To estimate the size of fish taken as prey by piscivorous predators, linear or non-linear relationships between bone measures (pharyngeal, opercula, cleithra, anal and dorsal spine bones, otoliths) and body length were elaborated for eleven Eurasian cyprinid fish species captured in three lakes of Turkey: rudd Scardinius erythrophthalmus, Baltic vimba Vimba vimba, Danube bleak Chalcalburnus chalcoides, gibel carp Carassius gibelio, roach Rutilus rutilus, silver bream Blicca bjoerkna, common carp Cyprinus carpio, chub Leuciscus cephalus, Dnieper chub Petroleuciscus borysthenicus, tench Tinca tinca and tarek Alburnus tarichi (endemic species for Lake Van). All calculated regressions were highly significant, with coefficients of determination >81% in most of cases. The results suggest that the biometric relationships between fish length and some bones (pharyngeal, opercula, cleithra) are well suited for use in prey-predator studies of all the studied species, but otoliths and the dorsal and anal spines can be used for some fish species only (rudd, Baltic vimba, roach, silver bream, gibel carp).
A comparison of the effects of ultrasound produced by low- and high-frequency ultrasonic apparatuses upon biological systems is one of the basic problems when studying ultrasound cavitation effects. One possibility for how to compare these effects is the indirect method which uses well-known physical quantities characterizing the interaction of ionizing radiation with matter and which also converts these quantities to one common physical quantity. The comparison was performed with two methods applied to the chemical dosimetry of ionizing radiation. The first method employed a twocomponent dosimeter which is composed of 50 % chloroform and 50 % re-distilled water (i.e. Taplin dosimeter). The other method used a modified iodide dosimeter prepared from a 0.5 M potassium iodide solution. After irradiation or ultrasound exposure, measurable chemical changes occurred in both dosimeters. The longer the exposure, the greater the chemical changes. These effects are described by the relationship of these changes versus the exposure times in both dosimeters. The UZD 21 ultrasonic disintegrator (with a frequency of 20 kHz, 50 % power output) was used as a lowfrequency ultrasound source, and the BTL-07 therapeutic instrument (with a frequency of 1 MHz and intensity of 2 W/cm2) was used as a high-frequency cavitation ultrasound source. For comparison, a 60Co gamma source was applied (60Co, gamma energies of 1.17 and 1.33 MeV, activity of 14 PBq). Results of this study have demonstrated that the sonochemical products are generated during exposure in the exposed samples of both dosimeters for all apparatuses used. The amount of these products depends linearly upon the exposure time. The resulting cavitation effects were recalculated to a gray-equivalent dose (the proposed unit is cavitation gray [cavitGy]) based on the sonochemical effects compared to the effects of ionizing radiation from the 60Co source., B. Kratochvíl, V. Mornstein., and Obsahuje bibliografii
Modern methods of monitoring landslides are based on observations of both: direct surveying (GNSS, electronic tachymetry, geometric levelling) and remote sensing (terrestrial and aerial photogrammetry, laser scanning, interferometry), as well as surface and subsurface geotechnical observations (e.g. inclinometers, extensometers, piezometers, etc.). Due to the high cost of installation of these devices and its measurement, the implementations of these methods are usually used on well-define d objects, with established landslide activity and high risk to people’s lives. The main objective of the project was to design, create and do practical tests of simple and inexpensive measurement devices, which detect first symptoms of a potential landslide movements and alert of an existing threat. These devices would be some kind of an early warning system that would register the occurrence of the first movements of the surface layers of soil, which would be a signal to start of geodetic and geotechnical monitoring of potential landslides., Bartłomiej Ćmielewski, Bernard Kontny and Kazimierz Ćmielewski., and Obsahuje bibliografické odkazy
In the deep and slightly eutrophic dam part of the Římov Reservoir (Czech Republic), the fish use of open water habitat was studied by means of gillnetting, hydroacoustics and diet analyses during the period from April to October 2005. The day and night acoustic surveys revealed majority of pelagic fish present in the upper 5 m of the water column. The highest gillnet catches of planktivorous fish in epipelagic waters were obtained in May and August. The lowest fish catches were recorded in April and October which resulted in significant positive correlation between the gillnet catch per unit effort and water temperature. The majority of captured fish were adults of three cyprinid species: roach Rutilus rutilus, bleak Alburnus alburnus and bream Abramis brama. In the early spring the food of the three species was diversified: bream consumed primarily cyclopoid copepods, bleak fed on terrestrial insects, and gut content of pelagic roach consisted mainly of littoral food components, algae and detritus. In the late spring and summer however, the diets of all three cyprinids were predominated by large cladocerans, thus proving the use of open water habitat abundant in this prey.
