• Journal of Korean Society for Quality Management
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• v.32 no.4
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• pp.265-273
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• 2004

We got the growth distance curve by spline smoothing method with observed marketing data and the growth velocity curve by the derivation of the growth distance curve. Using this growth velocity curve, we defined the several characteristic points which describe the variation of marketing data. In this paper, to specify several patterns of marketing data, we suggested characteristic function by using these characteristic points. In addition, we applied characteristic function to the seventeen brands of electric home products data.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.261-266
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• 2003

The growth behavior of the transverse crack, which was one of the most dangerous damages of rail defects, was investigated under mode I and mixed mode loading in rail steel. In the case of variable amplitude loading, the fatigue crack growth behavior was discussed using characteristic stress intensity factor ranges ${\Delta}_{rms}$. In addition, characteristic comparative stress intensity factor ranges ${\Delta}_{V,rms}$ was proposed to evaluate the quantitative effects of the variable amplitude under mixed mode loading. As a result, crack growth rate under variable amplitude loading was faster than that under constant amplitude loading.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.797-804
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• 2001

To obtain representative fatigue crack growth characteristic curve in residual stress field, fatigue crack growth test was carried out at various stress ratio and fatigue crack growth characteristic curve was represented using crack closure concept. Obtained results are as follows;K(sub)op/K(sub)max was independent of K(sub)max when R was lower than 0.5 and crack closure phenomenon was not observed when R is higher than 0.5. therefore neglecting crack closure behaviour, actual fatigue crack growth rate can be underestimated. Thus, considering crack closure phenomenon, fatigue crack growth characteristics curve of A 106 Gr B Steel weldment can be effectively estimated.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1040-1043
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• 2004

As time goes by, the market demand increases and each LCD panel manufacturing company makes every effort to produce more panels in a limited time. It is necessary to reduce the cost and time of production for the improvement of productivity in manufacturing companies. The increased speed of thin films growth used in the TFT process brings improvement of productivity but it is also accompanied by a drop in display quality due to a characteristic change of the thin film. So in our dissertation, we deal with the increased speed of a-Si layer growth and the proportioned a drop in characteristic quality. We discuss a drop in display quality by a characteristic change of a-Si layer and we propose a counter-plan through panel design improvement. We have already applied our plan to the 15" XGA panel and confirmed the improved result.

• International journal of steel structures
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• v.18 no.4
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• pp.1098-1106
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• 2018

The object of this study is to clarify fatigue limit and fatigue crack growth characteristic of SBHS700 base metal which is 780 MPa class steel. This study carried out the fatigue tests of SBHS700 base metal containing different defect size, and the fatigue limit was compared with that of the conventional steel. Test results indicate that the fatigue limit increased with decrease initial defect size, and can be precisely evaluated by using ${\sqrt{area}}$ parameter model. This paper also presents that crack growth characteristic was almost the same as that of the conventional steel from the observation of striations by using Scanning electron microscope and length of beach marks.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.88-94
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• 2013

As the results of analysis that are applying a heat pump using underground water as heat source of facility horticulture house, temperature change in house, growth of cultivated plants and the crop characteristic, the conclusion can be acquired as follows. It was possible to maintain the chamber temperature through operating heat pump with setting goal temperature at $16^{\circ}C$ and temperature variation at ${\pm}3^{\circ}C$. And cooling and heating coefficient of performance in heat pump system are different from setting room temperature and operation condition of equipment, totally in case that the setting temperature in house is low, the coefficient of performance and the in case that temperature departure is low. In case that the house does not heated, the result of the growth characteristic of cucumber planted last 50days is that cucumber grown in house equipped with heat pump is the most favorable growth characteristic due to maintaining a constant room temperature. After 90 days, the quantity and weight cucumber harvested in each house are averagely 9.8%, 13.1% increase and more heavy weight respectively. So it is researched that crop characteristic is superior.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.54-64
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• 1995

The effects of swirl on early flame development and late combustion characteristic were investigated using a high speed single-shot visualized 51 engine. LDV measurements were performed to get better understanding of the flow field in this combustion chamber. Spark plugs were located at half radius (R/2) and central location of bore. High speed schlieren photographs at 20,000 frames/sec were taken to visualize the detailed formation and development of the flame kernel with cylinder pressure measurements. This study showed that high swirl gave favorable effects on combustion-related performances in terms of the maximum cylinder pressure and flame growth rate regardless of spark position. However, at R/2 ignition the low swirl shown desirable effects at low engine speed gave worse performances as engine speed increased than without swirl. There were distinct signs of slow-down in flame growth during the period when the flame front expanded from 2.5mm in radius until it reached 5.0mm apparently due to the presence of ground electrode. There seemed to be heat transfer effect on the flame expansion speed which was evidenced in high swirl case by the slowdown of the late flame front presumably caused by relatively large heat loss from burned gas to wall compared with low- or no-swirl cases.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.407-412
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• 2012

This study investigated the process of thermal-induced growth of micro-crack developed at the crystalline solar cell using EL image, determined the output characteristic according to the pattern of micro-crack, analyzed the I-V characteristic according to the pattern of crack growth, and predicted the output value using simulation. The purpose of this study was, therefore, to investigate the process of thermal-induced growth of micro-crack developed at the early stage of PV module completion using EL image, to analyze the resulting decrement of output and predict the output value using simulation. It was observed that the crack grew increasingly by the thermal condition, and accordingly the lowering of output was accelerated. The output values of crack patterns with various direction were predicted using simulation, resulting in close I-V curve with only around 4% of error rate. It is considered that it is possible to predict the electric characteristic of solar cell module using only pattern of micro-crack occurred at solar cell based on our results.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.51-55
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• 2003

The interrelation into nucleation and thermodynamic parameters of solutions has been established by plotting of various dependencies: the enthalpy of dissolution, solubility product and super-solubility on ionic salt radii and also the extent of deviation from an ideal Debye -Huckel model of electrolyte solution on solubility product. The possible methods of perfect crystal growth from aqueous solution have been found a priori by separating of known set of pair values of solubility and super-solubility into no less than six-nine characteristic and distinctive sub-sets.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.217-221
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• 2007

To provide the basic data essential for developing varieties of broad-leaved tree, the study investigated the utmost growth requirement for the growth characteristic and biomass production in accordance with planting density of Styrax obassia. The planting density of seedling can be a significant factor in contributing growth of seedling for tree growing in general. While growth of tree according to $1m^2$ planting density of Styrax obassia showed an excellent growth in tree height and the root collar diameter from $49no./m^2$, those low planting density showed decreased tendency with tree height growth while increasing the root collar diameter growth. As similar to the growth characteristic, the biomass production showed significant and statistic difference in $49no./m^2$, showing high volume of biomass production which is $3.12{\pm}0.80g$ compare to other processing section and high figure with T/R ratio which is 1.59. The special trait of photosynthetic also showed relatively high photosynthetic rate in $49no./m^2\;and\;64no./m^2$ of Styrax obassia and as the density increase, photosynthetic efficiency decreased. The plant showed stable and physiological planting pattern, displaying the best photosynthetic rate, which was the final metabolism through reserving proper space in the growth and development environment condition. This obstacle of required space essential for growth substantially deteriorated planting and ultimately, it demonstrated lower tendency of photosynthetic rate, which is the highest level of metabolism.