• 한국초지조사료학회지
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• 제40권1호
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• pp.37-43
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• 2020

This study was conducted to evaluate the effects of different nitrogen levels on the yield and nutrient quality of a newly developed domestic hybrid of Teosinte, Geukdong 6〔Zea mays L. subsp. mexicana (Schrad.) H. H. Iltis〕. The field experiment was conducted in a randomized block design with three replicates and consisted of four nitrogen (N) application rates, T1 (200 kg/ha), T2 (300 kg/ha), T3 (400 kg/ha), and T4 (500 kg/ha). No differences were found in plant length, leaf length, leaf width, leaf number, dead leaves, stem hardness, tiller number, and fresh yield (p>0.05). The T3 showed significantly greater dry matter yield at harvest (heading stage) compared to the other treatments (p<0.05). The crude protein content of T4 (10.49%) was higher than those of T1 and T2 (p<0.05). However, there was no significant difference between T4 (10.49%) and T3 (9.63%). The effects on crude fat, crude ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber were not significant (p>0.05). The sugar content was higher in the T2 treatment than the other treatments (p<0.05). For Ca, T3 showed significantly greater content (p<0.05). However, no significant effects were found in the contents of Cu, Fe, K, Mg, Mn, Mo, and Zn (p>0.05). Na content was higher in order of T2 > T4 > T3 > T1 (p<0.05). Total mineral contents were not significantly different among the treatments (p>0.05). Given these results, we recommend the amount of nitrogen fertilization necessary for "Geukdong 6" to be around 400 kg per ha (T3), when considering, high fresh yield, dry matter yield, number of leaves and content of crude protein.

• Animal Bioscience
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• 제36권1호
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• pp.84-97
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• 2023

Objective: One hundred hybrid male ducks (Mojosari×Alabio) were used to examine the efficacy of chicory supplementation as nutritional feed manipulation on production performance, and blood lipid profile of hybrid ducks. Methods: The ducks were tagged, weighed, and then allotted randomly to one of the four treatment diets using a completely randomized design. The experimental diets were: i) P0 (100% basal diets+0% chicory as control), ii) P1 (95% basal diets+5% chicory), iii) P2 (90% basal diets+10% chicory) and iv) P3 (85% basal diets+15% chicory). For each treatment group, there were 5 replicates of 5 birds each. All experimental diets were isonitrogenous and isocaloric using locally available ingredients. Results: Hybrid ducks with fed diets supplemented fresh chicory (5%, 10%, and 15%) showed increased feed intake and body weight gain, as well as feed conversion ratio to be smaller than those ducks fed diets without chicory supplementation (control). The ducks fed 10% chicory supplementation contained significantly (p<0.05) lower ash and higher organic matter contents of meat than those ducks fed other diets. The ducks fed 15% chicory supplementation showed the lowest crude protein and cholesterol content of meat among the treatment diets. Ducks fed chicory supplementation showed lower (p<0.05) blood cholesterol and triglyceride levels than those ducks fed without chicory supplementation, while dietary interventions had no major (p>0.05) influence on low-density lipoprotein and high-density lipoprotein levels in duck blood. Conclusion: In this study, 10% chicory supplementation showed the best results characterized by an increase in growth performance, carcass quality, small intestinal histomorphology, and lower cholesterol levels of meat.

• Restorative Dentistry and Endodontics
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• 제45권2호
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• pp.13.1-13.10
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• 2020

Objective: The aim of this study was to evaluate the influence of different modeling agents on the surface microhardness (Vickers hardness number; VHN), roughness (Ra), and color change (ΔE) of a nano-hybrid composite with or without exposure to discoloration by coffee. Materials and Methods: Sixty-four cylinder-shaped nano-hybrid composite specimens were prepared using a Teflon mold. The specimens' surfaces were prepared according to the following groups: group 1, no modeling agent; group 2, Modeling Liquid; group 3, a universal adhesive (G-Premio Bond); and group 4, the first step of a 2-step self-adhesive system (OptiBond XTR). Specimens were randomly allocated into 2 groups (n = 8) according to the storage medium (distilled water or coffee). VHN, Ra, and ΔE were measured at 24 hours, 1 week, and 6 weeks. The Kruskal-Wallis test followed by the Bonferroni correction for pairwise comparisons was used for statistical analysis (α = 0.05). Results: Storage time did not influence the VHN of the nano-hybrid composite in any group (p > 0.05). OptiBond XTR Primer application affected the VHN negatively in all investigated storage medium and time conditions (p < 0.05). Modeling Liquid application yielded improved Ra values for the specimens stored in coffee at each time point (p < 0.05). Modeling Liquid application was associated with the lowest ΔE values in all investigated storage medium and time conditions (p < 0.05). Conclusion: Different types of modeling agents could affect the surface properties and discoloration of nano-hybrid composites.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.391.2-391.2
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• 2014

