• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.173-180
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• 2008

The influence of temperature and relative humidity in infection and cross-infection of Nosema bombycis and N. mylitta respectively in mulberry silkworm, Bombyx mori L. on larval mortality, multiplication of pathogens, larval weight and growth rate in three different seasons were studied. Seasons were selected in such condition, when very less fluctuations between minimum and maximum temperature and minimum and maximum relative humidity ($25{\sim}28^{\circ}C$ and $65{\sim}72%$ R.H) was observed i.e., season-1. Fluctuations between minimum and maximum temperature were less ($28.05{\sim}34.50^{\circ}C$) but R.H % was more ($55{\sim}81%$) in season-2. Fluctuations between minimum and maximum temperature and R.H % were more ($20.00{\sim}40.5^{\circ}C$ and $64.00{\sim}90.00%$) in season-3. Growth rate of microsporidian-infected silkworm is directly related to the prevailing temperature and relative humidity in silkworm. Silkworm can tolerate slight variation of temperature but slight variation of relative humidity disfavours the development of silkworm and favours the multiplication of pathogens.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3110-3114
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• 2009

Rotor temperature variation is a significant issue in the design of induction motor controls. In the literature, numerous studies have mentioned significant performance degradation due to rotor temperature variation unless it is taken into account. However, those studies have mainly focused on field-oriented control in terms of tracking performance. There was little research about the influence of rotor temperature variation on performance particularly in the case of optimal controls such as maximum torque per amp (MTPA) control strategy. This work investigates how to affect the performance of maximum torque per amp (MTPA) control strategy as rotor temperature varies in time. To this end, investigation was carried out in two ways to see whether the objective of MTPA control strategy is achieved regardless of rotor temperature variation. It is to produce a desired torque with the minimum possible stator current at the same time. Laboratory experiment shows that tracking performance and maximum torque per amp condition is significantly affected by rotor temperature variation as rotor temperature varies, thus ending up with performance degradation of MTPA control.

• Solar Energy
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• v.12 no.2
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• pp.1-8
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• 1992

Identifying characteristics of heating and cooling systems requires estimation of thermal load of specific time interval, especially in cases that its system is operated intermittently, by using thermal storage, of in a partial load condition. Estimating the thermal load, however, needs to forecast hourly weather data variation. Hence, this paper attempts to examine characteristics of hourly ourdoor temperature variation as a preliminary research for the mathematical modeling of the hourly weather variation. Speculating characteristics of daily minimum and maximum temperature occurances, hourly outdoor temperature variation, and daily temperature differences in the increasing range ($07h{\sim}15h$) and decreasing range($15h{\sim}07h$), we were able to analyze changing patterns of daily temperature differences in each range in terms of daily solar amount, cloud ratio, and other weather data. Results from the multiple regression analysis enables us to conclude that daily differences in the increasing range are strongly affected last night temperature itself while the other range's differences are influenced by many weather data, which are solar amount, the variation of cloud, and the maximum temperature of the previous day.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.51-53
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• 2005

This study was to measure the minuteness structure, dielectric properties of 0.03PCW-0.07PNN-0.9PZT ceramics according to sintering temperature manufacture the specimens with a general method. The results of this study were gotten such as follows. The crystal structure of ceramic changed the rombohedral structure into teteragonal structure according to rising sintering temperature in XRD. Dielectric constant at $20^{\circ}C$ showed its maximum value 510.599 in specimens sintered at $1100^{\circ}C$ and dielectric loss showed its minimum value 7.43% in specimens sintered at $1100^{\circ}C$. The variation rate of dielectric constant according to the change of frequency showed its minimum value 0.029/kHz at $1100^{\circ}C$. The variation rate of dielectric constant according to the change of temperature showed its minimum value $1.40/^{\circ}C$ at $1500^{\circ}C$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.746-752
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• 2010

Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.109-110
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.27-28
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.361-362
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• 2010

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.805-811
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• 1995

Final biomass yields (peak optical density) and growth rates (divisions/day) of seven clones of Skeletonema costatum from Korean coastal waters were measured to understand their intraspecific variations in the light intensity niche component under $25^{\circ}C$ condition. Daily growth rates of 6 of 7 S. costatum, clones were maximum at 6000 lux while that of YS4, a neritic clone, was maximum at 9000 lux. The final biomass yields of 4 of the 7 S. costatum clones were maximum at the lowest light intensity of 2000 lux. Minimum final biomass yields were found at 9000 lux in all the S. costatum clones other than an estuarine clone, HDC9. The intraspecific variations of the mean growth rate and mean final biomass yield under each of the three different light intensity in terms of the coefficient of variation were not greater than 10% in any of the 7 S. costatum clones.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.1
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• pp.44-51
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• 2009

In order to determine air temperature difference by canopy layer in the forest, air temperatures were observed at Seolleung Park, Gahngnam-ku, Seoul. from November 9, 2007 to November 8, 2008 by 10 minute interval. The data were analyzed in terms of diurnal variation based on annual and monthly temperature difference. Using calm, less cloudy and no rainy weather data, average air temperature difference between forest and grass was observed as $0.8^{\circ}C$. The maximum air temperature difference was observed at 22:10, 23:20, 23:30 and 23:40 by $2.13^{\circ}C$ and the minimum one observed at 13:00 by $-0.84^{\circ}C$ in diurnal variation. The maximum temperature difference occurred at 19 : 50 on September by $3.67^{\circ}C$, Overall the air temperature in the forest was higher than that of grass at night and lower in midday.