331 research outputs found

    Hirvien aiheuttamat satomenetykset pajuviljelmällä.

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    Stump sprouting in an Alnus-Betula-Salix stand following fertilization.

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    Havaintoja Keski-Eurooppaan tehdyltä opintomatkalta 14.6. -1.7.1980

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    2 liitett

    Paju- ja poppelipistokkaiden juurtuminen. Tuloksia vuoden 1976 juurruttamiskokeista

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    Estimation of wastewater flowrate in a gravitational sewer line based on a low-cost distance sensor

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    AbstractWastewater flowrate exhibits valuable information on the conditions in a sewer line. However, existing hardware flowrate sensors are rather expensive, vulnerable to fouling and breakages, and require frequent and laborious maintenance. Therefore, they are typically only mounted in a few key locations of a sewer system, leading to a lack of important information in a major part of the network. Utilizing more cost-effective sensors and a soft sensor approach is advisable for estimating the flowrate at locations where hardware sensors are lacking. Here, the development and testing of a data-driven soft sensor for estimating the wastewater flowrate based on the water level information obtained from a low-cost ultrasonic distance sensor are presented. The research included a long-term functionality testing period of the sensor in a cold region. The soft sensor-based flowrate was applied to estimate inflow and infiltration, indicating the conditions of the sewer line. The harsh conditions inside the sewer manhole caused challenges for the reliability of the distance measurement based on an ultrasonic principle. With the developed model-based soft sensor, it seems possible to accurately estimate the wastewater flowrate. Together with additional information, it might also enable accurate monitoring of inflows and infiltrations.Abstract Wastewater flowrate exhibits valuable information on the conditions in a sewer line. However, existing hardware flowrate sensors are rather expensive, vulnerable to fouling and breakages, and require frequent and laborious maintenance. Therefore, they are typically only mounted in a few key locations of a sewer system, leading to a lack of important information in a major part of the network. Utilizing more cost-effective sensors and a soft sensor approach is advisable for estimating the flowrate at locations where hardware sensors are lacking. Here, the development and testing of a data-driven soft sensor for estimating the wastewater flowrate based on the water level information obtained from a low-cost ultrasonic distance sensor are presented. The research included a long-term functionality testing period of the sensor in a cold region. The soft sensor-based flowrate was applied to estimate inflow and infiltration, indicating the conditions of the sewer line. The harsh conditions inside the sewer manhole caused challenges for the reliability of the distance measurement based on an ultrasonic principle. With the developed model-based soft sensor, it seems possible to accurately estimate the wastewater flowrate. Together with additional information, it might also enable accurate monitoring of inflows and infiltrations

    Incentives for organizations to publish software source code

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    The software stack opened under Open Source Software (OSS) licenses is growing rapidly. Commercial actors have released considerable amounts of previously proprietary source code. These actions beg the question why companies choose a strategy based on giving away software assets? Research on outbound OSS approach has tried to answer this question with the concept of the “OSS business model”. When studying the reasons for code release, we have observed that the business model concept is too generic to capture the many incentives organizations have. Conversely, in this paper we investigate empirically what the companies’ incentives are by means of an exploratory case study of three organizations in different stages of their code release. Our results indicate that the companies aim to promote standardization, obtain development resources, gain cost savings, improve the quality of software, increase the trustworthiness of software, or steer OSS communities. We conclude that future research on outbound OSS could benefit from focusing on the heterogeneous incentives for code release rather than on revenue models

