• Fibers and Polymers
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• 제6권3호
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• pp.186-199
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• 2005

A selection of commercially available poly(ethy1ene terephtha1ate) fibers with different degrees of molecular alignment and crystallinity have been investigated utilizing a wide range of techniques including optical microscopy, infrared spectroscopy together with thermal and wide-angle X-ray diffraction techniques. Annealing experiments showed increased molecular alignment and crystallinity as shown by the increased values of birefringence and melting enthalpies. Crystallinity values determined from thermal analysis, density, unpolarized infrared spectroscopy and X-ray diffraction are compared and discussed in terms of the inherent capabilities and limitations of each measurement technique. The birefringence and refractive index values obtained from optical microscopy are found to decrease with increasing wavelength of light used in the experiments. The wide-angle X-ray diffraction analysis shows that the samples with relatively low orientation possess oriented non-crystalline array of chains whereas those with high molecular orientation possess well defined and oriented crystalline array of chains along the fiber axis direction. X-ray analysis showed increasing crystallite size trend with increasing molecular orientation. SEM images showed micro-cracks on low oriented fiber surfaces becoming smooth on highly oriented fiber surfaces. Excellent bending characteristics were observed with knotted fibers implying relatively easy fabric formation.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.163-170
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• 2016

Because of rapid technological advancements, increased data rate support has become the key criterion for future communication medium selection. Multimode optical fibers and multicore optical fibers are well matched to high data rate throughput requirements because of their tendency to support multiple modes through one core at a time, which results in higher data rates. Using the numerical mode solver OptiFiber, we have designed a concentric core fiber by investigating certain design parameters, namely core diameter (µm), wavelength (nm), and refractive index profile, and as a result, the number of channels, material losses, bending losses, polarization mode dispersion, and the effective nonlinear refractive index have been determined. Space division multiplexing is a promising future technology that uses few-mode fibers in parallel to form a multicore fiber. The experimental tests are conducted using the standard second window wavelength of 1,550 nm and simulated results are presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.178-179
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• 2022

This study evaluated the crack reduction characteristics of concrete by type of fiber reinforced concrete. As a result of the experiment, it was shown that the fluidity decreased due to the mixing of the fiber reinforcing material. The higher the amount of fiber reinforced material used, the higher the decrease in fluidity. It was confirmed that the tensile strength was improved by the mixing of the fiber reinforcing material. The selection of fiber reinforcement has a great influence on the crack reduction effect.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.536-539
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• 2002

The use of concatenated codes in noncoherent synchronous optical fiber CDMA networks is proposed. The concatenated code sequences are generated using balanced Walsh code sequences and Walsh code sequences. The selection of balanced Walsh code sequences is presented and the design of fully programmable transmitter and receiver is reported. The analysis of the system BER performance shows that multiple-access interference is completely eliminated and the BER performance of the proposed system is better than that of the non-coherent synchronous optical fiber CDMA system using optical orthogonal codes with double hard-limiters.

• 한국정보전자통신기술학회논문지
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• 제6권4호
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• pp.272-277
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• 2013

In this paper the effect of instability and chaos in optical fiber networks based on the Internet is described. Nonlinear optical fiber effect especially Brillouin scattering in networks has emerged as the essential means for the construction of active optical devices used for all-optic in-line switching, channel selection, amplification, oscillation in optical communications and a host of other applications. The inherent optical feedback by the back-scattered Stokes wave in optical networks also leads to instabilities in the form of optical chaos. This paradigm of optical chaos in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical fiber communication. This paper attempts to present a survey and some of our research findings on the nature of Brillouin chaotic effect on Internet based optical communication.

• 한국공작기계학회논문집
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• 제10권3호
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• pp.38-42
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• 2001

In the machining of glass fiber reinforced plastics(GFRP), turning has been often used. But the most of past studies have been interested in the effect of fiber orientation on tool wear. In this study, the effects of fiber contents and cutting speeds on tool wear, cutting force and surface roughness are investigated experimentally. By proper selection of cutting tool, the variables are cutting speed, fiber contents and cutting length with fixed feed rate and depth of cut. The fiber contents have major effects on coated tool wear which observed as abrasive wear type.

