• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.119-128
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• 2016

This study was conducted to compare nutritional composition and taste-related compounds of breast and thigh meats from four lines of Korean native chickens (KNC) Yeonsan Ogye, Hyunin Black, Hwangbong, and Hoengseong Yakdak. White Leghorn (WL) was used as a control. Fifteen male chickens (three chickens in each line) were grown under same condition and slaughtered at 53 weeks old. The contents of Fe and K in KNC, especially Hwangbong breast meat and thigh meat of Hyunin Black and Hoengseong Yakdak, were higher than WL. The contents of Na were lower in KNC compared with WL regardless of parts (p<0.05). Vitamin A contents were higher in thigh meat of WL and Hyunin Black, and vitamin $B_1$ contents were lower in Hoengseong Yakdak than other lines. Vitamin $B_3$ were higher in breast meat of four lines of KNC and thigh meat of Hoengseong Yakdak than WL. Total amino acid contents were higher in breast meat of KNC than WL. The level of good-tasting amino acids were significantly higher in breast meat of Hoengseong Yakdak and WL, and thigh meat of Hyunin Black and WL than other lines of chickens (p<0.05). The ratio of good-tasting amino acids to bitter tasting amino acids was higher in breast meat of Hoengseong Yakdak and thigh meat of Hyunin Black than WL. IMP contents were higher in Hyunin Black and WL than other lines of chickens. Based on these results, it can be concluded that four lines of KNC may have superior nutritional quality and taste when compared with WL.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.335-345
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• 2015

This study was conducted to compare carcass yield and meat quality among four lines of Korean native chickens (Yeonsan Ogye, Hyunin Black, Hoengseong Yakdak and Hwangbong) and White Leghorn as control. Chickens (N=23, male) were grown under same conditions and slaughtered at 56 weeks old to observe the physicochemical differences in breast and leg meats. The live and carcass weights of Hwangbong were significantly higher than other chickens (p<0.05). Four lines of Korean native chickens, regardless of the part, had higher shear force value than White Leghorn (p<0.05). In addition, the breast meat of Korean native chickens had higher cooking loss and lower water holding capacity than that of White Leghorn. The cooked meat of Hwangbong particularly were more chewy, gummy and cohesive with lower tenderness than other chickens (p<0.05). Oleic acid content which is related to meat flavor was significantly higher in the breast meat of Hoengseong Yakdak (39.6%). The meat of Korean native chickens had lower n6/n3 ratio, in which the breast and leg meat of Hoengseong Yakdak contained the lowest ratio (p<0.05). The meat of Hwangbong and Hoengseong Yakdak were more acceptable than the others according to sensory test (p<0.05).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.464-467
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• 2005

Among several polishing techniques for micro structures, polishing process using magnetorheological(MR) fluid has advantages in the finishing process of 3-D micro structures because abrasives in the fluid can reach surfaces with complex feature and play their role. Although many researchers have been trying to reveal its polishing mechanism of the MR polishing, it has not been successful because in-situ measurement of state variables is difficult and process parameters are complex. In fact, one of the key factors for applying process control methodologies, such as Run-to-Run control, is the measuring and monitoring of slurry quality because the process strongly depends on the fluid property. Therefore, it is necessary to maintain consistent slurry quality to guarantee the process repeatability. The proposed equipment achieves the longer life cycle of MR fluid and reduces the variability of products. A new method to measure the material removal rate in MRF polishing process is also proposed and discussed.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1149-1156
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• 2012

In this study, we proposed the most efficient driving posture based on the analysis of quantitative muscular strength and fatigue degree according to posture. Since driving include complicated actions required by a variety of ability and cause by extremes concentration or strain, drivers tend to feel tired easily. However, drivers can't recognize the fatigue degree by themselves. Moreover, the method for measuring the quantitative fatigue degree exactly is quite difficult to be secured. 9 professional bus drivers were participated. We analyzed the quantitative legs' muscular strength when operating each pedal. And then we also analyzed the muscular strength and muscular fatigue degree according to driving pattern during bus driving. Therefore, we suggested the most efficient driving posture.

• Korean Journal of Poultry Science
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• v.43 no.3
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• pp.135-142
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• 2016

This study was conducted to compare the general composition and immunomodulatory activity of breast and thigh meats from four lines of Korean native chickens: Yeonsan Ogye, Hyunin Black, Hwangbong, and Hoengseong Yakdak. White Leghorn was used as a control. Fifteen male chickens (three chickens in each line) were grown under the same conditions and slaughtered at 13 weeks old. The four lines of Korean native chickens, regardless of the part, had higher contents of crude fat (p<0.05) than White Leghorn. The cholesterol contents were significantly higher in Hyunin Black and significantly lower in Hoengseong Yakdak than those of other chickens (p<0.05). The immunomodulatory effect, assessed by macrophage cell proliferation and nitric oxide production, was only observed in the breast meat of the four lines of Korean native chickens. The phagocytic activity of macrophage cells was significantly augmented by the breast meat of Hyunin Black and Hoengseong Yakdak. Furthermore, the mRNA expressions of pro-inflammatory cytokines, such as IL-4, IL-10 and $IFN-{\gamma}$, was significantly suppressed by Korean native chickens compared with White Leghorn. These results suggested that the four lines of Korean native chickens exhibited greater immune-enhancing activity than White Leghorn.