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Results 841 to 870 of 1506:

Vliv typu zemní pasti a konzervační látky na odchyt druhů čeledi Carabidae (Coleoptera)

Jaroslav Šafář, Pavla Šťastná, Vladimír Hula

Acta 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 technologií

Václav Sebera, Milan Šimek

Acta 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 stěnami

Miljan Erbez, Daniel Falta, Gustav Chládek

Acta 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 grafů

František Dařena, Alexander Troussov, Jan Žižka

Acta 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 DOLINA

Jiří Schneider, Kateřina Rebrošová

Acta 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.
The measurement was based on "The methodology of research dynamics of natural forests left spontaneous development" (Vrška et al., 2006). When measurements are distinguished tree concepts and strain. The tree indicates the individual, which consists of one or more strains. Focus and describe all strains with DBH of at least 10 cm with bark. For each strain is aimed its location, DBH, height, high-pitched crown, crown projection, set the species of trees and nature of health. In addition to living trees and stumps are aimed "dead wood", stumping for distinguishing their origin, whether it arose naturally (break) or artificially (harvesting), all aimed "dead wood" must originate in the area.
The permanent research "Máchova dolina" area the size of 0.5 hectares has been targeted 146 trees. Diameter breast height (DBH) ranging from 10-72 cm; most tribes are represented with DBH between 30-39 cm. Most site conditions reflects vegetation height. Height of trees ranged from 2.5 m to 31.5 m, most often in the range of 15-20 m. For comparison, can be as old stands in a nature reserve on a set of "Holý kopec" forest types 3B, where the average height of vegetation around 38 m (max. 45 m). Surface projections are mostly CZK range of 30-50 m2. Although the vegetation time and even get involved exposure provides sufficient sunshine is no natural vegetation regeneration.
The aim of this article is description of spatial stand structure in natural monument Máchova dolina in Chřiby hills.

ŠANCE A RIZIKA V ROZVOJI NEJMENŠÍCH OBCÍ KRAJE VYSOČINA

Marie Prášilová, Tomáš Hlavsa

Acta 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 EU

Helena Chládková

Acta 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.
During the recent period of time there have been many researchers from the FBE Mendel University in Brno, who focused on the analysis of the small and medium-sized enterprise, e.g. Bohušová (2007); Chládková (2009); Nerudová a Bohušová (2008); Kubíčková a Peprný (2006); Zrůst a Pyšný (2008).
This paper is the part of the Research proposal MSM 6215648904 being solved at the FBE Mendel University in Brno.

ROZBOR AKTUÁLNÍHO VÝVOJE TRHU ZEMĚDĚLSKÉHO POJIŠTĚNÍ V ČESKÉ REPUBLICE

Eva Vávrová

Acta 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.
This presented paper aims to identify and discuss the possibility of eliminating risks possibly threatening the agricultural production and to analyze forms of covering risks associated with agricultural production on the commercial insurance market in the Czech Republic. The paper analyzes the current situation and current development of the agricultural insurance on the insurance market in the Czech Republic.
This paper was written as a part of the research project MSM 6215648904, carried out by the Faculty of Business and Economics, under the title "The Czech economics in the processes of integration and globalization, and the development of the agriculture and service sector in the new conditions of the integrated European market", following the goals and methodology of the research project.

Způsoby filtrace dat a jejich vliv na výsledný obraz kmene při elektronickém snímání jeho rozměrů

Veronika Hunková, Karel Janák

Acta 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.
The goal of presented work was to analyse the effect of different filtration methods on original data and to recommend the methods, which results correspond to the real shape of the logs with their defects on a surface as close as possible.
Methods of filtration are based on simple mathematical and statistical procedures, which are subsequently variously combined, because the simplest comparative methods did not fulfil the expectations.
More than 50 methods were combined and analyzed. Approximately 15 of them were selected and tested. The methods were applied to data scanned on ca 150 logs randomly selected from thousands of files in the sawmill log yard. The filtration effects of different methods were visually assessed. The most applicable three methods were selected and they will be tested practically at sawmill in the next step of research. These three methods are described in following paper.
Results refer, that all proposed methods correspond to necessities for log dimensions determination. It is not possible to define the best method generally. Different properties of these methods make them suitable for calculation of log dimensions if different type of use is requested. It means for mid diameter determination necessary for volume calculation by using Huber method; for section diameter determination for volume calculation by using section method; for top diameter determination necessary for sorting; for filtration of drive dogs of the conveyor passing through the measuring equipment.

