57 research outputs found
Integrating object detection with 3d tracking towards a better driver assistance system
No full textDriver assistance helps save lives. Accurate 3D pose is required to establish if a traffic sign is relevant to the driver. We propose a real-time system that integrates single view detection with region-based 3D tracking of road signs. The optimal set of candidate detections is found, followed by AdaBoost cascades and SVMs. The 2D detections are then employed in simultaneous 2D segmentation and 3D pose tracking, using the known 3D model of the recognised traffic sign. We demonstrate the abilities of our system by tracking multiple road signs in real world scenarios.Victor Adrian Prisacariu, Radu Timofte, Karel Zimmermann, Ian Reid, Luc Van Goo
Combining traffic sign detection with 3D tracking towards better driver assistance
No full textWe briefly review the advances in driver assistance systems and present a real-time version that integrates single view detection with region-based 3D tracking of traffic signs. The system has a typical pipeline: detection and recognition of traffic signs in independent frames, followed by tracking for temporal integration. The detection process finds an optimal set of candidates and is accelerated using AdaBoost cascades. A hierarchy of SVMs handles the recognition of traffic sign types. The 2D detections are then employed in simultaneous 2D segmentation and 3D pose tracking, using the known 3D model of the recognized traffic sign. Thus, we achieve not only 2D tracking of the recognized traffic signs, but we also obtain 3D pose information, which we use to establish the relevance of the traffic sign to the driver. The performance of the system is demonstrated by tracking multiple road signs in real-world scenarios.Radu Timofte, Victor Adrian Prisacariu, Luc Van Gool, and Ian Rei
The Influence of the Developmental Stage and Culture Medium upon the Somatic Embryo Induction in <i>Quercus petraea</i>
Get PDFThe somatic embryogenesis is an advanced method for clonal propagation and a useful tool for ex situ conservation of genetic resources. In this paper an experimental device was designed, composed of: one oak species (Quercus petraea), one provenance, four types of explants (developmental stages of the zygotic embryo) and four variants of culture medium. It was released the two-way statistical analyses of the two analyzed factors affecting the embryo induction efficiency: the stage of explant and culture medium (4 stages x 4 culture media). The most important factor affecting the efficiency of somatic embryogenesis was found to be the developmental stage of the zygotic embryos used as juvenile explants. The high embryogenic ability of young zygotic embryos and low embryogenic ability of maturing zygotic ones showed the strong positive relationship between somatic embryo induction and accumulation of reserve nutrients in cotyledons. The best results were obtained with the youngest embryos (stage 1), with a linear decrement towards the stage 4. The embryo induction efficiency ranged between 44% and 10% in Q. petraea. Two nutritive culture media and two growth hormone combinations were tested. The effect of culture medium proved to be totally insignificant, besides the differences observed among the variants cultivated on different media. The situation was the same as well for the nutrients as for growth regulators
Review of: Eva Blome: Reinheit und Vermischung. Literarisch-kulturelle Entwürfe von ‚Rasse‘ und Sexualität (1900–1930). Köln u.a.: Böhlau Verlag 2011.
