• Journal of Electrical Engineering and Technology
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• v.4 no.3
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• pp.401-404
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• 2009

A simple analytical expression for a current gain of IGBT is derived in terms of the device parameters as well as a gate length dependent parameter, which allows for the determination of the current components of the device as a function of its gate length. The analytical results are compared with those from simulation results. A good agreement is found.

• Journal of the Korean Professional Engineers Association
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• v.34 no.2
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• pp.31-36
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• 2001

The Otto Cycle of conventional gasoline engine has no difference between compression ratio and expension ratio. because of the same length of 4 strokes : Intake, compression, expension, exhaust. On the other hand, miller cycle engine achieves both low-compression ratio and high-compression ratio by shortening the length of compression stroke among 4 strokes. Therefore miller cycle engine is essential for lessening knocking and improving heat efficiency. This paper Is designed to discribe not only principle and the development trend of miller cycle engine but also the control system and the technical characteristics of it.

• Journal of Ginseng Research
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• v.18 no.2
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• pp.134-136
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• 1994

The effects of soil phosphorus level on seed emergence, seedling mortality, plant and root development of American ginseng (Panax quinquefolium L.) were evaluated in a newly planted commercial ginseng garden. Phosphorus levels were increased from 58 ppm to 100, 150 and 200 ppm with triplephosphate (0-45-0). Higher phosphate levels increased, seed emergence and reduced seedling mortality. Root length, diameter, fresh root weight and total leaflet length were not affected by phosphate levels.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.175.3-175
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• 2001

A control system for crop cutting in Hot strip Mill is developed. The development system is composed of three sub-systems. one is crop shape system which captures the shapes of the strip's head and tail using the area CCD camera. Another is Laser Speed System which measures the speed and length of strip. and, the other is control system which controls the optimal cutting length and crop shear motor. As a result, with a developed system we can reduce crop loss considerably.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.68-68
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• 2022

• Development and Reproduction
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• v.18 no.1
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• pp.13-23
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• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.116-120
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• 1991

Technique of length measurement error is widely used in the accuracy assessment of CMMS(Coordinate measuring machines) and machine tools, as it is simple and direct measurement within the working volume of a machine. In this paper, a new method is proposed for the evaluation of the length measurement error in relation to the volumetric accuracy. lD, 2D, and 3D measuring lines are considered for recpective length measurement error: 1D, 2D, and 3D length measurement uncertainties are evaluated from volumetric accuracy. The relationship between the volumetric accuracy md length measurement error to is discussed. PC based system for length measurement error evaluation and simulation is developed.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.171-174
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• 1995

Freshly harvested American ginseng (Panax quinquefolium L.) seeds were stratified at two locations over each of three years. Seed development and temperature in the stratification boxes were investigated until the seed was removed 12 months later and direct-seeded in the field. During stratification and seeding (14 months) three embryo stages were identified. In Stage I of 250 days (Sept. to mid-May) embryo length increased from about 0.5 to 1.0 mm: in Stage II of 100 days (mid-May to late Aug. when seeded) length increased to 2.0 mm and in Stage III (late Aug. to late Nov.) length increased to 5.3 mm. Excerpt split width could also be placed in three stages. Changes in embryo length correlated with embryo endosperm length ratio. Insertion compression tests showed that the excerpt softened rapidly in late Stage II and throughout Stage III. The stratification box temperatures at all depths (10, 25 and 50 cm) never exceeded -2$^{\circ}C$ even when the air temperatures dropped to -13$^{\circ}C$ and were, therefore not damaging to the seeds.

• Design & Manufacturing
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• v.15 no.3
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• pp.19-25
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• 2021

The bending process of a press die is to bend a flat blank to the required angle. There are V-bending, U-bending, Z-bending, O-bending etc. for bending processing, and the basic principle of calculating the unfolding length of die processing is used as the neutral plane length. Since the constant of the length value of the neutral surface is different depending on the type of bending, it is impossible to accurately calculate it. In particular, Z-bending processing is performed twice, and it is set on the upper and lower surfaces of the blank, and bending processing occurs at the same time as the upward and downward bending, and the elongation of the material occurs and the material increases. It is not possible to check with the calculated value, and it occurs in many cases where the mold is modified after start-up. This study aims to minimize die modification by developing a formula to calculate the development length of Z-bend.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.128-131
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• 2007

Head length, snout length, postorbital length, and eye diameter were measured in 209 brown croaker, Miichthys miiuy, ranging from 3.0 to 650.0 mm in total length (TL). All of the four head dimensions were regressed against the TL respectively and were increased linearly with the relative size of the head. The determination coefficients ($r^2$) ranged from 0.9823 to 0.9916, and all analysis of variance values were significant (P<0.0001). Those results suggest that these head dimensions may be useful indicators for detecting morphological deformities or for individual and population growth histories to aid in the successful rearing of brown croaker fingerlings.