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        검색결과 1,895

        963.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Cowherd Star and the Weaving Maid Star have been famous stars in East Asian countries. Nowadays Altair is defined to be the Cowherd Star in public materials including science books, mass media, public outreach programs, and movies played in public planetariums and science museums. However, in astronomical books and star-charts in history, the Cowherd Big Star (牽牛大星) has been known to be Dabih or β Cap in the constellation Capricorn, and the asterism Cowherd consists of six stars including Dabih. Since the same title is given to the different objects simultaneously, considerable misunderstanding and confusion among the public have occurred. In this paper we consider this problem in two aspects. One aspect is which star has been defined to be the Cowherd Star in ancient literatures; the other is which stars were regarded as the Cowherd or the Cowherd Star in the historical records of occultation or conjunction in History of Koryo, Annals of the Choson Dynasty, and Daily Records of Royal Secretariat of the Choson Dynasty. As a result, we see that Altair has been regarded as the Cowherd Star in folklore and literature, but Dabih has been defined to be the Cowherd Big Star in astronomical works. An explanation proposed by previous researchers on the reason why such double meanings have been appeared is introduced. In the explanation, the fact that the Altair was defined as the Cowherd Star in ancient times had not been handed over properly, and the name of Cowherd was later put to the Dabih and its surrounding five stars to form one of 28 lunar lodges. Based upon these facts, we suggest the following ideas: (1) Altair should be introduced to be the Cowherd Star in public-friendly programs, and Dabih should be noticed to be the Cowherd Big Star in the field of history of astronomy. Dabih should be added as the astronomical Cowherd Big Star in academic books such as a dictionary of astronomical terminology. (2) The Korean pronunciation for Altair should be al-tear instead of al-tairu in accordance with the definition in the astronomical terminology dictionary compiled by the Korean Astronomical Society.
        4,200원
        964.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 폐기되고 있는 제지슬러지의 자원 재활용을 위한 육묘용 상토로서 이용 가능성을 알아보기 위해 수행되었다. 상업 용토 토실이를 대조구로 하여 제지슬러지와 토실이의 혼합 상토 (1:1, v:v), 그리 고 제지 슬러지 단용 상토를 처리로 하였다. 토마토의 육묘 결과, 제지슬러지 혼합 상토에서의 생육은 토실이 상토와 비교하여 초장, 근장, 생체중과 건물중 등에서 그 차이 없었다. 반면, 제지슬러지 단용 상토에서의 생육은 현저히 억제되는 것으로 나타났다. 이러한 결과는 오이묘의 생육결과에서도 반영 되 어 제지슬러지 단용 상토의 오이묘 생육은 현저히 억제되었다. 본 시험의 결과, 제지슬러지의 자원 재활 용을 높이기 위해서는 미 가공 제지슬러지의 높은 pH와 EC의 안정화, 그리고 Zn의 함량을 낮추는 등의 처리가 선행 되어야 할 것으로 판단된다.
        4,000원
        965.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Films consisting of a silicon quantum dot superlattice were fabricated by alternating deposition of silicon rich silicon nitride and Si3N4 layers using an rf magnetron co-sputtering system. In order to use the silicon quantum dot super lattice structure for third generation multi junction solar cell applications, it is important to control the dot size. Moreover, silicon quantum dots have to be in a regularly spaced array in the dielectric matrix material for in order to allow for effective carrier transport. In this study, therefore, we fabricated silicon quantum dot superlattice films under various conditions and investigated crystallization behavior of the silicon quantum dot super lattice structure. Fourier transform infrared spectroscopy (FTIR) spectra showed an increased intensity of the 840 cm-1 peak with increasing annealing temperature due to the increase in the number of Si-N bonds. A more conspicuous characteristic of this process is the increased intensity of the 1100 cm-1 peak. This peak was attributed to annealing induced reordering in the films that led to increased Si-N4 bonding. X-ray photoelectron spectroscopy (XPS) analysis showed that peak position was shifted to higher bonding energy as silicon 2p bonding energy changed. This transition is related to the formation of silicon quantum dots. Transmission electron microscopy (TEM) and electron spin resonance (ESR) analysis also confirmed the formation of silicon quantum dots. This study revealed that post annealing at 1100˚C for at least one hour is necessary to precipitate the silicon quantum dots in the SiNx matrix.
