Browsing by Subject "ennusteet"

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  • Toppinen, Anne; Laaksonen, Susanna; Hänninen, Riitta (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1996)
    This study investigates the relationship between Finnish sulphate pulp export prices and international pulp inventories using the Johansen cointegration method. Long-run equilibrium is found to exist between pulp price and NORSCAN inventory for the study period, 1980–94. Granger causality is found to exist from inventory to price but not vice versa. A simple short-run forecasting model for the Finnish pulp export price is formed. In preliminary analysis, the explanatory power of model is found to be acceptable but only under stable market conditions.
  • Saramäki, Jussi (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1992)
  • Ritvanen, Jenna; Harnist, Bent; Aldana, Miguel; Makinen, Terhi; Pulkkinen, Seppo (IEEE, 2023)
    IEEE journal of selected topics in applied earth observations and remote sensing
    Nowcasts (i.e., short-term forecasts from 5 min to 6 h) of heavy rainfall are important for applications such as flash flood predictions. However, current precipitation nowcasting methods based on the extrapolation of radar echoes have a limited ability to predict the growth and decay of rainfall. While deep learning applications have recently shown improvement compared to extrapolation-based methods, they still struggle to correctly nowcast small-scale high-intensity rainfall. To address this issue, we present a novel model called the Lagrangian convolutional neural network (L-CNN) that separates the growth and decay of rainfall from motion using the advection equation. In the model, differences between consecutive rain rate fields in Lagrangian coordinates are fed into a U-Net-based CNN, known as RainNet, that was trained with the root-mean-squared-error loss function. This results in a better representation of rainfall temporal evolution compared to the RainNet and the extrapolation-based LINDA model that were used as reference models. On Finnish weather radar data, the L-CNN underestimates rainfall less than RainNet, demonstrated by greater POD (29% at 30 min at 1 mm·h −1 threshold) and smaller bias (98% at 15 min). The increased ETS values over LINDA for leadtimes under 15 min, with maximum increases of 7% (5 mm·h −1 threshold) and 10% (10 mm·h −1 ), show that the L-CNN represents the growth and decay of heavy rainfall more accurately than LINDA. This implies that nowcasting of heavy rainfall is improved when growth and decay are predicted using a deep learning model.
  • Meichsner, Julia (2001)
    The objective of this study is to analyse the applicability of growth predictions in the case of the Eastern enlargement. For this purpose the growth model developed by Uwe Walz (1998) was chosen and compared to empirical data as well as to further studies about the process of Eastern enlargement. In the first part of the paper Walz´ model is introduced. The production patterns of a trade union consisting of two countries are described before the enlargement. Then, a third technology-deficient country is integrated in two steps: First, barriers to trade are removed, and secondly migration is liberalized. The model shows that free trade between the two trade blocks with specialization patterns of the Heckscher-Ohlin type causes the growth rate to shift. This holds true in the next step, when skilled workers are assumed to immigrate to the countries with the higher level of technology. On the contrary, the growth rate declines when unskilled workers are assumed to migrate to the technologically-advanced countries. In the second part, the growth predictions of Walz´ model are decomposed in their underlying assumptions, defined and compared to empirical data regarding the process of the Eastern enlargement. The comparison reveals a high degree of congruency between the theoretical assumptions and the corresponding developments in reality. This congruency comes to an end when further studies on the Eastern enlargement are called in. In the final part of the paper, the results of the comparisons between Walz´ model and the data and studies about the Eastern enlargement are evaluated trying to give an answer to the question as to how applicable the theoretical growth predictions are in the case of the Eastern enlargement.
