• Title/Summary/Keyword: integration point

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Numerical solution of singular integral equation for multiple curved branch-cracks

  • Chen, Y.Z.;Lin, X.Y.
    • Structural Engineering and Mechanics
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    • v.34 no.1
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    • pp.85-95
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    • 2010
  • In this paper, numerical solution of the singular integral equation for the multiple curved branch-cracks is investigated. If some quadrature rule is used, one difficult point in the problem is to balance the number of unknowns and equations in the solution. This difficult point was overcome by taking the following steps: (a) to place a point dislocation at the intersecting point of branches, (b) to use the curve length method to covert the integral on the curve to an integral on the real axis, (c) to use the semi-open quadrature rule in the integration. After taking these steps, the number of the unknowns is equal to the number of the resulting algebraic equations. This is a particular advantage of the suggested method. In addition, accurate results for the stress intensity factors (SIFs) at crack tips have been found in a numerical example. Finally, several numerical examples are given to illustrate the efficiency of the method presented.

Pose Tracking of Moving Sensor using Monocular Camera and IMU Sensor

  • Jung, Sukwoo;Park, Seho;Lee, KyungTaek
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.8
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    • pp.3011-3024
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    • 2021
  • Pose estimation of the sensor is important issue in many applications such as robotics, navigation, tracking, and Augmented Reality. This paper proposes visual-inertial integration system appropriate for dynamically moving condition of the sensor. The orientation estimated from Inertial Measurement Unit (IMU) sensor is used to calculate the essential matrix based on the intrinsic parameters of the camera. Using the epipolar geometry, the outliers of the feature point matching are eliminated in the image sequences. The pose of the sensor can be obtained from the feature point matching. The use of IMU sensor can help initially eliminate erroneous point matches in the image of dynamic scene. After the outliers are removed from the feature points, these selected feature points matching relations are used to calculate the precise fundamental matrix. Finally, with the feature point matching relation, the pose of the sensor is estimated. The proposed procedure was implemented and tested, comparing with the existing methods. Experimental results have shown the effectiveness of the technique proposed in this paper.

A NEW STUDY IN EUCLID'S METRIC SPACE CONTRACTION MAPPING AND PYTHAGOREAN RIGHT TRIANGLE RELATIONSHIP

  • SAEED A.A. AL-SALEHI;MOHAMMED M.A. TALEB;V.C. BORKAR
    • Journal of applied mathematics & informatics
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    • v.42 no.2
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    • pp.433-444
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    • 2024
  • Our study explores the connection between the Pythagorean theorem and the Fixed-point theorem in metric spaces. Both of which center around the concepts of distance transformations and point relationships. The Pythagorean theorem deals with right triangles in Euclidean space, emphasizing distances between points. In contrast, fixed-point theorems pertain to the points that remain unchanged under specific transformations thereby preserving distances. The article delves into the intrinsic correlation between these concepts and presents a novel study in Euclidean metric spaces, examining the relationship between contraction mapping and Pythagorean Right Triangles. Practical applications are also discussed particularly in the context of image compression. Here, the integration of the Pythagorean right triangle paradigm with contraction mappings results in efficient data representation and the preservation of visual data relation-ships. This illustrates the practical utility of seemingly abstract theories in addressing real-world challenges.

GIS-based Spatial Integration and Statistical Analysis using Multiple Geoscience Data Sets : A Case Study for Mineral Potential Mapping (다중 지구과학자료를 이용한 GIS 기반 공간통합과 통계량 분석 : 광물 부존 예상도 작성을 위한 사례 연구)