        4,000원
        966.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources.The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use ofmaterials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorptionof incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap.Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the 1st and 2nd generation solarcells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using anSi quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an SiOx matrix system was investigatedand analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QDSLS) were prepared by alternating deposition of Si rich oxide (SRO; SiOx (x=0.8, 1.12)) and SiO2 layers using RF magnetronco-sputtering and subsequent annealing at temperatures between 800 and 1,100oC under nitrogen ambient. Annealing temperaturesand times affected the formation of Si QDs in the SRO film. Fourier transform infrared spectroscopy (FTIR) spectra and x-rayphotoelectron spectroscopy (XPS) revealed that nanocrystalline Si QDs started to precipitate after annealing at 1,100oC for onehour. Transmission electron microscopy (TEM) images clearly showed SRO/SiO2 SLS and Si QDs formation in each 4, 6, and8nm SRO layer after annealing at 1,100oC for two hours. The systematic investigation of precipitation behavior of Si QDsin SiO2 matrices is presented.
        4,000원
        967.
        2010.11 구독 인증기관 무료, 개인회원 유료
        호남권 해안은 대한민국의 전체해안선 중에서도 갯벌의 면적이 가장 크며, 세계적으로 인정받는 청정 갯벌지역을 보유하고 있다. 본 연구에서는 갯벌을 대상으로 하고 있는 관광 자원과 활용 방법을 알아보고자 한다
        3,000원
        968.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The regeneration of periodontium is the goal of periodontal therapy. Many periodontologists try to achieve this goal by using guided tissue regeneration(GTR) method. However, these procedures always include several disadvantages. Recombinant human bone morphogenetic protein-2 (rhBMP-2) stimulated ectopic bone formation when it was implanted in rat muscles with insoluble bone matrix by differentiating muscle cells into chondrocytes and osteoblasts. The purpose of this study was to evaluate the osteoinductive potential of the mixture of rhBMP-2 (5 μg/ml) and heparin (0.25 or 25 μg/ml ) at the critically sized rabbit calvarial defects. And this study aimed to reveal that heparin also acts to enhance the bone forming activity of rhBMP-2. The 12 rabbits (4-month-old; NewZealand White) were used in the present study. 5 μg/ml of rhBMP-2 and 0, 0.25 or 25 μg/ml of heparin were mixed and blotted into anorganic bovine bone and filled cranial defects. The animals were sacrificed following a time schedule (1, 3, and 6 weeks). Sections were made in 7 μm thicknesses, stained with H&E and Masson's trichrome method, and examined under a light microscope. The differences among each obtained percent value were evaluated by one-way analysis of variance. A p value of p<0.05 was considered statistically significant and an ANOVA test was performed to verify significant differences. To adjust for multiple comparisons when one-way analysis of variance showed a significant difference between groups (p<0.05), Scheffe`s post hoc test was used to identify which group differences accounted for the significant p-value. In control group, osteoinduction was not outstanding, however, in experimental groups, osteoinduction was significantly outstanding, and as the concentration of heparin mixed with rhBMP-2 increased, osteoinduction was increased. Mixtures of rhBMP-2 and heparin affect bone formation at initial bone formation, but that effect disappeared following a time lapse.
        4,300원
        969.
