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간척지에서 이앙기 및 수확시기가 쌀의 품질 특성에 미치는 영향
정명식,채제천,전대경 한국작물학회 2003 Korean journal of crop science Vol.48 No.5
The yield and quality characteristics of three rice varieties(Seojinbyeo, Ilpumbyeo, and Chuchungbyeo) in reclaimed saline paddy field were investigated under different cultural practices, three transplanting times (May 15, May 30 and June 15) and four harvest times (40, 50, 60 and 70days after heading) in order to obtain basic information for the production of high quality rice. Brown rice yield of three rice varieties were significantly higher in early and medium than late season cultivation. The protein content of milled rice showed high interaction effect between transplanting time and harvest time. Palatability values of Seojinbyeo and Ilpumbyeo were significantly higher in late than medium season cultivation, but Chucheongbyeo did not show any difference in its palatability value by different transplanting time. The palatability values of three rice variety was the highest in the harvest at 40 days after heading. The grain yield of three rice varieties were higher in early and medium than late season cultivation, whereas palatability values of three rice varieties were significantly higher in the early and late season cultivation than medium season cultivation. The palatability value measured by rice taster showed a highly negative correlation(r=-0.43/sup **/) with cumulative air temperature during ripening period. 이앙기 및 수확시기에 따른 쌀 품질을 식미 관점에서 검토하여 고품질 쌀 생산을 위한 기초 자료를 얻고자 2001년 서진벼, 일품벼, 추청벼를 공시하여 인천광역시 서구 경서동에 위치한 농업기반공사 김포간척지에서 실험한 결과는 다음과 같다. 1. 현미수량은 이앙시기간 고도로 유의한 차이가 있어서 3품종 모두 조기, 보통기재배가 만기재배보다 수량이 유의하게 많았다. 2. 백미의 단백질 함량은 이앙기와 수확시기간 고도의 상호작용이 있어서 발의 단백질 함량이 저하되는 수확시기는 이앙기에 따라 달랐다. 3. 이앙기에 따른 식미값은 서진벼와 일품벼는 조기와 만기재배에서 유의하게 높으나 추청벼는 만기재배에서도 떨어지지 않는 경향이었다. 4. 백미의 식미치는 등숙적산기온과 고도로 유의한 부의 상관(-0.43/sup **/)이 있어서 적산기온이 높을수록 식미치가 저하하였다. 5. 수량과 품질을 동시에 고려할때 조기 또는 보통기재배를 하되 수확시기는 출수후 40일로 다소 빠르게 하는 것이 유리한 것으로 판단되었다.
Green Alternative Processing Technology for a Spring Guide Pin of Stamping Die Set
정명식,최태훈,이상곤,성지현,김강은,이신옥,이강원 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.
In this research, a multi-stage cold forging process for a spring guide pin of stamping die set is designed through alternative process for sustainable production. Highly energy and material consuming process needs to be converted to an energy saving process. Up to now, a spring guide pin for stamping die set is usually manufactured by machining process in order to achieve dimensional accuracy. However, machining process has some disadvantages such as excessive material loss, low productivity, and poor mechanical properties. In order to overcome these problems, a multi-stage cold forging process is applied to manufacturing spring guide pin for achieving less material loss and higher productivity. Multi-stage forging process requires careful design steps to prevent the defects of the final product. So, the design must consider the material flow during the whole process and the loading limit of the press in order to avoid product defects such as folding and underfilling. To develop multi-stage forging process for spring guide pin the forming load and material flow at each step is analyzed using a commercial finite element code, DEFORM. The guide pin is then manufactured by the developed multistage forging process, and is compared to the simulation results. Also the efficiency of the developed forging process is compared to the machining process. The developed process is a green manufacturing process minimizing material loss,which achieves cost reduction through improved material usage and productivity compared to the more widely used machining process.
정명식 대한기계학회 1988 大韓機械學會誌 Vol.28 No.5
우리나라의 철강업은 수요산업의 견실한 성장에 힘입어 향후 속도는 다소 둔화되겠지만 2000년 까지는 성장이 지속될 전망이다. 현재 선진국도 철강산업의 구조개편으로 혁신적 합리화에 힘을 쏟고 있으며, 이들 국가의 경쟁력이 회복될 경우 국제경쟁은 더욱 치열해 질 것으로 보며 이 러한 환경 속에서 우리나라 철강업이 안정 성장을 이룩해 나가기 위해서는 먼저, 현재 선진국과 같이 수요감퇴에 대비 안정적 수익확보를 위해 경영다각화를 적극 추진해 나가야 하겠으며, 둘 째로 R & D 투자확대를 통해 신기술개발 강화와 신제품개발 확대로 고급강 등 고부가가치 제 품의 비중을 늘려 나가며, 셋째로, 설비합리화를 적극 추진하여 국제경쟁력을 확보해 나가며, 장기적으로 시장다변화 등 국제화 전략을 강화해 나가야 할 것이다.
Green Manufacturing Process for Helical Pinion Gear Using Cold Extrusion Process
정명식,이상곤,윤정환,성지현,김다혜,이신옥,최태훈 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.
In this research, a cold extrusion process that can replace conventional machining process is developed for sustainable production. The cold extrusion method requires an analytical design process to assure desired dimensional accuracy of the final product. Therefore, the design must consider the material flow during the process in order to avoid product defects such as folding and underfilling. The forming load and material flow were analyzed using a commercial finite element code, DEFORM3D. To improve the dimensional accuracy, the shape of die and initial billet were designed using minimum distance analysis via FE simulation. Also the developed process included ejection for improving dimensional accuracy, and it was verified by a gear accuracy test. Isothermal annealing and spheroidizing were applied for increasing the formability of high strength workpiece. Finally a helical pinion gear was manufactured using the developed process and the product was compared to the simulation results. In conclusion, the developed process is a scrap reducing and energy saving method for manufacturing extrusion product with high dimensional accuracy.