RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
        • 원문제공처
          펼치기
        • 등재정보
          펼치기
        • 학술지명
          펼치기
        • 주제분류
          펼치기
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • Bainite 球狀黑鉛鑄鐵의 磨滅特性에 미치는 殘留Mg의 影響

        權赫茂,朴相俊,金水泳 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.2

        Bainite spheroidal graphite cast iron specimens of 0∼0.054wt % residual Mg were casted into a green sand mold, 25 mm thickness Y-block. The microstuctures of the castings were studied for mechanical properties and abrasion characteristics. The results obtained from this study are summerized as follows: 1) Under the present expermental conditions, the relation between the abrasion speed and the abraded amount are; 0.5m/sec for 1^st abrasive wear and 2.38m/sec for 2^nd abrasive wear. 2) Increasing the residual Mg, the first abrasion speed for 2nd abrasive wear moved to the low abrasion speed. 3) The maximum amount of abraded material during 2^nd abrasive wear decreases with the increasing residual Mg content, and moves to the high abrasion speed as the residual Mg is increased over 0.042 wt %. 4) The amount of abraded materials increases with the decreasing residual Mg at abrasion speed 2.38 m/sec and with the increasing residual Mg at abrasion speed 0.62∼1.14 m/sec. 5) Increasing the abrasion speed, abrasion mechanisms are as follows; ⓐ 1^st abrasive wear ⓑ 1^st corrosive wear ⓒ 2^nd abrasive wear ⓓ 2^nd corrosive wear. But, Under the present expermental condition the adhesive wear mechanism didn't appear.

      • WDM-PON Link에서 upstream, transmission 성능 향상에 대한 연구

        권혁춘,정구익,하상진,한상국 연세대학교 전파통신연구소 2001 電波通信論文誌 Vol.5 No.1

        본 논문에서는 파장 분할 WDM-PON 구조를 제안하였으며, CW source를 가지고 Fabry-Perot laser에 injection 시키는 방법을 사용하여 4 channel 155Mbps를 20km upstream 전송하여 분석해 보았다. 제안된 WDM-PON 시스템에서의 이 injection locking 방법은 약 -7dBm ∼ -4dBm 정도의 높은 출력 파워를 제공하였고, 155Mbps 전송시 BER=10-9에서 receiver sensitivity 는 -38dBm정도를 유지하였다. 또한 제안된 구조에서 CW source로 파장 분할된 LED와 FP laser를 사용하여 각각에 대한 시스템에서의 성능을 비교 분석해 보았다. In this paper, we propose a spectrally sliced WDM-PON architecture and analyze the upstream transmission of 4 channels 155Mbps signals by 25km using an injection locking method of Fabry-Perot laser as a CW source. For a proposed WDM-PON system, This injection locking method provides high output power of -7dBm ∼ -4dBm and satisfies receiver sensitivity -38dBm for 10-9 Bit Error Rate for 155Mbps transmission. Also, we compare performances using spectrum-sliced LED and FP laser respectively as CW source for a proposed WDM-FON system.

      • Urechis unicinctus 난세포의 인공수정에 의한 구조적 변화

        권혁제,김완종,신길상 순천향대학교 1994 논문집 Vol.17 No.3

        The artificial insemination in Urechis unicinctus oocyte revealed some fine structural changes under electron microscope. The degradation of surface coat, retraction of microvilli, fusion of cortical granules with oocyte membrane are the events of fine structural changes after the fertilization. At fertilization, the cortical granules of oocyte are transported from the inner cortex toward oocyte membrane. After the fusion, the contents of cortical granules are discharged into the perivitelline space, the extracelluar space which in future develops into fertilization membrane. There are some indications that the fertilization occur on the microvillous tip in U. uicinctus. Under light microscope, one of the evidences on the fertilization was the formation of fertilization cone, which seemed to sperm entry site, on membrane of round mature oocyte.

      • 전주기술을 이용한 로터리스크린 제조에 관한 연구

        권혁홍,박상호 대진대학교 2004 大眞論叢 Vol.11 No.-

        To simple the manufacturing process of rotary screen, this study was adopted electroforming technology and produced silicon rubber mandrel. Furthermore, to indicate the optimal condition for the acquisition of high-qualified rotary screen product, the experiment was executed with pH, time, sulfamate nickel solution according to density which were the main factors to decide the condition, then compared it with the product made by original "S" Company in Holland. As a result, the figure of Hole was more obvious and correct. Also the open size increased more than 2-3%.

