• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1611-1618
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• 2018

Objective: The objective of this experiment was to examine the effects of different amylose/amylopectin ratios on rumen fermentation and development of fattening lambs. Methods: Forty-eight 7-day-old male Small-tailed Han sheep${\times}$Northeast fine wool sheep were randomly assigned to four treatments of dietary amylose/amylopectin ratios (0.12, 0.23, 0.24, and 0.48 in tapioca starch, corn starch, wheat starch and pea starch diets, respectively). Three lambs from each treatment were slaughtered at 21, 35, 56, and 77 days of age to determine the rumen fermentation and development. Results: Compared with tapioca starch diet, the pea starch diet significantly increased the concentration of ammonia nitrogen in the ruminal fluid of lambs but significantly decreased the bacterial protein content. At 56 and 77 d, the rumen propionate concentration tended to be greatest in the tapioca starch group than in other groups. The rumen butyrate concentration was the greatest in lambs fed on pea starch compared with those fed on other starch diets. Furthermore, the pea starch diet significantly stimulated rumen development by increasing the papillae height, width and surface area in the rumen ventral or dorsal locations in lambs. However, different amylose/amylopectin ratios diets did not significantly affect the feed intake, body weight, average daily gain, the relative weight and capacity of the rumen in lambs with increasing length of trial periods. Conclusion: Lambs early supplemented with a high amylose/amylopectin ratio diet had favourable morphological development of rumen epithelium, which was not conducive to bacterial protein synthesis.

• 한국컴퓨터산업학회논문지
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• 제7권3호
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• pp.245-252
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• 2006

양극화로 인한 소외계층이 심화되고 고령화에 따른 사회복지가 대응하는 시간적 간격이 너무나 커지고 있다. 특히, 독거노인 환자의 증가로 인한 무관심이 사회문제로 비화되고 있는 실정이다. 더불어, 재택 골절환자의 비율도 급상승하고 있다. 국내적으로는 BT기술, 의료솔루션 기술은 현대기술의보조적 역할보다는 중추적인 역할을 제공하고 창조적 기술로 활용할 수가 있다. 특히, 초음파를 골절치료에 적용하면, 뼈가 잘 안 붙는 뼈의 골절치료 기간을 40% 가량 줄일 수 있다는 논문자료도 있다. 본 연구에서는 초음파 작동주파수가 1mHz, 1.3mHz, 1.5mHz의Piezo-ceramic crystal tranducer물질을 가지는 초음파 발생원 각각 4개를 한조로 하여 양단에 사용하였고, 임피이던스 및 Phase측정결과에 따라 외부직경이 각각4mm, 5.4mm, 두께0.5mm, 길이 70mm의 트랜스듀스를 사용하였다. 용량 50mW급으로 제작하였고, 초음파분포도를 조사하였다. <중략> 차후 시스템을 보완하면 골다공증 환자에도 적용이 될 것이고, 본 연구에서는 시제품을 직접 설계하고 비정형화 특성을 연구하고 기본적인 형태를 모델링 하여 접근해 보고자 노력해 보았다.

• 한국환경복원기술학회지
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• 제8권1호
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• pp.63-72
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• 2005

Chirisan National Park, the first and largest one out of 20 national parks in Korea, is divided into five zones. They are composed of nature preservation zone, natural environment zone, natural residential zone, concentrated residential zone, and collective facility zone. However, the park is not a continuous habitat: roads, trails, local residences, and various facilities created the habitat mosaics severely fragmented. We investigated the fragmentation pattern of the park due to roads and mountain trails using GIS. Based on perimeter length, area, and the ratio of perimeter to area of each patch, we obtained landscape analysis indices which reflect the regularity of the patch shape. The 1 m-wide hiking trails divided the park into 491 fragments. The legal trails with 1.5 m - 3 m width which have been heavily used by hikers generate 58 fragments. Even the nature preservation zone, corresponding to a core zone comprising 31.8% of the park area, was divided into 37 fragments because of the roads and mountain trails. With the different widths of buffer applied, the core sizes of the fragments were reduced. When the 60 m buffer was applied, the patch interior areas ranged from 0.0001 to 47.77 $km^2$ with a mean of 7.08 $km^2$. The landscape shape indices were far greater than 1 for most of the cases with a maximum value of 25. These results clearly indicate that Chirisan National Park is not a continuous habitat, but mosaics of small, irregularly shaped habitat fragments. It is necessary to take the size and shape of the fragmented habitats into consideration when nature conservation is planned, especially for large wildlife such as brown bears.

