3D 프린팅 방식의 적층방향에 따른 시제품의 기계적 특성 비교에 관한 연구

박찬(Chan Park),김명훈(Myung Hun Kim),홍성무(Sung Moo Hong),고정상(Jeung Sang Go),신보성(Bo Sung Shin) 한국생산제조학회 2015 한국생산제조학회지 Vol.24 No.3

This paper summarizes the results of an investigation into the environmental factors that have an indirect impact on parts quality, as well as those process variables and modeling information that have a direct impact. The effects of strength, surface hardness, roughness, and accuracy of shape, that is, qualities that users generally need to know, were evaluated with laminating direction experimentally. The 3D printing methods used in this experiment were fused deposition modeling (FDM), stereolithography apparatus (SLA), selective laser sintering (SLS), 3D printing (3DP) and laminated object manufacturing (LOM). The goal was to achieve a high standard of quality control and product quality by optimizing the fabrication process.

동 박막의 피로한도

허용학(Yong-Hak Huh),김동진(Dong Jin Kim),이해무(Hae Moo Lee),홍성구(Sung Gu Hong),박준협(Jun Hyub Park) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.10

Fatigue limit of the copper film coated by Sn was estimated using Goodman diagram and Gerber diagram. To obtain the high cycle fatigue life curve, S-N curve, of the film, the high cycle fatigue test was carried out by applying the constant amplitude load to the film specimen with three different stress ratio of 0.05, 0.3 and 0.5 and the frequency of 40 ㎐ at room temperature in air. The free-standing film specimen 15.26㎛ thick was fabricated by etching process. The fatigue limits and S-N curves at the respective stress ratios were determined from the experimental works. It was shown that the S-N curves were dependent on the stress ratio and the fatigue limit was increased with decreasing the stress ratio. The dependency of the fatigue behavior was presented in empirical relationship. Using these relationships, the fatigue limit was predicted.

Kaolin 충진제 표면처리에 관한 연구(제1보) : Kaolin의 기초성상 및 고무물성에 대한 처리효과 Fundamental Properties of Kaolin Filler and Treatment Effect on Physical Properties of Rubers

홍성일,이용무,권동용 한국고무학회 1983 엘라스토머 및 콤포지트 Vol.18 No.3

Fundamental properties and surface treatment effects of domestic kaolin calcined at higher temperature were studied to develop reinforcing fillers for rubbers. The results obtained are as follows: (i) X-ray diffraction and scanning electron microscopy studies revealed kaolinite as a major constituent of the raw kaolin used in this study. (ii) Physical properties of natural rubber vulcanizates compounded with the calcined kaolin fillers treated with poly(maleic anhydride) and sodium polyphosphate are favorably improved. Particularly, the kaolin filler treated with sodium polyphosphate(designated as PT series) shows excellent physical properties compared with hydrated silica. PT Series Hydrated Silica Tensile strength, ㎏/㎠ (average) 182 132 Elongation, % (average) 629 587 300% Modulus, ㎏/㎠ (average) 65.6 55.0

도서지역 청소년층의 체용적에 관한 연구 : 제주도 초 중 고교생을 중심으로

홍성무 한국보건통계학회 1982 한국보건정보통계학회지 Vol.7 No.1

A study on 2,692 primary, middle and high school students (1328 boys and 1344 girls) in rural areas of jeijuu Island was conducted from May 1 to May 30 in 1979 for assessing their physical growth and development in terms of physical indices, and the correlation between body weight and volume is obtained. Following are the results. A. Physical Growth and Development. Rapid growth of physical growth in terms of body height and weight has been observed among 15 year-old boys and girls. Growth in terms of physical growth and development turned out to be slower among students of higher ages, irrespective of male or female. The maximum annual growth rates were as follows; Body height; 7.73cm during the age 13-14 for boys. r.59cm during the age 12-13 for girls. Body weight; 5.02kg during the age 14-15 for boys. 4.83kg during the age 12-13 for girls. This indicates that girls enter a rapidly growing stage one year earlier than boys of the body height. ON the average girls were found to enter a rapidly growing stage two year earlier than the boys. The greatest individual differences in growth and development were observed during 10-14 years of age. The standards of growth of rescent Korean students show much improved than that of 1967. B. Relative Body Weight. The smallest values of relative body weight was obtained with both boys and girls aged 10 which was found to be increasing rather slowly there after with advancing ages. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed boys and at 14.5 boys su passed girls. The maximum annual growth rates of relative body weight were 3.22 from 13 to 14 years of age in boys and 2.33 from 13 to 14 years of age in girls. C. Body Surface Area and Volume. The mean value of the surface area and body volume was calculated by indirect method from body height and body weight. Rapid growth of surface area was shown in both sex during the period from 10 to 16 years of age. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed appeared at age 10.5 at which girls surpassed boys and at 14.5 boys surpassed girls. The maximum annual growth rates of boy surface area were 0.1407m^2 from 13 to 14 years of age in boys and 0.1021m^2 from 12 to 13 years of age in girls. This indicates that girls enter a rapidly growing stage one year earlier than boys of the suface area. Rapid growth of the body volume was shown in both sex during the period 10-16 years of age. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed boys and at 14.5, boys surpassed girls. The maximum annual growth rates of body volume were 6.48ℓ from 13 to 14 years of age in boys and 4.65ℓ from 12 to 13 in girls. D. Correlation between Relative Body Weight and Body Volume by Age. The correlation coefficient and equation between body weight or relative body weight and body volume by age are as shown in Table 7 and 8.

