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
      • KCI등재

        3T Multi Voxel Spectroscopy에서 SENSE와 NEX 변화에 따른 정상인 뇌 대사물질 변화 분석

        성열훈,임재동,이재현,조성봉,우동철,최보영,Seong, Yeol-Hun,Rhim, Jae-Dong,Lee, Jae-Hyun,Cho, Sung-Bong,Woo, Dong-Chul,Choe, Bo-Young 한국의학물리학회 2008 의학물리 Vol.19 No.4

        자기공명분광법(magnetic resonance spectroscopy: MRS)은 인체내 대사물질을 정량분석하여 병변의 조기진단 및 정밀진단에 도움을 주고 있으며, 최근 임상에 이용되고 있는 자기공명분광법은 single voxel spectroscopy (SVS) 기법과 multi voxel spectroscopy (MVS) 기법이 있다. 본 연구에서는 SENSE와 NEX를 변화시킨 multi voxel spectroscopy (MVS)의 데이터와 기존 single voxel spectroscopy (SVS)의 데이터를 비교 분석하여, 각각의 데이터의 유의성 차이를 평가하고자 하였다. 정상 성인 지원자 13명(남자: 5명, 여자: 8명, 평균 41세, 표준편차 11.65세)을 대상으로 chemical shift image (CSI)를 이용한 MVS검사를 시행하였다. 장비는 3.0T Achieva Release Version 2.1 (Philips Medical System, Netherland)을 이용하였고, 8 channel head coil을 사용하여 brain thalamus 부위에서 CSI spectrum을 1 slice 획득하였다. Scan parameter로는 FOV (field of view): $230{\times}184mm^2$, TR (time to repetition): 2000 msec, TE (time to echo): 288 msec, matrix: $15{\times}12$, VOI(view of interest): $110{\times}110mm^2$, voxel size: $15{\times}15{\times}15mm^3$로 하였다. SENSE factor (S)와 NEX (N)는 S1*N1, S2*N1, S2*N2, S3*N2로 변화하여 스펙트럼을 획득하였고, 각 scan time은 5분 54초, 3분 32초, 6분 20초, 4분 20초였다. 얻은 모든 MRS 데이터는 jMRUI 3.0 Version 프로그램에서 분석하였고, SENSE factor와 NEX를 변화시켜 얻은 MVS data 그룹들이 정상 성인 뇌 대사물질의 변화에 영향을 주는지 검증하기 위해 그룹 간에 ANOVA분석을 실행하여 P 값이 0.05보다 크게 나오면 그룹들 사이에 유의한 차이가 없다고 분석하였다. NAA/Cr과 Cho/Cr의 상대적 비율은 MV와 SVS사이에서는 유의한 차이가 없었다. 즉, SENSE factor와 NEX를 변화시켜 얻은 MVS data에서 정상 성인 뇌조직의 대사물질의 변화를 관찰한 결과, S1*N1의 NAA/Cr은 $1.45{\pm}0.03$, Cho/Cr은 $0.88{\pm}0.03$이고, S2*N1의 NAA/Cr은 $1.44{\pm}0.03$, Cho/Cr은 $0.87{\pm}0.05$, S2*N2의 NAA/Cr은 $1.43{\pm}0.02$, Cho/Cr은 $0.87{\pm}0.04$이며, S3*N2의 NAA/Cr은 $1.45{\pm}0.03$, Cho/Cr은 $0.87{\pm}0.03$으로 나타났다(F-value : 1.37, D.F : 3, P-value : 0.262). 그러나 데이터의 질을 측정하기 위한 MVS 데이터의 NAA Peak line-width는 SVS 데이터의 NAA Peak line-width 보다 약 3배 정도 넓었다. 본 연구에서는 MVS에서 SENSE factor와 NEX 값을 다양하게 변화시킨 MVS의 데이터와 SVS의 데이터가 큰 차이가 없음을 확인하였다. 즉, 어는 특정 부위의 뇌 조직의 대사물질은 MVS와 SVS 기법 모두 큰 차이가 없음을 확인할 수 있었다. 그러므로 MVS는 SVS보다 광범한 부위를 짧은 시간 안에 검사할 수 있으므로 매우 유용한 방법이라고 사료된다. To evaluate the metabolic changes in normal adult brains due to alterations SENSE and NEX (number of excitation) by multi voxel MR Spectroscopy at 3.0 Tesla. The study group was composed of normal volunteers (5 men and 8 women) with a mean ($\pm$ standard deviation) age of 41 (${\pm}11.65$). Their ages ranged from 28 to 61 years. MR Spectroscopy was performed with a 3.0T Achieva Release Version 2.0 (Philips Medical System-Netherlands). The 8 channel head coil was employed for MRS acquisition. The 13 volunteers underwent multi voxel spectroscopy (MVS) and single voxel spectroscopy (SVS) on the thalamus area with normally gray matter. Spectral parameters were as follows: 15 mm of thickness; 230 mm of FOV (field of view); 2000 msecs of repetition time (TR); 288 msecs of echo time (TE); $110{\times}110$ mm of VOI (view of interest); $15{\times}15{\times}15$ mm of voxel size. Multi voxel spectral parameters were made using specially in alteration of SENSE factor (1~3) and 1~2 of NEX. All MRS data were processed by the jMRUI 3.0 Version. There was no significant difference in NAA/Cr and Cho/Cr ratio between MVS and SVS likewise the previous results by Ross and coworkers in 1994. In addition, despite the alterations of SENSE factor and NEX in MVS, the metabolite ratios were not changed (F-value : 1.37, D.F : 3, P-value : 0.262). However, line-width of NAA peak in MVS was 3 times bigger than that in SVS. In the present study, we demonstrated that the alterations of SENSE factor and NEX were not critically affective to the result of metabolic ratios in the normal brain tissue.

