• Journal of Biosystems Engineering
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• v.42 no.4
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• pp.242-250
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• 2017

Purpose: This study was conducted to determine the appropriate operating conditions through a factorial experiment for the secondary separating part of the self-propelled pepper harvester. Methods: An experimental setup that simulates the secondary separating part of the self-propelled pepper harvester was organized. Test samples were classified into three types according to the number of peppers on a stem, and 12 sets were prepared for each type. Among the operating conditions of the secondary separating part, the rotational speed of drum B (four levels), radial clearance between drums and cylindrical teeth (three levels), and speed ratio between the three drums (two levels) were set as the test factors, and tests were repeated three times for different levels of each factor. The appropriate operating conditions were determined by analyzing the separation ratio and damage ratio of the peppers collected through the secondary separating part. Results: The test factors changed the overall separation ratio and overall damage ratio in similar trends. In other words, the conditions that caused high overall separation ratios also exhibited high overall damage ratios. Owing to the high overall damage ratio in the condition with the highest overall separation ratio, the operating conditions should be selected considering both ratios. Conclusions: When the condition with more than 60% of overall separation ratio and less than 15% of overall damage ratio was considered as the appropriate operating condition, 70 rpm of the rotational speed of drum B, 5 mm of the radial clearance between drums and cylindrical teeth, and 7:3:5 for the speed ratio of the three drums A, B, and C should be applied for the secondary separating part used in this study. Supplementary studies will be required in the future to find optimal operating conditions through the actual field test under further divided test factors.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.443-453
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• 2012

This study examines visual perception and spatial satisfaction according to lighting conditions. Field measurements and surveys were performed in three rest space of university buildings where various lighting conditions were employed. Results indicate that overall impression of space improved when low color temperature, such as 3,000 K governed overall lighting environment and accent lighting was used for wall surfaces. Lighting conditions that kept uniform illuminance levels using area light sources containing fluorescent lamps with 6,500 K failed to keep favorable spatial satisfaction for space. High color temperature was not recommended for lighting in rest space. Asymmetrical illuminance levels formed by low color temperature such as 3000 K is recommended to keep positive mood and improve spatial satisfaction in rest space. Overall impression of the space was influenced by visual comfort, color temperature, spatial satisfaction and brightness. Spatial satisfaction for space was effectively impacted by psychological comfort, color temperature and overall impression for lighting conditions. Psychological comfort in space was influenced by color temperature, spatial satisfaction and visual annoyance from reflected light.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.72-77
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• 1997

In the temperature analysis of hot metal forming process, the heat transfer conditions between the work-piece and the tool have improtant influences upon the temperature distribution. The accuracy of thermal analysis depends on the proper description of boundary conditions including heat transfer. At the contact surface of two materials with different temperatures, this requires the knowledge of the overall heat transfer coefficient. In order to determine the overall heat transfer coefficient, a technique is developed. The technique involves temperature measurement by using thermocouples during hot upsetting operations and finite element computation. The overall heat transfer coefficient is determined using a non-linear optimization technique.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.914-919
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• 1998

This work was designed to determine the optimum extraction conditions for imporving the quality of Eucommia ulmoidesl leaf-tea. Soluble solid content was 27.7% in the tea extracted at 99.3$^{\circ}C$(extraction temperature) and 67.8 min(extraction time) which were maximum points by the ridge analysis. The extraction conditions for the maximum organoleptic scores were 72.9$^{\circ}C$ and 59.6 min in color, 80.$0^{\circ}C$ and 90.0 min in aroma, 77.8$^{\circ}C$ and 55.5 min in aftertaste, and 77.9$^{\circ}C$ and 53.1 min in overall palatability. The extraction conditions for the minimum organoleptic scores were 77.8$^{\circ}C$ and 52.7 min in astringent taste, and 75.1$^{\circ}C$ and 49.4 min in Chinese medicine taste. The optimum ranges of the conditions based on soluble solid content and overall palatability of the tea wre 75~83$^{\circ}C$ and 55~65 min. The soluble solid content and overall palatability predicted at ooptimum condition(78$^{\circ}C$ and 60 min) werw similar to experimental values.

