• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.633-638
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• 2023

In this study, the effect of the change in cable tension on the track irregularity of railway ballasted track on a railway steel composite bridge was analyzed. As a result of comparing design and analysis results for cable tension, a difference of less than 3% was found, and analysis modeling was analyzed to reflect the design conditions well. In addition, the adequacy of the analysis modeling was demonstrated by comparing the field measurement results with the analysed cable tension. By considering the change in cable tension as a variable, the track irregularity of the railway steel composite bridge was analyzed. As a result of the analysis, it was analyzed that the total and one-sided cable tension change had a direct effect on the vertical irregularity among the track irregularity items. In addition, it was found that the change in track irregularity occurred in the section close to the cable position. It was analyzed that the change in cable tension had a more direct effect on track irregularity that had a direct correlation with the vertical direction rather than the lateral direction.

• Journal of Korean Society on Water Environment
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• v.29 no.5
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• pp.681-690
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• 2013

Watershed models have been increasingly used to support an integrated management of land and water, non-point source pollutants, and implement total daily maximum load policy. However, these models demand a great amount of input data, process parameters, a proper calibration, and sometimes result in significant uncertainty in the simulation results. For this reason, uncertainty analysis is necessary to minimize the risk in the use of the models for an important decision making. The objectives of this study were to evaluate three different uncertainty analysis algorithms (SUFI-2: Sequential Uncertainty Fitting-Ver.2, GLUE: Generalized Likelihood Uncertainty Estimation, ParaSol: Parameter Solution) that used to analyze the sensitivity of the SWAT(Soil and Water Assessment Tool) parameters and auto-calibration in a watershed, evaluate the uncertainties on the simulations of runoff and sediment load, and suggest alternatives to reduce the uncertainty. The results confirmed that the parameters which are most sensitive to runoff and sediment simulations were consistent in three algorithms although the order of importance is slightly different. In addition, there was no significant difference in the performance of auto-calibration results for runoff simulations. On the other hand, sediment calibration results showed less modeling efficiency compared to runoff simulations, which is probably due to the lack of measurement data. It is obvious that the parameter uncertainty in the sediment simulation is much grater than that in the runoff simulation. To decrease the uncertainty of SWAT simulations, it is recommended to estimate feasible ranges of model parameters, and obtain sufficient and reliable measurement data for the study site.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.772-778
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• 2012

In this paper, the states and the parameters in the dynamic system are simultaneously estimated by applying the UKF(Unscented Kalman Filter), which is widely used for estimating the state of non-linear systems. Estimating the parameter is very important in various fields, such as system control, modeling, analysis of performance, and prediction. Most of the dynamic systems which are dealt with in engineering have non-linearity as well as some noise. Therefore, the parameter estimation is difficult. This paper estimates the states and the parameters applying to the UKF, which is a non-linear filter and has strong noise. The augmented equation is used by including the addition of the parameter factors to the original state equation of the system. Moreover, it is simulated by applying to a 2-DOF(Degree of Freedom) dynamic system composed of the pendulum and the slide. The measurement noise of the dynamic equation is assumed to be a Gaussian distribution. As the simulation results show, the proposed parameter estimation performs better than the LSM(Least Square Method). Furthermore, the estimation errors and convergence time are within three percent and 0.1 second, respectively. Consequentially, the UKF is able to estimate the system states and the parameters for the system, despite having measurement data with noise.

• Structural Engineering and Mechanics
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• v.72 no.6
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• pp.689-712
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• 2019

Time-series models like AR-ARX and ARMAX, provide a robust way to capture the dynamic properties of structures, and their residuals can be effectively used as features for damage detection. Even though several research papers discuss the implementation of AR-ARX and ARMAX models for damage diagnosis, they are basically been exploited so far for detecting the time instant of damage and also the spatial location of the damage. However, the inverse problem associated with damage quantification i.e. extent of damage using time series models is not been reported in the literature. In this paper, an approach to detect the extent of damage by combining the ARMAX model by formulating the inverse problem as a multi-constrained optimization problem and solving using a newly developed hybrid adaptive differential search with dynamic interaction is presented. The proposed variant of the differential search technique employs small multiple populations which perform the search independently and exchange the information with the dynamic neighborhood. The adaptive features and local search ability features are built into the algorithm in order to improve the convergence characteristics and also the overall performance of the technique. The multi-constrained optimization formulations of the inverse problem, associated with damage quantification using time series models, attempted here for the first time, can considerably improve the robustness of the search process. Numerical simulation studies have been carried out by considering three numerical examples to demonstrate the effectiveness of the proposed technique in robustly identifying the extent of the damage. Issues related to modeling errors and also measurement noise are also addressed in this paper.

