• Title/Summary/Keyword: Best fitting

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Selecting the Best Soil Particle-Size Distribution Model for Korean Soils

  • Hwang, Sang-Il
    • Journal of Environmental Policy
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    • v.2 no.1
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    • pp.77-86
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    • 2003
  • Particle-size distributions (PSDs) are widely used for the estimation of soil hydraulic properties. The objective of this study was to select the best model among the nine PSD models with different underlying assumptions, by using a variety of Korean soils. The Fredlund model with four parameters, the logistic growth curve, and Weibull distribution model showed the highest performance compared to the other models with the majority of soils studied. It was interesting to find that the logistic growth function with no fitting parameters showed a great fitting performance.

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Derivation of Optimal Distribution for the Frequency Analysis of Extreme Flood using LH-Moments (LH-모멘트에 의한 극치홍수량의 빈도분석을 위한 적정분포형 유도)

  • Maeng, Sung-Jin;Lee, Soon-Hyuk
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.229-232
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    • 2002
  • This study was conducted to estimate the design flood by the determination of best fitting order of LH-moments of the annual maximum series at six and nine watersheds in Korea and Australia, respectively. Adequacy for flood flow data was confirmed by the tests of independence, homogeneity, and outliers. Gumbel (GUM), Generalized Extreme Value (GEV), Generalized Pareto (GPA), and Generalized Logistic (GLO) distributions were applied to get the best fitting frequency distribution for flood flow data. Theoretical bases of L, L1, L2, L3 and L4-moments were derived to estimate the parameters of 4 distributions. L, L1, L2, L3 and L4-moment ratio diagrams (LH-moments ratio diagram) were developed in this study.

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Frequency Analysis of Extreme Rainfall using Higher Probability Weighted Moments (고차확률가중모멘트에 의한 극치강우의 빈도분석)

  • Lee, Soon-Hyuk;Maeng, Sung-Jin;Ryoo, Kyong-Sik;Kim, Byeong-Jun
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.511-514
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    • 2003
  • This study was conducted to estimate the design rainfall by the determination of best fitting order for Higher Probability Weighted Moments of the annual maximum series according to consecutive duration at sixty-five rainfall stations in Korea. Design rainfalls were obtained by generalized extreme value distribution which was selected to be suitable distribution in 4 applied distributions and by L, L1, L2, L3 and L4-moment. The best fitting order for Higher Probability Weighted Moments was determined with the confidence analysis of estimated design rainfall.

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Pattern Development of Tight-fitting Pants for Men Using Measurements of Size Korea 2004 (Size Korea 2004의 한국인 인체치수를 이용한 남성용 밀착 팬츠 패턴 개발)

  • Jeong, Yeon-Hee
    • Korean Journal of Human Ecology
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    • v.15 no.5
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    • pp.791-802
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    • 2006
  • The construction of athlete's tight-fitting garments by reducing the elastic knit pattern is an interesting subject, which directly influences the performance of the wearer. Therefore, relationships between the reduction rates of the men's pants pattern obtained using measurements of Size Korea 2004 and clothing fitting were explored to improve clothing comfort. Two pattern making methods were developed and the reduction rates were applied to those pants depending on the parts of human body. The four male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales during 4 consecutive days. While wearing the garments, subjects were kept four various postures including waist flexion and sitting etc by requests of the researchers. Likert type scale was used for the evaluation and 7 point indicates that it gave the best fit as tight-fitting pants. As results, differences in the length and girth between two piece pants pattern(style 1) and one piece pants pattern(style 2) were 0.0$\sim$0.3cm. Between two pattern making methods, one piece pants pattern(the style 2) was superior to two piece pants pattern in terms of subjective sensation and fit. Among eight tight-fitting pants, C, D, G, H pants were superior in terms of fitting and stability of waist and hip part to the others. ill case of tight-fitting pants, the reduction rate of the pattern in the course direction, the reduction rate of T2/3(66%) was better than that of T/2(50%), but the reduction rate of the pattern in the wale direction, that of the part of crotch, which was very sensitive part, should be kept the same as suggested earlier by Ziegert(1988).

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The Global Geopotential Models in the Region of Korean Peninsula

  • Yun, Hong-Sic;Adam, Jozsef
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.12 no.1
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    • pp.95-106
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    • 1994
  • The purpose of this paper is to establish the optimum reference field as testing some geopotential model, gravity data and GPS data. We have to decide a best fitting geopotential model as a reference surface for establishing the optimum geoid solutions. We conduct some tests on the Korean Peninsula gravity data to establish which of the model would be prove to be the best one. Three ways were used to compare the geopotential coefficient solutions. One of the tests is to compare the residual gravity anomaly remaining after the anomaly computed from the geopotential model has been subtracted from the "observed" gravity anomaly. The second method is a comparison of several geopotential solutions in terms of differences in gravity anomalies and quasi-geoid undulations. The third method is a comparison between the undulation obtained by GPS and the corresponding undulation from each geopotential model. The result showed that OSU91A model is a best fitting model as a reference in the region of Korean Peninsula.Peninsula.