Vývoj a změny spotřebních výdajů obyvatelstva

Zuzana Toufarová, Klára Ondrášková

Acta 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.

Nematocid effects of watercress (Nasturtium officinale R. Br.)

Helena Zahradníková, Kristína Petříková

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(1), 233-236 | DOI: 10.11118/actaun201361010233

Ostrich eggs geometry

Šárka Nedomová, Jaroslav Buchar

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(3), 735-742 | DOI: 10.11118/actaun201361030735

Carotenoids and lycopene content in fresh and dried tomato fruits and tomato juice

Andrea Mendelová, Martina Fikselová, Ľubomír Mendel

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(5), 1329-1337 | DOI: 10.11118/actaun201361051329

Fin condition of fish kept in aquacultural systems

Ondřej Klíma, Radovan Kopp, Lenka Hadašová, Jan Mareš

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(6), 1907-1916 | DOI: 10.11118/actaun201361061907

Impact of taxes on redistribution in the Czech Republic

Leoš Vítek, Jan Pavel

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(7), 2931-2938 | DOI: 10.11118/actaun201361072931

Tax justice of the reform of higher education: tuition fees or tax relief?

Pavel Semerád, Veronika Sobotková

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(7), 259-264 | DOI: 10.11118/actaun201260070259

Corporate performance indicators for agriculture and food processing sector

Jiří Hřebíček, Ondřej Popelka, Michael Štencl, Oldřich Trenz

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(4), 121-132 | DOI: 10.11118/actaun201260040121

Time series classification using k-Nearest neighbours, Multilayer Perceptron and Learning Vector Quantization algorithms

Jiří Fejfar, Jiří Šťastný, Miroslav Cepl

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(2), 69-72 | DOI: 10.11118/actaun201260020069

Shifts in spruce and beech flushing in the context of global climate change

Radek Pokorný, Ivana Tomášková, Alexander Ač

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(1), 163-167 | DOI: 10.11118/actaun201361010163

Epigeic spiders (Araneae) from the Malá Dohoda Quarry (Moravian Karst Protected Landscape Area, Czech Republic)

Ondřej Košulič, Lucie Nováková, Pavla Šťastná

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(3), 651-662 | DOI: 10.11118/actaun201361030651

Ecology of beech regeneration in the allochthonous spruce stands - a case study

Lumír Dobrovolný, Miroslav Cháb

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(5), 1261-1268 | DOI: 10.11118/actaun201361051261

A rainfall distribution and their influence on flood generation in the eastern Slovakia

Lenka Gaňová, Martina Zeleňáková, Pavol Purcz, Žofia Kuzevičová, Helena Hlavatá

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(6), 1645-1652 | DOI: 10.11118/actaun201361061645

Current account imbalances in the euro area

Klára Plecitá, Ladislava Grochová, Luboš Střelec

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(7), 2631-2638 | DOI: 10.11118/actaun201361072631

The application of method suppliers' complex evaluation. Case study

Ekaterina Chytilová, Marie Jurová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(7), 139-146 | DOI: 10.11118/actaun201260070139

Association analysis of interleukin-18 gene with performance traits in Czech Large White pigs

Pavla Chalupová, T. Urban, A. Knoll

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(5), 97-102 | DOI: 10.11118/actaun201260050097

Yield and quality of head lettuce after 24-epibrassinolide application under optimal and reduced irrigation

Martin Koudela, František Hnilička, Jaroslava Martinková, Lenka Svozilová, Jitka Doležalová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2012, 60(3), 93-100 | DOI: 10.11118/actaun201260030093

Fatigue strength tests of layered steel

Michal Černý, Pavel Mazal, Josef Filípek, Petr Dostál

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(1), 39-49 | DOI: 10.11118/actaun201361010039

Comparison of specific production performances by two crystalline silicon PV systems

Martin Fajman, Josef Vacuška

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(3), 611-621 | DOI: 10.11118/actaun201361030611

Business cycle coherence and OCA endogeneity testing during the integration period in the European Union

Nikola Najman, Petr Rozmahel

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(4), 1033-1040 | DOI: 10.11118/actaun201361041033

Trends in temperature and precipitation in the period of 1961-2010 in Žabčice locality

Zdeněk Žalud, Jan Brotan, Petr Hlavinka, Miroslav Trnka

Acta Univ. Agric. Silvic. Mendelianae Brun. 2013, 61(5), 1521-1531 | DOI: 10.11118/actaun201361051521

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