• 한국정보전자통신기술학회논문지
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• 제1권1호
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• pp.61-66
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• 2008

In this paper the effect of instability and chaos in optical fiber networks based on the Internet is described. Nonlinear optical fiber effect especially Brillouin scattering in networks has emerged as the essential means for the construction of active optical devices used for all-optic in-line switching, channel selection, amplification, oscillation in optical communications and a host of other applications. The inherent optical feedback by the back-scattered Stokes wave in optical networks also leads to instabilities in the form of optical chaos. This paradigm of optical chaos in fiber Internet serves as a test for fundamental study of chaos and its suppression and exploitation in practical application in optical fiber communication. This paper attempts to present a survey and some of our research findings on the nature of Brillouin chaotic effect on Internet based optical communication.

• 한국작물학회지
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• 제19권
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• pp.83-99
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• 1975

우리나라에서의 섬유용 아마의 육종 목표와 관련된 육종상의 기초적 문제를 구명하고 답전작 섬유용 아마육종사 필요한 정보를 얻기 위하여, 도입된 4개품종의 이면교잡 잡종집단에 관하여 개화시까지의 일수, 초장, 경장, 건경중등 양적형질의 유전양식, 유전력 및 그들의 지역적 변이에 관한 시험을 하였다, 그 결과를 요약하면 다음과 같다. 1. 개화시까지의 일수는 짧은 것이 긴것에 대하여 완전 우성으로 나타났다. 2. 초장과 경장은 짧은 것이 긴것에 대하여 부분 우성으로 나타났다. 3. 건경중은 비대립유전자 간의 상호작용으로 분명치 않으나 무거운 것이 가벼운 것에 대하여 열성으로 나타났다. 4. 개화기간, 건경중 및 섬유비율의 유전력은 대체로 높았고 개화일수, 경장 및 섬유중의 유전력은 대체로 높았고 개화일수, 경장 및 섬유중의 유전력은 비교적 낮게 나타났다. 5. 섬유수량과 건경중 그리고 건경중과 초장간에는 높은 정의 상관을 보였다. 6. 섬유수량과 섬유비율, 섬유수량과 개화기간, 초장과 개화기간 중에는 각각 부의 상관이 있었다. 7. 초장($X_1$), 건경중($X_2$) 및 섬유중( $X_3$ ) 의 3개형질을 고려한 선발지수의 이용이 가장 능률적이었으며 이때의 각형질의 선발지수는 0.002$X_1$+0.0047$X_2$+0.0181$X_3$였다. 8. 선발시 고려되는 형질중 유전획득량과 선발효율을 가장 높일 수 있는 형질은 초장이었다. 9. 조사된 형질들은 모두 지역간 차가 현저하고 유전형 대 지역의 교호작용도 유의한 경우가 많았다.

• Membrane and Water Treatment
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• 제8권2호
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• pp.137-147
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• 2017

A water treatment utility in South Korea operates a large system of pressurized hollow fiber membrane (PHFM) modules. The optimal selection of membrane module for the full scale plant was critical issue and carried out using Risk-based Life Cycle Cost (RbLCC) analysis based on the historical data of operation and maintenance. The RbLCC analysis was used in the process of decision-making for replacing aged modules. The initial purchasing cost and the value at risk during operation were considered together. The failure of modules occurs stochastically depending on the physical deterioration with usage over time. The life span of module was used as a factor for the failure of Poisson's probability model, which was used to obtain the probability of failure during the operation. The RbLCC was calculated by combining the initial cost and the value at risk without its warranty term. Additionally, the properties of membrane were considered to select the optimum product. Results showed that the module's life span in the system was ten years (120 month) with safety factor. The optimum product was selected from six candidates membrane for a full scale water treatment facility. This method could be used to make the optimum and rational decision for the operation of membrane water purification facility.

• Fibers and Polymers
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• 제1권1호
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• pp.55-58
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• 2000

We present a new approach to bale laydown grouping, which improves the laydown to laydown uniformities, compared to conventional approaches. In this approach, we use a frequency-relative picking method based on an HVI quality index for cotton bale selection and laydown formation. We demonstrate the effectiveness of this approach by computer simulation on real HVI data of 1500 cotton bales. Simulation results show that the proposed method significantly outperforms random picking.