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A simple approach for circular Arc detection using a least squares fitting and preprocessing (최소자승법과 전 처리를 이용한 원호 검출의 간단한 접근)

  • Nkurunziza, Armel;Kim, Jong-nam
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.840-843
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    • 2016
  • The circular arc is a very useful feature for object detection and recognition in industrial environments. In this paper, a new method to detect circular arcs is proposed. The detection of the circular arc includes the estimation of the center, the radius and the two ending points of the arc. This new method is based on determining the best part of the circular arc (part which does not contains outliers points) using 3 points designated along the arc. A least square method is applied to the best part of the arc and the center and the radius of the arc are obtained. The distance between the remaining edge's points (points which are not lying on the best part of the arc) and the radius is used to the two ending points of the arc.

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GALAXY SED FITTING

  • Denis, Burgarella;Mederic, Boquien;Veronique, Buat;Laure, Ciesla;Yannick, Rhoelly
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.205-208
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    • 2017
  • Modelling and fitting the spectral energy distribution (SED) of galaxies or regions of galaxies is one of the most useful methods available to the astronomer nowadays. By modelling the SEDs and comparing the models to the observations, we can collect important information on the physical processes at play in the formation and evolution of galaxies. The models allow to follow the evolution of the galaxies from their formation on. The versatility of code is crucial because of the diversity of galaxies. The analysis is only relevant and useful if the models can correctly reproduce this diversity now and across (as best as possible) all redshifts. On the other hand, the code needs to run fast to compare several million or tens of millions of models and to select the best (on a probabilistic basis) one that best resembles the observations. With this important point in mind, it seems logical that we should efficiently make use of the computer power available to the average astronomer. For instance, it seems difficult, today, to model and fit SEDs without a parallelized code. We present the new Python version of CIGALE SED fitting code and its characteristics. CIGALE comes in two main flavours: CIGALE Classic to fit SEDs and CIGALE Model to create spectra and SEDs of galaxies at all redshifts. The latest can potentially be used in conjunction with galaxy evolution models of galaxy formation and evolution such as semi-analytic ones.

Neutral detergent fiber rather than other dietary fiber types as an independent variable increases the accuracy of prediction equation for digestible energy in feeds for growing pigs

  • Choi, Hyunjun;Sung, Jung Yeol;Kim, Beob Gyun
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.4
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    • pp.615-622
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    • 2020
  • Objective: The objectives were to investigate correlations between energy digestibility (digestible energy [DE]:gross energy [GE]) and various fiber types including crude fiber (CF), total dietary fiber (TDF), soluble dietary fiber (SDF), insoluble dietary fiber (IDF), neutral detergent fiber (NDF), and acid detergent fiber (ADF), and to develop prediction equations for estimating DE in feed ingredients and diets for growing pigs. Methods: A total of 289 data with DE values and chemical composition of feeds from 39 studies were used to develop prediction equations for DE. The equations were validated using values provided by the National Research Council. Results: The DE values in feed ingredients ranged from 2,011 to 4,590 kcal/kg dry matter (DM) and those in diets ranged from 2,801 to 4,203 kcal/kg DM. In feed ingredients, DE:GE was negatively correlated (p<0.001) with NDF (r = -0.84), IDF (r = -0.83), TDF (r = -0.82), ADF (r = -0.78), and CF (r = -0.72). A best-fitting model for DE (kcal/kg) in feed ingredients was: 1,356 + (0.704 × GE, kcal/kg) - (60.3 × ash, %) - (27.7 × NDF, %) with R2 = 0.80 and p<0.001. In diets, DE:GE was negatively correlated (p<0.01) with NDF (r = -0.72), IDF (r = -0.61), TDF (r = -0.52), CF (r = -0.45), and ADF (r = -0.34). A best-fitting model for DE (kcal/kg) in diets was: 1,551 + (0.606 × GE, kcal/kg) - (22.1 × ash, %) - (25.6 × NDF, %) with R2 = 0.62 and p<0.001. All variables are expressed as DM basis. The equation developed for DE in feed ingredients had greater accuracy than a published equation for DE. Conclusion: All fiber types are reasonably good independent variables for predicting DE of swine feeds. The best-fitting model for predicting DE of feeds employed neutral detergent fiber as an independent variable.

AN ALGORITHM FOR FITTING OF SPHERES

  • Kim, Ik-Sung
    • The Pure and Applied Mathematics
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    • v.11 no.1
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    • pp.37-49
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    • 2004
  • We are interested in the problem of fitting a sphere to a set of data points in the three dimensional Euclidean space. In Spath [6] a descent algorithm already have been given to find the sphere of best fit in least squares sense of minimizing the orthogonal distances to the given data points. In this paper we present another new algorithm which computes a parametric represented sphere in order to minimize the sum of the squares of the distances to the given points. For any choice of initial approximations our algorithm has the advantage of ensuring convergence to a local minimum. Numerical examples are given.

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Errors in Recorded Information and Calibration of a Catchment Modelling System(II) - Monitoring Calibration Approach - (기록치 오차와 유역모형의 검정(II) - 모니터링 검정방법 -)

  • Choi, Kyung Sook
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.117-125
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    • 2003
  • Since the recorded information used for operation of a catchment modelling system contain errors that influence the calibration of catchment modelling system control parameter values, the accurate estimation of these parameters is difficult. Despite these influences, existing traditional calibration approaches focus only on achieving the best "curve fitting" between simulated and recorded data, and not on generic evaluation of control parameter values. This paper introduces an Early Stopping Technique which is aimed at avoiding the procedure of curve-fitting through monitoring improvements in the objective function used for assessing the optimal parameter set. Application of this approach to the calibration of SWMM (Storm Water Management Model) on the Centennial Park catchment in Sydney, Australia is outlined. outlined.