Size-frequency data were collected for two rheophilic fish species, Cottus perifretum and Leuciscus cephalus, at the confluences of 18 lowland tributaries along the regulated River Meuse (the Netherlands) between May 2004 and April 2005. Cottus perifretum is a resident species, using these stream mouth habitats throughout its entire life: i.e. as a spawning, nursery and adult habitat. Leuciscus cephalus is a transient species that uses these stream mouth habitats only as a temporary 0+ juvenile habitat during fall and early winter. This study suggests that the stream mouth habitats along the River Meuse fulfil different ecological functions for C. perifretum and L. cephalus.
A new method of wild boar, Sus scrofa (Linnaeus), census tentatively called the “Carpathian technique” was tested in Poland during February and March 2000–2004. This method is based on the relationship between absolute population density (N/1000 ha of forest) and a snow track index (T/Km x day-1). The absolute density of wild boar was estimated on the basis of 177 sampling plots, of 400–500 ha. Snow tracks of wild boar were counted along line transects with a total length of 4,442 km. High correlation (r=0.59 - 0.88) between the density of tracks counted along line transects (T/Km*day-1) and species density calculated from sampling plots (N/1000 ha) has been obtained. This relationship was employed to calculate the density of wild boar in 58 Forest Districts and 2 National Parks. In forest districts and National Parks, the lowest density of wild boar i.e. 0.49 animals/1000 ha of forest was recorded in Bieszczady Mountains, and the highest density (120.7 individuals/1000 ha) was recorded in the Myślibórz Forest District. Over respective regions (that includes several forest districts and the sampled National Parks), density of wild boar was the lowest in Carpathian and Sudety Mountains, near density = 4.06 animals/1000 ha, while in north-eastern and southern lowland regions density varied from 9.0 to 19.71 animals/1000 ha, respectively. The highest density (36.7 animals/1000 ha) was recorded in north-western lowland forest region.
The article deals with the description and creation of a parametric model of the generator s stator winding coil using the Unigraphics(NX program. It contains a detailed procedure for designing a parametric model, including the creation of basic planes, link to another application, and entering parametric environment.
In the real-life engineering practice, non-linear regression models have to be designed rather often. To ensure their technical or physical feasibility, such models may, in addition, require another coupling condition. This paper describes two procedures for designing a specific non-linear model using AI methods. A Radial Basis Functions (RBF) based optimization is presented of the model using Genetic Algorithms (GA). The problem solved was based on practical measurements and experiments. The results presented in the paper can be applied to many technical problems in mechanical and civil engineering and other engineering fields. and Obsahuje seznam literatury
The mobile robot path planning involves finding the shortest and least difficult path from a start to a goal position in a given environment without collisions with known obstacles.
The main idea of case-based reasoning (CBR) is a presumption that similar tasks probably also have similar solutions. New tasks are solved by adapting old proved solutions of similar tasks to new conditions. Tasks and their solutions (cases) are stored in a case base.
The focal point of this paper is the proposition of a path planning method based on CBR combined with graph algorithms in the environment represented by a rectangular grid. On the basis of the experimental results obtained, it is possible to say that case-based reasoning can significantly save computation costs, particularly in large environments. and Obsahuje seznam literatury