        2010.10 구독 인증기관·개인회원 무료
        썩덩나무노린재(Halyomorpha halys Stal))는 노린재목(Hemiptera) 노린재과 (Pentatomidae)의 곤충으로서 감귤을 비롯해 감, 복숭아등 과수와 콩과식물을 가 해하는 작물 해충으로 알려져 있다. 본 연구는 썩덩나무노린재 방제약제선발, 유 인물질 연구 등에 이용하고자 실내 개체군을 수립하였으며 산란행동을 구명하였 다. 2009년 10월~11월 제주시 유기농 감귤원에서 채집한 약 20마리 썩덩나무노린 재 성충을 초기 개체군으로 시작하였다. 아크릴 케이지(크기 110×70×55cm)에 자 율적으로 먹이에 접근하도록 하였고 최대한 인위적인 노력이 투입되지 않도록 관 리하였다. 산란재료 및 수분공급을 위한 식물재료로 칼랑코에 및 페페(소형 포트 20개)를 제공하였다. 주먹이로는 검은콩 및 생땅콩을 충분히 제공하였고, 사육실 온도 25±1℃, 상대습도 40~70%, 광 16L:8D 조건에서 사육하였다. 상기와 같은 방법으로 초기 개체군이 효과적으로 정착하여 규모화 된 실내 개체군(2010년 9월 현재)을 유지 시킬 수 있었다. 교미행동 관찰결과 수컷이 더듬이 및 머리 앞부분을 이용 뒤쪽에서 암컷의 복부 끝을 두드리고, 이 때 암컷이 교미를 수락하는 경우 복 부 끝을 들어 올리게 되며, 그러면 수컷이 돌아서서 교미에 성공하였다. 산란은 적 게는 13개에서 많게는 39개까지 무더기로 알을 낳았고, 난괴 당 평균 알 수는 28.5 개 이었다. 알을 낳는데 걸리는 시간은 1개의 알을 낳는데 2분 27초에서 2분 32초 사이가 걸렸고, 총 산란시간은 1시간 18분에서 21분까지 소요되었다.
        974.
        2010.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Adsorption of a water molecule on a Si (001) surface and its dissociation were studied using density functional theory to study the distribution of -OH fragments on the Si surface. The Si (001) surface was composed of Si dimers, which buckle in a zigzag pattern below the order-disorder transition temperature to reduce the surface energy. When a water molecule approached the Si surface, the O atom of the water molecule favored the down-buckled Si atom, and the H atom of the water molecule favored the up-buckled Si atom. This is explained by the attractions between the negatively charged O of the water and the positively charged down-buckled Si atom and between the positively charged H of the water and the negatively charged up-buckled Si atom. Following the adsorption of the first water molecule on the surface, a second water molecule adsorbed on either the inter-dimer or intra-dimer site of the Si dimer. The dipole-dipole interaction of the two adsorbed water molecules led to the formation of the water dimer, and the dissociation of the water molecules occurred easily below the order-disorder transition temperature. Therefore, the 1/2 monolayer of -OH on the water-terminated Si (001) surface shows a regular distribution. The results shed light on the atomic layer deposition process of alternate gate dielectric materials, such as HfO2.
        4,000원
        975.
        2010.09 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate the characteristics within ages and freezing tolerance of spermatozoa in Jindo Dog. Experimental animals were selected 12 herds within 1~8 year’s old and collected semen for 2 times in a week. Collected semen was evaluated whole volume and sperm number with CASA system (SIAS, Medical Supply, Korea). Then seminal plasma were separated and diluted with modified Tris-egg yolk extender and added 4, 6 and 8% glycerol for 4 times to final concentration and equilibrated for 1.5 hrs. Before and after freezing, equilibrated semen were evaluated the survival rates. Total volume of sperm at 1~2 year old group is as 5.2×108 cells/ ml largest and there were no significance among groups. The motility of 1~2 year old group is highest as 90.9% and there were significance among groups. Abnormal sperm showed similar among groups. The survival rate in terms of pre-freezing and post-freezing were decreased all levels of glycerol and reveled 87.0% to 64.5% in 4%, 87.5% to 51.9% in 6% and 73.4% to 29.7% in 8%, there were significant difference among the groups (p<0.05). These results suggest that the optimal sperm-freezing methods in Jindo Dog are utilized with modified Tris egg-yolk extender with 4% glycerol and were improve the reproductive activity by these methods.
