• 제목/요약/키워드: non local

검색결과 2,552건 처리시간 0.03초

Fundamental and plane wave solution in non-local bio-thermoelasticity diffusion theory

  • Kumar, Rajneesh;Ghangas, Suniti;Vashishth, Anil K.
    • Coupled systems mechanics
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    • 제10권1호
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    • pp.21-38
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    • 2021
  • This work is an attempt to design a dynamic model for a non local bio-thermoelastic medium with diffusion. The system of governing equations are formulated in terms of displacement vector field, chemical potential and the tissue temperature in the context of non local dual phase lag (NL DPL) theories of heat conduction and mass diffusion. Based on this considered model, we study the fundamental solution and propagation of plane harmonic waves in tissues. In order to analyze the behavior of the NL DPL model, we construct basic theorem in the terms of elementary function which determine the existence of three longitudinal and one transverse wave. The effects of various parameters on the characteristics of waves i.e., phase velocity and attenuation coefficients are elaborated by plotting various figures of physical quantities in the later part of the paper.

Retrieval of Non-rigid 3D Models Based on Approximated Topological Structure and Local Volume

  • Hong, Yiyu;Kim, Jongweon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권8호
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    • pp.3950-3964
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    • 2017
  • With the increasing popularity of 3D technology such as 3D printing, 3D modeling, etc., there is a growing need to search for similar models on the internet. Matching non-rigid shapes has become an active research field in computer graphics. In this paper, we present an efficient and effective non-rigid model retrieval method based on topological structure and local volume. The integral geodesic distances are first calculated for each vertex on a mesh to construct the topological structure. Next, each node on the topological structure is assigned a local volume that is calculated using the shape diameter function (SDF). Finally, we utilize the Hungarian algorithm to measure similarity between two non-rigid models. Experimental results on the latest benchmark (SHREC' 15 Non-rigid 3D Shape Retrieval) demonstrate that our method works well compared to the state-of-the-art.

NUMERICAL TREATMENT OF NON-MONOTONIC BLOW-PROBLEMS BASED ON SOME NON-LOCAL TRANSFORMATIONS

  • BASEM S. ATTILI
    • Journal of applied mathematics & informatics
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    • 제42권2호
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    • pp.321-331
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    • 2024
  • We consider the numerical treatment of blow-up problems having non-monotonic singular solutions that tend to infinity at some point in the domain. The use of standard numerical methods for solving problems with blow-up solutions can lead to significant errors. The reason being that solutions of such problems have singularities whose positions are unknown in advance. To be able to integrate such non-monotonic blow-up problems, we describe and use a method of non-local transformations. To show the efficiency of the method, we present a comparison of exact and numerical solutions in addition to some comparison with the work of other authors.

Post buckling mechanics and strength of cold-formed steel columns exhibiting Local-Distortional interaction mode failure

  • Muthuraj, Hareesh;Sekar, S.K.;Mahendran, Mahen;Deepak, O.P.
    • Structural Engineering and Mechanics
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    • 제64권5호
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    • pp.621-640
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    • 2017
  • This paper reports the numerical investigation conducted to study the influence of Local-Distortional (L-D) interaction mode buckling on post buckling strength erosion in fixed ended lipped channel cold formed steel columns. This investigation comprises of 81 column sections with various geometries and yield stresses that are carefully chosen to cover wide range of strength related parametric ratios like (i) distortional to local critical buckling stress ratio ($0.91{\leq}F_{CRD}/F_{CRL}{\leq}4.05$) (ii) non dimensional local slenderness ratio ($0.88{\leq}{\lambda}_L{\leq}3.54$) (iii) non-dimensional distortional slenderness ratio ($0.68{\leq}{\lambda}_D{\leq}3.23$) and (iv) yield to non-critical buckling stress ratio (0.45 to 10.4). The numerical investigation is carried out by conducting linear and non-linear shell finite element analysis (SFEA) using ABAQUS software. The non-linear SFEA includes both geometry and material non-linearity. The numerical results obtained are deeply analysed to understand the post buckling mechanics, failure modes and ultimate strength that are influenced by L-D interaction with respect to strength related parametric ratios. The ultimate strength data obtained from numerical analysis are compared with (i) the experimental tests data concerning L-D interaction mode buckling reported by other researchers (ii) column strength predicted by Direct Strength Method (DSM) column strength curves for local and distortional buckling specified in AISI S-100 (iii) strength predicted by available DSM based approaches that includes L-D interaction mode failure. The role of flange width to web depth ratio on post buckling strength erosion is reported. Then the paper concludes with merits and limitations of codified DSM and available DSM based approaches on accurate failure strength prediction.

Numerical simulations of localization of deformation in quasi-brittle materials within non-local softening plasticity

  • Bobinski, J.;Tejchman, J.
    • Computers and Concrete
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    • 제1권4호
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    • pp.433-455
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    • 2004
  • The paper presents results of FE-calculations on shear localizations in quasi-brittle materials during both an uniaxial plane strain compression and uniaxial plane strain extension. An elasto-plastic model with a linear Drucker-Prager type criterion using isotropic hardening and softening and non-associated flow rule was used. A non-local extension was applied in a softening regime to capture realistically shear localization and to obtain a well-posed boundary value problem. A characteristic length was incorporated via a weighting function. Attention was focused on the effect of mesh size, mesh alignment, non-local parameter and imperfections on the thickness and inclination of shear localization. Different methods to calculate plastic strain rates were carefully discussed.

