• Journal of the Korean Society for Heat Treatment
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• v.30 no.4
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• pp.156-163
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• 2017

In the present study, we investigated the optimal austenitizing temperature of high-alloyed tool steels from an industrial point of view. Austenitizing temperatures for manufacturing 25 commercial tool steels were surveyed with their alloy compositions. The relationship between the austenitizing temperatures and the critical equilibrium temperatures by thermodynamic-based calculation was analyzed and a correlation was found. Based on the austenitizing temperatures of 25 commercial tool steels and the thermodynamic calculation results, we proposed a simple equation to predict an optimal austenitizing temperature to achieve superior mechanical properties of high-alloyed tool steels. The applicability of the proposed equation was experimentally validated with a new developed tool steel.

• Korean Journal of Veterinary Research
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• v.32 no.3
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• pp.421-427
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• 1992

The study was basically carried out to establish the appropriate condition for applying the Westergren method for erythrocyte sedimentation rate(W-ESR) in Throughbred racehorses at recess. To do this, we examined the correlationship among some factors including the kind of anticoagulants, optimal ambient temperature and reading time for W-ESR in healthy racehorses. The difference between the blood samples treated with only 3.8% solution of sodium citrate(SC) and both EDTA and SC as a coagulant, there was not recognized any significant difference(p<0.05) in the levels of W-ESR irrespective of the ambient temperature of $20^{\circ}C$ or $30^{\circ}C$. The best optimal ambient temperature for W-ESR in horses was proved at $30^{\circ}C$ resulting from the tendency of the most reduced dispersion in mean values analyaed from repeatly 4 times to the same blood samles compared with those of $10^{\circ}C$ and $20^{\circ}C$. The optimal reading time was determined as 60 minutes(Y=237.2~4.1X, $r^2=0.998$) and 70 minutes(Y=247.8~4.2X, $r^2=0.999$) under the same temperature of $30^{\circ}C$; the latter showed the better result on the basis of the correlation of packed cell volume(PCV) and ESR values. About 13 healthy racehorses, we compared the real values of W-ESR respectively obtained at 60 minutes and 70 minutes at $30^{\circ}C$ with the anticipated values of PCV by means of the analysis of linear regression equitation. As the result of this, the strong correlation between both of them was confirmed. For practical use of W-ESR in Thoroughbred racehorese, we can recommend the condition of 60 or 70 minutes for the optimal reading time as well as $30^{\circ}C$ for the best ambient temperature.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.14-20
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• 2015

It is important to understand psychological and physiological responses of occupants who seated in a chair in order to shape a comfortable indoor official environment. So it is needed to find out optimal seated conditions. The purpose of this study was to explore optimal condition of seat air conditioning control based on psychological or subjective responses (perceived temperature and comfort sensation) and physiological responses (heartrate variability; HRV). To do this, experimental conditions were designed by the difference of indoor temperature and seat air conditioning temperature. In the experiment 1, seven experimental conditions were designed with one control condition which was not used seat air conditioning system, and six experimental conditions which the difference of indoor temperature and seat air conditioning temperature ($-1^{\circ}C{\sim}-6^{\circ}C$). In the experiment 2, four experimental conditions were designed with one control condition and three experimental conditions ($-3^{\circ}C{\sim}-5^{\circ}C$). In addition, participants' psychological or subjective response was measured by CSV (comfort sensation vote) and PTS (perceived temperature sensitivity) as a psychological or subjective response, and heartrate variability was measured as a physiological response. As a result, in the experiment 1, it was reported that the optimal conditions of seat air conditioning control based on participants' psychological or subjective comfort were from $-3^{\circ}C$ to $-5^{\circ}C$ experimental conditions. In addition, in the experiment 2, it was reported that the optimal condition of seat air conditioning control based on participants' physiological comfort was $-4^{\circ}C$ experimental condition. These results suggested that seat air conditioning could affected to comfort sensation of occupants in an appropriate range, rather than unconditionally.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.144-149
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• 2013

This work deals with the optimal design of a coreless PMLSM (Permanent Magnet Linear Synchronous Motor) with consideration of rising winding temperature. The temperature distribution caused by copper loss in the coreless PMLSM was analyzed using a FEM (Finite Element Method). The thrust and current density where the winding temperature reaches the allowable temperature were calculated. The optimal model provides maximum thrust per unit weight.