No full textEva Blome setzt sich in ihrer umfassenden Dissertation erstmalig aus literaturwissenschaftlicher Perspektive mit den interdiskursiven Transformationen des Themas ‚Rassenmischung‘ im deutschen kolonialen Kontext auseinander. Die Autorin nimmt den Einsatz der ‚Rassenmischung‘ als biopolitische und poetologische Argumentationsfigur in den Fokus, indem sie die deutschsprachige Kolonialliteratur um 1900 und die Kunst und Literatur des europäischen Primitivismus behandelt und sich abschließend mit den Kultur- und Rassentheorien der Weimarer Republik beschäftigt. Zentrale Verdienste des Buches liegen darin, dass eine Forschungsnische gefüllt und weiterführende Forschungsfragen zum Thema ‚rassisch‘ transgressiver Sexualität aufgeworfen werden.For the first time, Eva Blome’s comprehensive dissertation deals with the interdiscoursive transformations of the topic ‘miscegenation’ in the German colonial context from a literary studies perspective. In discussing the German-language colonial literature from around 1900 and the art and literature of European primitivism and in conclusively dealing with theories of culture and race of the Weimar Republic, the author focuses on the usage of ‘miscegenation’ as a biopolitical and poetological figure of reasoning. The book’s most central merits are that it fills a research niche and that it poses additional research questions on the topic of ‘racially’ transgressive sexuality
The Effect of Different Factors upon the in vitro Propagation in Quercus robur and Q. frainetto by Somatic Embryogenesis
Get PDFThe somatic embryogenesis is an advanced method for clonal propagation and a useful tool for ex situ conservation of genetic resources. In this paper, the results of an experiment to investigate the influence of development stage of explants and culture medium on the germination percentage in two oak species (three provenances of Quercus robur and two provenances of Q. frainetto), are presented. A high significant influence of the development stage of explants and a significant influence of the interaction provenance x stage on the germination percentage were recorded for Q. robur explants, whilst no significant differences between the germination percentages against the nutritive media used were fould for both oak species
Mycorrhizal status of several Quercus species in Romania (Quercus cerris, Q. frainetto, Q. robur) and the optimization perspective of growth conditions for in vitro propagated plants transplanted in the field
No full textThere is an increasing interest for important tree species conservation in the context of climate change, anthropogenic pressure and invasion of alien tree species. A key factor in the survival of trees is represented by the mycorrhizal association. The success of micropropagated trees also depends on the acquisition of mycorrhizal mutualists. Ectomycorrhizal roots samples from several Quercus species (Q. cerris, Q. frainetto, Q. robur) were examined for mycorrhizal morphotypes’ characterization. The samples were collected during the vegetation season from stands located in Southern and North-Western Romania. 30 morphotypes of active mycorrhizaewere identified with Cenococcum geophilum Fr. (Ascomycota) asdominating morphotype. Previous studies on somatic embryogenesis inQ. robur and Q. frainetto demonstrated the utility of in vitro techniques in obtaining plants from these recalcitrant seed producing species, considered at risk in various areas of the country, due to increasingly stressful conditions. The success rate of the acclimatization process depends on the mycorrhization performed either artificially, in the laboratory, either naturally, in the field. Ex situ mycorrhization solutions are considered as less costly, yet efficient alternative to improve the ex vitro survival ofmicropropagated plants or endangered tree species or for those with economic importance, in vitro propagation is an important conservation tool combined with the acquisition of appropriate mycorrhizal mutualists
Homogenization of pseudoparabolic reaction-diffusion-mechanics systems [Elektronisk resurs] : Multiscale modeling, well-posedness and convergence rates
No full textIn this dissertation, parabolic-pseudoparabolic equations are proposed to couple chemical reactions, diffusion, flow and mechanics in heterogeneous materials using the framework of mixture theory. The weak solvability is obtained in a one dimensional setting for the full system posed in a homogeneous domain - a formulation which we have obtained using the classical mixture theory. To give a glimpse of what each component of the system does, we illustrate numerically that approximate solutions according to the Rothe method exhibit realistic behaviour in suitable parameter regimes. The periodic homogenization in higher space dimensions is performed for a particular case of the initial system of partial differential equations posed in perforated domains. Besides obtaining upscaled model equations and formulas for computing effective transport coefficients, we also derive corrector/convergence estimates which delimitate the precision of the upscaling procedure. Finally, the periodic homogenization is performed for a thin vanishing multidomain. Corrector estimates are obtained for a comb-like domain placed on a thin plate in a monotone operator setting for pseudoparabolic equations.</p
ECONOMIC ASPECTS REGARDING THE EXTRACTION OF WOOD USING HORSES: A CASE STUDY
