• Title/Summary/Keyword: Taylor's power law

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Dispersion Indices and Sequential Sampling Plan for the Citrus Red Mite, Panonychus citri (McGregor) (Acari: Tetranychidae) on Satsuma Mandarin on Jeju Island (온주밀감에서 률응애의 공간분포분석 및 표본추출법)

  • 송정흡;이창훈;강상훈;김동환;강시용;류기중
    • Korean journal of applied entomology
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    • v.40 no.2
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    • pp.105-109
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    • 2001
  • Dispersion pattern of the citrus red mite (CRM), Panonychus citri (McGregor) was determined to develop a monitoring method in the satsuma mandarin fields, Citrus unshiu L., in Jeju-do, during 1999 and 2000. CRM population was sampled by collecting leaves. Taylor's power law provided better description of mean-variance relationship for the dispersion indices compared to Iwao's patchiness regression. Slopes and intercepts of Taylor's power law from leaf samples did not differ among surveyed groves. Fixed-precision levels (D) of a sequential sampling plan were developed using Taylor's power law parameters generated from all motile stages of CRM in leaf sample. This sampling plan for leaf sample estimate was tested with resampling validation for sampling plan using 4 independent data sets. Resampling simulation analysis demonstrated that actual fixed-precision level values were better than desired D values of 0.20, 0.25 and 0.30. Required numbers for tree sampling at the density of more than 7 mites per tree were fewer than 18.

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Taylor's Power Law and Quasilikelihood

  • Park, Heung-Sun;Cho, Ki-Jong
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.10a
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    • pp.253-256
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    • 2003
  • In ecological studies, animal science, or entomology, the variance of count is considered to have the power of the mean relationship with the mean count as Taylor (1961) presented his famous 'Taylor's Power Law'. In this talk, we are going to review the development of TPL and its extension toward pest management sampling scheme. Different estimation methods are compared. Quasilikelihood approach is suggested to incorporate covariate information. Possible extensions will be discussed.

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Efficient Occurrence Monitoring by Yellow Sticky Traps for Major Flying Pests in Strawberry Greenhouses (시설딸기 주요 비행해충의 황색끈끈이트랩 이용 효율적인 발생예찰)

  • Yang, Cheol Jun;Song, Jeong Heub;Yang, Young Taek;Kim, Hyo Jeong;Song, Min A;Jwa, Chang Sook
    • Korean journal of applied entomology
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    • v.56 no.3
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    • pp.309-314
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    • 2017
  • Sampling plan using yellow sticky traps for the major strawberry flying pests - western flower thrips Frankliniella occidentalis adults, cotton aphid Aphis gossypii alate and greenhouse whitefly Trialeurodes vaporarium adults was developed to determine the initial occurrence time. The analyzed trap data were obtained from three commercial strawberry greenhouses for the whole growing season (September to May of the following year) during 2013 to 2017 in Jeju province. Three flying pests showed the aggregated distribution patterns resulted from commonly used regression techniques - Taylor's power law and Iwao's patchiness regression. Taylor's power law was better description of mean-variance relationship of the western flower thrips and the cotton aphid than Iwao's patchiness regression, otherwise greenhouse whitefly was better described by Iwao's patchiness regression. There were highly significant correlated among mean density per trap, maximum density and proportion of traps with more than 10 individuals. To estimate 4.0 heads of mean density per trap, the minimum number of traps were required 13 traps for western flower thrips, 11 traps for cotton aphid and 10 traps for greenhouse whitefly. The sequential sampling plans at the fixed precision level 0.25 were developed using parameters of Taylor's power law for western flower thrips and cotton aphid, and of Iwao's patchiness regression for greenhouse whitefly.

Use of Pseudo-Likelihood Estimation in Taylor's Power Law with Correlated Responses

  • Park, Bum-Hee;Park, Heung-Sun
    • Communications for Statistical Applications and Methods
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    • v.15 no.6
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    • pp.993-1002
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    • 2008
  • Correlated responses have been widely analyzed since Liang and Zeger (1986) introduced the famous Generalized Estimating Equations(GEE). However, their variance functions were restricted to known quantifies multiplied by scale parameter. In so many industries and academic/research fields, power-of-the-mean variance function is one of the common variance function. We suggest GEE-type pseudolikelihood estimation based on the power-of-the-mean variance using existing software and investigate it's efficiency for different working correlation matrices.

