Automated Machine Learning Techniques for Data Streams

Automated machine learning techniques benefited from tremendous research progress in recently. These developments and the continuous-growing demand for machine learning experts led to the development of numerous AutoML tools. However, these tools assume that the entire training dataset is available upfront and that the underlying distribution does not change over time. These assumptions do not hold in a data stream mining setting where an unbounded stream of data cannot be stored and is likely to manifest concept drift. Industry applications of machine learning on streaming data become more popular due to the increasing adoption of real-time streaming patterns in IoT, microservices architectures, web analytics, and other fields. The research summarized in this paper surveys the state-of-the-art open-source AutoML tools, applies them to data collected from streams, and measures how their performance changes over time. For comparative purposes, batch, batch incremental and instance incremental estimators are applied and compared. Moreover, a meta-learning technique for online algorithm selection based on meta-feature extraction is proposed and compared while model replacement and continual AutoML techniques are discussed. The results show that off-the-shelf AutoML tools can provide satisfactory results but in the presence of concept drift, detection or adaptation techniques have to be applied to maintain the predictive accuracy over time.Comment: 11 pages, 14 figures, Originally published as https://essay.utwente.nl/80548 at the 32nd Twente Student Conference on IT Jan. 31st, 2019, Enschede, The Netherlands, Supervised by: dr. Doina Bucur, dr. Claudio Pinho Rebelo de S\'

Researches Concerning the Medicinal and Aromatic Herbs in the Caraşova Area

The area taken in the study is located in the South-West of Romania, in the northern Anina Mountains, area partial included in the National Park Semenic-Caras Gorge. The researches were conducted, for this reason, in buffer zones and the area of sustainable development where recovery is possible, and in the areas outside the park. Objectives taken into account refer to the identification of medicinal and aromatic herbs and quantitative assessment of the main medicinal species identified in the area

STUDIES CONCERNING THE ROCK VEGETATION IN THE CHEILE GLOBULUI NATURE RESERVE (SOUTH-WESTERN ROMANIA)

The area under study is located in South-Western Domasnea Mehadia Depression (Caras - Severin County), a typical intra-mountain depression, surrounded by the Almaj, Semenic, and Cernei Mountains. The Cheile Globului Nature Reserve goes along the Globul Craiovei River valley and is flanked by abrupt mountain slopes 100 - 200 m high above the watercourse. The rocky slopes vegetation is represented by four plant associations frequently met: Festucetum rupicolae Burduja et al. 1956, corr. Burduja et al. 1972-1973, Melico Phleetum montani Bo?caiu et al. 1966, Carpino orientalis Quercetum cerris Klika 1938 (Boscaiu et al. 1969), and Syringo Fraxinetum orni Borza 1958 em. Resmerita 1972 together with other two plant associations identified on smaller areas

ALLUVIAL AND LOWLAND HAY MEADOWS IN THE MEDIAN BASIN OF THE RIVER TIMI? (SOUTH-WESTERN ROMANIA)

In this paper we present some aspects concerning the chorology, floristic composition, syn-ecology, and dynamics of the alluvial and lowland hay meadows in the River Timi? basin. Agrostis stolonifera dominates depression areas with high moisture for the entire year, while meadows of Alopecurus pratensis can be found on plane lands that are moist in spring and drier in summer. Lowland hay meadows with Arrhenatherum elatius are fragmentary and are met on the flooding plain terraces and on slightly sloppy lands. On moister lands, not cultivated recently, around the villages, there are frequent coenoses edified by Elymus repens, together with Agrostis stolonifera and numerous species considered weeds

The Influence of Fertilization on Crop Quality and Field Beans (Vicia Faba L.)

Results obtained on the cambic chemozen soil Timisoara in thet good behaviour of the Montana cultivar in which, due to fertilising with N90P60K60 yield was over 2700 kg/ha. Content in protein depending on cultivar and nitrogen dose varied between 23,8% and 25.5%, and protein yield varied between 381 and 692 kg/h

Researces Regarding the Interaction Between Cultivating Variety – Fertilized – Planting Distance Between Rows at the Oilseed Rape

