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

      • 좁혀본 항목

      • 좁혀본 항목 보기순서

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

        오늘 본 자료

        • 오늘 본 자료가 없습니다.
        더보기
        • 무료
        • 기관 내 무료
        • 유료
        • KCI등재

          SDR-Based Frequency Interference Emulator in the Space-Time Domain and Its Application

          윤현구,엄중선,박진수,장병준 한국전자파학회 2018 Journal of Electromagnetic Engineering and Science Vol.18 No.1

          In this study, we propose a software-defined radio-based frequency interference emulator in the space-time domain. This emulator can easily model actual interference environments because of the versatile programming capability of the universal software radio peripheral and LabVIEW. As an example of an interfering network using the contention-based multiple access scheme in the time domain, we emulate a coordinated Wi-Fi network that consists of one access point and two Wi-Fi nodes. Results show that our emulator can suc-cessfully model multiple interfering signals in the Wi-Fi network and easily adjust various space–time domain parameters.

        • KCI등재

          조골세포수 MC3T3-E1 세포기능에 대한 갑상선 호르몬의 영향

          윤현구,우정택,김진우,김영설,김광원,최영길,서광식 대한내과학회 1993 대한내과학회지 Vol.44 No.1

          연구배경 : 갑상선호르몬은 골격계 성장, 발달 및 대사에 중요한 영향을 미치며 조골세포 및 파골세포를 모두 자극하는 것으로 알려졌으나, 골형성에 미치는 직접적인 영향은 아직 확실히 규명되어 있지않다. 본 연구에서는 조골세포의 특성을 지닌 조골세포주 MC3T3-E1를 이용하여 T_3를 여러 농도로 첨가하여 DNA 합성, 교원질합성 및 Ⅰ형 교원질 mRNA 발현능 비교와 부갑상선호르몬에 대한 cAMP 반응을 측정하여 T3의 조골세포에 미치는 영향을 비교하였다. 방법 : 10% FBS(fetal bovine serum)이 첨가된 aMEM으로 배양한 후 0.1% FBS와 여러 농도의 T3를 첨가하였다. DNA 합성은 [^3H] thymidine incorporation과 교원질합성은 [^3H] proline incorporation을 이용하여 관찰하였으며, Ⅰ형 교원질 mRNA 발현능은 Northern blot 분석하였다. 결과 : 부갑성호르몬에 대한 조골세포의 반응 증가를 확인하였으며, Northern blot을 이용한 Ⅰ형 교원질 mRNA의 크기는 6.4kb로 발현됨을 관찰하였다. T_3를 세포배지에 첨가하여 DNA 합성과 교원질합성 비율은 농도증가에 따라 유의한 차이가 없었다. T_3에 의한 Ⅰ형 교원질 mRNA 발현은 농도 변화에 따른 유의한 차이가 없었다. 결론 : 조골세포주 MC3T3-EI 세포는 부갑성선호르몬의 자극에 cAMP의 증가 및 6.4kb의 Ⅰ형 교원질 mRNA 발현으로 조골세포의 특성이 관찰되어 골대사 연구에 유용한 세포로 생각된다. 이 세포를 이용한 연구에서 T_3는 MC3T3-E1 세포에 대해 DNA 합성, 교원질 합성비율 및 전사부위에 영향을 미치지 않았으나 갑상선 호르몬 농도와 노출시간을 달리한 추시가 필요할 것으로 생각된다. Background : Thyroid hormone appears to stimulate both the osteoclast and the osteoblast, but is direct effect on bone formation its not yet clear. This study was designed to investigate the effects of triiodothyronine(T_3) on DNA synthesis, collagen protein synthesis and type Ⅰ collagen transcript levels in osteoblastlike MC3T3-E1 cells. Methods : The cells used in the present experiments were found to be PTH-responsive in terms of cAMP formation. The cells were cultured in a-MEM supplemented with 10% fetal bovine serum (FBS) and then changed to 0.1% FBS with various concentration of triiodothyronine. DNA synthesis was studied by examing effects on the incorporation of [^3H] thymidine into DNA, collagen synthesis was determined by studying into the incorporation of [^3H] proline into collagenase digestible protein (CDP) and noncollagen protein (NCP).Type Ⅰ collagen mRNA expression was studied by Northern blot analysis. Results : Northern blot analysis showed the presence of 6.4 kb type Ⅰ collagen transcript in control and T_3-treated cultures. From this study. There was no significant differences in DNA synthesis and percentage of collagen synthesized between T_3-treated cells and control. Northern blot analysis of T_3-treated cells, using a type Ⅰ a_2 collagen probe, revealed no significant changes in type Ⅰ collagen transcripts. Conclusion : In MC3T3-E1 cells, which responded to PTH by increasig cAMP formation, the presence of 6.4 kd type Ⅰ collagen transcript was found. Thus MC3T3-E1 cells are a useful model for the investigation of osteoblastic cells. Based on the data, T_3 exerted no significant effects on DNA, collagen synthesis and transcript levels in osteoblast like MC3T3-E1 cells.