        3,000원
        976.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose : In order to verify using Convergence Insufficiency Symptom Survey(CISS) is proper method to distinguish convergence insufficiency(CI) group and normal binocular vision(NBV) group in adults. Methods : 97 subjects 19 to 35 with normal VA and no strabismus participated in this study. Phoria, positive fusional vergence(PFV), nearpoint of convergence(NPC) and accommodation convergence/ accommodation(AC/ A) of 97 were measured. Results : According to criteria, 62 subjects were included in this study and analysed with CISS. Nine subjects had CI and 53 had NBV. General symptoms of CI group were significantly greater occurrence of Jose concentration, tiredness, sleepiness, uncomfort, double vision and blurring in that order. A significant difference between CISS seore of CI subjects (mean±SD: 25.67±7.67) and NBV group(l2.74 ±4.80) were found(p=O.OOO). The area under the ROC curve was 0.955 indicating outstanding discrimination using the CISS. Using seores of 21 or higher to denote CI, a sensitivity of 88.9% and specificity of 98.1% were obtained. Conclusions : The results suggest that the CISS is a valid instrument for differentiating adults with symptomatic CI from those with symptomatic NBV. Adopting score 21 as cutoff value, it is proved that distinguishing Cl from normal is most precise. Additionally, Adults in this age group were able to respond to a broad range of symptom questions associated with CI. It. therefore, demonstrates CISS is a valid preliminary examination to scan CI patient.
        4,000원
        977.
        2010.09 구독 인증기관 무료, 개인회원 유료
        스크린 인쇄공법을 이용하여 구형 실리콘 태양전지용 전면 전극을 제작하였고 그 물성을 검토하였다.집광형 구형 실리콘 태양전지는 종래의 결정질 실리콘 태양전지 발전 시스템 설치비용 중 21%를 차지하는 실리콘 소재의 사용량을 줄이기 위해 볼 형태의 구형 실리콘을 사용하였고, 입사되는 태양광을 최대한 활용하기위해 알루미늄으로 된 집광판을 사용하는 것을 특징으로 한다. 전도성 필러로써 Flake 형태의 Ag 파우더를 사용하였고, 기재와의 접착력을 부여하기 위한 유기 바인더로서 에폭시수지, 폴리에스테르수지,아크릴수지 등을 비교 검토한 결과, 에폭시수지 고형분 12%를 첨가한 paste가 기재와의 접착성, 태양전지 광전변환효율, 내구성에서 가장 우수함을 알 수 있었다.
        4,200원
        978.
        2010.09 구독 인증기관 무료, 개인회원 유료
        최근 전자 디스플레이에서 각광받고 있는 터치스크린은 급속한 정보화 사회 속에서 비약적인 발전을 거듭하고 있다. 터치패널은 키보드나 마우스와 같은 입력장치를 사용하지 않고, 화면에 나타난 문자나 특정 위치에 사람의 손 또는 물체가 닿으면 그 위치를 파악하여 특정한 기능을 처리하도록 한 패널이다. 이러한 터치스크린에서의 터치패널용 Ag 페이스트는 대부분 열 경화형 페이스트를 사용하고 있다. 이러한 열 경화형 페이스트는 건조공정에 따른 열에너지 소비와 유기용제에 따른 작업환경 개선의 문제점을 가지고 있다. 본 연구에서는 기존에 사용되는 열 경화형 Ag 페이스트가 아닌 친환경적이고 경제적인 UV 경화형 페이스트를 제조하였다. 현재 시판중인 열 경화형 바인더 대신 UV 경화형 올리고머를 사용하였고 유동특성을 부여하기 위해 단관능 모노머를 첨가하여 전도성 Ag paste 패턴형성을 할 수 있었다. 그 결과 열 경화형 Ag 페이스트만큼 접착력, 경도, 내성 등이 우수하였으며 미세패턴의 재현이 가능했으며 스크린 인쇄를 이용한 친환경적인 패터닝 기술로서의 가능성을 확인할 수 있었다.