      • KCI등재
      • 처리기 메쉬를 이용한 정규화된 재귀규칙의 증명-이론적 의미 계산

        조우현,박승섭 釜慶大學校 1998 釜慶大學校 論文集 Vol.3 No.2

        A deductive database consists of facts stored in the extensional database and rules representing the intensional database. Because of the difficulty of evaluating rules, many parallel evaluation algorithms for rules have been presented. This paper proposes a new paradigm to evaluate linear recursion rules which contain transitive dependency by using a mesh of processors. An evaluation of normalized rules is a computation of the proof-theoretic meaning of a collection of rules. The normalized recursion rule which contains transitive dependency is defined, the existence of an equivalent expression for the rule is proved, a paradigm using transitive closure operations for parallel evaluation of normalized rule based on the equivalent expression is proposed, and the comparative performances of the parallel evaluation algorithms are presented.

      • Helicobacter pylori와 대장균의 Shuttle Vector 개발

        조명제,이우곤,이상룡,김경희,안영숙,김성희,김현주,류복덕,최여정,윤영혜,백승철,전영석,이광호 경상대학교 유전공학연구소 1997 遺傳工學硏究所報 Vol.16 No.-

        In this study, a vehicle vector using cryptic plasmids was constructed for gene transfer in Helicobacter pylori. pHP51(3.9 kb) and pHP489(1.2 kb) were selected for constructing vectors from cryptic plasmid of H. pylori isolates in Korea. The HindⅢ-digestedDNA fragment(1.2kb) of pHP489 and 1.6kb DNA fragment of pHP51 were ligated with a kanamycin resistance gene(aph3'-Ⅲ) from C. jejuni to produce the recombinant plasmids pHP489K and pHP51K, respectively. Transformation frequency of pHP51K by electroporation was low. But pHP489K could be effectively transformed into various H. pylori strains. In order to design an intermdiate vehicle vector for gene transfer into H. pylori, pBlueHP489K was prepared by recloning pHP489K DNA into pBluescript and pTZ19R vector. This vector permitted the DNA fragment containing pHP489 sequence, aph3'-Ⅲ, and cloned DNA to be cut and self-ligated in the SacⅠ site after cloning. ureA and ureB gene were inserted into pBlueHP489K, resulting in pBlueHP489K/AB. The DNA fragment containing pHP489, kanamycin resistance gene(aph3'-Ⅲ), and urease structural gene was cut away from pBlueHP489K/AB and self-ligated to generate pBlueHP489K/AB. pBlueHP489K/AB made urease-negative H. pylori strains restore their urease activity. By this experiment, pBlueHP489K was confirmed to be the vehicle system for transferring H. pylori genes.

