• The Korean Journal of Malacology
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• v.25 no.2
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• pp.121-126
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• 2009

This study was performed to determine the effect of temperature condition on growth of juvenile abalone Haliotis discus hannai with the different feeds. Two types of feed (dry sea tangle and experimental diet) at water temperatures of 20 and $23^{\circ}C$, and 23 and $26^{\circ}C$ were applied to experimental abalone twice. Forty-five juvenile abalone averaging 10.1 g in the first feeding trial and 11.5 g in the second feeding trial were randomly stocked into 6 of 50 L plastic rectangular containers each. Fishmeal, soybean meal and shrimp head meal was used as the primary protein source in the experimental diet. And dextrin and wheat flour, and soybean oil were used as the primary carbohydrate and lipid sources in the experimental diet, respectively. The dry sea tangle and experimental diet were fed to abalone once a day at the ratio of 1.5-2.0% total biomass of abalone with a little leftover in each experimental condition. Weight gain of abalone was significantly affected by feed type, but not by water temperature in the first feeding trial. Regardless of water temperature, weight gain of abalone fed the experimental diet was significantly higher than that of abalone fed the dry sea tangle. However, weight gain of abalone was significantly affected by water temperature, but not by feed type in the second feeding trial. Weight gain was highest in abalone fed the experimental diet at $23^{\circ}C$, followed by abalone fed the dry sea tangle at $23^{\circ}C$, abalone fed the experimental diet and dry sea tangle at $26^{\circ}C$, which was lowest. Moisture and crude protein content of the edible portion of abalone was significantly affected by feed type, but not by water temperature in the second feeding trial. However, ash content of the edible portion of abalone was significantly affected by water temperature, but not by feed type. In considering these results, it can be concluded that the well formulated feed was superior to the dry sea tangle for growth of juvenile abalone, and water temperature conditions of 20 and $23^{\circ}C$ seemed to be better than $26^{\circ}C$ to improve weight gain of abalone.

• Journal of environmental and Sanitary engineering
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• v.15 no.3
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• pp.24-30
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• 2000

In this study, to determine the optimum fermentation process for the feed production of food wastes and estimate the practical value of fermented feed using kudzu creeper and sawdust as bulking agent. This study considered initial C/N ratio control as the fermentation process variables. The result are summarized as follows. Minimum water contents of byproducts in the fermentation feed production showed 39%(kudzu), 37%(sawdust) at the C/N ratio 25 and 45%(kudzu, sawdust) at the C/N ratio 35. Temperature variations in the fermentation feed production at the C/N ratio 25 indicated $68^{\circ}C$(kudzu), $70^{\circ}C$(sawdust). Optimum condition of fermentation process of water content, C/N ratio and permeability (porous structure of the mixture). For optimum fermentation gravitationally dewatered garbage, the proper mixing ratios of kudzu(moisture contents : 17.3%) and sawdust(moisture contents : 13.2%) were 41% and 39%, respectively. Major biological reaction in the aerobic fermentation feed production occurred during 12~24hrs.

• Journal of Internet Computing and Services
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• v.25 no.2
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• pp.49-55
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• 2024

This paper proposes PredFeed Net, a neural network model that mimics the food distribution of fish farming experts. Unlike existing food distribution automation systems, PredFeed Net predicts food distribution by learning the food distribution patterns of experts. This has the advantage of being able to learn using only existing environmental data and food distribution records from food distribution experts, without the need to experiment by changing food distribution variables according to the environment in an actual aquarium. After completing training, PredFeed Net predicts the next food ration based on the current environment or fish condition. Prediction of feed ration is a necessary element for automating feed ration, and feed ration automation contributes to the development of modern fish farming such as smart aquaculture and aquaponics systems.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.8
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• pp.27-33
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• 2004

The ultra-precision cutting is a key technique for the manufacture of optical components such as aluminium mirrors, electroless nickel mirror, plastic mirror in a variety of advanced science and technology applications. The paper presents experimental results of ultra-precision diamond fuming of electroless nickel materials. In general, the cutting condition such as feed rate and depth of rut, have effect on the surface roughness in ultra-precision diamond turning. To obtain an optimal cutting condition, we studied the effect of the cutting speed. the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness. So, the relationship of the surface roughness and cutting condition has been clarified. From the experimental results, the machined surface roughnesses were obtained less than 1nm rms.