  • Rajakallio, Maria; Jyväsjärvi, Jussi; Muotka, Timo; Aroviita, Jukka (Blackwell, 2021)
    Journal of Applied Ecology 58: 7, 1523-1532
    1. Growing bioeconomy is increasing the pressure to clear-cut drained peatland forests. Yet, the cumulative effects of peatland drainage and clear-cutting on the biodiversity of recipient freshwater ecosystems are largely unknown. 2. We studied the isolated and combined effects of peatland drainage and clear-cutting on stream macroinvertebrate communities. We further explored whether the impact of these forestry-driven catchment alterations to benthic invertebrates is related to stream size. We quantified the impact on invertebrate biodiversity by comparing communities in forestry-impacted streams to expected communities modelled with a multi-taxon niche model. 3. The impact of clear-cutting of drained peatland forests exceeded the sum of the independent effects of drainage and clear-cutting, indicating a synergistic interaction between the two disturbances in small streams. Peatland drainage reduced benthic biodiversity in both small and large streams, whereas clear-cutting did the same only in small streams. Small headwater streams were more sensitive to forestry impacts than the larger downstream sites. 4. We found 11 taxa (out of 25 modelled) to respond to forestry disturbances. These taxa were mainly different from those previously reported as sensitive to forestry-driven alterations, indicating the context dependence of taxonomic responses to forestry. In contrast, most of the functional traits previously identified as responsive to agricultural sedimentation also responded to forestry pressures. In particular, taxa that live temporarily in hyporheic habitats, move by crawling, disperse actively in water, live longer than 1 year, use eggs as resistance form and obtain their food by scraping became less abundant than expected, particularly in streams impacted by both drainage and clear-cutting. 5. Synthesis and applications. Drained peatland forests in boreal areas are reaching maturity and will soon be harvested. Clear-cutting of these forests incurs multiple environmental hazards but previous studies have focused on terrestrial ecosystems. Our results show that the combined impacts of peatland drainage and clear-cutting may extend across ecosystem boundaries and cause significant biodiversity loss in recipient freshwater ecosystems. This information supports a paradigm shift in boreal forest management, whereby continuous-cover forestry based on partial harvest may provide the most sustainable approach to peatland forestry.
  • Vepsäläinen, Sampo; Calderón, Silvia M.; Malila, Jussi; Prisle, Nønne L. (Copernicus Publ., 2022)
    Atmospheric chemistry and physics
    Surface active compounds (surfactants) are frequently found in atmospheric aerosols and droplets. As they adsorb to the surfaces of microscopic systems, surfactants can decrease aqueous surface tension and simultaneously deplete the bulk concentration. These processes may influence the activation of aerosols into cloud droplets and investigation of their role in cloud microphysics has been ongoing for decades. In this work, we have used six different models documented in the literature to represent surface activity in Köhler calculations of cloud droplet activation for particles consisting of one of three moderately surface active organics (malonic, succinic or glutaric acid) mixed with ammonium sulfate in varying mass ratios. For each of these organic acids, we find that the models predict comparable activation properties at small organic mass fractions in the dry particles, despite large differences in the predicted degree of bulk-to-surface partitioning. However, differences between the model predictions for the same dry particles regarding both the critical droplet diameters and supersaturations increase with the organic fraction in the particles. Comparison with available experimental data shows that models assuming complete bulk-to-surface partitioning of the moderately surface active component (total depletion of the bulk) do not adequately represent the droplet activation of particles with high organic mass fractions. When reduced droplet surface tension is also considered, these predictions somewhat improve. Models that consider partial bulk-to-surface partitioning of surface active components yield results comparable to experimental supersaturation data, even at high organic mass fractions in the particles, but predictions of the degree of organic bulk–surface partitioning strongly differ. This work highlights the need to use a thermodynamically consistent model framework to treat the surface activity of atmospheric aerosols and for firm experimental validation of model predictions across a wide range of droplet states relevant to the atmosphere.
