산란계 개량에 관한 연구 1 . 순계의 생산능력 비교시험

상병찬,강만석,김동곤,한성욱 ( B . C . Sang,M . S . Kang,D . K . Kim,S . W . Han ) 한국축산학회 1980 한국축산학회지 Vol.22 No.5

This experiment was carried out to test performance of the domentic purebred fowl. The purpose of this experiment was to compare the productive performance of the purebred fowl to obtained basic materials for laying performance improvement by means of cross breeding. In this study, 1, 200 chickens was used-that is 6 purebred strains White Leghorns(720 chickens), 1 purebred strain Rhode Island Reds (120 chickens), 1 purebred strain New Hampshires (120 chickens). The results obtained in this study are as follows; 1. The average Viability of brooding, rearing and laying period was best for Rhode Island Reds and E. Strain among White Leghorns. 2. The average body weight at 8 weeks, first egg production days, 500days of age in W. L. was 546.86g. 1431.37g, 1738.34g, respectively, but there was no significant difference among. purebred strains of W. L. 3. The average Sexual maturity of 50% egg production was 170.58 days in W. L., but R. I. R. and S. N. H. were 189.94 days, 182.42days, respectively. There was significant difference at 1 % level among Strains. 4. The average hen-housed egg production was 214.16 eggs in W. L., but R. I. R. and S. N. H. were 214.22 eggs, 196.74 eggs, respectively. There was significant difference at 1% level among Strains, but the highest hen-housed egg production (231.84 eggs) was E. Strain among strains. 5. The average egg weight was 54. 48g in W. L, but R. I. R. and .S. N. H. were 56.12g, 54.90g, respectively, The highest egg weight (57.69g) was Coronial Strain of W. L. among strains. There was significant difference at 1 % Level among strains. 6. The average feed requirement was 3.01 in W. L. but R. I. R. and S. N. H. were 3.23, 3.52, respectively the highest feed requirement (2.79) was Coronial Strain of W. L. among strains. There was significant difference at 1 % level among strains. 7. On the basis of the results of this study, the productive performance was best for C. D. E. strains among W. L. and R. I. R.

기계요소부품을 이용한 3D 프린팅 부품의 고기능화 및 단가 절감 설계 방법

오원정(W. J. Oh),김동현(D. H. Kim),황슬기(S. G. Hwang),강동기(D. K. Kang),김동현(D. H. Kim),김충수(C. S. Kim) Korean Society for Precision Engineering 2021 한국정밀공학회 학술발표대회 논문집 Vol.2021 No.11월

항공산업 및 자동차 산업 등 여러 산업분야에서, 핵심 부품에 대한 높은 기계적 성능을 요구할 뿐만 아니라 연비 및 단가와 같은 경제성에 대한 요구도 동시에 증가하고 있다. 전통적인 제조 방법은 특정 수준의 복잡성 이상으로 제조가 불가능 하여 많은 제약이 있었으나, 위상 최적화(Topology Optimization) 방법을 통해 형상을 최적화하고, 3D 프린팅 공정으로 제조를 할 경우 제품의 기계적 성능을 유지하며, 경량화를 통해 경제성 또한 만족시킬 수 있다. 하지만 일반적으로 3D 프린팅으로 제조된 재료는 이방성을 가지기 때문에 원하는 기계적 성능을 확보하는데 어려움이 있으며, 제조원가 또한 높다는 단점이 존재한다. 따라서 본 연구에서는 3D 프린팅을 통하여 제품의 부피를 감소시킴과 동시에 중요 위치에 축계 및 중공축계 등의 낮은 단가의 기계부품 요소를 적용하여 제품의 안정성 및 낮은 공정단가를 확보하는 기계요소 부품 조립을 고려한 설계방법론을 제시하였다. PA 12 Polyamide 로 구성된 브라켓(Bracket)에 대해 기계요소 부품 조립을 고려한 설계를 수행하였고, 이 설계에 대한 구조해석 및 단가를 산출하였다. 산출된 결과는 기존 브라켓의 데이터와 비교되었으며, 그 결과 제안된 브라켓의 휨 변위는 65%, 단가는 30% 이상 감소된 것으로 나타났다. 본 연구를 통해 3D 프린팅의 도입을 고려하는 산업 외 다양한 산업에서 3D 프린팅의 도입을 재고할 수 있을 것이다.

