• Title/Summary/Keyword: strong correlation

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A CLUSTER SURVEY AROUND THE UNIDENTIFIED EGRET SOURCES

  • KAWASAKI WATARU;TOTANI TOMONORI
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.141-144
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    • 2005
  • Based on optical galaxy data, we executed a systematic search for galaxy clusters around the 15 steady unidentified EGRET GeV gamma-ray sources in high Galactic-latitude sky ([b] > $30^{\circ}$). We found a strong correlation with 3.7$\sigma$ level between close cluster pairs (merging cluster candidates) and the unidentified EGRET sources, though, in contrast, no correlation with single clusters. This result implies that merging clusters of galaxies are a possible candidate for the origin of high galactic-latitude, steady unidentified EGRET gamma-ray sources.

A Study on Characteristics Analysis of Low Velocity Impact Response of CF/Epoxy Composite Plates (CF/Epoxy 복합적층판의 저속충격 특성평가에 관한 연구)

  • 임광희;박노식;김영남;김정호;김선규;심재기;양인영
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.85-88
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    • 2002
  • We have implemented a system of falling weight impact tester. Absorbed energy of orthotropic composites with using T300 fiber, which are composed of the same fiber and stacking number is higher than that of quasi-isotropic specimen over impact energy 7J, but in case of using T700 fiber, much difference does not show. Also, absorbed energy of orthotropic composites with using T300 fiber, which are composed of stacking number and orientation became more than that of T700 fiber specimen; however great change doesn't show in case of quasi-isotropic specimens. Delamination area of impacted specimens was measured with ultrasonic C-scanner to find correlation between impact energy and delamination area. Delamination area and frequency responses was evaluated between impacted and unimpacted specimens. There is a strong correlation between frequency responses and impact-induced delamination. The presence and scale of damages have been investigated based on the variations of frequency responses.

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Time Series Analysis of SPOT VEGETATION Instrument Data for Identifying Agricultural Pattern of Irrigated and Non-irrigated Rice cultivation in Suphanburi Province, Thailand

  • Kamthonkiat, Daroonwan;Kiyoshi, Honda;Hugh, Turral;Tripathi, Nitin K.;Wuwongse, Vilas
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.952-954
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    • 2003
  • In this paper, we present the different characteristics of NDVI fluctuation pattern between irrigated and non-irrigated area in Suphanburi province, in Central Thailand. For non-irrigated rice cultivation area, there is a strong correlation between NDVI fluctuation and peak rainfall, while there is a lower correlation with irrigated area. In this study, the 'peak detector' classifier was developed to identify the area of non-irrigated and irrigated cropping and its cropping intensity (number of crops per year). This classifier was created based on cropping characteristics such as number of crops, time or planting period of each crop and its relationship with the peak of rainfall. The classified result showed good accuracy in identification irrigated and nonirrigated rice cultivation areas.

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The decision of position of a partial discharge in power transformer by measurement of ultra sonic signal (초음파 신호측정에 의한 변압기내의 부분방전위치측정)

  • 문영재
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1992.06a
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    • pp.87-90
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    • 1992
  • Detecting acoustic emission (AE) provides an appropriate method to diagonize on-line transformers, since acoustic signal is not influenced by strong electric field. Then AE versus AE signal processing method is investigated. But this processing is difficult that decision of starting point of AE wave with acoustic noise. This problem is sloved by correlation which calculate time interval between two signals eactly. This paper presents a technique locating the eact position of the partial discharge (PD) in a power transformer by the correlation of the AE signals from two ultrasonic sensors. And PD position is displayed on monitor. Laboratory tests confirmed that the proposed method can be used for locating the PD in power transformer.

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Visualization of Vortex Lock-on to Oscillatory Incident Flow in the Cylinder Wake Using Time-Resolved PIV (고속 PIV계측에 의한 실린더 근접후류 공진 유동 가시화)

  • 송치성
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.6
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    • pp.1353-1361
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    • 2001
  • Vortex lock-on or resonance behind a circular cylinder is visualized using a time-resolved PW when a single frequency oscillation is superimposed on the mean incident velocity. For vector processing, a cross-correlation algorithm in conjunction with a recursive correlation and interrogation window shifting techniques is used. Measurements are made of the Karmas and streamwise vertices in the wake-transition regime at Reynolds lumber 360. When lock-on occurs, the vortex shedding frequency is found to be half the oscillation frequency as expected from previous experiments. At the lock-on state, the Karman vortices are observed to be more disordered by the increased strength and spanwise wavelength of the streamwiee vortices, which lead? to a strong three-dimensional motion.

