• Title/Summary/Keyword: Global Curve Fitting

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A Prediction Model of CO2 Emissions for Construction Equipment Using Curve Fitting (Curve Fitting을 이용한 건설장비 CO2 배출량 예측 모델)

  • Noh, Jaeyun;Kim, Yujin;Lee, Jiyeon;Lee, Minwoo;Han, Seungwoo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.107-108
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    • 2020
  • The severity of the global climate crisis is increasing due to greenhouse gases caused by human activities. As a result, countries and industries are making efforts to reduce carbon dioxide emissions, the biggest cause of global warming. Many studies have been conducted to predict carbon emissions in the construction sector to reduce this, but they have not actually produced a highly usable formula in the field. Therefore, the two variables 'Curve Fitting' were performed based on the data of excavators and trucks measured at the field. As a result, we have obtained a carbon dioxide emission prediction model for construction equipment, and we would like to use it to help establish an eco-friendly process plan.

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New Global Curve-Fitting Method Using Frequency Response Function (주파수 전달함수를 이용한 신 포괄 곡선맞춤법)

  • Min, Cheon-Hong;Park, Han-Il;Bae, Soo-Ryong;Jeon, Jae-Jin
    • Journal of Ocean Engineering and Technology
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    • v.23 no.6
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    • pp.82-86
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    • 2009
  • Several damping materials have been employed to reduce the vibration of structures. While it is important to estimate the damping matrix when analyzing damped composite structures using the finite element method (FEM), at present, there is no FEM program that can correctly estimate the damping matrix. In this paper, a new global curve-fitting method is proposed for identifying the system parameters of non-proportional damping structures using a frequency response function. An experimental test for a cantilever beam attached damping material was carried out to verify the performance of the method proposed in this study.

Vibration transfer characteristic of foaming sponge chair seat (발포스펀지 의자시트의 진동전달 특성)

  • Kim, S.H.;Kang, H.J.;Kim, T.K.;Moon, D.H.
    • Journal of Power System Engineering
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    • v.16 no.1
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    • pp.24-29
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    • 2012
  • Recently, in the movie theater, the special chair is installed to maximize the viewing effect of movies. It is structured to convey a vibrational stimulus to a specially-designated parts of human body by attaching a vibration transducer to a existing theater chair. This paper describes the analysis of the vibration transfer characteristic of a foaming sponge seat for the design of the special chair. We could not apply the structural analysis S/W because it is difficult to obtain the mechanical properties and damping coefficients of the various type sponges. And then we computed the transfer functions by the global curve fitting program based on experimental modal analysis. The experimental response results comparatively coincide with those by the global curve fitting program. We also could obtain the natural frequencies, the modal damping coefficient ratio, the modal vectors and the whole transfer functions. Therefore we could analyze the dynamic characteristic for design of foaming sponge seat.

IMPROVEMENT OF RIDE AND HANDLING CHARACTERISTICS USING MULTI-OBJECTIVE OPTIMIZATION TECHNIQUES

  • KIM W. Y.;KIM D. K.
    • International Journal of Automotive Technology
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    • v.6 no.2
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    • pp.141-148
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    • 2005
  • In order to reduce the time and costs of improving the performance of vehicle suspensions, the techniques for optimizing damping and air spring characteristic were proposed. A full vehicle model for a bus is constructed with a car body, front and rear suspension linkages, air springs, dampers, tires, and a steering system. An air spring and a damper are modeled with nonlinear characteristics using experimental data and a curve fitting technique. The objective function for ride quality is WRMS (Weighted RMS) of the power spectral density of the vertical acceleration at the driver's seat, middle seat and rear seat. The objective function for handling performance is the RMS (Root Mean Squares) of the roll angle, roll rate, yaw rate, and lateral acceleration at the center of gravity of a body during a lane change. The design variables are determined by damping coefficients, damping exponents and curve fitting parameters of air spring characteristic curves. The Taguchi method is used in order to investigate sensitivity of design variables. Since ride and handling performances are mutually conflicting characteristics, the validity of the developed optimum design procedure is demonstrated by comparing the trends of ride and handling performance indices with respect to the ratio of weighting factors. The global criterion method is proposed to obtain the solution of multi-objective optimization problem.

Development for the Azimuth Measurement Algorithm using Multi Sensor Fusion Method (멀티센서 퓨전 기법을 활용한 방위 측정 알고리즘의 설계)

  • Kim, Tae-Yeong;Kim, Young-Chul;Song, Moon-Kyou;Chong, Kil-To
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.2
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    • pp.865-871
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    • 2011
  • Presently, the location and direction information are certainly needed for the autonomous vehicle of the ship. Among them, the direction information is a essential elements to automatic steering system. And the gyro-compass, the magnetic-compass and the GPS compass are the sensor indicating the direction. The gyro-compasses are mainly used in the large-sized ship of the GMDSS(Global Maritime Distress & Safety System). The precision and the reliability of the gyro-compasses are excellent but big volume and high price are disadvantage. The magnetic-compass has relatively fine precision and inexpensive price. However, the disadvantage is in the influence by the magnetism object including the steel structure of a ship, and etc. In the case of the GPS compass, the true north is indicated according to the change of the location information but in case of the minimum number of satellites or stopping of a ship or exercise in the error range, the exact direction cannot be obtained. In this paper, the performance of the GPS compass was improved by using the least-square curve fitting method for the mutual trade off of the angle sensor. The algorithm which improves the precision of an azimuth by applying the weighted value according to the size of covariance error was proposed with GPS-compass and magnetic compass. The characteristic and the performance of the proposed algorithm were analyzed and verified through experimentation. The applicability of the proposed algorithm was shown through the experimental result.