  • Karl, Matthias; Pirjola, Liisa; Grönholm, Tiia; Kurppa, Mona; Anand, Srinivasan; Zhang, Xiaole; Held, Andreas; Sander, Rolf; Dal Maso, Miikka; Topping, David; Jiang, Shuai; Kangas, Leena; Kukkonen, Jaakko (Copernicus Publ., 2022)
    Geoscientific model development
    Numerical models are needed for evaluating aerosol processes in the atmosphere in state-of-the-art chemical transport models, urban-scale dispersion models, and climatic models. This article describes a publicly available aerosol dynamics model, MAFOR (Multicomponent Aerosol FORmation model; version 2.0); we address the main structure of the model, including the types of operation and the treatments of the aerosol processes. The model simultaneously solves the time evolution of both the particle number and the mass concentrations of aerosol components in each size section. In this way, the model can also allow for changes in the average density of particles. An evaluation of the model is also presented against a high-resolution observational dataset in a street canyon located in the centre of Helsinki (Finland) during afternoon traffic rush hour on 13 December 2010. The experimental data included measurements at different locations in the street canyon of ultrafine particles, black carbon, and fine particulate mass PM1. This evaluation has also included an intercomparison with the corresponding predictions of two other prominent aerosol dynamics models, AEROFOR and SALSA. All three models simulated the decrease in the measured total particle number concentrations fairly well with increasing distance from the vehicular emission source. The MAFOR model reproduced the evolution of the observed particle number size distributions more accurately than the other two models. The MAFOR model also predicted the variation of the concentration of PM1 better than the SALSA model. We also analysed the relative importance of various aerosol processes based on the predictions of the three models. As expected, atmospheric dilution dominated over other processes; dry deposition was the second most significant process. Numerical sensitivity tests with the MAFOR model revealed that the uncertainties associated with the properties of the condensing organic vapours affected only the size range of particles smaller than 10 nm in diameter. These uncertainties therefore do not significantly affect the predictions of the whole of the number size distribution and the total number concentration. The MAFOR model version 2 is well documented and versatile to use, providing a range of alternative parameterizations for various aerosol processes. The model includes an efficient numerical integration of particle number and mass concentrations, an operator splitting of processes, and the use of a fixed sectional method. The model could be used as a module in various atmospheric and climatic models.
  • Harstela, Pertti (Suomen metsätieteellinen seura, 1974)
  • Velling, Pirkko; Tigerstedt, P. M. A. (Suomen metsätieteellinen seura, 1984)
  • Janssen, Annette B. G.; Janse, Jan H.; Beusen, Arthur H. W.; Chang, Manqi; Harrison, John A.; Huttunen, Inese; Kong, Xiangzhen; Rost, Jasmijn; Teurlincx, Sven; Troost, Tineke A.; van Wijk, Dianneke; Mooij, Wolf M. (Elsevier, 2019)
    Current Opinion in Environmental Sustainability 36 (2019), 1-10
