• Design & Manufacturing
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• v.13 no.1
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• pp.25-30
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• 2019

This paper presents the design strategy for the optimal RTM molds of Carbon Fiber Reinforced Plastic (CFRP) by carbon fiber draping and resin flow simulation. First, the mold shape and molding condition were determined considering the undercut and die face of the product in the draping simulation, which made the preliminary shape of the product by compressing the carbon fiber. After that, the diffusion behavior during the injection of resin in the mold was predicted by the resin flow simulation. Finally, the optimal mold shape was designed by selecting the locations of resin injection port and vent based on total results of simulations. In this paper, the mold of automotive side mirror case was selected as the representative product. Also, the actual mold was manufactured based on the simulation design to confirm the practicality of it. This study is expected to contribute to the industry as a technology to improve the reliability and productivity of CFRP producted by RTM process.

• Fiber Technology and Industry
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• v.1 no.3
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• pp.389-400
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• 1997

• Fiber Technology and Industry
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• v.1 no.4
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• pp.481-487
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• 1997

• Korean Journal of Human Ecology
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• v.19 no.2
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• pp.389-398
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• 2010

This study examines the relationship between the concern about well-being lifestyle and the perceived image of Hanji fiber. A survey was conducted among male and female consumers aged 20 and over in Jeonju and Daejon from January 4th to 11th, 2008. A total of 168 responses were analyzed by using descriptive statistics, factor analysis, and ANOVA via the SPSS ver. 12. As a result, four factors were determined in the concern for a well-being lifestyle; product consumption, enjoying culture, using therapy and managing the household. The perceived image of Hanji fiber were classified into four elements; traditional, high-quality, functional and popular images. Among the factors of the concern for a well-being lifestyle and the perceived image of Hanji fibers, a partial relationship was observed. There is a positive relationship, especially between the product consumption factor of a well-being lifestyle and the high-quality and functional image of Hanji fiber. Also, there was a positive relationship between the factor of managing the household and the traditional image of Hanji fiber. However, the therapy interest factor of a well-being lifestyle was negatively related to the traditional image of Hanji fiber.

• Journal of the Korea Concrete Institute
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• v.13 no.4
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• pp.346-353
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• 2001

This research investigates the mixture proportioning of waste newsprint paper fiber for thin-cement product. Waste newsprint paper fibers obtained through shredded mechanically by a dry process. Waste newsprint paper fiber reinforced cement composites was manufacted by slurry-dewatering method. The waste newsprint paper fiber reinforcement conditions (fiber mass fraction, level of substitution of virgin fibers, level of fiber beating) and processing variables (pressed, unpressed) are optimized through experimental studies and statistical analyses based on factorial design of experiments and analyses of variance. The optimized recycled waste newsprint paper fiber reinforced cement composites were technically evaluated. The results are shown to possess acceptable properties and strong potentials of the recycling of waste newsprint paper of the reinforcement of thin-cement products.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.54-61
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• 2012

Makgeolli lees is a by-product of the makgeolli brew processing. Makgeolli lees contains high levels of fibers, which can be separated and used to develop foods rich in dietary fibers. The purpose of this study was to determine the effect of makgeolli fibers (0-4%) on proximate composition, caloric content, pH, color, cooking yield, textural profile, and sensory characteristics of chicken-emulsion sausages. The moisture content of 1, 2, and 3% makgeolli lees fiber-amended product was higher than the control, while that of the 4% product was not. Total calorie estimates of makgeolli lees fiber-amended sausages were lower than the control, except for in the case of the 4% treatment. Moreover, chicken sausages supplemented with makgeolli lees fiber had higher cooking yields and improved textural properties. Chicken emulsion sausages prepared with makgeolli lees fiber had improved overall acceptability, and the best results of sensory characteristics were obtained for the emulsion sausages containing 2% makgeolli lees fiber.

• Composites Research
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• v.28 no.6
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• pp.340-347
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• 2015

As resin impregnates through the fiber preform in vacuum assisted resin transfer molding process, the volume of fibers is changed by expansion of fiber mat according to filling time. It causes not only the change in dimension but also the decrease of mechanical properties of the composite product. Moreover, it results in the economic loss by increase of the used amount of resin especially in the large product such as wind turbine blade. In this study, the ways to control fiber volume fraction were investigated by both the experimental and theoretical analyses on the expansion of fiber preform as the preform was impregnated by resin in the VARTM process. Two kinds of swelling stage were observed as flow front progressed, which was analyzed by comparing the experimental and simulation results. The process parameters are expected to be optimized by investigating the swelling behavior of fiber preform in the manufacturing process of the composite product.

• Laser Solutions
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• v.16 no.3
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• pp.22-26
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• 2013

Fiber laser welding was performed on SUS Materials metal bellows. The results can be summarized as follows: When we tried to change welding focus location. we get the best welding line when focus location placed 0mm. In product welding, We could make a satisfactory product in constant area by applying optimized conditions and show a table that is able to help producer easily to apply it to manufacturing. In comparison with existing TIG and plasma welding, welded bellows by fiber laser has faster processing speed, smaller thermal effect, very narrow welding area and fine surface.

• Journal of the Korean Mathematical Society
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• v.60 no.2
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• pp.255-271
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• 2023

In this paper, we deal with random attractors for dynamical systems forced by a deterministic noise. These kind of systems are modeled as skew products where the dynamics of the forcing process are described by the base transformation. Here, we consider skew products over the Bernoulli shift with the unit interval fiber. We study the geometric structure of maximal attractors, the orbit stability and stability of mixing of these skew products under random perturbations of the fiber maps. We show that there exists an open set U in the space of such skew products so that any skew product belonging to this set admits an attractor which is either a continuous invariant graph or a bony graph attractor. These skew products have negative fiber Lyapunov exponents and their fiber maps are non-uniformly contracting, hence the non-uniform contraction rates are measured by Lyapnnov exponents. Furthermore, each skew product of U admits an invariant ergodic measure whose support is contained in that attractor. Additionally, we show that the invariant measure for the perturbed system is continuous in the Hutchinson metric.

• Journal of the Korean Wood Science and Technology
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• v.52 no.2
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• pp.191-203
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• 2024

Persimmon wood (Diospyros kaki) is a seasonal fruit-producing plant with a beautiful dark pattern in its wood that is suitable for high-quality furniture, sculptures and musical instruments. The utilization of persimmon wood can be improved by determining its anatomical characteristics, such as juvenile and mature wood. This study aimed to determine the boundaries between juvenile and mature wood and observe the anatomical properties of juvenile and mature wood and their variations in the axial direction. Three 30-year-old persimmon (D. kaki) trees grown in Karo, North Sumatra, Indonesia, were used in this study. The boundary between juvenile and mature wood was determined by measuring the fiber length and vessel element length from near the pith to near the bark. Anatomical observations were conducted in the juvenile and mature wood areas. The results showed that the average boundaries between juvenile and mature wood were 44.11 mm from the pith and were not significantly different in the axial direction of the trees. Furthermore, the wood anatomy categories of juvenile and mature wood differed significantly in terms of fiber diameter, fiber proportion, vessel proportion, and axial parenchyma proportion. In the axial direction, vessel diameter, ray parenchyma frequency, and ray parenchyma proportion at the base, middle, and top of the tree were significantly different.