      • KCI등재

        Iridoid 화합물이 치수절단 후 잔존치수 조직에 미치는 영향

        권혁춘,박동성,손호현 大韓齒科保存學會 1997 Restorative Dentistry & Endodontics Vol.22 No.2

        Aucubin, an iridoid glucoside, which is isolated form Aucuba japonica, has some biological effects. This study was to investigate the effect of aucubin on the remainig pulp tissues after pulpotomy. Mongrel dog's coronal pulps were mechanically exposed with a sterile round bur and excised with sterile sharp excarvator. After bleeding was controlled, in control group, Ca(OH)_2 powder was applied on the remaining pulps and the cavities were sealed with Z.O.E cement. In experimental group 1, mixed powder with Ca(OH)_2 and aucubin(1:1 by weight) was applied on the pulotomized pulp surfaces. After th cavities were covered with sterile aluminum foil, they were sealed with Z.O.E. cement. In experimental group 2, only aucubin powder was applied on the remaining pulps and then they were treated the same as experimental group 1. In the all groups, the pulps were histopathologically observed by light microscope at the time intervals of 1, 2 and 4 weeks after experiment. The results were as follows: 1. In control and experimental groups, mild vascular congestion and bleeding were found in most of the specimens. Less inflammatory infiltration was observed in experimental groups than in control group. 2. Dentin bridge formation was found after 1 week at both control and experimental group 1. Dentin birdge had discontinuous osteodentin like appearance of contained some dentin chips. In experimental group 2, dentin bridge was not seen. 3. The coagulation necrosis layer on the remaining pulp tissues was seen in all groups. In experimental group 2, the thickest layer was observed. And in control group, coagulation necrosis layer was similar as in experimental group 1.

      • 신경섬유종증 환자에게서 발생한 특발성 혈소판 감소증 1예

        권세훈,김형호,강지인,장재혁,원경준,장재현,김상용,배학연 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.3

        Idiopathic thrombocytopenic purpura is a disease characterized by thrombocytopenia in peripheral blood with positive anti-platelet antibody titer, no splenomegaly, the presence of megakarocyte. The causes of idiopathic thrombocytopenic purpura were usually related to autoimmune disease, infection and drugs. A 46-years-old man was admitted for evaluation of abdominal mass. He has many cafe-au-lait spots and nodules in almost skin for 30 years. Several years ago, he palpated mass in Lt. inguinal area. hIe has known the abdominal mass after checking abdomen CT in local clinic and visited our hospital for evaluation of abdominal mass. At admission, laboratory tests showed hemoglobin 12.5 g/dL, hematocrit 38.4 %, WBC 5,460 /㎣ (neutrophil 64.5%, lymphocyte 21.7%, monocyte 4.1%, eosinophil 5.4%), reticulocyte 0.7%, Platelet 52,000 /㎣, total protein 6.51 g/dL, albumin 3.80 g/dL, alkaline pohsphatase 161 IU/L, AST 110.7 IU/L, ALT 64.9 IU/L, total bilirubin 0.44 ㎎/dL, BUN 18.4 ㎎/dL, creatinine 0.79 ㎎/dL. Peripheral blood smear showed normocytic normochromic anemia, thrombocytopenia. Bone marrow aspiration smear showed normoplastic myeloid and erythroid precursor. The bone marrow biopsy section shows normocellular marrow (35%) for his age and mildly increasing myeloid cell lineage. We have experienced a case of idiopathic thrombocytopenic purpura in a patient being in neurofibromatosis and therefore reporting it with documentary records. 저자들은 신경섬유종증 환자에서 특별한 원인을 발견할 수 없었음에도 특발성 혈소판 감소증이 발생한 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