Radiological Recurrence Patterns after Bevacizumab Treatment of Recurrent High-Grade Glioma: A Systematic Review and Meta-Analysis

  • Se Jin Cho;Ho Sung Kim;Chong Hyun Suh;Ji Eun Park
    • Korean Journal of Radiology
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    • 제21권7호
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    • pp.908-918
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    • 2020
  • Objective: To categorize the radiological patterns of recurrence after bevacizumab treatment and to derive the pooled proportions of patients with recurrent malignant glioma showing the different radiological patterns. Materials and Methods: A systematic literature search in the Ovid-MEDLINE and EMBASE databases was performed to identify studies reporting radiological recurrence patterns in patients with recurrent malignant glioma after bevacizumab treatment failure until April 10, 2019. The pooled proportions according to radiological recurrence patterns (geographically local versus non-local recurrence) and predominant tumor portions (enhancing tumor versus non-enhancing tumor) after bevacizumab treatment were calculated. Subgroup and meta-regression analyses were also performed. Results: The systematic review and meta-analysis included 17 articles. The pooled proportions were 38.3% (95% confidence interval [CI], 30.6-46.1%) for a geographical radiologic pattern of non-local recurrence and 34.2% (95% CI, 27.3-41.5%) for a non-enhancing tumor-predominant recurrence pattern. In the subgroup analysis, the pooled proportion of non-local recurrence in the patients treated with bevacizumab only was slightly higher than that in patients treated with the combination with cytotoxic chemotherapy (34.9% [95% CI, 22.8-49.4%] versus 22.5% [95% CI, 9.5-44.6%]). Conclusion: A substantial proportion of high-grade glioma patients show non-local or non-enhancing radiologic patterns of recurrence after bevacizumab treatment, which may provide insight into surrogate endpoints for treatment failure in clinical trials of recurrent high-grade glioma.

Local-Based Iterative Histogram Matching for Relative Radiometric Normalization

  • Seo, Dae Kyo;Eo, Yang Dam
    • 한국측량학회지
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    • 제37권5호
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    • pp.323-330
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    • 2019
  • Radiometric normalization with multi-temporal satellite images is essential for time series analysis and change detection. Generally, relative radiometric normalization, which is an image-based method, is performed, and histogram matching is a representative method for normalizing the non-linear properties. However, since it utilizes global statistical information only, local information is not considered at all. Thus, this paper proposes a histogram matching method considering local information. The proposed method divides histograms based on density, mean, and standard deviation of image intensities, and performs histogram matching locally on the sub-histogram. The matched histogram is then further partitioned and this process is performed again, iteratively, controlled with the wasserstein distance. Finally, the proposed method is compared to global histogram matching. The experimental results show that the proposed method is visually and quantitatively superior to the conventional method, which indicates the applicability of the proposed method to the radiometric normalization of multi-temporal images with non-linear properties.

혼합 norm 기반의 가중치 함수를 이용한 평균 노이즈 제거 기법 (Non-Local Means Denoising Method using Weighting Function based on Mixed norm)

  • 김동영;오종근;홍민철
    • 전기전자학회논문지
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    • 제20권2호
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    • pp.136-142
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    • 2016
  • 본 논문에서는 혼합 norm을 이용한 가중치 함수 기반의 비국부 평균 노이즈 제거 방식을 제안한다. 비국부 평균 노이즈 제거 방식에서 중심 패치와 참조 패치의 오차에 대한 신뢰도는 노이즈 양 및 국부 활동성에 의존적인 특성을 갖고 있다. 본 논문에서는 혼합 norm 기반의 새로운 가중치 함수를 제안하고, 혼합 norm의 차수를 노이즈 정도 및 중심 패치의 국부 활동성에 의해 적응적으로 결정하여 비국부 평균 노이즈 제거 방식의 성능을 개선하고자 하였다. 실험 결과를 통해 기존의 비국부 평균 노이즈 제거 방식과 비교하여 제안 방식의 정량적 및 정성적 성능의 우수성을 확인할 수 있었다. 더불어, 제안 방식은 표준 유클리드 norm 기반의 다른 형태의 비국부 평균 노이즈 방식의 성능을 개선할 수 있는 능력이 있음을 확인할 수 있었다.

Intraosseous anesthesia using a computer-controlled system during non-surgical periodontal therapy (root planing): Two case reports

  • Han, Keumah;Kim, Jongbin
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제18권1호
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    • pp.65-69
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    • 2018
  • Local anesthesia is administered to control pain, but it may induce fear and anxiety. Root planing is a non-surgical periodontal therapy; however, when it is performed in an extensive manner, some tissue removal is inevitable. Notably, this removal may be so painful that local anesthesia is required to be administered to the area scheduled for the treatment. Although patients tend to accept root planing easily, they frequently express a fear of local anesthesia. Intraosseous anesthesia (IA) is an intraosseous injection technique, whereby local anesthetic is injected into the cancellous bone supporting the teeth. A computer-controlled IA system (CIAS) exhibits multiple benefits, such as less painful anesthesia, reduced soft tissue numbness, and the provision of palatal or lingual, as well as buccal, anesthesia via single needle penetration. In this report, we present two cases of root planing that were performed under local anesthesia, using a CIAS.

The role of softening in the numerical analysis of R.C. framed structures

  • Bontempi, Franco;Malerba, Pier Giorgio
    • Structural Engineering and Mechanics
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    • 제5권6호
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    • pp.785-801
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    • 1997
  • Reinforced Concrete beams with tension and compression softening material constitutive laws are studied. Energy-based and non-local regularisation techniques are presented and applied to a R.C. element. The element characteristics (sectional tangent stiffness matrix, element tangent stiffness matrix restoring forces) are directly derived from their symbolic expressions through numerical integration. In this way the same spatial grid allows us to obtain a non-local strain estimate and also to sample the contributions to the element stiffness matrix. Three examples show the spurious behaviors due to the strain localization and the stabilization effects given by the regularisation techniques, both in the case of tension and compression softening. The possibility to overestimate the ultimate load level when the non-local strain measure is applied to a non softening material is shown.