• Journal of Ginseng Research
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• v.9 no.2
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• pp.248-255
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• 1985

In order to investigate the optimal drying condition of white ginseng by using bulk air drier(130 x 62 x 65cm), drying curves, diffusion coefficient at various drying temperature, the energy of activation, variation of color intensity and chemical components during drying of white ginseng were studied. Fick's second low of diffusion for diffusion out of spheres was successfully applied to describe the drying of white ginseng. It was found that the diffusion coefficient of water was 2.2x107, 9.0x107 cm2/sec at drying temperature 4$0^{\circ}C$, 55$^{\circ}C$, respectively. An Arrhenius type temperature dependency of moisture diffusivity was found, the energy of activation being 18.8 Kcal/g mol. Color intensity of white ginseng dried at various drying temperature was increased with an increase in drying temperature. The contents of crude protein, reducing sugar and crude saponin during drying of white ginseng were gradually decreased as increasing of drying time. And with the sensory evaluation by multiple comparison difference analysis, the optimal drying temperature of white ginseng was between 45$^{\circ}C$ and 5$0^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.61-69
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• 2024

Considering the threats of climate change, this study was conducted to investigate the influence of temperature and day-length on soybean growth and yield when sown late in comparison to the optimal sowing time in the southern region of the Korean Peninsula. Sowing was executed in 10-day intervals, including on July 1, 10, 20 and 30 and August 10, considering that the optimum sowing time of the three soybean varieties with different ecotypes is June 20. Emergence rates did not differ significantly between late-sowing and optimal sowing in all ecotypes; however, the number of days to emergence, flowering, and maturity was smaller after late sowing. A multiple-regression approach was used to test the effect of temperature and day length on the number of growing days after late sowing compared to the optimal sowing time. This analysis revealed that the number of days required from sowing to flowering was positively correlated with both day length and temperature, and the number of days from flowering to harvest was positively correlated with day length and negatively with temperature. A multiple regression equation can be calculated as follows: the number of days required from sowing to flowering (Y) = 3.177 + (0.030 × (sum of day length + sum of temperature)), and the number of days required from flowering to maturity (Y) = 20.945 + (0.021 × (sum of day length + sum of temperature)). Multiple growth parameters were significantly correlated with yield components, depending on growing days. Optimal sowing resulted in the best yield, while later sowing decreased yield compared to optimal sowing. To avoid a significant decrease in yield, early-maturing species should be sown by July 20, while late-maturing species should be sown by July 10.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.6
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• pp.441-446
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• 2000

This paper presents an approach for the prediction of optimal heating load using a diagonal recurrent neural networks(DRNN) and data base system of outdoor temperature. In the DRNN, a dynamic backpropagation(DBP) with delta-bar-delta teaming method is used to train an optimal heating load identifier. And the data base system is utilized for outdoor temperature prediction. Compared to other kinds of methods, the proposed method gives better prediction performance of heating load. Also a hardware for the controller is developed using a microprocessor. The experimental results show that prediction enhancement for heating load can be achieved with the proposed method regardless of the its inherent nonlinearity and large time constant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.1023-1026
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• 2007

Optimal damping layout of the constrained viscoelastic damping layer on beam is identified with temperatures by using a gradient-based numerical search algorithm. An optimal design problem is defined in order to determine the constrained damping layer configuration. A finite element formulation is introduced to model the constrained damping layer beam. The four-parameter fractional derivative model and the Arrhenius shift factor are used to describe dynamic characteristics of viscoelastic material with respect to frequency and temperature. Frequency-dependent complex-valued eigenvalue problems are solved by using a simple resubstitution algorithm in order to obtain the loss factor of each mode and responses of the structure. The results of the numerical example show that the proposed method can reduce frequency responses of beam at peaks only by reconfiguring the layout of constrained damping layer within a limited weight constraint.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.627-634
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• 2012

Squid Sikhae is traditional salt-fermented food in Korea. We evaluated the standardization of optimal processing conditions for desirable quality-controlled squid Sikhae using analyses of physiochemical properties, microbiological species, and organoleptic tests. Among several squid Sikhae preparation processes, the optimal fermentation temperature sun-dried sea salt concentration, and fermentation period for squid Sikhae of acceptable quality were $10^{\circ}C$, 4%, and 6 days, respectively. Amino-N and volatile basic nitrogen (VBN) contents of the acceptable quality squid Sikhae were 162.51 mg/100 g and 15.25 mg/100 g, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.1
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• pp.185-192
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• 1997

We propose a method of paramete estimation using order-of-magnitude analysis for optimal boundary smoothing in Mean Field Annealing(MFA) technique in this paper. We previously proposed two boundary smoothing methods for consistent object representation in the previous paper, one is using a constratined regulaization(CR) method and the other is using a MFA method. The CR method causes unnecessary smoothing effects at corners. On the other hand, the MFA method method smooths our the noise without losing sharpness of corners. The MFA algorithm is influenced by several parameters such as standard deviation of the noise, the relativemagnitude of prior ter, initial temperature and final temperature. We propose a general parameter esimation method for optimal boundary smoothing using order-of-magnitude analysis to be used for consistent object representation in this paper. In addition, we prove the effectiveness of our parameter estimation and also show the temperature parameter sensitivities of the algorithm.