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      • WDM 시스템용 광대역 증폭기의 시뮬레이션

        李鎬俊,沈雲用,鄭白鎬 湖西大學校工業技術硏究所 1999 工業技術硏究所論文集 Vol.18 No.-

        In recent years, the biggest issue of WDM system is in increasing its bandwidth. Transmission bandwidth of WDM may be limited by many kinds of component, and the bandwidth plays impotent role in most of all optical amplifiers. Transmission bandwidth of recent WDM is limited in about 40 nm. This limit depends on EDFA(?? Fiber Amplifier) gain bandwidth. To overcome this problem, we may use L and S band using Yb/Nd doped fiber amplifier. Wideband amplifier, which is consisted of RFA for L band and EDFA for M band using single pump laser diode, is presented. The amplifiers have been analyzed numerically for the design.

      • KCI등재
      • 濟州道産 가무락, Cyclina sinensis의 生殖週期에 關한 組織學的 硏究

        李定宰,趙雲三 濟州大學校 海洋資源硏究所 1985 해양과환경연구소 연구논문집 Vol.9 No.-

        濟州道産 가무락, Cyclina sinensis의 生殖巢 構造, 生殖細胞形成過程 및 生殖過期를 光學顯微鏡 및 電子顯微鏡을 使用하여 調査하였다. 1. 生殖巢는 內臟囊의 肝中腸腺 上端에서 足部까지 外側의 大部分을 싸고 있으며 卵巢는 많은 卵巢小囊으로, 精巢 또한 小管狀의 精巢小囊으로 構成되어 있으며 이들 小囊의 內脫上皮가 生殖細胞의 機能을 한다. 2. 生殖巢 外壁은 420∼600㎛로 매우 두꺼우며 上皮層은 30∼40㎛의 單層圓柱상계로 構成되어 있고 이들 上皮層 下方에는 50㎛두께의 結綿纖膠原纖維와 筋纖維가 緻密하게 結合되어 있으며, 下方으로 80㎛두께의 立方形 粘液腺細胞層과 上下層은 從으로, 中層은 橫으로 排列된 結綿纖膠原纖維와 筋纖維가 260∼430㎛의 두꺼운 層으로 되어있다. 3. 未分化間充織과 好酸性顆粒細胞들은 生殖巢 및 生殖細胞형성과 發達에 管養을 供給하는 一種의 管養細胞로 간주된다. 4. 卵母細胞가 70㎛ 前後로 成長하여 卵柄에서 離脫되어 完熟卵의 크기는 90∼120㎛ 前後였다. 5. 卵母細胞의 卵膜과 核膜은 二重膜狀 構造이며, 細胞質內의 卵黃顆粒은 皮質層 內側으로 擴散되며, 脂質顆粒은 核膜 附近에서 出現하여 皮質層으로 分散되었다. 6. 完熟精子의 頭部는 約 5㎛, 尾部는 20㎛ 內外로서 前端의 尖體는 電子密屠가 相異한 두 區域으로 區分되고 尖體와 核 사이에 透明腔이 存在하고 鞭毛의 軸絲構造는 9+2型이며 4個의 球型 mitochondria가 中心體를 둘러싸고 있다. 7. 生殖巢의 發達段階는 分裂增殖期(1∼4月), 成長期(3∼6月). 成熟期(5∼8月), 放出期(7∼9月初), 退化期(9∼12월), 回復期(12∼2月)로 區分할 수 있었다. 8. 産卵期는 水溫이 20℃ 以上으로 上昇하는 7月 初旬부터 9月 初旬으로, 産卵 最盛期는 7月 中旬부터 8月未 사이였다. 9. 雌雄同體는 調査材料 390 個體中 8個體였다. The structure of gonad, gametogenesis and the reproductive cycle of the clam, Cyclina sinensis were investigated mainly employing photomicrography and electron micrography. The materials were sampled monthly at Seongsanpo, Cheju Island from October 1982 to September 1983. 1. The gonad is located between the mid-intestinal gland in the visceral sac and the connective tissue of the foot. The ovary is composed of a number of ovarian sacs. The testis is composed of a number of seminiferous tubules, which form the tubulan structure, and the epithelium of the tubule has the function of germinal epithelium. 2. The outer wall of the gonad is 420-600㎛ thick, and the epithelial layer consists of simple columnar epithelial cells, which are 30-40㎛ thick. Under the epithelial layer are sequentially collagenous fiber layers, mucous gland cells fibromscular capsules compacted by collagenous fibers and muscle fibers. These thicknesses are 50㎛, 80㎛ and 260-430㎛ respectively. The upper and lower fibromuscular capsules are arranged of vertically, and the middle fibromuscular capsules are arranged of longitudinally. 3. Undifferentiated mesenchymal tissue and eosinophilic granular cells function as nutritive cells in the formation and development early stage of germ cells. 4. The oocytes reach approximately 70㎛ in diameter seceded from the yolk stalk, the mature eggs were about 90-120㎛. 5. The plasma membrane the uncleus membrane of oocytes are composed of a double membrane. Accumulation of yolk granules in the cytoplasm begins in the cortical layer and diffusion occurs outside the nuclear envelope and diffuse towards the corticalilayer. 6. The head of the spermatozoa is approximately 5㎛ in length and its tail is about 20㎛. The conical acrosome at the distal part of the head is distinguished by two regions with different electron densities. There is a clear space between the acrosome and nucleus. The flagellum of the tail consits of nine pairs of microtubules at the periphery, on e pair at the center fiber, and four spherical mitochondria form the paranucleus around the centrioles. 7. The development process may be divided into six succesive stages : multiplication (January-April), growing(March-June), mature(May-August), spent(July-eary September), degenerative(September-December) and recovery stages(December-February). 8. Spawnig of C. sinensis occurs from early July ot early September when the sea water temperature was normally above 20℃ and its peak spawing occured from late July ot August. 9. The hermaphroditic were eight individiuals among the 390 individuals examined.

