• Title/Summary/Keyword: differential-basis

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Variation in Demography of Taraxacum officinale Seeds Harvested from Different Seasons

  • Yang, Hyo-Sik;Oh, Man-Ho
    • The Korean Journal of Ecology
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    • v.26 no.2
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    • pp.82-86
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    • 2003
  • We investigated the variation in adaptation to growth for four ecotypically-differentiated population of Taraxacum officinale found naturally in temporal environmental heterogeneity. Seeds collected from the four seasons were germinated in incubators and were grown for four months in greenhouse to test genetic variation among biotypes. Biotypes, segregated by seeds collected seasonally, were the part of natural population in Mokpo, South Korea. Each biotype was different in total dry weight of seeds, biomass, and leaf area, confirming previous finding. Differences between biotypes grown under a common environment indicated a genetic basis to their distinct demographic rates. Therefore, biotypes with similar annual rates of growth and contrasting seasonal rates should persist in the population. This differential response suggests that temporal variation in environment may be responsible, in part, for the maintenance of genetic variation within populations.

A Study on Tourist shopping needs and its spatial characteristics

  • Cao, Lin-Sen;Zhang, Rui;Piao, Yong-Ji;Cho, Tae-Dong
    • Journal of Environmental Science International
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    • v.24 no.4
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    • pp.555-559
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    • 2015
  • Tourists travel demand can be divided into the watch the natural landscape, such as shopping, entertainment and other projects. Each travel demand with motivation for meet the requirements of appropriate tourism space environment in order to complete. In this paper, through questionnaire investigation and SD (Semantic Differential) method for the basic attributes of shopping tourists and spatial characteristics of commercial pedestrian street. And analyzes the basic attributes of shopping as the main demand of tourists characteristics and the spatial characteristics of the suitable shopping demand, to provide a scientific basis for the design of tourist shopping space.

Early-Age Behavior of Base Restrained RC Walls (철근콘크리트 벽체의 초기재령 거동 해석)

  • 곽효경;하수준
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.251-258
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    • 2003
  • The early -age behavior of base restrained reinforced concrete (RC) walls is analyzed using a three-dimensional finite element method in this study. After calculating the temperature and internal relative humidity variations of an RC wall, determination of stresses due to thermal gradients, differential drying shrinkage, and average drying shrinkage is followed, and the relative contribution of these three stress components to the total stress is compared. The mechanical properties of early-age concrete, determined from many experimental studies, are taken into consideration, and a discrete reinforcing steel derived using the equivalent nodal force concept is also used to simulate the cracking behavior of RC walls. In advance, to Predict the crack spacing and maximum crack width in a base restrained RC wall, an analytical model which can simulate the post-cracking behavior of an RC tension member is introduced on the basis of the energy equilibrium before and after cracking of concrete.

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A Safety Evaluation of Motor-Operated Valves of Nuclear Power Plants By Using PPM (PPM을 이용한 원자력 발전소 모터구동밸브의 안전성 평가)

  • Park, Su-Ki;Kim, Tae-Woong;Jeong, Hee-Kweon;Park, Sung-Keun
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.718-723
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    • 2001
  • PPM (Performance Prediction Methodology) developed by EPRI was introduced and applied to calculate the stem thrust of 3 and 4 inches flexible-wedge gate valves. The calculated stem thrusts of open and close strokes including cracking were compared with the results measured at in-situ differential pressure tests. The comparison has shown that PPM is an extremely conservative method to predict the minimum required stem thrust to operate motor-operated valves in a design basis accident condition of nuclear power plants.

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Particle Growth in Oxalate Process II; Control of Barium Titanyl Oxalate Particle Size

  • Hyo-Soon Shin;Zee Hoon Park;Chang Hyun Kim;Byung Kyo Lee
    • The Korean Journal of Ceramics
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    • v.2 no.2
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    • pp.70-75
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    • 1996
  • On the basis of growth mechanism proposed by recent work, partile of barium titanyl oxalate was controlled by aging in water. From aging at $25^{\circ}C$ for 3 hours, uniform particles of 0.3 ${\mu}$m were obtained. During aging, abnormal particle growth was observed, which were thought to be caused by impurities in water. With increase of aging time and temperature, particle grows more, and differential growth was promoted. In aging for long time, grown particles were cracked.

