Viorel Popescu

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Conservation of forest amphibians is dependent on finding the right balance between management for timber production and meeting species' habitat requirements. For many pond-breeding amphibians, successful dispersal of the juvenile stage is essential for long-term population persistence. We investigated the influence of timber-harvesting practices on the(More)
Vector (multichannel) signal processing has arisen in the last decades as a major area of interest. The classical single-channel (scalar valued) processing techniques cannot deal with the interchannel dependencies, yielding to the development of new methods. This paper investigates two approaches to the median filtering of vector valued signals: filtering(More)
Primarily based on Serra's framework [5], mathematical morphology has become one of the most used nonlinear processing and analysis techniques. Later work extended the initially set operators to functions, in a general algebraic definition [4] for multidimensional scalar signals. The case of vector valued images (or signals) is not included in this theory.(More)
Understanding wildlife movements and habitat selection are critical to drafting conservation and management plans. We studied a population of eastern Hermann’s tortoise (Testudo hermanni boettgeri) in a traditionally managed rural landscape in Romania, near the northern edge of the species geographic distribution. We used telemetry to radio-track 24(More)
Rapid climate change represents one of the top threats to biodiversity, causing declines and extinctions of many species. Range shifts are a key response, but in many cases are incompatible with the current extent of protected areas. In this study we used ensemble species distribution models to identify range changes for 21 reptile and 16 amphibian species(More)
The Natura 2000 network is regarded as one of the conservation success stories in the global effort to protect biodiversity. However, significant challenges remain in Natura 2000 implementation, owing to its rapid expansion, and lack of a coherent vision for its future. Scientific research is critical for identifying conservation priorities, setting(More)
In this paper modeling, computer simulation, design approach and analysis for matrix converters input filter are presented. This filter design procedure makes possible to achieve the required EMI attenuation, the desired power factor and a high efficiency with a significant filter size reduction and minimum cost components. Also it is presented analyses of(More)
In contrast to its original version that deals with the band structure of periodically ordered solids more or less like any other all-electron band structure method, the modern version of the KKR (Korringa-Kohn-Rostoker) method represents the electronic structure of a system directly and efficiently in terms of its single-particle Green's function (GF).(More)