      • SCOPUSKCI등재

        졸 - 겔법에 의한 다공성 알루미나 미분체 제조에 관한 연구 : 2 . 물과 알콕시드의 비가 알루미나 미분체의 결정화 공정에 미치는 영향 2 . The Effect of [ H2O ] / [ Al - alkoxide ]on The Crystallization Mechanism of As - Prepared Particles

        이성원,박형상,윤호성,황운연,구기갑,유승준,김용렬,이정운 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.2

        알루미늄 알콕시드의 반응속도를 제어하기 위한 혼합용매와 입자제조 과정에서의 응집을 방지하기 위한 분산제로 HPC를 첨가하는 방법에 의하여 구형의 다공성 알루미나 미분체를 제조하였으며, XRD, FT-IR 및 TG-DTA 분석을 통하여 공정변수로 선정한 물과 알루미늄 알콕시드의 비가 제조된 미분체의 결정화 공정에 미치는 영향에 대하여 고찰하였다. 축중합 반응에 첨가된 물과 Al-알콕시드의 비는 제조된 미분체 및 하소 공정을 거친 미분체의 결정구조에 영향을 미침을 알 수 있었다. [H₂O]/[ASB]의 비가 증가할수록 제조된 미분체는 비정질의 Al(OH)₃로부터 점진적으로 AlO(OH)의 화학조성을 갖는 의사-보헤마이트로 결정성이 바뀌었다. 그리고 건조 공정을 거친 미분체의 결정성이 좋을수록 δ와 θ-Al₂O₃는 저온에서 생성되었으나, α-Al₂O₃는 고온에서 생성되었다. 이와 같은 결과는 Al^(3+)이온의 결정 내에서의 배위체 변화와 관계됨을 알 수 있었다. 그리고 [H₂O]/[ASB]=2의 조건에서 제조된 입자는 다른 시료와 달리 600℃에서 η-Al₂O₃로 1,100℃에서 α-Al₂O₃2로 상전이 되었다. Spherical porous alumina particles were prepared by mixed solvent to control the reaction rate of Al-alkoxide and the particle shape with hydroxy-propyl cellulose(HPC). HPC was used as a dispersant to prevent aggregation during the formation of particles. The effect of [H₂O]/[ASB] ratio on the crystallization reactions of as-prepared particles was studied by XRD, FT-IR, and TG-DTA analysis. The mole ratio of water and Al-alkoxide added in the condensation reaction had an important effect on the crystal structure of as-prepared particles and the calcined particles. As the [H₂O]/[ASB] ratio increase, the crystal structure of as-prepared particles was continuously varied from amorphous Al(OH)₃ to pseudo-boehmite with chemical composition of AIO(OH). The samples which have higher crystallinite after drying process were transformed into the δ- and θ-Al₂O₃ at lower calcination temperature, but these sample were transformed into α-Al₂O₃ at higher calcination temperature. This result was thought to be the transformation of the coordination number of Al^(3+) ion in the crystal structure. The particles prepared by [H₂O]/[ASB]=2 condition crystallized to α-Al₂O₃at 600℃ and converted to η-Al₂O₃at 1,100℃ without intermediate phases.