세라믹 3D 프린팅 형상 측정 및 결함 감지를 위한 층간 모니터링 방법

오원정(W. J. Oh),고종완(J. W. Ko),김동현(D. H. Kim),하정홍(J. H. Ha),박유진(Y. J. Park),강동기(D. K. Kang),김충수(C. S. Kim) Korean Society for Precision Engineering 2021 한국정밀공학회 학술발표대회 논문집 Vol.2021 No.11월

세라믹은 전기·전자, 광학, 의료 등 여러 분야에서 요구되는 특성을 구현하는 우수한 소재이지만, 절삭 가공이 어려운 난삭재로 분류되며 3D 프린팅 제조 또한 기술의 난이도가 높은 실정이다. 특히 3D 프린팅 제조를 통해 생산된 제품은 절삭 공정에 비해 낮은 형상 정밀도를 가지며, 반응 경화 시 결함으로 인한 내부 기공은 세라믹 제품에 있어 치명적이다. 낮은 형상정밀도의 문제는 연마 등의 후처리 공정의 비중이 커지고 비용의 증가로 이어지게 된다. 또한 내부 기공의 경우 취성 재료인 세라믹의 특성상, 직접 균열의 원인이 되거나 기공에 집중되는 응력으로 인해 미세균열의 원인이 될 수 있다. 따라서 한 층씩 적층되는 3D 프린팅 제조에서 있어서 층간 모니터링은 매우 중요하다. 본 연구에서는 선택적 반응 경화 기반 세라믹 3D 프린팅 공정에서 비전 센서를 이용한 층간 형상 모니터링 및 머신 러닝(Machine Learning)을 이용한 결함 탐지 시스템을 제안하였다. 제안된 모니터링 시스템은 상단에 고정된 비전센서를 통해 데이터를 확보하고 결함을 감지하는 방식이다. 제안된 모니터링 시스템을 이용할 경우 층간 형상은 선택적으로 반응된 경화물의 색상을 통해 추출하며, 적층 중 결함은 머신 러닝 알고리즘 중 하나인 YOLO (You only Look Once)를 이용하여 탐지한다. 본 연구에서 제안된 모니터링 시스템을 통해 세라믹 3D 프린팅의 형상 최적화 및 세라믹 제조품의 불량률을 감소시킬 수 있을 것이다.

시료내 라이신 : 에너지 비율이 이유 자돈의 성장 및 영양소 소화율에 미치는 영향 DE RATIO ON THE GROWTH PERFORMANCE AND NUTRIENT DIGESTIBILITY IN WEANED PIGS

