• Title/Summary/Keyword: Point Density

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DIGITAL INFRARED THERMAL IMAGING IN OSTEOPOROSIS

  • Lee, Kyung-Sub;Kim, Yong-Suk
    • Journal of Oriental Medical Thermology
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    • v.1 no.1
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    • pp.1-6
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    • 2002
  • This study examined the relationship between bone mineral density and DITI in the diagnosis of osteoporosis. An analysis was performed on the thermographic findings of 20 patients without osteoporosis, 20 with osteopenia and 20 with osteoporosis at the Kangnam Korean Hospital, KyungHee University, Seoul, Korea, from June 1998 to February 1999. The osteoporosis was measured by LUNAR PIXI and the body temperature was assessed by DITI. Thermogrphic measurements were performed on 4 areas(acupuncture point: CV12, CV4, BL23 and BL26). All data were coded for computer analysis and significances were tested by Duncan test. There was no significant difference in age among the three groups of patients. DITI revealed the significant hypothermia (p<0.001) on the osteoporosis patients compared with osteopenia and normal bone density patients. It is believed that DITI may be a favorable alternative to the diagnosis of osteoporosis.

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Improvement of the resistance to Treeing by additive in Low Density Polyethylene (첨가재에 의한 저밀도 폴리에틸렌의 내트리잉성 향상)

  • 김봉협;임기조
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.35 no.1
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    • pp.17-25
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    • 1986
  • Discussions on this paper are related to the effects of organic materials to treeing phenomena of low density polyethylene. As additives, 11 kinds of organic compounds are selected by considering the respective features such as melting point, boiling point, electron affinity as well as molecular structure, and then the specimens of low density polyethylene are prepared by blending with 10wt% of the selected additives. For the comparison of effectiveness of treeing resistance and interpretation of the mechanism of compounds as treeing retardants, several investigations such as the tree acceleration test, the prestressed test and the measurement of internally occurred partial discharge are carried out. As the results, meta-Cresol is regard as the most effective retardant among those, and it is supposed that this aromatic compound to be comprised of radical having large electron affinity has strong capability to accept energetic electron to prevent or delay the growth of discharge streamer. Furthermore, by activating partial discharge at the wall of tree pit through the function of trapped electron at this material, the gas pressure in the pit is increased up to prevent the growth of streamer.

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Electrical Characteristics of Helicon Wave plasmas (헬리콘 플라즈마의 전기적 특성)

  • 윤석민;김정형;서상훈;장흥영
    • Journal of the Korean Vacuum Society
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    • v.5 no.1
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    • pp.85-92
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    • 1996
  • The external electricla characteristics of helicon wave plasmas were measured over a wide range of RF power and magnetic filed. External parameters. such as antenna voltage , current, phase shift, and interanl parameter, electron density were measured at 7MHz, 1mTorr Ar discharge . The equivalent discharge resistance and reactance, and the power transfer efficiency were calculated through these measurements. There are a helicon mode which produces high density plasma by helicon wave and a lowmode which produces low density plasma by capaictive electric field. In case of the helicon mode, the anternna voltage and current were lower than those of the low-mode. The phase difference between voltage and current decreased suddenly at the transition point from the low-mode to the helicon mode. Equivalent resistance and power efficiency increased and reactance decreased suddenly at the transition point. These results mean that the power transperred to plasma and the nutual coupling between the antenna and plasma increase as the mode changes from the low-mode to the helicon mode.

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A STUDY ON THE PREDICTION OF GROUNDWATER CONTAMINATION USING GIS (지하수오염 예측을 위한 GIS 활용연구)

  • Jo, SiBeom;Shon, HoWoong
    • Journal of the Korean Geophysical Society
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    • v.7 no.2
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    • pp.121-134
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    • 2004
  • This study has tried to develop the modified DRASTIC Model by supplying the parameters, such as structural lineament density and land-use, into conventional DRASTIC model, and to predict the potential of groundwater contamination using GIS in Hwanam 2 District, Gyeonggi Province, Korea. Since the aquifers in Korea is generally through the joints of rock-mass in hydrogeological environment, lineament density affects to the behavior of groundwater and contaminated plumes directly, and land-use reflect the effect of point or non-point source of contamination indirectly. For the statistical analysis, lattice-layers of each parameter were generated, and then level of confidence was assessed by analyzing each correlation coefficient. Groundwater contamination potential map was achieved as a final result by comparing modified DRASTIC potential and the amount of pollutant load logically. The result suggest the predictability of contamination potential in a specified area in the respects of hydrogeological aspect and water quality.

