Temat: Mesh - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Optimization of mesh representation for progressive transmission
Optymalizacja reprezentacji siatek progresywnych dla potrzeb przesyłu danych
Autorzy:: Skabek, K.
Pojda, D.
Tematy:: progressive mesh
quadric error
mesh transmission; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/375679.pdf Link otwiera się w nowym oknie
Opis:: The paper presents the implementation of methods for progressive mesh encoding. The described implementation is a modification of the software published in 2008 by Zhao He, which is based on studies by Michael Garland and Hugues Hoppe. We focused on improving the performance of the software. In particular we modified the data structures to ensure their better indexing, which significantly improved the computational complexity of the algorithm. We also implemented the support for simplified meshes with textures. The authors present the comparison of the performance of these methods in relation to the original He Zhao's algorithm. The performance of progressive mesh encoding in our implementation was significantly improved.
W artykule przedstawiono implementację algorytmu kodowania siatek trójwymiarowych do postaci progresywnej. Opisana implementacja jest rozwinięciem oprogramowania opublikowanego w 2008 roku przez He Zhao, które bazuje na opracowaniach Michaela Garlanda [1] oraz Huguesa Hoppe [5]. Celem autorów było wykorzystanie prezentowanego oprogramowania do kodowania siatek o znacznym rozmiarze, reprezentujących między innymi skany eksponatów muzealnych lub modele uzyskane w wyniku obrazowania medycznego. Wobu przypadkach kodowanie do postaci progresywnej ma na celu zapewnienie efektywnego przesyłania i szybkiej prezentacji siatek na różnych poziomach wizualizacji szczegółów (levels of detals). Jednocześnie powinno ono umożliwiać szybkie odzyskanie oryginalnej siatki w razie potrzeby wykonania pomiarów. Skupiono się na poprawie szybkości działania algorytmu poprzez wprowadzenie struktur danych zapewniających ich odpowiednie indeksowanie, co znacząco poprawiło złożoność obliczeniową. W porównaniu do możliwości oferowanych przez oprogramowanie He Zhao została także dodana uproszczona obsługa progresywnego kodowania siatek z teksturami. Przeprowadzono i przedstawiono w artykule porównanie czasów działania oprogramowania w prezentowanej wersji oraz w implementacji He Zhao i wykazano, że wydajność czasowa uległa znaczącej poprawie.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Leadership competencies for knowledge translation in public health : A consensus study
Autorzy:: Czabanowska, Katarzyna
Rodríguez-Feria, Pablo
Flórez, Luis Jorge Hernández
Opis:: Background: In 2010, 240 billion US dollars was invested worldwide to conduct research for health; unfortunately, 200 billion was misused in the production and reporting of the evidence researched. Universities could facilitate students to acquire leadership competencies to move well-conducted research findings into practical use; this could be an essential move to reduce the misuse of investment. Methods: A literature review was done based on the Equator Network and Cochrane guidelines, followed by three Delphi rounds to select competencies. Results: Eleven papers were analysed out of 1121 items and 39/78 identified competencies were prioritized to be presented in the Delphi. Four out of 12 participants accepted to be involved in this project, and 22 competencies reached consensus and stability after three rounds. This framework conceptualizes competencies as the knowledge, skills, attitudes and values. The competencies were framed in four domains: knowledge management, engage diverse others in public health initiatives, training and capacity building/change management and communication. Conclusion: This framework offers guidance to universities when instructing students with leadership competencies for KT. This project emphasizes that effective leadership should include personal conscience and self-determination values.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 3.

Tytuł:: Application of overset mesh approach in the investigation of the Savonius wind turbines with rigid and deformable blades
Autorzy:: Marchewka, Emil
Sobczak, Krzysztof
Reorowicz, Piotr
Obidowski, Damian Stanisław
Jóźwik, Krzysztof
Tematy:: CFD
savonius
deformable blade
overset mesh
sliding mesh; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/1955051.pdf Link otwiera się w nowym oknie
Opis:: Machines utilising renewable energy constantly undergo research aimed at raising their efficiency. One of them is a Savonius wind turbine, where scientists propose adjustments to improve its aerodynamic properties. At present, their assessment is usually performed by means of transient computational fluid dynamics simulations with two- or threedimensional models. In this paper, the overset (chimera) mesh approach was applied to investigate the performance of a Savonius wind turbine equipped with deformable blades. They were continuously deformed during rotation by a dedicated mechanism to increase a positive torque of the advancing blade, and meanwhile, decrease a negative torque of the returning blade. A quasi-two-dimensional model with a two-way fluid-structure interaction method was applied, where the structural solver determined blade deflection caused by the predefined deformation mechanism and aerodynamic loads, whereas the coupled computational fluid dynamics solver determined the transient flow. The deformable blades rotor performance was calculated and compared with a conventional rigid Savonius turbine, both simulated using the overset mesh approach. The average value of the power coefficient achieved a 55% rise in the case of deformable blades turbine. Additionally, to validate the overset method, its results were compared with the classical sliding mesh method for a conventional rigid rotor.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: A comparison of objective functions of optimization-based smoothing algorithm for tetrahedral mesh improvement
Autorzy:: Dai, C.