        4,200원
        979.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bone morphogenetic proteins (BMPs) are known to promote osteogenesis, and clinical trials are currently underway evaluating the ability of BMPs to promote bone formation in grafting procedures and fracture healing. Some studies, have independently reported that sulfated polysaccharides particularly heparin, enhance the osteoblastic differentiation induced by BMPs in vitro, and another study demonstrated that heparin enhanced the bone formation induced by BMP‐2 in vivo. This study was performed to examine adipose stem cell responses to rhBMP‐2 alone and rhBMP‐2 with heparin at 0.25, and 25 μg/㎖ concentrations, respectively, in culture media. Adipose stem cells were cultured for 2, 4, and 8 days toward the osteoblastic differentiation in rhBMP‐2 alone and rhBMP‐2 with heparin at 0.25, and 25 μg/㎖ concentrations, respectively, in culture media. Verification of the stem cell lineage was performed in two ways. The first method was a continuous sequential culture until 5th generation. The second method was using monoclonal antibodies for STRO‐1 and CD 90. Naphthol AS phosphate‐fast blue BB staining for alkaline phosphatase was used for verifying osteoblastic differentiation because Alkaline phosphatase activity had been used as an osteoblastic differentiation marker and degree of osteoblastic activity. Alizarin red staining was also used as an osteoblastic differentiation marker because it quantifies the calcium levels in cells or tissues. During the 5th generation culture, cultured cells actively proliferated, and these cultured cells showed a positive reaction to STRO‐1 and CD90 cell surface molecules. Naphthol AS phosphate‐fast blue BB staining and Alizarin red staining were positive in most samples of each group at 2, and 4 days and positive reaction was proportioned to degree of morphological differentiation. In the concentration of 25 μg/ml of heparin, the ALP activity was highest at the 2nd day in the culture, and then the activities of ALP were decreased significantly at 4, and 8 days. The ALP activity was greatest at the 4th day of the culture, and then decreased significantly at the 8th day in 0 μ g/ml and 0.25 μg/ml of heparin concentrations, Adipose stem cells could be differentiated in rhBMP‐2 in culture media, and the addition of heparin to BMP‐2 promoted differentiation of osteoblasts. Moreover, morphological differentiation was associated with the activity of osteoblasts. This study was shown that, when heparin concentration increases, the early differentiation of the cells was brought about, but the early differentiated cells were rapidly progressed to degenerative changes
        4,000원
        980.
        2010.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구지역의 지형은 해안과 인접한 소규모의 곡저평야에 속한다. 이 곡저평야는 낮은 구릉지 사이 개석된 곳에 충적물이 매적되어 형성되었다. 본 연구에서는 탄소안정동위원소비 분석과 토양유기탄소 분석을 이용하여 과거의 기후환경 복원을 시도하였다. I 시기(약 6,600±60 yr B.P.-5,350±60 yr B.P.)는 전반적으로 온난하고 습윤한 기후환경이었으나, 건습변화에 있어서는 약건조(또는 약습윤)→습윤의 미변화가 감지된다. II 시기(약 5,350±60 yr B.P.-2,200 yr B.P.)는 현재와 비슷한 온난습윤한 기후환경을 나타낸다. 4,720±60 yr B.P.와 4,210±50 yr B.P. 사이는 전체 퇴적층 중 가장 습윤했던 것으로 파악된다. 4,210±50 yr B.P. 이후에는 점차 습윤에서 약습윤(또는 약건조)환경으로 이행하는 과정이 나타난다. III 시기(약 2,200 yr B.P.-210±60 yr B.P.)는 앞선 두 시기와 확연히 구분되며, 약습윤(또는 약건조)의 기후환경을 나타낸다.
        4,000원