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Kaolinitzation Process in Intensely Weathered Granitic Rocks, Ganghwa Island (강화도(江華島) 온수리(溫水里) 지역(地域) 화강암(花崗岩)의 풍화작용(風化作用)에 의한 카올리나이트의 형성(形成))

  • Moon, Hi-Soo;Kim, Shin Ae
    • Economic and Environmental Geology
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    • v.22 no.1
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    • pp.65-80
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    • 1989
  • Strongly weathered granitic rocks are widely distributed in the south-eastern part of the Ganghwa island. Kaolinite developed during intense weathering on this granitic rocks have been studied mineralogically and chemically. Various weathering indexes were ca1culated on the basis of oxide. Those indexes are slightly varied with depth. It shows that the percentages of $Al_2O_3$ increase but that of $CaO+Na_2O+K_2O$ decrease as the weathering progress. These results indicate that day minerals, mainly kaolinite with the appreciable amount of halloysite, were formed by the weathering of feldspars in the granitic rocks. X-ray diffraction, differential thermal analysis, infrared spectrometry and electron microscopy were used to characterize and estimate crystallinity of the kaolinite. Generally, Kaolinite shows a less sharp basal reflection and relatively low dehydroxylation temperature, indicating disordered kaolinite. They usually occur aggregates as a vermicular kaolinites showing loose basal plane stacking arrangement.

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A Study on Characteristics of Sampling Flow and Pressure Conditions for Chemical Detection Optimization (화학탐지 최적화를 위한 유동 및 압력 특성 연구)

  • Son, In-Sung;Yoon, Soon-Min;Kim, Hak-Sin;Yuk, Young-Ho;Park, ByeongHwang;Kim, JuHyun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.2
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    • pp.258-264
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    • 2014
  • In terms of chemical detection performance related with chemical material sampling, this investigation shows optimized values, resulted from minimizing loss from air turbulence and other reasons when pressure changes on the basis of sampling flow rate Based on simulations and pressure control of the outside conditions it became possible to obtain ion mobility detection optimum values, and to derive standard pressure conditions that is appropriate for DMS characteristic.

Improvement of a characteristic point detection algorithm of arterial pulse (동맥맥파의 특징점 검출 알고리즘 개선에 관한 연구)

  • Jeon, Young-Ju;Lee, Jeon;Kim, Jong-Yeol;Lee, Lark-Beom;Im, Jae-Jong
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1916-1917
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    • 2007
  • Aortic AIx(augmentation index) has been used to measure aortic stiffness and evaluate ventricular load quantitatively. Algorithm for the detection of augmentation point gradually increases the differential order to detect inflection point rather than detects the distinctive point that appears after a specific time. Developed algorithm for AIx is proved to provide more accurate results than the ones developed by previous studies with the deviation from $-11.5{\pm}14.34$ points to $-3.75{\pm}1.26$ points. Results could provide the basis for the measurement of aortic stiffness using easily-measurable radial artery pulse waves, and could be extended to develop a system for early diagnosis of various vascular diseases.

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Dynamic stability of a metal foam rectangular plate

  • Debowski, D.;Magnucki, K.;Malinowski, M.
    • Steel and Composite Structures
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    • v.10 no.2
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    • pp.151-168
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    • 2010
  • The subject of the paper is an isotropic metal foam rectangular plate. Mechanical properties of metal foam vary continuously through plate of the thickness. A nonlinear hypothesis of deformation of plane cross section is formulated. The system of partial differential equations of the plate motion is derived on the basis of the Hamilton's principle. The system of equations is analytically solved by the Bubnov-Galerkin method. Numerical investigations of dynamic stability for family rectangular plates with respect analytical solution are performed. Moreover, FEM analysis and theirs comparison with results of numerical-analytical calculations are presented in figures.

Interaction Between Barbiturate and Membrane Components

  • Yu, Byung-Sul;Jo, Seong-Bong;Kim, Chong-Kook;Hwang, Young-Sik
    • Archives of Pharmacal Research
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    • v.13 no.3
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    • pp.246-251
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    • 1990
  • Intermolecular interaction between barbiturates and membrane components such as phospholipid and cholesterol were investigated on $^1$H-NMR spectra and infrared spectra. According to previous reports, barbiturates interacted with phospholipid through intermolecular hydrogen bonds. We also investigated thi observation using dipalmitoyl-phosphatidylcholine (DPPC) as phospholipid in deuterochloroform, and characterized quantitatively. Also, the observed drug could interact with cholesterol which is one of the major components of biomembranes through hydrogen bonds. It was the carbonyl groups of barbiturate and the hydroxyl group of cholesterol that formed hydrogen bond complex. In addition to spectroscopic studies, we investigated the direct effect of phenobarbital on lipid multibilayer vesicles, whose compositions were varied, by calorimetric method. Phenobarbital caused a reduction in the temperature of phase transition of vesicles. These studies may provided a basis for interpreting the mode of action of barbiturates.

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