<p>In this thesis, a computer program that in a simple way can calculate the performance of control loops at the refinery Preemraff Lysekil has been created. The computer program has been adapted to the environment at Preemraff Lysekil. Theories for evaluation has been studied in aspect of reliability and of automatic implementation. The evaluation has been carried out from data collected directly from control loops at the refinery and from simulated control loops with implemented errors. </p><p>Among the studied methods are Harris index and Stattin´s oscillation index. According to the literature the Harris index is the most used for measure of control performance, but the results show that it does not work as a single measure at Preemraff Lysekil. However Stattin´s oscillation index works well and can be used for detection of oscillations. Statistic measures like variance, IAE, ISE and a method based on histogram are also studied. All the statistical measures are simple to implement and are rather accurate. Several tests on control loops has been carried out and it has been shown that it ís enough to use the method based on histograms and Stattins oscillation index to get a good picture of the performace of the control loops at Preemraff Lysekil. </p><p>The work has resulted in a MATLAB tool that evaluates the control loops and can be run at any time. The tool first calculates Stattin´s oscillation index. The loops that are oscillating are marked. In the next step, the method based on histograms is used and a list with the worst performing loops at the top is created.</p>

In this thesis, a computer program that in a simple way can calculate the performance of control loops at the refinery Preemraff Lysekil has been created. The computer program has been adapted to the environment at Preemraff Lysekil. Theories for evaluation has been studied in aspect of reliability and of automatic implementation. The evaluation has been carried out from data collected directly from control loops at the refinery and from simulated control loops with implemented errors. Among the studied methods are Harris index and Stattin´s oscillation index. According to the literature the Harris index is the most used for measure of control performance, but the results show that it does not work as a single measure at Preemraff Lysekil. However Stattin´s oscillation index works well and can be used for detection of oscillations. Statistic measures like variance, IAE, ISE and a method based on histogram are also studied. All the statistical measures are simple to implement and are rather accurate. Several tests on control loops has been carried out and it has been shown that it ís enough to use the method based on histograms and Stattins oscillation index to get a good picture of the performace of the control loops at Preemraff Lysekil. The work has resulted in a MATLAB tool that evaluates the control loops and can be run at any time. The tool first calculates Stattin´s oscillation index. The loops that are oscillating are marked. In the next step, the method based on histograms is used and a list with the worst performing loops at the top is created.

Magistriniame darbe įvertinamas Ignalinos atominės elektrinės ir gamtinių sąlygų poveikis terminiam Drūkšių ežero režimui. Tyrimo tikslas – įvertinti Ignalinos atominės elektrinės ir gamtinių sąlygų poveikį terminiam Drūkšių ežero režimui. Tyrimo objektas – atominė elektrinė ir Drūkšių ežeras. Nuo l984 m. Lietuvos didžiausias Drūkšių ežeras pradėjo tarnauti kaip Ignalinos atominės elektrinės (IAE) aušintuvas. Todėl natūralus hidrologinis režimas ir šilumos balansas ežere buvo sutrikdyti. Ypač pakito Drūkšių ežero terminis režimas. Vidutiniškai Drūkšių ežero vandens temperatūra pakilo apie 3,5 ºC. Tačiau pastaraisiais metais Lietuvoje stebimos klimato atšilimo tendencijos. Per pastaruosius dešimtmečius vidutinė oro temperatūra padidėjo apie 1 ºC. Oro temperatūros augimas taip pat turėjo įtakos visų vandens telkinių, tuo pačiu ir Drūkšių ežero vandens temperatūrai. Todėl tiek antropogeniniai veiksniai (atominė elektrinė), tiek gamtiniai veiksniai (klimato kaita) turi įtakos Drūkšių ežero terminiam režimui. Lietuvos energetikos instituto ir kitų mokslinių institucijų darbuotojai atliko daug tyrimų, susijusių su Drūkšių ežero hidrologine, hidrotermine bei ekologine būkle. Tačiau šiuose tyrimuose mažai dėmesio buvo skirta gamtinės kaitos įtakos Drūkšių ežero terminiam režimui nustatymui. Šio tyrimo tikslas buvo įvertinti atominės elektrinės ir gamtinių sąlygų poveikį terminiam Drūkšių ežero režimui. Norint įvertinti Drūkšių ežero terminio režimo pokyčius veikiant IAE... [toliau žr. visą tekstą] / The paper evaluated the Ignalina nuclear power and natural conditions, the thermal effect of the lake Drūkšiai regime. Purpose of the survey - to assess the Ignalina nuclear power and natural conditions on the thermal regime of Lake Drūkšiai. The object of research - nuclear power and natural environment impacts. Since l984, the Lithuanian Drūkšiai largest lake began to serve as the Ignalina Nuclear Power Plant (INPP) cooler. Therefore, the natural hydrological regime and heat balance in the lake has been disturbed. In particular, changes in lake thermal regime Drūkšiai. On average, Drūkšiai lake temperature has risen approximately 3.5 ° C. However, in recent years, Lithuania observed warming trends. Over the past decades, the average air temperature increased about 1 ° C. Air temperature rise is also affected by the water at the same time and lake water temperatures. Therefore, both anthropogenic factors (NPP) and natural factors (climate change) affect the thermal regime of Lake Drūkšiai. Lithuanian Energy Institute and other scientific staff, the large number of tests and touching Drūkšiai lake hydrology, hydrothermal and ecological condition. However, these studies little attention was given to natural changes affect Drūkšiai lake thermal regime. Purpose of this study was to evaluate nuclear power and natural conditions on the thermal regime of Lake Drūkšiai. To assess Drūkšiai Lake thermal regime change operation IAE... [to full text]

