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        검색결과 5

        1.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        흰꽃세덤(Sedum album)은 포복성으로 자라며 무리 지어 개화하는 특성을 가진 다육식물의 일종이다. 흰꽃세덤은 의약 품에 사용될 수 있는 플라보놀 배당체(flavonol glycoside)를 많이 생산하는 것으로 알려져 있다. 뿐만 비생물적 스트레 스 요인에 대해 강한 저항성을 가지고 있고 옥상녹화 시스템 (green roof systems)에 많이 사용되는 식물이다. 흰꽃세덤 은 강인한 생명력과 특이한 외형을 기반으로 실내에서 관상식 물로 사용될 수 있는 잠재력도 가지고 있다. 그러나 흰꽃세덤 이 실내식물로써 활용되기 위해서는 생장에 적합한 광질이 구명되어야 한다. 이에 따라 본 실험에서는 인공광원으로 시중 에 상용으로 판매되고 있는 3000, 4100, 6500K 백색 T5 LED를 사용하였으며 식물은 흰꽃세덤의 우량종인 ‘아툼’(S. album cv. Athoum)을 선발하여 본 실험에 적용하였다. 결과 적으로 초장, 초폭, 피복면적, 근장, 분지의 개수와 같은 식물 의 크기를 나타내는 지표는 4100K 백색 LED 처리구에서 크 게 증가하는 것으로 나타났다. 식물의 생체중과 수분함량은 4100K 백색 LED에서 증가하였으나 건물중은 3000K 백색 LED에서 증가하는 것으로 나타났다. CIELAB 중 명도를 나타 내는 L*은 4100K 백색 LED에서 가장 높게 나타났는데 이는 식물의 높은 수분함량으로 인한 세포의 팽창 혹은 에피큐티큘 러 왁스층(epicuticular waxes)의 발달로 추측되었다. CIE76 color difference(ΔE * ab)는 4100K 백색 LED 처리 구와 6500K 백색 LED 처리구 간에 ΔE* ab=5.51로 가장 크게 나타났다. RHS 분석에서는 모든 처리구가 동일하게 N137A, 147A로 평가되었다. 결론적으로 식물을 판매하거나 관상가치 를 향상시킬 목적으로 식물의 크기를 유의미하게 증대시키고 자 하는 경우 4100K 백색 LED를 사용할 것을 권고한다. 한 편, 살아있는 식물체를 약용으로 사용하거나 2차 대사산물을 추출하고자 하는 경우 4100K 백색 LED의 사용을 권고하며 말린 식물체를 활용하고자 한다면 3000K 백색 LED를 사용 할 것을 권고한다.
        4,000원
        2.
        1999.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to assess the fatigue in lumbar and abdominal muscles in patients with chronic low back pain compared with normal subjects using spectral analysis with mean power frequency and median power frequency. The experimental group consisted of twenty subjects who had experienced chronic low back pain for over one year after the onset day. A control group consisted of twenty normal subjects with no history of low back pain. All subjects stood in an apparatus to perform sustained contraction in the lumbar and abdominal muscles for 30 seconds with 60% maximal voluntary isometric contraction (MVIC). The resulting electromyographic (EMG) recorded time serial data were transformed into frequency serial data by Fast Fourier Transformation (FFT). The results were as follows: 1) lumbar muscles measured, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group group (p<0.05). In measured two abdominal muscles (inferior rectus abdominis, obliquus externus abdominis) except superior rectus abdominis, the frequency change ratio of both median power frequency and mean power frequency was significantly greater for experimental group compared with control group (p<0.05). 2) In all three (longissimus thoracis, iliocostalis lumborum, multifidus) lumbar muscles measured, the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). In the two (inferior rectus abdominis, obliquus externus abdominis) abdominal muscles measured (superior rectus abdominis not included), the initial frequency value of both median power frequency and mean power frequency was significantly lower for the experimental group compared with the control group (p<0.05). These results suggest that in patients with chronic low back pain there is a trend for more fatigue to occur in both lumbar and abdominal muscles than in the normal control group. This would seem to suggest that in treatment programs for patients with chronic low back pain, improvement of endurance in all trunk muscles should be considered.
        4,900원
        3.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Trunk holding test (Sorensen test) appear to have more value than strength test in prediction the occurrence of low back pain. Electromyographic activity of trunk extensor muscles during these test may provide clues to the etiology of neuromuscular-based low back pain. This study investigated the difference in back muscle endurance between healthy adult men and women using surface electromyographic (EMG) power spectral analysis. Thirty hea1thy subjects (15 men and 15 women) performed an unsupported trunk holding test for 60 seconds. Recording surface electrodes were placed over the erector spinae medially and laterally at vertebral levels of and . Slope of total frequency was evaluated using the MP100WSW Fast Fourier Transform spectrum analysis program. The slopes of all indices of back muscle fatigue, except right , were significantly steeper in men than in women (p<0.05). Our results indicated that the trunk holding test using EMG power spectral analysis of erector spinae muscles is useful for the evaluation of fatigue rate of these muscles. Our results also showed a higher muscle endurance in healthy adult women than in men.
        4,000원
        4.
        1988.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A power spectral analysis is made seasonally for the data of daily mean temperature and pressure at Seoul(37°34'N, 126°58'E), Chupungnyong(36°13'N, 128°00'E), Kwangju(35°08'N, 126°55'E) from March 1961 to February 1986. The time sequences of the power spectra for the daily mean pressure show that power spectral density is generally high at the period of 20-30days and 10 days in winter, 15-20 days and 8.6 days in spring, summer and autumn. For the daily mean temperature, the power spectral density is generally lower than that of pressure and changes largely following the seasons, high in winter and low in summer. The time sequences of the' power spectra are much the same pattern as that of pressure in spring and autumn, but in winter show high power spectral density at the period of 5.5-7.5 days, much the same period as '3 cold days and 4 warm days' which is the popular weather lore on the winter temperature fluctuations in Korea. Judging from the phase differences between observation stations of temperature and pressure changes, which is less than 20 degrees, the phase changes of temperature occurs in sequence of Seoul, Chupungnyong, Kwangju and in case of pressure much the same as in the temperature at the period of above 15 days, but below the period of about 15 days in the opposite sequence. The correlations between the interannual changes of seasonal mean of weather elements and the power spectral density at each period are investigated to show that the positive correlation is between the power spectral density at the period of above 20 days and temperature in summer, that at below 4.5 days and precipitation in spring, that at below 6.7 days and temperature in winter.
        4,000원
        5.
        2012.02 KCI 등재 서비스 종료(열람 제한)
        Power spectral analysis for PM10 observed at 10 cities in the Korean Peninsula from 2004 to 2010 was carried out to examine the spatial and temporal features of PM10 evolution cycle. The power spectrum analysis proposed 9 typical cycles (0.5 day, 1day, 5.4day, 8~10day, 19~21day, 26day, 56day, 180day and 365day) for PM10 evolution and the cycles are strongly associated with dilution and transportation due to the meterological influence. The spectrum intensity of 5.4day and 26day PM10 evolution cycles mainly depend on the advection cycles of synoptic pressures system and long-term variation of climatological forcing, respectively. The intensity of PM10 evolution with longer temporal cycles than one day tends to be stronger in La niña period in comparison with that in El niño period. Mean of typical intensity of PM10 evolution in La niña period estimated to be 30% larger than El niño period. Thus the global scale meteorological phenomena such as El niño and La niña also can influence the variation of wind system in the Korean Peninsula and PM10 evolution. but global scale forcing tends to influence different manner for PM10 evolution in accordance with its temporal cycles.