    Life Cycle Analysis of Convective Cells through Image Processing and Data Fusion

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    Nykyaikana numeeriset säänennustusmallit pystyvät ennustamaan suuren skaalan sääilmiöitä merkittävällä tarkkuudella. Nämä mallit ovat kuitenkin liian karkeita pienen skaalan sääilmiöille, kuten paikallisille ukkosmyrskyille. Paikallinen, lyhyen ajan säänennustaminen eli lähihetkiennustaminen on haastava meteorologinen ongelma. Tämä vaatii erityisesti ajallisesti ja paikallisesti tarkkojen modernien kaukokartoitusinstrumenttien sekä tietokonenäköön perustuvien menetelmien soveltamista. Tämä diplomityö käsittelee paikallisten ukkosmyrskyjen eli konvektiosolujen lähihetkiennustamista. Erityisesti tarkastelemme oliopohjaista konvektiosolun jäljitystä, joka on yleisesti käytetty lähestymistapa ukkosen lähihetkiennustamisessa. Perinteisesti konvektiosolun lähihetkiennustamiseen sovelletaan säätutkadataa. Työ esittelee uuden konvektiosolujen jäljitysmenetelmän, joka hyödyntää sekä säätutka- että salamainformaatiota. Koska salamadata antaa tärkeää lisäinformaatiota ukkosmyrskyjen paikasta ja liikkeestä, uusi datafuusiopohjainen menetelmä parantaa algoritmin toimintavarmuutta. Työssä testataan algoritmin toimintaa useiden esimerkkitapausten avulla. Suunniteltu jäljitysmenetelmä tarjoaa tärkeän apuvälineen moniin käytännön tarkoituksiin. Ensisijainen sovelluskohde on vaarallisten konvektiosolujen monitorointi sekä liikkeen ennustaminen. Lisäksi menetelmää voidaan soveltaa ukkosen elinkaaren ja ominaisuuksien analysointiin. Tämä työ tarkastelee ukkossolun tilastollisia ominaisuuksia uuden jäljitysmenetelmän avulla. Menetelmällä tuotettua informaatiota sovelletaan myös solun salamoinnin ja erilaisten tutkaparametrien välisen yhteyden analysointiin. Lisäksi työssä suunnitellaan probabilistiseen päättelyyn perustuva malli, jonka avulla voidaan tarkastella yksittäisen konvektiosolun salamariskiä. Työssä suunnitellaan myös uusi sumeaan logiikkaan perustuva automaattinen asiantuntijamalli, jonka avulla voidaan antaa informaatiota konvektiosolun elinvaiheista. Mallin päätehtävä on analysoida asiantuntijan tavoin konvektiosolun voimistumista tai heikkenemistä.Today numerical weather models can predict large scale weather phenomena with a reasonable accuracy. Still, these models are too coarse for small scale rapidly changing weather phenomena, such as thunderstorms. Therefore, doing short term local forecasts, i.e. nowcasting, is a challenging task for the contemporary weather forecasting. State-of-the-art remote sensing instruments and computer vision techniques are the key to this challenging task. This thesis discusses nowcasting of thunderstorms, i.e. convective cells, through different computer vision techniques that are applied to spatially and temporally accurate weather radar and lightning data. Emphasis is on object-oriented convective cell tracking, which is widely accepted as an important concept regarding the nowcasting of convective cells. Conventionally, the nowcasting of convective cells is performed through weather radar data. In this thesis, we propose a novel cell tracking method, which fuses both weather radar and important lightning information. The aim of the data fusion is to consolidate the tracking, as more information is incorporated in the procedure. The functioning of the algorithm is tested with several case studies. The proposed tracking algorithm provides an important tool for several applications. Primarily, convective cell tracking is applied to monitoring and predicting movement of hazardous thunderstorms. It can also be used for analyzing cell properties and life cycle. Therefore, this thesis examines also convective cell properties and derives descriptive statistic of the convective cell by means of the proposed tracking algorithm. The results are based on tests, which are carried out through an extensive case material provided by the Finnish Meteorological Institute. The thesis elaborates also on the lightning properties of the convective cell. The information extracted by the tracking algorithm is applied to analyze the relationship between lightning and different radar parameters within the cell. In addition, probabilistic reasoning is applied to determine possible lightning hazard of individual cells. Finally, this thesis proposes a new fuzzy logics model for analyzing cell life cycle phases. The model provides an automated method, which mimics expert made reasoning and infer whether the cell is intensifying or dissipating
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