A população de foraminíferos e tecamebas no SELCI evidenciou variação espacial, caracterizando alta dominância de hialinos e porcelanáceos no verão, e aglutinantes no inverno. Essa distribuição da microfauna estava associada a maior influência marinha dos setores externos e a forte influência do regime regional de chuvas nos setores internos. Constatou-se como bioindicadores a espécie Pararotalia cananeiaensis indicando o alcance da cunha salina nas porções internas do sistema, os miliolídeos indicando ambientes com renovação de águas marinhas e fluxos mais energéticos no sistema, o gênero Miliammina spp. e as tecamebas indicando ambientes de baixa salinidade. Através do Ic foi possível detectar o impacto do balanço entre as influências continentais e marinhas no sistema, com a intrusão salina sazonalmente distinta, devido às próprias condições regionais e geomorfológicas do sistema. Na tentativa de encontrar ambientes hipóxicos foi aplicado o IAE, porém este índice não gerou resultados satisfatórios neste sistema estuarino, visto que outros fatores representaram ser variáveis mais importantes do que a concentração de oxigênio dissolvido. O cálculo da BFAR foi testado revelando que a geomorfologia do SELCI foi um fator determinante na distribuição das espécies e que a BFAR foi uma medida qualitativa do fluxo de MO no sistema. Através das análises estatísticas multivariadas foi possível determinar as associações da microfauna, sendo estas condicionadas, nas duas campanhas, principalmente pelos fatores salinidade, substrato e profundidade. / The population of foraminifera and thecamoebians in the CILES (Cananéia-Iguape Lagoon Estuarine System) evidenced spatial variation, characterizing high dominance of hyalines and porcelanaceous during the summer and agglutinated in the winter. This microfauna distribution was associated to stronger marine influence in the outer sections and to strong regional pluviosity in the inner sections. The bioindicator species were Pararotalia cananeiaensis, evidencing the extent of the salt water wedge in the inner portion of the system, the miliolidae, indicating environments with renewal of marine water and more energetic fluxes in the system and the gender Miliammina spp. and thecamoebians indicating areas of low salinity. Trough the Ic it was possible to identify the impact of the balance between marine and fresh waters influence in the system, with saline intrusion seasonally distinct, due to the system\'s own regional and morphological conditions. An attempt to identify hypoxia areas was made using the AEI (Ammonia-Elphidium Index) test, however, this index did not reveal satisfactory results in this estuarine system, since other factors seem to be more representative than the dissolved oxygen concentration. The geomorphology of the CILES was proved to be a determinant factor in the distribution of the species through the BFAR (Benthic Foraminifera Accumulation Rate) calculation, which was also a qualitative measure of the flux of organic matter (TOC) in the system. Statistical analysis proved that the associations of microfauna, was driven, in both campaigns, by salinity, substract and depth.

A população de foraminíferos e tecamebas no SELCI evidenciou variação espacial, caracterizando alta dominância de hialinos e porcelanáceos no verão, e aglutinantes no inverno. Essa distribuição da microfauna estava associada a maior influência marinha dos setores externos e a forte influência do regime regional de chuvas nos setores internos. Constatou-se como bioindicadores a espécie Pararotalia cananeiaensis indicando o alcance da cunha salina nas porções internas do sistema, os miliolídeos indicando ambientes com renovação de águas marinhas e fluxos mais energéticos no sistema, o gênero Miliammina spp. e as tecamebas indicando ambientes de baixa salinidade. Através do Ic foi possível detectar o impacto do balanço entre as influências continentais e marinhas no sistema, com a intrusão salina sazonalmente distinta, devido às próprias condições regionais e geomorfológicas do sistema. Na tentativa de encontrar ambientes hipóxicos foi aplicado o IAE, porém este índice não gerou resultados satisfatórios neste sistema estuarino, visto que outros fatores representaram ser variáveis mais importantes do que a concentração de oxigênio dissolvido. O cálculo da BFAR foi testado revelando que a geomorfologia do SELCI foi um fator determinante na distribuição das espécies e que a BFAR foi uma medida qualitativa do fluxo de MO no sistema. Através das análises estatísticas multivariadas foi possível determinar as associações da microfauna, sendo estas condicionadas, nas duas campanhas, principalmente pelos fatores salinidade, substrato e profundidade. / The population of foraminifera and thecamoebians in the CILES (Cananéia-Iguape Lagoon Estuarine System) evidenced spatial variation, characterizing high dominance of hyalines and porcelanaceous during the summer and agglutinated in the winter. This microfauna distribution was associated to stronger marine influence in the outer sections and to strong regional pluviosity in the inner sections. The bioindicator species were Pararotalia cananeiaensis, evidencing the extent of the salt water wedge in the inner portion of the system, the miliolidae, indicating environments with renewal of marine water and more energetic fluxes in the system and the gender Miliammina spp. and thecamoebians indicating areas of low salinity. Trough the Ic it was possible to identify the impact of the balance between marine and fresh waters influence in the system, with saline intrusion seasonally distinct, due to the system\'s own regional and morphological conditions. An attempt to identify hypoxia areas was made using the AEI (Ammonia-Elphidium Index) test, however, this index did not reveal satisfactory results in this estuarine system, since other factors seem to be more representative than the dissolved oxygen concentration. The geomorphology of the CILES was proved to be a determinant factor in the distribution of the species through the BFAR (Benthic Foraminifera Accumulation Rate) calculation, which was also a qualitative measure of the flux of organic matter (TOC) in the system. Statistical analysis proved that the associations of microfauna, was driven, in both campaigns, by salinity, substract and depth.