• Plant Resources
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• v.6 no.1
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• pp.11-15
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• 2003

To determine as optimal sowing time of forage rape in spring time in southern areas of Korea, forage rape cv. Velox, the highest yielding variety among introduced varieties of forage rape, was grown under five different sowing times. Yield components such as plant length, number of branches and number of leaves etc. were higher at the sowing time of Mar. 15 and Mar. 25. The plants sown at Mar. 15 and Mar. 25 also showed highest fresh and dry matter yield. When plants were grown under later sowing time, they showed higher values in content of crude protein and lower values in contents of crude fiber such as Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), cellulose and lignin. There was no relationship between variation of In Vitro Dry matter Digestibility (IVDMD) and sowing time. The plants sown at Mar. 15 and Mar. 25 showed highest digestible dry matter yields.

• Journal of Mechanical Science and Technology
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• v.15 no.12
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• pp.1616-1622
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• 2001

Fiber composite materials are widely used in aerospace industries due to their high specific strength and stiffness. Especially, the increasing use of polymer composite materials for injection of automobile components has led to a considerable interest in the application of stress pattern analysis by thermal emission to these composite materials. Therefore, in this study the microstructure of glass fiber orientation at the parent and weld line of polycarbonate is observed by a light transmission. And we also investigate a stress concentration model of a notch including short glass fibers. Especially the polymer injection weld reorients the fiber to suggest a new method for the evaluation of inhomogeneous deformation.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.508-512
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• 1999

In order to qualify and quantify carotenoid pigment of pumpukin were analyzed by HPLC column chromatography and spectrophotometry. Eightyseven percent of total carotenoids in the pumpkin was in the fiber amounting 65.33mg%. however flesh and skin contained 6.61 and 3.31mg% respectvely. A silica gel column chromatography of the carotenoids produced 2 different peaks. The components eluted in peak II showed blue color when treated with hydrochloric acid. The fact suggested it contained epoxide and the component in peak II was a monol. By the separation with HPLC. $\alpha$ and $\beta$-carotene were the major compounds in the carotenoids. In fiber the total $\beta$-carotene content was 1.6 times higher than in the flesh and skin. The fiber contained less unidentified compounds than other part which contained 27.3~32.8%.

• Journal of the Korea Safety Management & Science
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• v.21 no.4
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• pp.45-49
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• 2019

The basalt fiber is expected to become a trend for industrial fibers as they have better properties of heat-resistant, non-combustion, absorbent, soundproof, moistureproof, lightweight, corrosion resistant, and high strength properties. Also, the fiber is found to be non-toxic and harmless to the human body. Therefore, in this study, we analyzed the chemical and mineral compositions of powdered sludge of basalt produced at seven sites on Jeju Island for the development of fire resistance insulating material for a building. The results showed that the basalt stone sludge is made from only sodium calcium aluminum silicate and ferridioside components unlike the basalt rock.

• Structural Engineering and Mechanics
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• v.57 no.2
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• pp.201-220
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• 2016

A general model of equations of the two-temperature theory of generalized thermoelasticity is applied to study the wave propagation in a fiber-reinforced magneto-thermoelastic medium in the context of the three-phase-lag model and Green-Naghdi theory without energy dissipation. The material is a homogeneous isotropic elastic half-space. The exact expression of the displacement components, force stresses, thermodynamic temperature and conductive temperature is obtained by using normal mode analysis. The variations of the considered variables with the horizontal distance are illustrated graphically. Comparisons are made with the results of the two theories in the absence and presence of a magnetic field as well as a two-temperature parameter. A comparison is also made between the results of the two theories in the absence and presence of reinforcement.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.6
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• pp.37-44
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• 2005

This paper presents fabrication techniques of the optical fiber position sensor (or spindle state monitoring. These include selection of components such as optical fibers, a laser-diode, a photo-diode, and op-amp IC of the signal process circuit. We also describe electric runout problem. The fabricated sensor has a linearity of $1.7\%$ FSO in the air gap range $0.1\~0.6mm$, a resolution of $0.37{\mu}m$ and a bandwidth of 6.3kHz. Finally, we have successfully operated a magnetic bearing spindle system using the sensors.

• Plant Resources
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• v.7 no.3
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• pp.170-173
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• 2004

To determine optimal plant density of forage rye in southern areas of Korea, forage rye cv. Paldanghomil, the highest yielding variety among experimental varieties of forage rye, was grown under five different plant density. Yield components such as plant height, and number of leaves were highest at the broad casting. Plants sown at broadcasting also showed highest fresh and dry matter yield. When plants were grown of the broad casting, they showed higher values in content of crude protein and lower values in contents of crude fiber such as neutral detergent fiber(NDF), acid detergent fiber(ADF), cellulose and lignin. There was no relationship between variation of in vitro dry matter digestibility(IVDMD) and plant density. Plants sown at the broad casting showed highest digestible dry matter yields.

• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.228-234
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• 2010

This paper presents the joint characteristic function of the first- and second-order polarization-modedispersion (PMD) vectors in installed optical fibers that are almost linearly birefringent. The joint characteristic function is a Fourier transform of the joint probability density function of these PMD vectors. We regard the random fiber birefringence components as white Gaussian processes and use a Fokker-Planck method. In the limit of a large transmission distance, our joint characteristic function agrees with the previous joint characteristic function obtained for highly birefringent fibers. However, their differences can be noticeable for practical transmission distances.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.125-129
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• 1990

One method for time-division multiplexing (TDM) of Michelson type fiber-optic interferometric sensor arrays is proposed and demonstrated experimentally. This method has some advantages; fewer fiber-optic components. low cost. and high reliability.bility.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.4
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• pp.1216-1224
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• 1996

In the use of glass fiber reinforced plastics it is often necessary to cutting the components, but the cutting GFRP is often made difficult by the delamination of composites and the short tool life. In this paper, the machinability of GFRP by mean of tool materials and type was experimentally investigated. By proper selection of cutting tool material and type excellent machining of this workpiece is achieved. The surface quality relate closely with the feed rate and cutting tools.