387 resultados para Heikkinen, Kaija
Resumo:
Seloste artikkelista: Peltoniemi, M., Heikkinen, J. & Mäkipää, R. 2007. Stratification of regional sampling by model-predicted changes of carbon stocks in forested mineral soils. Silva Fennica 4 (3): 527-539.
Resumo:
Tutkimus eettiset sijoitusrahastot Suomessa – nykytilan arviointi, on kvalitatiivinen, teorialähtöinen kirjallisuustutkimus, jossa selvitetään eettisten sijoitusrahastojen nykytilannetta Suomessa. Päätavoitteena on selvittää, mitä ja minkälaisia eettiset sijoitusrahastot ovat Suomessa. Alatavoitteena tutkitaan myös eettisten rahastojen kehitystä niin Suomessa kuin kansainvälisestikin. Tutkimuksessa on kartoitettu Suomessa toimivat eettiset sijoitusrahastot ja vertailtu niitä keskenään sekä selvitetty niiden sijoituspolitiikkaa ja toimintaa. Aineistona on käytetty tieteellisen kirjallisuuden lisäksi pankkien ja pankkiiriliikkeiden aineistoja. Tutkimus on tehty kirjallisuuden pohjalta ja tutkimus perustuu kirjallisuuden ja tutkimusaineiston analysointiin sekä siitä tehtäviin johtopäätöksiin. Tutkimuksessa havaittiin, että suomalaiset eettisiksi luokiteltavat rahastot ovat hyvin identtisiä ja niissä näkyy vahva painotus ympäristöön ja ilmastoon. Eettisten rahastojen määrä ja koko on kasvanut nopeasti koko 2000 – luvun ja tutkimuksen tekovaiheessa Suomessa toimii 22 eri eettistä rahastoa ja näiden yhteenlaskettu rahastopääoma on noin 5,8 Mrd. euroa, joka on noin 8 % koko rahastopääomasta (66 Mrd. euroa, (2007)) Suomessa eettinen sijoittaminen on vielä suhteellisen uusi ilmiö ja kansainvälisesti vertailtuna eettinen sijoittaminen on toistaiseksi pientä.
Resumo:
In this thesis the X-ray tomography is discussed from the Bayesian statistical viewpoint. The unknown parameters are assumed random variables and as opposite to traditional methods the solution is obtained as a large sample of the distribution of all possible solutions. As an introduction to tomography an inversion formula for Radon transform is presented on a plane. The vastly used filtered backprojection algorithm is derived. The traditional regularization methods are presented sufficiently to ground the Bayesian approach. The measurements are foton counts at the detector pixels. Thus the assumption of a Poisson distributed measurement error is justified. Often the error is assumed Gaussian, altough the electronic noise caused by the measurement device can change the error structure. The assumption of Gaussian measurement error is discussed. In the thesis the use of different prior distributions in X-ray tomography is discussed. Especially in severely ill-posed problems the use of a suitable prior is the main part of the whole solution process. In the empirical part the presented prior distributions are tested using simulated measurements. The effect of different prior distributions produce are shown in the empirical part of the thesis. The use of prior is shown obligatory in case of severely ill-posed problem.
Toimialamuutos ja trendien mukaiset mahdollisuudet yhteistyön avulla – kuitu- ja lastulevyteollisuus
Resumo:
Tämä tutkimus tarkastelee toimialamuutosta kuitu- ja lastulevyteollisuuden näkökulmasta. Metsäteollisuus elää Suomessa murroskautta, johon tarvitaan nopeasti radikaaleja ratkaisuja. Uusia mahdollisuuksia tulisi pohtia, tutkia ja luoda yli toimialarajojen yhteistyössä muiden tahojen kanssa. Tutkimus on tulevaisuudentutkimus ja tutkimus rajattiin kolmen teeman ympärille: raaka-aine, ympäristö ja terveys. Teemojen muodostamisessa huomioitiin kohdeyritysten, Puhos Board Oy:n ja Suomen Kuitulevy Oy:n, lähtötilanteet yhdistämällä ne yrityksille oleellisiin ja potentiaalisiin trendeihin ja signaaleihin. Tutkimuksen empiirinen osio muodostui innovaatiosessiosta, johon osallistui 29 henkilöä. Keskeiset tulokset tutkimuksesta olivat, että mielikuvat kuitu- ja lastulevyteollisuudesta ovat heikot ja kuluttajiin pitäisi saada parempi kosketus. Trendien huomioiminen liiketoiminnassa tuo teollisuuden lähemmäksi kuluttajaa. Trendejä voisi myötäillä esimerkiksi lisäämällä tarkoituksenmukaisen ainesosan tuotteeseen. Kohdeyritysten tulisi miettiä mihin toimialaan kuitu- ja lastulevyteollisuus oikeastaan kuuluu, jolloin koko liiketoiminnan suuntaa voitaisiin muuttaa. Apua liiketoiminnan suunnan muuttamiseen saa innovaatioverkoston kautta.