Spatial Distribution and Sampling Plan for Pink Citrus Rust Mite, Aculops pelekassi (Acari: Eriophyidae) in Citrus Orchard (감귤원에서 귤녹응애 공간분포 분석과 표본조사법 개발)

  • Song, Jeong-Heub;Hong, Soon-Yeong;Lee, Shin-Chan
    • Korean journal of applied entomology
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    • v.51 no.2
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    • pp.91-97
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    • 2012
  • The dispersion indices, spatial pattern and sampling plan for pink citrus rust mite (PCRM), Aculops pelekassi, monitoring was investigated. Dispersion indices of PCRM indicated the aggregated spatial pattern. Taylor's power law provided better description of variance-mean relationship than Iwao's patchiness regression. Fixed-precision levels (D) of a sequential sampling plan were developed using by Taylor's power law parameters generated from PCRM on fruit sample (cumulated number of PCRM in $cm^2$ of fruit). Based on Kono-Sugino's empirical binomial the mean density per $cm^2$ could be estimated from fruit ratio with more than 12 rust mites per $cm^2$: $ln(m)=4.61+1.23ln[-ln(1-p_{12})]$. To determine the optimal tally threshold, the variance (var(lnm)) for mean (lnm) in Kono-Sugino equation was estimated. The lower and narrow ranged change of variance for esimated mean showed at a tally threshold of 12. To estimate PCRM mean density per $cm^2$ at fixed precision level 0.25, the required sample number was 13 trees, 5 fruits per tree and 2 points per fruit (total 130 samples).

Tension Modeling and Looper-Tension ILQ Servo Control of Hot Strip Finishing Mills (열간 사상압연기의 장력 연산모델과 루퍼-장력 ILQ 서보 제어)

  • Hwang, I.C.;Park, C.J.
    • Journal of Power System Engineering
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    • v.12 no.1
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    • pp.72-79
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    • 2008
  • This paper designs a looper-tension controller for mass-flow stabilization in hot strip finishing mills. By Newton's 2nd law and Hooke's law, nonlinear dynamic equations on the looper-tension system are firstly derived, and linearized by a linearization algorithm using a Taylor's series expansion. Moreover, a tension calculation model is obtained from the nonlinear dynamic equations which is called as a soft sensor of strip tension between two neighboring stands. Next, a looper-tension servo controller is designed by an ILQ(Inverse Linear Quadratic optimal control) algorithm, and it is combined with a minimal disturbance observer which to attenuate speed disturbances by AGC and operator interventions, etc.. Finally, it is shown from by a computer simulation that the proposed ILQ controller with a disturbance observer is very effective in stabilizing the strip mass-flow under some disturbances, moreover it has a good command following performance.

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Spatial Dispersion and Sampling of Adults of Citrus Red Mite, Panonychus citri(McGregor) (Acari: Tetranychidae) in Citrus Orchard in Autumn Season (감귤원에서 가을철 귤응애 성충의 공간분포와 표본조사)

  • 송정흡;김수남;류기중
    • Korean journal of applied entomology
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    • v.42 no.1
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    • pp.29-34
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    • 2003
  • Dispersion pattern for adult citrus red mite (CRM), Panonychus citri (McGregor) using by Taylor's power law (TPL) and Iwao's patchiness regression (IPR) was determined to develop a monitoring method on citrus orchards, on Jeju, in Autumn season, during 2001 and 2002.CRM population was sampled by collecting leaves and fruits. The relationships of CRM adults between leaf and fruit were analyzed by different season. The regression equation for CRM adults between leaf (X) and fruit (Y) was ln(Y+1) : 1.029 ln(X+1) ( $r^2$ : 0.80). The density of CRM was higher on fruit than on leaf according to fruit maturing level. TPL provided better description of mean-variance relation-ship for the dispersion indices compared to IPR. Slopes and intercepts of TPL from leaf and fruit samples did not differ between sample units and surveyed years. Fixed-precision levels (D) of a sequential sampling plan were developed using Taylor's power law parameters generated from adults of CRM in leaf sample. Sequential sampling plans for adults of CRM were developed for decision making CRM population level based on the different action threshold levels (2.0,2.5 and 3.0 mites per leaf) with 0.25 precision. The maximum number of trees and required number of trees sampled on fixed sample size plan on 2.0,2.5 and 3.0 thresholds with 0.25 precision level were 19, 16 and 15 and their critical values T$_{critical}$ at were 554,609 and 659, respectively. were 554,609 and 659, respectively.