Solution-processible hybrid bipolar field effect transistors (HBFETs) with balanced hole and electron mobilities were fabricated using a combination of the organic p-type poly (3-hexylthiophene) (P3HT) layer and inorganic n-type ZnO material. The hole and electron mobilities were first optimized in single layer devices by using acetonitrile as a solvent additive to process the P3HT and annealing to process the ZnO layer. The highest hole mobility of the P3HT-only-devices with 5% acetonitrile was 0.15 cm2V-1s-1, while the largest electron mobility was observed in the ZnO-only-devices annealed at $200^{\circ}C$ and found to be $7.2{\times}10-2cm2V-1s-1$. The inorganic-organic HBFETs consisting of P3HT with 5% acetonitrile and ZnO layer annealed at $200^{\circ}C$ exhibited balanced hole and electron mobilities of $4.0{\times}10-2$ and $3.9{\times}10-2cm2V-1s-1$, respectively. The effect on surface morphology and crystallinity by adding acetonitrile and thermal annealing were investigated through X-ray diffraction and atomic force microscopy (AFM). Our findings indicate that techniques demonstrated herein are of great utility in improving the performance of inorganic-organic hybrid devices

• Biomaterials and Biomechanics in Bioengineering
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• 제1권2호
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• pp.63-71
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• 2014

This study aimed to develop a novel bioactive hybrid xerogel consisting of silk fibroin /$SiO_2-CaO-P_2O_5$ by sol-gel process at room temperature. Scanning electron microscopy (SEM), FT-IR Spectroscopy, pore measurement, mechanical property testing, in vitro bioactivity test and cytotoxicity assay were performed to characterize the xerogel for bone tissue engineering application. We have found that the xerogel possessed excellent pore structures and mechanical property. Once immersed in a simulated fluid (SBF), the xerogel exhibited profound bioactivity by inducing hydroxyapatite layers on its surfaces. The cell toxicity study also demonstrated that there was little toxic to MC3T3-E1 cells. These results indicate that silk fibroin /$SiO_2-CaO-P_2O_5$ hybrid xerogel potentially could be used as a bone tissue engineering material.

• 한국초지조사료학회지
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• 제11권2호
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• pp.116-120
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• 1991

남부지방에서 유숙기에 수확한 수수의 사일리지 생산과 지엽출현기에 수확한 수수-수단그라스 교잡 종의 청예사료 생산에 알맞는 파종량을 알기 위하여 수수 2품종(P 931, P 956)과 수수-수단그라스 교잡 종 1품종을 4수준의 파종량(1. 2, 3, 4 kg/lOa)에서 재배하였다. 수수 P 931은 7월 22일, P 956은 7월 31 일에 1차 수확하였고, 수수-수단그라스 교잡종은 7 월 26일,8월 16일에 수확하였으며, 수수의 2차 및 수수-수단그라스의 3차 수확은 수확적기에 도달하지 않았으나 모두 10월 13일에 수확하여 그들의 사료가치와 생산성을 비교한 결과는 다음과 같다. 1. 수수와 수수-수단그라스 모두 파종량간에 수 확기, 간장, 초장, 건물비율은 차이가 없었다. 수수의 건물비율은 26.9~31. 2%로서 품종과 수확차수간에 차이가 없었으나 수수-수만그라스의 1자 수확은 10.0-10.7%, 2차 수확은 18.2~19.9%, 3차 수확은 24.6~27.8%로서 수확차수가 높을수록 건물비율이 높았다. 2. 수수 P 931이 P 956에 비하여 조섬유 함량은 높고, 가용성 무질소물은 더 낮았으나 조단백질과 조 지방 함량은 비슷하였다. 수수는 수수-수단그라스 보다 조단백질과 조회분의 함량은 낮고, 조섬유와 가용성 무질소물의 함량은 높았으나 조지빙은 비슷하였다. 3 .총 건물수량은 P 931>P 956>P 988의 순으로 높았다. 수수와 수수-수단그라스 교잡종의 1차 수확량은 파종량이 증가할수록 높았으나 2차 수확량은 파종량이 많을수록 감소하여 총 건물수량은 파종량 2-4 kg/lOa 사이에서는 차이가 없었다.