    Algal blooms increasingly threaten lake and reservoir water quality at the global scale, caused by ongoing climate change and nutrient loading. To anticipate these algal blooms, models to project future algal blooms worldwide are required. Here we present the state-of-the-art in algal projection modelling and explore the requirements of an ideal algal projection model. Based on this, we identify current challenges and opportunities for such model development. Since most building blocks are present, we foresee that algal projection models for any lake on earth can be developed in the near future. Finally, we think that algal bloom projection models at a global scale will provide a valuable contribution to global policymaking, in particular with respect to SDG 6 (clean water and sanitation).
  • Kuusela, Kullervo (Suomen metsätieteellinen seura, 1964)
  • Kuusela, Kullervo (Suomen metsätieteellinen seura, 1959)
  • Unknown author (Vesihallitus, 1974)
    Vesihallitus. Tiedotus 59
  • Hellstén, Juho (Helsingin yliopisto, 2019)
    Tässä Pro gradu -tutkielmassa tarkastellaan suomalaisten kuluttajien taloudellisten odotusten muodostumista, niihin vaikuttavia tekijöitä sekä niiden suhdetta reaalitalouden lukuihin Suomessa aikavälillä 1987-1995. Odotusten muodostumista on tarkoitus tarkastella suhteessa aikavälin historialliseen tapahtumakulkuun. Tutkimuksessa kuvataan odotuksia Tilastokeskuksen kuluttajabarometrin saldolukujen avulla. Aineistosta käytetään kolmea eri odotusmuuttujaa: odotuksia omasta taloudesta, Suomen taloudesta sekä työttömyydestä. Vuosina 1987-1995 Suomessa koettiin ensin ennennäkemättömän voimakas nousukausi, joka huipentui talouden ylikuumenemiseen ja poikkeuksellisen pitkäksi ja syväksi osoittautuneeseen lamaan. Odotusten muodostumisen teoreettisena viitekehyksenä toimii rationaalisten odotusten hypoteesi. Rationaalisten odotusten hypoteesin mukaan odotuksiin sisältyy kaikki relevantti informaatio, ja ne ovat talousteorian mukaisia parhaita mahdollisia ennusteita muuttujien arvoista. Odotuksiin vaikuttavaa tapahtumakulkua hahmotetaan työssä kahdella toisiinsa kytkeytyvällä tavalla: 1. ensisijaisesti median välittämän julkisen keskustelun ja yleisen ilmapiirin eli niin kutsutun talouspuheen kautta, sekä 2. yksittäisten merkittävien poliittisten tapahtumien kautta, joita aikavälillä ilmeni. Tapahtumakulun ja odotusten välistä suhdetta tarkastellaan aineistolähtöisesti tilastoaineiston aikasarjojen ja kirjallisuuslähteiden pohjalta. Tarkoitus on paikantaa tapahtumakulun ja odotusten muutosten ajoitukset, muutokset ja murrokset sekä trendit. Näin saadaan selville, minkälainen suhde tapahtumakulun ja odotusten välillä on mahdollista havaita. Tutkimuksessa on myös tarkoitus tarkastella reaalitalouden lukujen, jotka tulevat Tilastokeskukselta, ja odotusten suhdetta sekä odotusten mahdollista subjektiivista harhaisuutta. Tutkimustulosten mukaan odotukset Suomen taloudesta ja työttömyydestä vaihtelevat aikavälillä paljon enemmän kuin odotukset omasta taloudesta, joiden trendi on tasaisempi. Odotukset Suomen taloudesta ja työttömyydestä vaikuttavatkin olevan alttiimpia ulkoisille vaikutuksille, kuten aikavälin merkittäville tapahtumille tai talouspuheen sävylle. Oman talouden odotusten voidaan näin ollen katsoa perustuvan Suomen talouteen ja työttömyyteen liittyviä odotuksia enemmän relevanttiin informaatioon, jolloin ne ovat myös enemmän rationaalisten odotusten hypoteesin mukaisia. Lamauutisten lisääntyminen näyttää vaikuttavan ensisijaisesti odotuksiin omasta taloudesta, kun taas Suomen talouteen liittyvien odotusten kannalta merkittävämpää on talouspuheen ja todellisen taloustilanteen ristiriita. Aikavälin talouspuhetta leimasivat mm. rahoitusmarkkinoiden vapautukseen ja vakaan markan linjaan liittyneet keskustelemattomuus ja kritiikin tukahduttanut yhden hallitsevan näkökulman talouspoliittinen linja, josta pidettiin kiinni ongelmien välttämiseksi. Marraskuun 1991 devalvaatiota edeltäneen talouspuheen