistics industry in small and medium-sized cities. However, It seems that further studies related to this will be needed in the future.