The research was made for quantification the interaction between cultivating variety –fertilized-planting distance between rows at the oilseed rape in the favorable pedoclimatic conditions for rape on the Vest Plain where can be obtained the highest productions. In this way, was studied to the influence of the fertilization upon the productions, at an assortment of seven rape varieties. The researched biological material was formed of seven rape varieties new for the reference area, as follows: Valesca, Orkane, Ader, Potomac, LG, Belini, Milena. To point the negative effect of the nitrogen fertilization, to optimize the doses upon the productions, was accounted the agrofond dose, in domain N0-N225. The research was made on a fund of P80 K80, so that varieties can expose their productive potential and the specific oil content. The results obtained accentuated the fact that the seven rape varieties studied, in the fertilization domain N0-N225, In average on the 4 agrofonds and the two distances between the rows, it resulted that in the researched area the most appropriate is Valesca variety, on which the harvest exceeded 2800 kg/ha. Varieties Milena, Potomac and Orkane registered harvests of over 2200 kg/ha. Yield increases obtained for the varieties fertilized with nitrogen at all doses level, are very significant. Distance between rows, represents a technological element studied in all the countries that cultivates autumn rapeseed. The results obtained in the experimental cycle, regarding this aspect, leads to the conclusion that for the studied varieties, a distance between 12,5 and 25 cm, ensures an harvest increase the exceeds 300 kg/ha. The researches results are important for the growers, because they increase the possibility to obtain productions higher than 3700 kg/ha

INFLUENCE OF FERTILISING ON YIELD AND GRAIN QUALITY IN MAIN WHEAT CULTIVARS IN THE WESTERN PLAIN

Experiments were carried out during the experimental cycle 2005-2007 in the Western Plain of Romania in order to improve cultivar structure and cultivar response to fertilization (influence on yield and bread-making quality).Regarding the climate, in the Western Plain of Romania is classified in the climatic region Cfbx (according to Monografia geografica a RPR, 1960); besides the general character, which is temperate-continental, the climate bears some Mediterranean influences.This means that the winters are milder and not too long, the springs are early and short, the summers are hot and the autumns are long, sometimes droughty.All these provide good conditions for the cultivation of winter wheat.Yield results in the Western Plain showed on the average for the three years and per experimental fertilization levels the following yields in the cultivars under study: Romulus 5,368 kg/ha, Partizanka 5,134 kg/ha, Europa 90 4,916 kg/ha, Alex 4664 kg/ha, and Flamura 85 4354 kg/ha

Monitoring the Impact of Electromagnetic Waves on Yield and Quality in Maize

Experimenting new technology of cultivating maize is an important step forward in order to optimise the yielding capacity if a crop that ranks second among crops cultivated worldwide and first among crops cultivated in Romania. Using low frequency radiations to stimulate yield and quality in maize allows increases in yield between 10 and 15% compared to the classical cultivation method and an improvement of the quality indicators (protein content increased with 6-11% determining an increase of the protein yield per ha; starch content increased with 7-14%, which also determined an increase of the starch yield per ha; while fat content, another indicator we monitored, increased with 2-6%)

Studies Concerning the Influence of Radiations on Biological Features During Imbibition and Sprouting

The method of stimulation with impulsive electro-magnetic resonance we have used is based on the action of the impulsive electro-magnetic field characterized by well-established frequencies. In establishing frequencies we have had in mind only frequencies that stimulate plant growth and improve quality. In this paper we present a study on the influence of these treatments on maize seed germination since electro-magnetic waves act on water structure in the cell with a beneficial effect on germination.    .   

Results in Ecological Technology Appliance for Cynara Scolymus L. at Cluj-Napoca

The artichoke (Cynara scolymus L.) is a biennial or perennial herbaceous plant, very sensitive at low temperatures during the Romanian winters, which is cultivated for her leaves with medicinal properties (Cynarae folium). The active constituents from leaves are: 0,2-0,3% cynarin (1,4-dicaffeilchinic acid); chlorogenic acid (3-caffeilchinic acid); caffeic acid; neoclorogenic acid; 1% polyphenol; 0,2% flavonoids (cynarozid-lutheoline-7 glycoside, scolimozyd-luteoline-7 rutinozyd, cynarotriozid-luteoline-7 rutynozid-4 glycoside); lactones sescviterpenice (cyneropitrine, dehidrocinaropitrine, groseimine); tarasterol (triterpenic alcohol) etc. Cynarin and polyphenols are used for their bile secretor and choleric properties. This study evaluates the yielding capacity of Unirea artichoke variety cultivated at Cluj-Napoca during experimental year 2007