• Title/Summary/Keyword: Curve Fitting

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Final Settlement Prediction Methods of Embankments on Soft Clay by Back Analysis (역해석에 의한 연약지반 최종침하량 추정)

  • Lim, Seong Hun;Kang, Yea Mook;Lee, Dal Won
    • Korean Journal of Agricultural Science
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    • v.25 no.2
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    • pp.247-259
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    • 1998
  • Analyses which loads were regarded as instant load and gradual step load were performed with data measured on gradually loaded field, and the results were inspected to find effect of load condition, and final settlements predicted by Hyperbolic, Tan's, Asaoka's, and Monden's method were compared with each other. According to above analyses, the following conclusions were obtained. Settlement curves which loads were regarded as instant load and gradual step load were beginning to coincide at time of twice duration of embankment. On the ground installed vertical drain, the result of Hyperbolic, Tan's, Asaoka's, Monden's, curve fitting I, and curve fitting II (simple, Carrillo) methods make conclude that Asaoka, curve fitting I, and curve fitting II methods agree with measured settlement.

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Use of the Modified Linear Curve Fitting Method in Analyzing Slug Tests to Evaluate Hydraulic Conductivity of Vertical Cutoff Walls (순간 변위시험 (Slug Test)을 이용한 연직차수벽의 투수계수 산정시 수정된 Linear Curve Fitting 방법의 적용)

  • Choi, Hang-Seok;Daniel David E.
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.338-347
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    • 2006
  • 연직차수벽은 오염지역이나 폐기물 매립장에서 오염된 지하수 (때로는 오염된 수증기) 흐름을 차단하거나 또는 오염지역의 정화처리시 효율을 높이기 위하여 외부로부터 지하수 흐름을 막기 위해 설치된다. 이 논문에서는 연직차수벽의 가장 중요한 설계요소인 차수벽체의 현장 투수성을 평가하는 방법들중 가장 보편적으로 사용되는 단공식 순간 변위시험 (slug test)을 소개한다. 연직차수벽에서 실행된 단공식 순간 변위시험 결과를 해석하기 위해서, 연직차수벽의 압축성과 기하학적인 특성을 고려한 수정된 linear curve fitting 방법을 제안하고 그 적용성을 case study를 통해 평가한다. 기존의 대수층 투수계수 산정에 이용된 curve fitting 방법들에 비하여 수정된 linear curve fitting 방법은 보다 정확한 연직차수벽체의 투수성을 평가하도록 한다.

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Modal Parameter Identification from Frequency Response Functions Using Legendre Polynomials (Legendre 다항식을 이용한 주파수 응답 함수의 곡선접합과 모드 매개변수 규명)

  • Park, Nam-Gyu;Jeon, Sang-Youn;Suh, Jeong-Min;Kim, Hyeong-Koo;Jang, Young-Ki;Kim, Kyu-Tae
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.7
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    • pp.769-776
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    • 2006
  • A measured frequency response function can be represented as a ratio of two polynomials. A curve-fitting of frequency responses with Legendre polynomialis suggested in the paper. And the suggested curve-fitting algorithm is based on the least-square error method. Since the Legendre polynomials satisfy the orthogonality condition, the curve-fitting with the polynomials results to more reliable curve-fitting than ordinary polynomial method. Though the proposed curve-fitting with Legendre polynomials cannot cover all frequency range of interest, example shows that the suggested method is quite applicable in a limited frequency band.

Final Settlement Prediction Methods of Embankments on Soft Clay

  • Lee, Dal-Won;Lim, Seong-Hun
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42
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    • pp.68-77
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    • 2000
  • Analyses, in which load was regarded as instant load and gradual step load, respectively, were performed with data measured on a gradually loaded field, and the results were inspected to find the effect of load conditions, and the final settlements which were predicted by Hyperbolic, Tan's, Asaoka's, and Monden's methods were compared with each other. Settlement curves in which load was regarded as instant load and gradual step load being to coincide at twice the time of duration of embankment. On the ground installed vertical drain, from the results of Hyperbolic, Tan's, Asaoka's, Monden's, Curve fitting I, and Curve fitting II (simple, carrillo) methods it was concluded that Asaoka, Curve fitting I, and Curve fitting II methods are reliable for prediction final settlement with back analysis.