      • 기지 패턴의 카메라 Calibration에 기반한 물체의 3차원 형상계측

        조현우,김태효 경남대학교 공업기술연구소 2001 硏究論文集 Vol.19 No.-

        본 논문에서는 기지패턴에 대한 카메라 calibration을 이용하여 물체의 깊이정보를 추출하기 위한 새로운 계측시스템을 구축하였다. 3차원 실세계좌표와 2차원 영상좌표계의 관계를 해석하였고, 이로부터 카메라의 Calibration 알고리즘을 확립하여 카메라의 내부 변수와 외부 변수를 구하였다. 이로부터 x-z 평면의 2D 영상을 획득하였다. 이 과정을 물체를 이동시키면서 연속으로 획득하여 3D 영상 정보를 얻었다. 3D 형상을 모니터에 표시하기 위해 OpenGL을 이용하여 계측된 3D 형상을 얻을 수 있었다. 계측 결과, 분해 능에서 약 ±1%의 오차가 발생하였으며, 이는 선형 모-터의 진동성분과 계측시스템의 광학적 오차에 기인된 것이라 판단되었다. 이를 개선하기 위해 기구적 시스템의 안정과 정밀용 카메라를 사용이 필요하다고 판단된다. In this paper, a new measurement system is implemented for depth data extraction based on the camera calibration with the known pattern. The relation between 3D world coordinate and 2D image coordinate is analyzed. A new camera calibration algorithm is established from the analysis and then, the internal variable from the CCD camera are obtained. From the measurement system, a 2D image obtained on the x-z plane. A 3D shape image can be obtained as the 2D (x-z)images are continuously acquired, during the object is moving to the r direction. The 3D shape images are displayed on computer monitor using OpenGL software. In the result, we found that the resolution of pixels have ±1% of error in depth data. It contains that the error components are created by the vibration of mechanic and optical system. In order to reduce the error, the system need to have some of mechanical stability and precision optical design.

      • 플라이애시를 다량 사용한 콘크리트의 수화발열 특성과 압축강도 특성에 관한 실험적 연구

        조규현,박무영,백민수,김우재,임남기,정상진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

        This study is for the great quantity use of fly-ash. For the producing of high volume concrete from the use of fly-ash, the method of replacement between bonding agents and fine aggregate by fly-ash at the slt was used that the adiabatic temperature rise of concrete about the mass member which bad been produced by the method that was mentioned before, and the hydration heat of the core test pieces in concrete was measured. Also the core test pieces which were replaced with fly-ash was studied by the compressive strength's comparison between standard care test pieces and core test pieces. In the case of mass test pieces, hydration heat and the time to reach the highest temperature were decreased by an increase in replaced fly-ash's amounts of concrete. In addition, among the test pieces having the same amounts of concrete, the test pieces having more replaced amounts of fly-ash's fine aggregate showed higher hydration heat and the increased time to reach the highest temperature. Compressive strength was also increased by hydration heat's decrease according to fly-ash replacement. Replacement of fly-ash was more effective in high temperature environment.

      • KCI등재
      • KCI등재
      • 유도 고교선수와 대학선수간 스트레스 요인에 관한 비교 분석

        조현철,김백윤,임성우,이갑철 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.2

        The research selected Judo players (480) belonged to high schools, universities and enterprises at random and asked them what is the most severe stressful factor to them, what is the best solution on it, and what is the interaction between the cause of stress and method of settlement to examine the above factors closely. For this purpose, this study researched them through a survey and the results are as follows. 1. The level of stress in the high school athletes (96.84±23.57) was lower than in the university athletes (106.99±18.86) (t=4.577, p<.001). 2. The factor of inner stress in the high school athletes(57.05±14.45) was lower than in the university athletes (t=4.638, p<.001). And the factor before competition, the factor of competition result, the factor on competition, the factor on drill were lower in the high school athletes than in the university athletes. 3. The factor of outer stress was lower in the high school athletes (39.79±10.01) than in the university athletes (43.62±8.16). The factor of face to face relationship the factor of leisure, social factor, and the outer stress were lower in the high school athletes than in the university athletes. 4. The physical factor, reward factor, the factor of cause examination, discussion factor were lower in the high school athletes than in the university athletes. But forgetful factor, the factor of stress settlement didn't show slight difference between the high school athletes and the university athletes. This study suggests a program that can overcome the respective stress factor. Also the education of coping with stress is necessary to the high school athletes that didn't recognize the stress and were lack of stress knowledge. It is indispensable to being the greatest in improving of competition and achieving of training.

      • Cu-Al-Ni 合金에 있어서 마르텐사이트 變態에 따른 內部摩擦

        趙顯麒,禹基道,金圭鎭 慶北大學校 1984 論文集 Vol.37 No.-

        The internal friction measurement was carried out by the torsion pendulum method with automatic recording of the virbration patterns. The critical range of the martensitic transformation was checked by measuring the electrical resistance and by morphological observation. The extent of internal friction in the region of the peak depends on the previous rate of temperature change and decreases sharply during a few minutes of isothermal holding. The high level of internal friction found in Cu~Al-Ni alloy is likely to due to the reversible movement of interfacial and twin boundaries on exposure to alternating stresses.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