• Journal of Environmental Health Sciences
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• v.27 no.3
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• pp.107-112
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• 2001

This work reports the application of a hollow fiber module(HFM) for Cr(VI) extraction from heavy metal salts mixed solution by using microporous hydrophobic hollow fiber module. In HFM configuration, the organic extraction used for the extraction of Cr(VI) was di-(2-ethyl hexyl) phosphoric acid(D2EHPA) diluted with n-heptane. The study of HFM includes the influence of hydrodynamic and chemical condition, i.e., the flow rate of feed solution, the time of reactive extraction, the concentration of feed solution, and the pH of aqueous phase solutions. Several experiments with synthetic solution of different mixed components system of Cr(VI) solutions established optimum condition to achieve a clean separation of Cr(VI). It was possible to separate Cr(VI) in the presence of metal salts mixed solution, such as Zn(II), Ni(II), Cu(II), and Cd(II) using the HFM technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.970-976
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• 1997

The ultra-precision machining is widely used for final machining process of precision parts, so in this study, mirror surface finishing systems using the micro abrasive film, one of ultra-precision machining method, have to examine mirror surface characteristics of the cylindrical workpiece(SM45) such as surface roughness, workpiece removal and evaluated under the condition varing film feed rate, applied pressure, grinding speed after fixing other condition. It was found that varrious machining condition have significant influences on workpiece removal, surface roughness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.553-556
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• 2003

End-milling have been used in the industrial world because it is very effective to the manufacture of mechanical parts with various shape. Recently the end-milling processing is needed the high-precise technique with good surface roughness and rapid time in aircraft, automobile part and molding industry. Therefore this study carried to decide the optimum cutting condition for surface roughness and rapid manufacturing time using design of experiment and ANOVA. From the results of experimentation, surface roughness have an effect on cutting direction, spindle speed and depth of cut. And then the optimum condition used Taguchi design is upward cutting in cutting direction, 600rpm in spindle speed, 240mm/min feed rate, 2mm in axial depth of cut and 0.25mm radial depth of cut. By using design of experiment, it is effectively represented shape characteristics of working surface in end-milling.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.98-104
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• 2012

In this paper, precision processing is carried out for the pre hardened steel(HRC 54), which is one of injection mould materials. Processing characteristics are estimated according to the number of tool cutting blade and roundness is observed by the 3-Dimensional measuring machine. The surface roughness affected by the wire electric discharge machining are measured. Cutting component force of STAVOX is the highest in condition of 2F processing because load per a blade of cutting tool is high. Especially, the difference in Fz is over 20N by cutting load. The slower spindle rotation speed and tool feed rate are, the better cutting component force is. The roundness of hole processed in condition of 4F is good because feed rate is able to be fast. When rotation speed is increased, the surface roughness is decreased. The surface roughness acquired in condition of 2F processing is higher about 50% than 4F processing.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.78-83
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• 1996

This paper presents the characteristics of surface roughness and cutting force in ultraprecision cutting of aluminium alloy using natural diamond tools whose edge radii are smaller than those of tools made of other materials. The feed rate and depth of engagement were set to be a micrometer order. After measuring the surface roughness of machined surface and cutting force for each cutting condition, the relations between the surface quality and its condition were investigated qualitatively. If the feed rate was under a certain limit, the machined surface quality was deteriorated unexpectedly. This is supposed to have happened due to vibration leading its condition to abnormal one. In a certain situation the machined surface roughness by a natural diamond tool was inferior to that made by a carbide tool whose cutting edge radius is larger. This is supposed to be caused by not normal machining but burnishing effect.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.5
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• pp.46-52
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• 2003

End-milling have been used widely in industrial system because it is effective to a material manufacturing with various shape. Recently the end-milling processing is needed the high-precise technique with good surface roughness and rapid time in precision machine part and electronic part. The optimum surface roughness has an effect on end-milling condition such as, cutting direction spindle speed, feed rate and depth of cut, etc. Therefore this study was carried out to presume for mutual relation of end-milling condition to get the optimum surface roughness by regression analysis. The results shown that coefficient of determination($\textrm{R}^2$) of regression equation has a fine reliability of 87.5% and regression equation of surface rough is made by regression analysis.