Liu, H.-L.
Dong, L.
Tematy:: objective function
mesh quality metric
optimization-based smoothing
mesh quality improvement
mesh generation; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/279637.pdf Link otwiera się w nowym oknie
Opis:: The objective function based on mesh quality metric has a major impact on smoothing unstructured tetrahedral meshes. The ability of seven mesh quality metrics to distinguish four kinds of poor-quality elements and their effects on the change of element shape are analyzed in detail. Then, four better mesh quality metrics are chosen to construct objective functions. In addition, the rational determination of searching direction and the optimal step size in the optimization algorithm of solving the objective function are proposed. Finally, comparisons with the other three objective functions are made according to different number of elements, iteration limit, and the desired accuracy in the improved mesh. It is found that with the increase of the number of elements, the time consumed during optimization increases, but the changes of the worst quality element are different. The number of iterations has little effect on the mesh quality and the time cost. The increasing of the desired degree of accuracy will improve the mesh quality and cost more time. Furthermore, the approach using objective function is compared with Freitag’s common approach. It is clearly shown that it performs better than the existing approach.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Randomised controlled trial: standard lightweight mesh vs self-gripping mesh in Lichtenstein procedure
Autorzy:: Zamkowski, Mateusz
Ropel, Jerzy
Makarewicz, Wojciech
Tematy:: Hernia
inguinal hernia
Lichtenstein
mesh
Progrip
self-gripping mesh; Pokaż więcej
Wydawca:: Index Copernicus International
Powiązania:: https://bibliotekanauki.pl/articles/58559598.pdf Link otwiera się w nowym oknie
Opis:: Introduction: Lichtenstein hernioplasty has been a gold standard of hernioplasty for 30 years now. However, the procedure may be followed by an unacceptably high rate of chronic pain, numbness and discomfort. Aim: To compare outcomes of Lichtenstein repair using a Parietene ProGrip self-fixing mesh versus the standard lightweight macroporous mesh. Material and methods: As many as 141 patients with unilateral primary inguinal hernia participated in this single-centre, randomised, prospective, single-blind (patient-blinded) study. Randomisation yielded two treatment groups: control group of 88 patients treated with Lichtenstein method using lightweight standard mesh (LS) and study group of 53 patients receiving treatment with self-fixing mesh (PG). Patients were followed up for 6 months. Primary outcome was the presence and severity of postoperative pain at discharge, at 30 days and 6 months post-procedure. Other study parameters were: duration of the procedure, duration of hospitalisation, presence of early and late complications, time needed to return to full activity and patient satisfaction. Results: No statistically significant differences in pain severity were demonstrated at discharge or at long-term follow-up. In the first 30 days post-procedure the patients in the PG group complained of pain of greater severity on the NRS (2.0 vs 1.4) (P = 0.0466). The duration of the procedure in the PG group was 9.4 minutes shorter than in the LS group (P = 0.0027). No statistically significant differences between the groups were found in other studied parameters. Conclusions: Self-fixing mesh can be safely used in inguinal canal repair procedures. It significantly shortened the duration of the procedure but at the same time did not reduce the severity of pain, including the rate of chronic postoperative inguinal pain.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Preparation of control space for remeshing polygonal surfaces
Autorzy:: Jurczyk, T.
Głut, B.