한인규,김진동,현충남,이지훈,강완병,현영 한국영양사료학회 1999 韓國營養飼料學會誌 Vol.23 No.5

본 연구는 현대의 빠르게 성장하는 이유자돈에서 사료내 Lys : DE 비율이 이유자돈의 성장 및 영양소 소화율에 미치는 영향을 알아보기 위하여 실시되었다. 평균체중 5.70±0.14의 이유자돈 (Yorkshire×Landrace×Duroc) 100두를 공시하였고, 제 1기 (0∼14일) 동안, 두 수준의 에너지 (3,400과 3,600 ㎉ DE/㎏)와 두 수준의 Lys : DE 비율 (4.4와 4.9 g/Mcal), 제 2기 (15∼28일) 동안, 두 수준의 에너지 (3,300과 3,500 ㎉ DE/㎏)와 두 수준의 Lys : DE 비율 (4.4와 4.9 g/Mcal)이 되도록, 2×2 요인법으로 설계하였으며 4처리 5반복 반복당 5두의 이유자돈이 공시되었다. 시험 전기간 (0∼28일)동안, 일당중체량 (ADG)은 저 에너지-고 Lys : DE구가 저 에너지-저 Lys : DE구 보다 높았으며, 사료요구율 (FCR)은 고 에너지-고 Lys : DE구가 저 에너지-고 Lys : DE구를 제외한 나머지 처리구들 보다 낮은 경향을 보여 주었으나 유의한 수준은 아니였다. 사료내 Lys : DE 비율이 높아짐에 따라 ADG가 높아지는 경향을 보여 주었으나 유의하지는 않았다 (P>0.05). 그러나 FCR은 Lys : DE 비율이 높아짐에 따라 유의하게 개선되었으며 (P<0.05). 에너지 수준에 따른 차이는 관찰되지 않았다. 제 1기 동안 영양소 소화율은 사료내 에너지수준에 따라 영향받지 않았다. 건물소화율과 총에너지 소화율은 Lys : DE 비율이 증가함에 따라 유의하게 개선되었다 (P<005). 제 2기 동안 조지방을 제외한 영양소 소화율은 사료내 에너지 수준간에 따라 영향받지 않았다. 사료내 Lys : DE 비율에 따른 영양소 소화율에 있어 유의한 차이는 관찰되지 않았다. 제 1기 동안 필수 및 비필수 아미노산 소화율에 있어서는, 처리에 따른 유의한 차이가 관찰되지 않았다. 그러나 제 2기 동안 총필수 아미노산과 총 아미노산 소화율이 사료내 Lys : DE 비율이 증가함에 따라 유의하게 개선되었다 (P<0.05). 본 실험결과는 이유자돈이 4.4 g Iysine/Mcal DE 수준보다 4.9 g Iysine/Mcal DE 수준의 사료를 효과적으로 이용할 수 있음을 제시해 주었다. This study was carried out to evaluate the effect of lysine:energy ratio (Lys : DE) on growth performance and nutrient digestibility of weaned pigs. A total of 100 pigs (Yorkshire × Landrace × Duroc) averaging 5.7±0.14 ㎏ of initial body weight were employed. Two levels of dietary energy (3,400 and 3,600 ㎉ DE/㎏) with two levels of Lys : DE ratio (4.4 and 4.9 g/Mcal) for phase I period (0 to 14 d) and two levels of energy (3,300 and 3,500 ㎉ DE/㎏) with two levels of Lys : DE ratio (4.4 and 4.9 g/Mca1) for phase II period (15 to 28 d) were involved in a two × two factorial arrangement, respectively. Each treatment had five replicates with five pigs per replicate. During phase I period (0 to 14 d), no difference between groups in ADFI, and feed conversion rate (FCR) was significant. However, FCR was significantly improved with increased Lys : DE ratio (P<0.05). During phase II period (15 to 28 d), ADG, ADFI and FCR were not significantly (P<0.05) different among groups. There was no interaction between dietary energy concentration and Lys : DE ratio in growth performances of weaned pigs. FCR, however, was improved with increased energy level and Lys : DE ratio (P<0.05). During the overall period (0 to 28 d), there was no interaction between dietary energy concentration and Lys : DE ratio in growth performances of weaned pigs. However, there was a tendency for higher ADG with higher Lys : DE ratio. FCR was significantly improved with increased Lys : DE ratio (P<0.05), but was not affected by dietary energy concentration. During phase I period (0 to 14 d), no differences in nutrients digestibilities were observed between dietary energy levels. Between dietary Lys : DE ratios, dry matter (DM) and gross energy (GE) digestibilities were significantly (P<0.05) improved with higher Lys : DE ratio. During phase II period (15 to 28 d), no differences in nutrients digestibilities except energy levels. Between dietary Lys : DE ratios, no significant differences in nutrients digestibilities was observed. In regard to amino acids digestibilities, during phase I period (0 to 14 d), average values of essential amino acids (EAA), non-essential amino acids (NEAA) and total amino acids digestibilities were not significantly influenced by dietary energy levels and Lys : DE ratios. During phase II period ( 15 to 28 d), pigs fed high Lys : DE ratio diets showed significantly (P<0.05) higher total EAA and total amino acids digestibilities. The digestibilities of threonine, methionine, phenylalnine and serine were significantly improved as the dietary Lys : DE ratio increased. In conclusion, the results of the current experiment indicate that fast-growing weaned pigs might be able to use more effectively diets contatining 4.9 g lysine/Mcal DE compared to diets containing 4.4 g lysine/Mcal DE.

Implication of intracellular ROS formation, caspase-3 activation and Egr-1 induction in platycodon D-induced apoptosis of U937 human leukemia cells

Shin, D.Y.,Kim, G.Y.,Li, W.,Choi, B.T.,Kim, N.D.,Kang, H.S.,Choi, Y.H. Masson Pub. USA, Inc 2009 BIOMEDICINE AND PHARMACOTHERAPY Vol.63 No.2

Platycodon D is a major constituent of triterpene saponins found in the root of Platycodon grandiflorum, Platycodi Radix, which is widely used in traditional Oriental medicine for the treatment of many chronic inflammatory diseases. The results of previous studies have shown that this compound has in vitro growth-inhibitory activity in human cancer cells, however, the mechanism by which this action occurs is poorly understood. In this study, we examined the effects of platycodon D on the production of reactive oxygen species (ROS) and evaluated the association of these effects with apoptotic tumor cell death using a human leukemic U937 cell line. The results of this study demonstrate that platycodon D mediates ROS production, and that this mediation is followed by a decrease in mitochondrial membrane potential (MMP, ΔΨ<SUB>m</SUB>), activation of caspase-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Both the cytotoxic effects and apoptotic characteristics induced by platycodon D treatment were significantly inhibited by z-DEVD-fmk, a caspase-3 inhibitor, which demonstrates the important role that caspase-3 plays in the observed cytotoxic effect. Additionally, the transcription factor early growth response-1 (Egr-1) gene was transcriptionally activated and the levels of non-steroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1) protein were elevated in platycodon D-treated U937 cells. However, the quenching of ROS generation in response to treatment with a ROS scavenger, N-acetyl-l-cysteine, reversed the platycodon D-induced apoptosis effects via inhibition of Egr-1 activation, ROS production, MMP collapse, and the subsequent activation of caspase-3. Although further studies are needed to demonstrate that increased expression of Egr-1 by platycodon D leads directly to NAG-1 induction and subsequent apoptosis, our observations clearly indicate that ROS induced through Egr-1 activation are involved in the early molecular events involved in the platycodon D-induced apoptotic pathway.

