Fulltext search in archive
Results 841 to 870 of 1506:
Vliv typu zemní pasti a konzervační látky na odchyt druhů čeledi Carabidae (Coleoptera)Jaroslav Šafář, Pavla Šťastná, Vladimír HulaActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(2), 213-218 | DOI: 10.11118/actaun201058020213 This paper focuses on the type of cover and preserving agent influence on composition of entrapped fauna of Carabidae beetles. The research took place in the northern part of the protected landscape area of Žďárské vrchy, south from Kameničky municipality in rural district of Chrudim. Epigeic fauna was monitored one month from April 30th to June 5th 2008 - in the period of the highest activity of most Carabidae species. Traps were located in Latin square with five meter distance, using three preserving agents (formaldehyde, ethylene glycol, sodium chloride solution) and three types of covers above pitfall traps (acrylic glass cover, no cover, or wooden board put above the trap). Within the research 1123 Carabidae specimens belonging to 21 species were entrapped. The most numerous was Poecilus cupreus (915 specimens) in which also the strongest relationship to formaldehyde was detected. The redundancy analysis (RDA) from CANOCO package was used for statistical evaluation. With monitored variables, a significant influence (T = 0.137, F = 3.020, P = 0.0240) of formaldehyde on presence of some Carabidae species was confirmed (Poecilus cupreus, Amara lunicollis, Pterostichus diligens, and Bembidion guttula). Influence of the cover above the pitfall trap on species range in the trap was not confirmed (T = 0.062, F = 2.574, P = 0.0710). |
Numerická analýza ozubového spoje vyrobeného CNC technologiíVáclav Sebera, Milan ŠimekActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(5), 321-328 | DOI: 10.11118/actaun201058050321 The objective of the paper is the parametrization and the finite element analysis of mechanical properties of a through dovetail joint made with the use of a specific procedure by a 3-axis CNC machine. This corner joint was used for the simulation of the bending load of the joint in the angle plane - by compression, i.e. by pressing the joint together. The deformation fields, the stress distribution, the stiffness and the bending moment of the joints were evaluated. The finite element system ANSYS was used to create two parametric numerical models of the joint. The first one represents an ideally stiff joint - both joint parts have been glued together. The second model includes the contact between the joined parts. This numerical model was used to monitor the response of the joint stiffness to the change of the static friction coefficient. The results of both models were compared both with each other and with similar analyses conducted within the research into ready-to-assemble furniture joints. The results can be employed in the designing of more complex furniture products with higher demands concerning stiffness characteristics, such as furniture for sitting. However, this assumption depends on the correction of the created parametric models by experimental testing. |
Vztahy mezi teplotou a vlhkostí vně a uvnitř stáje pro dojnice s trvale otevřenými stěnamiMiljan Erbez, Daniel Falta, Gustav ChládekActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(5), 91-96 | DOI: 10.11118/actaun201058050091 The aim of this research was to estimate relations between temperature and humidity outside and inside of a permanently open sides barn for cows. This study was carried out in the period from February 1st, 2009 to January 31st, 2010 at a commercial dairy farm located in the South-Moravian region of the Czech Republic. During the study period temperature and humidity inside and outside the barn were systematically assessed. The research batch had 98 ± 3 cows. The barn had permanently open sides and during summer the main doors were mostly open. The cows in the research barn were of Czech Fleckvieh breed. The air temperature (°C) and humidity (%) were measured every fifteen minutes during the whole study period using 4 data loggers (HOBO technology; RH/Temp/), out of which were three (L1, L2 and L3), located inside the barn (Figure 1) and one (L0) outside the barn. The values of temperature-humidity index (THI) were calculated using the equation proposed by HAHN (1999). Mean daily outside and inside temperatures corresponded with each other, with outside temperatures always being lower than inside temperatures. The difference between the inside and outside temperature was lowest in March (0.01 °C) and highest in October (3.48 °C). Mean values of humidity outside and inside also corresponded; however, they were sometimes higher outside and sometimes inside the barn. The smallest difference between the inside and outside humidity was recorded in August (0.18 %) and the greatest in March (13.21 %). Mean values of temperature-humidity index (THI) inside and outside the barn also corresponded, with outside values being in most cases lower than inside values. The difference between inside and outside THI values was lowest in December (0.07) and highest in October (5.96). The mutual relationships between the values recorded by individual loggers were very close (including the outside logger). Slightly weaker was the relationship between L2 and other, both outside and inside, loggers. |
Simulace šíření aktivace v sociálních sítích s využitím teorie grafůFrantišek Dařena, Alexander Troussov, Jan ŽižkaActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(3), 21-28 | DOI: 10.11118/actaun201058030021 The social-network formation and analysis is nowadays one of objects that are in a focus of intensive research. The objective of the paper is to suggest the perspective of representing social networks as graphs, with the application of the graph theory to problems connected with studying the network-like structures and to study spreading activation algorithm for reasons of analyzing these structures. The paper presents the process of modeling multidimensional networks by means of directed graphs with several characteristics. The paper also demonstrates using Spreading Activation algorithm as a good method for analyzing multidimensional network with the main focus on recommender systems. The experiments showed that the choice of parameters of the algorithm is crucial, that some kind of constraint should be included and that the algorithm is able to provide a stable environment for simulations with networks. |
