• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.180-187
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• 2003

A theoretical presentation by using a three-dimensional finite difference beam propagating method (3-D FD-BPM) for the evanescent coupling is offered with respect to the refractive indexes between a side-polished optical fiber and an infinitely planar waveguide with a conductor cladding (PWGCC). The PWG is suspended at a constant distance from an unclad fiber core and attached with a perfect conductor (PEC) on one side. The coupling and propagation of light are found to depend on both the relationship between the refractive index values of two structures and the configuration of the side-polished fiber used in the PWGCC. The spreading of light in the unconfined direction of a PWGCC is presented with the distribution of electric fields in xy - plane and the absolute amplitude of electric fields along the x and y axis. The power of the light propagation in a fiber decreases exponentially along the fiber axis as it is transferred to the PWGCC, where it is carried away.

• Current Optics and Photonics
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• v.4 no.2
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• pp.141-147
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• 2020

To understand the cause of the high light transmittance of the human eye, the optical effects of the collagen fibers of the stroma layer, which constitute the majority of the cornea, were analyzed. These collagen fibers, approximately 20 nm in diameter, have a regular arrangement. Accordingly, the optical properties of the collagen fibers and the fiber layer were analyzed by simulation. A standing wave was formed in the incident space by the overlapping incident light and the light reflected by the plate. In addition, it was confirmed that when the collagen fibers are arranged in a layer, the light transmittance periodically changes, depending on the number of fiber layers. The standing wave was formed in the incident space, and the light's intensity distribution was changed by the nanoscale collagen fibers in the section with the collagen layer, which affected the transmittance. To explain this phenomenon, the collagen fiber was defined as a second light source, and an attempt was made to describe the simulation results in terms of overlap of the incident light with the light emitted from the collagen fiber.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.2
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• pp.103-114
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• 2001

During a compression molding process of Unidirectional Fiber Reinforced Plastic Composites, control of filling patterns in mold and distribution of fiber is needed to predict the effects of molding parameters on the flow characteristics. To obtain an excellent product and decide optimum molding conditions, it is important to know the relationship between molding conditions and viscosity. In this study, the anisotropic viscosity of the Unidirectional Fiber Reinforced Plastic Composites is measured by using the parallel plastometer. The model for flow state has been simulated by using the viscosity. The composites is treated as an incompressible New-tonian fluid. The effects of longitudinal/transverse viscosity ration A and slip parameter $\alpha$ on buldging phenomenon and mold filling patterns, are also discussed.

• Computers and Concrete
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• v.9 no.3
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• pp.171-178
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• 2012

This paper presents numerical studies of stiff fiber pullout behaviors of fiber reinforced cementitious composites based on a progressive damage model. The ongoing debonding process is simulated. Interfacial stress distribution for different load levels is analyzed. A parametric study, including bond strength and the homogeneity index on the pullout behaviors is carried out. The numerical results indicate that the bond stress decreases gradually from loaded end to embedded end along fiber-cement interface. The debonding initially starts from loaded end and propagates to embedded end as load increasing. The embedded length and bond strength affect the load-loaded end displacement curves significantly. The numerical results have a general agreement with the experimental investigation.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.6
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• pp.434-439
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• 2016

Optical fiber splice closure serves to protect connection parts from external environment. Moreover, it functions as a connection, junction, and distribution in diverse surroundings such as aerial, underground, duct, and pole. In this research, first, the optical fiber splice closure, its configuration, and the design problem were briefly investigated. Second, the design and application for in-line cable closure were studied to satisfy its construction and technical features. The injection molding conditions and optimal design were conducted to save time and cost during the manufacturing process. Third, methods to minimize loss via of optical fiber cable while strongly fixing optical fiber cable with optical cable holder to prevent fracture were researched, and tests such as perfect air tightness and mechanical and environmental performance were conducted.

• International Journal of Concrete Structures and Materials
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• v.3 no.1
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• pp.47-56
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• 2009

The first diagonal cracking and ultimate shear load of reinforced girder made of ultra high performance fiber reinforced concrete (UHPFRC) were investigated in this paper. Eleven girders were tested in which eight girders failed in shear. A simplified formulation for the first diagonal cracking load was proposed. An analytical model to predict the ultimate shear load was formulated based on the two bounds theory. A fiber reinforcing parameter was constituted based on the random assumption of steel fiber uniform distribution. The predicted values were compared with the conventional predictions and the test results. The proposed equation can be used for the first cracking status analysis, while the proposed equations for computing the ultimate shear strength can be used for the ultimate failure status analysis, which can also be utilized for numerical limit analysis of reinforced UHPFRC girder. The established fiber reinforcing theoretical model can also be a reference for micro-mechanics analysis of UHPFRC.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.28-29
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• 2014

In this study, flexural strength by fiber reinforced for steel fiber and reinforced polyamide fiber concrete, and concrete fracture properties by improvement of flexural toughness and high-velocity projectile impact were evaluated. As a result, it was confirmed that flexural strength are improved by distribution of stress and suppress of cracks, and the back desquamation of concrete by high-velocity projectile impact is suppressed. In addition, It was observed that the spalling of rear is caused when tension stress is caused as shock wave by high-velocity projectile impact was transferred to the rear and tension stress is suppressed by fiber reinforcement.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.27-35
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• 2001

Four different sources of wood-fibers from Eucalyptus, Italian poplar, hemlock, and mixed species fibers were used to study the influence of their fiber characteristics on the performance of medium density fiberboard (MDF) panels bonded with both urea-formaldehyde (UF) and phenol-formaldehyde (PF) adhesives. Included fiber characteristics were fiber length, size distribution, bulk density, and acidity. Physical and mechanical properties of MDF panels manufactured by dry process using these different fibers were determined for the comparison of board performance. Two hardwood species had a large fraction of short fibers resulting in a higher bulk density while very long hemlock fibers had lower bulk density. Fiber acidity was revealed to strongly affect the internal bond (IB) strength of MDF panels bonded with UF resins. MDF panels made from mixed species fibers showed highest IB strength of all panels prepared. UF-bonded MDF panels showed poor dimensional stability. In conclusion, the present study showed that wood-fiber characteristics such as fiber length, bulk density, and acidity affect the performance of MDF boards, and also suggested that fiber characteristics be considered for MDF panel manufacture.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.53-54
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• 2003

Fukusuke applied for beginning "Civil affairs reproduction procedure" on June 21, 2003. It′s bankrupt. After obtaining the data of "Commodity Attribute, Sales, Sates Cost, Stock, Ordinary Profit, And Special Loss" based on the financial statement at the time of the bankruptcy, the influence of the production method improves checking. They are compared with a similar apparel company. The production method is close with the distribution circumstances. As a result, it searches for the limit of "Mass-Sail system" in fiber ＆ fashion product by "Make To Stock(MTS) Production Method".

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.112-113
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• 2003

한국섬유섬유산업에 있어서 섬유장에 대한 정보를 알아야 하는 이유로는 원료로부터 섬유를 분리 시키고, 길이 방향으로 배향시키며, 곧게 펼치는 과정에서 섬유의 절단을 최소화할 수 있는 기계의 조건을 산출하는데 있다. 또한 제품의 강도를 결정하는데 있어서 섬유의 길이는 중요한 역할을 한다. 그러나 섬유의 길이를 측정하는 데에는 많은 어려움이 있다. 그것은 섬유의 한올 한올의 길이를 측정하는 것은 쉽지만 수많은 섬유들을 빠른 속도로 측정해야하기 때문이다. (중략)