• Applied Microscopy
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• v.51
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• pp.17.1-17.10
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• 2021

Our previous study on the binding activity between Cel5H and clay minerals showed highest binding efficiency among other cellulase enzymes cloned. Here, based on previous studies, we hypothesized that the positive amino acids on the surface of Cel5H protein may play an important role in binding to clay surfaces. To examine this, protein sequences of Bacillus licheniformis Cel5H (BlCel5H) and Paenibacillus polymyxa Cel5A (PpCel5A) were analyzed and then selected amino acids were mutated. These mutated proteins were investigated for binding activity and force measurement via atomic force microscopy (AFM). A total of seven amino acids which are only present in BlCel5H but not in PpCel5A were selected for mutational studies and the positive residues which are present in both were omitted. Of the seven selected surface lysine residues, only three mutants K196A(M2), K54A(M3) and K157T(M4) showed 12%, 7% and 8% less clay mineral binding ability, respectively compared with wild-type. The probable reason why other mutants did not show altered binding efficiency might be due to relative location of amino acids on the protein surface. Meanwhile, measurement of adhesion forces on mica sheets showed a well-defined maximum at 69±19 pN for wild-type, 58±19 pN for M2, 53±19 pN for M3, and 49±19 pN for M4 proteins. Hence, our results demonstrated that relative location of surface amino acids of Cel5H protein especially positive charged amino acids are important in the process of clay mineral-protein binding interaction through electrostatic exchange of charges.

• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.428-439
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• 2011

It is well known that the sound characteristics of Korean bell depend on the shape and the alloy constituents. Development of the methods to acquire exact shape data and alloy constituents of the whole body of the bell is very important for the study and systematic management of Korean bells. The practical scanning and modeling methods to get shape data from optical triangulation laser scanners are proposed. The 3D shape data by the proposed methods can be the basis of diverse measurements such as curvature, volume, thickness and the distance between any two points. A nondestructive alloy constituents measuring method which can overcome the limitations of partial data collection and damages to Korean bells is also suggested to get the whole alloy characteristics. Following the developed methods, the data of the shapes and alloy constituents of 18 Korean bells are collected and the errors of existing measurement data for the shape have been corrected.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.81-89
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• 1997

The size and shape of the human body has been an important factor not only in anthropology but in integration of designs aimed for daily use. Although the three-dimensional measurements have been proposed and obtained introducing new methods, there still remains many problems concerning how to analyze and evaluate the results. In this study, we have got the internal and external orientation factors, image coordinates from the ac-quired photographs, have calaulated the object coordinates through Bundle Adjustment, have matched multi-images. have drawn the object in the computer, and smoothly handled the surface of the body model using the Au-to-CAD system or graphic processing utility then we could generate the digital model of human body. The. results show that once digital modeling of the body is generated. the information which a designer needs can be acquired and the adequate calculations for many application fields can be done easily and many geometrical properties could be extracted. Therefore we propose the possibility of indirect human body measurement through digital model generation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.289-296
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• 2009

Natural frequency is a key parameter to determine the seismic and wind loading of tall flexible structures, and to assess the wind-induced vibration for serviceability check. In this study, natural frequencies and associated mode shapes were obtained from measured acceleration data and system identification technique. Subsequently, finite element(FE) models for a tall reinforced concrete buildings were built using a popular PC-based finite element analysis program and calibrated to match their natural frequencies and mode shapes to actual values. The calibration of the FE model included: 1) compensation of modulus of elasticity considering the mix design strength, 2) flexural stiffness of floor slabs, and 3) major non-structural components such as plain concrete walls. Natural frequencies and mode shapes from the final FE model showed best agreement with the measured values.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.742-749
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• 2016

To cope with the rising cost of the fossil fuel and the need of renewable energy, many wind farms are being constructed along the coasts of Korean peninsula. However, construction of these wind farms may cause negative influences by the shielding effect and the Doppler frequency from the wind turbine on the military radars operated in the nearby region. Therefore, the analysis of electromagnetic phenomenon with the real wind turbine is required. This paper compare the measured electromagnetic shielding effect and Doppler effect with theoretical shielding effect according to obstacle in literature and the extracted Doppler frequency through signal modeling.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.3
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• pp.149-163
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• 2004

Evapotranspiration (ET) is a critical component of the hydrologic cycle which influences economic activities as well as the natural ecosystem. While there have been numerous studies on ET estimation for homogeneous areas using point measurements of meteorological variables, monitoring of spatial ET has not been possible at landscape - or watershed - scales. We propose a site-specific application of the land surface model, which is enabled by spatially interpolated input data at the desired resolution. Gyunggi Province of South Korea was divided into a regular grid of 10 million cells with 30m spacing and hourly temperature, humidity, wind, precipitation and solar irradiance were estimated for each grid cell by spatial interpolation of synoptic weather data. Topoclimatology models were used to accommodate effects of topography in a spatial interpolation procedure, including cold air drainage on nocturnal temperature and solar irradiance on daytime temperature. Satellite remote sensing data were used to classify the vegetation type of each grid cell, and corresponding spatial attributes including soil texture, canopy structure, and phenological features were identified. All data were fed into a standalone version of SiB2(Simple Biosphere Model 2) to simulate latent heat flux at each grid cell. A computer program was written for data management in the cell - based SiB2 operation such as extracting input data for SiB2 from grid matrices and recombining the output data back to the grid format. ET estimates at selected grid cells were validated against the actual measurement of latent heat fluxes by eddy covariance measurement. We applied this system to obtain the spatial ET of the study area on a continuous basis for the 2001-2003 period. The results showed a strong feasibility of using spatial - data driven land surface models for operational monitoring of regional ET.