      • KCI등재

        Smear layer 처리에 따른 미세누출에 대한 연구

        이정민,박상혁,최기운 대한치과보존학회 2006 Restorative Dentistry & Endodontics Vol.31 No.5

        본 연구는 도말층 제거 여부에 따른 근관 밀폐효과를 평가하기 위해 단근관 치아를 3% NaOCI 하에서 Ni-Ti file을 이용하여 crown-down 법으로 근관 형성 후 최종세정제로 NaOCI을 사용한 군과 EDTA를 사용한 군, 6개월 보관한 NaOCI-6군과 EDTA-6군으로 분류하였다. Continuous wave법으로 근관 충전 시행 후 색소 침투를 시행한 다음 해부학적 근첨에서 1.5 mm(Level l), 3.0 mm(Level 2), 4.5 mm (Level 3)에서 수평절단 하여 누출률을 측정하였다. 1. 모든 실험군에서 평균 누출률은 치근단부에서 치경부로 갈수록 감소하였다. 2. NaOCI 군의 누출률이 EDTA 군보다 level l, 2, 3에서 높게 나타났으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 3. NaOCI-6 군의 누출률이 EDTA-6 군보다 Level l, 2, 3에서 높게 나타났으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 4. NaOCI-6 군의 누출률이 NaOCI 군에 비해 Level l, 2, 3에서 증가하였으나 level l에서만 통계학적 유의차를 보였다 (p<0.05). 5. EDTA-6 군의 누출률이 EDTA 군에 비해 Level l, 2, 3에서 증가하였으나 통계학적 유의차는 없었다. 6. 주사전자현미경 관찰 결과 NaOCI 군과 NaOCI-6 군은 도말층이 제거되지 않아 상아세관내로 sealer 및 근관충전 재가 침투하지 못한 반면, EDTA 군과 EDTA-6 군에서는 도말층이 제거되고 상아세관내로의 sealer와 근관충전 재의 침투가 관찰되었다. 이상의 연구결과 EDTA를 이용하여 도말층을 제거한 경우 근관충전 즉시와 6개월 후 치근단 1/3 부위의 근단부 미세누출을 감소시킬 수 있을 것으로 사료된다. The purpose of this study was to compare the sealing ability of root canal obturation with or without the treatment of smear layer. Eighty extracted human teeth with one canal were selected. Instrumentation was performed with crown-down technique. After instrumentation, root canals of the NaOCI group and NaOC1-6 group were irrigated with 3% NaOCI. EDTA group and EDTA-6 group were irrigated with 17% EDTA. Then all teeth were obturated using continuous wave obturation technique. NaOCI group and EDTA group were immersed in methylene blue solution for 84hours. NaOCI-6 group and EDTA-6 group were immersed in methylene blue solution for 6months. The teeth were sectioned at 1.5 mm (Level 1), 3.0 mm (Level 2) and 4.5 mm (Level 3) from the root apex. The length of dye-penetrated interface and the circumferential length of canal at each level were measured using Sigma-Scan Pro 5.0. 1. The mean leakage ratio was decreased cervically. 2. NaOCI group showed higher mean leakage ratio than EDTA group at each level. But there was significant difference at level 1 only (p<0.05). 3. NaOCI-6 group showed higher mean leakage ratio than EDTA-6 group at each level. But there was significant difference at level 1 only (p<0.05). 4. NaOCI-6 group showed higher mean leakage ratio than NaOCI group at each level. But there was significant difference at level 1 only (p<0.05). 5. EDTA-6 group showed higher mean leakage ratio than EDTA group at each level. But there was no significant difference. 6. In NaOCI group and NaOCI-6 group, scanning electron micrographs of tooth sections generally covered with smear layer. In EDTA group and EDTA-6 group, tooth sections showing the penetration of sealers to opened dentinal tubules. The results suggest that removal of smear layer was effective to reduce the apical microleakage of the root canal.

