• Title/Summary/Keyword: relative difference

Search Result 2,540, Processing Time 0.034 seconds

Impedence and Q-factor of frequence dependance accoding to ferrites on electrodeless fluorescent lamp (무전극 형광램프의 주파수에 따른 임피던스 및 Q-factor 변화 연구)

  • Pack, Gwang-Hyoen;Yang, Jong-Kyung;Lee, Jong-Chan;Choi, Jong-Sung;Park, Dae-Hee
    • Proceedings of the KIEE Conference
    • /
    • 2004.11a
    • /
    • pp.153-156
    • /
    • 2004
  • An electric power efficiency of electrodeless fluorescent lamp has big relative property of gas in lamp, gas pressure, lamp formation, ingredients of magnetic substance and shape and action frequency etc. We used magnetic substance that open self examination material of electrodeless fluorescent lamp antenna. Ferrite that is used in this experiment was Mn-Zn type. We have examined resistance kind, impedance, Q-factor's frequency characteristic by ferrite. Impedance, resistance and capacitance did not show difference in start frequency 2.65 [MHz] but there was difference quantity. We could know Q-factor's difference according to material, and Q-factor's is important part of antenna design.

  • PDF

Nonparametric two sample tests for scale parameters of multivariate distributions

  • Chavan, Atul R;Shirke, Digambar T
    • Communications for Statistical Applications and Methods
    • /
    • v.27 no.4
    • /
    • pp.397-412
    • /
    • 2020
  • In this paper, a notion of data depth is used to propose nonparametric multivariate two sample tests for difference between scale parameters. Data depth can be used to measure the centrality or outlying-ness of the multivariate data point relative to data cloud. A difference in the scale parameters indicates the difference in the depth values of a multivariate data point. By observing this fact on a depth vs depth plot (DD-plot), we propose nonparametric multivariate two sample tests for scale parameters of multivariate distributions. The p-values of these proposed tests are obtained by using Fisher's permutation approach. The power performance of these proposed tests has been reported for few symmetric and skewed multivariate distributions with the existing tests. Illustration with real-life data is also provided.

Study of Equivalent Retention among Different Polymer-Solvent Systems is Thermal Field-Flow Fractionation

  • 김원숙;박영훈;문명희;유유경;이대운
    • Bulletin of the Korean Chemical Society
    • /
    • v.19 no.8
    • /
    • pp.868-874
    • /
    • 1998
  • An equivalent retention has been experimentally observed in thermal field-flow fractionation (ThFFF) for different polymer-solvent systems. It is shown that iso-retention between two sets of polymer-solvent systems can be obtained by adjusting the temperature difference (ΔT) according to the difference in the ratio of ordinary diffusion coefficient to thermal diffusion coefficient. This method uses a compensation of field strength (ΔT) in ThFFF at a fixed condition of cold wall temperature. It is applied for the calculation of molecular weight of polymers based on a calibration run of different standards obtained at an adjusted AT. The polymer standards used in this study are polystyrene (PS), polymethylmethacrylate (PMMA), and polytetrahydrofuran (PTHF). Three carrier solvents, tetrahydrofuran (THF), methylethylketone (MEK) and ethylacetate (ETAc) were employed. Though the accuracy in the calculation of molecular weight is dependent on the difference in the slope of log λ vs. log M which is related to Mark-Houwink constant a, it shows reasonable agreement within about 6% of relative error in molecular weight calculation for the polymer-solvent systems having similar a value.

Binding Free Energy Simulations of the HIV-1 Protease and Hydroxyethylene Isostere Inhibitors

  • Won, Yeong Do
    • Bulletin of the Korean Chemical Society
    • /
    • v.21 no.12
    • /
    • pp.1207-1212
    • /
    • 2000
  • The free energy simulation technique is used to evaluate the relative binding affinity of a set of hydroxyethylene isostere inhibitors of the HIV-1 protease. The binding reactions and an alchemical mutation construct the thermodynamic cycle, which reduces the free energy difference of the binding interactions into that of the alchemical processes. In the alchemical process, a methyl group is mutated into a hydrogen atom. Albeit the change is a small perturbation to the inhibitor-protease complex, it results in 25 fold difference in the binding constants. The simulation reproduces the experimentally measured binding affinities within 2% of the free energy difference. The protonation state of the catalytic aspartic acid residues is also investigated through the free energy simulations.