Influence of water activity on inactivation of Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes in peanut butter by microwave heating

Song, W.J.,Kang, D.H. ACADEMIC PRESS LTD 2016 FOOD MICROBIOLOGY Vol.60 No.-

<P>This study evaluated the efficacy of a 915 MHz microwave with 3 different electric power levels to inactivate three pathogens in peanut butter with different a(w). Peanut butter inoculated with Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium and Listeria monocytogenes (0.3, 0.4, and 0.5 a(w)) were treated with a 915 MHz microwave with 2, 4, and 6 kW for up to 5 min. Six kW 915 MHz microwave treatment for 5 min reduced these three pathogens by 1.97 to >5.17 log CFU/g. Four kW 915 MHz microwave processing for 5 min reduced these pathogens by 0.41-1.98 log CFU/g. Two kW microwave heating did not inactivate pathogens in peanut butter. Weibull and Log-Linear + Shoulder models were used to describe the survival curves of three pathogens because they exhibited shouldering behavior. T-d and T-5d values were calculated based on the Weibull and Log-Linear + Shoulder models. T-d values of the three pathogens were similar to D-values of Salmonella subjected to conventional heating at 90 degrees C but T-5d values were much shorter than those of conventional heating at 90 degrees C. Generally, increased a(w) resulted in shorter T-5d values of pathogens, but not shorter T-d values. The results of this study can be used to optimize microwave heating pasteurization system of peanut butter. (C) 2016 Published by Elsevier Ltd.</P>

Valeriana officinalis extract and its main component, valerenic acid, ameliorate d-galactose-induced reductions in memory, cell proliferation, and neuroblast differentiation by reducing corticosterone levels and lipid peroxidation

Nam, S.M.,Choi, J.H.,Yoo, D.Y.,Kim, W.,Jung, H.Y.,Kim, J.W.,Kang, S.Y.,Park, J.,Kim, D.W.,Kim, W.J.,Yoon, Y.S.,Hwang, I.K. Pergamon Press ; Elsevier Science Ltd 2013 Experimental Gerontology Vol.48 No.11

Valeriana officinalis is used in herbal medicine of many cultures as mild sedatives and tranquilizers. In this study, we investigated the effects of extract from valerian root extracts and its major component, valerenic acid on memory function, cell proliferation, neuroblast differentiation, serum corticosterone, and lipid peroxidation in adult and aged mice. For the aging model, d-galactose (100mg/kg) was administered subcutaneously to 6-week-old male mice for 10weeks. At 13weeks of age, valerian root extracts (100mg/kg) or valerenic acid (340μg/kg) was administered orally to control and d-galactose-treated mice for 3weeks. The dosage of valerenic acid (340μg/kg), which is the active ingredient of valerian root extract, was determined by the content of valerenic acid in valerian root extract (3.401+/-0.066mg/g) measured by HPLC. The administration of valerian root extract and valerenic acid significantly improved the preferential exploration of new objects in novel object recognition test and the escape latency, swimming speeds, platform crossings, and spatial preference for the target quadrant in Morris water maze test compared to the d-galactose-treated mice. Cell proliferation and neuroblast differentiation were significantly decreased, while serum corticosterone level and lipid peroxidation in hippocampus were significantly increased in the d-galactose-treated group compared to that in the control group. The administration of valerian root extract significantly ameliorated these changes in the dentate gyrus of both control and d-galactose-treated groups. In addition, valerenic acid also mitigated the d-galactose-induced reduction of these changes. These results indicate that valerian root extract and valerenic acid enhance cognitive function, promote cell proliferation and neuroblast differentiation, and reduce serum corticosterone and lipid peroxidation in aged mice.

Evaluation on the Characteristic of Tapered-Hole Clinching for Al 5052 to Fiber Metal Laminates

D. S. Kang(강동식),E. T. Park(박으뜸),B. S. Kang(강범수),W. J. Song(송우진) 한국소성가공학회 2015 한국소성가공학회 학술대회 논문집 Vol.2015 No.10

AISI M2 파우더를 이용한 레이저 메탈 디포지션 트랙특성 평가

김원혁(W. H. Kim),정병훈(B. H. Jung),오명환(M. H. Oh),최성원(S. W. Choi),강대민(D. M. Kang) 한국소성가공학회 2015 한국소성가공학회 학술대회 논문집 Vol.2015 No.5

3D 스테레오비전을 활용한 딥러닝 육계 체중예측 시스템

윤도현(D. Yoon),이우도(W. Lee),강환구(H. Kang),전형민(H. Jun) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.4