• Computers and Concrete
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• 제20권4호
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• pp.391-407
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• 2017

Fiber reinforced polymer (FRP) bars have been recently used to reinforce concrete members in flexure due to their high tensile strength and especially in corrosive environments to improve the durability of concrete structures. However, FRPs have a low modulus of elasticity and a linear elastic behavior up to rupture, thus reinforced concrete (RC) components with such materials would exhibit a less ductility in comparison with steel reinforcement at the similar members. There were several studies showed the behavior of concrete beams with the hybrid combination of steel and FRP longitudinal reinforcement by adopting the experimental and numerical programs. The current study presents a numerical and analytical investigation based on the data of previous researches. Three-dimensional (3D) finite element (FE) models of beams by using ANSYS are built and investigated. In addition, this study also discusses on the design methods for hybrid FRP-steel beams in terms of ultimate moment capacity, load-deflection response, crack width, and ductility. The effects of the reinforcement ratio, concrete compressive strength, arrangement of reinforcement, and the length of FRP bars on the mechanical performance of hybrid beams are considered as a parametric study by means of FE method. The results obtained from this study are compared and verified with the experimental and numerical data of the literature. This study provides insight into the mechanical performances of hybrid FRP-steel RC beams, builds the reliable FE models which can be used to predict the structural behavior of hybrid RC beams, offers a rational design method together with an useful database to evaluate the ductility for concrete beams with the combination of FRP and steel reinforcement, and motivates the further development in the future research by applying parametric study.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.467-470
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• 2009

외부적으로 직렬 및 병렬로 접속된 50개의 DSSC로써 새로운 8 V DC 전원을 만들었다. 한 개의 DSSC는 $5.2{\times}2.6$ cm(유효면적 8 $cm^2$) 약 4.2%의 효율을 보이며, 전기화학적 임피던스 분석법 및 I-V 곡선으로 특성이 분석되었다. 또한 펄스형 Nd:YAG 레이저 빔을 활용하여 투명 도전층을 식각함으로써, 최종효율 약 45%를 달성하였다.

• ALGAE
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• 제39권2호
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• pp.97-108
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• 2024

The Ralfsiaceae family, part of the Ralfsiales order and consisting of crustose brown algae, includes five genera: Analipus, Endoplura, Fissipedicella, Heteroralfsia, and Ralfsia. In this study, a novel crustose genus named Ramipedicella gen. nov. is introduced within the Ralfsiaceae based on molecular and morphological analyses. Phylogenetic analyses using both concatenated dataset (rbcL + COI-5P genes) and rbcL indicate that the crustose brown algae that we collected from Korea and Russia form a unique grouping within the Ralfsiaceae. This grouping is strongly supported by both bootstrap analysis and Bayesian posterior probabilities. The genetic differences in the rbcL and COI-5P sequences between Ramipedicella and other genera within Ralfsiaceae range from 6.7 to 9.3% for rbcL and from 15.5 to 20.8% for COI-5P. Ramipedicella is characterized by crustose thalli having new crusts growing on top of old ones with a hypothallial basal layer and erect perithallial filaments, long cells with width-to-length ratio of 1 : 1-16, single chloroplast per cell, plurangia with one to several sterile cells, one to several unangia produced from unicellular stalks or from the lateral-basal region to the paraphyses, and unangia arising sequencially in irregularly branched specialized filaments. Ramipedicella, the recently identified genus, comprises two distinct species. Ramipedicella miniloba, the type species, is distinguished by crusts with small lobes, numerous hair tufts, plurangia terminated by 1-4 sterile cells, and large oblong unangia. Ramipedicella longicellularis is identified by generally smooth crusts, absence of phaeophycean hairs, plurangia terminated by 1-2 apical sterile cells, and smaller mostly oblanceolate unangia.

• 한국안전학회지
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• 제23권2호
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• pp.87-97
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• 2008

일선대교는 복부 파형강판 복합교랑 형식으로서 연장파 폭원으로는 세계 최대의 규모이다. 총 14개 경간으로 구성된 일선대교는 압출공법(ILM)에 의하여 12개 경간이 연속구조로 건설되고 나머지 2개 경간은 동바리공법(FSM)에 의하여 건설된다. 본 논문에서는 동일한 구조형식으로는 국내에서 최초로 건설되며 해외에서도 유례가 없는 광폭과 장경간의 복부 파형강판 복합교량인 일선대교를 압출공법에 의하여 시공하면서 수행된 구조 안전성분석과 관련된 주제들을 다루고 있다. 이러한 과정을 통하여 지간-형고비, 복부 파형강판의 전단응력, 그리고 압출추진코의 최적 길이 등이 파형강판 복합구조 교량의 시공중 및 사용중 안전성에 큰 영향을 미칠 수 있는 것으로 분석되었다. 특히, 일선대교와 같은 복부 강재구조를 갖는 복합교량은 박스거더, 추진코, 그리고 연결 격벽의 강성차가 크기 때문에 기존의 방법에 의한 단면력 분석은 적합하지 않은 것으로 확인되었다. 이에 따라 압출 추진코의 길이, 구조물의 강성 등을 변수로 압출중 최대 부모멘트에 대한 검토를 수행하였으며 최종적으로는 상세 구조해석을 통하여 구조물의 시공 중 안전성을 확인하였다.