靑少年에 있어서 身長과 體重을 利用한 體脂肪量에 關한 硏究

洪性茂 최신의학사 1980 最新醫學 Vol.23 No.10

Kaolin 충진제 표면처리에 관한 연구(제2보) : 주조전자현미경에 의한 morphology

홍성일,이용무,허동섭,권동용 한국고무학회 1983 엘라스토머 및 콤포지트 Vol.18 No.4

Scanning electron microscopy studies were conducted to examine the surface treatment effects of treating agents the proposed in the previous studies on various vulcanizates. Fracture surfaces of the vulcanizates compounded with kaolin treated with sodium polyphosphate or poly(maleic anhydride) presented favorable results as expected from the results of the previous studies. Tn other words, treating agents such as sodium polyphosphate and poly(maleic anhydride) show considerable reinforcing effects on the vulcanizates.

大都市地域 靑少年層의 成長發育과 營養狀態에 關한 硏究

洪性茂 최신의학사 1980 最新醫學 Vol.23 No.9

환경이 참굴에 미치는 영향

이승무,홍성무,최청송 한국공업화학회 2002 응용화학 Vol.6 No.2

In this study, the oyster, Crassostrea Gigas which is composed of alternating nanoscale layers of calcium carbonate plate and organic matrix and is widely cultivated in Korea, is mainly focused to get a better understanding of the effect of environmental conditions on the formation of shell. It is suggested that environmental conditions are main factor for the transition normal shell into deformed shell through EA, EDS and crystal growth.

島嶼地域 靑少年層의 體容積에 關한 硏究 : 제주도 初中高校生을 中心으로

申吉洙,朴淳永,朴喆斌,洪性茂 圓光大學校 附設 體力科學硏究所 1982 體力科學硏究 Vol.5 No.-

A study on 2692 primary, middle and high school students(1348 boys and 1344 girls) in rural areas of Jeiju Island was conducted from May 1 to May 30 in 1979 for assessing their physical growth and development in terms of physical indices, and the correlation between body weight and volume is obtained. Following are the results. A. Physical Growth and Development. Rapid growth of physical growth in terms of body height and weight has been observed among 15 yearold boys and girls. Growth in tearms of physical growth and development turned out to be slawer among students of higher ages, irrespective of male of female. The maximum annual growth rates were as follows; Body height; 7.73cm during the age 13∼14 for boys, 5.59cm during the age 12∼13 for girls. Body weight; 5.02kg during the age 14∼15 for boys. 4.83kg during the age 12∼13 for girls. This indicates that girls enter a rapidly growing stage one year earlier than boys of the body height. On the average girls were found to enter a rapidly growing stage two year earlier than the boys. The greatest individual differences in growth and development were observed during 10∼14 years of age. The standards of growth of rescent Korean students show much improved then that of 1967. B. Relative Body Weight The smallest values of relative body weight was obtained with both boys and girls aged 10, which was found to be increasing rather slowly thereafter with advancing ages. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed boys and at 14.5, boys surpassed girls. The maximum annual growth rates of relative boy weight were 3.22 from 13 to 14 years of age in boys and 2.33 from 13 to 14 years of age in girls. C. Body Surface Area and Body Volume The mean volue of the surface area and body volume was calculated by indirect method from body height and body weight. Rapid growth of surface area was shown in both sex during the period from 10 to 16 years of age. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed boys and at 14.5, boys surpassed girls. The maximum annual growth rates of body surface area were 0.1407㎡ from 13 to 14 years of age in boys and 0.1021㎡ from 12 to 13 years of age in girls. This indicates that girls enter a rapidly growing stage one year earlier than boys of the surface area. Rapid growth of the body volume was shown in both sex during the period 10∼16 years of age. The crossing point of boys and girls appeared at age 10.5 at which girls surpassed boys and at 14.5, boys surpassed girls. The maximum annual growth rates of body volume were 6.48ℓ from 13 to 14 years of age in boys and 4.65ℓ from 12 to 13 in girls. D. Correlation between Raletive Body Weight and Body Volume by Age. The correlation coefficient and regression equation between body weight or relative body weight and body volume by age are as shown in Table 7 and 8.