Behavior of Underground Flexible Pipe According to Ground Characteristics (지반특성에 따른 지중 연성관의 거동특성)

  • Chang, Yongchai;Kim, Yonghyu;Lee, Seungeun;Park, Kichul;No, Jinsuk
    • Journal of the Korean GEO-environmental Society
    • /
    • v.10 no.4
    • /
    • pp.41-48
    • /
    • 2009
  • A flexible pipe was buried 10cm below the ground formed with standard sand to observe changes in the shape of the pipe according to the behavior of ground at each relative density. Changes in the shape of the pipe in each ground were observed to examine the behavior of the pipe under the state of reinforced ground after installing geogrid under the pipe. Ground reinforced using geogrid formed tensile force on the reinforcement material with increase in the vertical load and showed reduction in settlement under identical vertical load with existence of reinforcement. Distributions of ground deformation of 100% relative density and 70% relative density had clear difference. Reinforced ground with 70% density converged to the ground reaction of final settlement of non-reinforced ground with 100% density at final settlement of 100 mm. Because the shape of lower part strain of the buried pipe is similar to that of un-reinforced ground with relative density of 100%, reinforcement effect by geogrid in soft ground can be anticipated.

  • PDF

Structure and Succession of Zooplankton Community in Several Artificial Lakes in the Han River System (한강 수계 주요 댐호에서의 동물플랑크톤 군집 구조와 천이)

  • You, Kyung-A;Park, Hae-Kyung;Kong, Dong-Soo;Hwang, Soon-Jin
    • Journal of Korean Society on Water Environment
    • /
    • v.26 no.5
    • /
    • pp.850-859
    • /
    • 2010
  • Structure and succession of zooplankton community studied by hydraulic and ecological characteristics targeting the five lakes in the Han river system from March to December 2008. Results separated by river-type lake and lake-type lake depending on the type of hydraulic, Paldang lake and Cheongpyeong lake were river-type lake, while Chungju lake, Hoengseong lake and Doam lake was lake-type lake. The Paldang lake was a eutrophic lake, zooplankton community density and species number were the most among the five lakes. Relative dominance of the rotifera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Cheongpyeong lake was a mesotrophic-eutrophic lake, hydraulic characteristics and zooplankton community changes were similar the Paldang lake. Relative dominance of the cladocera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Chungju lake was a oligotrophic-mesotrophic lake, zooplankton community density was the least among the five lakes. Relative dominance of the copepoda was the largest and the yearly first dominant species was a large cladocera Daphnia galeata. The Hoengseong lake was a oligotrophic-mesotrophic lake, relative dominance of the rotifera was the largest and the yearly first dominant species was a small cladocera Bosmina longirostris. The Doam lake was a mesotrophic-eutrophic lake, zooplankton community density showed dramatic difference at the investigation time. Relative dominance of the rotifera was the largest and the yearly first dominant species was the copepoda Nauplius.

Effects ofRelative Humidity on Russet Occurrence in Whangkeumbae Pear (Pyrus pyrifolia Nakai cv,) (상대습도가 황금배(pyrus pyrifolia Nakai cv.) 동녹발생에 미치는 영향)

  • 조일환;우영회;최장전;한점화;서흥수
    • Journal of Bio-Environment Control
    • /
    • v.11 no.1
    • /
    • pp.1-4
    • /
    • 2002
  • The occurrence rate of russet in 'Whangkeumbae' pear showed significant difference by years because the russet occurrence is greatly affected by the amount of rainfall. This study was conducted to analyse the relationship between rainfall and russet occurrence by artificial treatment of high humidity. Under high relative humidity condition, stomatal resistance decreased and average fruit weight was higher since the increased net photosynthesis rate accumulation accelerated fruit growth. The russet occurrence began on July 25, when the growth speed of fruit weight and fruit surface is the most fast. Russet occurrence rate was higher in high relative humidity condition because the fruit growth was accelerated. Since the fruit calcium concentration change is extreme in late July, it is assumed that the deceased calcium content is related to the occurrence of russet in 'Whangkeumbae' pear, When the high relative humidity condition is maintained after rainfall, the amount of net photosynthesis rate increase and fruit growth is accelerated. Therefore, the unbalance in the amounts of transferred photosynthesis assimilation product, water and mineral elements would be one of the reasons for the russet occurrence in 'Whangkeumbae' pear.

