• Macromolecular Research
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• v.16 no.4
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• pp.314-319
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• 2008

An image analysis processing method for the measurement of nanofiber diameter was developed. For the analysis, scanning electron microscopy (SEM) images of electrospun fiber were prepared and applied to the individual measurement of the fiber diameter by using the developed and the traditional manual methods. Both methods provided a similar fiber distribution. The fiber average diameters were similar but the variance of the new method was larger than that of the manual method. The average diameters from the two methods exhibited a linear relationship with a high coefficient. The developed method can be used as a practical tool to estimate the fiber diameter of the electro spun web.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.13-21
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• 2002

A new method for measuring fiber length and fiber coarseness was developed using image analysis technique. Measured fibers were transferred to a glass slide on a filter paper placed on a wire of the laboratory paper machine. After staining the fibers on the slide, mean fiber lengths and coarseness were measured by a commercial image analysis software, named KS400. The resultant data obtained from the image analysis displayed a close correlation with those from FS-200 and also showed excellent reproducibility as well as those from FS-200. The length of synthetic fibers over 10 mm long could be readily measured by this new analysis technique. Finally, a substantial improvement in precision for measuring fiber length and coarseness was made with less operator's effort for a given time.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.319-325
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• 2004

In this study, analysis and design programs of bending of RC beams strengthened with fiber sheets are developed by using Visual Basic Language. The program consists two groups, ultimate strength method and nonlinear flexural analysis method. Ultimate strength method regards concrete compressive stress as a rectangular stress block and do not consider tensile stress of concrete and load-deflection curves. On the other hand, nonlinear flexural analysis considers tensile stress of concrete, load-deflection curves, state of stress distribution and failure strain of strengthening material. Also, the analysis method used in this study regards nonlinear flexural stress as compressive stress of concrete. This program can be a good tool for determining the bending strength of strengthened RC beams and estimating the amount of fiber sheets for practical use.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.35-40
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• 1998

This study was conducted to examine the pathological changes of rat peripheral nervous system during exposure to tellurium known to be a demyelinating agent by using teasing nerve fiber method and quantitative light microscopic analysis by image analyzer. The pellet containing 1.2% of tellurium were fed for 3, 5, 7, 9, 13 days to male wistar rats (21 days old) and then neurologic symptom and the feature of nerve fiber myelination were studied. From this study, following results were obtained. In 3 days treated group, it showed various neurologic symptom and teased nerve fiber showed slight irregularity of the myeline sheath. In 5 days and 7 days treated groups, it showed the segmental demyetination in larger size fiber and widening of nodes of ranvier. In 9 days and 13 days treated groups, the remyelinated fibers were observed and it was generally small in size. We consequently suggest that teasing nerve fiber method and quantitative analysis of nerve fiber were useful pathologic screening method of neurotoxicity of the peripheral nervous system.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.3 s.22
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• pp.29-35
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• 2006

Fiber element method in earthquake response analysis of bridges is used to represents a realistic flexural deformation according to nonlinear behavior of beam-column section. Nonlinear pseudo-static analysis of two column bent using fiber element is accomplished and failure mechanism of the plastic hinge region is studied. Load-displacement curve obtained by nonlinear pseudo-static analysis can be applicable to earthquake response analysis by capacity spectrum method. The nonlinear time history analysis of a full bridge model using fiber element experienced by the ground motion corresponding to the target response spectrum is accomplished. The result of time history analysis is similar to that of capacity spectrum method.

• Fibers and Polymers
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• v.7 no.2
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• pp.191-194
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• 2006

This paper adopts nonlinear vibration method to analyze the fluctuation process of fiber movement. Based on Hamilton Principle, this paper establishes differential equation of fiber axial direction movement. Using variable-separating method, this paper separates time variable from space variable. By using the disperse movement equation of Galerkin method, this paper also discusses stable region of transition curve and points out those influencing factor and variation trend of fiber vibration.

• Korean Journal of Optics and Photonics
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• v.23 no.6
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• pp.246-250
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• 2012

We derive analytical expressions for the output spectral density and the noise power $P_{\beta}$ in noise loading analysis using Volterra kernels to characterize fiber nonlinearities. The bandwidth of the input noise source has little effect on $P_{\beta}$, but the power of the input noise source and the dispersion parameter value of the fiber have a significant effect on $P_{\beta}$. The Volterra method predicts ${\Delta}P_{\beta}[dB]$ = 30 dB/decade, which agrees very accurately over a wide range of fiber parameters compared with the numerical results by the split-step Fourier method. Therefore the Volterra method could be useful to predict the performance of a dense WDM system when we plan to upgrade fiber or increase signal power.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.89-96
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• 2007

A volume integral equation method (VIEM) is applied for the effective analysis of plane elastostatic problems in unbounded solids containing single isotropic inclusion of two different shapes considering composite fiber volume fraction. Single cylindrical inclusion and single square cylindrical inclusion are considered in the composites with six different fiber volume fractions (0.25, 0.30, 0.35, 0.40, 0.45, 0.50). Using the rule of mixtures, the effective material properties are calculated according to the corresponding composite fiber volume fraction. The analysis of plane elastostatic problems in the unbounded effective material containing single fiber that covers an area corresponding to the composite fiber volume fraction in the bounded matrix material are carried out. Thus, single fiber, matrix material with a finite region, and the unbounded effective material are used in the VIEM models for the plane elastostatic analysis. A detailed analysis of stress field at the interface between the matrix and the inclusion is carried out for single cylindrical or square cylindrical inclusion. Next, the stress field is compared to that at the interface between the matrix and the single inclusion in unbounded isotropic matrix with single isotropic cylindrical or square cylindrical inclusion. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of inclusions. Through the analysis of plane elastostatic problems, it will be established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing inclusions considering composite fiber volume fraction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.12 s.255
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• pp.1518-1525
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• 2006

Finite element analyses of structures made of the fiber reinforced composites require an adequate method to characterize the high anisotropic behavior induced by one or several layers of fiber cords with different spatial orientation embedded in a rubber matrix. This paper newly proposes a continuum based rebar element considering change of the orientation of the fiber during deformation of the composite. The mechanical behavior of the embedded fiber is modeled using two-node bar elements in order to consider the relative deformation and spatial orientation of the embedded fiber. For improvement of the analysis accuracy, the load-displacement curve of fiber is applied to the stiffness matrix of fiber. A finite element program is constructed based on the total Lagrangian formulation considering both geometric and material nonlinearity. Finite element analyses of the tensile test are carried out in order to evaluate the validity of the proposed method. Analysis results obtained with the proposed method provides realistic representation of the fiber reinforced rubber composite compared to results of other two models by the Halpin-Tsai equation and a rebar element in ABAQUS/Standard.

• Fibers and Polymers
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• v.7 no.1
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• pp.73-78
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• 2006

The ability to absorb liquid and the dust removal performance are important factors for wiping cloths used to remove contaminants. We have developed a method that can determine the contaminant removal performance of wiping cloths. In the gravimetric method, experimental errors are unavoidable because the contaminant plate is much heavier than the contaminant material. However, we used image analysis to reduce the experimental errors, and did not use the heavy contaminant plate. The correlation coefficient between the image. analysis and the gravimetric methods was very high, at R=0.97, with a significance level of 95%. From the correlation analysis and empirical data, the image analysis method is a useful tool for measuring wiping efficiency. The wiping efficiency measured using image analysis has a close relationship to the wiping speed, viscosity of the contaminant, and wiping pressure, at the significance level of 95%.