Tematy:: remeshing
anisotropic metric
control space
mesh adaptation
polygonal mesh; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:: https://bibliotekanauki.pl/articles/305758.pdf Link otwiera się w nowym oknie
Opis:: The subject of the article concerns the issues of remeshing, transforming a polygonal mesh into a triangular mesh adapted to its surface. From the initial polygonal mesh, the curvature of surface and boundary is retrieved and used to calculate a metric tensor varying in three-dimensional space. In the proposed approach, the curvature is computed using local approximation of surfaces and curves on the basis of vertices of the polygonal mesh. An essential part of the presented remeshing procedure is a creation of a control space structure based on the retrieved discrete data. The subsequent process of remeshing is then supervised by the contents of this auxiliary structure. The article presents various aspects related to the procedure of initialization, creation, and adjustment of the control space structure.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Pre-shape calculus and its application to mesh quality optimization
Autorzy:: Luft, Daniel
Schulz, Volker
Tematy:: shape optimization
mesh quality
mesh deformation method
shape calculus; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:: https://bibliotekanauki.pl/articles/2183466.pdf Link otwiera się w nowym oknie
Opis:: Deformations of the computational mesh, arising from optimization routines, usually lead to decrease of mesh quality or even destruction of the mesh. We propose a theoretical framework using pre-shapes to generalize the classical shape optimization and calculus. We define pre-shape derivatives and derive corresponding structure and calculus theorems. In particular, tangential directions are featured in pre-shape derivatives, in contrast to classical shape derivatives, featuring only normal directions. Techniques from classical shape optimization and calculus are shown to carry over to this framework. An optimization problem class for mesh quality is introduced, which is solvable with the use of pre-shape derivatives. This class allows for simultaneous optimization of the classical shape objectives and mesh quality without deteriorating the classical shape optimization solution. The new techniques are implemented and numerically tested for 2D and 3D.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Simultaneous shape and mesh quality optimization using pre-shape calculus
Autorzy:: Luft, Daniel
Schulz, Volker
Tematy:: shape optimization
mesh quality
mesh deformation method
shape calculus; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Badań Systemowych PAN
Powiązania:: https://bibliotekanauki.pl/articles/2183472.pdf Link otwiera się w nowym oknie
Opis:: Computational meshes arising from shape optimization routines commonly suffer from decrease of mesh quality or even destruction of the mesh. In this work, we provide an approach to regularize general shape optimization problems to increase both shape and volume mesh quality. For this, we employ pre-shape calculus as established in Luft and Schulz (2021). Existence of regularized solutions is guaranteed. Further, consistency of modified pre-shape gradient systems is established. We present pre-shape gradient system modifications, which permit simultaneous shape optimization with mesh quality improvement. Optimal shapes to the original problem are left invariant under regularization. The computational burden of our approach is limited, since additional solution of possibly larger (non-)linear systems for regularized shape gradients is not necessary. We implement and compare pre-shape gradient regularization approaches for a 2D problem, which is prone to mesh degeneration. As our approach does not depend on the choice of metrics representing shape gradients, we employ and compare several different metrics.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Perineal hernia after abdominoperineal resection – a systematic review
Autorzy:: Salati, Sajad Ahmad
Arkoubi, Amr Y.
Tematy:: abdominoperineal resection
biological mesh
perineal hernia
recurrence
synthetic mesh; Pokaż więcej
Wydawca:: Index Copernicus International
Powiązania:: https://bibliotekanauki.pl/articles/58574235.pdf Link otwiera się w nowym oknie
Opis:: Introduction: Perineal hernia (PH), also termed pelvic floor hernia, is a protrusion of intraabdominal viscera into the perineum through a defect in the pelvic floor. Aim: The study was conducted to evaluate the cases of perineal hernia resulting as a complication of abdominoperineal resection (APR) of rectal cancer. Material and methods: 30 cases from 24 articles published in reputable peer reviewed journals were evaluated for eight variables including [I] patient age, [II] gender, [III] time since APR, [IV] clinical presentation, [V] approach to repair, [VI] type of repair, [VII] presence/absence of pelvic adhesions [VIII] complications. Results: There was a total of 30 cases (18 males and 12 females) with a mean age of 71.5 years. The time of onset of symptoms ranged from 6 days to 12 years. Perineal lump with pain was the chief presenting feature followed by intestinal obstruction. Different approaches were adopted to repair by various methods. Conclusions: Perineal hernia as a complication of abdominoperineal resection is reported increasingly nowadays, as the approach to management of rectal cancer has gradually got shifted from open to minimally invasive in recent years. There is a need to spread awareness about this condition, so that it is actively looked for, during the postoperative follow-up. Management is surgical repair; the approach and type of repair should be individualized.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Algorithms for reliable networks deployment in mesh topology with flow control
Autorzy:: Debita, G.
Staniec, K.
Tematy:: mesh
network
planning; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/226158.pdf Link otwiera się w nowym oknie
Opis:: The article presents innovative methods for designing and controlling topology in mesh networks. The authors of the paper simulate the procedure of deploying a mesh structure and prove that the shortest path for such a network is also one with the least number of hops in the sense of intermediate nodes.
Dostawca treści:: Biblioteka Nauki

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