Get PDFThis study was embarked upon to evaluate the performance of micro broiler businesses in Calabar metropolis. The objectives of the study included; to describe the socioeconomic characteristics of broiler business owners, to analyse the effects of selected socio-economic characteristics of micro broiler business owners on the survival of micro broiler businesses in Calabar metropolis, and to analyze the marketing mix and managerial practices of business owners in Calabar metropolis. It made use of primary data obtained from a random sample of 112 micro broiler operators. The data were analyzed using descriptive statistics, and Ordinary Least Square Multiple regression approach. The result of analysis revealed that micro broiler business ownership is almost evenly distributed among males 47.32 percent and females 52.68 percent; and that more than half (56.25 percent) of the respondents are within the age brackets of 36-45 years. The study also revealed that respondents had one form of formal education or the other with tertiary education accounting for 75.89 percent. On the survival/competitive advantage of micro broiler firms in the study area, the result of Ordinary Least Square analysis showed that output of broiler, flock size, business experience, mortality and extension contact significantly contributed to a firm survival in broiler business. The study revealed that firms applied some management practices and marketing mix activities in operating their businesses. The managerial practices adopted and their mean weights included; planning (M = 3.80), organizing (M = 3.47), directing (M = 3.80), coordinating (M = 3.63) and controlling (M = 3.91). Also, the analysis showed that the marketing mix practices adopted and their mean values were; product (M = 3.23), price (M = 3.04), place (M = 3.77) and promotion (M = 2.26). The study shows that micro broiler operators showed positive attitude to all the management function and marketing mix practices. The study recommended that micro broiler operators should organize themselves into cooperative societies to enable them enjoy the benefits of economies of size and credit facilities from lending agencies. It was also recommended that relevant extension services should be made available to broiler operators to improve their skills and knowledge in broiler business operations. Policy action of government should be directed towards capacity utilization of operators. Also, subsidies should be provided for cost of feeds and day old chicks as well as instituting a flexible credit policy to reduce cost of production
Severe weather events in Moldavia region, on June 23, 2019
Get PDFThe forecast of torrential rainfall is quite laborious and sometimes difficult. The difficulty lies in estimating the quantitative threshold and the spatial distribution of rainfall. Such a study is necessary because it has been found that in the last 30-40 years, the severity of convective phenomena has increased. Through such studies, it is desired to improve the short and very short-term weather forecasts, so that the population and the authorities can limit, as much as possible, the damage in the field. In operational meteorology we constantly work with the concepts of isobars, isohypses, isohyets. In our study, we used another meteorological parameter, less used in the operative routine (in addition to those commonly used) - the equipotential temperature, respectively the map of vertical section with the distribution of isentropes, to analyze severe meteorological phenomena, which took place in the Moldavia region. Forecasts are easy when forecast models are heading in the same direction. But, things get complicated when the atmospheric instability is much more severe than initially anticipated and the phenomena are in full development. The solution to this is found in the fact that the forecasting activity also has a special segment - very short-term forecasts, namely nowcasting forecast (which is based on the interpretation of radar imaging). In this paper, such an example is presented. Due to minor changes in the air circulation in the lower troposphere, the convective phenomena were much more severe than those anticipated by the forecast models. On June 23, 2019, 23 immediate warning messages were issued until midnight, regarding torrential rains, storms and hail. From those issued, 21 were orange code warnings and 2 were red code warnings. In this way, the authorities intervened in due time, so that the losses in the field were minimized as much as possible
RADIOMETRIC MEASUREMENTS IN EASTERN MOLDAVIA. CORRELATIONS BETWEEN TOTAL CLOUDINESS AND THE SUNSHINE DURATION
Get PDFAbstract. Because during a period of time with clear sky, a maximum of solar radiation is obtained, it is obvious that the degree of sky coverage and the cloud type influence the sunshine duration and thus solar radiation (global solar radiation). In the case of both direct and diffuse solar radiations, cloudiness represents one of the key factors which influence their variation. Our purpose is to obtain information on some meteorological parameters (global, diffuse, direct solar radiations etc.) and to underline their close connection to the sunshine duration, as well as the degree of sky coverage, registered at the weather stations in the eastern part of Moldavia. Introduction A great amount of energy is emitted by the Sun into the cosmic space (5.316×10 27 cal ≈ 2.225×10 25 kJ in one minute). Out of this total amount, the Earth gets only a very small part (approximately a second billion part). Of the total amount of solar radiation at the upper limit of the atmosphere, 7% goes to the ultraviolet radiations, 47% goes to the visible radiations of the spectrum and 46% to the infrared radiations. In the solar spectrum, the maximum energy corresponds to the radiation with the wavelength of 0.475 μm, value which allowed for the calculus of the temperature at the Sun surface. Because the greatest part of solar radiation lays in the short-wavelength region, it was conventionally established that the solar radiation which comes from the Sun (direct and diffuse) should be named short wave radiation, unlike the radiations emitted by the atmosphere and the surface of the Earth, which are called long wave radiations (Neacşa, Berbecel, 1979)
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