• Title/Summary/Keyword: fourth order

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MEDICAL IMAGE ANALYSIS USING HIGH ANGULAR RESOLUTION DIFFUSION IMAGING OF SIXTH ORDER TENSOR

  • K.S. DEEPAK;S.T. AVEESH
    • Journal of applied mathematics & informatics
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    • v.41 no.3
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    • pp.603-613
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    • 2023
  • In this paper, the concept of geodesic centered tractography is explored for diffusion tensor imaging (DTI). In DTI, where geodesics has been tracked and the inverse of the fourth-order diffusion tensor is inured to determine the diversity. Specifically, we investigated geodesic tractography technique for High Angular Resolution Diffusion Imaging (HARDI). Riemannian geometry can be extended to a direction-dependent metric using Finsler geometry. Euler Lagrange geodesic calculations have been derived by Finsler geometry, which is expressed as HARDI in sixth order tensor.

Numerical Study on Extended Boussinesq Equations with Wave Breaking (쇄파구조를 고려한 확장형 Boussinesq 방정식의 수치 실험)

  • 윤종태;이창훈
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.11 no.3
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    • pp.149-155
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    • 1999
  • A treatment of wave breaking is included in the extended Boussinesq equations of Nwogu. A spatially distributed source function and sponge layers are used to reduce the reflected waves in the computa¬tional domain. The model uses fourth-order Adams predictor-corrector method to advance in time, and discretizes first-order spatial derivatives to fourth-order accuracy, and thus reducing all truncation errors to a level smaller than the dispersive terms. The generated wave fields are found to be good and the corresponding wave heights are very close to their target values. For the tests of wave breaking, although agreement is considered to be reasonable, wave heights in the inner surf zone are over-predicted. This indicates the breaking parameters in the model should be adjusted.

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Source Localization of Single Impact Based on Higher Order Time Frequency (고차-시간 주파수 기술을 이용한 평판에서의 충격 위치추적)

  • Moon, Yoo-Sung;Lee, Sang-Kwon;Yang, Hong-Goon
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.2
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    • pp.129-136
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    • 2011
  • The aim of this paper is to present the method of identifying the impact location on the plate. This basic research has the future purpose to achieve the human-interaction technology based on the signal processing, piezoelectric materials, and wave propagation. The present work concerning the location identification of a single impact on the plate simulated the waveform numerically generated by impact force and applied the SWFOM(sliced Wigner higher fourth order moment) to the waveform to get the arrival time differences due to impact force between three sensors attached to the plate. The simulated signal is useful to get the information for time interval for the only direct wave. This information is used the source localization by using experimental work. The measured signal is also used for source localization of a single impact based on the higher order time frequency as a novel work.

Dynamic behaviour of thick plates resting on Winkler foundation with fourth order element

  • Ozdemir, Yaprak I.
    • Earthquakes and Structures
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    • v.16 no.3
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    • pp.359-368
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    • 2019
  • This paper focuses on the study of dynamic analysis of thick plates resting on Winkler foundation. The governing equation is derived from Mindlin's theory. This study is a parametric analysis of the reflections of the thickness / span ratio, the aspect ratio and the boundary conditions on the earthquake excitations are studied. In the analysis, finite element method is used for spatial integration and the Newmark-${\beta}$ method is used for the time integration. While using finite element method, a new element is used. This element is 17-noded and it's formulation is derived from using higher order displacement shape functions. C++ program is used for the analyses. Graphs are presented to help engineers in the design of thick plates subjected to earthquake excitations. It is concluded that the 17-noded finite element is used in the earthquake analysis of thick plates. It is shown that the changes in the aspect ratio are more effective than the changes in the aspect ratio. The center displacements of the reinforced concrete thick clamped plates for b/a=1, and t/a=0.2, and for b/a=2, and t/a=0.2, reached their absolute maximum values of 0.00244 mm at 3.48 s, and of 0.00444 mm at 3.48 s, respectively.

MSP58 Knockdown Inhibits the Proliferation of Esophageal Squamous Cell Carcinoma in Vitro and in Vivo

  • Xu, Chun-Sheng;Zheng, Jian-Yong;Zhang, Hai-Long;Zhao, Hua-Dong;Zhang, Jing;Wu, Guo-Qiang;Wu, Lin;Wang, Qing;Wang, Wei-Zhong;Zhang, Jian
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.7
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    • pp.3233-3238
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    • 2012
  • Esophageal carcinoma (EC) is one of the most aggressive cancers with a poor prognosis. Understanding the molecular mechanisms underlying esophageal cancer progression is a high priority for improved EC diagnosis and prognosis. Recently, MSP58 was shown to behave as an oncogene in colorectal carcinomas and gliomas. However, little is known about its function in esophageal carcinomas. We therefore examined the effects of MSP58 knockdown on the growth of esophageal squamous cell carcinoma (ESCC) cells in vitro and in vivo in order to gain a better understanding of its potential as a tumor therapeutic target. We employed lentiviral-mediated small hairpin RNA (shRNA) to knock down the expression of MSP58 in the ESCC cell lines Eca-109 and EC9706 and demonstrated inhibition of ESCC cell proliferation and colony formation in vitro. Furthermore, flow cytometry and western blot analyses revealed that MSP58 depletion induced cell cycle arrest by regulating the expression of P21, CDK4 and cyclin D1. Notably, the downregulation of MSP58 significantly inhibited the growth of ESCC xenografts in nude mice. Our results suggest that MSP58 may play an important role in ESCC progression.