• Restorative Dentistry and Endodontics
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• 제47권2호
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• pp.21.1-21.11
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• 2022

Objectives: This study aimed to investigate the bonding effects of cleaning protocols on dentin impregnated with endodontic sealer residues using ethanol (E) or xylol (X). The effects of dentin acid etching immediately (I) or 7 days (P) after cleaning were also evaluated. For bonding to dentin, universal adhesive (Scotchbond Universal; 3M ESPE) was used. The persistence of sealer residues, hybrid layer formation and microshear bond strength were the performed analysis. Materials and Methods: One hundred and twenty bovine dentin specimens were allocated into 4 groups (n = 10): G1 (E+I); G2 (X+I); G3 (E+P); and G4 (X+P). The persistence of sealer residues was evaluated by SEM. Confocal laser scanning microscopy images were taken to measure the formed hybrid layer using the Image J program. For microshear bond strength, 4 resin composite cylinders were placed over the dentin after the cleaning protocols. ANOVA followed by Tukey test and Kruskal-Wallis followed by Dunn test were used for parametric and non-parametric data, respectively (α = 5%). Results: G2 and G4 groups showed a lower persistence of residues (p < 0.05) and thicker hybrid layer than the other groups (p < 0.05). No bond strength differences among all groups were observed (p > 0.05). Conclusions: Dentin cleaning using xylol, regardless of the time-point of acid etching, provided lower persistence of residues over the surface and thicker hybrid layer. However, the bond strength of the universal adhesive system in etch-and-rinse strategy was not influenced by the cleaning protocols or time-point of acid etching.

• 식물조직배양학회지
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• 제22권2호
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• pp.105-110
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• 1995

Petunia hybrida와 Nicotiana sanderae의 원형질체를 융합하여 체세포잡종식물을 얻고자 융합산물의 배양에 의해 얻은 개체들에 대해 유전분석을 하였다. 재분화 개체중 융합된 것으로 인정되는 개체의 peroxidase pattern은 두 모본의 band를 모두 가진 개체(A-D patterns)에서 나타난 band중 p. hybrida에서 나타난 band 이외에 최상부에 1개의 band가 추가되었는데 이는 융합을 판별할 수 이는 중요한 marker 로서 가능성이 있으며, aspartate aminotransferase isoenzyme pattern은 두 모본의 양상이 모두 나타나거나 N. sanderae의 상부 band가 소실된 개체도 있었다. 염색체 검경에서 P.hybrida는 2n=14, M sanderae는 2n=18개로 나타났으며, 동위효소검정에서 체세포 잡종일 것으로 추정되는 개체들은 2n=32-36으로 나타났다. 표현형 관찰에서 체세포잡종으로 인정되는 개체의 형태적 특징은 두 모본의 중간형태를 나타내었다.

• 한국통신학회논문지
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• 제25권10B호
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• pp.1701-1706
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• 2000

본 연구에서 GaAs pHEMT와 도파관-마이크로스트립 변환구조를 이용하여 38 GHz 대역 하이브리드 전력증폭기 모듈이 개발되었다. 10 mil duroid 기판이 전력증폭가와 도파관-마이크로스트립 변환구조 제작에 사용되었다. 제작된 도파관-마이크로스트립 변환구조는 32 - 40 GHz 대역까지 약 I dB 삽입손실(back to back)의 측정 결과를 보였다. 전력증폭기 모듈의 측정 결과, 36.8 - 38.5 GHz에서 대략 출력 전력 29 dBm(P1.5 dB), 전력 이득은 7.2 dB, PAE 는 11.2 % 였다.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2003년도 추계학술발표대회(하)
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• pp.766-769
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• 2003

최근 수 년간 클라이언트/서버 모델에서 발생하는 문제인 서버 병목 현상, DoS(Denial of Service) 공격, 그리고 시스템의 확장성에 따르는 비용 증가 등의 문제를 해결하기 위한 방법으로 P2P(Peer-to-Peer)의 프로토콜 개선과 통신 모델 개선에 대해서 연구가 활발히 진행되고 있다. 본 논문에서는 기존의 멀티캐스트 프로토콜들을 살펴보고 제안하는 멀티캐스트 프로토콜인 GSAKMP(Group Secure Association Key Management Protocol )를 이용한 보안 멀티캐스트 환경을 구현 한다.