Comparison of Relative Accommodation, Accommodative Facility, and Addition Based on Occupation of Initial Presbyopia (직업에 따른 초기 노안의 상대조절력, 조절용이성, 가입도 비교)

  • Kim, Hyun-Mok;Son, Jeong-Sik;Lee, Won-Jin;Lee, Jae Yoon;Cho, Hyun Gug
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.14 no.4
    • /
    • pp.59-63
    • /
    • 2009
  • Purpose: This study was designed to compare the relative accommodation, the accommodative facility, and the addition whose 40's initial presbyopia divided into five occupations (driver, official worker, housewife, field worker, teacher). Methods: We measured the values of near point convergence (NPC), positive relative accommodation (PRA), negative relative accommodation (NRA), accommodative facility, and addition. Results: Official worker group had lower PRA, higher NRA, and lower accommodative facility compared with them of the other groups. The average of addition was as follows: official worker > driver > field worker > housewife > teacher. Conclusions: Because the difference of working environment based on occupation affects the accommodative functions and addition, it is important to consider the patient's occupation when opticians measure the addition for near vision of initial presbyopia.

  • PDF

Relative Efficiency of Taxi Services by Data Envelopment Analysis among Cities and Counties in Gyeonggi Province (DEA를 이용한 경기도내 시·군별 택시서비스 효율성 분석)

  • Kim, Dae Hoon;Jang, Tae Youn;Song, Je Ryong
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.33 no.4
    • /
    • pp.1571-1580
    • /
    • 2013
  • This study analyzes the relative efficiences through satisfaction on taxi services of thirty-one cities and counties in Gyeonggi Province. The DEA (Data Envelopment Analysis) is used to measure efficiencies on the privately owned taxies and the corporate taxies respectively. Efficiency in the DEA is measured relative to the highest observed performance rather than against some average. Pyeongtaek, Pocheon, Osan, Yangpyeong, and Gapyeong have the highest efficiency in the private owned taxies. And Pyeongtaek, Pocheon, Osan, and Gapyeong have the highest one in the corporate taxies. These cities and counties have the ability to use less resources for equal efficiency relative to others. Rank-sum test proves that there is no statistical difference in efficiency between the privately owned taxies and the corporation owned taxies.

Comparison of the PM-10 mass concentration in different measurement methods and meteorological conditions (측정방법 및 기상상태에 따른 PM-10 질량농도 비교)

  • Jung, Chang Hoon;Park, Jin Hee;Hwang, S.M.;Jung, Y.G.
    • Particle and aerosol research
    • /
    • v.5 no.2
    • /
    • pp.53-62
    • /
    • 2009
  • In this study, the continuous monitoring of the concentration of PM-10 atmospheric particulate matter using beta ray attenuation method was compared with gravimetric method from September, 2006 to August, 2007. On the effects of the PM-10 concentration and mass difference by relative humidity and precipitation were considered. The result showed that the measurement error between beta ray method and gravimetric method are within -3~6% in average, which means PM-10 concentration data with beta ray method are relatively comparable. The current study also shows that the high PM-10 concentration events are mainly due to haze, Asian dust, and high relative humidity and the PM-10 mass concentration is closely related with relative humidity and precipitation events. Based on daily mean data, the PM-10 increases as relative humidity increases up to 70~80%, then decreases over 80% due to the precipitation. However, the distinct measurement discrepancy was not shown between beta ray method and gravimetric method based on current results. Consequently, this study shows that the collocated measurement in different instrument is essential in order to quantify the accuracy of PM-10. Furthermore, the more comprehensive and spatially distributed comparison is needed and this is remained for future study.

  • PDF