Graafinen ekvalisointi taajuusvarpattujen digitaalisten suotimien avulla

The aim of this thesis is to design a graphic equalizer with frequency warped digital filters. The proposed design consists of a warped FIR filter for the low frequency bands and a standard FIR filter for the high frequency bands. This de- sign is used to implement both an octave and a one-third octave equalizer in Matlab. Low frequency equalization with FIR filters requires high filter orders. The frequency resolution of the lowest band of the graphic equalizer requires filter orders that are impractical for real life applications. With frequency warping filter orders can be lowered, so that a practical graphic equalizer can be designed. With this design common gain build-up problems, which are present in most of the IIR designs, can be avoided. The proposed equalizer design is found to be accurate and comparable to the previous equalizer designs. Filter orders required are small enough to this design to be used in real life applications. The gain build-up problem is avoided in this design, as several equalizer bands are filtered with a single filter. The computational costs of the design are higher than the costs of the other compared designs. However, the difference can be smaller if the accuracy restrictions are lowered.Tämän työn tavoitteena on suunnitella graafinen ekvalisaattori taajuusvarpattujen digitaalisten suotimien avulla. Ehdotettu ekvalisaattorimalli koostuu taajuusvarpatusta ja tavallisesta FIR suotimesta. Varpattua suodinta käytetään alimpien taajuuskaistojen suodattamiseen ja tavallista FIR suodinta ylimpien kaistojen suodattamiseen. Tätä mallia käytetään sekä oktaavi- että terssikaista-ekvalisaattorien totetutamiseen Matlabilla. Matalien taajuuksien ekvalisointi edellyttää korkeaa astelukua FIR suotimilta. Alimpien taajuuskaistojen taajuusresoluutio edellyttää astelukuja, jotka ovat epäkäytännöllisiä tosielämän sovelluksissa. Taajuusvarppauksella suotimien astelukuja voidaan pienentää, jolloin graafinen ekvalisaattori voidaan toteuttaa käytännössä. Tällä mallilla voidaan välttää IIR ekvalisaattorien yleinen ongelma, jossa ekvalisaattorien kaistojen vahvistus vaikuttaa viereisiin kaistoihin. Ehdotettu ekvalisaattorimalli todetaan olevan tarkka ja vertailukelpoinen aikaisempien toteutuksien kanssa. Suotimien asteluvut ovat tarpeeksi pieniä, jotta tätä mallia voidaan käyttää tosielämän toteutuksissa. Kaistojen välinen vaikutus vältetään tällä mallilla, sillä useampi kaista suodatetaan yhdellä suotimella. Laskennallinen kuorma on tällä toteutuksella suurempi kuin muilla vertailluilla toteutuksilla. Eroa voidaan pienentää, jos ekvalisaattorin tarkkuusvaatimuksia lasketaan

Development of Organic Food Production in some European Countries

The aim of the study was to compare the development of organic food production in eight European countries: Austria, Denmark, Estonia, France, Finland, Germany, Norway and Sweden. The comparison was done between years 1998 and 2014. Many countries have set similar targets for organic agriculture: the most general for the production is 20 % of the field area before year 2020. Austria as the first European country has already reached it, but it had an earlier start for the organic development. Best practices to increase production are better targeted subsidies, national development programs with precise goals and proper actions to reach them and co-operation between farmers and research. Best countries in consumption of organics are Denmark, Sweden and Austria. The best methods to increase the consumption in Denmark were providing information to the consumers (pesticides, when found) and efficient marketing campaigns. The municipality level programs to enhance the welfare of the nature and humans by including organic food into public catering were effective especially in Denmark and Sweden. The diversification of production has been made possible with policy actions and national level decisions to better target subsides e.g. for plants and products that need an increase in production (Austria, Estonia, Finland, France, Germany, Sweden). The reasons for the differences pointed out, are basically cultural. In some countries organic food production is more generally accepted and promoted (Austria, Denmark, Sweden) than in others. In some countries consumers are actively demanding organic food (France, Denmark, Sweden). If the conventional production is considered good enough by the citizens, national food policy is targeted to that more than to organic production (Norway, Finland)

Paikallista luomuruokaa kuluttajalle - ketjukokeiluja Etelä-Savossa

Toimittanut Sinikka Mynttine