Search results for " menetelmä"

A New Method to Reconstruct Quantitative Food Webs and Nutrient Flows from Isotope Tracer Addition Experiments

2020

Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from descriptive studies to modeling approaches of varying complexity. Increasingly, isotope tracer data are being used to compare ecosystems and analyze experimental manipulations. Currently, a formal statistical framework for analyzing such experiments is lacking, making it impossible to calculate the estimation errors associated with the model fit, the…

Mikrojärjestelmien virtausdynamiikka numeerisen mallintamisen näkökulmasta

2005

Prospectives to tractor cabin design with computational acoustics tools

2011

Computational acoustical models allow automated optimization of tractor design with respect to acoustic properties, which could speed up significantly the design process of tractor cabin prototypes. This article gives insightful prospectives to the tractor design process by considering modern computational acoustics technology. Mathematical formulation for a system consisting of vibrating elastic tractor structure and airfilled acoustic enclosure are given and a related numerical solution technique with finite element method (FEM) is presented. Simulation results produced with commercially available software are reviewed. nonPeerReviewed

Multiobjective muffler shape optimization with hybrid acoustics modelling

2010

Shape optimization of a duct system with respect to sound transmission loss is considered. The objective of optimization is to maximize the sound transmission loss at multiple frequency ranges simultaneously by adjusting the shape of a reactive muffler component. The noise reduction problem is formulated as a multiobjective optimization problem. The sound attenuation for each considered frequency is determined by a hybrid method, which requires solving Helmholtz equation numerically by finite element method. The optimization is performed using non-dominated sorting genetic algorithm, NSGA-II, which is a multi-objective genetic algorithm. The hybrid numerical method is flexible with respect …

Äänenvaimentimien mallinnuspohjainen monitavotteinen muodonoptimointi

2011

Multiobjective muffler shape optimization with hybrid acoustics modelling

2011

This paper considers the combined use of a hybrid numerical method for the modeling of acoustic mufflers and a genetic algorithm for multiobjective optimization. The hybrid numerical method provides accurate modeling of sound propagation in uniform waveguides with non-uniform obstructions. It is based on coupling a wave based modal solution in the uniform sections of the waveguide to a finite element solution in the non-uniform component. Finite element method provides flexible modeling of complicated geometries, varying material parameters, and boundary conditions, while the wave based solution leads to accurate treatment of non-reflecting boundaries and straightforward computation of the …

Optimization of the domain in elliptic variational inequalities

1986

Electromagnetic wave propagation in non-homogeneous waveguides

2015

We investigate an electromagnetic waveguide, having several cylindrical ends. The waveguide is assumed to be empty and to have a perfectly conductive boundary. We study the electromagnetic field, excited in the waveguide in the presence of charges and currents. The field can be described as a solution of the stationary Maxwell system with conductive boundary conditions and “intrinsic” radiation conditions at infinity. We prove the problem to be well-posed. Electromagnetic waves propagation in the waveguide can be described by means of a scattering matrix. We introduce such a matrix for all values of the spectral parameter k in the waveguide continuous spectrum and study its properties. Moreove…

Luovat terapiat ja empaattisen kohtaamisen kaipuu suomalaisten mielisairaalamuistojen valossa

2018

Tutkin suomalaisten mielisairaalamuistoja Muistoihin kaivertuneet tilat ‐hankkeessa. Muistelukeruuseen lähetetyt potilaiden muistot ovat suurelta osin häpeän ja traumantäyteisiä, vaikka positiivisiakin kokemuksia mahtuu joukkoon. Luovien terapioiden kannalta ilahduttavaa on se, että niiden osalta kenelläkään muistojaan lähettäneellä potilaalla ei ollut pahaa sanottavaa. Luovia terapioita olen käyttänyt myös muisteluaineiston hyödyntämisessä. Olen järjestänyt neljä työpajaa, joissa olen käyttänyt aineiston karuimpia potilaskokemuksia terapeuttisen kirjoittamisen materiaalina tavoitteenani aktivoida ihmisten empatiakykyä ja sen kautta tarkastella traumatisoivan ja vastaavasti hoitavan kohtaam…

High‐resolution 3D forest structure explains ecomorphological trait variation in assemblages of saproxylic beetles

2022

1. Climate, topography and the 3D structure of forests are major drivers affecting local species communities. However, little is known about how the specific functional traits of saproxylic (wood-living) beetles, involved in the recycling of wood, might be affected by those environmental characteristics. 2. Here, we combine ecological and morphological traits available for saproxylic beetles and airborne laser scanning (ALS) data in Bayesian trait-based joint species distribution models to study how traits drive the distributions of more than 230 species in temperate forests of Europe. 3. We found that elevation (as a proxy for temperature and precipitation) and the proportion of conifers p…