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Study on Torque precision measuring System using Curve Fitting Algorithm (커브피팅 알고리즘이 적용된 토크 정밀 측정 시스템 개발에 관한 연구)

  • Lee, Ki Won;Ha, Jae Seung;Kang, Seung Soo
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.4
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    • pp.1-11
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    • 2012
  • This paper is the study on the development of a torque precision measuring system using the curve fitting algorithm. This system can be divided into the hardware part and the software part. The hardware part consists of the main base board, the DAQ(Data Aquisition) board and Calibration parts. The software part consists of the software filter module and the curve fitting algorithm module. We have tested the torque transducer including the strain gauge for 200 Nm range and have analyzed the data acquired with the curve fitting algorithm by using this system. The DAQ board converts the electric signal induced by the transducer to the digital value precisely by using the shunt calibration procedure. The main board including the curve fitting algorithm calculates the exact digital torque value by using the digital value from the DAQ board. In this study, we confirmed that the result of the appropriate high-order power-series polynomial function is more accurate than the result of the low-order power-series polynomial through the system.

A Curve-Fitting Channel Estimation Method for OFDM System in a Time-Varying Frequency-Selective Channel (시변 주파수 선택적 채널에서 OFDM시스템을 위한 Curve-Fitting 채널추정 방법)

  • Oh Seong-Keun;Nam Ki-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.3
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    • pp.49-58
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    • 2006
  • In this paper, a curve-fitting channel estimation method is proposed for orthogonal frequency division multiplexing (OFDM) system in a time-varying frequency-selective fading channel. The method can greatly improve channel state information (CSI) estimation accuracy by performing smoothing and interpolation through consecutive curve-fitting processes in both time domain and frequency domain. It first evaluates least-squares (LS) estimates using pilot symbols and then the estimates are approximated to a polynomial with proper degree in the LS error sense, starting from one preferred domain in which pilots we densely distributed. Smoothing, interpolation, and prediction are performed subsequently to obtain CSI estimates for data transmission. The channel estimation processes are completed by smoothing and interpolating CSI estimates in the other domain once again using the channel estimates obtained in one domain. The performance of proposed method is influenced heavily on the time variation and frequency selectivity of channel and pilot arrangement. Hence, a proper degree of polynomial and an optimum approximation interval according to various system and channel conditions are required for curve-fitting. From extensive simulation results in various channel environments, we see that the proposed method performs better than the conventional methods including the optimal Wiener filtering method, in terms of the mean square error (MSE) and bit error rate (BER).

A study on the biarc curve fitting of involute curve (Involute Curve의 Biarc Curve Fitting에 관한 연구)

  • Lee, C.M.;Lee, S.H.;S.R. Cho
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.12
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    • pp.78-85
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    • 1996
  • The determination of the optimum biarc curve passing through a given set of points along involute curve is studied. The method adopted is that of finding the optimum no. of span and the optimum length of the span such that the error between the biarc curve and involute curve is minimum. Irregular curve span method is effectively used to describe the involute curve with reduced length of NC-Code.

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A Study on the Optimized Biarc Curve Fitting of Involute Curve (인벌류트 곡선의 Biarc Curve Fitting 최적화에 관한 연구)

  • Cho, Seung-Rae;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.4
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    • pp.71-78
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    • 1999
  • The determination of the optimum biarc curve passing through a given set of points along involute curve is studied. The method adopted is that of finding the optimum number of span and the optimum length of the span such that error between the biarc curve and involute curve minimum. Iterative method is effectively used to find the optimim number and length of the span on involute curve with reduced length of NC-code.

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Infrared Quantitative Analysis of Multicomponent Fiber Blends by Least-Squares Curve-Fitting (Least-Squares Curve-Fitting에 의한 다성분 혼방섬유의 적외 정량분석)

  • 김갑진;이기훈
    • Textile Science and Engineering
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    • v.27 no.2
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    • pp.32-42
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    • 1990
  • Five different least-squares curve-fitting methods proposed by Antoon and Haaland were applied to the infrared quantitative analysis of multicomponent composition in various fiber blends and were compared with each other. The spectral region and threshold value for each blend were suggested to obtain accurate results. More accurate results could be obtained by methods I-III for all fiber blends than by methods IV and V. It could be considered that errors in measured spectra consist mainly of random noise error for all fiber blends.

Analytical Interpretation of Stress Relaxation Behaviors of Polyester Film -Interpretation by Polynomial Curve Fitting Method- (폴리에스테르 필름의 응력완화거동에 관한 해석학적 고찰 -Polynomial Curve Fitting법에 의한 해석-)

  • 전한영;최영엽
    • Textile Science and Engineering
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    • v.26 no.5
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    • pp.34-41
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    • 1989
  • To interpretation the overall stress relaxation behaviors of drawn polyester film in solvents(NaOH solution (3$0^{\circ}C$ and 8$0^{\circ}C$) and ionic solutions (KCl and CaCl2)), 5-element mechanical model and its constitutive equations were proposed. And polynomical curve fitting method was chosen as an optimum analytical method and used for the examination of correspondence those equations for overall relaxation process to the experimental data. The polynomial curve fitting program was applied to the interpretation of these relaxation behaviors. As a result, it was shown that the application of the constitutive equations for 5-element mechanical model to the experimental data was reasonable.