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Effect of Foliar Treatment of KCl on Chlorophyll, Total Sugars, Soluble Protein, In Vivo Nitrate Reductase Activity and Leaf Yield in Mulberry (Morus alba L. CV.S1)

  • Das, C.;Ghosh, M.K.;Das, B.K.;Misra, A.K.;Mukherjee, P.K.;Urs, S.Raje
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.1
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    • pp.45-49
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    • 2003
  • Foliar treatment with different concentrations of potassium chloride (KCl) to mulberry plants resulted in higher level of total chlorophyll, total sugars, soluble protein, in vivo nitrate reductase activity (NRA), net photosynthetic rate (NPR), pWUE and leaf yield. Optimal concentration was found to be 10.0 mM KCl with limited irrigation provided in the mulberry plantation planted in 90 ${times}$ 90 cm spacing. The deleterious effect of soil moisture stress condition has been found to be overcome by KCl foliar spray twice at 15 days interval. Regression and correlation coefficients were analyzed, and a strong positive correlation was found between chlorophyll and total sugars, soluble protein and in vivo nitrate reductase activity, leaf dry weight and net photosynthetic rate and pWUE and net photosynthetic rate.

Effect of the polymer wall boundary condition on the dynamic and memory behavior of the ferroelectric liquid crystal

  • Lee, Ji-Hoon;Lim, Tong-Kun;Park, Seo-Kyu;Kwon, Soon-Bum
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1132-1134
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    • 2006
  • In this research, we examined the correlation between the polymer wall boundary condition and the dynamic/ memory behavior of the ferroelectric liquid crystal (FLC) molecules. It was shown that the polymer wall perpendicular to the rubbing direction induces asymmetric switching to the rubbing direction and induce smaller cone angle angle of LC. On the contrary, in the cell with polymer wall parallel to the rubbing direction, the FLC molecules are oriented in the rubbing direction and shows symmetric switching and has larger cone angle. Memory behavior of each cell has strong correlation with the dynamic state of the FLC molecules. Response time of each cell was also examined.

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Correlation between Attractions and Susceptibilities of Rice Varieties to Aphelenchoides besseyi Christie, 1942

  • Lee Young-Bae;Evans A.A.F.
    • Korean journal of applied entomology
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    • v.12 no.4 s.17
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    • pp.147-151
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    • 1973
  • A laboratory observation and a greenhouse pot experiment were carried out to know the correlationship between the attraction and the susceptibility of rice varieties to Aphelenchoides besseyi. Degrees of attraction of rice seedling extract to A. besseyi and the multiplication rates of the nematode varied greatly according to the rice varieties used. And there was strong correlation between the two variables; i.e., the more the seedling extract of a variety attracted by the nematode in agar observation, the more the variety was susceptible in greenhouse pot experiment.

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Vertical Temperature Profile in the Yellow Sea according to the Variations of Air Temperature

  • CHO Kyu-Dae;CHO Kwang-Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.1
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    • pp.1-10
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    • 1988
  • The vertical temperature profiles of the Yellow Sea in summer are investigated by means of the nine air temperature (AT) patterns which are classified with the AT of winter and summer. The sea surface temperature (SST) is high when the AT of summer is high, and vice versa. The gradient of thermocline in the offshore region is higher than that in the coastal region and is not always favorable with the AT patterns. The relation between sea bottom temperature (SBT) and the AT of winter is favorable when the SBT is averaged in the coastal and offshore stations. In addition, the SST of coastal stations is higher than that of offshore stations because of the strong mixing by the tidal current in the coastal region. The correlation between the AT and the SST of August is favorable (r=0.44-0.69), while the correlation between the AT of February and the SBT of August is not favorable except the stations, A2 (r=0.57) and B2 (r=0.61).

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Comparison of Bone Mineral Density with Pencil Beam and Fan Beam DXA Machine

  • Park, Jeong-Hoon;Lee, Jae-Mun;Youn, Je-Woong;Suh, Tae-Suk;Lee, Heung-Kyu
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.425-426
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    • 2002
  • The bone densitometer is to investigate the bone mineral content and density for the osteoporosis assessment by using dual energy X-ray photons. For the clinical verification of the ISOL's OSTEO plus, the clinical study was performed with healthy and non-menopausal 30 female volunteers. The fan-beam DXA machine (Lunar, Expert) was chosen as a reference. After correlation analysis of their bone mineral densities, a strong correlation was obtained. From the results, it is claimed that the new forearm bone densitometer is clinically useful in osteoporosis diagnosis.

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