PROSTOROVÁ STRUKTURA POROSTU ZAKRSLÝCH KYSELÝCH BUČIN V PŘÍRODNÍ PAMÁTCE MÁCHOVA DOLINAJiří Schneider, Kateřina RebrošováActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(1), 175-184 | DOI: 10.11118/actaun201058010175 Natural Monument "Máchova dolina" represents a unique sample of dwarfed acidic beech forests in Chřiby hills (Buček, Lacina; 2002). It comprises more than 180 years old beech stand time, where according to certain characters (the basal part of deformation strain, frequent occurrence of damage) we can infer that, with the vegetation stool origin. As a result of adverse site conditions and the influence of origin to the emergence of the crop trees have a shape looks like an apple. Forest biocoenoses "Máchova dolina" is bounded to the board and limited site conditions ecosystem surface is less than 0.5 ha. As part of this unique site was established a permanent research area rectangle of dimensions 50 × 100 meters and by the Field-Map technology has been carried out measurements dendrometric variables (see below). The aim of the research was to compare different spatial structures (a total of 4 plots) in beech forest stands in Chřiby hills and knowledge of the functional effects of structurally variant types of forest. |
ŠANCE A RIZIKA V ROZVOJI NEJMENŠÍCH OBCÍ KRAJE VYSOČINAMarie Prášilová, Tomáš HlavsaActa Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(3), 165-174 | DOI: 10.11118/actaun200856030165 Vysočina is the region with highest numbers of the smallest villages in the Czech Republic. The current levels of the infrastructure, conditions of living of the inhabitants and chances for development of the communities were examined by means of a questionnaire area survey over the entire number of villages and towns of Vysočina Region in 2007. Survey results were tested as concerns representativity, statistically grouped and ordered in the manner of contingenc tables. For those aspects, where the community representatives felt a degree of deterioration a detailed statistical analysis was carried out. For the groups of villages up to 199 head and up to 499 head significance tests were carried out first and the degree of dependence measured by the Cramer coefficient. Statistical significance was an argument for deeper analyses. Sign sketches for 0,1 %, 1 % and 5 % significance levels were prepared for all the contingency tables. The answers of the conjuncture research were reduced to an alternative statistical variable and association was further studied between the village size and the problem areas of the community development. Probabilities of the separate variants were stated and risks and chances were evaluated for the possibilities for the smallest villages to be threatened as compared with the larger ones. The research results are presented in the shape of risk probabilities, both the relative and absolute ones, using the less applied measures for the risk measurement in two-way contingency tables. The computations are commented verbally and they bring new looks upon the perception of increased risk and chances improvement problems by means of qualitative statistical attributes. The solution is not only practically important but it offers an applicable general methodology instruction, too, for detailed analyses in the empirical research of qualitative phenomena. |
SPECIFIKA MALÝCH A STŘEDNÍCH PODNIKŮ V ČR A EUHelena ChládkováActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(6), 161-170 | DOI: 10.11118/actaun201058060161 Small and medium enterprises (SME) are the engine of the European economy. They are an essential source of jobs, create entrepreneurial spirit and innovation in the EU and are thus crucial for fostering competitiveness and employment. In the enlarged European Union of 27 countries, some 20 million SMEs provide around 75 million jobs and represent 99 % of all enterprises. However, they are often confronted with market imperfections. SMEs frequently have difficulties in obtaining capital or credit, particularly in the early start-up phase. Their limited resources may also restrict access to new technology or innovation. It is therefore necessary to monitor the development of SMEs in individual EU countries and highlighting their problems and mainly to their importance. |
ROZBOR AKTUÁLNÍHO VÝVOJE TRHU ZEMĚDĚLSKÉHO POJIŠTĚNÍ V ČESKÉ REPUBLICEEva VávrováActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(6), 613-624 | DOI: 10.11118/actaun201058060613 Proactive approach to risk management of agriculture companies is the way to ensure the efficiency of agricultural production even affected by natural disasters, to ensure the continuity of agricultural business and ultimately affect the level of development of rural regions. The instrument that solves the problem of reduction and elimination of risks associated with agricultural production is a systemic approach to the insurance of agricultural production, both crop insurance and livestock insurance, linked to a support program for SME in agriculture. |
Způsoby filtrace dat a jejich vliv na výsledný obraz kmene při elektronickém snímání jeho rozměrůVeronika Hunková, Karel JanákActa Univ. Agric. Silvic. Mendelianae Brun. 2010, 58(1), 77-86 | DOI: 10.11118/actaun201058010077 The data taken at the electronic reception of logs are tasked with mistaken values and do not correspond to the real shape of a stem. The aim of the data filtration is to remove the incorrect data and replace them by the ones, closer to the real values. |
Vývoj a změny spotřebních výdajů obyvatelstvaZuzana Toufarová, Klára OndráškováActa Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(6), 167-176 | DOI: 10.11118/actaun200856060167 The paper deals with development and changes in consumption expenditures of population. It uses secondary data to analyze consumption expenditures of EU-25 and the Czech Republic and concetrates on changes in the expenditure groups over the period of past years. Other part of this paper is devoted to primary data analysis. Primary data were obtained in a questionnaire survey. Primary data analysis is based on statistical methods and it investigates changes in the structure of consumption expenditures of households in relation to changes in household income. By using dependency analysis the paper verifies dependency of surveyed groups of consumption expenditures and groups of households sorted by identification characteristics. Additionally, also based on the primary research, the paper tries to find out the way households allocate money surplus remaining after covering all the adequate expenses. |
Ostrich eggs geometryŠárka Nedomová, Jaroslav BucharActa Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(3), 735-742 | DOI: 10.11118/actaun201361030735 |
Impact of taxes on redistribution in the Czech RepublicLeoš Vítek, Jan PavelActa Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(7), 2931-2938 | DOI: 10.11118/actaun201361072931 |
Current account imbalances in the euro areaKlára Plecitá, Ladislava Grochová, Luboš StřelecActa Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(7), 2631-2638 | DOI: 10.11118/actaun201361072631 |
Fatigue strength tests of layered steelMichal Černý, Pavel Mazal, Josef Filípek, Petr DostálActa Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(1), 39-49 | DOI: 10.11118/actaun201361010039 |