Resumo:
Low quality mine drainage from tailings facilities persists as one of the most significant global environmental concerns related to sulphide mining. Due to the large variation in geological and environmental conditions at mine sites, universal approaches to the management of mine drainage are not always applicable. Instead, site-specific knowledge of the geochemical behaviour of waste materials is required for the design and closure of the facilities. In this thesis, tailings-derived water contamination and factors causing the pollution were investigated in two coeval active sulphide mine sites in Finland: the Hitura Ni mine and the Luikonlahti Cu-Zn-Co-Ni mine and talc processing plant. A hydrogeochemical study was performed to characterise the tailingsderived water pollution at Hitura. Geochemical changes in the Hitura tailings were evaluated with a detailed mineralogical and geochemical investigation (solid-phase speciation, acid mine drainage potential, pore water chemistry) and using a spatial assessment to identify the mechanisms of water contamination. A similar spatial investigation, applying selective extractions, was carried out in the Luikonlahti tailings area for comparative purposes (Hitura low-sulphide tailings vs. Luikonlahti sulphide-rich tailings). At both sites, hydrogeochemistry of tailings seepage waters was further characterised to examine the net results of the processes observed within the impoundments and to identify constraints for water treatment. At Luikonlahti, annual and seasonal variation in effluent quality was evaluated based on a four-year monitoring period. Observations pertinent to future assessment and mine drainage prevention from existing and future tailings facilities were presented based on the results. A combination of hydrogeochemical approaches provided a means to delineate the tailings-derived neutral mine drainage at Hitura. Tailings effluents with elevated Ni, SO4 2- and Fe content had dispersed to the surrounding aquifer through a levelled-out esker and underneath the seepage collection ditches. In future mines, this could be avoided with additional basal liners in tailings impoundments where the permeability of the underlying Quaternary deposits is inadequate, and with sufficiently deep ditches. Based on the studies, extensive sulphide oxidation with subsequent metal release may already initiate during active tailings disposal. The intensity and onset of oxidation depended on e.g. the Fe sulphide content of the tailings, water saturation level, and time of exposure of fresh sulphide grains. Continuous disposal decreased sulphide weathering in the surface of low-sulphide tailings, but oxidation initiated if they were left uncovered after disposal ceased. In the sulphide-rich tailings, delayed burial of the unsaturated tailings had resulted in thick oxidized layers, despite the continuous operation. Sulphide weathering and contaminant release occurred also in the border zones. Based on the results, the prevention of sulphide oxidation should already be considered in the planning of tailings disposal, taking into account the border zones. Moreover, even lowsulphide tailings should be covered without delay after active disposal ceases. The quality of tailings effluents showed wide variation within a single impoundment and between the two different types of tailings facilities assessed. The affecting factors included source materials, the intensity of weathering of tailings and embankment materials along the seepage flow path, inputs from the process waters, the water retention time in tailings, and climatic seasonality. In addition, modifications to the tailings impoundment may markedly change the effluent quality. The wide variation in the tailings effluent quality poses challenges for treatment design. The final decision on water management requires quantification of the spatial and seasonal fluctuation at the site, taking into account changes resulting from the eventual closure of the impoundment. Overall, comprehensive hydrogeochemical mapping was deemed essential in the identification of critical contaminants and their sources at mine sites. Mineralogical analysis, selective extractions, and pore water analysis were a good combination of methods for studying the weathering of tailings and in evaluating metal mobility from the facilities. Selective extractions with visual observations and pH measurements of tailings solids were, nevertheless, adequate in describing the spatial distribution of sulphide oxidation in tailings impoundments. Seepage water chemistry provided additional data on geochemical processes in tailings and was necessary for defining constraints for water treatment.
Resumo:
This thesis describes the process of the integration of a real-time simulator environment with a motion platform and a haptic device as a part of the Kvalive project. Several programs running on two computers were made to control the different devices of the environment. User tests were made to obtain information of needed improvements to make the simulator more realistic. Also new ideas for improving the simulator and directions of further research were obtained with the help of this research.