The Analysis of Research Trends in Technology to the Fourth Industrial Revolution using SNA (소셜 네트워크 분석을 이용한 4차 산업혁명 기술 분야의 연구 동향 분석)

  • Kim, Hong-Gwang;Ahn, Jong-Wook
    • Journal of Cadastre & Land InformatiX
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    • v.49 no.1
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    • pp.113-121
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    • 2019
  • The fourth industrial revolution technology focused on the fusion of infrastructure and various advanced technologies related city. Therefore, technical cooperation in various fields of research is essential. In order to activating the fourth industrial revolution technologies, it is necessary to research the state of technology in various fields. Consequently, this paper aims to analysis of domestic and foreign research trends on technology to the fourth industrial revolution using SNA and text mining for web site. We collected text, date data of research paper and report in web site for five years, that is, from January 1st in 2014 to December 31st in 2018. Next, we have deduced the major keywords in public data through analyzing the morphemes. Then we have analyzed the core and related keyword lists through an SNA. In Korea, the focus is on R&D and legal/institutional solution in relation to the fourth industrial revolution technology. On the other hand, in the case of foreign, there was focus on practical technologies for urban services in detail aspects.

The Kinematics of Damage for Elasto-Plastic Large Deformation (탄소성 대변형 거동에서의 손상의 운동학)

  • Park, Tae hyo;Kim, Ki Du
    • Journal of Korean Society of Steel Construction
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    • v.9 no.3 s.32
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    • pp.401-419
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    • 1997
  • In this paper the kinematics of damage for finite strain, elasto-plastic deformation is introduced using the fourth-order damage effect tensor through the concept of the effective stress within the framework of continuum damage mechanics. In the absence of the kinematic description of damage deformation leads one to adopt one of the following two different hypotheses for the small deformation problems. One uses either the hypothesis of strain equivalence or the hypotheses of energy equivalence in order to characterize the damage of the material. The proposed approach in this work provides a general description of kinematics of damage applicable to finite strains. This is accomplished by directly considering the kinematics of the deformation field and furthermore it is not confined to small strains as in the case of the strain equivalence or the strain equivalence approaches. In this work, the damage is described kinematically in both the elastic domain and plastic domain using the fourth order damage effect tensor which is a function of the second-order damage tensor. The damage effect tensor is explicitly characterized in terms of a kinematic measurure of damage through a second-order damage tensor. Two kinds of second-order damage tensor representations are used in this work with respect to two reference configurations.

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A SIXTH-ORDER OPTIMAL COLLOCATION METHOD FOR ELLIPTIC PROBLEMS

  • Hong, Bum-Il;Ha, Sung-Nam;Hahm, Nahm-Woo
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.513-522
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    • 1999
  • In this paper we present a collocation method based on biquintic splines for a fourth order elliptic problems. To have a better accuracy we formulate the standard collocation method by an appro-priate perturbation on the original differential equations that leads to an optimal approximating scheme. As a result computational results confirm that this method is optimal.

A PREDICTOR-CORRECTOR SCHEME FOR THE NUMERICAL SOLUTION OF THE BOUSSINESQ EQUATION

  • Ismail, M.S.;Bratsos, A.G.
    • Journal of applied mathematics & informatics
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    • v.13 no.1_2
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    • pp.11-27
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    • 2003
  • A fourth order in time and second order in space scheme using a finite-difference method is developed for the non-linear Boussinesq equation. For the solution of the resulting non-linear system a predictor-corrector pair is proposed. The method is analyzed for local truncation error and stability. The results of a number of numerical experiments for both the single and the double-soliton waves are given.

A GENERAL FORM OF MULTI-STEP ITERATIVE METHODS FOR NONLINEAR EQUATIONS

  • Oh, Se-Young;Yun, Jae-Heon
    • Journal of applied mathematics & informatics
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    • v.28 no.3_4
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    • pp.773-781
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    • 2010
  • Recently, Yun [8] proposed a new three-step iterative method with the fourth-order convergence for solving nonlinear equations. By using his ideas, we develop a general form of multi-step iterative methods with higher order convergence for solving nonlinear equations, and then we study convergence analysis of the multi-step iterative methods. Lastly, some numerical experiments are given to illustrate the performance of the multi-step iterative methods.