Model Fitting using an Active Surface with Global Detormations (전역 변형을 갖는 활성곡면을 사용한 모델 적합)

  • Kim, Dong-Geun;Choe, Jeung-Won;Hwang, Chi-Jeong
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.3
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    • pp.792-801
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    • 1997
  • In this paper we propose an algorithm which fits a surface to noise-corrupted data points using an aceive sur-vace with global deformations.It is 3-dimensional surface extension of our precious works on 2-dimensional curve modell[11,12].We use fimite differences,and represent shapes of surface as global transfromation suring evolution based on the ballon [odel[2,3]which allows partial inflation or deflation by using niegborhood'sextermal foreces on each node points.At first,we make local deformations based on the balloon [odel,and then the blobal transformation from the surface before deformations to the defomed surface is calcualted by the deterministic lest squre method,finally we apply the global transformation to the surface before deformations.In experiments we fit a surface(elliposid,B-spline)to noise-corrupted 3D data points using the active surface with affine deformations.

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Segmentation of tooth using Adaptive Optimal Thresholding and B-spline Fitting in CT image slices (적응 최적 임계화와 B-spline 적합을 사용한 CT영상열내 치아 분할)

  • Heo, Hoon;Chae, Ok-Sam
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.4
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    • pp.51-61
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    • 2004
  • In the dental field, the 3D tooth model in which each tooth can be manipulated individually is an essential component for the simulation of orthodontic surgery and treatment. To reconstruct such a tooth model from CT slices, we need to define the accurate boundary of each tooth from CT slices. However, the global threshold method, which is commonly used in most existing 3D reconstruction systems, is not effective for the tooth segmentation in the CT image. In tooth CT slices, some teeth touch with other teeth and some are located inside of alveolar bone whose intensity is similar to that of teeth. In this paper, we propose an image segmentation algorithm based on B-spline curve fitting to produce smooth tooth regions from such CT slices. The proposed algorithm prevents the malfitting problem of the B-spline algorithm by providing accurate initial tooth boundary for the fitting process. This paper proposes an optimal threshold scheme using the intensity and shape information passed by previous slice for the initial boundary generation and an efficient B-spline fitting method based on genetic algorithm. The test result shows that the proposed method detects contour of the individual tooth successfully and can produce a smooth and accurate 3D tooth model for the simulation of orthodontic surgery and treatment.

Development of Removal Techniques for PRC Outlier & Noise to Improve NDGPS Accuracy (국토해양부 NDGPS 정확도 향상을 위한 의사거리 보정치의 이상점 및 노이즈 제거기법 개발)

  • Kim, Koon-Tack;Kim, Hye-In;Park, Kwan-Dong
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.2
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    • pp.63-73
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    • 2011
  • The Pseudorange Corrections (PRC), which are used in DGPS as calibration messages, can contain outliers, noise, and anomalies, and these abnormal events are unpredictable. When those irregular PRC are used, the positioning error gets higher. In this paper, we propose a strategy of detecting and correcting outliers, noise, and anomalies by modeling the changing pattern of PRC through polynomial curve fitting techniques. To validate our strategy, we compared positioning errors obtained without PRC calibation with those with PRC calibration. As a result, we found that our algorithm performs very well; the horizontal RMS error was 3.84 m before the correction and 1.49 m after the correction.

Comparison of mass operator methods considering test uncertainties

  • Olympio, K.R.;Blender, F.;Holz, M.;Kommer, A.;Vetter, R.
    • Advances in aircraft and spacecraft science
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    • v.5 no.2
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    • pp.277-294
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    • 2018
  • In the space industry, structures undergo several vibration and acoustic tests in order to verify their design and give confidence that they will survive the launch and other critical in-orbit dynamic scenarios. At component level, vibration tests are conducted with the aim to reach local or global interface loads without exceeding the design loads. So, it is often necessary to control and limit the input based on a load criterion. This means the test engineer should be able to assess the interface loads, even when load cannot be measured. This paper presents various approaches to evaluate interface loads using measured accelerations and by referring to mass operators. Various methods, from curve fitting techniques to finite element-based methods are presented. The methods are compared using signals with known imperfection to identify strengths and weaknesses of each mass operator definition.

Vibration Transfer Characteristic of Seat with the Auxiliary Plastic Member for Movie Theater Chair (플라스틱 보조재를 갖는 영화관 의자 시트의 진동전달 특성)

  • Kang, Hwa-Joong;Kim, Tae-Gyun;Moon, Deok-Hong
    • Journal of Power System Engineering
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    • v.18 no.6
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    • pp.45-50
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    • 2014
  • In the previous paper, we have reported on the development of foaming sponge seat with the auxiliary spring member and suggested new possibility of the special seat with the auxiliary plastic member for movie theater chair. In this study, we have examined the major design parameters needed in the development of a foaming sponge seat in which the mesh type plastic member are inserted to improve the vibration transfer effect of a chair seat. Through analyzing several prototypes by applying experimentation as well as the experimental modal analysis method, it was confirmed that the effect of vibration transfer can be improved through the use of a mesh type plastic member and applied to the design of practical chair seat.