      • Hall 소자를 이용한 승강기용 로프의 평가

        이종오,윤운하,손영호,김정우,이종규 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

        홀 소자를 이용한 누설자속 측정으로 승강기용 와이어 로프의 결함 검출에 대한 연구를 수행하였다. 소선파단, 마모, 내부 소선파단 형태의 인공결함을 제작하여 시험편에 영구자석으로 자장을 걸어 결함에서 누설되는 누설자속을 홀 센서를 사용하여 검출하였다. 로프의 소선은 0.5, 0.8mm 두 종류로 시험결과 단선모델 시험에서 0.4mm, 내부의 소선 파단의 경우 1mm 정도 깊이를 가진 인공결함까지 검출이 가능하여 1개의 소선 파단도 검출할 수 있는 것으로 보인다. 마모모델에서 결함의 폭이 작은 경우 검출이 불가능하였으나, 폭이 4mm이상인 경우 자극이 결함을 통과할 때 자속의 변화에 의해 깊이가 0.2mm 정도의 작은 결함도 구별이 가능하였다. 따라서 Hall 센서에 의한 누설자속 측정이 wire rope의 결함 검출에 좋은 도구가 된다고 본다. Defect detection of wire rope for an elevator was investigated through the measurement of magnetic flux leakage. The types of defect usually found in wire rope categorized such as inner and outer wire breakage and wear. The specimens that has artificial defects were magnetized via permanent magnet, and measurement of magnetic flux leakage on the defects was performed with Hall sensor. In wire broken model, a defect smaller than 0.4mm and 1mm in depth on outer and inner wire rope, respectively, could be detected well. In wear model, smaller defect could not be detected clearly, however, appearance of changing of total magnetic flux during magnetic pole of the sensor passing through a defect 0.2mm in depth at 4mm or above width could make possible to detect it. From the results, the measurement via Hall sensor might be useful tool for defect detection of wire rope.

      • 정상과 만성염증성 활막배양세포에서 Corticotropin releasing hormone(CRH)이 cyclooxygenaase-1(COX-1)과 cyclooxygenase-2(COX-2) mRNA발현에 미치는 영향