• International Journal of Air-Conditioning and Refrigeration
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• v.13 no.3
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• pp.152-157
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• 2005

This paper reviews the literature on the performance of fin-and-tube heat exchangers under frosting and defrosting conditions. The effects of frosting and defrosting on the following parameters were discussed: frost growth, overall heat transfer coefficient, surface roughness, and surface characteristics on the heat exchanger. Comparisons of the experimental results and empirical correlations that were obtained from open literature were presented. In addition, a review of the defrosting methods was conducted.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1727-1733
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• 2015

In the present study, the heat transfer performance of dimpled double-pipe heat exchangers for fuel cells that are utilized as cooling systems of fuel cells was studied. In addition, to comparatively analyze the heat transfer performance of dimpled double-pipe heat exchanger for fuel cells, plain double-pipe heat exchangers were also studied. Experimental results were derived on changes in the Reynolds numbers of the cooling water flowing in dimpled and plain double-pipe heat exchangers and changes in the heat flux of the air. Thereafter, to verify the reliability of the experimental results, the theoretical overall heat transfer coefficients and the experimental overall heat transfer coefficients were comparatively analyzed and the following results were derived. The heat transfer rate lost by the hot air and that of the heat transfer rate obtained by the cooling water were well balanced. The experiments of plain double-pipe heat exchangers and dimpled double-pipe heat exchangers were conducted under normal conditions and the theoretical overall heat transfer coefficient and the experimental overall heat transfer coefficient coincided well with each other. In both plain double-pipe heat exchangers and dimpled double-pipe heat exchangers, heat transfer rates increased as the cooling water flow velocity increased. Under the same experimental conditions, the heat transfer performance of dimpled double-pipe heat exchangers was shown to be higher by 1.2 times than that of plain double-pipe heat exchangers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.834-841
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• 2020

Laver Pyropia sp. is the most exported seafood in Korea and is one of the most consumed edible seaweeds. The export of laver has been centered on seasoned laver products; of note, laver snack products coupled with rice papers or glutinous rice paste are becoming more popular in Western countries. These laver snacks are manufactured using a deep frying process. Therefore, the frying conditions affect the physicochemical and sensory characteristics of fried laver snacks. In this study, we optimized the deep-frying conditions for laver snacks with gelatinized rice dough using a response surface methodology. The frying temperature (X1, 190-220℃) and frying time (X2, 10-30 sec) were selected as independent variables; the dependent variables were the overall acceptance (Y1, points), hardness (Y2, N), and oil content (Y3, %). The optimal values of the frying temperature (X1) and time (X2) as per the overall acceptance (Y1) were 208℃ and 23.1 sec, respectively. The predicted overall acceptance (Y1=8.0 points), hardness (Y2=98.74N), and oil content (Y3=27.69%), were similar to the experimental values under the optimal conditions. Overall, the acceptance was inversely proportional to hardness; the decrease in hardness caused an increase in the crispiness of the laver snacks.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.192-198
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• 2004

A numerical study was conducted to determine the effects of high temperature air, including equivalent ratio on flow field, temperature, evaporation, and overall temperature distribution in gas turbine combustor. A sector model of a typical wall jet can combustor, featuring introduction of primary air and dilution air via wall jet, was used in calculations. Flow field and temperature distribution were analyzed. Operating conditions such as inlet temperature and overall equivalent ratio were varied from 373 to 1300 K, and from 0.3 to 0.6, respectively, while any other operating conditions were fixed. The RNG ${\kappa}-{\varepsilon}$ model and eddy breakup model were used for turbulence and combustion model respectively. It was found that the increase with the inlet air temperature, velocity in the combustor is accelerated and evaporation of liquid fuel is not affected in primary zone, high temperature inlet air enhances the evaporation and improves overall temperature distribution factor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.783-786
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• 1996

In the temperature analysis, the heat transfer between the workpiece and the die has an important influence upon the temperature distribution. The accuracy of thermal analysis depends on the proper description of boundafy conditions. A t the contact surface of two materials with different temperature, this requires the knowledge of overall heat transfer coefficients. In order to evaluate the overall heat transfer coefficients, a technique is developed. This technique involves temperature measurement at the contact surface during hot upsetting operations and finite element computation to calcualte the overall heat transfer coefficient.

• Journal of Family Resource Management and Policy Review
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• v.4 no.2
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• pp.31-44
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• 2000

In this study, we compare and analysis the family rite consciousness and it’s actual conditions between yanbian university students who have lived in different culture and political system from Korean students. Total 645 Yanbian and Korean student’s data was collected in Jun 1998. Statistics methods, Cronbach’α, Frequency, Percentage, $x^2$, t-test are used to analyse the data. The result are follows. First, in view of overall rite conditions, Korean students show more traditional tendency than Yanbian students. Second, in view of ritual process which is sub-domain of overall ritual consciousness Yanbian student keep more traditional attitude than Korean students. Third, Koran students’s score which presents the need of education of rite is higher than that of Yanbian students’s