voidaan nähdä olleen odotuksia harhaanjohtavaa ja ongelmia peittelevää, minkä seurauksena kahteen odotusmuuttujaan, odotuksiin Suomen taloudesta ja työttömyydestä, syntyi harhainen kasvuperiodi mittausajankohtien 02/1991 ja 02/1992 välille. Toteutettu devalvaatio kuitenkin monipuolisti talouspuhetta, jonka jälkeen myös odotukset Suomen taloudesta ja työttömyydestä kääntyivät kohti ”oikeampaa” suuntaa. Tämä harhainen periodi, jossa odotukset tulevasta paranivat keskellä pahinta lamaa ja loivat talouskehityksen valossa perusteetonta optimismia, on tutkielman kiinnostavin tulos. Myös tärkeimmät poliittiset tapahtumat, kuten markan arvon kellutus ja Ahon hallituksen valtaan astumiseen johtaneet vuoden 1991 eduskuntavaalit voidaan nähdä mahdollisina odotuksiin vaikuttaneina murroksina, jotka ajoittuvat juuri samoihin ajankohtiin odotusmuuttujien arvojen muutosten kanssa. Odotukset Suomen taloudesta näyttävät ennakoivan muutoksia reaalitalouden luvuissa, kuten talouskasvussa, tuloissa ja kulutuksessa, mutta harhainen periodi koituu ongelmaksi. Odotukset omasta taloudesta puolestaan vaihtelevat yllättävän vähän laman pituuteen ja syvyyteen nähden, mutta se ei sisällä samanlaista harhaista periodia kuin odotukset Suomen taloudesta. Korot ja työttömyys näyttävät kuitenkin olevan muuttujina sellaisia, joilla on vaikutusta nimenomaan odotuksiin omasta taloudesta. Odotukset Suomen taloudesta ja työttömyydestä vaihtelevat liiaksi, jotta niiden yhteyttä talouden reaalitalouden lukuihin voitaisiin pitää selvänä. Myös odotusten muodostajat itse näkevät erityisesti Suomen talouteen liittyvät odotuksensa harhaisina, kun niitä tarkastellaan vuoden päästä subjektiivisen kokemuksen kautta. Mainittu harhainen periodi onkin tutkielmani yllättävin ja kiinnostavin tulos. Sen aikana, kesken pahimman laman, Suomen talouteen liittyvät odotukset ennustavat kasvukautta, joka ei toteudu, vaan korjaavat itsensä lopulta normaalimmalle tasolle. Suomen talouteen liittyviä odotuksia saattoivat johtaa harhaan mm. viranomaisten optimistiset kasvuennusteet, talouspuheen harhaanjohtavuus ja ristiriita oikean taloustilanteen kanssa, vaihtoehdoista keskustelemattomuus, tulotason kasvu vielä vuonna 1991, eduskuntavaalien aiheuttama optimistisuus tai usko väistämättömän devalvaation kykyyn ratkaista mahdolliset ongelmat. Harhainen periodi, mutta myös verraten matalat odotukset 1980-luvun lopulla, asettavat myös kyseenalaisiksi aiemmassa tutkimuksessa esitetyn näkemyksen siitä, että nousukausi olisi ollut erityisen optimistista ja lama pessimististä aikaa. Vuodesta 1993 eteenpäin odotukset kuitenkin seuraavat toteutunutta kehitystä. Tutkimustulosten mukaan odotukset eivät siis näytä muodostuvan täysin rationaalisten odotusten hypoteesin mukaisesti johtuen harhaanjohdettavuudesta, mikä johti systemaattisten virheiden muodostumiseen. Voidaan sanoa, että kuluttajien on hyvin vaikea muodostaa odotuksia relevantin informaation pohjalta varsinkaan yleisestä talouden tilasta. Tämä vaikuttaisi erityisesti pätevän juuri poikkeuksellisina aikoina, joista erinomaisena esimerkkinä toimii tarkasteltu nousukauden ja laman aikaväli.
  • Holstila, A (Kela, 1997)
    Sosiaali- ja terveysturvan tutkimuksia ; 18
    Tuki- ja liikuntaelinsairaudet aiheuttavat monille suomalaisille haittaa ja työkyvyttömyyttä. Sairastuneille annetaan kuntoutusta avohoidossa ja uhkaavaa työkyvyttömyyttä pyritään ehkäisemään laitoskuntoutuksella. Tässä tutkimuksessa on verrattu avohoidossa annetun kuntoutuksen vaikuttavuutta laitoksessa annetun hoidon vaikutuksiin. Erityisesti on selvitetty kuntoutuksen vaikutusta pitkään tuki- ja liikuntaelinvaivoja sairastaneiden toimintakykyyn.