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Change-point and Change Pattern of Precipitation Characteristics using Bayesian Method over South Korea from 1954 to 2007 (베이지안 방법을 이용한 우리나라 강수특성(1954-2007)의 변화시점 및 변화유형 분석)

  • Kim, Chansoo;Suh, Myoung-Seok
    • Atmosphere
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    • v.19 no.2
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    • pp.199-211
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    • 2009
  • In this paper, we examine the multiple change-point and change pattern in the 54 years (1954-2007) time series of the annual and the heavy precipitation characteristics (amount, days and intensity) averaged over South Korea. A Bayesian approach is used for detecting of mean and/or variance changes in a sequence of independent univariate normal observations. Using non-informative priors for the parameters, the Bayesian model selection is performed by the posterior probability through the intrinsic Bayes factor of Berger and Pericchi (1996). To investigate the significance of the changes in the precipitation characteristics between before and after the change-point, the posterior probability and 90% highest posterior density credible intervals are examined. The results showed that no significant changes have occurred in the annual precipitation characteristics (amount, days and intensity) and the heavy precipitation intensity. On the other hand, a statistically significant single change has occurred around 1996 or 1997 in the heavy precipitation days and amount. The heavy precipitation amount and days have increased after the change-point but no changes in the variances.

Density, Absorption and Table Flow properties of the Lower melting Point of the Modified Sulfur and General Industrial Sulfur (일반 공업용 유황과 융점을 낮춘 개질유황의 유동성, 흡수율 및 밀도 특성)

  • Kim, Heon-Tae;Lee, Yong;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.11a
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    • pp.45-46
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    • 2015
  • Recently, the large amount of sulfur is globally generated by the development of the petroleum refining industry every year. In this study, without the use of the sulfur with a high melting point used in the previous studies, the modified sulfur mortar with addition of a melting point of about 65℃ were tested to determine their distribution and strength properties according to the mixing method and curing conditions. This study is a test to find out the Density, Absorption and Table Flow of the modified sulfur and general sulfur. As result, general industrial sulfur flow was lower, showed a high absorption rate.

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Urban Stormwater Capture Curve using 3-Parameter Mixed Exponential Probability Density Function (3변수 혼합 지수 확률밀도함수를 이용한 도시 강우 유출수 포착곡선의 작성)

  • Han, Suhee;Park, Moo Jong;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.24 no.4
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    • pp.430-435
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    • 2008
  • In order to design Non-point source management, the aspect of statistical features of the entire precipitation data should be focused since non-point source discharge is driven by continuous rainfall runoffs. 3-parameter mixed exponential probability density function is used to establish urban stormwater capture curve instead of previous single-parameter exponential PDF. Then, recent 10-year data in Busan are applied to establish the curve. The result shows that 3-parameter mixed PDF gives better resolution.

An Algorithm of Score Function Generation using Convolution-FFT in Independent Component Analysis (독립성분분석에서 Convolution-FFT을 이용한 효율적인 점수함수의 생성 알고리즘)

  • Kim Woong-Myung;Lee Hyon-Soo
    • The KIPS Transactions:PartB
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    • v.13B no.1 s.104
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    • pp.27-34
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    • 2006
  • In this study, we propose this new algorithm that generates score function in ICA(Independent Component Analysis) using entropy theory. To generate score function, estimation of probability density function about original signals are certainly necessary and density function should be differentiated. Therefore, we used kernel density estimation method in order to derive differential equation of score function by original signal. After changing formula to convolution form to increase speed of density estimation, we used FFT algorithm that can calculate convolution faster. Proposed score function generation method reduces the errors, it is density difference of recovered signals and originals signals. In the result of computer simulation, we estimate density function more similar to original signals compared with Extended Infomax and Fixed Point ICA in blind source separation problem and get improved performance at the SNR(Signal to Noise Ratio) between recovered signals and original signal.

Studies on the Competition-Density Effect of Some Higher Plants (수종 식물의 밀도-경쟁효과에 관한 연구)

  • 진희성
    • Journal of Plant Biology
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    • v.15 no.2
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    • pp.7-19
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    • 1972
  • The studies of density effect or the effect of population density on plant growth have been done on basis of dry matter production with Raphanus acanthiformis var. simoodaeguen, Brassica campestris var. Pekinensis f. namsounsokoombecheu, Oryza sativa f. kimmajae and O. sativa f. mangyeng grown in the various spacing. 1. In the early period of plant growth in dry weight was not different each other among varying densities, but as time advanced the plant grown vast space grew sufficiently compared with those of narrow one. 2. Iogarithmic relation between the growth of plant (W) and the density (P), log W-log P in the material plants, were approximated by two straight lines, one was horizontal line and another inclined: the former showed non-competition density and the latter competition density addition to these the point interlinking both lines were implied of the optimum density per unit land area at certain growth period. 3. The values of relatvie growth rate (RGR) and net assimilation rate (NAR) were decreased as increase in the density, while those of leaf area ratio (LAR) were rather increased in the same condition, with minor exception. From these results and relation between the productive structure and due to lack of the recieved light intensity owing to the mutal shading among the plants.

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TOPOLOGICAL CHARACTERIZATIONS OF CERTAIN LIMIT POINTS FOR MOBIUS GROUPS

  • Hong, Sung-Bok;Kim, Han-Doo
    • Bulletin of the Korean Mathematical Society
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    • v.38 no.4
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    • pp.635-641
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    • 2001
  • A limit point p of a Mobius group acting on$ B^m$ is called a concentration point if for every sufficiently small connected open neighborhood of p, the set of translates contains a local basis for the topology of p. For the case of two generator Schottky groups acting on $B^2$, we give characterizations for several different kinds of limit points.

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