Applications of 3D PCA method for extraction of mean shape and geometrical features of biological objects set

This article presents application of the Principal Component Analysis method for analysis of geometry of biological objects and computation of three dimensional anthropometric database. In this work as the biological objects the fifteen human femur bones were used. The geometry of each bone was obtained by using 3D structural light scanner. For PCA analysis all objects have to be described with the same FEM mesh. To achieve this, the modified fluid registration was used. PCA decomposes the set of 3D objects into mean geometry and individual features (empirical modes) describing deviations from mean value. In this paper the mean shape and features of real bones were presented and discussed. First Published Online: 14 Oct 201

Reduced order Galerkin models of flow around NACA‐0012 airfoil

The construction of low‐dimensional models of the flow, containing only reduced number of degrees of freedom, is the essential prerequisite of closed‐loop control of that flow. Presently used models usually base on the Galerkin method, where the flow is approximated by the number of modes and coefficients. The velocities are computed from a system of ordinary differential equations, called Galerkin System, instead of Navier‐Stokes equation. In this paper, reduced order models of the flow around NACA‐0012 airfoil are presented. The chosen mode sets include POD modes from Karhunen‐Loeve decomposition (which require previous direct numerical simulation), as well as different eigenmodes from global stability analysis of the flow. First Published Online: 14 Oct 201

A Finite-Time Thermodynamics of Unsteady Fluid Flows

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Turbulent fluid has often been conceptualized as a transient thermodynamic phase. Here, a finite-time thermodynamics (FTT) formalism is proposed to compute mean flow and fluctuation levels of unsteady incompressible flows. The proposed formalism builds upon the Galerkin model framework, which simplifies a continuum 3D fluid motion into a finite-dimensional phase-space dynamics and, subsequently, into a thermodynamics energy problem. The Galerkin model consists of a velocity field expansion in terms of flow configuration dependent modes and of a dynamical system describing the temporal evolution of the mode coefficients. Each mode is treated as one thermodynamic degree of freedom, characterized by an energy level. The dynamical system approaches local thermal equilibrium (LTE) where each mode has the same energy if it is governed only by internal (triadic) mode interactions. However, in the generic case of unsteady flows, the full system approaches only partial LTE with unequal energy levels due to strongly mode-dependent external interactions. The FTT model is first illustrated by a traveling wave governed by a 1D Burgers equation. It is then applied to two flow benchmarks: the relatively simple laminar vortex shedding, which is dominated by two eigenmodes, and the homogeneous shear turbulence, which has been modeled with 1459 modes

Meningkatkan Kemampuan Bahasa Inggris Siswa Melalui Model Pembelajaran Kooperatif Tipe Think Pair and Share (TPS) Berbasis Karya Sastra pada Sekolah Menengah Pertama di Kota Makassar

Ringkasan: Kurikulum Tingkat Satuan Pendidikan (KTSP) dalam pelaksanaannya lebih cenderung kepada pendekatan Manajemen Berbasis Sekolah (MBS) atau desentralisasi; guru mengembangkan KTSP dan silabusnya berdasarkan kerangka dasar kurikulum dan standar kompetensi lulusan dari Standar Nasional Pendidikan. Bahasa Inggris untuk satuan tingkat pendidikan menengah termasuk mata pelajaran wajib yang harus diajarkan kepada para siswa di SMP. Apakah pembelajaran bahasa Inggris menggunakan kooperatif learning, Tipe Think Pair ami Share (TPS) berbasis karya sastra dapat meningkatkan kemampuan bahasa Inggris siswa? Penelitian ini bertujuan untuk mengetahui apakah pembelajaran bahasa Inggris menggunakan kooperatif learning. Tipe. Think Pair and Share (TPS) berbasis karya sastra dapat meningkatkan kemampuan bahasa Inggris siswa. Penelitian Hasil penelitian menunjukkan bahwa pembelajaran bahasa Inggris pada Sekolah Menengah Pertama pada SMP Negeri 36 Makassar menggunakan model pembelajaran kooperatif learning, Tipe Think Pair and Share f TPS) berbasis karya sastra dapat meningkatkan kemampuan bahasa Inggris siswa

¿Superar el rentismo?: el cooperativismo en Venezuela

El proceso iniciado con la llegada al gobierno de Hugo Chávez Frías abrió un ciclo de gobiernos progresistas que interpeló a las Ciencias Sociales en su comprensión de la realidad, reactualizando debates sobre el Estado y la política. La reforma constituyente, así como la sucesión de elecciones locales, regionales, legislativas, presidenciales y diversos referéndums, fueron algunos de los hitos que son referencias ineludibles a la hora de encarar los mencionados temas cuando se trata de estudios latinoamericanos sobre el pasado más reciente y el presente de nuestro continente. En este trabajo me propongo iluminar una de las áreas de mayor desarrollo aunque pero de menor estudio durante la Revolución Bolivariana: el sector cooperativista. Este proceso será encarado desde diferentes ángulos para revelar sus múltiples complejidades y las posibilidades que alumbra dentro del proyecto de la revolución bolivariana. Se revisará el vínculo con el proceso político, el modelo de acumulación vigente en Venezuela, la relación con el mundo sindical y el inicio proceso de construcción del estado comunal.Eje 4: Balances y perspectivas sobre las políticas públicas en la región. Sus impactos en la desigualdad, la construcción de derechos y constitución de sujetos.Facultad de Trabajo Socia

The need for prediction in feedback control of a mixing layer

International audienceWe present the first application of a Smith predictor in the model-based feedback control of a convectively unstable flow. The two-dimensionalincompressible mixing layer is chosen as a plant and integrated with a finite-element Navier–Stokes solver. The flow is actuated by a modulation of the inflow mimicking a pulsed jet actuator. The state is monitored by a down-stream velocity sensor. The control goal is to command the fluctuation level at the sensor location. As an additional challenge, the incoming shear-flow profile is perturbed by the small noise level. The starting point of this study is a standard low-order control without prediction. A Smith predictor is included to compensate for the convective delay from actuation to sensing. The closed-loop results with a Smith predictor are distinctly better than without it. The design of the linear robust controllers is performed with an open-loop control. We conjecture that predictors may augment feedback control for a large class of convectively unstable flows with significant time-delay from actuation to sensing

Reduced-order modeling of the fluidic pinball

International audienc