        정운원,이승관,이창규,조경진,김성욱,하주희,서장훈 高麗大學校 倂設 保健大學 保健科學硏究所 2000 保健科學論集 Vol.26 No.1

        Corticotropin-releasing hormone(CRH) is a major regulator of the hypothalamic-pituitaryadrenal axis(HPA). In inflammatory stress, the cytokines TNF-, IL-6 stimulate the production of CRH, a 41 amino acids neuropeptide, in the hypothalamus. The release of CRH leads to pituitary production of adrenocorticotropic hormone, followed by glucocorticoid secretion by the adrenal cortex. Glucocorticoids suppress namy components of the inflammatory process. Recently, CRH and CRH receptor were reported to be located in the periphery such as Immune system and chronic inflammatory sites as rheumatoid arthritis (RA). Cyclooxygenase consisted of two isoforms, COX-1 and COX-2, converts arachdonate to prostaglandins(PGs) which are important mediators of inflammation. insymoviocyte in RA, it was described that COX-2 mRNA was markedly increased by inflammatory agents, PMA or IL-1 and COX-1 transcripts were not modulated. We examined the modulation of COX by immune CRH in cultured normal and rheumatoid synoviocytes. Our results were shown that COX-1 mRNA expression decreased with the each stimulation of PMA and IL-1 in normal synoviocyte. In RA synoviocyte, PMA and IL-1 were increased mRNA expression of COX-1. In simultaneous treatment with CRH, PMA group was decreased, but IL-1 group was increased mRNA expression of COX-1. COX-2 mRNA expression was slightly increased by the treatment with PMA and highly increased by IL-1. After CRH treatment, PMA and IL-1 addictively increased COX-2 mRNA expression. We think that these results are contributed to the influence of increased cANP by CRH on the promoter of COX-2 in normal and synoviocytes. Because many cytokines, neuropeptides, and signal transduction pathways are involved in chronic inflammation, the exact role of CRH on inflammation is not fully elucidated. To achieve this goal, further experiments are needed.

      • DNA Microarray를 이용한 인유두종 바이러스(Human Papilloma Virus:HPV)의 진단

        정운원,이승관,이창규,조경진,김성욱 高麗大學校 倂設 保健大學 保健科學硏究所 2001 保健科學論集 Vol.27 No.1

        Human papillomavirus(HPV) has been known as one of the important pathogenic agent in uterine cervical carcinoma. The molecular works such as PCR enable the detection of large number of HPV genotypes obtained from viginal swab. Many of the PCR-based methods for HPV detection involve an amplification step followed by any of a number of methods for distinguishing different HPV types. In this study, we adopted the DNA chip technology enabling a HPV type-specific differentiation both low-risk group(type-6, 11, 34, 40, 42, 43, and 44) and high-risk group(type-16, 18, 31, 33, 35, 39, 45, 51,52,54, 56, and 58). MY09/MY11 and GP5+/GP6+primers covered LI region are used in nested PCR to improve PCR amplification. HPV type-specific probes for DNA chip were modified with NH2-C6, followed by spotting on silylated slides, washing slides and hybridization with each PCR products. Of 163 DNA samples chosen randomly, 42 samples were negative, 8 ones for low-risk group of HPV and 96 ones for high-risk group of HPV. Especially, co-infections with various HPVs were shown in 17 samples. A recent study found that multiple HPV is a factor in persistent HPV infection, resulting in the development of cervical dysplasia. This result emphasized the necessity to detect multiple HPV infection. The application of DNA-chip to determinate specific HPV typing will be a stronger candidate than any other PCR-based methods. Furthermore, the sequencing data of the positive PCR products were shown no discrepancy with DNA chip results. This means that DNA chip is very useful tool for both HPV detection and typing.

      • 박막 크로멜-알루멜 열전퇴형 교류-직류 변환기

        정인식,김호운,김진섭,이정희,이종현,신장규,박세일,권성원 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

        A planar chromel-alumel multijunction ac-dc converter was fabricated on a LPCVD Si_(3)N_(4)/SiO_(2)/Si_(3)N_(4)-diaphragm, prepared by silicon bulk micromachining, which thermally isolated a bifilar evanohm-heater and the hot junctions of a chromel-alumel thermopile from the silicon substrate. The voltage responsivity, the ac-dc transfer error, and the fluctuation of the output thermoelectric voltage of the converter were investigated. The respective voltage responsivities in air and in a vacuum of the converter were about 3.16 mV/mW and 9.41 mV/mW. The ac-dc voltage and the current transfer errors in air were about ±1.5 ppm and ±0.7 ppm in a frequency range from 10 Hz to 10 kHz, respectively. The fluctuation of the output thermoelectric voltage from 5 seconds to 120 seconds after preheating in air for 5 seconds was about 0.06 % for a heater input of dc 1 V.

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