Sample Size Determination for the Estimation of Population Density of Marine Benthos on a Tidal Flat and a Subtidal Area, Korea

  • Koh, Chul-Hwan;Kang, Seong-Gil
    • Journal of the korean society of oceanography
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    • v.33 no.3
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    • pp.113-122
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    • 1998
  • The requisite numbers of sample replicates for the population study of soft-bottom benthos were estimated from survey data on the Songdo tidal flat and subtidal zone in Youngil Bay, Korea. Large numbers of samples were taken; two-hundred-fifty 0.02 m$^2$ box corers and fifty 0.1m$^2$ van Veen grabs were taken on the Songdo tidal flat and in Youngil Bay, respectively. The effect of sampler size on sampling efforts was investigated by pooling the unit samples in pairs, fours, eights, etc. The requisite number of sample replicates (n$_r$) was determined by sample variance (s$^2$) and mean (m) function (n$_r$:s$^2$/P$^2$m$^2$), at P=0.2 level, in which s$^2$ and m were calculated from the counts of individuals collected. For example, seven samples of 0.02 m$^2$ corer for the intertidal and two samples of 0.1 m$^2$ van Veen grab for subtidal fauna were required to estimate the total density of community. The smaller sampler size was more efficient than larger ones when sampling costs were compared on the basis of the total sampling area. The requisite number of sample replicates was also predicted ($\^{n}$n$_r$) by substituting $\^{s}$$^2$ obtained from the regression of s$^2$ against m using the Taylor's power law ($\^{s}$$^2$:am$^b$). The regression line of survey data on s$^2$ and m plotted on log scale was well fitted to the Taylor's power law (r$^2$${\geq}$0.95, p<;0.001) over the whole range of m. The exponent b was, however, varied when it was estimated from m which was categorized into classes by its scale. The fitted exponent b was large when both density class and the sampler size were large. The number of sample replicates, therefore, could be more significantly estimated, if regression coefficients (a and b) would be calculated from sample variance and mean categorized into density classes.

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Development of Sequential Sampling Plan of Bemisia tabaci in Greenhouse Tomatoes (토마토 온실내 담배가루이의 축차표본조사법 개발)

  • SoEun Eom;Taechul Park;Kimoon Son;Jiwon Jeong;Jung-Joon Park
    • Korean journal of applied entomology
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    • v.62 no.4
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    • pp.299-305
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    • 2023
  • Bemisia tabaci is one of polyphagous insect pests that transmits Tomato Yellow Leaf Curl Virus (TYLCV) and Cassava Brown Streak Disease (CBSD). Insecticides are primarily applied to control B. tabaci, but it has limits due to the development of resistance. As a result, a fixed precision sampling plan was developed for its integrated pest management (IPM). The tomato plants were divided into top (more than 130cm from the ground), middle (70 cm to 100 cm above the ground), and bottom (50 cm or less above the ground) strata, before visual sampling of the larvae of B. tabaci. The spatial distribution analysis was conducted using Taylor's power law coefficients with pooled data of top, middle, bottom strata. Fixed precision sampling plan and control decision-making were developed with precision levels and action threshold recommended from published scientific papers. To assess the validation of the developed sampling plans, independent data not used in the analysis were evaluated using the Resampling Validation for Sampling Plan (RVSP) program.

An Analytical Model of Maximum Simultaneous Switching Noise for Ground Interconnection Networks in CMOS Systems (CMOS 그라운드 연결망에서의 최대 동시 스위칭 잡음의 해석 모형)

  • Kim, Jung-Hak;Baek, Jong-Humn;Kim, Seok-Yoon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.50 no.3
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    • pp.115-119
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    • 2001
  • This paper presents an efficient and simple method for analyzine maximum simultaneous switching noise (SSN) on ground interconnection networks in CMOS systems. For the derivation of maximum SSN expression, we use ${\alpha}$-power law MOS model and Taylor's series approximation. The accuracy of the proposed method is verified by comparing the results with those of previous researches and HSPICE simulations under the contemporary process parameters and environmental conditions. The proposed method predicts the maximum SSN values more accurately when compared to existing approaches even in most practical cases such that exist some output drivers not in transition.

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