      • KCI등재후보

        국내 살모넬라 분리주에서 spvR 유전자 분포와 단일 뉴클레오티드 다형 연구

        권혁준,박경윤,박주연,박용호,김선중,유한상 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

        목적 : 지금까지 병원성 살모넬라를 확인하기 위해 분자량이 큰 플라스미드의 존재 유무를 확인하여 왔으나 살모넬라 혈청형 및 검출 방법에 따라 양성율에 큰 차이를 보이고 있고, 일부 병원성 살모넬라 분리주에서 병원성 플라스미드가 관찰되지 않아 spv 유전자들의 유무에 대한 아른 확인방법이 필요하다. 본 실험은 국내 동물 유래 주요 살모넬라 혈청형에서 spvR 유전자의 분포를 알아보고, 병원성 살모넬라 분자진단을 위한 분자표지로써의 가치를 평가하기 위해 실행하였다. 재료 및 방법 : 국내 가축 유래 S. lyphimurium (ST, 26주), S. enteritidis (SE, 10주), S. pullorum (SP, 40주), S. gallinarum (SG, 53주)에 대해 GenBank에 등록된 ST, SE, SP의 spvR 유전자를 비교하여 ST와 SE 간에 차이를 보이는 single nucleotide polymorphism (SNP, 625번 뉴클레오티드)을 포함하도록 시발자를 합성하여 집락-PCR을 수행하였다. 증폭 산물(194bp)은 자동 염기서열장치를 이용하여 염기서열을 결정하였고, 제한효소인 MseI을 사용하여 PCR-RFLP를 실시하였다. 결과 : 집락-중합효소연쇄반응 결과 SP, SG, SE의 모든 (100%) 분리주에서 특이 증폭산물이 검출되었으나 ST의 경우 19주(73%)에서만 증폭되었다. 특히 병원성 관련 플라스미드가 관찰되지 않았던 SP 4주에서 특이적인 증폭산물이 검출되었다. 염기서열 분석결과 SE, SG, SP는 625번 뉴클레오티드에 아데닌을, ST는 구아닌을 가지고 있어 PCR-RFLP를 이용하여 쉽게 구분할 수 있었다. 결 론 : spvR에 대한 집락-중합효소연쇄 반응법은 병원성 플라스미드 검출법보다 SE, SP, SG 병원성 주를 신속하게 검출하는데 유용하고, 625번 뉴클레오티드의 SNP는 ST와 SE, SG, SP를 구분하는 분자표지로 사용될 수 있을 것으로 기대되며, ST에 비해 SE는 진화적으로 SG와 SP에 가까운 것으로 생각되었다. Background : The Salmonella virulence plasmid (spv) genes (spvR, A, B, C and D) on the large virulence plasmids of pathogenic Salmonella serotypes can replace the virulence of the whole plasmid. Recently, virulence plasmid-negative pathogenic Salmonella isolates were isolated. However, positive rates of spv genes among Korean Salmonella serotypes have been obscure. spv genes are conserved in compared to other virulence genes but there are single nucleotide polymorphisms (SNPs) conserved in only certain serotype. Such SNPs are useful for differentiation and understanding evolution of certain serotypes. Materials and Methods : Salmonella serotypes isolated from live stocks [Salmonella typhimurium (ST, 26), S. enteritidis (SE, 10), S. gallinarum (SG, 40) and S. pullorum (SP, 53)] were used for colony-PCR. A primer set covering single nucleotide polymorphism (SNP) at 625th nucleotide of spvR was designed. The nucleotide sequences of amplicons were determined by cyclic sequencing method and RFLP was performed by using MseI. Results : All isolates of SE, SG and SP, including four plasmid-negative isolates, showed specific amplicons but not all of ST (19/26, 73%) were positive to spvR. Based on the nucleotide sequence of 625th nucleotide and PCR-RFLP, SE, SG and SP [A(625)] and ST [G(625)] could be differentiated. Conclusion : spvR can be used as a molecular marker to detect virulent SE, SG, SP and the SNP may be useful for differentiation of SE, SG, SP and ST. According to the SNP study SE may be evolutionarily closer to SG and SP than ST.

      • 불소가 첨가된 실리콘 산화막의 다층금속절연 특성에 관한 연구

        權大赫,南基泓,吳相光 慶一大學校 1997 論文集 Vol.14 No.2

        The characteristics of fluorinated silicon oxide (SiOF) films prepared by plasma enhanced chemical vapor deposition(PECVD) were discussed. The deposition of these films was carried out in the temperature range of 80 - 220℃ in a conventional parallel plate plasma reactor with 〈 ±3% uniformity by flowing 2 sccm of disilane (Si₂H6), 100 sccm of nitrous oxide (N₂O), and 20 sccm of tetrafluoromethane (CF₄). AS the deposition temperature increased from 80 to 220℃, the deposition rate of the films increased from 16.7 to 18.4 nm/min; meanwhile, the etch rate decreased from 2.69 to 1.48 nm/sec. The refractive index was 1.46 regardless of the deposition temperature. The Fourier transform infrared (FTIR) spectra of the films showed decreasing Si-O stretching wave number with increasing full width at half maximum (FWHM) as deposition temperature increased. The high frequency capacitance-voltage (C-V) measurements of the metal-oxide-semiconductor (MOS) capacitors fabricated using the films showed increasing effective oxide charge density and decreasing dielectric constant with increasing deposition temperature. Deposition temperature of 180℃ resulted in films with the smallest dielectric constant of 3.75. These films showed an average breakdown strength of 9.14 MV/cm with 77.5% of the MOS capacitors having breakdown field strength ≥9.5 MV/cm

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