  • 이기원;박노욱;권병두;지광훈
    • Korean Journal of Remote Sensing
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    • v.15 no.2
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    • pp.91-105
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    • 1999
  • Spatial data integration using multiple geo-based data sets has been regarded as one of the primary GIS application issues. As for this issue, several integration schemes have been developed as the perspectives of mathematical geology or geo-mathematics. However, research-based approaches for statistical/quantitative assessments between integrated layer and input layers are not fully considered yet. Related to this niche point, in this study, spatial data integration using multiple geoscientific data sets by known integration algorithms was primarily performed. For spatial integration by using raster-based GIS functionality, geological, geochemical, geophysical data sets, DEM-driven data sets and remotely sensed imagery data sets from the Ogdong area were utilized for geological thematic mapping related by mineral potential mapping. In addition, statistical/quantitative information extraction with respective to relationships among used data sets and/or between each data set and integrated layer was carried out, with the scope of multiple data fusion and schematic statistical assessment methodology. As for the spatial integration scheme, certainty factor (CF) estimation and principal component analysis (PCA) were applied. However, this study was not aimed at direct comparison of both methodologies; whereas, for the statistical/quantitative assessment between integrated layer and input layers, some statistical methodologies based on contingency table were focused. Especially, for the bias reduction, jackknife technique was also applied in PCA-based spatial integration. Through the statistic analyses with respect to the integration information in this case study, new information for relationships of integrated layer and input layers was extracted. In addition, influence effects of input data sets with respect to integrated layer were assessed. This kind of approach provides a decision-making information in the viewpoint of GIS and is also exploratory data analysis in conjunction with GIS and geoscientific application, especially handing spatial integration or data fusion with complex variable data sets.

Performance Evaluation of the Gas Turbine of Integrated Gasification Combined Cycle Considering Off-design Operation Effect (탈설계점 효과를 고려한 석탄가스화 복합발전용 가스터빈의 성능평가)

  • Lee, Chan;Kim, Yong Chul;Lee, Jin Wook;Kim, Hyung Taek
    • 유체기계공업학회:학술대회논문집
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    • 1998.12a
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    • pp.209-214
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    • 1998
  • A thermodynamic simulation method is developed for the process design and the performance evaluation of the gas turbine in IGCC power plant. The present study adopts four clean coal gases derived from four different coal gasification and gas clean-up processes as IGCC gas turbine fuel, and considers the integration design condition of the gas turbine with ASU(Air Separation Unit). In addition, the present simulation method includes compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. The present prediction results show that the efficiency and the net power of the IGCC gas turbines are seperior to those of the natural gas fired one but they are decreased with the air extraction from gas turbine to ASU. The operation point of the IGCC gas turbine compressor is shifted to the higher pressure ratio condition far from the design point by reducing the air extraction ratio. The exhaust gas of the IGCC gas turbine has more abundant wast heat for the heat recovery steam generator than that of the natural gas fired gas turbine.

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The Meshfree Method Based on the Least-Squares Formulation for Elasto-Plasticity (탄소성 최소 제곱 수식화와 이를 이용한 무요소법)

  • Youn Sung-Kie;Kwon Kie-Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.29 no.6 s.237
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    • pp.860-875
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    • 2005
  • A new meshfree method for the analysis of elasto-plastic deformations is presented. The method is based on the proposed first-order least-squares formulation, to which the moving least-squares approximation is applied. The least-squares formulation for the classical elasto-plasticity and its extension to an incrementally objective formulation for finite deformations are proposed. In the formulation, the equilibrium equation and flow rule are enforced in least-squares sense, while the hardening law and loading/unloading condition are enforced exactly at each integration point. The closest point projection method for the integration of rate-form constitutive equation is inherently involved in the formulation, and thus the radial-return mapping algorithm is not performed explicitly. Also the penalty schemes for the enforcement of the boundary and frictional contact conditions are devised. The main benefit of the proposed method is that any structure of cells is not used during the whole process of analysis. Through some numerical examples of metal forming processes, the validity and effectiveness of the method are presented.

Design and Simulation Tools for Moored Underwater Flexible Structures (계류된 수중 유연구조물의 설계 및 시뮬레이션 도구 개발)

  • Lee, Chun-Woo;Lee, Ji-Hoon;Choe, Moo-Youl;Lee, Gun-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.2
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    • pp.159-168
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    • 2010
  • This paper presents a mathematical model and simulation method for investigating the performance of set net systems and fish cage systems influenced by currents and waves. Both systems consist of netting, mooring ropes, a floating collar and sinkers. The netting and ropes were considered flexible structures and the floating collar was considered an elastic structure. Both were modeled on a mass-spring model. The structures were divided into finite elements and mass points were placed at the mid-point of each element, and the mass points were connected by mass-less springs. Each mass point was subjected to external and internal forces and the total force was calculated at every integration step. An implicit integration scheme was used to solve the nonlinear dynamic system. The computation method was applied to dynamic simulation of actual systems simultaneously influenced by currents and waves in order to evaluate their practicality. The simulation results improved our understanding of the behavior of the structure and provided valuable information concerning the optimized design of set net and fish cage systems exposed to an open ocean environment.