• 한국산학기술학회논문지
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• 제19권7호
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• pp.481-492
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• 2018

본 강판 콘크리트 합성보는 강판, 콘크리트 및 전단 연결재로 구성되어 2개의 이질 재료를 결합한다. 일반적으로 강판은 기존의 합성보에 용접하여 조립된다. 이 연구에서, SPC 보는 스터드가 없는 강판과 콘크리트로 구성된다. 절곡한 강판은 용접 대신 고강도 볼트로 조립된다. 현장 건설의 작업성을 향상시키기 위해 슬래브와 접합부에 모자 모양의 Cap이 부착되어있다. Cap을 전단연결재로 사용하여 SPC 보의 휨성능을 분석하기 위해 변위 제어 모드에서 단조 하중 2점가력 실험을 수행 하였다. 전단 연결재 유형, 돌출 길이, 강판의 두께의 변수를 갖는 5개의 시험편을 제작하여 시험 하였다. KBC 2009에서 제시하는 전단강도비와 휨강도비의 관계를 분석하였다. 시험 결과로 전단 강도비를 40% 이상으로 나타냈다. 전단 연결재와 Cap을 부착하였음에도 완전합성보로 가정한 휨강도의 70% 이상의 휨강도를 발휘하였다. 또한 Cap이 스터드 보다는 작은 전단강도를 보였으나, Cap이 전단연결재 역할을 하였다. 강판두께를 변수로 한 경우, 완전합성보 대비 약 70%의 휨강도를 발휘하였으며, 유사한 변형성능을 나타내었다. 불완전합성거동함에 따라 국부좌굴이 발생하였으나, 상대적으로 두꺼운 강판의 경우 5% 높은 강도에서 국부좌굴이 발생하였다. 또한 좌굴폭이 15% 감소하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.52-52
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• 2009

To date, chalcogenide alloy such as $Ge_2Sb_2Te_5$(GST) have not only been rigorously studied for use in Phase Change Random Access Memory(PRAM) applications, but also temperature gap to make different states is not enough to apply to device between amorphous and crystalline state. In this study, we have investigated a new system of phase change media based on the In-Sb-Te(IST) ternary alloys for PRAM. IST chalcogenide thin films were prepared in trench structure (aspect ratio 5:1 of length=500nm, width=100nm) using Tri methyl Indium $(In(CH_3)_4$), $Sb(iPr)_3$ $(Sb(C_3H_7)_3)$ and $Te(iPr)_2(Te(C_3H_7)_2)$ precursors. MOCVD process is very powerful system to deposit in ultra integrated device like 100nm scaled trench structure. And IST materials for PRAM can be grown at low deposition temperature below $200^{\circ}C$ in comparison with GST materials. Although Melting temperature of 1ST materials was $\sim 630^{\circ}C$ like GST, Crystalline temperature of them was ~$290^{\circ}C$; one of GST were $130^{\circ}C$. In-Sb-Te materials will be good candidate materials for PRAM applications. And MOCVD system is powerful for applying ultra scale integration cell.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.249-253
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• 2014

An 8-week feeding experiment was conducted to determine the influence of dietary distillers dried grain (DDG) on the growth and body composition of juvenile abalone Haliotis discus hannai. Five diets were formulated to contain 0% (DDG0), 15% (DDG15), 30% (DDG30), 45% (DDG45), and 60% (DDG60) DDG, and three replicate groups of abalone (average body weight: $3.6{\pm}0.21$ g) were fed one of the experimental diets at a feeding rate of 5% body weight per day once daily (17:00 h) for 8 weeks. Survival, shell length, and shell width of juvenile abalone were not affected by dietary DDG levels (P > 0.05). Weight gains of juvenile abalone fed DDG15 and DDG30 diets were not different compared to DDG0, but abalone fed DDG45 and DDG60 diets gained less weight than those fed DDG0 (P < 0.05). Soft body weight/body weight ratio of juvenile abalone fed the DDG60 diet was lower than that of those fed the DDG0 diet (P < 0.05), but proximate composition of the soft body was not affected by dietary DDG levels (P > 0.05). The results of this experiment suggest that DDG is a good replacement for wheat flour and soybean meal, and can be used up to 30% in the diet to maintain the growth performance of the juvenile abalone.