        • KCI등재

          Characteristics of Patients Diagnosed with Osteoporosis in South Korea: Results from the National Claim Registry

          윤현구,이영균,하용찬 대한골대사학회 2017 대한골대사학회지 Vol.24 No.1

          Background: Although osteoporosis is increasing medical issue in the elderly population, attempts to analyze the characteristics of patients diagnosed with osteoporosis are rare in South Korea. We investigated the characteristics of patients diagnosed with osteoporosis using Korea's National Health Insurance claims data, which includes almost Korean population. Methods: We evaluated the patients who were diagnosed and treated with osteoporosis in medical institute in South Korea, using the national database by the Health Insurance Review & Assessment Service (HIRA). We evaluated the characteristic of patients and state of medical service utilization in 2010. Results: The number of patients who were diagnosed with osteoporosis were 1,733,685, and almost of them (91.1%) were females. Fourteen point three percent of the patients had experienced osteoporosis-related fracture. The most commonly used type of institute and department was hospital and orthopedic surgery. Conclusions: Considering increasing age population, basic information including characteristic of patients and current state of medical service utilization could be useful to perform appropriate management and treatment for osteoporosis patients in South Korea, using the National Health Insurance claims data.

        • KCI등재

          Gestational Diabetes Mellitus, Fetal Growth and Vitamin D

          윤현구 대한골대사학회 2017 대한골대사학회지 Vol.24 No.3

          Vitamin D is an important secosteroid hormone in skeletal and non-skeletal systems. Vitamin D has relevance to muscle and immune function, hypertension, diabetes mellitus, cancer, and pregnancy because vitamin D receptors (VDR) are present in many non-skeletal tissues. Vitamin D acts on target tissues via the binding of its active form to VDR. As vitamin D affects not only bone metabolism but also glucose metabolism, vitamin D deficiency may affect the development of gestational diabetes mellitus and fetal growth. Although vitamin D deficiency is prevalent during pregnancy, there are conflicting reports on the effect of vitamin D deficiency on pregnancy complications, such as fetal growth restriction and gestational diabetes. This article reviews published papers on the effects of vitamin D on gestational diabetes and fetal growth.

        • KCI등재SCIESCOPUS

          Incidence and Mortality Following Hip Fracture in Korea

          윤현구,박찬미,장선미,장수현,이영균,하용찬 대한의학회 2011 Journal of Korean medical science Vol.26 No.8

          The authors evaluated the incidence of hip fracture and subsequent mortality in Korea using nationwide data obtained from the Health Insurance Review and Assessment Service. This study was performed on patient population, aged 50-yr or older who underwent surgical procedures because of hip fracture (ICD10; S720, S721). All patients were followed using patient identification code to identify deaths. Crude hip fracture rates increased from 191.9/100,000 in 2005 to 207.0/100,000 in 2008 in women and from 94.8/100,000 in 2005 to 97.8/100,000 in 2008, in men respectively. Crude mortality within 12 months after hip fracture showed a similar trend (18.8% in 2005 and 17.8% in 2007). The mean of standardized mortality ratio of hip fracture was 6.1 at 3 months, 3.5 at 1 yr, and 2.3 at 2 yr post-fracture. The increasing incidence and the high mortality after hip fracture are likely to become serious public health problems and a public health program should begin to prevent hip fractures in Korea.

        • KCI등재
        • KCI등재

          908.5~914MHz 대역에서 RFID와 USN 시스템의 주파수 공유 조건에 관한 연구

          윤현구,강민수,장병준,Yoon,,Hyun-Goo,Kang,,Min-Soo,Jang,,Byung-Jun 한국전자파학회 2008 한국전자파학회논문지 Vol.19 No.6

          본 논문에서는 $908.5{\sim}914MHz$ 대역을 RFID와 USN 시스템이 공유하기 위한 간섭 분석 결과를 제시한다. 먼저, 평균 간섭 전력은 통계적인 간섭 분석 모델을 사용하여 이론값과 시뮬레이션 값을 각각 구하고 이를 비교 검증하였다. 그리고 간섭원의 수, 최소 이격 거리에 따른 고출력 및 저출력 RFID 시스템과 USN 시스템 간의 간섭 전력의 누적 확률 분포를 시뮬레이션 하였다. 시뮬레이션 결과, 저출력 RFID 시스템 1개와 다수의 USN node가 서로 보호 영역을 1 m 이상으로 유지할 경우, 상호 최대 허용 간섭 레벨을 만족할 확률은 95 %로 계산되었다. 향후 간섭에 의한 시스템 throughput등과 같은 추가적인 간섭 영향에 대한 검토가 추가된다면 $908.5{\sim}914MHz$ 주파수 대역 공유를 위한 기초 연구로 본 연구의 결과가 활용되리라 기대된다. In this paper, we present interference power distribution results when radio frequency identification(RFID) and ubiquitous sensor network(USN) systems share the $908.5{\sim}914MHz$ frequency bands. Average interference powers are obtained by simulation and statistical analysis, respectively. Simulation results are then verified by statistical analysis. According to the number of interferers and the diameter of the protection area, the cumulative density functions(CDFs) of interference power are simulated under the various conditions. From the simulation results, the probability that both USN and RFID systems meet the required maximal interference power levels is 95 % on condition that there are 1 low revered RFID reader and several USN nodes and that the minimum distance between a RFID reader and an USN node is greater than 1 m. Our results can be used as an basic research for coexistence analysis of RFID and USN systems in the $908.5{\sim}914MHz$ frequency bands.

        • KCI등재SCOPUS
        맨 위로 스크롤 이동