• Journal of Korean Society for Quality Management
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• v.33 no.1
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• pp.32-41
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• 2005

This paper presents a six sigma application case study for an automobile steering wheel manufacturing process using rolled throughput yield improvement activity. Hidden factory and first pass yield concept is introduced and a DMAIC procedure is implemented to maximize the first pass yield. The result of the six sigma project amounts to the reduction of failure cost of 1.2 billion won per year in the steering wheel manufacturing process. This paper can benefit six sigma practitioners in some ways.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.139-144
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• 1998

In Semi-Solid Forging, it is necessary to control the forming variables accurately in order to make near-net-shape products. Generally, the defects of products may occur due to liquid segregation which can be caused by the degree of deformation and strain rate, and condition of friction in Semi-Solid Forging, where the segregation is to be predicted by flow analysis. This paper presents the feasibility of theoretical analysis model using the new yield function for compressible P/M materials which is proposed by Doraivelu et at. to the flow analysis of the semi-solid dendritic Sn-15％Pb alloys instead of adopting the yield criterion of Shima and Oyane which is used by Charreyron and Flemings. The simple compression process is taken into consideration as the model to confirm the usefulness of the adopted yield function. The distribution of the liquid fraction at various strains and strain rates in radial direction, and the influence of friction are estimated by upper-bound method.

• Journal of Biosystems Engineering
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• v.30 no.6 s.113
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• pp.360-365
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• 2005

Precision agriculture attempts to improve cropping efficiency by variable application of crop treatments such as fertilizers and pesticides, within field on a point-by-point basis. Therefore, a more complete understanding of the relationships between yield and soil properties is of critical importance in precision agriculture. In this study, the functional relationships between measured soil properties and rice yield were investigated. A supervised back-propagation neural network model was employed to relate soil chemical properties and rice yields on a point-by point basis, within individual site-years. As a results, a positive correlation was found between practical yields and predicted yields in 1999, 2000, 2001, and 2002 are 0.916, 0.879, 0.800 and 0.789, respectively. The results showed that significant overfitting for yields with only the soil chemical properties occurred so that more of environmental factors, such as climatological data, variety, cultivation method etc., would be required to predict the yield more accurately.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.534-538
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• 2006

The effects of Rhizobium inoculant, compost, and nitrogen on nodulation, growth, dry matter production, yield attributes, and yield of pea (Pisum sativum) var, IPSA Motorshuti-3 were assessed by a field experiment. Among the treatments Rhizobium inoculant alone performed best in recording number and dry weight of nodules/plant. The highest green seed yield of 8.38 ton/ha (36.9% increase over control) and mature seed yield of 2.97 ton/ha (73.7% increase over control) were obtained by the application of 90 kg N/ha. The effects of 60 kg N/ha, Rhizobium inoculant alone and Rhizobium inoculant along with 5 ton compost/ha were same as the effect of 90 kg N/ha in recording plant height, root length, dry weight of shoot, and root both at preflowering and pod filling stages, number of mature pods/plant, number of mature seeds/pod, 1000-seed weight, green, and mature seed yields of pea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.112-116
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• 1993

The experiment was carried out to investigate the influence of rhizome size and mulching materials on some agronomic characters and flower-head yield of Gingiber mioga ROSCOE. The larger the size of rhizome was, the more the number of leaves developed, and the higher the yield was. The most suitable rhizome size for planting was found to be from I2cm to 15cm. Rice straw and polyethylene film mulching materials increased the soil porosity and reduced change of the soil moisture content. The yield of flower-head was highest in the straw-mulching plot, indicating that straw would be the best mulching material for growth and yield of flower-head in Gingiber mioga ROSCE.

• Journal of Magnetics
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• v.16 no.4
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• pp.427-430
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• 2011

The rolled steels for welded structure applied tensile stress have been examined by means of magnetic Barkhausen noise (MBN) method and of a physical parameter obtained from a hysteresis loop. The behaviors of MBN parameters and coercive force with tensile stress were discussed in relation to microstructure changes. There is no change in MBN parameters and coercive force below yield strength. The coercive force rises rapidly with tensile stress above yield strength. On the other hand, the rms voltage and the peak in averaged rms voltage take a maximum around yield strength and then decreases. The magnetomotive force at peak in the averaged rms voltage shows a minimum around yield strength. These phenomena are attributed to the combined effects of cell texture and dislocation density. In addition, the behaviors of MBN parameters around yield strength may be reflected by the localized changes in strain field due to the formation of dislocation tangles.

• Mycobiology
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• v.41 no.1
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• pp.42-46
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• 2013

The effects of the composition of a mixture containing food waste compost (FWC), rice bran (RB), and oak sawdust (SD) on the antler-type fruiting body (FB) yield of Ganoderma lucidum were studied. Experiments were performed using 0 (control), 5, 10, 15, 20, 25, 30, 35, and 40% (w/w) FWC added to a basal growth medium consisting of 20% (w/w) RB and 80% (w/w) SD. The content of 15% FWC gave the highest FB yield ($27.0{\pm}1.3$ g/bottle), which was 44% higher than the yield ($18.6{\pm}2.8$ g/bottle) of the control treatment. However, FWC contents of 20~40% showed reduced yield (2.4~23.0 g/bottle), partly because FWC had a high Na concentration (0.6%). These results demonstrate the potential for use of FWC as a component of a growth medium for production of G. lucidum FBs.

• Korean Journal of Plant Resources
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• v.19 no.6
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• pp.697-699
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• 2006

To find out the best complex fertilizer for high yielding of rapeseed crop, experiment was conducted on complex fertilizers at the experiment field in upland of rapeseed in Mokpo Experiment Station, Nat'l Institute of Corp Science, RDA, Korea. Experiment was laid out in randomized complete block (RCBD) design. The effects of complex fertilizer (22-22-11) on the number of branches, pod length, percentage of seed set and seed yield were highest but on the plant height, ear length, and number of pods per ear were negligible. On th basis of the results reported above, for getting higher yield of rapeseed crop, among the tested fertilizers complex fertilizer (22-22-11) gave the superior performance and is recommended for application.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.05a
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• pp.34-37
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• 2000

To determine the optimum planting density in Alisma plantago in the southern areas of Korea, Alisma plantago local cultivar was grown under different planting density. The plant height, number of stems and diameter of root were 30cm, 12 and 3.4mm respectively on the planting density, row 20cm $\times$ intrarow 35cm. The fresh yield of root and dry yield of root were 261.2Kg110a, 211.5Kg/10a respectively on the planting density, row 20cm x intrarow 35cm. Therefore, the proper planting density for high yield bumper crop of Alisma plantago for exporting to Japan is planting density with row 20cm $\times$ intrarow 35cm.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.5
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• pp.319-329
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• 2016

The Eradi Quake System (EQS) is a seismic isolation bearing system designed to minimize forces and displacements experienced by structures subjected to ground motion. The EQS dissipates seismic energy through friction of Poly Tetra Fluoro Ethylene (PTFE) disk pad. In general, a force-displacement relationship of EQS has post yield stiffness hardening during large inelastic displacement. In this study, seismic responses of seismically isolated nuclear power plant (NPP) subjected to design basis earthquake (DBE) and beyond design basis earthquakes (150% DBE and 167% DBE) are compared considering the post yield stiffness hardening effect of EQS. From the results, it can be observed that if the post-yield stiffness hardening effect of EQS is increased, the displacement response of EQS is reduced, and the acceleration and shear responses of containment structures of NPP is increased.