• ETRI Journal
• /
• v.35 no.5
• /
• pp.915-918
• /
• 2013

This work presents an accurate finite-difference time-domain (FDTD) dispersive modeling of concrete materials with different water/cement ratios in 50 MHz to 1 GHz. A quadratic complex rational function (QCRF) is employed for dispersive modeling of the relative permittivity of concrete materials. To improve the curve fitting of the QCRF model, the Newton iterative method is applied to determine a weighting factor. Numerical examples validate the accuracy of the proposed dispersive FDTD modeling.

• Journal of Broadcast Engineering
• /
• v.7 no.4
• /
• pp.368-375
• /
• 2002

In this paper, we apply multiresolution wavelet transform for the digital image watermarking. For better result, we insert watermark into the images and set a proper weighting factor for each subband based on HVS model. With proposed algorithm, we confirm that the image quality is satisfactory and this method outperforms the previous methods against image compression and cropping.

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• pp.285-288
• /
• 2004

This study presents a numerical procedure to optimize the shape of dimple surface to enhance turbulent heat transfer in rectangular channel. The response surface based optimization method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analysis of fluid flow and heat transfer with shear stress transport (SST) turbulence model. The dimple depth-to -dimple print diameter ratio, channel height- to- dimple print diameter ratio. and dimple print diameter-to-pitch ratio are chosen as design variables. The objective function is defined as a linear combination of heat transfer coefficient and friction drag coefficient with a weighting factor. Full factorial method is used to determine the training points as a mean of design of experiment.

• Structural Engineering and Mechanics
• /
• v.54 no.3
• /
• pp.597-605
• /
• 2015

In this study, linear vibrations of an axially moving beam under non-ideal support conditions have been investigated. The main difference of this study from the other studies; the non-ideal clamped support allow minimal rotations and non-ideal simple support carry moment in minimal orders. Axially moving Euler-Bernoulli beam has simple and clamped support conditions that are discussed as combination of ideal and non-ideal boundary with weighting factor (k). Equations of the motion and boundary conditions have been obtained using Hamilton's Principle. Method of Multiple Scales, a perturbation technique, has been employed for solving the linear equations of motion. Linear equations of motion are solved and effects of different parameters on natural frequencies are investigated.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.12
• /
• pp.44-52
• /
• 2019

Industrial accidents differ considerably according to the industry and the scale of these industries. These industrial disasters have been analyzed in various ways. Therefore, a technique was developed to evaluate the disaster level among companies using the ANP method and the data derived from the disaster statistics over the past five years(2013~2017), as well as the safety information characteristics through questionnaires. The objective of the study was to determine the disaster level and safety level of a company. In this paper, six factors that are considered important for assessing the disaster level of the enterprise among the disaster statistics were selected. These factors included the industry type and size, age of employee, duration of treatment, duration of employment, and typical occurrence. Most companies use the accident rate for their disaster level to compare only with other companies. In this study, the weighting factors of the company were derived taking the characteristics of each company into consideration. Therefore, the disaster level of each company can be evaluated using the disaster statistics from each company and the derived weighting factors.

• The Journal of Engineering Geology
• /
• v.19 no.1
• /
• pp.99-108
• /
• 2009

Since the preexisting evaluation methods of landslide susceptibility take somehow long time to determine the slope stability based on the field survey and laboratory analysis, there are several problems to acquire immediate evaluation results in the field. In order to overcome the previously mentioned problems and incorrect evaluation results induced by some subjective evaluation criteria and methods, this study tried to develop a method of landslide susceptibility by a quantitative and objective evaluation approach based on the field survey. Therefore, this study developed an evaluation chart for landslide susceptibility on natural terrain using the AHP analysis method to predict landslide hazards on the field sites. The AHP analysis was performed by a questionnaire to several specialists who understands mechanism and influential factors of landslide. Based on the questionnaire, weighting values of criteria and alternatives to influence landslide triggering were determined by the AHP analysis. According to the scoring results of the analysed weighting values, slope angle is the most significant factor. Permeability, water contents, porosity, lithology, and elevation have the significance to the landslide susceptibility in a descending order. Based on the assigned scores of each criterion and alternatives of the criteria, an evaluation chart for landslide susceptibility was suggested. The evaluation chart makes it possible for a geologist to evaluate landslide susceptibility with a total score summed up each alternative score.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.134-137
• /
• 2003

Newton-Raphson is most used algorithm in EIT(electrical impedance tomography), cross-sectional distribution of resistivity is reconstructed by mean of both generating and sensing electrodes attached onto the surface of the object. EIT has been suffered from the severe ill-posedness which is caused by the inherent low sensitivity of boundary measurements to any changes of internal resistivity values. In this paper, we propose modified cost function and weighting factor that compensate for low sensitivity between boundary measurements and internal resistivity and improve performance of Newton-Raphson for EIT in region of interest.

• Journal of Auto-vehicle Safety Association
• /
• v.3 no.2
• /
• pp.28-33
• /
• 2011

This paper presents driving path estimation algorithm for adaptive cruise control system and advanced emergency braking system using multi-sensor fusion. Through data collection, yaw rate filtering based road curvature and vision sensor road curvature characteristics are analyzed. Yaw rate filtering based road curvature and vision sensor road curvature are fused into the one curvature by weighting factor which are considering characteristics of each curvature data. The proposed driving path estimation algorithm has been investigated via simulation performed on a vehicle package Carsim and Matlab/Simulink. It has been shown via simulation that the proposed driving path estimation algorithm improves primary target detection rate.

• Proceedings of the KIEE Conference
• /
• 1992.07a
• /
• pp.319-322
• /
• 1992

This paper proposes indirect adaptive pole placement adaptive controller using a modified least squares method. If an adaptive controller has good performance, it is necessary that an estimator have fast convergence. This paper presents a modified least squares method which guarantees the stability of estimator and has fast convergence. In this algorithm, information on signal level is obtained from the determinent of covariance matrix and according to it, weighting factor is tuned.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03a
• /
• pp.229-232
• /
• 2008

This study presents a numerical procedure to optimize the shape of stepped circular pin-fins to enhance turbulent heat transfer. The KRG method is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis of fluid flow and heat transfer with shear stress transport turbulent model. The objective function is defined as a linear combination of heat transfer and friction loss related terms with a weighting factor. Ten training points are obtained by Latin Hypercube Sampling for two design variables. Optimum shape has been successfully obtained with the increased objective function.