New Calibration Methods for improving the Accuracy of AFM (원자간력 현미경의 자율교정법)

  • Kweon, Hyun-Kyu;Go, Young-Chae
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.48-52
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    • 2001
  • In this paper presents an accurate AFM used that is free from the Z-directional distortion of a servo actuator is described. Two mathematical correction methods by the in-situ self-calibrationare employed in this AFM. One is the method by the integration, and the other is the method by inverse function of the calibration curve. The in situ self-calibration method by the integration, the derivative of the calibration curve function of the PZT actuator is calculated from the profile measurement data sets which are obtained by repeating measurements after a small Z-directional shift. Input displacement at each sampling point is approximately estimated first by using a straight calibration line. The derivative is integrated with reference to the approximate input to obtain the approximate calibration curve. Then the approximation of the input value of each sampling point is improved using the obtained calibration curve. Next the integral of the derivative is improved using the newly estimated input values. As a result of repeating these improving process, the calibration curve converges to the correct one, and the distortion of the AFM image can be corrected. In the in situ self-calibration through evaluating the inverse function of the calibration curve, the profile measurement data sets were used during the data processing technique. Principles and experimental results of the two methods are presented.

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Uncertainty analysis of containment dose rate for core damage assessment in nuclear power plants

  • Wu, Guohua;Tong, Jiejuan;Gao, Yan;Zhang, Liguo;Zhao, Yunfei
    • Nuclear Engineering and Technology
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    • v.50 no.5
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    • pp.673-682
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    • 2018
  • One of the most widely used methods to estimate core damage during a nuclear power plant accident is containment radiation measurement. The evolution of severe accidents is extremely complex, leading to uncertainty in the containment dose rate (CDR). Therefore, it is difficult to accurately determine core damage. This study proposes to conduct uncertainty analysis of CDR for core damage assessment. First, based on source term estimation, the Monte Carlo (MC) and point-kernel integration methods were used to estimate the probability density function of the CDR under different extents of core damage in accident scenarios with late containment failure. Second, the results were verified by comparing the results of both methods. The point-kernel integration method results were more dispersed than the MC results, and the MC method was used for both quantitative and qualitative analyses. Quantitative analysis indicated a linear relationship, rather than the expected proportional relationship, between the CDR and core damage fraction. The CDR distribution obeyed a logarithmic normal distribution in accidents with a small break in containment, but not in accidents with a large break in containment. A possible application of our analysis is a real-time core damage estimation program based on the CDR.

Psychosocial aging and age integration awareness : The Moderating Effect of Familism and Family solidarity (심리사회적 노화와 연령통합 인식: 가족주의 및 가족결속의 조절효과 분석)

  • Chung, Soon-Dool;Kim, Min-Kyoung;Kim, Eun-Joo;Kim, Ju-Hyun
    • Korean Journal of Family Social Work
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    • no.54
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    • pp.187-224
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    • 2016
  • This study aims to investigate the effect of psychosocial aging on age integration and the moderating effect of Familism and Family solidarity. In particular, this study has significance for establishing a basis of practical and political intervention in family level for improving age integration. We employed data from the 'Ageing Society Awareness Investigation' funded by Korean National Research Foundation in 2014. Our analysis sample consisted of 702 adults who were from 40 to 90 years old. Also, this study conducted descriptive statistics and multiple regression analysis by using STATA13. First of all, the lower psychosocial aging awareness is the higher age integration awareness. Familism and family solidarity were not a significant predictor for age integration. However, the interaction effects between familism as well as family solidarity and psychosocial aging ware statistically associated with age integration. That is to say that as psychosocial aging is negative, when decrease age integration, the net moderating effects of familism and family solidarity were found between age integration and psychosocial aging. Based on the results, this study provides implications that reinforcing family value and promoting interaction and solidarity with family members are positively contributed to age integration awareness at this point of negative psychosocial aging.