  • Pukkala, Timo (Suomen metsätieteellinen seura, 1987)
  • Kalenoja, Hanna; Vihanti, Kaisuliina; Voltti, Ville; Korhonen, Annu; Karasmaa, Nina (Ympäristöministeriö, 2008)
    Suomen ympäristö 27/2008
    Tähän julkaisuun on koottu tietoja erilaisten maankäytön toimintojen – kuten asumisen, kaupan toimipaikkojen ja työpaikkojen – tuottamasta liikenteestä. Liikennetarvetta koskevia matkatuotostietoja voidaan hyödyntää maankäytön ja liikenteen suunnittelutilanteissa, joissa on tarpeen arvioida ratkaisujen liikenteellisiä vaikutuksia tai vertailla vaihtoehtoisia sijaintikohteita toisiinsa. Liikennetarvetta koskevat tiedot on esitetty kuntaryhmittäin, sillä matkatuotokset ja erityisesti kulkutapajakauma ovat eri alueilla erilaisia. Tiedot on esitetty yhdyskuntarakenteen eri vyöhykkeille, joissa kaupunkimaiset seutukunnat on jaettu jalankulku-, joukkoliikenne- ja autovyöhykkeisiin joukkoliikennetarjonnan ja yhdyskuntarakenteellisen sijainnin perusteella. Erilaisten toimintojen tuottamien matkojen määrä on yleisimmin esitetty kävijöiden määränä kerrosalaa, asukasta tai työntekijää kohti tai vuorokauden kokonaiskävijämääränä.
  • Krogerus, Kirsti; Pasanen, Antti (Suomen ympäristökeskus, 2016)
    Reports of the Finnish Environment Institute 39/2016
    Although mining companies have long been conscious of water related risks, they still face environmental management challenges. Several recent environmental incidents in Finnish mines have raised questions regarding mine site environmental and water management practices. This has increased public awareness of mining threats to the environment and resulted in stricter permits and longer permitting procedures. Water balance modelling aids in predictive water management and reduces risks caused by an excess or shortage of water at a mining site. In this study the primary objective was to exploit online water quantity and water quality measurements to better serve water balance management. The second objective was to develop and test mathematical models to calculate the water balance in mining operations. The third objective was to determine how monitoring and modelling tools can be integrated into the management system and process control. According to the experience gained from monitoring water balances, the main recommendation is that the data should be stored in a database where it is easily available for water balance calculations. For real-time simulations, online measurements should be available from strategically defined positions in the mine site. Groundwater may also act as a source or sink with respect to mine site surface water, and therefore monitoring and investigations should be designed to account for the full water balance. In Finland it is possible to calculate water balance for planning or for operative purposes by using the Watershed Simulation and Forecasting System (WSFS) developed at the Finnish Environment Institute (SYKE). This system covers every sub-basin (10-50 km2) over the whole of Finland. WSFS automatically obtains the latest observations of temperature, precipitation, water level, discharge and other needed data provided by the Finnish Meteorological Institute (FMI), SYKE, as well as other sources. The system also uses these observations to follow-up on simulation and forecasting accuracy. The water balance model was further developed to simulate and forecast the water balance at the Yara Siilinjärvi mine site. The WSFS-model was also extended with one-way coupling to the groundwater flow model. The model is operated via a web-based user interface and can produce water-balance forecasts automatically, if necessary, several times a day. The water balance and water flow in the area are simulated using real-time weather observations. The model enables forecasting water levels and planning discharges and pumping at the mine site. Possible uses of the model include preparation for spring floods by emptying ponds for storage of water from snow melt, estimation of the effect of heavy rainfall and calculating the required outflow from the mine site reservoir. Thus, overflows and dam-breaks can be avoided and consequently prevent the leakage of contaminated water. Furthermore, as the model can be modified to simulate changes at the mine site, it can also be beneficial during the mine site-planning process. The water balance model is currently operational for Yara Siilinjärvi mine site and hydrological forecasts are produced on a daily basis. Water level, discharge and pumping data, essential for modelling the area, are provided by the mine operator and EHP-Tekniikka Ltd. The model uses meteorological observations and forecasts from FMI as inputs for the simulations and forecasts. In addition to the accurate weather forecasts, the real time observations are a key factor in the accuracy of the model forecasts. GoldSim is the most popular commercial simulation software solution chosen, not only by mines worldwide, but also in many other sectors. One of the main reasons for its extensive use is its versatility and the ability to expand the program as the needs of the mine require. As the mine project progresses, one of GoldSim’s strongest assets is risk analysis at different phases during both the planning and execution of mine operations. The use of the GoldSim platform was tested during the project and some new features were developed. The project has paid special attention to commercialization of the developed products and well thought out policies for possible joint bids.